全文获取类型
收费全文 | 465篇 |
免费 | 19篇 |
国内免费 | 166篇 |
专业分类
安全科学 | 24篇 |
废物处理 | 21篇 |
环保管理 | 37篇 |
综合类 | 291篇 |
基础理论 | 89篇 |
污染及防治 | 140篇 |
评价与监测 | 19篇 |
社会与环境 | 13篇 |
灾害及防治 | 16篇 |
出版年
2023年 | 5篇 |
2022年 | 28篇 |
2021年 | 27篇 |
2020年 | 22篇 |
2019年 | 15篇 |
2018年 | 14篇 |
2017年 | 18篇 |
2016年 | 27篇 |
2015年 | 27篇 |
2014年 | 44篇 |
2013年 | 41篇 |
2012年 | 33篇 |
2011年 | 40篇 |
2010年 | 36篇 |
2009年 | 36篇 |
2008年 | 25篇 |
2007年 | 32篇 |
2006年 | 22篇 |
2005年 | 18篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 19篇 |
2000年 | 11篇 |
1999年 | 17篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有650条查询结果,搜索用时 828 毫秒
451.
Dezhen Chen Zhenzhen Guan Guangyu Liu Gongming Zhou Tong Zhu 《Frontiers of Environmental Science & Engineering in China》2010,4(2):235-243
Aged municipal solid wastes (MSW) excavated from landfills and dumpsites were characterized to analyze their fraction composition,
moisture content, and lower heat value (LHV). The necessity and feasibility of recycling combustibles from aged MSW to improve
the incineration of fresh MSW were investigated. The results showed that combustibles in aged MSW were easily separated from
other components and than LHV of the separated combustibles are higher than 11000 kJ/kg. The fresh MSW are of high moisture
contents with average LHV below 6500 kJ/kg, making their stable combustion difficult to maintain in MSW incinerators. For
both fresh MSW and aged MSW, plastics are the main contributor to their LHV. To improve incineration of fresh MSW that are
characterized with low LHV, combustibles separated from aged MSW were made into refuse derived fuel (RDF) pellets and were
then added to fresh MSW by 2% wt.–5% wt. LHV variation and air supply resistance change of the MSW layer on the incinerator
grate caused by the addition of RDF was checked, and no significant changes were found. No obvious difference was observed
for the ‘burn-out time’ between RDF pellets and fresh MSW either. RDF made from aged MSW combustibles is found to be a promising
auxiliary fuel to improve the incineration of fresh MSW, and aged MSW from old landfill cells and dumpsites can be finally
disposed of jointly with fresh MSW by recycling combustible from the former to be coincinerated with the latter in the incineration
plants. 相似文献
452.
453.
454.
455.
对硫磷的紫外光解研究 总被引:4,自引:0,他引:4
采用^31PNMR谱推测对硫磷的光解机理,拟合了对硫磷初级光解的动力学方程,详细地研究了光催化剂,酸度,溶解氧等因素对光解速率的影响。 相似文献
456.
457.
以乙酸钠和丙酸钠1:2混合作为碳源,进水COD浓度分别为200,400,600,800mg/L,研究混合碳源浓度对单级好氧生物脱氮除磷的影响,并通过比较微生物体内储能物质的变化,探讨混合碳源浓度对生物脱氮除磷性能影响的机理.结果表明,当进水磷和氨氮浓度分别为12,30mg/L时,随着进水COD由200增加至800mg/L,磷去除率由39.9%提升至86.4%(氮去除率从13.5%提升至96.4%).进水COD为400mg/L时单位挥发性悬浮固体(VSS)的磷和氮去除量达到最高[分别为(4.31±0.08)和(6.15±0.22)mg/g].当进水COD由200增加至400mg/L时生物除磷活性增强,而COD继续增加会使污泥沉降性能变差,脱氮除磷生物活性降低.好氧吸磷和同步硝化反硝化主要由微生物体内储能物质多β羟基烷酸盐(PHA)驱动,当进水COD为400mg/L时单位VSS消耗的PHA最多.混合碳源浓度通过影响碳源的好氧代谢,使微生物体内储能物质的积累/转化量不同,进而影响系统的脱氮除磷性能. 相似文献
458.
