How government-led land consolidation efforts achieve grain production stability? An empirical analysis in Hubei Province,China

China has been conducting massive land consolidation (LC) projects since the late 1990s to ensure national food security which has been one of the common issues in the world. How the implementation of LC projects affects grain production stability is a question should be answered. Basing on an empirical analysis at the county level in Hubei Province, China, this paper separates the trend component and the fluctuation component from a time series of grain production over 1991-2016 using the H-P filtering method. Then we estimate the impacts of LC projects and climate change on the trend and fluctuation rate of grain production for the entire Hubei Province. Moreover, the effects on the production of different major crops for the central, eastern, southwestern, northwestern and northern areas are also examined, respectively. The results show that: (1) the production trends for five subareas and the whole area all have followed a trajectory of “increase-decrease-increase” from 1991 to 2016. The magnitude of fluctuation rate was large but became smaller in recent years. (2) The contribution of LC to the long-term trends of grain production for the entire samples in Hubei Province mainly benefits from the growth in the cultivated land area through LC; more LC investment and newly-added arable land area promote the sudden increase in grain production above the long-term trends, while the impacts of LC area are negative. (3) The impacts of LC on the major crop production vary across areas. LC exerts significant impacts on the production of major crops in the central and eastern Hubei, and this effect persists to the following year. Similarly, this influence also exists in the southwestern and northern area, while becomes insignificant in the following year. No significant effect of LC variables is found in the northwestern area. These findings may provide reference for the government to address LC inefficiency and food security problems, and an effective and innovative mechanism combining the agricultural production, land consolidation and meteorological factors needs to be established to ensure food security and long-term and stable agricultural production. In addition, the regional difference in natural conditions and LC orientations should also be considered.     

土地整治地方标准化实践与思考

本分在充分调研9省（区、市）土地整治地方标准化建设工作的基础上，系统总结了现阶段土地整治地方标准化建设现状，并对存在的问题进行了深入分析，提出了新时期推进土地整治地方标准化建设的6点建议。     

反相高效液相色谱法快速分析紫脲酸

为了给咖啡因生产中的亚硝化反应、还原工艺提供准确的中间体检测数据,寻找紫脲酸含量快速分析方法,利用反相高效液相色谱法,通过进行紫脲酸样品波长选择实验、系统适用性实验、定量摸索实验、精密度实验、线性实验,确定了检测波长和紫脲酸样品质量浓度与样品峰面积之间的线性关系。在15.80~188.60mg/L范围内,紫脲酸样品质量浓度与样品峰面积之间的线性方程为y=71.785x,相关系数R2=0.999 8,表明紫脲酸样品质量浓度与样品峰面积之间具有良好的线性关系。使用反相高效液相色谱法能准确、快速检测紫脲酸样品含量,及时对还原反应进行过程监控。     

中国区域长寿的环境机制

用健康地理学综合研究方法,开展了中国典型长寿区的环境研究。发现中国长寿区主要分布在我国南方,尤其是川渝、中原和东南地区以及长江三角洲、珠江三角洲聚集区;长寿区的饮用水呈弱碱性,Se、Fe、K含量适度,且高Ca、Co、Mn,低Cr、Cd、Pb;土壤、粮食中有益的微量元素较高;百岁老人头发中Li、Mg、Mn、Ca、Zn等元素普遍含量较高,Cd、Cr、Cu、Ni低。百岁老人健康还得益于良好的社会环境因素,如生理健康、心理状态积极、膳食清淡、蔬菜比例高等。该研究首次定量提示了长寿与自然环境和人文环境的关系,为促进中国"长寿之乡"发展,实现我国生态文明建设提供科学依据。     

我国各区域农业生产资源配置效率分析

本文运用数据包络分析法测算了我国各区域农业经济的投入产出效率,指出目前我国各省市农业经济资源配置效率差异较大,其中人均化肥施用量对全国大多数省市农业劳动生产率都是最重要的,这种生产方式属于典型的“化肥农业”,并由此引发了一系列问题。文章认为,制度创新可以再造农业经济主体之间的相互关系,减少信息成本和不确定性,降低交易成本,提高生产要素配置效率,从而促进农业经济快速增长;在制度创新先行的前提下,实现农业经济组织创新与制度创新、知识创新的互动,是转变“化肥农业”生产方式,走可持续的新型农业发展道路的关键所在。     

经营规模、契约特征对新型农业经营主体农地整治积极性的影响——基于5省15县的调研

研究目的：分析经营规模、农地契约特征对农业经营主体农地整治行为与程度的影响。研究方法：采用Probit和Tobit模型对465位经营者调查数据进行实证分析。研究结果：（1）对于绝大多数农业经营主体，经营规模扩大对农地整治积极性存在微弱的负向影响；（2）农地经营面积和转入比例对土地类整治积极性存在负向影响，但相对设施类整治，农业经营者开展土地类整治的积极性更低；（3）契约价格、契约形式、契约对象为村集体、转入农地时具有担保等契约特征对农业经营者农地整治积极性存在显著影响，但契约时长的影响并不显著。研究结论：现阶段要提高新型农业经营者的农地整治积极性，有必要从多方面完善农地契约，而扩大农地流转规模和延长契约期限不一定有效。     

省级以上土地开发整理项目实施现状及对策——以江苏省如东县为例

以江苏省如东县2001-2013年16个省级以上土地开发整理项目为例,项目实施过程中存在规划设计先天不足、前期准备不细不实、监管不到位、按期竣工难等问题。对比2007年前后项目实施的改革措施,提出四项保证省级以上土地开发整理项目的顺利实施对策:(1)从项目组织者、资金管理和参与者角色等方面调整项目实施管理办法模式;(2)强化基层村组群众参与、质量申报和重点申报意识;(3)从预算审核、报账审查和竣工验收三方面加强资金管理;(4)从廉政建设、项目法人、项目审计、档案管理和综合效益评价等方面完善制度建设。     

化学计量之pH计分析

科技要发展,计量要先行。计量在社会的发展中起着至关重要的作用。化学计量更是其中不可或缺的一部分。本文从化学计量中一个基本仪器——pH计的角度,进行了分析。     

六家煤矿北翼运输大巷围岩注浆加固及底板组合锚索

本文介绍了松软岩层在原支护状态被破坏后重新采用注浆及锚网索联合支护维修加固技术的应用方法。     

Macroeconomic policy cooperation and the G20

Has the G20 achieved its goals in macroeconomic cooperation since 2008? The paper organises the G20's efforts under five themes: macroeconomic stimulus, fiscal consolidation, monetary policy, the global financial safety net and global imbalances. The G20 was initially successful in each of these areas, but this success was short‐lived. While the G20 met its goals on macroeconomic stimulus, it has been less successful in reducing deficits and debt. While it was successful in increasing its resources, the global financial safety net remains too small, too fragmented and institutional reform is incomplete. While the G20 succeeded in moving to more market‐determined exchange rates and avoiding competitive devaluations, it struggled to avoid negative spillovers. Despite years of effort, the G20 has made limited progress in reducing global imbalances. Current account imbalances are creeping back to pre‐crisis levels. Public debt remains high and most economies are moving in the wrong direction in correcting imbalances in household savings and debt. The paper concludes that the G20 has done better in some areas than others. But to suggest the G20 is a forum in decline ignores its shift from reactive crisis response to longer‐term structural challenges outside of the pressing need of an immediate crisis.