For small-scaled rift lake basins with a low exploration degree, it is of great significance to search for effective source rocks for the exploration purpose. Based on a large number of analysis test data of new drillingwells in Tiancao sag,the authorsstudiedthe geochemical characteristics and sedimentary environment of the hydrocarbon source rocks in the vertical and horizontal directions of the Lower Cretaceous Bayingebi Formation, and described the effect of sedimentary environment changes on the development of effective source rocks.The results reveal that the organic matter abundance of the source rocks of the Bayingebi Formation reachesa medium to good level, and the second member of the Bayingebi Formation has the highest organic matter abundance(average w(TOC)=1.1%). The organic matter is of type Ⅱ₁-Ⅱ₂, and the proportion of type Ⅱ1in the second member of the Bayingebi Formation is higher, belonging to humic-sapropelic.The thermal evolution degree of the source rocks isat low-mature to mature stage. The second member of the Bayingebi Formation belongs to mature source rocks with high potential of hydrocarbon generation.The lower limit of the effective source rock of the Bayingebi Formation is defined as w(TOC)=1.0%, the organic matter wasderived from a mixed source of higher plants and aquatic organisms, and the contribution proportion of lower aquatic organisms is slightly higher. The Bayingebi Formation was deposited in areducingenvironment with high salinity.The algal bloom within the basin and the appropriate terrestrial organic matter input outside the basin are necessary conditions for the increase of water paleo-productivity in the lacustrine basin, and the continuous and stable anoxic environment provides good conditions for the preservation of organic matter. These are the two key conditions to form effective source rocks.The southern sub-sag is more suitable for the development of the effective source rocks than the northern sub-sag in Tiancao sag, and the effective source rocks have higher organic matter abundance and maturity. So the southern sub-sag is the favorable area for oil and gas exploration.

The characteristics and genetic mechanism of authigenic mineralshave important influence on the physical properties of deep clastic rock reservoirs. By taking the Jurassic clastic reservoirsin Qinan fault step belt of Qikou sag, offshore Bohai Sea as anexample, the types, characteristics, genetic mechanism of authigenic minerals, and their controlling effect on the development of high-quality reservoirs were studied on the basis of core observation, thin section identification, scanning electron microscope, electron probe, isotope, inclusion, and X-diffraction analyses. The results show that the Jurassic clastic reservoirs in the study area have moderate porosity and low permeability with strong heterogeneity. The main types of authigenic minerals are siliceous minerals, carbonate minerals, and clay minerals. The early microcrystalline quartz liners are distributed along the surface of the particles that effectively inhibited the overgrowth of late quartz and enhanced the resistance to compactionof the rock, which was beneficial to the preservation of primary pores; The early carbonate cementation enhanced the anti-compaction ability of the reservoirs, and provided the material foundation for the formation of dissolution pores generated by the late dissolution, which was conducive to the formation of high-porosity reservoirs; The clay minerals controlled the difference in reservoir permeability, which is positively correlated with the content of authigenic kaolinite. The reservoirs with higher permeability are distributed in the kaolinite enrichment zone in the middle part of the Jurassic. Two types of favorable reservoirs are developed in the study area:Type Ⅰ is with high content primary poresand well-developed microcrystalline quartz gaskets; Type Ⅱ is with more developed intergranular dissolution pores and more obvious epidiagenesis characteristics, and they are significantly different in pore evolution. Type Ⅰis mainly controlled by the compaction resistance of the microcrystalline quartz liners in the early to middle diagenesis stage, and the high-porosity reservoirs can be developed in both shallow and deep layers; Type Ⅱ is mainly controlled by the weathering and leaching in the supergene stage, and high-quality reservoirs can be formed near the weathering crust. Type Ⅰ reservoir has better physical properties than type Ⅱ.

Based on the data of seismic, drilling, cores, and thin sections, the characteristics of the sequential stratigraphic framework and its controls on the Lower-Paleozoic karst reservoirs in southwest of Bohai Sea area were discussed. The results show that:1) There are negative carbon and oxygen isotopic anomalies and positive Th/K anomalies in the natural gamma spectrum near the third-order sequence boundary, and according to these characteristics the Lower Paleozoic is divided into 21 third-order sequences; 2) The dolomite is the most important reservoir rocks in the study area, and the sequences control the development of the high quality reservoir by controlling the change of vertical lithology; 3) The twelve third-order sequences where dolomite developed are defined as "dominant reservoir sequences", which control the scale of buried-hill reservoir and also the capacity of the production when coupled with the weathering interfaces of Caledonian movement. Inner-reservoirs are developed in the Cambrian with dissolved pores as the main spaces, and are also strictly controlled by the "dominant reservoir sequences". In future exploration, priority should be given to drilling in the areas where the "dominant reservoir sequences" coupled with weathering interfaces, while taking inner-reservoirs into account.

