Dayangshu basin is a Late Mesozoic residual basin with a low degree of exploration and research. It shows a good exploration prospect with the industrial oil flows obtained from several wells in recent years in the southern depression. A systematic understanding of the source rocks and the hydrocarbon origin of Jiufengshan Formation is still uncertain. Based on the geochemical analysis data of source rocks and crude oils, including TOC、Rock-Eval、GC-MS, and carbon isotope, the hydrocarbon generation potential of source rocks of Jiufengshan formation are evaluated, the properties of crude oils and oil source are studied. The results show that medium-good source rocks are developed in the first member (K1j1) and the third member(K1j3) of Jiufengshan Formation, with w（TOC） of 1.76% and 2.59%, w（ S1 + S2） of 4.44 mg/g and 7.36 mg/g, bitumen of 0.21% and 0.09% respectively. The organic matter type of the K1j1 is mainly type Ⅱ1 including some typeⅠ, K1j3 is mainly type Ⅱ1 including some typeⅡ2, and the vitrinite reflectance (Ro) of the source rocks in K1j1 is mainly 0.70% to 1.60%, at the mature to high mature evolution stage. Ro in K1j3 is mainly from 0.50% to 1.10% and at the mature evolution stage. The hydrocarbon generation threshold of the source rock is about 1 300 m, and the hydrocarbon generation peak is about 1 750 m. The source rock has the characteristics of early hydrocarbon generation. The crude oils are light to medium, characterized by high viscosity, high wax, low sulfur, and high saturated hydrocarbon. The crude oil enriches light carbon isotope with δ13Coil from -30.40‰ to -29.38‰, δ13C sat from -30.78‰ to -29.07‰, and δ13Caro from -29.73‰ to -27.91‰, which indicates the source of lacustrine algae. The main peaks of alkane in oil are nC19 and nC21, OEP is 1.07 to 1.08, and Pr / Ph is 0.83 to 1.10. The crude oil can be divided into two groups based on terpenoid steroid marker. Group one includes the crude oil of Wells YC1 and Y3, with relatively high tricyclic terpane, C30D, Ts/Tm, C29Ts/C29 hopane, sterane C27R/C29R, regular sterane / hopane, rearranged sterane / regular sterane, C2920S / 20 (S+R), C29ββ/(ββ++αα) and low β-carotene. Group two includes the crude oil of Well YX4 and Well Y6, with high β-carotene and relatively low sterane terpane ratios, indicating that the maturity of Well YC1 and Well Y3 oil is higher than that of Well YX4 and Well Y6, and there are slight differences in sedimentary environment and parent material source. The oil and rock correlation of biomarkers shows that the crude oil of Wells YC1 and Y3 mainly comes from the source rock of K1j1, and the crude oil of YX4 and Y6 wells mainly comes from the source rock of K1j3. The potential hydrocarbon accumulations in this area are source-reservoir integrated accumulations and lower source rocks generation-upward migration accumulations.

The Lower Cambrian black rock series in Ziyang, Shaanxi Province is rich in organic matter and metal elements (Ba, V, Cr, Ni, Mo, Au), while there is still a lack of understanding of its organic geochemical characteristics. Based on the experimental results of polarized electron microscope, morphology under scanning electron microscope, organic carbon (TOC) and saturated hydrocarbon gas chromatography-mass spectrometry(GC-MS)，the coupling relationship of organic matter and inorganic matter, organic matter source and maturity, sedimentary environment were discussed. The results show that the content of organic matter is high in the study area, and there are two kinds of occurrence modes, dispersed organic matter and aggregated organic matter. The relationship between dispersed organic matter and clay minerals is close. The average total organic carbon (TOC) content was 2.95%, affected by lithologic differences, pyrite content and types. All the samples were rich in n-alkanes, isoprenoids, steroids and terpenes. The distribution range of carbon number was from C14 to C34, which showed obvious bimodal distribution characteristics and no obvious odd-even advantage. Isoprenoid alkenes indications showed obvious phytoalkane advantage, with low value of Pr/nC17(0.36) and Ph/nC18 (0.50); The abundance of terpenoids was tricyclic terpane > pentacyclic terpane > tetracyclic terpane, a small amount of gamma wax, and the distribution of tricyclic terpane C21-C23-C24 is asymmetric inverted “V” with low average value of Tm/ Ts ratio(1.03); The distribution of regular steranes in steroids showed an asymmetric “V” distribution of C29>C27 > C28 with low average ratio of C27 rearranged steranes / C27 regular steranes(0.18) and pregnane/ C29-20r steranes(0.84). As indicated above, the origin of organic matter is mainly marine lower organisms (such as bacteria, algae, and microorganisms) and plankton, and a small amount of terrestrial lower plants are involved in the source of organic matter in some rocks (siliceous rocks); The organic matter of the whole rock has a high maturity, but it has not reached the stage of over maturity; The black rock series comes from the semi closed-closed alkaline seawater environment with anoxic reduction and low salinity.

