全文获取类型
收费全文 | 1169篇 |
免费 | 34篇 |
国内免费 | 1篇 |
专业分类
林业 | 116篇 |
农学 | 43篇 |
基础科学 | 5篇 |
190篇 | |
综合类 | 96篇 |
农作物 | 41篇 |
水产渔业 | 164篇 |
畜牧兽医 | 432篇 |
园艺 | 21篇 |
植物保护 | 96篇 |
出版年
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 16篇 |
2020年 | 11篇 |
2019年 | 18篇 |
2018年 | 14篇 |
2017年 | 20篇 |
2016年 | 29篇 |
2015年 | 15篇 |
2014年 | 44篇 |
2013年 | 98篇 |
2012年 | 63篇 |
2011年 | 68篇 |
2010年 | 39篇 |
2009年 | 47篇 |
2008年 | 65篇 |
2007年 | 64篇 |
2006年 | 64篇 |
2005年 | 71篇 |
2004年 | 52篇 |
2003年 | 55篇 |
2002年 | 29篇 |
2001年 | 45篇 |
2000年 | 47篇 |
1999年 | 28篇 |
1998年 | 14篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1993年 | 11篇 |
1992年 | 7篇 |
1991年 | 13篇 |
1990年 | 15篇 |
1989年 | 6篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1972年 | 3篇 |
1968年 | 4篇 |
排序方式: 共有1204条查询结果,搜索用时 0 毫秒
61.
Maeda Y Tanaka R Ohtsuka H Matsuda K Tanabe T Oikawa M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(7):957-960
This study compared the immunosuppressive effects of dexamethasone (DEX), flunixin meglumine (FLU) and meloxicam (MEL) on the peripheral blood mononuclear cells (PBMCs) of seven healthy Holstein calves in vitro. DEX significantly inhibited lymphocyte proliferation and expression of interferon (IFN)-γ, interleukin (IL)-2 and IL-4 messenger RNA (mRNA) in comparison with FLU and MEL. FLU and MEL dose-dependently inhibited lymphocyte proliferation, but did not significantly reduce mRNA expression. Our in vitro study indicates that steroidal anti-inflammatory drugs (SAIDs) as well as nonsteroidal anti-inflammatory drugs (NSAIDs) have immunosuppressive effects on calf PBMCs. These findings are important for assessing the indications and complications of NSAIDs in calves. 相似文献
62.
Soichi Tanaka Keiichiro Shiraga Yuichi Ogawa Yoshihisa Fujii Shogo Okumura 《Journal of Wood Science》2014,60(2):111-116
The use of an effective medium theory is important when accurately measuring wood density using millimeter and terahertz wave techniques. To confirm the applicability of this theory to the evaluation of wood density, the relative permittivity and dielectric loss of oven-dry flat-sawn specimens of 11 different wood species were measured in a frequency range of 0.15–1.2 THz using a transmission measurement system for terahertz time-domain spectroscopy. A mixture model based on the effective medium theory well explained the density dependence of relative permittivity over the entire frequency range, while it did not fully explain that of dielectric loss, especially for higher frequencies. This indicates that wood scatters the terahertz wave with a wavelength close to the transverse sectional dimensions of the pores in wood in the same way as Mie scattering. It was found from the dielectric loss spectrum of wood substance that the frequency around 0.23 THz was preferable for the nondestructive evaluation of wood. 相似文献
63.
Effects of high dose of vitamin A on reproduction and egg quality of Japanese flounder Paralichthys olivaceus 总被引:2,自引:0,他引:2
Hirofumi Furuita Hideki Tanaka Takeshi Yamamoto Manabu Shiraishi Toshio Takeuchi 《Fisheries Science》2001,67(4):606-613
ABSTRACT: The present study was conducted to investigate the effects of dietary vitamin A on reproduction and egg quality in Japanese flounder Paralichthys olivaceus . Broodstock were fed experimental pellets containing two levels of vitamin A [11 × 103 IU/100 g (control diet; CD), 337 × 103 IU/100 g (experimental diet; ED)] for approximately 2 months before spawning and during the spawning period. Two groups of five females (average weight 1.4 kg) and 10 males (average weight 0.7 kg) were randomly allocated to two 30 m3 indoor tanks. Total egg production of the CD group was slightly higher than the ED group. Percentage of buoyant eggs and hatching rate of the ED group were significantly higher than the CD. In other egg quality parameters, such as percentage abnormal larvae and starvation tolerance of larvae, no notable difference was found between these two groups. At the end of the experiment, the skin color of broodstock in the ED group was darker than that of the CD group. Vitamin A content in eggs of the ED group was significantly higher than that of the CD group. However, the difference in vitamin A content in eggs between the ED and CD groups was much smaller than that in the liver of the females between the two groups. These results indicate that feeding broodstock a higher level of vitamin A increases the vitamin A content in eggs but does not affect egg quality in Japanese flounder because excess dietary vitamin A was stored mainly in the broodstocks' liver. 相似文献
64.
