Gongchangling-Xiuyan area is located in the eastern part of the Jiao-Liao-Ji orogenic belt, where thick layers of the Paleoproterozoic metasedimentary rocks are developed. We studied on these metamorphic sedimentary rocks in petrography and zircon U-Pb chronology. The petrographic characteristics show that the metamorphic degree of these rocks is low, overall greenschist facies metamorphism with no highly metamorphosed minerals formed. Quartz is the main mineral in the rocks, and carbonate minerals are common in the North Liaohe Group. The distinct oscillatory zoning and high Th/U ratios (>0.3) of detrital zircons in the Paleoproterozoic metasedimentary rock suggest these zircons are of magmatic origin. Combining the data of U-Pb geochronology, we found that detrital zircons from the Li’eryu, Gaojiayu, Dashiqiao and Gaixian Formations yield age peaks at 2 159 Ma, 2 500 Ma, 2 189/2 530 Ma, and 2 044/2 197 Ma, respectively, indicating that their sediments are from the Liao-Ji Paleoproterozoic granitoids and the adjacent Archean complex. Combining the data of previous researches, We considered that the South and North Liaohe Groups formed in the same tectonic setting and underwent the same evolution process. Therefore, the Paleoproterozoic arc-continent collision model may be more applicable to interpret the evolution of the Jiao-Liao-Ji orogenic belt.

Based on core and thin section observation, fluorescence microscope, cathode luminescence microscope, isotope mass spectrometer, and heating/freezing stage, the strong calcareous cementation sandstone and its nearby oil-bearing sandstone of Chang 7 oil formation in Ordos basin were studied. Thin section observation indicates that calcite cementation is the main factor that causes oil-bearing heterogeneity in tight sandstone reservoir, and the majority of cementation occurs at the same period. The result of clumped isotope of the calcite shows that the formation temperature is from 18 to 42 ℃. The corresponding geological period is from the Middle and Late Triassic to Middle Jurassic, a product of early diagenesis related to the early small scale tectonic movement of the basin. The homogenization temperature of the saltwater inclusions associated with oil and gas inclusions is from 90 to 120 ℃, which means that the time of oil filling is Early Cretaceous. In Chang 7 oil Formation, the formation time of the calcareous cement in the non oil tight sandstone is earlier than the oil filling time in the oil-bearing sandstone.

This study mainly focuses on different coal-measures source rocks (coal, carbon mudstone, and dark mudstone) in Pinghu Formation of Xihu sag. Based on the thermal simulation experiment of closed-system gold tube-high pressure vessels, the differences of hydrocarbon products, yield characteristics, and the hydrocarbon generation dynamics among the three coal series source rocks were analyzed. It is discovered that coal, carbon mudstone, and dark mudstone have high generation capacity of gas and liquid hydrocarbon, but their hydrocarbon generation evolution models are different. The carbonaceous mudstone has the earliest hydrocarbon generation and the highest intensity; the coal rock ranks the second in hydrocarbon generation and the hydrocarbon generation intensity; the mudstone has the latest hydrocarbon generation, and its hydrocarbon generation intensity is the lowest. According to the characteristics of pyrolysis hydrocarbon generation, Xihu sag has the potential of coal-derived oil exploration, and the western slope belt is a favorable area for oil exploration.

Chang 6 is the main producing layer of Y block in Ordos basin, and cracks are developed. At present, the productivity of single well is low, water flooding and water channeling are serious, and some wells are seriously affected. In order to solve the fracture problem,the authors studied the development characteristics of natural fractures and artificial fractures, the influencing factors of artificial fractures, and the influencing factors of natural fractures on artificial fractures through the macroscopic and microcosmic observation of outcrops and cores in the field, the analysis of water injection indication curve, the analysis of pressure drop test data, the measurement of stress, and the analysis of the relationship between the pressure gradient of pump stop and the overlying stress gradient. Combined with the sedimentary environment, the influence of artificial fracture properties, artificial fracture form, and distribution law were studied. The results show that the macro-fractures of Chang 6 oil reservoir are mainly vertical regional structures, while the micro-fractures are mainly horizontal diagenetic fractures. The artificial fractures are mainly controlled by natural fractures, and the natural fractures are mainly controlled by the thickness and shale content of sand body. The thinner the sand body is, the easier the natural fracture is to form, the higher the shale content is, the easier the deformation structure is to form.

