Located in the northeast of North China craton and the northern part of Jiao-Liao uplift, Liaodong Peninsula is one of the important gold resource producing areas in East China, where several large and medium sized gold deposits are developed including those occurred in Wulong, Baiyun, and Maoling areas with proven reserves up to more than 300 t. Because of the similarity of the geological and tectonic settings between Jiaodong Peninsula and Liaodong Peninsula, the gold mineralization and prospecting potential in Liaodong Peninsula has received attention, and the research on the mineralization settings and typical gold deposits has been going on. However, the lack of a systematic understanding of the relationship between the regional metallogenic geological settings and mineralization process restricts the deployment of deep resource exploration. Based on the investigation over the years of 2016-2019 on the geology and geochronology of the gold deposits, as well as the comprehensive analysis of the microstructural deformation and geochronology of the ore-related rocks, we discussed the ore-forming geological conditions of the gold deposits in Liaodong Peninsula. The results show that the discovered gold deposits in Liaodong Peninsula may be related to the two episodes of tectono-magmatic-ore forming systems in the Late Triassic and Early Cretaceous. The two kinds of gold mineralization are controlled by different structural patterns, macro-and microscopically. The gold ores are mainly formed under the brittle or brittle-shear deformation conditions with the extensive occurrences of ore-bearing clastic flows, caused by both a repetitive sequence of brittle or brittle-shear failure along the major fault systems and the related magmatic hydrothermal activities in the Late Triassic and Early Cretaceous. This genetic origin of the gold mineralization and ore-bearing clastic flows may support the idea of flashing vaporization by earthquakes in the mesothermal gold-bearing systems. We suggest that the exploration of the deep resources should target three regions:The north and south boundary fault zones of the Yingkou-Kuandian uplift and the structural composite sites between the north and south boundary fault zones and the accompanying NE or NW-trending fault zones;The main NE-trending fault zones and the accompanying lower or secondary structural systems along the east and west boundary of the Yingkou-Kuandian uplift; deep in the existing ore-bearing structural belt,where it is necessary to pay attention to the existence of porphyry-type gold mineralization (deposit) which is related to the magmatic activities of Indosinian and Yanshanian periods.

The hydrocarbon resource of flexure slope break zone as a broad prospect has become a hot spot of exploration, development and research in continental lacustrine basin. Due to the differences of paleogeomorphology or paleostructure, multiple flexural deformations occur in the multi-stage flexural slope strata. Meanwhile, there are great differences in structural and tectonic characteristics, sedimentary characteristics and source rock characteristics. All of these factors in the study area result in complex hydrocarbon distributions and hydrocarbon accumulation processes. Taking the multi-order flexure slope-Qibei slope in Huanghua depression for example, a good understanding of the characteristics of slope structure and tectonic, transport system, hydrocarbon migration path and force under the coupling of paleogeomorphology and faults during the formation and evolution of the slope could be used to reveal the hydrocarbon accumulation mechanism in multi-order flexure slope. The results show that there are great differences between the long and short axis direction of Qibei slope in paleogeography, fault and assemblage style, genetic type and extension range of sand body, contact relationship between sand body and source rock, hydrocarbon migration power and path, etc. Thereby, the long and short axis direction equip with the following characteristics, respectively. The high, medium and low slopes are differentiated by the flexure slope break structure. The large-scale faults are not developed and the range of delta sand bodies is limited. The medium and low slopes are mainly appeared as hydrocarbon transportation of near source sand bodies, in which the sand bodies possess a good connectivity. The hydrocarbon accumulation model of "advantage of bilateral ridge fault on gentle slope-source control type" is formed in the background of slope break. Additionally, the short axis direction is bounded by Binhai fault, Gangdong fault and Nandagang fault. The slope break structure of the fault near the east-west direction is developed, and the secondary fault and their combinations are also developed. The underwater fan sandbody has good connectivity, and forms a ladder transport path with a series of faults. Therefore, the hydrocarbon accumulation model of "near source-step transport-fault control" has been formed.