In recent years, major oil and gas breakthroughs have been made around the No. 1 and No. 5 strike-slip fault zones in Shunbei area, which reveals that the small-scale strike-slip faults developed in Tarim basin have the characteristics of controlling reservoir and reservoir of fault-controlled oil and gas reservoirs. The strike-slip faults cut through several sets of Paleozoic strata in the section, which complicates the longitudinal structures that show a style of deep linear strike-slip superimposed shallow echelon normal fault in space. Drilling reveals that the productivity of wells is significantly different in different sections of the fault zone, and the segmentations of the strike-slip faults at the top interface of Ordovician carbonate rocks plays an important role in controlling oil and gas accumulation. The middle-north section of Shunbei No. 5 fault is selected as the research object based on the correlation between the fault distances and segment lengths at different scales and the theory of multi-fault evolution. A method is proposed to carry out segmental research on the deep linear strike-slip faults by using the changes of statistical vertical distances along the strike faults. This method is universal, and it can be used to study the segmentation of different types of faults, combining with the intensity of fault activity, the degree of evolution, and the structural shape of the section, so as to analyze the segmentation characteristics of the faults. The study shows that the middle-north part of No. 5 fault can be divided into 14 segments at the top interface of Ordovician carbonate rocks and 10 segments at the top interface of Cambrian gypsum-salt strata. The fault segmentations of the two strata have the characteristics of inheritance and differential evolution in space. The result shows that the escape of gypsum salt from the detachment structure of the Cambrian gypsum salt rock has a destructive effect on the drainage of oil and gas; While the intensity of the fault activity, segmented overlap pattern, and different positions of fault segments on the top of Ordovician carbonate rocks play an important role in controlling the development scale of fault-controlled fracture-cave reservoirs. This implies that the segmented characteristics and vertical structure of in-plane faults play an important role in controlling fracture-cave hydrocarbon accumulation.

Burrowing animals as the builders of ecosystem engineering, their bioturbation structures affect the physical and chemical properies of sediments, which are important for the benthic ecosystems. Abundant of bioturbation structures are preserved in the laminated microcrystalline limestone in the middle part of the Cambrian Miaolingian Zhangxia Formation, Dengfeng area, western Henan Province. In this paper, the methods of geobiology, paleontology and bioturbation index (BI) are used to investigate the depositional environment of the bioturbation structures and their influence on sediments. Most of bioturbation structures have blurred boundaries. The bioturbation index is 2-5, indicating sufficient food supply and high oxygen content in the sediments during the deposition period. In addition, three types of trace fossils are recognized:Thalassinoides bacae, Planolites isp. and Rhizocorallium isp, indicate that the bioturbation sturctures are created by more than one trace maker. The research on the trace fossils and sedimentary characteristics of the Zhangxia Formation indicates a restricted platform environment between oolitic banks that occasionally affected by storms.

The structural evolution of Songliao basin can be divided into seven evolution stages:The pre Mesozoic craton basement evolution, the Late Jurassic compressional volcanic dome evolution, the Early Cretaceous extensional fault depression, the early stage of Upper Cretaceous cooling depression, the late stage of Upper Cretaceous reverse fold uplift and atrophy, the uplift and denudation of Paleogene extensional fault,and the Neogene Quaternary compression depression.The relationship between the structural evolutions and the uranium mineralization in the North of Songliao basin was studied systematically. The results show that the main stages of uranium mineralization are in the early stage of Upper Cretaceous cooling depression, late stage of Upper Cretaceous reverse fold uplift and atrophy, uplift, and denudation,and Paleogene extensional fault depression uplifting and denuding. The distribution of uranium mineralization is jointly controlled by the basement fracture and the reverse tectonic zone.The uranium metallogenic types of each tectonic division are controlled by the structural evolutions:The "paleo-interlayer oxidation" and interlayer oxidation sandstone type uranium deposit are the main types in the western slope area.The type of "Qianjiadian sandstone type uranium deposit" should be searched in the structural denudation skylight of Changqi Placantieline and Suileng anticline belt of central depression and northeastern uplift area; While the interlayer oxidation type sandstone type uranium deposit is the main type in the northern tilted area and the basin margins of the northeastern uplift area.