In order to further develop the tight sandstone gas in coal measures, a comprehensive research on various factors affecting the exploration potential of tight sandstone gas was conducted, and three secondary indicators (enrichment, hypertonicity, recoverability) and ten tertiary indicators were established for the evaluation of the tight gas potential of Shanxi Formation in Linxing area, northeast Ordos basin. Based on the development degree of sequence stratigraphic system, combined with fuzzy decision matrix and grey correlation analysis, the evaluation model of tight sandstone reservoir was established. Through sequence stratigraphic units, a fine division of favorable reservoirs is realized. The results show that the combination of the pairwise matrix method and the gray correlation analysis method not only improves the correlation between the data of six tertiary indicators in the "hypertonic" category, but also reduces the error caused by the subjectivity of the pairwise comparison method which depends on parameter weight. Combined with the distribution of coal and sand bodies in the sequence stratigraphic system tract, the reservoir division and evaluation are more accurate. It is concluded that the enrichment area of tight sandstone gas in Shan 1 Section is in the southwest, and in Shan 2 Section is in the northeast of the study area.

Based on digital rock technology, the core CT scanning images are processed to obtain the core fractal parameters with fractal theory, and then the core permeability is predicted by constructing an equivalent fractal model of digital rock. In this study, firstly, the micro-CT scanning experiments of two sandstones were carried out,the core pore network models were extracted, and the pore throat structures were analyzed. Further, these two digital rocks and nine digital rocks from the Imperial College were processed to obtain the fractal parameters including fractal dimension, tortuosity, tortuosity dimension, and maximum pore radius by using MATLAB and Image J. Finally, based on the fractal permeability model, the permeability of cores was predicted. The results show that the pore throat radius distribution and pore coordination number distribution have influence on core permeability. The predicted permeability has a good correlation with the core permeability, and the correlation coefficient is greater than 0.97. Therefore, the core permeability can be effectively predicted based on digital rock technology by constructing an equivalent fractal model.

The Muping-Rushan metallogenic belt is one of the three major gold metallogenic belts in the world-class Jiaodong gold province. However, its sources of ore-forming fluids is still hotly debated. The Fanjiazhuang deposit is a newly discovered gold deposit in this belt, and the study of its ore-forming fluid is relatively weak. Combined with the geological characteristics of the deposit, the fluid inclusions,hydrogen, and oxygen isotopic geochemistry were analyzed to understand the characteristics, origin, and evolution of the ore-forming fluids. The gold orebodies are mainly existed in Jurassic granites, in vein and lens shape, and are controlled obviously by fault structures. The hydrothermal mineralization of Fanjiazhuang deposit can be divided into 3 stages: Quartz-coarse pyrite (early metallogenic stage), quartz-Au polymetallic sulfide (major metallogenic stage), and quartz-carbonate (late metallogenic stage). The petrographic observation indicates that there are mainly two-phase aqueous and mono-phase liquid aqueous inclusions, with a few three-phase CO₂-bearing inclusions. The micro-thermometry shows that the homogeneous temperature of the fluid inclusions in the early and major metallogenic stages is 167.2-297.5 ℃ and 168.4-253.6 ℃, salinity is 3.55%-22.65% and 2.58%-12.05%, and density is 0.77-1.06 g/cm³ and 0.84-1.02 g/cm³, respectively. All these features indicate the characteristics of middle-low temperature, middle-low salinity, and low density, a typical mesothermal gold deposit. The ore-forming pressure in the major metallogenic stage is estimated to be 45.8-68.7 MPa (average 52.8 MPa), and the corresponding ore-forming depth is 5.38-6.71 km (average 5.93 km), medium-shallow mineralization. The hydrogen and oxygen isotopic compositions of the ore-forming fluids show the δD_H2O-SMOW value from -96.9‰ to -89.0‰ and the δ¹⁸O_H2O-SMOW value from -4.3‰ to 4.5‰ in the early stage. The δD_H2O-SMOW and δ¹⁸O_H2O-SMOW values in the major metallogenic stage change from -90.7‰ to -85.3‰ and from -5.4‰ to -0.2‰, respectively. All these above suggest that the ore-forming fluid of Fanjiazhuang gold deposit was derived from the mixture of magmatic water and meteoric water, and the proportion of the latter increased with the evolution of the ore-forming fluid. Based on the geological and fluid inclusion features, Fanjiazhuang deposit should be a mesothermal gold deposit.

