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621.
以活性污泥ASM2模型为基础,采用混合短链脂肪酸(SCFAs)作为基准物质,建立了增强生物除磷系统中聚磷菌和(PAO)的厌氧/好氧动力学模型.模型的显著特点是厌氧代谢过程中的糖原水解、聚羟基烷酸合成、以及聚磷水解速率由SCFAs的速率方程表示,并考虑了厌氧维持对动力学和计量学的影响.模型建立了过程计量学系数矩阵,包括3个溶解性组分、4个颗粒性组分,同时考虑了pH对代谢动力学的影响.最后,在PAO模型的基础上,建立了GAO的动力学模型,该模型包含7个过程,磷的浓度仅对其好氧生长有影响. 相似文献
622.
Eight typical drinking water supplies in China were selected in this study. Both source and tap water were used to investigate the
occurrence of chlorinated disinfection byproducts (DBPs), and seasonal variation in the concentrations of trihalomethanes (THMs) of
seven water sources was compared. The results showed that the pollution level for source water in China, as shown by DBP formation
potential, was low. The most encountered DBPs were chloroform, dichloroacetic acid, trichloroacetic acid, and chlorodibromoacetic
acid. The concentration of every THMs and haloacetic acid (HAA) compound was under the limit of standards for drinking water
quality. The highest total THMs concentrations were detected in spring. 相似文献
623.
Min Xiao Fengchang Wu Runyu Zhang Liying Wang Xinqing Li Rongsheng Huang 《环境科学学报(英文版)》2011,23(8):1249-1256
Low-molecular-weight organic acids (LMWOAs) in eutrophic lake water of Dianchi, Southwestern China Plateau were investigated
diurnally and vertically using ion chromatography. Two profiles (P1 and P2) were studied due to the difference of hydrochemical
features. Lactic, formic, pyruvic and oxalic acid were detected as major components at P1 and P2 which were on average 7.98 and
6.53 mol/L, respectively, corresponding to their proportions of 2.68% and 2.48% relative to DOC. Pyruvic acid was regarded as the
uppermost species at P1 and P2, reaching up to 3.82 and 3.35 mol/L and accounting for 47.9% and 51.3%, respectively, in individual
TOA. Although humus were of biogenetic production at both sites, the significant negative correlation between diurnal variations
of TOAs, fluorescence intensity (FI) of protein-like components and humic-like components at P1 indicated LMWOAs were greatly
originated from bacterioplankton excretion and degradation. However, correlations between diurnal variations of humic-like FI and
physicochemical parameters demonstrated algal origination of LMWOAs at P2. Although content of humus was high, TOA at P2 was
1.45 mol/L lower than that at P1, due to the co-influence of more intense photo-oxidation and aggregation at P2. Therefore, TOAs
exhibited quite opposite diurnal variation trends of increasing-decreasing and decreasing-increasing at P1 and P2, respectively. Except
for impact of solar radiation, bacterial decomposition and assimilation rendered shifts of maximal LMWOAs along water column at
P1. Covering with massive algae, UV rays penetrated shallower depth that LMWOAs assembled in surface layer water before 18:00 at
P2 and represented decreasing profiles. 相似文献
624.
卤乙酸是饮用水氯化消毒中一类主要的消毒副产物,由于存在的广泛性和潜在的健康危害,许多国家和卫生组织相继将其列为饮用水常规监测项目,而我国至今还没有相关规定;为了更好地控制饮用水中卤乙酸的形成,世界各国科研人员先后研究和开发出了性能逐趋完善的多种分析检测方法;本文在国内外文献调研的基础上,对卤乙酸的各种分析检测方法进行了简要的介绍,并指明了今后的发展方向. 相似文献
625.
采用效果检测、粒径分布与电镜扫描等方法,研究厌氧折流板反应器(ABR)在不同水力停留时间(HRT)下污水中有机物(COD)的转化过程及污泥形态变化特征.结果表明,HRT从15 h到4 h的各运行阶段,COD去除率稳定在90.0%以上.沿程分析表明,当HRT为10、 7.5、 5和4 h时,ABR第一隔室分别承担约90%、 78.56%、 74.18%及58.91%的去碳比重,且承担COD去除的主要功能隔室由第一隔室过渡到第一、二隔室.随着HRT缩短,ABR第一隔室中挥发性脂肪酸(VFAs)总量显著上升.组成分析知,乙酸在总VFAs的比重由51.36%逐渐升高至58.77%,丁酸、丙酸含量相对较少,变化较小.随着运行时间推移,ABR中污泥形态发生显著变化,到111 d时,基本实现颗粒化;同时,沿水流方向颗粒化程度呈递减趋势.扫描电镜(SEM)观察显示,ABR一定程度上存在生物相分离现象,各隔室分别以丝状菌、甲烷多球菌、单球菌和杆菌为主. 相似文献
626.