关于土木基础设施系统的基础研究

论述了土木基础设施系统对社会经济发展和人民生活质量提高所起的重要作用,总结了国内外土木基础设施系统的现状和研究趋势,指出了针对我国基础设施建设和更新改造中的重大科学问题开展多学科交叉研究的重要意义。同时建议重点开展以下几方面的研究：１．土木基础设施系统性能检测与寿命评估技术;２．土木基础设施系统的防灾减灾研究;３．材料性能研究;４．土木基础设施系统的维修和更新改造技术开发;５．土工技术基础问题研究     

Participatory Development of No-tillage Systems without Herbicides for Family Farming: The Experience of the Center-South Region of Paraná

It is currently estimated that 40 million hectares worldwide are cultivated through no-tillage systems (Derpsh, 1998). Small family farms account for less than 50,000ha, half of them located in South America's Southern Cone (Wall, 1998). Many hypotheses have been offered to explain why so few small farmers have adapted to this method. The most simplistic ones relate this limited adoption to small farmers' traditionalism and to their rejection of innovation. Others point to the low technological development of animal-drawn equipment needed for this technology or the low educational level of family farmers.Results of work done in the Center-South of Paraná, Southern Brazil, by AS-PTA¹ in partnership with the region's Forum of Family Farmers Organizations, challenge these hypotheses and draw attention to the need for new approaches and processes of research and extension if the goal is to disseminate and implement appropriate no-tillage systems among family farmers. One requisite is to lower production costs of this method through elimination of herbicides and using green manure and cover crops that shift the crop-weed balance in favor of crops.     

A MULTI-BASIN PLANNING STRATEGY1

ABSTRACT. The purpose of this paper is to present and discuss a procedure for finding an optimal staging plan for implementing a multi-basin water resource system-a system that must meet, with tolerable shortages, pre-specified but highly variable demands for water that increase over time-a system such as the proposed Texas Water System. The paper stresses that, in the past, planners have paid little attention to quantifying explicitly the impact that uncertainty has on the decision process, and in that context, presents a means for explicitly evaluating the impact that uncertainty has on finding and evaluating the performance of the optimal and several alternate staging plans. The procedure presented evaluates the impact that uncertainty, in both the hydrologic and the economic variables, has on the decisions that need to be made. The decisions requiring resolution are (1) which of an over-specified set of facilities should be constructed, (2) how large each of the facilities should be at various points in time, and (3) how should the system be operated so as to minimize the capital plus operational costs over the planning period.     

AN EXPANDING ROLE FOR SUBARCTIC WATERSHED RESEARCH1

ABSTRACT: It is increasingly recognized that natural resources research should in many cases be broadened in scope and oriented toward more general “environmental” problems. Locales with a history of “watershed” research can be eminently suited for development of comprehensive, environmental research programs. This is recognized in many research efforts of the International Biological Program (IBP), where watershed research sites have been successfully utilized for intensive investigations of process and function of selected ecosystems or ecosystem components. In the North American Subarctic there is almost no history of “watershed” studies. Basic data on hydrometeorologic parameters such as precipitation amounts and areal and seasonal distribution of runoff are scarce; the data framework within which environmental understanding can be structured is exceedingly sketchy. Opportunity exists in the discontinuous-permafrost settings of central Alaska to begin rectifying this situation. A basic program of multi-agency, multi-discipline research and data acquisition for the most significant hydrologic subregions is being developed, based around several existing environmental research areas (chiefly the Bonanza Creek Experimental Forest, the Caribou-Poker Creeks Research Watershed, the Wickersham Dome Fire Study Area, and a series of outlying sites).     

USER-ORIENTED RESEARCH DESIGNS1

ABSTRACT: A user-oriented research plan is presented herein. Its principal components are: (1) a mechanism for identifying social goals and translating them into research objectives; (2) procedures for setting priorities; (3) a program planning technique for designing projects to impact on important research objectives; (4) a mechanism for coordinating research activities of important research producers; (5) a structure for encouraging and establishing interdisciplinary team efforts when they are required; (6) a well-coordinated technology transfer plan; and (7) an effective method for promoting and sustaining user-researcher cooperation. Both basic and applied research designs are examined and criteria presented. The implementation of research plans is also discussed and various factors which play a role in implementation are outlined including: coordination, goal interpretation and priority setting, project Planning, Project review, interdisciplinary considerations and the user-researcher interface.     

PERCEPTION OF WATER QUALITY BY SELECT RESPONDENT GROUPINGS IN INLAND WATER-BASED RECREATIONAL ENVIRONMENTS1

ABSTRACT: This paper examines four lake environments which are paired by lake size and by trophic state, where trophic state is employed as an identifier of water quality. Two large lakes and two intermediate-sized lakes, with each pair having one oligotrophic lake and one eutrophic lake are selected for cross-sectional survey-oriented questionnaire research. This paper focuses upon one aspect of the research, namely, the perception of water quality by three user groups. The user groups examined are recreationists, cottage and homeowners, and fishermen. The groups are compared utilizing percentage response profiles and cluster level groupings. It appears from a preliminary analysis of the data that the lakes selected are viable trophic state endpoints for questionnaire analysis of respondents. Each user group surveyed does appear sensitive to select water quality parameters; where shifts in sensitivity appear within and between user groups with changes in ecological settings, as well as with factors independent of ecological settings.     

电厂烟气脱硫除尘一体化试验研究

提出了电厂锅炉利用灰水进行除尘脱硫一体化的简易脱硫工艺，探讨了该工艺除尘和脱硫的原理，同时，对影响系统脱硫效率的因素进行了现场试验。试验表明，该系统脱硫效率较高，投资和运行费用低。     

采动斜坡变形破坏模式分析及预测

介绍了国内一些学者在这方面的研究方法。考虑地下开采方向与斜坡岩体结构类型的不同组合，探讨了斜坡的变形破坏模式。根据采动斜坡的变形破坏特点，提出可以采用最初用于预测生物增长规律的费尔哈斯特模型来描述斜坡的变形趋势，在对国内某斜坡的预测实践中，发现该模型具有良好的适应性，能够有效的预测采动斜坡的变形趋势。     

微污染水源水生物硝化处理影响因素

通过对目前世界上规模最大的微污染水源水生物接触氧化处理工程运行过程中氨氮作效果的跟踪监测，较系统地对影响硝化处理效果的环境湿度、源水氨氮浓度、两类硝化细菌生长速率和转化能力的差异等因素进行了实验研究，为工程的运行参数控制提供了依据。     

The Precautionary Principle: Scientific Uncertainty and Omitted Research in the Context of GMO Use and Release

Commercialization of genetically modified organisms (GMOs) have sparked profound controversies concerning adequate approaches to risk regulation. Scientific uncertainty and ambiguity, omitted research areas, and lack of basic knowledge crucial to risk assessmentshave become apparent. The objective of this article is to discuss the policy and practical implementation of the Precautionary Principle. A major conclusion is that the void in scientific understanding concerning risks posed by secondary effects and the complexity ofcause-effect relations warrant further research. Initiatives to approach the acceptance or rejection of a number of risk-associated hypotheses is badly needed. Further, since scientific advice plays a key role in GMOregulations, scientists have a responsibility to address and communicate uncertainty to policy makers and the public. Hence, the acceptance of uncertainty is not only a scientific issue, but is related to public policy and involves an ethical dimension.