全文获取类型
收费全文 | 1232篇 |
免费 | 37篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 136篇 |
综合类 | 1篇 |
化学工业 | 315篇 |
金属工艺 | 38篇 |
机械仪表 | 36篇 |
建筑科学 | 22篇 |
矿业工程 | 3篇 |
能源动力 | 43篇 |
轻工业 | 121篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 96篇 |
一般工业技术 | 188篇 |
冶金工业 | 85篇 |
原子能技术 | 29篇 |
自动化技术 | 155篇 |
出版年
2023年 | 5篇 |
2022年 | 22篇 |
2021年 | 39篇 |
2020年 | 13篇 |
2019年 | 21篇 |
2018年 | 21篇 |
2017年 | 16篇 |
2016年 | 44篇 |
2015年 | 26篇 |
2014年 | 45篇 |
2013年 | 70篇 |
2012年 | 59篇 |
2011年 | 88篇 |
2010年 | 55篇 |
2009年 | 70篇 |
2008年 | 65篇 |
2007年 | 76篇 |
2006年 | 53篇 |
2005年 | 41篇 |
2004年 | 41篇 |
2003年 | 29篇 |
2002年 | 45篇 |
2001年 | 21篇 |
2000年 | 15篇 |
1999年 | 19篇 |
1998年 | 40篇 |
1997年 | 16篇 |
1996年 | 23篇 |
1995年 | 15篇 |
1994年 | 20篇 |
1993年 | 18篇 |
1992年 | 13篇 |
1991年 | 13篇 |
1990年 | 13篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1970年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有1272条查询结果,搜索用时 15 毫秒
991.
This paper proposes a torque control method for interior permanent magnet synchronous motors (IPMSMs). The proposed method uses state feedback control based on a new n‐t coordinate system and controls the voltage amplitude and phase based on the coordinate system. The t‐axis is a tangent line of the constant voltage ellipse, and the n‐axis is a normal line of the ellipse. The n‐axis current is utilized to place the poles of the transfer function at the desired position and reduce the mutual coupling between the voltage amplitude controller and phase controller. The proposed method realizes a high torque response even under parameter variation for the linear range and over‐modulation range of the inverter, including a 6‐step mode. The effectiveness of the proposed method was verified by simulation and experimental results. 相似文献
992.
Daisuke Hirose Jinwang Li Yoshitaka Murakami Shinji Kohara Tatsuya Shimoda 《Ceramics International》2018,44(15):17602-17611
Some types of oxide gels derived from solutions exhibit a thermal plasticity property. In our previous report, the thermal plasticity property was utilized to produce oxide patterns and thin film transistors. However, it was not clear why some oxide gels exhibited a thermal plasticity property. In this report, we prepared not only a plastic ZrO2 gel but also a non-plastic ZrO2 gel, and investigated the structural and thermal properties of these gels to clarify why some gels exhibit a thermal plasticity property. We identified a clustered structure in ZrO2 gels, with a Zr-O-Zr core coordinated by organic ligands. This structure was strongly related to the thermal plasticity property. The thermal plasticity property of ZrO2 gel resulted from desorption and oxidization of the extra ligands by heating. We determined that the plastically deformed gels were consisted of clusters, and that the behaviour of ligands was a trigger in making a gel plastically deformed. 相似文献
993.
Kim Cheolwoong Jung Mingook Yamada Takayuki Nishiwaki Shinji Yoo Jeonghoon 《Structural and Multidisciplinary Optimization》2020,62(1):439-455
Structural and Multidisciplinary Optimization - In this article, we present a simple FreeFEM++ code to represent high-resolution boundaries of the optimal shape using reaction-diffusion... 相似文献
994.