Together with the encouraging oil and gas discoveries in the pre-salt section in Santos basin, the reservoirs are also characterized by a wide occurrence of CO₂ and high gas-oil ratio (GOR), which leads to a series of challenges both in oil & gas exploration and development. Based on the CO₂ content and fluid phases, the reservoirs currently discovered in Santos basin could be divided into three types:Type Ⅰ conventional oil reservoirs containing dissolved CO₂ with high GOR, type Ⅱ CO₂ gas cap + oil ring reservoirs and type Ⅲ CO₂ gas reservoirs (containing dissolved hydrocarbons). For type Ⅰ oil reservoir and type Ⅲ CO₂ gas reservoir, the fluid properties, such as GOR, API and CH₄ content are uniform, and oil-water contact and gas-water contact are easily defined. For type Ⅱ gas cap+oil ring reservoirs, its fluid properties are not uniform anymore and are very complex. The authors proposed an innovative geological model, dynamic dissolving-extracting between CO₂ and hydrocarbon. The three types of reservoirs are likely to be a mixture of two different endmembers, supercritical CO₂ and fluid hydrocarbon. The crude oil dissolves CO₂ while CO₂ extracts lighter components of hydrocarbon. There is a dynamic balance point or scale under certain pressure and temperature. If CO₂ volume is less than the balance points, the crude oil could dissolve it completely and the reservoir belongs to type Ⅰ. If the CO₂ volume is larger than that, a gas cap will appear, and the reservoir become type Ⅱ. In some situations, the CO₂ volume is very large while hydrocarbon is very limited, the type Ⅲ CO₂ gas reservoir will be developed. Therefore, the relative amount of hydrocarbon and CO₂ determine the fluid phases and types of reservoirs finally. Meanwhile, the reservoir types could also change with temperature, pressure, or tectonic movement. Because these factors could break such balance and result in phase change and transition.

Based on the cluster analysis of crude oil biomarker parameters and the comparison of geochemical characteristics of source rocks of different strata in the Shahejie Formation, the genetic types, sources, and distribution of the crude oil discovered in the South-Central Miaoxi depression of Bohai Sea were analyzed. The results show that there are three main genetic types of crude oil. Type Ⅰ comes from the Third Member of Shahejie Formation(Es₃), and mainly distributed in Kenli 6-4 and Penglai 25 areas. It can be further divided into two sub-categories, Ⅰ₁ and Ⅰ₂, which correspond to high-maturity Es₃ crude oil and low-maturity Es₃ crude oil. Type Ⅱ mainly comes from the source rocks of Es₃ and Es₄, and mainly distributed in Penglai 31 area. Type Ⅲ mainly comes from the source rocks of Es₄ with a small amount of source rocks of Es₃, and mainly distributed in Bozhong 36 area. The geochemical characteristics and distribution regularity of crude oil indicate that the study area is characterized by near-source reservoir formation. Based on the analysis of distribution characteristics of source rocks and fault activity, it is considered that the types and distribution of crude oil in Penglai 25 and Kenli 6-4 areas are mainly controlled by source rocks, while the types and distribution of crude oil in Penglai 31 and Bozhong 36 areas are controlled by both faults and source rocks.

Many oilfields in China have entered the stage of high water cut, and the remaining oil production is becoming harder and harder. The division of compound channels and single channels cannot satisfy the demand of oil exploration. It is needed to identify the favorable sand bodies in distributary channels. Research on modern sediment is an effective means to understand the development characteristics of sand-bodies in distributary channels. Branch mouth bar is an important sand type in the distributary channel based on the study of Ganjiang delta in Poyang Lake, which is characterized by its development in the branch site of the distributary channel. According to the hydrodynamic conditions, sediments, and sedimentary structures, the branch mouth bar is divided into bar head, bar middle, and bar tail. From the bar head to the bar tail, the hydrodynamic energy weakens, the bedding size decreases, the single sand body becomes thinner, the sediments become finer, and the mud interlayers increase. Obstructed by the branch site, the velocity of flow decreases, and the sediment deposits to form branch mouth bars mainly stacking in countercurrent accretion. The branch mouth bar develops more beddings, interlayers, and heterogeneity than the waterway. Because of the blocking effect of interlayers, it is not easy to be watered out, so branch mouth bar is the favorable zone for remaining oil.

