首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   356篇
  免费   3篇
  国内免费   1篇
安全科学   142篇
废物处理   19篇
环保管理   24篇
综合类   78篇
基础理论   43篇
污染及防治   24篇
评价与监测   27篇
社会与环境   1篇
灾害及防治   2篇
  2022年   2篇
  2021年   3篇
  2020年   4篇
  2019年   4篇
  2017年   3篇
  2016年   6篇
  2015年   6篇
  2014年   7篇
  2013年   11篇
  2012年   14篇
  2011年   57篇
  2010年   51篇
  2009年   69篇
  2008年   32篇
  2007年   6篇
  2006年   7篇
  2005年   4篇
  2004年   5篇
  2003年   11篇
  2002年   12篇
  2001年   9篇
  2000年   1篇
  1999年   15篇
  1998年   4篇
  1997年   2篇
  1996年   1篇
  1995年   3篇
  1994年   6篇
  1993年   2篇
  1992年   1篇
  1984年   1篇
  1976年   1篇
排序方式: 共有360条查询结果,搜索用时 109 毫秒
91.
Knowledge of customer requirements (CRs) allows manufacturers to effectively reduce the time-to-market for products and maintain a high-level of quality through customer satisfaction. Acquisition, definition, and decomposition of such requirements is therefore a first step in the product design process and key for successful product development. Of building importance in these requirements is for sustainable or green products. Thus has developed the method of Design for Environment (DFE) in product design process, which calls designers to not only understand CRs for product function, structure and economic attributes, but in social and environmental impacts. Thus, the need for elicit environmental customer requirements (ECRs) from various traditional CRs becomes apparent along with the need to meet those requirements in the design process.In the present paper, initial CRs are decomposed and categorized into functional customer requirements (FCRs), performance customer requirements (PCRs) and ECRs. Such an analysis is made based on the analysis of environmentally friendly products (EFPs), environmentally conscious customers, and the characteristics of their CRs, Furthermore, the decomposing method based on semantic analysis is given along with a developed quality function deployment for environment (QFDE) method. These methods create a shift from initial CRs to DFE oriented technical parameters (TPs). Finally, the acquisition and conversion of CRs of the automatic soybean milk maker in the DFE process is taken as an example to validate and analyze the above-mentioned method.  相似文献   
92.
93.
94.
95.
Boyden S  Binkley D  Stape JL 《Ecology》2008,89(10):2850-2859
Genetic variation and environmental heterogeneity fundamentally shape the interactions between plants of the same species. According to the resource partitioning hypothesis, competition between neighbors intensifies as their similarity increases. Such competition may change in response to increasing supplies of limiting resources. We tested the resource partitioning hypothesis in stands of genetically identical (clone-origin) and genetically diverse (seed-origin) Eucalyptus trees with different water and nutrient supplies, using individual-based tree growth models. We found that genetic variation greatly reduced competitive interactions between neighboring trees, supporting the resource partitioning hypothesis. The importance of genetic variation for Eucalyptus growth patterns depended strongly on local stand structure and focal tree size. This suggests that spatial and temporal variation in the strength of species interactions leads to reversals in the growth rank of seed-origin and clone-origin trees. This study is one of the first to experimentally test the resource partitioning hypothesis for intergenotypic vs. intragenotypic interactions in trees. We provide evidence that variation at the level of genes, and not just species, is functionally important for driving individual and community-level processes in forested ecosystems.  相似文献   
96.