He RH Hashimoto M Karapetyan H Koralek JD Hinton JP Testaud JP Nathan V Yoshida Y Yao H Tanaka K Meevasana W Moore RG Lu DH Mo SK Ishikado M Eisaki H Hussain Z Devereaux TP Kivelson SA Orenstein J Kapitulnik A Shen ZX 《Science (New York, N.Y.)》2011,331(6024):1579-1583
The nature of the pseudogap phase of cuprate high-temperature superconductors is a major unsolved problem in condensed matter physics. We studied the commencement of the pseudogap state at temperature T* using three different techniques (angle-resolved photoemission spectroscopy, polar Kerr effect, and time-resolved reflectivity) on the same optimally doped Bi2201 crystals. We observed the coincident, abrupt onset at T* of a particle-hole asymmetric antinodal gap in the electronic spectrum, a Kerr rotation in the reflected light polarization, and a change in the ultrafast relaxational dynamics, consistent with a phase transition. Upon further cooling, spectroscopic signatures of superconductivity begin to grow close to the superconducting transition temperature (T(c)), entangled in an energy-momentum-dependent manner with the preexisting pseudogap features, ushering in a ground state with coexisting orders. 相似文献
65.
Protective immunity of sevenband grouper, Epinephelus septemfasciatus Thunberg, against experimental viral nervous necrosis 总被引:9,自引:0,他引:9
This paper describes the protective immune responses of sevenband grouper, Epinephelus septemfasciatus Thunberg, immunized with live piscine nodavirus, the causative agent of viral nervous necrosis (VNN), or the Escherichia coli – expressed recombinant coat protein. Nodavirus-neutralizing antibodies were detected at titres ranging from 1:158 to 1:1257 in serum of sevenband grouper which survived intramuscular injection with the virus, by a cell culture assay system. The virus-neutralizing ability of immune serum was also confirmed by injecting virus previously treated with serum into fish. This indicates establishment of acquired immunity in survivors and thus explains why survivors from natural infection are resistant to recurrence of the disease. Young sevenband grouper were immunized twice by intramuscular injections with the recombinant coat protein. Immunized fish produced neutralizing antibodies at high titres for at least 110 days and showed significantly lower mortalities in virus challenge tests. These results suggest the potential for vaccination against VNN in sevenband grouper, which is susceptible to piscine nodavirus at all life-stages. 相似文献
66.
Ujihara T Taniguchi F Tanaka J Hayashi N 《Journal of agricultural and food chemistry》2011,59(5):1557-1564
To develop cleaved amplified polymorphic sequence (CAPS) markers for cultivar identification of the tea leaf, 5 primer pairs designed on the basis of genes that encode proteins related to nitrogen assimilation and 26 primer pairs based on expressed sequence tag (EST) sequences of the root of tea plant were screened. From combinations of primer pair and restriction enzyme that showed polymorphism among tea plants, 16 markers were selected and applied to DNA fingerprinting of Japanese tea cultivars. Sixty-three cultivars, except for a bud sport (Kiraka) and its original cultivar (Yabukita) and a pair that was the progeny of the same crossing parent (Harumoegi and Sakimidori), were distinguished from one another. By combining the 16 markers with previously developed CAPS markers and observing the physical appearance, 67 cultivars were distinguishable. The cultivars involve approximately 95% of total tea cultivating area in Japan; therefore, about 95% of tea leaves produced in Japan can be authenticated by labeling their cultivars. 相似文献
67.