Based on the data of cast thin section, X-ray diffraction, cathodoluminescence, scanning electron microscope, physical property analysis, vitrinite reflectivity and wrapping temperature, combined with core observation method, the basic characteristics and diagenesis of Lower Cretaceous clastic reservoir in Bongor basin are studied. According to the volume fraction and morphology of cement, the distribution of clay mineral components, microscopic characteristics of rock structure, pore evolution and thermal evolution of organic matter, the rock diagenetic stages are divided, and the influence of diagenesis on physical properties is analyzed. The results show that:The reservoir rock type in this area is mainly feldspathic sandstone, and the cement is mainly carbonate and clay minerals; Dissolved pore intergranular pore combination has the best reservoir performance, followed by intergranular pore dissolved pore combination; Diagenesis mainly includes compaction, cementation, metasomatism and dissolution; The diagenetic stage of the target layer is mainly middle diagenetic stage A, and the diagenesis is weak to medium; Diagenesis is the main factor controlling reservoir physical properties. Compaction and cementation are destructive diagenesis, which make the original porosity lose 54.93% and 31.30% respectively; In the rock particles, feldspar, carbonate cement and other soluble substances are developed, with strong dissolution, which is the main constructive diagenesis.

In order to clarify the distribution law of oil and gas near the fault in the slope area outside the source of the petroliferous basin, first, the sand ground ratio of well point sand body formation is known in the statistical study area, and the minimum ratio is taken as the minimum value required for oil and gas reservoir sand body, and the distribution area of oil and gas reservoir sand body is trapped, second, the distribution of paleotectonic ridge on the top of sand body formation is obtained through calculation, the overlapping position of the two is determined as the oil and gas transportation path along the lateral migration of the sand body to the fault, third, by calculating the lateral sealing part of the fault and superimposing it with the distribution area of oil and gas reservoir sand body, the superimposed part can be determined as the oil and gas part of fault sand configuration trap. The authors establish a method to predict the favorable parts of oil and gas accumulation near the faults in the slope area outside the source, which predicts the oil and gas coupling parts of oil and gas transmission path and fault sand configuration trap as the favorable parts of oil and gas accumulation. The method is applied to predict the favorable parts of oil and gas accumulation in the Es^1x near Zhaobei fault in Qinan slope area outside the source of Qikou sag, Bohai Bay basin. The prediction results show that there are mainly two favorable parts for oil source accumulation in the Es^1x near Zhaobei fault in Qinan slope area outside the source, which are distributed in the west of Zhaobei fault, which is consistent with the fact that oil and gas in the Es^1x near Zhaobei fault are mainly distributed in the west, indicating that this method is feasible to predict oil and gas accumulation near Zhaobei fault in the slope area outside the source.

The Zhaxikang Pb-Zn polymetallic deposit is located in the polymetallic metallogenic belt of the eastern section of the Himalayas. In order to determine the electrical characteristics of the ore-controlling structure of the deposit, the authors set up two geophysical (AMT, MT) survey lines in the deposit area for data collection and obtained a good underground electrical structure profile after detailed data processing and inversion calculations. Combined with long-term field surveys, physical properties and drilling data, 9 faults were interpreted, including 4 ore-bearing faults, 4 concealed faults and 1 deep concealed rock mass, and 2 deep favorable prospecting points were delineated(deep fracture of F_t2 and F₂₄).

The Qingchengzi gold ore concentrated area is located in the Paleoproterozoic Liao-Ji rift zone in the eastern section of the northern margin of the North China craton, it is one of the important gold-rich areas in China, and the Baiyun gold deposit is a representative of the Qingchengzi gold ore concentrated area. The mineral area has large reserves and shallow mining with great prospecting potential. Through methods such as field survey, underground observation, data collection and indoor testing, and the combination of field conditions and indoor analysis, and the combination of macro and micro research methods, the distribution of ore bodies, surrounding rock alteration and mineralization period structural characteristicsare analyzed. The studies show that the deposit is mainly developed in mica schist and metagranulite of the Gaixian Formation in the Liaohe Group. It is a hydrothermal altered rock type gold deposit. The ore body is mainly controlled by the fault structures, and their main trend is east-west and mid-low angle to south, in gentle waves, or long lotus root joints, with the characteristics of reappearance of sharp extinction. The surrounding rocks of ore bodies are altered mainly through silicification, sericinization, graphitization, and chloritization, which are controlled by faults. The ore-conducting and ore-hosting structures are mainly near east-west thrust faults and their derived secondary structures. Through the analysis of the ore-controlling faults in the mineralization period and the distribution of Au grade, it is believed that the tectonic stress field in the mineralization period squeezed in the direction of NW-SE, so the ore bodies are lateral to SW.

