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Efficient Finite Difference WENO Scheme for Hyperbolic Systems withNon-conservativeProducts
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作者 Dinshaw S.Balsara Deepak Bhoriya +1 位作者 Chi-Wang Shu Harish Kumar 《Communications on Applied Mathematics and Computation》 EI 2024年第2期907-962,共56页
Higher order finite difference weighted essentially non-oscillatory(WENO)schemes have been constructed for conservation laws.For multidimensional problems,they offer a high order accuracy at a fraction of the cost of ... Higher order finite difference weighted essentially non-oscillatory(WENO)schemes have been constructed for conservation laws.For multidimensional problems,they offer a high order accuracy at a fraction of the cost of a finite volume WENO or DG scheme of the comparable accuracy.This makes them quite attractive for several science and engineering applications.But,to the best of our knowledge,such schemes have not been extended to non-linear hyperbolic systems with non-conservative products.In this paper,we perform such an extension which improves the domain of the applicability of such schemes.The extension is carried out by writing the scheme in fluctuation form.We use the HLLI Riemann solver of Dumbser and Balsara(J.Comput.Phys.304:275-319,2016)as a building block for carrying out this extension.Because of the use of an HLL building block,the resulting scheme has a proper supersonic limit.The use of anti-diffusive fluxes ensures that stationary discontinuities can be preserved by the scheme,thus expanding its domain of the applicability.Our new finite difference WENO formulation uses the same WENO reconstruction that was used in classical versions,making it very easy for users to transition over to the present formulation.For conservation laws,the new finite difference WENO is shown to perform as well as the classical version of finite difference WENO,with two major advantages:(i)It can capture jumps in stationary linearly degenerate wave families exactly.(i)It only requires the reconstruction to be applied once.Several examples from hyperbolic PDE systems with non-conservative products are shown which indicate that the scheme works and achieves its design order of the accuracy for smooth multidimensional flows.Stringent Riemann problems and several novel multidimensional problems that are drawn from compressible Baer-Nunziato multiphase flow,multiphase debris flow and twolayer shallow water equations are also shown to document the robustness of the method.For some test problems that require well-balancing we have even been able to apply the scheme without any modification and obtain good results.Many useful PDEs may have stiff relaxation source terms for which the finite difference formulation of WENO is shown to provide some genuine advantages. 展开更多
关键词 Hyperbolic PDEs Numerical schemes Non-conservative products Stiff source terms Finite difference WENO
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Analysis of Regional Difference of Agricultural Land Productivity in Heilongjiang Province
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作者 Linlin CAO Jinrong YANG Shiqin YANG 《Asian Agricultural Research》 2024年第8期9-13,16,共6页
The sustenance of humanity is contingent upon the production of food.The foundation of this production is agriculture,which in turn is dependent upon the cultivation of the land.As a fundamental element of agricultura... The sustenance of humanity is contingent upon the production of food.The foundation of this production is agriculture,which in turn is dependent upon the cultivation of the land.As a fundamental element of agricultural advancement,the rational development and utilization of land play a pivotal role in the process of rural revitalization.Agricultural land productivity serves as a principal indicator of the efficacy of land utilization and the extent of agricultural advancement.Nevertheless,there is a paucity of research examining the productivity of agricultural land,particularly a lack of specialized research on large agricultural provinces.In light of the aforementioned considerations,this paper presents a comprehensive examination of agricultural land productivity and its regional variations in Heilongjiang Province in 2022,with the aid of pertinent statistical data.The findings of the analysis indicate that among the prefecture-level cities,Daqing and Suihua exhibit the highest levels of agricultural land productivity.Additionally,Zhaodong City,Zhaozhou,Qinggang,Wangkui,and Lanxi counties exhibit high levels of agricultural land productivity within their respective prefecture-level cities.There are notable disparities in agricultural land productivity across various regions,including Yichun,Heihe,Harbin,Daqing,Hegang,and Suihua.In contrast,other regions demonstrate a more balanced spatial distribution.In order to facilitate the prosperous development of the agricultural industry in Heilongjiang Province,it is essential to optimize the spatial planning of the land,to investigate the potential for agricultural development in each region,to establish effective collaboration between resources and industries,and to create a development synergy that will collectively advance rural revitalization. 展开更多
关键词 AGRICULTURAL LAND productIVITY REGIONAL difference Heilongjiang PROVINCE
