Efficient Finite Difference WENO Scheme for Hyperbolic Systems withNon-conservativeProducts

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.

Analysis of Regional Difference of Agricultural Land Productivity in Heilongjiang Province

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.

Inter-stage performance and energy characteristics analysis of electric submersible pump based on entropy production theory

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.

Study Competition Channel Structure Based on the Differences of Cost and Products

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.

Effects of different processing methods on the quality of Polygonatum cyrtonema Hua

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.

Assessment of Electricity Productivity in China:Regional Differences and Convergence

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.

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

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.

High-Order Spatial FDTD Solver of Maxwell’s Equations for Terahertz Radiation Production

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.

General Differences between Spoken and Written Language

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.

Soil Quality Assessment of Acid Sulfate Paddy Soils with Different Productivities in Guangdong Province,China

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.

Study on Differences in Procyanidine Content Between Muscat Hamburg Grape From Different Producing Areas

[Objectives] This study was conducted to analyze the differences in procyanidine content in grapes caused by different producing areas. [Methods]With Muscat Hamburg grape from different producing areas as an experimental material,procyanidine content was determined by n-butanol-hydrochloric acid colorimetry. [Results] The procyanidins contents in different parts of the same variety ranked as grape seed > grape skin > grape flesh. The procyanidins contents in grapes from different producing areas were in order of Changli County,Hebei Province > Dazeshan Town,Shandong Province > Hangu District,Tianjin City.[Conclusions]The procyanidins contents in Muscat Hamburg grapes from different producing areas differ to a certain degree.

THEORY AND APPLICATION OF FRACTIONAL STEP CHARACTERISTIC FINITE DIFFERENCE METHOD IN NUMERICAL SIMULATION OF SECOND ORDER ENHANCED OIL PRODUCTION

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.

Differentiated Production and the Differentiated Film Market System

The relationship between the differentiated production and the differentiated film market system is paid more attention to.The paper clarifies how to explore“extended screening”and“differentiated screening”,how to give art films a place to survive and thrive,and how to give audiences a variety of choices.Some effective suggestions are given from three dimensions.The differentiated low and mid-budget films are tower base and trailblazer.It is also necessary to comprehensively promote the development of a differentiated film market system in order to make differentiated,localized and genre-based productions that are competitive in the market.

Content Determination of Total Flavonoids in Tetracera asiatica from 10 Different Production Areas in Guangxi

[Objectives] To determine the content of total flavonoids in Tetracera asiatica from different production areas in Guangxi and provide a basis for improving the quality standards of crude drug. [Methods] Using 50% ethanol as extractor,NaNO_2-Al(NO_3)_3-NaOH as chromogenic system and rutin as the reference substance,the content of total flavonoids from the crude drug was determined. [Results] A method for determining the content of total flavonoids was established,the content of total flavonoids was 11.35-21.35 mg·g^(-1),and the average content was 17.64 mg·g^(-1). [Conclusions] The method had high repeatability and stability,and the method was simple,rapid and sensitive and suitable for quantitative analysis.

战略差异度、技术创新与企业全要素生产率——来自A股上市公司的经验证据

战略差异度对企业的影响是学术界关注的重要问题,而企业能否通过加大战略差异度进而提升全要素生产率为研究企业战略决策方面提供了不同的切入点。采用2009-2020年沪深A股上市公司的数据样本,实证检验了战略差异度对企业全要素生产率的影响。研究结果表明,战略差异度对企业全要素生产率起到显著的正向作用,技术创新在战略差异度影响企业全要素生产率的传导路径上存在中介效应。进一步研究发现,高行业竞争水平、高信息透明度和低融资约束企业的战略差异度越大对全要素生产率的正向作用越显著。研究丰富了全要素生产率的相关文献,并为其提供了研究的新视角。同时有助于企业利益相关者理解战略决策的经济后果,对指导和促进企业进行战略变革及获取竞争优势提供理论参考。

