全文获取类型
收费全文 | 2386篇 |
免费 | 36篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 124篇 |
综合类 | 7篇 |
化学工业 | 758篇 |
金属工艺 | 113篇 |
机械仪表 | 50篇 |
建筑科学 | 32篇 |
矿业工程 | 2篇 |
能源动力 | 98篇 |
轻工业 | 167篇 |
水利工程 | 5篇 |
石油天然气 | 10篇 |
武器工业 | 1篇 |
无线电 | 164篇 |
一般工业技术 | 385篇 |
冶金工业 | 284篇 |
原子能技术 | 54篇 |
自动化技术 | 186篇 |
出版年
2023年 | 14篇 |
2022年 | 22篇 |
2021年 | 29篇 |
2020年 | 11篇 |
2019年 | 26篇 |
2018年 | 18篇 |
2017年 | 18篇 |
2016年 | 32篇 |
2015年 | 20篇 |
2014年 | 38篇 |
2013年 | 119篇 |
2012年 | 62篇 |
2011年 | 72篇 |
2010年 | 77篇 |
2009年 | 89篇 |
2008年 | 91篇 |
2007年 | 97篇 |
2006年 | 73篇 |
2005年 | 87篇 |
2004年 | 61篇 |
2003年 | 79篇 |
2002年 | 69篇 |
2001年 | 67篇 |
2000年 | 54篇 |
1999年 | 54篇 |
1998年 | 149篇 |
1997年 | 98篇 |
1996年 | 88篇 |
1995年 | 57篇 |
1994年 | 54篇 |
1993年 | 52篇 |
1992年 | 30篇 |
1991年 | 46篇 |
1990年 | 23篇 |
1989年 | 35篇 |
1988年 | 25篇 |
1987年 | 38篇 |
1986年 | 29篇 |
1985年 | 17篇 |
1984年 | 39篇 |
1983年 | 34篇 |
1982年 | 27篇 |
1981年 | 29篇 |
1980年 | 22篇 |
1979年 | 22篇 |
1978年 | 18篇 |
1977年 | 27篇 |
1976年 | 28篇 |
1975年 | 12篇 |
1973年 | 20篇 |
排序方式: 共有2440条查询结果,搜索用时 15 毫秒
1.
Sawao Honda Shinobu Hashimoto Benoît Nait-Ali David S. Smith Yusuke Daiko Yuji Iwamoto 《Journal of the American Ceramic Society》2022,105(10):6335-6344
Porous alumina with a highly textured microstructure was fabricated by pulse electric current sintering (PECS) using alumina platelets. Highly oriented porous alumina with a porosity of 3%–50% was obtained by a pressure-controlled method of PECS. The properties of the highly textured porous alumina were measured in two directions. The nitrogen gas permeance and thermal conductivity at room temperature were higher in the direction along the platelet length due to the higher continuity of pores and the connectivity of alumina platelets, respectively. The anisotropy of the thermal conductivity at room temperature was investigated and explained by the effect of grain size of platelets as well as morphology and orientation of pores. The bending strength was higher with the loading direction along the platelet thickness. The thermal shock strength was clearly different in the two directions. The difference in the thermal shock strength was investigated by the measurement of properties and thermal stress analysis. 相似文献
2.
Kazuaki Katagiri Shinya Honda Sayaka Minami Daiki Kimu Shimpei Yamaguchi Takuya Ehiro 《先进材料力学与结构力学》2020,27(18):1541-1550
Abstract The I-shaped cross-sectional beam of CFRP (CFRP I-beam) is usually manufactured by the continuous protrusion method. Carbon fibers can only be arranged in the longitudinal direction. The CFRP I-beam with arbitrary arrangement of carbon fiber was manufactured with applying the electro-activated deposition molding method. The carbon fiber fabric was immersed in the deposition solution and energized, epoxy resin precipitated around carbon fiber and impregnated. The resin-impregnated fabric was installed to the mold, and the CFRP I-beam was fabricated. The CFRP I-beam was subjected to three-point bending tests, and the relationship between load-deflection was simulated by finite-element analysis. 相似文献
3.
Hiroshi Takamatsu Hikaru Yamashiro Nobuo Takata Hiroshi Honda 《International Journal of Refrigeration》2003,26(6):79
Heat and mass transfer in a falling film vertical in-tube absorber was studied experimentally with LiBr aqueous solution. The presented results include the effect of solution flow rate, solution subcooling and cooling water temperature on the absorption in a smooth copper tube 16.05 mm I.D. and 400 mm long. The experimental data in the previous report for a 1200-mm-long tube was also re-examined and compared. It was demonstrated by the observation of the flow in the tube that the break down of the liquid film into rivulets leads to deterioration of heat and mass transfer at lower film Reynolds number or in longer tubes. An attempt to evaluate physically acceptable heat and mass transfer coefficients that are defined with estimated temperature and concentration at the vapor–liquid interface was also presented. 相似文献
4.