The 340 highland gold deposit in Heihe City, Heilongjiang Province is located in the northeast margin of Xing'an block and Duobaoshan Cu-Au-Mo-W-Fe metallogenic sub zone. Its landform is shallow covering area, which is difficult to find ore deposits. In this paper, shallow drilling technology was used to sampling and mapping the basement in study area, and the alteration mineralization zone with silicification as the center and qingpanshitization as the periphery was delineated. Through principal component analysis, six principal component eigenvalues are determined to be greater than 1. The second principal component is closely related to gold, which is an effective prospecting indicator in study area. The results of high-precision magnetic survey show that the structure in study area is mainly NNW trending, and its linear low value anomaly may be related to the demagnetization caused by alteration. Through engineering verification of geophysical and geochemical anomalies in this area, one gold deposit and one prediction target were found.

The variation of the ore-forming element grade, determined by the geological process, have strong random and nonlinearity features. Identifying the characteristics of ore-forming elements is of significance for better understanding the ore-forming process and mineral prospecting. In this paper, the multifractal detrending moving average (MFDMA) model is applied to describe the multifractal characteristics of Cu element distributions and their implications to mineralization intensity in the No.4 exploration line borehole from Pulang porphyry copper deposit in Yunnan, China. The results reveal that the sequence of Cu in all boreholes exhibits multifractal scaling and local singularity differences in different mineralization grades. The multifractal strength increases with the decrease of mineralization intensity. The high grade Cu of strongly mineralized boreholes is relatively enriched in the inner side of the potassium silicification-sericitization zone, while is relatively dispersed in the outer hornization-qingpanlithalization zone. Moreover, hrough analyzing the data that are arranged in random order in the shuffling procedure, we find that the multifractality structure of Cu grades series is due to both the fat-tail probability density function and long-range correlation, and the latter is more significant than the former.

The geochronology and geochemistry of Mesozoic intrusions in the Dayangshan Mo deposit in the Northeastern part of the Great Xing'an Range are studied in this paper, and the petrogenesis and tectonic setting are discussed. The U-Pb dating of the medium fine-grained granite using (LA-ICP-MS) is (177.3 ±2.6) Ma and (176.5 ±1.6) Ma, namely the Early Jurassic. The dating of the diorite porphyry is (158.0 ±2.7) Ma, that is, the Late Jurassic. The study of geochemistry shows that the medium fine-grained granite is characterized by its high Si, rich K poor Fe, Mn, and Mg. It is depleted of HFSE (such as Nb, Zr, P, Th, and HREE), and rich in LILE (such as Rb, K, and LREE), with a significant negative Eu anomaly (δEu=0.39). Combined with its low Cr, Ni, Co contents and low Mg^#, the medium fine-grained granite came from a source of lower crust. The diorite porphyry is relatively rich in Na,K,and alkaline, and the contents of Ca, Ti,and Mg are medium. It is rich in LILE (such as, Rb, K, and Sr) and depleted of HFSE (such as, Nb, Ta, Ti, Th, and HREE), indicating the characteristics of arc magmatic rocks in subduction zone. Combined with previous studies, we believe that the formation of medium fine-grained granite and diorite porphyry is influenced by the subduction of the Mongolian-Okhotsk Ocean, and the closing time of the residual Mongolian-Okhotsk Ocean in the Northeast of Great Xing'an Range can be limited to the Late Jurassic-Early Cretaceous.

Petrology, geochemistry and U-Pb geochronology of the Great Xing'an Range Tayuan and the Little Xing'an Range Erzhan Country granites in the northwest Heilongjiang Province were undertaken to determine the subduction and collisional processes of the Paleo-Asian Ocean. The Tayuan granites are mainly biotite monzogranites with zircon U-Pb age of 308 Ma, which is a Late Carboniferous intrusion, and they are characterized by high silica and total alkali contents, enrichment in light rare earth elements (LREE) and large ion lithophile elements (LILE), depletion in heavy rare earth elements (HREE) and high field strength elements (HFSE). Zircons from the Tayuan monzogranites have ε_Hf(t) values ranging from 0.8 to 2.5, suggesting that the granitic magmas were generated by partial melting of newly-accreted lower crust. The Erzhan Country granites are dominantly monogranite and alkali-feldspar granite with zircon U-Pb ages of 305 Ma and 293 Ma. They have high silica and total alkali contents, and are characterised by enrichment in LREEs and LILE relative to HREE and HFSE, implying that they were generated by the melting of juvenile continental crust. The Late Carboniferous monogranites belong to I-type granite, and the Early Permian alkali-feldspar granite is typical A-type granite. Zircon δEu ratios can be used to estimate the melting depths of granites:The formation depth of Tayuan monzogranite and Erzhan Country monzogranite is 38.8 km and 34.7 km,respectively,while the alkali-feldspar granite formed at a shallow depth of 28.7 km. The crustal thinning during the Late Carboniferous to Early Permian might record the tectonic transition from subduction to post-collisional extension related to the final closure of the Paleo-Asian Ocean.

