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   114篇
  免费   17篇
  国内免费   16篇
安全科学   50篇
废物处理   1篇
环保管理   10篇
综合类   46篇
基础理论   15篇
污染及防治   1篇
评价与监测   3篇
社会与环境   11篇
灾害及防治   10篇
  2023年   5篇
  2022年   4篇
  2021年   6篇
  2020年   1篇
  2019年   8篇
  2018年   4篇
  2017年   4篇
  2016年   9篇
  2015年   8篇
  2014年   1篇
  2013年   8篇
  2012年   10篇
  2011年   7篇
  2010年   15篇
  2009年   8篇
  2008年   6篇
  2007年   9篇
  2006年   4篇
  2005年   5篇
  2004年   5篇
  2003年   6篇
  2002年   3篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1992年   1篇
  1989年   1篇
  1971年   1篇
排序方式: 共有147条查询结果,搜索用时 265 毫秒
101.
Toxic or hazardous substances pose two types of risks in the environment, namely `short-term or acute risk' and `long-termor chronic risk'. The short-term risk is associated with the one-time acute exposure to potentially hazardous substancesaccidentally released in the environment, whereas the long-termrisk is resulted from continuous exposure to potentially harmfulsubstances present in different environmental media. This articledeals with the assessment of potential health risks related to certain carcinogens and non-carcinogens (e.g. cadmium, chromiumand nickel) present in three environmental media, viz. air, waterand food in different Indian states (regions). Appropriate dose-response models have been identified and used for this purpose with the assumptions and input data as per the Indian context. Mean values of ambient air concentration levels of Cd,Cr and Ni have been used to estimate the individual and societalrisks of extra cancer in different states of India. The hazardquotients and hazard index representing the non-carcinogenic chronic health effects caused by chromium and cadmium due to their long-term exposure through water and food have also beenestimated. The risk results have been compared with the diseasesurveillance data. A definite correlation between the estimatedrisk results and the reported number of lung cancer cases and chronic liver diseases have been observed in different regions. As a matter of fact, it is not possible to derive precise risk estimates due to various uncertainties included both in availabledata and in the models which are used to calculate potency factors and effective concentration. However, average risk levelsas estimated and presented in this article are quite useful forplanning purposes.  相似文献   
102.
Trochkine  D.  Iwasaka  Y.  Matsuki  A.  Yamada  M.  Kim  Y.-S.  Zhang  D.  Shi  G.-Y.  Shen  Z.  Li  G. 《Water, Air, & Soil Pollution: Focus》2003,3(2):161-172
The Asian continent is recognized as one of the most important sources of mineral (or soil) particles. These particles have a large potential to effect global changes through the biogeochemical cycle of particulates and through radiative balance (IPCC Third Assessment Report, 2001). Therefore, comparison of particle compositions near the source region and those after long-range transport is important in understanding the long-range particle transport phenomenon. Individual aerosolparticles were collected in Dunhuang (40°09N; 94°41E), China. Particles were collected at the campus of the Meteorological Bureau of Dunhuang City (17 August 2001) and near the Mogao Grots, located approximately 30 km from Dunhuang (18 August 2001, 18 October 2001 and 13 January 2002) using a two-stage low-volume impactor. The morphology of individual aerosol particles and their elemental compositions were examined via a scanning electron microscope (Hitachi, S-3000N) equipped with an energy dispersive X-ray (EDX) analyzer (Horiba, EMAX-500). The particles collected at these locations were comprised primarily of minerals, with the exception of sulphateparticles in the submicron range that were contained in thesample collected on 18 October 2001 (likely, ammonium sulphate). The most abundant elements were found to be Si and Al. Approximately 46–77% of the collected particles were Si-richparticles (composed primarily of quartz and aluminosilicate),and 13–41% of the collected particles were Ca-rich particles,such as calcite (CaCO3), dolomite (CaMg(CO3)2),and gypsum (CaSO42H2O). The fractions of Fe-rich, Mg-rich, Ti-rich, K-rich, and Cl-rich were 3–10, 0–7, 0–3, 0–1, and 0–1%, respectively. Similar types of mineral particles were found in the free troposphere over Japan(Trochkine et al., 2002). A number of differences were found to exist between the particles collected in China and thosecollected in Japan, and these differences can be explained bychemical modification of the particles during transport fromChina to Japan.  相似文献   
103.
