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101.
CHRISTOPHER F. CLEMENTS BEN COLLEN TIM M. BLACKBURN OWEN L. PETCHEY 《Conservation biology》2014,28(4):971-981
Correctly classifying a species as extinct or extant is of critical importance if current rates of biodiversity loss are to be accurately quantified. Observing an extinction event is rare, so in many cases extinction status is inferred using methods based on the analysis of records of historic sighting events. The accuracy of such methods is difficult to test. However, results of recent experiments with microcosm communities suggest that the rate at which a population declines to extinction, potentially driven by varying environmental conditions, may alter one's ability accurately to infer extinction status. We tested how the rate of population decline, driven by historic environmental change, alters the accuracy of 6 commonly applied sighting‐based methods used to infer extinction. We used data from small‐scale experimental communities and recorded wild population extirpations. We assessed how accuracy of the different methods was affected by rate of population decline, search effort, and number of sighting events recorded. Rate of population decline and historic population size of the species affected the accuracy of inferred extinction dates; however, faster declines produced more accurate inferred dates of extinction, but only when population sizes were higher. Optimal linear estimation (OLE) offered the most reliable and robust estimates, though no single method performed best in all situations, and it may be appropriate to use a different method if information regarding historic search efforts is available. OLE provided the most accurate estimates of extinction when the number of sighting events used was >10, and future use of this method should take this into account. Data from experimental populations provide added insight into testing techniques to discern wild extirpation events. Care should be taken designing such experiments so that they mirror closely the abundance dynamics of populations affected by real‐world extirpation events. Efectos del Cambio Ambiental Reciente sobre la Precisión de las Inferencias sobre el Estado de Extinción 相似文献
102.
Fenton试剂对富营养化湖水黑臭的氧化降解作用 总被引:3,自引:0,他引:3
通过室内实验,研究Fenton试剂对富营养化水体黑臭物质氧化降解作用。实验结果表明,在黑臭的富营养化水中投加Fenton试剂20 min后,水体臭味明显降低,90 min后水体臭味全部消除;水体浊度、色度有显著改善,水体浊度、色度去除率分别达73.73%和93.11%,显著高于对照组的53.4%和22%;水体溶解氧量显著提高;水体的pH值保持在7左右。鱼类毒理实验结果表明,最佳剂量的Fenton试剂对实验鱼类无急性毒性作用。 相似文献
103.
Li Qi Yu Shuili Yang Shengfa Yang Wei Que Sisi Li Wenjie Qin Yu Yu Weiwei Jiang Hui Zhao Deqiang 《Environmental science and pollution research international》2021,28(14):17417-17430
Environmental Science and Pollution Research - In this study, 18S rRNA high-throughput sequencing was applied to investigate the eukaryotic community in a full-scale drinking water treatment plant.... 相似文献
104.
Risk assessment and monitoring of dinotefuran and its metabolites for Chinese consumption of apples 总被引:1,自引:0,他引:1
Weiwei Yu Min Huang Jiaojiao Chen Sizhuo Wu Kunming Zheng Song Zeng Kankan Zhang Deyu Hu 《Environmental monitoring and assessment》2017,189(10):521
Residues of dinotefuran and its metabolites, 1-methyl-3-(tetrahydro-3-furylmethyl)urea (UF) and 1-methyl-3-(tetrahydro-3-furylmethyl)guanidine (DN), in apple were investigated using a “QuEChERS” (quick, easy, cheap, effective, rugged, safe) pretreatment and liquid chromatography–tandem mass spectrometry. Limits of detection (LODs) and quantification (LOQs) of dinotefuran, UF, and DN in apples were 0.011–0.960 and 0.037–3.200 μg/kg, respectively. The average recoveries of dinotefuran, UF, and DN in apple ranged from 70.0 to 83.6% with relative standard deviations less than 13%. A formulation of 20% water-dispersible dinotefuran granules was sprayed at 1–1.5-fold the recommended dose 3–4 times on apple trees. Total terminal residues of dinotefuran in apple were less than 2 mg/kg, which is the maximum residue limit (MRL) set by Japan. When following the recommended application guidelines, dinotefuran is unlikely to present significant health concerns to the Chinese population because the risk quotient (RQ) is less than 100%. This work could provide guidance for the safe use of dinotefuran and serve as a reference for the establishment of a maximum residue limit of dinotefuran in apple in China. 相似文献
105.
接种比例对酒糟与餐厨垃圾混合厌氧发酵产沼气的影响 总被引:1,自引:0,他引:1
采用酒糟与餐厨垃圾作为混合发酵物料,并接种消化污泥进行厌氧干式发酵,比较接种比例(inoculum to substrate ratios,ISRs)(VS质量比)分别为0.5、0.8、1.0、2.0时的甲烷产率和产量、体系VFA、碱度、游离氨等指标。结果表明:接种比例的提高可有效提高甲烷产生速率,缩短发酵周期,减弱较高浓度VFA引起的抑制作用。当ISRs=1.0时产甲烷效果较好,累计产甲烷率为222.58mL/g,VS去除率达83.4%,继续增加接种比例对发酵效果影响不显著。此外,试验中适宜的VFA/碱度值为0.3~1.2,过大或过小都有可能抑制产甲烷过程。 相似文献
106.
107.
室内空气由于影响因素多,随环境变化较大,监测值具有很大不确定性.本文论述了室内空气监测时的注意事项,采样体积、采样时间、家具放置状态等都会对其产生影响.保证采样体积、时间等对数据的准确性具有重大意义. 相似文献
108.
本文介绍了衡阳气象地质灾害预警系统的工作原理,系统架构设计、系统关键技术及预报效果验证情况。在Delphi环境下以Server2003为基础数据库,以Serfur为图形绘制工具完成了系统开发。系统以遍及衡阳的近300个自动气象站的降水实况资料及日本每天2次(08、20时)滚动数值预报产品为原始数据,通过模型计算未来24小时衡阳各乡镇出现地质灾害的危险等级,并自动形成预警服务产品。从2012年6月11日的地质灾害监测效果来看,系统能较好地监测气象地质灾害的发生,但由于数值预报精度不够,监测点预警危险系数粗放,放大了系统空报率。 相似文献
109.
Bu Qingwei Cao Hongmei Li Qingshan Zhang Handan Jiang Weiwei Yu Gang 《Environmental science and pollution research international》2021,28(11):13515-13523
Environmental Science and Pollution Research - The goal of this study was to identify antibiotics with potential risk in river water of the megacity Beijing, China. This was accomplished by using a... 相似文献
110.
Rong Hu Weiwei Huang Congmian Ren Ling Liu Yaping Hou Yunan Wang Jian Lu 《黑龙江环境通报》2023,43(10):1355-1365