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排序方式: 共有1042条查询结果,搜索用时 31 毫秒
991.
992.
Al3+对序批式生物膜反应器(SBBR)中污泥脱氢酶活性(DHA)和胞外聚合物(EPS)的影响 总被引:2,自引:0,他引:2
通过向序批式生物膜反应器(SBBR)中投加氯化铝,研究了化学协同生物除磷过程中Al~(3+)对污泥脱氢酶活性(DHA)、胞外聚合物(EPS)及系统处理效果的影响.结果表明,氯化铝投加量少于0.1 mmol·L~(-1)时,Al~(3+)对微生物的活性有促进作用,多于0.1 mmol·L~(-1)的Al~(3+)对其活性有明显的抑制作用.氯化铝投加量少于0.1 mmol·L~(-1)时,Al~(3+)能够促进EPS中多糖(PS)和蛋白质(PN)的分泌,多于0.1 mmol·L~(-1)的Al~(3+)则只促进多糖的分泌,但对EPS的分泌总量没有影响.Al~(3+)会使污泥的SVI值显著降低,大大改善其沉降性能.MLSS、MLVSS基本上是随着Al~(3+)投加量的增加而增大,MLVSS/MLSS随着投药量的增加先减小后增大再减小.Al~(3+)对COD和TN的去除具有轻微抑制作用,但对TP的去除具有显著的改善作用.当Al~(3+)的投加为0.5 mmol·L~(-1)时,TP的去除效果最好,出水浓度仅为0.44 mg·L~(-1),满足一级A排放标准.此时,TP的去除率为92.7%,比不加药时提升了10.2%. 相似文献
993.
含镍三氯化铁蚀刻废液的综合利用 总被引:1,自引:0,他引:1
针对显像管荫罩生产工艺中产生的含镍三氯化铁蚀刻废液的处理,先用铁粉将 3价的铁还原,再以硫化亚铁将镍置换回收镍,而铁以液体三氯化铁或固体氯化亚铁的形式得到综合利用,处理工艺技术先进、简单有效,环境效益及经济效益显著。 相似文献
994.
聚硅酸氯化铝铁絮凝剂制备及絮凝效果的研究 总被引:10,自引:0,他引:10
以粉煤灰和硫铁矿烧渣两种工业固体废弃物为主要原料,制取聚硅酸氯化铝铁(PSAFC)无机高分子絮凝剂。粉煤灰、硫铁矿烧渣和纯碱按1:1:0.8混合.在800~900(焙烧15~30min,用定量1:1盐酸浸取,固体溶出率高达94%,陈化后即为PSAFC絮凝剂。通过模拟和真实印染废水絮凝试验.表明PSAFC絮凝效果与聚合氯化铝(PAC)相当,在沉降速度、污泥体积等方面要优于PAC,且成本比PAC低.具有较大的市场前景。 相似文献
995.
Tingting Zhu Zhongxian Su Wenxia Lai Jiazeng Ding Yufen Wang Yingxin Zhao Yiwen Liu 《Frontiers of Environmental Science & Engineering》2023,17(1):7
996.
目的 研究热带海洋大气环境中不同地貌下氯离子沉积速率的分布规律及主要影响因素。方法 通过挂片法采集万宁地区的氯离子沉积速率,并分析离海距离、地形地貌对氯离子沉积速率的影响,以及其与海水因素、自然环境因素间的相关性。结果 近海开阔区域氯离子沉积速率受离海距离和地貌的影响显著,在300 m处降低至90 m处的1/3左右,地貌的变化导致同一距离点处的氯离子沉积速率相差30倍。另外,高的海水有效波高、风速和东风占比使春季氯离子沉积速率高于夏季。结论 不同地貌下的氯离子沉积速率均与海水有效波高、风速间呈较强的正相关性。 相似文献
997.