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Study Competition Channel Structure Based on the Differences of Cost and Products 被引量:1
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作者 周岚 艾兴政 张迟 《Journal of Electronic Science and Technology of China》 2004年第1期84-88,共5页
The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under differe... The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under different conditions. We find that like product difference, cost difference have important influence on the choice of channel structure. This paper has improved the present result and provided proof for the choice of channel structure under different environments. 展开更多
关键词 channel structure evolution equilibrium cost difference product difference
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Construction of Value Models of Consumer Creation for Agricultural Products Based on the Analytic Hierarchy Process(AHP) 被引量:2
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作者 杨庆先 汤自英 《Agricultural Science & Technology》 CAS 2010年第4期180-183,共4页
With the increased competition of modern economy and globalization,consumer creation which based on the analysis of consumer behavior was more and more attentioned and respected by business.Based on the meaning and ch... With the increased competition of modern economy and globalization,consumer creation which based on the analysis of consumer behavior was more and more attentioned and respected by business.Based on the meaning and characteristics of agricultural product consumer creation,index system of value model of agricultural product consumer creation was put forward through analytical hierarchy process(AHP).The weights of the indicators and related indicators of impact on the value were analyzed,and value models of agricultural product consumer creation were constructed to provide ideas for development of agricultural product consumer market and research of consumer value.Consumer creation was constructed to provide ideas for development of agricultural product consumer market and research of consumer value. 展开更多
关键词 Agricultural products Consumer Creation Analytic hierarchy Process(AHP) Value Model
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Comparative Study on the Development Levels of Cold Chain Logistics for Agricultural Products between China and Developed Countries Based on Analytic Hierarchy Process 被引量:4
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作者 周兴建 《Agricultural Science & Technology》 CAS 2012年第5期1110-1114,共5页
By introducing the analytic hierarchy process (AHP), a model is constructed to compare the logistics development level of cold chain for agricultural products between China and other developed countries such as Unit... By introducing the analytic hierarchy process (AHP), a model is constructed to compare the logistics development level of cold chain for agricultural products between China and other developed countries such as United States, Japan and Euro- pean. The paper makes a comparative study on the development levels of agricultural cold chain logistics in China and developed countries from the aspects of the level of cold chain logistics facilities and equipments, the degree of cold chain logistics market-oriented and the capacity of cold chain logistics, then determines the problems of cold chain logistics in China. With the experiences learning from developed countries, some countermeasures are proposed to resolve those problems of cold chain logistics for agricultural products development combining with the national conditions in China. 展开更多
关键词 Analytic hierarchy process Agricultural products Cold chain logistics Comparative study
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Integrated Assessment of Environmental and Economic Performance of Chemical Products Using Analytic Hierarchy Process Approach 被引量:9
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作者 钱宇 黄智贤 闫志国 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第1期81-87,共7页
With the increasing public consciousness on environmental issues, chemical products and process designs require simultaneous satisfaction and compromise of environmental and economical requirements. To fulfill the two... With the increasing public consciousness on environmental issues, chemical products and process designs require simultaneous satisfaction and compromise of environmental and economical requirements. To fulfill the two conflicting while complementary objectives, a systematic approach for life cycle design of a chemical product is proposed in this article. Multiattribute decision-making is adopted in a trade-off consideration of both technical economical evaluation and environmental impacts assessment using the analytic hierarchy process (AHP) approach. On the basis of an evaluation of the relative importance of the criteria multicriteria decision making is performed. In this study, an AHP model is used to derive single a criteria score by analyzing the environmental impact and life cycle cost of a product, respectively. And a fluctuant weight analysis is put forth to calculate the integrated index of the product to enable products to be ranked or selected intuitionally and conveniently. The proposed AHP model has been applied to a case study, a comparative study on chamber cleaning with NF3 and C2F6. The resuits show that the protposed AHP model is Capable of providing a rational and relevant evaluation. 展开更多
