全文获取类型
收费全文 | 161篇 |
免费 | 4篇 |
专业分类
林业 | 17篇 |
农学 | 16篇 |
12篇 | |
综合类 | 3篇 |
农作物 | 2篇 |
水产渔业 | 26篇 |
畜牧兽医 | 65篇 |
园艺 | 2篇 |
植物保护 | 22篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 5篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 3篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1984年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有165条查询结果,搜索用时 15 毫秒
31.
Preparation and characterization of the phenolated wood using hydrochloric acid (HCl) as a catalyst 总被引:7,自引:0,他引:7
Summary Birch (Betula maximowicziana Regel) wood meal was liquefied in the presence of phenol using hydrochloric acid (HCl) as a catalyst at a temperature of
150 °C for 2 h in an autoclave. It was found out that HCl acid could be used as an effective catalyst for the hydroxy phenylation
of wood under the experimental conditions. In this study the effect of the concentration of the acid catalyst and the phenol-to-wood
ratio on the liquefaction were investigated. The results showed that the phenol-to-wood ratio and the concentration should
be increased to a certain degree in order to achieve a less residual rate and sufficient amount of combined phenol. The phenolated
woods had apparent flow temperatures in the range of 134.4 to 199.8 °C, being higher than that of a commercial novolak resin.
Furthermore, increases in the HCl concentration during liquefaction reaction led to increase in the apparent flow temperature
of the resulting phenolated woods. However, the changes in the liquid ratio did not bring about evident changes. The relationship
between shear stress (τ) and shear rate
showed that the phenolated wood resin melts were shear thinning fluids. The dependences of the apparent melt-viscosities
(η) of the phenolated woods and a commercial novolak resin on the shear rates (
) have the similar tendencies, however, it was found the viscosities of the phenolated woods are about one order higher than
that of commercial novolak resin. 相似文献
32.
Application ofN
6-benzylaminopurine (BAP) and gibberellin (GA3) to a grafted Japanese red pine (Pinus densiflora Sieb. et Zucc.) clone promoted flowering. BAP (250 mg/l) was sprayed five times to the top of branches in July or September
1992. GA3 (100 or 500 mg/l) was applied five times to the whole plants by spray treatment during the above period, or GA3 solution of the same concentration was injected once into a small incision made in the main stem of clone trees at the beginning
of July or the middle of September 1992. In May 1993, no apical female strobili were observed at the top of the new shoots
in any treatment. However, lateral female and bisexual strobili were produced in the lower part of new shoots by BAP application
in September, regardless of GA3 application. BAP applied in September without GA3 application was sufficient to produce lateral female and bisexual strobili. In such treatment, production of female and bisexual
strobili was 47 and 25, and they occurred in 16 out of 68 new shoots, 11 out of 15 treated branches and 5 out of 5 treated
trees. The average number of female and bisexual strobili per new shoot was 1.06. BAP treatment either in July or in September
significantly decreased (p<0.05) the production of male strobili. These results indicate that BAP application induces the development of lateral female
strobili in Japanese red pine when applied during the period of floral differentiation.
A part of this paper was presented at the 105th annual meeting of the Japanese Forestry Society. 相似文献
33.
Mariko Yoshioka Keiji Takabe Junji Sugiyama Yoshiyuki Nishio 《Journal of Wood Science》2006,52(2):121-127
New biodegradable cellulose acetate/layered silicate grafted poly(ε-caprolactone) [(CA/layered silicate)-g-PCL] nanocomposites were prepared by in situ polymerization of ε-caprolactone in the presence of cellulose acetate (CA) and organically modified layered silicate (OMLS). The structures of
the resulting composites were investigated. X-ray diffractometry was carried out to survey general structural features of
(CA/OMLS)-g-PCL nanocomposites, and revealed that OMLSs having hydroxyl groups in the organic modifiers greatly altered the layered silicate
structure by monomer intercalation and successive exfoliation through its polymerization. Two of the representative cases
were characterized by wide-angle and small-angle X-ray scattering analyses with a synchrotron source. The morphology of these
nanocomposites was further examined by transmission electron microscopy. When SPN, one of OMLSs having one hydroxyl group
in its modifier, was used, the silicate layers could not be dispersed thoroughly, but existed as aggregates consisting of
several silicate layers. Among them, the crystal growth of PCL developed by transcrystallization, where the crystal growth
was restricted in the confined space. When Cloisite 30B, having two hydroxyl groups within the modifier, was used, the silicate
layers forming the clay were dispersed completely in the composite and random orientation of the OMLS was observed. 相似文献
34.
Shimada N Murata H Mikami O Yoshioka M Guruge KS Yamanaka N Nakajima Y Miyazaki S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(10):1113-1115
Genetically modified corn Bt11 is insect-resistant and expresses Cry1Ab toxin, an insecticidal protein, in kernels. Although Bt11 corn is considered safe based on animal performance, there are no reports available on the clinico-biochemical effects of feeding it to cattle. In this study, we evaluated the effects of feeding Bt11 to calves, using blood and ruminal clinico-biochemical parameters. Our three-month-long feeding experiment demonstrated that calves (n=6), fed with a ration containing 43.3% of Bt11 corn kernels as dry matter, did not develop any discernible clinical, hematological, biochemical, or ruminal abnormalities as compared with control calves (n=6) fed non-Bt11 corn. The results suggest that the transgenic Bt11 has no negative clinico-biochemical effects on calves. 相似文献
35.
