全文获取类型
收费全文 | 358篇 |
免费 | 15篇 |
国内免费 | 174篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 3篇 |
环保管理 | 18篇 |
综合类 | 295篇 |
基础理论 | 168篇 |
污染及防治 | 49篇 |
评价与监测 | 3篇 |
社会与环境 | 2篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 11篇 |
2020年 | 19篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 21篇 |
2016年 | 25篇 |
2015年 | 20篇 |
2014年 | 15篇 |
2013年 | 90篇 |
2012年 | 20篇 |
2011年 | 23篇 |
2010年 | 22篇 |
2009年 | 20篇 |
2008年 | 21篇 |
2007年 | 19篇 |
2006年 | 16篇 |
2005年 | 8篇 |
2004年 | 8篇 |
2003年 | 20篇 |
2002年 | 12篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 21篇 |
1994年 | 11篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 5篇 |
排序方式: 共有547条查询结果,搜索用时 218 毫秒
271.
Amira Mahjoubi-Samet Hamadi Fetoui Kamel Jamoussi Khansa Chaabouni Fèriel Ellouze Fadhel Guermazi 《毒物与环境化学》2013,95(4):551-558
The purpose of our study is to assess the effect of chlorpyrifos (CPF) on rat cerebral and cerebellar maturity during the suckling period. Female Wistar rats were given 0.2?g?L?1 of CPF in drinking water, equivalent to 40?mg?kg?1 of body weight?day?1, from day zero until day ten after delivery. In treated pups, plasma butyrylcholinesterase (BuChE) activity was inhibited by 70%. Cerebrum and cerebellum acetyl-cholinesterase (AchE) activities were reduced by 71 and 75%, respectively. The results suggest that CPF was distributed in pup tissues through the milk of lactating mothers, resulting in inhibition of AchE activities. At age 10 days, the CPF-treated pups showed a 28% decrease in body weight, a 23 and 41% decrease in plasma free T3 and T4 levels and reduction in cerebral and cerebellar protein content by 36 and 38%, respectively. Consistent histological changes were found in the cerebellum of CPF treated pups, with the external granular layer being markedly developed, the Purkinje cell bodies being poorly differentiated and abnormally distributed into the internal granular layer. 相似文献
272.
Medicinal herbs are steadily increasing in complementary use for chronic and alterative therapies. The health risks associated with herbal supplements have therefore been identified as a top research priority. Tecoma stans (Tronadora), a Bignoniaceae plant, is a herbal drug traditionally consumed as tea in South America for the control of diabetes. It contains the alkaloids of tecomine and tecostanine which were shown as functional compounds responsible for hypoglycemic activity. However, the side effects of aqueous extracts of this herbal tea have not been reported. In this study, studies sought to evaluate the cytotoxicity of water extracts from T. stans in human hepatoblastoma (HepG2). Toxic effects of T. stans were concentration- and time-dependent in the presence and absence of fetal bovine serum (FBS). Cells were incubated for up to 72-h with varying concentrations of herbal extracts (60–100%), cytotoxicity was determined spectrophotometrically by MTT and reported in terms of % cell viability. For IC50 assay (24 h exposure), cytotoxicity was found at concentration of 60–100%. Evaluation of the effects of T. stans and Brickellia cavanillesi (Asteraceae) in combination revealed that extracts of both herbal extracts' nontoxic levels of T. stans significantly reduced cell viability in a time-dependent manner. Further studies are needed regarding the identification, toxicity, and molecular mechanism of action of active compounds, as well as their cytotoxicity to other cell lines following exposure to both single and combined herbal extracts of these plants with anti-diabetic properties. 相似文献
273.
Nonylphenol (NP) is the final biodegradation product of nonylphenol polyethoxylates, which are widely used as surfactants in domestic and industrial products. NP was reported to exert estrogenic actions and shown to potentially adversely affect reproductive functions. However, NP influence on immune system function remains unclear. To address this issue, the effects of NP on spleen and thymus were examined in this study. Female Sprague-Dawley rats were treated with NP orally at doses of 0, 20, 80, or 200 mg/kg respectively. Data showed that NP increased the levels of natural killer (NK) cells and natural killer T (NKT) cells in peripheral blood and decreased the levels of interleukin-4 (IL-4) and interferon gamma (IFN-γ) in serum. These findings suggest that exposure to NP by oral route may induce adverse effects on the spleen and thymus and affect the immune function of female rats. 相似文献
274.
The present investigation reports the effect of repeated (90 days) administration of carbendazim on the biochemical and hematological parameters in male goats. Carbendazim administered orally at a daily dose of 50 mg kg?1 body weight for 90 consecutive days resulted in increased plasma concentration of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), gamma-glutamyl transferase (GGT), creatinine and albumin, while alkaline phosphatase (ALP) and glucose levels were decreased. Decrease in total leukocyte (TLC) and neutrophil count and increase in lymphocyte count was observed in the treatment group. The findings of the present investigation indicate that sub-chronic exposure to carbendazim in male goats causes hepatic and slight kidney dysfunctions. 相似文献
275.
