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   47篇
  免费   6篇
林业   1篇
农学   1篇
  8篇
综合类   1篇
农作物   7篇
水产渔业   10篇
畜牧兽医   19篇
园艺   2篇
植物保护   4篇
  2022年   2篇
  2019年   3篇
  2018年   7篇
  2017年   4篇
  2016年   1篇
  2015年   2篇
  2013年   1篇
  2012年   4篇
  2011年   4篇
  2010年   2篇
  2009年   1篇
  2008年   2篇
  2007年   6篇
  2006年   2篇
  2005年   2篇
  2004年   1篇
  2003年   1篇
  2000年   1篇
  1996年   1篇
  1993年   1篇
  1982年   1篇
  1980年   1篇
  1979年   2篇
  1973年   1篇
排序方式: 共有53条查询结果,搜索用时 46 毫秒
1.
Concept maps have become a ubiquitous tool in education in the last 20 years and are used extensively to teach scientific concepts. A concept map is a tool learners can use to organize information about a topic in terms of key concepts and the relationships among them. As a graphical representation, the map provides an overall picture of a particular concept or topic. This article describes how we have used concept maps to teach physiology to veterinary medical and veterinary technician students enrolled in our on-campus and distance-learning programs.  相似文献   
2.
A 14 week experiment was carried out to study the effects of replacing three different levels (33%, 66%; and 100%;) of berseem leaf meal (BLM) by leucaena leaf meal (LLM) treated in four different ways (drying for 48 h at 60 C, autoclaved for 15 min, sprayed with 1% sodium hydroxide and incubated with rumen liquor for 24 h). Groups of Nile tilapia, Oreochromis niloticus (L.), fingerlings (5.07 g mean weight) were fed one of 13 isonitrogenous (30% crude protein) and isocaloric (19.67 kJ per g dry matter) diets, with two replicates (10 fish per aquarium) for each treatment. The results indicated that weight gain, specific growth rate, feed conversion ratio and protein utilization parameters were significantly (p < 0.05) increased by the higher percentage of dried or cooked LLM in tilapia diets. On the other hand, the lowest growth performance and feed utilization parameters were observed in the groups fed LLM diets treated with sodium hydroxide or incubated with rumen liquor. Carcass protein and fat increased significantly (p < 0.05) with increasing levels of LLM and simultaneously decreasing ash content.  相似文献   
3.
Three objectives were included in this research work. The first objective compared different immune components in healthy mature males, mature females, and female kids of local and imported Saanen goats, reared under a sub-tropical environment. The significantly differing immune components were the blood monocyte percent, blood CD8 count, and the total white blood cell count. The second objective compared the performance of Saanen versus local does. The means of the milk yield and prolificacy of the imported Saanen does were significantly higher than those of the local does (p < 0.05). The third objective compared the immune responses (hemagglutination-HA titers) and complement fixation (CF) titers in mature does of the two breeds to chicken red blood cells (c-RBC). The HA titers showed a significant seroconversion only in imported Saanen (p < 0.05) but not in local does; however, the CF titers increased significantly at 4 weeks following priming with c-RBC in local (p < 0.05) but not in the imported Saanen does. The impact of the differences in blood immune components and responses to antigens in the compared goats on protection potential against prevalent diseases in the sub-tropical zone of the eastern Mediterranean countries is discussed.  相似文献   
4.
Protein hydrolysates from Chinese sturgeon were prepared using Alcalase 2.4L enzyme. Under the optimum conditions (enzyme–substrate ratio of 3.5%, pH of 8.5, and temperature of 55°C), the degree of hydrolysis (DH) was 13.8%, 16.7%, and 19.1% after 1, 3, and 6 h, respectively. The contents of crude protein and amino acid increased at DH of 19.1% to 86.97% and 78.29%, respectively. There was an obvious increase in the low-molecular-weight peptides, which could enhance the hydrolysate’s functional properties such as solubility, representing more than 90% at different pH levels. The obtained protein hydrolysates revealed good emulsification properties and high oil absorption. Furthermore, good antioxidant activities such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) inhibition, ferric reducing power, and ferrous ion (Fe2+) chelating ability were attained depending on the solution concentration. The findings indicate that the functional and antioxidant properties of protein hydrolysates could be useful in many applications of the food industry.  相似文献   
5.