The Qitaihe fault depression in the Boli basin is rich in coalbed methane resources, but the exploration level is low, and the understanding of the enrichment and accumulation laws and mechanisms is insufficient, which restricts exploration practice. Based on a detailed dissection of the geological conditions of coalbed methane in the Qitaihe fault depression, this article reveals the enrichment characteristics and reservoir formation mechanism of coalbed methane in the study area. The study found that the coalbed methane reservoir in the Qitaihe fault depression has good conditions, with many coal seams in the Lower Cretaceous Chengzihe Formation, a large total thickness of coal seams, multiple developed coal rich centers, and a high degree of thermal evolution. The physical properties of coal reservoirs are favorable, and the gas content of coal seams is generally characterized by high in the west and low in the east. The structure, the hydrology,  the sealing and other preservation conditions benefit coalbed methane reservoir formation. There are three types of models of coalbed methane reservoir formation, syncline-hydraulic sealing, fault sealing-hydraulic sealing, and fault-multi seam self-sealing. Under moderate burial depth and slow stagnant water environment, the reverse fault sealing area, secondary structural high point, and middle coal seam stratification are favorable locations for coalbed methane enrichment. On this basis, a multi-level fuzzy mathematics evaluation model for coalbed methane selection was established, and favorable areas were evaluated. Seven coalbed methane favorable areas were selected, including Qinglongshan-Taoshan district and Machang district.

The Lufeng 22 subsag is a magmatic diapir reformed subsag in Dongsha uplift，Pearl River Mouth basin. In order to clarify the structural deformation characteristics and evolution process of such kind of subsag, the research reconstructed the evolution process of the study area based on the structural interpretation of seismic data, the analysis of residual stratum thickness, and the balanced profile technology. it is found that, The west slope and the east sub-depression of Lufeng 22 subsag was subjected to three stages of strong magmatic diapirism, and the most active diapri is in member 4 of Wenchang Formation. The effect of magma diapirism on the depression structure is mainly shown in three aspects. First, magma diapir destroyed the initial structural style of the subsag, caused the boundary fault to bend and even break, showed a characteristics of plane zoning; Second, the strong uplift of magma lead to the strong tilting of the strata, thus the gentle slope strata was greatly uplifted and subjected to strong denudation; Third, the magma diapir produced secondary bulge, which influenced the location, scale and evolution of the sedimentary center, thus showed a very complex structural characteristics and evolution process. The west slope and eastern subsag with strong magmatic diapirism only experienced evolution stages of fault-down thrown basin and faulted-sag basin, while the western subsag, high-in-sag and east slope with weak magmatic diapirism completely developed three evolution stages of fault-down thrown basin, faulted-sag basin and sag basin. The tectonic units showed lateral zoning characteristics.

In order to study the law of hydrocarbon enrichment at the oil-source fault in the petroliferous basin, based on the study on the conditions and evolution stage of oil-source fault transport, the method of determining the evolution stage of oil-source fault transport is established by determining the activity period of oil-source fault and the formation period of the oil-source fault transport in the oil source and the oil source outside the oil transfer station. The method is used to determine the evolution stage of oil and gas transport from Nandagang fault to the Lower Member of the Shahejie Formation in Qikou sag, Bohai Bay basin. The results show that, the oil and gas stage of Nandagang fault to the Lower Member of the Shahejie Formation to the Third Member of the Shahejie internal transfer station starts from the deposition of Guantao Formation to the middle deposition of Minghuazhen Formation; The oil and gas stage of the transfer station of the third stage is from the middle deposition to the end of the Minghuazhen Formation. After two evolutionary stages, the oil and gas transporting period is relatively long, which is conducive to the large-scale accumulation and accumulation of oil and gas from the underlying source rocks of the Third Member of the Shahejie Formation in the Lower Member of the Shahejie Formation. According to the method of this paper, it can reasonably explain the phenomenon of oil and gas enrichment in the lower sub-member of the Nandagang fault. This method is suitable for determining the evolution stage of oil and gas transport by oil-source faults.