关键词 life cycle assessment life cycle cost analytic hierarchy process chemical product
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THEORY AND APPLICATION OF FRACTIONAL STEP CHARACTERISTIC FINITE DIFFERENCE METHOD IN NUMERICAL SIMULATION OF SECOND ORDER ENHANCED OIL PRODUCTION 被引量:1
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作者 袁益让 程爱杰 +1 位作者 羊丹平 李长峰 《Acta Mathematica Scientia》 SCIE CSCD 2015年第6期1547-1565,共19页
A kind of second-order implicit fractional step characteristic finite difference method is presented in this paper for the numerically simulation coupled system of enhanced (chemical) oil production in porous media.... A kind of second-order implicit fractional step characteristic finite difference method is presented in this paper for the numerically simulation coupled system of enhanced (chemical) oil production in porous media. Some techniques, such as the calculus of variations, energy analysis method, commutativity of the products of difference operators, decomposition of high-order difference operators and the theory of a priori estimates are introduced and an optimal order error estimates in l^2 norm is derived. This method has been applied successfully to the numerical simulation of enhanced oil production in actual oilfields, and the simulation results ate quite interesting and satisfactory. 展开更多
关键词 enhanced (chemical) oil production three-dimensional porous coupled system second-order implicit characteristic fractional step differences optimal order l^2 estimate application in actual oilfields
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Inter-stage performance and energy characteristics analysis of electric submersible pump based on entropy production theory
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作者 Hui Wang Yang Yang +5 位作者 Bin Xi Wei-Dong Shi Chuan Wang Lei-Lei Ji Xiang-Yu Song Zhao-Ming He 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1354-1368,共15页
The electric submersible pump(ESP) is a crucial apparatus utilized for lifting in the oil extraction process.Its lifting capacity is enhanced by the multi-stage tandem structure, but variations in energy characteristi... The electric submersible pump(ESP) is a crucial apparatus utilized for lifting in the oil extraction process.Its lifting capacity is enhanced by the multi-stage tandem structure, but variations in energy characteristics and internal flow across stages are also introduced. In this study, the inter-stage variability of energy characteristics in ESP hydraulic systems is investigated through entropy production(EP) analysis,which incorporates numerical simulations and experimental validation. The EP theory facilitates the quantification of energy loss in each computational subdomain at all ESP stages, establishing a correlation between microscopic flow structure and energy dissipation within the system. Furthermore, the underlying causes of inter-stage variability in ESP hydraulic systems are examined, and the advantages and disadvantages of applying the EP theory in this context are evaluated. Consistent energy characteristics within the ESP, aligned with the distribution of internal flow structure, are provided by the EP theory, as demonstrated by our results. The EP theory also enables the quantitative analysis of internal flow losses and complements existing performance analysis methods to map the internal flow structure to hydraulic losses. Nonetheless, an inconsistency between the energy characterization based on EP theory and the traditional efficiency index when reflecting inter-stage differences is identified. This inconsistency arises from the exclusive focus of the EP theory on flow losses within the flow field, disregarding the quantification of external energy input to the flow field. This study provides a reference for the optimization of EP theory in rotating machinery while deeply investigating the energy dissipation characteristics of multistage hydraulic system, which has certain theoretical and practical significance. 展开更多
关键词 Electric submersible pump(ESP) Entropy production theory Energy characteristics Inter-stage differences
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Evaluation and Optimization of the Logistics Service of Agricultural Products:an Empirical Analysis Based on Analytic Hierarchy Process
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作者 WANG Bo WEI Leqin +3 位作者 CHEN Jinxiong TSAI Sangbing CHANG Lichung BIAN Fang 《Journal of Donghua University(English Edition)》 EI CAS 2019年第6期599-614,共16页
This research,from the theories of management science,supply chain management and logistics engineering,on the basis of extensive investigations,and using the method of analytic hierarchy process(AHP),evaluates the pr... This research,from the theories of management science,supply chain management and logistics engineering,on the basis of extensive investigations,and using the method of analytic hierarchy process(AHP),evaluates the present situation of logistics service of agricultural products.Taking Nanping City(Nanping)as a case,it explores the obstacles existing in current logistics service system and the factors limiting the development of agricultural product logistics service.Combining with the theory of modern logistics system,it reveals the problems in the logistics system and the causes,and then constructs the strategy of optimization for agricultural product logistics service in Nanping.The conclusion of the study can be references for the government to make scientific strategies for the development of the agricultural product logistics service and help logistics enterprises improve their service level. 展开更多
