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   293篇
  免费   14篇
林业   8篇
农学   6篇
  29篇
综合类   24篇
农作物   9篇
水产渔业   73篇
畜牧兽医   133篇
园艺   1篇
植物保护   24篇
  2023年   1篇
  2022年   4篇
  2021年   6篇
  2020年   6篇
  2019年   4篇
  2018年   8篇
  2017年   5篇
  2016年   8篇
  2015年   13篇
  2014年   11篇
  2013年   10篇
  2012年   16篇
  2011年   24篇
  2010年   16篇
  2009年   10篇
  2008年   30篇
  2007年   14篇
  2006年   22篇
  2005年   16篇
  2004年   14篇
  2003年   10篇
  2002年   11篇
  2001年   8篇
  2000年   5篇
  1999年   2篇
  1998年   2篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1992年   4篇
  1991年   4篇
  1990年   4篇
  1989年   3篇
  1988年   3篇
  1986年   1篇
  1985年   1篇
  1975年   1篇
  1971年   1篇
  1970年   2篇
  1966年   1篇
排序方式: 共有307条查询结果,搜索用时 15 毫秒
1.
A 2-year-old female Japanese domestic cat weighing 3.6 kg was presented due to marked abdominal distention and was diagnosed as hepatic cyst. The bile acid concentration of the hepatic cyst was as low as the serum bile acid concentration. The membrane of the cysts was excised from the edge of the compressed hepatic tissue and no other surgical manipulation was performed. This surgical procedure is simple and quick compared to hepatic lobectomy, however, it is necessary to evaluate the fluid of the cyst before performing this procedure.  相似文献   
2.
The genome of Vibrio anguillarum strain H775-3 was partially determined by a random sequencing procedure. A total of 2,300 clones, 2,100 from a plasmid library and 200 from a cosmid library, were sequenced and subjected to homology search by the BLAST algorithm. The total length of the sequenced clones is 1.5 Mbp. The nucleotide sequences were classified into 17 broad functional categories. Forty putative virulence-related genes were identified, 36 of which are novel in V. anguillarum, including a repeat in toxin gene cluster, haemolysin genes, enterobactin gene, protease genes, lipopolysaccharide biosynthesis genes, capsule biosynthesis gene, flagellar genes and pilus genes.  相似文献   
3.
The effect of bleeding on white muscle quality in amberjack and red sea bream was evaluated by measuring ATP-related compounds, volatile basic nitrogen (VBN), and the trimethylamine (TMA) content. The freshness was evaluated by the K value, and the degree of spoilage was elucidated by VBN and TMA. ATP was rapidly converted to ADP and AMP in the muscle and IMP was the main product of ATP degradation during iced storage. For both species, the IMP content was higher in the muscles of fish that were bled than in those unbled during iced storage. Conversely, the K value and the levels of hypoxanthine (Hx) and VBN were higher in the muscle tissue of unbled fish than in the bled tissue of both species. Similarly, the TMA content was higher in the unbled muscle tissues of both species after a week of storage.  相似文献   
4.
5.
6.
Strains of the Japanese pear pathotype of Alternaria alternata were screened for double-stranded RNAs (dsRNAs). Four strains had several dsRNAs; strain N18 was associated with several dsRNAs and had impaired growth phenotypes such as irregular mycelium and abnormal pigmentation. We isolated dsRNA-cured isolates from strain N18 by single-conidium isolation. The dsRNA-cured isolates had recovered normal growth and pigmentation. Enlarged vesicles were observed in mycelial cells of the original dsRNA-carrying N18 strain. DAPI nuclear staining revealed regression of the nuclei in dsRNA-carrying N18 cells. These results indicate that the dsRNAs might have negative effects, such as apoptosis-like cell death, on the host fungus.  相似文献   
7.
To establish a method to predict postpartum diseases using prepartum back fat thickness (BFT), the peripartum BFTs of 54 healthy multiparous cows before calving, which were diagnosed with postpartum displacement of the abomasum (DA), clinical ketosis or subclinical ketosis were compared with those of healthy cows from 8 weeks before the expected calving date to 8 weeks after calving. The peripartum BFTs of the cows with DA or clinical ketosis were significantly higher than those of healthy cows. The peripartum BFTs of the cows with subclinical ketosis were not significantly higher than those of the healthy cows.  相似文献   
8.
The masticatory muscles and their related structures of the skull were observed in the Indian gavial (Gavialis gangeticus), the false gavial (Tomistoma schlegelii), and the African slender-snouted crocodile (Mecistops cataphractus) to detail some morphological differences in comparison with the other crocodile species, and to compare and elucidate the functional strategy of themasticatory apparatus in these long-snouted species. The Musculus pterygoideus posterior was relatively smaller in the three species compared with many short-snouted crocodiles. It suggests that the masticatory power in fish-eating long-snouted species is not so high as in the short-snouted crocodiles, while the masticatory muscles were morphologically different among the three long-snouted species as follows. The M. pterygoideus posterior of the false gavial was extended in the lateral side of the lower jaw unlike the Indian gavial. The M. pseudotemporalis and the Fenestra supratemporalis were largely developed in the Indian gavial, however we suggest that the other two species possess the weak bundles in this muscle. The false gavial and the African slender-snouted crocodile have the pterygoid bone well-developed extending dorso-ventrally and it is suggested that the M. adductor mandibulae posterior attached to the pterygoid bone may be much larger than the Indian gavial. These data morphologically clarify the masticatory mechanism in the long-snouted crocodiles different from the short-snouted species, and demonstrate that the evolutional strategy to share the functional role in the masticatory muscles have been differently established between the Indian gavial and the other two species. We also obtained the morphological data in the fossil skull of the Machikane crocodile (Toyotamaphymeia machikanense) and concluded from the fossil characters that the considerable developments of the M.pterygoideus posterior and the M.pseudotemporalis in this species had not morphologically been consistent with both the Indian and false gavials.  相似文献   
9.
10.
In order to understand the kraft pulp decolouring mechanism on using a nonionic detergent, the pulp washing process and the resulting pulp handsheets were investigated by examining the brightness, kappa number, thioacidolysis product yield, and dewatering efficiency in the pressing sheet making process. The pulp decolouring could be attributed to a decrease in the lignin content and an improvement in the dewatering efficiency. Furthermore, the detergent distribution in the aqueous pulp suspension obtained during the pulp washing process was visualised using cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM). The detergent was clearly observed at the transverse surface of the pulp fibre cell wall and was also detected in the lumen of the fibres, suggesting the permeation of the detergent into the pulp fibre cell wall. Based on these results, the pulp decolouring mechanism can be proposed as follows: the detergent permeates into the pulp fibre cell wall and promotes the solution-exchange between the inside and the outside parts of the fibre cell wall, finally washing away the chromophoric substances such as lignin and its degradation products owing to the enhanced dewatering efficiency.  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