低档计算机的合理再利用

本文介绍厂一种通过将Windows 2000 Server的终端服务功能和第3方软件的有机结合，把低档计算机(286、386等)作为Windows 2000 Server服务器的终端，在终端上运行Windows 2000，Officc2000、PhotoShop、C语言、PAPAL语言等常用软件和下具的低档计算机再利用的方法。     

Action of deltamethrin on N-type (Cav2.2) voltage-sensitive calcium channels in rat brain

Isolated presynaptic nerve terminals prepared from whole rat brain were used to evaluate the action of deltamethrin on voltage-sensitive calcium channels by measuring calcium influx and endogenous glutamate release. Deltamethrin-enhanced K⁺-stimulated calcium influx and subsequent Ca²⁺-dependent glutamate release. The effect of deltamethrin was concentration-dependent, stereospecific, blocked by ω-conotoxin MVIIC but unaltered in the presence of tetrodotoxin. These results suggest that N-type voltage-sensitive calcium channels are a site of action at the presynaptic nerve terminal. Electrophysiological studies were carried out using rat brain Ca_v2.2 and β₃ subunits coexpressed in Xenopus oocytes to validate such action. Deltamethrin reduced barium peak current in a concentraion-dependent and stereospecific manner, increased the rate of activation, and prolonged the inactivation rate of this channel. These experiments support the conclusion that N-type voltage-sensitive calcium channel operation is altered by deltamethrin.     

利用冷却塔的进、出水温差给T2航站楼供冷

介绍了空调系统冷却塔的制冷原理，提出了用冷却塔进、出水温差给T2航站楼供冷的具体措施。     

农民大学生移动学习探索

通过调查分析农民大学生的特征以及移动学习的特点和优势，发现移动学习能够对农民大学生的课程学习起到促进作用，提高学习效率，是一种重要的远程教育方式。     

Drought Stress in Grain Legumes during Reproduction and Grain Filling

Water scarcity is a major constraint limiting grain legume production particularly in the arid and semi‐arid tropics. Different climate models have predicted changes in rainfall distribution and frequent drought spells for the future. Although drought impedes the productivity of grain legumes at all growth stages, its occurrence during reproductive and grain development stages (terminal drought) is more critical and usually results in significant loss in grain yield. However, the extent of yield loss depends on the duration and intensity of the stress. A reduction in the rate of net photosynthesis, and poor grain set and grain development are the principal reasons for terminal drought‐induced loss in grain yield. Insight into the impact and resistance mechanism of terminal drought is required for effective crop improvement programmes aiming to improve resistance to terminal drought in grain legumes. In this article, the impact of terminal drought on leaf development and senescence, light harvesting and carbon fixation, and grain development and grain composition is discussed. The mechanisms of resistance, management options, and innovative breeding and functional genomics strategies to improve resistance to terminal drought in grain legumes are also discussed.     

The value of incorporating carcass trait phenotypes in terminal sire selection indexes to improve carcass weight and quality of heavy lambs

Genetic selection for carcass traits is paramount to maximize the profitability and long‐term sustainability of any meat‐producing livestock species. The main objectives of this research were to evaluate the efficiency of indicator traits for the genetic improvement of lamb carcass traits and to determine the value of including carcass traits into terminal sire selection indexes for the Canadian sheep industry. The carcass traits included hot carcass weight (HCW), fat depth at the GR site (FATGR) and average carcass conformation score (AVGCONF), and were measured on heavy lambs (slaughter age less than 365 days and HCW greater than 16.3 kg) in commercial abattoirs. Growth traits were found to be moderately efficient indicator traits for the genetic improvement of HCW but selection on ultrasound traits was necessary to substantially improve the carcass quality traits (FATGR and AVGCONF). Economic selection indexes were designed by adding various combinations of carcass traits into the Canadian Sheep Genetic Evaluation System terminal indexes. Records measured on individuals and progeny were assumed to be the sources of information for live animal and carcass traits, respectively. The changes in index accuracy, efficiency and expected correlated response were used to assess the value of their inclusion. HCW was found to have a large economic value, and its inclusion into terminal selection indexes was expected to substantially increase their accuracy (0.08–0.12 points) and efficiency (20%–30%). However, further including FATGR (measured 110 mm from the carcass midline over the 12th rib) and AVGCONF had little impact on the accuracy (≤0.03) and efficiency (1%–7%) of the proposed indexes. Thus, the inclusion of carcass traits into the existing terminal selection indexes could be beneficial for the genetic improvement of HCW, but further research is needed to determine optimal methods of increasing carcass fatness and muscularity.     

自主式移动机器人定位坐标平滑算法研究

为了提高基于全局视觉导航的移动机器人的全局绝对定位精度，提出了一种适用于较大工作空间的摄像机参数分区标定方法，并借用数字图像中邻域的概念，定义了小区域的8—邻域关系，利用模糊数学的方法确定了中心区域及其邻域的权值函数，有效解决了各小区域边界的定位坐标平滑过渡问题。该平滑算法是一种计算模板，计算量不会因小区域的面积和小区域的个数的增加而增加，对于区域的内部和边缘计算一样有效。     

农业机器人移动平台的研究现状与发展趋势

简要介绍了农业机器人在农业信息化智能化中的重要地位以及机器人移动机构的类型,综述了当今农业机器人移动平台的研究现状,展望了今后这一领域的发展趋势。     

四端法土壤电导率传感器恒流源设计与试验

土壤信息对于指导农业生产有着极为重要的作用,土壤电导率反映了土壤含水量、盐分、粘粒含量和类型等土壤信息,准确获取土壤电导率对于实现农业精细化生产意义重大。在各种土壤电导率测量方法中,四端法因其成本低、精度高、测量快速和操作简便而大量应用于实际测量;恒流源是四端法测量仪器的重要组成部分,其性能直接决定着测量仪器的精度以及测量范围。本文对比了3种恒流源对测量仪器测量性能的影响,发现采用Howland恒流源的四端法测量仪器高电导率测量能力强而低电导率测量范围较小,测量精度最高;采用改进型Howland恒流源的四端法测量仪器低电导率测量范围有所扩大,测量精度良好;采用基于差动放大器的恒流源的电导率仪低电导率测量范围最大,高电导率测量范围较优,测量精度良好。     

农村电力负荷管理系统的研究与开发

随着我国农村经济的发展,造成了农村地区电力的持续紧缺,给农业生产带来了不利影响,要求电力部门加强对农村电力负荷的管理,以确保农业生产的电力需求.为此,介绍了一种集多种功能于一体的农村电力负荷管理系统,阐述了该系统的主要功能、终端的硬件设计和主控站软件的设计.本系统支持230M无线专网和GPRS/CDMA无线公网两种通讯方式.