Aiming to the problems that the most graph contrastive learning algorithms use random data augmentation strategies that may destroy the critical community structure in the network and the contrastive pair selection strategy that may select nodes with similar topology or attributes as negative samples, this paper proposes a community detection algorithm based on adaptive graph contrastive learning, and designs an adaptive graph enhancement strategy that considers the importance of nodes and a K-nearest neighbor-based positive sample selection strategy to solve the above problems. Experiments on real-world networks show that the method proposed in this paper is able to achieve an accuracy more than 4% higher than the best existing algorithms in community detection task and more than 3% higher accuracy than the best existing algorithms in the supply chain finance risk control task.

为稳定烟区、 烟田产业基础,促进烟农持续增收,推动现代烟草农业转型升级及烤烟产业可持续发展,贵州省积极探索烟区产业综合体的发展模式.研究通过厘清烟区产业综合体的内涵与发展特征,剖析贵州烟区产业综合体发展模式的内在形成机制,在此基础上总结了农业内部融合型、延伸农业产业链型,农业功能拓展型和新技术渗透型4种发展模式,并提炼出烟区产业综合体"六位一体"的"贵州模式";总结因地制宜地发展复合模式、因势利导地创新实践方式与注重"生态、高效、循环"等发展建议,以期实现贵州烟区产业综合体农业产业链的延伸与价值链的提升.

本研究采用2000-2015年气象站点数据,分析贵州不同烟区主要气象因子的时间、空间动态特征,结合烤烟种植适宜条件与省外邻近烟区进行比较,解析贵州烟区气象条件的生态适宜性,阐明贵州烟区大田不同生育期的主要气象资源匹配、限制问题,并提出相应的农艺解决措施.结果表明:(1)贵州烟区对比邻近烟区日均气温总体呈现先升高后下降的趋势,日均气温变异系数在前期和后期较高,中期相对稳定;黔西地区日均气温未满足烤烟生育期内对热量条件的要求;(2)贵州烟区及对比烟区降水基本集中在年积日(day of the year,DOY)121～271的时间范围内,该时期降水量变异系数也相对较低且变幅较小,降水总量为838.51 mm,满足了烤烟不同生育期对降水的需求;(3)贵州烟区日照时数在DOY 1～181和DOY 271～361时间范围内明显偏低,变异系数偏大;在DOY 182～270的时间范围内日照时数及其变异系数与对比烟区基本吻合;(4)与对比烟区相比,相同时间贵州烟区相对湿度偏高,尤其以DOY 1～166和DOY 286～361时间段内差异显著;(5)基于气候资源匹配下烤烟生育期时间优化研究后,黔北地区4月20日左右、黔东地区4月26日左右、黔南和黔中地区4月21-26日左右、黔西地区5月1日左右是当地烤烟适宜移栽期.综上,依据区域内不同地区主要气象指标的动态特征,结合地膜覆盖、群体结构调整等栽培措施,将烤烟移栽期适当前移有利于烤烟的优质生产,本研究为合理确定不同地区烤烟适宜移栽期提供了理论依据.

当前,随着农业现代化的深入推进,我国农业产业融合发展模式日益多元化,发展动力更加强劲.但如何协调各经营主体的利益关系,平衡双方的谈判地位,维持利益联结机制的长效化运行,成为确保农业产业融合持续发展的重要问题.由陈慈、陈俊红和龚晶编著,中国经济出版社出版的《农业产业融合发展的理论与实践》一书,面向农业现代化发展未来,聚焦农业产业融合课题,从理论层面针对其类别构成、发展动因、运作激励等进行了系统介绍,并且以北京为案例,详细分析了农业产业融合的核心问题,构架起完善的利益联结机制,具有良好的参考意义和应用价值.

