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61.
Makoto NISHIZAWA Nobuaki TAKAHASHI Kumiko SHIMOZAWA Takako AOYAMA Kouichi JINBOW Yukari NOGUCHI Kiyoshi HORITA Hideo BANDO Takashi YAMAGISHI 《Fisheries Science》2003,69(3):639-643
ABSTRACT: Four steroidal ketones were isolated from the holdfast of cultivated Laminaria japonica . The structures were characterized as ergosta-4,24(28)-diene-3-one (1), ergosta-4,24(28)-diene-3,6-dione (2), stigmasta-4,24(28)-diene-3-one (3) and stigmasta-4,24(28)-diene-3,6-dione (4), by spectral data. Compounds 2 and 4 were shown to be cytotoxic against the MCF-7 human breast cancer cell, and the growth of MCF-7 was inhibited by 96% and 79%, respectively, at 10 µg/mL. It is the first report on the isolation of cytotoxic steroidal ketones from the kelp in the genus of Laminaria. 相似文献
62.
Yoshinobu INOUE Akira MATSUI Yo ASAI Fumiki AOKI Kenji YOSHIMOTO Tohru MATSUI Hideo YANO 《Journal of Equine Science》2008,19(4):83-89
We studied the response of biochemical markers of bone metabolism to exercise intensity
in horses. Four horses were walked on a mechanical walker for one week (pre-exercise).
Then they performed low-speed exercise on a high-speed treadmill in the first week and
medium-speed exercise in the second week and high-speed exercise in the third week of
training. We measured two indices of bone resorption, serum hydroxyproline concentration
and the urinary deoxypyridinoline/creatinine ratio, and serum osteocalcin (OC)
concentration as an index of bone formation. Both indices of bone resorption gradually
decreased during the experiment. Serum OC concentration did not change in the first week
but was significantly lower in the second and the third weeks compared to in the
pre-exercise period and in the first week. These results suggest that the low-speed
exercise decreased bone resorption but did not affect bone formation, which possibly
results in increasing bone mineral content and strengthening of bones. The high-speed
exercise decreased bone formation and bone resorption, i.e., bone turnover was suppressed.
The low-speed exercise may be preferable for increasing bone mineral content. 相似文献
63.
John E. Casida Ella C. Kimmel Hideo Ohkawa Reiko Ohkawa 《Pesticide biochemistry and physiology》1975,5(1):1-11
The microsome-NADPH system of mouse liver oxidizes each of benthiocarb, butylate, cycloate, EPTC, molinate, pebulate, and vernolate herbicide chemicals to the corresponding thiocarbamate sulfoxide which is then cleaved by the liver soluble-glutathione system. These sulfoxides are also detected as transient metabolites in the liver of mice injected with EPTC, molinate, pebulate, and vernolate but not with the other three thiocarbamates. Thiocarbamate sulfones are not detected as metabolites of the thiocarbamates. Studies in vivo and in vitro with [14C]EPTC and -pebulate or their corresponding sulfoxides and/or sulfones further indicate that sulfoxidation is the initial metabolic step in cleavage of the thiocarbamate ester group. Sulfoxidation appears to be a detoxification mechanism for thiocarbamate herbicides in mammals. 相似文献
64.
65.
Hideo Ohashi Tetsuya Kyogoku Takahiro Ishikawa Shin-ichiro Kawase Shingo Kawai 《Journal of Wood Science》1999,45(1):53-63
The present work was undertaken from the standpoint of radical-capturing ability with regard to the antioxidative ability of flavonoids, especially flavonols distributed widely in woody plants. In regard to the flavonols, six methyl derivatives were initially prepared from quercetin and its litinoside. Their radical-capturing constants were determined strictly by the stopped-flow spectroscopic method. It was proved that the radical-capturing ability of quercetin mainly involves the vicinal C3. and C4, hydroxyl groups and the C3 hydroxyl group. To clarify the reaction mechanism begun at the C3 hydroxyl group of quercetin, 5,7,3,4-tetramethylquercetin (TMQ), flavon-3-ol (F30) and so on were treated with 2,2-azo-bis-(2,4-dimethylvaleronitrile) (AMVN). Six products (1–6) containing one depside and its two hydrolytic products, two valeronitrile adducts, and others were isolated from the reaction mixture of TMQ and their structures determined by instrumental analyses. Similarly, F30 gave four products, 7–10, which corresponded to the above products 1–3 and 5 (one depside, its two hydrolytic products, and one adduct), respectively. 3,5,7,3,4-Pentamethylquercetin (PMQ) and flavon-3-O-methylate (F3M) gave no products. The quantitative change of the products with reaction time was determined spectroscopically. An initial reaction pathway for the radical-capturing reaction of flavon-3-ols with AMVN was proposed based on the products and their amounts. The main route — formation of depside and its hydrolytic products via ketohydroperoxide (3) or ketohydroperoxy radical (4) - was similar to that of the oxidation reaction of quercetin with quercetinase and light.Part of this paper was presented at the 46th and 47th annual meetings of the Japan Wood Research Society, Kumamoto and Kouchi, April 1996 and 1997 相似文献
66.
