全文获取类型
收费全文 | 54篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
林业 | 1篇 |
农学 | 2篇 |
基础科学 | 2篇 |
4篇 | |
综合类 | 13篇 |
农作物 | 3篇 |
水产渔业 | 2篇 |
畜牧兽医 | 8篇 |
园艺 | 1篇 |
植物保护 | 23篇 |
出版年
2022年 | 2篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1984年 | 1篇 |
1978年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有59条查询结果,搜索用时 46 毫秒
11.
在哈纳斯地区地衣研究的基础上,主要分析石蕊科(Cladoniaceae)地衣的地理区系成分、生态分类,并对保护区环境保护,发展旅游业,生物资源开发与保护和生物多样性研究提供科学依据与参考. 相似文献
12.
Ramesh Chandra Malick Asit Kumar Bera Hemanta Chowdhury Manojit Bhattacharya Tanuja Abdulla Himanshu Sekhar Swain Raju Baitha Vikas Kumar Basanta Kumar Das 《Aquaculture Research》2020,51(6):2410-2420
The disease outbreaks in aquaculture system of wetlands are the major cause of fish mortality. Among various bacterial septicaemic diseases, fish mortality caused by Acinetobacter spp. is recently reported in different fish species. Fish disease outbreak was investigated in a wetland of West Bengal, India to identify the aetiological factors involved. The moribund fish were examined and subjected to bacterial isolation. Two bacterial causative agents were identified as Acinetobacter junii and Acinetobacter pittii by biochemical characterization and 16S rRNA gene amplification. Both the isolates were oxidase‐negative, nitrate‐negative, catalase‐positive and indole‐negative. The molecular identification using 16S rRNA gene sequencing and phylogenetic tree analysis further confirmed the two Acinetobacter spp. with 97%–99% similarity. The antibiotic resistance patterns of these two bacteria revealed that both of them were resistant to β‐lactam, cefalexin, cephalothin, amoxyclav, cefuroxime, cefadroxil, clindamycin, vancomycin and penicillin. In addition, A. pittii was also resistant to other antibiotics of cephams group such as ceftazidime and cefotaxime. In the challenge experiment, both A. junii and A. pittii were found to be pathogenic with LD50 of 1.24 × 105 and 1.88 × 107 cfu/fish respectively. Histopathological examination of gill, liver and kidney revealed prominent changes supporting bacterial septicaemia. The investigation reports for the first time on concurrent infection by A. junii and multidrug‐resistant (MDR)‐A. pittii as emerging fish pathogens to cause severe mortality in Labeo catla and Hypophthalmichthys molitrix in a freshwater wetland. 相似文献
13.
14.
为了查明新疆乌鲁木齐县石人沟地区的地衣物种多样性及其区系和群落特征,在石人沟地区的不同植被带设立16个样点,对地衣进行了样方调查、标本采集和标本鉴定,并对地衣区系成分和生长型进行了分析。结果表明,石人沟地区地衣共有30种,隶属于17属,10科,5目,其中叶状地衣和壳状地衣种类较丰富。地衣区系成分划分为世界广布成分、环北极成分、温带成分、中亚物种和中国特有物种等5个区系成分;按照该地区地衣生长的现状,把其划分为岩面生、树生、藓丛生和地面生等4个类型;该地区地衣的生长型主要以壳状地衣为主,其次为叶状地衣,缺乏枝状地衣种类。同时基于30种地衣及盖度数据,应用双向指示种分析方法(TWINSPAN)和除趋势对应分析(DCA)将该地区的地衣划分为3个样点组,并计算了物种多样性和均匀度指数。 相似文献
15.
An attempt was made to study the effects of oil pollution in a desert location (the Greater Al-Burgan oil fields, an area damaged in the second Gulf War) in Kuwait on the behaviour of the Sand lizard A. scutellatus. Polluted sites with apparently different degrees of contamination (namely tar mat, soot and clear sites) were compared with control areas outside this region. Between 2002 and 2003, ten lizards (5 of each sex) on each polluted and each control site were observed in the field at a time of the year when they were highly active. Air, substrate and burrow temperatures were recorded and lizards were monitored for their morning emergence times, as well as their basking and foraging activities. The present study confirmed that the morning emergence times and the basking behavior varied in sand lizards among the different pollution site categories. Physical changes in the tar mat sites caused the substrate temperatures in these locations to rise more quickly in the morning in response to solar gain than was the case in the other sites. This gives lizards in these locations the opportunity to emerge earlier and to start eating more quickly, giving them an energetic advantage (perhaps, in turn, influencing their rates of growth and fecundity). The clear sites had the next earliest emergence and were the next hottest but it is difficult to account for this in terms of the physical characteristics of this site. The basking times were clearly shorter on the dark soot and tar mat sites that appeared to have higher solar gain than control or clear sites. There did not appear to be any obvious differences in foraging activity of lizards in the different locations. It appears that some aspects of simple behaviour in these lizards provides a reliable, noninvasive indices for assessing oil pollution in desert locations. The precise impact of these changes in these reptiles on their long-term viability needs to be evaluated. 相似文献
16.
17.
Yashika Walia Yogesh Kumar Tanuja Rana Pooja Bhardwaj Raja Ram Pritam Das Thakur Usha Sharma Vipin Hallan A. A. Zaidi 《Journal of General Plant Pathology》2009,75(4):307-311
Apple scar skin viroid (ASSVd) infection is a major limitation to apple fruit quality and causes huge economic losses. In surveys of apple orchards
in the northern Indian state of Himachal Pradesh, fruits with dappling symptoms were noticed. ASSVd was detected from these
fruits and molecularly characterized. Ten clones from three isolates were sequenced, of which seven were new sequence variants
of ASSVd. The clones had significant sequence variability (94–100%) with each other. Variability was more common in the pathogenic
domain of the viroid genome. Four of the clones were 330 nucleotides (nt) long, and the other six had an additional nucleotide.
Phylogenetic analysis showed close affinity of the present isolates with some Chinese and Korean isolates. The study reports
seven new variants of ASSVd and also provides the first molecular evidence of viroid infection (ASSVd) in apple in India. 相似文献
18.
利用东方黄梅和犬地卷微核千分率研究环境污染 总被引:1,自引:0,他引:1
本文通过地衣植物藻类细胞微核检测技术测定了分布于天山菊花台和后峡地区地衣藻类细胞微核千分率(MCN‰)及环境污染指数,并进行了t检查。结果表明(MCN‰)有明显差异。从两个分布区2种地衣细胞观察分析来看,后峡地区地衣藻类细胞的污染指数都在3.5以上,通过t检查也可以看到,差异极度显著所获得的数据表明,后峡区受到严重的污染。 相似文献
19.
20.