Scheelite is a common accessory mineral in all kinds of deposits. The analysis of its rare earth element (REE) and the standardized distribution patterns can provide important discrimination basis for the evolution of ore-forming fluids. Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) in situ analysis of REE in scheelite was conducted by taking the samples from the two typical deposits in Northeast China, Yangjingou hydrothermal vein deposit and Yangbishan Skarn deposit. The REE distribution curves obtained by LA-ICP-MS of Yangbishan scheelite is completely consistent with the results obtained by the traditional solution-ICP-MS analysis, which show that using 193 nm ArF laser with denudation frequency of 7 Hz and denudation spot of 44 μm, the NIST 610 as the external standard and Ca as the internal standard element, the method is proved to be feasible with the least effective matrix and the reliable obtained data. The results of Yangjingou scheelite solution-ICP-MS and LA-ICP-MS analysis have similarities and differences, while the REE distribution patterns in different mineral particles and different parts of the same mineral of Yangbishan scheelite is consistent. The result is that Yangbishan scheelite is of skarn-type with small size, and short-term formation; while Yangbishan scheelite is of hydrothermal vein type with large grain size, and long-term precipitation and crystallization. Based on the above comparative study, the LA-ICP-MS in situ analysis method has obvious advantages over traditional solution-ICP-MS analysis method, in aspect of sampling, testing process, and data accuracy. The advantages mainly display in that the simple sample form, low requirements in particle size and content, short test period, low cost, and high precision results, at the same time the contents of REE are obtained under the fine determination for different ore-forming stages or in a different part of scheelite, more detailed and accurate data information can be obtained at a higher spatial resolution. In addition, in the process of LA-ICP-MS in situ analysis of scheelite (especially those without obvious zonation), the content of Ca can be accurately determined by electron probe microanalysis (EPMA) or directly calculated by standard chemical formula. The data obtained from the analysis also can be reasonably geologically interpreted.

Xiagalaiaoyi Pb-Zn deposit is located in the west section of the intersection line between the south edge of the Erguna block Ermul Mountain uplift and the north margin of the Great Xing’an Range volcanic belt, northwest of Heilongjiang Province. Non-contemporaneous intrusive rocks are widely distributed in Xiagalaiaoyi district, and the ore bodies occur in the intermediate-acrid hypabyssal intrusive rocks and their contact zone with marble. LA-ICP-MS zircon U-Pb dating results show that the diagenetic age of moyite is (168.9±2.1) Ma-(165.9±2.1) Ma, suggesting that the metallogenic age of Xiagalaiaoyi Pb-Zn deposit is Middle Jurassic. Based on the geochemical data, the moyite belongs to quasi-aluminous to weakly per-aluminous alkaline A-type granite,which is characterized by high Si, K and alkali, poor Al, A/CNK value of 0.97-1.02, and the saturation temperature of zircons ranges from 760 to 851℃ (average 811℃). The granite exhibits weakly negative Eu anomalies (δEu=0.01-0.27), enrichment of LREE, large ion lithophile elements (such as Rb and K), high-field strength elements (such as Th, U, Zr and Hf), and depletion of HREE and high-field strength elements (such as P, Ti, Nb and Ta). The rocks belong to low-Sr and high-Yb type granites with Sr (13.20-62.80)×10^-6(average 38.95×10^-6)and Yb(2.44-7.81)×10^-6(average 4.50×10^-6). Combined with the relevant regional tectonic evolution research, we conclude that the moyite formation is closely related to the extensional environment after the closure of the Mongolia Okhotsk Ocean during Middle Jurassic.

