Under the background of the strategic goal of"double carbon,"the carbon reduction and consumption reduction of the iron and steel industry,especially in the ironmaking process,need to be further improved.The...Under the background of the strategic goal of"double carbon,"the carbon reduction and consumption reduction of the iron and steel industry,especially in the ironmaking process,need to be further improved.The raceway of tuyere provides the chemical environment,fuel and power source for blast furnace smelting.The research on the characteristics of its action mode and mechanism is of great significance to clarify the way of reducing carbon and consumption of blast furnace.In general,the formation mechanism,energy distribution,research progress,extended resource injection and directional regulation are studied and expounded.The research results of various scholars on the characteristics of the raceway show that the raceway is a complex process including multiphase turbulent flow,heat,momentum,mass and homogeneous and heterogeneous chemical reactions.With the development of multi-source fuel injection technology,the complexity of problem research is more obvious.Therefore,the collection of multi-factor,multi-directional and multi-process characteristic information in the raceway can provide guarantee for the stability,smooth operation,high yield,carbon reduction and consumption reduction of blast furnace and provide new ideas for the green and low-carbon development of iron and steel industry.展开更多
High-quality reservoirs with sufficient physical properties of ultra-deep tight gas reservoirs in the Lower Cretaceous Bashijiqike Formation exhibit significant relationship with gas production across the Dabei Gas Fi...High-quality reservoirs with sufficient physical properties of ultra-deep tight gas reservoirs in the Lower Cretaceous Bashijiqike Formation exhibit significant relationship with gas production across the Dabei Gas Field.Clarifying the characteristics,controlling factors,evolution and distribution of the high-quality reservoirs is important for the deployment of"sweet spots".An integrated approach of petrography,SEM,cathode luminescence,XRD,physical property,NMR experiment,well logs and 3D pre-stack depth migration data was carried out.This study examined the sedimentation,diagenesis,tectonism,gypsumrock and overpressure to reveal the formation and distribution of the high-quality reservoirs.The sandstones are very fine-to coarse-grained lithic arkose.The variation in detrital grains texture and mineralogical composition affects diagenetic evolution,pore structure and gas-bearing characteristic.Three diagenetic facies(diagenetic facies A to C)are classified.Different diagenetic facies underwent different evolution of reservoir quality.The medium-fine to medium-grained lithic arkose(diagenetic facies A)underwent medium vertical compaction,tectonic compression and cementation,and exhibited relatively porous,which makes partial primary pores preserved with the occurrence and persistence of overpressure.Conversely,the very fine to fine-grained and mud gravel-rich medium-grained lithic arkose(diagenetic facies B)and diagenetic facies C appeared premature densification by strong compaction and tight carbonate cementation,respectively,which makes them free from overpressure effects.Natural fractures increased the permeability by several orders of magnitude.Gypsum-rock weakened the vertical compaction and tectonic compression,and delayed cementation,promoted and preserved overpressure.With the injection of internal high alkaline fluids,anhydrite/dolomite cements/veins and dissolution of siliceous developed.Diagenetic facies A exhibited sufficient physical properties and gas volume,making it the high-quality reservoir in tight gas sandstone.Diagenetic facies B and C mainly were used as barriers for hydrocarbon charging.Diagenetic facies A was mainly distributed in the middle-lower part of distributary channel or the middle-upper part of mouth bar.This distribution model provides guidance for exploration in ultra-deep tight sandstone gas reservoir.展开更多
The development characteristics of Semiothisa cinerearia Bremer ＆ Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and ac...The development characteristics of Semiothisa cinerearia Bremer ＆ Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and actively carrying out comprehensive management to control the pests damage in the economic permissible level.展开更多
[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers （CRFs） on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to i...[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers （CRFs） on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to investigate the agronomic characteristics and physiological indices of corn fertilized with controlled release fertilizers compared with conventional fertilizer （CF）. [Result] Plant height, stem girth, leaf area and root volume of corn were significantly increased under the CRF treatments; photosynthetic rate and soluble protein content were also improved. Dry matter accumulations under the two CRF treatments were increased by 21.3% and 17.0% compared with CF application at one time （CF1）, and 19.6% and 15.4% with CF application at two times （CF2）, respectively. Accumulation amounts of N, P and K in whole plant under the two CRF treatments were increased by 44.0% -24.7% , 40.0%-25.9% and 20.1% -13.9% ; and the nutrient use efficiencies of N, P and K were improved by 22.9% -13.4% , 11.2% -9.6% and 17.5% -12.1% , respectively. [Conclusion] The results implied that the CRFs could significantly improve nutrient use efficiency and plant yield.展开更多
The special geography and human environment of the Qinghai-Tibet Plateau has created the unique hydrochemical characteristics of the region’s natural water,which has been preserved in a largely natural state.However,...The special geography and human environment of the Qinghai-Tibet Plateau has created the unique hydrochemical characteristics of the region’s natural water,which has been preserved in a largely natural state.However,as the intensity of anthropogenic activities in the region has continued to increase,the water environment and hydrochemical characteristics of the Qinghai-Tibet Plateau have altered.In this study,water samples from the western,southern,and northeastern border areas of the Qinghai-Tibet Plateau,where human activities are ongoing,were collected,analyzed,and measured.The regional differences and factors controlling them were also investigated.The key results were obtained as follows.(1) Differences in the physical properties and hydrochemical characteristics,and their controlling factors,occurred in the different boundary areas of the Qinghai-Tibet Plateau.These differences were mainly the consequence of the geographical environment and geological conditions.(2) The water quality was good and suitable for drinking,with most samples meeting GB (Chinese national) and WHO (World Health Organization) drinking water standards.(3) The chemical properties of water were mainly controlled by the weathering of carbonates and the dissolution of evaporative rocks,with the former the most influential.(4) The biological quality indicators of natural water in the border areas were far superior to GB and WHO drinking water standards.展开更多
