全文获取类型
收费全文 | 279篇 |
免费 | 13篇 |
国内免费 | 3篇 |
学科分类
工业技术 | 295篇 |
出版年
2023年 | 3篇 |
2021年 | 10篇 |
2020年 | 11篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 2篇 |
2013年 | 25篇 |
2012年 | 10篇 |
2011年 | 19篇 |
2010年 | 9篇 |
2009年 | 19篇 |
2008年 | 17篇 |
2007年 | 10篇 |
2006年 | 11篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 11篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 7篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
排序方式: 共有295条查询结果,搜索用时 31 毫秒
1.
John McGrady Shinichi Yamashita Atsushi Kimura Sho Kano Huilong Yang Zhengang Duan 《Journal of Nuclear Science and Technology》2020,57(4):463-471
ABSTRACTTypical metal oxide corrosion products of structural materials have been irradiated with γ-rays in ultra-pure water to investigate the effect of radiation on the surface oxide and the nature of adsorbed water. Analysis techniques including thermal gravimetric analysis, differential thermal analysis, diffuse reflectance infrared Fourier transform spectroscopy, and X-ray photoelectron spectroscopy before and after γ-irradiation were employed to investigate surface structural effects and adsorbed water behaviour. The production of H2 in the oxide nanoparticle mixtures was investigated by gas chromatography to probe the mechanism of radiolysis in the water/oxide mixtures and the relationship with surface water. The nature of water at the surface of the oxides was affected by γ-radiation and the relationship was dependent on the particle composition. The rate of H2 production was shown to be oxide dependent, and higher rates of H2 formation were attributed to the decomposition of surface adsorbed water. Changes to the surface chemistry and H2 production rates were found to be highly dependent on the surface chemistry of the metal oxide nanoparticle and no bulk structural changes were observed. 相似文献
2.
Sho Watanabe Vinayak S. Bhat Korbinian Baumgaertl Dirk Grundler 《Advanced functional materials》2020,30(36)
Quasicrystalline structures and aperiodic metamaterials find applications ranging from established consumer gadgets to potential high‐tech photonic components owing to both complex arrangements of constituents and exotic rotational symmetries. Magnonics is an evolving branch of magnetism research where information is transported via magnetization oscillations (magnons). Their control and manipulation are so far best accomplished in periodic metamaterials which exhibit properties artificially modulated on the nanoscale. They give rise to functional components, such as band stop filters, magnonic transistors and nanograting couplers. Here, spin‐wave excitations in artificial ferromagnetic quasicrystals created via aperiodic arrangement of nanoholes are studied experimentally. Their ten‐fold rotational symmetry results in multiplexed magnonic nanochannels, suggesting a width down to 50 nm inside a so‐called Conway worm. Key elements of design are emergent magnon motifs and the worm‐like features which are scale‐invariant and not present in the periodic metamaterials. By imaging wavefronts in quasicrystals, insight is gained into how the discovered features materialize as a dense wavelength division multiplexer. 相似文献
3.
Sho Kano Huilong Yang John McGrady Tomonori Ihara Hazuku Tatsuya Hiroaki Abe 《Journal of Nuclear Science and Technology》2019,56(3):300-309
The radiation-induced surface activation (RISA) effect will be applied to the core design in supercritical light water reactor (SCWR) in order to achieve a high performance with excellent economy and safety. The purpose of the present study is to investigate the RISA effect in the candidate fuel cladding materials in SCWR such as PNC1520. The change of weldability due to RISA effect and the related microstructure analysis were performed in oxidized PNC1520 and 304 stainless steel with various oxidization periods. The phases contained in the surface oxide layer of the present specimen were identified as Fe2CrO4, γ-Fe2O3, and Fe2O3. The lifetime of 13.8 days for wettability improving factor was confirmed in the ultraviolet (UV) irradiation. Meanwhile, the long life of 13.8 days and short life of 0.8 days for wettability improving factors were identified in the γ-ray irradiation. Based on the fact that the band gap energies of Fe2CrO4, γ-Fe2O3, and Fe2O3 were, respectively, 2.1, 2.0, and 2.2 eV, and the photo energies of UV and γ-ray irradiation were 4.48 eV and 13.3 MeV, it is therefore clarified that the hydrophilization on the oxide layer is ascribed to the RISA effect. 相似文献
4.
Analysis and modeling of char particle combustion with heat and multicomponent mass transfer 总被引:1,自引:0,他引:1
A char combustion model suitable for a large-scale boiler/gasifier simulation, which considers the variation of physical quantities in the radial direction of char particles, is developed and examined. The structural evolution within particles is formulated using the basic concept of the random pore model while simultaneously considering particle shrinkage. To reduce the computational cost, a new approximate analytical boundary condition is applied to the particle surface, which is approximately derived from the Stefan–Maxwell equations. The boundary condition showed reasonably good agreement with direct numerical integration with a fine grid resolution by the finite difference method under arbitrary conditions. The model was applied to combustion in a drop tube furnace and showed qualitatively good agreement with experiments, including for the burnout behavior in the late stages. It is revealed that the profiles of the oxygen mole fraction, conversion, and combustion rate have considerably different characteristics in small and large particles. This means that a model that considers one total conversion for each particle is insufficient to describe the state of particles. Since our char combustion model requires only one fitting parameter, which is determined from information on the internal geometry of char particles, it is useful for performing numerical simulations. 相似文献
5.
