全文获取类型
收费全文 | 9011篇 |
免费 | 674篇 |
国内免费 | 13篇 |
专业分类
林业 | 267篇 |
农学 | 149篇 |
基础科学 | 33篇 |
792篇 | |
综合类 | 653篇 |
农作物 | 237篇 |
水产渔业 | 387篇 |
畜牧兽医 | 6733篇 |
园艺 | 136篇 |
植物保护 | 311篇 |
出版年
2023年 | 125篇 |
2022年 | 26篇 |
2021年 | 87篇 |
2020年 | 259篇 |
2019年 | 102篇 |
2018年 | 209篇 |
2017年 | 217篇 |
2016年 | 177篇 |
2015年 | 205篇 |
2014年 | 326篇 |
2013年 | 423篇 |
2012年 | 419篇 |
2011年 | 486篇 |
2010年 | 344篇 |
2009年 | 388篇 |
2008年 | 382篇 |
2007年 | 344篇 |
2006年 | 305篇 |
2005年 | 309篇 |
2004年 | 364篇 |
2003年 | 355篇 |
2002年 | 362篇 |
2001年 | 212篇 |
2000年 | 171篇 |
1999年 | 167篇 |
1998年 | 200篇 |
1997年 | 202篇 |
1996年 | 192篇 |
1995年 | 190篇 |
1994年 | 167篇 |
1993年 | 188篇 |
1992年 | 203篇 |
1991年 | 179篇 |
1990年 | 213篇 |
1989年 | 164篇 |
1988年 | 145篇 |
1987年 | 167篇 |
1986年 | 80篇 |
1985年 | 103篇 |
1984年 | 113篇 |
1983年 | 99篇 |
1982年 | 46篇 |
1981年 | 27篇 |
1980年 | 15篇 |
1979年 | 14篇 |
1978年 | 13篇 |
1977年 | 14篇 |
1975年 | 16篇 |
1974年 | 16篇 |
1973年 | 16篇 |
排序方式: 共有9698条查询结果,搜索用时 15 毫秒
21.
Sabine Chahory DVM Bernard Clerc DVM PhD Patrick Devauchelle DVM Aziz Tnibar DVM PhD 《Journal of Equine Veterinary Science》2002,22(11)
A 7-year-old Selle français gelding was presented for a recurrent conjunctival tumour on the left eye. A previous histologic analysis revealed a conjunctival squamous cell carcinoma. As it was the third recurrence after surgical excision in a 1½-year period, we decided to perform interstitial radiotherapy combined with the surgical excision. Two Iridium-192 pins were implanted in the subcutaneous fascia of the lower eyelid over the tumor site and were removed 3 days later. No postoperative adverse reactions were observed. Twelve months postoperatively, there were no signs of local recurrence. Surgical excision combined with Iridium-192 therapy appeared to be an effective treatment in this case. 相似文献
22.
23.
24.
D. E. Hudson M. D. Volz B. B. DePhillips Gene A. Mathia Frank Haynes N. A. Wynn Allen E. Abrahams Lewis A. Schaper Paul H. Orr Earl C. Yaeger Combs Joseph Robert L. Mercer T. O. Diener W. B. Raymer R. P. Singh T. J. Morris F. E. Manzer J. A. Frank Otto E. Schultz J. E. Huguelet D. Corsini G. F. Stallknecht J. J. Pavek P. Jatala P. R. Rowe S. J. Turner S. S. Leach Raymon E. Webb D. R. Douglas 《American Journal of Potato Research》1975,52(8):239-248
25.
Background
Phages are thought to play a crucial role in the maintenance of diversity in natural bacterial communities. Theory suggests that phages impose density dependent regulation on bacterial populations, preventing competitive dominants from excluding less competitive species. To test this, we constructed experimental communities containing two bacterial species (Pseudomonas fluorescens and Pseudomonas aeruginosa) and their phage parasites. Communities were propagated at two environmental temperatures that reversed the outcome of competition in the absence of phage. 相似文献26.
27.
28.
Actinobacillus pleuropneumoniae (APP) is the aetiological agent of porcine pleuropneumonia. An increased understanding of its molecular basis of pathogenicity and vaccine development will be facilitated by the availability of sequence data from a complete genome which, by analogy to other bacteria, is predicted to encode many proteins in the molecular mass range 3-20kDa. However, conventional techniques to study bacterial protein expression, such as SDS-PAGE and 2-dimensional electrophoresis, typically focus on the 15-200kDa range. In this study we have evaluated Surface Enhanced Laser Desorption Ionisation-ProteinChip (SELDI) technology for the analysis of protein expression, in particular those of <20kDa, of APP grown under different environmental conditions. Cytoplasmic/periplasmic and outer membrane protein fractions were obtained from the APP wildtype serotype 1 strain 4074 grown in Brain Heart Infusion (BHI) broth (+different concentrations of NAD), BHI containing pig serum or defined medium. Optimum conditions for SELDI profiles included a sample size of 1 microg and the use of sinapinic acid as the energy absorbing matrix. In the <20kDa range, the SELDI profiles obtained from wild-type bacteria grown in rich medium plus 33-66% pig serum were most similar to those grown in defined medium. The SELDI profiles of extracts of the wild-type and of an rpoE mutant were similar although there were clear differences. The results suggest that SELDI is a useful complementary approach to conventional proteomic analytical methods with APP, and presumably other bacterial pathogens, being particularly suited for analysis of proteins in the <20kDa mass range. 相似文献
29.
30.
Allyson C. Berent DVM Jeffrey Todd DVM Jennifer Sergeeff DVM DACVIM Lisa L. Powell DVM DACVECC 《Journal of Veterinary Emergency and Critical Care》2005,15(2):128-135
Objective: To describe diagnostics, therapy, and sequelae of acute carbon monoxide (CO) toxicity because of a motor vehicle generator in 4 dogs and 2 cats. Series summary: Four dogs and 2 cats presented for recumbency, disorientation, dyspnea, and stiffness after an estimated 6–8 hour exposure to exhaust from a generator. Diagnostics included a serum carboxyhemoglobin levels evaluation, arterial blood gas analysis, pulse oximetry readings, and blood pressure measurements. Initial therapy included oxygen (O2) administration, intravenous bronchodilators, fluids, and a hemoglobin‐based O2 carrying (HBOC) molecule. Following administration of the HBOC, 4 of the 6 animals showed dramatic clinical improvement. Two weeks after hospital discharge, the owner reported potential hearing deficits in all animals. Brain auditory evoked response (BAER) tests were conducted in all surviving animals and some degree of hearing impairment was documented in all cases, with complete clinical resolution noted 6 weeks later. Unique information provided: This report describes the therapeutic use of an HBOC in acute isolated CO toxicity (i.e. without the complications of smoke inhalation). In addition, delayed nervous system dysfunction was documented in all surviving animals. 相似文献