全文获取类型
收费全文 | 818篇 |
免费 | 43篇 |
国内免费 | 319篇 |
专业分类
安全科学 | 48篇 |
废物处理 | 53篇 |
环保管理 | 83篇 |
综合类 | 462篇 |
基础理论 | 170篇 |
污染及防治 | 283篇 |
评价与监测 | 22篇 |
社会与环境 | 34篇 |
灾害及防治 | 25篇 |
出版年
2023年 | 13篇 |
2022年 | 33篇 |
2021年 | 33篇 |
2020年 | 28篇 |
2019年 | 25篇 |
2018年 | 31篇 |
2017年 | 46篇 |
2016年 | 33篇 |
2015年 | 52篇 |
2014年 | 62篇 |
2013年 | 95篇 |
2012年 | 73篇 |
2011年 | 58篇 |
2010年 | 42篇 |
2009年 | 47篇 |
2008年 | 55篇 |
2007年 | 38篇 |
2006年 | 44篇 |
2005年 | 24篇 |
2004年 | 27篇 |
2003年 | 16篇 |
2002年 | 25篇 |
2001年 | 29篇 |
2000年 | 28篇 |
1999年 | 34篇 |
1998年 | 32篇 |
1997年 | 22篇 |
1996年 | 22篇 |
1995年 | 25篇 |
1994年 | 23篇 |
1993年 | 17篇 |
1992年 | 16篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1981年 | 4篇 |
排序方式: 共有1180条查询结果,搜索用时 406 毫秒
461.
462.
Haiyan Jiang Hongxing Dai Xue Meng Lei Zhang Jiguang Deng Yuxi Liu Chak Tong Au 《环境科学学报(英文版)》2012,24(3):449-457
Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100℃ with poly(vinyl pyrrolidone) (PVP) and urea (pH = 2) and at 160℃ with NaHCO3 (pH = 7 and 8), respectively. The PVP-derived BiVO4 showed much higher surface areas (5.0-8.4 m2/g) and narrower bandgap energies (2.45-2.49 eV). The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture. 相似文献
463.
钙对紫外辐射B胁迫下小麦幼苗若干生物学特性的影响 总被引:3,自引:1,他引:3
采用模拟紫外辐射(UV-B,280~320nm)的盆栽实验法,研究钙离子对紫外B辐射胁迫下小麦幼苗若干生物学特性的影响.结果显示,在紫外辐射胁迫下(0.35W/m2,每日照射6h,连续照射7d),2mmol/L钙离子处理的小麦,地下与地上部生长指标均明显低于对照植株(降幅为8.1%~36.1%).而6mmol/L钙离子处理的小麦幼苗,各种生长指标的降幅(3.2%~28.6%)低于2mmol/L钙离子处理的小麦幼苗.表明钙离子具有缓解紫外辐射伤害小麦幼苗的效应,这同钙离子对小麦幼苗部分生理生化指标的影响有关. 相似文献
464.
序批式膜生物反应器同时脱氮除磷的比较研究 总被引:12,自引:1,他引:12
对比了厌氧-好氧(AO)及厌氧-缺氧-好氧(A2O)2种运行模式序批式膜生物反应器(SBMBR)对模拟生活污水同时脱氮除磷的性能.结果表明,2种运行模式的SBMBR对有机物及氨氮的去除率分别可保持在90%和95%以上.A2O MBR具有更强的释磷能力,其SPRR30(前30min比释磷速率)比AO MBR高出47.5%;但SPUR30(前30min比吸磷速率)却比AO MBR低,这是导致前者膜出水中TP值较后者高的原因之一.2个系统内污泥均有反硝化除磷能力,A2O MBR中DPAO(反硝化聚磷菌)的比例比AO MBR提高了57%;硝酸盐为电子受体时单位电子转移所吸收的磷,前者比后者高30%.这2个因素双重作用的结果导致了A2O MBR反硝化除磷能力的提高.A2O MBR系统曝气时间减半并没有加重膜污染,反而该系统的膜污染相对较轻.膜对有机物有较好的过滤截留作用,污泥沉降性能对SBMBR出水水质影响很小. 相似文献
465.
上海市郊4种地表径流污染负荷调查与评价 总被引:27,自引:1,他引:27
地表径流属于非点源污染,地表径流的产生取决于复杂的降雨过程,径流中污染物浓度,径流深度,产流面积是地表径流污染负荷的3大要素,该文对上海郊的4种地表径流进行了调查,并在污染源评价的基础上与市郊非点源污染总量进行了比较。结果表明,上海市郊进入水全的污染负荷,CODcr约为62634.7t/a,总氮为6288.2t/a,总磷为1244.6t/a,此结果说明地表径流是上海市郊仅次于畜禽类尿的重要非点污染 相似文献
466.