Martensitic stabilization caused by deformation in a TiNi shape memory alloy was studied.Special attention was paid to the deformed microstructures to identify the cause of martensitic stabilization.Martensitic stabilization was demonstrated by differential scanning calorimetry for the tensioned TiNi shape memory alloy.Transmission electron microscopy revealed that antiphase boundaries were formed because of the fourfold dissociation of[110]B19'super lattice dislocations and were preserved after reverse transformation due to the lattice correspondence.Martensitic stabilization was attributed to dislocations induced by deformation,which reduced the ordering degree of the microstructure,spoiled the reverse path from martensite to parent phase compared with thermoelastic transformation,and imposed resistance on phase transformation through the stress field. 相似文献
6.
Synthesis of non-equilibrium phases in immiscible metals mechanically mixed by high pressure torsion
Tatsuya Miyazaki Daisuke Terada Yoji Miyajima Challapalli Suryanarayana Reiko Murao Yoshihiko Yokoyama Kazumasa Sugiyama Minoru Umemoto Yoshikazu Todaka Nobuhiro Tsuji 《Journal of Materials Science》2011,46(12):4296-4301
The structural changes in mechanically mixed metals of immiscible combinations of elements caused by bulk mechanical alloying
(MA) through the use of high pressure torsion (HPT) were investigated in Ag–Ni and Nb–Zr systems. There was no alloying between
Ag and Ni on atomic scale even after 100 rotations of HPT. On the other hand, the β-Zr phase started to appear after HPT 2
rotations in the Nb–Zr system, even though β-Zr is a high temperature phase. Further, Nb and Zr were completely mixed to form
a bcc structured single phase after HPT 100 rotations. The sequence of alloying in the Nb–Zr system during HPT was discussed.
These results clearly suggest that non-equilibrium phases can form in the Nb–Zr system by bulk MA by the use of HPT. 相似文献
7.
Yasushi Sekine Haruka Takamatsu Sho Aramaki Kazuki Ichishima Mitsuko Takada Masahiko Matsukata Eiichi Kikuchi 《Applied Catalysis A: General》2009,352(1-2):214-222
The water gas shift (WGS) reaction over Pt and Pd catalysts supported on various perovskite oxides has been investigated at 573 K without catalyst pretreatment. The Pt and Pd catalysts on LaCoO3 support showed high catalytic activity. Interaction between Pt or Pd and the support is considered to promote the WGS reaction: Pt/LaCoO3 had high initial activity but deactivated immediately; Pd/LaCoO3 was less active than Pt/LaCoO3, but had superior stability. Catalysts were characterized using XRD, STEM, XPS, and H2-temperature programmed reduction (TPR). Results of this study showed that reduction of the support decreased the CO conversion on Pt/LaCoO3. On the other hand, Pd/LaCoO3 showed stable activity for the WGS reaction. Therefore, Pd was added to Pt/LaCoO3 for stabilizing the catalyst activity, and 0.5 wt.% Pd/1 wt.% Pt/LaCoO3 catalyst showed higher activity and stability. 相似文献
8.
This paper describes an autoselection method for the pedal load of an electric cart, and the control system. The method checks the driver’s physical condition just before the start of driving, calculates the driver’s rating of perceived exertion, and uses that to automatically select a suitable pedal load. To ensure that the level of physical exertion is safe, the largest pedal load is determined on the basis of Borg’s CR10, the Karvonen formula, a pedaling experiment, and statistical data. A driver’s degree of fatigue is estimated from his heart rate, and a pedal load (between the largest and almost zero) is automatically selected. In addition, a dynamic output-feedback cart control system was designed that guarantees the stability of the cart system for any allowable pedal load. A stability condition is derived by employing the concept of dynamic parallel distributed compensation. Finally, experiments demonstrate the validity of the method. 相似文献
9.
10.
Three diamensional (3D) measurement method by Scanning Electron Microscope (SEM) has already been proposed by using the principle
of shadow moiré. In the method, the image of original grid in shadow moiré image must be clearly removed in fringe analysis
process in order to perform high resolution analysis. A new method based on the principle of projection moiré is proposed
to solve the trouble concerning the grid. In this paper, the mechanism of producing some shadows of grid on the surface of
the object by back scattering electron beam in the new method is discussed. Fringe image as shadow of grid is analyzed by
Wavelet transform. The precise 3D measurement is realized by using the phenomenon of shadows of grid. Furthermore, a 3D micro
structure on the head of a hard disk is measured. From the comparison of results obtained by Atomic Force Microscope (AFM),
it is confirmed that the proposed method has high-resolution power(about 20nm). 相似文献