 A lot of geological work has been carried out in the prospecting for sandstone-type uranium deposits in the southern Songliao basin, resulting in significant achievements. In contrast, the geological exploration work for uranium deposits in the northern Songliao basin is currently inadequate. In this paper, based on the analysis of uranium mineralization conditions, such as uranium-bearing rocks, basin tectonic evolution, paleoclimate, stratigraphic evolution, distribution of sedimentary facies, development of sand bodies and epigenetic reformation, etc., the mineralization potential of sandstone-type uranium deposits in the northern Songliao basin is comprehensively evaluated, and its prospecting direction is discussed. The northern Songliao basin is rich in uranium sources and has good metallogenic conditions. Since the Cretaceous, the basin has experienced four periods of tectonic inversion, forming two main uranium prospecting targets, Upper Cretaceous Yaojia Formation and Sifangtai Formation. Inside the basin, the Yaojia and Sifangtai Formations have well-developed sedimentary facies and sandbody conditions, and the oxidation is noticeable in some areas, and the oxidation zone and uranium mineralization are also relatively developed, providing important clues for ore prospecting. Comprehensive analysis shows that the overall uranium metallogenic conditions are good in the northern Songliao basin, with the Yaojia Formation being the key prospecting strata in the eastern section, and the Sifangtai Formation in the western section. The ore exploration type is interlayer oxidation zone type.

Garnet granites and anatectic source rocks (pelitic gneiss) in Daqingshan and Jining-Liangcheng areas at the northern margin of the North China craton gradually transition and closely coexist in the field. The garnet granites contain many source rock enclaves, residual bodies and residual mineral phases/peritectic minerals. There are also a large number of garnet granite blocks in anatectic source rock. All these migmatites have heterogeneity macroscopically. Petrographic studies show that the mineral composition of garnet granites and the anatectic source rocks are similar and both contain garnet with similar characteristics. This can be considered a residual mineral/peritectic minerals facies type. Geochemical studies indicate that garnet granites are relatively well integrated with their anatectic source rocks, both have high Al2O3 values and TFeO/MgO ratio, with a large variation in CaO values and K2O/Na2O ratio. They are relatively enriched in light REE and large ion lithophile elements, and relatively depleted in Ta, Nb, Ti  and P. Deviating from the composition range of typical S-type granites in the world, garnet granites have lower SiO2(50.30%-73.10%) and greater MgO+TFeO(1.6%-14.8%). It is believed that this deviation from the normal S-type granite compositon is related to the introduction of residual garnet and the addition of mantle-derived materials. The garnet granites in the Daqingshan  and the Jining-Liangcheng areas were formed by two episodes of anatexis at the 2.45-2.37 Ga and 1.95-1.90 Ga respectively, consistent with the regional mantle-derived magma underplating in this area. This indicates that garnet granites are the products of large-scale partial melting of metasedimentary rocks caused by mantle-derived basic magma intruding into granulite facies metasedimentary rocks.

The volcanic rocks in the Yitong area of central Jilin Province are located in the eastern segment of the northern margin of the North China plate. This paper presents zircon LA-ICP-MS U-Pb geochronology and geochemical data of the volcanic rocks in this area, aiming to explore their petrogenesis. The zircons in the andesite present euhedral-subhedral, and obvious magmatic oscillation zone, with Th/U ratios of 0.06-0.95, indicating their magmatic origin. Zircon dating results indicate that basaltic andesites were formed at (285±2) Ma, the Early Permian. The rock assemblage of the Early Permian volcanic rocks is basaltic andesite and andesite. The SiO2 mass fraction of the samples is 51.29%-58.91%, and the Mg# values are 39-66, belonging to the tholeiitic series, relatively enriched in light rare earth elements (LREEs), large ion lithophile elements (LILEs), and depleted in high field strength elements (HFSEs). Comprehensive studies suggest that the Early Permian volcanic magma originated from the depleted mantle wedge metasomatized by subducting fluids, and was formed in the active continental margin environment of the southward subduction of the Paleo-Asian Ocean. Combined with regional research results, it is believed that the northern margin of the North China plate was under the southward subduction of the Paleo-Asian Ocean in the Early Permian.