AbstractThe in vitro anti-inflammatory and antioxidant properties of extract of Oldenlandia auricularia with 70% aqueous alcohol have been evaluated. The inhibition of nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells in lipopolysaccharide stimulated murine macrophage cells was evaluated. Messenger ribonucleic acid levels of tumor necrosis factor-α and cyclooxygenase-2 were analysed by quantitative real time polymerase chain reaction. O. auricularia (100?mg/L) showed better anti-inflammatory and antioxidant activities when compared to its lower doses, whereas the standard drugs curcumin and diclofenac sodium showed significant anti-inflammatory and antioxidant potential. Treatment at this concentration inhibited the signalling pathway of nuclear factor kappa-light-chain-enhancer of activated B cells and messenger ribonucleic acid expression of tumor necrosis factor- α, and cyclooxygenase-2. Liquid chromatography/quadrupole time-of-flight mass spectrometry revealed the presence of previously reported compounds auricularine, ursolic acid and β-sitosterol. The observed anti-inflammatory property of O. auricularia could be due to the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells p65 sub unit nuclear translocation and inhibition of its signalling pathway. 相似文献
276.
The aim of this study was to investigate the nephroprotective and antioxidant property of Manasamitra vatakam (MMV) against aluminum (Al)-induced toxicity in rats. The kidney function marker parameters such as serum urea, uric acid, and creatinine were significantly increased in Al-treated rats as compared with controls. Similarly, the antioxidant enzyme activities such as superoxide dismutase, glutathione S-transferase, Na+/K+-ATPase and Mg-ATPase, reduced glutathione were also found significantly increased in Al-treated rats. A significantly decreased level of these parameters was observed in the MMV (orally 100?mg?kg?1 body weight)-treated group along with a reduced level of malonaldehyde, molecular chaperones of an antioxidative stress protein, and mRNA expression of HSP70. The biochemical observations were also supported by histopathological observations. Thus, this study supports the nephroprotective and antioxidant activities of MMV. 相似文献
277.
The objective of this study was to investigate the effectiveness of the oral administration of Jatropha curcas seed meal (JCSM) on serum biochemical parameters and histopathology of skin, liver, and kidney of rabbits experimentally infested by Hyalomma marginatum marginatum. Thirty healthy mixed-breed rabbits were randomly divided into five equal groups. The first group was kept as a control and fed soya bean meal. The remaining groups were fed diets containing 2.5%, 5%, 7.5%, or 10% JCSM. At the sixth week, each group was divided into two subgroups. Ticks were introduced to all members of one subgroup, the other subgroup being kept as control. Blood samples were collected and analyzed for biochemical parameters before (zero time) and after the treatment, on the 6th and 8th weeks. Histopathological studies were conducted 8 weeks after the treatment. The results revealed that JCSM could be used in the treatment of ectoparasites at levels of less than 10% in the diet without any serious effects on liver and kidney functions. 相似文献
278.
279.
The effects of Ni on hepatic enzymes of tilapia, viz. acid‐ and alkaline phosphatases, catalase and glucose‐6‐phosphatase, both under in vivo and in vitro conditions reflected the following tendencies. In vivo conditions indicated maximal increase in activity for acid phosphatase at 3.00 ppm, equivalent to 28.5%, followed by a slight decrease and increase thereafter. As for alkaline phosphatase, gradual increase in activity was observed with maximal activity at 9 ppm of Ni, equivalent to 16.8%. Catalase demonstrated similar tendencies with maximal activity at 9.0 ppm, equivalent to 101.2%. In the case of glucose‐6‐phosphatase, the tendency was the reverse with maximal inhibition at 9.00 ppm, i.e. 41.9%. In contrast to in vivo conditions, in vitro systems indicated that all investigated enzymes were inhibited in the region of 4–10% except for catalase which demonstrated a slight increase by 5–6% in activity between concentrations of 10–15 ppm of Ni but thereafter continuous inhibitory effects prevailed. At cellular level, exposure of tilapia to a lethal dose of 9 ppm of Ni indicated not much of an adverse effect except for a slight depletion in fat and glycogen content. In the case of mitochondria, they were normal and a few large secondary lysosomes were observed. In relation to the cell membrane no dramatic change was detected. 相似文献
280.
固定化梭形气芽孢杆菌在降解废水时微观形态的观察和比较 总被引:3,自引:1,他引:2
针对含有油墨的废水,筛选到1株微生物菌种,经鉴定为梭形气芽孢杆菌(Aerobacillus fusiformis).分别用海藻酸钙,聚乙烯醇(PVA)和多孔陶瓷作为载体固定化梭形气芽孢杆菌,比较其在处理油墨废水时微观形态的变化情况.通过扫描电子显微镜(SEM)对固定化梭形气芽孢杆菌的微观形态进行观察,发现海藻酸钙在处理含油墨废水时容易溶解,用PVA作为载体时,由于细胞被包埋在PVA内部,和底物的接触时扩散阻力较大,因而废水中COD的去除效率较低.而用多孔陶瓷固定化细胞,不仅简便易行,固定牢固,而且对废水COD的去除效果也较好. 相似文献