全文获取类型
收费全文 | 228篇 |
免费 | 24篇 |
专业分类
林业 | 9篇 |
农学 | 2篇 |
47篇 | |
综合类 | 6篇 |
农作物 | 33篇 |
水产渔业 | 20篇 |
畜牧兽医 | 126篇 |
园艺 | 2篇 |
植物保护 | 7篇 |
出版年
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 6篇 |
2014年 | 10篇 |
2013年 | 22篇 |
2012年 | 16篇 |
2011年 | 22篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 13篇 |
2007年 | 10篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 11篇 |
2003年 | 14篇 |
2002年 | 11篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有252条查询结果,搜索用时 31 毫秒
1.
2.
正Many proteins are regulated by post-translational modifications,such as the reversible covalent attachment of ubiquitin and ubiquitin-like proteins in eukaryotes(Kerscher et al, 2006). Post-translational modification of proteins by the SUMO protein family is involved in diverse cellular processes, including development, hormonal responses, and biotic and abiotic stress signaling(Park et al, 2011). SUMO modification can modulate protein-protein interactions, intracellular localization or the activities of the protein(Gareau and Lima, 2010). 相似文献
3.
Kai‐Min Niu Sanaz Khosravi Damini Kothari Woo‐Do Lee Bong‐Joo Lee Sang‐Gu Lim Sang‐Woo Hur Sang‐Min Lee Soo‐Ki Kim 《Journal of the World Aquaculture Society》2021,52(1):244-261
A 12‐week feeding trial was designed to assess the probiotic potential of indigenous Bacillus amyloliquefaciens and/or Bacillus subtilis singly or in combination with Bacillus licheniformis in an extruded feed for olive flounder (Paralichthys olivaceus) juveniles. A high fish meal (FM) diet (control) and a low‐FM diet containing an alternative protein blend (30% FM replacement, FM30) were formulated. Three other experimental diets were prepared by inclusion of B. amyloliquefaciens (BA), B. subtilis (BS), or a mixture of B. amyloliquefaciens, B. subtilis, and B. licheniformis (BASL) into FM30 diet, with a final concentration of 106 CFU/g diet. Results indicated that the FM30 diet was well tolerated by flounder, and the overall performance was not affected by dietary treatments. Lysozyme activity and total immunoglobulin level were significantly reduced in flounders when fed with the FM30 diet compared with the BASL and BA diets, respectively. The Bacillus additives neither enriched the relative abundance of the corresponding Bacillus spp. in the relevant gut microbiota of olive flounder nor modulated the presumptive gene functions of the gut microbiome. Despite the absence of growth‐promoting effect, the tested probiotics could still be economically viable for use as immunostimulants in commercial flounder diets with partial FM replacement. 相似文献
4.
This study established a prediction model for bending properties of glued-laminated timber (glulam) using optimized knot and
modulus of elasticity (MOE) distributions of lumber laminate as the main input variables. For this purpose, knot and MOE data
were investigated for all pieces of lumber that were prepared for glulam manufacturing, and statistical distributions of knot
size, knot number in one lumber, and MOE of each laminate were optimized as distribution functions. These knot and MOE data
were used as input variables in the prediction model for bending properties, and were also used in generating virtual glulam
using the inverse transform method. Prediction of bending properties for glulam was carried out using the transformed section
method, which is partially provided in ASTM D 3737 (Annex A4). Predicted values were compared with those from full-scale four-point
bending tests for 60 six-layered glulams with 10 different laminar combinations. Finally, the allowable bending properties
of glulam for each specific laminate combination were determined by calculating the fifth percentile of the modulus of rupture
and the average modulus of elasticity from virtual test results of more than 1000 virtual glulams. From the results of this
study, predicted bending properties for glulam and their distributions could be used for structural design in both allowable
stress design and limit state design. 相似文献
5.
Lee KW Kim YJ Kim DO Lee HJ Lee CY 《Journal of agricultural and food chemistry》2003,51(22):6516-6520
The contribution of each phytochemical to the total antioxidant capacity of apples was determined. Major phenolic phytochemicals of six apple cultivars were identified and quantified, and their contributions to total antioxidant activity of apples were determined using a 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay and expressed as vitamin C equivalent antioxidant capacity (VCEAC). Average concentrations of major phenolics and vitamin C in six apple cultivars were as follows (mg/100 g of fresh weight of apples): quercetin glycosides, 13.20; procyanidin B(2), 9.35; chlorogenic acid, 9.02; epicatechin, 8.65; phloretin glycosides, 5.59; vitamin C, 12.80. A highly linear relationship (r (2) > 0.97) was attained between concentrations and total antioxidant capacity of phenolics and vitamin C. Relative VCEAC values of these compounds were in the order quercetin (3.06) > epicatechin (2.67) > procyanidin B(2) (2.36) > phloretin (1.63) > vitamin C (1.00) > chlorogenic acid (0.97). Therefore, the estimated contribution of major phenolics and vitamin C to the total antioxidant capacity of 100 g of fresh apples is as follows: quercetin (40.39 VCEAC) > epicatechin (23.10) > procyanidin B(2) (22.07) > vitamin C (12.80) > phloretin (9.11) > chlorogenic acid (8.75). These results indicate that flavonoids such as quercetin, epicatechin, and procyanidin B(2) rather than vitamin C contribute significantly to the total antioxidant activity of apples. 相似文献
6.
