The United States has become the world's largest oil producer of shale oil. China has abundant shale oil resources, but its resource potential has not yet been exploited. The core of the evaluation is the selectio...The United States has become the world's largest oil producer of shale oil. China has abundant shale oil resources, but its resource potential has not yet been exploited. The core of the evaluation is the selection of parameters and their reliability. By combining the parameters of the shale oil resource evaluation, we investigated the key parameters in the evaluation model and reviewed the research results. The adsorption and retention of heavy hydrocarbons, loss of light hydrocarbons, and original oil saturation are key in the evaluation of shale oil resources. The adsorption and retention of heavy hydrocarbons can be determined by the pyrolysis, FID curve, and hydrocarbon generation kinetics of shale before and after extraction. The loss of light hydrocarbons mainly occurs in coring(change in temperature and pressure),sample treatment, which can be evaluated using the GC spectrum, rock pyrolysis, crude oil volume coefficient, mass balance, component hydrocarbon generation kinetics, and other methods. The original oil saturation evaluation includes indirect, direct, logging, and simulation methods. The most reliable parameters can be obtained by using the sealed or pressure-maintained coring immediately after thawing(without crushing), and the recovery of light hydrocarbon loss is critical for the resource evaluation of medium to high mature shale. Therefore, the experimental determination of shale oil content and the study of the influencing factors of the parameters should be strengthened.展开更多
As an efficient clean energy,natural gas hydrate(NGH)has become a hot topic in recent researches.Since1990 s,China has made great achievements and progress in NGH exploration in the South China Sea(SCS),including dete...As an efficient clean energy,natural gas hydrate(NGH)has become a hot topic in recent researches.Since1990 s,China has made great achievements and progress in NGH exploration in the South China Sea(SCS),including determination of the favorable distribution areas and favorable strata thickness,identification of the dual source for accumulation,evaluation of the prospective gas contents,verification of the widespread existence,and confirmation of the technical recoverability of NGH resources.However,there are three major challenges in the NGH studies.First,all the 24 national key and major projects in the SCS focused on trial production engineering and geological engineering in the past 20 years,while 8 of the 10 international NGH research projects focused on resource potential.Second,resource evaluation methods are outdated and some parameter selection are subjective.Third,the existing resource evaluation results are low-level with a great uncertainty,and cannot be used to guide NGH exploration and production or strategic research.To improve the evaluation of NGH resources in the SCS,future researches should focus on four aspects:(1)improve the research on the criterion of the objective existence of NGH and the method of prediction and evaluation;(2)apply new theories and methods from the global NGH research;(3)boost the research on the difference and correlation of the conditions of hydrocarbon migration and accumulation in different basins;(4)innovate the theory and method of NGH resource potential evaluation.展开更多
China Geological Survey conducted the second trial production of natural gas hydrate(NGH)in the Shenhu Area in South China Sea(SCS)from 2019 to 2020.Compared with the first trial production in 2017,the second trial sh...China Geological Survey conducted the second trial production of natural gas hydrate(NGH)in the Shenhu Area in South China Sea(SCS)from 2019 to 2020.Compared with the first trial production in 2017,the second trial showed significantly increased daily gas production and total gas production,and removed some technical obstacles for large-scale NGH resource developments in the SCS.However,current NGH resource evaluation in the SCS is still at the stage of prospective gas content assessment,which is unable to guide further NGH exploration and development.This study utilized the hydrate phase balance to delineate the NGH distribution range and effective thickness and volumetric method to evaluate NGH resource.Based on the latest exploration and production data from the Shenhu Area,Monte Carlo simulation was performed to calculate the NGH resource amount with different probabilities.By assuming a 50%cumulative probability,the in-situ NGH resources in the SCS was estimated to be11.7×10^(12)m^(3) and the recoverable NGH resources was 2.8×10^(12)m^(3).These results will provide a more reliable resource basis for China to formulate comprehensive development strategies for oil and gas exploration in the SCS.展开更多
There are more than 30 fossil-dominated geoparks established in China.Most of them are of high scientific values.Compared to landscape-dominated geoparks,the fossil-dominated ones generally lack of charming natural sc...There are more than 30 fossil-dominated geoparks established in China.Most of them are of high scientific values.Compared to landscape-dominated geoparks,the fossil-dominated ones generally lack of charming natural sceneries,but the abundant and exquisite preserved fossils in geoparks are very attractive to the public.In order to protect and exploit these fossils,the evaluation plays an important role in the geopark construction.Ningcheng geopark is famous for the Mesozoic Daohugou biota.The fossil assemblage is different from Jehol biota,which attracts many experts.In this paper the展开更多
Enterprises are continuously aiming at improving the execution of processes to achieve a competitive edge.One of the established ways of improving process performance is to assign the most appropriate resources to eac...Enterprises are continuously aiming at improving the execution of processes to achieve a competitive edge.One of the established ways of improving process performance is to assign the most appropriate resources to each task of the process.However,evaluations of business process improvement approaches have established that a method that can guide decision-makers to identify the most appropriate resources for a task of process improvement in a structured way,is missing.It is because the relationship between resources and tasks is less understood and advancement in business process intelligence is also ignored.To address this problem an integrated resource classification framework is presenting that identifies competence,suitability,and preference as the relationship of task with resources.But,only the competence relationship of human resources with a task is presented in this research as a resource competence model.Furthermore,the competency calculation method is presented as a user guider layer for business process intelligencebased resource competence evaluation.The computed capabilities serve as a basic input for choosing the most appropriate resources for each task of the process.Applicability of method is illustrated through a heathcare case study.展开更多
