全文获取类型
收费全文 | 470篇 |
免费 | 11篇 |
专业分类
林业 | 27篇 |
农学 | 10篇 |
基础科学 | 1篇 |
36篇 | |
综合类 | 15篇 |
农作物 | 9篇 |
水产渔业 | 51篇 |
畜牧兽医 | 309篇 |
园艺 | 8篇 |
植物保护 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 7篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 9篇 |
2013年 | 25篇 |
2012年 | 21篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 29篇 |
2007年 | 22篇 |
2006年 | 31篇 |
2005年 | 38篇 |
2004年 | 28篇 |
2003年 | 27篇 |
2002年 | 18篇 |
2001年 | 25篇 |
2000年 | 25篇 |
1999年 | 17篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1993年 | 2篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1974年 | 3篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有481条查询结果,搜索用时 0 毫秒
31.
Sera collected from 447 dairy cattle on 14 dairy farms were tested for Neospora caninum antibodies by use of an immunofluorescent antibody technique. Positive reactions with titres > or =1:200 were found in 63 (14.09%) of animals. Neospora positive sera were also tested for Toxoplasma gondii antibodies by using a commercial latex agglutination test. Antibodies to T. gondii were detected in 3 (4.76%) of 63 N. caninum positive sera. These results indicate that N. caninum infection is widespread among dairy cattle in Bahia state. 相似文献
32.
Abstract One of the mechanisms of eosinophil infiltration is its induction by chemoattractants such as regulated upon activation, normal T-expressed and secreted (RANTES) which is a cysteine–cysteine chemokine that mediates chemotaxis and activation of eosinophils in humans and mice. Skin lesions of feline eosinophilic plaque are characterized by a predominant infiltration of eosinophils. The mechanism(s) of eosinophilic infiltration in the skin and/or mucosa of cats is unknown. It is possible that RANTES is involved. To investigate the presence of RANTES in the skin of cats with eosinophilic plaques and nonaffected skin, we cloned and sequenced the full-length feline RANTES cDNA gene, in order to determine whether it is present in the skin of cats with eosinophilic plaques and/or if it is present in normal adjacent skin. We were able to document the the expression of RANTES mRNAs in skin with feline eosinophilic plaque as well as in normal cat skin. The full-length cDNA sequence of the RANTES gene (742 bp) contained a single open reading frame of 276 bp encoding a protein of 92 amino acids. The amino acid sequence of feline RANTES shared 67 and 74% sequence identity with that of bovine and mouse RANTES genes, respectively. RT–PCR analysis on RANTES mRNA in the skin of cats with eosinophilic plaque revealed that its expression was higher in the eosinophilic plaque skin lesions than in the normal skin. The result suggested that RANTES might play a role to induce eosinophil infiltration in feline eosinophilic plaque lesions. 相似文献
33.
Distribution, host preference and pathogenicity of Japanese Armillaria species on conifers were investigated on the basis of field collections of 65 isolates. We identified seven Armillaria species from 19 conifer species including six major Japanese plantation conifers using mating tests and sequences of the translation elongation‐1 α gene. Armillaria mellea, Armillaria ostoyae, Armillaria cepistipes and Armillaria sinapina were frequently collected, whereas Armillaria nabsnona, Armillaria tabescens and a biological species Nagasawa’s E were rare. On the basis of host condition when the isolates were collected, A. mellea, A. ostoyae, A. cepistipes and A. tabescens are considered as moderate to aggressive pathogens of conifers in Japan. 相似文献
34.
Isolation of new limonoate dehydrogenase from Pseudomonas 总被引:1,自引:0,他引:1
35.
Modification of the reconstruction of an Au(111) surface with a scanning tunneling microscope (STM) is demonstrated. This modification is accomplished by transferring a number of surface atoms to the STM tip to generate a surface multivacancy (hole), which modifies the stress distribution at the surface. The structural changes that follow the tip-induced surface perturbation are imaged in a time-resolved manner. The structural modification is the result of both short-range interactions, which lead to local atomic relaxation, and long-range elastic interactions, which produce large-scale rearrangements. 相似文献
36.
