Hybrid 2D/3D Graphitic Carbon Nitride-Based High-Temperature Position-Sensitive Detector

Ultraviolet position-sensitive detectors(PSDs)are expected to undergo harsh environments,such as high temperatures,for a wide variety of applications in military,civilian,and aerospace.However,no report on relevant PSDs operating at high temperatures can be found up to now.Herein,we design a new 2D/3D graphitic carbon nitride(g-C_(3)N_(4))/gallium nitride(GaN)hybrid heterojunction to construct the ultraviolet high-temperature-resistant PSD.The g-C_(3)N_(4)/GaN PSD exhibits a high position sensitivity of 355 mV mm^(-1),a rise/fall response time of 1.7/2.3 ms,and a nonlinearity of 0.5%at room temperature.The ultralow formation energy of-0.917 eV atom^(-1)has been obtained via the thermodynamic phase stability calculations,which endows g-C_(3)N_(4)with robust stability against heat.By merits of the strong built-in electric field of the 2D/3D hybrid heterojunction and robust thermo-stability of g-C_(3)N_(4),the g-C_(3)N_(4)/GaN PSD delivers an excellent position sensitivity and angle detection nonlinearity of 315 mV mm^(-1)and 1.4%,respectively,with high repeatability at a high temperature up to 700 K,outperforming most of the other counterparts and even commercial silicon-based devices.This work unveils the high-temperature PSD,and pioneers a new path to constructing g-C_(3)N_(4)-based harsh-environment-tolerant optoelectronic devices.

Effects of Stylosanthes scabra Forage Supplementation on in Vitro Gas Production and Fiber Degradation of Eragrostis Grass Hay

Natural pastures constitute a major component of ruminant livestock feed, and are the most cost-effective feed resource available for smallholder subsistence farmers. However, this feed resource does not meet animal nutritional requirement due to deficiency in nitrogen, energy and minerals. In addition, at maturity lignification is the major concern since it reduces digestibility and contributes to methane emission. Thus, the objective of this study was to evaluate the effect of supplementing low-quality Eragrostis grass hay with five (9281, 11,252, 11,255, 11,595 and 11,604) selected Stylosanthes scabra accessions on in vitro ruminal fermentation and neutral detergent fiber degradation. Therefore, in vitro study was conducted on grass hay, accessions and the mixture of grass hay with each accession included at two (15%, 30%) levels. The substrates (grass hay, accessions and the mixtures) were incubated in separate serum bottles for 72 h. Neutral detergent fiber (NDF) of the accessions ranged from 300 to 350 g/kg DM with crude protein (CP) value ranging from 177.5 to 184.1 g/kg DM. Eragrostis grass hay had NDF value of 813 g/kg DM, with CP value of 34.3 g/kg DM. Grass hay fermented slowly, it took 30 h for grass hay to produce gas volume above 50 mL, while Stylosanthes scabra accessions took 12 h. Supplementing grass hay with accessions significantly improved fermentation. However, it was observed that 15% inclusion took 30 h to produce gas volume above 50 mL, whereas at 30% inclusions it took 24 h for accession 9281, 11,595 and 11,604. Accession 11,604 improve grass fermentation by almost three times the value of grass hay in 2 h. Grass hay supplemented with accession 11,604 at 30% had a positive associative effect and significantly improved NDF degradability. In conclusion, accession 11,604 may be fed strategically as forage supplement to low-quality forage for ruminants.

Study on the Effects of Helium-Argon Gas Mixture on the Laser Welding Performance of High Temperature Alloys

In order to solve the problem of porosity in laser deep penetration welding of GH3625 high-temperature alloy plates,five different ratios of high-purity helium gas and high-purity argon gas mixed gases were compared in welding experiments after various process parameter improvements and adjustments failed to achieve Class I welds.The experimental results show that using high-purity helium gas or a mixture of 50%high-purity helium gas and 50%high-purity argon gas can both achieve Class I welds.This indicates that using high-purity helium gas or an appropriate mixed gas instead of pure argon is one of the effective ways to solve the problem of porosity in laser deep penetration welding of high-temperature alloys.The mixture of 50%high-purity argon gas and 50%high-purity helium gas can reduce the consumption of high-purity helium gas,lower production costs,and is more suitable.

