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61.
近20-30年来,很多国家引进了综合性环境保护法律.然而,人们逐渐认识到,在进行具体技术调控的同时,也需要意识上和管理原则上的改变.为帮助各公司在公司层次上减少、评估、监测和控制环境影响,已经开发了各种环境管理技术.本文根据对丹麦公司的一次调查,论述了下列问题:这些技术是如何在工业中采用的?以及发生态度上的变化了吗?  相似文献   
62.
The formation and fate of sulfide in a force main and a downstream-located gravity sewer were investigated in an extensive field study. Sulfide formation in the force main was significant. However, during 14 minutes of transport in the gravity sewer, the sulfide concentration decreased 30%, on average. An application of a conceptual sewer process model for simulating the formation and fate of sulfide was demonstrated. Overall, the model predicted that approximately 90% of the decrease of the sulfide concentration in the gravity sewer was the result of sulfide oxidation and that only a small fraction entered the sewer atmosphere, causing odor and corrosion. Even so, the model predicted concrete corrosion rates of up to 1.2 mm/y in the gravity sewer section.  相似文献   
63.
Pictures of sides of beef, hanging from overhead rails in refrigerated warehouses and meat-processing plants, often leave a feeling of unease. These pictures provoke the notion that human beings have no right to inflict suffering and death on other sentient beings for the sole purpose of providing food. However, the ethical analysis conducted in this study shows that meat production, if animal welfare and deaths per calorie created are considered, is less of a pressing problem compared to the production of milk. While meat can be provided with minimal suffering to animals, the consumption of milk is always associated with considerable suffering during the dairy cow’s life-span and the lives of their offspring. Moreover, more bovine deaths per unit of calorific value created are associated with milk production compared to meat production. The vegan movement, which is currently growing, wishes to minimise farm animal suffering as much as possible. However, if a vegan diet is not possible, consumers should make an informed decision about the products they consume. Replacement of the calories obtained from meat with those from milk and dairy products is not rational if animal welfare is considered.  相似文献   
64.
Metabolic changes and toxic effects in Crangon crangon (collected during summer 1989 near Helsingør, Denmark and at Kulhuse in the Isefjord) were observed during exposure to different arsenate concentrations. Survival, respiration, and concentrations of hemolymph glucose, muscle glycogen andadenine nucleotides were measured. C. crangon was very tolerant of arsenate; survival was only affected at arsenate concentrations >25 ppm. Small individuals (0.2 to 0.29 g wet weight) were less tolerant than medium-sized and large individuals (0.5 to 0.59 g and 0.8 to 0.89 g wet weight), e.g. at 50 ppm the LT50 for small individuals was 180 h compared to 343 h and 360 h in middle-sized and large individuals. The relation between size and toxicity is probably due to the change in surface/volume ratio. Under clean conditions the respiration of C. crangon showed a clear relation between routine MO2 (O2 in mlg-1 h-1) and wet weight (r2=0.89; P<0.001). During shortterm exposure to arsenate (10 and 50 ppm), the respiratory rates (MO2) seemed to decrease in a size-dependent manner. The concentrations of blood glucose and muscle glycogen did not change in response to arsenate exposure. The concentrations of adenylate phosphates were high and constant throughout the experiments. C. crangon had maximal adenylate energy charge (AEC) values of ca. 0.8. No decrease in AEC due to the exposure to arsenate was observed.  相似文献   
65.