The static and dynamic magnetic controlling characteristics of NiMnGa magnetically controlled shape memory alloy （MSMA） were experimentally studied. The results show that the characteristics of induced strain with r...The static and dynamic magnetic controlling characteristics of NiMnGa magnetically controlled shape memory alloy （MSMA） were experimentally studied. The results show that the characteristics of induced strain with respect to the magnetic field are nonlinear with saturation nature, and dependent on the temperature as well as the load applied to the MSMA. The magnetic shape memory effect can be observed only in complete martensite phase at room temperature. The magnetic permeability of MSMA is not constant and reduces with the increment of magnetic field. The relative saturation magnetic permeability of MSMA is about 1.5.展开更多
Active magnetic bearings （AMBs） have found a wide range of applications in high-speed rotating machinery industry. The instability and nonlinearity of AMBs make controller designs difficult, and when AMBs are couple...Active magnetic bearings （AMBs） have found a wide range of applications in high-speed rotating machinery industry. The instability and nonlinearity of AMBs make controller designs difficult, and when AMBs are coupled with a flexible rotor, the resulting complex dynamics make the problems of stabilization and disturbance rejection, which are critical for a stable and smooth operation of the rotor AMB system, even more difficult. Proportional-integral-derivative （PID） control dominates the current AMB applications in the field. Even though PID controllers are easy to implement, there are critical performance limitations associated with them that prevent the more advanced applications of AMBs, which usually require stronger robustness and performance offered by modern control methods such as H-infinity control and if-synthesis. However, these advanced control designs rely heavily on the relatively accurate plant models and uncertainty characterizations, which are sometimes difficult to obtain. In this paper, we explore and report on the use of the characteristic model based all-coefficient adaptive control method to stabilize a flexible rotor AMB test rig. In spite of the simple structure of such a characteristic model based all-coefficient adaptive controller, both simulation and experimental results show its strong performance.展开更多
Although anastomosing fluvial rivers are given much attention recently by some research workers because the result channel sandstone of which is one typical primary reservoirs of petroleum and natural gas, of which th...Although anastomosing fluvial rivers are given much attention recently by some research workers because the result channel sandstone of which is one typical primary reservoirs of petroleum and natural gas, of which the flood plains and the interchannel wetlands are pay zones where coals had formed, the comprehension of anastomosing river is some extent limited at present. Some researchers regard that the anastomosing river river and the anabranched river are the same kind of rivers. In this paper, the sedimentary, geomorphic and hydraulic characteristics and the main controlling factors of anastomosing fluvial system are summarized systematically. Some of the characteristics are compared with others fluvial rivers. Humid climate is suitable to form anastomosing channel systems, in arid semiarid regions anastomosing river maybe develop if many befitting factors combine together. The authors of the paper think that anastomosing river is one typical channel pattern and is dissimilar to anabranched channel pattern.展开更多
Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recogniz...Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer.展开更多
The movement characteristics and control response of oblique wing aircraft(OWA) are highly coupled between the longitudinal and lateral-directional axes and present obvious nonlinearity. Only with the implementation o...The movement characteristics and control response of oblique wing aircraft(OWA) are highly coupled between the longitudinal and lateral-directional axes and present obvious nonlinearity. Only with the implementation of flight control systems can flying qualities be satisfied. This article investigates the dynamic modeling of an OWA and analyzes its dynamic characteristics.Furthermore, a flight control law based on model-reference dynamic inversion is designed and verified. Calculations and simulations show that OWA can be trimmed by rolling a bank angle and deflecting the triaxial control surfaces in a coordinated way. The oblique wing greatly affects longitudinal motion. The short-period mode is highly coupled between longitudinal and lateral motion,and the bank angle also occurs in phugoid mode. However, the effects of an oblique wing on lateral mode shape are relatively small. For inherent control characteristics, symmetric deflection of the horizontal tail will generate not only longitudinal motion but also a large rolling rate. Rolling moment and pitching moment caused by aileron deflection will reinforce motion coupling, but rudder deflection has relatively little effect on longitudinal motion. Closed-loop simulations demonstrate that the flight control law can achieve decoupling control for OWA and guarantee a satisfactory dynamic performance.展开更多
