全文获取类型
收费全文 | 226篇 |
免费 | 1篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 41篇 |
金属工艺 | 3篇 |
机械仪表 | 2篇 |
建筑科学 | 1篇 |
能源动力 | 3篇 |
轻工业 | 10篇 |
石油天然气 | 1篇 |
无线电 | 22篇 |
一般工业技术 | 40篇 |
冶金工业 | 78篇 |
原子能技术 | 1篇 |
自动化技术 | 11篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 16篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 24篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有227条查询结果,搜索用时 31 毫秒
61.
Koichi Kanaya Eisaku Oho Michiaki Naka Takehiko Koyanagi Toshihide Sasaki 《Microscopy research and technique》1985,2(2):73-87
Based on the information transmission theory, topographic image signals in scanning electron microscopy are used to evaluate contrast, gradient, acutance, and Laplacian operator, the total of which represent the image sharpness of an edge line. One may consider the impulse and step functions as an input to the Gaussian system function of a low-pass filter, the impulse and step response functions possibly representing a single spot and image contrast of an edge profile, respectively. It is shown that the response function of acutance defined as the power of the gradient normalized by density is a more realistic representation of image edge sharpness. Also, edge sharpness can be greatly enhanced by utilizing the Laplacian operator through digital image processing for a disk specimen model with a rounded edge. Contrast increased by specimen tilt, and an edge effect due to side-scattered electrons, as well as the signal attenuation by specimen collection, are consistently obtained as the response function in the system. The exact measurement of spot size and edge-to-edge resolution, and image sharpness improvement, are derived by digital image processing. 相似文献
62.
63.
Masayuki Taira Tadayoshi Kagiya Hidemitsu Harada Minoru Sasaki Shigenobu Kimura Takayuki Narushima Takashi Nezu Yoshima Araki 《Journal of materials science. Materials in medicine》2010,21(1):267-275
This study was performed to microscopically observe and measure inflammatory cytokine production by human macrophages phagocytosing
submicron titanium (Ti) particles. Observations with secondary electron microscopy (SEM), SEM/electron probe microanalysis
(EPMA) and transmission electron microscopy (TEM) indicated that macrophages [phorbol-12-myristate-13-acetate (PMA)-differentiated
THP-1 cells] at 24 h in culture actively phagocytosed and accumulated submicron Ti particles in intracellular phagosomes,
in which refinement of Ti particles occurred. The macrophages were also cultured for 24 h in four media with and without submicron
Ti particles and lipopolysaccharide (LPS; components of bacteria). Whilst neither stimulus reduced cell viability, submicron
Ti particles and LPS activation independently and synergistically caused the macrophages to produce three inflammatory cytokines
(TNF-α, IL-1β and IL-6) at high levels in the culture supernatants. The inflammatory and osteolysis conditions caused by macrophages
phagocytosing submicron Ti particles would be worsened by challenge with LPS in patients wearing Ti prostheses. 相似文献
64.
Hidemitsu Aoki Shinji Tokuyama Takuro Masuzumi Makoto Hara Motaharu Kabir Mazumder Daisuke Watanabe Chiharu Kimura Takashi Sugino 《Diamond and Related Materials》2009,18(5-8):1048-1051
Low dielectric constant (k) materials for the ULSI interconnect insulator are required to meet the fast development of high-speed devices. We have investigated low-k material of boron nitride containing methyl (methyl boron nitride) by using tris-di-methyl-amino-boron (TMAB) gas. The dielectric constant (k) of the film decreases with decreasing RF plasma power and the k value of the methyl BN film can be achieved as low as 1.8 at 10 W RF plasma power.Absorption band of the film was observed at 2960 cm? 1 due to unsymmetrical stretching mode of C–H in CH3. It is thought that increasing C–H bond with low polarizability and reducing CN bond with high polarizability can realize a lower k value. The film has also high resistivity of more than 1 × 109 Ω cm and sufficient Young modulus of more than 26 GPa for the interlayer of LSI interconnection. There is a possibility that the dielectric constant can be decreased keeping the BN structure with high strength. The methyl BN film is an extremely attractive material as low-k material of next generation devices. 相似文献
65.
