Commuting distances to local non‐farm workplaces and out‐migration: The case of Northeast Thailand

The relationship between commuting distances and where people work has been studied for urban contexts in both developed countries and developing countries. However, few studies have examined the situation in rural areas, and none look at commuting distances to non‐farm workplaces in rural areas of developing countries. This paper investigates how commuting distance, and thus accessibility, to local non‐farm work influences non‐farm employment and out‐migration from rural villages in Northeast Thailand. The main issues examined are: (i) the distance that rural residents travel to work in local non‐farm jobs; and (ii) the influence that local non‐farm employment has on the number of outmigrants from rural villages. The study finds: (i) distance between villages and non‐farm work sites impact the number of villagers who are employed in regular wage work; (ii) beyond 20 km villagers are less likely to travel to non‐farm employment using their own means of transportation; and (iii) employment in regular wage work decreases outmigration. The findings from this study contribute to the debates over the drivers of rural out‐migration, rural livelihood changes, and agrarian changes that are taking place in Southeast Asia.     

楼房养猪空气过滤系统设计与应用

土地成本在集约化养殖总成本中占比越来越高,尤其是在城镇化大背景之下。如何显著提高养猪场土地利用率,摊平综合成本,提高土地亩均产出,是整个行业都在考虑的问题。2019年12月17日,自然资源部、农业农村部在《自然资源部农业农村部关于设施农业用地管理有关问题的通知》中指出:"养殖设施允许建设多层建筑",使楼房养猪得到政策支持,但是,配套的楼房养猪空气过滤系统成为亟待解决的问题。文章汲取既往养猪场空气过滤系统设计、应用中积累的经验,为楼房养猪空气过滤系统方案作出综合探究,阐述楼房养猪空气过滤系统设计的理论依据,以及实际应用中需要注意的问题,为逐步实现楼房养猪空气过滤系统标准化提供思路。     

结构创新的楼房猪场是防非保供的一种可行模式

传统的养猪模式难以应对诸如非洲猪瘟这样的疫病,普通平层猪场叠加而成的楼房没有从本质上得到改进,而结构创新之后的楼房猪场在养猪的可靠性上大大增强,并可能发展为城市养猪新模式,为防非保猪、稳产保供提供一种解决方案。在此基础上升级的"料、养、宰、商一体化"造肉工厂模式,更是一种能把运猪变为运肉的可行解决方案。当这些模式得到应用和推广时,困扰行业的"猪周期"问题也将得到妥善解决。     

农机远程智能管理平台研发及其应用

本研究针对农机管理实时数据少、农机实时作业监管困难、服务信息不对称等问题，首先提出专业化远程管理平台设计时应具有五大原则：专业化、标准化、云平台、模块化以及开放性。基于这些原则，本研究设计了基于大田作业智能传感技术、物联网技术、定位技术、遥感技术和地理信息系统的可定制化的通用农机远程智能管理平台。平台分别为各级政府管理部门、农机合作社、农机手、农户设计并实现了基于WebGIS 的农机信息库及农机位置服务、农机作业实时监测与管理、农田基础信息管理、田间作物基本信息管理、农机调度管理、农机补贴管理、农机作业订单管理等多个实用模块。研究着重分析了在当前的技术背景下，平台部分关键技术的实现方法，包括采用低精度GNSS定位系统前提下的作业面积的计算方法、GNSS定位数据处理过程中的数据问题分析、农机调度算法、作业传感器信息的集成等，并提出了以地块为核心的管理平台建设思路；同时提出农机作业管理平台将逐步从简单作业管理转向大田农机综合管理。本平台对同类型管理平台的研发具有一定的参考与借鉴作用。     

基于网络嵌入性的我国东北国有林区知识转移机理

文中从社会网络视角分析我国东北国有林区职工、家庭及林业企业知识转移的过程和影响因素，以期通过社会关系和网络结构促进林业企业转型。应用知识转移基本理论构建东北国有林区多层次知识转移理论模型，在此基础上从社会网络视角分析林区职工、家庭和林业企业3个层面的知识转移机理。研究表明:增强林区知识转移个体与利益相关者的联系程度、占据更多的结构洞位置以及提高个体网络中心度和凝聚程度有利于知识获取和内化；林区待岗职工与利益相关者的弱联系有利于其获得更多就业机会；国有森工企业由于过度嵌入社会网络，知识内化和创新动力不足。     

A data transfer method for improving seed identification of maize (Zea mays) haploid breeding based on genetic similarity

Maize haploid breeding technology is able to identify haploid seeds non‐destructively, rapidly and at low cost with the help of Near‐infrared (NIR) spectral analysis. However, due to the hybridization of numerous parents and the low production rate of haploid, the haploid data collection becomes a burden for engineering this technology. Biologically, there are considerable similarities between the progeny of the same female parent and different male parents. Based on this advantage, similar spectral data can be transferred when the NIR technology is employed. A revised method of Transfer adaptive boost (TrAdaBoost) is proposed to improve identifying for the backpropagation neural network (BPNN) classifier. To avoid the negative transfer, a screening thresh is used to select out similar data, and the amount of these data are limited to join current training. The results show that the identification performances are improved significantly when the data amount is small. This method shows a high ability to make the seed identification more convenient for engineering maize haploid breeding.     

