全文获取类型
收费全文 | 694篇 |
免费 | 30篇 |
专业分类
林业 | 11篇 |
农学 | 16篇 |
基础科学 | 2篇 |
85篇 | |
综合类 | 123篇 |
农作物 | 11篇 |
水产渔业 | 15篇 |
畜牧兽医 | 426篇 |
园艺 | 7篇 |
植物保护 | 28篇 |
出版年
2020年 | 5篇 |
2018年 | 4篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 38篇 |
2012年 | 29篇 |
2011年 | 48篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 31篇 |
2007年 | 37篇 |
2006年 | 22篇 |
2005年 | 21篇 |
2004年 | 29篇 |
2003年 | 16篇 |
2002年 | 22篇 |
2001年 | 21篇 |
2000年 | 22篇 |
1999年 | 16篇 |
1998年 | 6篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 22篇 |
1989年 | 19篇 |
1988年 | 19篇 |
1987年 | 14篇 |
1986年 | 16篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1973年 | 10篇 |
1971年 | 9篇 |
1970年 | 10篇 |
1969年 | 5篇 |
1968年 | 5篇 |
1967年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有724条查询结果,搜索用时 0 毫秒
1.
Outbreaks of infection due to a parapoxvirus were reported on eight New Zealand deer farms. Scabby lesions were seen variably on the muzzle, lips, face, ears and neck of red deer (Cervus elaphus) with morbidity rates reaching 100%. On three farms multifocal lesions were also present on the velvet. Deaths were reported on two properties where the lesions were extensive and secondary bacterial infections had occurred. On one of these farms multifactorial disease was suspected. Poxvirus particles were seen by negative contrast electron microscopy in scab material from all eight properties. Morphologically the deer virus resembled a parapoxvirus, but restriction endonuclease analysis showed its DNA fragment patterns were distinct from those of orf (contagious ecthyma) virus. 相似文献
2.
In conscious pigs the influence of intravenous infusion of live E. coli (7×108/kg), of the equivalent amount of endotoxin (20 g/kg) or of a high dose of endotoxin (2.5 mg/kg) on the hemodynamic, clinical and pathological parameters and on survival rate was studied. E. coli and endotoxin infusion resulted in pulmonary hypertension, systemic arterial hypotension, a decrease in cardiac output and an increase in heart rate. Clinical signs were characterized by respiratory and nervous disturbances, whereas necropsy revealed hemorrhages and edema in several organs. Although these findings were similar in the three groups, a marked difference in lethality was observed. Infusion of E. coli or of the high dose of endotoxin resulted in a significant mortality, whereas all pigs survived the infusion of the low dose of endotoxin. This suggests that the lethal pathophysiological mechanisms may only become activated when a sufficient amount of endotoxin is released into the circulation. 相似文献
3.
Prevalence of gastrointestinal nematodes in dairy heifers in western Canada 总被引:3,自引:2,他引:1
下载免费PDF全文
![点击此处可从《The Canadian veterinary journal. La revue veterinaire canadienne》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Cox WR Lemiski D 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(8):666-668
A survey was conducted to estimate the prevalence of gastrointestinal nematodes in grazing dairy replacement heifers in western Canada. Fecal samples were collected from 566 animals on 34 farms distributed over the three prairie provinces. Fecal egg counts were performed using a modified Wisconsin centrifugation technique. The overall mean farm fecal egg count was 16.0 eggs per gram feces (range 0.7-78.1 epg). Gastrointestinal nematodes were demonstrated on every farm examined, and 93.3% of all individuals tested were positive. 相似文献
4.
5.
6.
7.
Clinical and in vitro efficacy of amoxicillin against bacteria associated with feline skin wounds and abscesses 总被引:1,自引:0,他引:1
Roy J Messier S Labrecque O Cox WR 《The Canadian veterinary journal. La revue veterinaire canadienne》2007,48(6):607-611
A clinical trial involving 122 cats with infected skin wounds or abscesses presented to 10 veterinary clinics was conducted to evaluate the efficacy of 2 oral amoxicillin drug products (a paste and a suspension). A 2nd objective of the study was to identify bacteria involved in such infections and verify their in vitro sensitivity to amoxicillin. Samples of wound exudate were harvested at the time of presentation and submitted for aerobic and anaerobic culture. The sensitivity to amoxicillin of isolates thought to be infecting agents was tested, using a standard minimum inhibitory concentration method. Pasteuralla multocida and obligate anaerobes of the genera Prevotella, Fusobacterium, and Porphyromonas were the most frequently isolated pathogens. Overall, their in vitro susceptibility to amoxicillin was very good. Both drug products were clinically efficacious with a global success rate of 95.1% for cats administered oral amoxicillin at 11-22 mg/kg bodyweight (mean 13.8 mg/kg bodyweight) twice daily for 7 to 10 days. 相似文献
8.