This study was conducted to evaluate the microbiological quality of a mangrove estuary in the Vitória Bay region, Espírito Santo, Brazil. We analyzed the presence and concentration of enteric viruses and thermotolerant coliforms in water, mussels (Mytella charruana and Mytella guyanensis), and oysters (Crassostrea rhizophorae), collected over a 13-month period. Human adenovirus, rotavirus A (RVA), and norovirus genogroup II were analyzed by quantitative PCR. The highest viral load was found in RVA-positive samples with a concentration of 3.0 × 104 genome copies (GC) L−1 in water samples and 1.3 × 105 GC g−1 in bivalves. RVA was the most prevalent virus in all matrices. Thermotolerant coliforms were quantified as colony-forming units (CFU) by the membrane filtration method. The concentration of these bacteria in water was in accordance with the Brazilian standard for recreational waters (< 250 CFU 100 mL−1) during most of the monitoring period (12 out of 13 months). However, thermotolerant coliform concentrations of 3.0, 3.1, and 2.6 log CFU 100 g−1 were detected in M. charruana, M. guyanensis, and C. rhizophorae, respectively. The presence of human-specific viruses in water and bivalves reflects the strong anthropogenic impact on the mangrove and serves as an early warning of waterborne and foodborne disease outbreaks resulting from the consumption of shellfish and the practice of water recreational activities in the region.

  相似文献   
97.
正Dr.Samuel M.Cohen of the University of Nebraska Medical Center,who has recently published in the Journal of Environmental Sciences(Cohen et al.,2016),is the recipient of the Merit Award from the Society of Toxicology(USA)."The Merit Award is presented to a member of the Society of Toxicology in recognition of distinguished contributions to toxicology throughout an  相似文献   
98.
To better understand the role of fairness in creativity, we developed and tested a multi‐foci social exchange model of creativity. Specifically, we examined the effect of both the organization and supervisor as distinct sources of interpersonal and informational justice types on creativity through the mediating mechanisms of trust and social exchange relationships. The data were collected from 205 employees and their supervisors at a large chemical engineering plant in India. Structural equation modeling was used to test the model. Results show that both interpersonal and informational justice types influence creativity via different mechanisms but both justice types were not equally important for employee creativity. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
99.
Dispersal kernels in grid-based population models specify the proportion, distance and direction of movements within the model landscape. Spatial errors in dispersal kernels can have large compounding effects on model accuracy. Circular Gaussian and Laplacian dispersal kernels at a range of spatial resolutions were investigated, and methods for minimizing errors caused by the discretizing process were explored. Kernels of progressively smaller sizes relative to the landscape grid size were calculated using cell-integration and cell-center methods. These kernels were convolved repeatedly, and the final distribution was compared with a reference analytical solution. For large Gaussian kernels (σ > 10 cells), the total kernel error was <10−11 compared to analytical results. Using an invasion model that tracked the time a population took to reach a defined goal, the discrete model results were comparable to the analytical reference. With Gaussian kernels that had σ ≤ 0.12 using the cell integration method, or σ ≤ 0.22 using the cell center method, the kernel error was greater than 10%, which resulted in invasion times that were orders of magnitude different than theoretical results. A goal-seeking routine was developed to adjust the kernels to minimize overall error. With this, corrections for small kernels were found that decreased overall kernel error to <10−11 and invasion time error to <5%.  相似文献   
100.
Sustainable development or sustainability has been highlighted as an essential principle in urban master planning, with increasing recognition that uncontrollable urbanization may well give rise to various issues such as overexploitation of natural resources, ecosystem destruction, environmental pollution and large-scale climate change. Thus, it is deemed necessary to modify the existing urban and regional administrative system so as to cope with the challenges urban planning is being confronted with and realize the purpose of urban sustainability. This paper contributed to proposing a mechanism which helps to make urban planning with full consideration of issues with respect to sustainable development. We suggested that the integration of urban planning, SEA and ecological planning be a multi-win strategy to offset deficiency of each mentioned political tool being individually applied. We also proposed a framework where SEA and ecological planning are fully incorporated into urban planning, which forms a two-way constraint mechanism to ascertain environmental quality of urban planning, although in practice, planning and SEA processes may conditionally be unified. Moreover, as shown in the case study, the integration of the three political tools may be constrained due to slow changes in the contextual factors, in particular the political and cultural dimensions. Currently within the context of China, there may be three major elements which facilitate integration of the three political tools, which are (1) regulatory requirement of PEIA on urban planning, (2) the promotion or strong administrative support from government on eco-district building, and (3) the willingness of urban planners to collaborate with SEA experts or ecologists.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号