土地规模化经营能否促进农业社会化服务获取?——基于全国3类农户样本的实证分析

土地流转和农业社会化服务是经营规模化和服务规模化的根本途径,研究二者关系对农业供给侧结构性改革、农业现代化发展乃至乡村振兴具有重要意义。基于第二期"全国新型农业经营主体发展指数调查"数据,运用负二项回归模型实证分析土地流转及转入不同特征土地对普通农户、专业大户和家庭农场农业社会化服务获取的影响。结果表明,单纯的土地转入对不同类型农户农业社会化服务获取均不具有显著影响。但如果转入土地有利于规模化经营、农业基础设施较好,则能显著促进社会化服务获取。另外,农户经营能力越强,对不同类型社会化服务的应用程度也越高。因此,政府应推动更有效率的土地流转,实现农业适度规模经营;加强农业社会化服务供给,提升农户生产经营效率;强化经营主体培训,增强联结带动能力。     

徐州某规模猪场防疫措施的建立与实施——“五流”生物安全防控

非洲猪瘟在我国流行已有两年多的时间,尽管很多科研团队都在致力于非洲猪瘟疫苗的研发,但尚未有治疗措施和有效的疫苗来控制该病。因此现阶段“生物安全”是控制非洲猪瘟最为有效,也是唯一的方法。文章总结出目前规模化猪场常见的感染风险有“人员流动、物品流动、车辆流动、水源流动、猪群流动”(即“五流”),并提出严格控制“五流”的生物安全防控措施(即“五流”生物安全防控),以减少外界病原与猪只的接触,稀释病原浓度,降低病原载量,最大程度地降低规模化养猪场感染疾病的风险。为当前规模化猪场建立有效的生物安全措施提供参考。     

轻型木结构墙体稳态传热性能及其保温材料影响比较

轻型木结构墙体的热工性能对建筑节能至关重要,其稳态传热性能是节能效率评估指标之一。工程调研发现,轻型木结构墙体墙骨柱热传递过程易产生冷热桥,改善墙体保温构造并通过试验测试,对得到不同构造的墙体传热系数等指标进行分析研究,有利于设计人员优选墙体设计参数、研发墙体新型保温材料。试验采用标定热箱法与热流计法相结合的试验方法——控温箱-热流计法对改善保温措施的墙体进行试验,分析了12种墙体试件的热流密度、传热系数、热阻以及日传热量参数,并与理论计算结果进行比较验证,试验结果与理论计算结果吻合性较好。研究发现:气凝胶毡放置在墙骨柱位置能够有效降低平均传热系数3.8%~15.0%,随厚度增加可逐渐减弱或消除墙骨柱冷热桥效应;聚苯乙烯保温板可有效降低传热系数32.4%~35.1%,墙体蓄热能力较好;纳米纤维保温材料可有效降低传热系数5.9%~8.7%,提高墙体冷热面温差,平衡室内温度。选取的3种保温材料中,聚苯乙烯保温板相比气凝胶毡和纳米纤维保温材料,对墙体整体热工性能的提升更为显著。     

Understanding farmers’ potato production practices and use of improved varieties in Chencha,Ethiopia

This study was carried out to better understand non-adoption of improved varieties of potato (Solanum tuberosum) and associated technologies by smallholder farmers in Chencha, Ethiopia. Data were collected through a survey (n = 47) and in-depth interviews (n = 20). It shows how wealth status was a factor of major importance. Most wealthy and some medium-wealthy farmers adopted improved potato varieties and many of the improved production practices; they had access to seed, associated knowledge and support, and sufficient resources that were necessary to apply the improved practices. Non-adoption was common among many medium-wealthy and most poor farmers: they lacked—next to access to the technologies and knowledge—cash, land, and labor. Results indicated the need to rethink research and intervention efforts. Next to paying attention to differences in the access to technology and the related knowledge, there is a need to consider the variation in technology needs, supporting microcredit services, and room to experiment. As a result, different combinations of improved production practices may be adopted.