Study on Characteristics of Consumption Demand and Its Constraints of Rural Areas in China

Combining the statistic data of 1997~2009,this paper analyzes the income of farmers in eight minority areas, structure of consumption demand, the marginal propensity to consume and its constraints factors on eight minority provinces,finally, concludes with some specific proposals. That includes increasing peasant’s income, strengthening rural infrastructure construction, establishing perfect rural social security system and promoting reasonable and healthy consumption of peasants.

Factors in fluencing farmers' participation in crop intensification program in Rwanda

The crop intensification program（CIP）was introduced in Rwanda in 2007 by the Ministry of Agriculture and Animal Resources（MINAGRI）,Rwanda,as a solution to the land fragmentation,low use of agricultural inputs and low access to extension services.However,due to the voluntary nature of farmers’participation and their reluctance to participate,this study aimed at assessing the factors that influence their participation.Data were collected from 340 respondents through a household survey in Mayange and Rusarabuye sectors.Descriptive statistics and binary logistic regression model were used to analyze the data.Results show that the factors that significantly influenced the farmers’participation in the CIP include gender,non-farm income,farmland size,farming experience,land acquisition means,market access,trust and agro-ecological conditions.In fact,the non-farm income significantly increased the farmers’decisions to participate in the CIP（P〈0.001）as it eases the financial capital needed to invest in the CIP activities.On the land acquisition means,the farmers who inherited or bought the land positively and significantly participated in the CIP（P〈0.05）because they had the land tenure security.However,the participation in the CIP was hindered by inadequate irrigation and mechanization facilities,lack of farmers’participation in the CIP planning process,inadequate extension services,inadequate agricultural inputs and inadequate post-harvest technologies.Closer collaboration between farmers,local leaders,extension agents and agricultural service providers as well as the farmers’practical skills in irrigation and mechanization could enhance the participation to the program.Therefore,there is a need on the part of policymakers to empower farmers with adequate knowledge on better cropping practices and agricultural technologies through appropriate extension services and bottom-up based program.

AHP Analysis of the Factors Influencing Credit for Temporarily Poor Farmers: Based on the Survey of Rongchang County of Chongqing Municipality

From the perspective of the influence on credit for farmers,this paper takes the temporarily poor farmers in Rongchang County of Chongqing Municipality as the respondents,and employs the expert survey method and on-site analysis to analyze the reasons and put forward three hypotheses. Using the AHP model,we carry out the empirical analysis of three major hypotheses concerning the credit for farmers. The study demonstrates that the state's unclear definition of property rights of farmers and farmers' lack of collateral are the primary factor influencing the credit for farmers,followed by insufficient targeted financial and technical support for the farmers who are engaged in the agricultural sector affected by the nature; farmers do not really get the assistance for them to use the natural resources to develop the rural economy,so that the banks complicate the loan procedures and increase the requirements of loans for farmers in order to ensure the capital liquidity and safety,thus further deepening the plight of credit for farmers.

Stability analysis of particle swarm optimization without Lipschitz constraint

There are some adjustable parameters which directly influence the performance and stability of Particle Swarm Optimization algorithm. In this paper, stabilities of PSO with constant parameters and time-varying parameters are analyzed without Lipschitz constraint. Necessary and sufficient stability conditions for acceleration factor P and inertia weight w are presented. Experiments on benchmark functions show the good performance of PSO satisfying the stability condition, even without Lipschitz constraint. And the inertia weight ω value is enhanced to (-1,1). Keywords Lipschitz constraint - Time-varying discrete system - Adaptive acceleration factor - Stability

新时期河北省粮食综合生产能力现状与对策研究

保障粮食安全是社会经济发展的根基。文章阐述了河北省粮食产业发展现状,如粮食播种面积趋稳回升、粮食单产稳步增长、粮食总产量呈上升趋势、粮食供给储备总量充足等,分析了河北省粮食生产的制约因素,并从加强高标准农田建设、加强京津冀合作、强化科学防灾减灾、加强经营主体培育等方面提出了促进河北省粮食生产的对策和建议。