The Cenozoic continental strata of the Bohai Bay Basin are rich in shale oil resources, and they contain various types of reservoir spaces that are controlled by complex factors. Using field emission scanning electron...The Cenozoic continental strata of the Bohai Bay Basin are rich in shale oil resources, and they contain various types of reservoir spaces that are controlled by complex factors. Using field emission scanning electron microscopy(FESEM), automatic mineral identification and characterization system(AMICS), CO2 and N2 gas adsorption, and focused ion beam scanning electron microscopy(FIB-SEM), the types of shale reservoir spaces in the Bohai Bay Basin are summarized, the spatial distribution and connectivity of the various types of pores are described in detail, the microscopic pore structures are characterized, and the key geological mechanisms affecting the formation and evolution of the reservoir spaces are determined. Three conclusions can be drawn in the present study. First, the shale reservoir spaces in the Bohai Bay Basin can be divided into three broad categories, including mineral matrix pores, organic matter pores, and micro fractures. Those spaces can be subdivided into seven categories and fourteen sub-categories based on the distribution and formation mechanisms of the pores. Second, the complex pore-throat structures of the shale reservoir can be divided into two types based on the shape of the adsorption hysteresis loop. The pore structures mainly include wedge-shaped, flat slit-shaped, and ink bottle-shaped pores. The mesopores and micropores are the main contributors to pore volume and specific surface area, respectively. The macropores provide a portion of the pore volume, but they do not significantly contribute to the specific surface area. Third, the factors controlling the development of microscopic pores in the shale are complex. The sedimentary environment determines the composition and structure of the shale and provides the material basis for pore development. Diagenesis controls the types and characteristics of the pores. In addition, the thermal evolution of the organic matter is closely related to inorganic diagenesis and drives the formation and evolution of the pores.展开更多
One of the primary difficulties in using powered parafoil(PPF) systems is the lack of effective trajectory tracking controllers since the trajectory tracking control is the essential operation for PPF to accomplish au...One of the primary difficulties in using powered parafoil(PPF) systems is the lack of effective trajectory tracking controllers since the trajectory tracking control is the essential operation for PPF to accomplish autonomous tasks. The characteristic model(CM) based all-coefficient adaptive control(ACAC) designed for PPF systems in horizontal and vertical trajectory control is proposed. The method is easy to use and convenient to adjust and test. Just a few parameters are adapted during the control process. In application, vertical and horizontal CMs are designed and ACAC controllers are constructed to control vertical altitude and horizontal trajectory of PPF based on the proposed CMs, respectively. Result analysis of different simulations shows that the applied ACAC control method is effective for trajectory tracking of the PPF systems and the approach guarantees the transient performance of the PPF systems with better disturbance rejection ability.展开更多
Thermodynamic characteristics are of great importance for the performance of a high-temperature flow-rate control valve,as high-temperature environment may bring problems,such as blocking of spool and increasing of le...Thermodynamic characteristics are of great importance for the performance of a high-temperature flow-rate control valve,as high-temperature environment may bring problems,such as blocking of spool and increasing of leakage,to the valve.In this paper,a high-temperature flow-rate control valve,pilot-controlled by a pneumatic servo system is developed to control the fuel supply for scramjet engines.After introducing the construction and working principle,the thermodynamic mathematical models of the valve are built based on the heat transfer methods inside the valve.By using different boundary conditions,different methods of simulations are carried out and compared.The steady-state and transient temperature field distribution inside the valve body are predicted and temperatures at five interested points are measured.By comparing the simulation and experimental results,a reasonable 3D finite element analysis method is suggested to predict the thermodynamic characteristics of the high-temperature flow-rate control valve.展开更多
To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental r...To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental results are introduced in this paper. The experimental data show that the canard is an inefficient rolling control device for canard-controlled missile with fixed tail fins; but for the free-spinning tail fin configuration, the canard can conduct rolling control of the missile, and even have higher controlling efficiency under larger canard deflection angle.展开更多
Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fra...Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated.展开更多
In order to study the failure characteristics and control method of deep tunnel surrounding rock, based on the stress test, the structure and stress state of the main transportation tunnel surrounding rock in Mine Zha...In order to study the failure characteristics and control method of deep tunnel surrounding rock, based on the stress test, the structure and stress state of the main transportation tunnel surrounding rock in Mine Zhaogezhuang level 14 was analyzed, and it shows that the surrounding rock is exposed to an interphase hard and soft disadvantageous structure state and complex high stress repeated addition area;Through the theoretical analysis and the statistical data, the relation between the tunnel stress transformation and the surrounding rock deformation was proposed;Through the numerical simulation of the tunnel surrounding rock failure process with the help of RFPA procedure, the results show that the damage of the transportation tunnel level 14 mainly occurs in the bottom and the two coal ribs, and the failure process is spreading from the bottom to the two coal ribs, and the effect of the surrounding rock deformation control is obvious by using the way of 2.5 m anchor with 1.0 m grouting strengthening.展开更多
