In repeated zero-sum games,instead of constantly playing an equilibrium strategy of the stage game,learning to exploit the opponent given historical interactions could typically obtain a higher utility.However,when pl...In repeated zero-sum games,instead of constantly playing an equilibrium strategy of the stage game,learning to exploit the opponent given historical interactions could typically obtain a higher utility.However,when playing against a fully adaptive opponent,one would have dificulty identifying the opponent's adaptive dynamics and further exploiting its potential weakness.In this paper,we study the problem of optimizing against the adaptive opponent who uses no-regret learning.No-regret learning is a classic and widely-used branch of adaptive learning algorithms.We propose a general framework for online modeling no-regret opponents and exploiting their weakness.With this framework,one could approximate the opponent's no-regret learning dynamics and then develop a response plan to obtain a significant profit based on the inferences of the opponent's strategies.We employ two system identification architectures,including the recurrent neural network(RNN)and the nonlinear autoregressive exogenous model,and adopt an efficient greedy response plan within the framework.Theoretically,we prove the approximation capability of our RNN architecture at approximating specific no-regret dynamics.Empirically,we demonstrate that during interactions at a low level of non-stationarity,our architectures could approximate the dynamics with a low error,and the derived policies could exploit the no-regret opponent to obtain a decent utility.展开更多
This research was to introduce the characteristics of and countermeasures for ecological compensation. From the analysis of the current situation of ecological compensation, a series of characteristics of ecological c...This research was to introduce the characteristics of and countermeasures for ecological compensation. From the analysis of the current situation of ecological compensation, a series of characteristics of ecological compensation in resource exploitation and economic development were elaborated. The principles and practical issues are complex in ecological compensation, and the corresponding object, entity, financial system of ecological compensation are the keys to set up compensation mechanism, and studying of ecosystem service function and ecological footprint calculation are important ways to quantitatively assess ecological compensation, and are also important foundations for establishing calculation system of green GDP. Advocating the benefit compensation mechanism of ecological economy and enclosing ecological compensation principle are important ways for establishing the new environmental management pattern and manifesting social justice and the ecological civilization ideas. This research proposed some views of and approaches to ecological compensation mechanism for constructing natural resource development and utilization.The establishment of ecological compensation is an important approach to prevent the imbalance of resource allocation, the system guarantee for sustainable development, and the important basis of saving resources.展开更多
The global burden of cancer,with over 19 million new cases annually,underscores the urgent need for effective therapies.Among the most promising anticancer compounds is camptothecin(CPT),a monoterpene alkaloid predomi...The global burden of cancer,with over 19 million new cases annually,underscores the urgent need for effective therapies.Among the most promising anticancer compounds is camptothecin(CPT),a monoterpene alkaloid predominantly derived from Nothapodytes species.Despite its significantpharmaceutical value,the exploitation of such Threatened Plant Species with Widespread Distribution(TPSWD),particularly driven by the global demand for natural compounds in anticancer therapies,presents a paradox in which their widespread distribution fails to ensure their secure conservation status.Furthermore,the lack of in-depth biogeographic and systematic studies complicates efforts to balance resource utilization with biodiversity preservation.The asymmetric distribution of CPT within plant taxa,along with limited knowledge of its biosynthetic pathways and the enzymes and genes involved,further hampers sustainable production.Here,we review the current knowledge on the production and protection of Nothapodytes,focusing on their plant resources,active ingredients,and natural drug derivatives.We also explore strategies for rescuing and sustainably utilizing Nothapodytes,including biotechnological advancements and integrated conservation practices.Finally,we propose future directions to address conservation challenges,ensuring a sustainable supply of CPT while safeguarding these TPSWD species.展开更多
Regional Sustainability(ISSN 2097-0129;CN 65-1317/X)is an international,peer-reviewed and open access journal publishing high-quality articles in multi-disciplinary and interdisciplinary subjects relating to sustainab...Regional Sustainability(ISSN 2097-0129;CN 65-1317/X)is an international,peer-reviewed and open access journal publishing high-quality articles in multi-disciplinary and interdisciplinary subjects relating to sustainability.The journal advances our understanding of the sustainability dimensions of environmental protection,economic development,and social development.It publishes theoretical and experimental research papers on resources exploitation and utilization,environment pollution and management,biodiversity conservation,ecosystem function and services,land use and land use change,forestry sustainability,soil and water conservation,climate change.展开更多
This paper introduces a novel nature-inspired metaheuristic algorithm called the Gekko japonicus algorithm.The algo-rithm draws inspiration mainly from the predation strategies and survival behaviors of the Gekko japo...This paper introduces a novel nature-inspired metaheuristic algorithm called the Gekko japonicus algorithm.The algo-rithm draws inspiration mainly from the predation strategies and survival behaviors of the Gekko japonicus.The math-ematical model is developed by simulating various biological behaviors of the Gekko japonicus,such as hybrid loco-motion patterns,directional olfactory guidance,implicit group advantage tendencies,and the tail autotomy mechanism.By integrating multi-stage mutual constraints and dynamically adjusting parameters,GJA maintains an optimal balance between global exploration and local exploitation,thereby effectively solving complex optimization problems.To assess the performance of GJA,comparative analyses were performed against fourteen state-of-the-art metaheuristic algorithms using the CEC2017 and CEC2022 benchmark test sets.Additionally,a Friedman test was performed on the experimen-tal results to assess the statistical significance of differences between various algorithms.And GJA was evaluated using multiple qualitative indicators,further confirming its superiority in exploration and exploitation.Finally,GJA was utilized to solve four engineering optimization problems and further implemented in robotic path planning to verify its practical applicability.Experimental results indicate that,compared to other high-performance algorithms,GJA demonstrates excep-tional performance as a powerful optimization algorithm in complex optimization problems.We make the code publicly available at:https://github.com/zhy1109/Gekko-japonicusalgorithm.展开更多
