全文获取类型
收费全文 | 17040篇 |
免费 | 898篇 |
国内免费 | 17篇 |
专业分类
林业 | 828篇 |
农学 | 560篇 |
基础科学 | 122篇 |
2505篇 | |
综合类 | 2664篇 |
农作物 | 911篇 |
水产渔业 | 950篇 |
畜牧兽医 | 8310篇 |
园艺 | 197篇 |
植物保护 | 908篇 |
出版年
2020年 | 161篇 |
2019年 | 184篇 |
2018年 | 310篇 |
2017年 | 365篇 |
2016年 | 261篇 |
2015年 | 198篇 |
2014年 | 316篇 |
2013年 | 665篇 |
2012年 | 496篇 |
2011年 | 620篇 |
2010年 | 428篇 |
2009年 | 410篇 |
2008年 | 628篇 |
2007年 | 552篇 |
2006年 | 513篇 |
2005年 | 453篇 |
2004年 | 420篇 |
2003年 | 429篇 |
2002年 | 369篇 |
2001年 | 486篇 |
2000年 | 475篇 |
1999年 | 373篇 |
1998年 | 180篇 |
1997年 | 201篇 |
1996年 | 156篇 |
1995年 | 193篇 |
1993年 | 164篇 |
1992年 | 280篇 |
1991年 | 313篇 |
1990年 | 307篇 |
1989年 | 312篇 |
1988年 | 289篇 |
1987年 | 246篇 |
1986年 | 295篇 |
1985年 | 253篇 |
1984年 | 209篇 |
1983年 | 207篇 |
1979年 | 250篇 |
1978年 | 165篇 |
1977年 | 155篇 |
1975年 | 171篇 |
1974年 | 234篇 |
1973年 | 215篇 |
1972年 | 251篇 |
1971年 | 230篇 |
1970年 | 203篇 |
1969年 | 192篇 |
1968年 | 158篇 |
1967年 | 160篇 |
1966年 | 161篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
Eriksen T Kuiper H Pielmeier R Ganter M Distl O Staszyk C 《Research in veterinary science》2012,93(3):1122-1127
Craniofacial malformation in 64 sheep was phenotypically described as mandibular distoclusion. Digital radiographs were examined in order to determine the degree of morphological changes in certain bones of the skull. Therefore, laterolateral standardised digital radiographs were used to determine anatomic reference points. Subsequently, five reference lines were defined and 16 linear and seven angular measurements were determined to describe malformations in the bones of the skull. Statistical analysis revealed a significant shortening of the rostral part of the corpus mandibulae and of the ramus mandibulae. However, the molar part of the mandible remained unchanged. These morphological changes caused premolar and molar malocclusion. No further craniofacial abnormalities, such as an elongation of the maxilla or of the incisive bone, were identified. In conclusion, the phenotypically observed mandibular distoclusion is caused by a shortening of specific parts of the mandible. This form of ovine craniofacial malformation is therefore best described as brachygnathia inferior. 相似文献
133.
134.
I. Srugo O. Chai D. Yaakov L. Sharon M. H. Shamir 《The Journal of small animal practice》2010,51(8):447-450
Thoracolumbar disc herniation was diagnosed in a two-year-old ferret using a myelogram followed by a computed tomography scan. The ferret was paraplegic with no control over urination and defecation. Conservative treatment that included cage rest and passive range of motion exercises for three weeks followed by extensive physiotherapy and hydrotherapy resulted in full recovery two months after the onset of treatment. Although intervertebral disc disease has been reported previously in four ferrets, this is the first report in which a postmyelogram computed tomography was used to demonstrate the herniated disc, and physiotherapy was used as principal treatment modality. 相似文献
135.