塔里木盆地下寒武统玉尔吐斯组沉积特征及有机质富集模式

塔里木盆地是我国西北部规模最大的含油气盆地,盆内下寒武统玉尔吐斯组为一套富含有机质的泥岩和碳酸盐岩沉积,构成盆内最重要的烃源岩之一。本文基于露头、钻测井、地震、岩心岩屑等资料综合分析,简述玉尔吐斯组的岩相、沉积相和古地理分布特征,揭示富有机质沉积的分布及其控制因素。玉尔吐斯组以古暴露面为界可划分为三个层序,总体形成于被动陆缘混积的缓坡陆棚环境。可识别出10种岩相和7个岩相组合以及4种主要的沉积相类型;沉积古地理编图揭示由南西向北东方向依次展布混积潮坪、浅水内陆棚、深水外陆棚到深水盆地的沉积相带分布。富有机质沉积主要发育于深水外陆棚相带,以发育具有异常高的TOC值和丰度极高的微量元素的黑色泥页岩为特征。有机质的富集与高的古生产力和保存条件有关。热液活动带来了丰富的营养元素;上升洋流促进营养元素与正常海水的混合和扩散,形成富营养化的表层水;深水外陆棚区缺氧条件有利于有机质的保存富集。

金融能力、正规信贷约束与农户创业行为

基于金融能力和正规信贷约束视角,利用2017年和2019年CHFS微观数据,通过构建Probit模型实证分析金融能力对农户创业行为的影响,探讨正规信贷约束在金融能力和农户创业行为关系中发挥的中介效应。结果表明:金融能力对农户创业行为具有显著正向影响,且在考虑内生性的情况下,该结论仍然成立;中介机制检验表明,金融能力能够通过缓解正规信贷约束来促进农户创业行为;异质性分析表明,中、西部地区和三线及以下城市的农户金融能力对其创业行为的影响更为显著。据此,建议建立完善的金融能力培养体系,加大对欠发达地区的政策扶持,且提高正规信贷支持力度。

扩大我国企业年金制度覆盖面研究:理论基础、制约因素与对策建议

提高企业年金覆盖率是人口老龄化背景下,发展我国多层次多支柱养老保险体系的重要举措。现阶段,我国企业年金制度在参与规模与投资收益增长上成效显著,但覆盖率长期偏低、参与企业的类型失衡等问题也不容忽视。在明确企业年金本质是企业利润分享、直接目标是留住与吸引人才、表现形式近似延期工资或企业福利的基础上,结合对多地区、多行业与多类型的尚未及已经建立企业年金计划的企业的调研,从主体与制度两个维度,构建了企业建立年金计划的制约因素分析框架,提出应从重新审视企业年金制度定位、探索设立简易企业年金计划、适度放宽建立企业年金计划的条件、适时优化企业年金计划各运作环节的政策设计、扎实推进企业年金政策宣传工作等方面入手,推动我国企业年金扩面工作的高质量开展。

社保费征管与企业投资——基于社会保险法实施的准自然实验

经济下行压力下,稳投资是关系国计民生的重大战略方向。以社会保险法实施为准自然实验,采用双重差分法探究社保费征管对企业投资的影响,研究发现:社保费征管加强显著提升了企业投资,该效应在超额雇佣、行业竞争激烈、外部社保压力大以及由税务部门征收社保费的企业更为明显。机制检验表明,社保费征管加强会通过“要素替代效应”促进企业投资,同时也会产生“现金流约束效应”抑制企业投资,而前者为核心作用机制。进一步研究显示,社会保险法实施后,企业会增加创新投入和债务融资,最终提高了企业绩效和企业价值。

