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971.
安全科技人才教育发展战略研究   总被引:6,自引:3,他引:3  
我国当前安全事故频发与安全科技人才匮乏有一定的关系,安全科技人才教育公共性的缺失是安全科技人才减少的主要原因,国家要走政府主导型的安全科技人才教育发展之路,从战略的高度对其进行研究,本文就这一问题进行尝试性的探索,旨在为我国安全产生提供数量足够的高质量的安全科技人才,为国家作出更大的贡献。  相似文献   
972.
SUMMARY

The sun is the ultimate energy source of the Earth. This energy is a resource if utilised, a menace if not. Plants collect and transform radiant energy to chemical energy through photosynthesis. Part of the converted energy is used for their maintenance, while the remainder is stored as biomass. The living biomass plays a vital role in ecological processes and relationships, and provides essential services: soil and water conservation, a buffer against the adverse effects of rain, wind and sun, aesthetics, recreation, and environmental cleaning. Harvested biomass provides safe energy and materials for production of valuable products through industrial processes and household-based technologies. In the absence of vegetation, solar radiation dries soil moisture and disrupts natural processes essential for healthy ecosystem sustenance. Light-use efficiency of plants is positively correlated with rate of growth and bamboos are among the fastest growing perennial plants. This paper is not a thorough review of radiation or bamboo. The following issues are highlighted: (1) The flow of sunlight to the Earth and its usefulness as a resource if used properly and its tendency to become a nuisance if not. (2) The virtues of bamboos as light interceptors and providers of goods and services, better than many tree species. (3) The endowment of Ethiopia with large natural bamboo resources, the availability of denuded land for expansion, and the urgency for proper management, expansion and utilisation for faster socio-economic development and environmental improvement.  相似文献   
973.
《淮河流域可持续发展战略研究》采取系统科学的方法,提出了较为完整的淮河流可持续发展战略体系,既是中国水利事业步入“大水利”举措的尝试,也弥补了从整体上研究中国大河流域可持续发展战略的不足,对于其他大河流域的可持续发展战略研究具有借鉴意义。  相似文献   
974.
With the effect of the human trade doctrine in the international trade field, almost all the countries have paid more attention to the sustainable development of international trade. This article chose the export sustainable development as the research object. On the basis of the analysis of the theoretical connotation of the export sustainable development, this article tried to establish an evaluation indices system and set up an evaluation model of the export sustainable development level, and finally made some empirical research on China. The result indicates that the comprehensive level of the export sustainable development in China showed a tendency to rise from 1985 to 2003 and the export sustainable development level of China in these years can be divided into four grades: excellent, good, moderate and poor. In most years, the social economic benefits of export was obtained at the cost of the deterioration of environment and the depletion of resources, and the economic profit of export did not increase with the enlargement of the export scale because of the deterioration of the terms of trade. Therefore, China should be careful about the problem of poverty accompanied by the increase of export.  相似文献   
975.
David Gibbon 《Disasters》1987,11(1):53-58
It is the principal proposition of this paper that formal agricultural research, and its supporting policies and planning, has not responded adequately to the special situation that exists in semi-arid Africa. In many cases the transfer of research approaches based on temperate and more humid tropical experience has contributed to greater instability and the growing environmental crisis. Radically different research structures, objectives, methods and expectations are necessary to contribute to the redevelopment of long term regenerative systems of production that will provide the short and long term needs of the people who live in the semi-arid regions and at the same time protect these environments.  相似文献   
976.
Farmers attempting to subsist in tropical uplands often rely upon unsustainable resource use practices that lead to soil erosion, declining crop yields, and a loss of soil productivity capacity. Other uses of tropical uplands, including logging and conversion of forest to rangelands, have similar results. The undesirable effects of these actions are felt on-site, at the watershed level, and even nationally. Ecological cause-effect relationships are poorly understood, and few examples exist of the successful integration of ecological knowledge with upland development. It is hypothesized that recent results of ecological research could be applied to uplands management so that stable sustainable systems of human use may be established. A second hypothesis is that statistically reliable data can be obtained from experiments in upland situations, although natural variations of soils, weather, and vegetation are great. To test these hypotheses, research involving multinational collaboration among American and Southeast Asian scientists has begun. The objective of the work is to provide credible quantitative information to help policy and decision makers and resident farmers to plan and implement improved practices based on ecological principles.Some findings to date include:
1.  Ecological principles are difficult to relate to the practical context of upland agroecosystems. Indeed, the null hypothesis is necessary for planning experiments and demonstrations.
2.  The signal-to-noise ratio in these field experiments is low, and the detection of changes due to human intervention in soil erosion, nutrient movement, and plant productivity is difficult.
