农村宅基地置换模式的差异性及其机理分析

基于对江苏省、河北省50个乡镇的调查数据,利用多元Probit模型,对农村宅基地置换模式差异性所在及其形成的内在机理进行了分析。结果表明:当前农村宅基地置换主要采用置换商品房、置换小产权房以及置换宅基地三种模式,具有显著的区域差异性。土地稀缺程度、农地流转稳定程度、非农就业机会和社会保障稳定程度是导致农村宅基地置换模式差异性产生的主要原因。土地稀缺程度、农地流转稳定程度、非农就业机会以及社会保障稳定程度较高的地区,倾向于采用置换商品房模式进行置换;反之,则倾向于采用置换宅基地模式进行置换。因此,在推进农村宅基地置换工作时,应因地制宜,综合衡量选取适宜的宅基地置换模式,保证农村宅基地置换工作的顺利推进和农民的置换福利性不受损失。     

楼房补偿、货币补偿与城郊农民宅基地退出意愿——基于上海3100户农户的调研

城郊农村作为空心化严重、农业依赖度较小的特定区域,宅基地退出的宏观诉求强烈且具备改革的微观条件.文中基于对上海市3100户农民的微观调查,深入分析了城郊农民面临实物补偿和货币补偿时退出宅基地的意愿及影响因素.研究发现:城郊农民宅基地退出意愿整体较高,不同补偿模式下愿意退出宅基地的农户达到83.5％;实物性即城镇楼房补偿...     

多功能视角下农户宅基地流转行为研究——兼论市场环境的调节作用

正确理解宅基地的多功能性是切实保障农民差异化权益需求的关键所在。文中基于451份农户微观调研数据,运用Probit模型、调节效应模型,重点探究影响农户宅基地流转行为的功能因素及其区位异质性,同时兼论市场环境的调节作用。研究发现：1)影响农户宅基地流转行为的主要功能因素是生产功能和资产功能,生产功能促进农户选择抵押方式流转宅基地,资产功能促进农户选择入股方式流转宅基地,但抑制农户选择租赁方式流转宅基地。2)生产功能抑制城中村农户宅基地流转行为,资产功能抑制近郊村农户宅基地流转行为,但促进纯农村农户宅基地流转行为。3)市场环境可以削弱生产功能对城中村农户宅基地流转的负向影响,可以增强资产功能对纯农村农户宅基地流转行为的正向影响,但对近郊村不具有显著的调节作用。因此,建议重视宅基地多功能性及区位差异,加强制度“松绑”与“创新”、完善宅基地流转市场机制,切实保障农民差异化的权益需求。     

宅基地价值观——概念的界定、量表开发与效度检验

随着我国新型城镇化进程的加快,宅基地问题越来越引起社会的广泛关注。文中以河西走廊地区调查的625份有效问卷的数据为基础,对农村宅基地价值观的概念和维度进行划分与界定。研究结果表明:1)宅基地价值观是指从农户自身角度出发对各种利用宅基地行为的认知和评价,包括宅基地保障观、宅基地亲和观和宅基地财富观;2)宅基地价值观16个测度项均通过了信度检验且相关性较强,潜在变量可以很好地解释其指标变量。3)宅基地保障观的相关系数和权重较其他两个维度最高,16个测度项中以地换房的绝对权重最大,说明农户对宅基地的生存依赖很强。     

农户闲置宅基地退出意愿及影响因素研究——以河南省为例

闲置宅基地退出是实现耕地保护和新型城镇化健康发展的重要途径。把握农户的闲置宅基地退出意愿及其与影响因素的关系对于制定合理的宅基地退出机制至关重要。文中采用相关分析和通径分析对河南省农户闲置宅基地退出意愿及其影响因素进行分析,结果显示农户闲置宅基地退出意愿与其影响因素存在空间分异性,高城镇化率地区农户退出意愿高于低城镇化率地区,丘陵地区农户退出意愿高于平原地区。其中,"对退出结果的预期"、"生计类型"、"对相关政策的了解度"、"家庭年收入"、"闲置宅基地数量"与农户退出意愿均呈显著正相关;"附属建筑新旧程度"、"家庭规模"、"对居住环境的满意度"与退出意愿呈显著负相关。研究结果表明尊重农民意愿、增加政策的透明度、建立有效的利益驱动机制有利于提高农户的退出意愿,促进农村闲置宅基地合理有序的退出。     

宅基地退出加剧了农村劳动力非农转移吗?——来自安徽省金寨县农户的证据

基于宅基地退出试点区安徽省金寨县626户农户的微观调研数据,系统考察宅基地退出是否加剧了农村劳动力非农转移?结果表明:宅基地退出对农村劳动力非农转移有显著正向影响,在利用倾向得分匹配法和处理效应模型纠正选择性偏误后,所得结果依然稳健;基于中介效应模型的分析表明,宅基地退出通过提高农业经营成本、增加家庭负债和提升外出务工...     

