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681.
682.
我国的生物质废物具有产生量大、可降解有机物含量高的特点,如果能对其进行有效的利用,不但能减少污染,还将会有助于缓解我国能源短缺的现状。介绍了我国生物质废物的污染现状及生物质废物资源化的主要途径,指出我国生物质废物资源化中存在的问题,并提出今后的发展方向及发展对策。 相似文献
683.
684.
685.
山东威海-日照近岸海域浮游细菌的分布特征 总被引:1,自引:0,他引:1
于2006年8月~2007年10月,分春夏秋冬四个航次对山东威海-日照近岸海域进行了现场调查,研究了该海区浮游细菌丰度、生物量及可培养异养细菌生物量的分布特征,探讨了它们与温度、溶解氧、总有机碳、总N、总P和活性磷酸盐之间的关系。结果表明:浮游细菌生物量具有一定的时间、空间分布特征,冬季浮游细菌生物量明显低于其他三个季节,近岸生物量高于远岸区域;浮游细菌丰度及生物量与温度、溶解氧、总有机碳呈非常显著相关关系(P0.01);夏冬季节可培养异养细菌数与总N、总P及PO4-P均呈现显著相关关系,表明以上三种环境生态因子可能是该海域可培养异养细菌生长的限制因子。 相似文献
686.
Transformation of organic matters in fresh leachate during anaerobic
degradation under long hydraulic retention time 总被引:1,自引:0,他引:1
This study investigated the biodegradability of fresh leachate from a young municipal solid waste landfill at the inoculum to substrate
ratios (V/V) of 10/100, 25/100, 50/100 and 100/100, as well as the transformation of organic matters in leachate under prolonged
hydraulic retention time (HRT) of 50 d. Fresh leachate showed a good biodegradability, with chemical oxygen demand (COD) removal
e ciency as high as 87%–92% and cumulative methane yield close to theoretical value (0.35 L CH4/g CODdeg). Methane production
and COD depletion presented biphasic characteristics associated with the successive utilization of two major intermediates, acetate and
propionate. The biphasic degradation of fresh leachate was resulted from the di erent hydrolysis rates of diverse substrates and the
changes in microorganism community structure. After 50 d, the e uents were dominated by high-MW organic compounds (MW > 10
kDa) at each inoculum ratio, which might be refractory compounds released from cell lyses. 相似文献
687.
In order to understand its response towards nickel stress, watercress (Nasturtium o cinale R. Br.) was exposed to nickel (1–25 mg/L)
for 1, 3, 5 and 7 days. The accumulation and translocation of nickel were determined and the influence of nickel on biomass, protein
content and enzymatic antioxidants was examined for both roots and leaves. It was determined that N. o cinale could accumulate
appreciable amounts of Ni in both roots and leaves. Nickel accumulated particularly in the roots of plants. Biomass increased at low
nickel concentrations but certain measurable change was not found at high concentrations. Under stress conditions the antioxidant
enzymes were up-regulated compared to control. An increase in protein content and enzyme activities was observed at moderate
exposure conditions followed by a decline at both roots and leaves. The maximum enzyme activities were observed at di erent exposure
conditions. Our results showed that N. o cinale had the capacity to overcome nickel-induced stress especially at moderate nickel
exposure. Therefore, N. o cinale may be used as a phytoremediator in moderately polluted aquatic ecosystems. 相似文献
688.
In order to understand its response towards nickel stress,watercress(Nasturtium officinale R.Br.) was exposed to nickel(1-25 mg/L) for 1,3,5 and 7 days.The accumulation and translocation of nickel were determined and the influence of nickel on biomass,protein content and enzymatic antioxidants was examined for both roots and leaves.It was determined that N.officinale could accumulate appreciable amounts of Ni in both roots and leaves.Nickel accumulated particularly in the roots of plants.Biomass increased at low nickel concentrations but certain measurable change was not found at high concentrations.Under stress conditions the antioxidant enzymes were up-regulated compared to control.An increase in protein content and enzyme activities was observed at moderate exposure conditions followed by a decline at both roots and leaves.The maximum enzyme activities were observed at different exposure conditions.Our results showed that N.officinale had the capacity to overcome nickel-induced stress especially at moderate nickel exposure.Therefore,N.officinale may be used as a phytoremediator in moderately polluted aquatic ecosystems. 相似文献
689.
介绍了我国生物质资源利用现状及存在的主要问题,以某电厂利用生物质发电为例,从原燃料的用量、污染物排放情况及环境经济效益等方面进行分析,说明利用生物质发电是节能减排的重要途径。 相似文献
690.
Alteration of microbial properties and community structure in soils exposed to
napropamide 总被引:1,自引:1,他引:0
The effect of pesticide napropamide (N,N-diethyl-2-(1-naphthalenyloxy) propanamide) on soil microorganisms for long-term (56 d)
was assessed by monitoring changes in soil microbial biological responses. Soils were treated with napropamide at 0, 2, 10, 20, 40, and
80 mg/kg soil and sampled at intervals of 1, 3, 7, 14, 28, 42, and 56 d. The average microbial biomass C declined in napropamide-treated
soils as compared to control. The same trend was observed on microbial biomass N after napropamide application.We also determined
the basal soil respiration (BSR) and observed a high level in soils treated with napropamide during the first 7 d of experiment. But
with the passage of incubation time, BSR with napropamide decreased relatively to control. Application of napropamide at 2–80
mg/kg soil had inhibitory e ects on the activity of urease and invertase. Activity of catalase was enhanced during the initial 7 d
of napropamide application, but soon recovered to the basal level. The depressed enzyme activities might be due to the toxicity of
napropamide to the soil microbial populations. To further understand the e ect of napropamide on microbial communities, a PCRDGGE-
based experiment and cluster analysis of 16S rDNA community profiles were performed. Our analysis revealed an apparent
di erence in bacterial-community composition between the napropamide treatments and control. Addition of napropamide apparently
increased the number of bands during the 7–14 d of incubation. These results imply that napropamide-induced toxicity was responsible
for the disturbance of the microbial populations in soil. 相似文献