The geochemical characteristics and the LA-ICP-MS zircon U-Pb ages of the granodiorites in Lancai area, Tongren, Qinghai were studied,and the petrogenesis and tectonic significance were discussed. The results show that the crystallization age of Lancai granodiorite is (231.4±2.9) Ma (MSWD = 0.024). The ∑REE of the granitoide is 138.76×10^-6-197.19×10^-6. The REE patterns is rightward inclined with negative Eu anomaly. The trace element geochemistry is characterized evidently by the negative anomalies of Nb, Ta, Ti, Sr, Ba, P, etc. and positive anomalies of Rb, K, Th, U, etc. The granodiorites show the characteristics of metaluminous and belong to high-K calc-alkaline series. Lancai granodiorite is I-type granitoids. Based on the existing research results, Lancai granodiorite may be formed through partial melting of basic rocks in the crustal thickening geodynamic environment characterized mainly by compression on the whole and local shear extension,and the mantle-derived magmas may play an important role in the formation of the granodiorite.

Jimunai Formation is located in Sawuer area of west Junggar basin, which is mainly composed of lava, pyroclastic rocks, and sedimentary rocks. Basaltic andesite from the upper section is (294.0±1.4) Ma by LA-ICP-MS zircon U-Pb dating. The result indicates that the lava underwent crystallization during Early Permian. Combined with local paleontological fossil assemblages, Jimunai Formation was formed in Late Carboniferous or Permian. The SiO₂ content varies from 48.10% to 54.35%, belonging mainly to basalt and basaltic andesite. The total FeO content is between 7.38%-10.92%, MgO content is between 3.35%-5.16%, and Mg^# index is between 41.02-55.05, mainly belonging to tholeiitic series. The rare earth element (REE) distribution pattern is right deviated, and rich in LREE ((La/Yb)_N=4.00-6.04), with slight fractionation of HREE((Gd/Yb)_N=1.68-2.26), δEu=0.91-1.07, δCe=0.91-1.06. The trace element spider diagram shows the enrichment of LILE (Rb, Ba, Sr, P), and moderate depletion of HFSE (Nb, Ta, Ti) except for the samples of JM2 and JM3. The ratios of (Th/Nb)_N are mainly between 1.39 and 2.10, and Nb/La are between 0.39 and 0.74, indicating that the magma was partially contaminated by the lithospheric mantle and the crust. Based on the geochemical characteristics of high Zr/Y ratio, high trace element contents, the volcanic rocks of Jimunai Formation was derived from basaltic magma of asthenospheric mantle upwelling under post-collision tectonic background, and the magma was partially contaminated by lithospheric mantle and crust in the process of ascending.

The detrital zircon LA-ICP-MS U-Pb dating of the glutenite assemblage with lacking of biological fossils in Linxi County, Inner Mongolia was carried out to clarify the ages and material origin of the coarse clastic rocks and explore the tectonic evolution of the Xar Moron River suture. The detrital zircon ages fall in six groups of ca. (285±4)-(246±4) Ma (peak 264 Ma), (317±5)-(293±4) Ma (peak 310 Ma), (610±10)-(344±6) Ma (peak 423 Ma), (992±14)-(907±13) Ma, (1 467±18)-(1 424±22) Ma,and (1 948±14)-(1 768±16) Ma; besides, there are three zircons with the age of (1 171±17) Ma, (1 238±17) Ma, and (2 443±31) Ma, respectively. Most of the zircons show oscillatory or linear zoning in CL images and high Th/U ratios(>0.1), indicating that they are magmatic origin. We conclude that the depositional age of the coarse-grained clastic rocks is younger than 264 Ma, which should be Upper Permian Linxi Formation. The sedimentary provenance of Linxi Formation in Huichangdi area is mainly from the Jiamusi-Mongolia block with minor from the North China plate, which implies that the North China plate and the Jiamusi-Mongolia block merged in Late Permian at the position of Xar Moron River suture.

The salt resolving slump characteristics of sodic saline soil in the western part of Jilin Province are the main engineering problem of lining-free channels in the connectivity of rivers and lakes in the region. This study of salt resolving slump characteristics of sodic saline soil can provide the basis for problem solving. By taking the saline soil area passing through a planning channel in Qian’an as the research object, through the indoor dissolution test on undisturbed soil, the variation law of the salt resolving slump coefficient of sodic saline soil with the pressure load and the relationship between the salt resolving slump coefficient and the soil above 150 cm were obtained. The results are as follows: Under the pressure of 200 kPa, sodic soil produced the largest amount of slump deformation when it first encountered water, and the salt resolving slump coefficient was the largest; with the pressure increased, the salt resolving slump coefficient decreased. The soil with a depth of less than 30 cm and more than 120 cm was not collapsible, and the sodic saline soil with a depth of 30-120 cm was slightly collapsible. The soil with a depth of 30 cm or more acted as a salt accumulation layer, the high concentration of exchangeable sodium made the soil particles coalesced, the void ratio low, the soil moisture infiltration blocked, the seepage effect weak, and the salt not easy to dissolve and lose. The sodic saline soil with a depth of 30-120 cm had slight disintegration. The difference of physical and chemical properties between the upper and lower layers is one of the causes of the slump of saline soil, which is also the key area of channel regulation.