化工园区安全容量分析探讨   总被引:6,自引:3,他引:3  
化工园区的安全容量问题一直是地方政府普遍关心的重要问题。本文采用量化风险分析的方法着重对化工园区的运输风险进行分析,以此来评判化工园区的安全容量是否合适,并给出了运输风险分析的模型和风险接受标准。通过对南方某化工园区整个危险品物流的统计分析,经风险计算给出了不同水平个人风险的半宽。结合化工园区的远期规划,经反算给出了新增合理安全容量在约30~90万m^3之间,总安全容量在470~530万m^3之间。  相似文献   
104.
Competition between individuals permeates people's lives as they strive for limited resources, services, and status. However, research on competition and competitiveness in organizations is limited despite its relevance to relational dynamics (e.g., rivalry), individual differences (e.g., traits and gender), social factors (e.g., competitive climate), and organizational outcomes (e.g., work performance and unethical behavior). In this article, we propose a multilevel model of competition and competitiveness that includes the individual, the group, and the situation. By providing a holistic overview of research across a broad array of disciplines, we organize the field and create a usable framework to advance knowledge of competition and competitiveness. In doing so, we identify what we know, what we still need to discover, and provide direction for future research. The article closes with an assessment of methods and measures used in studying competition. In conclusion, this review establishes a multilevel and integrative structure that incorporates individual and team competitiveness with competitive situations that prompt competitive processes and important organizational outcomes.  相似文献   
105.
为了更合理地分析事故风险,提出了基于贝叶斯网络的多级多米诺效应计算方法及其计算步骤,并从个人风险和社会风险2个角度,定量分析了生产安全事故的多级多米诺效应。同时以某企业的2个汽油罐区为例,运用上述方法对其生产安全事故的多米诺效应进行定量计算,并将计算结果与未考虑多米诺效应、仅考虑一级多米诺效应时的计算结果进行比较。研究结果表明:基于贝叶斯网络的计算方法,同时考虑了多级多米诺效应和事故的协同效应,可以使计算的个人风险和社会风险更接近于实际。  相似文献   
106.
为研制矿山呼吸性粉尘浓度个体监测仪,采用MIE光散射方法,试制以红外线发光二极管作为光源的呼吸性粉尘浓度个体监测仪,该监测仪主要由气路部分、光路部分及电路部分组成。利用中国安全生产科学研究院自制的粉尘简易试验装置,在气体流量为2 L/min、颗粒粒径不大于5 μm的条件下,研究试制仪器电压输出值和流入粉尘质量浓度二者的对应关系。结果表明:根据不同粉尘质量浓度下的输出电压数据,在0~300 mg/m3测量范围内,试制仪器输出电压值和粉尘浓度之间具有线性函数关系,说明呼吸性粉尘浓度个体监测仪是合理可行的;粉尘监测仪测试结果与比对仪器测量结果对比分析可知,测量误差最大为1.59%,满足粉尘检定规程要求。  相似文献   
107.
