全文获取类型
收费全文 | 80篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
林业 | 2篇 |
农学 | 1篇 |
基础科学 | 1篇 |
1篇 | |
综合类 | 25篇 |
农作物 | 8篇 |
水产渔业 | 6篇 |
畜牧兽医 | 41篇 |
园艺 | 2篇 |
植物保护 | 3篇 |
出版年
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 2篇 |
2010年 | 6篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1960年 | 1篇 |
1948年 | 1篇 |
1945年 | 1篇 |
1944年 | 1篇 |
1943年 | 1篇 |
1941年 | 1篇 |
1938年 | 1篇 |
1936年 | 2篇 |
1934年 | 1篇 |
1931年 | 1篇 |
1924年 | 1篇 |
1914年 | 1篇 |
1913年 | 1篇 |
1909年 | 1篇 |
1892年 | 1篇 |
1891年 | 1篇 |
1884年 | 1篇 |
排序方式: 共有90条查询结果,搜索用时 15 毫秒
11.
Comparative Earth History and Late Permian Mass Extinction 总被引:6,自引:0,他引:6
The repeated association during the late Neoproterozoic Era of large carbon-isotopic excursions, continental glaciation, and stratigraphically anomalous carbonate precipitation provides a framework for interpreting the reprise of these conditions on the Late Permian Earth. A paleoceanographic model that was developed to explain these stratigraphically linked phenomena suggests that the overturn of anoxic deep oceans during the Late Permian introduced high concentrations of carbon dioxide into surficial environments. The predicted physiological and climatic consequences for marine and terrestrial organisms are in good accord with the observed timing and selectivity of Late Permian mass extinction. 相似文献
12.
Assembly of chick brain tubulin onto isolated basal bodies of Chlamydomonas reinhardi 总被引:26,自引:0,他引:26
W J Snell W L Dentler L T Haimo L I Binder J L Rosenbaum 《Science (New York, N.Y.)》1974,185(148):357-360
Basal bodies isolated from Chlamydomonas reinhardi will serve as initiation centers for the assembly of chick brain microtubule protein subunits (tubulin) into microtubules. The rate of microtubule assembly is tubulin-concentration dependent; this assembly occurs onto both distal and proximal ends of the basal body mnicrotubules, with distal assembly greatly favored. In vitro assembly of brain tubulin also occurs onto the mid-lateral aspects of the basal bodies, presumably onto the fiber connecting the two basal bodies. 相似文献
13.
14.
Assumption of a water-impermeable coat on bacterial spores is inconsistent with known permeabilities of organic materials. A low water content may arise through compressive contraction of the cortex during spore maturation. 相似文献
15.
16.
17.
Colin F Quinn John L Freeman Ray JB Reynolds Jennifer J Cappa Sirine C Fakra Matthew A Marcus Stormy D Lindblom Erin K Quinn Lindsay E Bennett Elizabeth AH Pilon-Smits 《BMC ecology》2010,10(1):19
Background
Hyperaccumulation, the rare capacity of certain plant species to accumulate toxic trace elements to levels several orders of magnitude higher than other species growing on the same site, is thought to be an elemental defense mechanism against herbivores and pathogens. Previous research has shown that selenium (Se) hyperaccumulation protects plants from a variety of herbivores and pathogens. Selenium hyperaccumulating plants sequester Se in discrete locations in the leaf periphery, making them potentially more susceptible to some herbivore feeding modes than others. In this study we investigate the protective function of Se in the Se hyperaccumulators Stanleya pinnata and Astragalus bisulcatus against two cell disrupting herbivores, the western flower thrips (Frankliniella occidentalis) and the two-spotted spider mite (Tetranychus urticae). 相似文献18.
MIN SU LEE JEFF KO AH RA LEE IN HYE LEE MI AE JUNG BRENDA AUSTIN HYUNWOO CHUNG SANGSOEP NAHM KIDONG EOM 《Veterinary radiology & ultrasound》2010,51(2):130-135
The purpose of this study was to assess the effects of four anesthetic protocols on normal canine brain uptake of 2‐deoxy‐2‐[18F]fluoro‐d ‐glucose (FDG) using positron emission tomography/computed tomography (PET/CT). Five clinically normal beagle dogs were anesthetized with (1) propofol/isoflurane, (2) medetomidine/pentobarbital, (3) xylazine/ketamine, and (4) medetomidine/tiletamine–zolazepam in a randomized cross‐over design. The standard uptake value (SUV) of FDG was obtained in the frontal, parietal, temporal and occipital lobes, cerebellum, brainstem and whole brain, and compared within and between anesthetic protocols using the Friedman test with significance set at P<0.05. Significant differences in SUVs were observed in various part of the brain associated with each anesthetic protocol. The SUV for the frontal and occipital lobes was significantly higher than in the brainstem in all dogs. Dogs receiving medetomidine/tiletamine–zolazepam also had significantly higher whole brain SUVs than the propofol/isoflurane group. We concluded that each anesthetic protocol exerted a different regional brain glucose uptake pattern. As a result, when comparing brain glucose uptake using PET/CT, one should consider the effects of anesthetic protocols on different regions of the glucose uptake in the dog's brain. 相似文献
19.
AH RA LEE MIN SU LEE IN SEONG JUNG DAE YOUNG KIM SANG SEOP NHAM HYUN WOO CHUNG KIDONG EOM 《Veterinary radiology & ultrasound》2010,51(2):145-147
An 8‐year‐old Shih Tzu developed abdominal pain and hyperglobulinemia. A round splenic mass was noted radiographically and sonographically. The patient was evaluated by fluorodeoxyglucose positron emission tomography coupled with computed tomography (FDG‐PET/CT). There was no evidence of metastasis or bone marrow involvement on PET/CT images. The standardized uptake value (SUV) of the splenic mass was increased over the reference range (SUV=4.83). The patient was diagnosed as splenic extramedullary plasmacytoma through immunohistopathologic study. After the splenectomy, the globulin level normalized and the patient is alive without complications. 相似文献
20.