全文获取类型
收费全文 | 5758篇 |
免费 | 418篇 |
国内免费 | 3篇 |
专业分类
林业 | 149篇 |
农学 | 123篇 |
基础科学 | 50篇 |
642篇 | |
综合类 | 1468篇 |
农作物 | 192篇 |
水产渔业 | 224篇 |
畜牧兽医 | 3083篇 |
园艺 | 62篇 |
植物保护 | 186篇 |
出版年
2020年 | 48篇 |
2019年 | 49篇 |
2018年 | 72篇 |
2017年 | 67篇 |
2016年 | 79篇 |
2015年 | 57篇 |
2014年 | 87篇 |
2013年 | 229篇 |
2012年 | 165篇 |
2011年 | 184篇 |
2010年 | 104篇 |
2009年 | 105篇 |
2008年 | 203篇 |
2007年 | 197篇 |
2006年 | 204篇 |
2005年 | 180篇 |
2004年 | 177篇 |
2003年 | 187篇 |
2002年 | 159篇 |
2001年 | 141篇 |
2000年 | 167篇 |
1999年 | 142篇 |
1998年 | 54篇 |
1997年 | 53篇 |
1995年 | 49篇 |
1992年 | 123篇 |
1991年 | 125篇 |
1990年 | 122篇 |
1989年 | 117篇 |
1988年 | 97篇 |
1987年 | 94篇 |
1986年 | 135篇 |
1985年 | 152篇 |
1984年 | 119篇 |
1983年 | 113篇 |
1982年 | 70篇 |
1981年 | 83篇 |
1980年 | 65篇 |
1979年 | 110篇 |
1978年 | 98篇 |
1977年 | 59篇 |
1976年 | 50篇 |
1975年 | 54篇 |
1974年 | 57篇 |
1973年 | 77篇 |
1972年 | 77篇 |
1971年 | 67篇 |
1970年 | 56篇 |
1969年 | 62篇 |
1968年 | 62篇 |
排序方式: 共有6179条查询结果,搜索用时 250 毫秒
101.
Ophthalmic examination under anesthesia of a 5-yr-old, captive, male New Zealand fur seal (Arctocephalus forsteri) with reduced visual capacity revealed bilateral cataracts. Surgical extraction of the lenses was performed by phacofragmentation. Preoperative mydriasis was unsuccessful using common topical mydriatic agents. Intraoperative intracameral epinephrine 1:10,000 produced minimal pupillary dilation, but excellent dilation was achieved with intracameral epinephrine at 1:1,000. Postoperative uveitis was controlled with oral prednisolone. Postoperative complications included generalized corneal edema persisting for approximately 1 wk and corneal ulceration caused by the lateral canthotomy sutures. Vision was restored in both eyes. 相似文献
102.
J Jill Heatley Annette N Smith 《Veterinary Clinics of North America: Exotic Animal Practice》2004,7(3):561-77, v
Many of the same neoplastic processes reported in companion animal medicine have been documented in lagomorphs. With only a few reports in the literature regarding rabbits and hares, the behavior of many of these tumors cannot be predicted. Further, based on limited current knowledge, the practitioner is left to make decisions for diagnostics and therapeutics in these cases based upon current recommendations for companion animals with adjustments for lagomorph physiology. We hope that this review of lagomorph neoplasia will inform the general practitioner of the occurrence of these tumors, promote further documentation and research of these processes in rabbits, and encourage the practitioner of rabbit medicine along with rabbit owners to consult with veterinary oncologists regarding neoplastic processes in rabbits rather than just giving a guarded prognosis. 相似文献
103.
Geoffrey W Smith David S Rotstein Cecil F Brownie 《Journal of veterinary diagnostic investigation》2004,16(4):356-359
Abdominal fat necrosis was diagnosed in an 11-year-old female pygmy goat with a 10-day history of lethargy, anorexia, and progressive abdominal distension. Gross necropsy findings revealed multiple firm, dark yellow, nodular masses of fat throughout the abdominal cavity, which compressed several abdominal organs including the rumen, small intestine, spiral colon, and gall bladder. Histologically, multiple to coalescing adipocyte necrosis, saponification, and infiltration with variable numbers of macrophages, lymphocytes, and plasma cells was observed. Fat necrosis in this case was attributed to tall fescue toxicity based on the presence of high levels of endophyte (Neotyphodium coenophialum)-infected fescue identified in the goat's pasture. This is the first known report of abdominal fat necrosis in a goat and demonstrates the fat necrosis syndrome of fescue toxicosis in ruminants. 相似文献
104.
Stephanie A Smith Anthony H Tobias 《Veterinary Clinics of North America: Small Animal Practice》2004,34(5):1245-1271
ATE remains a devastating complication of cardiac disease. Despite some improvements in our understanding of the underlying causes and clinical features of this disease, short-term management remains a challenge, and mortality is high. Long-term mortality is primarily attributable to the severe underlying cardiac disease. Many questions remain to be answered regarding the ideal management approach for feline ATE. The authors' preferred diagnostic and therapeutic approaches for these difficult patients are detailed in Box. 1. 相似文献
105.