结构性货币政策对绿色企业全要素生产率的影响

结构性货币政策对于精准支持绿色企业发展具有重要作用,本文以2018年央行担保品框架扩容这一结构性货币政策为准自然实验,借助双重差分模型研究央行将绿色债券纳入担保品框架后对绿色企业全要素生产率的影响。研究发现:担保品框架扩容可以显著提升绿色企业的全要素生产率。企业异质性研究发现担保品框架扩容对民营绿色企业全要素生产率的提升显著高于国有绿色企业;区域异质性研究发现担保品框架扩容对于处在金融发达地区的绿色企业全要素生产率的提升更为显著;行业异质性研究发现央行将绿色债券纳入担保品框架后更能促进专利密集行业中绿色企业全要素生产率的提升。进一步研究发现担保品框架扩容有效缓解了绿色企业融资约束,提升了企业的绿色创新水平,有助于绿色企业提升全要素生产率。

黄河流域水土保持新质生产力发展路径思考

水土流失是黄河流域主要的生态环境问题之一,发展水土保持新质生产力是推进黄河流域生态保护和高质量发展的重要着力点。为给改善黄河流域生态环境、推动黄河流域生态保护和高质量发展提供参考,结合黄河流域水土保持工作实际,阐释了水土保持新质生产力的内涵;从水土保持的体制机制建设、基础研究、监测评价、监管、水土流失综合治理五方面,总结了黄河流域水土保持工作成效;依据劳动者、劳动资料、劳动对象的内涵,探讨了人才培养、科技创新、生产实践等方面对发展黄河流域水土保持新质生产力的制约因素;从劳动者、劳动资料、劳动对象三方面提出黄河流域水土保持新质生产力的发展路径,在劳动者方面要强化体制机制创新、专业基础教育,在劳动资料方面要强化智慧黄河水土保持建设、高精尖科学技术融合、水土保持碳汇体系研究和黄土高原重力侵蚀机理研究等,在劳动对象方面要强化重点领域科技攻关、监测评价深度应用、生产建设项目水土保持管理和水土流失治理提质增效等。

Early constraint-induced movement therapy affects behavior and neuronal plasticity in ischemia-injured rat brains

Constraint-induced movement therapy is an effective rehabilitative training technique used to improve the restoration of impaired upper extremity movement after stroke. However, whether constraint-induced movement therapy is more effective than conventional rehabilitation in acute or sub-acute stroke remains controversial. The aim of the present study was to identify the optimal time to start constraint-induced movement therapy after ischemic stroke and to explore the mechanisms by which constraint-induced movement therapy leads to post-stroke recovery. Sixty-four adult male Sprague-Dawley rats were randomly divided into four groups: sham-surgery group, cerebral ischemia/reperfusion group, early constraint-induced movement therapy group, and late constraint-induced movement therapy group. Rat models of left middle cerebral artery occlusion were established according to the Zea Longa line embolism method. Constraint-induced movement therapy was conducted starting on day 1 or day 14 in the early constraint-induced movement therapy and late constraint-induced movement therapy groups, respectively. To explore the effect of each intervention time on neuromotor function, behavioral function was assessed using a balance beam walking test before surgery and at 8 and 21 days after surgery. The expression levels of brain-derived neurotrophic factor, nerve growth factor and Nogo receptor were evaluated using real time-polymerase chain reaction and western blot assay to assess the effect of each intervention time. The results showed that the behavioral score was significantly lower in the early constraint-induced movement therapy group than in the cerebral ischemia/reperfusion and late constraint-induced movement therapy groups at 8 days. At 21 days, the scores had significantly decreased in the early constraint-induced movement therapy and late constraint-induced movement therapy groups. At 8 days, only mild pyknosis appeared in neurons of the ischemic penumbra in the early constraint-induced movement therapy group, which was distinctly better than in the cerebral ischemia/reperfusion group. At 21 days, only a few vacuolated cells were observed and no obvious inflammatory cells were visible in late constraint-induced movement therapy group, which was much better than at 8 days. The mRNA and protein expression levels of brain-derived neurotrophic factor and nerve growth factor were significantly higher, but expression levels of Nogo receptor were significantly lower in the early constraint-induced movement therapy group compared with the cerebral ischemia/reperfusion and late constraint-induced movement therapy groups at 8 days. The changes in expression levels at 21 days were larger but similar in both the early constraint-induced movement therapy and late constraint-induced movement therapy groups. Besides, the protein nerve growth factor level was higher in the late constraint-induced movement therapy group than in the early constraint-induced movement therapy group at 21 days. These results suggest that both early(1 day) and late(14 days) constraint-induced movement therapy induces molecular plasticity and facilitates functional recovery after ischemic stroke, as illustrated by the histology. The mechanism may be associated with downregulation of Nogo receptor expression and upregulation of brain-derived neurotrophic factor and nerve growth factor expression.

