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991.
吹脱+A/O工艺处理氮肥企业高氨氮废水的工程实践 总被引:1,自引:3,他引:1
针对河南某氮肥企业高氨氮废水采用吹脱+A/O工艺处理的成功实践(当进水氨氮浓度在641~868mg/L时,出水始终稳定在1mg/L左右),分析了工程设计与调试中应注意的问题,可供此类污水处理工程设计参考。 相似文献
992.
蔗糖厂废水除废醪液外,还有洗滤布水和冲灰水,混合后先作物化预处理,再进入生化系统,最后依次经物化处理及生物滤池后可达标排放。这一工艺可一水多用,提高循环用水率,还可用于膜除尘,回收物又是较好复混肥。 相似文献
993.
灰色层次分析法在中小型电厂安全性评价中的应用 总被引:13,自引:3,他引:13
施泉生 《中国安全科学学报》2005,15(7):21-25
电厂安全性评价是综合运用安全系统工程的方法对系统的安全性进行度量和预测。笔者确定了电厂安全性评价的指标体系,提出了应用灰色层次分析法评价电厂安全性的方法与步骤。该方法能在缺资料、少信息条件下完成建模、预测和决策,将评价专家的分散信息处理成一个描述不同灰类程度的权向量并进行单值化处理,从而可得到受评电厂安全性体系的综合评价值和电厂安全性的等级划分,再应用灰色层次分析法对模型电厂进行了实际评价,其结论是可信、方法适用。 相似文献
994.
新疆火电行业SO2排放现状及控制对策 总被引:2,自引:0,他引:2
新疆火电行业是新疆SO2排放大户,其排放量占全疆工业SO2排放量的43.4%,且有逐年递增的趋势,而其去除率却一直处于较低水平.乌鲁木齐华电红雁池电厂等5家火电厂SO2的排放量排在新疆火电行业之首,应而需将这5家火电厂SO2排放作为重点监控对象,并提出了火电厂减排SO2的几点对策和建议. 相似文献
995.
Conservation biologists and other environmentalists confront five obstacles in building support for regulatory policies that seek to exclude or remove introduced plants and other non-native species that threaten to harm natural areas or the natural environment. First, the concept of “harm to the natural environment” is nebulous and undefined. Second, ecologists cannot predict how introduced species will behave in natural ecosystems. If biologists cannot define “harm” or predict the behavior of introduced species, they must target all non-native species as potentially “harmful”. an impossibly large regulatory task. Third, loss of species richness may constitute harm to an environment, but introduced organisms typically, generally, and significantly add to species richness in ecosystems. If species richness correlates with desirable ecosystem properties, moreover, such as stability and productivity, as some ecologists believe, then introduced organisms, by increasing species richness, would support those desirable properties. Fourth, one may plausibly argue that extinction constitutes environmental harm, but there is no evidence that non-native species, especially plants, are significant causes of extinction, except for predators in certain lakes and other small island-like environments. Fifth, while aesthetic, ethical, and spiritual values may provide a legitimate basis for invasive species policy, biologists often cite concepts such as “biodiversity” and ecosystem “health” or “integrity” to provide a scientific justification. To assert that non-native species threaten biodiversity or undermine ecosystem health, however, may be to draw conceptual entailments or consequences from definitions of “biodiversity” and “integrity” that arbitrarily exclude non-native species or make the presence of exotic species a per se indicator of decline. 相似文献
996.
Edith?T.?Lammerts?Van?Bueren Paul?C.?StruikEmail author 《Journal of Agricultural and Environmental Ethics》2005,18(5):479-493
In addition to obviating the use of synthetic agrochemicals and emphasizing farming in accordance with agro-ecological guidelines, organic farming acknowledges the integrity of plants as an essential element of its natural approaches to crop production. For cultivated plants, integrity refers to their inherent nature, wholeness, completeness, species-specific characteristics, and their being in balance with their (organically farmed) environment, while accomplishing their “natural aim.” We argue that this integrity of plants has ethical value, distinguishing integrity of life, plant-typic integrity, genotypic integrity, and phenotypic integrity. We have developed qualitative criteria to ethically evaluate existing practices and have applied these criteria to assess whether current plant breeding and propagation techniques violate the integrity of crop plants. This process has resulted in a design of a holistic, scientific approach of organic plant breeding and seed production. Our evaluation has met considerable criticism from mainstream (crop) scientists. We respond to the following questions: (1). Can ethics be incorporated into objective crop sciences? (2). What is the nature of the intrinsic value of plants in organic farming? We argue that criteria to take integrity into account can only be assessed from a holistic perspective and we show that a holistic approach is needed to design such ethical notions in a consistent way. The ethical notions have been further elaborated by formulating human responsibility and respect towards crop plants. Responsibility and respect can only be shown by providing crop plants the right to be nurtured and to express natural behavior at all levels of integrity. 相似文献
997.
998.
999.
T. Vaněk A. Nepovím R. Podlipná S. Zeman M. Vágner 《Water, Air, & Soil Pollution: Focus》2003,3(3):259-267
The phytoremediation of trinitrotoluene (TNT), nitroglycerine (NG) and pentaerytritoltetranitrate (PETN) using in vitrocultures of Rheum palmatum, Saponaria officinalisand Populus simonii were studied. All above mentioned explosives were degradated to less toxic products and finally probably bound to the cell wall or further involved in the metabolism. The formation of trinitrobenzene (TNB) during degradation of TNT which is a product of alternative degradation pathway was found too. 相似文献
1000.
Biodegradability of Urea-Aldehyde Condensation Products 总被引:1,自引:0,他引:1
Thomas Jahns Heiko Ewen Heinrich Kaltwasser 《Journal of Polymers and the Environment》2003,11(4):155-159
Condensation products of urea and different aldehydes (formaldehyde, isobutyraldehyde, crotonaldehyde) are used in large amounts (more than 300,000 tons per year) as resins, binders, and insulating materials for industrial applications, as well as in controlled-release nitrogen fertilizer for greens, lawns, or bioremediation processes. The biodegradability of these condensates and the enzymic mechanism of their degradation was studied in mircoorganisms isolated from soil, which were able to use these compounds as the sole source of nitrogen for growth. Different pure cultures of both gram-positive and gram-negative bacteria completely degraded methylenediurea, dimethylenetriurea, isobutylidenediurea, and crotonylidenediurea to urea, ammonia, and the corresponding aldehydes and carbon dioxide. Enzymes initiating this degradation were purified and characterized and turned out to be different with regard to their regulation of expression, their physicobiochemical properties, and their reaction mechanism. 相似文献