The Zhangguangcai Range is a collision orogenic belt between the Songnen massif and the Jiamusi massif, and is an important part of the "Giant Granite Province" in Northeast China. Based on zircon U-Pb dating and petrogeochemical analysis, we have studied the chronology, geochemical characteristics and tectonic setting of the Early Jurassic monzogranites in the southern Zhangguangcai Range. The zircon U-Pb dating results show that the diagenetic age of the fine-grained monzogranite granite sample is (176.4±1.1) Ma; The medium-grained monzogranite samples are(178.9±1.3)Ma,(177.7±1.1)Ma; The coarse-grained monzogranite samples are(180.0±1.8)Ma, (179.9±1.2)Ma. These ages belong to the Early Jurassic. Petrogeochemical results show that the fine-grained monzogranite samples, medium-grained monzogranite samples and coarse-grained monzogranite samples are rich in silicon, poor in aluminum, high in alkali, low in calcium, enriched in Zr, Hf, Rb, K, depleted in Ba, Sr, Nb, P, Ti, swallow-type rare earth distribution model and other characteristics, the diagenetic type belongs to post-orogenic A2 granite. Combining the characteristics of chronology and geoch emistry, the authors believe that the Early Jurassic monzonitic granite in the study area was formed in the post-collision tectonic setting, representing an extension during the collision-assembly process of the Jiamusi and Songnen blocks, indicating the Early Jurassic the regional tectonic environment gradually changed from compression orogenic to post-orogenic extensional environment.

The Kalatage area is located in the north central part of the Eastern Tianshan, where the Permian continental volcanic rocks are widely distributed. Their petrography, geochemistry, zircon U-Pb geochronology,and Lu-Hf isotope analysis for basalt and dacite are presented in this paper. The LA-ICP-MS zircon U-Pb dating of (267.5±1.5) Ma and (296.7±1.7) Ma from two dacite samples represents the crystallization age of dacite in the Early Permian. The geochemical data show that the basalt is of alkaline series with high Al₂O₃,Na₂O/K₂O, low TFeO, Mg^#, and Cr. The Ta, La, and Nb contents standardized by Yb indicate its basaltic magmatic origin from the enriched mantle source. The low La/Ba, (Th/Nb)_N>1 and Nb/La<1 suggest that the magma was mixed with lithospheric material during its ascent. The samples have w(Zr)>100×10^-6 and Zr/Y>5, indicating the characteristics of continental intraplate basalt. The dacite is of calc-alkaline type with enrichment of silicon and aluminum, high contents of Rb, Ba, Th, U, Zr, etc, and low content of Ti, Nb, Ta, Sr, P, etc. These features are obviously different from those of the basalt but similar to the crust. The dacite has positive ε_Hf(t) value (5.4-14.7), indicating that the source region is the new crust. The w(Y+Nb)-w(Rb) discrimination diagrams of tectonic setting show that the dacite was formed in the continental extensional setting. Combined with the previous research results, we believe that the Kalatage Early Permian volcanic rocks formed in the continental extensional setting, and they are part of the Carboniferous-Permian rift-related volcanism in Tianshan, which restricted the closure of Paleo-Asian Ocean in this area before the Early Permian.

The research on the spatial distribution of muddy interlayers is of great significance in engineering practice and science,however, the published works mainly focus on qualitative description. The objective of this work is to quantitatively investigate the spatial distribution and geometrical morphology of muddy interlayers. By taking the high slope excavation sections of Yunnan Yuxi municipal solid waste incineration power plant as an example, the point clouds of excavation sections and muddy interlayers were obtained by Leica ScanStation C10 3D laser scanner and ROMER RA-7520-2 arm 6-axis 3D measuring instrument, and the 3D spatial distribution, orientation, spacing, roughness, and geometrical morphology of muddy interlayers were analyzed after post-processing of the point cloud data using Cyclone and Geomagic Wrap software. The results show that most of the muddy interlayers are laterally distributed in the whole scanning section, and only a few are locally distributed. The mean inclination and mean dip angle of the muddy interlayers are 196.41°±5.51° and 22.27°±2.23°, respectively. The spacing varies from 3.7 to 49.1 cm with an average of (20.4±12.0) cm. The thickness of different lateral positions of muddy interlayers in different layers and the same layer is different, the thickest is about 20 mm, and the thinnest is less than 1 mm. For the typical area of the top surface of muddy interlayers, the plane fitting deviation is between -22.4 mm and 32.5 mm, and the roughness coefficient along the interlayer trend ranges from 5.67 to 16.77 with an average of 10.11±3.25. The ratio of surface area to volume of muddy interlayers is between 5.14 and 5.86 cm^-1. These findings suggest that it is feasible to study the spatial distribution and geometrical morphology of muddy interlayers in rock slopes by using the 3D laser scanning technique. In the high slope of Yuxi municipal solid waste incineration power plant, at the macroscopic level, the muddy interlayers are characterized by relatively straight, approximately parallel to each other, non-isometric distribution, small spacing, many layers, and thin thickness, while at the microscopic level, the muddy interlayers have rough top surface with relatively smooth bottom and complex three-dimensional geometrical morphology.

