全文获取类型
收费全文 | 497篇 |
免费 | 26篇 |
国内免费 | 2篇 |
专业分类
林业 | 21篇 |
农学 | 21篇 |
基础科学 | 1篇 |
57篇 | |
综合类 | 58篇 |
农作物 | 15篇 |
水产渔业 | 66篇 |
畜牧兽医 | 230篇 |
园艺 | 6篇 |
植物保护 | 50篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 10篇 |
2019年 | 12篇 |
2018年 | 5篇 |
2017年 | 12篇 |
2016年 | 12篇 |
2015年 | 6篇 |
2014年 | 13篇 |
2013年 | 14篇 |
2012年 | 36篇 |
2011年 | 40篇 |
2010年 | 24篇 |
2009年 | 19篇 |
2008年 | 30篇 |
2007年 | 43篇 |
2006年 | 26篇 |
2005年 | 23篇 |
2004年 | 26篇 |
2003年 | 29篇 |
2002年 | 29篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1992年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1972年 | 8篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1967年 | 3篇 |
1966年 | 1篇 |
1965年 | 3篇 |
1964年 | 1篇 |
1961年 | 1篇 |
1960年 | 2篇 |
1936年 | 1篇 |
排序方式: 共有525条查询结果,搜索用时 46 毫秒
151.
William Phillip Young 《Veterinary Clinics of North America: Small Animal Practice》2002,32(3):601-19, vi-vii
The development of the carbon dioxide (CO2) surgical laser has given veterinarians a new perspective in the field of surgery. Recently developed techniques and improvisations of established procedures have opened the field of surgery to infinite applications never before dreamed of as little as 10 years ago. Today's CO2 surgical laser is an adaptable, indispensable tool for the everyday veterinary practitioner. Its use is becoming a common occurrence in offices of veterinarians around the world. 相似文献
152.
Gray GA Dascanio JJ Kasimanickam R Sponenberg DP 《The Canadian veterinary journal. La revue veterinaire canadienne》2007,48(7):741-744
A 4-year-old alpaca stud was presented for examination of his reproductive tract. Ultrasonographic examination of the gonads revealed 2 cystic structures associated with the head of each epididymis. Biopsies of each testicle evidenced mild testicular degeneration. Histopathologic examination of the gonads revealed cystic efferent ductules in the head of each epididymis. 相似文献
153.
Phillip F. Steyn BVSc MRCVS MS Gregory Ogilvie DVM 《Veterinary radiology & ultrasound》1995,36(5):411-416
Technetium-99m methoxy-isobutyl-isonitrile (sestamibi) imaging of malignant canine lymphoma was performed in thirteen dogs 1 hour after intravenous injection of 99m Tc-sestamibi at 13 MBq (0.35 mCi) per kilogram body weight. Abnormal tracer uptake was visualized in the liver, spleen, bone marrow, and mesenteric, inguinal, popliteal, sternal, cranial cervical and mandibular lymph nodes. Radiopharmaceutical uptake was also noted in a nasal mass. One large neoplastic renal mass did not have demonstrable sestamibi uptake. Other regions had no significant difference in the target:background ratios when compared with values from normal dogs ( P > 0.05). 99m Tc-sestamibi can be used to image malignant lymphoma, and has potential applications in the management of patients to document response to treatment and to stage of extent of disease. 相似文献
154.
J I Phillip 《Journal of the American Veterinary Medical Association》1992,200(3):302-304
155.
Graebing PW Chib JS Hubert TD Gingerich WH 《Journal of agricultural and food chemistry》2004,52(4):870-878
The photodegradation of [(14)C]niclosamide was studied in sterile, pH 5, 7, and 9 buffered aqueous solutions under artificial sunlight at 25.0 +/- 1.0 degrees C. Photolysis in pH 5 buffer is 4.3 times faster than in pH 9 buffer and 1.5 times faster than in pH 7 buffer. In the dark controls, niclosamide degraded only in the pH 5 buffer. After 360 h of continuous irradiation in pH 9 buffer, the chromatographic pattern of the degradates was the same regardless of which ring contained the radiolabel. An HPLC method was developed that confirmed these degradates to be carbon dioxide and two- and four-carbon aliphatic acids formed by cleavage of both aromatic rings. Carbon dioxide was the major degradate, comprising approximately 40% of the initial radioactivity in the 360 h samples from both labels. The other degradates formed were oxalic acid, maleic acid, glyoxylic acid, and glyoxal. In addition, in the chloronitroaniline-labeled irradiated test solution, 2-chloro-4-nitroaniline was observed and identified after 48 h of irradiation but was not detected thereafter. No other aromatic compounds were isolated or observed in either labeled test system. 相似文献
156.
157.
Along-term goal of inertial-confinement fusion research is the generation of energy by imploding capsules containing deuterium-tritium fuel. Progress in designing the capsules is aided by accurate imaging of the fusion burn. Penumbral coded-aperture techniques have been used to obtain neutron images that are a direct measurement of the fusion burn region in the capsules. 相似文献
158.
159.
Linda L. Smith Phillip G. Lee Addison L. Lawrence Kirk Strawn 《Aquaculture (Amsterdam, Netherlands)》1985,46(2):85-96
Growth, survival and digestibility of Penaeus vannamei were studied in three experiments. P. vannamei averaging 4.0, 9.8 and 20.8 g were monocultured in circular fiberglass tanks (2650 l) for 30 days. Six diets having protein contents of 22, 29 and 36% and an animal: plant protein source ratio of 2:1 or 1:1 were fed ad libitum. Survival ranges for small, medium and large shrimp were 81.7–93.3, 65.6–90.0 and 65.0–80.0%, respectively, and were unrelated to diet.Growth (g/day) decreased significantly with increased size of shrimp, whereas digestibility varied independently of size. Growth by all three sizes of shrimp fed the 2:1 diet series was not significantly (α = 0.05) higher than that of the 1:1 diet series.Digestibility ranges for protein, lipid and total diet were 78.6–85.8, 45.1–64.8 and 43.9–53.8%, respectively, for small shrimp; 80.7–84.5, 52.8–63.8 and 46.9–53.0%, respectively, for medium shrimp; and 78.7–85.4, 49.2–63.2 and 41.8–58.4%, respectively, for large shrimp. Protein digestibility by small shrimp was strongly correlated with dietary protein level. Only small shrimp showed a strong correlation between protein digestibility and growth. No size exhibited a relationship between growth and either lipid or total diet digestibility.Growth of small P. vannamei appeared to be more influenced by protein level where-as growth of medium and large P. vannamei appeared to be more influenced by protein source. 相似文献
160.