全文获取类型
收费全文 | 654641篇 |
免费 | 50370篇 |
国内免费 | 27645篇 |
学科分类
工业技术 | 732656篇 |
出版年
2024年 | 1641篇 |
2023年 | 8639篇 |
2022年 | 14787篇 |
2021年 | 23394篇 |
2020年 | 18049篇 |
2019年 | 14539篇 |
2018年 | 16818篇 |
2017年 | 19333篇 |
2016年 | 17431篇 |
2015年 | 24878篇 |
2014年 | 31614篇 |
2013年 | 38062篇 |
2012年 | 41705篇 |
2011年 | 46154篇 |
2010年 | 41111篇 |
2009年 | 39218篇 |
2008年 | 38332篇 |
2007年 | 37071篇 |
2006年 | 37895篇 |
2005年 | 33532篇 |
2004年 | 22277篇 |
2003年 | 19715篇 |
2002年 | 18501篇 |
2001年 | 16523篇 |
2000年 | 16488篇 |
1999年 | 18064篇 |
1998年 | 14095篇 |
1997年 | 12054篇 |
1996年 | 11245篇 |
1995年 | 9308篇 |
1994年 | 7668篇 |
1993年 | 5338篇 |
1992年 | 4238篇 |
1991年 | 3204篇 |
1990年 | 2442篇 |
1989年 | 1990篇 |
1988年 | 1603篇 |
1987年 | 984篇 |
1986年 | 767篇 |
1985年 | 492篇 |
1984年 | 359篇 |
1983年 | 245篇 |
1982年 | 246篇 |
1981年 | 158篇 |
1980年 | 167篇 |
1979年 | 77篇 |
1978年 | 29篇 |
1977年 | 29篇 |
1976年 | 35篇 |
1951年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 264 毫秒
21.
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
22.
Chenchen Zhou Jia Man Haibo Yu He Xia Luming Man Bin Qi Jianfeng Li 《Ceramics International》2021,47(8):10866-10872
Ceramic microparticles have great potentials in various fields such as materials engineering, biotechnology, microelectromechanical systems, etc. Morphology of the microparticle performs an important role on their application. To date, it remains difficult to find an effective and controllable way for fabricating nonspherical ceramic microparticles with 3D features. This work demonstrates a method that combines UV light lithography and single emulsion opaque-droplet-templated microfluidic molding to prepare the crescent-shaped ceramic microparticles. By tailoring the intensity of UV light and flow rate of fluid, the shapes of microparticles are accordingly tuned. Therefore, varieties of crescent-shaped microparticles and their variations have been fabricated. After sintering, the crescent-shaped alumina ceramic microparticles were obtained. Benefitting from the light absorption and scattering behavior of most ceramic nanoparticles, this system can serve as a general platform to produce crescent-shaped microparticles made from different materials, and hold great potentials for applications in microrobotics, structural materials in MEMS, and biotechnology. 相似文献
23.
Wireless Networks - In this paper, a grouping-based uplink orthogonal frequency division multiple access (OFDMA) random access method is studied which can improve users’ satisfaction in the... 相似文献
24.
25.
26.
27.
28.
Zhang Nan Zhao Man Liu Guangfa Wang Jiaoyang Chen Yunzhi Zhang Zhengjian 《Journal of Materials Science》2022,57(19):8687-8700
Journal of Materials Science - A green modification method for effectively enhancing toughness of PLA was established. Herein, alkaline lignin (LG) was firstly alkylated with dodecane, and then... 相似文献
29.
Wang Chen Bao Chun-Hui Wu Wan-Yu Hsu Chia-Hsun Zhao Ming-Jie Zhang Xiao-Ying Lien Shui-Yang Zhu Wen-Zhang 《Journal of Materials Science》2022,57(26):12341-12355
Journal of Materials Science - Molybdenum oxide (MoOx) films had been grown by using plasma-enhanced atomic layer deposition (PEALD) with Mo(CO)6 precursor and O2 plasma reactant in a substrate... 相似文献
30.