全文获取类型
收费全文 | 937篇 |
免费 | 27篇 |
国内免费 | 2篇 |
专业分类
林业 | 129篇 |
农学 | 33篇 |
基础科学 | 1篇 |
113篇 | |
综合类 | 40篇 |
农作物 | 53篇 |
水产渔业 | 171篇 |
畜牧兽医 | 345篇 |
园艺 | 11篇 |
植物保护 | 70篇 |
出版年
2023年 | 2篇 |
2022年 | 15篇 |
2021年 | 50篇 |
2020年 | 21篇 |
2019年 | 18篇 |
2018年 | 14篇 |
2017年 | 24篇 |
2016年 | 29篇 |
2015年 | 28篇 |
2014年 | 51篇 |
2013年 | 58篇 |
2012年 | 50篇 |
2011年 | 63篇 |
2010年 | 31篇 |
2009年 | 37篇 |
2008年 | 59篇 |
2007年 | 54篇 |
2006年 | 58篇 |
2005年 | 50篇 |
2004年 | 49篇 |
2003年 | 59篇 |
2002年 | 44篇 |
2001年 | 39篇 |
2000年 | 21篇 |
1999年 | 10篇 |
1998年 | 13篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 2篇 |
1980年 | 2篇 |
排序方式: 共有966条查询结果,搜索用时 15 毫秒
61.
62.
Toshio Akiyama Takeshi Murai Yasuhiro Hirasawa Takeshi Nose 《Aquaculture (Amsterdam, Netherlands)》1984,37(3):217-222
In a 6-week feeding experiment, chum salmon, Oncorhynchus keta, swim-up fry, were fed fish meal diets supplemented with silkworm pupae powder (5%), dried beef liver (5%), krill meal (5%) or earthworm powder (5%) at the expense of fish meal, or substituting glucose (13%) for dextrin. Fish fed the diet with earthworm powder showed the best growth performance (675% weight gain in 6 weeks) and feed efficiency (117%). The growth rate and feed efficiency of the krill meal group were also significantly better than those of the control group (without supplement or substitution). Substitution of glucose and supplementation of silkworm pupae or beef liver failed to improve the growth rate, but significantly improved feed efficiency. Food consumption of fish fed the diet supplemented with earthworms was lowest, and none of the dietary treatments appreciably increased food intake of the fish over that of the control group. The dietary group receiving earthworm powder also showed significantly higher body fat content than the remaining dietary groups. No significant differences were noted in body protein and ash contents among all dietary treatments. 相似文献
63.
64.
65.
66.
67.
Manami Inaba Takeshi Kimura Rika Kikukawa Mitsuko Iwasaki Masato Nose Satoru Suzuki 《Fisheries Science》2007,73(3):615-622
ABSTRACT: Seasonal changes in the infection state of marine birnavirus (MABV) in Japanese flounder Paralichthys olivaceus and in rearing sea water are described. Sea water and 10–11 healthy fish were sampled monthly from April 2002 to February 2003. The MABV genome was detected throughout the year in > 80% of the fish examined at each sampling. The virus was isolated from the liver, kidney, and spleen, but not from the brain. The detection rate in each organ increased from April to October, and then decreased. Detection of virus antigen by the indirect fluorescent antibody technique also showed that the virus was present from spring to autumn (June–September) in the liver, kidney, and spleen, but not the brain. Sequence analysis of the MABV genome at the VP2–NS region revealed two specific mutations compared to the standard yellowtail strain (Y-6). It is suggested that the infection state of MABV in Japanese flounder changes to a latent or persistent infection after autumn. MABV was detected in sea water between September and February, suggesting that virus particles in the environment are relatively higher during cool seasons. 相似文献
68.
Shinsuke Torisawa Tsutomu Takagi Yasunori Ishibashi Yoshifumi Sawada Takeshi Yamane 《Fisheries Science》2007,73(5):1202-1204
69.
Effects of photoperiod on gonadotropin-releasing hormone levels in the brain and pituitary of underyearling male barfin flounder 总被引:2,自引:0,他引:2
Masafumi AMANO Takeshi YAMANOME Hideaki YAMADA Koichi OKUZAWA Kunio YAMAMORI 《Fisheries Science》2004,70(5):812-818
ABSTRACT: A pleuronectiform fish, the barfin flounder Verasper moseri , expresses three gonadotropin-releasing hormone (GnRH) forms in the brain: salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II) and seabream GnRH (sbGnRH). To clarify the effects of photoperiod on GnRH systems, changes in brain and pituitary GnRH peptide levels were examined using time-resolved fluoroimmunoassays. In experiment 1, 5-month-old male barfin flounder (mean total length 9.0 cm, body weight 11.0 g) were divided into short (8:16 h light : dark [L:D] cycle; lights on 08.00–16.00 hours) and long photoperiod (16:8 h L:D cycle; lights on 04.00–20.00 hours) groups in mid September and maintained until November under natural water temperature (19.3–15.2°C). Brain sGnRH concentrations were significantly higher in the 16:8 h L:D group than in the 8:16 h L:D group, whereas no significant differences were observed in total length, body weight, plasma testosterone concentration, brain cGnRH-II concentration and pituitary sbGnRH content. In experiment 2, 7-month-old male barfin flounder (mean total length 16.5 cm, body weight 76.8 g) were divided into short and long photoperiod groups in mid December and maintained until February under natural water temperature (12.5–6.6°C). Total length, body weight and condition factor were significantly greater in the 16:8 h L:D group than in the 8:16 h L:D group, whereas no significant differences were observed in plasma testosterone concentration and GnRH levels in the brain and pituitary. These results indicate that levels of sGnRH in barfin flounder are influenced by photoperiodic treatment dependent on water temperature and/or body size. 相似文献
70.