全文获取类型
收费全文 | 12371篇 |
免费 | 760篇 |
国内免费 | 41篇 |
学科分类
工业技术 | 13172篇 |
出版年
2024年 | 3篇 |
2023年 | 155篇 |
2022年 | 77篇 |
2021年 | 395篇 |
2020年 | 282篇 |
2019年 | 326篇 |
2018年 | 367篇 |
2017年 | 420篇 |
2016年 | 457篇 |
2015年 | 378篇 |
2014年 | 554篇 |
2013年 | 825篇 |
2012年 | 833篇 |
2011年 | 1016篇 |
2010年 | 734篇 |
2009年 | 781篇 |
2008年 | 722篇 |
2007年 | 569篇 |
2006年 | 494篇 |
2005年 | 447篇 |
2004年 | 414篇 |
2003年 | 368篇 |
2002年 | 374篇 |
2001年 | 274篇 |
2000年 | 227篇 |
1999年 | 212篇 |
1998年 | 337篇 |
1997年 | 226篇 |
1996年 | 168篇 |
1995年 | 123篇 |
1994年 | 110篇 |
1993年 | 93篇 |
1992年 | 64篇 |
1991年 | 57篇 |
1990年 | 50篇 |
1989年 | 56篇 |
1988年 | 30篇 |
1987年 | 39篇 |
1986年 | 18篇 |
1985年 | 30篇 |
1984年 | 16篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1973年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Kim Jungtaek McCourt Michael You Tackgeun Kim Saehoon Choi Seungjin 《Machine Learning》2021,110(5):857-879
Machine Learning - We propose a practical Bayesian optimization method over sets, to minimize a black-box function that takes a set as a single input. Because set inputs are permutation-invariant,... 相似文献
42.
43.
Kim Kye-Sun Oh Seon-Min Choi Seung-Hyun Choi Jong-Hyun Bae Ji-Eun Kim Hui-yun Ye Sang-Jin Baik Moo-Yeol 《Food science and biotechnology》2021,30(10):1339-1346
Food Science and Biotechnology - Fluorescein isothiocyanate-dextrans (FDs) of different molecular weights were infused into corn, waxy rice, tapioca, and potato starches under atmospheric and high... 相似文献
44.
Chi-Yeong Ahn Sun Young Kang Hyuck Jae Choi Ok-Hee Kim Yung-Eun Sung Yong-Hun Cho 《International Journal of Hydrogen Energy》2021,46(27):14713-14723
An ideal polymer electrolyte membrane fuel cell (PEMFC) is one that continuously generates electricity as long as hydrogen and oxygen (or air) are supplied to its anode and cathode, respectively. However, internal and/or external conditions could bring about the degradation of its electrodes, which are composed of nanoparticle catalysts. Particularly, when the hydrogen supply to the anode is disrupted, a reverse voltage is generated. This phenomenon, which seriously degrades the anode catalyst, is referred to as cell reversal. To prevent its occurrence, iridium oxide (IrO2) particles were added to the anode in the membrane-electrode assembly of the PEMFC single-cells. After 100 cell reversal cycles, the single-cell voltage profiles of the anode with Pt/C only and the anodes with Pt/C and various IrO2 contents were obtained. Additionally, the cell reversal-induced degradation phenomenon was also confirmed electrochemically and physically, and the use of anodes with various IrO2 contents was also discussed. 相似文献
45.
With the development of social media, television viewing is perceived no longer as an isolated activity. This study explores the underlying mechanism of the effects of social viewing discussion networks (i.e., bridging and bonding social viewing networks) on emotions (i.e., anger, fear, and enthusiasm), and moreover on opinion consolidation as well as opinion weakening in the context of the 2017 South Korean presidential debates. Overall, the main results are: a) Social viewing discussion networks influenced emotional states of social viewers, b) Emotions influenced attitude formation during social viewing, and c) Enthusiasm served as a catalyst that links bonding and bridging social viewing, and opinion consolidation. Implications and theoretical contributions are discussed. 相似文献
46.
Liang Wang Jung-Hoon Park Nak-Sam Choi 《Journal of Mechanical Science and Technology》2020,34(3):1049-1058
The fracture of ductile materials such as Al6061-T6 usually starts from void nucleation. In this study, we investigated strengthening effect and stress triaxiality behavior in notched Al alloy specimens. Various specimens, one un-notched and two with different U-types of notch, one with large diameter (L-notched) and another with small diameter (S-notched), having the same width were selected. The distribution of strain in the full-field was examined using the digital image correlation (DIC) method. Under the tensile test, S-notched specimens showed a more pronounced strengthening effect than the L-notched specimens. The results of DIC confirmed that the notch tip of the S-notched specimen experienced high strain, while the L-notched specimen experienced high strain at the center. The maximum stress triaxiality moved rapidly from the notch tip to the center with the increase in notch radius over 10 mm. The results of the stress triaxiality analysis by finite element method were in good agreement with the above DIC measurement results and predicted the void generation and fracture sites in L-notched and S-notched specimens. 相似文献
47.
Kang Sungwoo Ngo Long Cu Choi Hyounggwon Chung Wanjin Yoo Yo-Han Yoo Jung Yul 《Journal of Mechanical Science and Technology》2020,34(3):1175-1184
Journal of Mechanical Science and Technology - In this paper, the performances of various ILU type parallel preconditioners for the finite element discretization of the incompressible Naiver-Stokes... 相似文献
48.
49.
50.
Mu-Hyon Kim Kyeongsoon Park Kyung-Hee Choi Soo-Hong Kim Se Eun Kim Chang-Mo Jeong Jung-Bo Huh 《International journal of molecular sciences》2015,16(5):10324-10336
The authors describe a new type of titanium (Ti) implant as a Modi-anodized (ANO) Ti implant, the surface of which was treated by sandblasting, acid etching (SLA), and anodized techniques. The aim of the present study was to evaluate the adhesion of MG-63 cells to Modi-ANO surface treated Ti in vitro and to investigate its osseointegration characteristics in vivo. Four different types of Ti implants were examined, that is, machined Ti (control), SLA, anodized, and Modi-ANO Ti. In the cell adhesion study, Modi-ANO Ti showed higher initial MG-63 cell adhesion and induced greater filopodia growth than other groups. In vivo study in a beagle model revealed the bone-to-implant contact (BIC) of Modi-ANO Ti (74.20% ± 10.89%) was much greater than those of machined (33.58% ± 8.63%), SLA (58.47% ± 12.89), or ANO Ti (59.62% ± 18.30%). In conclusion, this study demonstrates that Modi-ANO Ti implants produced by sandblasting, acid etching, and anodizing improve cell adhesion and bone ongrowth as compared with machined, SLA, or ANO Ti implants. These findings suggest that the application of Modi-ANO surface treatment could improve the osseointegration of dental implant. 相似文献