Environmental fungi become a potential Indoor Air Quality (IAQ) problem when adequate moisture and nutrients are present in building materials. Because of their potential to rapidly spread contamination throughout a building, ventilation system materials are of particular significance as potential microbial contamination sources. Current recommendations are to discard fibrous glass insulation that appears to be wet or moldy. Unfortunately, this advice is not always followed. Instead, cleaning is sometimes being used in buildings to remediate fibrous glass duct liner that is already contaminated with microbial growth. The objectives of this research program were to: 1) determine, under dynamic test conditions, whether fungal spore levels on heating, ventilating, and air-conditioning (HVAC) duct material surfaces could be substantially reduced by thorough vacuum cleaning, 2) evaluate whether subsequent fungal growth could be limited or contained by mechanical cleaning, and 3) provide data concerning the advisability of cleaning duct materials. The constant high relative humidity (RH) environment to which the test materials were exposed during this study was selected as a favorable growth environment that is frequently found in Southeastern United States HVAC systems. The results showed that, following cleaning, the levels of the two test fungi, A. versicolor and P. chrysogenum, recovered to preclean levels within 6 weeks. Therefore, mechanical cleaning by contact vacuuming alone was able to only temporarily reduce the surface fungal load. The current guidelines to discard contaminated materials should be followed.  相似文献   
66.
在解决复杂的土地管理问题时,对短缺或者有争执的资源进行地理评估有助于不同利益相关者之间沟通认识和增进理解.本文中,我们说明如何使用遥感和GIS收集和汇总瑞典北部驯鹿放牧者和其他土地使用者(林业、采矿业、旅游业等等)的土地使用活动及使用模式的信息.该项目主要基于最终的土地使用者,即驯鹿放牧者们所做的工作,体现了面向土地使用者的新的努力.发展驯鹿业的土地利用规划的基础有以下几个方面:收集并数字化传统的驯鹿栖息地生态学和景观信息将这些信息与来自野外调查及基于人造卫星观测的植被分类结果整合;绘制其他土地使用者的活动情况图.最终的土地利用规划提供的信息有利于驯鹿放牧者与其他利益相关者之间的磋商,并有助于驯鹿管理实施.该项目可作为一种大众参与和计划编制的模式,从而使本土信息和先进的遥感技术融入一个交互式的过程中.  相似文献   
67.
68.
Summary The social organization of the pipistrelle bat (Pipistrellus pipistrellus) was studied by means of bat boxes in southern Sweden. The males set up territories around a roosting site in the beginning of the summer at the same time as the females formed nursing colonies. After breeding, the females joined the single males in their day roosts establishing transient mating harems. Subsequently, immatures arrived at the mating grounds. The immature females, which probably attained sexual maturity during their first autumn, were admitted to the day roosts of the harem males, in contrast to the immature males. The size of the harem was dependent on the total number of females present on the mating grounds. The size, however, was also restricted by some factor, presumably the quantity of food resources in the surroundings of the specific roost site, or the capability of the harem male for mating. The mating system in the pipistrelle bat is best characterized as a resource defence polygyny. Available data on other related temperate species indicate a similar social organization in Pipistrellus nathusii and Nyctalus noctula.  相似文献   
69.
Predictions of natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone rely critically on information about microbial biodegradation kinetics. This study aims at determining kinetic rate laws for the aerobic biodegradation of a mixture of 12 volatile petroleum hydrocarbons and methyl tert-butyl ether (MTBE) in unsaturated alluvial sand. Laboratory column and batch experiments were performed at room temperature under aerobic conditions, and a reactive transport model for VOC vapors in soil gas coupled to Monod-type degradation kinetics was used for data interpretation. In the column experiment, an acclimatization of 23 days took place before steady-state diffusive vapor transport through the horizontal column was achieved. Monod kinetic parameters Ks and vmax could be derived from the concentration profiles of toluene, m-xylene, n-octane, and n-hexane, because substrate saturation was approached with these compounds under the experimental conditions. The removal of cyclic alkanes, isooctane, and 1,2,4-trimethylbenzene followed first-order kinetics over the whole concentration range applied. MTBE, n-pentane, and chlorofluorocarbons (CFCs) were not visibly degraded. Batch experiments suggested first-order disappearance rate laws for all VOCs except n-octane, which decreased following zero-order kinetics in live batch experiments. For many compounds including MTBE, disappearance rates in abiotic batch experiments were as high as in live batches indicating sorption. It was concluded that the column approach is preferable for determining biodegradation rate parameters to be used in risk assessment models.  相似文献   
70.
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