全文获取类型
收费全文 | 1185篇 |
免费 | 151篇 |
国内免费 | 989篇 |
专业分类
安全科学 | 56篇 |
废物处理 | 51篇 |
环保管理 | 96篇 |
综合类 | 1475篇 |
基础理论 | 315篇 |
污染及防治 | 271篇 |
评价与监测 | 49篇 |
社会与环境 | 10篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 7篇 |
2023年 | 26篇 |
2022年 | 59篇 |
2021年 | 71篇 |
2020年 | 87篇 |
2019年 | 91篇 |
2018年 | 73篇 |
2017年 | 71篇 |
2016年 | 88篇 |
2015年 | 87篇 |
2014年 | 100篇 |
2013年 | 151篇 |
2012年 | 123篇 |
2011年 | 152篇 |
2010年 | 97篇 |
2009年 | 144篇 |
2008年 | 97篇 |
2007年 | 120篇 |
2006年 | 118篇 |
2005年 | 84篇 |
2004年 | 66篇 |
2003年 | 82篇 |
2002年 | 52篇 |
2001年 | 39篇 |
2000年 | 43篇 |
1999年 | 44篇 |
1998年 | 23篇 |
1997年 | 20篇 |
1996年 | 17篇 |
1995年 | 29篇 |
1994年 | 12篇 |
1993年 | 20篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有2325条查询结果,搜索用时 92 毫秒
691.
实时荧光定量PCR技术对氨氧化细菌的研究 总被引:4,自引:0,他引:4
传统的PCR技术只能实现对核酸的定性检测而无法对其进行定量研究。随着分子生物学技术的发展,在传统PCR技术的基础上发展起来的实时荧光定量PCR技术实现了对核酸的定量研究。该技术是向常规PCR反应体系中加入荧光染料或荧光探针,通过监测PCR反应过程中荧光信号的变化来实现对核酸的定量。实时荧光定量PCR技术具有应用范围广、灵敏度高、操作简单、工作量低等特点,在医学和微生物学领域已广泛地应用于疾病诊断、病毒定量检测、微生物群落结构分析及演替规律的研究。文章综述了该项技术的原理、特点及其在环境氨氧化细菌研究中的应用,同时也指出了该技术存在的问题及其发展应用前景。 相似文献
692.
693.
A membrane aerated biofilm reactor is a promising technology for wastewater treatment. In this study, a carbon-membrane aerated biofilm reactor (CMABR) has been developed, to remove carbon organics and nitrogen simultaneously from one reactor. The results showed that CMABR has a high chemical oxygen demand (COD) and nitrogen removal efficiency, as it is operated with a hydraulic retention time (HRT) of 20 h, and it also showed a perfect performance, even if the HRT was shortened to 12 h. In this period, the removal efficiencies of COD, ammonia nitrogen (NH4^+-N), and total nitrogen (TN) reached 86%, 94%, and 84%, respectively. However, the removal efficiencies of NH4^+-N and TN declined rapidly as the HRT was shortened to 8 h. This is because of the excessive growth of biomass on the nonwoven fiber and very high organic loading rate. The fluorescence in situ hybridization (FISH) analysis indicated that the ammonia oxidizing bacteria (AOB) were mainly distributed in the inner layer of the biofilm. The coexistence of AOB and eubacteria in one biofilm can enhance the simultaneous removal of COD and nitrogen. 相似文献
694.
The activated carbon-supported TiO2 nanoparticles(TiO2/AC)were prepared by a properly controlled sol-gel method.The effects of activated carbons(AC)support on inactivated properties of TiO2 nanoparticles were evaluated by photocatalytic inactivation experiments of Escherichia coli.The key factors affecting the inactivation effciency were investigated,including electric power of lamp, temperature,and pH values.The results show that the TiO2/AC composites have high inactivation properties of E.coli in compari... 相似文献
695.
The activated carbon-supported TiO2 nanoparticles (TiO2/AC) were prepared by a properly controlled sol-gel method. The effects of activated carbons (AC) support on inactivated properties of TiO2 nanoparticles were evaluated by photocatalytic inactivation experiments of Escherichia coli. The key factors affecting the inactivation efficiency were investigated, including electric power of lamp, temperature, and pH values. The results show that the TiO2/AC composites have high inactivation properties of E. coli in comparison with pure TiO2 powder. The kinetics of photocatalytic inactivation of E. coli was found to follow a pseudo-first order rate law for TiO2/AC composites, and kinetic behavior could be described in terms of a modified Langmuir-Hinshelwood model. The values of the adsorption equilibrium constants for the bacteria, Kc, and for the rate constants, kr, were certainly depended on TiO2 content. At 47 wt.% TiO2 coatings with the highest rate constant, the Kc and kr were 1.17 × 10−8L/cfu and 1.43 × 106 cfu/(L·min), respectively. The variety of parameters shows significant effects on inactivation rate. The outer layer of bacteria decomposed first resulting in inactivation of cell, and with further illumination, the cells nearly decomposed. 相似文献
696.
Decomposition and phosphorus release from four different size fractions of Microcystis spp. taken from Lake Taihu, China 总被引:1,自引:1,他引:0
Decomposition of Microcystis is accompanied by the release of phosphorus,during bacteria play an important role.A series of experiments were undertaken to evaluate the effect of bacteria on the decomposition of Microcystis taken from Lake Taihu,China,a lake that is suffering from dense Microcystis blooms.The 16 experiments involved four size fractions of colonial Microcystis with or without the addition of lake sediment and Gram-negative bacterial inhibitor NAN_3.The highest decomposition rates were reco... 相似文献
697.
固定化三维电极-生物膜法去除污水中硝酸盐氮 总被引:3,自引:0,他引:3
本研究将固定化细胞技术用于三维电极-生物膜反应器的阴极微生物挂膜,对现有的三维电极-生物膜反应器进行了改进。同时,以城市污水二级生化处理系统的出水为研究对象,利用自制的固定化三维电极-生物膜反应器进行了反硝化深度脱氮试验。考察了电流强度、HRT、不同C/N值等因素对硝态氮和COD去除率的影响,并通过对比试验证实了固定化细胞技术的使用可提高反应器的反硝化性能。试验结果表明,在电流强度30mA,进水流量9mL/min时,COD的去除率为50%,硝态氮的去除率可达82.03%,反应器NO3--N负荷为0.297mg NO3--N(/cm2.d);同等操作条件下,采用固定化方法挂膜的反应器的脱氮效率可比普通反应器提高20%以上。 相似文献
698.
699.
700.
从生物净化器/强化浮床组合工艺处理农村生活污水工程的生物净化器中提取菌种。在以乙酸钠为碳源的专性脱氮培养基上分离筛选出厌氧反硝化菌株A-5,运用生物量和脱氮率的实验测试其最适生长条件为:30℃、pH值为7.7、最适接种量为20%。在最适条件下的降解能力为:培养液初始NO3-N浓度为100mg·L^-1,24h内脱氮率达90.1%。通过形态学和生理特性观察经过菌种鉴定测定A-5为门多萨假单胞菌属(Pseudomonas Medoeina)。该菌株脱氮效果明显,可广泛用于农村生活污水的处理。 相似文献