Fluid seepage and associated heat transfer within the enhanced geothermal system(EGS)regulate the extraction of heat from hot,low-water-saturation thermal reservoirs,sometimes referred to as hot dry rock(HDR).To under...Fluid seepage and associated heat transfer within the enhanced geothermal system(EGS)regulate the extraction of heat from hot,low-water-saturation thermal reservoirs,sometimes referred to as hot dry rock(HDR).To understand these complex heat recovery processes,we simulated long-term heat extraction in a surrogate HDR using a true triaxial apparatus.A circulation test was first implemented to analyze the connectivity between different wells.Suitable injection and production wells were then selected for the laboratory heat extraction tests in granite,which lasted 14.5 h.Under variable injection rate conditions,we systematically analyzed the time-varying curves of temperature and flow rate in the production wells and pressure in the injection wells.Our findings showed that the advantage channel was dominant in the flow distribution when several paths existed in EGS.Changes in fracture conductivity are attributed to injection pressure.These included an increase in fracture width and activation of a localized closed area of fracture.These two mechanisms influenced the production temperature,and this is consistent with the field data monitored at the Fenton Hill and Hijiori projects.Fluid leak-off was an important factor affecting the production flow rate.For a fracture with low hydraulic conductivity,a lower injection rate could effectively prevent excessive fluid leak-off.In addition,by comparing injection rates and fluid recovery rates,production wells in different phases or injection modes had different fluid recovery rates even when the injection rates were the same.展开更多
Carbonate gas reservoirs are often characterized by strong heterogeneity,complex inter-well connectivity,extensive edge or bottom water,and unbalanced production,challenges that are also common in many heterogeneous g...Carbonate gas reservoirs are often characterized by strong heterogeneity,complex inter-well connectivity,extensive edge or bottom water,and unbalanced production,challenges that are also common in many heterogeneous gas reservoirs with intricate storage and flow behavior.To address these issues within a unified,data-driven framework,this study develops a multi-block material balance model that accounts for inter-block flow and aquifer influx,and is applicable to a wide range of reservoir types.The model incorporates inter-well and well-group conductive connectivity together with pseudo–steady-state aquifer support.The governing equations are solved using a Newton–Raphson scheme,while particle swarm optimization is employed to estimate formation pressures,inter-well connectivity,and effective aquifer volumes.An unbalanced exploitation factor,UEF,is introduced to quantify production imbalance and to guide development optimization.Validation using a synthetic reservoir model demonstrates that the approach accurately reproduces pressure evolution,crossflow behavior,and water influx.Application to a representative case(the Longwangmiao)field further confirms its robustness under highly heterogeneous conditions,achieving a 12.9%reduction in UEF through optimized production allocation.展开更多
Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of mineral...Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of minerals,with reserves of at least 38 of over 80 widely used minerals worldwide accounting for more than30%of the global total reserves.Asia continent experienced three main tectonic evolution and mineralization stages:The Precambrian,the Paleozoic,and the Mesozoic to Cenozoic.The abundant mineral resources in this continent can be divided into seven first-order metallogenic belts(metallogenic domains),18 second-order metallogenic belts(metallogenic provinces),61 third-order metallogenic belts(metallogenic zones),and nine main minerogenetic series.Asia continent exhibits the most significant metallogenic specialization among all continents.Specifically,granite belts of Asia continent manifest pronounced metallogenic specialization of tin,rare metals,and porphyry Cu-Au-Mo deposits.Its maficultramafic rock belts and ophiolite belts display notable metallogenic specialization of lateritic nickel deposits and magmatic type chromite deposits,while its Mesozoic to Cenozoic basalt belts show remarkable metallogenic specialization of lateritic bauxite deposits.Consequently,many giant metallogenic belts were formed,including the Southeast Asian tin belt,the Qinghai-Xizang Plateau rare metal metallogenic belt,the Tethyan porphyry Cu-Au-Mo metallogenic belt,the circum-Pacific porphyry Cu-Au-Mo metallogenic belt,the Southeast Asian lateritic bauxite metallogenic belt,the Deccan Plateau lateritic bauxite metallogenic belt in India,the Southeast Asian lateritic nickel metallogenic belt,and the Tethyan magmatic type chromite metallogenic belt—all of which are significant metallogenic belts in Asia continent.Future mineral exploration in Asia should focus primarily on the Precambrian mineralization of ancient cratons,the Paleozoic mineralization of the Central Asian-Mongolian orogenic belt,and the Mesozoic to Cenozoic mineralization of the Tethyan and circum-Pacific mobile belts.Asia's mining industry not only underpins its own economic growth but also propels global economic development and industrialization,contributing significantly to the world economy.Asia boasts the highest production value of minerals,the largest annual production of minerals,and the greatest trade value of mineral products among all the continents,having emerged as the trade center of global mineral products and the center of the mining industry economy.China is identified as one of the few countries that possess the most comprehensive kinds of minerals,and its mining industry has supported and driven the economic development and industrialization of Asia and even the world.Standing as the largest mineral producer worldwide,China ranked first in the production of 28 mineral commodities in the world in 2022.Besides,China exhibits the highest annual production value of minerals and the largest trade value of mineral products among all countries.Therefore,China's demand for global mineral products influences the global supply and demand patterns of minerals and the world economic situation.展开更多
Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer （salt deposit） in Qarhan Salt Lake was studied by using the Pitzer theory. Th...Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer （salt deposit） in Qarhan Salt Lake was studied by using the Pitzer theory. The concept of macroscopic solubility product and its relation with accumulated ore dissolving ratio were presented, which are used in the numerical model of dissolving and driving exploitation of potassium salt in Qarhan Salt Lake. And secondly, with a model forming idea of transport model for reacting solutes in the multi-component fresh groundwater system in porous media being a reference, a two-dimensional transport model coupled with a series of chemical reactions in a multi-component brine porous system （salt deposits） was developed by using the Pitzer theory. Meanwhile, the model was applied to model potassium/magnesium transport in Qarhan Salt Lake in order to study the transfer law of solid and liquid phases in the dissolving and driving process and to design the optimal injection/abstraction strategy for dissolving and capturing maximum Potassium/ Magnesium in the mining of salt deposits in Qarhan Salt Lake.展开更多
An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve misc...An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.展开更多