In order to achieve better effect of siphon drainage technology in slope application in a loess area, the design of siphon drainage hole spacing considering loess anisotropy was carried out. Based on Neuman theory, according to the different degree of soil permeability coefficient, the anisotropic seepage law of loess was considered, the concept of interception ratio was introduced, and the relationship between depth drop and influence radius was combined. An analytical solution of siphon drainage spacing suitable for anisotropic soils was derived. The results show that the spacing of siphon drainage holes is not only related to permeability coefficient and depth drop, but also to the ratio of vertical permeability coefficient to horizontal permeability coefficient. In the actual case project in Heifangtai loess area, 0.4 m is the optimal distance between the siphon drainage holes. The numerical simulation and analytical calculation show that the interception ratio (49.7%) meets the practical requirements when the spacing of single row of drainage holes is 0.4 m.

Current flood risk analysis is mainly based on typical design standard floods, which cannot meet the needs of actual flood control management. In order to improve the real-time flood risk analysis and adapt to the dynamics of flooding, in this study, a dynamic real-time flood risk analysis framework was designed. In this framework, one-dimensional and two-dimensional dynamic coupled hydrodynamic numerical methods were used to couple the dyke breach model, and then a flooding simulation model was established in Qiaosang flood protection area. Through improvement, the flood inundation conditions can be simulated and analyzed based on real-time water conditions or arbitrary design floods. By flexibly set the boundary conditions and dynamically set the breach function, the flooding process of the protected area after single breach or combined breach was calculated. According to this framework, the dynamic real-time flood risk map compilation and management application system of the Qiaosang flood protection area was developed, and further verified by using the historical flood data. The verification results show that the absolute errors of the highest water level measured at Makou Station, Sanshui Station, Da'ao Station, and Ganzhu (1) Station during the 2008-06 flood and the highest water level calculated by the model are -0.10 m, 0.10 m, 0.09 m, and 0.04 m, respectively, which meet the requirements of the precision of flood simulation. The model was used to calculate the flood discharge and the water level inside and outside the breach of Jianggen dike when the flood occurs once every 200-year in Xijiang River, when the simulated width of the breach was 168 m, the maximum flow of the breach reached 5 190 m³. The village inundation caused by the flood of 3 h, 6 h and 24 h after the dyke breach was analyzed, and the results satisfy the rationality analysis.

In order to find out the suitability zoning of groundwater source heat pump in Shijiazhuang City, the suitability evaluation index system of groundwater source heat pump was constructed based on the geological, hydrogeological, and environmental geological conditions, the comprehensive weights of evaluation index were determined by fuzzy AHP method, and the groundwater source heat pump suitability zoning in Shijiazhuang City was divided combining with the spatial analysis function of GIS. The results show that the suitable areas for the development and utilization of the groundwater source heat pumps in the research area are distributed in the Hutuo River area covering about 19.74 km², accounting for 5.85% of the whole area. The relatively suitable areas are distributed in most of the study area, covering an area of about 251.22 km², and accounting for 74.40% of the total area. The suitability zoning is mainly distributed in the area with poor hydrogeological conditions in the northwest and the over-exploitation funnel area in the east of the study area, with an area of about 66.71 km², accounting for 19.75% of the whole area. Except for the underground water funnel area and the areas with poor hydrogeological conditions, which are not suitable for the development of groundwater source heat pumps, most areas in Shijiazhuang are suitable for the utilization of groundwater source heat pump technology.