乡村振兴背景下农村闲置宅基地退出意愿及障碍因素分析——基于农户宅基地价值观视角

探究闲置宅基地退出意愿及障碍因素对于制定合理的宅基地退出政策和乡村振兴战略的深入实施具有重要的价值和意义。基于农户宅基地价值观视角,根据计划行为理论并运用结构方程模型实证分析了甘肃835名农户的宅基地退出意愿及障碍因素。结果表明：1)乡村振兴战略背景下,主观规范是农户退出意愿形成的主要因子,行为态度是次要因子。2)乡村振兴战略实施中,居住生活、教育医疗等条件的改善对农户闲置宅基地退出意愿及行为态度具有积极影响,农户对退宅后的风险错误感知和政策模糊认知是闲置宅基地退出的主要障碍因素,会导致退宅意愿减弱。3)农户宅基地价值观会通过行为态度、主观规范、感知行为控制等间接对闲置宅基地退出意愿产生影响,且不同宅基地价值观对退出意愿的影响各异。最后,从细化农户退出类型、改善农户生存条件、加强政策宣传解读等方面提出了建议。     

宅基地集约利用的空心化格局:华北平原典型村庄的微观尺度分析

分析华北平原典型村庄宅基地集约利用水平及空心化微观格局，对识别农户用地逻辑、乡村发展肌理，推动空心村整治具有重要意义。通过构建综合体系评价山东德州钱屯村682宗宅基地集约利用水平，基于GIS分析微观空间格局特征，并构建多元回归模型探究集约度影响因素。结果表明：1)以居民点几何中心、宗地重心作为空心格局的参考点，钱屯村宅基地集约度表现出由四周向中心降低的圈层式空心化特征，高低集约度单元呈现交通区位导向与空间不平衡性。2)宗地到村庄中心距离对宅基地集约利用存在促进作用，宗地到基本农田、建成区、公交站距离对宅基地集约利用存在抑制作用，宗地到公交站距离强化了宗地到建成区距离对集约水平的影响。研究建议，确立精明收缩的村庄规划理念，构建基于集约评价的整治方案，为改善微观农户宅基地集约利用创造条件。     

资本禀赋、功能认知与农户闲置宅基地退出决策行为——基于山东省典型试点区调查数据的实证

建立农村宅基地自愿有偿退出机制，推进闲置宅基地进一步腾退和盘活，是缓解当下中国农村土地资源低效利用的重要举措。基于山东省典型试点区农户的实地调研，运用SEM模型实证分析兰陵县农户家庭宅基地退出决策行为。结果表明：1)资本禀赋对农户宅基地退出决策行为具有重要影响，且人力资本、社会资本、经济资本、政策资本均具有显著正向影响，其影响强度由强到弱依次为：人力资本>经济资本>社会资本>政策资本。2)功能认知在资本禀赋对农户宅基地退出决策行为影响中发挥着中介作用，形成“资本禀赋-功能认知-宅基地退出决策行为”的影响路径。据此，宅基地退出首先需要考虑农户家庭资本禀赋及其宅基地功能认知因素，结合农户家庭差异化的宅基地功能需求具体问题具体分析，最终做到在充分尊重农户意愿的基础上，积极引导农户有序退出宅基地。     

地权结构、制度盈余与土地流转契约——来自于租佃制的解释

农业供给侧结构性改革背景下,土地流转更具经济效率毋庸置疑。文中以狭义的土地流转为研究对象,回顾了我国农村地权结构变动及"三权分置"格局的形成;总结现有文献对租佃制度经济效率的研究结论,分析传统租佃关系与现行土地流转之间的区别和联系;以1978年和2003年为时间节点,从制度总盈余的角度对自耕农、定额地租及分成地租等不同地权结构的经济效率进行对比,提出当前阶段普遍存在的分成地租契约形式一方面来源于土地承包者对风险的厌恶,另一方面由土地经营者"内部化"交易成本的动力和规模化生产比较优势的内在属性决定。此外,资本密集型的规模化大生产要求制定长期的土地流转契约以回收前期固定成本投入,单个经营者可同时通过规模经济和范围经济降低长期平均成本和生产风险。     

Phenoxy ester herbicide identification and analysis

A test for the identity of specific phenoxy ester herbicides was required. Work with packed column and capillary GLC showed that the retention times could be used to identify major ester components. An esterification method with acetyl chloride produced a mean yield of 98% with a range of phenoxy acids and alcohols. This method could be used to produce standards for the specific quantitative analysis of esters in formulations.     

