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   14篇
  免费   1篇
  2篇
水产渔业   1篇
畜牧兽医   12篇
  2016年   1篇
  2014年   1篇
  2010年   1篇
  2007年   2篇
  2006年   2篇
  2005年   1篇
  1997年   1篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
排序方式: 共有15条查询结果,搜索用时 156 毫秒
1.
中草药提取技术的概述   总被引:1,自引:0,他引:1  
简述了中草药的系列提取方法及其应用。其中对101-澄清剂提取法作了较详细的介绍,因为该法是目前应用最广、效果最好、简易可行、经济实用的可替代醇沉法的一种新型提取方法。  相似文献   
2.
This study compares the details and performance of fisheries management between the EU and a selection of other countries worldwide: Iceland, New Zealand, and Australia, which are considered in many respects to be among the most advanced in the world in fisheries management. Fisheries management in the EU, Iceland, Australia, and New Zealand has developed following different paths, despite being based on similar instruments and principles. Iceland, Australia, and New Zealand have been at the forefront of developing management practices such as stakeholder involvement, legally binding management targets (Australia, New Zealand), individual transferable quotas, and discard bans (Iceland, New Zealand). The EU has since the beginning of the 21st century taken significant steps to better involve stakeholders and establish quantitative targets through management plans, and a landing obligation is gradually being implemented from 2015 onward. The management of domestic fisheries resources in Australia, New Zealand, and Iceland has, overall, performed better than in the EU, in terms of conservation and economic efficiency. It should, however, be stressed that, compared to Australia, New Zealand, and Iceland, (i) initial over‐capacity was more of an issue in the EU when management measures became legally binding and also that (ii) EU has been progressive in developing common enforcement standards, on stocks shared by sovereign nations. The situation of EU fisheries has substantially improved over the period 2004–2013 in the northeast Atlantic, with fishery status getting close to that in the other jurisdictions, but the lack of recovery for Mediterranean fish stocks remains a concern.  相似文献   
3.
A fast, one-step gas chromatographic method was developed to analyze trimethylsilyl (TMS) derivatives of sugars, fruit acids, and ascorbic acid in sea buckthorn (Hippoha? rhamnoides L.) berries. The method was applied to berry press juice of sea buckthorn of different origins grown in Finland during the 2003 and 2004 seasons. The method gave reliable results for D-fructose, D-glucose, ethyl-D-glucose, and malic, quinic, and ascorbic acids, which are the major sugars and acids in sea buckthorn juice. For the first time in sea buckthorn and evidently in any berry, the presence of ethyl beta-D-glucopyranoside is reported. The structure of ethyl glucose was verified by high-performance liquid chromatography (HPLC), gas chromatography (GC), MS, and NMR analyses of both the isolated and the synthesized compounds. In the GC method, vitamin C was analyzed as ascorbic acid only, and dehydroascorbic acid was thus not taken into account.  相似文献   
4.
Objective To investigate wool organophosphorus concentrations resulting from a range of farm pesticide application methods.
Design Random sampling of wool for pesticide residues and on-farm interviews to determine associated treatments.
Procedure Tasmanian fleece wool lots were sampled at random and tested for organophosphorus residues. The grower was identified and the pesticide treatments applied to the sheep were ascertained by on-farm interview.
Results The residue concentrations showed a large variation that was not accounted for by differences in treatments by growers. Organophosphorus concentrations were proportional to the number of treatments applied, and inversely related to the time between pesticide application and the subsequent shearing, and were significantly influenced by the method of application. After allowing for the time of application, plunge dipping resulted in pesticide residue concentrations 2 to 2.5 times greater than shower dipping, using spray races or hand jetting, and the use of these methods caused larger residues than the use of jetting races.
Conclusions We recommend that plunge or shower dipping should not be used more than 7 weeks after shearing, nor at higher concentration than the standard dose rate used for lice control, whereas jetting may be satisfactory for up to 7 months after shearing, provided only one application is administered.  相似文献   
5.
6.
7.
8.
The influence of trehalose on European mouflon spermatozoa cryopreservation during the non-breeding season was tested. Semen was frozen in two different extenders: (a) recommended Tris-based ram extender (CTR); (b) CTR extender supplemented with trehalose 0.147 mm (TRH). Sperm viability and acrosome integrity were assessed using propidium iodide and fluorescein isothiocynate labelled Pisum Sativum agglutinin. Trehalose significantly enhanced sperm viability after thawing compared with CTR extender (62.7% vs 51.8%; p < 0.05), whereas no differences were observed on acrosome integrity (42.9% vs 42.1%). Trehalose influence was also evidenced in the in vitro fertility test performed with sheep oocytes matured in vitro. Both fertilization rates (60.9% TRH vs 43.6% CTR; p < 0.05) and cleavage rates (58% TRH vs 39.8% CTR; p < 0.001) were higher for trehalose frozen semen compared with control extender frozen semen. A higher percentage of zygotes resulting from fertilization with trehalose cryopreserved semen presented the first cleavage earlier if compared with the group fertilized with control semen (48.7% vs 31.5%, respectively; p < 0.01). This result was confirmed by embryo kinetic development. Fertilization with trehalose cryopreserved semen leaded to an higher percentage of blastocysts (40.2% vs 27.8% CTR; p < 0.05), and enhanced in particular the number of blastocysts that developed on the day 6th of culture (28.6% vs 17% CTR; p < 0.05). Our data demonstrated that, during mouflon non-breeding season, trehalose extender enhances spermatozoa viability and its in vitro fertilizing capacity, allowing the production of an higher number of blastocysts.  相似文献   
9.
Hydrolysis of extracellular phytate (InsP(6)) by high-phytase yeast strains and survival of yeast cells were studied at simulated digestive conditions using yeast peptone dextrose growth medium and wheat gruel as model meals. An in vitro digestion method was modified to better correlate with the gastric pH gradient following food intake in vivo. High-phytase yeast gave a strong reduction of InsP(6) (up to 60%) in the early gastric phase, as compared to no degradation by wild-type strains. The degree of InsP(6) degradation during digestion was influenced by the type of yeast strain, cell density, and InsP(6) concentration. Despite high InsP(6) solubility, high resistance against proteolysis by pepsin, and high cell survival, degradation in the late gastric and early intestinal phases was insignificant. Dependency on pH for phytase expression and/or activity seemed thus to be an important limiting factor. Although further studies are needed, our results show the potential of using yeast as a phytase carrier in the gastrointestinal tract.  相似文献   
10.
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