全文获取类型
收费全文 | 176篇 |
免费 | 11篇 |
国内免费 | 153篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 8篇 |
环保管理 | 5篇 |
综合类 | 190篇 |
基础理论 | 59篇 |
污染及防治 | 54篇 |
评价与监测 | 5篇 |
社会与环境 | 11篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 14篇 |
2020年 | 6篇 |
2019年 | 21篇 |
2018年 | 8篇 |
2017年 | 12篇 |
2016年 | 6篇 |
2015年 | 14篇 |
2014年 | 11篇 |
2013年 | 27篇 |
2012年 | 16篇 |
2011年 | 19篇 |
2010年 | 13篇 |
2009年 | 14篇 |
2008年 | 9篇 |
2007年 | 24篇 |
2006年 | 10篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 19篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
排序方式: 共有340条查询结果,搜索用时 15 毫秒
91.
92.
93.
Anaerobic ammonium oxidation (ANAMMOX) technology has potential technical superiority and economical efficiency for the nitrogen removal from landfill leachate, which contains high-strength ammonium nitrogen (NH4 -N) and refractory organics. To complete the ANAMMOX process, a preceding partial nitritation step to produce the appropriate ratio of nitrite/ammonium is a key stage. The objective of this study was to determine the optimal conditions to acquire constant partial nitritation for landfill leachate treatment, and a bench scale fixed bed bio-film reactor was used in this study to investigate the effects of the running factors on the partial nitritation. The results showed that both the dissolved oxygen (DO) concentration and the ammonium volumetric loading rate (Nv) had effects on the partial nitritation. In the controlling conditions with a temperature of 30±1℃, Nv of 0.2-1.0 kg NH4 -N/(m3d), and DO concentration of 0.8-2.3 mg/L, the steady partial nitritation was achieved as follows: more than 94% partial nitritation efficiency (nitrite as the main product), 60%-74% NH4 -N removal efficiency, and NO2--N/NH4 -N ratio (concentration ratio) of 1.0-1.4 in the effluent. The impact of temperature was related to iVv at certain DO concentration, and the temperature range of 25-30癈 was suitable for treating high strength ammonium leachate. Ammonium-oxidizing bacteria could be acclimated to higher FA (free ammonium) in the range of 122-224 mg/L. According to the denaturing gradient gel electrophoresis analysis result of the bio-film in the reactor, there were 25 kinds of 16S rRNA gene fragments, which indicated that abundant microbial communities existed in the bio-film, although high concentrations of ammonium and FA may inhibit the growth of the nitrite-oxidizing bacteria and other microorganisms in the reactor. 相似文献
94.
LIU Ting-feng SUN Cheng TA N HONG Jun YANG Shao-gui CHEN Chuan-xiang 《环境科学学报(英文版)》2007,19(10):1235-1238
The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers. 相似文献
95.
CAI Peng HUANG Qiao-yun LU Yan-du CHEN Wen-li JIANG Dai-hu LIANG Wei 《环境科学学报(英文版)》2007,19(11):1326-1329
Polymerase chain reaction(PCR)was used to amplify a 600-base pair(bp)sequence of plasmid pGEX-2T DNA bound on soil colloidal particles from Brown soil(Alfisol)and Red soil(Ultisol),and three different minerals(goethite,kaolinite,montmorillonite). DNA bound on soil colloids,kaolinite,and montmorillonite was not amplified when the complexes were used directly but amplification occurred when the soil colloid or kaolinite-DNA complex was diluted,10- and 20-fold.The montmorillonite-DNA complex required at least 100-fold dilution before amplification could be detected.DNA bound on goethile was amplified irrespective of whether the complex was used directly,or diluted 10- and 20-fold.The amplification of mineral-bound plasmid DNA by PCR is,therefore,markedly influenced by the type and concentration of minerals used.This information is of fundamental importance to soil molecular microbial ecology with particular reference to monitoring the fate of genetically engineered microorganisms and their recombinant DNA in soil environments. 相似文献
96.
97.
天然红树林土壤微生物大片段宏基因组文库的构建 总被引:2,自引:0,他引:2
采用改良及优化后的原位裂解法提取红树林土壤环境DNA,通过脉冲场电泳图谱显示所得DNA片段主要集中于23~50 kbp范围, 表明大片段DNA在总DNA中的比率明显提高; 对改良后的原位裂解提取法与不同DNA纯化方法的组合进行比较分析, 确定电洗脱为最佳纯化方法; 运用改良后的原位裂解提取法与电洗脱纯化法联用实验方案,构建了4个季节天然红树林土壤Cosmid宏基因组文库. 随机挑取克隆子,提取质粒后经BamHI酶切验证, 平均插入片段均大于35 kbp,且片段类型各不相同, 推测该文库至少包含了335 Mbp潮间带微生物基因组信息. 该方法的建立使得开发红树林湿地生态系统的特色微生物资源成为可能, 并为探索其它生境的未培养微生物资源提供借鉴. 相似文献
98.
Biodegradation of polymeric materials affect a wide range of industries, information on degradability can provide fundamental information facilitating design and life-time analysis of materials. Among the methods currently used in testing, traditional gravimetric and respirometric techniques are tailored to readily degradable polymeric materials mostly and polymer blends with biodegradable components, but they are not applicable to the new generation of engineering polymers which are relatively resistant to biodegradation. However, electrochemical impedance spectroscopy (EIS) has been tested for monitoring biodeterioration of high strength materials and the technique has very high sensitivity. A wide range of materials including electronic insulation polyimides, fiber-reinforced polymeric composites (FRPCs) and corrosion protective polyurethane coatings have been successfully measured under inoculation of degradative microorganisms using EIS. In addition, the mechanism of degradation of high strength polymers is mainly due to the presence of plasticizers in the polymer matrices. The information on various methods discussed in this review is intended to illustrate a suite of methods for those who are interested in testing biodeterioration of polymeric materials under different environmental conditions and in selecting appropriate techniques for specific applications. 相似文献
99.
100.
付欢 《辽宁城乡环境科技》2013,(8):62-63,67
为研究石化污水处理场生化处理过程中微生物相的特性与曝气池运行状态、处理效果之间的关系,选用锦西石化分公司污水处理场合建式完全混合曝气池为研究对象,以其活性污泥做样品直接进行镜检。通过观察丝状菌、游离细菌、钟虫、变形虫、鞭毛虫生长繁殖变化,分析各种微生物对应水质条件,得出活性污泥微生物对合建式曝气池运行状态和水质的指示规律。 相似文献