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991.
废铁屑—H2O2法处理炼油厂含酚废水 总被引:6,自引:0,他引:6
用废铁屑作催化剂,H2O2作氧化剂,对炼厂汽提后含硫废水进行了除酚试验研究,考察了初始PH、H2O2投加量、废铁屑投加量对酚去除率的影响。对含酚量为331.5mg/L的废水,将其初始PH调至7.2,30%H2O2的投加量为7.5mL/L,废铁屑的投加量为3-8g/L,经2h反应后,酚的脱除率可达99.9%。 相似文献
992.
John F. Elder Richard H. Fuller Alexander J. Home 《Journal of the American Water Resources Association》1979,15(6):1608-1617
ABSTRACT: Some physical and chemical characteristics of Lake Perris, a new southern California reservoir, were investigated with regard to their influence on phytoplankton biomass and community structure. The concentration of three major nutrients – nitrogen, phosphorus, and iron – was approximately equivalent to the demand ratio of fresh water plants. Large increases in iron and phosphorus concentrations in late summer due to releases from sediments, however, tended to shift the balance toward a nitrogen-limited situation. Nitrogen limitation favored nitrogen-fixing blue-green algae, and after a decline of competing algae during the summer, the blue-green population bloomed in September. Series of measurements taken over one-day periods during summer stratification showed that some iron, phosphorus, and manganese from the hypolimnion could move upward, corresponding to diel shifts in the thermocline depth. Vertical transport of nutrients could thus occur long before complete lake mixing and could support summer/fall algal blooms. 相似文献
993.
Clean-up techniques, which were developed for removing cationic heavy metals from contaminated soils, are inappropriate for the metalloid As, which is a common and highly toxic pollutant. Because arsenic is mainly found associated with the hydrous ferric oxides of the soil, a possible mechanism for the mobilisation of this element is the reductive dissolution of Fe(III) oxyhydroxides. In this paper we investigate the possibility to mobilise arsenic, using the Fe(III)-reducing bacterium Desulfuromonas Palmitatis. The initial experiments were carried out using a crystalline ferric arsenate as model compound, i.e. scorodite (FeAsO4.2H2O). D. palmitatis was found able to reduce the trivalent iron of scorodite at a percentage of 80% within 16 days, but arsenic remained in the pentavalent state, and reprecipitated with Fe(II) in the form of low solubility ferrous arsenates. To avoid the precipitation of ferrous arsenates the subsequent experiments with soil were conducted by combining the reducing ability of D. palmitatis with the chelating strength of EDTA (ethylenediamine tetracetic acid), which can form strong aqueous complexes with Fe(II). Approximately 60% of Fe and 75% of As were recovered in the aqueous solution in the presence of EDTA, while in the simple biological treatment no Fe was dissolved and only a 3% of As was mobilised. 相似文献
994.
995.
The cycling of iron and sulfur in mine tailings depends on various chemical and microbial reactions. The present study was undertaken in order to assess the role played by populations of sulfate-reducing bacteria (SRB) on the fate of Fe and SO4
2- in Cu–Zn and Au tailings. Samples were taken along a 50-cm deep profile at all sites and analyzed for SRB populations, solid-phase mineralogy and porewater geochemistry. Results indicated that the Cu–Zn tailings were highly oxidized near the surface, as shown by the very low pH, high redox potential, large concentrations of soluble Cu, Zn and sulfate in the porewaters, and the depletion of pyrite. On the other hand, Au tailings were more pH neutral, slightly anoxic, and showed low concentrations of Fe and SO4
2- in the porewaters and very little pyrite oxidation. SRB populations in the Cu–Zn tailings increased with depth, just below the oxic/anoxic interface and were linked to a decline of sulfate and DOC concentrations around the same depths. However, large concentrations of dissolved Fe were also observed around the same depth intervals. Our results suggest that SRB could be involved in sulfate reduction in the Cu–Zn tailings, because the solubility of sulfate was not controlled by the precipitation of sulfate-rich minerals. However, the presence of soluble Fe in the reduced portion of the tailings was also indicative of the presence of iron reducing bacteria (IRB). These bacteria were not enumerated in the present study, but their co-occurrence with SRB has been reported in the past in similar mining environments. The decline of sulfate and the release of soluble iron into the porewaters were also paralleled by a pH increase and the generation of alkalinity. In the Au tailings, SRB populations were generally constant throughout the depth profile and could not be ascribed to sulfate reduction in the porewaters. The solubilities of sulfate and iron in these tailings were partially controlled by jarosite and Fe-oxide minerals. It is then clear that SRB populations could be recovered from various mining sites, but their activity cannot be ascertained based on microbial enumeration and geochemical data. 相似文献
996.
997.
巫志鹏 《中国安全科学学报》2007,17(8):126-130
笔者采用冶金物理化学、炼铁学、炼钢学方法结合系统安全分析方法,现场调查、分析了钢铁企业的生产、安全现状;认为我国炼钢、炼铁企业,从规模、冶炼及连铸过程机理、防护层次等方面看,固有危险性高,且不次于化工行业。钢铁企业本身固有危险性大,生产、设备事故易导致安全事故,防护层次少,生产管理中过于依赖技术骨干的经验,一些企业安全设计存在某些问题,以及管理上的问题,都是钢铁企业事故多发的深层次原因。 相似文献
998.
随着我国钢铁工业的发展,焦化行业进入到一个大发展时期。大量焦炉煤气的产生,为焦炉煤气的合理开发利用提出了新的课题。焦炉煤气的有效利用可产生巨大的经济效益,并且可避免环境污染和二次能源的浪费。 相似文献
999.
M. Amine Dahmani Kunchang Huang George E. Hoag 《Water, Air, & Soil Pollution: Focus》2006,6(1-2):127-141
This study has been conducted at the University of Connecticut (UCONN) in connection with the USEPA Superfund Innovative Technology
Evaluation (SITE) program to evaluate a chemical oxidation technology (sodium persulfate) developed at UCONN. A protocol to
assess the efficacy of oxidation technologies has been used. This protocol, which consists of obtaining data from a treatability
study, tested two in-situ chemical oxidation technologies that can be used on soil and groundwater at a site in Vernon, Connecticut.
Based on the treatability report results and additional field data collected at the site, the design for the field implementation
of the chemical oxidation remediation was completed. The results indicate that both sodium persulfate and potassium permanganate
were able to effectively degrade the target VOCs (i.e., PCE, TCE and cis-DCE) in groundwater and soil-groundwater matrices.
In the sodium persulfate tests (120 hrs), the extent of destruction of target VOCs was 74% for PCE, 86% for TCE and 84% for
cis-DCE by Na2S2O8 alone and 68% for PCE, 76% for TCE, and 69% for cis-DCE by Fe(II)-catalyzed Na2S2O8. The results demonstrate the sodium persulfate's ability to degrade PCE, TCE and cis-DCE. It is expected that given sufficient
dose and treatment time, a higher destruction rate of the dissolved phase contamination can be achieved. The data also indicates
that the catalytic effect of the iron chelate on persulfate chemistry was much less pronounced in the soil-groundwater matrix.
This indicates an interaction between the iron chelate solution and the soil, which may have resulted in a lower availability
of the chelated iron for catalysis. The study showed that the remediation of the VOCs-contaminated soil and groundwater by
in-situ chemical oxidation using sodium persulfate is feasible at the Roosevelt Mills site. As a result, the USEPA SITE program
will evaluate this technology at this site. 相似文献
1000.