To study the spatio-temporal distribution pattern and mechanism of land subsidence, the Chaobai River alluvial fan, a typical subsidence area in Beijing, was selected as the study area, and the spatial heterogeneity and the driving factors of land subsidence were analyzed by using PS-InSAR, global and local moran indices, and geographic detectors. The results showed that the temporal and spatial distribution characteristics of land subsidence in the study area from January 2017 to January 2019 were mainly general subsidence, the subsidence rate was[-133,3] mm/a, and the maximum cumulative subsidence was 261 mm. It was slightly distributed in the north, more severe in the middle, and lighter in the south. The severe and extremely severe land subsidence mainly occurred in eastern Houshayu of Shunyi and Lucheng town at the junction of the middle and lower parts. The land subsidence in different areas presents different spatial heterogeneity, that is, the uneven distribution characteristics are obvious. The middle and lower parts show low-low agglomeration characteristics. Different driving factors of land subsidence are different under different distribution characteristics. The main driving factors in the middle part are the groundwater level change in the second confined aquifer and the thickness of the compressible layers, while the driving factors in the lower part are the groundwater level change in the shallow groundwater and the groundwater level change in the first confined aquifer. This study suggestes that Moran index can be used to effectively analyze the spatial heterogeneity of land subsidence and identify the characteristics of agglomeration, and the geographic detector can be used to find out the causes of spatial heterogeneity of land subsidence and obtain the main driving factors. This study also provides data support and reference for the prevention and control of land subsidence in different hydrogeological units.

In recent years, with the intensification of human activities and reduction of sediment into the sea, some estuarine tidal flat wetlands in our country have been facing serious erosion and degradation, which poses a huge threat to the development of coastal cities. Therefore, the scientific management and rational use of estuarine tidal flat wetlands are extremely urgent. In this study, the regional chart topography data before and after the multi-phase of Yangtze Estuary deepwater channel north dyke project and the Hengsha Island land forming and silting promoting project from 1990 to 2017 were used to analyze the evolution of the wetland landforms in Hengsha Island, and the ArcGIS geographic registration, contour digitization, digital elevation model establishment, and overlay analysis were used to analyze the landform isobaths changes in morphology, terrain erosion-sediment thickness, and spatiotemporal changes of Hengsha Island. The result indicates that the implementation of the north guide dike project of the deepwater channel of Yangtze Estuary and the land forming and silting promoting project of Hengsha Island has changed the hydrological and sediment conditions to certain extent in the waters around the tidal flat wetlands of Hengsha Island, and its status of landscape erosion and deposition:1) It has greatly promoted the outward orientation of the characteristic isobaths. The maximum annual growth rate of 0, 2,and 5 m isobaths envelope area (2009-2013) is 42.13, 280.73, and 235.65 times that of the project (1990-1998). The overall envelope volume of 0-1, 1-2, 2-3, 3-4, 4-5 m isobaths shows an overall increase in 1990-1998, 1998-2009, and 2009-2013, and the tidal flat wetland shows a trend of "growing up but not extending". 2) The frequency characteristics of erosion-deposition are micro-deposition before engineering (1990-1998), micro-deposition after engineering (1998-2009), significant increase in deposition (2009-2013), and micro-erosion (2013-2017). At the same time, the reduction of sediments from Yangtze Estuary into the sea may have produced a certain impact on the development of tidal flats below the 2 m isobaths.

In order to study the response of soil organic carbon (SOC) mineralization of upland and paddy soils with different salinity to the addition of nitrogen and phosphorus, and to quantify the magnitude and direction of its priming effect, three saline-alkali upland sample plots (H1, H2, H3) and three saline-alkali paddy sample plots (S1, S2, S3) in western Jilin were selected and simulated in the laboratory. The inorganic nutrients ((NH₄)₂SO₄, KNO₃,and KH₂PO₄) were added to the 0-15 cm soil samples in seven forms. The CO₂ emission was continuously monitored for 32 d in a 25℃ incubator, and the effects of seven nitrogen and phosphorus treatments on SOC mineralization and priming were analyzed. The results showed:1) The addition of 200 mg/kg and 1 000 mg/kg nitrogen or phosphorus significantly increased the SOC mineralization accumulation and the SOC mineralization rate by 158.5%-876.5%. The higher the concentration of the same additive, the greater the SOC mineralization accumulation; With the extension of the incubation time, the SOC mineralization rate decreased gradually. 2) During the period of incubation, a positive priming effect was produced in each group. 3) During the incubation period, the SOC mineralization, priming effect, and alkalinity of some treatment groups showed significant negative correlation (p<0.05). The higher the alkalinity, the weaker the SOC mineralization and priming effect; The greater the mineralization, the lower the positive priming effect. 4) Compared with paddy soil, the response of SOC mineralization and priming effect to the nitrogen and phosphorus addition was larger in upland soil.

