全文获取类型
收费全文 | 437篇 |
免费 | 57篇 |
国内免费 | 193篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 16篇 |
环保管理 | 41篇 |
综合类 | 429篇 |
基础理论 | 96篇 |
环境理论 | 1篇 |
污染及防治 | 52篇 |
评价与监测 | 22篇 |
社会与环境 | 8篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 28篇 |
2021年 | 23篇 |
2020年 | 25篇 |
2019年 | 21篇 |
2018年 | 27篇 |
2017年 | 18篇 |
2016年 | 24篇 |
2015年 | 25篇 |
2014年 | 37篇 |
2013年 | 43篇 |
2012年 | 42篇 |
2011年 | 33篇 |
2010年 | 27篇 |
2009年 | 38篇 |
2008年 | 13篇 |
2007年 | 30篇 |
2006年 | 33篇 |
2005年 | 26篇 |
2004年 | 15篇 |
2003年 | 15篇 |
2002年 | 22篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 9篇 |
1998年 | 10篇 |
1997年 | 18篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有687条查询结果,搜索用时 609 毫秒
181.
182.
183.
废轮胎热解炭黑及其改性后的特性研究 总被引:1,自引:0,他引:1
对废轮胎热解炭黑(简称热解炭黑)采用硝酸酸洗及酸洗后加入硬脂酸2种改性方法,制备出热解炭黑、酸洗炭黑及硬脂酸改性酸洗炭黑3种炭黑。运用SEM、XPS等分析手段进行了表征。研究表明,硝酸酸洗后热解炭黑的灰分从20.5%降到了4.0%,BET表面积从54.92 m2/g增大到69.62 m2/g,DBP吸收值从123 mL/100g提高到170 mL/100 g。加入硬脂酸后BET表面积和DBP吸收值略有下降。XPS结果显示:热解炭黑表面覆盖有碳质沉积物,表面官能团极性较低;酸洗炭黑表面C—C,C—H含量降低,C—OR、C—OEt和COOR、COOH官能团含量增加;硬脂酸改性后表面含碳官能团基本没有变化,但其表面双键氧的含量高于热解炭黑和酸洗炭黑。 相似文献
184.
185.
环境卫星CCD影像在太湖湖泛暗色水团监测中的应用 总被引:1,自引:0,他引:1
太湖地区2009年5月11日、2010年8月21日、2011年7月28日和2011年9月24日的环境卫星CCD影像显示,在太湖西部沿岸带、竺山湖等水域存在湖泛暗色水团现象。由于环境CCD缺少辅助反演气溶胶信息的2.1um波段,试验了基于空气自动监测子站获得的与环境卫星CCD成像时间接近的地面能见度测量数据进行FLAASH大气校正的方法,反演结果总体上符合水体光谱特征。提取了湖泛水体、对照水体阳区在CCD各波段的光谱反射率数据统计特征。结果表明,和对照水体相比,湖泛水体在环境卫星CCD的可见光—近红外波段具有较低的反射率,与人眼观察湖泛水色暗黑的感官一致,另一方面,湖泛水域由于仍有一定的藻类存在,在环境卫星CCD近红外(波段4 )具有比可见光(波段3)略高的反射率,其规律与基于Landsat ETM的湖泛暗色水团遥感分析结果相一致。 相似文献
186.
苏州市黑碳气溶胶的污染特征分析 总被引:2,自引:1,他引:1
2012年1—12月,对苏州市区黑碳气溶胶浓度进行监测和分析。结果表明,苏州市区黑碳平均质量浓度为3.3μg/m3,且季节变化明显,即夏季的平均浓度最低,秋末、冬初、春末时段黑碳浓度易出现高值,其分布规律与春季秸秆焚烧、秋冬季逆温雾霾时期相吻合;与周围生物质燃烧和工业排放有关。日变化有明显的峰值、谷值,一般在每日的6:00—9:00、18:00—20:00出现高值,低值则出现在午后12:00—15:00;与国外城市相比,苏州黑碳浓度偏高,但与国内城市(北京、天津、沈阳、本溪)相比,则浓度相对较低。 相似文献
187.