Microscopic computed tomography(Micro-CT)is used to visualize microscopic flow in sandstone core samples during emulsion flooding.The images obtained during the experiment are processed quantitatively with a series of...Microscopic computed tomography(Micro-CT)is used to visualize microscopic flow in sandstone core samples during emulsion flooding.The images obtained during the experiment are processed quantitatively with a series of methods to evaluate the occurrence characteristics and oil recovery enhancement mechanisms of emulsion.(1)The emulsion is distributed in the cores in spherical shape,and its sphericity is significantly different from that of the remaining oil.Sphericity can be taken as a characteristic parameter to identify emulsion.(2)The emulsion with specific size prefers to stay in pores with matching sizes;when the emulsion volume is smaller than the product of the lower limit of pore occupancy and the corresponding pore vol-ume,it will not be able to effectively trap in the pore to achieve conformance control.In the process of emulsion displacement designing,we need to design emulsion with suitable particle size according to the pore distribution of the reservoir.(3)Mobi-lization ratio of the pores can be increased from 23.1%to 59.3%by emulsion flooding after subsequent water flooding,and the average oil displacement efficiency at the pore-scale can be increased from 22.9%to 75.8%under the test conditions;(4)After emulsion flooding,the clustered remaining oil and the oil phase in the trapped emulsion are the main targets for further EOR.展开更多
As the traditional control algorithm is over-dependent on accurate vehicle model in intelligent vehicle steering control,a human-simulated intelligent control method is proposed based on experienced driver steering ch...As the traditional control algorithm is over-dependent on accurate vehicle model in intelligent vehicle steering control,a human-simulated intelligent control method is proposed based on experienced driver steering characteristics.Intelligent vehicle unmanned steering system dynamics model and the driver model are set up.Through experienced drivers'trial run experiment,the analysis is mainly conducted on the double lanes condition.After the transformation of coordinates on global positioning system(GPS)derivative,the path information of local coordinates is accessed.The ideal driver steering path is obtained through fuzzy C-means clustering algorithm.The human-simulated intelligent controller is designed.Characteristic model is established according to the ideal and practical steering angle deviation and the deviation rate.Besides,the corresponding control rules and control modality set are designed.The joint simulation under CarSim joint/Simulink environment shows that the humanoid steering controller designed in this paper has better tracking performance than the model predictive control.展开更多
The municipal solid waste incineration fly ash (MSWI-FA) contains a large amount of heavy metals, and the process of iron ore sintering and treating fly ash needs to pay attention to the migration characteristics of h...The municipal solid waste incineration fly ash (MSWI-FA) contains a large amount of heavy metals, and the process of iron ore sintering and treating fly ash needs to pay attention to the migration characteristics of heavy metals. The impact of the application of MSWI-FA in the sintering process on the emission law of heavy metals in the collaborative treatment process was studied, and corresponding control technologies were proposed. The results showed that the direct addition of water washing fly ash (WM-FA) powder resulted in varying degrees of increase in heavy metal elements in the sinter. As the amount of WM-FA added increases, the content of heavy metal elements correspondingly increases, and an appropriate amount of WM-FA added is 0.5%–1.0%. The migration mechanism of heavy metals during the sintering treatment of WM-FA was clarified. Heavy metals are mainly removed through direct and indirect chlorination reactions, and Cu and Cr can react with SiO_(2) and Fe_(2)O_(3) in the sintered material to solidify in the sinter. Corresponding control techniques have been proposed to reduce the heavy metal elements in WM-FA through the pre-treatment of WM-FA. When the WM-FA was fed in the middle and lower layers of the sintered material, the high temperature of the lower layer was utilized to promote the removal of heavy metals. The Ni element content has decreased from 130 to 90 mg kg^(−1), and the Cd removal rate has increased by 23%. The removal rates of Cd and Cr elements increase by 2.4 and 5.5 times, respectively. There is no significant change in sintering indexes.展开更多
In this paper,the dynamic evolution for a dualarm space robot capturing a spacecraft is studied,the impact effect and the coordinated stabilization control problem for postimpact closed chain system are discussed.At f...In this paper,the dynamic evolution for a dualarm space robot capturing a spacecraft is studied,the impact effect and the coordinated stabilization control problem for postimpact closed chain system are discussed.At first,the pre-impact dynamic equations of open chain dual-arm space robot are established by Lagrangian approach,and the dynamic equations of a spacecraft are obtained by Newton-Euler method.Based on the results,with the process of integral and simplify,the response of the dual-arm space robot impacted by the spacecraft is analyzed by momentum conservation law and force transfer law.The closed chain system is formed in the post-impact phase.Closed chain constraint equations are obtained by the constraints of closed-loop geometry and kinematics.With the closed chain constraint equations,the composite system dynamic equations are derived.Secondly,the recurrent fuzzy neural network control scheme is designed for calm motion of unstable closed chain system with uncertain system parameter.In order to overcome the effects of uncertain system inertial parameters,the recurrent fuzzy neural network is used to approximate the unknown part,the control method with H∞tracking characteristic.According to the Lyapunov theory,the global stability is demonstrated.Meanwhile,the weighted minimum-norm theory is introduced to distribute torques guarantee that cooperative operation between manipulators.At last,numerical examples simulate the response of the collision,and the efficiency of the control scheme is verified by the simulation results.展开更多
基金financially supported by the Major Science and Technology-Special Plan“Unveiling and Leading”Project of Shanxi Province(No.202201050201011)National Natural Science Foundation of China(No.52274316)+4 种基金China Baowu Low-Carbon Metallurgy Innovation Foundation(No.BWLCF202116)National Key R&D Program of China(No.2022YFE0208100)Major Science and Technology Project of Xinjiang(No.2022A01003)Major Science and Technology Projects of Anhui Province(No.202210700037)Special Funding for Science and Technology of China Minmetals Corporation(No.2021ZXD01).
