全文获取类型
收费全文 | 559篇 |
免费 | 19篇 |
国内免费 | 1篇 |
专业分类
林业 | 97篇 |
农学 | 16篇 |
73篇 | |
综合类 | 28篇 |
农作物 | 6篇 |
水产渔业 | 56篇 |
畜牧兽医 | 236篇 |
园艺 | 1篇 |
植物保护 | 66篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 18篇 |
2020年 | 10篇 |
2019年 | 13篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 13篇 |
2015年 | 18篇 |
2014年 | 21篇 |
2013年 | 33篇 |
2012年 | 47篇 |
2011年 | 29篇 |
2010年 | 18篇 |
2009年 | 16篇 |
2008年 | 30篇 |
2007年 | 40篇 |
2006年 | 32篇 |
2005年 | 27篇 |
2004年 | 28篇 |
2003年 | 29篇 |
2002年 | 23篇 |
2001年 | 22篇 |
2000年 | 18篇 |
1999年 | 14篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 3篇 |
1972年 | 1篇 |
1971年 | 3篇 |
1897年 | 1篇 |
排序方式: 共有579条查询结果,搜索用时 203 毫秒
1.
K. Kita S. Nakagawa R. Pinontoan J. Okumura T. Muramatsu 《British poultry science》1993,34(5):1043-1047
1. Whole body protein synthesis was measured in chick embryos cultured in vitro. On day 7 of incubation chick embryos were cultured for 60 min in synthetic serum‐free medium containing 4‐[3H]phenylalanine. Specific radioactivities in free and protein‐bound phenylaline in the whole embryo were measured, starting 2 min after commencement of the culture process.
2. The values for fractional synthesis rate (FSR) estimated in vitro at 20, 30, 45 and 60 min during the embryo culture agreed well, ranging from 35 to 40%/d, suggesting that the method would serve as a useful model for studying the effect of growth promoters in chick embryos.
3. Bovine insulin in the synthetic medium did not affect FSR of protein in chick embryos cultured in vitro. 相似文献
2.
3.
Sakase M Kawate N Nakagawa C Fukushima M Noda M Takeda K Ueno S Inaba T Kida K Tamada H Sawada T 《Veterinary journal (London, England : 1997)》2007,173(3):691-693
Ovsynch is a program developed to synchronize ovulation for timed breeding. In this paper, the authors investigate whether controlled internal drug release (CIDR)-based protocols prevent premature ovulation before timed-artificial insemination (AI) when Ovsynch is started a few days before luteolysis in cycling beef cows. Nine beef cows at 16 days after oestrus were treated with (1) Ovsynch, i.e. gonadotropin releasing hormone (GnRH) analogue on day 0, prostaglandin (PG) F(2alpha) analogue on day 7 and GnRH analogue on day 9 with timed-AI on day 10, (n=3); (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from day 0, n=3), or (3) oestradiol benzoate (OB)+CIDR+GnRH (OB on day 0 in lieu of the first GnRH treatment, followed by the Ovsynch+CIDR protocol, n=3). In the Ovsynch group (1) plasma progesterone concentrations fell below 0.5 ng/mL earlier (day 5) than in both CIDR-treated groups (2) and (3), where this occurred on day 8. Plasma oestradiol-17beta concentrations peaked on day 8 in the Ovsynch group and on day 9 in both CIDR-treated groups. The dominant follicle ovulated on day 10 in the Ovsynch group and on day 11 in both CIDR-treated groups. Thus, both CIDR-based protocols prevented premature ovulation before timed-AI in Ovsynch when the protocol was started a few days before luteolysis. This reflects the fact that progesterone levels remained high until the beef cattle were treated with PGF(2alpha). 相似文献
4.
5.
