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101.
102.
In this paper, the authors present generation and treatment information for corrosive hazardous wastes (EPA Hazaradous Waste Codes D002 and K062). The authors discuss the state of the art for several treatment trains used to process specific types of corrosive waste. Treatment trains incorporate various unit processes selected from but not limited to the following: neutralization, filtration, carbon adsorption, biological oxidation, distillation, air flotation, and incineration. Unit processes are selected to form trains according to the corrosive characteristics of each individual waste stream. The treatment processes discussed are proposed to be used instead of landfills for disposal of corrosive waste.  相似文献   
103.
Some evidence exists to relate elevated oxidant levels, as measured by iodine colorimetry or coulometry, to the presence of roof tar evaporates or the oxidation products produced from such evaporates in the presence of sunlight.  相似文献   
104.
Selkoe KA  Gaines SD  Caselle JE  Warner RR 《Ecology》2006,87(12):3082-3094
The scales of population structure in marine species depend on the degree to which larvae from different populations are mixed in the plankton. There is an intriguing trend in marine population genetic studies of significant genetic structure for larvae, recruits, or populations at fine scales that is unpatterned across space and changes through time. This "chaotic genetic patchiness" suggests that larval pools are not well mixed in the plankton. However, few studies have been able to distinguish among potential causes of spatial and temporal genetic heterogeneity: changes in larval migration patterns, changes in environmental selection, or stochasticity caused by "sweepstakes" reproductive success of spawners creating detectable family structure. Here we use microsatellite markers to show that significant allele frequency shifts occurred sporadically in space and time for cohorts of recruits of Paralabrax clathratus (kelp bass) collected once every two weeks over two years from five sites in the Santa Barbara Channel, California, USA. We found that the pattern of genetic differentiation among cohorts was explained by a combination of (1) family structure in some cohorts, evidenced by half and full siblings, and (2) an indication of changes in larval delivery. It is unlikely but possible that environmental selection also plays a role. Although sampling of potential source populations was incomplete, cohorts arriving during western current flows show most genetic similarity with a population sample collected in the west, and cohorts arriving during current flows from the southeast show similarity with population samples collected in the south and east. Despite the family structure apparent in some cohorts, these "sweepstakes" events occur on too fine a scale to create lasting year class genetic structure. The results corroborate oceanographic models of larval dispersal, which suggest that larval mixing in the plankton is less extensive than previously believed.  相似文献   
105.
突发性气象灾害监测系统的设计   总被引:2,自引:0,他引:2  
本文探讨了一种以新一代多普勒天气雷达为探测手段,应用GIS技术,借助Surfer等值线分析功能,获取灾害性天气落区、面积等定量化信息的方法,并据此以VB及VBA开发了一套突发性气象灾害监测系统,并给出了该系统一次典型冰雹过程的应用实例.  相似文献   
106.
为了从价值观和调节焦点的双重视角给煤矿企业新生代员工的安全管理提供科学依据,在文献研究和问卷调查的基础上,对 244 个有效样本进行分析,揭示煤矿企业新生代员工工作价值观的具体内容,结合动机理论和调节焦点理论,构建煤矿企业新生代员工工作价值观、调节焦点和安全绩效的结构方程模型。研究结果表明:煤矿企业新生代员工的工作价值观包含发展导向、自我导向、关系认同、独立自主、利益导向和创造导向6个因子结构;煤矿企业新生代员工的工作价值观、调节焦点和安全绩效两两之间均显著相关;煤矿企业新生代员工的工作价值观不仅可以直接预测安全绩效,还可以通过调节焦点的中介作用间接影响煤矿员工的安全绩效。  相似文献   
107.
Recently the Vietnamese government has endorsed a long-term policy plan in which it is proposed to restore controlled seasonal flooding in the upper regions of the Vietnamese part of the Mekong delta. Restoring controlled flooding would contrast a period of several decades characterized by a dominant flood prevention approach to enable intensive rice production in the delta. This article investigates a series of long-term policy plans, which have been developed for the Mekong delta since the 1960s, on their take on flood control sensu flood prevention, or the opposite, controlled seasonal flooding. By doing so it is demonstrated how perspectives on flood management have gradually evolved and, in the specific case of suggesting controlled flooding, have been framed in various ways by various actors. Contemporary proposals for controlled seasonal flooding are supported by actors ranging from governmental institutes to environmental NGOs, and connect to on-going debates about environmental challenges and sustainable development of the Mekong delta. We adopt a systems approach to analyze social, environmental and technological dynamics in the Mekong delta, and discuss whether the different interpretations of controlled flooding may contribute to the long-term sustainability of the delta.  相似文献   
108.
近45a宁夏气温、降水及植被指数的变化分析   总被引:14,自引:3,他引:11  
利用1961~2005年宁夏气温、降水资料,并结合1982~2003年植被指数(NDVI)数据,分析了宁夏气温、降水和NDVI的时空变化特征。结果表明:近45a来,宁夏气温明显升高,降水总体呈减少趋势;冬季和引黄灌区升温最明显,冬季降水增加,其它季节及各地区降水减少,其中秋季和宁夏南部山区减少最明显;秋冬季降水在1968年前后发生了突变,突变后,冬季降水增多,秋季降水减少;1985~1996年间发生了气温突变,突变后各季及各地区气温明显升高,冬春季和引黄灌区降水增多,其它季节和地区降水减少,极端气候事件较突变前发生更为频繁;近20a宁夏区域内NDVI值呈增加趋势,荒漠化面积整体得到控制。进一步分析表明,前一年气温偏高、夏季降水增加时,有利于当年NDVI值增加。  相似文献   
109.
南极作为世界上最后一块“净土”,其丰富的自然资源和内在的科研、美学等价值受到了越来越多国家的关注。在全球变暖与人类活动(科学考察、商业捕捞、旅游等)因素的影响下,南极出现了海冰面积区域性增减,南极生物物种数量波动,环境污染加重等问题。而现有的以“南极条约体系”为基础的管理政策因理念抽象等问题尚不能完全规范人类活动,南极生态环境保护的形势日益严峻。国际社会应通过跨学科间的国际协作,加强科学研究与管理之间的联系,完善南极生态环境管理政策,最大限度减少人类对南极生态环境的破坏。  相似文献   
110.
SPE-HPLC-MS/MS法检测水体和沉积物中六种甾体雌激素   总被引:1,自引:0,他引:1  
建立了三种天然雌激素和三种人工合成雌激素在水体和沉积物中的HPLC-MS/MS分析方法.该方法运用固相萃取技术进行富集及净化,有效降低了基质的干扰,六种雌激素在水体中的回收率为76.4%~110.3%,沉积物中的回收率为63.7%~88.5%,相对标准偏差在1.04%~9.23%间.质谱采用负离子扫描模式,定量的碎片离...  相似文献   
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