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   81篇
  免费   8篇
林业   1篇
农学   6篇
基础科学   1篇
  9篇
综合类   4篇
农作物   1篇
水产渔业   3篇
畜牧兽医   64篇
  2020年   5篇
  2019年   5篇
  2018年   2篇
  2017年   2篇
  2016年   5篇
  2015年   2篇
  2014年   5篇
  2013年   6篇
  2012年   2篇
  2011年   5篇
  2010年   4篇
  2009年   7篇
  2007年   4篇
  2005年   3篇
  2004年   2篇
  2003年   2篇
  2002年   3篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1998年   4篇
  1997年   1篇
  1996年   4篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1990年   2篇
  1989年   1篇
  1978年   1篇
排序方式: 共有89条查询结果,搜索用时 15 毫秒
1.
2.
Outbreaks of proliferative haemorrhagic enteropathy on two pig farms   总被引:2,自引:0,他引:2  
SUMMARY Clinical signs of proliferative haemorrhagic enteropathy (PHE) including anaemia, dysentery and sudden death were observed in finisher pigs and young breeding stock on 2 farms. On farm A, PHE occurred 12 months after repopulation of the farm. Other outbreaks of PHE occurred after the withdrawal of therapeutic concentrations of in-feed antibacterial agents (farm A), or after monensin sodium (100 g/t) replaced olaquindox (100 g/t) in feed (farm B). The outbreaks, the possible sources of contamination and the role of antibacterial feed additives in the treatment and control of PHE are described.  相似文献   
3.
4.
5.
Clinical exercise testing in the normal Thoroughbred racehorse   总被引:1,自引:0,他引:1  
To evaluate normal cardiorespiratory and metabolic responses of Thoroughbred horses to a standardised treadmill exercise test, we examined 28 horses ranging in age from 1 to 4 years. The group consisted of eight yearlings, eight 2-year-olds and twelve 3 and 4-year-olds. All horses except the yearlings were in training, and either racing or ready to race, at the time of examination. None of the horses had histories of performance problems. On the first day the horses received a full physical examination, resting electrocardiogram, upper respiratory tract endoscopy and either one or two acclimatisation runs on the treadmill. The following day they were given an exercise test on a treadmill inclined at 6 degrees (+10% slope). The test consisted of 3 min at 4 m/sec, 90 sec at 6 m/sec and 60 sec intervals at 8, 10, 11, 12 and 13 m/sec. During the last 15 sec of each step, blood samples were collected for plasma lactate determination, expired respiratory gases were obtained using an open flow mask system for measurement of oxygen uptake, and heart rate was measured using telemetry electrocardiogram. From these measurements, various derived values were calculated, which have been used by others as indices of exercise capacity. These values included: V200 (speed at HR of 200 bpm), VHRmax (speed at which horses reached maximum HR), VO2-200 (oxygen uptake at a HR of 200 bpm), VO2max (maximum oxygen uptake), VLA4 (speed at which horses reached a plasma lactate of 4 mmol/l) and HRLA4 (HR at which horses reached a plasma lactate of 4 mmol/l). The yearlings had significantly lower values than the older age groups for most of the derived values.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
6.
S. Nayak    G. R. Rout 《Plant Breeding》2005,124(6):599-602
Isolation and characterization of microsatellites was analysed in Bambusa arundinacea and cross species amplification studied in other bamboos. Microsatellites, tandem repeats of short nucleotide (1–6 bp) sequences, are the DNA marker of choice because of their highly polymorphic, ubiquitous distribution within the genome, ease of genotyping through Polymerase chain reaction, selectively neutral, co‐dominant and multiallelic nature. Six microsatellites, three polymorphic and three monomorphic have been characterized for the first time in a bamboo species, Bambusa arundinacea belonging to the family Poaceae. The numbers of alleles per locus ranged from 2 to 13. Cross species amplification was tested in 18 other bamboo species. Monomorphic simple sequence repeats (SSRs) were found to be cross amplified in most of the species tested and polymorphic ones in only three to four species. The utility of SSR loci in a genetic diversity study of B. arundinacea and other cross‐amplified bamboo species has been discussed. This study will help in population genetic studies in bamboo species.  相似文献   
7.
Anther culture of an interspecific rice hybrid from a cross of Oryza sativa× O. rufipogon was attempted. Of the 117 regenerated pollen clones, 56 could survive to maturity. A majority of these were either haploids or doubled haploids and very few turned out to be chromosomal variants. Comparative study of doubled haploids and the seed derived F2 plants indicate the distinct advantages of anther culture techniques. (1) Androgenic plants, though few in number, showed greater ariation for all the traits with the exception of ear bearing tillers. (2) Predominance of recombinants with wild traits was observed in F2 segregation. (3) It was possible to recover indica type recombinants among the anther-derived plants with one or two traits introgressed from O. rufipogon. These results suggest the feasibility and utility of anther culture in distant hybridization for incorporation of alien variation into cultivated rice.  相似文献   
8.
The conformation of oat globulin dispersions (10% in D2O) under the influence of pH, chaotropic salts, protein structure perturbants, and heating conditions was studied by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectrum of oat globulin showed major bands from 1670 to 1634 cm(-1), corresponding to the four major types of secondary structures, that is, beta-turns, beta-sheets, alpha-helices, and random coils. At extreme acidic and alkaline pH conditions, there were changes in intensity in the bands attributed to beta-sheet structures (1626, 1634, and 1682 cm(-1)), and shifts of the bands to higher or lower wavenumbers, indicating changes in conformation. In the presence of some chaotropic salts, the 1626 and 1634 cm(-1) bands were shifted upward, with a marked decrease in the intensity of the 1634 cm(-1) peak. The addition of several protein structure perturbants led to a slight shift in the alpha-helix/random coil bands and a marked reduction in the beta-sheet peaks, suggesting protein unfolding. Heating under aggregating conditions led to slight shifts in all of the major bands and progressive changes in the intensity of the alpha-helix, beta-sheet, and beta-turn peaks, suggesting protein denaturation. This was accompanied by marked increases in intensity of the two intermolecular beta-sheet bands (1682 and 1624-1626 cm(-1)) associated with the formation of aggregated strands. The IR spectra of soluble and insoluble aggregates showed a redistribution of native and extensively denatured proteins in the two fractions.  相似文献   
9.
10.
Productivity and sustainability of rice-rice cropping system depend upon the soil quality which is primarily governed by application of fertilizers and manures. However, such information is limited and hence, the present investigation was carried out in a 9-year-old long-term fertilizer experiment at Bhubaneswar, India. There were seven treatments (control, application of 100% NPK, 150% NPK, 100% NPK + Zn, 100% NPK + FYM, 100% NPK + Zn + B, and 100% NPK + Zn + S) laid out in randomized block design with four replications. Indicators of soil quality (physical, chemical, and biological) were diagnosed from 30 numbers of soil properties measured on the post-wet season soil and soil quality was assessed taking productivity and sustainability of dry season rice as goal functions. Results revealed that the highest productivity and sustainability of dry season rice was found with application of 100% NPK + FYM. This treatment, in general, showed better physical, chemical, and biological properties than rest of the treatments. The highest soil quality index (SQI) was recorded in 100% NPK + FYM (0.941) treatment followed by 150% NPK (0.826) with CEC diagnosed as the only key indicator for rice productivity. For yield sustainability in dry season, reserve K and total N were important contributing 89% and 11%, respectively to the SQI. Therefore, these soil properties could be used to monitor soil quality in wet season. Application of FYM along with 100% NPK could sustain the productivity of dry season rice by improving soil properties under subtropical rice-rice system.  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