全文获取类型
收费全文 | 664篇 |
免费 | 29篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 34篇 |
化学工业 | 220篇 |
金属工艺 | 16篇 |
机械仪表 | 11篇 |
建筑科学 | 22篇 |
矿业工程 | 1篇 |
能源动力 | 24篇 |
轻工业 | 91篇 |
水利工程 | 6篇 |
无线电 | 48篇 |
一般工业技术 | 119篇 |
冶金工业 | 28篇 |
原子能技术 | 23篇 |
自动化技术 | 51篇 |
出版年
2022年 | 11篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 16篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 21篇 |
2015年 | 18篇 |
2014年 | 29篇 |
2013年 | 34篇 |
2012年 | 43篇 |
2011年 | 46篇 |
2010年 | 34篇 |
2009年 | 30篇 |
2008年 | 45篇 |
2007年 | 33篇 |
2006年 | 25篇 |
2005年 | 31篇 |
2004年 | 20篇 |
2003年 | 19篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 17篇 |
1999年 | 12篇 |
1998年 | 16篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 13篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有694条查询结果,搜索用时 18 毫秒
21.
22.
Yoshitaka Shingaya Tomonobu Nakayama Masakazu Aono 《Science and Technology of Advanced Materials》2004,5(5-6):647
Nanorods of substoichiometric tungsten oxide (WOx) were grown on W(001) substrates. Two methods for the growth of nanorods were used: oxidation of the substrate under appropriate conditions and the deposition of tungsten oxide from a tungsten foil heated in the presence of oxygen. The grown nanorods were observed using a scanning electron microscope and an atomic force microscope. The diameters of the nanorods were 5–20 nm. The nanorods were slightly inclined from the directions parallel or normal to the surface. The inclination of nanorods was explained in terms of the epitaxial relationship between WO3 crystals and the W(001) substrate. The WO3 crystals formed at the initial stage of growth act as the nuclei of WOx nanorods. We observed selective enhancement of the growth in a certain epitaxial direction depending on the method of growth, and an array of WOx nanorods was produced on the W(001) substrate. 相似文献
23.
AgGaTe2 and AgAlTe2 layers were grown on a-plane sapphire substrates by closed-space sublimation. These compounds replace Cd in CdTe with group I and III elements, and are, hence, expected to be ideal novel candidate materials for solar cells. The grown layers were confirmed to be stoichiometric AgGaTe2 and AgAlTe2 by x-ray diffraction (XRD). The AgAlTe2 layers had strong preference for the (112) orientation. The XRD spectrum of the AgGaTe2 layer was different from that of the AgAlTe2 layer, and strong peaks were observed for (103) and (110) diffraction. The variation in orientations of the grown layers was analyzed in detail by use of XRD pole figures, which revealed that the AgGaTe2 layers had an epitaxial relationship with the a-plane sapphire substrates. 相似文献
24.
Jiangchao Wang Masakazu Shibahara Xudong Zhang Hidekazu Murakawa 《Journal of Materials Processing Technology》2012,212(8):1705-1715
The welding distortion of thin plate was selected as research subject, which causes loss of dimensional control, structural integrity and increases fabrication costs for straightening. To study the characteristic of the welding distortion on thin plate structures, experiments were conducted. The test model was a thin plate stiffened structure and a large twisting distortion was observed. The welding distortion of the same structure was analyzed as a large deformation problem using a thermal elastic plastic FEM and an elastic FEM based on the concept of inherent deformation. The computed results by both methods showed the twisting distortion which is a typical buckling type deformation and the magnitude of this distortion agreed well with the experimental measurement. 相似文献
25.