文摘Under the background of the strategic goal of"double carbon,"the carbon reduction and consumption reduction of the iron and steel industry,especially in the ironmaking process,need to be further improved.The raceway of tuyere provides the chemical environment,fuel and power source for blast furnace smelting.The research on the characteristics of its action mode and mechanism is of great significance to clarify the way of reducing carbon and consumption of blast furnace.In general,the formation mechanism,energy distribution,research progress,extended resource injection and directional regulation are studied and expounded.The research results of various scholars on the characteristics of the raceway show that the raceway is a complex process including multiphase turbulent flow,heat,momentum,mass and homogeneous and heterogeneous chemical reactions.With the development of multi-source fuel injection technology,the complexity of problem research is more obvious.Therefore,the collection of multi-factor,multi-directional and multi-process characteristic information in the raceway can provide guarantee for the stability,smooth operation,high yield,carbon reduction and consumption reduction of blast furnace and provide new ideas for the green and low-carbon development of iron and steel industry.
基金supported by the National Natural Science Foundation of China,China(No.U21B2062).
文摘High-quality reservoirs with sufficient physical properties of ultra-deep tight gas reservoirs in the Lower Cretaceous Bashijiqike Formation exhibit significant relationship with gas production across the Dabei Gas Field.Clarifying the characteristics,controlling factors,evolution and distribution of the high-quality reservoirs is important for the deployment of"sweet spots".An integrated approach of petrography,SEM,cathode luminescence,XRD,physical property,NMR experiment,well logs and 3D pre-stack depth migration data was carried out.This study examined the sedimentation,diagenesis,tectonism,gypsumrock and overpressure to reveal the formation and distribution of the high-quality reservoirs.The sandstones are very fine-to coarse-grained lithic arkose.The variation in detrital grains texture and mineralogical composition affects diagenetic evolution,pore structure and gas-bearing characteristic.Three diagenetic facies(diagenetic facies A to C)are classified.Different diagenetic facies underwent different evolution of reservoir quality.The medium-fine to medium-grained lithic arkose(diagenetic facies A)underwent medium vertical compaction,tectonic compression and cementation,and exhibited relatively porous,which makes partial primary pores preserved with the occurrence and persistence of overpressure.Conversely,the very fine to fine-grained and mud gravel-rich medium-grained lithic arkose(diagenetic facies B)and diagenetic facies C appeared premature densification by strong compaction and tight carbonate cementation,respectively,which makes them free from overpressure effects.Natural fractures increased the permeability by several orders of magnitude.Gypsum-rock weakened the vertical compaction and tectonic compression,and delayed cementation,promoted and preserved overpressure.With the injection of internal high alkaline fluids,anhydrite/dolomite cements/veins and dissolution of siliceous developed.Diagenetic facies A exhibited sufficient physical properties and gas volume,making it the high-quality reservoir in tight gas sandstone.Diagenetic facies B and C mainly were used as barriers for hydrocarbon charging.Diagenetic facies A was mainly distributed in the middle-lower part of distributary channel or the middle-upper part of mouth bar.This distribution model provides guidance for exploration in ultra-deep tight sandstone gas reservoir.
文摘The development characteristics of Semiothisa cinerearia Bremer ＆ Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and actively carrying out comprehensive management to control the pests damage in the economic permissible level.
基金Supported by the Effect and Mechanism of Gel-based Controlled Release Fertilizers on Controlling the Nutrient Loss in Soil Erosion (10501-291)Research and Demonstration of New Special Fertilizer for Seawater Fishes and Shellfish (2012-931)+1 种基金Key Techniques and Demonstration of Tobacco Controlled Release Fertilizer Industrialization (2012-045)Research and Application of Gel-based Controlled Release Fertilizers (2002N002)~~
文摘[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers （CRFs） on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to investigate the agronomic characteristics and physiological indices of corn fertilized with controlled release fertilizers compared with conventional fertilizer （CF）. [Result] Plant height, stem girth, leaf area and root volume of corn were significantly increased under the CRF treatments; photosynthetic rate and soluble protein content were also improved. Dry matter accumulations under the two CRF treatments were increased by 21.3% and 17.0% compared with CF application at one time （CF1）, and 19.6% and 15.4% with CF application at two times （CF2）, respectively. Accumulation amounts of N, P and K in whole plant under the two CRF treatments were increased by 44.0% -24.7% , 40.0%-25.9% and 20.1% -13.9% ; and the nutrient use efficiencies of N, P and K were improved by 22.9% -13.4% , 11.2% -9.6% and 17.5% -12.1% , respectively. [Conclusion] The results implied that the CRFs could significantly improve nutrient use efficiency and plant yield.
