全文获取类型
收费全文 | 171239篇 |
免费 | 15723篇 |
国内免费 | 9462篇 |
专业分类
电工技术 | 11209篇 |
技术理论 | 10篇 |
综合类 | 15970篇 |
化学工业 | 26384篇 |
金属工艺 | 9697篇 |
机械仪表 | 10996篇 |
建筑科学 | 12797篇 |
矿业工程 | 4326篇 |
能源动力 | 4711篇 |
轻工业 | 16305篇 |
水利工程 | 3515篇 |
石油天然气 | 7795篇 |
武器工业 | 1564篇 |
无线电 | 19196篇 |
一般工业技术 | 18000篇 |
冶金工业 | 6636篇 |
原子能技术 | 2086篇 |
自动化技术 | 25227篇 |
出版年
2024年 | 360篇 |
2023年 | 2338篇 |
2022年 | 4343篇 |
2021年 | 6304篇 |
2020年 | 4858篇 |
2019年 | 3986篇 |
2018年 | 4323篇 |
2017年 | 4976篇 |
2016年 | 4553篇 |
2015年 | 6679篇 |
2014年 | 8791篇 |
2013年 | 10345篇 |
2012年 | 12296篇 |
2011年 | 13371篇 |
2010年 | 12270篇 |
2009年 | 11786篇 |
2008年 | 11746篇 |
2007年 | 11120篇 |
2006年 | 10727篇 |
2005年 | 8722篇 |
2004年 | 6645篇 |
2003年 | 5759篇 |
2002年 | 6336篇 |
2001年 | 5433篇 |
2000年 | 4103篇 |
1999年 | 3234篇 |
1998年 | 2238篇 |
1997年 | 1781篇 |
1996年 | 1580篇 |
1995年 | 1278篇 |
1994年 | 991篇 |
1993年 | 710篇 |
1992年 | 580篇 |
1991年 | 441篇 |
1990年 | 333篇 |
1989年 | 247篇 |
1988年 | 188篇 |
1987年 | 143篇 |
1986年 | 85篇 |
1985年 | 72篇 |
1984年 | 51篇 |
1983年 | 51篇 |
1982年 | 39篇 |
1981年 | 40篇 |
1980年 | 50篇 |
1979年 | 23篇 |
1977年 | 13篇 |
1976年 | 17篇 |
1959年 | 15篇 |
1951年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Feng Wenran Li Zhen Chen Yingying Chen Jinyang Lang Haoze Wan Jianghong Gao Yan Dong Haitao 《Journal of Materials Science》2022,57(3):1881-1889
Journal of Materials Science - Although chalcogenide materials continue to generate considerable interest due to great potentials for various optoelectronic devices, annealing for a long time in... 相似文献
2.
3.
Kelin Hu Feipeng Wang Yuyang Yan Hongcheng Liu Zijia Shen 《Ceramics International》2021,47(11):15228-15236
In this paper, a novel hybrid structure of Pd doped ZnO/SnO2 heterojunction nanofibers with hexagonal ZnO columns was one step synthesized from electrospun precursor nanofibers. Due to the synergistic effect of hexagonal ZnO, SnO2 and Pd, the structure exhibited excellent hydrogen (H2) gas sensing properties. At low-temperature of 120 °C, the response (Ra/Rg) to 100 ppm H2 gas exceeded 160, the response/recovery time was only 20 s and 6 s respectively and the limit of detection was only 0.5 ppm. Meanwhile, it also had good selectivity for H2 gas and excellent linearity. In addition, the materials were characterized by XRD, FESEM, HRTEM, XPS, and the synthesis mechanism and gas sensing mechanism were proposed. 相似文献
4.
Peng Wang Yan Li Yujiao Qu Baowei Wang Jingxin Sun Chunwei Miao Ming Huang He Huang Congxiang Zhang 《International Journal of Food Science & Technology》2022,57(6):3428-3439
The effects of cellulose microfibres (CMFs, Average size: 100 ± 5 μm) and cellulose nanofibres (CNFs, Average size: 60 ± 3 nm) on the properties of myofibrillar protein (MP) gels from duck breast meat were studied. The results demonstrated that CMFs and CNFs were mostly connected to MP by non-covalent bonds, the diffusion and cross-linking of MP molecules was promoted, and a denser and more complete gel network was formed. With the increases of CMFs and CNFs concentration (0–10%), the hardness was increased by 13.15% and 19.78% for CMFs10% and CNFs10% gels, respectively, and the elasticity was increased by 40% and 80%, respectively. At the same concentration (0–10%), the increase in gel hardness, viscoelasticity and immobilised water content was greater in the CNFs-MP group than in the CMFs-MP group. The CNFs-MP group had a tighter gel network, and CNFs had a better potential to improve the gelation performance of MP. 相似文献
5.
Fan Deng-Ping Huang Ziling Zheng Peng Liu Hong Qin Xuebin Van Gool Luc 《国际自动化与计算杂志》2022,19(4):257-287
Machine Intelligence Research - This paper aims to conduct a comprehensive study on facial-sketch synthesis (FSS). However, due to the high cost of obtaining hand-drawn sketch datasets, there is a... 相似文献
6.
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
7.
8.
Hong Sae Jin Park Nam Il Hwang Dae Keun Yi Tae Gyu Eum Hyang Lan 《Food science and biotechnology》2022,31(6):669-679
Food Science and Biotechnology - Various hilling materials (rice hulls, pine sawdust, and perlite) were compared to produce sprout vegetables using beach silvertop (Glehnia littoralis Fr. Schm. ex... 相似文献
9.
International Journal of Information Security - Machine learning techniques have been widely used and shown remarkable performance in various fields. Along with the widespread utilization of... 相似文献
10.
Zhen Hong Mingshan Xue Yidan Luo Zuozhu Yin Chan Xie Junfei Ou Fajun Wang 《应用聚合物科学杂志》2021,138(2):49657
With the continuous development of bionics, such as, geckos and virginia creeper with both superhydrophobic and super-adhesive, the surface wetting and super-adhesive properties of various porous materials have attracted extensive attention of the scientific and medical communities. Here, the honeycomb polyurethane (PU) porous films with strong adhesion were successfully prepared by microphase separation method and the effects of growth parameters on their microstructure and adhesive strength to ice were investigated. It was found that a high relative humidity (e.g., 100%) and a low solution concentration (e.g., 2%) facilitated the formation of ordered honeycomb PU porous films, and as-prepared PU pores with average pore diameter as small as 5 μm are better ordered and more uniform than these in related documents. Although the contact angle of water droplets on the surface of PU porous films increased from the premodification value of 85–130° to more than 160° after surface modification with polydopamine (PDA), the corresponding rolling angle remained approximately constant (180°), indicating that the surface of PU porous films has strong adhesion similar to geckos and virginia creeper. Furthermore, at lower temperature, the PU porous films exhibited the high adhesive strength of 142.13 kPa on ice, which was strongly dependent on the porous microstructures and surface compositions. The improved adhesive behavior to ice of honeycomb PU porous films modified with PDA provides new strategies for surface modification of materials and potential applications in medical domain. 相似文献