Nuclear magnetic resonance ‐based metabolomics was applied to study effects of egg aging on ovarian fluid metabolites in rainbow trout, Oncorhynchus mykiss. The eggs of three females were pooled and then assigned to three plastic vials for 18 days in vitro storage at 4°C. Ovarian fluid samples were taken 0, 6, 12 and 18 days after storage. Three groups of metabolites including amino acids, osmolytes and energy metabolites were found to change during storage period. The glucose levels of ovarian fluid showed significant decreases on days 12 and 18 after storage (< .05). For acetoacetate and acetate, significant increases were observed, respectively, on days 12 and 18 after storage (< .05). The creatine levels of ovarian fluid increased significantly on days 12 and 18 after storage (< .05). Lactate levels in ovarian fluid elevated during storage period (< .05). Glycerol levels showed a significant increase on days 12 and 18 after storage (< .05). The values of osmolytes in ovarian fluid (e.g., betaine, taurine, trimethylamine‐N‐oxide, N,N‐dimethylglycine) showed a decreasing trend on day 12 which continued until the end of storage on day 18 (< .05). Almost all amino acids elevated on days 12 and 18 after storage (< .05). After an apparent elevation in isoleucine levels on days 6 and 12, this amino acid decreased on day 18 after storage (< .05). The osmolytes might act as antioxidant against free‐radicals produced as a result of over‐ripening. Glucose can be used as energy resource for eggs and bacteria during ova storage. Also, change pattern of amino acids indicate hydrolysis of proteins as the time of storage increases.  相似文献   
6.
The plant pathogenic oomycete, Phytophthora infestans, is the causal agent of late blight disease in tomato and potato. For characterizing Egyptian P. infestans isolates by DNA marker analysis, 40 isolates of P. infestans were collected from different locations in Egypt during two growing seasons (2012/2013 and 2013/2014). The 40 isolates were grouped into seven genotypes, in which 24 alleles were detected. The identified genotypes were not completely associated with geographic location and sample collection years. These results provide genetic and geographical information for developing a program to manage late blight disease.  相似文献   
7.
Chemical investigation of the Mediterranean sponge Sarcotragus spinosulus led to the isolation of a new hydroxylated nonaprenylhydroquinone, along with two known metabolites, hepta- and octaprenylhydroquinones. The structure of the new metabolite was assigned by extensive 1D and 2D NMR analyses and MS studies. The antileukemic effect of the three compounds towards the chronic myelogenous leukemia (CML) cells line K562 was also evaluated.  相似文献   
8.
This study aimed to evaluate the efficacy of semi fermented and non fermented Camellia sinensis extracts (Black and Green tea) and comparison between them against Streptococcus mutans ATCC 25175, S. mitis ATCC 9811 and S. sanguis ATCC 10556 that are responsible for dental caries and bacteremias following dental manipulations. Minimum inhibitory concentrations of both tea extracts were assessed by Well diffusion and Broth dilution methods and examination of cell adherence (Biofilm inhibitory concentrations) was observed on glass slides under phase contrast microscope and colony counts from glass beads. Concentration of 1 mg mL(-1) of semi fermented tea extract was completely biofilm inhibitor but biofilm formation by these bacteria was seen 7 days after treatment with 1 mg mL(-1) of non fermented Camellia sinensis on glass beads and BIC for oral streptococci treated with this extract was 1.5, 2.5 mg mL(-1) of semi fermented and 3 mg mL(-1) of non fermented extracts had bactericidal effect on these bacteria. Semi fermented and non fermented Camellia sinensis extracts were able to prevent growth of oral streptococci. Therefore dental caries significantly reduce and the efficiency of semi fermented tea was higher due to rich content of volatile components rather than non fermented extracts.  相似文献   
9.
Tropical Animal Health and Production - The objective of this work was to study the effect of the incorporation of argane by-products (meal and pulp) in ewe’s diet on the production and...  相似文献   
10.
Summary

Multiple applications of methyl jasmonate (Me-J), at 10.mM, enhanced the rate of fruit ripening in peach ‘Redhaven’. The effect of Me-J on red colour development and fruit firmness was most pronounced in fruit treated six times with Me-J. Lower concentrations of Me-J had no effect of fruit colour. Me-J, at 10.mM, significantly reduced stomatal conductance, photosynthetic rate and transpiration rate of crabapple leaves, but had no effect on these parameters in peach leaves. The short-term inhibitory effects of Me-J on leaf gas exchange in crabapple persisted for up to 24 h. Fourteen applications of Me-J over a period of 28 days resulted in a 60% decrease in the concentration of chlorophyll in leaves. These Me-J applications also reduced the length of new branches, leaf number and leaf fresh weight by 65%, 31% and 47%, respectively. In peach, Me-J induced some leaf chlorosis and early leaf senescence within two weeks of the treatments which resulted in significant reductions in shoot length.  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