发展烟农专业合作社是推进传统烟草农业向现代烟草农业转变最为有效的载体.本文基于烟草行业的特殊性,从竞争力、服务能力、社会影响力和发展潜力4个方面考虑,结合德尔菲法和层次分析法确定指标权重,构建了烟农专业合作社绩效评价指标体系,并应用该指标体系对贵州省30家烟农专业合作社绩效进行实证分析.研究发现,贵州省烟农专业合作社整体绩效水平良好,但仍存在区域发展不均衡、自身发展能力不足、社员满意度不高、运行不规范、带头人能力不强等问题.建议加强对烟农专业化合作社政策扶持力度,烟农专业化合作社要健全专业化服务体系、提高社员满意度、培养优秀的合作社带头人并实现规范与发展并重.

烟叶产业综合体是在农业综合体的基础上提出的新概念,是探索烟叶转型升级、稳定核心烟区和烟农持续增收的新路径、新模式,是实现脱贫攻坚和乡村振兴的重要途径.本文回顾了烟叶产业综合体的发展历程,并与农业综合体和田园综合体的概念进行辨析,从已有研究中提炼出主要的基础理论,进一步对综合体的发展模式、组织运行模式进行归纳总结,为烟叶产业综合体今后的实践和推广提供了坚实的理论支撑和经验参考.最后,本文从研究方法、研究内容和研究视角提出现有研究的不足以及进一步研究的方向.

当前我国烟叶产业发展进入"稳规模,优结构,提质量,增效益"新阶段,为确保烟叶持续稳定健康发展,烟叶工作必须把握新形势,适应新常态,走高质量发展路径.本文以贵州省烟叶产业综合体为主体,首先介绍其主要成效并剖析其发展制约瓶颈;然后构建了新结构经济学理论框架,并解释分析烟叶产业综合体实现高质量发展的作用机制;最后为贵州省烟叶产业综合体未来建设优化发展提出一些思考.研究发现,贵州省烟叶产业综合体应立足自身禀赋特征并充分发挥"有效市场"和"有为政府"的作用,探索以"三变"改革为主的土地流转模式、加大农业产业新型主体引进和培育力度、培育"烤烟+多元产业"新业态、完善利益联结机制并加强政策保障,从而走上高质量发展道路.

Planting scale, unit production value, average household income, and other indicators in 2013 of 3554 household growers from Zunyi municipality were investigated. Work related performance of 300 employees of local tobacco company was also surveyed and analyzed. Results showed that: irrational structure, high labor intensity, high risk, low comparative effectiveness, low professional service level, ageing employees and low literacy levels were all important factors affecting the sustainable and stable development of tobacco industry. Suggestions were proposed that a young and professional team of tobacco growers should be set up, development of tobacco grower cooperatives should speed up, and more and more well-educated and young employees should be encouraged to dedicate into modern tobacco agriculture.

To solve the problems of long seedling culture time and poor quality of tobacco seedlings bred by floating culture technique of seedlings in high-altitude to-bacco areas, a comparative trial between seedling nursing on moist trays + fermen-tation heating using farmyard manure and conventional floating culture of seedlings in Fenggang County was carried out in 2013. The results showed that seedling nursing on moist trays + fermentation heating using farmyard manure can improve 4-5 ℃ of pool water temperature, shorten 8 d of seedling age, increase 4.45 cm of seedling height, thicken 0.46 cm of stem girth and make lateral root system devel-oped. The method can shorten the time of floating breeding of flue-cured tobacco, improve the quality of tobacco seedlings, thus it was suitable to popularize in high-altitude tobacco areas of Fenggang County.

为解决烤烟漂浮育苗技术在高海拔烟区育苗时间长、成苗素质差的问题，2013年在凤冈县采用农家肥发酵增热＋湿润育苗法与常规漂浮育苗的对比研究。结果表明：采用农家肥发酵增热＋湿润育苗法可提升池水温度4～5℃，缩短苗龄8 d，苗高增高4.45 cm，茎围增粗0.46 cm，侧根系发达。本方法能缩短烤烟漂浮育苗时间，提高烟苗的素质，适宜在当地高海拔烟区推广应用。