Sand production is a crucial problem during the process of extracting natural gas from hydrate reservoirs. To deal with sand-production problems systematically, a sand-production control system (SCS) is first proposed...Sand production is a crucial problem during the process of extracting natural gas from hydrate reservoirs. To deal with sand-production problems systematically, a sand-production control system (SCS) is first proposed in this paper, specialized for pore-distributed clayey silt hydrate reservoirs. Secondly, a nodal system analysis method (NSAM) is applied to analyze the sand migration process during hydrate exploitation. The SCS is divided into three sub-systems, according to different sand migration mechanisms, and three key scientific problems and advances in SCS research in China Geological Survey are reviewed and analyzed. The maximum formation sanding rate, proper sand-control gravel size, and borehole blockage risk position were provided for clayey hydrate exploitation wells based on the SCS analysis. The SCS sub-systems are closely connected via bilateral coupling, and coordination of the subsystems is the basis of maintaining formation stability and prolonging the gas production cycle. Therefore, contradictory mitigation measures between sand production and operational systems should be considered preferentially. Some novel and efficient hydrate exploitation methods are needed to completely solve the contradictions caused by sand production.展开更多
In the current data-intensive era, the traditional hands-on method of conducting scientific research by exploring related publications to generate a testable hypothesis is well on its way of becoming obsolete within j...In the current data-intensive era, the traditional hands-on method of conducting scientific research by exploring related publications to generate a testable hypothesis is well on its way of becoming obsolete within just a year or two. Analyzing the literature and data to automatically generate a hypothesis might become the de facto approach to inform the core research efforts of those trying to master the exponentially rapid expansion of publications and datasets. Here, viewpoints are provided and discussed to help the understanding of challenges of data-driven discovery.展开更多
Environmental tracers are proving to be a unique tool for assessing groundwater sustainability, such as characterization of recharge, identification of pathways and sources of contaminants, and prediction of groundwat...Environmental tracers are proving to be a unique tool for assessing groundwater sustainability, such as characterization of recharge, identification of pathways and sources of contaminants, and prediction of groundwater change in response to excessive abstraction. This paper helps to better understand the groundwater sustainability in the Quaternary aquifer from the tracer data in the North China Plain. Relatively modern ground waters occur in the piedmont plain with 3H-3He age less than 40 a within a depth 100 m. These ground waters are mainly recharged from the local precipitation and irrigation return. The recharge rate estimated by tracers is in the range of 0.24 to 0.32 m/a. Paleowater which is dated from 10 000 a B.P. to more than 35 000 a B.P. by radiocarbon dating is found in highly-confined portions of Quaternary aquifer systems. This indicates that water recharge took place during the past glacial period. The tracers have suggested a slow natural replenishment rates to the central plain. The aquifer has been overexploited currently. Some strategies that can be implemented to promote a sustainable groundwater supply are needed to implement in future.展开更多
Based on the ArcGIS geographic information system and the ORACLE database management system,this paper reports our studies on the technology of Marine Engineering Geological Exploration Information System(MEGEIS). By ...Based on the ArcGIS geographic information system and the ORACLE database management system,this paper reports our studies on the technology of Marine Engineering Geological Exploration Information System(MEGEIS). By analyzing system structure,designing function modules and discussing data management,this paper systematically proposes a framework of technol-ogy to integrate,manage,and analyze the seabed information comprehensively. Then,the technology is applied to the design and development of the Bohai Sea Oilfield Paradigm Area Information System. The system can not only meet the practical demands of marine resources exploration and exploitation in the Bohai Sea oilfield,but also serve as a preparatory work in theory and technology for the realization of the 'Digital Seabed'.展开更多
The Tahe Oilfield is a complex petroleum reservoir of Ordovician carbonate formation and made up of spatially overlapping fracture-cavity units. The oilfield is controlled by a cave system resulting from structure-kar...The Tahe Oilfield is a complex petroleum reservoir of Ordovician carbonate formation and made up of spatially overlapping fracture-cavity units. The oilfield is controlled by a cave system resulting from structure-karst cyclic sedimentation. Due to significant heterogeneity of the reservoir, the distribution of oil and water is complicated. Horizontally, a fresh water zone due to meteoric water can be found in the north part of the Akekule uplift. A marginal freshening zone caused by water released from mudstone compaction is found at the bottom of the southern slope. Located in a crossformational flow discharge zone caused by centripetal and the centrifugal flows, the main part of the Tahe Oilfield, featuring high salinity and concentrations of CI^- and K^＋＋Na^＋, is favorable for accumulation of hydrocarbon. Three types of formation water in the Tahe Ordovician reservoir are identified： （1） residual water at the bottom of the cave after oil and gas displacement, （2） residual water in fractures/pores around the cave after oil and gas displacement, and （3） interlayer water below reservoirs. The cave system is the main reservoir space, which consists of the main cave, branch caves and depressions between caves. Taking Cave System S48 in the Ordovician reservoir as an example, the paper analyzes the fluid distribution and exploitation performance in the cave system. Owing to evaporation of groundwater during cross-formational flow, the central part of the main cave, where oil layers are thick and there is a high degree of displacement, is characterized by high salinity and Br^- concentration. With high potential and a long stable production period, most wells in the central part of the main cave have a long water-free oil production period. Even after water breakthrough, the water content has a slow or stepwise increase and the hydrochemistral characteristics of the produced water in the central part of the main cave are uniform. From the center to the edge of the main cave, displacement and enrichment of oil/gas become weaker, residual water increases, and the salinity and concentration of Br^- decrease. At the edge of the main cave, although the wells have a high deliverability at the beginning with a short stable production period and water-free production period. After water breakthrough, the pressure and deliverability drop quickly, and the water content rises quickly. The hydrochemistral characteristics of the produced water are relatively uniform. Wells in the branch caves have a relatively low deliverability at the beginning, with a short stable production period. Water breakthrough appears quickly and then the pressure and deliverability drop quickly. The salinity and concentrations of CI^-and K^＋＋Na^＋ are usually fluctuant or descend slowly in the produced water. Wells in low areas of ancient karst have a low deliverability and a short stable production period. The yield drops quickly and the water content is high, while the characteristics of the produced water may vary significantly well to well. The salinity and concentrations of CI^-and K^＋＋Na^＋ in the produced water are usually fluctuant with a precipitous decline.展开更多
