全文获取类型
收费全文 | 18010篇 |
免费 | 183篇 |
国内免费 | 163篇 |
专业分类
安全科学 | 512篇 |
废物处理 | 745篇 |
环保管理 | 2497篇 |
综合类 | 2438篇 |
基础理论 | 4805篇 |
环境理论 | 4篇 |
污染及防治 | 5229篇 |
评价与监测 | 1165篇 |
社会与环境 | 837篇 |
灾害及防治 | 124篇 |
出版年
2022年 | 127篇 |
2021年 | 156篇 |
2020年 | 99篇 |
2019年 | 141篇 |
2018年 | 245篇 |
2017年 | 243篇 |
2016年 | 402篇 |
2015年 | 339篇 |
2014年 | 506篇 |
2013年 | 1537篇 |
2012年 | 594篇 |
2011年 | 769篇 |
2010年 | 604篇 |
2009年 | 713篇 |
2008年 | 820篇 |
2007年 | 872篇 |
2006年 | 758篇 |
2005年 | 635篇 |
2004年 | 658篇 |
2003年 | 613篇 |
2002年 | 611篇 |
2001年 | 754篇 |
2000年 | 557篇 |
1999年 | 308篇 |
1998年 | 233篇 |
1997年 | 220篇 |
1996年 | 267篇 |
1995年 | 265篇 |
1994年 | 253篇 |
1993年 | 228篇 |
1992年 | 205篇 |
1991年 | 185篇 |
1990年 | 206篇 |
1989年 | 189篇 |
1988年 | 180篇 |
1987年 | 171篇 |
1986年 | 148篇 |
1985年 | 146篇 |
1984年 | 176篇 |
1983年 | 174篇 |
1982年 | 166篇 |
1981年 | 168篇 |
1980年 | 136篇 |
1979年 | 159篇 |
1978年 | 108篇 |
1977年 | 100篇 |
1976年 | 88篇 |
1975年 | 94篇 |
1973年 | 92篇 |
1972年 | 99篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
251.
252.
253.
254.
255.
J. M. Martinez A. Fortuny C. Comas B. Puerto A. Borrell M. Palacio O. Coll 《黑龙江环境通报》1994,14(8):669-672
A case of body stalk anomaly diagnosed prenatally by ultrasound during the 24th week of pregnancy in a cocaine abusing mother is presented. Accurate visualization of the fetal organs was difficult due to the severe oligohydramnios caused by premature rupture of membranes, probably related to the cocaine use. The sonographic findings were an omphalocoele, fetal attachment to the placenta, kyphoscoliosis, and absence of a floating umbilical cord. The prenatal diagnosis of the syndrome and the possible relationship with cocaine abuse are discussed. 相似文献
256.
G. A. Hackett Dr. J. H. Smith M. T. Rebello C. T. H. Gray D. E. Rooney R. W. Beard F. E. Loeffler D. V. Coleman 《黑龙江环境通报》1991,11(5):311-315
Early arnniocentesis between 11 and 14 weeks' gestation was offered to 110 women at risk of a chromosomally abnormal fetus due to maternal age. Four were found to be unsuitable for the procedure, and 106 early amniocenteses were performed. In 102 cases, clear amniotic fluid was obtained with a single tap. There were two dry taps and two bloodstained tapis; sampling was repeated in three of these cases before 15 weeks. In the fourth case, placental biopsy was performed at 16 weeks. Thus, we were able to obtain a satisfactory sample in all but three cases(2.8 percent). Karyotyping of cells harvested from the early amniotic fluid samples was successful in all the 105 cases. Cell culture from the initial samples revealed a normal karyotype in 99 cases, two balanced translocations, two tetraploid karyotypes, and two cases of pseudomosaicism. Of the 105 pregnancies successfully sampled, there have been two losses to date (1–8 per cent). Two further patients presented with premature rupture of membranes, both pregnancies having successful outcomes. Sixty-two babies have delivered to date, with four congenital anomalies. There were no respiratory problems. Twenty-nine pregnancies are continuing without known complications, and details are not yet available on the remaining 12. The results indicate that early arnniocentesis may replace the traditional test at 15–17 weeks. 相似文献
257.
A case of mosaic 46,XY/47,X,i(Xq)Y is diagnosed at 18 gestational weeks in amniotic fluid cells and confirmed at birth in the lymphocytes of the child. The literature on Klinefelter's syndromes with structural chromosome X rearrangements is reviewed. This is the first case reported of a mosaic isochromosome Xq in a boy. 相似文献
258.
A 46,XX; 47,XX,+9; 47,XX, + ?mar karyotype was detected in an amniotic fluid cell culture and confirmed in a subsequent fetal blood sample from a 40-year-old woman. After termination of the pregnancy, none of the 186 mitoses obtained from a second blood sample was trisomic for chromosome 9 (p<0.001). Selection against cells containing trisomy 9 is postulated to explain the disappearance of the lymphocyte clone. 相似文献
259.
Dr J. L. Carrasco Juan A. Otero Gómez M. C. Vilar Mesa J. L. García Miranda J. M. Troyano Luque O. Morales Ruiz J. Parache Hernández 《黑龙江环境通报》1989,9(6):443-445
A dicentric X chromosome was found in a female fetus during cytogenetic studies performed on amniotic cells. Blood samples from the parents showed normal karyotypes and the pregnancy was terminated. The mechanism for the formation of this ‘de novo’ rearrangement is discussed. 相似文献
260.
Marcy C. Speer Margaret A. Pericak-Vance Larry H. Yamaoka James Koh Wu-Yen Hung Peter C. Gaskell Jr. Jeffery M. Vance Richard J. Bartlett Allen D. Roses 《黑龙江环境通报》1988,8(6):427-437
Accurate carrier testing and prenatal diagnosis in Duchenne muscular dystrophy (DMD) families is facilitated when an Xp21 deletion is found to be segregating within a family. We discuss the results of the DNA testing in two families, one in which DNA from affected males was available for study and the other in which no DNA from an affected male was available. Factors complicating the counselling of DMD deletion families are outlined. 相似文献