全文获取类型
收费全文 | 314篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
林业 | 22篇 |
农学 | 11篇 |
57篇 | |
综合类 | 8篇 |
农作物 | 9篇 |
水产渔业 | 45篇 |
畜牧兽医 | 125篇 |
园艺 | 4篇 |
植物保护 | 45篇 |
出版年
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 17篇 |
2014年 | 19篇 |
2013年 | 25篇 |
2012年 | 22篇 |
2011年 | 19篇 |
2010年 | 9篇 |
2009年 | 16篇 |
2008年 | 18篇 |
2007年 | 20篇 |
2006年 | 16篇 |
2005年 | 17篇 |
2004年 | 23篇 |
2003年 | 8篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1995年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有326条查询结果,搜索用时 46 毫秒
121.
Wei Wang Yuichi Hanai Chisato Takenaka Rie Tomioka Kazuya Iizuka Hajime Ozawa 《Journal of Forest Research》2016,21(5):251-258
Absorption of radiocesium (137Cs and 134Cs) through bark, and its subsequent translocation into wood and needles, has been suggested as a potential source of tree contamination, but the process is not well understood. Field experiments were conducted to confirm whether Cs could enter a Japanese cedar tree through the bark and how Cs moves within a tree. Stable Cs (133Cs) was applied to the bark at 1.2-m height on 10- and 26-year-old Japanese cedars. The 133Cs concentrations were determined in the bark, sapwood, and heartwood (for 26-year-old cedar only) of stem disks from several heights, as well as in current-year needles from the canopy. The 133Cs concentrations were considerably higher in the sapwood and heartwood of stem disks from 1.2-m height in treated trees than in untreated trees, suggesting that 133Cs penetrated the bark to enter the wood. The average 133Cs concentrations were higher in the heartwood than the sapwood, indicating 133Cs accumulation in the heartwood. High 133Cs concentrations in the needles of treated trees implied acropetal movement of 133Cs to actively growing organs. Our results demonstrate that Cs can enter Japanese cedar trees through the bark and that Cs is transported radially to the heartwood and vertically to the apex. 相似文献
122.
Fuminori Kobayashi Tsuyoshi Tanaka Hiroyuki Kanamori Jianzhong Wu Yuichi Katayose Hirokazu Handa 《Breeding Science》2016,66(2):213-225
A core collection of Japanese wheat varieties (JWC) consisting of 96 accessions was established based on their passport data and breeding pedigrees. To clarify the molecular basis of the JWC collection, genome-wide single-nucleotide polymorphism (SNP) genotyping was performed using the genotyping-by-sequencing (GBS) approach. Phylogenetic tree and population structure analyses using these SNP data revealed the genetic diversity and relationships among the JWC accessions, classifying them into four groups; “varieties in the Hokkaido area”, “modern varieties in the northeast part of Japan”, “modern varieties in the southwest part of Japan” and “classical varieties including landraces”. This clustering closely reflected the history of wheat breeding in Japan. Furthermore, to demonstrate the utility of the JWC collection, we performed a genome-wide association study (GWAS) for three traits, namely, “days to heading in autumn sowing”, “days to heading in spring sowing” and “culm length”. We found significantly associated SNP markers with each trait, and some of these were closely linked to known major genes for heading date or culm length on the genetic map. Our study indicates that this JWC collection is a useful set of germplasm for basic and applied research aimed at understanding and utilizing the genetic diversity among Japanese wheat varieties. 相似文献
123.
Yuichi Yamaoka Naoki Yamanaka Hajime Akamatsu Kazuhiro Suenaga 《Journal of General Plant Pathology》2014,80(2):184-188
Six races were identified among 26 single-lesion isolates of Phakopsora pachyrhizi from rust-infected leaves of nine samples of cultivated soybean and one sample of the wild host plant kudzu (Pueraria lobata) collected in Tsukuba and vicinity in Ibaraki, Central Honshu, Japan. Six races were detected on soybean cultivars and four races on kudzu. When two or more isolates obtained from the same samples were examined, the isolates were different races except from two samples. These results indicate that two or more races may be distributed on the same soybean cultivar and that the same races share soybean and kudzu hosts. 相似文献
124.
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
125.
Kyoko Suzuki Tsutomu Suzuki Yukio Takahashi Mitsuhiro Okimoto Tetsuo Yamada Noriyasu Okazaki Yuichi Shimizu Masashi Fujiwara 《Journal of Wood Science》2009,55(1):60-68
The yields and properties of oil and gas fractions coproduced during carbonization of larch wood loaded with Ni 2%, Ni 2%+Ca
1%, and Ni 4% and without catalyst (None) at 700°–900°C were examined to clarify the catalytic effect in terms of conversion
into fluid fuels. The net calorific value of oil occurred mainly below 500°C and increased in the order None < Ni 2% < Ni
4% < Ni 2%+Ca 1%, while the yield decreased in this order. The same order held for the production of gases enriched with hydrogen
at 500°–700°C. Even above 800°C, markedly promoted evolution of hydrogen took place for all catalyst systems. These observations
confirmed the effectiveness of nickel-catalyzed carbonization at 900°C, particularly Ni 2%+Ca 1%, for both upgrading of oil
and gaseous fractions, although the quality of oil was not satisfactory. The catalysis of nickel with and without calcium
is discussed on the basis of the modified Broid-Shafizadeh scheme, and the scheme was altered to adapt to the high temperature
region where oil was no longer produced.