In order to understand the content and distribution characteristics of trace elements in reservoir sediments under the influence of acid mine drainage(AMD),the concentration and distribution of twenty-six trace elements were analyzed in the sediment cores from Maoshitou Reservoir and its inflow tributaries in Guizhou Province, Southwest China. The results show that the mean contents of Sr, Ba, Zr, V, Cr and As in the sediment cores are higher than 100 μg/g, and the content of As is the highest, the average content exceeds 800 μg/g; while the mean values of Be, Ta, Co, Ag are lower than 5 μg/g, the values of other elements lie in the range of 10 and 60 μg/g. Compared with the stream sediments without affected by AMD, the reservoir sediments in the study area are obviously rich in As and Sb. There are obvious positive correlations between Li, Be, Rb, Sr, Cs, Ba, Sc, Y, Zr, Hf, Nb, Ta,and Th in reservoir sediments, and their distribution is basically similar, while there is a significant negative correlation between As and these elements. Element correlation analysis, factor analysis,and trace element diagrams show that Li, Be, Rb, Sr, Cs, Ba, Sc, Y, Zr, Hf, Nb, Ta, Th, Cr,and Sb etc. are controlled by chemical weathering and physical erosion of watershed rock, which is the most important factor controlling the distribution of elements in the study area; while heavy metals (such as Cu and Cd etc.) are related to the dissolution of elements in the formation of AMD and the adsorption of fine particles such as organic matter. In addition, the ecological risks of Cd, Cu, Pb, Cr, and Zn are low, while the ecological risks of As and Sb are high.

The hydrological properties of calcareous sand in South China Sea are very important for the study of the formation of underground freshwater lens on islands. The permeability, specific water capacity,and specific yield of calcareous sands were studied by laboratory test first; and combined with the two-dimensional numerical model, their influence on the formation of freshwater lens of islands was analyzed. The result shows that the calcareous sand in South China Sea is poorly gradated and unevenly distributed, and the permeability coefficient is usually between 0.023 and 110 m/d, greatly changed in the study area. The porosity and specific yield are mainly between 0.40-0.55 and 0.012-0.310, respectively, which reflects that the calcareous sand has the characteristics of good water capacity but poor water supply compared with the continental sand with the same particle size range. The influence of hydrological properties of calcareous sand on the formation of freshwater lens is mainly reflected in the velocity, thickness, resource reserve,and formation time. Among them, the better the permeability of calcareous sand is, the faster the groundwater flow rate is, which strengthens the mixing effect between brackish and fresh water, resulting in a thinner freshwater lens and less reserves. Specific yield mainly affects the resources and reserves of freshwater lens in calcareous sand, but has little influence on the thickness and shape of freshwater lens.

In the process of recovery of polluted groundwater by pumping treatment technology,the extraction efficiency of pump decreases gradually over time,and it is difficult to determine the end point of pumping treatment. In order to improve the efficiency of extraction, reduce repair costs, repair time of the treatment, multiple optimization of pumping scheme is proposed. By using the analytic hierarchy process and expert scoring method, the index weight, quantitative characterization of the optimal time node, and the extraction endpoint are realized. Taking a chromium salt plant in Hebei as an example, the above method was applied to optimize the pumping scheme. The results showed that when the pumping efficiency was 20%-40%, the proportion of the pumping scheme (P₃) was the largest. In the first time optimization, P₃ should be re-arranged after 100 d pumping. The second optimization plan is to combine with other rehabilitation technologies after the first optimization, that is to continue pumping for 300 d after the first optimized pumping scheme was used; and then, to treat the remaining contaminated groundwater of the site with other rehabilitation technologies. After evaluation, the second optimization can effectively improve the pumping efficiency of the pumping well, shorten the repair time by 600 d, and increase the removal rate of hexavalent chromium in the aquifer by 8.31% in the same time.

