全文获取类型
收费全文 | 791篇 |
免费 | 15篇 |
国内免费 | 1篇 |
专业分类
林业 | 92篇 |
农学 | 14篇 |
基础科学 | 1篇 |
210篇 | |
综合类 | 53篇 |
农作物 | 139篇 |
水产渔业 | 34篇 |
畜牧兽医 | 201篇 |
园艺 | 33篇 |
植物保护 | 30篇 |
出版年
2021年 | 10篇 |
2018年 | 9篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 7篇 |
2014年 | 17篇 |
2013年 | 51篇 |
2012年 | 27篇 |
2011年 | 28篇 |
2010年 | 9篇 |
2009年 | 18篇 |
2008年 | 29篇 |
2007年 | 25篇 |
2006年 | 36篇 |
2005年 | 27篇 |
2004年 | 29篇 |
2003年 | 29篇 |
2002年 | 22篇 |
2001年 | 20篇 |
2000年 | 11篇 |
1999年 | 24篇 |
1998年 | 7篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1994年 | 9篇 |
1993年 | 12篇 |
1991年 | 12篇 |
1990年 | 9篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1981年 | 8篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1973年 | 7篇 |
1972年 | 8篇 |
1971年 | 6篇 |
1970年 | 8篇 |
1969年 | 7篇 |
1936年 | 7篇 |
1935年 | 8篇 |
1934年 | 5篇 |
1928年 | 6篇 |
1926年 | 9篇 |
1924年 | 6篇 |
排序方式: 共有807条查询结果,搜索用时 15 毫秒
101.
102.
103.
The environmental conditions in 103 fresh-water aquaria were examined and the results compared to the standards as described in part 1 of this publication. The aim was to assess whether the care of aquarium fish was adequate in regard to management and the legal requirements of animal welfare. Disclosed faults are discussed and recommendations for their elimination and avoidance are suggested. 相似文献
104.
R E Werner A J Straughan D Vezin 《Journal of the American Veterinary Medical Association》1992,200(1):64-66
Nylon cable bands used as ligatures caused postsurgical complications in 5 ovariohysterectomized bitches. Clinical signs included fever, stiffness, strangury, draining fistulae, vaginal discharge, and tenesmus. Most signs first appeared several years after surgery, and all signs were resolved after removal of the bands. On the basis of our experience, we suggest that nylon cable bands not be used for ovariohysterectomy ligations. 相似文献
105.
L L Werner N T Gorman 《Veterinary Clinics of North America: Small Animal Practice》1984,14(5):1039-1064
Immune-mediated disorders in cats share many clinical and pathologic similarities with their counterparts in other species. Cats, however, are unique among domestic animals owing to the involvement of feline leukemia virus. In addition, a number of other infectious organisms can produce immune-mediated sequelae--that is, FIP virus, FeSFV, and H. felis. Therefore, the diagnostic and therapeutic aims in the management of feline immune-mediated disorders must take into account the probability of a primary or underlying disease process. 相似文献
106.
Kinzel S Koch J Stopinski T Afify M Krombach G Buecker A Küpper W 《Berliner und Münchener tier?rztliche Wochenschrift》2004,117(7-8):334-340
We report our results of partial lumbosacral laminectomy for treatment of canine Cauda equina Compression Syndrome due to a lumbosacral stenosis. Opposite to conventional techniques of dorsal laminectomy, only widening of the Spatium interarcuale is performed. This is achieved by exstirpation of the Lig. flavum and partial dorsal laminectomy of the first sacral segment. The Proc. spinosi and integrity of facet joints are fully maintained by this technique. In 96.5% of 86 dogs treated with this method relief of dorsal pressure and permanent rapid regression of clinical symptoms was achieved. In two cases recurrence of clinical symptoms was observed during follow up and one case showed no improvement at all. In conclusion partial dorsal laminectomy is a minimal invasive technique for treatment of Cauda equina compression syndrome expressed by pain reaction accompanied by minor neurological deficits caused by lumbosacral stenosis. Maintained spinal stability allows short reconvalescence and the unrestricted use of dogs immediately post operation. 相似文献
107.
Horvatovich P Werner D Jung S Miesch M Delincee H Hasselmann C Marchioni E 《Journal of agricultural and food chemistry》2006,54(6):1990-1996
The use of a column containing 60 g of silica gel for cleanup and the use of isobutane as a reactant reagent for chemical ionization-mass spectrometric analysis of the saturated and monounsaturated alkyl side-chain 2-alkylcyclobutanones (2-ACBs; specifically induced by irradiation from fat in foods until the proof of contrary) has improved both the sensibility and the selectivity of the method when applied for the detection of irradiated foods. The quality of the chromatograms obtained was improved, allowing the detection of food samples (avocados) irradiated at low doses (0.1 kGy) or irradiated ingredients included in low proportions (less than 5%, wt/wt) in nonirradiated culinary foods. These analytical modifications for the detection of 2-ACBs on the official EN 1785 method enable an extension of its current field of application using common equipment of food quality control laboratories. 相似文献
108.
