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971.
Vitellogenin (vtg) concentrations were measured in plasma and liver samples from 12 hybrid Tilapia oreochromis niloticus x O. aureus to compare concentrations in these tissues. The results were calculated under two different normalizations: volume per gram of sample used (similar to normalization usually published in the literature and typically used for ELISA) and volume per total protein (similar to normalization used in polyacrylamide gel electrophoresis; PAGE). It was observed that the normalization procedure used in PAGE (per gram total protein) minimized the method detection limit by about 1000 and 2500 times in plasma and liver respectively, compared to the normalization usually reported in the literature. It was also observed that normalizing per gram total protein makes it possible to eliminate a potential problem of accidental dilution of plasma samples during sample collection. Moreover, the normalization on a per gram of total protein makes it possible even to compare results from the two different methods namely PAGE and ELISA. It also allows comparison between different tissues. Using the normalization procedures as used in PAGE (per gram total protein) for liver and the normalization method as reported in literature for ELISA (per volume of sample used), it was observed that liver samples had higher vtg levels (mean: 62 microg vtg/g) compared to the corresponding plasma samples (mean: 0.24 microg vtg/ml). However, when both results were normalized per gram total protein all but one liver sample were lower (62 microg vtg/g) than the corresponding plasma concentrations (mean = 246 microg vtg/g).  相似文献   
972.
The results of epidemiological studies in various countries show that radon and its progeny cause carcinogenic effects on mine workers. Therefore, it becomes of paramount importance to monitor radon concentrations and consequently determine the radon dose rates in coal mines for the protection of coal miners. A new calibration curve was obtained for radon concentration estimation using hybrid techniques. A calibration curve was generated using 226Ra activity concentration measured by a HPGe detector-based gamma-ray spectrometer versus alpha-track-density rate due to radon and its progeny on CR-39 track detector. Using the slope of the experimentally determined curve in the units of Becqueral per kilogram (Bq kg-1) per unit alpha-track-density per hour (cm-2 h-1), radon concentrations (Bq m-3) were estimated using coal samples from various coal mines in two provinces of Pakistan, Punjab and Balochistan. Consequently, radon dose rates were computed in the simulated environment of the coal mines. Results of these computations may be considered with a caveat that the method developed in this paper provides only a screening method to indicate the radon dose in coal mines. It has been shown that the actual measurements of radon concentrations in the coal mines are in agreement with the estimated radon concentrations using the hybrid-technique calibration curve.  相似文献   
973.
Sanjad–Sakati syndrome (SSS) is an autosomal recessive disorder characterized by congenital hypoparathyroidism, growth and mental retardation. In Saudi Arabia, the disease is caused by a deletion of 12 bp (155-166nt) in the tubulin-specific chaperone E gene. In a family with two affected siblings with SSS, preimplantation genetic diagnosis (PGD) was performed. Fluorescent PCR (F-PCR) was utilized to check the heterozygosity and the homozygosity status of the parents and the affected children, respectively. F-PCR was then optimized for single-cell analysis by using peripheral blood lymphocytes. The patient underwent a cycle with intra-cytoplasmic sperm injection. A total of 11 embryos were obtained and biopsied. There were five heterozygous, three homozygous affected and three normal embryos. One heterozygous and one normal embryo were transferred because of their very good quality (morula). A singleton pregnancy was obtained, and amniosynthesis confirmed the presence of the heterozygous fetus. These results show for the first time, the feasibility of PGD for SSS. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
974.
Accumulation of lead in different parts of vegetables growing around six Egyptian traffic roads was investigated. Results of this work showed that leafy vegetables such as lettuce and cabbages accumulated lead up to 78.4 p.p.m. in their edible portions while the least lead accumulators were carrots and radish. The highest concentration of lead found in carrots sampled from locations adjacent to the busiest traffic road was 10.2 p.p.m. with an average concentration of 3.8 p.p.m. Lead concentrations in fruits of pepper and tomato were in the range of 0.7–18.6 p.p.m. depending on several factors such as traffic densities and distances from the road. The average ratio between lead in soil to lead in fruit of tomatoes at the first 10 m from roads was about 15 compared with a ratio of 50 at distances more than 100 m. These findings suggest that lead was accumulated in plants through both foliage and root systems, but lead absorption through foliage is more pronounced at locations close to the emission source of lead vapour and fine particles. The concentration of lead in fruit was dependent on its concentration in the leaf rather than in the roots or soil.  相似文献   
975.
The importance of preserving both protected areas and their surrounding landscapes as one of the major conservation strategies for tigers has received attention over recent decades. However, the mechanism of how land-use surrounding protected areas affects the dynamics of tiger populations is poorly understood. We developed Panthera Population Persistence (PPP)—an individual-based model—to investigate the potential mechanism of the Sumatran tiger population dynamics in a protected area and under different land-use scenarios surrounding the reserve. We tested three main landscape compositions (single, combined and real land-uses of Tesso-Nilo National Park and its surrounding area) on the probability of and time to extinction of the Sumatran tiger over 20 years in Central Sumatra. The model successfully explains the mechanisms behind the population response of tigers under different habitat landscape compositions. Feeding and mating behaviours of tigers are key factors, which determined population persistence in a heterogeneous landscape. All single land-use scenarios resulted in tiger extinction but had a different probability of extinction within 20 years. If tropical forest was combined with other land-use types, the probability of extinction was smaller. The presence of agroforesty and logging concessions adjacent to protected areas encouraged the survival of tiger populations. However, with the real land-use scenario of Tesso-Nilo National Park, tigers could not survive for more than 10 years. Promoting the practice of agroforestry systems surrounding the park is probably the most reasonable way to steer land-use surrounding the Tesso-Nilo National Park to support tiger conservation.  相似文献   
976.
Environmental Science and Pollution Research - This study provides insight into the decolorization strategy for crude glycerol obtained from biodiesel production using waste cooking oil as raw...  相似文献   
977.
Environmental Science and Pollution Research - Electronic waste is termed as e-waste and on recycling it produces environmental pollution. Among these e-waste pollutants, polychlorinated biphenyls...  相似文献   
978.
Environmental Science and Pollution Research - Copper deficiency (CuD) is a common mineral disorder in ruminants, which causes histomorphological changes in the heart due to disturbances in...  相似文献   
979.
Environmental Science and Pollution Research - Revival of natural colorants in textile dyeing is one of the important strategies to reduce synthetic chemical-based environmental pollution. The...  相似文献   
980.
Environmental Science and Pollution Research - Per- and polyfluoroalkyl substances (PFASs) are today considered important constituents of the continuously growing substance group of persistent...  相似文献   
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