Bayesian network has a powerful ability for reasoning and semantic representation, which combined with qualitative analysis and quantitative analysis, with prior knowledge and observed data, and provides an effective ...Bayesian network has a powerful ability for reasoning and semantic representation, which combined with qualitative analysis and quantitative analysis, with prior knowledge and observed data, and provides an effective way to deal with prediction, classification and clustering. Firstly, this paper presented an overview of Bayesian network and its characteristics, and discussed how to learn a Bayesian network structure from given data, and then constructed a Bayesian network model for land resource evaluation with expert knowledge and the dataset. The experimental results based on the test dataset are that evaluation accuracy is 87.5% , and Kappa index is 0.826. All these prove the method is feasible and efficient, and indicate that Bayesian network is a promising approach for land resource evaluation.展开更多
Based on the geochemical characteristics of oil-cracking gas and kerogen-cracking gas revealed by simu-lation experiments and the chemical composition of natural gases in actual gas reservoirs, two kinds of natural ga...Based on the geochemical characteristics of oil-cracking gas and kerogen-cracking gas revealed by simu-lation experiments and the chemical composition of natural gases in actual gas reservoirs, two kinds of natural gases with different relationships between C2/C3 and C1/C2, C2/C3 and C1/C3, C2/C3 and 100×C1/(C1-C5) were identified in the Tarim Basin, and proposed further by the authors. The relationship charts of C2/C3 and C1/C2, C2/C3 and C1/C3, C2/C3 and 100×C1/(C1-C5) can be used to effectively distinguish oil-cracking gas from kerogen-cracking gas. Petro-leum geological analysis of the oil-cracking gas reservoirs showed that the distribution of oil-cracking gas is mostly related with deep-seated faults or faults with a large fault throw, and the burial depth of paleo-oil reservoir is rela-tively high; crude oil-cracking gas resources have been evaluated by using both forward and inversion methods. The plots of C2/C3 vs. C1/C2, C2/C3 vs. C1/C3, and C2/C3 vs. 100×C1/(C1-C5) were used to distinguish between oil-crack-ing gas and kerogen-cracking gas, and estimate the mixed ratios of the two kinds of natural gases in the main gas reservoirs of the platform area.展开更多
Base on the oil shale data model,the authors analyz the four main data types and their mutual relations,grasped the focus on the oil shale data management,established UML visual demand model for oil shale resources in...Base on the oil shale data model,the authors analyz the four main data types and their mutual relations,grasped the focus on the oil shale data management,established UML visual demand model for oil shale resources in the field of evaluation,constructed three-tier system and developed oil shale resource evaluation database management system. The system can be used for managing oil shale data storage,enhancing the efficiency and quality of the oil shale resource evaluation.展开更多
The pyrolysis parameter S1,which indicates the amount of free hydrocarbons present in shale,is often underestimated due to hydrocarbon loss during sample handling and measurement processes.To remedy this issue,we stro...The pyrolysis parameter S1,which indicates the amount of free hydrocarbons present in shale,is often underestimated due to hydrocarbon loss during sample handling and measurement processes.To remedy this issue,we strongly recommend an immediate three-step hydrocarbon thermal desorption(HTD)approach to be conducted on oil shale at the drilling site.This approach measures S_(g),S_(O),and S_(1)^(*),which refer to gaseous,light,and free hydrocarbons,respectively.The new shale oil content value,calculated from the total of these three parameters,is far more precise and reliable than traditional pyrolysis S1.Moreover,we thoroughly investigated the components and microscopic occurrence features of hydrocarbons thermally desorbed at three temperature stages using gas chromatography(GC)and X-ray microcomputed tomography(CT).For example,we selected Chang 7_(3)mud shale.Our experimental results irrefutably indicate that the ultimate shale oil content of poor resource rocks is significantly impacted by evaporative loss,with this effect being greater when the total organic carbon(TOC)is lower.Additionally,C_(1-5)and C_(1-7)hydrocarbons constitute almost all of S_(g)and S_(O),respectively.S_(g)and S_(O)are predominantly composed of C_(1-3)gaseous hydrocarbons,with a maximum proportion of 42.93%.In contrast,S_(1)^(*)contains a substantial amount of C_(16-31)hydrocarbons.A three-dimensional reconstruction model of an X-ray micro-CT scan shows that while the amount of shale organic matter greatly decreases from the frozen state to 300℃,the pore volume significantly increases,particularly between 90 and 300℃.The increased pore volume is mainly due to macropores and fractures.It is imperative to note that the shale oil triple-division boundaries must be adjusted based on more accurate oil content,although this would not affect the resource zones to which the samples already belong(ineffective,low-efficient,and enriched resources).In conclusion,we strongly advise conducting an immediate well-site analysis or utilizing preservation procedures,such as deep freezing or plastic film wrapping followed by core waxing,to minimize volatile loss.展开更多
The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.U...The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.展开更多
