Prediction of Total Output Value of Construction Industry in Jiangxi Province Based on Grey Prediction Model

In order to realize the accurate prediction of the total output value of construction industry in the future,the grey prediction model is used to compare the measured value with the predicted value from 2012 to 2021,and based on the existing data,the total output value of construction industry in Jiangxi Province in the next five years is predicted.The results show that the grey prediction model has a good prediction effect,and the error between the predicted value and the measured value is within 14%,which provides a basis for policy adjustment and resource optimization.

The Application of LM-BP Neural Network in the Prediction of Total Output Value of Agriculture

Gross agricultural product is an important indication to measure the agricultural development level of a region. It would be affected by many factors,having the characteristics of non- linearity. For this reason,LM- BP neural network was put forward as the model and method for predicting gross agricultural product. Taking the indications of the sown area of crop,the output of grain,sugarcane,cassava,tea,meat,aquatic products,turpentine and camellia seed,etc. as inputs,during 2000 to 2012 in Guangxi,the gross agricultural product data from the analysis of simulation experiment show that the prediction of LM- BP neural network fits well with actual results.

河北省农业科技试验区发展思考与探讨

农业科技试验区以注重科技落地和解决生产难题为核心,发挥引领示范作用,促进农业经济持续增长。在梳理河北省农业科技试验区发展历程和现状基础上,研究其对农业经济发展的推动作用。但近年来河北省农业科技试验区发展缓慢且地位下降,分析其原因,主要存在对试验区的认识有偏差、试验区工作力度减弱和试验区立项难3种问题。针对问题提出恢复农业科技试验区项目支持、注重农业科技试验区科技人才队伍培养和加强试验区科技工作指导的对策建议。

“双碳”目标下黄河流域旅游绿色生产率时空分异特征及影响因素——以陕西段为例

陕西作为黄河流域旅游资源赋存高密度区,其绿色发展对黄河流域高标准高质量地实现“双碳”目标起着重要作用。收集2010—2021年相关数据,采用非期望产出的SBM模型、ML指数及Tobit回归模型等方法对陕西旅游绿色生产率(TGTFP)的时空分异特征及影响因素进行了分析。研究表明:(1)在时序发展上,2010—2021年内陕西旅游能源消耗与碳排放总量呈上升态势,其静态TGTFP唯有2017年实现有效,动态ML指数在2010—2013年和2014—2019年内实现有效,但其他年份均表现为无效,在发展过程中均呈左高右低的山峰型。(2)在空间分异上,TGTFP呈现“关中最强,陕北高于陕南”的分异特征,三大区域内部市域发展渐趋均衡,而三大区域间分化显著导致了陕西总差异扩大。(3)影响因素上,政府干预、环境规制及城镇化水平等外部因素对陕西旅游绿色生产率具有显著的推动作用,但仍有强烈的内部阻力来自旅游总收入、旅游能源消费及碳排放。

数字化转型对企业全要素生产率的影响——基于产业链关联视角

文章选取上市公司年报以及投入产出表的相关数据,通过面板数据模型考察数字化转型对企业全要素生产率的影响效应及其作用机制。结果表明:数字化转型能够提升企业全要素生产率,并且在缓解内生性问题和进行一系列稳健性检验后结论依然成立;数字化转型能够通过前向关联、后向关联两种渠道来增强产业链关联的创新效应和结构效应,进而促进企业全要素生产率增长;数字化转型对企业全要素生产率增长的促进作用存在行业异质性,在劳动密集型和竞争性行业的作用效果更为明显。

一种基于稀疏重构的多视角MIMO雷达关联成像算法研究

为改善复杂目标的成像表现、提升雷达图像的视觉效果,提出一种基于稀疏重构的多视角多输入多输出(multiple input multiple output,MIMO)雷达关联成像方法,设计了多视角雷达散射面积(radar cross section,RCS)起伏的稀疏重构关联成像模型。所提算法能提高辐射场信号随机性,改善复杂目标雷达关联成像参考信号与回波之间相关性退化的情况,减小多视角RCS起伏对相关性的影响,提升多视角下的关联成像质量。最后,通过仿真验证了所提方法的有效性。

