全文获取类型
收费全文 | 1562篇 |
免费 | 56篇 |
专业分类
林业 | 97篇 |
农学 | 70篇 |
基础科学 | 1篇 |
280篇 | |
综合类 | 56篇 |
农作物 | 60篇 |
水产渔业 | 238篇 |
畜牧兽医 | 661篇 |
园艺 | 10篇 |
植物保护 | 145篇 |
出版年
2023年 | 6篇 |
2022年 | 21篇 |
2021年 | 20篇 |
2020年 | 16篇 |
2019年 | 14篇 |
2018年 | 27篇 |
2017年 | 39篇 |
2016年 | 39篇 |
2015年 | 45篇 |
2014年 | 47篇 |
2013年 | 145篇 |
2012年 | 76篇 |
2011年 | 93篇 |
2010年 | 40篇 |
2009年 | 41篇 |
2008年 | 84篇 |
2007年 | 102篇 |
2006年 | 96篇 |
2005年 | 91篇 |
2004年 | 78篇 |
2003年 | 69篇 |
2002年 | 69篇 |
2001年 | 53篇 |
2000年 | 42篇 |
1999年 | 35篇 |
1998年 | 23篇 |
1997年 | 6篇 |
1996年 | 14篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 18篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 15篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1975年 | 10篇 |
1974年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有1618条查询结果,搜索用时 15 毫秒
981.
Watanabe O Ishii J Kitagaki T Okawa H Matsumoto H Kameyama M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(5):573-581
Establishment of a disposal plan for carcasses in advance is important for prevention of epidemics. A disposal plan for contaminated goods such as poultry carcasses infected with highly pathogenic avian influenza (HPAI) virus was studied in Hyogo Prefecture, Japan. We investigated all poultry farms with over 1,000 birds for their locations, species and numbers of birds, structure and size of poultry facilities and land spaces of the farms. Moreover, we judged whether they could dispose of all the carcasses at their farms. In 2005, 5.5 million layers and 2.7 million broilers were being kept. If HPAI had broken out, 44.0% of the farmers could bury all the carcasses, and 65.6% could compost them at their farms. However, 23.4% could not dispose of them except by burning them at incineration facilities. We decided to choose burning first for rapid disposal as long as the virus was not a pandemic type. 相似文献
982.
Tatsuki Yoshinaga Michael J. Miller Kazuki Yokouchi Tsuguo Otake Shingo Kimura Jun Aoyama Shun Watanabe Akira Shinoda Machiko Oya Sachie Miyazaki Kei Zenimoto Ryusuke Sudo Tetsuya Takahashi Hyojin Ahn Ryotaro Manabe Seishi Hagihara Hiroshi Morioka Hikaru Itakura Masamichi Machida Kazuyuki Ban Mayu Shiozaki Bunpei Ai Katsumi Tsukamoto 《Fisheries Science》2011,77(6):983-992
Eggs of the Japanese eel Anguilla japonica collected in the western North Pacific were identified by onboard species-specific polymerase chain reaction (PCR) and DNA nucleotide sequencing after the cruise. Fish eggs of various species were collected by large plankton net tows at 12 stations along the southern part of the West Mariana Ridge on 19–25 May 2009. A total of 43 fish eggs were distinguished morphologically as possibly being of A. japonica. Thirty-one of those were analyzed by PCR, which included 15 eggs collected at 12°50–55′N, 141°15–20′E (in 5 tows) that showed positive results. The 16S ribosomal RNA (rRNA) gene sequences of eggs determined after the cruise indicated that 31 A. japonica eggs had been collected. The remaining eggs were of mesopelagic eel species (Serrivomeridae and Derichthyidae), or unidentified species. The morphological characteristics of the A. japonica eggs were consistent with those of artificially spawned eggs, except they had a slightly larger diameter. The egg diameter range did not overlap with those of mesopelagic eels of the Serrivomeridae, which often spawn in the same area as A. japonica. These results suggest that egg diameter and embryo shape can be used to morphologically identify naturally spawned A. japonica eggs. 相似文献
983.
Yong Li Takeshi Watanabe Jun Murase Susumu Asakawa Makoto Kimura 《Journal of Soils and Sediments》2014,14(9):1587-1598
Purpose
Nitrification is a key process in the global nitrogen cycle, of which the first and rate-limiting step is catalyzed by ammonia monooxygenase. Root cap cells are one of substrates for microorganisms that thrive in the rhizosphere. The degradation of root cap cells brings about nitrification following ammonification of organic nitrogen derived from the root cap cells. This study was designed to gain insights into the response of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) to mineralized N from root cap cells and the composition of active bacterial and archaeal ammonia oxidizers in rice soil.Materials and methods
Rice callus cells were used as a model for root cap cells, and unlabelled (12C) and 13C-labelled callus cells were allowed to decompose in aerobic soil microcosms. Real-time quantitative polymerase chain reaction (PCR), DNA-based stable isotope probing (SIP), and denaturing gradient gel electrophoresis (DGGE) were applied to determine the copy number of bacterial and archaeal amoA genes and the composition of active AOB and AOA.Results and discussion
The growth of AOB was significantly stimulated by the addition of callus cells compared with the growth of AOA with a much lesser extent. AOB communities assimilated 13C derived from the callus cells, whereas no AOA communities grew on 13C-callus. Sequencing of the DGGE bands in the SIP experiments revealed that the AOB communities belonging to Nitrosospira spp. dominated microbial ammonia oxidation with rice callus amendment in soil.Conclusions
The present study suggests that root cap cells of rice significantly stimulated the growth of AOB, and the active members dominating microbial ammonia oxidation belonged to Nitrosospira spp. in rice rhizosphere. 相似文献984.
