首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   249篇
  免费   18篇
  国内免费   24篇
  2023年   2篇
  2022年   5篇
  2021年   7篇
  2020年   6篇
  2019年   16篇
  2018年   15篇
  2017年   7篇
  2016年   11篇
  2015年   11篇
  2014年   25篇
  2013年   29篇
  2012年   20篇
  2011年   18篇
  2010年   11篇
  2009年   8篇
  2008年   8篇
  2007年   14篇
  2006年   18篇
  2005年   11篇
  2004年   7篇
  2003年   7篇
  2002年   9篇
  2001年   6篇
  2000年   6篇
  1998年   1篇
  1996年   2篇
  1995年   3篇
  1992年   3篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
排序方式: 共有291条查询结果,搜索用时 15 毫秒
1.
2.
Colistin is one of the antibiotics of last resort for human health. However, the dissemination of the plasmid-mediated colistin resistance gene mcr-1 is of great concern globally. In the One Health framework, the environment is an important component for managing antimicrobial resistance. However, little information is available concerning the prevalence of mcr-1 in water environments. We aimed to reveal the prevalence of mcr-1 in different water environments in Hanoi, Vietnam. Quantitative PCR was applied to detect mcr-1 in four urban drainages receiving untreated domestic wastewater, three rivers, five lakes and two groundwater samples. Urban drainages contained higher concentrations of mcr-1, suggesting that urban residents carry the gene. The class 1 integron-integrase gene was identified as a good surrogate of antibiotic resistance genes including mcr-1. A significant correlation was found between the levels of mcr-1 and the human-specific cross-assembly phage, which is an indicator of human faecal pollution. These results indicated that the primary source of mcr-1 in urban water environments is human faeces, which is consistent with the fact that most domestic wastewater is untreated in Hanoi. The control of untreated wastewater is critical for alleviating the spread of mcr-1 in water environments in Vietnam.  相似文献   
3.
The carrageenan-producing red algaKappaphycus alvarezii (Doty) Doty was brought to Vietnam from Japan in 1993. Branch fragments of this species were cultivated in a pond, lagoon, inlet and offshore in Vietnam for the first time. The best daily growth rate (DGR) of plants grown in the lagoon area attained 9–11 % day–1 in May to June (cold season). The water temperature and salinity in this area ranged from 27.2–32.4 °C and 31.4–33.7 °C, respectively. DGR of plants grown in the inlet ranged from 7 to 9% day–1 in June. Grazing by fish has been observed to occur in this area. The DGR of plants grown in the pond ranged from 5–6% in January–July, but decreased to less than 4% day–1 in August (hot season). K. alvarezii in Vietnam showed a carrageenan yield of 18.8–24.6% and gel strength of 1566–1712 g cm–2. These values are similar ones obtained fromK. alvarezii cultivated in the Philippines and Indonesia.  相似文献   
4.
Data concerning the status, habitat, and vocalizations of yellow-cheeked crested gibbons (Hylobates gabriellae) were collected during a short field trip to the Nam Bai Cat Tien National Park (southern Vietnam). Nam Bai Cat Tien may be the southernmost locality where crested gibbons (i.e. theHylobates concolor group) still survive. Fewer songs were heard at Nam Bai Cat Tien National Park than at other crested gibbon sites visited by the author. At least two gibbon groups appear to have been greatly reduced in number since previous surveys in the park. There is some evidence that both the gibbon population and the gibbon habitat in Nam Bai Cat Tien are disturbed. The first case of a great call solo song in wild gibbons of theconcolor group is reported. Great calls ofH. gabriellae are described and documented with sonagrams for the first time. They differ from those previously described forH. leucogenys.  相似文献   
5.