Sugita S Ootsubo T Kadono T Honda M Sako S Miyata T Sakon I Yamashita T Kawakita H Fujiwara H Fujiyoshi T Takato N Fuse T Watanabe J Furusho R Hasegawa S Kasuga T Sekiguchi T Kinoshita D Meech KJ Wooden DH Ip WH A'Hearn MF 《Science (New York, N.Y.)》2005,310(5746):274-278
The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (approximately 10(6) kilograms) of dust and formed two wings approximately +/-45 degrees from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust. 相似文献
37.
Hasegawa K Martin F Huang G Tumas D Diehl L Chan AC 《Science (New York, N.Y.)》2004,303(5658):685-689
Protein tyrosine kinases and phosphatases cooperate to regulate normal immune cell function. We examined the role of PEST domain-enriched tyrosine phosphatase (PEP) in regulating T cell antigen-receptor function during thymocyte development and peripheral T cell differentiation. Although normal na?ve T cell functions were retained in pep-deficient mice, effector/memory T cells demonstrated enhanced activation of Lck. In turn, this resulted in increased expansion and function of the effector/memory T cell pool, which was also associated with spontaneous development of germinal centers and elevated serum antibody levels. These results revealed a central role for PEP in negatively regulating specific aspects of T cell development and function. 相似文献
38.
Although frontal cortex is thought to be important in controlling behavior across long periods of time, most studies of this area concentrate on neuronal responses instantaneously relevant to the current task. In order to investigate the relationship of frontal activity to behavior over longer time periods, we trained rhesus monkeys on a difficult oculomotor task. Their performance fluctuated during the day, and the activity of prefrontal neurons, even measured while the monkeys waited for the targets to appear at the beginning of each set of trials, correlated with performance in a probabilistic rather than a determinist manner: neurons reflected past or predicted future performance, much more than they reflected current performance. We suggest that this activity is related to processes such as arousal or motivation that set the tone for behavior rather than controlling it on a millisecond basis, and could result from ascending pathways that utilize slow, second-messenger synaptic processes. 相似文献
39.
Poly ion complexes of anionic lignosulfonic acid (LSA) with cationic poly(2-vinyl pyridine) or poly(4-vinyl pyridine) were
prepared by mixing the polymer solutions in dimethyl sulfoxide or dilute hydrochloric acid. The complexes were formed as soon
as the polymer solutions were mixed. Fourier transform infrared (FTIR) measurements for the complexes revealed the presence
of strong ionic interactions between sulfonate anions of LSA and pyridinium cations of the vinyl pyridine (VPy) polymers.
The strong interaction was supported by detection of a glass transition temperature (T
g) much higher than pristine T
g values of VPy polymers in differential scanning calorimetry. By using the ionic complexation, a coating of LSA onto VPy polymer
films was undertaken to modify their original surface property. Formation of a thin complex film was confirmed by observation
of absorption bands that are characteristic of the pyridinium cation in reflection FTIR spectra measurements, and by visualization
of the attached LSA component in atomic force microscopy. This treatment resulted in the surface of the VPy polymer films
becoming hydrophobic. An adhesion test was also conducted by pasting two veneered woods with the polymer complex, followed
by shear-tearing them off. The adhesive strength of the complex was estimated to be 1.1 MPa.
Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan
Wood Research Society 相似文献
40.
Glycated hemoglobin fractions in normal and diabetic dogs measured by high performance liquid chromatography. 总被引:1,自引:0,他引:1
S Hasegawa T Sako N Takemura H Koyama S Motoyoshi 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(1):65-68
We established a new analytical condition to measure the canine glycated hemoglobin by high performance liquid chromatography (HPLC) using cation exchange column. The canine hemoglobin gave five peaks consisting of 2 major and 3 minor hemoglobin fractions such as HbA1a, HbA1b and HbA1c. Measurement was done in 38 clinically normal dogs and 10 diabetic dogs. Mean HbA1c values (% of total Hb) in normal and diabetic dogs were 2.60 and 6.41%, respectively. And mean HbA1 values were 3.58 and 7.41%, respectively. The mean values of the canine HbA1c and HbA1 in diabetic dogs was higher than those in normal dogs, significantly (p less than 0.01). Advantages of the HPLC method and applicability for monitoring effectiveness of insulin therapy in the canine diabetes mellitus are discussed. 相似文献