全文获取类型
收费全文 | 499篇 |
免费 | 11篇 |
国内免费 | 2篇 |
专业分类
林业 | 30篇 |
农学 | 12篇 |
基础科学 | 1篇 |
84篇 | |
综合类 | 14篇 |
农作物 | 6篇 |
水产渔业 | 70篇 |
畜牧兽医 | 270篇 |
植物保护 | 25篇 |
出版年
2023年 | 1篇 |
2022年 | 12篇 |
2021年 | 38篇 |
2020年 | 8篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 23篇 |
2014年 | 29篇 |
2013年 | 65篇 |
2012年 | 22篇 |
2011年 | 28篇 |
2010年 | 12篇 |
2009年 | 13篇 |
2008年 | 32篇 |
2007年 | 21篇 |
2006年 | 26篇 |
2005年 | 27篇 |
2004年 | 29篇 |
2003年 | 25篇 |
2002年 | 24篇 |
2001年 | 10篇 |
2000年 | 15篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有512条查询结果,搜索用时 15 毫秒
451.
Chemical changes ordinarily occuring in flooded paddy soils in Japan had been investigated in detail by Dr. SHIOIRI and his coworkers (1). The problem of degraded paddy soils had also been discussed by them on the basis of the experimental results on the deficiency of free iron oxides which affect the root of rice plant. As described in the previous report (2), causes for low rice production in the peaty Paddy fields seemed to be different from those in the degraded paddy ones. Thereupon, for a comprehensive understanding of the properties of peaty paddy soils, many important aspects such as the nature and role of each soil layer, and the behaviour of iron and nitrogen in soil Will have to be studied. 相似文献
452.
Ken-Ichi Yuhashi Kiwamu Minamisawa Yasuo Minakawa Dennis J. Tobias Masatsugu Kubota Shoichiro Akao 《Soil Science and Plant Nutrition》2013,59(2):473-478
Attempts to improve the symbiotic nitrogen fixation with effective (Brady) rhizobium strains do not always succeed under field conditions due to the lower nodulation competitiveness of the introduced strains than that of the indigenous rhizobia (Triplett and Sadowsky 1992). An introduced strain needs to be marked for monitoring its nodule occupancy under competitive nodulation conditions. 相似文献
453.
Abstract A wide range of metabolites accumulates under water stress depending on certain metabolic alterations. For example, free amino acids, especially free proline, accumulate in response to water stress ((l)). Proline accumulation is closely connected with carbohydrate metabolism. Thus, a carbohydrate requirement for proline accumulation in water-stressed leaves has been reported (2, 3). 相似文献
454.
Masahiro Miura Ikuma Watanabe Yasutaka Shimotori Masakazu Aoyama Yasuo Kojima Yoshiaki Kato 《Wood Science and Technology》2013,47(3):515-522
A hemicellulose hydrolysate containing 19 g L?1 xylose was prepared from the culm of bamboo (Phyllostachys pubescens) by hydrolysis with 3 % sulphuric acid with a liquor to solid ratio of 10 (g g?1) at 121 °C for 1 h. After detoxification of the hydrolysate with a commercially available activated char followed by neutralisation with calcium carbonate, the resulting sugar solution was subjected to fermentation using the yeast, Candida magnoliae. The maximum xylitol production (10.5 g L?1) and the maximum xylitol volumetric productivity (0.42 g L?1 h?1) were attained under agitation set at 400 min?1 and aeration rate of 0.67 vvm (volume of air per volume of medium per minute). According to the results, a suitable control of the oxygen supply permits the xylitol formation from bamboo hemicellulose hydrolysate. 相似文献
455.
Maeda Y Ohtsuka H Tomioka M Tanabe T Nambo Y Uematsu H Oikawa MA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(5):629-632
Escherichia coli(E. coli) isolated from the uterus of a Thoroughbred mare with bacterial endometritis was used to evaluate the effect of progesterone (P(4)) on the immune response of mares. Peripheral blood mononuclear cells (PBMCs) were collected from 10 nonpregnant clinically healthy adult mares (range, 4-12 years) during diestrus, four Thoroughbreds and six Hokkaido native horses. Cell proliferation and expression of cytokine mRNA, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-10, of PBMCs stimulated with E. coli and P(4) were examined in vitro. P(4) was shown to have significantly inhibited E. coli induced proliferation and expression of IFN-γ in PBMCs. These results indicate that P(4) inhibits the immune response to E. coli in mares. 相似文献
456.
Namimatsu T Asai T Osumi T Imai Y Sato S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(2):187-188
To determine the prevalence of the virulence plasmid in Salmonella Typhimurium isolates from pigs in Japan, a total of 106 porcine isolates were subjected to PCR amplification for the detection of the virulence plasmid. Out of the isolates of S. Typhimurium, 38 (35.8%) harbored the virulence plasmid. The presence of the virulence plasmid was widely observed in the isolates from systemically infected pigs (92.0%, 23/25), compared with diarrheic (18.8%, 12/64) and apparently healthy pigs (17.6%, 3/17) (P<0.01). 相似文献
457.
Konosuke OTOMARU Takuro FUJIKAWA Yasuo SAITO Takaaki ANDO Takeshi OBI Naoki MIURA Chikara KUBOTA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1191-1193
A 10-month-old Japanese black heifer was diagnosed as having an intra-abdominal
cyst using computed tomography (CT). Through a posterior ventral midline incision, the
cyst was removed, and the heifer completely recovered after the surgery. CT scans enabled
detection of the intra-abdominal cyst and measurements of the diameter of the cyst before
the surgery. 相似文献
458.
Yuko KAMIYA Mitsuru KAMIYA Masahito TANAKA Shigeru SHIOYA 《Animal Science Journal》2005,76(4):325-330
Eight pregnant heifers (primiparous cows) and seven pregnant cows in their second, third and forth pregnancies (multiparous cows) were assigned to two groups and fed either a low calcium (Ca) diet (Ca, 0.46%) or a high Ca diet (Ca, 0.86%) ad libitum from 3 weeks before the expected calving date to 3 days after parturition. All cows were examined for a change in dry matter intake (DMI), plasma minerals and bone turnover around parturition. The dietary Ca level did not affect the DMI in both primiparous and multiparous cows. The DMI of primiparous cows was significantly lower than that of multiparous cows (P < 0.05) in both the low and high dietary Ca groups. The dietary Ca level did not affect the concentrations of plasma Ca, phosphorus, magnesium and parathyroid hormone throughout the experimental period. Plasma phosphorus in primiparous cows was significantly higher (P < 0.05) than that of multiparous cows around parturition. Plasma Ca and magnesium tended to be higher (P < 0.10) in primiparous cows. The dietary Ca level did not affect the plasma osteocalcin (OC) level measured as bone formation or the urinary deoxypyridinoline (DPD) excretion measured as bone resorption before parturition in both primiparous and multiparous cows. After parturition, the plasma OC level was lower than it was before parturition in multiparous cows fed a low Ca diet, and in primiparous cows. There were no significant differences in urinary DPD excretion between each group before and after parturition. Both the plasma OC level and urinary DPD excretion of primiparous cows were significantly higher than those of multiparous cows in both the low and high dietary Ca groups. 相似文献
459.
460.