全文获取类型
收费全文 | 644篇 |
免费 | 42篇 |
专业分类
林业 | 20篇 |
农学 | 14篇 |
基础科学 | 1篇 |
44篇 | |
综合类 | 130篇 |
农作物 | 8篇 |
水产渔业 | 23篇 |
畜牧兽医 | 417篇 |
园艺 | 14篇 |
植物保护 | 15篇 |
出版年
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 12篇 |
2018年 | 6篇 |
2016年 | 15篇 |
2015年 | 5篇 |
2014年 | 14篇 |
2013年 | 28篇 |
2012年 | 19篇 |
2011年 | 15篇 |
2010年 | 12篇 |
2009年 | 24篇 |
2008年 | 33篇 |
2007年 | 28篇 |
2006年 | 17篇 |
2005年 | 17篇 |
2004年 | 35篇 |
2003年 | 12篇 |
2002年 | 17篇 |
2001年 | 20篇 |
2000年 | 16篇 |
1999年 | 12篇 |
1998年 | 19篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 15篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 17篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1974年 | 12篇 |
1973年 | 11篇 |
1972年 | 5篇 |
1971年 | 6篇 |
1970年 | 6篇 |
1966年 | 4篇 |
1942年 | 4篇 |
1911年 | 4篇 |
排序方式: 共有686条查询结果,搜索用时 31 毫秒
101.
102.
Summary The pathology of adenovirus pneumonia in 16 dogs is described. Clinically, these dogs had been severely ill, with severe dyspnoea and listlessness, but only faint coughing. Histopathological lesions could be associated directly with the presence of adenovirus antigens in the lungs of these dogs by using an unlabelled immunoperoxidase technique on paraffin tissue sections. The lesions were focal and located in alveoli and bronchioles. Infected cells were mostly alveolar macrophages and less frequently type I and 2 pneumocytes and bronchiolar epithelial cells. Infiltrating neutrophils and lymphocytes were not observed to be infected. This type of pneumonia appears to be a fairly well defined clinical and pathological entity in kennel dogs. 相似文献
103.
Abstract CASE HISTORY: A 13-year-old Thoroughbred mare was presented with a history of mild colic over 3 days. This colic had acutely exacerbated and was unresponsive to analgesic treatment, and was referred to Massey University Veterinary Teaching Hospital. CLINICAL FINDINGS: On examination the heart rate was 100 beats per minute, and mucous membranes were pale and tacky. A large mass was detected on transrectal palpation in the caudal abdomen to the left of midline. Explorative laparotomy revealed severe haemoperitoneum and several masses that were associated with the reproductive tract. The mare was then subject to euthanasia. On post-mortem examination, adjacent and attached to each ovary were soft, lobulated dark red masses up to 200 mm in diameter. Similar masses were present in the omentum and on the peritoneal surface of the diaphragm and the serosa of the spleen and liver. Histopathology revealed that the neoplastic component of the masses comprised proliferating cuboidal to columnar cells forming disorganised acini and cords separated by dense collagenous stroma. Immunohistochemistry showed the neoplastic cells were positive for cytokeratin AE1/AE3 and vimentin, but negative for cytokeratin 7 and inhibin α. DIAGNOSIS: Bilateral ovarian adenocarcinoma with transcoelomic metastasis and terminal decompensation due to rupture of a neoplastic mass and consequent haemoperitoneum. CLINICAL RELEVANCE: To the authors' knowledge, bilateral ovarian adenocarcinoma has not been previously reported in a horse. Ovarian adenocarcinoma should be considered when horses present with haemoperitoneum and colic. Further research is required on the immunohistochemical differentiation of adenocarcinoma of ovarian and intestinal origin in the horse. 相似文献
104.
105.
106.
