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1.
真鲷的营养需要及配合饲料的研究初报   总被引:8,自引:0,他引:8  
本文综述了真鲷的营养需要,研究了不同植物蛋白源对真鲷生长的影响,并在此基础上设计了三种饲料配方,试验结果表明I号饲料配方的增长率最高。  相似文献   
2.
Under the assumptions of triangular cross section channel and uniform stable flow, an analytical solution of the minimum ecological in-stream flow requirement (MEIFR) is deduced. Based on the analytical solution, the uncertainty of the wetted perimeter method is analyzed by comparing the two techniques for the determination of the critical point on the relationship curve between wetted perimeter, P and discharge, Q. It is clearly shown that the results of MEIFR based on curvature technique (corresponding to the maximum curvature) and slope technique (slope being 1) are significantly different. On the P-Q curve, the slope of the critical point with the maximum curvature is 0.39 and the MEIFR varied prominently with the change of the slope threshold. This indicates that if a certain value of the slope threshold is not available for slope technique, curvature technique may be a better choice. By applying the analytical solution of MEIFR in the losing rivers of the Western Route South-to-North Water Transfer Project in China, the MEIFR value via curvature technique is 2.5%-23.7% of the multi-year average annual discharge, while that for slope technique is 11%-105.7%. General conclusions would rely on the more detailed research for all kinds of cross-sections.  相似文献   
3.
This paper analyses participatory forest policy and the ways it has influenced the relationships between people as it relates to the forest resource management. This case study was conducted in the middle hills of Nepal, and information was collected through direct observation, individual interviews, group discussion and secondary information analysis. It substantiates a few examples of how the community forestry programme can be used as a means to promote the participation of the women, the poor and dalit (untouchables) in forest resource management, as well as enhancing social justice and improving the forest resources in their locality. However, it also demonstrates that though the community forestry programme has a positive impact, it faces several constraints and challenges. The local Forest User Group is controlled by a few élites making the poor and disadvantaged vulnerable to further marginalization. The results of the case study strongly indicate that community forestry processes must address the political, economic and social needs of the forest users, and also provide a neutral platform on which the poor can present their cases.  相似文献   
4.
国家级气象资料存储检索系统的建立   总被引:6,自引:8,他引:6       下载免费PDF全文
对国家级气象资料存储检索系统的需求进行了分析,进而对系统进行了功能设计,并在技术调研和分析的基础上确定了功能实现的技术路线:在数据管理方面采用数据库和文件系统相结合的方式;在存储管理方面采用分级存储管理模式,并解决了数据库的分级存储管理技术;在检索应用方面提供了程序调用式检索方式,并通过采用中间件技术实现了基于B/S结构的程序调用式检索;通过选用HPSS技术解决了由异种机型构成的高性能计算机群存储池问题;通过分别建立实时数据库和综合数据库解决了气象资料的规范化存储和实时业务使用需求之间的矛盾;在应用软件开发方面严格按照有关规范进行。  相似文献   
5.
A key geodetic contribution to both the three Global Observing Systems and initiatives like the European Global Monitoring for Environment and Security is an accurate, long-term stable, and easily accessible reference frame as the backbone. Many emerging scientific as well as non-scientific high-accuracy applications require access to an unique, technique-independent reference frame decontaminated for short-term fluctuations due to global Earth system processes. Such a reference frame can only be maintained and made available through an observing system such as the Global Geodetic Observing System (GGOS), which is currently implemented and expected to provide sufficient information on changes in the Earth figure, its rotation and its gravity field. Based on a number of examples from monitoring of infrastructure, point positioning, maintenance of national references frames to global changes studies, likely future accuracy requirements for a global terrestrial reference frame are set up as function of time scales. Expected accuracy requirements for a large range of high-accuracy applications are less than 5 mm for diurnal and sub-diurnal time scales, 2–3 mm on monthly to seasonal time scales, better than 1 mm/year on decadal to 50 years time scales. Based on these requirements, specifications for a geodetic observing system meeting the accuracy requirements can be derived.  相似文献   
6.
This paper uses spatial, temporal, and use-intensity data for 27 major marine uses in Washington waters to feature a method for assessing potential use conflicts in a variety of scenarios. The study represents a first step towards quantifying potential conflicts within Washington’s Marine Spatial Planning (MSP) study area by using a cumulative analysis to highlight high- and low-use intensity areas and the novel Marine Potential Conflict Index (MPCI), which incorporates space, time, and intensity of use, to quantify pairwise potential conflicts between uses. About 10% of pairs of uses do not overlap spatially and are likely compatible with one another. Temporally, the number of uses peaks in July and August and falls during January and February. Additionally, the MPCI identified three important use types with a substantial degree of potential conflict: commercial fishing, tribal fishing, and shipping. External data were used in three cases to ground-truth the analysis, as a limited test of its utility in managing any potential conflict. This article assesses the extent of Washington’s existing marine uses along spatial, temporal, and intensity axes, and more broadly provides a straightforward way to examine potential conflicts between marine uses.  相似文献   
7.
随着国家地下水监测工程的启动,国土资源部提出了国家、省、市新的三级地下水监测站网建设要求。该文介绍了各级地下水监测站网的基本概念、主要建设内容,各级地下水监测站网建设服务对象、基本要求,细化了各级地下水监测站网建设要求,规范了建设行动。  相似文献   
8.
The Swedish Geotechnical Society has adopted a general methodology for risk management in geotechnical engineering projects to reduce the costs related to negative outcomes of geotechnical risks. This technical note highlights the main features of the methodology and strives to inspire the international geotechnical community to apply sensible risk management methods. In the authors’ opinion, a successful geotechnical risk management needs to be structured, be tailored to the project, and permeate the engineers’ everyday work. Then, sufficient quality can be achieved in the project with larger probability.  相似文献   
9.
地理信息公共服务平台的用户分类及服务分类   总被引:2,自引:1,他引:1  
地理信息技术的发展经历了集中式、模块化、组件化的过程,目前正向地理信息的Web服务方向发展。传统的集中式地理信息系统中,功能的分类决定了用户的分类;而在地理信息服务的架构中,用户的分类导致服务的分类及其与用户分类的映射。本文从地理信息服务的架构出发,分析并提出了面向服务的地理信息公共服务的用户群分类与对应的服务分类,为地理信息公共服务平台的构建和地理信息服务资源的有效组织和整合提供理论依据。  相似文献   
10.
我国资源卫星资料应用对空间分辨率的需求   总被引:6,自引:0,他引:6  
在简介了我国3种对地遥感卫星的基础上,归纳出我国主要应用领域对遥感图像空间分辨率的需求状况。  相似文献   
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