为探讨41%草甘膦水溶液(农达)对雄性生殖细胞的毒性及其作用机制以及N-乙酰半胱氨酸(N-acetylcysteine, NAC)的干预效应。以GC-1小鼠精原细胞为受试细胞,设正常对照组、草甘膦染毒组(60、90、120、150、180 mg·L-1)、NAC干预组(10 mmol·L-1 NAC+90 mg·L-1农达)。MTT法检测细胞存活率,Giemsa染色法观察细胞的形态学改变,彗星试验检测细胞DNA损伤,比色法检测细胞培养液乳酸脱氢酶(LDH)以及细胞内超氧化物歧化酶(SOD)、谷胱甘肽(GSH)及丙二醛(MDA)水平的变化。结果显示,随着草甘膦染毒浓度增加,细胞存活率逐渐下降(p<0.01),彗星阳性率逐渐升高(p<0.01);与对照组相比,草甘膦染毒组LDH活性增加(p<0.05,60 mg·L-1组除外),MDA生成量增多(p<0.05),GSH含量降低(p<0.05)和SOD活性降低(p<0.05)。抗氧化剂NAC预处理具有相应的拮抗作用。研究表明,60~180 mg·L-1浓度草甘膦对GC-1细胞有明显的损伤作用,其机制可能是草甘膦诱导氧化应激,导致细胞通透性增加和DNA损伤。抗氧化剂NAC对草甘膦的细胞毒性具有一定保护作用。 相似文献
459.
Junlian QIAO Zimin CUI Yuankui SUN Qinghai HU Xiaohong GUAN 《Frontiers of Environmental Science & Engineering》2014,8(2):169-179
A1-Fe (hydr)oxides with different A1/Fe molar ratios (4:1, 1:1, 1:4, 0:1) were prepared using a co- precipitation method and were then employed for simultaneous removal of arsenate and fluoride. The 4A1 : Fe was superior to other adsorbents for removal of arsenate and fluoride in the pH range of 5.0-9.0. The adsorption capacity of the A1-Fe (hydr)oxides for arsenate and fluoride at pH 6.50.3 increased with increasing A1 content in the adsorbents. The linear relationship between the amount of OH released from the adsorbent and the amount of arsenate or fluoride adsorbent by 4A1 : Fe indicated that the adsorption of arsenate and fluoride by A1- Fe (hydr)oxides was realized primarily through quantita- tive ligand exchange. Moreover, there was a very good correlation between the surface hydroxyl group densities of A1-Fe (hydr)oxides and their adsorption capacities for arsenate or fluoride. The highest adsorption capacity for arsenate and fluoride by 4A1 : Fe is mainly ascribed to its highest surface hydroxyl group density besides its largest pHpzc. The dosage of adsorbent necessary to remove arsenate and fluoride to meet the drinking water standard was mainly determined by the presence of fluoride since fluoride was generally present in groundwater at much higher concentration than arsenate. 相似文献
460.
生命线工程综合防灾规划决策方法研究与应用 总被引:1,自引:0,他引:1
在对生命线工程综合防灾规划编制的技术路线进行分析的基础上,引入了综合灾害指数的概念,提出了一种城市生命线工程综合防灾规划的决策方法,该方法利用综合灾害指数的计算来获得综合防灾规划的决策依据。在综合灾害指数的计算过程中,以给水工程综合防灾为例,采用层次分析法,得到10种灾害最终的评价权重;以地震灾害影响因素识别和地震灾害风险指标的计算为例给出潜在灾害的风险指标计算。最终以综合灾害指数为重要衡量标准,并结合生命线工程功能上的布局要求和系统的整体性要求来进行生命线工程的综合防灾规划。本方法在烟台市开发区生命线工程综合防灾规划中得到了实际应用,以期为我国其他城市的生命线工程综合防灾规划的编制提供借鉴。 相似文献