在线评论特征对生鲜电商农产品销量的影响——来自淘宝羊肉大数据的证据

为探索在线评论对生鲜电商运营效果的影响,本研究基于信息采纳模型的框架,搭建在线评论作用于销量的理论模型,以生鲜羊肉产品为研究对象,利用Python爬虫的数据采集方式,获取淘宝平台上所有生鲜羊肉产品的月度截面数据,运用"OLS+稳健标准误"逐步回归的方法,从农产品销量的维度分析在线评论的影响,探讨评论区域中获取的评论数量、评论长度、差评数量和可视化评论对生鲜电商农产品销量的直接作用及交互效应。结果表明:在线评论数量、可视化评论能够显著提高生鲜农产品销量,差评数量则会明显降低生鲜电商的销量,而评论长度作用于生鲜农产品销量的效果并不显著。在线评论特征间的交互效应分析表明,差评能够削弱图片以及评论数量对销量的正向作用,图片能够加强评论长度对销量的积极作用,而差评的负面作用能够被评论长度进行一定程度的中和。因此,生鲜电商经营应当注重差评反映的意见,规避差评的重复出现;采用合理措施鼓励消费者进行评论,且撰写含有图片、评论字数较多的评价,均是增进信任机制、促进生鲜电商销量行之有效的办法。     

Analysis of BioOne Journal Collections: Their Quality,Indexing Coverage,and Scholarly Content

This study examined the 130 current full-text titles in the BioOne.1 and BioOne.2 collections to determine whether they are peer-reviewed, contain book reviews, and are supplied by document delivery vendors. We identified indexing coverage in 11 major databases in agriculture and life sciences: Aquatic Sciences and Fisheries Abstracts (ASFA), AGRICOLA, Biological Abstracts, BIOSIS Previews, CAB Abstracts, Current Contents, Environmental Sciences and Pollution Abstracts, GeoRef, Scopus, ISI Web of Science, and Zoological Record. We concluded that the majority of the titles in BioOne collections are refereed and scholarly, indexed in several of the major indexing and abstracting journals in the field of agriculture and life sciences, and available via several major document delivery vendors. We find both BioOne collections to be valuable, useful, cost-effective journal aggregations.     

基于品牌效应的在线评论对稻米销量影响的实证研究

为探索品牌、在线评论与农产品销量之间的关系以及二者如何对农产品销量产生影响。利用网络爬虫技术和统计方法,基于品牌效应视角,扩展了采纳信息模型,并依据网络中采集的真实在线评论内容,从产品特征和评论特征两个角度出发对稻米农产品进行研究,构建了稻米销量的影响因素模型并运用实际数据分析得到验证。结果表明:评论数量与稻米销量显著相关,品牌强度、评论效价和评论时效度对于稻米销售具有显著的正向影响。此外,评论效价和评论时效度能够削弱品牌强度的作用,对弱势品牌稻米销量具有更为显著的影响。     

中国土地整治“十二五”研究重点评述与“十三五”研究展望

以CNKI中国期刊全文数据库作为数据源进行文献检索,对我国“十二五”期间土地整治研究进展进行系统梳理,展望“十三五”国内土地整治研究趋势,为土地整治学科发展及进一步研究提供参考和借鉴。采用文献综述与归纳对比分析法,对“十二五”期间公开发表的土地整治相关研究成果进行归纳分析综述。结果表明:在土地整治战略基础理论、土地整治潜力与绩效评价、土地整治规划设计模式、土地整治生态环境影响以及土地整治工程措施方面取得重要进展,“十三五”期间,应加强土地整治的景观生态效应、土地整治的多功能性、土地整治工程技术标准以及土地整治监管运行机制方面的相关研究,进一步发挥土地整治在提高农业生产能力与促进城乡统筹发展方面的作用。     

南方红豆杉扦插繁殖技术研究

指出了南方红豆杉生长缓慢,种子繁殖系数低,对其无性繁殖的研究比较多,分析了其生物学特性,就扦插繁殖技术的研究进行了探讨。     

农业物联网发展评价指标体系设计:研究综述和构想

农业物联网发展涉及社会、经济、科技、市场等多个方面,这决定了构建农业物联网发展评价体系的复杂性。文章梳理了与信息化、物联网相关的几类评价体系,并分析了物联网技术在农业资源利用、农业生态环境监测、农业精细管理、农产品与食品质量安全管理与追溯等领域的应用现状。目前我国农业物联网发展面临技术标准体系建设滞后、核心和关键技术产品缺失、资金瓶颈制约严重、成熟的商业化模式缺失、产业发展滞后、政策法规不健全等制约因素。提出了建立农业物联网发展评价体系的原则和思路,进而尝试性地搭建了农业物联网发展评价指标体系,以期为农业物联网发展的科学评价提供参考。最后,从加大农业物联网的政策扶持和资金支持,加快推进农业物联网标准规范建设,逐步建立农业物联网信息采集体系,加强农业物联网技术创新和产品研发等方面提出了促进农业物联网发展的建议。     