Effect of La_2O_3/Ce O_2 particle size on high-temperature oxidation resistance of electrodeposited Ni-La_2O_3/Ce O_2 composites

Ni-La2O3/CeO2 composite films were prepared by electrodeposition from a nickel sulfate bath containing certain content of micrometer and nanometer La2O3/CeO2 particles. The effect of La2O3 or CeO2 particle size on the oxidation resistance of the electrodeposited Ni-La2O3/CeO2 composites in air at 1000 °C was studied. The results indicate that, compared with the electrodeposited Ni-film, Ni-La2O3/CeO2 composites exhibit a superior oxidation resistance due to the codeposited La2O3 or CeO2 particles blocking the outward diffusion of nickel. Moreover, compared with nanoparticles, La2O3 or CeO2 microparticles have stronger effect because La2O3 or CeO2 microparticles also act as a diffusion barrier layer at the onset of oxidation.

Gas Condensate Two Phase Flow Performance in Porous Media Considering Capillary Number and Non-Darcy Effects

Retrograde condensation frequently occurs during the development of gas condensate reservoirs. The loss of productivity is often observed due to the reduced relative permeability to gas as condensate accumulates near the well bore region. How to describe the condensate blockage effect exactly has been a continuous research topic. However, up to now, the present methods usually over-estimate or underestimate the productivity reduction due to an incorrect understanding of the mechanism of flow in porous medium, which inevitably results in an inaccurate prediction of production performance. It has been found in recent numerous theoretical and experimental studies that capillary number and non-Darcy flow have significant influence on relative permeability in regions near the well bore. The two effects impose opposite impacts on production performance, thus leading to gas condensate flow showing characteristics different from general understanding. It is significant for prediction of performance in gas condensate wells to understand the two effects exactly. The aim of the paper is to describe and analyze the flow dynamics in porous media accurately during the production of gas condensate reservoirs. Based on the description of three-zone flow mechanism, capillary number and non-Darcy effect are incorporated in the analysis of relative permeability, making it possible to describe the effect of condensate blockage. The effect of capillary number and inertial flow on gas and condensate relative permeability is analyzed in detail. Novel Inflow Performance Relation (IPR) models considering high velocity effects are formulated and the contrast analysis of different IPR models is conducted. The result shows that the proposed method can help predict the production performance and productivity more accurately than conventional methods.

Experimental and theoretical study on the dynamic effective stress of loaded gassy coal during gas release

In the process of mining coalbed methane(CBM),an unsteady state often arises due to the rapid extraction,release and pressure relief of CBM.In this case,the effective stress of coal changes dynamically,affecting the stability of the gassy coal seam.In this paper,gas release tests of gassy coal under conventional triaxial compression were performed,and the dynamic effective stress(DES)during gas release was obtained indirectly based on a constitutive equation and deformation of coal.The results show that the maximum increases in DES caused by the release of free gas and adsorbed gas under the stress of 1.1 MPa were 0.811 and 5.418 MPa,respectively,which seriously affected the stress state of the coal.During the gas release,the free gas pressure and the adsorbed gas volume were the parameters that directly affected the DES and showed a positive linear relationship with the DES with an intercept of zero.The DES of the coal sample increased exponentially with time,which was determined by the contents of free and adsorbed gas.Based on the experimental results and theoretical analysis,an effective stress model was obtained for loaded gassy coal during gas release.The results of verification indicated accuracy greater than 99%.