中越边境喀斯特地区有着异乎寻常的植物多样性,已经成为全球生物多样性研究和保护的热点区域,近年来在该区发现了多个苦苣苔科植物的新种或新属。凹柱苣苔属是2010年才被建立的新属,该属的花与叶相比,花较大,叶相对较小,叶片边缘稍外卷,花序仅单花,柱头盘状或凹坑状,蒴果长椭球形而有别于苦苣苔科的其他属。凹柱苣苔属为喀斯特专性植物,目前仅包括分布于黔西南的凹柱苣苔和分布于滇东南的水晶凹柱苣苔两个物种。作者在开展中越边境喀斯特地区植物多样性调查时,在越南北部的河江省发现了水晶凹柱苣苔,基于该新发现居群的植物标本,对其进行了补充描述,确认其花期为11月—12月,并对该物种濒危状况进行了重新评估,同时提供了野外生态照片以资辨认。目前,越南已记录苦苣苔科植物32属150余种,凹柱苣苔属在越南北部的发现,不仅丰富了该国苦苣苔科植物的多样性,再一次充分证明了中越边境喀斯特地区是一个完整的植物区系地理单元,而且为稀有的水晶凹柱苣苔提供了更加丰富的野外本底资料,对其将来的深入研究和保护具有重要的生物地理学和保护生物学意义。  相似文献   
6.
A new temperate wood bamboo endemic to Vietnam is described and illustrated as Chimonocalamus bidoupensis N.H.Nghia & V.T.Tran. The new species is similar to C. baviensis in general appearance, but differs by its densely ciliate culms, culm sheaths that are concave at the apex with dense, white hairs on the abaxial surface of the sheath, and perfect florets 7–8 mm long.  相似文献   
7.
The genus Lasinus Sharp, 1874 of the Pselaphodes complex of genera (Pselaphitae: Tyrini: Tyrina) is revised. The three so far known species, Lasinus mandarinus Raffray, 1890, Lasinus monticola Sawada, 1961 and Lasinus spinosus Sharp, 1874 are redescribed. Eight new species, Lasinus sinicus sp. n. from China, Lasinus mikado sp. n., Lasinus yamamotoi sp. n., Lasinus inexpectatus sp. n., Lasinus yakushimanus sp. n., Lasinus amamianus sp. n., Lasinus saoriae sp. n., and Lasinus okinawanus sp. n. from Japan, are described. And all species are illustrated. Lectotypes are designated for Lasinus mandarinus and Lasinus spinosus. An identification key to species of the genus Lasinus is provided.  相似文献   
8.
Primulina elegans (Gesneriaceae), a new species from Vietnam is described. This species is similar to P. gemella and P. diffusa in having stolons and papillose-hispid leaves, but is easily distinguished from them by having 9–15 cymes and corollas with two brown stripes on the adaxial lip and nine purplish lines on the abaxial lip. Furthermore, Primulina elegans differs from P. gemmella by its broadly infundibuliform corollas with purplish glandular pubescent filaments, and from P. diffusa by having three slightly purplish glandular pubescent staminodes.  相似文献   
9.
An ocular Toxocara canis infection is reported for the first time in Vietnam. A 34-year-old man residing in a village of Son La Province, North Vietnam, visited the National Eye Hospital (NEH) in August 2011. He felt a bulge-sticking pain in his left eye and loss of vision occurred over 3 months before visiting the hospital. The eye examination in the hospital showed damage of the left eye, red eye, retinal fibrosis, retinal detachment, inflammation of the eye tissues, retinal granulomas, and a parasitic cyst inside. A larva of Toxocara was collected with the cyst by a medical doctor by surgery. Comparison of 264 nucleotides of internal transcribed spacer 2 (ITS2) of ribosomal DNA was done between our Vietnamese Toxocara canis and other Toxocara geographical isolates, including Chinese T. canis, Japanese T. canis, Sri Lankan T. canis, and Iranian T. canis. The nucleotide homology was 97-99%, when our T. canis was compared with geographical isolates. Identification of a T. canis infection in the eye by a molecular method was performed for the first time in Vietnam.  相似文献   
10.
A new species group, the Protohermes fruhstorferi group of the dobsonfly genus Protohermes, is recognised. Three species belonging to the new species group are described and illustrated, including one new species from northern Vietnam.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号