Pantaleon LG Furr MO McKenzie HC Donaldson L 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(6):1422-1428
BACKGROUND: Small volume resuscitation has been advocated as a beneficial therapy for endotoxemia in horses but this therapy has not been investigated in a prospective manner. The objective of this study was to determine the cardiopulmonary effects of small-volume resuscitation using hypertonic saline solution (HSS) plus Hetastarch (HES) during experimental endotoxemia in anesthetized horses. HYPOTHESIS: Treatment of horses with induced endotoxemia using HES-HSS does not alter the response of various cardiopulmonary indices when compared to treatment with either small- or large-volume isotonic crystalloid solutions. ANIMALS: Eighteen healthy horses were randomly assigned to 1 of 3 groups. Anesthesia was maintained with halothane. Endotoxemia was induced by administering 50 microg/kg of Escherichia coli endotoxin IV. The horses were treated over 30 minutes with 15 mL/kg of balanced polyionic crystalloid solution (control), 60 mL/kg of balanced polyionic crystalloid solution (ISO), or 5 mL/kg of HSS followed by 10 mL/kg of HES (HSS-HES). METHODS: Prospective randomized trial. RESULTS: Cardiac output (CO) after endotoxin infusion increased significantly (P < .05) from baseline in all groups, whereas mean central venous pressure increased significantly (P < .05) in the ISO group only. Mean pulmonary artery pressure increased from baseline (P < .05) in horses treated with isotonic fluids and HSS-HES. There was no effect of treatment with HSS-HES on CO, systemic vascular resistance (SVR), mean arterial pressure, blood lactate concentrations, or arterial oxygenation. CONCLUSIONS AND CLINICAL IMPORTANCE: The use of HSS-HES failed to ameliorate the deleterious hemodynamic responses associated with endotoxemia in horses. The clinical value of this treatment in horses with endotoxemia remains unconfirmed. 相似文献
136.
The department of National Parks and Protection of Wild Nature sent five (two males, three females) adult long-legged buzzards for investigation of their deaths to Ankara University Veterinary Faculty. Facial bones of buzzards were evaluated. Distinguishing facial features such as strong os premaxillare, cavum nasale filled with spider webbing-like structures, prominent os prefrontalis and processes, H-shaped paraglossum were determined. In this study, we investigated the anatomic properties of facial bones in long-legged buzzard. We also aimed to identify the data using these bones in order to separate different bird species. 相似文献
137.
Poxvirus infections are common in domestic birds in Germany, but they are rare in birds of prey. Only species of falconidae imported from Arabian or Asian countries have so far tested positive for poxvirus, and, among these, only raptors kept for falconry. As part of a reintroduction programme in the northern county of Mecklenburg-Western Pomerania, which is adjacent to the Baltic Sea, 21 young peregrine falcons were released into the wild; six of them died and one was examined postmortem, its tissues being examined by light and electron microscopy. In addition, an ELISA for fowlpox, pigeonpox and canarypox was applied. No virus could be isolated and propagation in culture failed, but virus particles were detected by electron microscopy in lesions from its skin and tongue. 相似文献
138.
Bussières G Jacques C Lainay O Beauchamp G Leblond A Cadoré JL Desmaizières LM Cuvelliez SG Troncy E 《Research in veterinary science》2008,85(2):294-306
This study addresses development and validation of a composite multifactorial pain scale (CPS) in an experimental equine model of acute orthopaedic pain. Eighteen horses were allocated to control (sedation with/without epidural analgesia - mixture of morphine, ropivacaine, detomidine and ketamine) and experimental groups: amphotericin-B injection in the tarsocrural joint induced pain and analgesia was either i.v. phenylbutazone administered post-induction of synovitis, or pre-emptive epidural mixture, or a pre-emptive combination of the 2. Inter- and intra-observer reproducibility was good (0.8相似文献
139.
V. Albanese B. Credille A. Ellis L. Baldwin P. O. E. Mueller A. Woolums 《Equine Veterinary Education》2011,23(6):281-285
The purpose of this report is to describe the clinical course and pathological findings in a horse admitted to the emergency service of the University of Georgia Large Animal Teaching Hospital for evaluation of colic, fever and diarrhoea of several days' duration. A presumptive historical diagnosis of colitis was made initially, but, due to the lack of faecal output during the first 12 h of hospitalisation and subsequent examination findings, an impaction of the ascending colon was suspected. Initial therapy consisted of rehydration with oral fluids and management of the abdominal pain with analgesic therapy. The horse did not respond to medical therapy and because of signs of persistent abdominal pain and financial constraints, the owner elected euthanasia after several days of supportive care. At necropsy, the horse was diagnosed with a colocolic intussusception. 相似文献
140.
E C Burgess A Gendron-Fitzpatrick W O Wright 《Journal of the American Veterinary Medical Association》1987,191(11):1468-1470
Infection with Borrelia burgdorferi caused arthritis, myocarditis, glomerulonephritis, and pneumonitis in a cow. Spirochetes were detected by use of immunofluorescent staining in liver and lung specimens and were isolated from the liver. The carpal, stifle, and tarsal joints had marked synovial proliferation, and synovial fluid obtained from these joints had high antibody titers against B burgdorferi. The cow was from an area of Wisconsin that is not endemic for borreliosis. 相似文献