全文获取类型
收费全文 | 914篇 |
免费 | 64篇 |
国内免费 | 109篇 |
出版年
2024年 | 1篇 |
2023年 | 29篇 |
2022年 | 53篇 |
2021年 | 26篇 |
2020年 | 35篇 |
2019年 | 42篇 |
2018年 | 29篇 |
2017年 | 32篇 |
2016年 | 50篇 |
2015年 | 70篇 |
2014年 | 101篇 |
2013年 | 131篇 |
2012年 | 63篇 |
2011年 | 79篇 |
2010年 | 34篇 |
2009年 | 19篇 |
2008年 | 31篇 |
2007年 | 33篇 |
2006年 | 22篇 |
2005年 | 18篇 |
2004年 | 20篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 11篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 29篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1973年 | 3篇 |
排序方式: 共有1087条查询结果,搜索用时 198 毫秒
941.
942.
Two new species of oribatid mites of the genus Pergalumna (Oribatida, Galumnidae), P. elongatiporosa
sp. n. and P. striatiprodorsum
sp. n., are described from leaf litter of a secondary forest in Costa Rica. Pergalumna elongatiporosa
sp. n. is most similar morphologically to P. horvathorum P. Balogh, 1997 and P. sura P. Balogh, 1997, however, it differs from both by the body size, body surface ornamentation and morphology of notogastral porose areas A1 and A3. Pergalumna striatiprodorsum
sp. n. is most similar morphologically to P. hawaiiensis hawaiiensis (Jacot, 1934) and P. strigulata Mahunka, 1978, however, it differs from P. hawaiiensis by the length of interlamellar setae and surface ornamentation of the prodorsum; from P. strigulata by the surface of ornamentation of the notogaster, length of interlamellar setae and morphology of bothridial setae. An identification key to known species of Pergalumna from the Neotropical region is given. 相似文献
943.
944.
ChiloKey is a matrix-based, interactive key to all 179 species of Geophilomorpha (Chilopoda) recorded from Europe, including species of uncertain identity and those whose morphology is known partially only. The key is intended to assist in identification of subadult and adult specimens, by means of microscopy and simple dissection techniques whenever necessary. The key is freely available through the web at: http://www.biologia.unipd.it/chilokey/ and at http://www.interactive-keys.eu/chilokey/. 相似文献
945.
自县级公立医院改革试点以来,在各领域都有所探索并形成初步的改革思路。但是,在改革中仍有不少关键问题未得到解决,诸如:改革的多元顶层设计思路、补偿机制的持续性与稳定性、地方政府财政压力加重、医院管理体制机制改革未能协同进行、调动和保障医务人员积极性的机制亟待完善、医疗服务定价无法体现医疗服务价值、人才队伍建设滞后、医保基金的使用等。建议下一步县级公立医院改革应在多元化、多层次的顶层设计指导下,坚持公益性与医院经营效益相结合,建立县级公立医院的现代医院管理制度。改革要从创新人力资本管理机制、完善破除“以药补医”后的补偿机制和配套措施、推进法人治理和政事分开、加强医保基金对居民医疗需求的引导、加快医院信息化建设等方向上寻求突破。 相似文献
946.
947.
948.
949.
记述剑盾狭背瘿蜂属Prosaspicera Kieffer 2新种:天目剑盾狭背瘿蜂P.tianmunensis sp.nov.和福建剑盾狭背瘿蜂P.fujianensis sp.nov.以及2中国新记录种:异剑盾狭背瘿蜂P.confusa Ros-Farré,2006和东方剑盾狭背瘿蜂P.orientalis Pujade-Villar,2006,提供了中国该属的分种检索表。模式标本保存于浙江农林大学昆虫标本室。 相似文献
950.
A new species of deep‐living dragonet Callionymus omanensis from Oman is described on the basis of a single male specimen collected in a trawl from 500 m depth off the coast of Oman. The new species is characterized within the subgenus Bathycallionymus by having a small branchial opening; head short (3·9 in proportion to standard length); eye large (2·4 in proportion to head length); preopercular spine with a long, upcurved main tip, with a small antrorse barb and a larger antrorse spine, and with a strong antrorse spine laterally at the preopercular‐spine base, ventral margin smooth; first dorsal fin slightly higher than second dorsal fin (male); second dorsal fin distally straight; 17 pectoral fin rays; distal end of caudal fin slightly pointed, with two median unbranched rays bearing short filaments; first dorsal fin with basal black spot reaching from first to fourth membranes, third membrane with an ocellated distal black blotch; second dorsal fin with vertical dark grey bars; distal three‐fourths of anal fin black; upper half of caudal fin with oblique dark grey bars; pelvic fin dark grey, second ray basally with a black blotch. The new species is compared with similar species. Revised keys to callionymid species of the western Indian Ocean and the Red Sea, as well as species of the subgenus Bathycallionymus, are presented. 相似文献