Division arithmetic and generalized exploiting modification direction （DA-GEMD） method has perfect efficiency in data-hiding. However, there exist some weaknesses in DA-GEMD. Because the benchmarks are their median ...Division arithmetic and generalized exploiting modification direction （DA-GEMD） method has perfect efficiency in data-hiding. However, there exist some weaknesses in DA-GEMD. Because the benchmarks are their median of nine pixels in each block of cover-image, it will give a hint for the attacker to hack the stego-image. In the paper, we utilize the Sudoku table to randomize the benchmark for each 3×3 block of cover-image. It will mix up the pixels in each image block and prevent the secret information from being extracted. The proposed method still keeps the original efficiency as DA-GEMD while promoting the security for data-hiding.展开更多
Based on the groundwater resources evaluation, the groundwater exploitation potentiality evaluation is aiming at providing references for management, planning and development of groundwater. Traditional evaluation met...Based on the groundwater resources evaluation, the groundwater exploitation potentiality evaluation is aiming at providing references for management, planning and development of groundwater. Traditional evaluation methods mainly adopted individual indicator as a method which cannot fully reflect the affecting factors of the groundwater exploitation potential in a scientific way. The idea that the spatial distribution and dynamic change of groundwater is not only affected by socio-economic development and exploitation technology but also influenced by its regulation is coincided with the niche theory. This paper has preliminarily applied the niche theory to groundwater exploitation potential analysis, and proposed the concept of groundwater niche as well as its related definition, connotation and calculation formula. Meanwhile, by taking the Hebei Plain as an example, the article has made an evaluation of groundwater exploitation potentiality and a contrast with the results of the traditional evaluation methods on the construction of groundwater niche index system, and then verified the feasibility and rationality of this index system. It turns out that, it is truly comprehensive, scientific and rational to make groundwater niche calculation and exploitation potential analysis by using the evaluation index system. Niche theory has provided a new and fundamental attempt for the analysis and competition strategy for the groundwater exploitation potentiality evaluation.展开更多
Sea asparagus is a newly emerging seawater-irrigated vegetable. Firstly, the economic value of sea asparagus was introduced, and then, someexploiting approaches of sea asparagus werefully reviewed. The exploiting appr...Sea asparagus is a newly emerging seawater-irrigated vegetable. Firstly, the economic value of sea asparagus was introduced, and then, someexploiting approaches of sea asparagus werefully reviewed. The exploiting approaches mainly include fresh vegetable, pickle, bio-salt, health-care products, animal feed, vegetable oil, bio-diesel and skin-care products.展开更多
The ecosystem and biodiversity conservation plan in progress in Hiroshima City was reviewed. Hiroshima City had prospered as a castle town, but severely suffered from A bomb damage at the end of World War II. Since th...The ecosystem and biodiversity conservation plan in progress in Hiroshima City was reviewed. Hiroshima City had prospered as a castle town, but severely suffered from A bomb damage at the end of World War II. Since then, Hiroshima City performed greenery activities with restoration and planted trees in public facilities. At present, Hiroshima City is promoting a 3rd tree planting campaign. As part of this campaign, the master plan of greenery of Hiroshima City is being laid. This plan aims not only at beautification in city area but also at ecosystem and biodiversity conservation in expanded city areas. In this paper, we report on the development of the situation in Hiroshima City since the end of World War II and the conservation planning of greenery which, for the most part, concerns zoning.展开更多
More and more accounts or devices are shared by multiple users in video applications,which makes it difficult to provide recommendation service.Existing recommendation schemes overlook multiuser sharing scenarios,and ...More and more accounts or devices are shared by multiple users in video applications,which makes it difficult to provide recommendation service.Existing recommendation schemes overlook multiuser sharing scenarios,and they cannot make effective use of the mixed information generated by multi-user when exploring users’potential interests.To solve these problems,this paper proposes an adaptive program recommendation system for multi-user sharing environment.Specifically,we first design an offline periodic identification module by building multi-user features and periodically predicting target user in future sessions,which can separate the profile of target user from mixed log records.Subsequently,an online recommendation module with adaptive timevarying exploration strategy is constructed by jointly using personal information and multi-user social information provided by identification module.On one hand,to learn the dynamic changes in user-interest,a time-varying linear upper confidence bound(LinUCB)based on personal information is designed.On the other hand,to reduce the risk of exploration,a timeinvariant LinUCB based on separated multi-user social information from one account/device is proposed to compute the quality scores of programs for each user,which is integrated into the time-varying LinUCB by cross-weighting strategy.Finally,experimental results validate the efficiency of the proposed scheme.展开更多
基金the Science and Technology Innovation 2030-"New Generation Artificial Intelligence"Major Project(No.2018AAA0100901)。
文摘In repeated zero-sum games,instead of constantly playing an equilibrium strategy of the stage game,learning to exploit the opponent given historical interactions could typically obtain a higher utility.However,when playing against a fully adaptive opponent,one would have dificulty identifying the opponent's adaptive dynamics and further exploiting its potential weakness.In this paper,we study the problem of optimizing against the adaptive opponent who uses no-regret learning.No-regret learning is a classic and widely-used branch of adaptive learning algorithms.We propose a general framework for online modeling no-regret opponents and exploiting their weakness.With this framework,one could approximate the opponent's no-regret learning dynamics and then develop a response plan to obtain a significant profit based on the inferences of the opponent's strategies.We employ two system identification architectures,including the recurrent neural network(RNN)and the nonlinear autoregressive exogenous model,and adopt an efficient greedy response plan within the framework.Theoretically,we prove the approximation capability of our RNN architecture at approximating specific no-regret dynamics.Empirically,we demonstrate that during interactions at a low level of non-stationarity,our architectures could approximate the dynamics with a low error,and the derived policies could exploit the no-regret opponent to obtain a decent utility.