Cobalt rich sulfide minerals are developed in Baicao mining area of Hongge ore field in Panxi. The research on their genesis and formation environment is relatively weak. In this paper, the mineralogy and mineral chemistry are used for a systematic study. The results show that the main cobalt-rich sulfides in the ore are pyrrhotite, pyrite, pentlandite, and siegenite. The average contents of Co and Ni in pyrrhotite are 0.21% and 0.42% respectively, and the average value of Co/Ni is 1.10; The average contents of Co and Ni in pyrite are 0.18% and 0.29% respectively, and the average value of Co/Ni is 0.77; The average contents of Co and Ni in pentlandite are 2.67% and 34.30% respectively, and the average value of Ni/Fe,S/Fe and M/S^# are 1.08,1.91 and 1.13 respectively; The average contents of Co and Ni in siegenite are 24.30% and 22.90% respectively, and the average value of Co/Ni is 1.06. According to the pyrrhotite-pyrite mineral thermometer, the crystallization temperature of the Baicao cobalt rich sulfide is about 267-490℃, which indicates that it was formed at medium high temperature. Compared with the characteristic values of S/Fe and M/S^# of the mantle xenolith pentlandite, the pyrrhotite has the characteristics of troilite (Tr) homomorphic polycrystal, which reflects that the ore-forming materials were derived from the mantle. The geochemical characteristics of cobalt in Baicao mining area show that in the process of sulfide melt separation, cobalt migrated to mono-sulfide solid solution to form Po-Py solid solution, and then migrated further to form Pn and Se solid solution, forming the phenomenon that the content of Co in Se, Pn, Po-Py and Ccp decreases gradually.

In this paper, the granite porphyry geochemistry, zircon U-Pb geochronology and Hf isotopes are studied to discuss the petrogenesis, tectonic setting of the granitic porphyry dike, and the relationship between the rock vein and mineralization of Xiaokelehe. Our data show that the samples are characterized by high content of SiO₂(69.85%-70.48%) and alkali (9.74%-9.89%), and low content of MgO (0.34%-0.40%) and CaO (1.04%-1.20%). The A/CNK values range from 0.98 to 1.02, the granitic porphyry is quasi-aluminum-weak per-aluminum. The rock is rich in LREE and poor in HREE, with obviously negative Eu anomalies. They are rich in LILEs (Rb and K) and HFSEs (Th, U, Hf, and Zr), and depleted of LILEs (Srand Ba) and HFSEs (Nb, Ta, Ti, and P). The samples have 10⁴Ga/Al values ranging from 2.32 to 3.68 and I_D values ranging from 87.63 to 89.01. All these characteristics indicate that the granite porphyry is fractionated I-type granite. The zircon U-Pb dating indicates that the rock was formed in the Early Cretaceous ((124.0±0.6) Ma). The Hf isotope results show that the ε_Hf (t) values of the granite porphyry range from 0.5 to 3.3, and two-stage Hf model ages (T_DM2) range from 1 150 to 970 Ma, which indicates that the magma originated from the partial melting of Meso-Neoproterozoic juvenile crust that was derived from the depleted mantle, and there was a small amount of ancient crust added. The granite porphyry was formed in the extensional environment under the background of the Mongolia-Okhotsk closure in the Late Early Cretaceous. At that time, the Paleo-Pacific plate continued to subduct toward the Eurasian continent, but its influence on this area was limited.

In order to further study the mechanism and influcing factors of the toppling of layered anti-dip slopes, the discrete element simulation based on centrifugal model test was adopted. The formation of rupture surface was realized by presetting random cracks in the rock layers. The simulation results are in good agreement with the physical test. Slope deformation can be divided into three stages:Initial creep, steady-state deformation, and instability failure. The results show that:The rupture surface is straight-line after the failure load (G_f) is reached, and the occurrence is controlled by the dip angle of the rock layer; The G_f value is related to the power function of the slope angle; The failure of the anaclinal slope needs to satisfy the initial conditions, and the deformation is closely related to the bending moment of the rock layer, when the dip angle is 70°-80° and the slope angle is larger than 60°, it is the most vulnerable state. There are three typical failure modes:Toppling-rupture-block detachment type, toppling-bend-rupture type, and toppling-reversal type, which are controlled by the combination of dip and slope angle. The orthogonal simulations on material parameters show that the sensitivity of each parameter to G_f from large to small is density, friction angle of beddings, layer thickness, density ratio, and cohesion of beddings; The value of friction angle of beddings can affect the occurrence of the rupture surface, thus controlling the size of the deformation area, while other parameters only affect the value of G_f.