绿色金融对黄河流域工业企业绿色全要素生产率影响机理研究

提升工业企业绿色全要素生产率是黄河流域绿色高质量发展的关键一环,而这离不开绿色金融的大力支持。本文基于2010—2021年黄河流域A股上市工业企业数据,采用SBM-DDF-GML指数测算黄河流域工业企业绿色全要素生产率,检验了绿色金融对其影响及作用机理。结果显示:绿色金融与工业企业绿色全要素生产率呈现先抑后扬的“U型”关系;机理检验表明,融资约束和技术创新分别在绿色金融与工业企业绿色全要素生产率的“U型”关系之间发挥中介和调节作用;异质性检验发现,黄河流域中上游工业企业绿色全要素生产率相比下游受绿色金融影响更大。研究结论丰富并拓展了绿色金融与工业企业绿色全要素生产率间的关系研究,为通过绿色金融促进黄河流域高质量发展提供了经验证据和决策支持。

Nonnegative Matrix Factorization with Zellner Penalty

Nonnegative matrix factorization (NMF) is a relatively new unsupervised learning algorithm that decomposes a nonnegative data matrix into a parts-based, lower dimensional, linear representation of the data. NMF has applications in image processing, text mining, recommendation systems and a variety of other fields. Since its inception, the NMF algorithm has been modified and explored by numerous authors. One such modification involves the addition of auxiliary constraints to the objective function of the factorization. The purpose of these auxiliary constraints is to impose task-specific penalties or restrictions on the objective function. Though many auxiliary constraints have been studied, none have made use of data-dependent penalties. In this paper, we propose Zellner nonnegative matrix factorization (ZNMF), which uses data-dependent auxiliary constraints. We assess the facial recognition performance of the ZNMF algorithm and several other well-known constrained NMF algorithms using the Cambridge ORL database.

基于储能系统多重约束的一次调频策略

基于荷电状态(state of charge,SOC)控制储能系统参与一次调频时,由于储能系统出力约束条件较为单一,因而限制了储能系统的性能。针对此问题提出一种基于储能系统多重约束的一次调频策略。首先,把通过双层模糊控制方法确定储能系统多时间尺度调频死区作为第1重约束条件,避免火电机组与储能电池频繁动作。其次,将SOC作为第2重约束条件,约束因子作为第3重约束条件,基于logistic曲线构建惯性与下垂综合控制模型,约束储能系统出力。最后,通过高精度SOC构建快速均衡函数,缩短SOC均衡时间。通过搭建仿真模型分别在阶跃负荷扰动和连续负荷扰动的工况下验证所提控制策略有效性。

企业ESG实践、全要素生产率提升与中国经济高质量发展——基于中国上市公司微观数据的分析

近年来,绿色发展和可持续发展理念逐渐深入人心,而以ESG为代表的绿色投资不仅为“双碳”目标的实现注入了新的动力,也为企业低碳转型、实现可持续发展奠定了基础。利用2012-2021年1 229家上市公司数据,从理论和实证两个方面研究企业ESG实践对全要素生产率的积极影响。研究发现:(1)企业ESG实践能够显著降低企业融资约束、优化人力资本结构、促进技术创新能力提升,从而实现全要素生产率的稳健提升;(2)在重污染企业及国有企业中,企业ESG实践促进全要素生产率的效果更加显著,对不同类型企业具有显著的非对称影响;(3)创新性地将企业ESG实践、全要素生产率及GDP进行联系,发现企业ESG实践对地区GDP有正向贡献,且从国家层面看,企业ESG实践对经济高质量发展发挥着日益重要的作用。

