自压喷灌系统管道减压的研究

本文对自压喷灌系统的合理减压方式和布置形式进行了分析。用递推法导出确定减压池级数及位置的计算公式。根据减压池的工况分析,探讨了减压池调节容积的计算方法。本文为自压喷灌系统的减压设计提供了方法和依据。     

Ranking and classification of irrigation system performance using fuzzy set theory: case studies in Australia and China

A methodology for ranking and classifying performance of irrigation systems through multidimensional performance indicators is developed using fuzzy set theory. The procedure uses the concepts of fuzzy resemblance and fuzzy dominance. Preference levels reflecting management priorities are incorporated into the analysis using appropriate weighting factors. The application of the procedure is demonstrated through two case studies: the Shi-Jin irrigation district in Hebei Province, China and the Goulburn irrigation region in Victoria, Australia. The classification of performance periods for the Australian system shows three clusters indicating the predominant effect of the increase in waterlogged area when higher priority is given to this indicator. No clear trend appeared when equal weight was assigned to all indicators. The effect of economic reforms implemented in 1977–78 in China is clearly reflected in the resulting ranking and clustering of the performance periods in the Shi-Jin irrigation district. Performance levels following reforms are shown to be consistently higher.Units mu unit of area equal to 1/15 ha (666 m²) - jin unit of weight equal to 0.5 kg.     

Ascorbate levels and the activity of key enzymes in ascorbate biosynthesis and recycling in the leaves of 22 Chinese persimmon cultivars

The objective of this study was to determine diversities of ascorbic acid (AsA) and activities of enzymes involved in AsA metabolism, and to determine their relationships to AsA content in the leaves of Chinese persimmon (Diospyros kaki) cultivars. Results showed that there were huge differences not only in the contents of AsA and glutathione (GSH) but also in the enzyme activities of l-galactono-1,4-lactone dehydrogenase (GLDH, EC 1.3.2.3), dehydroascorbate reductase (DHAR, EC 1.8.5.1), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) in the leaves of 22 Chinese persimmon cultivars. Control of AsA levels mainly depended on the capacity for biosynthesis and GLDH activity played a main role in determining AsA levels in the leaves of persimmon. Both MDHAR and DHAR, MDHAR in particular, also played an important role in maintaining AsA redox state by reducing oxidized AsA back to AsA. But contents of GSH and hydrogen peroide (H₂O₂) and activity of APX were not significantly correlated with AsA content in the leaves of persimmon.     

丹参开花与繁育特性研究

 通过田间观察和人工授粉等方法, 对丹参( Salvia miltiorrhiza Bge. ) 的开花生物学和繁育特性进行了初步研究。结果表明: 丹参为无限开花植物, 总状花序上通常有两性花近50朵, 单花花期5～7d, 从花前2 d到开花6 h花粉活力和柱头可授性都较大, 两者有效可遇期约为1.5 d, 可同花自交; 丹参自交结实和自然结实主要是通过同株异花传粉获得; 结合花粉/胚珠比、杂交指数以及繁育处理的结果认为,丹参不存在无融合生殖, 繁育类型为兼性异交, 自交亲和, 需要传粉者; 传粉媒介主要是蜂类。初步推断丹参为常异花授粉植物, 并对丹参育种中适宜采用的杂交方法及育种途径进行了探讨。     

青贮玉米收获机打捆装置自动控制系统设

青贮玉米收获机可在玉米摘穗的同时,将切碎的秸秆打成圆捆,以便于青贮.为提高作业效率、简化机手操作流程,设计了一套喂料与送绳自动控制系统,该系统由传感检测元件、控制电路及执行机构3部分组成.采用四路换向开关作为传感检测元件,并结合RS去抖电路,可有效提高控制系统工作可靠性.执行元件为两电磁离合器,接收控制电路的输出信号,完成对喂料和送绳过程的实时控制.试验表明:该系统工作安全、可靠,料捆成捆率达到1009%;与手动控制方式相比,有效强化了料捆密度控制的准确性,使机具的作业效率提高20%.     

基于DSP快速原型控制的道路模拟振动台控制系统

根据道路模拟振动台的试验要求,设计了控制系统的整体方案.为了提高控制系统的实时性和快速性,在硬件方面,采用了DSP TMS320C2812采集振动台反馈的模拟量和数字量,利用DSP TMS320C6713处理算法并且与嵌入式处理器S3C2410进行通讯.利用快速原型控制系统实现了该方案,利用Matlab/Simulink建立道路模拟振动台的控制系统模块,在CCS集成开发环境中可以自动生成代码,然后将可执行代码下载到DSP TMS320C2812和DSP TMS320C6713中,即可实现道路模拟振动台的控制系统设计.     

温室环境控制系统智能故障诊

分析了温室环境控制系统中执行机构、传感器、控制柜、控制软件的主要故障;根据故障可能对系统造成的损失将故障分为4个级别,并提出了相应的处理策略,编制了完整的智能故障诊断软件.试验结果表明,故障诊断识别正确,系统运行可靠.     

基于温度-含氧量的全自动堆肥通风控制系统设计

采用工业计算机和下位机的监测控制方式,开发了基于温度-含氧量的全自动堆肥通风控制系统,并实现了软硬件的配套设计.运行试验表明:采用该工艺堆肥,时间一般为2周,高温期(55～65℃)可维持9 d以上,能有效杀灭病原微生物,产品稳定性好;可在整个堆肥过程中实现自动在线监控堆体温度、含氧量和湿度,运行稳定.     

基于控制局域网的拖拉机液压悬挂电控系统

根据拖拉机悬挂系统机电液一体化的控制方式要求,以单片机C8051F040/1为主控制器,设计了基于CAN总线的拖拉机电控液压悬挂电子控制系统,开发了系统的CAN网络、硬件电路、软件程序,提出了控制系统的CAN传输信息帧的身份码(ID)和数据的编写方式,并实现了通过CAN网络对拖拉机悬挂的操作以及对其工作状态的监测与调控.     

视频和GIS技术在森林防火中的应用

针对浙江省森林覆盖率高,并且发生森林火灾的频率也高,单纯的视频监控在夜晚无法识别等问题,提出了视频技术与地理信息系统技术相结合来监控森林火灾的方案。该方案是在森林的某个高程点上架设视频摄像设备,通过远程传输到达视频监控系统的后台,显示在森林地理信息系统上,然后根据显示的区域来监控森林火情。该方案通过同步跟踪算法实现视频技术与地理信息系统的融合,在森林防火地理信息系统上实时同步跟踪,能够提高森林防火的效率。