Slope seepage law with interaction of seepage and stress is very important for slope stability analysis. The anisotropic seepage-stress coupled model established based on the equivalent continuum model and Louis empirical formula is applied to the numerical simulation of seepage in dip layered rock slope. The numerical simulation results show that for the dip layered rock slope, the value of drawdown first increases then decreases with the dip angle of structural plane θ. The outline is like a shoulder, low on both sides and high in the middle. In addition, the closer to the spill points of water is, the greater the influence on the drawdown value of structural plane dip angle; When θ is about 42°, the drawdown reaches its maximum, meanwhile, the anisotropic ratio of permeability also reaches its maximum. When the attitude of strata of dip layered rock slope is given, the anisotropic ratio of permeability decreases with the increase of the buried depth, and the seepage field controlled by the layered structural planes becomes weak gradually, showing a trend of transition to isotropic seepage.

Foundation pit support engineering plays an important role in the process of urbanization in China. The emergence of some new support forms has greatly enriched the diversity of foundation pit support. In this paper, by taking the Hengshui field foundation pit support experiment project as the background, the prefabricated recyclable support structure and pile-anchor support structure are studied; By using the finite element software PLAXIS3D, the constitutive model parameters are determined through indoor geotechnical test data, and the three-dimensional finite element model is established. Further, the process of foundation pit excavation and support is simulated, and the stress and deformation of foundation pit soil and support structure characteristics are analyzed. Through comparing the stability of the assembled recyclable support structure and the pile-anchor support structure under the same soil and excavation conditions, the following conclusions are obtained:The assembled recyclable deep foundation pit support form can not only better control the soil uplift deformation, which is more conducive to limit the displacement of deep soil, but also can better control the horizontal displacement of the pit top. The fabricated support structure is simple, quick in construction, recyclable, and conforms to the concept of green building in China.

In order to quantitatively evaluate the degree of groundwater hydraulic connection between aquifers, the concept of "hydraulic connection coefficient" C is first proposed. Based on the drawdown of groundwater level in full penetrating wells during the steady-state pumping test when the groundwater level is stable, the hydraulic connection coefficient C is defined as the ratio of the drawdown of groundwater level of the target aquifer to the drawdown of groundwater level of the pumping/dewatering aquifer in the observation borehole. The hydraulic connection coefficient can be used to quantitatively evaluate the degree of hydraulic connection between two points in different directions and different distances on the aquifer plan, and also between different aquifers in the vertical direction. According to the hydraulic connection coefficient C value of the aquifers in Luohe Formation in Ordos basin, the degree of groundwater hydraulic connection between the aquifers is divided into five grades:Among them, 0.000 0 ≤ C<0.062 5, the hydraulic connection is very weak; 0.062 5 ≤ C<0.125 0, the hydraulic connection is weak; 0.125 0 ≤ C<0.250 0, the hydraulic connection is medium; 0.250 0 ≤ C<0.500 0, the hydraulic connection is strong; C ≥ 0.500 0, the hydraulic connection is very strong. Taking the data of pumping test and dewatering test in Gaojiabu mine field as an example, the hydraulic connection coefficient and the response time of groundwater level in the observation borehole beginning to fall are used to quantitatively evaluate the internal groundwater hydraulic connection of the thick and layered Luohe Formation. Among them, when the hydraulic connection coefficient of the middle-upper layers in Luohe Formation is 0.373 0 and 0.413 8 respectively, and the response time of groundwater level in the observation borehole beginning to fall is very short (about 5 min), the groundwater hydraulic connection is strong; The hydraulic connection coefficient of the lower layers in Luohe Formation is 0.440 1 and 0.491 1, respectively, and the response time of groundwater level in observation borehole beginning to fall is short (9-20 min), the groundwater hydraulic connection is strong; When the hydraulic connection coefficient between the middle-upper and lower layers in Luohe Formation is 0.000 2, 0.007 2 and 0.089 7, respectively, and the response time of groundwater level in the observation borehole is longer (more than 60 min), the groundwater hydraulic connection is weak or very weak.