Takeshi Kondo Hiroyuki Ito Kazuhide Kusakabe Kazuhiro Ohkawa Kensuke Honda Yasuaki Einaga Akira Fujishima Takeshi Kawai 《Diamond and Related Materials》2008,17(1):48-54
The effect of CF4 plasma etching on diamond surfaces, with respect to treatment time, was investigated using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. SEM observations and Raman spectra indicated an increase in surface roughening on a scale of 10–20 nm, and an increase in crystal defect density was apparent with treatment time in the range of 10 s to 30 min. In contrast, alteration of the diamond surface terminations from oxygen to fluorine was found to be rather rapid, with saturation of the F/C atomic ratio estimated from XPS analysis after treatment durations of 1 min and more. The redox kinetics of Fe(CN)63−/4− was also found to be significantly modified after 10 s of CF4 plasma treatment. This behavior shows that C–F terminations predominantly affect the redox kinetics compared to the effect on the surface roughness and crystal defects. The double-layer capacitance (Cdl) of the electrolyte/CF4 plasma-treated boron-doped diamond interface was found to show a minimum value at 1 min of treatment. These results indicate that a short-duration CF4 plasma treatment is effective for the fabrication of fluorine-terminated diamond surfaces without undesirable surface damage. 相似文献
5.
Arun K. Nanda Honda Shing Ten-Hwan Tzen Lionel M. Ni 《Journal of Parallel and Distributed Computing》1991,12(4)
A standard metric conventionally employed to compare the performance of different multiprocessor systems is speedup. Although providing a measure of the improvement in execution speed achievable on a system, this metric does not yield any insight into the factors responsible for limiting the potential improvement in speed. This paper studies the performance degradation in shared-memory multiprocessors as a result of contention for shared-memory resources. A replicate workload framework with a flexible mechanism for workload specification is proposed for measuring performance. Two normalized performance metrics—efficiency and overhead factor—are introduced to quantify the factors limiting performance and facilitate comparison across architectures. Finally, the proposed model is employed to measure and compare the performance of three contemporary shared-memory systems, with special emphasis on the newly released BBN Butterfly-II (TC2000), currently undergoing Beta test. 相似文献
6.
Kotaro Matsuuchi Tadashi Fukami Nobuyuki Naoe Ryoichi Hanaoka Shinzo Takata Toshio Miyamoto 《Electrical Engineering in Japan》2005,150(2):43-49
This paper presents a method of predicting the steady‐state performance of a new hybrid‐excitation synchronous machine (HESM) theoretically. The field pole of this HESM is axially divided into two parts; one is an excitation part and the other a permanent‐magnet (PM) part. A nonlinear equivalent circuit, which can include the saliency of the rotor and the magnetic saturation due to the iron core, is derived. Based on this equivalent circuit, the steady‐state performance of the HESM is calculated, and the results are confirmed through experiments. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(2): 43–49, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20033 相似文献
7.
Kenji Nomura Hiromichi OhtaKazushige Ueda Toshio Kamiya Masahiro HiranoHideo Hosono 《Thin solid films》2003,445(2):322-326
We have investigated the characteristics of transparent metal-insulator-semiconductor field-effect transistors (MISFETs) fabricated using InGaO3(ZnO)m (m=integer) single-crystalline thin films as n-channel layers and amorphous alumina as gate insulator films. The MISFETs exhibit good characteristics such as insensitivity to visible light illumination, off-current as low as ∼1 nA with a positive threshold voltage of ∼3 V and on/off current ratio of 105. The field-effect mobility increased from ∼1 to ∼10 cm2 (V s)−1 as the m-value increased. Room temperature Hall mobility also increased. However, unexpectedly these values were lower than the field-effect mobility. It is explained by existence of shallow localized state in the homologous compounds. 相似文献
8.
M. Hara Y. Hatano T. Abe K. Watanabe T. Naitoh S. Ikeno Y. Honda 《Journal of Nuclear Materials》2003,320(3):265-271
To improve the durability of hydrogen storage materials against surface poisoning by impurity gases, effectiveness of Pd-coating layer prepared by using a Barrel-Sputtering System was examined for ZrNi powder. The effectiveness of Pd-coating was evaluated by activation temperature, at which Pd/ZrNi poisoned by air could be activated to absorb hydrogen. Characterization of Pd-coated ZrNi (denoted as Pd/ZrNi) by scanning electron microscopy, electron probe microanalysis and X-ray diffraction showed that a uniform Pd-coating layer was formed with the barrel-sputtering system. It was found that the poisoned Pd/ZrNi sample could be activated even at 423 K to absorb hydrogen at room temperature. This exhibits remarkable contrast to bare ZrNi, which could be only activated appreciably above 1073 K. It is concluded that the Pd-coating by barrel sputtering is quite effective to avoid the effect of surface poisoning of powdery hydrogen storage materials. However, the activation at excessively high temperature resulted in the loss of high activity to absorb hydrogen. It was concluded that this phenomenon was associated with reactions between Pd and ZrNi to form PdZr and other byproducts. 相似文献
9.
10.
Toshio Kimura Hideto Kajiyama Ryuichi Yazaki Takashi Yamaguchi 《Journal of Materials Science》1996,31(15):4149-4157
The densification and microstructure development of ZnO containing Zn7Sb2O12, ZrO2, and aggregated ZnO were investigated to elucidate the effect of nondensifying inclusions on the sintering of ceramic/ceramic composites. The inclusion retarded the densification, and the degree of retardation was found to depend on the chemical species of inclusion; Zn7Sb2O12 had the largest effect, followed by ZrO2 and then aggregated ZnO last. The experimental results for aggregated ZnO was explained by the theory which predicts the generation of backstresses. The backstresses give a less significant effect on the densification. For Zn7Sb2O12 and ZrO2, the microstructure of the matrix varied with distance from an inclusion particle; much porosity was observed in the region surrounding the inclusion. Circumferential voids, which are responsible for the suppression of densification, form during the initial stage of sintering. Inclusion particles generate an anchoring effect which retards the densification of the matrix immediately surrounding the inclusion particle during the intermediate stage.Supported by the Inamori Foundation. 相似文献