Riaz Hasan Keiichiro Nishimura Yoshiaki Nakagawa Norio Kurihara Tamio Ueno 《Pest management science》1996,46(3):221-225
N-Arylcarbamoylpyrazolines with various substituents at the para position of the carbamoyl benzene ring inhibited ATP-dependent Ca2+-uptake in synaptosomes prepared from the rat brain. The activity of these compounds was evaluated as log(1/I50), the reciprocal logarithm of half inhibitory concentration, I50 (m ), from the concentration–response curve for the inhibition of Ca2+-uptake. Among the compounds tested, methyl 3-(4-chlorophenyl)-4-methyl-1-[N-(4-trifluoromethylphenyl)carbamoyl]-2-pyrazoline-4-carboxylate was the most potent, the I50 value of which as 9·12×10−7 m . Variations in the activity in terms of log(1/I50) were quantitatively analysed using a substituent parameter, showing that the higher the electron-withdrawing effect of the substituent, the higher was the activity. The substituent effects were similar to those on insecticidal activity against the Americal cockroach. The higher the inhibitory activity against Ca2+ uptake, the higher seemed to be the insecticidal activity. Methyl(4S) - 3 - (4 - chlorophenyl) - 4 - methyl - 1 - [N - (4 - chlorophenyl)carbamoyl] - 2 - pyrazoline -4-carboxylate had higher inhibitory activity against Ca2+-uptake and higher in-secticidal activity than the R-isomer, but the difference was greater in theCa2+-uptake system. 相似文献
6.
In 12th century, the Buddhist priest Eisai brought tea ( Camellia sinensis L.) seeds to Japan from China and now tea plants are cultivated all over Japan except in the Hokkaido and Tohoku districts. The quality (reflected in the price) of Japanese green tea is affected by the nitrogen content. Consequently in tea fields, for last three decades large amounts of fertilizer have been applied to produce high quality tea. As a result, problems such as acidification of soil have been caused. It is also known that the growth of tea plants is stimulated by the addition of aluminum (Al) under acidic conditions. In this keynote address, some problems caused by excess applications of fertilizer in tea fields and the growth characteristics of tea plants related to Al are presented. 相似文献
7.
8.
9.
Nakagawa Koki Murase Jun Asakawa Susumu Watanabe Takeshi 《Journal of Soils and Sediments》2020,20(11):4034-4041
Journal of Soils and Sediments - To reveal whether microaerophilic Fe(II)-oxidizing bacteria (FeOB) participate in the Fe(II) oxidation at the oxic-anoxic interface in flooded paddy field soil,... 相似文献
10.
Yoshikazu Kiriiwa Sunao Osumi Masanobu Endo Akira Nukaya Akio Morita Hiromi Yokota 《Soil Science and Plant Nutrition》2013,59(7):1119-1124
Abstract In alkaline soils, plant growth is impaired mainly by high pH and high concentration of bicarbonates. The bicarbonate concentration increases the pH value, and causes deficiency of iron. A bicarbonate-resistant cell line (BR line) of tobacco (Nicotiana tabacum L. cv. Burley21) was selected by adding excess bicarbonate ions (20 mmol L?1) to the culture medium. The pH of the medium was buffered 8.0 to 8.3. Under these conditions, about 80% of iron in the medium became insoluble. However, under such conditions, the BR line grew well. In this report, we examined some characteristics of the growth and iron uptake in the BR line under iron-deficient (i.e. high pH or no-iron) condition. At pH 5.8, the Fe3+ reduction activity was not significantly different between the non-selected line and the BR line. At pH 8.0, however, the Fe3+ reduction activity of the BR line was higher than that of the non-selected line. In no-iron condition, the growth of the non-selected line was markedly reduced after 2 weeks, while the BR line was not affected. The content of malic acid in both lines increased with the medium pH, and the content in the BR line was higher than that in the non-selected line. The BR line was able to adapt to the conditions, which restricted iron uptake, such as high bicarbonate concentration, high pH, and low iron conditions. The high ability of Fe3+ reduction was maintained at even high pH conditions. Further, the BR line may be able to improve the utilization of iron in the cells. 相似文献