As a basic natural resource and strategic economic resource,the development and utilization of water resources is an important issue related to the national economy and people's livelihood.How to scientifically ev...As a basic natural resource and strategic economic resource,the development and utilization of water resources is an important issue related to the national economy and people's livelihood.How to scientifically evaluate the water resources carrying capacity is the premise to improve the regional water resources carrying capacity and ensure the regional water security.The Gansu section of the Yellow River basin is an important water conservation and recharge area.Whether the water resources in this area can ensure the normal operation of the ecosystem and whether it can carry the sustainable development of social economy is the key to realize the high-quality development of the Yellow River basin.In this study,from the three dimensions of water consumption per capita,water consumption of 10000 yuan GDP and ecological water use rate,by constructing the evaluation index system and index grading standard of water resources carrying capacity,the fuzzy comprehensive evaluation model was used to evaluate the water resources carrying capacity of Gansu section of the Yellow River Basin,in order to provide theoretical decision-making basis for the comprehensive development,utilization and planning management of water resources in Gansu section of the Yellow River basin and even the whole basin,and help the high-quality development of the Yellow River basin.展开更多
[Objectives]To protect the local rare citrus germplasm resources and further develop and cultivate new citrus varieties.[Methods]The germplasm resources of Shatangju(Citrus flamea Hort.Ex Tseng Shiyueju)in Sihui City ...[Objectives]To protect the local rare citrus germplasm resources and further develop and cultivate new citrus varieties.[Methods]The germplasm resources of Shatangju(Citrus flamea Hort.Ex Tseng Shiyueju)in Sihui City of Guangdong Province and other 8 citrus varieties from the same origin were evaluated.The appearance characteristics of tree shape,the length and thickness of shoot at each shoot stage,the appearance characteristics of leaves and the fruit quality of each variety were investigated.[Results]Through the comparison of various citrus varieties grafted with sour mandarin,the results showed that the overall advantages of the length and thickness of the shoots of Shatang tangerine in summer and autumn were more prominent,which was conducive to fruit setting.The sprouting time of the three shoots of each variety was different,and there were sporadic sprouting phenomena in different seasons,so the growth was different,and the length and thickness of the shoots were different in different seasons.There were significant differences in shoot length and diameter among different varieties in the same season.The coefficient of variation of Shatangju's leaves was low,and the traits were stable;leaf shape,leaf base shape,leaf margin and other indicators among the three shoots of the same variety and the differences among the same shoots of different varieties were compared.All varieties had strong flavor,separately sweet and sour,sweet and sweet taste.Shatangju has many segments,orange pericarp,rough texture,easy peeling,and high oblate fruit shape.The orange pericarp was favored by the participants,while the rough and thick peel was not favored by the participants.[Conclusions]Based on the improvement of local varieties,it is recommended to improve the smoothness of pericarp,reducing the thickness of pericarp and improving the flavor of fruit will be conducive to increasing sales.In the cultivation process of various quality resources,especially in the period of fruit growth and development,the plan of nutrition and fertilization should be formulated according to the rules of fruit growth and development,the rules of yield formation and the rules of quality composition,so as to establish the integrated nutrient management system of various varieties.展开更多
As part of its efforts to promote a sustainable and high-quality development,China has pledged to reduce water consumption and create a water-efficient society.On the basis of identifying the institutional root causes...As part of its efforts to promote a sustainable and high-quality development,China has pledged to reduce water consumption and create a water-efficient society.On the basis of identifying the institutional root causes of excessive capital allocation and excessive water consumption in China’s water-intensive industrial sectors,this study elaborates how the national water-efficient cities assessment contributes to optimized capital allocation.Our research shows that national water-efficient cities assessment has motivated local governments to compete for water efficiency.To conserve water,local governments regulated the entry and exit of water-intensive enterprises,discouraged excessive investments in water-intensive sectors,and phased out obsolete water-intensive capacities within their jurisdictions.This approach has resulted in mutually beneficial outcomes,including improved allocation of capital,enhanced water efficiency,and reduced emissions.This paper offers policy recommendations for establishing a water-efficient society throughout the 14^(th) Five-Year Plan(2021-2025)period by presenting empirical evidence on the policy effects of resource efficiency evaluation.展开更多
Geothermal resource,a green and sustainable energy resource,plays an important role in achieving‘emission peak’and‘carbon neutrality’targets.The Yingjiang Basin is located in the eastern branch of the Mediterranea...Geothermal resource,a green and sustainable energy resource,plays an important role in achieving‘emission peak’and‘carbon neutrality’targets.The Yingjiang Basin is located in the eastern branch of the Mediterranean-Himalayan high-temperature geothermal belt and exhibits considerable potential for geothermal resources.However,current investigations into the distribution of deep geothermal resources in this region are somewhat limited.In this paper,the transient plane source(TPS)method is used to measure the thermal conductivity parameters of 31 rock samples within the study area.Additionally,the one-dimensional steady-state heat conduction equation is employed to calculate the deep geothermal field,considering the constraints of rock thermal properties and terrestrial heat flow in the study area.Furthermore,the“stripping method”is used to determine the contribution rate of sedimentary layer to terrestrial heat flow,while the volume method is applied to estimate the geothermal resources at burial depths of 3000-5000 m.The results show that(1)The heat generation rate of granite is the highest with an average value of 4.52 mW/m^(3),followed by gneiss with an average value in the range of 2.0-3.5 W/(m·K),mudstone and sandstone being the lowest with an average value between 1.0 and 2.0 W/(m·K).(2)The main contributor of terrestrial heat flow in the study area is mantle heat flow,and the contribution of sedimentary layers to terrestrial heat flow only accounts for about 2%.(3)The geothermal resources in Yingjiang Basin within the depth range of 3000-5000 m is 93.6×10^(15)kJ,or 3.2×10^(9)tonnes standard coal equivalent(SCE).展开更多