基金Supported by National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science&Technology(2006BAD26B0902)National Program on Key Basic Research Project(973program)(2006CB705809)+2 种基金Knowledge Innovation Program of the Chinese Academy of Sciences(KSCX-YW-09)Program of Soft Sciences from China Meteorological Administration(QR2008-39)Scientific Re-search Fund of Nanjing University of Information Science and Technology(20070105)~~
文摘This research was to introduce the characteristics of and countermeasures for ecological compensation. From the analysis of the current situation of ecological compensation, a series of characteristics of ecological compensation in resource exploitation and economic development were elaborated. The principles and practical issues are complex in ecological compensation, and the corresponding object, entity, financial system of ecological compensation are the keys to set up compensation mechanism, and studying of ecosystem service function and ecological footprint calculation are important ways to quantitatively assess ecological compensation, and are also important foundations for establishing calculation system of green GDP. Advocating the benefit compensation mechanism of ecological economy and enclosing ecological compensation principle are important ways for establishing the new environmental management pattern and manifesting social justice and the ecological civilization ideas. This research proposed some views of and approaches to ecological compensation mechanism for constructing natural resource development and utilization.The establishment of ecological compensation is an important approach to prevent the imbalance of resource allocation, the system guarantee for sustainable development, and the important basis of saving resources.
基金supported by the National Key R&D Program of China(2024YFF1306700)the Key Project of Basic Research of Yunnan Province,China(202301AS070001)the Regional Innovative Development Joint Fund of NSFC(U23A20149).
文摘The global burden of cancer,with over 19 million new cases annually,underscores the urgent need for effective therapies.Among the most promising anticancer compounds is camptothecin(CPT),a monoterpene alkaloid predominantly derived from Nothapodytes species.Despite its significantpharmaceutical value,the exploitation of such Threatened Plant Species with Widespread Distribution(TPSWD),particularly driven by the global demand for natural compounds in anticancer therapies,presents a paradox in which their widespread distribution fails to ensure their secure conservation status.Furthermore,the lack of in-depth biogeographic and systematic studies complicates efforts to balance resource utilization with biodiversity preservation.The asymmetric distribution of CPT within plant taxa,along with limited knowledge of its biosynthetic pathways and the enzymes and genes involved,further hampers sustainable production.Here,we review the current knowledge on the production and protection of Nothapodytes,focusing on their plant resources,active ingredients,and natural drug derivatives.We also explore strategies for rescuing and sustainably utilizing Nothapodytes,including biotechnological advancements and integrated conservation practices.Finally,we propose future directions to address conservation challenges,ensuring a sustainable supply of CPT while safeguarding these TPSWD species.
文摘Regional Sustainability(ISSN 2097-0129;CN 65-1317/X)is an international,peer-reviewed and open access journal publishing high-quality articles in multi-disciplinary and interdisciplinary subjects relating to sustainability.The journal advances our understanding of the sustainability dimensions of environmental protection,economic development,and social development.It publishes theoretical and experimental research papers on resources exploitation and utilization,environment pollution and management,biodiversity conservation,ecosystem function and services,land use and land use change,forestry sustainability,soil and water conservation,climate change.
基金CHINA POSTDOCTORAL SCIENCE FOUNDATION(Grant No.2025M771925)Young Scientists Fund(C Class)(Grant No.32501636)Special Fund of Fundamental Scientific Research Business Expense for Higher School of Central Government(Grant No.2572025JT04).
文摘This paper introduces a novel nature-inspired metaheuristic algorithm called the Gekko japonicus algorithm.The algo-rithm draws inspiration mainly from the predation strategies and survival behaviors of the Gekko japonicus.The math-ematical model is developed by simulating various biological behaviors of the Gekko japonicus,such as hybrid loco-motion patterns,directional olfactory guidance,implicit group advantage tendencies,and the tail autotomy mechanism.By integrating multi-stage mutual constraints and dynamically adjusting parameters,GJA maintains an optimal balance between global exploration and local exploitation,thereby effectively solving complex optimization problems.To assess the performance of GJA,comparative analyses were performed against fourteen state-of-the-art metaheuristic algorithms using the CEC2017 and CEC2022 benchmark test sets.Additionally,a Friedman test was performed on the experimen-tal results to assess the statistical significance of differences between various algorithms.And GJA was evaluated using multiple qualitative indicators,further confirming its superiority in exploration and exploitation.Finally,GJA was utilized to solve four engineering optimization problems and further implemented in robotic path planning to verify its practical applicability.Experimental results indicate that,compared to other high-performance algorithms,GJA demonstrates excep-tional performance as a powerful optimization algorithm in complex optimization problems.We make the code publicly available at:https://github.com/zhy1109/Gekko-japonicusalgorithm.