The effect of high-temperature annealing on LaFe_(11.5)Si_(1.5) and the magneto-caloric properties of La_(1-x)Ce_xFe_(11.5)Si_(1.5) compounds

The powder X-ray diffraction patterns of LaFell.sSil.5 compounds annealed at different high temperatures from 1323 K （5 h） to 1623 K （2 h） show that a large amount of 1：13 phase begins to form in LaFell.sSiL5 compound annealed at 1423 K （5 h）. In the temperature range from 1423 to 1523 K, ^-Fe and LaFeSi phases rapidly decrease to form 1：13 phase. LaFeSi phase is rarely observed, and the most amount of 1：13 phase is obtained in the compound annealed at 1523 K （5 h）. With the annealing temperature increasing to 1573 and 1623 K, LaFeSi is detected again in the LaFell.sSil.s compound. According to the results of annealing at different high-temperatures, the Lal-xCexFelt.sSit.5 compounds are annealed at high temperatures of 1373 K （2 h） ＋ 1523 K （5 h）. The main phase is NaZn13-type phase, and the impurity is a small amount of et-Fe in Lal-xCexFexx.sSil.5 compounds with 0 〈 x 〈 0.35, and there is a large amount of CeaFe17 phase in Lao.sCeo.sFela.sSil.s. It indicates that the substitution of cerium atoms for La in LaFelLsSil.5 compounds has limit. At the same time, the substitution of Ce for La has large effect on magnetocaloric properties. With increasing Ce content from x = 0 to x = 0.35, the Curie temperature decreases linearly from 196 to 168 K, the magnetic entropy change increases from 16.5 to 57.3 J-kg-kK-1 in a low magnetic field change of 0-2 T, and the thermal hysteresis also increases from 3 K to 8 K.

Geothermal energy exploitation from depleted high-temperature gas reservoirs by recycling CO_(2): The superiority and existing problems

CO_(2) can be used as an alternative injectant to exploit geothermal energy from depleted high-temperature gas reservoirs due to its high mobility and unique thermal properties.However,there has been a lack of systematic analysis on the heat mining mechanism and performance of CO_(2),as well as the problems that may occur during geothermal energy exploitation at specific gas reservoir conditions.In this paper,a base numerical simulation model of a typical depleted high-temperature gas reservoir was established to simulate the geothermal energy exploitation processes via recycling CO_(2) and water,with a view to investigate whether and/or at which conditions CO_(2) is more suitable than water for geothermal energy exploitation.The problems that may occur during the CO_(2)-based geothermal energy exploitation were also analyzed along with proposed feasible solutions.The results indicate that,for a depleted low-permeability gas reservoir with dimensions of 1000 m×500 m×50 m and temperature of 150℃ using a single injection-production well group for 40 years of operation,the heat mining rate of CO_(2) can be up to 3.8 MW at a circulation flow rate of 18 kg s^(-1)due to its high mobility along with the flow path in the gas reservoir,while the heat mining rate of water is only about 2 MW due to limitations on the injectivity and mobility.The reservoir physical property and injection-production scheme have some effects on the heat mining rate,but CO_(2)always has better performance than water at most reservoir and operation conditions,even under a high water saturation.The main problems for CO_(2) circulation are wellbore corrosion and salt precipitation that can occur when the reservoir has high water saturation and high salinity,in which serious salt precipitation can reduce formation permeability and result in a decline of CO_(2) heat mining rate (e.g.up to 24%reduction).It is proposed to apply a low-salinity water slug before CO_(2)injection to reduce the damage caused by salt precipitation.For high-permeability gas reservoirs with high water saturation and high salinity,the superiority of CO_(2) as a heat transmission fluid becomes obscure and water injection is recommended.

Real Gas Effects on Charging and Discharging Processes of High Pressure Pneumatics

The high pressure pneumatic system has been applied to special industries. It may cause errors when we analyze high pressure pneumatics under ideal gas assumption. However, the real gas effect on the performances of high pressure pneumatics is seldom investigated. In this paper, the real gas effects on air enthalpy and internal energy are estimated firstly to study the real gas effect on the energy conversion. Under ideal gas assumption, enthalpy and internal energy are solely related to air temperature. The estimation result indicates that the pressure enthalpy and pressure internal energy of real pneumatic air obviously decrease the values of enthalpy and internal energy for high pressure pneumatics, and the values of pressure enthalpy and pressure internal energy are close. Based on the relationship among pressure, enthalpy and internal energy, the real gas effects on charging and discharging processes of high pressure pneumatics are estimated, which indicates that the real gas effect accelerates the temperature and pressure decreasing rates during discharging process, and decelerates their increasing rates during charging process. According to the above analysis, and for the inconvenience in building the simulation model for real gas and the difficulty of measuring the detail thermal capacities of pneumatics, a method to compensate the real gas effect under ideal gas assumption is proposed by modulating the thermal capacity of the pneumatic container in simulation. The experiments of switching expansion reduction （SER） for high pressure pneumatics are used to verify this compensating method. SER includes the discharging process of supply tanks and the charging process of expansion tank. The simulated and experimental results of SER are highly consistent. The proposed compensation method provides a convenient way to obtain more realistic simulation results for high pressure pneumatics.

