全文获取类型
收费全文 | 264篇 |
免费 | 2篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 1篇 |
环保管理 | 4篇 |
综合类 | 232篇 |
基础理论 | 9篇 |
污染及防治 | 10篇 |
评价与监测 | 7篇 |
社会与环境 | 1篇 |
灾害及防治 | 4篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 11篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 6篇 |
2003年 | 2篇 |
1998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 |
1979年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有271条查询结果,搜索用时 0 毫秒
111.
We describe here the first case of neonatal death due to the hyperornithinaemia, hyperammonaemia, and homocitrullinuria (HHH) syndrome and the first prenatal diagnosis of this disorder in a subsequent pregnancy in this family. 相似文献
112.
Loh-Chung Yu John Williams III MD Boris B. T. Wang Marc Vooljs Heinz-Ulrich G. Weier Masaru Sakamoto Kuang-Lin Ying 《黑龙江环境通报》1993,13(5):355-361
A case is presented in which chorionic villus direct preparation and cultured chorionic villus cells revealed a 47,XX, + mar karyotype. The marker was a small metacentric chromosome and appeared to be i(18p)—isochromosome 18p. Follow-up studies in both amniotic fluid and fetal fibroblasts confirmed the karyotype. In order to characterize the marker, a panel of biotinylated DNA probes was used, including a whole chromosome 18 probe, chromosome 18-specific alpha satellite DNA, Yac clones, and a pan-telomeric probe. These studies show that the marker is a monocentric i(18p) in which about 80 per cent of chromosome 18 alpha satellite DNA has been lost. 相似文献
113.
The sonographic diagnosis of fetal neural tube defects (NTDs) has been enhanced by the recognition of associated brain and skull anomalies. Previous reports have found these anomalies to be accurate in predicting spina bifida after 16 weeks' gestation, and an inverse correlation was suggested between the presence of these sonographic markers and gestational age. Therefore, we assumed that early second-trimester sonography would be at least as accurate as that performed after 16 weeks' gestation. To examine this hypothesis, we looked for the presence of these cranial sonographic markers suggestive of open NTDs in 8011 low-risk cases, using transvaginal sonography (TVS), between the 12th and 17th week of gestation (menstrual age). Fetal NTDs were identified in ten cases (l.25%o). The NTDs were cervico-cranial in three, lumbo-sacral in six, and thoracal in one of the ten cases. None of the seven cases examined was dyskaryotic. Cerebellar dysmorphism, ‘banana’ sign, cerebellar absence, and hypoplasia were detected in all the low NTDs, usually before the detection of the spinal lesion. All the sonographically diagnosed malformations were confirmed by post-abortal examination except in one case, where the patient decided to continue the pregnancy and refused follow-up. We therefore conclude that transvaginal sonographic examination of the fetal skull before the 17th week of gestation is an accurate method for the detection of low NTDs. 相似文献
114.
John Williams III MD Boris B. T. Wang Cathi H. Rubin Robin D. Clark T. K. Mohandas 《黑龙江环境通报》1992,12(3):163-168
A case is presented in which apparent non-mosaic trisomy 16 was found in chorionic villi (direct and culture) obtained from a patient undergoing first-trimester prenatal diagnosis. The fetal karyotype subsequently was determined to be 46,XX by follow-up amniocentesis. Serial ultrasonographic examinations revealed placental sonolucencies and intrauterine growth retardation. At 37 weeks, a small-for-gestational-age female was delivered by Caesarean section for fetal distress. Postnatal cytogenetic studies revealed a normal female karyotype in cord blood and mosaic trisomy 16 in plaental tissues. These findings suggest that in cases where aneuploidy is confined to placental tissues, it may have biological significance, as evidenced by the apparent placental dysfunction and poor fetal growth in this case. 相似文献
115.
Frans J. Los MD Adriana M. Hagenaars Jan Marrink Titia E. Cohen-Overbeek Johannes L. J. Gaillard Helen Brandenburg 《黑龙江环境通报》1992,12(4):285-292
Early second-trimester oligohydramnios was associated with normal maternal serum alpha-fetoprotein (MSAFP) levels in nine out of 26 cases (35 per cent). Congenital malformations of the fetal urinary tract resulting in fetal anuria were present in nine cases; in seven of them, normal MSAFP levels were measured. In contrast, normal MSAFP levels were established in only 2 out of the 17 cases without fetal malformations. These data suggest that fetal urine is the major source of elevated AFP in the maternal compartment in early second-trimester oligohydramnios. This is further supported by the lack of any relationship between concentrations of MSAFP non-reactive with Concanavalin A, originating mainly from the yolk sacderived amniotic fluid AFP pool, and the presence of fetal diuresis. Three out of 26 women had experienced early second-trimester oligohydramnios in a previous pregnancy, suggesting the existence of a recurrence risk for this condition. 相似文献
116.
Caroline Kinnear MSc Maruti Haranal MCh Patrick Shannon MD Edgar Jaeggi MD David Chitayat MD Seema Mital MD 《黑龙江环境通报》2019,39(1):38-44
用溶剂萃取-白土精制法对4种废机油进行了再生研究,萃取过程剂油质量比为3∶1,萃取温度为60℃,减压蒸馏回收溶剂。白土精制过程中白土质量为油质量的10%,精制温度为185℃。精制后4种废机油的密度、凝点、黏度、闪点、酸值等都有不同程度的改善。 相似文献
117.
118.
MD.?Monir.?HossainEmail author Andrew?B.?Lawson 《Environmental and Ecological Statistics》2005,12(3):259-273
This paper illustrates a method based on local likelihood (LL) for detecting disease clusters. The approach is based on estimating
a lasso distance for each region: within which regions are considered to be clustered. An important advantage in implementing
this approach is that it does not require any special Monte Carlo Markov Chain (MCMC) algorithm, e.g., reversible jump MCMC,
which is essential in hidden Markov model approach. Another advantage is that extending the model to incorporate covariates
is straightforward. We illustrate three ways of doing this by using Eastern Germany lip cancer data. By using simulated data,
we have made a comparison with the BYM model [Besag et al. (1991) Annals of the Institute of Statistical Mathematics, 43, 1–59] and the mixture model [Lawson and Clark (2002) Disease Mapping and Risk Assessment for Public Health, Chapman and Hall]. We also did a limited examination of the ability of the LL model to recover true relative risk under
different priors for lasso parameter. In order to check the edge effects, which has been overlooked in many spatial clustering
models for disease mapping but deserves special attention as it lacks observable neighbors, we have adapted here a simple
approach to observe the changes in relative risks when the edge regions are omitted.
An erratum to this article is available at . 相似文献
119.
Ariel J. Jaffa Ariel Many Joseph Hartoov Michael J. Kupferminc M. Reuben Peyser MD 《黑龙江环境通报》1993,13(1):73-77
Congenital malignant tumours are rare. Neuroblastoma is the most common solid tumour, accounting for about 30–50 per cent of tumours evident during the neonatal period. A case of metastatic, rapidly growing neuroblastoma, diagnosed prenatally by ultrasound at 32 weeks' gestation, is presented. 相似文献
120.
The tibial hemimelia syndrome is a rare autosomal dominant condition associated with limb deficiencies. We recently diagnosed this condition in a pregnancy at 16·5 weeks' gestation by ultrasound and a positive family history. To our knowledge, this represents the first case to be detected prenatally. 相似文献