基金supported by the National Natural Science Foundation of China(Grant No.52192622)the Natural Science Foundation of Sichuan Province,China(Grant No.2025ZNSFSC0371)the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(Grant No.SKLGP2022Z018).
文摘Fluid seepage and associated heat transfer within the enhanced geothermal system(EGS)regulate the extraction of heat from hot,low-water-saturation thermal reservoirs,sometimes referred to as hot dry rock(HDR).To understand these complex heat recovery processes,we simulated long-term heat extraction in a surrogate HDR using a true triaxial apparatus.A circulation test was first implemented to analyze the connectivity between different wells.Suitable injection and production wells were then selected for the laboratory heat extraction tests in granite,which lasted 14.5 h.Under variable injection rate conditions,we systematically analyzed the time-varying curves of temperature and flow rate in the production wells and pressure in the injection wells.Our findings showed that the advantage channel was dominant in the flow distribution when several paths existed in EGS.Changes in fracture conductivity are attributed to injection pressure.These included an increase in fracture width and activation of a localized closed area of fracture.These two mechanisms influenced the production temperature,and this is consistent with the field data monitored at the Fenton Hill and Hijiori projects.Fluid leak-off was an important factor affecting the production flow rate.For a fracture with low hydraulic conductivity,a lower injection rate could effectively prevent excessive fluid leak-off.In addition,by comparing injection rates and fluid recovery rates,production wells in different phases or injection modes had different fluid recovery rates even when the injection rates were the same.
基金supported by the National Natural Science Foundation of China(No.52104018,52274030)China National Petroleum Corporation(CNPC)Innovation Foundation(No.2024DQ02-0303)China National Petroleum Corporation(CNPC)14th Five-Year Plan Major Strategic Scientific and Technological Project for Prospective and Fundamental Research(2024DJ86).
文摘Carbonate gas reservoirs are often characterized by strong heterogeneity,complex inter-well connectivity,extensive edge or bottom water,and unbalanced production,challenges that are also common in many heterogeneous gas reservoirs with intricate storage and flow behavior.To address these issues within a unified,data-driven framework,this study develops a multi-block material balance model that accounts for inter-block flow and aquifer influx,and is applicable to a wide range of reservoir types.The model incorporates inter-well and well-group conductive connectivity together with pseudo–steady-state aquifer support.The governing equations are solved using a Newton–Raphson scheme,while particle swarm optimization is employed to estimate formation pressures,inter-well connectivity,and effective aquifer volumes.An unbalanced exploitation factor,UEF,is introduced to quantify production imbalance and to guide development optimization.Validation using a synthetic reservoir model demonstrates that the approach accurately reproduces pressure evolution,crossflow behavior,and water influx.Application to a representative case(the Longwangmiao)field further confirms its robustness under highly heterogeneous conditions,achieving a 12.9%reduction in UEF through optimized production allocation.
基金funded by geological survey project of China Geological Survey(DD20211404)。
文摘Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of minerals,with reserves of at least 38 of over 80 widely used minerals worldwide accounting for more than30%of the global total reserves.Asia continent experienced three main tectonic evolution and mineralization stages:The Precambrian,the Paleozoic,and the Mesozoic to Cenozoic.The abundant mineral resources in this continent can be divided into seven first-order metallogenic belts(metallogenic domains),18 second-order metallogenic belts(metallogenic provinces),61 third-order metallogenic belts(metallogenic zones),and nine main minerogenetic series.Asia continent exhibits the most significant metallogenic specialization among all continents.Specifically,granite belts of Asia continent manifest pronounced metallogenic specialization of tin,rare metals,and porphyry Cu-Au-Mo deposits.Its maficultramafic rock belts and ophiolite belts display notable metallogenic specialization of lateritic nickel deposits and magmatic type chromite deposits,while its Mesozoic to Cenozoic basalt belts show remarkable metallogenic specialization of lateritic bauxite deposits.Consequently,many giant metallogenic belts were formed,including the Southeast Asian tin belt,the Qinghai-Xizang Plateau rare metal metallogenic belt,the Tethyan porphyry Cu-Au-Mo metallogenic belt,the circum-Pacific porphyry Cu-Au-Mo metallogenic belt,the Southeast Asian lateritic bauxite metallogenic belt,the Deccan Plateau lateritic bauxite metallogenic belt in India,the Southeast Asian lateritic nickel metallogenic belt,and the Tethyan magmatic type chromite metallogenic belt—all of which are significant metallogenic belts in Asia continent.Future mineral exploration in Asia should focus primarily on the Precambrian mineralization of ancient cratons,the Paleozoic mineralization of the Central Asian-Mongolian orogenic belt,and the Mesozoic to Cenozoic mineralization of the Tethyan and circum-Pacific mobile belts.Asia's mining industry not only underpins its own economic growth but also propels global economic development and industrialization,contributing significantly to the world economy.Asia boasts the highest production value of minerals,the largest annual production of minerals,and the greatest trade value of mineral products among all the continents,having emerged as the trade center of global mineral products and the center of the mining industry economy.China is identified as one of the few countries that possess the most comprehensive kinds of minerals,and its mining industry has supported and driven the economic development and industrialization of Asia and even the world.Standing as the largest mineral producer worldwide,China ranked first in the production of 28 mineral commodities in the world in 2022.Besides,China exhibits the highest annual production value of minerals and the largest trade value of mineral products among all countries.Therefore,China's demand for global mineral products influences the global supply and demand patterns of minerals and the world economic situation.
