春小麦密度及农田生态效应优化模型的探讨

本文采用一元二次回归分析方法,对河套灌区当前的主栽品种春小麦永良4号.在采用两种主要播种工具,两种行距及不同播量下所产生的农田生态效应和产量结果,进行了综合研究,组建了复合优化模型.研究表明,在水肥、品种等条件一致的情况下,种肥分层播种机10厘米行距较15厘米行距和卫立耧10厘米行距更合理地调节了小麦单株营养面积,使个体生长健壮,群体发展合理,提高了土地利用率.这是实现河套灌区200万亩小麦再上新台阶的有效途径之一.     

湖南农业生态系统能值结构功能效率分析

为了探究湖南农业生态系统的能值投入产出结构功能与效率,揭示该区域人与自然资源和环境的相互关系,以能值理论为研究方法,以湖南农业2009年投入产出数据为依据,对湖南农业生态系统的能值结构、功能和效率进行实证分析。结果表明：（1）系统结构特点：湖南农业仍具有传统农业的生产特点,对劳动力、畜力的依赖性较大。工业辅助能值中,化肥对系统的贡献率最高,农业机械化水平低。工业辅助能值可更新比偏低,农业绿色能源的开发潜力和前景较大。系统产品定价偏低,忽视了自然资源和环境对农业生产的贡献,也反映出湖南农业产业链条相对短,产品附加值较低的特性。系统内部种植业和畜牧业的能值产出占绝对优势比例且其市场定价相对于林业和渔业偏低。（2）功能：该系统环境负载率虽不高,但是人口承受力超载。系统可持续发展指数为5.96,表明该系统富有活力和发展潜力,也意味着该系统经济并非常不发达、自然资源和环境的压力不是很大。（3）效率：该系统2009年的能值投入产出率略低于全国水平,表现出较明显的粗放型经济特点。因此,控制人口过快增长,转移剩余劳动力,进一步调整农业产业结构和产品结构,加强农业技术开发和利用,延长产业链,提高农业机械化和现代化水平是当前湖南农业的基本政策取向。     

基于扩展DEA模型的四川省油菜生产效率研究

为了客观评价四川油菜生产能力、市场竞争力,找到影响油菜生产效率提高的主要因素,运用扩展的DEA模型,对2008—2014 年间四川油菜生产效率进行了实证分析,同时将四川与中国油菜主产区中其他6 个省的生产效率进行了比较分析。结果表明：从整体来看四川油菜生产规模没有发挥到最佳状态,导致综合效率无效,实际单产低于潜在水平;另投入结构失衡程度较为严重,人工成本冗余量大。在省域层面上,湖北省油菜生产各效率较为突出,达到了生产前沿且生产较为稳定,其次是青海、江西,四川处于第四位,在比较区域中只具有比较优势。建议通过合理改善要素投入结构,适度调整生产规模,继续强化技术创新,提高生产机械化水平等途径提高四川油菜生产效率。     

基于DEA的甘肃农业产业化国家重点龙头企业绩效评价

运用数据包络分析方法,选取总资产、技术人员投入和主营业务成本作为输入指标,主营业务收入和净利润作为输出指标,对甘肃省10家典型农业产业化国家重点龙头企业生产效率进行评价。结果表明：龙头企业的总体效率趋于良好,但仍存在一定改进空间;DEA非有效企业的纯技术效率高于其规模效率;导致企业DEA非有效的主要原因是企业的资源利用效率不高与规模效益低;DEA非有效龙头企业普遍存在人力与资产冗余;强化资源利用效率、发挥技术规模效益是龙头企业发展中应关注的视角。     

设施蔬菜种植户的化肥施用效率及其影响因素研究

农户化肥施用量的快速增加不仅降低了化肥施用效率,同时造成了一系列的环境问题。通过明晰农户化肥施用效率和其影响因素,为今后政府制定相关政策引导农民合理施肥,减轻日益突出的农业面源污染借鉴与参考。基于辽宁、山东两省的113份设施蔬菜种植户调研数据,运用随机前沿分析模型,测度了调研地区设施蔬菜种植户的生产技术效率及化肥施用效率,并分析了农户化肥施用效率的影响因素。结果表明:调研地区大部分农户蔬菜种植技术效率介于60%和70%之间,而其化肥施用效率值介于10%和30%之间;农户是否参与技术培训与化肥施用效率间存在显著的正向关系,农户参与技术培训能够使其化肥施用效率提高8.6%,此外,农户受教育水平、是否具有正确的环保认知也与其化肥施用效率存在显著的正向关系。要进一步加强提高施肥效果的适用方法与技术的研究和实践推广,对种植户进行技术培训及有效的农业知识信息传递。     

Studies on the Structure Model of Coal and Its Polarization Characteristics

The macromolecular structures of coal samples collected from Yutianbao, Nantong and Qingnian coal mines in Sichuan were studied and a model of structure for these coals was set up. On the basis of above mentioned work,experimental studies and theoretical analyses were made to investigate the characteristics of coal polarization in applied electric field. The results indicate that the rotation polarzation and the space polarization are the essential reason for the attenuation of electric current through coal samples,and that the space polarization is the main form of coal polarization.     

