全文获取类型
收费全文 | 1554篇 |
免费 | 84篇 |
国内免费 | 292篇 |
专业分类
安全科学 | 113篇 |
废物处理 | 74篇 |
环保管理 | 253篇 |
综合类 | 698篇 |
基础理论 | 232篇 |
污染及防治 | 429篇 |
评价与监测 | 39篇 |
社会与环境 | 64篇 |
灾害及防治 | 28篇 |
出版年
2024年 | 4篇 |
2023年 | 46篇 |
2022年 | 38篇 |
2021年 | 56篇 |
2020年 | 57篇 |
2019年 | 68篇 |
2018年 | 42篇 |
2017年 | 49篇 |
2016年 | 62篇 |
2015年 | 68篇 |
2014年 | 72篇 |
2013年 | 143篇 |
2012年 | 145篇 |
2011年 | 123篇 |
2010年 | 61篇 |
2009年 | 79篇 |
2008年 | 67篇 |
2007年 | 116篇 |
2006年 | 111篇 |
2005年 | 77篇 |
2004年 | 67篇 |
2003年 | 50篇 |
2002年 | 48篇 |
2001年 | 40篇 |
2000年 | 52篇 |
1999年 | 31篇 |
1998年 | 39篇 |
1997年 | 20篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有1930条查询结果,搜索用时 9 毫秒
951.
Global demand for elephant ivory is contributing to illegal poaching and significant decline of African elephant (Loxondonta africana) populations. To help mitigate decline, countries with legal domestic ivory markets were recommended by the Convention on International Trade in Endangered Species of Wild Fauna and Flora to close domestic markets for commercial trade. However, implementing stricter regulations on wildlife trade does not necessarily mean compliance with rules will follow. Using an online questionnaire, we examined the relationship between self-reported compliance with ivory trade regulations among 115 ivory traders in the United Kingdom and 4 dimensions (control, deterrence, legitimacy, and social norms) hypothesized to influence compliance with conservation regulations. Although most traders supported regulations, a large number did not always check that they comply with them when trading objects containing ivory. The main factors influencing compliance with ivory trade regulations were traders’ ability to comply and their perceptions of the regulations and punishments to deter illegal trade. These findings demonstrate the utility of conservation criminology to improve wildlife trade regulations and identify opportunities to reduce illegal ivory entering the market in the United Kingdom. Compliance could be improved by clearer regulations that facilitate easier detection of illegal ivory products and stronger prosecution of violations. 相似文献
952.
Amrita Gupta Bistra Dilkina Dana J. Morin Angela K. Fuller J. Andrew Royle Christopher Sutherland Carla P. Gomes 《Conservation biology》2019,33(5):1023-1034
Ecological distance-based spatial capture–recapture models (SCR) are a promising approach for simultaneously estimating animal density and connectivity, both of which affect spatial population processes and ultimately species persistence. We explored how SCR models can be integrated into reserve-design frameworks that explicitly acknowledge both the spatial distribution of individuals and their space use resulting from landscape structure. We formulated the design of wildlife reserves as a budget-constrained optimization problem and conducted a simulation to explore 3 different SCR-informed optimization objectives that prioritized different conservation goals by maximizing the number of protected individuals, reserve connectivity, and density-weighted connectivity. We also studied the effect on our 3 objectives of enforcing that the space-use requirements of individuals be met by the reserve for individuals to be considered conserved (referred to as home-range constraints). Maximizing local population density resulted in fragmented reserves that would likely not aid long-term population persistence, and maximizing the connectivity objective yielded reserves that protected the fewest individuals. However, maximizing density-weighted connectivity or preemptively imposing home-range constraints on reserve design yielded reserves of largely spatially compact sets of parcels covering high-density areas in the landscape with high functional connectivity between them. Our results quantify the extent to which reserve design is constrained by individual home-range requirements and highlight that accounting for individual space use in the objective and constraints can help in the design of reserves that balance abundance and connectivity in a biologically relevant manner. 相似文献
953.
关于华北科技学院创建安全科技特色的探讨 总被引:2,自引:0,他引:2
创建鲜明的安全科技办学特色不仅是华北科技学院的生存战略,更是发展战略。创建安全科技特色是一项复杂的系统工程,要从宏观、中观和微观3个层面,从资源协同、能力协同和部门协同3个角度,从近期、中期和远期3个阶段创建安全科技特色。创建学院安全科技特色的具体措施主要包括五方面的内容开创和建设以安全技术及工程为主的特色优势学科;引进和培养具有安全科技特色的教师队伍;正确处理教学、科研、安全培训三者的关系;建立和形成支撑安全科技特色的规章制度;营造和突出具有安全科技特色的校园文化。 相似文献
954.
李宣东 《中国安全科学学报》2006,16(12):61-64
笔者将传统中医学理论与企业安全生产风险管理相结合,在事故致因、事故预防、安全管理等方面,借鉴中医的预防思想、整体观念、五行学说、辨证施治等理论方法,分析研究指出:企业发生安全事故如同人体得病,正气不足是发病的内在根据,邪气入侵是发病的重要条件。因此,发生事故的根本原因在于企业本身;要从研究企业自身的影响安全生产诸要素之间的相互滋生和相互制约的关系入手,加强事故预防工作,坚持整体性的原则,辨证分析事故原因,加大企业生产安全的精神和物质保障,才能全面提高企业的生产安全风险管理水平。 相似文献
955.
