全文获取类型
收费全文 | 1681篇 |
免费 | 33篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 55篇 |
综合类 | 1篇 |
化学工业 | 331篇 |
金属工艺 | 49篇 |
机械仪表 | 57篇 |
建筑科学 | 23篇 |
矿业工程 | 1篇 |
能源动力 | 40篇 |
轻工业 | 136篇 |
水利工程 | 4篇 |
石油天然气 | 2篇 |
武器工业 | 1篇 |
无线电 | 170篇 |
一般工业技术 | 262篇 |
冶金工业 | 423篇 |
原子能技术 | 31篇 |
自动化技术 | 133篇 |
出版年
2023年 | 10篇 |
2022年 | 21篇 |
2021年 | 22篇 |
2020年 | 8篇 |
2019年 | 18篇 |
2018年 | 18篇 |
2017年 | 15篇 |
2016年 | 23篇 |
2015年 | 22篇 |
2014年 | 20篇 |
2013年 | 54篇 |
2012年 | 48篇 |
2011年 | 66篇 |
2010年 | 63篇 |
2009年 | 50篇 |
2008年 | 60篇 |
2007年 | 63篇 |
2006年 | 43篇 |
2005年 | 54篇 |
2004年 | 50篇 |
2003年 | 71篇 |
2002年 | 49篇 |
2001年 | 34篇 |
2000年 | 36篇 |
1999年 | 49篇 |
1998年 | 184篇 |
1997年 | 94篇 |
1996年 | 85篇 |
1995年 | 56篇 |
1994年 | 32篇 |
1993年 | 46篇 |
1992年 | 19篇 |
1991年 | 22篇 |
1990年 | 16篇 |
1989年 | 20篇 |
1988年 | 17篇 |
1987年 | 20篇 |
1986年 | 16篇 |
1985年 | 16篇 |
1984年 | 13篇 |
1983年 | 8篇 |
1982年 | 19篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1977年 | 11篇 |
1976年 | 11篇 |
1975年 | 6篇 |
1970年 | 4篇 |
1968年 | 3篇 |
排序方式: 共有1719条查询结果,搜索用时 15 毫秒
1.
2.
The effect of humidity during storage on the crosslinking reactions of isocyanate groups was investigated with attenuated total reflectance Fourier transform infrared spectroscopy with pressure‐sensitive adhesives composed of poly[ethyl acrylate‐co‐(2‐ethylhexyl acrylate)‐co‐(2‐hydroxyethyl methacrylate)] as a base resin and polyisocyanate as a crosslinker. A peak‐resolving analysis of the amide II region revealed four bands. According to an analysis of the Fourier transform infrared spectra of the model compounds, these four bands were assigned to free urethane linkages, hydrogen‐bonded urethane linkages, free urea linkages, and hydrogen‐bonded urea linkages. As expected, storage under humid conditions led to the formation of free and hydrogen‐bonded urea linkages corresponding to the promotion of isocyanate consumption. Peak resolution of the amide II region was found to be a reasonable way of monitoring urethane and urea linkages during crosslinking reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3039–3045, 2003 相似文献
3.
Hiroto Imai Toshiyuki Ogawa Kazuo Sugimoto Masakazu Kataoka Yumo Tanaka Takehiko Ono 《Applied catalysis. B, Environmental》2005,55(4):259-265
The Co/MFI(SiO2/Al2O3 = 30) were prepared by a precipitation method with NaOCl in alkali solutions exhibited high activities to N2 at 250 °C for the selective catalytic reduction (SCR) of NOx. These catalysts showed two UV–vis bands at 700 and 400 nm, indicating the presence of octahedral Co(III) as well as tetrahedral Co(II). The high SCR activity over such Co(III, II)/MFI(30) seems to come from Co(III)---O moieties. The Co(II)MFI(30) catalysts prepared from Co(II)Cl2 exhibited low SCR activities due to the presence of tetrahedral Co(II) ions in MFI. Less CO formation occurred over Co/MFI catalysts. The Fe/MFI(30) catalyst exhibited high activity due to the presence of some Fe---O species in MFI but more amount of CO were produced during SCR. H/MFI(30) catalyst exhibited a good SCR activity. However, more amount of carbonaceous deposits were produced on it. The correlation between acid concentration and SCR activity was discussed over H/MFIs. 相似文献
4.
The fabrication process of a low-temperature poly-Si thin-film transistor (TFT) with a storage capacitor was studied. The atmospheric-pressure chemical-vapour deposited SiO2 protected the buried indium tin oxide (ITO) from reduction by a pure H2 plasma treatment that was essential for the effective improvement of the poly-Si TFT characteristics. Thus, a storage capacitor with an ITO (picture electrode)-SiO2-ITO (buried common electrode) structure was successfully fabricated. The poly-Si TFT with a channel width/length W/L ratio of 5 drove a 3 pF storage capacitor in 2 μs, and it showed superior driverability for LCD use. The TFT also had good hold characteristics under illumination for the realization of grey-scale representation. 相似文献
5.