As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crud...As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.展开更多
Users and edge servers are not fullymutually trusted inmobile edge computing(MEC),and hence blockchain can be introduced to provide trustableMEC.In blockchain-basedMEC,each edge server functions as a node in bothMEC a...Users and edge servers are not fullymutually trusted inmobile edge computing(MEC),and hence blockchain can be introduced to provide trustableMEC.In blockchain-basedMEC,each edge server functions as a node in bothMEC and blockchain,processing users’tasks and then uploading the task related information to the blockchain.That is,each edge server runs both users’offloaded tasks and blockchain tasks simultaneously.Note that there is a trade-off between the resource allocation for MEC and blockchain tasks.Therefore,the allocation of the resources of edge servers to the blockchain and theMEC is crucial for the processing delay of blockchain-based MEC.Most of the existing research tackles the problem of resource allocation in either blockchain or MEC,which leads to unfavorable performance of the blockchain-based MEC system.In this paper,we study how to allocate the computing resources of edge servers to the MEC and blockchain tasks with the aimtominimize the total systemprocessing delay.For the problem,we propose a computing resource Allocation algorithmfor Blockchain-based MEC(ABM)which utilizes the Slater’s condition,Karush-Kuhn-Tucker(KKT)conditions,partial derivatives of the Lagrangian function and subgradient projection method to obtain the solution.Simulation results show that ABM converges and effectively reduces the processing delay of blockchain-based MEC.展开更多
With the rapid development of Network Function Virtualization(NFV),the problem of low resource utilizationin traditional data centers is gradually being addressed.However,existing research does not optimize both local...With the rapid development of Network Function Virtualization(NFV),the problem of low resource utilizationin traditional data centers is gradually being addressed.However,existing research does not optimize both localand global allocation of resources in data centers.Hence,we propose an adaptive hybrid optimization strategy thatcombines dynamic programming and neural networks to improve resource utilization and service quality in datacenters.Our approach encompasses a service function chain simulation generator,a parallel architecture servicesystem,a dynamic programming strategy formaximizing the utilization of local server resources,a neural networkfor predicting the global utilization rate of resources and a global resource optimization strategy for bottleneck andredundant resources.With the implementation of our local and global resource allocation strategies,the systemperformance is significantly optimized through simulation.展开更多
First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism...First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism based on the time decay factor is proposed,taking into account the influence of historical interaction records.We weight the time attenuation factor to each historical interaction record for updating and got the new historical record data.We refer to the beta distribution to enhance the flexibility and adaptability of the direct trust assessment model to better capture time trends in the historical record.Then we propose an autoencoder-based trust clustering algorithm.We perform feature extraction based on autoencoders.Kullback leibler(KL)divergence is used to calculate the reconstruction error.When constructing a convolutional autoencoder,we introduce convolutional neural networks to improve training efficiency and introduce sparse constraints into the hidden layer of the autoencoder.The sparse penalty term in the loss function measures the difference through the KL divergence.Trust clustering is performed based on the density based spatial clustering of applications with noise(DBSCAN)clustering algorithm.During the clustering process,edge nodes have a variety of trustworthy attribute characteristics.We assign different attribute weights according to the relative importance of each attribute in the clustering process,and a larger weight means that the attribute occupies a greater weight in the calculation of distance.Finally,we introduced adaptive weights to calculate comprehensive trust evaluation.Simulation experiments prove that our trust evaluation mechanism has excellent reliability and accuracy.展开更多
基金funded by the National Natural Science Foundation of China (41922015, 42072147)Fundamental Research Funds for the Central Universities (20CX06085A)Qingdao Postdoctoral Science Foundation (ZX20210070)。
文摘The United States has become the world's largest oil producer of shale oil. China has abundant shale oil resources, but its resource potential has not yet been exploited. The core of the evaluation is the selection of parameters and their reliability. By combining the parameters of the shale oil resource evaluation, we investigated the key parameters in the evaluation model and reviewed the research results. The adsorption and retention of heavy hydrocarbons, loss of light hydrocarbons, and original oil saturation are key in the evaluation of shale oil resources. The adsorption and retention of heavy hydrocarbons can be determined by the pyrolysis, FID curve, and hydrocarbon generation kinetics of shale before and after extraction. The loss of light hydrocarbons mainly occurs in coring(change in temperature and pressure),sample treatment, which can be evaluated using the GC spectrum, rock pyrolysis, crude oil volume coefficient, mass balance, component hydrocarbon generation kinetics, and other methods. The original oil saturation evaluation includes indirect, direct, logging, and simulation methods. The most reliable parameters can be obtained by using the sealed or pressure-maintained coring immediately after thawing(without crushing), and the recovery of light hydrocarbon loss is critical for the resource evaluation of medium to high mature shale. Therefore, the experimental determination of shale oil content and the study of the influencing factors of the parameters should be strengthened.