Influenced by the Mesozoic tectonic movement, faults, and folds occurred in the central mountain area of Shandong, the strata tilted, strata, and forming a series of graben-semi-graben basins with extensional detachment and Yanshanian magmatic intrusion. By taking Laiwu basin as an example, the influence of Mesozoic tectonic activities on the present karst groundwater occurrence was studied by means of hydrogeological survey, data statistics, drilling construction, geological outcrop observation, and analysis of soluble components of carbonate rocks. The results show that it has typical hydrogeological characteristics of basin-mountain structure in the central mountain area of Shandong. The hydrogeological characteristics of the south and north sides of the basin are different. The interlayer collapse, voids, and fractured rock zones formed by the regional decollement structure make the Lower Cambrian Zhushadong Formation aquifer show "stratiform". The dissolution fissures and caves formed by the hydrothermal mixed karstification are good space for the occurrence of karst groundwater. The interlayer corrosion fissures and faults formed by Mesozoic detachment structure and hydrothermal karst activity are connected in the same period or later, forming a three-dimensional karst groundwater network. The karst groundwater flows and accumulates along the network, and forms the unique characteristics of karst groundwater occurrence in the central mountain area of Shandong.

In order to find out the reasons for the cut-off of Jinci Spring in Shanxi and the decline and rise of the spring mouth water level in recent years, and provide theoretical reference for spring reflow work, the annual and inter-annual dynamic characteristics of different hydrodynamic zones in Jinci Spring were analyzed based on a long series of meteorological, hydrological, mining, spring discharge and groundwater level data. The influencing factors of the karst groundwater level change in Jinci Spring area in different historical periods were discussed from the aspects of natural climate and human activities. The result shows that:From 1956 to 1994, because the artificial mining volume reached the historical peak in the 1980s and 1990s(at one time exceeded 2.4 m³/s), and after the 1980s, the development trend of drought in Northern China became more serious, the water flow of Jinci Spring gradually decreased until it ceased to flow; From 1994 to 2008, although the amount of artificial mining decreased to a certain extent, it remained at about 2.0 m³/s and coincided with consecutive dry years the precipitation and river runoff decreased by 11% and 27% respectively compared with the multi-year average value,and at this period, the water level at the spring mouth rapidly decreased to the lowest value in history; Since 2008, it has entered a relatively wet period, through taking a number of measures to reduce the exploitation of karst water in the spring area, the water level of Fenhe Reservoir Ⅱhas gradually increased, and its leakage or recharge of karst water has reached the discharge area of the spring area after a lag of about 2 a, and the water level of the Jinci Spring mouth has gradually increased in recent years.

In order to study the genesis and evolution of geothermal fluids in deep metamorphic rocks, the geological, radiometric, magnetic, hydrogeological, and hydrographic geochemistry surveys were carried out, the hydrographic and isotopic characteristics of Chibachu hot spring were thoroughly analyzed, and the cause of formation and characteristics of the hot spring were studied. The results show that:The hydrochemical type of the hot spring is HCO₃·SO₄·CO₃-Na, the content of Li⁺ in the hot spring is 0.220 mg/L, which reaches the naming standard of lithium mineral water; The F^- content is 8.29 mg/L, which can be called fluorine water with medical value. The cold water mixing ratio in the hot spring water is 0.72, the recharge elevation of the hot water is 1 166.83 m, the temperature of the recharge area is 9.96℃, the thermal storage temperature is 191.71℃, the circulation depth is 2 082.29 m, and the natural heat release of the hot spring is 9.49×10¹² J/a. The hot spring water comes from the atmospheric precipitation and is a deep-cycle rising spring. The genesis type of the groundwater hydro-chemical component is rock weathering, and its main component comes from water-rock interaction. The heat source is mainly the conduction heat of the deep uncooled magma and the tectonic heat produced by the active faults, and followed by the radiant heat produced by radionuclides in a small part of the rock mass. The pH, SO₄^2-, Cl^-, Na⁺, SiO₂ and total alkalinity content of hot springs in the deep metamorphic rock area are higher than that of cold springs,but Ca²⁺ and Mg²⁺ contents are lower than that of cold springs. Currently, the hot spring is used only for bathing, and needs to be further developed and utilized.