Gutiérrez Iris R. Watanabe Naoko Harter Thomas Glaser Bruno Radke Michael 《Journal of Soils and Sediments》2010,10(3):537-544
Purpose
Up to 90% of antibiotics that are fed to livestock are excreted unaltered or as metabolites and thus are present in manure. By application of manure as fertilizer, veterinary antibiotics can reach soil and groundwater. The aim of this study is to determine the effect of three commonly used (and simultaneously applied) sulfonamide antibiotics on both function and structural diversity of soil microorganisms. To this end, the activity of the enzymes urease and dehydrogenase was determined, and the composition of phospholipid fatty acids (PLFA) was analyzed. 相似文献985.
F(1) is an adenosine triphosphate (ATP)-driven motor in which three torque-generating β subunits in the α(3)β(3) stator ring sequentially undergo conformational changes upon ATP hydrolysis to rotate the central shaft γ unidirectionally. Although extensive experimental and theoretical work has been done, the structural basis of cooperative torque generation to realize the unidirectional rotation remains elusive. We used high-speed atomic force microscopy to show that the rotorless F(1) still "rotates"; in the isolated α(3)β(3) stator ring, the three β subunits cyclically propagate conformational states in the counterclockwise direction, similar to the rotary shaft rotation in F(1). The structural basis of unidirectionality is programmed in the stator ring. These findings have implications for cooperative interplay between subunits in other hexameric ATPases. 相似文献
986.
Yu Hsuan Wang Ji Seon Yoon Ryoko Okamura Kaori Ide Manabu Ohyama Toshio Nishiyama Toshiroh Iwasaki Koji Nishifuji 《Veterinary dermatology》2013,24(1):77-e20
Background – Keratinocytes in the hair follicle bulge region have a high proliferative capacity, with characteristics of epithelial stem cells. This cell population might thus be an ideal source for generating the interfollicular epidermis in a canine skin equivalent. Hypothesis/Objectives – This study was designed to determine the ability of canine hair follicle bulge cell‐enriched keratinocytes to construct canine living skin equivalents with interfollicular epidermis in vitro. Animals – Four healthy beagle dogs from a research colony. Methods – Bulge cell‐enriched keratinocytes showing keratin 15 immunoreactivity were isolated from canine hair follicles and cultured on dermal equivalent containing canine fibroblasts. Skin equivalents were subjected to histological, immunohistochemical, western blot and RT‐PCR analyses after 10–14 days of culture at the air–liquid interface. Results – The keratinocyte sheets showed an interfollicular epidermal structure comprising four to five living cell layers covered with a horny layer. Immunoreactivities for keratin 14 and desmoglein 3 were detected in the basal and immediate suprabasilar layers of the epidermis, while keratin 10 and desmoglein 1 occurred in more superficial layers. Claudin 1 immunoreactivity was seen in the suprabasalar layer of the constructed epidermis, and filaggrin monomers and loricrin were detected in the uppermost layer. Basal keratinocytes in the skin equivalent demonstrated immunoreactivity to antibodies against basement membrane zone molecules. Conclusions and clinical importance – A bulge stem cell‐enriched population from canine hair follicles formed interfollicular epidermis within 2 weeks in vitro, and thus represents a promising model for regenerative therapy of canine skin. 相似文献
987.
988.
Taira O Suzuki M Takeuchi Y Aramaki Y Sakurai I Watanabe T Motokawa K Arai S Sato H Maehara N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(5):543-545
Two kinds of FeIFN-alpha consisting of 166 amino acids (aa) and 171 aa were expressed in Escherichia coli, and the purified proteins were tested for antiviral activity on homologous and heterologous animal cells. Crude FeIFN induced in feline cells revealed antiviral activity on both homologous and heterologous animal cells. In contrast, both types of recombinant FeIFN-alpha revealed antiviral activity only on the feline cells. All of the FeIFN-alpha subtypes showed high activity to vesicular stomatitis virus, and the three species of feline viruses belonging to different families. 相似文献
989.
对科尔沁西部典型重度碱化草地进行了改良试验研究,采用的方法包括翻耙补播沙打旺Astragalus adsurgens、施N肥、施土壤改良剂(石膏).经过3年改良试验,结果表明,这些技术的有机结合可以显著地提高碱化草甸草地牧草的产量和质量,土壤理化性质明显改善:翻耙补播沙打旺增加草地产量2.18~3.52倍;土壤容重、pH值、含盐量下降;土壤水分状况、孔隙度、有机C、全N、速效N、速效P等均明显增加;在翻耙补播的基础上施用(NH4)2SO4 75~225 kg/hm2和CaSO4 1 500~4 500 kg/hm2,牧草产量可分别提高4.5%~20.2%和17.4%~49.9%. 相似文献
990.
Enache DI Edwards JK Landon P Solsona-Espriu B Carley AF Herzing AA Watanabe M Kiely CJ Knight DW Hutchings GJ 《Science (New York, N.Y.)》2006,311(5759):362-365
The oxidation of alcohols to aldehydes with O2 in place of stoichiometric oxygen donors is a crucial process for the synthesis of fine chemicals. However, the catalysts that have been identified so far are relatively inactive with primary alkyl alcohols. We showed that Au/Pd-TiO2 catalysts give very high turnover frequencies (up to 270,000 turnovers per hour) for the oxidation of alcohols, including primary alkyl alcohols. The addition of Au to Pd nanocrystals improved the overall selectivity and, using scanning transmission electron microscopy combined with x-ray photoelectron spectroscopy, we showed that the Au-Pd nanocrystals were made up of a Au-rich core with a Pd-rich shell, indicating that the Au electronically influences the catalytic properties of Pd. 相似文献