CO_2施肥时树脂膜培养容器在文心兰试管苗培养中的应用 总被引:4,自引:0,他引:4
采用在培养室内CO2 施肥的方法 ,以C3植物文心兰 (Oncidium)品种‘AlohaIwanaga’试管苗为实验植物材料 ,分别以氟乙烯树脂膜容器 (CP)和三角瓶作为培养容器进行培养 .结果表明 :CO2 施肥时 ,树脂膜培养容器 (CP)内生长的试管苗在株高、叶数、叶长、叶幅、根数、根长、鲜重、干物重、干物率、叶绿素指数 (SPAD值 )等生长指标上高于无CO2施肥处理 .采用SSR法进行比较 (显著水平P≤ 0 0 5 ) ,其中在株高、叶长、叶幅、根数、鲜重、干物重等重要生长指标之间存在显著性差异 .以三角瓶为培养容器时其生长虽优于无CO2 施肥处理 ,但多数指标差异并不显著 .实验证明 ,使用CP作为培养容器 ,培养室内CO2 施肥对促进文心兰试管苗的生长和提高其品质效果明显 . 相似文献
68.
Kyoji Hagiwara Takahiko Higashi Kazunari Takahashi Naho Hara Hideyuki Aoki Naoyuki Miyazaki Qing-Yu Wang Yafeng Zhu Osamu Yatou Hiroshi Tanaka Toshihiro Omura 《Journal of General Plant Pathology》2006,72(3):186-189
Transencapsidation of the Rice gall dwarf virus (RGDV) inner core by the Rice dwarf virus (RDV) outer capsid P8 protein was examined in vitro and in planta. When RGDV core particles were incubated with an extract
from RDV P8-transgenic rice leaf tissue, RDV P8 encapsidated the RGDV core particles to form double-shelled virus-like particles
in vitro. In contrast, when RDV P8-transgenic rice plants were inoculated with RGDV, progeny RGDV particles contained RGDV
P8 but RDV P8 was not detectable in the virions. No significant differences were found in acquisition by the vector insects
and subsequent transmission rates between RGDV infecting nontransgenic rice plants and those infecting RDV P8-transgenic rice
plants. These results indicate that mechanisms of and/or requirements for interactions between P8 and the inner core particles
of phytoreoviruses differ between in vitro and in planta. 相似文献
69.
Reversal of oncogenesis by the expression of a major histocompatibility complex class I gene 总被引:26,自引:0,他引:26
The classical transplantation antigens (the major histocompatibility complex class I antigens) play a key role in host defense against cells expressing foreign antigens. Several naturally occurring tumors and virally transformed cells show an overall suppression of these surface antigens. Since the class I molecules are required in the presentation of neoantigens on tumor cells to the cytotoxic T lymphocytes, their absence from the cell surface may lead to the escape of these tumors from immunosurveillance. To test this possibility, a functional class I gene was transfected into human adenovirus 12-transformed mouse cells that do not express detectable levels of class I antigens; the transformants were tested for expression of the transfected gene and for changes in oncogenicity. The expression of a single class I gene, introduced by DNA-mediated gene transfer into highly tumorigenic adenovirus 12-transformed cells, was sufficient to abrogate the oncogenicity of these cells. This finding has important implications for the regulation of the malignant phenotype in certain tumors and for the potential modulation of oncogenicity through derepression of the endogenous class I genes. 相似文献
70.
S. Tanaka S. Suzuki T. Teshima R. Yamashita Y. Hamamoto Y. Hara 《The Journal of small animal practice》2023,64(2):111-117
An 8.0-kg 8-year-old male dachshund was presented for surgical treatment of suspected pituitary-dependent hyperadrenocorticism with portal vein thrombosis. Advanced diagnostic imaging revealed a thrombus in the splenic and portal veins. For the portal vein thrombus, CT angiography showed an enhanced timing delay in the lateral right and caudate liver lobes. Blood tests showed a marked increase in the liver panel, including total bile acid. Brain MRI revealed a pituitary mass, suggesting pituitary-dependent hyperadrenocorticism. The mass was completely resected. The preoperative antithrombotic therapy of rivaroxaban (0.66 mg/kg, PO, once per day) and clopidogrel sulphate (1.66 mg/kg, PO, once per day) was continued postoperatively. Six months after resection of the pituitary mass, the thrombus had disappeared. Further studies are required to prove a causal association between the disappearance of the thrombus and the treatments provided. 相似文献