全文获取类型
收费全文 | 342169篇 |
免费 | 26089篇 |
国内免费 | 13335篇 |
专业分类
电工技术 | 18485篇 |
技术理论 | 38篇 |
综合类 | 21384篇 |
化学工业 | 57957篇 |
金属工艺 | 19557篇 |
机械仪表 | 21725篇 |
建筑科学 | 27298篇 |
矿业工程 | 10908篇 |
能源动力 | 9496篇 |
轻工业 | 21116篇 |
水利工程 | 5872篇 |
石油天然气 | 22916篇 |
武器工业 | 2693篇 |
无线电 | 37862篇 |
一般工业技术 | 40637篇 |
冶金工业 | 17599篇 |
原子能技术 | 3393篇 |
自动化技术 | 42657篇 |
出版年
2024年 | 667篇 |
2023年 | 5191篇 |
2022年 | 7931篇 |
2021年 | 13026篇 |
2020年 | 10029篇 |
2019年 | 8333篇 |
2018年 | 9547篇 |
2017年 | 10732篇 |
2016年 | 9481篇 |
2015年 | 13212篇 |
2014年 | 16458篇 |
2013年 | 19614篇 |
2012年 | 21358篇 |
2011年 | 23391篇 |
2010年 | 20093篇 |
2009年 | 19062篇 |
2008年 | 18599篇 |
2007年 | 18074篇 |
2006年 | 18778篇 |
2005年 | 16655篇 |
2004年 | 10897篇 |
2003年 | 9569篇 |
2002年 | 8821篇 |
2001年 | 7873篇 |
2000年 | 8595篇 |
1999年 | 10196篇 |
1998年 | 8299篇 |
1997年 | 7000篇 |
1996年 | 6561篇 |
1995年 | 5484篇 |
1994年 | 4563篇 |
1993年 | 3204篇 |
1992年 | 2584篇 |
1991年 | 1920篇 |
1990年 | 1443篇 |
1989年 | 1185篇 |
1988年 | 936篇 |
1987年 | 617篇 |
1986年 | 453篇 |
1985年 | 309篇 |
1984年 | 211篇 |
1983年 | 142篇 |
1982年 | 170篇 |
1981年 | 111篇 |
1980年 | 93篇 |
1979年 | 34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 734 毫秒
11.
以“创新、协调、绿色、开放、共享”为内核的新发展理念,是对马克思主义发展理念的继承和发扬,极具时代精神,富含问题意识,为高校思想政治教育发展、教育教学改革实践提供了强大的理论支撑。本文以“通信原理”为例,阐述了新发展理念在课程改革中的思路和方法,实现了思想政治教育与专业基础课程有机融合,为深化高校教学改革、创新人才培养模式提供了思路。 相似文献
12.
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
13.
14.
15.
16.
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
17.
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
18.
20.
Kai Liu Chenyang Zhou Jiaming Hu Song Zhang Qingqing Zhang Ce Sun Yusheng Shi Huajun Sun Changxia Yin Yuzhen Zhang Yu Fu 《Journal of the European Ceramic Society》2021,41(12):5909-5917
A digital light processing (DLP) technology has been developed for 3D printing lead-free barium titanate (BTO) piezoelectric ceramics. By comparing the curing and rheological properties of slurries with different photosensitive monomer, a high refractive index monomer acryloyl morpholine (ACMO) was chosen, and a design and preparation method of BTO slurry with high solid content, low viscosity and high curing ability was proposed. By further selecting the printing parameters, the single-layer exposure time was reduced and the forming efficiency has been greatly improved. Sintered specimens were obtained after a nitrogen-air double-step debinding and furnace sintering process, and the BTO ceramics fabricated with 80 wt% slurry shows the highest relative density (95.32 %) and piezoelectric constant (168.1 pC/N). Furthermore, complex-structured BTO ceramics were prepared, impregnated by epoxy resin and finally assembly made into hydrophones, which has significance for the future design and manufacture of piezoelectric ceramic-based composites that used in functional devices. 相似文献