全文获取类型
收费全文 | 158篇 |
免费 | 0篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 2篇 |
环保管理 | 37篇 |
综合类 | 55篇 |
基础理论 | 33篇 |
污染及防治 | 19篇 |
评价与监测 | 9篇 |
社会与环境 | 8篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 15篇 |
2012年 | 3篇 |
2011年 | 11篇 |
2010年 | 2篇 |
2009年 | 14篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 10篇 |
2005年 | 5篇 |
2004年 | 11篇 |
2003年 | 11篇 |
2002年 | 5篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
排序方式: 共有169条查询结果,搜索用时 15 毫秒
111.
Introduction: Crashes involving roadway objects and animals can cause severe injuries and property damages and are a major concern for the traveling public, state transportation agencies, and the automotive industry. This project involved an in-depth investigation of such crashes based on the second Strategic Highway Research Program (SHRP 2) Naturalistic Driving Study (NDS) data including detailed information and videos about 2,689 events. Methods: The research team conducted a variety of logistic regression analyses, complemented by Support Vector Machine (SVM) analyses and detailed case studies. Results: The logistic regression results indicated that driver behavior/errors, involvement of secondary tasks, roadway characteristics, lighting condition, and pavement surface condition are among the factors that contributed significantly to the occurrence and/or increased severity outcomes of crashes involving roadway objects and animals. Among these factors, improper turning movements (odds ratio = 88), avoiding animal or other vehicle (odds ratio = 38), and reaching/moving object in vehicle (odds ratio = 29) particularly increased the odds of crash occurrence. Factors such as open country roadways, sign/signal violation, unfamiliar with roadway, fatigue/drowsiness, and speeding significantly increased the severity outcomes when such crashes occurred. The sensitivity analysis of the three SVM classifiers confirmed that driver behavior/errors, critical speed, struck object type, and reaction time were major factors affecting the occurrence and severity outcomes of events involving roadway objects and animals. Practical Applications: The study provides insights on risk factors influencing safety events involving roadway objects, including their occurrence and the severity outcomes. The findings allow researchers and traffic engineers to better understand the causes of such crashes and therefore develop more effective roadway- and vehicle- based countermeasures. 相似文献
112.
113.
Conservation planning of critical habitats for wildlife species at risk is a priority topic that requires the knowledge of how animals select and use their habitat, and how they respond to future developmental changes in their environment. This paper explores the role of a habitat-modeling methodological approach, agent-based modeling, which we advocate as a promising approach for ecological research. Agent-based models (ABMs) are capable of simultaneously distinguishing animal densities from habitat quality, can explicitly represent the environment and its dynamism, can accommodate spatial patterns of inter- and intra-species mechanisms, and can explore feedbacks and adaptations inherent in these systems. ABMs comprise autonomous, individual entities; each with dynamic, adaptive behaviors and heterogeneous characteristics that interact with each other and with their environment. These interactions result in emergent outcomes that can be used to quantitatively examine critical habitats from the individual- to population-level. ABMs can also explore how wildlife will respond to potential changes in environmental conditions, since they can readily incorporate adaptive animal-movement ecology in a changing landscape. This paper describes the necessary elements of an ABM developed specifically for understanding wildlife habitat selection, reviews the current empirical literature on ABMs in wildlife ecology and management, and evaluates the current and future roles these ABMs can play, specifically with regards to scenario planning of designated critical habitats. 相似文献
114.
Hajo Holzmann Axel Munk Max Suster Walter Zucchini 《Environmental and Ecological Statistics》2006,13(3):325-347
We introduce a new class of circular time series based on hidden Markov models. These are compared with existing models, their
properties are outlined and issues relating to parameter estimation are discussed. The new models conveniently describe multi-modal
circular time series as dependent mixtures of circular distributions. Two examples from biology and meteorology are used to
illustrate the theory. Finally, we introduce a hidden Markov model for bivariate linear-circular time series and use it to
describe larval movement of the fly Drosophila.
Received: September 2003 / Revised: March 2004 相似文献
115.
116.
我国规模化畜禽养殖业存在的环境问题与防治对策 总被引:67,自引:0,他引:67
近年来,由于我国畜禽养殖业的养殖规模、养殖方式和分布区域发生了巨大的变化,它所带来的环境污染问题总体呈现出总量增加、程度加剧和范围扩大的趋势,归纳了我国规模化畜禽养殖业环境污染的特点,从生产、技术、政策和管理上分析了影响我国畜禽养殖业环境污染的主要因素,并提出了污染防治的对策建议,即借鉴发达国家畜禽养殖业的环境管理经验,以减量化、资源化、无害化及实用、廉价为原则,合理规划、防治结合,努力探索一条具有中国特色的规模化畜禽养殖污染防治道路。 相似文献
117.
Rapid growth of intensive animal industries in southeast Queensland, Australia, has led to large volumes of animal waste production,
which posses serious environmental problems in the Murray Darling Basin (MDB). This study presents a method of selecting sites
for the safe application of animal waste as fertiliser to agricultural land. A site suitability map for the Westbrook subcatchment
within the MDB was created using a geographic information system (GIS)-based weighted linear combination (WLC) model. The
factors affecting the suitability of a site for animal waste application were selected, and digital data sets derived from
up to 1:50,000 scale maps were acquired. After initial preprocessing, digital data sets were clipped to the size of the delineated
subcatchment boundary producing input factors. These input factors were weighted using the analytical hierarchy process (AHP)
that employed an objectives-oriented comparison (OOC) technique to formulate the pairwise comparison matrix. The OOC technique,
which is capable of deriving factor weight independently, formulated the weight derivation process by making it more logical
and systematic. The factor attributes were classified into multiple classes and weighted using the AHP. The effects of the
number of input factors and factor weighting on the areal extent and the degree of site suitability were examined. Due to
the presence of large nonagricultural and residential areas in the subcatchment, only 16% of the area was found suitable for
animal waste application. The areal extent resulting from this site suitability assessment was found to be dependent on the
areal constraints imposed on each input factor, while the degree of suitability was principally a function of the weight distribution
between the factors. 相似文献
118.
内蒙古主要畜牧气象灾害减灾对策研究 总被引:5,自引:0,他引:5
针对内蒙古自治区草地畜牧业生产中长期存在的实际问题,从草地雪灾、暴风雪、风冷灾害、旱灾等方面讨论了气象灾害对草地畜牧业生产的影响,并提出了相应的减灾对策,为草原牧区防灾减灾决策提供科学依据。 相似文献
119.
In this paper the authors argue that ethical considerations are relevant for evaluating animal production systems and that in consequence agrologists should seriously consider the arguments of animal welfare supporters. Furthermore, the authors point out the ethical basis for some (though not all) of the conclusions proposed by supporters of animal welfare. In consequence it is necessary to determine the nature of animal welfare and methods of evaluating the welfare of animals and to recognize when production systems fail to satisfy the needs of animals. 相似文献
120.
以北方农牧交错带典型生态示范村尧勒甸子村为例,应用参与式农村评估法(PRA)并结合GPS与野外测量,恢复了该村1949年后50 a来的土地利用历史过程与格局,利用GIS分析其1950-1999年的土地利用变化特点.运用因子分析和逐步回归分析方法揭示了人类活动因素对土地利用变化的作用.结果发现1985年以前耕地面积扩大,草地面积减小,沙地面积迅猛持续增加;1985年以后土地利用变化向相反的方向发展,土地利用结构趋向合理. 相似文献