Kosuke Anan Dr. Yasuyoshi Iso Dr. Takuya Oguma Dr. Kenji Nakahara Shinji Suzuki Dr. Takahiko Yamamoto Eriko Matsuoka Dr. Hisanori Ito Dr. Gaku Sakaguchi Shigeru Ando Dr. Kenji Morimoto Dr. Naoki Kanegawa Dr. Yasuto Kido Tomoyuki Kawachi Dr. Tamio Fukushima Dr. Ard Teisman Dr. Vijay Urmaliya Dr. Deborah Dhuyvetter Dr. Herman Borghys Dr. Nigel Austin Dr. An Van Den Bergh Peter Verboven Dr. Francois Bischoff Dr. Harrie J. M. Gijsen Dr. Yoshinori Yamano Dr. Ken-ichi Kusakabe 《ChemMedChem》2019,14(22):1894-1910
The β-site amyloid precursor protein cleaving enzyme 1 (BACE1, also known as β-secretase) is a promising target for the treatment of Alzheimer's disease. A pKa lowering approach over the initial leads was adopted to mitigate hERG inhibition and P-gp efflux, leading to the design of 6-CF3 dihydrothiazine 8 (N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-thiazin-4-yl)-4-fluorophenyl)-5-cyanopicolinamide). Optimization of 8 led to the discovery of 15 (N-(3-((4S,6S)-2-amino-4-methyl-6-(trifluoromethyl)-5,6-dihydro-4H-1,3-thiazin-4-yl)-4-fluorophenyl)-5-(fluoromethoxy)pyrazine-2-carboxamide) with an excellent balance of potency, hERG inhibition, P-gp efflux, and metabolic stability. Oral administration of 8 elicited robust Aβ reduction in dog even at 0.16 mg/kg. Reflecting the reduced hERG inhibitory activity, no QTc prolongation was observed at high doses. The potential for reactive metabolite formation of 15 was realized in a nucleophile trapping assay using [14C]-KCN in human liver microsomes. Utilizing covalent binding (CVB) in human hepatocytes and the maximum projected human dosage, the daily CVB burden of 15 was calculated to be at an acceptable value of below 1 mg/day. However, hepatotoxicity was observed when 15 was subjected to a two-week tolerance study in dog, which prevented further evaluation of this compound. 相似文献
995.
Shinji Fujimoto Hiroaki Tsuchiya Soma Ogawa Yoshihisa Iida Naoki Taniguchi 《工业材料与腐蚀》2021,72(1-2):333-338
Stress corrosion cracking (SCC) of pure copper in bentonite clay was examined using a slow strain rate test (SSRT). Bentonite was swollen with pure water or aqueous solutions containing NH3 of 5 and 10 mM. Thick corrosion films and particulate deposits were formed on the copper surface after the SSRT. Typical tarnish rupture-type SCC occurred on pure copper in swollen bentonite with and without NH3. The crack propagation rate was enhanced by NH3. It is confirmed that a thick oxide layer was formed on copper during plastic deformation, resulting in tarnish crack-type SCC. Many particulate deposits observed on the surface were formed due to the rapid dissolution of Cu2+ ions to form porous CuO at local deformed sites, regardless of the SCC occurrence. 相似文献
996.
997.
Shinji Kondoh Yuji Iwamoto Koichi Kikuta Shin-ichi Hirano 《Journal of the American Ceramic Society》1999,82(1):209-212
Mesoporous silica films with one-dimensional through channels perpendicular to the substrate surface have been fabricated successfully by a novel process, which was a combination of eutectic decomposition of amorphous films and subsequent chemical etching. In the case of the Fe–Si–O system, amorphous precursor films annealed under oxidizing conditions were decomposed to a regular array of needlelike hematite (Fe2 O3 ) crystals with a diameter of ∼4 nm surrounded by an amorphous silica matrix. Then, hematite crystals were preferentially removed by chemical etching. The pore surface areas of the remaining mesoporous SiO2 films were found to be more than 1000 m2 /g by an isothermal N2 gas adsorption and desorption measurement. 相似文献
998.
999.
This paper proposes a novel method for analyzing a textile fabric structure to extract positional information regarding each yarn using three-dimensional X-ray computed tomography (3D CT) image. Positional relationship among the yarns can be reconstructed using the extracted yarn positional information. In this paper, a sequence of points on the center line of each yarn of the sample is defined as the yarn positional information, since the sequence can be regarded as the representative position of the yarn. The sequence is extracted by tracing the yarn. The yarn is traced by estimating the yarn center and direction and correlating the yarn part of the 3D CT image with a 3D yarn model, which is moved along the estimated yarn direction. The trajectory of the center of the yarn model corresponds to the positional information of the yarn. The application of the proposed method is shown by experimentally applying the proposed method to a 3D CT image of a double-layered woven fabric. Furthermore, the experimental results for a plain knitted fabric show that this method can be applied to even knitted fabrics. 相似文献
1000.
Ono K Kamihira M Kuga Y Matsumoto H Hotta A Itoh T Nishijima K Nakamura N Matsuda H Iijima S 《Journal of Bioscience and Bioengineering》2003,95(3):231-238
We constructed a replication-defective retroviral vector plasmid for the expression of a single-chain antibody fragment (scFv), derived from a chicken anti-human prion protein monoclonal antibody, fused with the Fc region of human IgG1. CHO-K1 and NS-1 cells were transformed with the viral vector pseudotyped with vesicular stomatitis virus G protein (VSV-G), and scFv-Fc producer clones were established. Among the established clones, CHO-2A9 cells produced a large amount of the product with an antibody-like dimerized structure in serum-free culture that facilitated the purification of scFv-Fc. The scFv-Fc specifically recognized the epitope sequence of prion protein in solid-phase enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. The injection test into quails revealed that the scFv became more stable in vivo by fusion with the Fc region. The scFv-Fc will be a useful tool for the detection of mammalian prion proteins. 相似文献