碳排放权交易提高了城市全要素碳排放效率吗?——基于内生方向距离函数模型的研究

减碳措施一般会带来总产出的降低,因此有必要从全要素效率的角度评估减碳政策。本文构建了一个方向距离函数模型,允许各决策单元有不等的减排因子,扩大了生产可行集的范围,同时采用了内生的方向向量,避免在选择方向向量时过于主观。基于这一模型本文重新测算了城市层面全要素碳排放效率,并实证分析碳交易政策对其的影响,研究发现,试点政策能够提高城市全要素碳排放效率;中介效应表明,试点政策会通过产业结构和绿色创新等途径提高城市碳排放效率;异质性分析发现,试点政策对于高行政等级和人口规模较大城市的碳排放效率影响更明显。因此,应扩大政策试点范围、鼓励产业结构优化、推广绿色技术创新、制定因地制宜的试点政策等进一步提升碳排放权交易制度的绿色发展效应。

我国“一带一路”节点城市全要素能源效率空间分异研究

利用含非期望产出的SUPER-SBM-DEA模型测算2005—2019年我国“一带一路”17个节点城市的全要素能源效率,并从时间和空间两个维度分别进行对比分析,借助Tobit模型探究其影响因素。研究表明:各节点城市全要素能源效率总体水平较低,城市间全要素能源效率差异较大,存在不平衡性;“一路”节点城市全要素能源效率始终高于“一带”节点城市,但两者均呈收敛之势;各节点城市Malmquist指数均大于1,技术进步对“一带”节点城市能源效率增长贡献较“一路”节点城市更为显著,“一路”节点城市技术效率差异较大;生产要素比例、对外开放程度、科技研发和能源价格对节点城市全要素能源效率提高有积极影响,经济发展水平和工业污染则对其有消极影响;经济发展水平对“一带”节点城市能源效率的影响显著为正,生产要素比例、能源消费结构却抑制其发展,而这三个要素对“一路”节点城市能源效率的影响与之相反。

不同体位对健康成年人血流动力学和呼吸的影响:系统评价和荟萃分析

目的不同的体位对血流动力学和呼吸均有正向和负向的生理作用。本研究旨在进行文献综述并探讨不同体位的血流动力学和呼吸变化。方法研究方案在国际前瞻性系统评价登记处注册(注册号:CRD42021291464)。两名独立研究人员使用Down and Black检查表评估了所有纳入研究的方法学质量,而证据质量的评估则基于“推荐意见分级的评估、制定及评价”(Grading of Recommendations,Assessment,Development,and Evaluations,GRADE)。通过随机效应荟萃分析报告了不同体位的总体效果。结果3项低偏倚风险研究和10项高偏倚风险研究符合纳入标准。与70度直立倾斜位、坐位和站姿相比,仰卧位的心输出量最高(极低至中等质量的证据);与70度直立倾斜位和站姿相比,仰卧位的全身血管阻力最低(中等质量证据)。此外,与70度直立倾斜位、左侧和站姿相比,仰卧位的总呼吸阻力最高(极低至中等质量的证据),而其肺泡通气量则高于俯卧位(低质量证据)。结论仰卧位与血流动力学变量的正相关性最高,相对应的心输出量最高、全身血管阻力最低。直立体位(70度直立倾斜位和站姿)与呼吸变量的正相关性最高,相对应地总呼吸阻力最低。

Agricultural Policy, Climate Factors and Grain Output: Evidence From Household Survey Data in Rural China

This paper estimates a stochastic frontier function using a panel data set that includes 4 961 farmer households for the period of 2005-2009 to decompose the growth of grain production and the total factor productivity （TFP） growth at the farmer level. The empirical results show that the major contributor to the grain output growth for farmers is input growth and that its average contribution accounts for 60.92% of farmer’s grain production growth in the period of 2006-2009, whereas the average contributions sourced from TFP growth and residuals are only 17.30 and 21.78%, respectively. The growth of intermediate inputs is a top contributor with an average contribution of 44.46%, followed by the planted area （18.16%）, investment in fixed assets （1.05%）, and labor input （-2.75%）, indicating that the contribution from the farmer’s input growth is mainly due to the growth of intermediate inputs and that the decline in labor inputs has become an obstacle for farmers in seeking grain output growth. Among the elements consisting of TFP growth, the contribution of technical progress is the largest （32.04%）, followed by grain subsidies （8.55%）, the average monthly temperature （4.26%）, the average monthly precipitation （-0.88%）, the adjusted scale effect （-5.66%）, and growth in technical efficiency （-21.01%）. In general, the contribution of climate factors and agricultural policy factor are positive and significant.