关键词 AGRICULTURAL product LOGISTICS service ANALYTIC hierarchy process(AHP) evaluation optimization supply chain
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Effects of different processing methods on the quality of Polygonatum cyrtonema Hua
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作者 Xin-Ning Zhang Shuang-Hui Shi +13 位作者 Jun-Li Zhang Fan-Miao Kong Hai-Ting Zhu Si-Yuan Ma Yu-Feng Hu Ming-Rui Jiang Hui-Nan Wang Meng-Lin Wang Xiao-Tong Wei Jing-Qiu Zhang Nan Sun Meng-Yu Chen Qian-Qian Liu Ying-Zi Wang 《TMR Modern Herbal Medicine》 CAS 2024年第2期28-34,共7页
Background:In this study,we explored the effects of different processing methods on the quality of Polygonatum cyrtonema Hua(PC),and the role of Huangjiu in the processing procedure.Methods:The sensory characteristics... Background:In this study,we explored the effects of different processing methods on the quality of Polygonatum cyrtonema Hua(PC),and the role of Huangjiu in the processing procedure.Methods:The sensory characteristics of the crude product,steamed product,and wine-processed product of PC were described.The colorimeter was used to analyze the chromatic values of three different processed products on PC.At the same time,the contents of the water extract and alcohol extract were measured separately.The content of three different processing Polygonatum Polysaccharide(PCP)was determined using 0.2%anthrone-sulfuric acid.The correlation difference between the chromatic values and chemical composition of different PC products was analyzed using various analytical methods.Results:The surface colors gradually deepened,the sweetness increased,the viscosity strengthened,and the tongue-numbing sensation disappeared after PC processing.The contents of extract and L^(*) gradually decreased from the crude to the steamed to the wine-processed product,consistent with the pattern of surface color alteration.While,E^(*)ab gradually increased.The content of PCP was crude product>wine-processed product>steamed product.The results of multivariate statistical analysis showed that the samples processed for crude,steamed,and wine-processed product were clustered into three classes.The correlation analysis showed that L^(*)and E^(*)ab were highly significant positively correlated with the content of PCP,and a*was significantly negatively correlated with the content of PCP.Conclusion:The results showed that the wine-processed product had the best quality.The internal quality of the PC was correlated with its characteristics and chromatic value.In this study,we investigated the internal and external quality of three different products of PC in order to provide a reference for further research on the impact of different processing methods on PC quality,the standardization of PC processing,and the role of Huangjiu in the processing of PC. 展开更多
关键词 Polygonatum cyrtonema Hua different products chemical composition chromatic value CHARACTERISTICS
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Assessment of Electricity Productivity in China:Regional Differences and Convergence
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作者 Pinjie Xie Ying Zhai +2 位作者 Fan Yang Zhuowen Mu Chao Wang 《Energy Engineering》 EI 2021年第5期1353-1374,共22页
Electricity productivity is regarded as a major assessment indicator in the design of energy saving policies,given that China has entered a“New Normal”of economic development.In fact,enhancing electricity productivi... Electricity productivity is regarded as a major assessment indicator in the design of energy saving policies,given that China has entered a“New Normal”of economic development.In fact,enhancing electricity productivity in an all-round way,as is one of the binding indicators for energy and environmental issues,means that non-growth target of total electric energy consumption in the economic development is feasible.The Gini coefficient,Theil index,and Mean log deviation are utilized to measure regional differences in China’s electricity productivity from 1997 to 2016 in five regions,and conditionalβconvergence is empirically analyzed with the spatial Durbin model.The results show that:(1)China’s electricity productivity is improving,while the overall feature is that the eastern area has a higher efficiency than the western area.(2)The difference in electricity productivity is the smallest in the northeast and the largest in the northwest.Interregional difference plays an important role and is the main cause for the differences.(3)The electricity productivity in China exhibitsβconvergence,except for the northwest.The positive driving factor is urbanization level(0.0485%),and the negative driving factor is FDI(–0.0104%).Moreover,the urbanization rate(0.0669%),foreign direct investment(0.0960%),and the industrial structure(–0.0769%)have a spatial spillover effect on improving regional electricity productivity.Based on this conclusion,the study provides some recommendations for saving energy policy design in China’s power industry. 展开更多