High level expression of biologically active canine interferon-alpha subtype 4 using a baculovirus 总被引:1,自引:0,他引:1
Ruttanapumma R Anzai M Takegawa M Okamura M Maehara N Sato K Yoshioka K Itoh A Nakamura M Takehara K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(12):1347-1349
In this study, a high amount of bioactive recombinant canine interferon-alpha subtype 4 (CaIFN-alpha4) was expressed in a baculovirus system. For easy purification, it was expressed as a CaIFN-alpha4 bearing histidine hexamer at the C-terminal region, designated CaIFN-alpha4His. CaIFN-alpha4His was detected in culture supernatants of insect cells infected with the recombinant virus using sodium dodecyl sulfate-polyarcylamide gel electrophoresis (SDS-PAGE) and Coomassie Brilliant Blue staining. The level of expression was very high, and approximately 1 mg of purified protein, with 5.0 x 10(7) units/mg, was obtained from 300 ml of culture supernatant. The purified product showed antiviral activity against Vesicular stomatitis virus on canine tumor cell line A72 and chicken embryo fibroblast cells. 相似文献
36.
Takuya Mizuno Hiroko Hiraoka Chihiro Yoshioka Yoshiho Takeda Yuki Matsukane† Natsumi Shimoyama‡ Masahiro Morimoto‡ Toshiharu Hayashi‡ Masaru Okuda 《Veterinary dermatology》2009,20(1):72-79
An 11-year-old Shih Tzu presented with crusting and erythema, mainly on the abdomen and the root of the tail. Based on histopathological findings, blood examinations and necropsy findings, the condition was diagnosed as superficial necrolytic dermatitis associated with a glucagon-secreting extrapancreatic neuroendocrine tumour. Gross necropsy revealed tumour invasion into the spleen, liver, adrenal glands and mesenteric lymph nodes. Immunohistochemical analysis of the neoplastic cells revealed that the tumour was a glucagonoma, consistent with earlier findings of persistent glucagonaemia and hypoaminoacidaemia. 相似文献
37.
38.
Nagasao J Yoshioka K Amasaki H Tsujio M Ogawa M Taniguchi K Mutoh K 《Anatomia, histologia, embryologia》2005,34(1):42-47
We examined early morphological changes in pancreatic endocrine cells within 12 h of intravenous streptozotocin (STZ) administration (60 mg/kg). Thirty rats were allocated either to a control group (vehicle alone) or to one of four experimental groups tested after 3, 6, 9 and 12 h. Karyopyknosis and cytoplasmic vacuoles were first observed in beta-cell cytoplasm 3 h after STZ administration (STZ-3 h), and the most severe damage was found in beta cells at STZ-12 h. Insulin-positive non-islet cells were observed near the intercalated duct (ICD) and/or centroacinar (CA) cells at STZ-6 h and their numbers peaked at STZ-6 h. The distribution patterns of the insulin-positive cells and those of nestin and insulin-like growth factor-1 were similar and their nuclei were positive for proliferating cell nuclear antigen. Thus, ICD cells and/or CA cells reacted immediately to transform into insulin-secreting cells to replace injured beta cells (or to compensate for the lack of beta cells) within 12 h of STZ administration. 相似文献
39.
40.
Koichi Yoneyama Xiaonan Xie Kaori Yoneyama Takahito Nomura Ikuo Takahashi Tadao Asami Narumi Mori Kohki Akiyama Miyuki Kusajima Hideo Nakashita 《Pest management science》2019,75(9):2353-2359
Strigolactones (SLs) are carotenoid‐derived plant secondary metabolites that play important roles in various aspects of plant growth and development as plant hormones, and in rhizosphere communications with symbiotic microbes and also root parasitic weeds. Therefore, sophisticated regulation of the biosynthesis, perception and functions of SLs is expected to promote symbiosis of beneficial microbes including arbuscular mycorrhizal (AM) fungi and also to retard parasitism by devastating root parasitic weeds. We have developed SL mimics with different skeletons, SL biosynthesis inhibitors acting at different biosynthetic steps, SL perception inhibitors that covalently bind to the SL receptor D14, and SL function inhibitors that bind to the serine residue at the catalytic site. In greenhouse pot tests, TIS108, an azole‐type SL biosynthesis inhibitor effectively reduced numbers of attached root parasites Orobanche minor and Striga hermonthica without affecting their host plants; tomato and rice, respectively. AM colonization resulted in weak but distinctly enhanced plant resistance to pathogens. SL mimics can be used to promote AM symbiosis and to reduce the application rate of systemic‐acquired resistance inducers which are generally phytotoxic to horticultural crops. © 2019 Society of Chemical Industry 相似文献