This study presents an analysis of injuries (severe and fatal) sustained by “high-performance-small-motorcycle” users in Malaysia and establishes the relationship between fatality risk and human factors, exposure and vehicle factors resulting from motorcycle crashes. From the data gathered a statistical model based on logistic regression modeling technique has been developed. Five variables found to have a significant influence on fatality risk (p < 0.05) were age, location sites, engine capacity, object/vehicle struck and collision types. 相似文献
956.
Katarzyna Majchrzycka Beata Gutarowska Agnieszka Brochocka 《International journal of occupational safety and ergonomics》2013,19(2):275-280
The second part of the article presents the results of a study of antimicrobial activity of filter nonwovens with an addition of biocides, as a function of the presence of sweat in the environment and the method of microbe deposition on a nonwoven in the form of a liquid and a bioaerosol. At the same time, the filtration efficiency of nonwovens against microorganisms in the form of a bioaerosol was tested with the dynamic method. The results showed that the addition of sweat on the surface of a nonwoven resulted in an insignificant decrease of biological activity that still remained high. Moreover, an active nonwoven showed biostatic and biocidal activity only when microbes were deposited on the surface in the form of a solution. The nonwoven did not show any biological activity after deposition of microorganisms with the dynamical method in the form of a bioaerosol. 相似文献
957.
A. Azadeh Z. Jiryaei Sharahi B. Ashjari M. Saberi 《Journal of Loss Prevention in the Process Industries》2013,26(6):1159-1182
This study proposes a flexible intelligent algorithm for assessment and optimization of demographic features on integrated health, safety, and environment and ergonomics (HSEE)-ISO systems among operators of a gas transmission refinery. To achieve the objectives of this study, standard questionnaires with respect to HSEE and ISO standards are completed by 80 operators. Demographic features include age, education, gender, weight, stature, marital status, and work type. The average results for each category of HSEE are used as inputs and effectiveness of ISO systems (ISO 18000, ISO 14000, and ISO 9000) are used as output for the intelligent algorithm. Artificial Neural Networks (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) in addition to conventional regression are used in this paper. Result shows the applicability and superiority of the flexible intelligent algorithm over conventional methods through mean absolute percentage error (MAPE). Computational results show that the proposed ANN performs better than ANFIS and conventional regressions based on its relative error. Finally, the optimum mix of demographic variables from viewpoint of HSEE and ISO are identified. This is the first study that proposes a flexible intelligent algorithm for assessment of optimum mix of demographic features for HSEE and ISO systems in a complex system such as a gas transmission refinery. 相似文献
958.
提出了一种求解随机参数桁架结构在随机荷载作用下反应的概率密度函数和结构精确可靠度的方法.通过对随机参数桁架结构在随机荷载作用下的有限元分析方法的研究,考虑了结构的物理参数,构件的几何尺寸和作用荷载幅值等的随机性.应用随机向量函数的概率分布函数表达式,通过确定积分区间、变量替换、交换积分顺序等一系列数学上的处理,获得所求结构反应的概率密度函数.由干涉理论得到了结构位移和应力的可靠度.通过算例的结果与Monte-Carlo模拟法结果比较,表明该方法具有较高的精度及良好的实用性. 相似文献
959.
Adams C 《Journal of Safety Research》2005,36(1):33-37
INTRODUCTION: This study was designed to explore the temporal aspects of crashes for probationary and non-probationary drivers. METHODS: Data from the West Australian Road Injury Database from 1996-2000 were used to calculate age-sex-specific crash rates per 100,000 person-days and to plot proportions of fatal and hospital crashes by time for probationary and non-probationary drivers. The population attributable risk was used to estimate the potential number of lives saved by nighttime driving restriction in the probationary period. RESULTS: Probationary drivers were seven times more likely to crash than non-probationary drivers. While the highest number of crashes was in the daytime, probationary drivers had a higher proportion of fatal or hospitalization crashes at night than non-probationary drivers. CONCLUSION: Restrictions on driving at night could form part of graduated driver training. Even if some probationary drivers disobeyed the restriction, a substantial reduction in car occupant fatalities and hospitalizations could result. 相似文献
960.
随着民航事业的迅速发展和空中交通流量的不断增长.为有效地避免空管不安全事件的发生,辨识出空管运行中潜在危险源至关重要.目前空管单位缺乏对危险源的有效分类,对危险源的触发机制要素界定不够清晰.利用危险三角形对危险进行描述,并用M-SHEL模型对空管运行中首类危险源——管制"错误、遗忘、疏漏"的触发机制进行分类辨识与分析.构建了管制"错误、遗忘、疏漏"危险源辨识指标体系,一级指标5个,二级指标20个;运用灰色关联分析法计算出各类触发机制之间的关联系数和关联度.结果表明,人的因素是导致管制"错误、遗忘、疏漏"发生的最主要因素,而其中最主要的触发机制要素是个人能力问题. 相似文献