全文获取类型
收费全文 | 769篇 |
免费 | 34篇 |
国内免费 | 4篇 |
专业分类
林业 | 34篇 |
农学 | 14篇 |
基础科学 | 1篇 |
169篇 | |
综合类 | 90篇 |
农作物 | 29篇 |
水产渔业 | 41篇 |
畜牧兽医 | 368篇 |
园艺 | 23篇 |
植物保护 | 38篇 |
出版年
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 13篇 |
2020年 | 30篇 |
2019年 | 28篇 |
2018年 | 19篇 |
2017年 | 19篇 |
2016年 | 20篇 |
2015年 | 15篇 |
2014年 | 23篇 |
2013年 | 35篇 |
2012年 | 50篇 |
2011年 | 60篇 |
2010年 | 26篇 |
2009年 | 36篇 |
2008年 | 45篇 |
2007年 | 53篇 |
2006年 | 43篇 |
2005年 | 51篇 |
2004年 | 40篇 |
2003年 | 34篇 |
2002年 | 35篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 2篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有807条查询结果,搜索用时 15 毫秒
751.
752.
Phillips-Conroy J 《Science (New York, N.Y.)》2003,300(5628):2031
753.
Evaluation of Citrate-Phosphate- Dextrose-Adenine as a Storage Medium for Packed Canine Erythrocytes 总被引:1,自引:0,他引:1
G. Sylvester Price DVM P. Jane Armstrong DVM MS Deborah A. McLeod DVM Cynthia A. Babineau Michael R. Metcalf DVM MS Louis C. Sellett MS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1988,2(3):126-132
Packed canine red blood cells (RBCs) stored in the anticoagulant-preservative solution citrate-phosphate-dextrose-adenine (CPDA-1) were studied at 1, 10, 20, 30, and 40 days. The extracellular concentrations of potassium and sodium, erythrocyte mean corpuscular volume, and osmotic fragility increased during storage (P less than 0.05). There was a decrease in the pH, plasma concentration of glucose, and erythrocyte concentrations of 2,3-diphosphoglycerate (2,3-DPG) and adenosine-5'-triphosphate (P less than 0.05). Erythrocyte 2,3-DPG concentration decreased by 54% within the first 24 hours of storage (P less than 0.001). Posttransfusion viability (PTV) decreased from 90% on day 1 to 46% on day 40 (P less than 0.05). The PTV of the RBCs stored for 10 and 20 days complied with the Food and Drug Administration (FDA) standard. Although there are marked biochemical and hematologic changes in stored packed red blood cells (pRBCs), 20-day-old units may be expected to be of acceptable quality. The sharp decrease in 2,3-DPG concentration suggests a reduction in oxygen carrying capacity in erythrocytes stored as pRBCs. Hyperkalemia occurs during storage of pRBCs and does not appear to be associated with high intraerythrocytic potassium concentrations. 相似文献
754.
Greaves JS 《Science (New York, N.Y.)》2005,307(5706):68-71
Circumstellar disks play a vital evolutionary role, providing a way to move gas inward and onto a young star. The outward transfer of angular momentum allows the star to contract without breaking up, and the remnant disk of gas and particles is the reservoir for forming planets. High-resolution spectroscopy is uncovering planetary dynamics and motion within the remnant disk, and imaging at infrared to millimeter wavelengths resolves disk structure over billions of years of evolution. Most stars are born with a disk, and models of planet formation need to form such bodies from the disk material within the disk's 10-million-year life-span. 相似文献
755.
Naughton JF Mealey KL Wardrop KJ Oaks JL Bradway DS 《Journal of the American Animal Hospital Association》2005,41(2):128-132
Dogs may be infected by Mycobacterium (M.) tuberculosis, M. bovis, and M. avium complex, and the clinical signs associated with each of these infections may be indistinguishable. Rapid speciation of the infecting organism is desirable because of the public health concerns associated with M. bovis and M. tuberculosis infections. A mycobacterial infection was suspected in the dog of this report based on acid-fast staining of organisms in macrophages obtained from liver aspirates and buffy-coat preparations. Polymerase chain reaction (PCR) analysis of a buffy-coat preparation identified M. avium. 相似文献
756.
Pressler BM Gookin JL Sykes JE Wolf AM Vaden SL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(1):115-119
Records of 13 dogs with systemic infection with Prototheca sp. from 3 veterinary teaching hospitals were reviewed. Acute renal failure secondary to disseminated infection with Prototheca zopfii was diagnosed in 2 dogs. In 1 dog, acute renal failure developed during administration of immunosuppressive drugs for treatment of anterior uveitis. During diagnostic evaluation of this dog, Prototheca sp. organisms were noted in urine sediment and renal biopsy specimens. In the 2nd dog, acute renal failure was diagnosed after treatment for bacterial cystitis. After diagnosis of protothecosis, organisms were successfully isolated by aerobic urine culture. Both dogs with acute renal failure did not respond to conventional medical therapy. In total, Prototheca sp. was noted in urine sediment in 4 of 8 dogs and successfully cultured from urine in 5 of 7 dogs. Four of 5 dogs had organisms noted in the kidneys on histopathologic examination. In all dogs, the species identified was P zopfii. Sensitivity testing of 3 isolates revealed wide differences in in vitro drug resistance. Examination and culture of urine is recommended as a practical method for diagnosis of systemic infection with Prototheca sp. 相似文献
757.
Wardrop KJ Reine N Birkenheuer A Hale A Hohenhaus A Crawford C Lappin MR 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(1):135-142
Thousands of blood transfusions are performed each year on dogs and cats, and the demand for blood products continues to grow. Risks associated with transfusions include the risk of disease transmission. Appropriate screening of blood donors for bloodborne infectious disease agents should be performed to lessen this risk. Geographic restrictions of disease, breed predilection, and documentation of actual disease transmission by transfusion all are factors that might need to be considered when making a decision on what screening program to use. In addition, factors involving general health care and management of blood donors should be employed to further ensure blood safety. 相似文献
758.
Gauly M Vaughan J Hogreve SK Erhardt G 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(5):756-760
Auditory function of llamas and alpacas was assessed objectively by means of brainstem auditory-evoked response audiometry (BAER) to establish the normal hearing range and to test the hypothesis of a correlation between blue eyes, white coat, and deafness. Sixty-three camelids were available for the study. Thirteen animals had blue irides; 1 animal had 1 blue and 1 pigmented iris. Wave latencies, amplitudes, and interpeak latencies were measured under general anesthetic. Click stimuli (dB [HL]) were delivered by an insert earphone. Four to five positive peaks could be detected; waves I, II, and V were reproducible; wave II appeared infrequently; and wave IV generally merged with wave V to form a complex. Peak latencies decreased and peak amplitudes increased as stimulus intensity increased. A hearing threshold level of 10-20 dB (HL) was proposed as the normal range in llamas and alpacas. None of the animals with pigmentation of coat and iris showed any degree of hearing impairment. Seven of the 10 blue-eyed, pure-white animals were bilaterally deaf and one of them was unilaterally deaf. However, 2 blue-eyed, white animals exhibited normal hearing ability. Three blue-eyed animals with pigmented coat did not show any hearing impairment. All white animals with normal iris pigmentation had normal auditory function; so did the 1 animal with 1 normal and 1 blue iris. The high frequency (78%) of bilaterally deaf animals with pure white coat and blue iris pigmentation supports the hypothesis of a correlation between pigmentation anomalies and congenital deafness in llamas and alpacas. 相似文献
759.
760.