基金Key R&D and Transformation Program of Tibet,No.XZ201901NB08Major Science and Technology Project of Tibet,No.XZ201901NA03,No.XZ201801NA02
文摘The special geography and human environment of the Qinghai-Tibet Plateau has created the unique hydrochemical characteristics of the region’s natural water,which has been preserved in a largely natural state.However,as the intensity of anthropogenic activities in the region has continued to increase,the water environment and hydrochemical characteristics of the Qinghai-Tibet Plateau have altered.In this study,water samples from the western,southern,and northeastern border areas of the Qinghai-Tibet Plateau,where human activities are ongoing,were collected,analyzed,and measured.The regional differences and factors controlling them were also investigated.The key results were obtained as follows.(1) Differences in the physical properties and hydrochemical characteristics,and their controlling factors,occurred in the different boundary areas of the Qinghai-Tibet Plateau.These differences were mainly the consequence of the geographical environment and geological conditions.(2) The water quality was good and suitable for drinking,with most samples meeting GB (Chinese national) and WHO (World Health Organization) drinking water standards.(3) The chemical properties of water were mainly controlled by the weathering of carbonates and the dissolution of evaporative rocks,with the former the most influential.(4) The biological quality indicators of natural water in the border areas were far superior to GB and WHO drinking water standards.
基金This work was supported by the National Natural Science Foundation of China under grant No.50177019by the Education Department of China under grant No.20040142004.
文摘The static and dynamic magnetic controlling characteristics of NiMnGa magnetically controlled shape memory alloy （MSMA） were experimentally studied. The results show that the characteristics of induced strain with respect to the magnetic field are nonlinear with saturation nature, and dependent on the temperature as well as the load applied to the MSMA. The magnetic shape memory effect can be observed only in complete martensite phase at room temperature. The magnetic permeability of MSMA is not constant and reduces with the increment of magnetic field. The relative saturation magnetic permeability of MSMA is about 1.5.
文摘Active magnetic bearings （AMBs） have found a wide range of applications in high-speed rotating machinery industry. The instability and nonlinearity of AMBs make controller designs difficult, and when AMBs are coupled with a flexible rotor, the resulting complex dynamics make the problems of stabilization and disturbance rejection, which are critical for a stable and smooth operation of the rotor AMB system, even more difficult. Proportional-integral-derivative （PID） control dominates the current AMB applications in the field. Even though PID controllers are easy to implement, there are critical performance limitations associated with them that prevent the more advanced applications of AMBs, which usually require stronger robustness and performance offered by modern control methods such as H-infinity control and if-synthesis. However, these advanced control designs rely heavily on the relatively accurate plant models and uncertainty characterizations, which are sometimes difficult to obtain. In this paper, we explore and report on the use of the characteristic model based all-coefficient adaptive control method to stabilize a flexible rotor AMB test rig. In spite of the simple structure of such a characteristic model based all-coefficient adaptive controller, both simulation and experimental results show its strong performance.
文摘Although anastomosing fluvial rivers are given much attention recently by some research workers because the result channel sandstone of which is one typical primary reservoirs of petroleum and natural gas, of which the flood plains and the interchannel wetlands are pay zones where coals had formed, the comprehension of anastomosing river is some extent limited at present. Some researchers regard that the anastomosing river river and the anabranched river are the same kind of rivers. In this paper, the sedimentary, geomorphic and hydraulic characteristics and the main controlling factors of anastomosing fluvial system are summarized systematically. Some of the characteristics are compared with others fluvial rivers. Humid climate is suitable to form anastomosing channel systems, in arid semiarid regions anastomosing river maybe develop if many befitting factors combine together. The authors of the paper think that anastomosing river is one typical channel pattern and is dissimilar to anabranched channel pattern.
基金supported by the National High Technology Research and Development Program of China (863)(grant no.2007AA06Z220)Important Project of the Ministry of Education(grant no.307014)the Huainan Mining Group program
文摘Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer.
文摘The movement characteristics and control response of oblique wing aircraft(OWA) are highly coupled between the longitudinal and lateral-directional axes and present obvious nonlinearity. Only with the implementation of flight control systems can flying qualities be satisfied. This article investigates the dynamic modeling of an OWA and analyzes its dynamic characteristics.Furthermore, a flight control law based on model-reference dynamic inversion is designed and verified. Calculations and simulations show that OWA can be trimmed by rolling a bank angle and deflecting the triaxial control surfaces in a coordinated way. The oblique wing greatly affects longitudinal motion. The short-period mode is highly coupled between longitudinal and lateral motion,and the bank angle also occurs in phugoid mode. However, the effects of an oblique wing on lateral mode shape are relatively small. For inherent control characteristics, symmetric deflection of the horizontal tail will generate not only longitudinal motion but also a large rolling rate. Rolling moment and pitching moment caused by aileron deflection will reinforce motion coupling, but rudder deflection has relatively little effect on longitudinal motion. Closed-loop simulations demonstrate that the flight control law can achieve decoupling control for OWA and guarantee a satisfactory dynamic performance.