There are numerous Late Paleozoic acidic intrusive rocks in Wenquan area, which is located on the northern margin of the Yili block. In this paper, we present new zircon U-Pb geochronology, Lu-Hf isotopic and geochemical studies of the Early Devonian granites from Wenquan area, aiming to confirm their timing, discuss their petrogenesis, and explore their tectonic evolution process. The zircon LA-ICP-MS U-Pb age of the monzogranites is (418±7) Ma which indicates that their crystallization age is the product of Early Devonian magmatic activity. Meanwhile, the zircon Hf isotope compositions of the monzogranite are typically characterized by high εHf(t) values (8.2-14.0, with an average of 11.3), and the young two-stage model ages (TDM2=863-492 Ma), implying their derivation from a relatively juvenile crust. These two types of granites are characterized by high SiO2, weakly peraluminous, as well as low CaO and MgO contents. The trace elements of the granites are characterized by depletion in high field strength elements (Nb, Ti, P), and enrichment in large ion lithophile elements (K, Rb). The standardized distribution pattern of rare earth elements in chondrites is enriched in light rare earth elements and depleted in heavy rare earth elements, with significant negative Eu anomalies. The low zircon saturation temperature, negative correlation between P2O5 and SiO2, and other geochemical features suggest the granites are I-type granites. Several tectonic discrimination diagrams shows that they were formed in a continental magmatic arc setting. Combined with the regional tectonic background and the evolution information of magmatic rocks in the adjacent area, it is speculated that the granites were mainly derived from the crustal accretion in response to subduction of the Junggar-Balkhash Ocean. 

Geothermal energy exploitation and utilization are closely related to groundwater transport and the evolution of water environment. In this study, wereviewed the development status and typical mining technologies for the shallow geothermal energy stored in the soil and phreatic aquifers, median-to-high-temperature geothermal energy in deep aquifers, and high-temperature geothermal energy stored in the hot dry rocks for informational purposes of sustainable development and utilization of large-scale geothermal resources. In particular, the shallow geothermal energy can be classified into ground source heat pump and ground water heat pump according to the subsurface heat source; Median-to-high-temperature geothermal energy can be exploited mainly by direct mining, combination of production and injection and standing column well system; And high-temperature geothermal energy can be exploited using enhanced geothermal systems (EGS) through reservoir reconstruction technique such as hydraulic fracturing or chemical stimulation. Furthermore, the potential impact of geothermal energy exploitation on the groundwater resources was analyzed and summarized following the reported site cases, mainly focused on the cold and heat accumulation brought by heat pump technology, the decline of groundwater level caused by hydrothermal exploitation and the possibility of microseismic events or fracturing fluid leakage caused by hydraulic fracturing of hot dry rocks. In the end, the approaches were proposed to promote the sustainable development of geothermal resources and reduce the negative impacts on groundwater resources, including improving the recharge capacity, maintaining the water balance in the process of mining and irrigation, maintaining the heat exchange efficiency and the re-balance of underground heat, and adopting new materials. 

Abstract： To carry out engineering geological evaluation of hydraulic reclamation areas such as Chongming Dongtan, this paper aims at the change in shear strength of the underlying clayey soil layers in Chongming Dongtan. Considering different reclamation times, soil samples from boreholes in five different reclamation areas (within the 1949 cofferdam, 1949-1964, 1964-1976, 1976-1990, and 1990-1998) were selected for direct shear tests, and the variation of shear strength of soils in different periods and layers were analyzed.  Moreover, the microstructure of the soil samples was observed by scanning electron microscopy, and the change in shear strength was analyzed qualitatively and quantitatively from a microscopic perspective. The results revealed that: 1) The shear strength of the clayey layer varied as， the clay layer in the 1949-1964 reclamation zone had the largestshear strength, and the peak shear stress at 50, 100, 200, and 300 kPa is 33.31, 46.68, 102.10 and 147.15 kPa, respectively. Little difference in shear strength between boreholes in silty clay layer was observed under various levels of vertical pressure. From west to east, the shear strength indexes of the clay layer showed an opposite trend to that of the silty clay layer, in relation to the trend in natural water content. 2) From west to east, significant changes in the microstructure of the soil samples were observed. The soil microstructure in clay layer changed from a flocculent/aggregate to a matrix structure， and the soil microstructure in silty clay layer gradually transitioned from a skeletal/aggregate structure to a matrix structure and to a flocculent/aggregate structure. 3)  The average pore diameter of the particle was negatively related to the cohesion and positively related to internal friction angle. In addition, the average shape coefficient of the particle was positively related to the cohesion and negatively related to internal friction angle. This indicated that average pore diameter  and the average shape coefficient of the particles were directly related to the shear strength indexes of the soil.