1992-2020年京津冀全要素生产率的估算——基于3种估计方法

基于1992-2020年京津冀3地宏观数据,利用索洛余值法、隐性变量法和数据包络分析3种方法,测算京津冀3地全要素生产率水平、增长率以及对经济增长贡献度等重要指标。结果显示:北京全要素生产率水平明显高于天津、河北;不同方法测算的全要素生产率增长率具有相同变化趋势,天津、河北两地的增长率变化趋势较一致,但与北京的增长率变化趋势不一致;京津冀区域的全要素生产率增长乏力,增长出现放缓甚至略微下降的局面;京津冀的经济增长主要来源于要素投入而非全要素生产率的提高;全要素生产率的增长,主要来源于技术进步而非效率提高。

The Impact of Small Field’s Off-Set on Output Factor in Intensity Modulated Radiation Treatment

In intensity modulated radiation treatment (IMRT) planning, the use of asymmetrically collimated fields that are placed on central axis or its off-set is mostly required. Output is the main topic discussed today for extremely small and/or severe irregularly shaped fields. The air scatter data are involved directly or indirectly in obtaining the output. Despite the fact that extensive data have been published in many studies to provide a guide on the magnitude of output factor for clinical accelerators, there are very few data reviewed about output factor in-air or phantom for off-set fields. This study was aimed to investigate the impact of these conditions for small fields. This study was conducted in Elekta Synergy linear accelerator which produces 6 MV X-ray energy. The in-air output factor (Sc) has been measured by CC04 ion chamber with brass-alloy “build-up” cap and Dose-1 electrometer, and the total output (Scp) measurements were carried on at dose maximum depth in phantom by the same chamber and Thermoluminescence dosimeter (TLD) for 1 - 10 cm2 fields. The all measurements at center of isocenter and off-set fields at three directions (X2, Y1, Diagonal) were done. By decreasing field size from 10 to 2 cm2 at isocenter, the Sc value using CC04 was decreased to 5.4% and Scp using CC04 and TLD to 14.5% and 11% respectively. By increasing off-set value, the Sc and Scp values were increased in all directions comparing to central fields. The maximum increase was obtained in Y1 direction for Sc and Scp. TLD results for Scp is slightly higher than CC04. The dosimetric properties of small fields and their off-set should be evaluated and modelled appropriately in the treatment planning system to ensure accurate dose calculation in Intensity Modulated Radiation Treatment.

A Study on Input-Output Efficiency of Citrus in Jiangxi Province

This paper analyzes the citrus input-output efficiency by using the DEA-Malmquist productivity index methods based on the data of six counties in Jiangxi Province from 2010 to 2013.The result shows that TFP of Jiangxi citrus is at low level overall,but the development is rapid.Technological progress is the driving force to promote productivity growth.Based on the static analysis study of six counties in 2013,it is found that the available input factors on the whole are in an ideal condition,and the citrus input factors in a few counties are redundant.Therefore,according to the results,the following policy recommendations are proposed:speeding up the intensive production of citrus in Jiangxi Province,to maximize the scale effect;adjusting the input ratio of various factors of production,so as to improve the citrus input-output efficiency.

Analysis of the Contribution of Total Factor Productivity to Agricultural Yield in Anhui Province

By analyzing data concerning agricultural development from 1981 to 2010 in Anhui Province,the total factor productivity and growth rate of agriculture from 1981 to 2010 are estimated empirically.By dividing years from 1981 to 2010 into several subintervals,this paper evaluates and analyzes initial stage of reform and opening up,soft landing stage,the stage of financial crisis,the stage of subprime mortgage crisis and the impact of all factors on total factor growth rate of agriculture.Then it analyzes the contribution of growth of total factor productivity to total yield of agricultural economy.The research finds that the growth of total factor productivity in Anhui Province is significant to agricultural development.

Measuring Quality of Economic Growth Incorporating Environment and Social Welfare:a Total Productivity Approach with an Application on China

By extending the traditional productivity theory,a new concept total productivity( TP) is introduced. Using a directional distance function approach,the concept is applied to measuring economic growth of 8 economic regions of China covering an 18 years period( 1997—2014) and test its convergence. Results showed that TP grew at an average rate of 6. 6% per year led mainly by technical change( 6. 5%). When environmental undesirable outputs are included,the Middle Yellow River,Northwest and Southwest regions of China witnessed higher productivity changes. Results of the convergence analysis revealed that China had made progress in reducing regional imbalance in growth. Inclusion of undesirable output showed that the energy-saving emission reduction policies had speed up the convergence rate of TP and environment oriented productivity. However,China's welfare oriented productivity is still very low.