拟轮枝镰孢菌EST-SSR信息分析与标记开发

为开发可用于拟轮枝镰孢菌Fusarium verticillioides及其近缘种遗传多样性分析的SSR引物,利用生物信息学方法和PCR技术,通过对从NCBI下载的87 086条拟轮枝镰孢菌的EST序列信息进行分析,设计EST-SSR引物,检测其在拟轮枝镰孢菌及其近缘种中的扩增情况,并用筛选出的多态性引物对15株拟轮枝镰孢菌进行SSR遗传多样性分析。结果表明,在EST序列中,共查找到11 952个SSR位点,592种重复基元,SSR出现频率为1.09%,重复基元出现数量最多的为三核苷酸(54.00%),其中(CAA/TTG)n基元出现频率最高。设计的25对EST-SSR引物在拟轮枝镰孢菌种内的有效扩增率和多态率分别为80.00%与32.00%,对5种近缘镰孢菌种的通用率和多态率分别为40.00%和8.00%。遗传多样性分析结果表明,在相似系数为0.664水平下,供试菌株可划分为4个SSR类群,但类群的划分与菌株的地理来源无关;不同菌株间存在明显的遗传分化。表明基于拟轮枝镰孢菌EST序列开发的SSR引物可用于拟轮枝镰孢菌及其近缘种的遗传多样性分析。     

Insecticide discovery: An evaluation and analysis

There is an on-going need for the discovery and development of new insecticides due to the loss of existing products through the development of resistance, the desire for products with more favorable environmental and toxicological profiles, shifting pest spectrums, and changing agricultural practices. Since 1960, the number of research-based companies in the US and Europe involved in the discovery of new insecticidal chemistries has been declining. In part this is a reflection of the increasing costs of the discovery and development of new pesticides. Likewise, the number of compounds that need to be screened for every product developed has, until recently, been climbing. In the past two decades the agrochemical industry has been able to develop a range of new products that have more favorable mammalian vs. insect selectivity. This review provides an analysis of the time required for the discovery, or more correctly the building process, for a wide range of insecticides developed during the last 60 years. An examination of the data around the time requirements for the discovery of products based on external patents, prior internal products, or entirely new chemistry provides some unexpected observations. In light of the increasing costs of discovery and development, coupled with fewer companies willing or able to make the investment, insecticide resistance management takes on greater importance as a means to preserve existing and new insecticides.     

Environmental behavior and analysis of agricultural sulfur

Sulfur has been widely used for centuries as a staple for pest and disease management in agriculture. Presently, it is the largest‐volume pesticide in use worldwide. This review describes the sources and recovery methods for sulfur, its allotropic forms and properties and its agricultural uses, including development and potential advantages of nanosulfur as a fungicide. Chemical and microbial reactivity, interactions in soil and water and analytical methods for determination in environmental samples and foodstuffs, including inexpensive analytical methods for sulfur residues in wine, beer and other food/beverage substrates, will be reviewed. The toxicology of sulfur towards humans and agriculturally important fungi is included, with some restrictions on use to promote safety. The review concludes with areas for which more research is warranted. © 2015 Society of Chemical Industry     

Design and analysis of efficacy evaluation trials

Specific scope

This standard is intended for use in association with EPPO Standards of set PP 1 Standards for the efficacy evaluation of plant protection products and provides detailed advice on the design and analysis of efficacy evaluation trials.

Specific approval and amendment

First approved in 1989–09. First revision approved in 1998–09. Second revision approved in 2006–09. Revision mainly to reflect zonal assessment approved in 2012–09.     

Homoclime analysis and the prediction of weediness

Homoclime analysis of three weed species of potential significance to agriculture in New Zealand was undertaken. Using the Bio-climate Prediction System computer program (BIOCLIM), climatically suitable regions in New Zealand were estimated for Homeria flaccida Sweet, Chondrilla juncea L. and Emex australis Steinh., on the basis of their respective distributions in Australia. These estimates indicated that the current eradication campaign for Homeria is warranted, owing to the existence of extensive areas with a suitable climate on both of New Zealand's main islands. For Homeria, most of the known occurrences fell within regions predicted to be climatically suitable. For Chondrilla, only very small areas were predicted to be climatically suitable, due to the generally low temperatures that prevail during its reproductive period. This suggests that the designation of Chondrilla as a quarantine pest may be unwarranted. Much of the land in the interior of the North Island was estimated to be climatically suitable for Emex. However, invasion has not occurred, despite the presence of this weed in New Zealand for over 100 years. The failure of Emex to invade perennial pastures is probably a result of its poor competitiveness, since climatic and edaphic characteristics appear to be suitable over large areas. It is concluded that homoclime analysis can be used to identify regions at risk of invasion by a species which has been weedy elsewhere, when potentially modifying factors such as soils, land use/management practices and competitive interactions are taken into account.     

东亚飞蝗发生程度的主成分分析及聚类分析研究初报

利用主成分分析和聚类分析,介绍了东亚飞蝗发生程度及对不同发生程度进行分类的方法。主成分分析选出秋残蝗最高密度、夏蝗达标面积、秋残蝗面积、夏蝗发生面积等4个主因子。这4个因子能在84.56%的程度上反映东亚飞蝗的发生程度。聚类分析将东亚飞蝗20年的资料,在卡方距离近1.68处聚成3大类,分析结果与实际情况非常吻合。依据聚类分析结果可对东亚飞蝗进行分类综合防治。