Guohua Dai Xinhui Liu Gang Liang Xu Han Liu Shi Dengmiao Cheng Wenwen Gong 《环境科学学报(英文版)》2011,23(10):1640-1649
Persistent organochlorine compounds, including hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polychlorinated biphenyls (PCBs) were analyzed in surface water and sediments from Baiyangdian Lake, North China. Total concentrations of HCHs, DDTs and PCBs in surface water were in the range of 3.13-10.60, 4.05-20.59 and 19.46-131.62 ng/L, respectively, and total concentrations of HCHs, DDTs and PCBs in sediments were 1.75-5.70, 0.91-6.48 and 5.96-29.61 ng/g dry weight, respectively. Among the groups of HCHs (sum of α-HCH, β-HCH, γ-HCH and δ-HCH) and DDTs (sum of DDT, DDD and DDE), the predominance of β-HCH, DDE and DDD in water and sediment samples was clearly observed. This observation suggested that β-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD. For PCBs, penta-, hexa- and hepta-chlorinated congeners were the most abundant compounds in the both phases. Furthermore, the partitioning of chlorinated compounds between sediment and water was investigated to understand their transport and fates in aquatic ecosystems. The results indicated that average logs of organic carbon-normalized sediment-water partition coefficients (logKoc') for OCPs varied between 3.20 and 5.53, and for PCBs, logKoc' values ranged from 3.19 to 5.57. The observed logKoc' was lower than their equilibrium logKoc predicted from linear model, which may be attributed to the solubility enhancement effect of colloidal matter in water phase and the disequilibrium between sediment and water. 相似文献
467.
Mechanism of Cu(Ⅱ) adsorption inhibition on biochar by its aging process 总被引:13,自引:0,他引:13
Biochar exposed in the environment may experience a series of surface changes, which is called biochar aging. In order to study the effects of biochar aging on Cu(Ⅱ) adsorption, we analyzed the surface properties before and after biochar aging with scanning electron microscopy(SEM) coupled to an energy-dispersive X-ray spectrometer(EDX) and diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS), and then explored the influence of the aging process on Cu(Ⅱ) adsorption by batch experiments. After the aging process, the oxygen concentration, phenolic hydroxyl groups, aromatic ethers and other oxygen-containing functional groups on the biochar surface increased, while carboxyl groups slightly decreased. Thus, over a range of pH, the cation exchange capacity(CEC) and adsorption capacity of Cu(Ⅱ) on the aged biochar were smaller than those of new biochar,indicating that when biochar is incubated at constant temperature and water holding capacity in the dark, the aging process may inhibit Cu(Ⅱ) adsorption. Meanwhile, the dissociation characteristics of oxygen-containing functional groups changed through the aging process, which may be the mechanism by which the biochar aging process inhibits the Cu(Ⅱ) adsorption. Carboxyl groups became more easily dissociated at low pH(3.3–5.0),and the variation of maximum adsorption capability(qm) of Cu(Ⅱ) on the old biochar was enlarged. Phenolic hydroxyl groups increased after the aging, making them and carboxyl groups more difficult to dissociate at high pH(5.0–6.8), and the variation of qmof Cu(Ⅱ) on the aged biochar was reduced. 相似文献
468.
Nitrocellulose membrane (NCM) can produce hydroxyl radicals under illumination, which promotes the oxidative degradation of organic pollutants. In this paper, NCM was used to oxidize bisphenol A (BPA) under simulated sunlight. The effects of pH, temperature, light intensity, anion and cation on the degradation of BPA were analyzed. The photodegradation process of BPA was discussed. The optimal photolysis rate was 0.031 min?1 when the temperature was 30°C, the light intensity was 2.67 × 104 Lux, and the pH value was 9.0. The alkaline environment, temperature and light intensity can promote the photodegradation of BPA. Except for nitrate ions, anions and cations can inhibit the photodegradation of BPA. Compared with cations, anions have a greater inhibitory effect on BPA degradation. The degradation products of BPA by NCM were analyzed by gas chromatographic/mass. This study may provide useful information for the BPA degradation by NCM in complex water samples. 相似文献
469.
两室堆肥生物反应装置研究 总被引:1,自引:1,他引:0
以堆肥过程中物料平衡、热量平衡以及垃圾生物发酵特性为依据,设计了二室堆肥生物反应装置,并通过堆肥试验实际检验反应装置设计的合理性.装置主要结构包括:二室堆肥发酵仓、保温层、通风供氧系统、空气加热系统以及二次污染控制系统.装置的主要特点为:两发酵仓能够独立完成堆肥发酵,也可以实现堆肥一次、二次发酵串联工艺组合;通过二次污染控制系统,可以很好地减少堆肥过程中产生的废水臭气排放;采用空气加热系统,可以快速均匀地加热堆体,以满足不同堆肥工艺的需要.装置在试验研究以及小规模垃圾堆肥处理领域有一定的应用价值. 相似文献
470.
超声波/零价铁降解对氯苯胺性能及机理研究 总被引:3,自引:1,他引:2
在超声波/零价铁体系中考察了溶液初始pH值、浓度对对氯苯胺降解的影响.在pH值为3~11范围内最佳条件为pH=9;初始浓度为0.1、0.2和0.4 mmol/L时的降解率(180 min)分别为83.2%、63.5%和36.1%.对氯苯胺在单纯铁粉、单纯超声波和超声波/零价铁3种体系中降解符合拟一级反应动力学规律,速率常数分别为6.83×10-4、3.95×10-3和1.01×10-2 min-1,增强因子为218%,表明铁粉与超声波对对氯苯胺降解有明显的协同效应.在体系中加入自由基捕捉剂正丁醇能抑制对氯苯胺的降解,证实对氯苯胺降解主要是依靠羟基自由基的氧化作用. 相似文献