抚仙湖流域典型农田土壤质量状况及烟草种植障碍因素

以云南抚仙湖北岸澄江市约1130 hm^(2)农田土壤为研究对象,通过调查分析土壤物理、化学性质,评价了研究区土壤质量状况,并进一步利用空间分析、相关分析与主成分分析对研究区烟草种植的主要土壤障碍因子进行了分析。结果表明:研究区土壤整体偏黏(平均黏粒含量496.7 g/kg)、偏碱(pH均值7.45)、有机质含量较高(均值28.55 g/kg)、大中微量营养元素有效态含量也整体偏高(水解性氮均值119.10 mg/kg、有效磷均值68.85 mg/kg、速效钾均值208.44 mg/kg、有效锰均值28.14 mg/kg),但各土壤性质在空间上变异较大。土壤基础地力、人为施肥管理、质地、酸碱性、有效锰是影响该地区土壤肥力的主要障碍因素,这些因素可通过有机质、速效钾、黏粒、pH、有效锰等指标进行评价,并指导烟草种植的土壤管理。烟草种植过程中应根据土壤性质、烟草养分需求,结合土壤养分空间变异采取相应的土壤改良措施。

数据要素市场化对制造业全要素产率的影响研究

本文从数据要素市场化的组成视角出发,构建了数据要素市场化指标,为了解各省份数据要素市场化水平现状以供参考,并以2013-2020年中国制造业企业上市企业公司数据为样本,在构建数据要素市场化影响制造业企业全要素生产率理论框架的基础上,实证检验了数据要素市场化对企业全要素生产率的影响机理。研究发现:(1)数据要素市场对制造业全要素生产率具有显著正向影响,提高数据要素市场化水平有利于提升制造业全要素生产率。(2)内在机理表明,融资约束和企业创新的中介效应显著,数据要素市场化可以通过缓解企业融资约束和促进企业创新来提升制造业企业全要素生产率。(3)异质性效应表明,数据要素市场化对国营经济企业和处于明星型省份企业效果较好。

社保费负担、创新挤出与企业生产率--基于社保费征管体制改革的研究

税务部门全责征收社保费,有助于社保费征缴体系的规范,但社保征缴力度的加强增加了企业税费负担,挤出了企业创新投入,不利于生产率的提升。2019年中国开始全面推行税务部门全责征收社保费,但自2000年起,广东、浙江、福建等六个省份已陆续完成税务全责征收试点。本文利用1998-2013年中国工业企业数据,使用双重差分模型,评估了税务全责征收社保费改革对企业全要素生产率的影响。结果显示,改革显著降低了企业全要素生产率。政策实施后,企业全要素生产率平均降低16%。进一步检验税务全责征收模式影响企业全要素生产率的机制发现,改革增加了企业的社保费负担,缩减了企业现金流,加深了企业融资约束程度,从而挤出了企业的创新投入,导致企业研发投入和申请专利数量显著下降。本文结论表明,在推行税务全责征收社保费、规范社保征收体系的同时,应考虑激发市场主体的活力,缓释改革对企业生产带来的阵痛,为企业纾困解难。

资本市场发行制度改革如何提升企业全要素生产率?——基于推行股票发行注册制的经验分析

实行股票发行注册制能够提高金融资源配置载体的有效性和资本市场价格信号的准确灵敏性,进而通过优化金融资源配置提升企业的全要素生产率。基于我国逐步推行股票发行注册制的准自然实验,采用沪深A股上市公司2016—2022年的数据进行PSM—多期DID分析,结果显示:相比采用核准制发行股票的企业,采用注册制的企业全要素生产率更高,表明实行注册制能够显著提升企业全要素生产率;实行股票发行注册制可以通过缓解企业融资约束、增加企业创新投入、提高企业投资效率等金融资源优化渠道来提升企业全要素生产率;实行股票发行注册制对非国有企业和竞争程度较高行业的企业具有更显著的全要素生产率提升作用,但注册制影响企业全要素生产率的地区异质性不显著。因此,应继续推动股票发行制度改革走深走实,以市场化、规范化、国际化改革完善资本市场运行机制,通过优化金融资源配置赋能实体经济高质量发展。