海洋经济全要素生产率测算的研究进展

近年来,关于海洋经济全要素生产率测算与分析的研究较多,但尚未有文献对研究进展进行系统的综述。从海洋经济全要素生产率内涵及投入产出指标、测算分析以及海洋经济绿色全要素生产率的测算分析等方面进行文献梳理,系统总结了关于海洋经济全要素生产率测算的研究进展。通过梳理发现:已有研究多从资本、劳动、资源、技术等方面选择投入指标,将海洋生产总值作为产出指标,构建投入产出指标体系采用DEA-Malmquist指数法进行测算,实证分析多从海洋产业层面细化分析,后续研究可以结合新型生产要素及国家生态文明建设目标完善指标体系,并从各五年规划时期进行时空特征分析。

科技遏制导向对中国创新发展构成威胁吗?--基于美国对华经贸政策的事实与验证

美国近年来对华秉持科技封锁战略、依据出口管制条例(EAR),对我国相关高科技公司实体及相关产业进行技术封锁,企图抑制我国创新发展。本文根据EAR公布的实体清单构建上市公司面板数据,运用变时点DID(time-varying DID)模型研究美国科技封锁事件对我国创新产出的实际影响,并对模型可能存在的处理效应异质性等稳健性问题进行检验。研究表明,美国科技封锁战略短期内抑制我国创新产出,但长期内相关技术封锁措施对我国创新产出起倒逼促进作用。其次,科技遏制将通过技术距离提升、产出效应下降及贸易效应削减方式,对我国创新产出产生不利影响。结合目前的中国实际,我国需坚持创新发展战略目标毫不动摇,同时积极利用国际合作机制,与世界各国探讨建立国际社会新型经贸规则的可能性,多方面应对美国技术封锁事件对我国创新发展的影响。

2022年建筑业发展统计分析

基于翔实的统计数据,对2022年中国建筑业发展的总体状况和各地区建筑业的发展状况进行了分析。分析指标包括:建筑业增加值与国内生产总值、建筑业总产值、建筑业竣工产值、在外省完成产值、建筑业从业人数与企业数量、劳动生产率、利润总额与产值利润率、签订合同总额与新签合同额、房屋施工面积与竣工面积、对外承包完成营业额与新签合同额等。同时,对各地区建筑业主要指标总量及增速进行了位次分析。

基于超越对数生产函数的气象条件变化对京津冀地区行业产出的影响研究

全球气候变化对经济系统及其各个部门产生了重要影响,定量辨识气象条件变化对经济系统的影响是研究经济系统适应气候变化的迫切需要。利用京津冀地区工业、建筑业等五个行业的生产总值、资本存量等经济数据和气象数据,采用超越对数生产函数探究京津冀地区气象条件变化对行业产出的影响,定量揭示不同行业对气象条件变化的敏感性。结果表明,采暖度日(每增加1%)对建筑业、交通运输仓储邮政业、工业、批发零售业以及农业的边际产出弹性分别为-0.1501%、0.6197%、0.9309%、0.4473%以及-0.7311%,降温度日(每增加1%)对五个经济部门的边际产出弹性分别为0.0274%、-0.0208%、-0.0709%、-0.1028%以及0.0282%,降水距平百分率对五个部门的边际影响分别为-0.1643%、-0.1365%、-0.0005%、-0.0407%以及0.0407%。气候变暖对经济系统的负面影响逐渐增强,特别是对工业、交通运输仓储邮政业和批发零售业的影响更大,短期来看对建筑业和农业有利;降水对除农业以外的其他部门都为负面影响,对建筑业和交通运输业的负面影响最大。研究结果对探究气候变化对社会经济的影响规律,增强社会经济对气候变化的适应能力具有一定的参考意义。

中国式行政集权的企业减排效应——基于撤县设区改革的微观分析视角

基于1998~2013年中国1014家工业企业的平衡面板数据,来识别市县间集权式改革的环境管辖权上移对企业排放行为的影响路径,对于解决分权体制下属地化管理模式造成的环境污染负外部性问题具有重要现实意义.实证结果表明:撤县设区改革会增大企业COD去除量和减小SO_(2)排放量,说明了该改革起到了对企业排放行为的约束作用.机制研究发现:撤县设区改革通过提高企业全要素生产率或者减少企业产量两条路径来达到减排效果.异质性分析表明,撤县设区改革的企业减排效应在非国有企业、小型企业、南方地区以及中西部地区更为明显.结论通过了区县数据替换、删除特殊样本以及使用县与市中心距离的工具变量识别等一系列稳健性检验.由此,应该设置合理的奖惩措施,保证地方政府科学落实改革方案,并对北方地区进行市场化改革,创造良好的营商环境,同时关注小型企业的市场需求,进行有效的资金人才扶持.