Control of odours should be considered to be a fundamental issue in order to site, design and manage sanitary landfills. With regard to construction and demolition (C&;D) debris, landfilling was the mainly adopted solution in many European Countries; in particular, gypsum drywalls can produce high concentrations of hydrogen sulphide (H2S) in landfill gas ranging from 7 ppm to 100 ppm. In some cases also dangerous concentrations until to 12,000 ppm were detected. In this paper H2S removal efficiency in a lab-scale vertical packed scrubber was investigated. Hydrogen sulphide abatement was evaluated for inlet H2S concentrations of 1000–100–10 ppm, adjusting scrubbing liquid pH in the range 9–12.5 by means of caustic soda (NaOH 2N solution). Moreover, best operating conditions for the system were defined as well as H2S abatement along the tower and liquid recirculation effectiveness in case of inlet H2S concentration of 10 ppm (typical odour concentration). Results showed that pH of 11.5 in scrubbing liquid could be considered the best value for removal of different inlet H2S concentrations, also taking into account parasitical consumption of NaOH due to CO2 absorption. Moreover, in case of continuous working of the system at H2S concentration of 10 ppm, strong removal efficiency was already obtained with a packed bed height of about 70 cm. Significant performances were ensured after 1 h of constant activity, consuming about 3 ml of soda per cubic meter of polluted air. Subsequently liquid blowdown was necessary. 相似文献
998.
Stambuk-Giljanović N 《Environmental monitoring and assessment》2008,140(1-3):109-117
The objective of this paper is to study the hydrological characteristics and origin of the hydrogen sulphide spring water
from the Split spa in Southern Croatia in 1987, 1988 and 2003. This paper presents the results of monitoring the content of
chlorides and hydrogen sulphide as well as the temperature of the hydrogen sulphide spring water. Since the hydrogen sulphide
content during the dry periods significantly differs from the hydrogen sulphide content during rainy periods, this paper also
compares the results obtained for those two periods. Under the influence of great quantities of rainfall during cold periods
(winter and the beginning of spring) the ratio between seawater and surface water changes and thus the reduction of chlorides
and other minerals occurs. The lowered temperature also reduces hydrogen sulphide which can disappear completely. The concentration
of 12‰ chlorides (76–94.4% days/year) and 12 mg/L hydrogen sulphide (66.7–88.9% days/year) has been taken as a limit value
between water with a normal typical content and water in cold rainy periods. According to the monitoring results it can be
concluded that hydrogen sulphide spring water consists of seawater and hydrogencarbonate surface water with a fairly constant
content during dry periods while the hydrogencarbonate content increases during rainy periods. 相似文献
999.
Ali Deriszadeh Thomas G. Harding Maen M. Husein 《Process Safety and Environmental Protection》2008,86(4):244
The high demand for water in oil sands operations in addition to the shortage of fresh water resources mandate continuous search for reliable and cost effective water treatment technologies. Micellar-enhanced ultrafiltration (MEUF) is potentially applicable to produced water treatment. MEUF is, however, susceptible to membrane plugging and back contamination, especially at high surfactant dosages. Recent investigations showed that addition of small amounts of a non-ionic surfactant to an ionic surfactant solution reduces the critical micellar concentration (CMC) of the mixed surfactant solution, and consequently reduces the surfactant dosage required to achieve certain removal of contaminants using MEUF. In the present study a naphthenic acid, octanoic acid, typically existing in produced water is shown to play a similar role as the non-ionic surfactant when added to the cationic surfactant cetylpyridinium chloride (CPC). Cross-flow MEUF using three different molecular weight cutoffs (MWCOs) of polyacrylonitrile (PAN) hollow fiber membranes was used to treat synthetic produced water containing p-xylene. The mixed CPC/octanoic acid solution removed comparable percentages of p-xylene contaminant at much lower concentrations of CPC. Decreasing CPC concentration in the feed resulted in less fouling and higher permeate flux and reduced back contamination. This, in turn, enhanced the performance of MEUF. 相似文献
1000.
The future widespread use of hydrogen as an energy carrier brings in safety issues that have to be addressed before public acceptance can be achieved. The prediction of the consequences of a major accident release of hydrogen into the atmosphere or the contamination of high-pressure hydrogen storage facilities by air entrainment requires a good knowledge of the explosion parameters of hydrogen–air mixtures. The present paper reviews and comments on the current knowledge of dynamic parameters of hydrogen detonation for hazard assessment. The major problem that remains to be resolved involves the understanding of the effect of turbulence on the cellular detonation structure, the propagation of high-speed deflagrations and the transition from deflagration to detonations. It is recommended that future research should be aimed towards experiments that permit the quantitative understanding of the mechanisms of high-speed turbulent combustion rather towards large-scale tests in complex geometries where minimal quantitative information of fundamental significance could be extracted. In spite of its wide flammability and sensitivity to ignition and detonation initiation, it is felt that hydrogen can be produced, stored and handled safely with the appropriate considerations in the design of the hydrogen facilities. 相似文献