全文获取类型
收费全文 | 232篇 |
免费 | 36篇 |
国内免费 | 3篇 |
专业分类
林业 | 2篇 |
农学 | 4篇 |
基础科学 | 5篇 |
23篇 | |
综合类 | 68篇 |
农作物 | 7篇 |
水产渔业 | 10篇 |
畜牧兽医 | 132篇 |
园艺 | 4篇 |
植物保护 | 16篇 |
出版年
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 3篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 17篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 14篇 |
2012年 | 18篇 |
2011年 | 12篇 |
2010年 | 11篇 |
2009年 | 10篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 2篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1979年 | 3篇 |
1974年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1964年 | 1篇 |
1955年 | 1篇 |
1953年 | 3篇 |
1952年 | 1篇 |
1951年 | 2篇 |
1949年 | 2篇 |
1944年 | 1篇 |
排序方式: 共有271条查询结果,搜索用时 15 毫秒
1.
N. LA PORTA P. CAPRETTI K. KAMMIOVIRTA R. KARJALAINEN & K. KORHONEN 《Plant pathology》1997,46(5):773-784
Eighty-six Heterobasidion annosum isolates, mainly belonging to the F intersterility group and obtained from 32 different geographical localities in Italy, were subjected to genetic analysis by the Random Amplified Polymorphic DNA (RAPD) markers. The similarity between F and S groups was higher than that between F and P. In UPGMA Cluster Analysis, the F isolates originating from the same locality usually grouped in the same cluster. The isolates also showed a tendency to group at the level of larger geographical areas. Within the F group, isolates from the south of the Italian peninsula showed the highest genetic variation and northern isolates from the Alpine regions showed the lowest. This indicates a gradual cline along the peninsula. The genetic variability in the Italian F group is discussed in relation to the past and present distribution of the host species in Italy and Europe. 相似文献
2.
Laryngeal mask airway and transient hypercapnic hyperpnea for video‐endoscopic assessment of unilateral laryngeal paralysis in dogs
下载免费PDF全文
![点击此处可从《Veterinary surgery : VS》网站下载免费的PDF全文](/ch/ext_images/free.gif)
3.
甜菜SSR反应体系优化及重要农艺性状分子标记 总被引:5,自引:0,他引:5
[目的]为选育优质甜菜新品种,利用SSR法筛选与高糖、高产、耐盐相关的分子标注.[方法]研究对甜菜SSR-PCR反应体系进行优化,并利用SSR分子标记方法和分离群体分组分析法(Bulked SegregateAnalysis,BSA)对具有高糖/低糖、低产/高产、耐盐/不耐盐三种重要农艺性状的甜菜亲本和F2代植株进行分析.[结果]研究建立了适宜甜菜的SSR-PCR反应体系为:20μL反应体系中含l×Buffer、2.0 mmol/LMg2+、1.5 uTaq DNA聚合酶、0.20 mmol/L dNTP、1.5 μmol/L引物、60 ng DNA模板.依据优化体系,对不同农艺性状的甜菜亲本与F2代进行SSR-PCR扩增分析,高糖性状获得了200和100 bp两条与高糖性状连锁的标记,250和230 bp两条与高产性状连锁的标记,550、250和100 bp三条与耐盐性状紧密连锁的分子标记.[结论]研究获得的7条特异条带是与甜菜重要农艺性状连锁的分子标记,将为甜菜的育种工作提供重要的理论基础. 相似文献
4.
