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21.
利用原生质体诱变技术筛选脱落酸高产菌株 总被引:5,自引:1,他引:4
以葡萄孢属TB-3菌株为出发菌株制备其原生质体.在纤维素酶浓度为20g/L,蜗牛酶浓度为3g/L的酶解系统中,25℃酶解3h,其原生质体制备数可达67×105mL-1,在KYM上的再生率为46.1%,在KPDA上的再生率为33.6%,经过3轮原生质体紫外线诱变后回复再生,及对大量再生突变株进行发酵筛选,获得高产稳定株TB-3H8,其发酵液中ABA的质量浓度可达1.4g/L 相似文献
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Iniencephaly is a rare and lethal congenital malformation of the neural tube characterized by occipital bone defect, cervical dysraphism, fixed retroflexion of the fetal head and severe lordosis of the cervicothoracic spine. The etiology is unknown. Prenatally diagnosed cases of iniencephaly are rare because careful and early ultrasonographic evaluation is necessary. We present three cases of iniencephaly prenatally diagnosed by sonography at 20–22 weeks' gestation in which therapeutic abortion was induced. The sonographic findings were compatible with the postmortem findings. The present cases of iniencephaly were found to carry unusual associated malformations such as two lobes in the right lung and chorangiosis of the placenta. Only hypoplastic lungs have been reported by previous authors. We also studied the 677C→T mutation on the methylenetetrahydrofolate reductase gene in the parents in one of the present cases. The mother was found to be heterozygous for the 677CT polymorphism. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Paule Bénit Jean-Paul Bonnefont Ali Kara Mostefa Christine Francannet Arnold Munnich Pierre F. Ray 《黑龙江环境通报》2001,21(4):279-283
Tuberous sclerosis (TSC) is a frequent autosomal-dominant condition (affecting 1 in 6000 individuals) caused by various mutations in either the hamartin (TSC1) or the tuberin gene (TSC2). This allelic and non-allelic heterogeneity makes genetic counseling and prenatal diagnosis difficult, especially as a significant proportion of TSC cases are due to de novo mutations. For this reason the identification of the disease causing mutation is mandatory for accurate counseling, yet current mutation detection methods such as single-strand conformation polymorphism (SSCP) or denaturing gradient gel electrophoresis (DGGE) are labor intensive with limited detection efficiency. Denaturing high-performance liquid chromatography (DHPLC) is a high-throughput, semi-automated mutation detection system with a reported mutation detection rate close to 100% for PCR fragments of up to 800 bp. We used a recently described DHPLC assay allowing the efficient detection of mutations in TSC1 to analyze the DNA extracted from a chorion villus sample in order to perform a prenatal diagnosis for TSC. The fetus was found not to have inherited the deleterious mutation and the DHPLC diagnosis was confirmed by haplotype analysis. This represents the first DHPLC-based prenatal diagnosis of a genetic disease. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Abstract: Mate choice by females can introduce difficulties to captive breeding programs because there may be a conflict between the conservation manager's choice of mate (based on random allocation or maximizing heterogeneity) and the females' own preferences, often resulting in incompatibility and aggression. Similar effects are caused by inappropriate social contexts at the time of pairing. We manipulated the social experience of male and female harvest mice ( Micromys minutus ) to investigate whether we could enhance compatibility between randomly allocated mates by altering female preferences. In one experiment, we used a choice test to identify female preferences between two males and then varied the competitive context of unpreferred males by transferring competitor's scent marks into their cages. The manipulation caused them to increase their investment in a form of olfactory signaling (scent marking), which female rodents use as an indicator of male quality when choosing mates. The manipulation increased their attractiveness relative to the initially preferred male when the choice test was repeated. In a second experiment, we tested the effect of females' familiarity with the odor of males by transfer of male scent marks to female cages. Females preferred familiar males in choice tests and were less aggressive toward them when pairs were introduced than females paired with unfamiliar males. This kind of approach can influence mate choice, and transferring scent marks between cages or collections is an effective and practical behavioral means of improving success in conservation breeding programs. 相似文献
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