In order to quantitatively analyze the time-lag effect between displacement and inducing factors of step-like landslide, as well as to improve the accuracy of displacement prediction, in this study, the authors proposed a new prediction model and conducted comparative analysis. First, the cumulative displacement was separated into trend term and periodic term based on time series analysis. Then, using maximum information coefficient (Cmi) and multivariate empirical mode decomposition (MEMD) for multi-factor analysis and multi-scale analysis, the multi-factor and multi-scale MEMD prediction model was constructed. Finally, taking  Bazimen landslide in  Three Gorges Reservoir area as an example, the optimal lag period inducing factors were selected as the model input through Cmi, and multi-scale prediction model was established based on the decomposition of multivariate sequence by MEMD. The proposed model was compared with other models (single-factor and single-scale model, multi-factor and single-scale model, single-factor and multi-scale EMD model). The results showed that the optimal lag periods of rainfall and reservoir water level in  Bazimen landslide were 2 d and 4 d. After decomposing the landslide multivariate sequence by MEMD, three groups of mode functions were obtained, each group had seven components, and the time-scale of each corresponding component was consistent. The response of the periodic term displacement to the inducing factors had a time multi-scale characteristic. Compared with the comparison model, the root mean square error of the multi-factor and multi-scale MEMD prediction model decreased by 49.4%, 36.9% and 27.4% on average, and the mean absolute percentage error decreased by 38.0%, 26.4% and 15.8% on average.

During underground engineering construction in gypsum-enriched formations, the reaction between  gypsum and groundwater leads to the dissolution of Ca2+ and SO42-, which enhances the erosion effect on the concrete foundation of underground structures and affects the safety of underground engineering. In order to investigate the erosion characteristics and mechanisms of concrete under different  formation environmental conditions, commonly used C20 and C30 concrete in underground engineering construction were studied. The study focused on the gypsum-containing formation  conditions in the southern part of Chengdu basin and explored the erosion characteristics and mechanisms of concrete in both gypsum-containing and non-gypsum-containing formations under changing underground temperature conditions. The results show that: 1) The erosion degree of C20 and C30 concrete in gypsum-containing formations is significantly greater than in non-gypsum-containing formations. Under the erosionby different geological groundwater, the  maximum mass change rates of C20 and C30 concrete are 1.80% and 0.87%, with the maximum compressive strength reduction rates of 20.14% and 12.80%, respectively. C30 concrete exhibits a smaller attenuation in compressive strength under different groundwater conditions, making it more suitable as a construction material for underground engineering. 2) Increasing temperature enhances the erosion effect of SO42- on concrete, leading to a decrease in compressive strength. Among them, the maximum compressive strength reduction rates of C20 concrete under Quaternary and Guankou  Formation groundwater erosion reach 6.89% and 3.89%, respectively. 3) Concrete erosion occurs from the outside to the inside, where Ca2+ and SO42- in groundwater recrystallize to form gypsum on the  external surfaces of the concrete and then diffuse along cracks towards the interior, resulting in the formation of ettringite crystals, expansion forces, crack formation, and a decrease in compressive strength. Through correlation analysis, a relationship equation between the mechanical properties of concrete and temperature was established, achieving quantitative calculation of long-term changes in the mechanical properties of concrete in gypsum-containing formation engineering construction.

In order to explore the creep law of rock under the coupling action of hydration, freezing and thawing, taking the marble of an open-pit slope in Hubei as the research object, the uniaxial compression creep tests under different freeze-thaw cycles were carried out by soaking in acid, medium and alkali solutions, and the macro failure morphology and fracture micro characteristics of marble were compared and analyzed. The results showed that: 1) Under the same number of freeze-thaw cycles, the instantaneous, creep strain and creep rate in acidic environment were the largest, alkaline was the second, and neutral was the smallest. 2) The average long-term strength of marble was 0.685-0.812 of the instantaneous strength, and the long-term strength was greatly reduced. 3) The damage degree of acid solution to marble particle structure was stronger than that of alkaline solution, but with the enhancement of freeze-thaw effect, the damage degree of alkaline solution to rock structure was gradually close to that of acid solution.