基于SCP范式的中国水产品加工业的市场结构分析

水产品加工业在中国渔业的发展中发挥了举足轻重的作用,不仅是渔业产业增值增效的重要保障,而且也是发展现代渔业、优化渔业产业结构的有效途径。从产业层面分析,中国水产品加工业存在的很多矛盾和问题都与其市场结构特征有关,基于SCP范式,从市场集中度、产品差异化和进入退出壁垒等方面分析了中国水产品加工业的市场结构,为从调整市场结构入手来提高水产品加工业的市场绩效提供可以借鉴的理论基础和政策建议。     

Influencing Factors and the Concept Model of Human-information System Interaction Efficiency

The importance of human-information system interaction efficiency within enterprise informationization environment is analyzed.The intension of human-information system interaction efficiency is studied from definition,characteristic and evaluation.According to different properties,the influencing factors of human-information system interaction efficiency are divided into five kinds,including human factor,information system factor,management factor,environment factor,and technology factor.On this basis,the concept model of human-information system interaction efficiency is brought forward,and mechanisms of influencing factors to human-information system interaction efficiency are discussed in the model.The analysis indicates: As the core parts of the model,human factor and information system factor determine interaction efficiency directly.Management factor restricts or supports efficiency of human and information system.Environment factor and technology factor bring indirect influence to interaction efficiency by restricting or supporting human factor and information system factor.     

An Analysis on the Altitude of Industrial Structure of Chongqing

To supply an even more amplitude background for the analysis on the quality of the structure of Chongqing, this paper analyzed the altitudes of employment structure and production value structure among three industry structures in Chongqing, then an static and dynamic comparison with other countries of DIFFERENT levels on the basis of grasping Chongqing's status in Western Area. An structural explanation of ChongQing's economy development stage aiming at giving an even more amplitude background to analyze the essence of its industrial structure.     

碱处理对甜高粱秸秆渣组成结构及酶解糖化效果的影响

以甜高粱品种M81为试验材料,以清洗烘干后未经处理的甜高粱渣为对照,在常温、高温高压、微波条件下Ca(OH)₂和常温条件下NaOH处理甜高粱秸秆渣,调查处理后甜高粱秸秆渣木质纤维素组成结构及纤维素酶酶解糖化情况。结果表明,采用的4种处理都能有效地改变甜高粱渣木质纤维素组成结构,其中氢氧化钠常温长时间处理对于木质素与半纤维素的溶降效果最好,3种石灰处理对半纤维素的溶解也均有一定作用。扫描电镜观察石灰高温高压与氢氧化钠常温两种处理对于木质纤维素结构的改变不同,前者木质纤维素表层木质素结构被侵蚀严重,呈破碎状附着在纤维素表面,内部纤维结构仍紧密排列,后者木质纤维素束状结构溶胀降解,表层木质素成分被大量去除,被包裹的纤维素组分显露,纤维素网断裂且纤维素表面出现许多小孔。经这4种方式处理后的甜高粱渣,木质纤维素中纤维素与半纤维素经纤维素酶酶解糖化,葡萄糖和木糖产物浓度都有所提高,分别达到对照的1.5、2.1、1.9、4.2倍和3.1、5.0、4.9、2.4倍;木质纤维素纤维组分的直接转化率与相对转化率的含义与计算方法不同,两种计算方式对于甜高粱木质纤维素生物质原料预处理方式的选择和效果的综合评价具有指导意义。     

玉米主产省生产效率测度及影响因素分析——基于DEA-Tobit模型的实证研究

本文通过利用2004—2018年中国20省（直辖市、自治区）玉米投入产出面板数据,运用DEA-Malmquist方法,分析研究阶段内中国玉米生产效率的变化、空间差异及玉米生产过程中投入产出冗余情况,同时使用Tobit模型分析影响中国玉米生产效率的主要因素。研究结果表明:技术进步是促进中国玉米全要素生产率增长的主要关键因素,综合技术效率提升较小,其主要依赖于规模效率的增加;中国玉米生产综合技术效率总体呈现北方春播玉米区>西北灌溉玉米区>黄淮海夏播玉米区>西南山地玉米区;其中山西省、辽宁省、山东省、湖北省、云南省、陕西省、甘肃省均存在产出不足或投入冗余现象;农业机械总动力、受灾面积及地区差异对玉米生产技术效率影响显著。基于研究结论,提出3点建议,第一培育新型技术人才,加强玉米发展动力;第二改善基础设施建设,减缓自然灾害冲击;第三落实结构调整政策,开展规模适度经营。     

