全文获取类型
收费全文 | 527篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
林业 | 62篇 |
农学 | 31篇 |
56篇 | |
综合类 | 26篇 |
农作物 | 22篇 |
水产渔业 | 95篇 |
畜牧兽医 | 214篇 |
园艺 | 4篇 |
植物保护 | 44篇 |
出版年
2021年 | 13篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 20篇 |
2017年 | 18篇 |
2016年 | 22篇 |
2015年 | 18篇 |
2014年 | 15篇 |
2013年 | 31篇 |
2012年 | 23篇 |
2011年 | 35篇 |
2010年 | 11篇 |
2009年 | 15篇 |
2008年 | 36篇 |
2007年 | 23篇 |
2006年 | 22篇 |
2005年 | 30篇 |
2004年 | 29篇 |
2003年 | 25篇 |
2002年 | 28篇 |
2001年 | 25篇 |
2000年 | 20篇 |
1999年 | 16篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 3篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 2篇 |
排序方式: 共有554条查询结果,搜索用时 15 毫秒
1.
Mahmoud A. O. Dawood Shunsuke Koshio Manabu Ishikawa Mabrouk El-Sabagh Saichiro Yokoyama Wei-Long Wang Zhang Yukun Adissin Olivier 《Fish physiology and biochemistry》2017,43(1):179-192
Environmental stressors caused by inadequate aquaculture management strategies suppress the immune response of fish and make them more susceptible to diseases. Therefore, efforts have been made to relieve stress in fish by using various functional feed additives in the diet, including probiotics. The present work evaluates the effects of Lactobacillus rhamnosus (LR) on physiological stress response, blood chemistry and mucus secretion of red sea bream (Pagrus major) under low salinity stress. Fish were fed four diets supplemented with LR at [0 (LR0), 1 × 102 (LR1), 1 × 104 (LR2) and 1 × 106 (LR3) cells g?1] for 56 days. Before stress, blood cortisol, urea nitrogen (BUN) and total bilirubin (T-BIL) showed no significant difference (P > 0.05), whereas plasma glucose and triglyceride (TG) of fish-fed LR2 and LR3 diets were significantly lower (P < 0.05) than those of the other groups. Plasma total cholesterol (T-CHO) of fish-fed LR3 diet was significantly (P < 0.05) lower than that of the other groups. Furthermore, total plasma protein, mucus myeloperoxidase activity and the amount of mucus secretion were significantly enhanced in LR-supplemented groups when compared with the control group (P < 0.05). After the application of the low salinity stress test, plasma cortisol, glucose, T-CHO and TG contents in all groups showed an increased trend significantly (P < 0.01) compared to the fish before the stress challenge. However, plasma total protein and the amount of secreted mucus showed a decreased trend in all groups. On the other hand, BUN, T-BIL and mucus myeloperoxidase activity showed no significant difference after exposure to the low salinity stress (P > 0.05). In addition, the fish that received LR-supplemented diets showed significantly higher tolerance against low salinity stress than the fish-fed LR-free diet (P < 0.05). The physiological status and the detected immune responses, including total plasma protein and mucus myeloperoxidase activity in red sea bream, will provide a more comprehensive outlook of the effects of probiotics to relieve stress in fish. 相似文献
2.
3.
4.
Nattaya Lourith Takeshi Katayama Kimiko Ishikawa Toshisada Suzuki 《Journal of Wood Science》2005,51(4):379-386
To investigate the biosynthesis and stereochemistry of syringylglycerol-8-O-4′-(sinapyl alcohol) ether (SGSE), a syringyl 8-O-4′ neolignan, feeding experiments and enzyme assays using Eucommia ulmoides were carried out. Diastereoselective formation of erythro-SGSE was found. When [8-14C]sinapyl alcohol was administered to excised shoots of E. ulmoides, 14C was incorporated into free SGSE and SGSE glucosides. In stems, incorporation into (+)-erythro-[14C]SGSE (0.037%) with 9.1% enantiomeric excess (% e.e.) was found; incorporation into the threo isomer was not detectable. Erythro-[14C]SGSE glucosides (0.047%) dominated over threo forms (0.007%) with 74.0% diastereomeric excess (% d.e.); both diastereomers were levorotatory with 32.0% e.e. and 18.3% e.e., respectively. In leaves, higher incorporation into (−)-erythro-[14C]SGSE (0.500%, 15.9% e.e.) than into the threo isomer (0.206%, 7.4% e.e.) was observed (41.6% d.e.). (−)-Erythro-[14C]SGSE glucosides (1.692%, 25.0% e.e.) were produced at higher rates than threo isomers (0.177%, 16.4% e.e.) with 81.0% d.e. In incubations of a mixture of [8-14C]sinapyl and [8-14C]coniferyl alcohols with an insoluble enzyme preparation from stems of E. ulmoides, erythro-SGSE was preferentially produced. The highest % d.e. (82.8) was observed at 60 min with the (+)-erythro isomer (21.4% e.e.) and the (−)-threo form (4.3% e.e.).Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002, and the 47th Lignin Symposium, Fukuoka, October 2002 相似文献
5.
Shigeru Yamauchi Yoichi Sakai Yasuo Watanabe Michael Kenya Kubo Hideaki Matsue 《Journal of Wood Science》2007,53(4):324-331
The distributions of boron in Japanese cedar (Cryptomeria japonica D. Don) sapwood blocks treated with aqueous or methanolic boric acid [B(OH)3] solutions were explored through Raman spectroscopy and prompt gamma-ray analysis (PGA). B(OH)3 was the sole boron species observed in Raman spectra of the wood blocks treated with either solution. Plots of weight gain
of the treated wood blocks versus boron concentration in treatment solutions were found to be linear. The results indicated
that the methanolic solution makes it possible to impregnate wood with much larger amounts of boron than the aqueous solution.