Riki Shiroma Yuan Li Jeung-yil Park Long Wu Satoshi Kaneko Tomoyuki Takai Mitsuru Gau Masakazu Ike Ken Tokuyasu 《Journal of Applied Glycoscience》2016,63(3):77
Abstract: Sorghum bagasse samples from two sets (n6 and bmr6; n18 and bmr18) of wild-type and corresponding “brown midrib” (bmr) mutant strains of sweet sorghum were evaluated as the feedstock for fermentable sugar recovery via the calcium capturing by carbonation (CaCCO) process, which involves Ca(OH)2 pretreatment of bagasse with subsequent neutralization with CO2 for enzymatic saccharification. Saccharification tests under various pretreatment conditions of the CaCCO process at different Ca(OH)2 concentrations, temperatures or residence periods indicated that bmr strains are more sensitive to the pretreatment than their counterparts are. It is expected that variant bmr6 is more suitable for glucose recovery than its wild-type counterpart because of the higher glucan content and better glucose recovery with less severe pretreatment. Meanwhile, bmr18showed higher scores of glucose recovery than its counterpart did, only at low pretreatment severity, and did not yield higher sugar recovery under the more severe conditions. The trend was similar to that of xylose recovery data from the two bmr strains. The advantages of bmr strains were also proven by means of simultaneous saccharification and fermentation of CaCCO-pretreated bagasse samples by pentose-fermenting yeast strain Candida shehatae Cs 4R. The amounts needed for production of 1 L of ethanol from n6, bmr6, n18, and bmr18samples were estimated as 4.11, 3.46, 4.03, and 3.95 kg, respectively. The bmr strains seem to have excellent compatibility with the CaCCO process for ethanol production, and it is expected that integrated research from the feedstock to bioprocess may result in breakthroughs for commercialization. 相似文献
26.
27.
Dr. Masakazu Hachisu Dr. Akira Seko Dr. Shusaku Daikoku Dr. Yoichi Takeda Dr. Masafumi Sakono Dr. Yukishige Ito 《Chembiochem : a European journal of chemical biology》2016,17(4):300-303
In the endoplasmic reticulum (ER), nascent glycoproteins that have not acquired the native conformation are either repaired or sorted for degradation by specific quality‐control systems composed by various proteins. Among them, UDP‐glucose:glycoprotein glucosyltransferase (UGGT) serves as a folding sensor in the ER. However, the molecular mechanism of its recognition remains obscure. This study used pseudo‐misfolded glycoproteins, comprising a modified dihydrofolate reductase with artificial pyrene–cysteine moiety on the protein surface (pDHFR) and Man9GlcNAc2‐methotrexate (M9‐MTX). All five M9‐MTX/pDHFR complexes, with a pyrene group at different positions, were found to be good substrates of UGGT, irrespective of the site of pyrene modification. These results suggest UGGT's mode of substrate recognition is fuzzy, thus allowing various glycoproteins to be accommodated in the folding cycle. 相似文献
28.
29.
Kentaro Fujimoto Yoshiyasu Matsumoto Kohki Oikawa Jun-ichi Nomura Yasuyoshi Shimada Shunrou Fujiwara Kazunori Terasaki Masakazu Kobayashi Kenji Yoshida Kuniaki Ogasawara 《International journal of molecular sciences》2016,17(8)
The purpose of the present study was to determine whether cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). In patients undergoing CEA for internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emission computed tomography (SPECT) before and immediately after CEA. Microembolic signals (MES) were identified using transcranial Doppler during carotid exposure. Diffusion-weighted magnetic resonance imaging (DWI) was performed within 24 h after surgery. Of 32 patients with a combination of reduced cerebrovascular reactivity to acetazolamide on preoperative brain perfusion SPECT and MES during carotid exposure, 14 (44%) showed cerebral hyperperfusion (defined as postoperative CBF increase ≥100% compared with preoperative values), and 16 (50%) developed DWI-characterized postoperative cerebral ischemic lesions. Postoperative cerebral hyperperfusion was significantly associated with the absence of DWI-characterized postoperative cerebral ischemic lesions (95% confidence interval, 0.001–0.179; p = 0.0009). These data suggest that cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during carotid exposure in CEA, supporting the “impaired clearance of emboli” concept. Blood pressure elevation following carotid declamping would be effective when embolism not accompanied by cerebral hyperperfusion occurs during CEA. 相似文献
30.
The mechanical force to polymeric materials in vacuum at 77 K produces mechano radicals, mechano anions and mechano cations due to homogeneous and heterogeneous scissions of the covalent bonds comprising polymer main chain. The ionic degree of the covalent bond was estimated by calculating the “absolute ΔMulliken atomic charge,” which was defined as the difference between the Mulliken atomic charges of the two adjacent atoms comprising the covalent bond of the polymer main chain. The ionic yield of the covalent bond increased with increasing the absolute ΔMulliken atomic charge. The empirical formula for the ionic yield was obtained with the absolute ΔMulliken atomic charge, and indicates that the ionic yield could be estimated from its chemical structure. 相似文献