基金the National Natural Science Foundation of China
文摘Firstly, the macroscopic chemical equilibrium state of a series of chemical reactions between intercrystal brine and its media salt layer （salt deposit） in Qarhan Salt Lake was studied by using the Pitzer theory. The concept of macroscopic solubility product and its relation with accumulated ore dissolving ratio were presented, which are used in the numerical model of dissolving and driving exploitation of potassium salt in Qarhan Salt Lake. And secondly, with a model forming idea of transport model for reacting solutes in the multi-component fresh groundwater system in porous media being a reference, a two-dimensional transport model coupled with a series of chemical reactions in a multi-component brine porous system （salt deposits） was developed by using the Pitzer theory. Meanwhile, the model was applied to model potassium/magnesium transport in Qarhan Salt Lake in order to study the transfer law of solid and liquid phases in the dissolving and driving process and to design the optimal injection/abstraction strategy for dissolving and capturing maximum Potassium/ Magnesium in the mining of salt deposits in Qarhan Salt Lake.
文摘An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.
基金supported by the National Natural Science Foundation of China (41606078)National Key Research and Development Plan (2017YFC0307600)+1 种基金Qingdao National Laboratory for Marine Science and Technology (QNLM2016ORP0207,QNLM2016ORP0203)Marine Geological Survey Program (DD20190231,DD20190221).
文摘Sand production is a crucial problem during the process of extracting natural gas from hydrate reservoirs. To deal with sand-production problems systematically, a sand-production control system (SCS) is first proposed in this paper, specialized for pore-distributed clayey silt hydrate reservoirs. Secondly, a nodal system analysis method (NSAM) is applied to analyze the sand migration process during hydrate exploitation. The SCS is divided into three sub-systems, according to different sand migration mechanisms, and three key scientific problems and advances in SCS research in China Geological Survey are reviewed and analyzed. The maximum formation sanding rate, proper sand-control gravel size, and borehole blockage risk position were provided for clayey hydrate exploitation wells based on the SCS analysis. The SCS sub-systems are closely connected via bilateral coupling, and coordination of the subsystems is the basis of maintaining formation stability and prolonging the gas production cycle. Therefore, contradictory mitigation measures between sand production and operational systems should be considered preferentially. Some novel and efficient hydrate exploitation methods are needed to completely solve the contradictions caused by sand production.
文摘In the current data-intensive era, the traditional hands-on method of conducting scientific research by exploring related publications to generate a testable hypothesis is well on its way of becoming obsolete within just a year or two. Analyzing the literature and data to automatically generate a hypothesis might become the de facto approach to inform the core research efforts of those trying to master the exponentially rapid expansion of publications and datasets. Here, viewpoints are provided and discussed to help the understanding of challenges of data-driven discovery.
基金financially supported by The National Basic Research Program of China (No. 2010CB428803)the coordinated research project of International Atomic Energy Agency (No. 17314)
文摘Environmental tracers are proving to be a unique tool for assessing groundwater sustainability, such as characterization of recharge, identification of pathways and sources of contaminants, and prediction of groundwater change in response to excessive abstraction. This paper helps to better understand the groundwater sustainability in the Quaternary aquifer from the tracer data in the North China Plain. Relatively modern ground waters occur in the piedmont plain with 3H-3He age less than 40 a within a depth 100 m. These ground waters are mainly recharged from the local precipitation and irrigation return. The recharge rate estimated by tracers is in the range of 0.24 to 0.32 m/a. Paleowater which is dated from 10 000 a B.P. to more than 35 000 a B.P. by radiocarbon dating is found in highly-confined portions of Quaternary aquifer systems. This indicates that water recharge took place during the past glacial period. The tracers have suggested a slow natural replenishment rates to the central plain. The aquifer has been overexploited currently. Some strategies that can be implemented to promote a sustainable groundwater supply are needed to implement in future.
文摘Based on the ArcGIS geographic information system and the ORACLE database management system,this paper reports our studies on the technology of Marine Engineering Geological Exploration Information System(MEGEIS). By analyzing system structure,designing function modules and discussing data management,this paper systematically proposes a framework of technol-ogy to integrate,manage,and analyze the seabed information comprehensively. Then,the technology is applied to the design and development of the Bohai Sea Oilfield Paradigm Area Information System. The system can not only meet the practical demands of marine resources exploration and exploitation in the Bohai Sea oilfield,but also serve as a preparatory work in theory and technology for the realization of the 'Digital Seabed'.
