全文获取类型
收费全文 | 356篇 |
免费 | 24篇 |
国内免费 | 1篇 |
专业分类
林业 | 20篇 |
农学 | 16篇 |
35篇 | |
综合类 | 5篇 |
农作物 | 13篇 |
水产渔业 | 66篇 |
畜牧兽医 | 207篇 |
园艺 | 5篇 |
植物保护 | 14篇 |
出版年
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 26篇 |
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 22篇 |
2015年 | 10篇 |
2014年 | 26篇 |
2013年 | 28篇 |
2012年 | 30篇 |
2011年 | 28篇 |
2010年 | 8篇 |
2009年 | 19篇 |
2008年 | 22篇 |
2007年 | 19篇 |
2006年 | 18篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 14篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有381条查询结果,搜索用时 15 毫秒
21.
22.
Satoshi Yamashita Tsutomu Hattori Shin Abe Hideaki Goto Hiroki Sato 《Journal of Forest Research》2014,19(1):143-153
Improvement cutting, which decreases tree density by cutting and thinning while leaving logging residues, has been practiced on Okinawa Island since the 1970s and changes not only the vegetation composition but also the amount and composition of woody debris on the forest floor. To quantitatively compare the effect of improvement cutting with the effects of woody debris and vegetation on the community structure of aphyllophoraceous fungi, we conducted a field survey of vegetation composition, the amount and composition of woody debris, and the aphyllophoraceous fungi flora on Okinawa Island in December 2006. We established 3 plots in forest stands without logging and 13 plots in a forest that had undergone improvement cutting from 1 to 22 years before our field survey. The number and volume of woody debris tended to be highest soon after improvement cutting. We recorded 1,172 fungal samples belonging to 81 species in four orders. Fungal species richness was correlated with the composition of the woody debris. Fungal species composition in forest plots 1 year after improvement cutting differed from most of the other logged forests. Variation partitioning revealed that the effects of improvement cutting explained 14.1 % of the total variation in fungal species composition, and that differences in woody debris and vegetation not related to improvement cutting explained 40.4 %. Changes in the composition of woody debris caused by improvement cutting explained at most 2.7 % of the variation. This suggests that improvement cutting does not have a strong effect on fungal community structure, but woody debris does. 相似文献
23.
N. Naito Y. Koide T. Yada T. Azuma H. Kawauchi 《Fish physiology and biochemistry》2003,28(1-4):103-108
The sandwich cell immunoblot assay confirmed that salmon LH-cells secreted the free form α-subunit along with the dimeric LH, but lower in amounts than the LH. 相似文献
24.
Ramji K. Bhandari Mikihiko Higa Hiroki Komuro Shigeo Nakamura Masaru Nakamura 《Fish physiology and biochemistry》2003,28(1-4):141-142
To study the mechanism of protogynous sex change in honeycomb grouper, the wild fish of both sexes and transitionals were collected for one year, and changes in gonadal structures and serum levels of sex hormones in each individual were examined. The onset of sex change was associated with low serum estradiol - 17β (E2) levels. In order to clarify whether E2 deprivation causes sex change, maturing females were implanted with the non-steroidal aromatase inhibitor (Fadrozole, AI). AI caused complete sex change from female to functional males in two and half months. The present results suggest that E2 is an important endogenous factor which regulates protogynous sex change in the honeycomb grouper. 相似文献
25.
Kozue Yuge Hiroki Maeda Munehiro Tanaka Mitsumasa Anan Yoshiyuki Shinogi 《Paddy and Water Environment》2014,12(3):335-342
Promoting biomass utilization, the objectives of this study were to clarify the spatial distribution of nitrogen, one of the most important fertilizer components in the methane fermentation digested slurry (i.e., the digested slurry), and to establish an effective method to apply spatial-uniformly digested slurry with irrigation water in the rice paddy field. A numerical model describing the unsteady two-dimensional flow and solution transport of paddy irrigation water was introduced. The accuracy of this model was verified with a field observation. The tendencies of the TN simulated in inlet and outlet portions had good agreement with the measured data and the accuracy of the numerical model could be verified. Using the numerical model, scenario analyses were conducted to determine the method for spatial-uniform application of the digested slurry with irrigation water. The simulated results indicated that drainage of the surface water and trenches at the soil surface were effective for spatial-uniform application of the digested slurry with irrigation water in the rice paddy fields. The effect of the trenches was maximized when the surface water of the rice paddy field was drained adequately. 相似文献
26.
27.
Sato R Katayama S Sawabe T Saeki H 《Journal of agricultural and food chemistry》2003,51(15):4376-4381
Carp myofibrillar protein (Mf) was conjugated with alginate oligosaccharide (AO) through the Maillard reaction under low relative humidity, and the functional properties of the Mf-AO conjugate were investigated under different NaCl concentrations and pH levels. Mf became highly solubilized at lower NaCl concentrations by conjugation with AO, with a slight loss of available lysine. The thermal stability of Mf was effectively improved by conjugation with AO. Heat treatment at 80 degrees C for 2 h had no effect on the solubility of the Mf-AO conjugate attached to 227 microg/mg of AO regardless of the NaCl concentration and pH. Furthermore, the Mf-AO conjugate showed excellent emulsion-forming ability regardless of NaCl concentration. The improved functionalities of Mf by conjugation with AO remained even at a nearly isoelectric point. These results indicate that conjugation with AO through the Maillard reaction is an effective way to prepare high-functional food material from fish muscle protein. 相似文献
28.
Lahann J Mitragotri S Tran TN Kaido H Sundaram J Choi IS Hoffer S Somorjai GA Langer R 《Science (New York, N.Y.)》2003,299(5605):371-374
We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy and at a macroscopic level with the use of contact angle measurements. This type of surface design enables amplification of molecular-level conformational transitions to macroscopic changes in surface properties without altering the chemical identity of the surface. Such reversibly switching surfaces may open previously unknown opportunities in interfacial engineering. 相似文献
29.
30.
Growth characteristics of canine distemper virus in a new cell line CCT cells originated from canine malignant histiocytosis 总被引:1,自引:0,他引:1
Yamaguchi R Kojimoto A Sakai H Uchida K Sugano S Tateyama S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(2):203-206
Canine distemper virus (CDV) growth and the morphological characterization were examined in a cell line established from a canine malignant histiocytosis (CCT cell line). The susceptibility of the CCT cells to 3 CDV strains, FXNO, YSA-TC and MD-77 was shown by detection of the antigen in the indirect fluorescent assay. After passaging 4 and 9 times through the CCT cells, only FXNO strain could produce the syncytia where demonstrated the antigens. Titers of 9 passaged viruses through the CCT cells showed slightly higher in the CCT cells than those in Vero cells. Morphological characterization of karyorrhexis and specific DNA ladder by extracted DNA electrophoresis indicated apoptosis in the CDV infected CCT cells. 相似文献