Bradford P Smith 《Veterinary Clinics of North America: Equine Practice》2004,20(3):521-30, v
The science of control of infectious diseases in hospitals was born in 1847 when Semmelweis, a physician, ordered his medical students to scrub their hands in chlorinated lime water between patients and demonstrated that this simple procedure resulted ina dramatic decline in patient morbidity and mortality. In the late nineteenth century came huge breakthroughs in the understanding that microorganisms cause many disorders, and methods to eliminate and control these microorganisms were attempted. By 1910, sterile instruments, gowns, masks, and gloves had become standard for surgical procedures in large university human hospitals, and isolation of human and veterinary patients with contagious diseases became standard. With the advent of vaccines, many epidemic viral diseases could be controlled, and antimicrobial drugs allowed many previously devastating bacterial diseases to be treated effectively. Before long, however, bacterial resistance became an important issue and remains so today, particularly for Salmonella and Staphylococcus aureus in horses. Vaccination has decreased the number of animals susceptible to equine influenza and equine herpesvirus 1, yet these contagious diseases still pose a serious issue in large equine veterinary hospitals. The development of equine isolation facilities and improved methods of barn cleaning; mandatory application of procedures, such as handwashing or use of disinfectant hand wipes, to prevent the spread of infectious diseases; and monitoring of antimicrobial resistance and use of restricted antimicrobial drugs were driven by recognition and necessity and have given rise to current equine infection control programs. 相似文献
106.
Tropical Animal Health and Production - 相似文献
107.
Removal of hemangiosarcoma cells from canine blood with a cell salvage system and leukocyte reduction filter 下载免费PDF全文
108.
Pharmacokinetics of multiple doses of transdermal flunixin meglumine in adult Holstein dairy cows 下载免费PDF全文
M. D. Kleinhenz P. J. Gorden J. S. Smith J. A. Schleining K. E. Kleinhenz L. L. Wulf P. K. Sidhu D. Rea J. F. Coetzee 《Journal of veterinary pharmacology and therapeutics》2018,41(3):490-493
A transdermal formulation of the nonsteroidal anti‐inflammatory drug, flunixin meglumine, has been approved in the United States and Canada for single‐dose administration. Transdermal flunixin meglumine was administered to 10 adult Holstein cows in their second or third lactation at the label dose of 3.33 mg/kg every 24 hr for three total treatments. Plasma flunixin concentrations were determined using high‐pressure liquid chromatography with mass spectroscopy (HPLC ‐MS ). Pharmacokinetic analysis was completed on each individual animal with noncompartmental methods using computer software. The time to maximum drug concentration (T max) was 2.81 hr, and the maximum drug concentration was 1.08 μg/ml. The mean terminal half‐life (T½) was determined to be 5.20 hr. Clearance per fraction absorbed (Cl/F) was calculated to be 0.294 L/hr kg?1, and volume of distribution of fraction (V z/F ) absorbed was 2.20 L/kg. The mean accumulation factor was 1.10 after three doses. This indicates changes in dosing may not be required when giving multiple doses of flunixin transdermal. Further work is required to investigate the clinical efficacy of transdermal flunixin after multiple daily doses. 相似文献
109.
研究表明,镰刀菌毒素会导致泌乳母猪的采食量和日增重下降,具有延长母猪从断奶至发情间隔时间的倾向;葡甘露聚糖能够防止由镰刀菌毒素毒性作用引起的血清尿素和总蛋白浓度的下降。 相似文献
110.
C.B. Cowey J.W. Adron R. Hardy J.G.M. Smith M.J. Walton 《Aquaculture (Amsterdam, Netherlands)》1979,16(3):199-209
Three groups of rainbow trout were given diets containing different amounts (12–36%) of collagenous by-product derived from partially rendered hide fleshings still containing an appreciable amount of saturated fat. A fourth group of trout were given a control diet containing as protein source a fish protein concentrate, and, as a source of essential fatty acids, a marine oil. The diets were fed for 12 weeks, hide fleshings replacing part of the marine oil and fish protein concentrate in the three test diets. Weight gains and protein utilization of the four groups of rainbow trout were all similar with all four diet treatments. No adverse effects on the fish were observed from the use of hard fat, although an increase in the concentration of some monounsaturated fatty acids occurred in tissues of those fish given hide fleshings. Tests of mitochondrial function gave normal values for both control and test fish. Organoleptic tests demonstrated that trout given diets containing hide fleshings were not distinguishable from normal trout. The results show that provided nutritional requirements are met (especially in the present instance with respect to essential amino acids and essential fatty acids) this by-product can form a useful component in trout rations. 相似文献