全文获取类型
收费全文 | 253篇 |
免费 | 2篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 1篇 |
环保管理 | 1篇 |
综合类 | 232篇 |
基础理论 | 9篇 |
污染及防治 | 7篇 |
评价与监测 | 5篇 |
社会与环境 | 1篇 |
灾害及防治 | 3篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2014年 | 1篇 |
2013年 | 9篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 6篇 |
2003年 | 3篇 |
1997年 | 1篇 |
1995年 | 49篇 |
1994年 | 27篇 |
1993年 | 40篇 |
1992年 | 43篇 |
1991年 | 28篇 |
1990年 | 16篇 |
1989年 | 8篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有260条查询结果,搜索用时 15 毫秒
141.
Chowdhury R 《Environmental management》2005,35(6):716-725
Despite advances in short-range flood forecasting and information dissemination systems in Bangladesh, the present system is less than satisfactory. This is because of short lead-time products, outdated dissemination networks, and lack of direct feedback from the end-user. One viable solution is to produce long-lead seasonal forecasts—the demand for which is significantly increasing in Bangladesh—and disseminate these products through the appropriate channels. As observed in other regions, the success of seasonal forecasts, in contrast to short-term forecast, depends on consensus among the participating institutions. The Flood Forecasting and Warning Response System (henceforth, FFWRS) has been found to be an important component in a comprehensive and participatory approach to seasonal flood management. A general consensus in producing seasonal forecasts can thus be achieved by enhancing the existing FFWRS. Therefore, the primary objective of this paper is to revisit and modify the framework of an ideal warning response system for issuance of consensus seasonal flood forecasts in Bangladesh. The five-stage FFWRS—i) Flood forecasting, ii) Forecast interpretation and message formulation, iii) Warning preparation and dissemination, iv) Responses, and v) Review and analysis—has been modified. To apply the concept of consensus forecast, a framework similar to that of the Southern African Regional Climate Outlook Forum (SARCOF) has been discussed. Finally, the need for a climate Outlook Fora has been emphasized for a comprehensive and participatory approach to seasonal flood hazard management in Bangladesh. 相似文献
142.
Gabriel P. Hughes Annie E. Spikes Jeffrey D. Holland Matthew D. Ginzel 《Chemoecology》2011,21(2):99-105
Contact pheromones mediate mate recognition and play important roles in mating systems of longhorned beetles (Coleoptera:
Cerambycidae). One common bioassay of contact chemoreception in cerambycids involves presenting a freeze-killed female to
a male in a Petri dish arena. If the male attempts to mate with the female carcass, it confirms that mate recognition signals
are present and intact and behavior is not involved. Cuticular hydrocarbons are then stripped from the female with successive
solvent washes, rendering her unattractive to males and also resulting in a crude extract containing the cuticular hydrocarbons.
To test the bioactivity of the crude extract, the same female is then treated with the extract and presented again to the
male. Males of some species, including Megacyllene robiniae (F?rster), respond less readily to reconstituted females than to those same beetles before they were solvent-extracted. In
the present study, we test the hypothesis that the contact pheromone of M. robiniae, Z9:C25, exists as a layer on the surface of the epicuticle. We used solid phase microextraction (SPME) to sample cuticular hydrocarbons
of female beetles after they were freeze-killed, solvent washed, and treated with crude cuticular extracts. We found that
extracting cuticular hydrocarbons from females and applying the resulting crude extract back onto the solvent-washed cadaver
scrambles the wax layer and decreases the abundance of the contact pheromone presented on the surface of the insect. 相似文献
143.
144.
145.
146.