PGA confirmed that B(OH)3 was highly enriched near the end grains of the treated wood blocks. Raman measurements suggested that boron content in the
bulk of the wood block is not as large as expected from the weight gain of the treated wood blocks when an ordinary air-drying
method is used. It was concluded that the aqueous solution impregnates the cell walls of wood with boron more easily than
the methanolic solution.
Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan
Wood Research Society. This article follows the previous rapid communication “Analysis of boron in wood treated with boric
acid solutions using Doppler broadening method of prompt gamma-rays.” J Wood Sci (2006) 52:279–281 相似文献
6.
7.
BudiadiEmail author Yoichi?Kanazawa Hiroaki?T.?Ishii M.?Sambas?Sabarnurdin Priyono?Suryanto 《Agroforestry Systems》2005,64(2):143-155
Kayu putih oil, extracted from the kayu putih tree (Melaleuca leucadendron), is an important non-timber forest product (NTFP)
in Indonesia. We compared productivity of kayu putih tree plantations among three different sites in East, Central, and West
Java, Indonesia. Leaf-twig, and branch production per tree differed significantly among the three sites. Tree biomass production
was highest at the site in West Java practicing tumpangsari (a form of shifting cultivation) of kayu putih with rice (Oryza
sativa) on alluvial soils. Tree biomass production was lowest at the site in East Java, practicing tumpangsari of kayu putih
with maize (Zea mays) and cassava (Mani- hot esculenta). At this site, tree biomass production increased with increasing stand
age and low production was compensated by greater biomass yield of companion crops. Intermediate tree biomass production was
observed at the site in Central Java where intercropping is only practiced for the first two years after plantation establishment.
Production of tree biomass and kayu putih oil did not increase with increasing stand density, indicating that at a given site,
high tree stocking did not lead to high production. Stand-level productivity of the plantations increased with increasing
stand age and maximum productivity was attained at 15 to 35 years, after which productivity declined. This suggested unsustainable
stand productivity as plantations increase in age. 相似文献
8.
Evaluating the durability of wood-based panels using internal bond strength results from accelerated aging treatments 总被引:1,自引:0,他引:1
In this study, the durability of wood-based panels was evaluated by comparing the internal bond (IB) strength retention after
five different laboratory-based accelerated aging tests with the IB retention after 5 years of outdoor exposure in Shizuoka
City. In each accelerated aging test, the IB retention of MDI-bonded panels showed high retention compared to other panels.
Outdoor exposure in Shizuoka City resulted in an IB retention value for particleboard (PF) and oriented strandboard (aspen)
of less than 10% after the 5-year exposure period. Medium-density fiberboards maintained their initial IB strength over the
same period. Calculation of the mean IB retention for all board types allowed comparison of the severity of aging between
the accelerated test methods and outdoor exposure. The ASTM six-cycle test method was the most severe among the standard treatment
cycles applied. 相似文献
9.
Tian-Xiao Meng Shoko Furuta Sayaka Fukamizu Ryoko Yamamoto Hiroya Ishikawa Enos Tangke Arung Kuniyoshi Shimizu Shoji Ohga Ryuichiro Kondo 《Journal of Wood Science》2011,57(5):452-458
Pleurotus citrinopileatus Singer has recently become a popular delicacy in East Asian countries. We prepared a methanol extract, soluble fractions
from the methanol extract, and a hot water extract of the fruiting bodies of P. citrinopileatus. The biological activities such as melanin biosynthesis inhibition, tyrosinase inhibition, antioxidant activities [1,1-diphenyl-2-picrylhydrazyl
(DPPH) radical scavenging, oxygen radical absorbance capacity (ORAC), and superoxide dismutase (SOD)-like activity], antibacterial
activities, and antihyaluronidase activities of these extracts were evaluated. We found that the n-hexanesoluble, diethyl ether-soluble, and ethyl acetate-soluble fractions exhibited melanin biosynthesis inhibition in B16
melanoma cells, as well as antioxidant (ORAC) and antibacterial activities. However, the n-butanol-soluble and water-soluble fractions and the methanol and hot water extracts exhibited antioxidant (DPPH radical scavenging,
SOD-like activity) and antihyaluronidase activities. These results indicate that the fruiting bodies of P. citrinopileatus have the potential to be used as an ingredient in skin cosmetics. 相似文献
10.
Chhourn Orn Rieko Shishido Masahiro Akimoto Ryo Ishikawa Than Myint Htun Ken-Ichi Nonomura Yohei Koide Men Sarom Seng Vang Sakhan Sophany Ouk Makara Takashige Ishii 《Breeding Science》2015,65(5):430-437
A total of 448 samples in five natural populations of wild rice (Oryza rufipogon) were collected in Cambodia. They were examined using 12 SSR and two chloroplast markers to evaluate the degree of variation among populations and the genetic structure within populations. In the two annual populations, the number of plants with homozygous alleles at all 12 SSR loci were high (66.3% and 79.5%), suggesting that these plants propagate mainly through self-pollination. In the three perennial populations, no individuals had all homozygous genotypes, but redundant genotypes resulted from clonal propagation were observed. Percentages of the redundant genotypes were highly varied (3.6%, 29.2% and 86.0%). This may be due to the different stable levels of environmental conditions. As for chloroplast genome, most of the wild plants showed the same chloroplast types as most Indica-type cultivars have. However, plants with different chloroplast types were maintained, even in the same population. In tropical Asian countries, many wild rice populations were observed under similar ecological conditions examined in this study. Therefore, the present results concerning population structure will be important to further elucidate genetic features of wild rice, and will also give strong clues to utilize and conserve wild natural genetic resources. 相似文献