3.  Obstacles to field research in developing countries include logistic, cultural, political, and institutional factors. It is essential that local land managers participate from the start with scientific researchers in designing experiments.
4.  Planned collaboration among academic and government scientists facilitates design of relevant research and the implementation of results.
5.  The idea of ecologically based management has been well received by researchers and government officials in Asia. There is little argument with the logic of the approach.
6.  Pressures for quick responses to urgent problems in the uplands conflict with the need for careful, long-term, statistically valid scientific research.
7.  Ecological principles are vaguely understood and poorly articulated in the scientific literature. The transfer and application of ecological science to the developing world would be enhanced by clearer statements of principles.
  相似文献   
977.
生态承载力评价方法研究进展   总被引:2,自引:0,他引:2       下载免费PDF全文
生态承载力是当前生态学、地理学、经济学等领域的研究热点,生态承载力评价方法的研究对于区域社会经济协调可持续发展具有重要的意义。在详细阐述生态承载力概念、内涵、国内主要研究领域、研究机构的基础上,重点分析比较了目前生态承载力所涉及的研究方法,并比较了不同模型之间的优缺点,最后分析总结了目前生态承载力研究存在的不足和未来需要加强的领域和方向。从方法上来看,目前所用方法主要有:(1)指标体系综合评价法;(2)产品周期综合评价法;(3)结合不同学科和不同方法的综合评价法。目前生态承载力的研究缺乏科学完整的研究体系,尚未构建具有普适性的评价指标体系,演化趋势与模拟预测研究不足,格局分异研究较少,未来应该在以下几个方面深入研究:(1)加强生态承载力模型集成研究。由于生态承载力问题十分复杂,涉及资源、环境、生态、社会、经济等诸多要素,因此需要综合各个要素之间的相互关系及影响机制,进行不同模型集成和综合研究;(2)应从影响生态承载力的主动与被动因子,动态与静态因子出发,构建综合性和普适性较强的评价体系;(3)加强生态承载力的动态模拟研究,实现对生态承载力潜力的估算和动态变化过程的监测;(4)研究不同尺度下生态承载力时空变化特征及空间分异,并对比分析各模型对不同尺度的精度要求和结果的可靠性。  相似文献   
978.
本文主要研究电波传播模拟中重要的方法射线追踪法的算法改进问题。讨论在射线发射阶段的优化算法,通过设计一种新的数据结构来达到动态追踪的目的。最终在保证精度的前提下减少追踪射线的条数,减少追踪时间,实现算法优化。  相似文献   
979.
Traditional crop landraces play dynamic roles in the expression of native biological and cultural diversity via their central position in the genetic resource base, agroecosystems and social heritage of indigenous peoples. Farmer varieties provide farmers with an “agricultural survival kit” for household welfare and for adaptation to changing conditions. These varieties meet local cultural practices and environmental constraints, and play an intrinsic role in cultural survival by constituting a living repository of ancestral customs including cultivar-specific recipes, songs, handicrafts, stories of origin, and unique planting, harvesting, processing, and storage rituals and techniques. The centrality of rice in Southeast Asian agricultural and social systems, contrasted with the significant erosion of rice-based biological and cultural diversity in native communities, calls for increased attention to the links between traditional rice varieties and indigenous rice-based customs. This study represents the research efforts of rice farmers pertaining to the Tado clan, a Kempo Manggarai community on Flores␣Island, in association with USA academicians. Research results demonstrate: (i) a complex suite of upland rice-based ethnobotanical traditions; (ii) significant and␣dynamic regional flux and dissemination of “old” and “new” landraces; (iii)␣community-level maintenance of distinct genotypes across a range of microenvironments; (iv) localized “extinctions” of ancestral landraces within 1–2 generations and a concomitant loss of related traditions; and (v) the contributions of a collaborative (indigenous and academic) approach to ethnographic and agronomic research.  相似文献   
980.
The excessive application of fertilizer and pesticides in grain production in China has posed a threat to the environmental sustainability of agricultural production. One of the major reasons of the increasing usage of chemical inputs by farmers is their trying to reach higher yields, especially in absence of adequate public inputs, such as development and extension of appropriate technology and necessary production infrastructure, etc. Based on the crop specific data of the past 20 years, this paper examines how the public investments in agricultural researches could impact on the reduction of farmers' private material inputs of major grain crops in China. It manifests that the increased investments in public sector, especially in agricultural researches, is a favorable and effective way to reduce farmers' private material inputs and should be given a priority consideration in the policy emendation to increase yields and improve production sustainability.  相似文献   
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