MD. Mustafa Rahul Pathak A. K. Tripathi Rafat S. Ahmed Kiran Guleria B. D. Banerjee 《Environmental monitoring and assessment》2010,171(1-4):633-638
Aldrin and dieldrin, structurally similar organochlorine pesticides belong to cyclodiene family and were widely used for agriculture and public health program in India. Although the manufacturing, use and import of aldrin and dieldrin have been banned in India since 2003, these pesticides are still persistent in environment and may be associated with adverse neurological and reproductive effects. The aim of this study is to assess the recent exposure level of aldrin and dieldrin and their placental transfer to fetus in normal healthy full-term pregnant women belonging to north Indian population undergoing normal delivery at Obstetrics and Gynecology department of UCMS and GTB hospital, Delhi. Quantitative analysis of aldrin and dieldrin residues in maternal and cord blood samples were carried out by gas chromatography system equipped with electron capture detector. The results of our study clearly revealed that maternal and cord blood levels of aldrin and dieldrin of pregnant women are age and dietary habit dependent. The aldrin level in maternal blood and dieldrin level in cord blood are higher in women in the age group 25–30 years than in women in age group of 19–24 years. Similarly, aldrin level in maternal blood is significantly higher in women with non-vegetarian dietary habit than in women with vegetarian dietary habit. No significant association is found for maternal and cord blood level. The results of the present study clearly demonstrate prenatal uptake of aldrin and dieldrin and provide recent information on the subsequent transplacental transfer. 相似文献
147.
R. Achiron MD Z. Gottlieb Y. Yaron M. Gabbay U. Gabbay S. Lipitz S. Mashiach 《黑龙江环境通报》1995,15(2):155-160
Our objective was to establish nomograms for fetal eye measurements from 12 weeks' gestation by using transvaginal and transabdominal high-resolution ultrasound techniques. A prospective cross-sectional study was performed on 450 normal singleton pregnancies between 12 and 37 weeks' gestation. Vitreous and lens circumferences were measured by transvaginal ultrasonography until 17 weeks, and by abdominal ultrasound between 18 and 37 weeks' gestation. Regression analyses were used to create nomograms, and several transformations were done to obtain linearity. Eye measurements of 12 fetuses at risk for ocular disturbances were plotted on the constructed nomograms. Linear relationships were fitted between vitreous (r2=0.79) and lens (r2=0.88) circumferences and gestational age. In addition, there was a significant correlation between these measurements and the biparietal diameter. Data of the fetuses at risk showed that disturbances in ocular growth were associated mainly with abnormal cerebral development. These normative data may be helpful in the prenatal diagnosis of suspected congenital syndromes that include, among their manifestations, ocular growth disturbances such as microphthalmos and anophthalmos. 相似文献
148.
G. Martini G. Carillo F. Catizone A. Notarangelo R. Mingarelli B. Dallapiccola MD 《黑龙江环境通报》1993,13(8):763-766
A 49,XXXXX fetus was detected in amniotic fluid cell cultures from a 39-year-old mother. On ultrasonography, growth retardation and bilateral radioulnar synostosis were found. Additional clinical manifestations were mild facial anomalies and hypoplastic ovaries depleted of oocytes. Molecular analysis showed that this aneuploidy arose by successive maternal non-disjunction. 相似文献
149.
Mark T. Cullen MD Sandro Gabrielli Jacqueline J. Green Nicola Rizzo Maurice J. Mahoney Carolyn Salafia Luciano Bovicelli John C. Hobbins 《黑龙江环境通报》1990,10(10):643-651
Thirty cases of cervical cystic hygroma were diagnosed in the first trimester of pregnancy. Karyotype analysis was available in 29 (97 per cent). Fifteen (52 per cent) had a chromosomal abnormality. The ultrasound appearance was described as posterior cervical, lateral cervical, or cervical hygroma with hydrops. Of the 14 euploid embryos, six were electively aborted, two are undelivered, and six have been delivered as phenotypically normal infants. In cases in which the chromosomes were normal and the pregnancy continued, all lesions resolved by 18 weeks. 相似文献
150.
Intrauterine fetal brain death is a rare cause of a fixed fetal heart rate pattern. Seven cases have been previously reported in the literature, but only two of them were diagnosed prenatally and all the newborns died soon after delivery. Two additional cases of antepartum diagnosis of intrauterine fetal brain death, managed expectantly, are reported. We had the unique opportunity to document progressive sonographic cerebral changes during the follow-up period, following the neurological event, while the fetus continued life and growth in utero. The cardiographic and sonographic findings suggesting intrauterine fetal brain death were a prolonged fixed fetal heart rate, even following a vibroacoustic and contraction stress test; an atonic fetus without breathing and body movement; and the appearance of hydramnios and the development of ventriculomegaly. 相似文献