Combined effects of obstacle and fine water mist on gas explosion characteristics

Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated experimentally.In this study,the diameter of the water mist,the location,and the number of obstacles was considered.The results demonstrated that 5 μm water mist present a significant suppression affected while 45 μm shows a slight promotion effected on a gas explosion of the condition without obstacles.In the presence of an obstacle,however,the inhibitory effect of 5 μm water veils of mist dropped significantly during flame propagation,and the effect of 45 μm water veils of mist changed from the enhancement of inhibition,and its inhibitory effect was significant.The inhibitory effect of 45 μm water veils of mist on gas explosion weakened firstly and then enhanced with the increasing distance between obstacle location from the ignition location as well as in several obstacles.

Simulation of Gas-Water Two-Phase Flow in Tight Gas Reservoirs Considering the Gas Slip Effect

A mathematical model for the gas-water two-phase flow in tight gas reservoirs is elaborated.The model can account for the gas slip effect,stress sensitivity,and high-speed non-Darcy factors.The related equations are solved in the framework of a finite element method.The results are validated against those obtained by using the commercial software CMG(Computer Modeling Group software for advanced recovery process simulation).It is shown that the proposed method is reliable.It can capture the fracture rejection characteristics of tight gas reservoirs better than the CMG.A sensitivity analysis of various control factors(initial water saturation,reservoir parameters,and fracturing parameters)affecting the production in tight gas wells is conducted accordingly.Finally,a series of theoretical arguments are provided for a rational and effective development/exploitation of tight sandstone gas reservoirs.

Finite-size effects in a D-dimensional ideal Fermi gas

By using the Euler-MacLaurin formula, this paper studies the thermodynamic properties of an ideal Fermi gas confined in a D-dimensional rectangular container. The general expressions of the thermodynamic quantities with the finite-size corrections are given explicitly and the effects of the size and shape of the container on the properties of the system are discussed. It is shown that the corrections of the thermodynamic quantities due to the finite-size effects are significant to be considered for the case of strong degeneracy but negligible for the case of weak degeneracy or non-degeneracy. It is important to find that some familiar conclusions under the thermodynamic limit are no longer valid for the finite-size systems and there are some novel characteristics resulting from the finite-size effects, such as the nonextensivity of the system, the anisotropy of the pressure, and so on.

Investigation on nonlinear multi-scale effects of unsteady flow in hydraulic fractured horizontal shale gas wells

A unified mathematical model is established to simulate the nonlinear unsteady percolation of shale gas with the consideration of the nonlinear multi-scale effects such as slippage, diffusion, and desorption. The continuous inhomogeneous models of equivalent porosity and permeability are proposed for the whole shale gas reservoir includ- ing the hydraulic fracture, the micro-fracture, and the matrix regions. The corresponding semi-analytical method is developed by transforming the nonlinear partial differential governing equation into the integral equation and the numerical discretization. The nonlinear multi-scale effects of slippage and diffusion and the pressure dependent effect of desorption on the shale gas production are investigated.

NON-STATIONARY EFFECTS IN HYPERSONIC NONUNIFORM DUSTY-GAS FLOW PAST A BLUNT BODY

In the framework of the two-fluid model, a hypersonic flow of a nonuniform dusty gas with low inertial (non-depositing) particles around a blunt body is considered. The particle mass concentration is assumed to be small, so that the effect of particles on the carrier phase is significant only inside the boundary layer where the particles accumulate. Stepshaped and harmonic nonuniformities of the particle concentration ahead of the bow shock wave are considered and the corresponding nonstationary distributions of the particle concentration in the shock layer are studied. On the basis of numerical study of nonstationary two-phase boundary layer equations derived by the matched asymptotic expansion method, the effects of free-stream particle concentration nonuniformities on the thermal flux, and the friction coefficient in the neighborhood of stagnation point are investigated, in particular, the most “dangerous” nonuniformity periods are found.