The water chemical conditions of groundwater in coastal areas are complex. In order to find out the harm of groundwater quality to groundwater source heat pump system (GWHP), the harm mechanism was studied. Through the hydro-chemical analysis of the phreatic and First confined water in the Yancheng City, the main ion sources and causes were determined, and the harm of Mg2+, Ca2+ and Fe2+ was analyzed. Finally, the saturation index Is was calculated by PHREEQC, and the potential harm of groundwater overflow mixing and groundwater recharge superposition to the ground water source heat pump was analyzed. The results show that the TDS and hardness of groundwater in Yancheng area are high. Na+,Mg2+, Ca2+, Fe2+ HCO3- and  Cl- are the main abnormal ions. The diving ρ(TDS) is 180.42-4 497.00 mg/L, ρ (Na+)，ρ (Mg2+)，ρ (Ca2+) are 278.16，72.91，72.74 mg/L, respectively. The anions ρ(HCO3-) and ρ (Cl-) are 487.33 mg/L and 298.76 mg/L, respectively. The ρ (TDS) of  First confined water was 508.50-17 182.00 mg/L, ρ(Na+), ρ (Ca2+) and  ρ (Fe2+) were 1 595.06, 564.57 and 4.50 mg/L, respectively, and the ρ (Cl-) was 4 560.06 mg/L. The process of groundwater migration is influenced by various water-rock reactions such as dissolution and intrusion of ancient seawater. Major problems such as Fe(OH)3 scaling, CaCO3 and CaMg(CO3)2 precipitation and scaling will occur in the long-term operation of GWHP.

To evaluate the bioavailability of selenium in selenium-rich soil of Yinan, Shandong Province in different crops, and to speculate its source, soil, plant, and rock samples were collected accordingly from the research area, then the total   selenium content in each sample and the content  of five forms of selenium in water-soluble, weak acid extracted, reducible, oxidizable, and residual states were tested by ICP-MS, and the results were compared and analyzed. The results showed that: the total selenium content in soil is significantly constrained by spatial location and water system constraints; The effective selenium content  is positively correlated with the total selenium content, and the spatial distribution is consistent; The total selenium content in soil is positively correlated with the nitrogen and phosphorus content; The main form of selenium in soil is selenite. The fruits of three crops, peanuts, walnuts, and watermelons, grew on selenium-rich soil in the research area are enriched with selenium element. The selenium source in selenium-rich soil is related to shale, mudstone, and upstream iron ore in the regional strata, and it is speculated that the above rocks were weathered into soil and later transported to the clay and sandy clay areas by water flow, where they were adsorbed and deposited by soil clays to form selenium-rich areas.

In order to effectively solve the problem of iron and manganese overload in groundwater, this paper proposes a new method of removing iron and manganese by combining powdered activated carbon (PAC) and ozone, and explores the mechanism of the effect of PAC in treating iron and manganese in water by ozone oxidation. The effect of PAC and ozone on the treatment of Fe and Mn alone was firstly investigated; Then the effect of PAC and ozone on the treatment of Fe and Mn in combination was investigated, and the effect of different conditions (pH, temperature, PAC dosage, and oxidant concentration) on the removal of Fe and Mn in water was investigated; Finally, the mechanism of the effect of PAC on the treatment of Fe and Mn in ozone oxidation water was investigated. The results showed that PAC could enhance the oxidation of Fe and Mn by ozone under different conditions. Under the conditions of PAC dosage of 0.3 g/L, ozone mass concentration of 5 mg/L, pH of 7.0, and room temperature, the mass concentration of Fe and Mn mixed solution rapidly decreased from 0.5 mg/L to 0.1 mg/L within 5 min, which met the requirements of corresponding emission standards; With the increase of PAC dosage, the residual concentrations of Fe and Mn gradually decreased, which indicated that the reaction was highly dependent on the active sites on the surface of PAC, further confirming the effect of PAC on the removal of Fe and Mn from water. The characterization results such as scanning electron microscopy (SEM) and Mapping analysis showed that the reaction formed iron oxide and manganese oxide coatings on the surface of PAC, and these oxide coatings would further accelerate the removal of free iron and manganese from water.

