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361.
Variations in the chemical properties of landfill leachate 总被引:4,自引:0,他引:4
Landfill leachates were collected and their chemical properties analyzed once every two months over a ten-month period from
the Gin Drinkers' Bay (GDB) and Junk Bay (JB) landfills. The contents of solids, and inorganic and organic components fluctuated
considerably with time. In general, the chemical properties of the two leachates correlated negatively (P<0.05) with the amounts of rainfall prior to the sampling periods. However, magnesium and pH of the leachates remained relatively
constant with respect to sampling time. The JB leachate contained higher average contents of solids and inorganic and organic
matter than those of GDB with the exception of trace metals. Trace metals were present in the two leachates in trace quantities
(<1.0 mg/liter). The concentrations of average ammoniacal nitrogen were 1040 and 549 mg/liter, while chemical oxygen demand
(COD) values were 767 and 695 mg/liter for JB and GDB leachates, respectively. These results suggest that the leachates need
further treatment before they can be discharged to the coastal waters. 相似文献
362.
Yu Qingdong 《中国减灾(英文版)》1997,(1)
1TkeDefinitionandCIassificationofDisasterLossIngeneral,thenaturaldisasterlossisadeclinemeasurethatcausedbynaturaldisasterendan-geredhumanbeingsurvivalanddevelopment.Itcanbedividedintotwoparts-economiclossandnon-economicloss,accordingtodifferentobjectofdestroy.Onthecharacteristicoflossofnaturaldisaster(fromhereon,thelossreferstoeconomiclossifnotbenoted),aswellastheneedsofassessment,thelosscanbeclassifiedasinFig-l.(1)Thelossofbusinessfirmassetsandhouseholdpropertiesarethevaluereductionofasset… 相似文献
363.
We inventoried wetland impoundments in the Louisiana, USA, coastal zone from the late 1900s to 1985. Historically, impoundment
of wetlands for reclamation resulted in direct wetland loss after levees (dikes) failed and the impounded area was permanently
flooded, reverting not to wetland, but to open-water habitat. A current management approach is to surround wetlands by levees
and water control structures, a practice termed semi-impoundment marsh management. The purpose of this semi-impoundment is
to retard saltwater intrusion and reduce water level fluctuations in an attempt to reduce wetland loss, which is a serious
problem in coastal Louisiana. In order to quantify the total impounded area, we used historic data and high-altitude infrared
photography to map coastal impoundments. Our goal was to produce a documented inventory of wetlands intentionally impounded
by levees in the coastal zone of Louisiana in order to provide a benchmark for further research.
We inventoried 370,658 ha within the coastal zone that had been intentionally impounded before 1985. This area is equal to
about 30% of the total wetland area in the coastal zone. Of that total area, approximately 12% (43,000 ha) is no longer impounded
(i.e., failed impoundments; levees no longer exist or only remnants remain). Of the 328,000 ha still impounded, about 65%
(214,000 ha) is developed (agriculture, aquaculture, urban and industrial development, and contained spoil). The remaining
35% (114,000 ha) of impoundments are in an undeveloped state (wetland or openwater habitat). In December 1985, approximately
50% (78,000 ha) of the undeveloped and failed impoundments were open-water habitat. This inventory will allow researchers
to monitor future change in land-water ratios that occur within impounded wetlands and thus to assess the utility of coastal
wetland management using impoundments. 相似文献
364.
Wu Gang 《环境科学学报(英文版)》1998,10(2):210-215
In accordance with principle sand methods of ecology, this paper studied the effects of acidic deposition on productivity and volume increment of masson pine and Cinnamomum campora forest
which are widely distributed in southern suburbs of Chongqing. Based on the field data and measurements, a multivariable stepwise regression model was established to analyze the effects of multiple environmental factors on the productivity of the forest ecosystems. This model was used to assess the volume and economic losses of these two forest ecosystems caused by acidic deposition. The
results showed that, among the environmental factors, pH value of precipitation, soil depth, soil organic contents and slope are the dominant ones influencing the growth of masson pine forest. It is
also shown that the acidic deposition has no clear relation to the growth of C.Campora forest, so development of such broad-leaved forest is suitable in the area. 相似文献
365.
膜分离技术在油气回收中的应用 总被引:1,自引:0,他引:1
在油品储运、销售、应用过程中,存在着大量的油品蒸发损耗。可用膜分离技术来分离回收轻质油品蒸发排放出来的油气。介绍膜法油气回收的分离机理、应用实例和工艺设计数据,综合比较常用的吸收法、吸附法、冷凝法及膜法油气回收技术并获得各自的量化分值,认为膜法回收技术为目前较有可能及较容易取得突破成果的研究领域。最后指出今后的研究重点。 相似文献
366.
巴县1993年乡镇工业污染损失大约为2.29亿元,约占当年全县GNP的7.8%。其中农业损失约占45%,人体健康损失约占28%。受酸雨作用的钢材和建筑物的损失为0.26亿元,相当于全县当年新增的生产性固定资产的大部分。文章还论述了巴县乡镇工业污染损失贡献权重系数的参数取值过程。 相似文献
367.
云南森林生态破坏的经济损失分析 总被引:5,自引:0,他引:5
本文介绍了云南省森林资源状况因其遭到破坏而造成的危害,并分别用影 子工程法,替代市场法和土地价值法等基础方法对云南省森林破坏的泥沙流失损失,伴随土壤流失的氮素损失和林业产值补偿损失进行了分析。 相似文献
368.
通过对济宁化学染料厂工业废水的试验研究,提出了适宜的工艺参数,为进一步治理的工程设计提供了可靠的依据,并可作为石油废水治理的参考。 相似文献
369.
分光光度法在化学需氧量快速测定中的应用研究 总被引:10,自引:0,他引:10
通过实验研究,建立起化学需氧量(COD)分光光度快速测定方法.回流时间由原来的2h缩短为15min,并用分光光度法代替碘量法进行测定.该法与标准法相比,具有操作简便、测定快速等优点.该法对实际水样进行没定,测定结果与标准法相比,无显著性差异 相似文献
370.
水样的化学需氧量,可由于加入氧化剂的种类及浓度,反应溶液的酸度,反应温度和时间,以及催化剂的有无而获得不同的结果.因此,化学需氧量亦是一个条件性的指标,必须严格按操作步骤进行. 相似文献