关键词 Electricity productivity regional differences CONVERGENCE spatial Durbin model
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Measurement of Grain Production Efficiency in Main Grain-producing Areas and Analysis of Inter-provincial Differences--A Study Based on Super-SBM Model and Malmquist Index
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作者 Qi Heng Su Jing-yan 《Journal of Northeast Agricultural University(English Edition)》 CAS 2022年第2期86-96,共11页
China's food security mainly depends on the core areas of food production.Under the dual constraints of resource scarcity and environmental degradation,improving the grain production efficiency of the main grain-p... China's food security mainly depends on the core areas of food production.Under the dual constraints of resource scarcity and environmental degradation,improving the grain production efficiency of the main grain-producing areas has become the fundamental way to strengthen the grain production capacity and improve the national food security capability,and to improve the efficiency of grain production in major grain-producing areas requires empirical support.This paper used the Super SBM model and the Malmquist index to measure the grain production efficiency of the main grain-producing areas from 2001 to 2020 from both static and dynamic perspectives,and compared the differences in grain production efficiency among different soil types and different provinces(autonomous regions)in the main grain-producing areas.The results showed that from 2001 to 2020,the grain production in the main grain-producing areas was in a relatively ineffective state,and the differences in grain production efficiency among different soil types and different provinces(autonomous regions)in the main grain-producing areas were obvious.The order of grain production efficiency in different soil types was black soil region>red-yellow soil region>paddy soil region>fluvo-aquic soil region,and the order of grain production efficiency of the provinces(autonomous regions)in the main grain-producing areas was Jilin>Heilongjiang>Inner Mongolia>Jiangxi>Hunan>Sichuan>Hubei>Jiangsu>Liaoning>Henan>Anhui>Shandong>Hebei.From 2001 to 2020,the total factor productivity of grain in the main grain-producing areas increased,but due to the trade-off between the technological progress and the growth of technical efficiency,the increase in the total factor productivity of grain in the main grain-producing areas was small,and the growth mainly came from the increase of input factors in this period.The total factor productivity of grain in Hebei,Heilongjiang,Liaoning,Jilin,Inner Mongolia,Shandong,Jiangsu,Henan and Anhui increased,but the increase was small,while the total factor productivity of grain in Jiangxi,Sichuan,Hunan and Hubei provinces declined. 展开更多
关键词 main grain-producing area grain production efficiency inter-provincial difference
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Measuring potential food productivity for different areas in Songnen Plain based on analytic hierarchy process
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作者 YAO Zuo-fang LIU Xing -tu +3 位作者 YANG Fei YAN Min-hua MENG Jun LIU Qiu-mei 《Ecological Economy》 2010年第2期161-167,共7页
The improved analytic hierachy process method was utilized in this paper,and a variety of factors influencing the food production were classified into several interrelated orderly objectives layers;based on the works ... The improved analytic hierachy process method was utilized in this paper,and a variety of factors influencing the food production were classified into several interrelated orderly objectives layers;based on the works above,this paper made an scientific assessment on the influencing factors of food production and production potential of the various regions in the Songnen Plain.The weights and composite indices were calculated with the method of solving weight by AHP's accumulation factor sequence evaluating data,and were processed by single-level sorting and general sorting.The result showed that,the region of Changchun had the biggest potential for improving food production,but smallest for Heihe region.The key reason for the food production discrepancy of a variety of regions in Songnen Plain is the differences in scale of production and climatic conditions,the weight coefficients of which are 0.3654 and 0.2742;however,the weight coefficients of agricultural science and technology investment is very low just 0.1703,which should be increasted in the future. 展开更多
关键词 Analytic hierarchy process Accumulation factor Food productivity potential
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High-Order Spatial FDTD Solver of Maxwell’s Equations for Terahertz Radiation Production
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作者 Abdelrahman Mahdy 《Journal of Applied Mathematics and Physics》 2024年第4期1028-1042,共15页
