全文获取类型
收费全文 | 19125篇 |
免费 | 363篇 |
国内免费 | 3796篇 |
专业分类
安全科学 | 734篇 |
废物处理 | 1383篇 |
环保管理 | 2046篇 |
综合类 | 5988篇 |
基础理论 | 4651篇 |
环境理论 | 2篇 |
污染及防治 | 5521篇 |
评价与监测 | 1357篇 |
社会与环境 | 1206篇 |
灾害及防治 | 396篇 |
出版年
2024年 | 5篇 |
2023年 | 151篇 |
2022年 | 481篇 |
2021年 | 392篇 |
2020年 | 282篇 |
2019年 | 265篇 |
2018年 | 1780篇 |
2017年 | 1763篇 |
2016年 | 1664篇 |
2015年 | 784篇 |
2014年 | 820篇 |
2013年 | 1050篇 |
2012年 | 1343篇 |
2011年 | 2195篇 |
2010年 | 1353篇 |
2009年 | 1244篇 |
2008年 | 1601篇 |
2007年 | 1789篇 |
2006年 | 496篇 |
2005年 | 384篇 |
2004年 | 318篇 |
2003年 | 413篇 |
2002年 | 401篇 |
2001年 | 266篇 |
2000年 | 270篇 |
1999年 | 246篇 |
1998年 | 257篇 |
1997年 | 242篇 |
1996年 | 222篇 |
1995年 | 173篇 |
1994年 | 118篇 |
1993年 | 122篇 |
1992年 | 104篇 |
1991年 | 79篇 |
1990年 | 54篇 |
1989年 | 26篇 |
1988年 | 27篇 |
1987年 | 10篇 |
1986年 | 17篇 |
1985年 | 11篇 |
1984年 | 22篇 |
1983年 | 16篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1935年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
123.
以钛酸四丁酯为前驱物,采用水解沉淀法制备了N掺杂TiO_2光催化剂和H_2O_2改性的N掺杂TiO_2光催化剂.实验表明,H_2O_2改性的N掺杂TiO_2光催化剂的最佳制备条件为:氨水(质量分数28%)加入量20 mL,焙烧温度500 ℃,H_2O_2(质量分数30%)加入量2.0 mL.日光下,N掺杂TiO_2光催化剂及H_2O_2改性的N掺杂TiO_2光催化剂在反应90 min时的活性红紫去除率达99%,它们对活性红紫的去除率远高于P_(25)TiO_2光催化剂.H_2O_2改性的N掺杂TiO_2光催化剂中N质量分数比改性前明显提高,制备的两种催化剂中不仅含有N元素,同时还含有C和H元素. 相似文献
124.
以电解锰阳极泥与电解锌生产中产生的含SO_2尾气为原料,经过反应、浸出、浸出液两次净化和浓缩结晶制备硫酸锰,考察了反应时间、含SO_2尾气的流量及反应温度对Mn~(4+)转化率的影响.实验结果表明:在反应时间45 min、反应温度20~30 ℃、含SO_2尾气流量16 L/min的条件下,Mn~(4+)转化率达90%以上;尾气中SO_2利用率随尾气流量增加而降低;所得MnSO_4·H_2O产品质量达到GB1622-86<工业级硫酸锰标准>. 相似文献
125.
采用反相微悬浮乳液聚合技术制备了β-环糊精(β-CD)微球,用丁二酸酐对β-CD微球进行化学改性,制备了pH敏感性β-CD(pH-β-CD)微球.通过傅里叶红外光谱仪和扫描电子显微镜对微球的结构、粒径和形貌进行了表征.探讨了亚甲基蓝模拟染料废水pH、吸附时间和微球加入量对亚甲基蓝吸附性能的影响.实验结果表明,在亚甲基蓝模拟染料废水pH为10.0、吸附时间为90 min的条件下,当pH-β-CD微球加入量为50 mg时,pH-β-CD微球吸附量为16.1 mg/g;当pH-β-CD微球加入量为250 mg时,pH-β-CD微球对亚甲基蓝的脱色率达96.2%. 相似文献
126.
127.