Industrial waste coal chemical residues were selected as absorbent to remove perfluorooctanoic acid (PFOA) in water. Four kinds of coal chemical slag (particle size range from large to small was CGA1, CGA2, CGA3, and CGA4) prepared by different treatment methods were used to evaluate their sorption performance for PFOA. Scanning electron microscope (SEM), Raman, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) were used to characterize the structures of the four kinds of coal chemical slag, and the effects of initial concentration and pH of the PFOA solution on the adsorption process were investigated. The results showed that the absorbents had high efficiency for PFOA removal. The adsorption was well described by the pseudo-second-order kinetic model and the Langmuir isothermal model. With the increase of the initial concentration of PFOA solution, the adsorption capacity of the coal chemical slag for PFOA increased gradually. The initial pH value had almost no impact on CGA3 and CGA4; While for CGA1 and CGA2, it showed better adsorption performance under acidic conditions than alkaline conditions. It is concluded that CGA4 (the smallest particle size) has the best PFOA removal ability and is almost unrestricted by pH. The maximum adsorption capacity of CGA4 is 25.51 mg/g. The FTIR analysis suggested that the formation of hydrogen bonds dominates the adsorption process. The results of XPS and zeta potential showed that physical and electrostatic adsorption also plays important roles in the removal progress. Therefore, coal chemical slag can be used as a promising adsorbent to remove the difficult-to-treat pollutants and promote the recycling of waste and sustainable development.

Unmanned aerial vehicle (UAV) is affected by the disturbing gravity of the Earth during its flight. To control the UAV accurately, it is necessary to calculate the disturbing gravity of the flight trajectory points. In order to effectively restore the external gravitational field of the Earth, the Earth gravitational model is often used, but its calculation time increases exponentially with the increase of the order of the model. In this paper, an improved vectorization method for the calculation of perturbation gravity is proposed, and a CUDA(compute unified device architecture)heterogeneous parallel algorithm is used for parallelization to achieve the purpose of rapid calculation of single point perturbation gravity. The simulation results show that the proposed method can effectively reduce the time-consuming of single-point calculation of perturbation gravity:The acceleration ratio of single-point calculation can be more than eight times and the highest can be up to 13.20 times by using the step-by-step recursion method; By using Belikov recursion method, the acceleration ratio of single point calculation can be more than six times and the maximum can be 8.99 times.

Due to the late start of marine controlled-source electromagnetic (MCSEM) method in China,the current processing flow of marine EM data is relatively simple. In these classic data processing procedures, there is still a lack of processing methods for distorted EM data caused by reading and writing to storage device, ship speed, and long-line source moment changes. In this study, a spectrogram-based automatic suppression method was proposed for regular noise caused by storage device operation, the corresponding window-based distortion correction procedures were established for the interference of ship speed and long-line source moment changes, and finally, the synthetic aperture source technology was applied to further enhance the strength of the effective signal. The results of real field data processing indicate that by using these distortion correction and signal enhancement methods, the signal-to-noise ratio of EM data can be increased while enhancing the effective signal amplitude from the seafloor.

In the time domain airborne electromagnetic system, using high-frequency pseudo-random binary sequence as excitation source is an effective way to realize shallow high-resolution geological exploration. In order to improve the identification accuracy, a high-precision identification method based on time-domain cyclic correlation calculation is proposed in this paper. The impulse response of the Earth is obtained by eliminating the side lobe effect and solving the Wiener-Hoff equation in the time domain. The numerical simulation results show that the root mean square value of the relative error in identifying the Earth response is 2.2×10^-7,while the identification error of the Early earth response is less than 10^-10, which proves that this identification method is accurate. Further analysis shows that this high-precision identification method has strong noise suppression ability in a short observation time. The signal-to-noise ratio improved by the single-period identification method is 8.7 dB, which is better than the 6.1 dB improved by the linear superposition noise reduction method under the same conditions.

Rayleigh wave is a P-SV surface wave distributed near the free surface. It has the characteristics of strong amplitude, low frequency and dispersion, and is commonly used in engineering geophysical exploration. However, in oil and gas exploration and deep exploration, it is often a kind of ‘interference’ waves that affects the signal-to-noise ratio of seismic data. Therefore, denoising processing is required. The authors combine engineering geophysical prospecting methods with oil geophysical exploration technologies to obtain a high precision near-surface model by surface wave dispersion curve inversion, and then, carry out the forward modeling of surface wave on the basis of the three-dimensional near-surface shear wave velocity model. The surface wave is subtracted by the method of model matching subtraction. By this method, the influence of surface wave can be minimized, and the shortcomings of the conventional surface wave attenuation methods can be avoided to certain extent, such as damaging the effective wave, losing low-frequency weak information, narrowing the effective frequency band of data, and negatively affecting seismic structure interpretation and inversion. The effectiveness of this method has been verified by practical applications.

