全文获取类型
收费全文 | 5240篇 |
免费 | 571篇 |
国内免费 | 1820篇 |
专业分类
安全科学 | 488篇 |
废物处理 | 260篇 |
环保管理 | 424篇 |
综合类 | 3718篇 |
基础理论 | 826篇 |
环境理论 | 1篇 |
污染及防治 | 1091篇 |
评价与监测 | 337篇 |
社会与环境 | 266篇 |
灾害及防治 | 220篇 |
出版年
2024年 | 28篇 |
2023年 | 107篇 |
2022年 | 300篇 |
2021年 | 281篇 |
2020年 | 305篇 |
2019年 | 221篇 |
2018年 | 208篇 |
2017年 | 275篇 |
2016年 | 282篇 |
2015年 | 338篇 |
2014年 | 468篇 |
2013年 | 521篇 |
2012年 | 536篇 |
2011年 | 523篇 |
2010年 | 420篇 |
2009年 | 377篇 |
2008年 | 416篇 |
2007年 | 362篇 |
2006年 | 295篇 |
2005年 | 213篇 |
2004年 | 153篇 |
2003年 | 158篇 |
2002年 | 162篇 |
2001年 | 118篇 |
2000年 | 131篇 |
1999年 | 85篇 |
1998年 | 75篇 |
1997年 | 60篇 |
1996年 | 55篇 |
1995年 | 35篇 |
1994年 | 34篇 |
1993年 | 23篇 |
1992年 | 18篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有7631条查询结果,搜索用时 517 毫秒
521.
用絮凝#x02014;微波辐射#x02014;Fenton试剂氧化法深度处理焦化废水,研究了微波辐射时间、微波功率、FeSO4加入量、H2O2加入量和废水pH对废水处理效果的影响。实验结果表明:在聚合氯化铝加入量为350mg/L、聚丙烯酰胺加入量为12mg/L、废水pH=5、FeSO4加入量为250mg/L、H2O2总加入量为1400mg/L、H2O2分3次投加、微波功率为400W、微波辐射时间为60min的条件下,处理后出水的浊度、色度和COD去除率分别为98.59%,97.62%,86.21%。处理后出水澄清透明,COD为50.34mg/L,满足GB50050#x02014;2007《工业循环冷却水处理设计规范》的要求。 相似文献
522.
郭燕 《再生资源与循环经济》2013,6(1):28-30
随着人民生活水平的不断提高,居民家中淘汰的各类废旧纺织品的产生量快速增加。废旧纺织品作为一种可再生资源,其复杂性影响了回收后的资源化利用。废旧纺织品分类回收和再生纤维加工,提高了废旧纺织品回收及再利用水平,有助于弥补我国纺织原材料供给不足,实现织物资源的循环利用。 相似文献
523.
Li-Na Shi Yan Zhou Zuliang Chen Mallavarapu Megharaj Ravi Naidu 《Environmental science and pollution research international》2013,20(6):3639-3648
Clays such as kaolin, bentonite and zeolite were evaluated as support material for nanoscale zero-valent iron (nZVI) to simultaneously remove Cu2+ and Zn2+ from aqueous solution. Of the three supported nZVIs, bentonite-supported nZVI (B-nZVI) was most effective in the simultaneous removal of Cu2+ and Zn2+ from a aqueous solution containing a 100 mg/l of Cu2+ and Zn2+, where 92.9 % Cu2+ and 58.3 % Zn2+ were removed. Scanning electronic microscope (SEM) revealed that the aggregation of nZVI decreased as the proportion of bentonite increased due to the good dispersion of nZVI, while energy dispersive spectroscopy (EDS) demonstrated the deposition of copper and zinc on B-nZVI after B-nZVI reacted with Cu2+ and Zn2+. A kinetics study indicated that removing Cu2+ and Zn2+ with B-nZVI accorded with the pseudo first-order model. These suggest that simultaneous adsorption of Cu2+and Zn2+ on bentonite and the degradation of Cu2+and Zn2+ by nZVI on the bentonite. However, Cu2+ removal by B-nZVI was reduced rather than adsorption, while Zn2+ removal was main adsorption. Finally, Cu2+, Zn2+, Ni2+, Pb2+ and total Cr from various wastewaters were removed by B-nZVI, and reusability of B-nZVI with different treatment was tested, which demonstrates that B-nZVI is a potential material for the removal of heavy metals from wastewaters. 相似文献
524.
Bingzi Zhao Jiabao Zhang Yan Jiang 《Environmental science and pollution research international》2013,20(11):8245-8254
Virus contamination in wastewater is usually accompanied by the existence of various bacteria. Nanoparticles (NPs) have been shown to efficiently remove virus. In this study, bacterial cells, supernatants, and cultures were harvested separately from three strains at the culture ages of 6 and 24 h, corresponding to the log and stationary phases, respectively. The aim is to investigate how their presence affects virus adsorption on the three Fe and Al oxide NPs (α-Fe2O3, γ-Fe2O3-B, and Al2O3) and how these effects change with bacterial growth phase. Bacteriophage phiX174 was used as a virus model. Results showed that bacterial cells, supernatants, and cultures harvested at 6 h generally reduced virus adsorption by an average of 0.75?±?0.84, 7.7?±?9.0, and 10.3?±?8.6 %, respectively, while those harvested at 24 h reduced virus adsorption by an average of 2.1?±?0.93, 21.5?±?6.6, and 24.6?±?6.9 %, respectively. Among the NPs, α-Fe2O3 showed more sensitivity to bacteria than the other two, probably because of its relatively higher value of point of zero charge. It was found that cell-induced and supernatant-induced reductions were combined to achieve added results, in which the supernatants contributed much more than the cells, implying that the bacterial exudates might be more crucial in the reduced virus adsorption than the bacterial cells. These results strongly demonstrated that the bacteria-induced reduction in virus adsorption became more significant with culture age. It is suggested that studies conducted in the absence of bacteria may not accurately evaluate the potential of virus removal efficiency of the NPs in bacteria-containing environments. 相似文献
525.