文摘The Tahe Oilfield is a complex petroleum reservoir of Ordovician carbonate formation and made up of spatially overlapping fracture-cavity units. The oilfield is controlled by a cave system resulting from structure-karst cyclic sedimentation. Due to significant heterogeneity of the reservoir, the distribution of oil and water is complicated. Horizontally, a fresh water zone due to meteoric water can be found in the north part of the Akekule uplift. A marginal freshening zone caused by water released from mudstone compaction is found at the bottom of the southern slope. Located in a crossformational flow discharge zone caused by centripetal and the centrifugal flows, the main part of the Tahe Oilfield, featuring high salinity and concentrations of CI^- and K^＋＋Na^＋, is favorable for accumulation of hydrocarbon. Three types of formation water in the Tahe Ordovician reservoir are identified： （1） residual water at the bottom of the cave after oil and gas displacement, （2） residual water in fractures/pores around the cave after oil and gas displacement, and （3） interlayer water below reservoirs. The cave system is the main reservoir space, which consists of the main cave, branch caves and depressions between caves. Taking Cave System S48 in the Ordovician reservoir as an example, the paper analyzes the fluid distribution and exploitation performance in the cave system. Owing to evaporation of groundwater during cross-formational flow, the central part of the main cave, where oil layers are thick and there is a high degree of displacement, is characterized by high salinity and Br^- concentration. With high potential and a long stable production period, most wells in the central part of the main cave have a long water-free oil production period. Even after water breakthrough, the water content has a slow or stepwise increase and the hydrochemistral characteristics of the produced water in the central part of the main cave are uniform. From the center to the edge of the main cave, displacement and enrichment of oil/gas become weaker, residual water increases, and the salinity and concentration of Br^- decrease. At the edge of the main cave, although the wells have a high deliverability at the beginning with a short stable production period and water-free production period. After water breakthrough, the pressure and deliverability drop quickly, and the water content rises quickly. The hydrochemistral characteristics of the produced water are relatively uniform. Wells in the branch caves have a relatively low deliverability at the beginning, with a short stable production period. Water breakthrough appears quickly and then the pressure and deliverability drop quickly. The salinity and concentrations of CI^-and K^＋＋Na^＋ are usually fluctuant or descend slowly in the produced water. Wells in low areas of ancient karst have a low deliverability and a short stable production period. The yield drops quickly and the water content is high, while the characteristics of the produced water may vary significantly well to well. The salinity and concentrations of CI^-and K^＋＋Na^＋ in the produced water are usually fluctuant with a precipitous decline.
文摘Division arithmetic and generalized exploiting modification direction （DA-GEMD） method has perfect efficiency in data-hiding. However, there exist some weaknesses in DA-GEMD. Because the benchmarks are their median of nine pixels in each block of cover-image, it will give a hint for the attacker to hack the stego-image. In the paper, we utilize the Sudoku table to randomize the benchmark for each 3×3 block of cover-image. It will mix up the pixels in each image block and prevent the secret information from being extracted. The proposed method still keeps the original efficiency as DA-GEMD while promoting the security for data-hiding.
基金supported by the Graduate Student Innovation Fund of Hebei Province (No.197)
文摘Based on the groundwater resources evaluation, the groundwater exploitation potentiality evaluation is aiming at providing references for management, planning and development of groundwater. Traditional evaluation methods mainly adopted individual indicator as a method which cannot fully reflect the affecting factors of the groundwater exploitation potential in a scientific way. The idea that the spatial distribution and dynamic change of groundwater is not only affected by socio-economic development and exploitation technology but also influenced by its regulation is coincided with the niche theory. This paper has preliminarily applied the niche theory to groundwater exploitation potential analysis, and proposed the concept of groundwater niche as well as its related definition, connotation and calculation formula. Meanwhile, by taking the Hebei Plain as an example, the article has made an evaluation of groundwater exploitation potentiality and a contrast with the results of the traditional evaluation methods on the construction of groundwater niche index system, and then verified the feasibility and rationality of this index system. It turns out that, it is truly comprehensive, scientific and rational to make groundwater niche calculation and exploitation potential analysis by using the evaluation index system. Niche theory has provided a new and fundamental attempt for the analysis and competition strategy for the groundwater exploitation potentiality evaluation.
文摘Sea asparagus is a newly emerging seawater-irrigated vegetable. Firstly, the economic value of sea asparagus was introduced, and then, someexploiting approaches of sea asparagus werefully reviewed. The exploiting approaches mainly include fresh vegetable, pickle, bio-salt, health-care products, animal feed, vegetable oil, bio-diesel and skin-care products.
文摘The ecosystem and biodiversity conservation plan in progress in Hiroshima City was reviewed. Hiroshima City had prospered as a castle town, but severely suffered from A bomb damage at the end of World War II. Since then, Hiroshima City performed greenery activities with restoration and planted trees in public facilities. At present, Hiroshima City is promoting a 3rd tree planting campaign. As part of this campaign, the master plan of greenery of Hiroshima City is being laid. This plan aims not only at beautification in city area but also at ecosystem and biodiversity conservation in expanded city areas. In this paper, we report on the development of the situation in Hiroshima City since the end of World War II and the conservation planning of greenery which, for the most part, concerns zoning.
基金supported by the National Natural Science Foundation of China(Grant No.62277032,62231017,62071254)Education Scientific Planning Project of Jiangsu Province(Grant No.B/2022/01/150)Jiangsu Provincial Qinglan Project,the Special Fund for Urban and Rural Construction and Development in Jiangsu Province.
文摘More and more accounts or devices are shared by multiple users in video applications,which makes it difficult to provide recommendation service.Existing recommendation schemes overlook multiuser sharing scenarios,and they cannot make effective use of the mixed information generated by multi-user when exploring users’potential interests.To solve these problems,this paper proposes an adaptive program recommendation system for multi-user sharing environment.Specifically,we first design an offline periodic identification module by building multi-user features and periodically predicting target user in future sessions,which can separate the profile of target user from mixed log records.Subsequently,an online recommendation module with adaptive timevarying exploration strategy is constructed by jointly using personal information and multi-user social information provided by identification module.On one hand,to learn the dynamic changes in user-interest,a time-varying linear upper confidence bound(LinUCB)based on personal information is designed.On the other hand,to reduce the risk of exploration,a timeinvariant LinUCB based on separated multi-user social information from one account/device is proposed to compute the quality scores of programs for each user,which is integrated into the time-varying LinUCB by cross-weighting strategy.Finally,experimental results validate the efficiency of the proposed scheme.