With the significant improvement of high-density acquisition and daily acquisition efficiency, the amount of exploration data is growing exponentially. In order to save storage space and improve transmission efficiency, the research on high-fidelity compression and reconstruction of prestack seismic data is extremely urgent. EZW (embedded zerotree wavelet) algorithm has excellent compression performance. The traditional EZW algorithm for seismic data compression is based on data in the t-x domain. Because the wavenumber of prestack seismic data is wide and the frequency band is limited, the energy of the discrete cosine transform (DCT) data is mainly concentrated in the low-frequency in the DCT domain. This paper proposes a frequency division seismic data compression technology. Firstly, 2D-DCT is performed on the t-x data, and then frequency division is applied to the 2D-DCT data to obtain high-frequency and low-frequency data. By separately coding high-frequency and low-frequency data based on EZW, the low-frequency data has a high coding level to ensure the signal-to-noise ratio (SNR) of the reconstructed data, and the high-frequency data has a low coding level to improve the data compression ratio (CR). The synthetic data and field data experiments show that the compression ratio with the proposed method is higher than that with the conventional EZW at the same SNR.

Peridynamic theory uses integral form of motion equations, which can effectively avoid the problem that the spatial partial derivative does not exist. It is widely used in simulating discontinuous problems such as crack propagation and fracture damage in different material models. However, there are few studies on wave propagation and dispersion characteristics in peridynamic theory model. In order to study the propagation law of waves in peridynamic theory model, in the case of plane stress, the equations of motion in integral form are established, and the wavefield numerical simulation of isotropic plate model and plate model with parallel cracks are carried out, and the wavefields of longitudinal and shear waves in the classical continuum theory are compared and analyzed. Based on motion equations of ordinary state-based peridynamic theory, the dispersion relations for 1D and 2D are derived in detail. The influences of peridynamic parameters such as the number of material point, the radius of the horizon and the shape parameter on the dispersion curves are comprehensively discussed. In wavefield numerical simulation, the wavefield numerical simulation results of the linear peridynamic solid (LPS) model and the linear elastic solid of the classical continuum theory are in good agreement. The existence of cracks in the model will cause reflection and diffraction of waves during propagation. In the analysis of dispersion characteristics, the dispersion characteristics of LPS model are more consistent with those of the classical continuum model when the  radius of the horizon is smaller and the  shape parameter is larger.

Channel sand is one of the important oil and gas reservoirs. The quantitative prediction of sand body thickness is the key to improve the efficiency of oil and gas development. With the enhancement of non-homogeneity of target reservoir, the relationship between seismic attribute and reservoir lithology, physical property and pore fluid becomes more complicated. How to achieve efficient and intelligent quantitative prediction of complex reservoirs under the condition of limited geological information is currently a hot and difficult topic in the field of reservoir prediction. To achieve high accuracy and intelligent prediction of the tight sandstone reservoir, a reservoir effective sand thickness prediction method based on deep fully connected neural network is proposed in this paper. The method constructs a multilayer stacked fully connected neural network to optimize the seismic attributes predicted for the effective sand thickness of the reservoir layer by layer, and maps the optimized attributes directly to the sand thickness. We first analyze the influence of training samples on fully connected neural network modeling, and then compare the performance of the deep and shallow morphology of this network in the case of small samples when the model size is larger than the number of training samples and the model size is smaller than the number of training samples, and find that the deep network outperforms the shallow one when the training samples are small, provided that the number of training samples is larger than the model size. Finally, we apply the deep fully connected neural network to the effective sand body thickness prediction from real data of Shengli oilfield, and the application results show that the method achieves effective identification of sand bodies around 4 m in a tight sandstone reservoir, reflecting the ability of this end-to-end intelligent modeling method to mine latent geological information from seismic attributes, thus confirming its effectiveness in quantitative reservoir prediction.

The Jianbian farm area in Heilongjiang Province is located at the intersection of the Great and Lesser Xing’an Ranges. The multi-stage magmatic and tectonic evolution history in this area has resulted in a complex and diverse geological background for mineralization. Based on the interpretation of Landsat ETM image data in the Jianbian farm area of Heilongjiang, this paper combined the mineral spectral characteristics and the basic geological data, and used the method system of “de-interference, principal component analysis, and ratio method combined with anomaly screening” to extract the mineralized alteration information, such as iron staining and hydroxylation in the study area. Thirteen hydroxyl mineralization alteration anomalies and seventeen iron-stained mineralization alteration anomalies were identified. The mineralized alteration anomalies were mainly found in Cretaceous volcanic strata and were mainly distributed along the intersection of NE- and NW-trending faults, NNW- and SN-trending faults. They were closely related to the contact zone of Mesozoic volcanic rocks and Early Cretaceous-Early Carboniferous intrusive rocks. Combining the known geological and mineral data and field verification results, it is found that iron-stained anomalous minerals such as limonite and hematite, as well as anomalous hydroxyl minerals such as carbonation and chloritization, were commonly developed in this area. The extracted iron-stained and hydroxyl mineralized alteration anomalies closely matched physical and chemical exploration anomalies, and were highly consistent with known Au, Cu and Mo occurrences and mineralized occurrences. This provides a theoretical basis and direction for the next step of mineral exploration in the study area.