Shingo Kawai Yosuke Kobayashi Makoto Nakagawa Hideo Ohashi 《Journal of Wood Science》2006,52(4):363-366
Nonphenolic β-O-4 lignin substructure model dimer, 1,3-dihydroxy-2-(2,6-dimethoxyphenoxy)-1-(4-ethoxy-3-methoxyphenyl)propane (I) was degraded by horseradish peroxidase (HRP) in the presence of hydrogen peroxide and 1-hydroxybenztriazole (HBT). 4-Ethoxy-3-methoxybenzoic
acid (II), 1-(4-ethoxy-3-methoxyphenyl)-3-hydroxypropanone (III), 2,3-dihydroxy-1-(4-ethoxy-3-methoxyphenyl)-1-formyloxypropane (IV), 2,3-dihydroxy-1-(4-ethoxy-3-methoxyphenyl)propanone (V), 1-(4-ethoxy-3-methoxyphenyl)-1,2,3-trihydroxypropane (VI), 1-(4-ethoxy-3-methoxyphenyl)-1,2,3-trihydroxypropane-2,3-cyclic carbonate (VII), and 1-(4-ethoxy-3-methoxyphenyl)-1,2,3-trihydroxypropane-1,2-cyclic carbonate (VIII) were identified as degradation products by gas chromatography-mass spectrometry. These degradation products were qualitatively
the same as those of substrate I in the laccase/HBT system, but the yield of the products was apparently different. The products catalyzed by the HRP/H2O2/HBT system contained large amounts of the aromatic ring cleavage products IV, VII, and VIII compared with those catalyzed by the laccase/HBT system, while the amount of Cα-Cβ cleavage product II is relatively low. These results suggest that the role of HBT is not in a simple one-electron transfer between the enzymes
and substrates. 相似文献
67.
Hideo Tomizawa Masae Oikawa Fumihiko Nishio Akira Haraguchi 《Journal of Forest Research》1997,2(3):189-192
A survey was made of seasonal changes in pH and electronic conductivity (EC) of precipitation inAlnus japonica (Thunb.) Steud. forest in Kiritapp mire, Hokkaido, Japan. The average pH of throughfall and stem flow was higher than that
of bulk deposition. When the pH of bulk deposition exceeded 5.5, however, pH of throughfall and stem flow was lower than that
of bulk deposition. The EC of stem flow was always higher than throughfall, and that of throughfall higher than that of bulk
deposition. The EC of stem flow was highest during the first defoliation period ofA. japonica. On the other hand, the differences in the EC of throughfall and bulk deposition was very few just after the first defoliation
period ofA. japonica. This implies that the chemical properties of throughfall and stem flow are strongly affected by the phenology of the plants. 相似文献
68.
Enomoto H Li CP Morizane K Ibrahim HR Sugimoto Y Ohki S Ohtomo H Aoki T 《Journal of agricultural and food chemistry》2007,55(6):2392-2398
Beta-lactoglobulin (beta-Lg) was glycated with maltopentaose and subsequently phosphorylated by dry-heating in the presence of pyrophosphate to investigate the structural and functional properties of phosphorylated beta-Lg. The circular dichroism spectra showed that the change of the secondary structure in the beta-Lg molecule by glycation and subsequent phosphorylation was small. The differential scanning calorimetry thermograms of beta-Lg showed that the denaturation temperature of the most stable domain was only slightly affected, whereas the retinol-binding activity of beta-Lg was somewhat reduced by glycation and subsequent phosphorylation. These results indicated that the conformational changes of the beta-Lg molecule by glycation and subsequent phosphorylation were mild. The anti-beta-Lg antibody response was somewhat reduced by glycation, but significant changes were not observed by phosphorylation. Although the stability of beta-Lg against heat-induced insolubility was improved by glycation alone, it was further enhanced by phosphorylation. The calcium phosphate solubilizing ability of beta-Lg was enhanced by phosphorylation following glycation. 相似文献
69.
Takaishi N Yoshida K Satsu H Shimizu M 《Journal of agricultural and food chemistry》2007,55(13):5253-5259
Alpha-lipoic acid (LA) is used in dietary supplements or food with antioxidative functions. The mechanism for the intestinal absorption of alpha-lipoic acid was investigated in this study by using human intestinal Caco-2 cell monolayers. LA was rapidly transported across the Caco-2 cell monolayers, this transport being energy-dependent, suggesting transporter-mediated transport to be the mechanism involved. The LA transport was strongly dependent on the pH value, being accelerated in the acidic pH range. Furthermore, such monocarboxylic acids as benzoic acid and medium-chain fatty acids significantly inhibited LA transport, suggesting that a proton-linked monocarboxylic acid transporter (MCT) was involved in the intestinal transport of LA. The conversion of LA to the more antioxidative dihydrolipoic acid was also apparent during the transport process. 相似文献
70.
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