全文获取类型
收费全文 | 11201篇 |
免费 | 1438篇 |
国内免费 | 6387篇 |
专业分类
安全科学 | 1872篇 |
废物处理 | 551篇 |
环保管理 | 967篇 |
综合类 | 10329篇 |
基础理论 | 2349篇 |
环境理论 | 2篇 |
污染及防治 | 1796篇 |
评价与监测 | 583篇 |
社会与环境 | 348篇 |
灾害及防治 | 229篇 |
出版年
2024年 | 53篇 |
2023年 | 426篇 |
2022年 | 611篇 |
2021年 | 697篇 |
2020年 | 692篇 |
2019年 | 698篇 |
2018年 | 585篇 |
2017年 | 565篇 |
2016年 | 659篇 |
2015年 | 763篇 |
2014年 | 688篇 |
2013年 | 1216篇 |
2012年 | 1182篇 |
2011年 | 1231篇 |
2010年 | 852篇 |
2009年 | 974篇 |
2008年 | 811篇 |
2007年 | 987篇 |
2006年 | 956篇 |
2005年 | 709篇 |
2004年 | 597篇 |
2003年 | 507篇 |
2002年 | 399篇 |
2001年 | 332篇 |
2000年 | 304篇 |
1999年 | 253篇 |
1998年 | 211篇 |
1997年 | 186篇 |
1996年 | 158篇 |
1995年 | 146篇 |
1994年 | 97篇 |
1993年 | 95篇 |
1992年 | 83篇 |
1991年 | 57篇 |
1990年 | 39篇 |
1989年 | 31篇 |
1988年 | 25篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 5篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 14篇 |
1981年 | 11篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1971年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 683 毫秒
541.
在硫酸系统中,通过水平衡分析计算烟气带入净化工序的SO2体积分数和含水量,确定净化工序的能力,控制干燥塔进口烟气温度,使干吸工序生产出合格产品;通过计算,烟气带入净化工序的水量小于产品带出的水量,制酸净化污水经过污水处理工序处理后返回到净化工序重复使用,实现净化污水零排放,消除对环境的污染. 相似文献
542.
This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The
results showed that Cu(II) alone could induce a photo Fenton-like reaction to enhance the degradation of atrazine, in which hydroxyl
radical ( OH) was a main active species. Humic acids restrained atrazine degradation, nevertheless, when introducing Cu(II), the
photodegradation was accelerated, in which singlet oxygen (1O2) replaced OH acting as the prevailing species. A feasible mechanism
for the photochemical process was also proposed, which is helpful for better understanding the environmental photochemistry of
atrazine in the copper-polluted water. 相似文献
543.
This study compares the accumulation of Cr(VI) and biochemical changes (total chlorophyll, carotenoid, protein, malondialdehyde
(MDA) and cysteine contents) and roles of antioxidant enzymes (superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate
peroxidase (APX)) in tolerance to metal induced stress in Cucumis utillissimus L. grown in Cr contaminated soil (CS) with garden
soil (GS). Furthermore, Cr bioavailability was enhanced by ethylene diamine tetra-acetic acid (EDTA) addition to the soil to forecast
the plant’s accumulation pattern at elevated Cr environment. Accumulation of Cr in the leaves of the plant increased with increase in
substrate metals concentration. It further increased with the addition of EDTA by 1437% and 487% in GS and CS, respectively at the
highest treatment level. The lipid peroxidation increased proportionately with increase in Cr accumulation in the leaves. All the activity
of antioxidant enzymes (SOD, GPX and APX) and the level of cysteine increased with dose dependant manner. SOD and cysteine were
observed to be higher in the GS than in CS, but APX and GPX were found to be higher in CS than in GS. The increase in GPX and APX
activities with the increase in Cr concentration could be assumed that these two enzymes have a major role in the defense mechanism
towards stress induced by Cr in C. utillissimus. 相似文献
544.
