全文获取类型
收费全文 | 636篇 |
免费 | 13篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 64篇 |
废物处理 | 17篇 |
环保管理 | 156篇 |
综合类 | 129篇 |
基础理论 | 150篇 |
污染及防治 | 91篇 |
评价与监测 | 31篇 |
社会与环境 | 18篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 16篇 |
2019年 | 6篇 |
2018年 | 18篇 |
2017年 | 15篇 |
2016年 | 26篇 |
2015年 | 17篇 |
2014年 | 22篇 |
2013年 | 46篇 |
2012年 | 20篇 |
2011年 | 41篇 |
2010年 | 20篇 |
2009年 | 27篇 |
2008年 | 32篇 |
2007年 | 28篇 |
2006年 | 31篇 |
2005年 | 29篇 |
2004年 | 19篇 |
2003年 | 22篇 |
2002年 | 26篇 |
2001年 | 14篇 |
2000年 | 20篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1970年 | 1篇 |
1962年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有660条查询结果,搜索用时 112 毫秒
161.
Mary B. Janicki Christopher G. Fernandez Dorothy Wakefield Jonathan P. Shepherd Reinaldo Figueroa 《黑龙江环境通报》2020,40(2):223-231
To determine if using a checklist of specific ultrasound image criteria to screen the fetal heart improves the cardiac exam completion rate, defined as the ability to classify the heart as normal or abnormal. This is a retrospective cohort study of patients with singleton pregnancies who underwent a fetal anatomy survey between 18 and 28 weeks' gestation. A checklist was used from 1 September 2015 to 31 March 2016 to categorize exams as complete-normal, complete-abnormal, or incomplete. Performance was compared with a 7-month period prior to checklist introduction (1 December 2014 to 30 June 2015). Checklist utilization improved the cardiac exam completion rate by 8.9%. With the checklist, 1083 of 1202 exams (90.1%) were completed compared to 987 of 1193 (82.7%) pre-checklist, P < .001. We did not detect a change in cases classified as abnormal and referred for echocardiography: 25 (2.1%) with the checklist and 16 (1.3%) pre-checklist, P = .16. We did not detect more congenital heart disease (CHD), 12 (1.0%) with checklist screening, 5 (0.4%) pre-checklist, P = .14. Critical CHD was not missed in either group. Using the checklist improved the cardiac exam completion rate. There was no change in congenital heart disease detection. 相似文献
162.
Klinefelter syndrome (KS) or 47,XXY is the most common sex chromosome aneuploidy (SCA), occurring at a prevalence of 1 in 600 male pregnancies. Historically, only 25% of individuals with KS came to medical attention, for a range of issues across the life course including under-virilisation at birth, developmental and social concerns in childhood, absence, delay or arrest of puberty in adolescence or infertility in adulthood. Our understanding of the phenotypic spectrum of KS has been largely influenced by this ascertainment bias. With increasing uptake of antenatal noninvasive prenatal testing (NIPT), a corresponding increase in identification of KS has been documented. Population-based longitudinal data from infancy to adulthood on these individuals is lacking, which impedes balanced antenatal genetic counselling and raises issues for prospective parents and clinicians alike. 相似文献
163.
164.
165.
166.
167.
168.
169.
Castro-Castellon Ana Teresa Hughes Jocelyne Mary Rose Read Daniel Steven Azimi Yaldah Chipps Michael James Hankins Nicholas Peter 《Environmental science and pollution research international》2021,28(22):27731-27741
Environmental Science and Pollution Research - A continuous flow filtration system was designed to identify and quantify the removal mechanisms of Cyanobacteria (Microcystis aeruginosa) by... 相似文献
170.