For the effective detection of microcystin-LR (MCLR) in environmental water, in this study, the biochar particles were prepared from agricultural wastes,and it was utilized for the construction of a biotemplated electrode with electrochemical immunoassay capability toward microcystin-LR by differential pulse voltammetry. It is found that the electrode can identify the presence of microcystin-LR effectively in a short time (5 min), the linear detection range is 0.0-5.0 nmol/L and the lowest detection limit is 0.2 nmol/L. The electrode is also anti-interfere to various unrelated molecules and ions, indicating that the electrode can be used for fast and effective detection of microcystin-LR.

In order to solve the gravity sedimentation problem of micron iron, this paper uses xanthan gum to modify the micron iron. The stability of the modified micro iron slurry was explored through sedimentation experiments and the degradation ability was explored by removing Cr(Ⅵ) pollutant. The results show that when the dosages of xanthan gum are 0.0, 1.0, 1.5, 2.0, 2.5, 3.0, 6.0 g/L respectively, the corresponding relative spectrophotometric values are 0.05, 0.25, 0.46, 0.57, 0.65, 0.73, 0.87 at the end of 5 h sedimentation experiment. The suspension stability of the modified micro iron slurry is gradually strengthened with the increase of the mass concentration of xanthan. Xanthan has the ability to inhibit the adsorption of Cr(Ⅵ) by micron iron, which can promote the reduction of Cr(Ⅵ) and improve the removal rate. With the increase of the concentration of xanthan gum, the corresponding Cr(Ⅵ) removal rates are 33.37%, 41.23%, 47.45%, 51.05%, 52.97%, 63.91% and 64.08%, respectively. It can be seen from the results that 6.0 g/L xanthan gum modified micron iron slurry has the best suspension stability and the addition of xanthan gum improves the reactivity of micron iron. However, when the mass concentration of xanthan gum exceeds 3.0 g/L, the removal rate of Cr(Ⅵ) is not significantly improved. The greater the concentration of xanthan gum, the more obvious the buffering effect of xanthan gum.

The effective signal of seismic prospecting is often interfered by random noise, which is difficult to identify. It is necessary to separate the random noise from the effective signal. The traditional Shearlet global threshold does not change with the direction and scale, which leads to the loss of many effective signals during denoising. As a new multi-scale and multi-directional time-frequency analysis method, Shearlet transform has the best sparse representation ability, local feature, and direction sensitivity. In this paper, the noisy seismic signal is decomposed by Shearlet to calculate the L₂ norm of Shearlet domain coefficients in various scales and directions. After rearranging the data, it is found that the L₂ norm decreases as the direction changes. Based on the L₂ norm, a calculation method of adaptive threshold value of the scale direction of the number is proposed. Compared with wavelet transform, curvelet transform, and Shearlet global threshold denoising methods, the denoising results of simulated data and actual seismic records show that the method in this paper can remove the random noise and can also recover the weak deep signals well, and the signal noise ratio of the data is improved from 0.929 9 dB to 11.565 1 dB.

Multiple attenuation is a research focus in marine seismic data processing. Due to the advantages of high accuracy and low model dependence, the surface-related multiple elimination method achieves multiple attenuation through multiple prediction and adaptive subtraction, so it is widely used in the industry. However, the conventional adaptive subtraction method is not applicable at the primary and multiple intersections, and the phenomenon of primary damage and multiple residuals will increase the difficulty of subsequent seismic processing and interpretation. Based on previous research, in this paper, an adaptive multiple subtraction method based on empirical low-rank representation is proposed. We use the empirical mode decomposition method to improve the conventional low-rank representation method. By adaptively decomposing the seismic signal into low-rank subsets with high signal-to-noise ratio, simple inclination, and smooth event phase, the parameter selection of the local window during the low-rank representation processing is optimized, that is, to reduce the complexity of the dip component of the seismic signal; then the conventional adaptive subtraction method in different low-rank subsets is adopted to avoid the event intersections in the adaptive subtraction, and each subset is reconstructed to improve the multiple attenuation effect under the premise of ensuring the calculation efficiency. In order to verify the effectiveness of the proposed method, we apply it to the synthetic and field examples, the results are better than those of the conventional methods, and the noise sensitivity example proves the robustness of the proposed method.