【目的】为鉴定绵羊乳酸脱氢酶β(lactate dehydrogenase B,LDHβ)基因的分子特征,研究其在不同剩余采食量绵羊肝脏和肌肉组织中的表达差异.【方法】测定了137只‘湖羊’公羔的剩余采食量(residual feed intake,RFI),按RFI进行排序,分别筛选出RFI最高(high-residual feed intake,H-RFI)和RFI最低(low-residual feed intake,L-RFI)的羊各15只,屠宰后,采集肝脏和肌肉组织,利用Q-PCR技术检测绵羊LDHβ基因分别在H-RFI和L-RFI羊肝脏和肌肉中表达量,并利用生物信息学软件构建了该基因的系统进化树和预测其结构与功能.【结果】绵羊LDHβ基因开放阅读框(open reading frame,ORF)为1 005bp,编码334个氨基酸,其蛋白质分子质量为36 479.43U,理论等电点为6.40.绵羊LDHβ基因与山羊的亲缘关系较近,其次为牛,序列同源性高.功能结构域预测结果显示,该基因编码产物在内质网中参与辅酶因子生物合成的可能性最高.Q-PCR结果显示,绵羊LDHβ-mRNA基因在L-RFI羊肝脏和肌肉中表达量均显著低于H-RFI羊(P0.01).【结论】绵羊LDHβ基因作为能量代谢的关键酶参与绵羊饲料效率的调控. 相似文献
5.
LA Barre W McAllester DP Slotkin JS Stewart OC Tax S 《Science (New York, N.Y.)》1951,114(2970):582-583
6.
Palmer AC Callanan JJ Guerin LA Sheahan BJ Stronach N Franklin RJ 《The Veterinary record》2001,149(2):49-54
Progressive ataxia, with head tremor, developed in 10 captive-born cheetah cubs under six months of age. The condition was usually preceded by coryza and an ocular discharge. Initially the ataxia and weakness affected the hindquarters, then the forelegs, and head tremor developed later. Significant pathological changes were confined to the central nervous system. There was widespread Wallerian degeneration in the funiculi of the spinal cord (except those in the dorsal columns), in the medulla and in the cerebellum. In the cerebellum there was degeneration of Purkinje cells and of the molecular and granular cell layers. There was chromatolysis in the Purkinje cells, the ventral horn cells of the spinal cord and in the neurons of the lateral vestibular nucleus. The olivary nucleus was necrotic. There were foci of inflammatory cells in the molecular layer of the cerebellum and in the medulla. The cause of the disease remains unknown. 相似文献
7.
Seasonal patterns of dispersal of ascospores of Cryphonectria parasitica (chestnut blight) 总被引:1,自引:0,他引:1
Infected barks of chestnut blight cankers, caused by Cryphonectria parasitica , were collected from a naturally infected orchard and incubated at different temperatures. Cankers started to discharge ascospores about a week after incubation at 15–25°C; most ascospores were collected at 20 and 25°C. When incubated at 5, 10 or 30°C, only a few cankers released a small number of ascospores and only during the later stages of incubation. However, the rate of formation of perithecia was not affected by the incubation temperature. The number of airborne ascospores was monitored using a volumetric spore trap in a chestnut orchard during 1996 and 1997. In both years, the number of ascospores trapped daily varied greatly, but in general it increased sharply from March onwards, reached a peak in May, and then declined steeply. There was a significant correlation between daily counts of ascospores and air temperature. Time-series transfer function (TF) analysis showed a positive association of the daily number of ascospores with increasing temperature, rain events and wet/humid conditions. In general, values predicted by the TF model agreed well with the observed pattern. However, a multiple regression equation based on TF analysis failed to provide a satisfactory prediction of the daily number of ascospores. 相似文献
8.
9.
10.
B Keeley M Glyde S Guerin R Doyle 《Veterinary and comparative orthopaedics and traumatology》2007,20(3):198-203
Multiple ligament injuries of the canine and feline stifle joint which result in luxation are uncommon. Two cats and one dog, that had sustained such a joint injury were surgically treated. A rupture of the cranial and caudal cruciate ligaments, and at least one collateral ligament was observed in all of the three animals. Prosthetic reconstruction was used, as previously described, in combination with a novel technique of intraoperative placement of a temporary trans-articular pin (TTP) to maintain intra-operative anatomical reduction. TTP placement facilitated maintenance of joint alignment during surgical reconstruction and aided appropriate tensioning of the prosthetic sutures, preventing collapse of femorotibial joint compartments. The TTP was removed prior to closure of the joint allowing immediate post-operative joint mobilisation. Based on assessment by their owners, all the animals made a complete recovery. TTP was considered a relatively simple and effective adjunctive aid for surgical treatment of traumatic luxation of the stifle joint. 相似文献