基金financially supported by the CAS consultation project“South China Sea Oil and Gas Comprehensive Development Strategy”(2019-ZW11-Z-035)the National Basic Research Program of China(2006CB202300,2011CB201100)the National HighTech R&D(863)Program of China(2013AA092600)。
文摘As an efficient clean energy,natural gas hydrate(NGH)has become a hot topic in recent researches.Since1990 s,China has made great achievements and progress in NGH exploration in the South China Sea(SCS),including determination of the favorable distribution areas and favorable strata thickness,identification of the dual source for accumulation,evaluation of the prospective gas contents,verification of the widespread existence,and confirmation of the technical recoverability of NGH resources.However,there are three major challenges in the NGH studies.First,all the 24 national key and major projects in the SCS focused on trial production engineering and geological engineering in the past 20 years,while 8 of the 10 international NGH research projects focused on resource potential.Second,resource evaluation methods are outdated and some parameter selection are subjective.Third,the existing resource evaluation results are low-level with a great uncertainty,and cannot be used to guide NGH exploration and production or strategic research.To improve the evaluation of NGH resources in the SCS,future researches should focus on four aspects:(1)improve the research on the criterion of the objective existence of NGH and the method of prediction and evaluation;(2)apply new theories and methods from the global NGH research;(3)boost the research on the difference and correlation of the conditions of hydrocarbon migration and accumulation in different basins;(4)innovate the theory and method of NGH resource potential evaluation.
基金funded by the major consulting project of“South China Sea Oil and Gas Comprehensive Development Strategy Research”led by Academician Gao Deli and the Faculty of Chinese Academy of SciencesConsulting Project of Chinese Academy of Sciences(2019-ZW11-Z-035)+1 种基金National Key Basic Research and Development Program(973)(2006CB202300,2011CB201100)China High-Tech R&D Project(863)(2013AA092600)。
文摘China Geological Survey conducted the second trial production of natural gas hydrate(NGH)in the Shenhu Area in South China Sea(SCS)from 2019 to 2020.Compared with the first trial production in 2017,the second trial showed significantly increased daily gas production and total gas production,and removed some technical obstacles for large-scale NGH resource developments in the SCS.However,current NGH resource evaluation in the SCS is still at the stage of prospective gas content assessment,which is unable to guide further NGH exploration and development.This study utilized the hydrate phase balance to delineate the NGH distribution range and effective thickness and volumetric method to evaluate NGH resource.Based on the latest exploration and production data from the Shenhu Area,Monte Carlo simulation was performed to calculate the NGH resource amount with different probabilities.By assuming a 50%cumulative probability,the in-situ NGH resources in the SCS was estimated to be11.7×10^(12)m^(3) and the recoverable NGH resources was 2.8×10^(12)m^(3).These results will provide a more reliable resource basis for China to formulate comprehensive development strategies for oil and gas exploration in the SCS.
文摘There are more than 30 fossil-dominated geoparks established in China.Most of them are of high scientific values.Compared to landscape-dominated geoparks,the fossil-dominated ones generally lack of charming natural sceneries,but the abundant and exquisite preserved fossils in geoparks are very attractive to the public.In order to protect and exploit these fossils,the evaluation plays an important role in the geopark construction.Ningcheng geopark is famous for the Mesozoic Daohugou biota.The fossil assemblage is different from Jehol biota,which attracts many experts.In this paper the
基金the National Natural Science Foundation of China (No.40671145)the Natural Science Foundation of Guangdong Province (Nos.04300504 and 05006623)and the Science and Technology Plan Foundation of Guangdong Province (Nos.2005B20701008,2005B10101028,and 2004B20701006).