Hot dry rock (HDR) is a kind of clean and renewable geothermal resource. The utilization of HDR is of great significance to the improvement of energy structure of Guangxi. The early studies show that the eastern and southern areas of Guangxi have HDR development potential. Based on Guangxi aeromagnetic survey data, the Curie point depth was calculated by using Parker-Oldenburg interface inversion method. The terrestrial heat flow values and temperatures at several different depths were also calculated. It is found that the calculation results are consistent with the actual measurement temperature data, indicating that there are formation conditions for the HDR resources in Xichang and Changle sags in Hepu basin. The reservoir and seal conditions of the HDR resources in Hepu basin were analyzed based on the basic geological survey and a large number of borehole data. Two hot-dry rock exploration target areas C1 and C2 located in Xichang and Changle sags were initially circled, with an area of 167.10 km² and 72.90 km², respectively. The HDR resources are 182.48×10¹⁵ J in C1, and are 77.59 ×10¹⁵ J in C2. Based on 20% recovery rate, the total amount of HDR resources in Hepu basin is 52.01×10¹⁵ J, which is equivalent to 177.48×10⁴ t of standard coal. It accounts for 4.72 % of the total energy production of 3756.69×10⁴ t standard coal in Guangxi in 2018. Based on the resource evaluation, it is recommended that further exploration should be given to the C1 target area,which is located in Xichang sag of Hepu basin.

The Rehai geothermal field was taken as the geological background, the influence of well spacing, injection flow rate and temperature, and reservoir permeability on the heat extraction performance of the enhanced geothermal system were analyzed by using the orthogonal design method, and also the mutual influence between these factors. The results show that the injection flow rate is the key factor affecting the heat extraction performance and has a significant impact on the determination of injection temperature and well spacing. The larger the injection flow rate is, the shorter the stable heat extraction time and operating life are. The smaller the change of injection flow rate (increase 0.06 m³/s) is,the greater the impact will be on the heat extraction temperature (decrease 47 ℃); Increasing the injection temperature can improve the heat extraction temperature and operating life; however, the effect is limited. When the injection temperature is increased by 30 ℃, the heat recovery temperature is only increased by 10 ℃ after 50 a. The effects of well spacing, permeability, and production pressure on the heat extraction performance are similar and much smaller than the injection flow rate.

This thesis focuses on the activation of persulfate to degrade 4-chlorophenol by self-developed nitrogen-doped carbon materials. Firstly, three nitrogen doped carbon materials (NCs) (NC-700, NC-800, and NC-900) were synthesized via sol-gel method by using waste industrial syrup as carbon source and ammonia as nitrogen source, which were characterized by the methods of scanning electron microscope(SEM), X-ray diffraction(XRD), Raman spectra(Raman), and X-ray photoelectron spectroscopy(XPS). Then, the effects of NC-800 dosage, persulfate (PDS) dosage,and initial pH on the removal rate of 4-chlorophenol were investigated, and electron spin resonance (ESR) and free radical quenching experiments were carried out. It showed that all the three NCs could effectively activate persulfate (PDS) to degrade 4-chlorophenol; and NC-800 showed the best ctivation performance; the removal efficiency of 50 mg/L 4-chlorophenol reached 99.10 % in 30 min, when the dosage of NC-800 and PDS were 100 mg/L and 5 mmol/L, respectively; the initial pH had no effects on the removal efficiency of 4-chlorophenol; NC-800 activated persulfate degradation of 4-chlorophenol,which followed the non-radical pathway, and the singlet oxygen was the active substance for degrading of 4-chlorophenol. The cycling experiments showed that NC-800 has certain stability, and the removal efficiency could still reach to 73.80 % after four cycles.

