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   57篇
  免费   0篇
林业   4篇
基础科学   3篇
  7篇
综合类   2篇
农作物   2篇
水产渔业   4篇
畜牧兽医   30篇
植物保护   5篇
  2023年   1篇
  2022年   1篇
  2021年   3篇
  2019年   4篇
  2018年   6篇
  2017年   3篇
  2016年   2篇
  2014年   1篇
  2013年   1篇
  2011年   4篇
  2010年   2篇
  2008年   2篇
  2007年   1篇
  2004年   1篇
  1998年   1篇
  1997年   1篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1983年   1篇
  1978年   5篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1967年   1篇
  1966年   2篇
排序方式: 共有57条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Biological activities of cell-free culture filtrate of 3 virulent strains of fish Vibrio were examined to determine the relationship to the pathogenesis of fish vibriosis. Among the 3 strains examined, V anguillarum strains NCMB6 and NCMB571 produced hemolysin and protease, whereas V ordalii strain N7802 did not. Culture filtrate of strain NCMB571 were lethal to rainbow trout and produced a cytotoxic effect on fish cell line. Results revealed that the extracellular products may be involved in the pathogenesis of fish vibriosis.  相似文献   
7.
Gross anatomical examination of the organization of the maxillary artery was carried out in 10 formalin embalmed, latex injected adult donkeys. The results indicate that although there are variations from other domestic animals, the distribution of this artery in the donkey is similar to that of the horse.  相似文献   
8.
The health hazards of individual organophosphorus insecticides have been characterized by their acute toxicity, mainly by investigating their cholinesterase inhibition. However, the chronic effects of most of these toxicants on the drug-metabolizing enzymes have not been investigated. Profenofos (O-4-bromo-2-chlorophenyl O-ethyl S-propyl phosphorothioate) is an organophosphorus pesticide widely used in cotton cultivation. In the present study, we investigated the effect of profenofos on male-specific cytochrome P450 (CYP) enzymes in adult Wistar rats. We orally administered 17.8 mg/kg body weight, twice weekly for 65 days. Profenofos downregulated levels of hepatic and testicular CYP2C11 and CYP3A2 mRNA and protein expression. Testicular aromatase (CYP19A) mRNA was decreased in the profenofos-treated rats compared to controls. Overall, the present study suggests that profenofos acts as an endocrine disruptor of male-specific CYP enzymes and affects testosterone concentration, which implicates its deleterious effects on animal or human males chronically exposed to organophosphorus pesticide.  相似文献   
9.
There is increasing interest in the current conditions of dynamic soil properties and element concentration in the US Great Plains as well as the nature and magnitude of change due to land use and management practices. The study was conducted on Pawnee soil, a major U.S. benchmark soil in the Great Plains. The objectives were to investigate the effects of four common land uses [NoTill (NT), Conventional Till (CT), Grass (G), and Conservation Reserve Program (CRP)] on: i) selected soil properties [total organic carbon (TOC), bulk density (BD), pH, cation exchange capacity (CEC), and electric conductivity (EC)] and ii) water-soluble concentration of 14 heavy metals and micronutrients. The analysis of variance (ANOVA test) indicated that the land use had significant effects on the TOC, CEC, and EC, whereas no relation was detected for BD and pH. Irrespective of land use, the mean element concentration in soil could be arranged in the order: Si (Silicon) > Al (Aluminum) > Fe (Iron) > Mn (Manganese) > B (Boron) > Zn (Zinc) > Cr (Chromium) > Ni (Nickel) > Cu (Copper) > As (Arsenic) > Pb (Lead) > Co (Cobalt) > Mo (Molybdenum) > Cd (Cadmium). Silicon, Al, and Fe which are usually form the major components of soil minerals were present in much higher levels (91 to 308 mg/kg) than other elements in soil. Essential plant micronutrients such as B, Cu, Mn, Mo, and Zn, generally presented moderate levels in soil (7 to 698 µg/kg), whereas toxic heavy metals such as As, Cd, Co, Ni, and Pb were present in the lowest values (0.7–96.2 µg/kg). The ANOVA test indicated land use had significant effects on As, B, Cd, Co, Cu, Ni, and Si concentration in soil while effects were insignificant for other elements. The data proved the important effects of land use on dynamic soil properties as well as nutrient and heavy metal for a major benchmark soil. Thus, more studies on other major soils are warranted. The information is needed to modify and adapt management practices to improve and sustain soil health and water quality in the US Great Plains.  相似文献   
10.
Documentation is a major component of any traceability system where traceability is defined in the ISO Regulation 8402:1994 as the ability to trace the history, application and location of what is under consideration. Traceability systems are record keeping systems designed to track the flow of product or product attributes through the production process or supply chain. All international supply chains are forced to comply with traceability requirements. In this paper, we develop and implement an end-to-end mobile application prototype that traces the poultry production. This application consists of front-end and back-end systems. At the front-end, the worker uses a GPRS enabled handheld device (cell phone, PDA, etc.) to capture information on poultry operations collected at a remote chicken farm and transmit it to a back-end server in the main office. Through customized application the back-end server analyses all information received from the front-end and based on a built-in business process and business rules, intelligently updates various stakeholders of any breach of bio-security measures that requires immediate attention. The proposed system administrators can also access this application via Internet for management decision making. The back-end system consists of web server, defined business application logic and database server.  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