We applied a spatial high-order finite-difference-time-domain (HO-FDTD) scheme to solve 2D Maxwell’s equations in order to develop a fluid model employed to study the production of terahertz radiation by the filament... We applied a spatial high-order finite-difference-time-domain (HO-FDTD) scheme to solve 2D Maxwell’s equations in order to develop a fluid model employed to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma. We examined the performance of the applied scheme, in this context, we implemented the developed model to study selected phenomena in terahertz radiation production, such as the excitation energy and conversion efficiency of the produced THz radiation, in addition to the influence of the pulse chirping on properties of the produced radiation. The obtained numerical results have clarified that the applied HO-FDTD scheme is precisely accurate to solve Maxwell’s equations and sufficiently valid to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma. 展开更多
关键词 The Finite-difference-Time-Domain Terahertz Radiation production Filamentation of Femtosecond Laser Maxwell’s Equations Solution
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General Differences between Spoken and Written Language
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作者 古明 马博 《科技信息》 2010年第10期I0130-I0131,共2页
The history of language study shows widely different attitudes concerning the relationship between spoken and written language. After a person's born,he or she learns spoken language before learning written langua... The history of language study shows widely different attitudes concerning the relationship between spoken and written language. After a person's born,he or she learns spoken language before learning written language; therefore,many linguists consider written language a written form of spoken language,the function of which is to record the human sounds. Meanwhile,for centuries,the written language held a preeminent place. It was the medium of literature,which was felt to provide language with permanence and authority (David Crystal,2002). Therefore,what are the general differences between spoken and written language to make them present totally different functions? Accordingly,this essay will compare spoken language and written language to identify their general differences in three aspects. 展开更多
关键词 英语学习 英语语法 过去式 语言学
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Soil Quality Assessment of Acid Sulfate Paddy Soils with Different Productivities in Guangdong Province,China 被引量:20
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作者 LIU Zhan-jun ZHOU Wei +5 位作者 SHEN Jian-bo LI Shu-tian LIANG Guo-qing WANG Xiu-bin SUN Jing-wen AI Chao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第1期177-186,共10页
Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regi... Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regions. In our study, acid sulfate paddy soils were divided into soils with high, medium and low levels based on local rice productivity, and 60 soil samples were collected for analysis. Twenty soil variables including physical, chemical and biochemical properties were determined. Those variables that were significantly different between the high, medium and low productivity soils were selected for principal component analysis, and microbial biomass carbon (MBC), total nitrogen (TN), available silicon (ASi), pH and available zinc (AZn) were retained in the minimum data set (MDS). After scoring the MDS variables, they were integrated to calculate a soil quality index (SQI), and the high, medium and low productivity paddy soils received mean SQI scores of 0.95, 0.83 and 0.60, respectively. Low productivity paddy soils showed worse soil quality, and a large discrepancy was observed between the low and high productivity paddy soils. Lower MBC, TN, ASi, pH and available K (AK) were considered as the primary limiting factors. Additionally, all the soil samples collected were rich in available P and AZn, but deficient in AK and ASi. The results suggest that soil AK and ASi deficiencies were the main limiting factors for all the studied acid sulfate paddy soil regions. The application of K and Si on a national basis and other sustainable management approaches are suggested to improve rice productivity, especially for low productivity paddy soils. Our results indicated that there is a large potential for increasing productivity and producing more cereals in acid sulfate paddy soil regions. 展开更多
关键词 soil quality assessment acid sulfate paddy soil soil quality index different productivity
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Energy Efficiency Evaluation Based on Data Envelopment Analysis Integrated Analytic Hierarchy Process in Ethylene Production 被引量:2
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作者 韩永明 耿志强 刘启玉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第Z1期1279-1284,共6页
Energy efficiency data from ethylene production equipment are of high dimension, dynamic and time sequential, so their evaluation is affected by many factors. Abnormal data from ethylene production are eliminated thro... Energy efficiency data from ethylene production equipment are of high dimension, dynamic and time sequential, so their evaluation is affected by many factors. Abnormal data from ethylene production are eliminated through consistency test, making the data consumption uniform to improve the comparability of data. Due to the limit of input and output data of decision making unit in data envelopment analysis(DEA), the energy efficiency data from the same technology in a certain year are disposed monthly using DEA. The DEA data of energy efficiency from the same technology are weighted and fused using analytic hierarchy process. The energy efficiency data from different technologies are evaluated by their relative effectiveness to find the direction of energy saving and consumption reduction. 展开更多
