全文获取类型
收费全文 | 71933篇 |
免费 | 6124篇 |
国内免费 | 3179篇 |
专业分类
电工技术 | 4157篇 |
技术理论 | 10篇 |
综合类 | 4812篇 |
化学工业 | 12047篇 |
金属工艺 | 3884篇 |
机械仪表 | 4173篇 |
建筑科学 | 5644篇 |
矿业工程 | 1941篇 |
能源动力 | 2046篇 |
轻工业 | 5469篇 |
水利工程 | 1371篇 |
石油天然气 | 4019篇 |
武器工业 | 569篇 |
无线电 | 8553篇 |
一般工业技术 | 8817篇 |
冶金工业 | 3491篇 |
原子能技术 | 778篇 |
自动化技术 | 9455篇 |
出版年
2024年 | 244篇 |
2023年 | 1182篇 |
2022年 | 2039篇 |
2021年 | 2999篇 |
2020年 | 2303篇 |
2019年 | 1824篇 |
2018年 | 2093篇 |
2017年 | 2173篇 |
2016年 | 2136篇 |
2015年 | 2783篇 |
2014年 | 3504篇 |
2013年 | 4147篇 |
2012年 | 4587篇 |
2011年 | 4970篇 |
2010年 | 4123篇 |
2009年 | 3944篇 |
2008年 | 3911篇 |
2007年 | 3640篇 |
2006年 | 3552篇 |
2005年 | 3056篇 |
2004年 | 2295篇 |
2003年 | 2033篇 |
2002年 | 1853篇 |
2001年 | 1696篇 |
2000年 | 1860篇 |
1999年 | 2144篇 |
1998年 | 1793篇 |
1997年 | 1462篇 |
1996年 | 1448篇 |
1995年 | 1197篇 |
1994年 | 1041篇 |
1993年 | 711篇 |
1992年 | 562篇 |
1991年 | 402篇 |
1990年 | 351篇 |
1989年 | 311篇 |
1988年 | 218篇 |
1987年 | 149篇 |
1986年 | 104篇 |
1985年 | 76篇 |
1984年 | 57篇 |
1983年 | 41篇 |
1982年 | 50篇 |
1981年 | 35篇 |
1980年 | 33篇 |
1979年 | 15篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1974年 | 11篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
1.
Yuhang Xing Ruyi Li Lu Xue Mianhong Chen Xuli Lu Zhihao Duan Wei Zhou Jihua Li 《International Journal of Food Science & Technology》2022,57(8):5268-5279
Mangiferin (MGF) is a phenolic compound isolated from mango, but its poor solubility significantly limits its use. In this study, MGF was embedded into the inner aqueous phase of W1/O/W2 emulsions. Firstly, the dissolution method of MGF was determined. MGF remained stable in solution with pH 13 at 30 min, and its solubility reached 10 mg mL−1. When the pH of MGF solutions was adjusted from pH 13 to pH 6, MGF did not immediately crystallise, providing sufficient time to construct the MGF-loaded W1/O/W2 emulsions. Subsequently, the MGF-loaded W1/O/W2 emulsions were constructed using polyglycerol polyricinoleate (PGPR) and calcium caseinate (CAS). The formation and stability of the W1/O/W2 emulsions were investigated. The MGF-loaded W1/O/W2 emulsions stabilised with 1% PGPR and 1% – 3% CAS exhibited a low viscosity, limited loading capacity, and poor stability. Conversely, the MGF-loaded W1/O/W2 emulsions stabilised by 3%PGPR–3%CAS exhibited optimal loading capacity (encapsulation efficiency = 95.31% and loading efficiency = 0.91%) and stability, which was attributed to the fact that high viscosity and gel state retarded the migration of inner aqueous phase. These results indicated that the W1/O/W2 emulsions stabilised by PGPR and CAS may be a potential alternative for encapsulating mangiferin. 相似文献
2.
KH550, KH560, CTAB, and F127 were adopted to modify silicon (Si) to improve the dispersity and stability of Si in the polyacrylonitrile/dimethyl sulfoxide (PAN/DMSO) polymer solutions. The influence of surfactants on rheological behaviors of PAN/DMSO/Si blending polymer solutions was investigated by an advanced solution and melt rotation rheometer. The homogeneity and stability were also studied. The results showed that the surfactants could change the viscosity dependence of blending polymer solutions on shear rate, temperature and storage time by increase the steric hindrance of Si. Among the four solutions, PAN/DMSO/Si blending polymer solution with F127 exhibited the lowest viscosity, activation energy and the smallest structural viscosity index and exhibited the trend close to the Newtonian fluids. Moreover, PAN/DMSO/Si blending polymer solution with F127 exhibited the best dispersity and stability, indicating its best physical properties and machinability. 相似文献
3.
Wenlong Song Shoujun Wang Yang Lu Xuan Zhang Zixiang Xia Kai Sun Guangming Xin 《Ceramics International》2021,47(9):12631-12640
To enhance the tribological performance of Si3N4/TiC ceramics, MoS2/PTFE composite coatings were deposited on the ceramic substrate through spraying method. The micrographs and basic properties of the MoS2/PTFE coated samples were investigated. Dry sliding friction experiments against WC/Co ball were performed with the coated ceramics and traditional ones. These results showed that the composite coatings could significantly reduce the friction coefficient of ceramics, and protect the substrate from adhesion wear. The primary tribological mechanisms of the coated ceramics were abrasive wear, coating spalling and delamination, and the tribological property was transited from slight wear to serious wear with the increase of load because of the lower surface hardness and shear strength. The possible mechanisms for the effects of MoS2/PTFE composite coatings on the friction performance of ceramics were discussed. 相似文献
5.
以具有轻质高强优异性能的蜻蜓翅脉结构为设计灵感,在分析翅脉网格结构抗冲击原理的基础上,设计了传统和仿生两类对比结构。采用熔融挤出3D打印机成功制备了具有不同结构的连续碳纤维增强聚乳酸复合材料试样,并对不同结构复合材料试样的拉伸性能和抗冲击性能进行了测试和对比分析。研究分析结果表明:由于拉伸力方向上的连续碳纤维含量相对较少,限制了仿生结构复合材料抗拉强度的提高,但仿生结构的平均抗拉强度为传统结构的1.18倍;当仿生结构复合材料试样受到冲击力时,其内部六边形结构的连接角度会发生变化,从而极大消耗冲击能量,同时具有六边形网格结构的连续碳纤维可以有效阻碍裂纹的扩展,因此仿生结构的平均冲击韧性可以达到传统结构的2.46倍;仿生蜻蜓翅脉结构可以显著提高增材制造复合材料的综合力学性能,且对于抗冲击性能的提高具体突出效果。连续碳纤维增强树脂基复合材料的有效可行的仿生蜻蜓翅脉结构设计和增材制造,可极大扩展其在高冲击载荷领域中的相应应用。 相似文献
6.
Liang Yan-Jun Lu You-Jun Gao De-Xin Wang Zhong-Sheng 《International Journal of Control, Automation and Systems》2022,20(2):507-514
International Journal of Control, Automation and Systems - The vibration control problem of offshore jacket platforms is studied. The model of offshore platforms with nonlinear interactions of the... 相似文献
7.
8.
9.
10.