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   292篇
  免费   37篇
  国内免费   33篇
安全科学   73篇
废物处理   1篇
环保管理   23篇
综合类   144篇
基础理论   23篇
污染及防治   2篇
评价与监测   41篇
社会与环境   14篇
灾害及防治   41篇
  2024年   2篇
  2023年   4篇
  2022年   10篇
  2021年   15篇
  2020年   10篇
  2019年   15篇
  2018年   8篇
  2017年   9篇
  2016年   15篇
  2015年   20篇
  2014年   11篇
  2013年   16篇
  2012年   37篇
  2011年   38篇
  2010年   19篇
  2009年   22篇
  2008年   9篇
  2007年   13篇
  2006年   14篇
  2005年   13篇
  2004年   4篇
  2003年   9篇
  2002年   9篇
  2001年   5篇
  2000年   7篇
  1999年   3篇
  1998年   4篇
  1997年   1篇
  1996年   1篇
  1995年   7篇
  1994年   5篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
排序方式: 共有362条查询结果,搜索用时 31 毫秒
161.
One hundred and fourteen samples of amniotic fluid taken before 15 weeks of gestation were cultured for cytogenetic studies. The results of culturing these early amniotic fluid (EAF) samples were compared with the results of culturing 114 standard amniotic fluid (SAP) samples taken after 15 weeks of gestation matched for maternal age and received in the laboratory within the same week. Cell culture was successful in all 114 of the EAF samples and in 111 SAP samples. There was no significant difference in the days to harvesting and days to reporting in the two groups. Three samples of SAP failed to grow and two EAF samples produced tetraploid karyotypes, so that in these five cases amniocentesis had to be repeated. These problems were attributed to toxicity of a fungicide used in the culture medium. Pseudomosaicism was noted in two EAF samples and one SAP sample; and maternal cell contamination was noted in one EAF and one SAP sample. Thus, culturing and karyotyping cells harvested from EAF and SAP are similar, indicating that EAF samples from 12–14-week pregnancies could be used for prenatal diagnosis.  相似文献   
162.
为解决我国污染源在线监控数据缺乏深层次利用、监测数据对污染源不能有效预警的状况,对企业日常污水排放的污染物进行监控预警,综合运用层次分析法和频次分析法,分别确立了在线监控预警的指标体系和污水排放不同警情的阈值范围,并以某化工厂12个月的在线监测数据为案例对方法进行了验证.分析结果表明,某化工厂污染源废水中ρ(氰化物)在0~0.50 mg/L之间,其中88.54%的监控数据分布范围为0~0.20 mg/L,均未超过GB 8978—1996《污水综合排放标准》Ⅱ级标准限值;ρ(CODCr)在3.51~499.17 mg/L之间,其中51.74%的数据分布在>300~400 mg/L之间,接近GB 8978—1996 Ⅲ级标准限值,出水ρ(CODCr)偏高;ρ(NH4+-N)在0~45 mg/L之间,均未超过GB 8978—1996 Ⅱ级标准限值,其中91.13%的数据低于30 mg/L,出水ρ(NH4+-N)较低.对确定的预警阈值方法验证结果表明:①依据权重值的大小最终筛选出氰化物、CODCr及NH4+-N为预警指标.②某化工厂氰化物在排放正常、一般、不正常及极不正常状态对应的阈值范围分别可设为40%频次、30%频次、5%频次及超过5%频次所对应的浓度范围;CODCr和NH4+-N各状态对应阈值浓度范围一致,均为50%频次、40%频次、5%频次及超过5%频次对应的数值.研究显示,基于在线监测数据并结合相关标准、化工企业排污风险特征和化工厂的生产特征及工艺等基本条件,提出利用频次分析法确定化工厂各采样时刻不同警情阈值的方法较为科学合理.   相似文献   
163.
近年来,受极端地震和极端天气的影响,泥石流灾害日益加剧,山区城镇泥石流风险问题逐渐引起大众的关注。泥石流的早期识别和监测预警作为防灾减灾的有效途径之一,已在山区城镇及重大工程建设区发挥重要的减灾作用。分析总结泥石流早期识别与监测预警技术方法和理论的目的在于掌握其发展现状与问题,进一步为山区城镇泥石流灾害防灾减灾提供有效应急对策。同时指出改进当前存在问题可为后期发展提供参考依据。本文通过文献综述法在阅读大量文献基础上,从技术与设备、预警理论与模型和监测预警体系3个方面对泥石流早期识别和监测预警研究进行回顾与评述,并针对其不足提出了加强深度学习在泥石流早期识别中运用,注重构建地面因素与天上因素耦合的泥石流预警模型,完善泥石流灾害应急系统的初步看法。  相似文献   
164.
This study investigated the association between vaccination with the Hepatitis B triple series vaccine prior to 2000 and developmental disability in children aged 1–9 years (n = 1824), proxied by parental report that their child receives early intervention or special education services (EIS). National Health and Nutrition Examination Survey 1999–2000 data were analyzed and adjusted for survey design by Taylor Linearization using SAS version 9.1 software, with SAS callable SUDAAN version 9.0.1. The odds of receiving EIS were approximately nine times as great for vaccinated boys (n = 46) as for unvaccinated boys (n = 7), after adjustment for confounders. This study found statistically significant evidence to suggest that boys in United States who were vaccinated with the triple series Hepatitis B vaccine, during the time period in which vaccines were manufactured with thimerosal, were more susceptible to developmental disability than were unvaccinated boys.  相似文献   
165.