关键词 ETHYLENE production EQUIPMENT ENERGY EFFICIENCY Data envelopment analysis ANALYTIC hierarchy process
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Use of venous-to-arterial carbon dioxide tension difference to guide resuscitation therapy in septic shock 被引量:29
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作者 Jihad Mallat Malcolm Lemyze +2 位作者 Laurent Tronchon Beno?t Vallet Didier Thevenin 《World Journal of Critical Care Medicine》 2016年第1期47-56,共10页
The mixed venous-to-arterial carbon dioxide(CO_2)tension difference[P(v-a) CO_2]is the difference between carbon dioxide tension(PCO_2) in mixed venous blood(sampled from a pulmonary artery catheter) and the PCO_2 in ... The mixed venous-to-arterial carbon dioxide(CO_2)tension difference[P(v-a) CO_2]is the difference between carbon dioxide tension(PCO_2) in mixed venous blood(sampled from a pulmonary artery catheter) and the PCO_2 in arterial blood.P(v-a) CO_2 depends on the cardiac output and the global CO_2 production,and on the complex relationship between PCO_2 and CO_2 content.Experimental and clinical studies support the evidence that P(v-a) CO_2 cannot serve as an indicator of tissue hypoxia,and should be regarded as an indicator of the adequacy of venous blood to wash out the total CO_2generated by the peripheral tissues.P(v-a) CO_2 can be replaced by the central venous-to-arterial CO_2 difference(△PCO_2),which is calculated from simultaneous sampling of central venous blood from a central vein catheter and arterial blood and,therefore,more easy to obtain at the bedside.Determining the △PCO_2 during the resuscitation of septic shock patients might be useful when deciding when to continue resuscitation despite a central venous oxygen saturation(SCVO_2) > 70%associated with elevated blood lactate levels.Because high blood lactate levels is not a discriminatory factor in determining the source of that stress,an increased △PCO_2(> 6 mmHg)could be used to identify patients who still remain inadequately resuscitated.Monitoring the △PCO_2 from the beginning of the reanimation of septic shock patients might be a valuable means to evaluate the adequacy of cardiac output in tissue perfusion and,thus,guiding the therapy.In this respect,it can aid to titrate inotropes to adjust oxygen delivery to CO_2 production,or to choose between hemoglobin correction or fluid/inotrope infusion in patients with a too low ScvO_2 related to metabolic demand.The combination of P(v-a) CO_2 or △PCO_2 with oxygen-derived parameters through the calculation of the P(v-a) CO_2 or △PCO_2/arteriovenous oxygen content difference ratio can detect the presence of global anaerobic metabolism. 展开更多
关键词 Venous-to-arterial CARBON dioxide tension difference CARBON dioxide production OXYGEN supply dependency Cardiac output tissue hypoxia Anaerobic metabolism OXYGEN consumption RESUSCITATION SEPTIC shock
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An Improved Analytic Hierarchy Process and Application in Grain Production 被引量:4
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作者 Gao Chun-yu Wang Wen-long 《Journal of Northeast Agricultural University(English Edition)》 CAS 2012年第2期66-70,共5页
Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process (AHP) accumulation factor, namely Solving Weight by AHP's Accumulati... Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process (AHP) accumulation factor, namely Solving Weight by AHP's Accumulation Factor Sequence Evaluating Data. We used the arithmetical average to replace the expert marking, so that the possible decision mistakes by the subjective judgments could be avoided. We computed the case with this method, which obtained attribute value of 17 influencing factors of the potential food production in Heilongjiang Province, and the result of which was reasonable 展开更多
关键词 Analytic hierarchy Process (AHP) accumulation factor potential food production
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Evaluating the conceptual design schemes of complex products based on FAHP using fuzzy number 被引量:1
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作者 周凯波 冯珊 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第3期574-578,共5页
In the conceptual design stage of complex products, CBR(Case-Based Reasoning) tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and e... In the conceptual design stage of complex products, CBR(Case-Based Reasoning) tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and evaluation. The procedure is essentially a multiple criteria decision-making problem. The traditional multiple criteria programming is not flexible enough in executing the system evaluation algorithm due to both the limited experimental data and the lack of human experiences. To make the CBR tool to be more efficient, a new method for the best choice among the feasible schemes based on the Fuzzy AHP using Fuzzy numbers (FFAHP) is proposed. Since the final results become a problem of ranking the mean of fuzzy numbers by the optimism of decision-maker using the FFAHP, its execution is much more intuitive and effective than with the traditional method. 展开更多
关键词 complex products conceptual design fuzzy analytic hierarchy process fuzzy number.
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