The effect of intravenous fresh frozen plasma administration on fibrinogen and albumin concentrations in sick neonatal foals
下载免费PDF全文
![点击此处可从《Equine Veterinary Education》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. R. Hollis P. A. Wilkins B. Tennent‐Brown J. E. Palmer R. C. Boston 《Equine Veterinary Education》2016,28(3):145-149
This study investigated the immediate (6 h or less) effects of fibrinogen and albumin contained in transfused equine origin fresh frozen plasma on those proteins when measured in sick neonatal foals. Fibrinogen and albumin concentrations were measured in the administered plasma and in 31 sick foals at admission to a referral neonatal intensive care unit. Additional samples were obtained from the foals at 2 and 6 h following transfusion. No changes in albumin concentration were recognised. The main determinant of fibrinogen concentration following transfusion was the concentration of fibrinogen in the foal at admission. Importantly, intravenous transfusion of equine fresh frozen plasma did not result in immediate (6 h or less) increases or decreases in the fibrinogen concentration in the recipient foals. Fibrinogen from the donor contained within transfused plasma will not directly affect fibrinogen concentrations measured at later times. 相似文献
107.
Mitchell?A.?Ellison Michael?B.?McMahon Morris?R.?Bonde Cristi?L.?Palmer Douglas?G.?LusterEmail authorView authors OrcID profile 《Plant methods》2016,12(1):37
Background
Rust fungi are obligate pathogens with multiple life stages often including different spore types and multiple plant hosts. While individual rust pathogens are often associated with specific plants, a wide range of plant species are infected with rust fungi. To study the interactions between these important pathogenic fungi and their host plants, one must be able to differentiate fungal tissue from plant tissue. This can be accomplished using the In situ hybridization (ISH) protocol described here.Results
To validate reproducibility using the ISH protocol, samples of Chrysanthemum × morifolium infected with Puccinia horiana, Gladiolus × hortulanus infected with Uromyces transversalis and Glycine max infected with Phakopsora pachyrhizi were tested alongside uninfected leaf tissue samples. The results of these tests show that this technique clearly distinguishes between rust pathogens and their respective host plant tissues.Conclusions
This ISH protocol is applicable to rust fungi and potentially other plant pathogenic fungi as well. It has been shown here that this protocol can be applied to pathogens from different genera of rust fungi with no background staining of plant tissue. We encourage the use of this protocol for the study of plant pathogenic fungi in paraffin embedded sections of host plant tissue.108.
Numerical modeling of the orbital evolution of interplanetary dust particles revealed that, over the past 1.2 million years, the rate of accretion of dust by Earth has varied by a factor of 2 to 3. These variations display a 100,000-year periodicity and are anticorrelated with Earth's changing orbital eccentricity. Extraterrestrial helium-3 concentrations in a deep-sea sediment core display a similar periodicity but are 50,000 years out of phase with the predicted variations. Also, because collisions between large bodies in the asteroid belt are inevitable, it is expected that large-amplitude stochastic variations on 10(7)- to 10(8)-year time scales would be superimposed on the 10(5)-year periodic variations. 相似文献
109.
SJ Glaser T Schulte-Herbruggen M Sieveking O Schedletzky NC Nielsen OW Sorensen C Griesinger 《Science (New York, N.Y.)》1998,280(5362):421-424
Experiments in coherent magnetic resonance, microwave, and optical spectroscopy control quantum-mechanical ensembles by guiding them from initial states toward target states by unitary transformation. Often, the coherences detected as signals are represented by a non-Hermitian operator. Hence, spectroscopic experiments, such as those used in nuclear magnetic resonance, correspond to unitary transformations between operators that in general are not Hermitian. A gradient-based systematic procedure for optimizing these transformations is described that finds the largest projection of a transformed initial operator onto the target operator and, thus, the maximum spectroscopic signal. This method can also be used in applied mathematics and control theory. 相似文献
110.
During the last interglacial, Antarctic climate changed before that of the Northern Hemisphere. Large local changes in precession forcing could have produced this pattern if there were a rectified response in sea ice cover. Results from a coupled sea ice-ocean general circulation model supported this hypothesis when it was tested for three intervals around the last interglacial. Such a mechanism may play an important role in contributing to phase offsets between Northern and Southern Hemisphere climate change for other time intervals. 相似文献