In 2008, the International Federation of Red Cross and Red Crescent Societies (IFRC) used a seasonal forecast for West Africa for the first time to implement an Early Warning, Early Action strategy for enhanced flood preparedness and response. Interviews with disaster managers suggest that this approach improved their capacity and response. Relief supplies reached flood victims within days, as opposed to weeks in previous years, thereby preventing further loss of life, illness, and setbacks to livelihoods, as well as augmenting the efficiency of resource use. This case demonstrates the potential benefits to be realised from the use of medium‐to‐long‐range forecasts in disaster management, especially in the context of potential increases in extreme weather and climate‐related events due to climate variability and change. However, harnessing the full potential of these forecasts will require continued effort and collaboration among disaster managers, climate service providers, and major humanitarian donors.  相似文献   
166.
《Environmental Hazards》2013,12(4):313-328
Risk communication plays an increasingly central role in flood risk management, but there is a variety of conflicting advice about what does – and should – get transmitted, why, how, and to whom. The aim of this paper is to elucidate the underlying normative and conceptual models on which those competing assessments of ‘good’ risk communication depend. To that end, the paper identifies four broad models, or approaches, to risk communication: a risk message model of information transfer; a risk instrument model of behavioural change; a risk dialogue model of participatory deliberation; and a risk government model of self-regulation and normalization. These models differ in their theoretical and disciplinary origins and associated philosophical and political commitments, and consequently they define the basic purpose, practice, and future prospects of flood risk communication in quite different ways. Unless these different models of ‘good’ risk communication are acknowledged and understood, efforts to identify best practice for flood risk management are likely to produce inconsistent, if not contradictory, recommendations.  相似文献   
167.
《Environmental Hazards》2013,12(3):249-265
This paper discusses insights from post-tsunami early warning system (EWS) development in Thailand, Sri Lanka and Indonesia by analysing selected elements of resilience, based on the Coastal Community Resilience (CCR) framework, and by distinguishing between the cognitive, normative and procedural dimensions of EWSs. The findings indicate that (1) recent calls to develop participatory and people-centred EWSs as promoted by the Hyogo Framework for Action 2005—2015 have not been sufficiently translated into action in the implementation of national policies and strategies for early warning; (2) policy and guidance places significantly more emphasis on the procedural compared to the normative and cognitive dimensions of EWSs; (3) practitioners engaged in early warning and disaster risk reduction operate in contexts shaped by multiple stakeholder agendas and face considerable challenges in negotiating diverse needs and priorities; and (4) few platforms currently exist that enable stakeholders to coordinate and reconcile agendas, negotiate joint targets, share knowledge and critically reflect on lessons learnt, and to improve the integration of early warning with other priorities such as livelihoods improvement, natural resource management and community development.  相似文献   
168.
海上钻井平台安全风险预警模型应用研究   总被引:2,自引:1,他引:1  
2010年美国墨西哥湾“深水地平线”钻井平台爆炸和2011年我国蓬莱钻井平台井涌事故,引发社会各界对海上钻井平台安全问题的关注.介绍了海洋钻井平台的组成结构,对海洋钻井平台的危险源进行了系统辨识,试图通过对海上钻井平台作业现场危险因素加以观察,诊断、分析警源、警情,警兆,警级,结合专家意见,从人员、设施设备、安全管理、工程地质、海上环境等几个方面建立海上钻井平台安全风险预警体系,采用改进的层次分析法,得出指标权重,构建海洋钻井平台安全风险预警模型,得到量化的预警结果.并通过对某钻井平台的实例分析,提出安全风险的预控对策,以期本模型对海上钻井平台的事故的发生起到一定的防范作用.  相似文献   
169.
近年来,我国海外石油工程项目蓬勃发展的同时,面临公共安全极大挑战。现阶段我国石油企业的公共安全风险管理体系不尽完善,此方面的研究重点主要集中在应急救援等领域,为了及时应对复杂多变的公共安全风险,开展公共安全风险预警研究有着重要的现实意义。综合考虑现阶段海外石油工程项目面临的公共安全风险现状,从社会安定、自然灾害、公共卫生、事故灾难和综合管理五个方面系统分析其存在的公共安全风险,借助层次分析法和模糊综合评判,建立并计算公共安全风险预警指标体系的标准权重,确定预警评判集,最终提出一种海外石油工程公共安全风险预警方法,并给出应用步骤。将该风险预警方法运用到非洲某国,结果显示,与实际高度吻合,具有实际应用价值。  相似文献   
170.
庆安县绿色食品产地环境质量预警研究   总被引:2,自引:0,他引:2  
绿色食品产地环境质量预警是对自然变化、人类活动影响所引起的环境质量恶化进行预测,并及时提出警告.本文以国家级生态农业示范区庆安县的绿色食品产地为例,依据1993-2003年庆安县绿色食品产地环境质量监测数据及其状态转移矩阵,采用马尔可夫链模型预测未来5年环境质量状态发生概率,对该研究区进行环境质量负向演化预警研究.结果发出了巨宝村、东阳村和泥河农场的环境质量负向演化的预警信号.据此进行了警因分析并提出排警建议,为环境规划和管理部门提供科学治理依据和辅助决策.  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