文摘Enterprises are continuously aiming at improving the execution of processes to achieve a competitive edge.One of the established ways of improving process performance is to assign the most appropriate resources to each task of the process.However,evaluations of business process improvement approaches have established that a method that can guide decision-makers to identify the most appropriate resources for a task of process improvement in a structured way,is missing.It is because the relationship between resources and tasks is less understood and advancement in business process intelligence is also ignored.To address this problem an integrated resource classification framework is presenting that identifies competence,suitability,and preference as the relationship of task with resources.But,only the competence relationship of human resources with a task is presented in this research as a resource competence model.Furthermore,the competency calculation method is presented as a user guider layer for business process intelligencebased resource competence evaluation.The computed capabilities serve as a basic input for choosing the most appropriate resources for each task of the process.Applicability of method is illustrated through a heathcare case study.
文摘Bayesian network has a powerful ability for reasoning and semantic representation, which combined with qualitative analysis and quantitative analysis, with prior knowledge and observed data, and provides an effective way to deal with prediction, classification and clustering. Firstly, this paper presented an overview of Bayesian network and its characteristics, and discussed how to learn a Bayesian network structure from given data, and then constructed a Bayesian network model for land resource evaluation with expert knowledge and the dataset. The experimental results based on the test dataset are that evaluation accuracy is 87.5% , and Kappa index is 0.826. All these prove the method is feasible and efficient, and indicate that Bayesian network is a promising approach for land resource evaluation.
基金the National Natural Science Foundation of China (Grant No. 40973041)
文摘Based on the geochemical characteristics of oil-cracking gas and kerogen-cracking gas revealed by simu-lation experiments and the chemical composition of natural gases in actual gas reservoirs, two kinds of natural gases with different relationships between C2/C3 and C1/C2, C2/C3 and C1/C3, C2/C3 and 100×C1/(C1-C5) were identified in the Tarim Basin, and proposed further by the authors. The relationship charts of C2/C3 and C1/C2, C2/C3 and C1/C3, C2/C3 and 100×C1/(C1-C5) can be used to effectively distinguish oil-cracking gas from kerogen-cracking gas. Petro-leum geological analysis of the oil-cracking gas reservoirs showed that the distribution of oil-cracking gas is mostly related with deep-seated faults or faults with a large fault throw, and the burial depth of paleo-oil reservoir is rela-tively high; crude oil-cracking gas resources have been evaluated by using both forward and inversion methods. The plots of C2/C3 vs. C1/C2, C2/C3 vs. C1/C3, and C2/C3 vs. 100×C1/(C1-C5) were used to distinguish between oil-crack-ing gas and kerogen-cracking gas, and estimate the mixed ratios of the two kinds of natural gases in the main gas reservoirs of the platform area.
文摘Base on the oil shale data model,the authors analyz the four main data types and their mutual relations,grasped the focus on the oil shale data management,established UML visual demand model for oil shale resources in the field of evaluation,constructed three-tier system and developed oil shale resource evaluation database management system. The system can be used for managing oil shale data storage,enhancing the efficiency and quality of the oil shale resource evaluation.
基金This study is financially supported by the National Natural Science Foundation of China(Grant Number 41972122,42172139 and 42072186)the China Scholarship Council(CSC),the Open Foundation of Cooperative Innovation Center of Uncon-ventional Oil and Gas,Yangtze University(Ministry of Education&Hubei Province)(Grant Number UOGBX 2022-03)Petro-China Innovation Found(No.2020D-5007-0101)。
文摘The pyrolysis parameter S1,which indicates the amount of free hydrocarbons present in shale,is often underestimated due to hydrocarbon loss during sample handling and measurement processes.To remedy this issue,we strongly recommend an immediate three-step hydrocarbon thermal desorption(HTD)approach to be conducted on oil shale at the drilling site.This approach measures S_(g),S_(O),and S_(1)^(*),which refer to gaseous,light,and free hydrocarbons,respectively.The new shale oil content value,calculated from the total of these three parameters,is far more precise and reliable than traditional pyrolysis S1.Moreover,we thoroughly investigated the components and microscopic occurrence features of hydrocarbons thermally desorbed at three temperature stages using gas chromatography(GC)and X-ray microcomputed tomography(CT).For example,we selected Chang 7_(3)mud shale.Our experimental results irrefutably indicate that the ultimate shale oil content of poor resource rocks is significantly impacted by evaporative loss,with this effect being greater when the total organic carbon(TOC)is lower.Additionally,C_(1-5)and C_(1-7)hydrocarbons constitute almost all of S_(g)and S_(O),respectively.S_(g)and S_(O)are predominantly composed of C_(1-3)gaseous hydrocarbons,with a maximum proportion of 42.93%.In contrast,S_(1)^(*)contains a substantial amount of C_(16-31)hydrocarbons.A three-dimensional reconstruction model of an X-ray micro-CT scan shows that while the amount of shale organic matter greatly decreases from the frozen state to 300℃,the pore volume significantly increases,particularly between 90 and 300℃.The increased pore volume is mainly due to macropores and fractures.It is imperative to note that the shale oil triple-division boundaries must be adjusted based on more accurate oil content,although this would not affect the resource zones to which the samples already belong(ineffective,low-efficient,and enriched resources).In conclusion,we strongly advise conducting an immediate well-site analysis or utilizing preservation procedures,such as deep freezing or plastic film wrapping followed by core waxing,to minimize volatile loss.