Using Landsat 8 TIRS thermal infrared data, the surface temperature of Guide basin was identified by remote sensing through single window algorithm and split window algorithm, and the location of high temperature anomaly area was determined. Based on the formation conditions of dry hot rock, a multi information dry hot rock target prediction model including 12 factors, including strata, rock mass, faults, annular structure, linear structure, hydrothermal alteration anomaly, surface temperature anomaly, hot spring, geothermal drilling, regional gravity anomaly, regional aeromagnetic anomaly, and electromagnetic exploration information, was constructed, and the dry hot rock target in Guide basin was predicted. The results show that: 1) The Neogene, Triassic and Quaternary strata are the heat preservation covers of the dry hot rocks in Guide basin, the large NW trending Late Triassic intermediate acid concealed granite is the heat storage rock mass, the NNW trending Waligong Mountain deep fault and granite body are the heat conduction channels, the lower mantle asthenosphere heating and the partially molten layer heating are the main heat sources, and the rock radioactive heat generation is the superposition heat source. 2) The concealed rock mass prediction area, surface temperature anomaly area and hydrothermal alteration anomaly area in the basin all have the characteristics of distribution along the northwest southeast direction, and the distribution positions confirm each other. 3) According to the model, there is a large dry hot rock belt distributed along the northwest southeast direction in guide basin, with an area of about 820 km2. 

Karst rocky desertification is one of the serious ecological and environmental problems in Southwest China. As the inheritance and continuation of Landsat and SPOT (systeme probatoire d’observation de la terre) series satellite data, Sentinel data has better application prospect in ecological and environmental monitoring. By the traditional method, the Karst rocky desertification mapping extracted from Sentinel-2A is only at 20 m resolution and this method wastes the detailed information. In order to extract the Karst rocky desertification more accurately, this research constructs 10  m resolution rocky desertification index for rocky desertification mapping of Beimen River basin in Wenshan, Yunnan based on the characteristic of Sentinel-2A data and analyzes the geological causes. By comparing four fusion algorithms, à trous wavelet transform has the better effect than high pass filtering, principal component analysis and  Gram-Schmidt transform  in short-wave infrared band (B12). The results show that the 10 m  normalized differential rocky index (NDRI) and rock exposure rate (fr )  have good correlation with 20 m NDRI and fr (the correction coefficients are 0.90 and 0.81, respectively), and they can provide more information of different ground objects. It indicated that the 10 m resolution index of Sentinel-2A has better performance for Karst rocky desertification mapping in this study.  The geological causes analysis of Karst rocky desertification in  Beimen River basin shows that the Karst rocky desertification mainly consists of  potential Karst rocky desertification and light Karst rocky desertification, which account for  40.66% and 16.97% of the total  basin area.  Karst rocky desertification is distributed mostly in the Gejiu  Formation and Banna  Formation. Within slope range of 0°-25°, all types of Karst rocky desertification are concentrated development , accounting  for 82.71% of the total area of Karst rocky desertification. 

Target detection is a fundamental and routine task in remote sensing image processing. In this paper, we design a target detection algorithm for remote sensing images based on the YOLOX network. Firstly, ASFF is added to the feature extraction module PANet to deeply mine the fine features with inconsistent scale in target detection. Secondly, an ECA-based feature extraction module is designed with efficient channel interaction to reduce the complexity of the model while paying more attention to the positive sample feature information in the feature map. Then, to avoid the problem of gradient disappearance and weak activation effect caused by overfitting, the use of swish activation function is proposed. Finally, experiments are conducted on DOTA to verify the best mechanism and effectiveness of the improved method through qualitative analyses of the ablation experiments and quantitative comparison experiments. With the addition of ASFF and ECA mechanisms and the optimization of the swish activation function, the improved network model achieves an mAP of 74.42%, an improvement of 12.75% over the original network. Compared with the current widely used target detection algorithms Mobilenet-YOLOv4, YOLOv4, YOLOv5 and YOLOX, the proposed  algorithm achieves an improvement of 11.42%-17.84% in mAP accuracy.