Abstract:  Noninvasive genetic methods can be used to estimate animal abundances and offer several advantages over conventional methods. Few attempts have been made, however, to evaluate the accuracy and precision of the estimates. We compared four methods of estimating population size based on fecal sampling. Two methods used rarefaction indices and two were based on capture-mark-recapture (CMR) estimators, one combining genetic and field data. Volunteer hunters and others collected 1904 fecal samples over 2 consecutive years in a large area containing a well-studied population of brown bears ( Ursus arctos ). On our 49,000-km2 study area in south-central Sweden, population size estimates ranged from 378 to 572 bears in 2001 and 273 to 433 bears in 2002, depending on the method of estimation used. The estimates from the best model in the program MARK appeared to be the most accurate, based on the minimum population size estimate from radio-marked bears in a subsection of our sampling area. In addition, MARK models included heterogeneity and temporal variation in detection probabilities, which appeared to be present in our samples. All methods, though, incorrectly suggested a biased sex ratio, probably because of sex differences in detection probabilities and low overall detection probabilities. The population size of elusive animals can be estimated reliably over large areas with noninvasive genetic methods, but we stress the importance of an adequate and well-distributed sampling effort. In cases of biased sampling, calibration with independent estimates may be necessary. We recommend that this noninvasive genetic approach, using the MARK models, be used in the future in areas where sufficient numbers of volunteers can be mobilized.  相似文献   
108.
Summary. Stress has been widely studied in different mammals, but the physiological stress reaction that the odour of a predator could induce in preys has not received much attention. Besides, not all the animals would respond to the same extent to a known stressor. We developed an experimental procedure with eleven na?ve European rabbits (Oryctolagus cuniculus) in order to determine the individual physiological response to the olfactory detection of a potential predator. The rabbits were housed singly in small enclosures with a concrete burrow system and food and water were available ad libitum. The animals followed a control trial, without odour, and an experimental trial where we confronted the rabbits with fox (Vulpes vulpes) odour. Furthermore, another sample of eleven rabbits followed a control procedure subjected to the same housing and handling procedures but without facing the predator odour. In order to assess the physiological response we analysed the concentration of glucocorticoid metabolites in the faeces of the rabbits. Therefore, everyday faecal samples were collected and analysed with an enzyme immunoassay in order to measure the corticosterone metabolites (CM), particularly, those metabolites with a 5α-3β, 11β-diol structure. After validating the assay for wild rabbits, we found that the simulated presence of a predator (fox odour) in the enclosure resulted in an increase in faecal CM concentrations. However, the stressor did not affect all the animals in the same way. We found a general increase in the individual differences. In particular, males experienced a higher increase than females, though the overall response was similar for both sexes. To our knowledge this is one of the first attempts to analyse the assessment of the risk of predation by means of non-invasive methods.  相似文献   
109.
马斯京根模型参数估计的新方法   总被引:13,自引:1,他引:12  
提出了马斯京投模型参数估计的一种新方法—加速遗传算法,分析了该算法控制参数的优化特性,总结出了这些参数的简便设置技术.应用实例表明,该方法简便、直观、通用、适应性强,它可广泛应用于各种自然灾害模型的优化问题之中。  相似文献   
110.
What candidates say in an interview is important—but so is how they say it. We draw on dual-process theory to explain why interviewers rely on individuals' dynamic and static nonverbal cues to evaluate performance with quick, implicit inferences (System 1 processing). Yet, it remains unclear which cues most influence interviewers' judgments and whether moderators affecting interviewers' reliance on System 1 thinking (e.g., interview structure, modality, duration, and interviewee gender) impact the relationship between nonverbal cues and interview ratings. We performed the first meta-analysis to address these questions, integrating findings across 63 studies (N = 4868). The nonverbal cues demonstrating the strongest association with interview performance were professional appearance (ρ = .62), eye contact (ρ = .45), and head movement (ρ = .43). Moderator analyses highlight the persistent power of nonverbal cues, as the results were largely unaffected by interview structure, modality, or duration. Experimental design did play a role, as did interviewees' gender, with stronger effects for certain nonverbal cues (e.g., facial expressions and professional appearance) for women than men, conveying interviewers' reliance on gender-based stereotypes when judging their performance. Overall, these results suggest nonverbal cues and characteristics are an important influence on job applicants' success in employment interviews.  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