Meeta Lavani Priyangshu M. Sarm Ajoy K. Man Simrita Cheem Banwari La 《环境科学学报(英文版)》2011,23(8):1394-1402
We compared the efficacy of a natural biocide with four chemical tetrakishydroxymethyl phosphonium sulfonate, benzyl trimethyl
ammonium chloride, and formaldehyde, glutaraldehyde, to control microbial induced corrosion in oil pipelines. The efficacy of biocides
were monitored against Desulfovibrio vulgaris and Desulfovibrio gigas in experimental pipes by measuring cell counts, H2S production,
Fe(II) production, production of extracellular polymeric substances and structure of biofilm. The treatment with cow urine had minimum
planktonic cell counts of 3 102 CFU/mL as well as biofilm cell counts of 9 101 CFU/mL as compared with tetrakishydroxyl methyl
phosphonium sulfonate, benzyl trimethyl ammonium chloride, formaldehyde and glutaraldehyde. Sulfide production was the lowest
with cow urine (0.08 mmol/L), followed by tetrakishydroxymethyl phosphonium sulfonate 0.72 mmol/L. On day 90 of treatment,
Fe(II) production was also found to be the lowest with cow urine. The scanning electron microscopic studies indicated that the biofilm
bacteria were killed by cow urine. These results demonstrate the cow urine mediated control of microbially induced corrosion, and this
is indicative of its potential as a viable substitute of toxic biocides. To the best of our knowledge, this seems to be the first report which
screens possible biocidal activity by cow urine as compared to the most common biocides which oil industry is currently using. 相似文献
545.
响应面法优化复合微生物吸附剂对低浓度Cr3+的吸附 总被引:2,自引:1,他引:1
根据已有4种微生物吸附剂的吸附基团存在的差异特征,将其复配成复合吸附剂,借助统计学方法研究其对低ρ(Cr3+)废水的吸附性能.在单因素试验基础上,利用P-B(Plackett-Burman)法筛选出吸附过程4个主要影响因素分别为pH,初始ρ(Cr3+)及微生物吸附剂XB和TQ的投加量,应用最陡爬坡试验接近主要因素最优水平,采用Box-Behnken试验设计和响应面分析得到对低浓度Cr3+吸附过程的二阶模型.结果表明,最优吸附条件为pH 4.0,初始ρ(Cr3+)为4.86mg/L,XB和TQ的投加量分别为0.20和0.13 g/L,实际吸附率达到87.54%,与理论预测值(87.68%)接近,且高出单一吸附剂吸附率7.79%~17.35%.FT-IR扫描显示,复合微生物吸附剂性能提高与表面基团增多有关.通过响应面分析法优化复合微生物吸附,吸附性能明显提高. 相似文献
546.
547.
在突发环境污染事件和区域生态风险筛查中迫切需要环境样品中重金属离子的快速检测技术手段。环境样品中重金属离子的快速检测技术有电化学方法和生物学方法。电化学检测方法主要是阳极溶出伏安法(AnodicStripping Voltammetry,ASV),可以同时检测多种重金属离子,有标准化认证的产品,但是检测成本相对较高。随着纳米粒子技术(Nanoparticles,NPs)和石英微天平分析技术(Quartz Crystal Microbalance,QCM)的引入,ASV法的检测成本将不断降低;生物检测方法包括免疫检测(Immunoassay,IA)和功能DNA(Functional DNA)检测技术。重金属离子的免疫检测技术样品通量大,检测成本低,已经广泛用于食品行业,其中汞离子的免疫检测方法已经成为环境样品标准检测方法之一。免疫检测传感器技术将拓展重金属离子的快速检测的应用空间。功能DNA传感器检测的研究为重金属离子的快速检测提供了新的技术手段,但是这些仅限于实验室研究,还没有达到实际应用的水平。 相似文献
548.
549.
550.
微波酸活化粉煤灰吸附酸性大红染料废水实验研究 总被引:3,自引:0,他引:3
以微波酸活化改性后的粉煤灰为吸附剂,对酸性大红染料废水进行吸附脱色处理,考察了吸附时间、pH值、吸附剂投加量等对吸附脱色效果的影响。在酸性大红染料溶液初始浓度为100 mg/L、pH=5、活化粉煤灰投加量为10 g/L吸附1 h时,活化粉煤灰对酸性大红的脱色效果较好,去除率可达96%。对实验数据进行相关数学模型拟合,结果表明微波酸活化改性后的粉煤灰吸附去除酸性大红的等温吸附平衡符合Langmuir吸附等温式,改性前后的吸附过程动力学符合准二级吸附动力学模型,线性相关系数良好。 相似文献