Part of this study was presented at the 14th Annual Meeting of the Japan Institute of Energy, Suita, August 2005, and at the
18th Symposium, Session D, of the Materials Research Society of Japan, Tokyo, December 2007 相似文献
126.
Toshinori Sako Akihiro Mori Peter Lee Hiroshi Goto Hiroko Fukuta Hitomi Oda Kaori Saeki Yohei Miki Yuki Makino Katsumi Ishioka Hisashi Mizutani Yuzo Kojima Satoshi Koikeda Toshiro Arai 《Veterinary research communications》2010,34(2):161-172
Indigestible oligosaccharides have been shown to normalize blood glucose and insulin concentration thereby promoting good health and preventing diseases, such as diabetes. Transglucosidase (TG, α-glucosidase, enzyme code (EC) 3.2.1.20) is an enzyme capable of converting starch to oligosaccharides, such as iso-malto-oligosaccharides from maltose, via the action of amylase. The aim of this study was to evaluate whether oral administration of TG with maltose or dextrin is capable of reducing post-prandial serum glucose concentration in experimentally streptozotocin (STZ)-induced diabetic dogs fed on a high-fiber diet. Five healthy and five STZ-induced diabetic dogs were employed in this study. TG supplementation with dextrin or maltose had no detrimental effect in healthy dogs. In fact, TG and dextrin exhibited a flatlined serum glucose pattern, while reducing mean post-prandial serum insulin and glucose concentration as compared to control diet alone. When TG supplementation was tested in STZ-induced diabetic dogs under the context of a high fiber diet, a 13.8% and 23.9% reduction in mean glucose concentration for TG with maltose and dextrin, respectively was observed. Moreover, TG with dextrin resulted in a 13% lower mean post-prandial glucose concentration than TG with maltose, suggesting that dextrin may be a more efficient substrate than maltose when used at the same concentration (1 g/kg). Our results indicate that TG supplementation with diet can lead to lower postprandial glucose levels versus diet alone. However, the efficacy of TG supplementation may depend on the type of diet it is supplemented with. As such, TG administration may be useful for preventing the progression of diabetes mellitus and in its management in dogs. 相似文献
127.
Yamada K Hirotsu T Matsuki M Butcher RA Tomioka M Ishihara T Clardy J Kunitomo H Iino Y 《Science (New York, N.Y.)》2010,329(5999):1647-1650
Population density-dependent dispersal is a well-characterized strategy of animal behavior in which dispersal rate increases when population density is higher. Caenorhabditis elegans shows positive chemotaxis to a set of odorants, but the chemotaxis switches from attraction to dispersal after prolonged exposure to the odorants. We show here that this plasticity of olfactory behavior is dependent on population density and that this regulation is mediated by pheromonal signaling. We show that a peptide, suppressor of NEP-2 (SNET-1), negatively regulates olfactory plasticity and that its expression is down-regulated by the pheromone. NEP-2, a homolog of the extracellular peptidase neprilysin, antagonizes SNET-1, and this function is essential for olfactory plasticity. These results suggest that population density information is transmitted through the external pheromone and endogenous peptide signaling to modulate chemotactic behavior. 相似文献
128.
129.
Kazutaka Kido Masaru Hasegawa Hiroyuki Matsumoto Masaki Kobayashi Yuichi Takikawa 《Journal of General Plant Pathology》2010,76(3):208-218
Ninety-six strains of Pantoea ananatis were isolated from 14 plant species including melon, rice, tea and other crops of economic importance. They were classified
into three groups (group I, II, III) based on a welsh onion stabbing assay, tobacco infiltration test, and polymerase chain
reaction to detect indole acetic acid (IAA) biosynthesis genes (iaaM and iaaH) and a cytokinin biosynthesis gene (etz). Group Ι strains were characterized as causing significant blight symptom on welsh onion and inducing a hypersensitive response
(HR)-like reaction on tobacco leaves after 36–48 h and encompassed 20 isolates from foxtail millet, hydrangea, pineapple,
river water and rice. These 20 isolates did not possess iaaM, iaaH, or etz genes. Group II, consisting of 34 melon isolates, harbored iaaM,
iaaH and etz genes, but did not cause either blight on welsh onion or HR-like reaction on tobacco. Group III strains did not have the
iaaM, iaaH, and etz genes, nor did they cause any reaction on welsh onion or tobacco. The 42 strains in group III were isolated from bamboo grass,
Chinese silver grass, citrus, dogwood, melon, mugwort, silk tree, sweet corn, tea and welsh onion. Representative strains
of the three groups were tested for pathogenicity on melon and rice. Group Ι strains caused palea browning on rice but not
internal fruit rot on melon. On the contrary, group II strains did not cause disease on rice but caused internal fruit rot
on melon. Group III strains were not pathogenic on rice or melon. These results suggested that the host range of P. ananatis may be predicted by the reactions of welsh onion and tobacco and detection of iaaM, iaaH and etz genes. These tools may serve as rapid tests to identify the pathogenicity groups of P. ananatis. 相似文献
130.