长年关水稻田耕作改制的选择

试验研究表明,当早稻收获时间作晚稻才开始幼穗分化,即适宜早、晚稻出穗开花之间有60多天的时间,种植双杂间作稻就可获得好的收成,效果、效益都很显著。1992年用D 优287间汕优63,在达县永进乡的示范田中个别田块产量已达15t/ha,而盆地丘陵区适宜早、晚稻出穗开花之间的时间多数地区不到70天,种植双杂连作稻有困难。且双杂间作稻在抗灾增产,合理利用农村劳动力,提高稻田复种等方面优于双杂连作稻。因此,四川盆地丘陵区的中稻→冬水田在耕作改制中发展部分双杂间作稻是恰当的,其范围在巴中、盐亭、简阳一线以南海拔400m 以下的广大丘陵区。     

Water supply development and tariffs in Tanzania: From free water policy towards cost recovery

The article describes the historical development of water tariff policy in Tanzania from the colonial times to present. After gaining independence, the country introduced “free” water policy in its rural areas. Criticism against this policy was expressed already in the 1970s, but it was not until the late 1980s that change became unavoidable. All the while urban water tariffs continued to decline in real terms. In rural and periurban areas of Tanzania consumers often have to pay substantial amounts of money for water to resellers and vendors since the public utilities are unable to provide operative service. Besides, only a part of the water bills are actually collected. Now that the free water supply policy has been officially abandoned, the development of water tariffs and the institutions in general are a great challenge for the country.     

DEVELOPMENT OF WATERSIIED MODELS FOR TWO SIERRA NEVADA BASINS USING A GEOGRAPHIC INFORMATION SYSTEM1

ABSTRACT: Techniques were developed using vector and raster data in a geographic information system (GIS) to define the spatial variability of watershed characteristics in the north-central Sierra Nevada of California and Nevada and to assist in computing model input parameters. The U.S. Geological Survey's Precipitation-Runoff Modeling System, a physically based, distributed-parameter watershed model, simulates runoff for a basin by partitioning a watershed into areas that each have a homogeneous hydrologic response to precipitation or snowmelt. These land units, known as hydrologic-response units (HRU's), are characterized according to physical properties, such as altitude, slope, aspect, land cover, soils, and geology, and climate patterns. Digital data were used to develop a GIS data base and HRIJ classification for the American River and Carson River basins. The following criteria are used in delineating HRU's: (1) Data layers are hydrologically significant and have a resolution appropriate to the watershed's natural spatial variability, (2) the technique for delineating HRU's accommodates different classification criteria and is reproducible, and (3) HRU's are not limited by hydrographic-subbasin boundaries. HRU's so defined are spatially noncontiguous. The result is an objective, efficient methodology for characterizing a watershed and for delineating HRU's. Also, digital data can be analyzed and transformed to assist in defining parameters and in calibrating the model.     

几种事故预测方法的探讨

本文根据生产单位事故发生的随机性特点,论证了未来时段中事故次数及其时间分布等各项指标,是能够用多种随机数学模型和灰色系统理论来预测的。用非随机的函数模型预測事故是不合适的。给出了几种事故预測方法,并提出了几种值得研究和试用的方法。     

智能型地理信息系统（AIGIS）在城市抗震防灾规划中的应用

本文简要介绍地理信息系统GIS的发展概况、主要功能以及在国内外的应用现状.对现有的GIS软件技术加以改进,引进人工神经元网络和模糊综合评判技术,发展了一种智能型的GIS,在我国若干城市的抗震设防区划工作中应用,取得良好的效果。     

SIMULATION/OPTIMIZATION TECHNIQUES FOR MULTI-BASIN WATER RESOURCE PLANNING1

A set of simulation and optimization tools capable of analyzing the development and operation of a complex, multi-basin, interconnected water resource are explained. These models provide valuable information regarding the important questions: (1) “When should new projects be build?” (2) “How big should they be?” and (3) “How should the system be operated?” Since these tools were developed by and for practicing engineers, their applicability to real-world problems is mandatory. To assure this, testing was done on an actual proposed project, the Texas Water System.     

THE POLITICAL INFLUENCE OF RESIDENTIAL CONSUMERS ON WATER RATES1

ABSTRACT: The regulatory process such as that for water rates can be viewed as a bargaining process between regulators, utility management, and consumers. This bargaining process involves both political and economic influences. In an attempt to empirically verify that utility rates are a product of both economic and political factors, a sample of publicly-owned water utilities was subjected to regression analysis. As expected, cost and cost-related factors were positive and significant determinants of residential water rates. Using an admittedly imperfect measure of residential user political influence, there was evidence that increased political activity results in lower water rates. Furthermore, the political influence and water rate linkage is more evident in small water utilities than in larger suppliers.     

除尘系统加接新支管的理论和实践

对于一个现有的除尘系统,若其除尘器、通风机的工作能力有足够的富余量,则可以在该系统管网上加接新的支管,来治理新的扬尘点。     

灰关联分析在故障树诊断中的应用

介绍一种灰色诊断法。在故障诊断模式识别中,运用灰关联分析,依据故障树的底事件重要度,通过关联度计算及排序,对故障树分析中,各种故障模式发生的可能性大小作出了准确的判断,从而为处理事故的先后、缓急提供了依据。     

塔式起重机安全评判专家系统的研制

塔式起重机作为建筑施工的主要设备,在建筑等行业发挥着极其重要的作用,因而其安全问题受到各国有关部门的高度重视,但塔式起重机的事故率近年来仍未见下降,其安全问题仍然是建筑施工中的忧患之一。为此,笔者在建造了塔式起重机安全的依赖关系图的基础上,采用基于现代设计方法学的专家系统构造技术,使用ＶＩＳＵＡＬＣ＋ ＋ 开发了塔式起重机安全评判专家系统ＴＱＥＳ。该系统经全部测试通过,可对一般的塔式起重机进行安全评判