Large-scale gas accumulation mechanisms and reservoir-forming geological effects in sandstones of Central and Western China

Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects.Based on the geological theory and method of natural gas reservoir formation,this study examined the regional geological and structural background,formation burial evolution,basic characteristics of gas reservoirs,and fluid geology and geochemistry of typical petroliferous basins.The results show that the geological processes such as structural pumping,mudstone water absorption,water-soluble gas degasification and fluid sequestration caused by uplift and denudation since Himalayan stage all can form large-scale gas accumulation and different geological effects of gas accumulation.For example,the large-scale structural pumping effect and fluid sequestration effect are conducive to the occurrence of regional ultra-high pressure fluid and the formation of large-scale ultra-high pressure gas field;mudstone water absorption effect in the formation with low thickness ratio of sandstone to formation is conducive to the development of regional low-pressure and water free gas reservoir;the water-soluble gas degasification effect in large-scale thick sandstone can not only form large-scale natural gas accumulation;moreover,the degasification of water-soluble gas produced by the lateral migration of formation water will produce regional and regular isotopic fractionation effect of natural gas,that is,the farther the migration distance of water-soluble gas is,the heavier the carbon isotopic composition of methane formed by the accumulation.

Mathematical Statistics Method of Evaluating Application Effects of a New Type of Gas Anchor

Based on the basic formula of the confidence interval and the sampling error of mathematical statistics, the mathematical statistics method of evaluating application effects of a new type of gas anchor was given in this paper. By the method mentioned above, the confidence interval and the sampling errors of the relevant mean value differences of Daqing Oilfield S block’s 150 wells, according to the mean value differences of the liquid producing capacity per day, the oil production per day, the submergence depth of the 10 sampling test wells, in which before and after a new type of gas anchor were laid down, were calculated. The calculation results show that a new type of gas anchor has a better effect of increasing oil production of oil well and enhancing pump efficiency. Through the real value differences analysis of the liquid producing capacity per day, the oil production per day, the submergence depth of 150 wells mentioned above, in which before and after a new type of gas anchor were laid down, it was verified. By using the confidence interval and the sampling errors of the liquid producing capacity per day, the oil production per day, the submergence depth mentioned above, in which before and after a new type of gas anchor were laid down, the application effects of a new type of gas anchor could be evaluated. And a mathematical statistics method of evaluation application effects of a new type of gas anchor is presented.

A Comprehensive Observational Analysis for the Effects of Gas Cannons on Clouds and Precipitation

To analyze the effects of gas cannons on clouds and precipitation,multisource observational data,including those from National Centers for Environmental Prediction(NCEP)reanalysis,Hangzhou and Huzhou new-generation weather radars,laser disdrometer,ground-based automatic weather station,wind profiler radar,and Lin'an C-band dualpolarization radar,were adopted in this study.Based on the variational dual-Doppler wind retrieval method and the polarimetric variables obtained by the dual-polarization radar,we analyzed the microphysical processes and the variations in the macro-and microphysical quantities in clouds from the perspective of the synoptic background before precipitation enhancement,the polarization echo characteristics before,during and after enhancement,and the evolution of the fine three-dimensional kinematic structure and the microphysical structure.The results show that the precipitation enhancement operation promoted the development of radar echoes and prolonged their duration,and both the horizontal and vertical wind speeds increased.The dual-polarization radar echo showed that the diameter of the precipitation particles increased,and the concentration of raindrops increased after precipitation enhancement.The raindrops were lifted to a height corresponding to 0 to-20℃due to vertical updrafts.Based on the disdrometer data during precipitation enhancement,the concentration of small raindrops(lgN_(w))showed a significant increase,and the mass-weighted diameter D_(m)value decreased,indicating that the precipitation enhancement operation played a certain“lubricating”effect.After the precipitation enhancement,the concentration of raindrops did not change much compared with that during the enhancement process,while the Dm increased,corresponding to an increase in rain intensity.The results suggest the positive effect of gas cannons on precipitation enhancement.