Chia-Chang Wu Chun Chu Yei-Shung Wang Huu-Sheng Lur 《Journal of environmental science and health. Part. B》2013,48(1):58-68
A multiresidue method was developed to determine 19 carbamate pesticides in tea samples. Optimizations of different parameters, such as the type of extraction solvents, clean-up cartridges, and elution solvents were carried out. The developed method used acetonitrile as extraction solvent, amino cartridge for adsorbents and acetone-n-hexane as the eluting solution. Nineteen carbamate residues were then analyzed by high-pressure liquid chromatography (HPLC) with fluorescence detector. The present results showed good linearity by correlation coefficients of more than 0.9999 for all analyses. Limits of detection and quantification varied from 0.0005–0.023 mg L? 1, 0.008–0.077 mg L? 1, respectively. Recoveries of sixteen carbamate pesticides ranged from 65% to 135% at the spiked level of 0.5, 1.0 and 2.0 mg L? 1. The relative standard deviations were lower than 20% and coefficient of variations were lower than 15%. The results indicate that the proposed method provides an effective multi and trace level screening determination of carbamate pesticides residues for tea samples. 相似文献
188.
Shizuka Saito-Shida Satoru Nemoto Reiko Teshima 《Journal of environmental science and health. Part. B》2013,48(11):760-776
An efficient and reliable GC-MS/MS method for the multiresidue determination of pesticides in tea was developed by modifying the Japanese official multiresidue method. Sample preparation was carefully optimized for the efficient removal of coextracted matrix components. The optimal sample preparation procedure involved swelling of the sample in water; extraction with acetonitrile; removal of water by salting-out; and sequential cleanup by ODS, graphitized carbon black/primary secondary amine (GCB/PSA) and silica gel cartridges prior to GC-MS/MS analysis. The recoveries of 162 pesticides from fortified (at 0.01 mg kg?1) green tea, oolong tea, black tea and matcha (powdered green tea) were mostly (95–98% of the tested pesticides) within the range of 70–120%, with relative standard deviations of <20%. Poor recovery of triazole pesticides was considered to be due to low recovery from the silica gel cartridges. The test solutions obtained by the modified method contained relatively small amounts of pigments, caffeine and other matrix components and were cleaner than those obtained by the original Japanese official multiresidue method. No interfering peaks were observed in the blank chromatograms, indicating the high selectivity of the modified method. The overall results suggest that the developed method is suitable for the quantitative analysis of GC-amenable pesticide residues in tea. 相似文献
189.
利用废弃绿茶叶粉末(简称茶叶末)作为吸附剂,考察了pH、温度、时间等对水溶液中Co2+的影响。结果表明:(1)茶叶末对Co2+的吸附量随着pH的上升而上升,其中pH=5.50为最佳。茶叶末对Co2+的吸附量均随时间延长呈现上升趋势,吸附速度先快后慢,吸附最佳时间为90min。(2)不同温度下,茶叶末对Co2+的吸附较好地符合Langmuir模型。该吸附过程是化学离子交换过程,主要发生在重金属离子与羟基、氨基的氢原子之间。(3)茶叶末对Co2+的吸附是自发、放热过程,降温有利于吸附,反应时吸附界面上的混乱度增加。(4)盐酸是很好的解吸介质,解吸率为92.65%。通过灼烧(或燃烧)可以回收水溶液中绝大部分的Co2+,不仅减小了对环境的污染,而且节约了资源。 相似文献
190.
Kukutschová J Moravec P Tomášek V Matějka V Smolík J Schwarz J Seidlerová J Safářová K Filip P 《Environmental pollution (Barking, Essex : 1987)》2011,159(4):998-1006
The paper addresses the wear particles released from commercially available “low-metallic” automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (<100 nm) were by three orders of magnitude larger when compared to the microparticles. A significant release of nanoparticles was measured when the average temperature of the rotor reached 300 °C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles. 相似文献