Aishah S. A. K. Sharifah Hanafiah Zainal Abidin Mohamad R. Sulaiman Kheng H. Khoo Hairi Ali 《Journal of Material Cycles and Waste Management》2008,10(2):116-123
Malaysia is in dire need of alternatives to landfilling for solid waste management. Recently, landfills have faced the problems
of overfilling, overflowing of leachates leading to pollution of water resources, and uncontrolled dust emissions adversely
affecting the local environment. With the rising cost of urbanization coupled with the high rate of waste generation, one
possible method of waste treatment that is receiving particular attention by the government is incineration. Incineration
of solid waste is rather new in Malaysia, with limited usage in handling small sources of waste generation such as the municipal
solid waste (MSW) of resort islands; however, its potential in ameliorating the problems associated with solid waste treatment
may make it an attractive alternative to landfill. This article presents the results of test runs conducted to investigate
the performance of a locally designed and manufactured rotary kiln incinerator (RKI). The test runs were conducted using MSW
collected from the Shah Alam municipality. The combustion efficiency was analyzed by looking at the temperature profiles and
chemical species concentrations. To complement the combustion characteristics measurements, predictions of the air flow in
the incinerator during the process were also investigated. The overall performance of the RKI suggests that it is suitable
for treating MSW. 相似文献
128.
V. L. Finkenstadt C.-K. Liu P. H. Cooke L. S. Liu J. L. Willett 《Journal of Polymers and the Environment》2008,16(1):19-26
Sorbitol and glycerol were used to plasticize sugar beet pulp-poly(lactic acid) green composites. The plasticizer was incorporated
into sugar beet pulp (SBP) at 0%, 10%, 20%, 30% and 40% w/w at low temperature and shear and then compounded with poly(lactic
acid) (PLA) using twin-screw extrusion and injection molding. The SBP:PLA ratio was maintained at 30:70. As expected, tensile
strength decreased by 25% and the elongation increased. Acoustic emission (AE) showed correlated debonding and fracture mechanisms
for up to 20% w/w plasticizer and uncorrelated debonding and fracture for 30–40% sorbitol and 30% glycerol content in SBP–PLA
composites. All samples had a well dispersed SBP phase with some aggregation in the PLA matrix. However, at 40% glycerol plasticized
SBP–PLA composites exhibited unique AE behavior and confocal microscopy revealed the plasticized SBP and PLA formed a co-continuous
two phase system.
相似文献
V. L. FinkenstadtEmail: |
129.
Reiner Schroll Sabine Grundmann Ulrike Dörfler Bernhard Ruth Jean Charles Munch 《Water, Air, & Soil Pollution: Focus》2008,8(2):209-216
Several lysimeter scenarios and approaches exist to study the fate of agro-chemicals or contaminants from deposition in soil
columns. In many systems just transport and leaching of the parent compound is followed, in some systems the leaching and
transport of the metabolites is investigated as well. In more sophisticated lysimeter systems the volatilization and also
the mineralization of the applied chemicals can be additionally monitored. Depending on the lysimeter system used and on the
fact whether the applied chemicals are 14C-labeled or not, different results and various interpretations of the results might be achieved. Different lysimeter systems
are described in this paper and a real dataset of a specific lysimeter experiment was transferred and evaluated in a virtual
approach in the different lysimeter systems in order to show the advantages and disadvantages of the various systems. 相似文献
130.
Bryce A. Mihalevich Jeffery S. Horsburgh Anthony A. Melcher 《Environmental monitoring and assessment》2017,189(11):593
Stormwater runoff in urban areas can contribute high concentrations of dissolved organic matter (DOM) to receiving waters, potentially causing impairment to the aquatic ecosystem of urban streams and downstream water bodies. Compositional changes in DOM due to storm events in forested, agricultural, and urban landscapes have been well studied, but in situ sensors have not been widely applied to monitor stormwater contributions in urbanized areas, leaving the spatial and temporal characteristics of DOM within these systems poorly understood. We deployed fluorescent DOM (FDOM) sensors at upstream and downstream locations within a study reach to characterize the spatial and temporal changes in DOM quantity and sources within an urban water conveyance that receives stormwater runoff. Baseflow FDOM decreased over the summer season as seasonal flows upstream transported less DOM. FDOM fluctuated diurnally, the amplitude of which also declined as the summer season progressed. During storms, FDOM concentrations were rapidly elevated to values orders of magnitude greater than baseflow measurements, with greater concentrations at the downstream monitoring site, revealing high contributions from stormwater outfalls between the two locations. Observations from custom, in situ fluorometers resembled results obtained using laboratory methods for identifying DOM source material and indicated that DOM transitioned to a more microbially derived composition as the summer season progressed, while stormwater contributions contributed DOM from terrestrial sources. Deployment of a mobile sensing platform during varying flow conditions captured spatial changes in DOM concentration and composition and revealed contributions of DOM from outfalls during stormflows that would have otherwise been unobserved. 相似文献