Starick E Werner O Schirrmeier H Köllner B Riebe R Mundt E 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2006,53(8):370-375
A recombinant baculovirus (RBV) encoding the nucleoprotein (NP) of avian influenza virus (AIV) was generated and the appropriate protein was expressed in Sf9 cells. Purified recombinant NP and the NP-specific monoclonal antibody HB65 were used to establish a competitive ELISA (cELISA) system for the detection of NP-specific antibodies in sera of ducks, geese and wild birds. Tests to evaluate this method were carried out using sera of ducks experimentally infected with AIV, pre-immune duck and chicken sera, and poultry field sera, which tested negative in the haemagglutination inhibition (HI) assay, and field sera of several poultry species experimentally infected with other viruses. The evaluation of the test demonstrated a high sensitivity and specificity of this method. Tests carried out using field sera of duck and goose flocks revealed widely corresponding results obtained by HI assay and cELISA indicating that this test is applicable for flock diagnosis. Differing results were obtained for individual samples. It can be assumed that for the most part this was because of a better recognition of the conserved NP antigen by serum antibodies, although some results remained unclear. 相似文献
109.
OBJECTIVE: To analyze and compare the geometry of the anterior segment of rabbit and human eyes, with relevance for the evaluation of intraocular lenses, and to review rabbit models used in our laboratory for the evaluation of different ophthalmic devices and solutions. PROCEDURES: Fifteen rabbit and 15 human eyes (10 phakic and 5 pseudophakic/group) obtained postmortem were used. Anterior-posterior length, equatorial diameter, and white-to-white (corneal diameter) were measured with calipers. The eyes were then analyzed with a very high-frequency ultrasound (Artemis, Ultralink) for measurements of the anterior chamber depth, and anterior chamber and ciliary sulcus diameters. The capsular bag diameter was measured with calipers from a posterior view, and the diameter and thickness of the crystalline lenses were measured after their excision from the phakic eyes. RESULTS: Although the size of the rabbit eye is overall smaller than the size of the human eye, the dimensions of the anterior segment of rabbit eyes are generally larger. The differences between rabbit and human eyes were statistically significant (Wilcoxon rank sum test) in terms of anterior-posterior length, equatorial diameter, white-to-white measurements (P < 0.0001), anterior chamber diameter (P = 0.0004), ciliary sulcus diameter (P = 0.0012), and crystalline lens diameter and thickness (P = 0.0003). CONCLUSIONS: Experimental evaluation of design features of new phakic intraocular lenses in rabbit eyes may be inconclusive without adaptation of their size/design, contrary to the evaluation of new pseudophakic lenses by implantation in the capsular bag. The rabbit is a very valuable model for the experimental evaluation of different ophthalmic devices and solutions. 相似文献
110.
Crawford PC Levy JK Werner LL 《Journal of the American Veterinary Medical Association》2006,228(7):1038-1041
OBJECTIVE: To identify surrogate markers of passive transfer of immunity in kittens. DESIGN: Prospective clinical trial. ANIMALS: 55 kittens from 12 specific-pathogen-free queens. PROCEDURE: Kittens were allocated at birth into colostrum-fed (n = 27) and colostrum-deprived (28) groups. Blood was collected at birth and on days 1, 2, 4, 7, 14, 28, and 56. Serum samples were analyzed for activities of alkaline phosphatase (ALP), alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, gamma-glutamyltransferase, amylase, and lipase and for concentrations of albumin, total protein, bilirubin, urea nitrogen, creatinine, cholesterol, glucose, calcium, phosphorus, and triglycerides by use of an automated analyzer. Total serum solids concentrations were estimated by use of refractometry. Serum IgG concentrations were quantified by use of radial immunodiffusion. RESULTS: All kittens were agammaglobulinemic at birth. Colostrum-fed kittens had significantly higher IgG concentrations than did colostrum-deprived kittens from 1 though 28 days of age. Transient significant differences in serum biochemical variables between the colostrum-deprived and colostrum-fed groups were substantially resolved by day 4. Passive transfer of immunity could be reliably determined at 1 day of age and to a lesser extent at 2 days of age only by measurement of serum activity of ALP. CONCLUSIONS AND CLINICAL RELEVANCE: Adequacy of passive transfer in kittens initially correlated with serum activity of ALP, but quantification of serum IgG concentration was necessary after 2 days of age. 相似文献