基金the National Natural Science Foundation of China(Grant No.41572087)。
文摘The Cenozoic continental strata of the Bohai Bay Basin are rich in shale oil resources, and they contain various types of reservoir spaces that are controlled by complex factors. Using field emission scanning electron microscopy(FESEM), automatic mineral identification and characterization system(AMICS), CO2 and N2 gas adsorption, and focused ion beam scanning electron microscopy(FIB-SEM), the types of shale reservoir spaces in the Bohai Bay Basin are summarized, the spatial distribution and connectivity of the various types of pores are described in detail, the microscopic pore structures are characterized, and the key geological mechanisms affecting the formation and evolution of the reservoir spaces are determined. Three conclusions can be drawn in the present study. First, the shale reservoir spaces in the Bohai Bay Basin can be divided into three broad categories, including mineral matrix pores, organic matter pores, and micro fractures. Those spaces can be subdivided into seven categories and fourteen sub-categories based on the distribution and formation mechanisms of the pores. Second, the complex pore-throat structures of the shale reservoir can be divided into two types based on the shape of the adsorption hysteresis loop. The pore structures mainly include wedge-shaped, flat slit-shaped, and ink bottle-shaped pores. The mesopores and micropores are the main contributors to pore volume and specific surface area, respectively. The macropores provide a portion of the pore volume, but they do not significantly contribute to the specific surface area. Third, the factors controlling the development of microscopic pores in the shale are complex. The sedimentary environment determines the composition and structure of the shale and provides the material basis for pore development. Diagenesis controls the types and characteristics of the pores. In addition, the thermal evolution of the organic matter is closely related to inorganic diagenesis and drives the formation and evolution of the pores.
基金Project(61273138)supported by the National Natural Science Foundation of ChinaProject(14JCZDJC39300)supported by the Key Fund of Tianjin,China
文摘One of the primary difficulties in using powered parafoil(PPF) systems is the lack of effective trajectory tracking controllers since the trajectory tracking control is the essential operation for PPF to accomplish autonomous tasks. The characteristic model(CM) based all-coefficient adaptive control(ACAC) designed for PPF systems in horizontal and vertical trajectory control is proposed. The method is easy to use and convenient to adjust and test. Just a few parameters are adapted during the control process. In application, vertical and horizontal CMs are designed and ACAC controllers are constructed to control vertical altitude and horizontal trajectory of PPF based on the proposed CMs, respectively. Result analysis of different simulations shows that the applied ACAC control method is effective for trajectory tracking of the PPF systems and the approach guarantees the transient performance of the PPF systems with better disturbance rejection ability.
文摘Thermodynamic characteristics are of great importance for the performance of a high-temperature flow-rate control valve,as high-temperature environment may bring problems,such as blocking of spool and increasing of leakage,to the valve.In this paper,a high-temperature flow-rate control valve,pilot-controlled by a pneumatic servo system is developed to control the fuel supply for scramjet engines.After introducing the construction and working principle,the thermodynamic mathematical models of the valve are built based on the heat transfer methods inside the valve.By using different boundary conditions,different methods of simulations are carried out and compared.The steady-state and transient temperature field distribution inside the valve body are predicted and temperatures at five interested points are measured.By comparing the simulation and experimental results,a reasonable 3D finite element analysis method is suggested to predict the thermodynamic characteristics of the high-temperature flow-rate control valve.
文摘To study the rolling control characteristics of a canard-controlled missile, a series of wind tunnel experiment is conducted. The experimental method, the structure features of wind tunnel model and the experimental results are introduced in this paper. The experimental data show that the canard is an inefficient rolling control device for canard-controlled missile with fixed tail fins; but for the free-spinning tail fin configuration, the canard can conduct rolling control of the missile, and even have higher controlling efficiency under larger canard deflection angle.
基金financially supported by the CNPC Prospective Basic Science and Technology Special Project(2023ZZ08)the Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(2020CX050103)。
文摘Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated.
文摘In order to study the failure characteristics and control method of deep tunnel surrounding rock, based on the stress test, the structure and stress state of the main transportation tunnel surrounding rock in Mine Zhaogezhuang level 14 was analyzed, and it shows that the surrounding rock is exposed to an interphase hard and soft disadvantageous structure state and complex high stress repeated addition area;Through the theoretical analysis and the statistical data, the relation between the tunnel stress transformation and the surrounding rock deformation was proposed;Through the numerical simulation of the tunnel surrounding rock failure process with the help of RFPA procedure, the results show that the damage of the transportation tunnel level 14 mainly occurs in the bottom and the two coal ribs, and the failure process is spreading from the bottom to the two coal ribs, and the effect of the surrounding rock deformation control is obvious by using the way of 2.5 m anchor with 1.0 m grouting strengthening.