中国新质生产力的发展水平和演进趋势

新质生产力的测算是研究新质生产力发展水平的基础,但当前关于新质生产力的评价指标体系和测度方法尚处于探索阶段。鉴于新质生产力是质和量的统一、能力和效率的统一、现实性和可比性的统一,依据生产力理论,结合高质量发展的现实要求,以及新质生产力在科技创新、要素提升、生产组织等方面的特征,系统分析新质生产力的本质要求、构成要素、实现途径、培育载体和支撑环境,在此基础上构建包括技术、要素、数字、产业和环境五维度的指标体系,对中国30个省份2022—2022年的新质生产力发展水平进行测度,并分析其发展格局和演进趋势。结果表明:30个省份新质生产力发展水平增长较快,但区域差异、经济带差异、城市差异明显;要素生产力保持较高水平,数字生产力和创新生产力加快发展,绿色生产力和产业生产力成为发展的短板。其中,从区域格局来看,东部高于30个省份的平均水平,中西部和东北地区低于30个省份的平均水平;从经济格局来看,长江经济带最高,其次是泛珠三角,而丝绸之路经济带低于30个省份的平均水平;从城市格局来看,三大城市群从高到低依次为珠三角、长三角、京津冀,并且均高于30个省份的平均水平。

数字金融赋能农产品出口质量的作用机制

选取2011—2021年数字金融发展指数、联合国贸易数据库以及中国县域统计年鉴等数据,基于双固定效应模型实证研究了数字金融发展对中国农产品出口质量的影响及其作用机制。研究发现:数字金融发展能够显著促进中国农产品出口质量的提升;互联网发展水平和对外开放程度通过调节效应均显著强化了数字金融发展提升中国农产品出口质量;市场化进程在数字金融提升中国农产品出口质量中存在中介效应;此外,研究还发现数字金融发展对中国农产品出口质量存在区域异质性。

用能权交易制度对城市碳排放绩效改善的影响研究

用能权交易制度作为我国实现绿色发展的一项重要制度创新,对改善城市碳排放绩效具有重要意义。本文基于2006~2022年我国281个地级市的面板数据,采用双重差分模型检验用能权交易制度对城市碳排放绩效的作用机制及其溢出效应。研究发现:(1)用能权交易制度显著降低城市碳强度和提升碳全要素生产率;(2)用能权交易制度有利于非老工业基地和资源型城市碳强度的降低,同时也有利于非老工业基地和非资源型城市碳全要素生产率的提高;(3)用能权交易制度主要通过结构效应、创新效应和监管效应等途径改善城市碳排放绩效;(4)用能权交易制度的碳排放改善作用存在显著的正向空间溢出,能够实现环境红利和社会福利相容发展。因此,稳步扩大试点政策范围,积极探索实现路径和推进区域协同是实现绿色低碳的重要保障。

土地要素市场化改革能够提升企业生产效率吗?——基于工业用地市场化改革的准自然实验研究

深化土地要素市场化改革是提升全要素生产率、促进高质量发展的重要途径。基于微观企业视角,利用双重差分模型探究工业用地市场化改革对企业全要素生产率的影响,并从资源利用、资源配置和技术创新3个方面,探究具体的影响机制。结果表明:在研究期内,工业用地市场化改革整体上促进了企业全要素生产率提升约14%;对企业主体而言,规模越小、所属行业土地依赖程度越高,则全要素生产率的提升效果越明显;分区域来看,东北及西部地区企业生产效率的提升作用显著高于东部地区。进一步从中介效应看,该改革可以通过资源配置和技术创新来促进企业全要素生产率的提升;而资源利用机制并未发挥显著作用。综上,继续深化工业用地市场化改革,并着力优化土地资源在企业间的配置,提高企业技术创新水平,有利于企业生产率的提升。

碳排放权交易、数字经济与企业全要素生产率

“双碳”战略目标的提出契合高质量发展的内在需要,碳排放权交易市场是实现该目标的关键工具,2013—2014年,我国建立了首批七个试点碳交易市场,近十年以来,此项政策的减排效果已经受到广泛认可,但其对经济发展的影响依然值得探究。基于2010—2019年重污染行业A股上市公司的数据,本文以首批七个试点碳交易市场的正式启动为准自然实验,构建双重差分模型探讨该项政策对企业全要素生产率的影响,并从碳交易市场特征和数字经济发展的角度对作用机制进行分析。研究发现,碳交易政策能够显著提高企业的全要素生产率。机制分析表明,在碳交易政策对全要素生产率的作用过程中,企业数字化转型发挥了部分中介作用。此外,碳交易政策效果在非国有企业、风险承担水平高的企业中更强,并且碳市场的交易规模、流动性、数字基础设施、互联网普及率和数字普惠金融的发展都对碳交易政策效果发挥着正向调节效应,碳配额价格水平也具有一定的负向调节效应。