基金the financial support of the National Natural Science Foundation of China(42176212,41976074 and 41302034)the Marine S&T Fund of Shandong Province for Laoshan Laboratory(2021QNLM020002)the Marine Geological Survey Program(DD20221704)。
文摘The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.
基金Supported by Gansu Province 2023 Education Science and Technology Innovation Project(2023B-431).
文摘As a basic natural resource and strategic economic resource,the development and utilization of water resources is an important issue related to the national economy and people's livelihood.How to scientifically evaluate the water resources carrying capacity is the premise to improve the regional water resources carrying capacity and ensure the regional water security.The Gansu section of the Yellow River basin is an important water conservation and recharge area.Whether the water resources in this area can ensure the normal operation of the ecosystem and whether it can carry the sustainable development of social economy is the key to realize the high-quality development of the Yellow River basin.In this study,from the three dimensions of water consumption per capita,water consumption of 10000 yuan GDP and ecological water use rate,by constructing the evaluation index system and index grading standard of water resources carrying capacity,the fuzzy comprehensive evaluation model was used to evaluate the water resources carrying capacity of Gansu section of the Yellow River Basin,in order to provide theoretical decision-making basis for the comprehensive development,utilization and planning management of water resources in Gansu section of the Yellow River basin and even the whole basin,and help the high-quality development of the Yellow River basin.
基金Supported by China Agricalture Research System of MOF and MARA(CARS-26)Citrus Germplasm Resources Nursery Construction Project in Sihui City of Guangdong Province(KJ-20230310-H010)。
文摘[Objectives]To protect the local rare citrus germplasm resources and further develop and cultivate new citrus varieties.[Methods]The germplasm resources of Shatangju(Citrus flamea Hort.Ex Tseng Shiyueju)in Sihui City of Guangdong Province and other 8 citrus varieties from the same origin were evaluated.The appearance characteristics of tree shape,the length and thickness of shoot at each shoot stage,the appearance characteristics of leaves and the fruit quality of each variety were investigated.[Results]Through the comparison of various citrus varieties grafted with sour mandarin,the results showed that the overall advantages of the length and thickness of the shoots of Shatang tangerine in summer and autumn were more prominent,which was conducive to fruit setting.The sprouting time of the three shoots of each variety was different,and there were sporadic sprouting phenomena in different seasons,so the growth was different,and the length and thickness of the shoots were different in different seasons.There were significant differences in shoot length and diameter among different varieties in the same season.The coefficient of variation of Shatangju's leaves was low,and the traits were stable;leaf shape,leaf base shape,leaf margin and other indicators among the three shoots of the same variety and the differences among the same shoots of different varieties were compared.All varieties had strong flavor,separately sweet and sour,sweet and sweet taste.Shatangju has many segments,orange pericarp,rough texture,easy peeling,and high oblate fruit shape.The orange pericarp was favored by the participants,while the rough and thick peel was not favored by the participants.[Conclusions]Based on the improvement of local varieties,it is recommended to improve the smoothness of pericarp,reducing the thickness of pericarp and improving the flavor of fruit will be conducive to increasing sales.In the cultivation process of various quality resources,especially in the period of fruit growth and development,the plan of nutrition and fertilization should be formulated according to the rules of fruit growth and development,the rules of yield formation and the rules of quality composition,so as to establish the integrated nutrient management system of various varieties.
基金Sponsorship of the Outstanding Youth Innovation Team Development Program for Institutes of Higher Learning in Shandong Province(2021RW008)the Youth Program of the Natural Science Foundation of Shandong Province(ZR2021QG048).
文摘As part of its efforts to promote a sustainable and high-quality development,China has pledged to reduce water consumption and create a water-efficient society.On the basis of identifying the institutional root causes of excessive capital allocation and excessive water consumption in China’s water-intensive industrial sectors,this study elaborates how the national water-efficient cities assessment contributes to optimized capital allocation.Our research shows that national water-efficient cities assessment has motivated local governments to compete for water efficiency.To conserve water,local governments regulated the entry and exit of water-intensive enterprises,discouraged excessive investments in water-intensive sectors,and phased out obsolete water-intensive capacities within their jurisdictions.This approach has resulted in mutually beneficial outcomes,including improved allocation of capital,enhanced water efficiency,and reduced emissions.This paper offers policy recommendations for establishing a water-efficient society throughout the 14^(th) Five-Year Plan(2021-2025)period by presenting empirical evidence on the policy effects of resource efficiency evaluation.
