黑背唇瓢虫雌雄成虫的活体无损伤鉴别方法

为了对黑背唇瓢虫Chilocorus melas Weise成虫进行活体无损伤鉴别,通过在解剖镜下反复对比,发现雌雄黑背唇瓢虫成虫存在3处可在放大镜下观察到的不同特征,通过这3处不同特征,几乎不伤害虫体就能迅速、准确地鉴定该瓢虫的雌雄性别,为下一步研究其室内饲养技术研究提供参考。     

Dissolved oxygen controls summer habitat of Clear Lake Hitch (Lavinia exilicauda chi), an imperilled potamodromous cyprinid

Clear Lake Hitch is an imperilled minnow endemic to Clear Lake, Lake County, California, United States listed as threatened under the California Endangered Species Act (ESA) and a candidate for listing under the United States ESA. It exhibits a potamodromous life cycle whereby adults, which reach up to 6 + years in age and over 350 mm in length, migrate into Clear Lake's ephemeral tributaries briefly during spring to spawn. Conservation and management of Clear Lake Hitch is inhibited, in part, by a lack of information on the lacustrine habitat of nonbreeding individuals within Clear Lake. To address this problem, we sampled Clear Lake Hitch with gill nets in a stratified random sampling design to determine the distribution and habitat associations in early summer 2017 and 2018. We identified abundance-habitat relationships for juveniles and adults using Bayesian zero-inflated negative binomial generalised linear mixed modelling. Results indicated that dissolved oxygen concentration was the most important habitat feature measured; juveniles and adults were substantially more abundant in normoxic (≥2 mg/l) than in hypoxic (<2 mg/l) habitat. Both also exhibited weak positive relationships with chlorophyll fluorescence, suggesting relatively productive habitats may support higher numbers of Clear Lake Hitch. Spatially, juveniles were most abundant in nearshore habitats while adults were ubiquitous, indicating an ontogenetic habitat expansion that may be associated with a resource availability-predation risk trade-off. Management actions undertaken to improve hypoxia problems in Clear Lake would also improve Clear Lake Hitch habitat.     

抛石压重对土石坝抗滑稳定静力影响研究与分析

坝前抛石压重加固病险水库已是一种经济,有效的加固措施,但规范和设计手册均无规定压重长度和高度的尺寸取值,其对大坝稳定影响效果不明确。针对这一问题,结合杨庄水库工程采用简化毕肖普法探讨了不同压重长度及高度,在正常运行稳定渗流的情况下对土石坝抗滑稳定的影响,得出压重长度应为0.45～0.55倍坝高,高度应至少在0.19倍坝高以上,越高则安全系数越大,但不宜超过0.3倍坝高。     

气候因子对杂交稻金优组合结实率的影响研究

采用分期播种和定穗观察的方法研究了不同气候因子对金优组合结实率的影响。结果表明，在相同气候条件下，金优组合与对照汕优、威优组合相比，结实率没有明显差异；对不良气候条件的抗逆能力相当。同时还得出，影响杂交稻结实率的主要气候因子是灌浆结实阶段的日平均温度和抽穗扬花及灌浆结实阶段的降雨量     

江坪河放空洞有压洞口段衬砌混凝土冬季温控方案分析

冬季衬砌混凝土施工面临的寒潮等问题,容易导致混凝土产生裂缝.基于有限元分析软件ANSYS,对江坪河放空洞有压段洞口段衬砌厚度为1.0 m的混凝土的拆模时间、围岩特性以及在遭遇寒潮时保温与否等6种不同的方案的进行了分析,并提出相应的温控方案和温控标准供设计与施工参考.     

简析江苏农业科技服务现状

本文简述了新世纪以来国家对三农工作的重视,对现代农业建设发展的新要求,指出农业科技服务对解决新时期三农问题的重要意义。参考比较了国内同类研究成果之后,本文主要分析了近年江苏地区农业科技服务现状,找出在机构组建、人才队伍、服务能力、服务范围、服务成效等方面存在的问题,并就整合现有科技服务机构、科技服务人才培养、创建科技服务新模式、拓展科技服务范围以及政策资金保障等方面提出了解决方法。对研究我国科技服务发展情况有较强参考价值,有助于重构我国现代化农业科技服务体系,提高农业科技服务整体实力。     

黄河小浪底库区不同人工林水土保持效益研究

采用空间代替时间的方法,通过对黄河小浪底库区不同人工林水土保持效益浅要分析,结果表明:最大吸水率为刺槐>侧柏>20多年生栓皮栎>40多年生栓皮栎,凋落物储量和最大持水量均为20多年生栓皮栎>40多年生栓皮栎>侧柏>刺槐;土壤渗透性能和贮水性能变化较为复杂,侧柏林地的渗透性和贮水性能较其它林地好些,刺槐林地上下层之间变化最大。     

Human Simulated Intelligence Motion Control for Three-link Acrobot on Horizontal Bar

The design of multi-controller and multi-mode control law is presented for the three-link Acrobot on horizontal bar by employing Human simulated intelligent control method based on sensory-motor Schema.Imitated the characteristics of gymnast's swing-up and handstand movement,the control process of robot is divided by six sequence phase.Then the sensory cell and motor cell and the group of sensory-motor schema is designed based on the analysis of quality-quantity combination.The simulation results show that the controller ensures the gesture and the energy to the desired goal,farther more the motion control of giant swing backword is realized in the simulation.     

微灌地膜的节水保墒增温效应研究

在实验基础上 ,分析论述了微灌地膜的节水效果和增温保墒效应。试验结果表明 ,微灌地膜可比地面灌溉节水 61 % ,增加地温 3℃～ 6℃ ,近地面空气相对湿度提高 3 0 %～ 40 % ,综合效应明显。可供微灌地膜或膜下微灌的进一步研究设计参考