地力和养分管理模式对水稻产量和氮肥利用率的影响

为促进水稻高效生产,降低肥料投入对环境的影响,采用田间小区试验,研究了中、低两种地力水平下三种养分管理模式对水稻产量和氮肥利用率的影响。结果表明,施用氮肥在水稻生产中增产效果显著,与对照相比,早稻施氮比不施氮增产23.00％~26.10%,晚稻增产36.66％~71.43%,并且在相同的氮素水平下,低肥力地块平均增产效果要好于中肥力地块;三种养分管理模式中,最佳养分管理模式能显著提高氮肥利用率,早稻生产氮肥利用效率分别比相同地力水平的农民习惯施肥处理提高10.00%和8.36%,晚稻生产分别提高19.60%和16.89%;在不同的地力水平下,充足的氮素供应能提高水稻的实粒数和有效穗数,对氮素向籽粒的转化也起着积极的促进作用。     

A Study on Urban Land Structure Optimization Model

As far as the urban land structure is mentioned, it means the distribution of urban land among the different industries of the city. The problem of urban land structure is referred as unreasonable allocation of urban land caused by several factors, including the decision making mechanism of old economy and urban development policies. Different from using Fractal theory, Entropy theory and Functional theory, in this paper, with reference to Dissipative Structure Theory, one dynamic, systematic and historical optimization model of Max f(J_i, X_i) with two parameters of J_i and X_i will mainly be set up. This model can be used for analyzing the key factors determining the optimization of urban land structure.     

基于DEA分析中国绿茶生产效率实证的研究

生产效率是竞争力的一种体现,评价中国绿茶种植的生产效率,对中国茶产业的发展有重要意义;本文选用DEA方法,将中国绿茶十个主产省作为决策单元,对中国十省绿茶种植投入产出的有效性进行了评价;一方面得出浙江等省绿茶生产为非DEA有效,并分析了各非DEA有效单元原因所在,从规模来看,各决策单元都处于规模报酬递增阶段;另一方面根据投影分析测算了各单元投入冗余量;最后为茶农优化茶叶生产决策提出了建议。     

基于数据包络分析的农机维修企业技术效率研究

为综合评价农机维修企业运营情况,用数据包络分析(DEA)法和文本聚类法对调研的116个农机维修企业进行分类统计和技术效率分析.结果表明:农机维修企业技术效率处于较低水平,平均生产技术效率为0.642,纯技术效率和规模效率分别为0.736、0.880.不同类型农机维修企业效率不同,以组建方式分,品牌三包型技术效率最高、社...     

An Analysis on Specialization and Synthesis Development of ChongQing''s Industrial Structure

Through an analysis on specialization and synthesis development of Chongqing's three-D industrial structure and 13 major sectors, dominant specialization sectors and their status and functions, the relationships among dominant specialization sectors and non - specialization ones are given in this paper. This would be helpful for Chongqing to establish rational industrial policies, to upgrade its industrial structure level.     

Analysis on Efficiency and Fairness of Individual Income Tax

The relationship between efficiency and fairness of individual income tax is analyzed to get to know which one should be the first. By empirically researching on individual income tax and GD Pand analyzing on economic distributive rate and social unfair cost, the anthors conclude that efficiency of individual tax becomes weak and unfairness of it becomes strong. Thus, individual income tax should be reformed more fairly.     

The Dynamic Model Describing Influence of Industrial Structure and Technology Transfer on Economy Growth

The dynamic model of describing influence of industrial structure and technology transfer on economy growth is given in this paper. The model reflects three important results as follows (i) If Small Open Economy (SOE) is multiple and the number of employers in service department is increasing,then GNP per capital will grow;(ii) The change of industrial structure in manufacturing department will lead higher GNP per capitcal;(iii) If foreign direct investment (FDI) is realized by multisnational company with accompanying transfer of its own technology and productive service,then economy growth of the state which is imported the technology will be slowed down.     

Optimizing Capital Structure of Enterprises by Multiobjective Programming Model

This paper puts forward that capital structure is affected by cost of capital?risk?the agin ability? and the ability of capital value preserved and added, several factors, of and at the same time the authors analyzes them by approaching the limitation of regarding the weighted average cost of capital as the optimal standard of capital structure in the traditional capital structure decision-making method. Therefore multiobjective-programming method is applied in the capital structure to establish the target function and its subjection equations. Furthermore , this article shows its application.     

基于NC-DEA模型长株潭耕地利用经济效率的视窗分析

笔者利用长株潭地域15个县市区1996—2012时段面板数据,采用非控制变量数据包络模型视窗分析方法研究耕地利用效率的变化。结果发现:长株潭市区县地域单元耕地利用经济效率时间变化相对稳定,市域耕地利用经济效率高于其他地域,表明外部环境因素对经济效率产生明显影响,优越的社会经济环境条件有利于耕地效率的提高,非控制变量的数据包络方法在不删除其他要素条件下能评价耕地单要素效率,视窗分析能解释效率的动态变化,二者结合的特定要素的DEA视窗分析方法可以给其他类型土地效率评价提供重要的分析工具。