The deep reservoir of Dongying sag is a set of red beds under dry sedimentary environment. The reservoir of Ek₁^z has a great exploration potential with large thickness and less drilling. However, the reservoir prediction is very difficult,as the layer structure in the target area is complex, the burial depth becomes deeper from south to north gradually, and the consistency of well-to-seismic relationship is not good. Through a comprehensive analysis of well-to-seismic characteristics, the seismic attributes were optimized and the relationship of well-to-seismic thickness was established. Using the single best attribute method, multiple linear regression method, and learning-type nonlinear reservoir prediction method, the understandings and conclusions are drawn as follows:1) The red bed in the study area has the typical characteristics of thin inter-beds, with higher frequency than the overlying and underlying strata, medium amplitude seismic reflection, low continuity, and low signal-to-noise ratio; 2) Based on the dominant frequency, the newly developed mobility attribute has the best thickness correlation and the maximum amplitude, the root mean square amplitude, zero crossing count,and the energy half-time attribute is also better; 3) Whether it is linear regression or nonlinear support vector machine (SVM) method, the optimized five attributes reservoir prediction effect is better than that of seven attributes; 4) The cross-validation based SVM method is the most suitable one for the thickness prediction of small sample wells in deep reservoirs, and its effect is better than the single best attribute method and the multiple regression method.

The rock medium has viscous properties, and the viscoelastic medium model is closer to the real situation of the rock medium than the elastic medium model. According to the constitutive relationship of the Kelvin-Voigt viscoelastic element model, the staggered grid finite difference equations of the viscoelastic isotropic medium in the cylindrical coordinate system are derived, and the numerical simulation of acoustic field of the wellbore in viscoelastic medium are completed. The simulation results show that the rock quality factor and the acoustic source center frequency have effects on the acoustic field inside and outside the well in the viscoelastic medium:The attenuation of the acoustic field outside and inside the well decreases with the increase of the quality factor, and the wave amplitude outside the well and the reflected wave amplitude increase accordingly; The attenuation of the acoustic field outside the well decreases with the increase of the source center frequency, and the wave amplitude outside the well increases accordingly; The attenuation of the acoustic field in the well increases with the increase of the source center frequency, and the wave amplitude in the well decreases accordingly.

Lunar dust research has important scientific and engineering values. Although it has been studied for several decades,the transportation of natural dust activity near the Moon surface and its physical mechanism remain unclear due to the lack of quantitative measurements of relevant physical parameters,which is the bottle neck of lunar dust research. So far, Apollo's lunar dust observations still remain a scientific mystery. With China's Chang'e 3 lunar exploration data,scientists have obtained the dust deposition rates and maximum levitated height on the lunar surface. Compared with the previous Apollo measurements,these results indicate that the dust activity has significant regional differences. In Chang'e 5 lunar mission,the in-situ charging properties of levitated dust will be measured. To further promote the lunar dust research,it is very important to systematically and quantitatively measure the physical parameters of the lunar dust transportation in the high-latitude region in the future lunar missions,which will be vital to reveal the physical mechanism of dust transportation under different influence factors such as different latitude and longitude regions,different solar conditions,different solar wind conditions, and different terrain conditions. These measurements will provide quantitative constraints in theoretical models and will surely lead to new and important scientific discoveries.

Nighttime remote sensing images have been widely used in the extraction of city information,as nighttime light data are closely related to human activities. As a new generation of noctilucent remote sensing data source, LJ1-01 has higher spatial and spectral resolutions, and can express the scope and internal structure of urban built-up areas more clearly. In this study, LJ1-01 nighttime light remote sensing images were used to extract the urban built-up area of Changchun City based on human settlement index (HSI),vegetation and build adjusted nighttime light urban index(VBANUI), and support vector machine(SVM) supervised classification. The results were compared with those obtained by suomi national polar orbiting partnership/visible infrared imaging radiometer suite (NPP/VIIRS) using the same method. It showed that the extraction accuracy of the traditional vegetation adjusted nighttime light urban index(VANUI) is improved by VBANUI proposed in this paper. Among them, the urban built-up area extracted by VBANUI using LJ1-01 has the best result, with the Kappa coefficient of 0.80 and the overall classification accuracy of 90.74%; The optimal Kappa coefficients of urban built-up areas extracted by HSI using LJ1-01 and NPP/VIIRS are 0.75 and 0.72, respectively, and the overall classification accuracy is 88.27% and 86.54%, respectively; The kappa coefficients of Landsat-NDBI composite data, Landsat-NDBI-VIIRS composite data, Landsat-NDBI-LJ composite data, and Landsat-NDBI-LJlog composite data in SVM supervised classification are 0.602, 0.627, 0.643, and 0.681, respectively, and their overall classification accuracy is 81.11%, 81.52%, 82.25%, and 84.48% respectively. The results show that the LJ1-01 nighttime image is the best among the three extraction methods. This study proves that the LJ1-01 night light remote sensing image is more suitable for urban level built-up area extraction than NPP/VIIRS night light remote sensing image.