全文获取类型
收费全文 | 318篇 |
免费 | 44篇 |
国内免费 | 52篇 |
专业分类
安全科学 | 62篇 |
废物处理 | 26篇 |
环保管理 | 64篇 |
综合类 | 143篇 |
基础理论 | 20篇 |
污染及防治 | 21篇 |
评价与监测 | 65篇 |
社会与环境 | 10篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 8篇 |
2022年 | 8篇 |
2021年 | 17篇 |
2020年 | 14篇 |
2019年 | 5篇 |
2018年 | 11篇 |
2017年 | 6篇 |
2016年 | 20篇 |
2015年 | 14篇 |
2014年 | 18篇 |
2013年 | 26篇 |
2012年 | 25篇 |
2011年 | 25篇 |
2010年 | 18篇 |
2009年 | 20篇 |
2008年 | 12篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 19篇 |
2004年 | 12篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有414条查询结果,搜索用时 31 毫秒
71.
72.
73.
流动注射-氢化物发生-原子荧光光谱法测定土壤中铅 总被引:1,自引:0,他引:1
采用流动注射-氢化物发生-原子荧光光谱法测定土壤中的铅,工作曲线线性关系良好,检出限为0.25 mg/kg,相对标准偏差<3.5%,加标回收率为93.0%~105%.该方法简便快速,测定结果准确可靠. 相似文献
74.
Managing disposal of water produced with petroleum in Kuwait 总被引:1,自引:0,他引:1
Disposal of water produced with petroleum has been of great interest in Kuwait for the last 20 years. The current problem arose when the Burgan oil field, which is the second largest field in the world, experienced successive increases in the water content of the produced oil. This study introduces a decision-making analysis of the considered alternatives for the disposal of the produced water. Four alternative solutions exist for the industry as practical solutions for the disposal of water produced in Kuwait. The first method utilizes a large number of pits to discharge water. The second alternative depends on discharging water into sealed pits. The third approach to dispose water is by injecting the water underground. The last method is similar to the previous one, but takes into consideration the recovery of reservoir pressure to maintain the rate of oil production. A questionnaire was distributed to 48 experts at the top management level of the petroleum companies and the governmental authority. The data collected considered cost, efficiency, and environmental parameters. Based on the data, a statistical analysis was conducted using the factor analysis method to reduce the number of investigated variables. The analysis concluded that the optimal solution is to use the effluent injection method to discharge water produced with oil in Burgan and similar fields in Kuwait. 相似文献
75.
76.
采用超高效液相色谱-串联质谱法直接进样测定地表水中26种有机污染物,通过优化试验条件,使各目标化合物在1.00μg/L^100μg/L范围内线性良好,相关系数(r 2)>0.995,方法检出限为0.003μg/L^1.0μg/L。将该方法用于地表水样的测定,加标回收率为79.0%~120%,6次测定结果的RSD均<15%。 相似文献
77.
针对烟塔合一冷却塔(Natural Draft Dry Cooling Tower,NDDCT)在冬季关闭冷却塔百叶窗时存在烟气排放困难的现象,以及导致冷却塔内污染物浓度大幅升高、进而增加冷却塔内壁腐蚀风险的问题,提出了增加烟囱高度的改善措施,并开展了风洞试验。基于计算流体力学(Computational Fluid Dynamics,CFD)方法建立了烟塔合一数值模型以获得冷却塔内部流场和污染物浓度场的分布特性,模拟对比了春季工况和冬季工况条件下烟塔合一冷却塔内部及出口位置的流场和烟气扩散特性。结果表明,由于百叶窗关闭导致冷却塔的通气量和换热量大幅度下降,冷却塔内部的流场变得杂乱无章,污染物质量分数大大增加。与春季相比,冬季冷却塔内壁污染物最大质量分数增加了1.5倍。随烟囱高度增加,烟气可以凭借其初始动能抵御冷却塔内的湍流冲出塔外,冷却塔内部的烟气扩散情况逐渐改善。定性风洞试验结果较好地验证了数值模拟结果,验证了该方法的可行性。虽然增加烟囱高度会增加施工初期的投资,但该方案能有效降低冷却塔的腐蚀风险,不但节省了后期防腐的投资,而且降低了安全风险。从长远来看,该措施利大于弊。 相似文献
78.
During oil and gas production, water is often extracted from geological formations along with the hydrocarbons. These "produced
waters" have been discharged to Nueces Bay since the turn of the century. These effluents were found to be highly toxic, and
sediments in the vicinity of the discharges were also toxic. We developed a map of wells and produced-water discharge sites
in the vicinity of Nueces Bay and identified numerous unplugged wells suitable for conversion to produced water disposal wells.
An economic analysis of conversion to subterranean injection of produced water indicates that most of the wells currently
in production could pay out the cost of conversion to injection in one to three years. The use of one injection well for two
or more water-producing wells could yield greater savings. Wells that could not support the cost of injection are small producers,
and their loss would not constitute a major loss of jobs or dollars to the area. This study could serve as a useful model
for evaluating the economic feasibility of conversion to injection in other areas of Texas and Louisiana. 相似文献
79.
80.
Jiaen Liu Dr Willy Lissens Paul Devroey Andre Van Steirteghem Ingeborg Liebaers 《黑龙江环境通报》1993,13(9):873-880
The efficiency of the polymerase chain reaction (PCR) in detecting the cystic fibrosis (CF) ΔF508 mutation (which is the most common mutation of CF) was assessed in single human blastomeres. Twenty-one human immature oocytes (germinal-vesicle-stage oocytes) that had been donated for research were matured in vitro and a single spermatozoon from a carrier of the CF ΔF508 mutation was injected into the ooplasm. Fourteen embryos were obtained after intracytoplasmic sperm injection (ICSI). PCR analysis was carried out on 70 single blastomeres isolated from these 14 embryos. The results showed that the efficiency of DNA amplification by PCR in single nucleate blastomeres was 94 per cent (59/63). There were no false-positive results since none of the blank samples or the blastomeres without a nucleus showed an amplified signal. We found that nine embryos were homozygous for the unaffected genotype and that four embryos were heterozygous since they contained both the unaffected and the ΔF508 genotype. In a four-cell embryo, we observed the homozygous unaffected genotype in one blastomere and a heterozygous ΔF508/unaffected genotype in the other three blastomeres. 相似文献