全文获取类型
收费全文 | 390篇 |
免费 | 31篇 |
专业分类
林业 | 39篇 |
农学 | 10篇 |
基础科学 | 1篇 |
55篇 | |
综合类 | 26篇 |
农作物 | 11篇 |
水产渔业 | 54篇 |
畜牧兽医 | 209篇 |
园艺 | 1篇 |
植物保护 | 15篇 |
出版年
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 23篇 |
2015年 | 17篇 |
2014年 | 13篇 |
2013年 | 27篇 |
2012年 | 21篇 |
2011年 | 29篇 |
2010年 | 15篇 |
2009年 | 9篇 |
2008年 | 27篇 |
2007年 | 24篇 |
2006年 | 21篇 |
2005年 | 27篇 |
2004年 | 23篇 |
2003年 | 17篇 |
2002年 | 18篇 |
2001年 | 13篇 |
2000年 | 14篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1981年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有421条查询结果,搜索用时 0 毫秒
91.
92.
Kiran Prasad Bhatta Akira Ishida Kenji Taniguchi Raksha Sharma 《Irrigation and Drainage Systems》2006,20(2-3):177-191
Management reforms are considered one of the best alternatives in increasing efficiency of the irrigation systems. Transfer of day-to-day operation and maintenance to farmers is not a new concept. However due to lags, even now it is a hot issue in developing countries and Nepal is not an exception. In this context of growing argument about the transfer of management of public irrigation systems to the Water Users' Group, this paper examines the comparative performance of farmer-managed and agency-managed irrigation systems. Khageri Irrigation System in the Chitwan district of Nepal was taken as the study site where complete management transfer has been done in 1996. The situations before and after complete transfer were compared. Intensive case studies of the selected farmers showed that equity in distribution of water and leakage had significantly improved after management transfer. Logit analysis revealed that age and education level of the household head, distance from main canal, leakage of the canal and equity in distribution are significantly related to the satisfaction level of the beneficiary farmers from FMIS compared to AMIS. However, landholding size of the respondent farmer has no significant effect. Similarly results from t-test revealed that rice productivity and overall profits from agriculture has also increased significantly due to irrigation management transfer. 相似文献
93.
Morioka K Fukai K Ohashi S Sakamoto K Tsuda T Yoshida K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(7):653-658
At least two biotypes were observed at the 2nd passage stage after the isolation of Foot-and-mouth disease Virus (FMDV) O/JPN/2000 strain. These 2 types of viruses differed from their plaque phenotypes and were distinguishable by using a monoclonal antibody (MAb) 64G8 that was made for the FMDV O/JPN/2000 strain. One of these 2 biotypes formed small plaque (SP) and with immuno staining showed a positive reaction to MAb 64G8, while the other formed clear large plaque (LP) and did not react with MAb 64G8. The amino acid sequences of the capsid coding region (VP1-VP4) of the SP virus (SPV) and the LP virus (LPV) revealed two substitutions on the 133rd amino acid in VP2, and the 56th amino acid in VP3. These amino acid changes of SPV and LPV are Asn to Asp, Arg to His, respectively. The Arg of the 56th amino acid in VP3 that have been known as critical position of cell culture adapted virus. Only LPV showed high pathogenicity in suckling mice, and its LD(50) was calculated to be about 10(2) TCID(50)/0.1 ml. These results showed that the SPV that existed at the 2nd passage stage from isolation was a low virulence virus, which may suggest why the pathogenicity of O/JPN/2000 did not show clear symptoms in infected cattle. 相似文献
94.
95.
96.
97.
98.
Bacteriological evaluation of composted manure solids prepared from anaerobic digested slurry for hygienic recycled bedding materials for dairy cows 下载免费PDF全文
Eiryu Okamoto Hiroki Miyanishi Akinobu Nakamura Tomoyuki Kobayashi Norihiko Kobayashi Yoshinori Terawaki Hajime Nagahata 《Animal Science Journal》2018,89(4):727-732
Changes in mastitis‐causing pathogens, pH and water content in composted manure solids (CMS) prepared from digested slurry were evaluated during turning at 2‐day intervals for 8 days (C1–C4). The numbers of streptococci, coagulase‐negative staphylococci and coliforms were 2.6 × 101, 1.7 × 102 and 1.0 × 101 colony‐forming units (cfu)/g in CMS (C4) (summer), and these counts were markedly lower (P < 0.05) than those in CMS (C0 and C1). The bacterial counts ranged from 101 to 1.7 × 102 cfu/g in CMS (C4) (summer) and were within approved levels, <1 × 106 cfu/g, indicating a minimal mastitis risk. The temperatures in CMS (C1–C4) increased to 63°C–74°C in summer and 67°C–70°C in winter. The mean pH values in CMS (C0–C4) were 9.2 in summer and 8.7 in winter, and water contents ranged from 61.7% to 69.6% in summer and 73.2% to 66.2% in winter. The significant decrease of pathogenic bacteria in CMS appears to be closely related to temperature >63°C for 8 days, pH 8.7–9.2, and water content 62% to 73%. This study demonstrates that prepared CMS has value as a recycled material with the potential to alleviate udder health issues in dairy cows. 相似文献
99.
Yamamoto Y Fukushima T Suna Y Ishii N Saeki A Seki S Tagawa S Taniguchi M Kawai T Aida T 《Science (New York, N.Y.)》2006,314(5806):1761-1764
Controlled self-assembly of a trinitrofluorenone-appended gemini-shaped amphiphilic hexabenzocoronene selectively formed nanotubes or microfibers with different photochemical properties. In these nanotubes, which are 16 nanometers in diameter and several micrometers long, a molecular layer of electron-accepting trinitrofluorenone laminates an electron-donating graphitic layer of pi-stacked hexabenzocoronene. The coaxial nanotubular structure allows photochemical generation of spatially separated charge carriers and a quick photoconductive response with a large on/off ratio greater than 10(4). In sharp contrast, the microfibers consist of a charge-transfer complex between the hexabenzocoronene and trinitrofluorenone parts and exhibit almost no photocurrent generation. 相似文献
100.
Thanh‐Van Nguyen Lanh Thi Kim Do Tamas Somfai Takeshige Otoi Masayasu Taniguchi Kazuhiro Kikuchi 《Animal Science Journal》2019,90(12):1530-1536
Chlorogenic acid (CGA) is known to protect oocytes from oxidative stress. Here we investigated the effects of CGA on porcine oocyte maturation under heat stress and subsequent embryonic development after parthenogenetic activation. For in vitro maturation (IVM) at 41.0°C (hyperthermic condition), supplementation of the maturation medium with 50 μM CGA significantly improved the percentage of matured oocytes and reduced the rate of apoptosis relative to oocytes matured without CGA (p < .05). CGA treatment of oocytes during IVM under hyperthermia tended to increase (p < .1) percentage of blastocyst formation after parthenogenesis and significantly increased (p < .05) the total cell number per blastocyst relative to oocytes matured without CGA. For IVM at 38.5°C (isothermic condition), CGA significantly improved the rate of blastocyst development compared with oocytes matured without CGA (p < .05), but did not affect oocyte maturation, apoptosis rate or the number of cells per embryo. Omission of all antioxidants from the IVM medium significantly reduced the rate of oocyte maturation, but the rate was restored upon addition of CGA. These results demonstrate that CGA is a potent antioxidant that protects porcine oocytes from the negative effects of heat stress, thus reducing the frequency of apoptosis and improving the quality of embryos. 相似文献