Cabrera A Cox L Velarde P Koskinen WC Cornejo J 《Journal of agricultural and food chemistry》2007,55(12):4828-4834
The addition of organic amendments to soil increases soil organic matter content and stimulates soil microbial activity. Thus, processes affecting herbicide fate in the soil should be affected. The objective of this work was to investigate the effect of olive oil production industry organic waste (alperujo) on soil sorption-desorption, degradation, and leaching of diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] and terbuthylazine [N2-tert-butyl-6-chloro-N4-ethyl-1,3,5-triazine-2,4-diamine], two herbicides widely used in olive crops. The soils used in this study were a sandy soil and a silty clay soil from two different olive groves. The sandy soil was amended in the laboratory with fresh (uncomposted) alperujo at the rate of 10% w/w, and the silty clay soil was amended in the field with fresh alperujo at the rate of 256 kg per tree during 4 years and in the laboratory with fresh or composted alperujo. Sorption of both herbicides increased in laboratory-amended soils as compared to unamended or field-amended soils, and this process was less reversible in laboratory-amended soils, except for diuron in amended sandy soil. Addition of alperujo to soils increased half-lives of the herbicides in most of the soils. Diuron and terbuthylazine leached through unamended sandy soil, but no herbicide was detected in laboratory-amended soil. Diuron did not leach through amended or unamended silty clay soil, whereas small amounts of terbuthylazine were detected in leachates from unamended soil. Despite their higher sorption capacity, greater amounts of terbuthylazine were found in the leachates from amended silty clay soils. The amounts of dissolved organic matter from alperujo and the degree of humification can affect sorption, degradation, and leaching of these two classes of herbicides in soils. It appears that adding alperujo to soil would not have adverse impacts on the behavior of herbicides in olive production. 相似文献
9.
Olivier M Aggarwal A Allen J Almendras AA Bajorek ES Beasley EM Brady SD Bushard JM Bustos VI Chu A Chung TR De Witte A Denys ME Dominguez R Fang NY Foster BD Freudenberg RW Hadley D Hamilton LR Jeffrey TJ Kelly L Lazzeroni L Levy MR Lewis SC Liu X Lopez FJ Louie B Marquis JP Martinez RA Matsuura MK Misherghi NS Norton JA Olshen A Perkins SM Perou AJ Piercy C Piercy M Qin F Reif T Sheppard K Shokoohi V Smick GA Sun WL Stewart EA Fernando J Tejeda Tran NM Trejo T Vo NT Yan SC Zierten DL Zhao S 《Science (New York, N.Y.)》2001,291(5507):1298-1302
We have constructed a physical map of the human genome by using a panel of 90 whole-genome radiation hybrids (the TNG panel) in conjunction with 40,322 sequence-tagged sites (STSs) derived from random genomic sequences as well as expressed sequences. Of 36,678 STSs on the TNG radiation hybrid map, only 3604 (9.8%) were absent from the unassembled draft sequence of the human genome. Of 20,030 STSs ordered on the TNG map as well as the assembled human genome draft sequence and the Celera assembled human genome sequence, 36% of the STSs had a discrepant order between the working draft sequence and the Celera sequence. The TNG map order was identical to one of the two sequence orders in 60% of these discrepant cases. 相似文献
10.
Frees KE Gaughan EM Lillich JD Cox J Gorondy D Nietfeld JC Kennedy GA Cash W 《Journal of the American Veterinary Medical Association》2001,219(7):950-2, 939
Formalin was injected into an ethmoidal hematoma in an 18-year-old Arabian gelding. Abnormal neurologic signs were observed within minutes of the injection. The horse did not respond favorably to medical treatment of the neurologic signs and was euthanatized. Postmortem examination revealed erosion and necrosis of the ventral cribriform plate, which appeared to have allowed the injected formalin to reach the rostral portion of the frontal lobe of the brain. Endoscopy and radiography had been performed prior to euthanasia, but neither delineated the cribriform lesion. Before treating large progressive ethmoidal hematomas with formalin, it may be beneficial to perform computed tomography to assess the extent of damage caused by the lesion. 相似文献