6.
Chihiro J. Uchibori Y. Ohtani T. Oku Naoki Ono Masanori Murakami 《Journal of Electronic Materials》1997,26(4):410-414
Significant reduction of the contact resistance of In0.7Ga0.3As/Ni/W contacts (which were previously developed by sputtering in our laboratory) was achieved by depositing a W2N barrier layer between the Ni layer and W layer. The In0.7Ga0.3 As/Ni/W2N/W contact prepared by the radio-frequency sputtering technique showed the lowest contact resistance of 0.2 Ωmm after annealing
at 550°C for 10 s. This contact also provided a smooth surface, good reproducibility, and excellent thermal stability at 400°C.
The polycrystalline W2N layer was found to suppress the In diffusion to the contact surface, leading to improvement of the surface morphology and
an increase in the total area of the InxGa−As between metal and the GaAs substrate. These improvements are believed to reduce the contact resistance. 相似文献
7.
Masatsune Kato Takaaki Aoki Takashi Noji Yasuhiro Ono Yoji Koike Tomoyuki Hikita Yoshitami Saito 《Journal of Superconductivity and Novel Magnetism》1994,7(1):37-38
We have investigated the relation between the crystal structure and superconductivity in La1.9Bi0.1CuO4+δ , in which the phase separation observed in La2CuO4+δ is suppressed. A phase diagram in theT?δ plane is given for La1.9Bi0.1CuO4+δ with excess oxygen. For very smallδ values, the crystal structure is orthorhombic, and an orthorhombic-tetragonal phase transition occurs markedly atδ ~ 0.03 in the measured temperature range between 13 and 293 K. Superconductivity is observed in the range of 0.04<δ<0.11. This is clear evidence thathigh-T c superconductivity also appears in the tetragonal phase. 相似文献
8.
Saito M. Yoshitomi T. Hara H. Ono M. Akasaka Y. Nii H. Matsuda S. Momose H.S. Katsumata Y. Ushiku Y. Iwai H. 《Electron Devices, IEEE Transactions on》1993,40(12):2264-2272
A p-MOSFET structure with solid-phase diffused drain (SPDD) is proposed for future 0.1-μm and sub-0.1-μm devices. Highly doped ultrashallow p+ source and drain junctions have been obtained by solid-phase diffusion from a highly doped borosilicate glass (BSG) sidewall. The resulting shallow, high-concentration drain profile significantly improves short channel effects without increasing parasitic resistance. At the same time, an in situ highly-boron-doped LPCVD polysilicon gate is introduced to prevent the transconductance degradation which arises in ultrasmall p-MOSFETs with lower process temperature as a result of depletion formation in the p+-polysilicon gate. Excellent electrical characteristics and good hot-carrier reliability are achieved 相似文献
9.
A Matsumori Y Matoba R Nishio T Shioi K Ono S Sasayama 《Canadian Metallurgical Quarterly》1996,222(3):678-682
We investigated hepatitis C virus (HCV) infection in 35 patients with hypertrophic cardiomyopathy and 40 patients with ischemic heart disease who were consecutively admitted to our hospital. Frequency of positive anti-HCV antibody was significantly higher in patients with hypertrophic cardiomyopathy (6 of 35 patients, 17.1%) than that in patients with ischemic heart disease (1 of 40 patients, 2.5%, p = 0.036). In three of these six patients with hypertrophic cardiomyopathy, HCV RNA was detected in myocardial tissue. In two of these three patients, HCV RNA was detected from biopsy and autopsy specimens of the ventricles, but not in the serum, suggesting that HCV may replicate in myocardial tissue and may be relevant to ventricular hypertrophy. Thus, HCV infection may play a role in the development of hypertrophic cardiomyopathy. 相似文献
10.
Y. Miyamoto Y. Kubo N. Ono M. Hashimoto T. Takahashi I. Ito F. Arezzo P. Gimondo 《Thin solid films》1995,270(1-2):253-259
A new coil-coating pilot plant, capable of utilizing ion plating, sputtering and plasma-assisted chemical vapor deposition (PACVD) processes, independently or in series, was developed and optimum conditions for TiN, TiC, AlxOy, SiOx and Cr coating were established. This paper is mostly concerned with the results of characterization (conducted in parallel by the authors′ two institutions) of TiN films deposited by ion plating or sputtering onto type-304 stainless steel strips. In particular, the dependence of the basic properties such as chemical composition, structure, adhesion, and color on the coating process are discussed with respect to anti-corrosion, anti-wear, and decorative applications. TiN coatings with a very attractive gold coloration were obtained; they performed well in wear testing, but did not show satisfactory corrosion resistance. However, it was found that the latter can be improved significantly by depositing a SiOx, top layer by PACVD above the TiN coating. Thus the in-line dry coating processes are capable of producing highly functional steel surfaces with decorative color and high corrosion resistance. 相似文献