文摘Geothermal resource,a green and sustainable energy resource,plays an important role in achieving‘emission peak’and‘carbon neutrality’targets.The Yingjiang Basin is located in the eastern branch of the Mediterranean-Himalayan high-temperature geothermal belt and exhibits considerable potential for geothermal resources.However,current investigations into the distribution of deep geothermal resources in this region are somewhat limited.In this paper,the transient plane source(TPS)method is used to measure the thermal conductivity parameters of 31 rock samples within the study area.Additionally,the one-dimensional steady-state heat conduction equation is employed to calculate the deep geothermal field,considering the constraints of rock thermal properties and terrestrial heat flow in the study area.Furthermore,the“stripping method”is used to determine the contribution rate of sedimentary layer to terrestrial heat flow,while the volume method is applied to estimate the geothermal resources at burial depths of 3000-5000 m.The results show that(1)The heat generation rate of granite is the highest with an average value of 4.52 mW/m^(3),followed by gneiss with an average value in the range of 2.0-3.5 W/(m·K),mudstone and sandstone being the lowest with an average value between 1.0 and 2.0 W/(m·K).(2)The main contributor of terrestrial heat flow in the study area is mantle heat flow,and the contribution of sedimentary layers to terrestrial heat flow only accounts for about 2%.(3)The geothermal resources in Yingjiang Basin within the depth range of 3000-5000 m is 93.6×10^(15)kJ,or 3.2×10^(9)tonnes standard coal equivalent(SCE).
基金This work was financially supported by the National Natural Science Foundation of China(52074089 and 52104064)Natural Science Foundation of Heilongjiang Province of China(LH2019E019).
文摘As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.
基金supported by the Key Research and Development Project in Anhui Province of China(Grant No.202304a05020059)the Fundamental Research Funds for the Central Universities of China(Grant No.PA2023GDSK0055)the Project of Anhui Province Economic and Information Bureau(Grant No.JB20099).
文摘Users and edge servers are not fullymutually trusted inmobile edge computing(MEC),and hence blockchain can be introduced to provide trustableMEC.In blockchain-basedMEC,each edge server functions as a node in bothMEC and blockchain,processing users’tasks and then uploading the task related information to the blockchain.That is,each edge server runs both users’offloaded tasks and blockchain tasks simultaneously.Note that there is a trade-off between the resource allocation for MEC and blockchain tasks.Therefore,the allocation of the resources of edge servers to the blockchain and theMEC is crucial for the processing delay of blockchain-based MEC.Most of the existing research tackles the problem of resource allocation in either blockchain or MEC,which leads to unfavorable performance of the blockchain-based MEC system.In this paper,we study how to allocate the computing resources of edge servers to the MEC and blockchain tasks with the aimtominimize the total systemprocessing delay.For the problem,we propose a computing resource Allocation algorithmfor Blockchain-based MEC(ABM)which utilizes the Slater’s condition,Karush-Kuhn-Tucker(KKT)conditions,partial derivatives of the Lagrangian function and subgradient projection method to obtain the solution.Simulation results show that ABM converges and effectively reduces the processing delay of blockchain-based MEC.
基金the Fundamental Research Program of Guangdong,China,under Grants 2020B1515310023 and 2023A1515011281in part by the National Natural Science Foundation of China under Grant 61571005.
文摘With the rapid development of Network Function Virtualization(NFV),the problem of low resource utilizationin traditional data centers is gradually being addressed.However,existing research does not optimize both localand global allocation of resources in data centers.Hence,we propose an adaptive hybrid optimization strategy thatcombines dynamic programming and neural networks to improve resource utilization and service quality in datacenters.Our approach encompasses a service function chain simulation generator,a parallel architecture servicesystem,a dynamic programming strategy formaximizing the utilization of local server resources,a neural networkfor predicting the global utilization rate of resources and a global resource optimization strategy for bottleneck andredundant resources.With the implementation of our local and global resource allocation strategies,the systemperformance is significantly optimized through simulation.
基金This work is supported by the 2022 National Key Research and Development Plan“Security Protection Technology for Critical Information Infrastructure of Distribution Network”(2022YFB3105100).
文摘First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism based on the time decay factor is proposed,taking into account the influence of historical interaction records.We weight the time attenuation factor to each historical interaction record for updating and got the new historical record data.We refer to the beta distribution to enhance the flexibility and adaptability of the direct trust assessment model to better capture time trends in the historical record.Then we propose an autoencoder-based trust clustering algorithm.We perform feature extraction based on autoencoders.Kullback leibler(KL)divergence is used to calculate the reconstruction error.When constructing a convolutional autoencoder,we introduce convolutional neural networks to improve training efficiency and introduce sparse constraints into the hidden layer of the autoencoder.The sparse penalty term in the loss function measures the difference through the KL divergence.Trust clustering is performed based on the density based spatial clustering of applications with noise(DBSCAN)clustering algorithm.During the clustering process,edge nodes have a variety of trustworthy attribute characteristics.We assign different attribute weights according to the relative importance of each attribute in the clustering process,and a larger weight means that the attribute occupies a greater weight in the calculation of distance.Finally,we introduced adaptive weights to calculate comprehensive trust evaluation.Simulation experiments prove that our trust evaluation mechanism has excellent reliability and accuracy.