Xian-De Xie Xiao-Bo Min Li-Yuan Chai Chong-Jian Tang Yan-Jie Liang Mi Li Yong Ke Jie Chen Yan Wang 《Environmental science and pollution research international》2013,20(9):6050-6058
Floatation tailings (FT) are the main by-products of the hydrothermal sulfidation–flotation process. FT (FT1 and FT2) were obtained by treating two different neutralization sludges (NS) (NS1 and NS2). This paper quantitatively evaluated the environmental risks of heavy metals (Zn, Cd, Cu, Pb, and As) in FT versus NS. The total concentration and leaching rates (R 2) of heavy metals in FT were much lower than those in NS, demonstrating that the hydrothermal sulfidation–flotation process was able to effectively suppress the mobility and leachability of heavy metals. The BCR-three sequence leaching procedure of FT confirmed that all metals were transformed into more stable forms (residue and oxidizable forms) than were found that in NS. The potential ecological risk index indicated that the overall risks caused by heavy metals decreased significantly from 6627.59 and 7229.67 (very serious risk) in NS1 and NS2, respectively, to 80.26 and 76.27 (low risk) in FT1 and FT2, respectively. According to the risk assessment code, none of the heavy metals in FT posed significant risk to the natural environment except Zn (with low risk). In general, the risk of heavy metals in FT had been well controlled. 相似文献
526.
527.
Panax notoginseng (Burk.) F.H. Chen, a rare traditional Chinese medicinal herb, is a widely used phytomedicine used all over the world. In recent years, the arsenic contamination of the herb and its relative products becomes a serious problem due to elevated soil As concentration. This study aimed to evaluate the effects of different types and dosages of amendments on As stabilization in soil and its uptake by P. notoginseng. Results showed that comparing to control treatment, the As concentrations of P. notoginseng declined by 49–63%, 43–61% and 52–66% in 0.25% zero-valent iron (Fe(0)), 0.5% bauxite residue, and 1% zeolite treatment, respectively; whereas the biomasses were elevated by 62–116%, 45–152% and 114–265%, respectively. The As(III) proportions of P. notoginseng increased by 8%, 9%, and 8%, and the transfer factors of As from root to shoot increased by 37%, 42% and 84% in the optimal treatments of Fe(0), bauxite residue, and zeolite. For soil As, all the three amendments could transform the non-specifically adsorbed As fraction to hydrous oxides Fe/Al fractions (by Fe(0) and red mud) or specifically adsorbed As fraction (by zeolite), therefore reduced the bioavailability of soil As. With a comprehensive consideration of stabilization efficiency, plant growth, environmental influence, and cost, Fe(0) appeared to be the best amendment, and zeolite could also be a good choice. In conclusion, this study was of significance in developing As contamination control in P. notoginseng planting areas, and even other areas for medicinal herb growing. 相似文献
528.
以含铜废水为处理对象,重点考察了诱晶载体的表面性质及表面负荷对诱导结晶过程的影响。结果表明,在工艺启动初期,白云石以及碱式碳酸铜为诱晶载体时,铜的去除率在90%以上,石英砂对铜的去除率较低,但石英砂经表面改性后对铜的去除效率亦可达90%以上。在运行稳定后,几类诱导载体对铜的去除率皆能稳定在95%,说明诱晶载体的表面性质对诱导结晶工艺的影响主要在于反应启动初期,选择与目标结晶产物结构、成分相同或相似的诱晶载体有利于诱导结晶过程的进行。此外,研究结果还表明,诱晶载体表面负荷对结晶过程影响较大,诱导结晶除铜工艺中载体表面负荷不宜高于0.054gCu/(m2·d)。 相似文献
529.
湿地植物在处理高负荷有机废水时会受到不同程度的氧化胁迫。本研究基于对浮萍的有机污染胁迫模拟系统,通过对浮萍脂质过氧化和抗氧化防御系统的监测与分析,研究了浮萍对有机污染胁迫的耐受能力及胁迫去除后浮萍的恢复规律。结果表明,浮萍对有机污染胁迫具有较高的耐受性,在胁迫去除后,具有一定的恢复能力。在COD小于400mg/L时,浮萍并未受到氧化胁迫;当COD达到800 mg/L时,浮萍体内ROS含量上升,细胞膜脂过氧化加剧,但抗氧化酶活性升高,抗氧化物质含量增加,浮萍可保持生长,胁迫去除后,抗氧化防御系统可恢复到对照水平;当COD过高(≥1 000mg/L),ROS急剧上升,抗氧化防御系统遭受破坏,造成不可逆伤害,胁迫去除后不能恢复正常生长。 相似文献
530.
为了解决湿式氨法烟气脱硫生成不稳定亚硫酸铵((NH4)2SO3)副产物的问题,设计了以不锈钢弹簧和溶液分别作为高压和低压电极的沿面放电系统,对液相(NH4)2SO3的氧化进行了研究。空气从反应器上方进入后经放电区域形成活性物质,再由底部的曝气头鼓入溶液并与(NH4)2SO3发生反应。比较了沿面放电处理与传统曝气处理的氧化效率,考察了放电电压、载气气量和初始浓度等因素对(NH4)2SO3氧化的影响。结果表明,沿面放电对(NH4)2SO3有显著的氧化效果;优化条件下的(NH4)2SO3氧化率接近100%;溶液中(NH4)2SO4与(NH4)2SO3的浓度比小于1时有利于(NH4)2SO3的氧化。 相似文献