Greenhouse gas emissions from farmed organic soils: a review

Abstract. The large boreal peatland ecosystems sequester carbon and nitrogen from the atmosphere due to a low oxygen pressure in waterlogged peat. Consequently they are sinks for CO₂ and strong emitters of CH₄. Drainage and cultivation of peatlands allows oxygen to enter the soil, which initiates decomposition of the stored organic material, and in turn CO₂ and N₂O emissions increase while CH₄ emissions decrease. Compared to undrained peat, draining of organic soils for agricultural purposes increases the emissions of greenhouse gases (CO₂, CH₄, and N₂O) by roughly 1t CO₂ equivalents/ha per year. Although farmed organic soils in most European countries represent a minor part of the total agricultural area, these soils contribute significantly to national greenhouse gas budgets. Consequently, farmed organic soils are potential targets for policy makers in search of socially acceptable and economically cost-efficient measures to mitigate climate gas emissions from agriculture. Despite a scarcity of knowledge about greenhouse gas emissions from these soils, this paper addresses the emissions and possible control of the three greenhouse gases by different managements of organic soils. More precise information is needed regarding the present trace gas fluxes from these soils, as well as predictions of future emissions under alternative management regimes, before any definite policies can be devised.     

The application of knowledge synthesis methods in agri-food public health: Recent advancements,challenges and opportunities

Knowledge synthesis refers to the integration of findings from individual research studies on a given topic or question into the global knowledge base. The application of knowledge synthesis methods, particularly systematic reviews and meta-analysis, has increased considerably in the agri-food public health sector over the past decade and this trend is expected to continue. The objectives of our review were: (1) to describe the most promising knowledge synthesis methods and their applicability in agri-food public health, and (2) to summarize the recent advancements, challenges, and opportunities in the use of systematic review and meta-analysis methods in this sector. We performed a structured review of knowledge synthesis literature from various disciplines to address the first objective, and used comprehensive insights and experiences in applying these methods in the agri-food public health sector to inform the second objective. We describe five knowledge synthesis methods that can be used to address various agri-food public health questions or topics under different conditions and contexts. Scoping reviews describe the main characteristics and knowledge gaps in a broad research field and can be used to evaluate opportunities for prioritizing focused questions for related systematic reviews. Structured rapid reviews are streamlined systematic reviews conducted within a short timeframe to inform urgent decision-making. Mixed-method and qualitative reviews synthesize diverse sources of contextual knowledge (e.g. socio-cognitive, economic, and feasibility considerations). Systematic reviews are a structured and transparent method used to summarize and synthesize literature on a clearly-defined question, and meta-analysis is the statistical combination of data from multiple individual studies. We briefly describe and discuss key advancements in the use of systematic reviews and meta-analysis, including: risk-of-bias assessments; an overall quality-of-evidence approach; engagement of stakeholders; Bayesian, multivariate, and network meta-analysis; and synthesis of diagnostic test accuracy studies. We also highlight several challenges and opportunities in the conduct of systematic reviews (e.g. inclusion of grey literature, minimizing language bias, and optimizing search strategies) and meta-analysis (e.g. inclusion of observational studies and approaches to address the insufficient reporting of data and significant heterogeneity). Many of these developments have yet to be comprehensively applied and evaluated in an agri-food public health context, and more research is needed in this area. There is a need to strengthen knowledge synthesis capacity and infrastructure at the regional, national, and international levels in this sector to ensure that the best available knowledge is used to inform future decision-making about agri-food public health issues.     

网络环境下河北省高校图书馆信息服务创新研究

通过对河北省部分高校大学图书馆规章制度、人员结构、特色服务项目、自行研发数据库等方面进行调查研究,了解了河北省高校图书馆信息服务的建设与运行现状,提出了扩展读者受众服务和人性化、专门化、特色化的创新服务体系。旨在新的网络环境下,建立以读者需求为导向,提升图书馆整体服务水平为核心的读者书评数据库,开辟信息服务的新模式,提升信息服务水平,使图书馆在普通高校教育中发挥更大的作用。     

杂交水稻制种机械授粉研究现状及发展对策

制种是杂交水稻生产过程的重要组成部分,授粉是制种的关键环节,对杂交水稻制种的产量和效益有明显影响。研究国内外杂交水稻授粉技术与装备的现状表明目前所采用的授粉机械依据工作原理的不同有碰撞式和气力式二种。通过分析二种授粉装备的工作原理,总结出它们的特点和存在的不足。现用的授粉装备存在授粉不匀、损伤植株等问题,对授粉效果带有一定的盲目性和随机性。杂交水稻授粉应向机械化、多用途化综合发展,提出了探索不同机械授粉方式的科学性、研究不同机械授粉方式的适应性、寻求合理的工作参数、确保安全隔离防止生物学混杂和开发适用的授粉机械的对策和建议。