Nanometer iron sulfide (Nano-FeS) has small particle size, large specific surface and high reactivity, but its application in groundwater remediation is limited by its easy agglomeration and oxidation. The dispersion and stability of Nano-FeS can be improved by modification. In this study, two kinds of modifiers, sodium carboxymethyl cellulose (CMC) and pillared bentonite were used to prepare stable modified CMC-FeS and loaded Alb-FeS. The properties of the two modified Nano-FeS were investigated in terms of dispersivity, anti-sedimentation, anti-oxidation, reactivity,and migration. The results show that the dispersivity of Alb-FeS and CMC-FeS were improved obviously compared to Nano-FeS. After three days, Nano-FeS completely precipitated and oxidized, CMC-FeS precipitated 3 cm and began to oxidize, while Alb-FeS precipitated 16 cm without oxidation. Under the same experimental conditions, the removal rate of Alb-FeS,Nano-FeS, and CMC-FeS for Cr(Ⅵ) is 85.16%, 84.90%, and 82.78% respectively, and their removal ability is Alb-FeS > Nano-FeS > CMC-FeS. The migration ability of the three kinds of FeS in the medium of coarse sand, medium sand, and fine sand is CMC-FeS> Alb-FeS> Nano-FeS. The maximum migration distance of CMC-FeS in the three media is 6.1, 6.4 and 3.4 times of that of Nano-FeS, while the mobility of Alb-FeS is not significantly improved compared with that of Nano-FeS. Considering the dispersivity, anti-sedimentation, stability, reactivity, and migration, CMC-FeS should be selected as the in-situ remediation material for Cr (VI) contaminated groundwater in practical application.

In order to improve the detection performance of 17β-estradiol in complex environment water, the aptamer-modified graphene oxide complex was synthesized by immobilization of the aptamer on the surface of graphene oxide with direct adsorption,and it was used for high sensitive and specific homogeneous detection of 17β-estradiol contamination in water. The ultraviolet-visible spectroscopy was used to characterize the aptamer-modified graphene oxide complex. It was found that the complex had a wide peak at 250 nm, which proved that the nucleic acid aptamer was successfully immobilized on the surface of graphene oxide. The fluorescence intensity of the aptamer-modified graphene oxide complex before and after reaction with target 17β-estradiol was analyzed by the fluorescence spectrophotometer. It was found that the fluorescence intensities increased from 110 to 450, and the relative fluorescence intensities were proportional to the mass concentrations of 17β-estradiol in the range of 10-100 μg/L with a minimum detection limit of 6.2 μg/L. This indicates that the complex could be successfully used for the detection of 17β-estradiol.

Aiming at the problem of low vertical resolution of correlation imaging in gravity exploration, the authors propose a correlation imaging method with joint multiple gravity gradiometry data based on depth weighting. Compared with gravity anomaly, the gravity gradiometry data have a higher signal-to-noise ratio, and contain more frequency information. Combined with multiple tensors of gravity gradiometry data, based on correlation imaging principle, a depth weighting function is introduced with the prior information. Using the theoretical model of the prism combination, the optimal gradiometry data group is determined, and the improvement of the vertical imaging results is verified by depth weighting function. Through dividing research area, the effect of depth weighting is further improved. The proposed method is also proved to be anti-noised. The method is applied to the measured gravity gradiometry data of Vinton Dome, and the results clearly show the location of the cap rock.

Transient electromagnetic method (TEM) is widely used in metal mine exploration. Based on the new receiving technology of SQUID (superconducting quantum interference device), the TEM has the advantages of low intrinsic noise (5~7 fT/√Hz) and large bandwidth (>200 kHz). As an important mineral reserve, Siziwangqi in Inner Mongolia is rich in mineral resources. The reliability of SQUID instead of induction coil was verified by comparing the experimental results of the anomalous rings obtained by superconducting receiving system and EM67 TEM instrument. The superconducting TEM method was applied to the northern area of Dajingpo, Siziwangqi, Inner Mongolia. The underground anomalous response information in shallow and deep layers (>2 000 m) was obtained to deduce a continuous low resistivity layer. Combined with the existing geological and geophysical data, the inversion results effectively reveal a north-east trending fault zone at 500 m in the shallow layer near the survey line, and then infer that there is a similar trending fault zone at 2 000 m in the deep layer.