Young Jun Joo Khos-Erdene Khishigbayar Kwang Youn Cho Cheol Jin Kim 《Fibers and Polymers》2018,19(9):1806-1812
Low pressure curing method with iodine vapor was used on low softening temperature polycarbosilane (PCS) precursor for fabrication of continuous SiC fiber at relatively low temperature. The low curing temperature can provide with a wide range of softening temperature PCS precursors, especially with low softening PCSs, which have a good spinnability, but many difficulties with conventional oxidation curing method. The low pressure curing method having the presence of iodine vapor have shown the more positive effect on pyrolysis with early stage crystallization of β-SiC at 1300 °C. Crystal size of β-SiC, cured at 0.008 kPa is around 2–3 nm larger than cured at 101 kPa. In addition, the higher tensile strength of SiC fiber at elevated temperature can be obtained at 0.008 kPa with a value of 2.1 GPa, compare to 1.3 GPa at 101 kPa of curing pressure condition. 相似文献
7.
This study developed a novel PHB-lignin-jute biodegradable composite with preferable mechanical properties and low water absorption.
The appearances of fracture surface of composites were analyzed by scanning electron microscope. The result suggested a Gaussian-like
distribution of the size particles supporting the presence of lignin with a radius smaller than 0.5 μm. According to X-ray
diffraction, the presence of lignin and jute fibers was decreased the crystallization of PHB. Moreover, the glass transition
temperature of PHB increased, and the endotherm during glass transition was decreased. The maximum tensile strength and modulus
of composites were obtained with 30 wt% jute fiber contents and 4 wt% lignin contents. The presence of jute fibers was largely
increased the water absorption of composites. However, the presence of lignin was effectively decreased the water absorption
of composites at saturation levels. 相似文献
8.
A melt-process was used to prepare high molecular weight Poly(vinyl chloride) (PVC) films without the use of a conventional
plasticizer and heat stabilizer. Rigid PVC powder was swollen with dimethylformamide containing 4∼10 vol% water to reduce
its melting temperature. The swollen powder was pressed at a relatively low temperature of 75∼125 °C to form a film shape,
and then washed and dried. The visible light transmittance, X-ray diffraction, density and the tensile properties of the resulting
films were examined to estimate the success or failure of film formation. The films could be produced by not only the melt-process
but also a compression-process using the rigid, highly swollen PVC powder. The resulting films had no voids, which are generally
observed in PVC products formed by a solution process. The minimum temperature for these processes decreased with decreasing
water content in the mixture: The minimum temperatures according to the water content in the mixture to produce faultless
films through the melt-process were 4 %–105 °C, 6 %–115 °C, 8 and 10 %–125 °C, while those through the compression process
were 4 %–95 °C, 6 and 8 %–105 °C, 10 %–115 °C. 相似文献
9.
Sunhee Shin Seong Soo Joo Jeong Hee Jeon Dongsun Park Min-Jung Jang Tae-Ook Kim Hyun-Kyu Kim Bang Yeon Hwang Ki-Yon Kim Yun-Bae Kim 《Journal of veterinary science (Suw?n-si, Korea)》2010,11(3):273-275
Anti-inflammatory effects of Houttuynia cordata supercritical extract (HSE) were investigated in a carrageenan-air pouch model. HSE (200 mg/kg, oral) suppressed exudation and albumin leakage, as well as inflammatory cell infiltration. Dexamethasone (2 mg/kg, i.p.) only decreased exudation and cell infiltration, while indomethacin (2 mg/kg, i.p.) reduced exudate volume and albumin content. HSE lowered tumor-necrosis factor (TNF)-α and nitric oxide (NO), as well as prostaglandin E2 (PGE2). Dexamethasone only reduced TNF-α and NO, while indomethacin decreased TNF-α and PGE2. The suppressive activity of HSE on NO and PGE2 production was confirmed in RAW 264.7. These results demonstrate that HSE exerts anti-inflammatory effects by inhibiting both TNF-α-NO and cyclooxygenase II-PGE2 pathways. 相似文献
10.
Joo Ran KimSuraj Sharma 《Industrial Crops and Products》2012,36(1):485-499
This study investigates the development of thermoset plastics from plant-based oils (e.g., linseed, soybean, cottonseed, oilseed radish, and peanut oils) using an optimal process of solvent-free epoxidation. The epoxidation of plant oils can be accomplished economically by reacting the double bonds of fatty-acids with hydrogen peroxide. During the solvent-free process catalyzed by the ion-exchange resin, we observed that the influence of several variables was important: the molar ratio of hydrogen peroxide to unsaturation, acetic acid to unsaturation, and temperature. The epoxidation of plant oils was determined from the liquid mixture and the composite matrix by thermal and spectroscopic analyses. Compounds with a higher double-bond (iodine) value showed higher oxirane oxygen percent and selectivity, and a higher hydroxyl value because of a greater possibility of attack by solutions causing side reactions. Lower iodine values indicated fewer epoxy groups and selectivity, and a lower hydroxyl value. Benzyl pyrazinium hexafluoroantimonate (BPH) yielded good thermal curing properties; as little as 1% added to the plastics produced light-weight composites. Epoxidized linseed oil promises the highest modulus and impact resistance due to the largest number of double bonds to contribute more epoxy groups and the large proportion of linolenic acids to produce epoxy groups rapidly. 相似文献