基金Supported by the National Science and Technology Major Project(2017ZX05009-005-003)National Natural Science Foundation of China Funded General Project(52174045)+1 种基金Chinese Academy of Engineering Strategic Consulting Project(2018-XZ-09)China Nation al Petroleum Cor-poration-China University of Petroleum(Beijing)Strategic Cooperation Science and Technology Project(ZLZX2020-01)。
文摘Microscopic computed tomography(Micro-CT)is used to visualize microscopic flow in sandstone core samples during emulsion flooding.The images obtained during the experiment are processed quantitatively with a series of methods to evaluate the occurrence characteristics and oil recovery enhancement mechanisms of emulsion.(1)The emulsion is distributed in the cores in spherical shape,and its sphericity is significantly different from that of the remaining oil.Sphericity can be taken as a characteristic parameter to identify emulsion.(2)The emulsion with specific size prefers to stay in pores with matching sizes;when the emulsion volume is smaller than the product of the lower limit of pore occupancy and the corresponding pore vol-ume,it will not be able to effectively trap in the pore to achieve conformance control.In the process of emulsion displacement designing,we need to design emulsion with suitable particle size according to the pore distribution of the reservoir.(3)Mobi-lization ratio of the pores can be increased from 23.1%to 59.3%by emulsion flooding after subsequent water flooding,and the average oil displacement efficiency at the pore-scale can be increased from 22.9%to 75.8%under the test conditions;(4)After emulsion flooding,the clustered remaining oil and the oil phase in the trapped emulsion are the main targets for further EOR.
基金the National Key Research and Development Plan(No.2017YFB0102500)the Tianjin Science and Technology Commission Artificial Intelligence Major Project(No.17ZRXGGX00130)the Key Issues of China Automotive Technology and Research Center Co.,Ltd.(No.16190125)
文摘As the traditional control algorithm is over-dependent on accurate vehicle model in intelligent vehicle steering control,a human-simulated intelligent control method is proposed based on experienced driver steering characteristics.Intelligent vehicle unmanned steering system dynamics model and the driver model are set up.Through experienced drivers'trial run experiment,the analysis is mainly conducted on the double lanes condition.After the transformation of coordinates on global positioning system(GPS)derivative,the path information of local coordinates is accessed.The ideal driver steering path is obtained through fuzzy C-means clustering algorithm.The human-simulated intelligent controller is designed.Characteristic model is established according to the ideal and practical steering angle deviation and the deviation rate.Besides,the corresponding control rules and control modality set are designed.The joint simulation under CarSim joint/Simulink environment shows that the humanoid steering controller designed in this paper has better tracking performance than the model predictive control.
基金supported by the National Natural Science Foundation of China(No.52274344)the Science and Technology Innovation Program of Hunan Province(2023RC3042)Provincial Natural Science Foundation of Hunan(Nos.2022JJ30723 and 2023JJ20068).
文摘The municipal solid waste incineration fly ash (MSWI-FA) contains a large amount of heavy metals, and the process of iron ore sintering and treating fly ash needs to pay attention to the migration characteristics of heavy metals. The impact of the application of MSWI-FA in the sintering process on the emission law of heavy metals in the collaborative treatment process was studied, and corresponding control technologies were proposed. The results showed that the direct addition of water washing fly ash (WM-FA) powder resulted in varying degrees of increase in heavy metal elements in the sinter. As the amount of WM-FA added increases, the content of heavy metal elements correspondingly increases, and an appropriate amount of WM-FA added is 0.5%–1.0%. The migration mechanism of heavy metals during the sintering treatment of WM-FA was clarified. Heavy metals are mainly removed through direct and indirect chlorination reactions, and Cu and Cr can react with SiO_(2) and Fe_(2)O_(3) in the sintered material to solidify in the sinter. Corresponding control techniques have been proposed to reduce the heavy metal elements in WM-FA through the pre-treatment of WM-FA. When the WM-FA was fed in the middle and lower layers of the sintered material, the high temperature of the lower layer was utilized to promote the removal of heavy metals. The Ni element content has decreased from 130 to 90 mg kg^(−1), and the Cd removal rate has increased by 23%. The removal rates of Cd and Cr elements increase by 2.4 and 5.5 times, respectively. There is no significant change in sintering indexes.
基金supported by the National Natural Science Foundation of China(11372073,11072061)。
文摘In this paper,the dynamic evolution for a dualarm space robot capturing a spacecraft is studied,the impact effect and the coordinated stabilization control problem for postimpact closed chain system are discussed.At first,the pre-impact dynamic equations of open chain dual-arm space robot are established by Lagrangian approach,and the dynamic equations of a spacecraft are obtained by Newton-Euler method.Based on the results,with the process of integral and simplify,the response of the dual-arm space robot impacted by the spacecraft is analyzed by momentum conservation law and force transfer law.The closed chain system is formed in the post-impact phase.Closed chain constraint equations are obtained by the constraints of closed-loop geometry and kinematics.With the closed chain constraint equations,the composite system dynamic equations are derived.Secondly,the recurrent fuzzy neural network control scheme is designed for calm motion of unstable closed chain system with uncertain system parameter.In order to overcome the effects of uncertain system inertial parameters,the recurrent fuzzy neural network is used to approximate the unknown part,the control method with H∞tracking characteristic.According to the Lyapunov theory,the global stability is demonstrated.Meanwhile,the weighted minimum-norm theory is introduced to distribute torques guarantee that cooperative operation between manipulators.At last,numerical examples simulate the response of the collision,and the efficiency of the control scheme is verified by the simulation results.
