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131.
运用有限元分析软件,分析了不同的自紧压力对车用玻璃纤维环向缠绕气瓶疲劳性能的影响,采用新的许用应力幅度一循环次数曲线代替JB4752,对不同自紧压力下的疲劳寿命进行了计算,认为不经过自紧只打水压试验是无法满足气瓶疲劳试验要求的。  相似文献   
132.
The state of sea otter populations has been assessed by a comparative method using criteria such as the density of equilibrium populations (on Medny and Iturup islands), food supply, and effects of certain external factors. Optimal values of population density for larger islands have been calculated using the Arcview GIS 3.3 program. For the inhabited water area (from the shoreline to the 50-m isobath), they range from 3.1 to 3.4 ind./km2. The composition of sea otter diet and its changes on the Commander Islands, Kuril Islands, and southern Kamchatka are analyzed. The diameter of eaten sea urchins is considered as a parameter characterizing the degree of colonization of living space by sea otters. It is concluded that the abundance of these animals in the Russian part of the species range may slightly increase in the future due to the growth of their populations on the southern and middle Kurils.  相似文献   
133.
134.
Only two river basins in which the European pearl mussel has survived to date are known in Arkhangelsk oblast. These are the Solza and Kozha basins. The northeastern boundary of the European range of this species passes along the watershed between the basins of the Solza and the Shirshema (the Onega Peninsula) and then along the Onega-Northern Dvina watershed. The population density and the proportion of juveniles widely vary in different parts of the Solza Basin, and, therefore, the previously conclusion concerning the ageing of the population in the Kazanka River (Bolotov and Semushin, 2003) applies only to certain parts of this river. The highest density of the pearl mussel in the Solza Basin is 68 ind./m2. Fish cultivation contributes to the conservation of this pearl mussel population, as the release of Atlantic salmon juveniles ensures reproduction of the mollusk under conditions of regulated river flow.  相似文献   
135.
提出了一种舰载方舱的建设构想,在兵器发射前先进行规定时间的温湿度环境贮存处理,再进行实弹发射试验。舰载方舱连同军舰能够形成海上环境试验场的发射阵地,配合海上相关测量设备,能够完成对水中兵器实弹在经过温湿度贮存处理后实际使用性能的环境适应性考核。  相似文献   
136.
以某火电厂高架点源为例,运用AERMOD进行预测,对扇区进行粗划分和细划分,设置两组地表参数,分析SO2、NO2、PM10在敏感点的小时浓度、日均浓度和期间平均浓度最大值的差异.变化幅度分析方法表明,PM10的小时浓度、日均浓度、期间平均浓度最大值的变化幅度最大,NO2次之,SO2最小.高端值比较法分析表明,NO2小时浓度最大值的差异最大,SO2次之,PM10最小;NO2日均浓度最大值的差异最大,PM10次之,SO2最小;NO2期间平均浓度最大值的差异最大,SO2次之,PM10最小.  相似文献   
137.
抗生素企业VOCs排放清单及影响范围模拟   总被引:2,自引:2,他引:0  
药品生产要消耗大量的原材料,是公认的"高污染、高耗能"行业.鉴于制药行业排放清单研究匮乏,本研究首先依据典型抗生素企业的实际监测数据及生产信息,采用实测法确定了各VOCs物质的排放因子;然后结合同一园区内抗生素A~G厂的活动水平信息,采用排放因子法计算得到各个厂的排放量,建立排放清单,并运用Monte Carlo法对清单进行了不确定性分析;最后用CALPUFF模型对A~G厂进行春夏秋冬四季的环境影响范围模拟.结果表明,抗生素企业生产中的总VOCs排放因子(以抗生素计,下同)为6 655. 61 g·t-1,其中结晶工序排放因子最大,为3 603. 476 g·t-1. A~G厂每年生产抗生素会分别产生VOCs 6 655. 610、7 454. 283、998. 342、11 980. 098、4 492. 537、42 462. 792和18 302. 928 kg,其中排放量最大的前4种物质依次为乙酸丁酯、正丁醇、正己烷和丙酮.通过对A厂进行Monta Carlo模型验证发现,A厂排放量基本呈对数正态分布,95%置信区间的不确定性为(-60. 62%,131. 78%),处于可接受范围.通过CALPUFF模拟,各季节VOCs扩散方向和扩散范围均不同,夏季出现中心聚集现象.  相似文献   
138.
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   
139.
Rewilding is increasingly recognized as a conservation tool but is often context specific, which inhibits broad application. Rewilding in Australia seeks to enhance ecosystem function and promote self-sustaining ecosystems. An absence of large-bodied native herbivores means trophic rewilding in mainland Australia has focused on the restoration of functions provided by apex predators and small mammals. Because of the pervasive influence of introduced mesopredators, predator-proof fences, and establishment of populations on predator-free islands are common rewilding approaches. This sets Australian rewilding apart from most jurisdictions and provides globally relevant insights but presents challenges to restoring function to broader landscapes. Passive rewilding is of limited utility in arid zones. Although increasing habitat extent and quality in mesic coastal areas may work, it will likely be necessary to undertake active management. Because much of Australia's population is in urban areas, rewilding efforts must include urban areas to maximize effectiveness. Thus rewilding is not synonymous with wilderness and can occur over multiple scales. Rewilding efforts must recognize human effects on other species and benefit both nature and humans. Rewilding in Australia requires development of a shared vision and strategy and proof-of-concept projects to demonstrate the benefits. The repackaging of existing conservation activities as rewilding may confuse and undermine the success of rewilding programs and should be avoided. As elsewhere, rewilding in Australia should be viewed as an important conservation tool.  相似文献   
140.
Conservation of carnivores in an increasingly changing environment is greatly helped by understanding the decision-making processes underlying habitat patch choice. Foraging theory may give us insight into spatio-temporal search patterns and consequent foraging decisions that carnivores make in heterogeneous and fluctuating environments. Constraints placed on central-place foragers in particular are likely to influence both foraging decisions and related spatio-temporal movement patterns. We used discrete choice models to investigate the spatio-temporal ranging behaviour of GPS collared female wolverines (Gulo gulo) with dependent cubs in south-central Norway. Activity patterns, home range use and selection for elevation were analyzed in relation to spatial and temporal covariates (daily and seasonal) and related to different foraging behaviours. In spring, wolverines showed restricted movement patterns around rendezvous sites at high elevations by day, whereas during the night animals were active at lower elevations. Over the summer, this daily pattern in intensity of use diminished and their overall selectiveness for elevation decreased as cubs grow more mobile and independent. At the onset of autumn, wolverines showed intensive use of the profitable forest-alpine tundra ecotone. We argue that reproducing wolverines deployed a foraging strategy attuned to altering their movement patterns throughout the summer to address a continuous, but diminishing, trade-off between providing both food and shelter for their offspring. Incorporating spatially and temporally explicit activity patterns and home range use in discrete choice resource selection models thus enhances the understanding of the motives behind wolverine resource utilization in space and time. Such knowledge may provide guidance to managers designing regional-scale zoning, in order to facilitate carnivore recovery and to minimize conflicts with human activities.  相似文献   
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