Confinement effect on CO_(2)and CH_(4)permeability in shale

Gas flow in shales follows a number of physical mechanisms that include Knudsen diffusion,Darcy flow,and adsorption in the matrix and micro pores.The aim of the study is to resolve the interplay of gas transport in these media at increased effective stress as well as net pore pressure.In this research,we investigated the nature of gas transport in the matrix of shale by sending He,CH_(4)and CO_(2)gases through a transient upstream pressure pulse decay instrument.A series of experiments were conducted at constant pore pressures and a gradually increasing confining pressure.The same study was done in three different scenarios,injecting He,CO_(2)and CH_(4).At a constant pore pressure,gas permeability appears to decrease with an increasing confining pressure and effective stress.With increasing effective stress,the slip factor also decreases along with the permeability.The decrease in slip could be attributed to prestressing,that is likely to create new fractures.Among the three purged gases,permeability of shale to CH_(4)is the highest,and that to CO_(2)is the lowest owing to its high adsorption.Higher permeability of CH_(4)against He,could be attributed to the dual transport mechanism.

Gas hydrate saturation from NGHP 02 LWD data in the Mahanadi Basin

During the Indian National Gas Hydrate Program(NGHP)Expedition 02,Logging-while-drilling(LWD)logs were acquired at three sites(NGHP-02-11,NGHP-02-12,and NGHP-02-13)across the Mahanadi Basin in area A.We applied rock physics theory to available sonic velocity logs to know the distribution of gas hydrate at site NGHP-02-11 and NGHP-02-13.Rock physics modeling using sonic velocity at well location shows that gas hydrate is distributed mainly within the depth intervals of 150-265 m and 100 -215 mbsf at site NGHP-02-11 and NGHP-02-13,respectively,with an average saturation of about 4%of the pore space and the maximum concentration of about 40%of the pore space at 250 m depth at site NGHP-02-11,and at site NGHP-02-13 an average saturation of about 2%of the pore space and the maximum concentration of about 20%of the pore space at 246 m depth,as gas hydrate is distributed mainly within 100-246 mbsf at this site.Saturation of gas hydrate estimated from the electrical resistivity method using density derived porosity and electrical resistivity logs from Archie's empirical formula shows high saturation compared to that from the sonic log.However,estimates of hydrate saturation based on sonic P-wave velocity may differ significantly from that based on resistivity,because gas and hydrate have higher resistivity than conductive pore fluid and sonic P-wave velocity shows strong effect on gas hydrate as a small amount of gas reduces the velocity significantly while increasing velocity due to the presence of hydrate.At site NGHP-02-11,gas hydrate saturation is in the range of 15%e30%,in two zones between 150-180 and 245-265 mbsf.Site NGHP-02-012 shows a gas hydrate saturation of 20%e30%in the zone between 100 and 207 mbsf.Site NGHP-02-13 shows a gas hydrate saturation up to 30%in the zone between 215 and 246 mbsf.Combined observations from rock physics modeling and Archie’s approximation show the gas hydrate concentrations are relatively low(<4%of the pore space)at the sites of the Mahanadi Basin in the turbidite channel system.

Formation,evolution,reconstruction of black shales and their influence on shale oil and gas resource

Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human society.They also record the evolution process of the earth and improve the understanding of the earth.This review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and gas.In terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional facies.The formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom currents.From a geological perspective,the formation of black shales is often closely related to global or regional major geological events.The enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation rate.In terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore evolution.In terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore structure.Fluid activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black shales.Regarding resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales would have caused the heterogeneous distribution of oil and gas in shales.Exploring the formation mechanisms and interactions of black shales at different scales is a key to in-depth research on shale formation and evolution,as well as the key to revealing the mechanism controlling shale oil and gas accumulation.The present records can reveal how these processes worked in geological history,and improve our understanding of the coupling mechanisms among regional geological events,black shales evolution,and shale oil and gas formation and enrichment.