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991.
Decolorization of reactive Brilliant Blue KN-R by immobilized cells of Aspergillus ficuum 总被引:2,自引:0,他引:2
Aspergillus ficuum was immobilized with sodium alginate, and decolorization of Reactive Brilliant Blue KN-R was studied on immobilized and free Aspergillus ficuum. The optimal preparation condition of the strain immobilization was obtained by the orthogonal test, it is sodium alginate 3%, CaCl2 5%, wet mycelia 30 g/L, calcific time 8 h. It was found that the immobilized cells could effectively decolorize Reactive Brilliant Blue KN-R, the optimum temperature and pH were 33℃ and 5.0, respectively. The kinetics study of decolorization of immobilized cells showed that the decolorization of Aspergillus ficuum immobilized conformed to zero-order reaction model. The decolorization efficiency of immobilized cell compared with that of free cell in different physical conditions. Results showed that the decolorization of immobilized cells with mycelia had the best efficiency. The immobilized cells could be reused after the first decolorization. 相似文献
992.
993.
The detection of maternal cells in amniocyte cultures is thought to be due to the outgrowth of cells from small fragments of maternal tissue removed by the amniocentesis needle. An unusual case is reported in which maternal cell contamination (MCC) was found in the cell cultures from a woman in two different amniocenteses from two consecutive pregnancies. Both pregnancies were complicated by the presence of fibroids and the fibroid tissue may have been the source of the maternal cells. A history of an amniocentesis in which there was MCC of cell cultures, or the detection of fibroids, may pose an additional risk for MCC attributable misdiagnosis in prenatal genetic studies. 相似文献
994.
Adaptations of the techniques of modern molecular biology to prenatal diagnosis has opened new avenues for the detection of genetic diseases. We have taken advantage of the rapid adhesion of colony forming cells in cultured amniotic fluid samples to develop an improved method for molecular diagnosis. By employing the cell adherence regime sickle cell diagnosis using Mst II can be undertaken directly. In addition, hybridization with a cloned repetitive sequence that is of Y origin and has limited autosomal homology permits rapid fetal sexing in 3 to 4 days without compromising conventional cytogenetic or biochemical analysis. This combination of techniques provides a useful adjunct to convential prenatal genetic diagnosis in the second trimester. 相似文献
995.
以南通市为例,探索宏观层面的城市人居环境生态评估方法.通过统计、整理南通市人居环境数据资料,建立城市人居环境宏观评估模型及其评估指标体系(共25项指标),进而分析并评价南通市人居环境整体现状. 相似文献
996.
John Williams III Arnold L. Medearis Weimei H. Chu George D. Kovacs Michael M. Kaback 《黑龙江环境通报》1987,7(5):315-322
Maternal cell contamination of chorionic villi (CV) samples used for first trimester prenatal diagnosis can cause obvious and/or unrecognized diagnostic dilemmas. The purpose of this investigation is to assess the frequency of maternal cell contamination (MCC) in chorionic villus samples and to evaluate selected parameters which might predict where contamination is more likely to have occurred. Maternal lymphocytes, chorionic villi from ultrasonically directed transcervical catheter aspiration, and fetal tissue were obtained at 8–11 weeks gestation from 45 patients undergoing elective termination. Quinacrine (Q) banded metaphases were compared from duplicate direct preparations of chorionic villi; cultured chorionic villi, fetal fibroblast tissue cultures, and maternal lymphocyte cultures. Q-polymorphisms in metaphase chromosomes were 100 per cent concordant between fetal tissue and direct CV preparation. However, evidence for maternal cell contamination occurred in 13.1 per cent of cultured chorionic villi preparations where polymorphisms were found to be identical between maternal and cultured CV and both distinct from fetal tissue preparations. Where MCC was identified, it was noted that CV cell cultivation interval was prolonged (24.2±6.8 days) compared with non-contaminated cultures (14.1±4.4 days) (p <0.05). We conclude that maternal cell contamination is a significant problem with chorionic villus sampling. Where direct preparations are not employed or when cultures are ‘slow growing’, MCC may be a significant and unrecognized complication re: fetal diagnosis. Direct preparations, multiple cultures, quinacrine banding, and maternal Q-polymorphism comparisons can minimize diagnostic dilemmas secondary to maternal cell contamination. Q-polymorphism comparisons between maternal and fetal chromosomes should be included in all instances where cultured chorionic villi are utilized for fetal diagnosis and where direct preparations are not available. 相似文献
997.
Dr M. Bergere J. Selva M. Baud M. Volante B. Martin J. N. Hugues F. Olivennes R. Frydman M. Auroux 《黑龙江环境通报》1995,15(9):835-841
We performed fluorescence in situ hybridization (FISH) with a chromosome 18-specific probe on human abnormal cleaved embryos, fertilized either by two spermatozoa and exhibiting three pronuclei (3 PN) or normally fertilized and exhibiting two pronuclei (2 PN) with subsequent severe fragmentation and/or blocking. The aim of the study was to evaluate the incidence of chromosome 18 anomalies among these embryos, in order to evaluate the FISH efficiency on such material and to obtain more precise and complete data than those obtained with classical cytogenetic analysis. For the 3 PN cleaved embryos, FISH confirmed the frequent regulation towards diploidy (25 per cent) and the high frequency of mosaics (53 per cent). For the 2 PN blocked or damaged embryos, FISH permitted chromosome evaluation, which was otherwise impossible with classical cytogenetic techniques: we also found a high mosaic frequency (45 per cent) with these embryos. If this frequency were the same for normally developing embryos, it would be a major obstacle to the reliability of either chromosomal or genetic preimplantation diagnosis. 相似文献
998.
Jean Mossman A. D. Patrick A. H. Fensom Linda R. Tansley P. F. Benson V. M. Der Kaloustian Gertrud Dudin 《黑龙江环境通报》1981,1(2):121-124
Contamination of amniotic fluid cell cultures by maternal cells can be expected to lead to misdiagnosis of fetal genotype in 0·1 to 0·5/100 cultures, when assays are carried out directly on cultured cells. Chemical analysis of the cell-free amniotic fluid supernatant may overcome this source of error and has the added advantages of speed and independence from amniotic cell culture failure. We describe a pregnancy at risk for Hurler's disease where amniotic cells cultured at amniocentesis had a female karyotype and an α-iduronidase activity towards both phenyl and 4-methylumbelliferyl substrates at the lower end of the normal range, suggesting a heterozygous fetus. An affected fetus was predicted, however, because of a high concentration of dermatan sulphate in the amniotic fluid. The discrepancy between these findings was shown to be due to maternal cell contamination of amniotic fluid cell cultures by the birth of a male infant with Hurler's disease. 相似文献
999.
浅谈环境噪声的危害与控制 总被引:2,自引:0,他引:2
通过了解噪声的来源;具体分析了噪声对人体的危害,不同的噪声,级别不同,对人体的健康影响程度也不同,尤其是长期接触噪声的工作人员。如何有效地防治噪声,从噪声源、传播途径及个人防护方面进行了具体的分析。 相似文献
1000.
固定化细胞技术处理含酚废水的研究 总被引:9,自引:0,他引:9
固定化细胞技术的关键是所用载体材料的性能。本文力求寻找一种价格低、寿命长、效率高的载体。通过同一菌种在固定状态和游离状态降解含酚废水的实验对比,证明红砖碎粒是一种优良的载体材料。利用正交实验,确定了该菌种在固定时的最佳运行条件。并对游离细胞和固定细胞降解苯酚的过程进行了动力学分析。结果表明,在两种情况下,该菌种降解苯酚的过程均符合Monod模型。 相似文献