In the process of oil and gas field development, microseismic monitoring is an effective method to obtain the fracture distribution of hydraulic fracturing. Microseismic location imaging and crack interpretation need to use the location of effective microseismic signals; however,microseismic signals have the characteristics of low signal-to-noise ratio, and the traditional signal picking methods cannot effectively achieve the accurate picking at the first arrival time under the condition of low signal-to-noise ratio. In this paper, a new method based on time-spectral entropy for picking up the initial arrival point is proposed. This method first obtains the time-frequency spectrum of the signal containing noise through S transformation;then divides each sampling point in the spectrum into frames along the frequency direction, and calculates the approximate negative entropy value in each frame frequency band, with the smallest approximate negative entropy value as the negative entropy value of the point;finally, the approximate negative entropy values of all sampling points are compared in the time direction, and the time corresponding to the minimum value is the initial arrival position. In this study, a group of synthetic seismic data are used to verify the effect of the new method, and the results are compared with those obtained by the STA/LTA method. It is concluded that the two methods are both effective when the signal-to-noise ratio is -5 dB, but the time-spectral entropy method is better when the signal-to-noise ratio is -10 dB. Thus, the time-spectral entropy method is more suitable for the first arrival signal picking under low signal-to-noise ratio.

Microseismic positioning method is a core technology in the field of microseismic monitoring, and the criterion to consider the application effect of microseismic technology lies in the accuracy of the source positioning method. Given the application of unconventional oil and gas development in microseismic positioning, the authors expound on the microseismic positioning methods. Among them, the geometric mapping method has the advantages of robustness and high efficiency, but its positioning accuracy is low when the source location is deep; the linear positioning method does not need the accuracy of the velocity model, but has a great impact on the accuracy of first break pick-up; the nonlinear positioning method is more sensitive to first break picking and requires higher accuracy of the velocity model, but the calculation is small; the hybrid positioning method improves the positioning accuracy and efficiency to a certain extent, but the advantages are not obvious when the signal-to-noise ratio is low,and the speed model precision is not high; the positioning method based on waveform migration does not need to consider the precision of first break pick-up, but the calculation is large; the positioning method based on neural network using training network training is highly accurate, and the error is small. The authors also discuss the application of multi-method and multi-parameter information fusion technology in microseismic location of oil and gas reservoir.

This research is based on high resolution satellite image data, remote sensing,and GIS technology. The latest data of natural resources and eco-geological environment factors in Zhaoyuan County of Heilongjiang Province were obtained as follows:cultivated land area 2 541.75 km², forest land area 161.88 km², grassland area 349.00 km², river area 128.05 km², lake area 215.80 km², swamp area 109.17 km², other waters area 84.65 km², building used land area 191.25 km², unused land area 329.94 km²,wetland area 1 334.54 km², and desertification area 775.47 km². A comprehensive study was carried out through calculating coverage rate, per capita occupancy,and landscape index (patch density, area-weighted mean patch fractal dimension, fractal dimension, Shannon diversity index, and Shannon evenness index). Based on the study result,it is concluded that wetland resources, especially natural wetlands, are more disturbed by human activities,while desertified land is less disturbed by human activities. Through multi-stage remote sensing dynamic monitoring and field verification for the selected Laoshan Village and other typical areas,some ecological and environmental problems are recognized, such as wetland degradation and land desertification in Songnen low plain area.

Hyperspectral remote sensing image classification is an important part of hyperspectral remote sensing image processing and application. However, hyperspectral remote sensing image has the characteristics of large number of bands and high spatial resolution, which brings some challenges to image classification. To improve the classification accuracy of hyperspectral image and make full use of the spatial and local information, a classification method based on guided filtering combined with local discrimination embedding is proposed. Firstly, the hyperspectral remote sensing image is normalized, the feature extraction is realized by principal component analysis, and the extracted first principal component image is used as the guided image. Secondly, the spatial characteristics of each band are extracted by using the guided filter. Then, the extracted spatial image features are superimposed,and low-dimensional embedding is completed by local Fisher discriminant analysis. Finally, the embedded features are input into SVM to acquire classification results. The experimental results of two hyperspectral images, Indian Pines and Pavia University, show that compared to other relevant methods, the proposed method can obtain higher classification accuracy. When 10% and 100 samples from various ground objects were randomly selected as training samples, the overall classification accuracy increased to 98.28% and 99.45% respectively. At the same time of low dimensional embedding, the proposed method can effectively use the spatial information of images and improve the classification effect.