Aiming at the characteristics of fuzzy edges and complex structures of rock particles, an improved C3 coherence algorithm is proposed to identify the edges of particles more effectively. The improved C3 coherence algorithm is based on eigenvalues, in which the multi-scale and multi-angle feature expressions are infused for improvement. It comprehensively considers the angle domain optical characteristics, spatial scale information, and anisotropy information of rock slice images so that the grain edges are characterized more effectively, which have strong noise resistance and adaptability to complex mineral structures. The proposed algorithm has been verified on the acquired orthogonal polarized images of rock slices. The experimental results show that compared with the native C3 coherence algorithm, the improved C3 coherent algorithm increases the variance and gray-scale difference product of the global image by 68.41% and 22.91%, and decreases the information entropy by 21.61%.

The magmatic and metamorphic rocks in Gansu Beishan area are widely exposed, vegetation is sparse, and the terrain is gentle. It is an ideal area for UAV remote sensing geological mapping experiments. In order to solve the problems of traditional geological mapping, such as topography and environmental constraints, high investment, and long work cycle, etc., the 20 km² geochemical exploration key work area in Changliushui area of Beishan was selected as a target, the DJI Phantom 4 professional drone was used to collect images, and the photoscan software was used to synthesize high-resolution orthophotos and three-dimensional models, so as to establish interpretation signs, and perform geological interpretation of the target area to obtain a more refined geological map than the previous 1:10 000 geological map. Compared with the traditional mapping method, this method can capture more detailed geological contents such as geological body shape, dike occurrence, and micro-faults, and this can provide a basis for dividing dike stages.

In order to study the improvement of surveying accuracy by tilt photogrammetry, taking two survey areas A and B as an example, the two-piece and multi-piece intersection, vertical and tilt images are used as contrast conditions to establish a stereoscopic model and a real scene 3D model. Through the error statistics of the checkpoints in the models and digital line graphic, the plane accuracy and elevation accuracy are compared and analyzed. Compared with the stereoscopic model based on the two-piece front intersection, the real scene 3D model based on the multi-piece front intersection has higher accuracy. In the survey area A where the terrain is highly mountainous, the errors in plane and elevation are increased from decimeter level to centimeter level, and combining with Specifications for Aerotriangulation of Digital Aerophotogrammetry, it can reach the mapping standard of 1:500 scale. Compared with vertical photogrammetry, oblique photogrammetry has more intersection rays, so its model accuracy is higher. In the survey area B where the terrain is mountainous, the elevation accuracy can be equivalent to the plane accuracy, and the median error is within 5 cm, which solves the problem of poor elevation accuracy in aerial photogrammetry due to image acquisition methods, and by 3D mapping based on the tilted real 3D model, the error in the contour meets the accuracy requirements of the 1:500 scale in Specifications for Aerophotogrammetric Office Operation of 1:500 1:1 000 1:2 000 Topographic Maps.

In order to effectively preprocess the traditional remote sensing image change detection, we proposed a change detection method of building remote sensing image based on random patches and DeeplabV3+. This method builds a DeepLabV3+ semantic segmentation network based on the ResNet50, which is a feature extraction network, crops the random patches of 224 pixels×224 pixels in the image and label them as the network input to train the building extraction network,and then, modify the input layer of the building extraction network to six channels. The two-phase remote sensing images are converted into a 6-channel non-RGB image through matrix operation, which are used for network training and validating the change detection accuracy. In Experiment 1, the Mahalanobis distance classification method was used to detect the change by ENVI5.3 software. In Experiment 2, the improved U-Net network and random patches were used to complete the network training and accuracy verification. Experiment 3 used the training data and verification data of Experiment 2, and used random patches and DeepLabV3+ network to train the change detection network and verify the accuracy.The results of Experiment 1, 2, and 3 show that the average intersection-over-union of this method is 24.43%, 83.14%, and 89.90% respectively, and the boundary matching score is 61.47%, 80.24%, and 96.51% respectively.