K. Akai T. Uemura K. Kishimoto T. Tanaka H. Kurisu S. Yamamoto T. Koyanagi K. Koga H. Anno M. Matsuura 《Journal of Electronic Materials》2009,38(7):1412-1417
We calculated electronic structures of Ba8Al16Ge30 in some Al-Ge framework configurations without nearest-neighbor Al-Al bonds by using a first-principles method. The calculated
band structures are similar in outline but different in detail. We also calculated thermoelectric properties by using the
electronic structures to analyze the experimental results on a sintered Ba8Al16Ge30 sample. The calculated properties nearly agree with the experimental results; however, the calculated temperature dependences
of electrical conductivity are slightly different from one another, because of differences in electronic structure. In this
paper, we discuss the temperature dependence from the viewpoints of nonparabolic band effects. 相似文献
66.
A cruciform specimen test and a single-fiber pull-out test are used to examine two glass–epoxy interface-failure envelopes under a combined stress state. A single fiber embedded in various off-axis directions for the cruciform specimen test creates various combined stress states. Finite-element analysis considering an inelastic constitutive equation of matrix resin and thermal residual stress is implemented for both tests. For the single-fiber pull-out test, a resin cone serving as the fiber entrance part, called the resin meniscus in this study, is modeled in finite-element analysis. This enables more precise calculation of interface stress around the interface failure point than calculations not considering the resin meniscus. The interface failure strengths obtained using the cruciform specimen and single-fiber pull-out tests show good agreement for both interfaces. 相似文献
67.
Yoshihiko Arao Okudoi Yukie Jun Koyanagi Shin-ichi Takeda Hiroyuki Kawada 《Mechanics of Time-Dependent Materials》2012,16(2):169-180
A simple method for obtaining viscoelastic parameters from the results of static tensile tests is presented herein. Viscoelastic
parameters were obtained by fitting experimental results and calculated results based on the power law model and linear viscoelasticity.
The static tensile tests were carried out at various pre-aging times and the effect of physical aging was determined. The
data confirmed that the physical aging process has a significant effect on the viscoelastic behavior. A creep test was conducted
in order to discuss the validity of the prediction using the results of the static tensile test. It was confirmed that the
predictions based on the viscoelastic parameters obtained from static tensile tests cannot adequately model actual viscoelastic
behavior. The effective time theory was incorporated into the prediction in order to account for the progress of physical
aging. It was verified that incorporating effective time theory into the prediction allows for the precise prediction of the
long-term viscoelastic behavior. 相似文献
68.
Akira Urano Ken Syoji Taiki Sato Hidemitsu Koyanagi Masayuki Oguro Yasushige Morikawa 《Building Simulation》2014,7(2):123-129
We have developed a simulation system for a year-round assessment of environmental comfort, energy conservation, and CO2 emissions in buildings and street blocks where active utilization of sunshine, vegetation and solar energy resources is fully considered. An analysis model has been constructed for handling interactions between highly complex street-block wide solar radiation patterns and building air-conditioning load. As a demonstration case of the present system, coupled solar radiation-thermal load analysis for an eleven-story office building has been performed. By comparing the result of a building located in a city block with a reference case of a self-standing building, the proper arrangement of buildings and spaces such as solar reflectance of building surface may be proposed. 相似文献
69.
Taiki Tominaga Vijay R. Tirumala Eric K. Lin Jian Ping Gong Hidemitsu Furukawa Yoshihito Osada Wen-li Wu 《Polymer》2007,48(26):7449-7454
Double-network hydrogels (DN-gels) are a new class of crosslinked polymer networks with extraordinary mechanical properties while containing 80–90 vol.% water. Small-angle neutron scattering (SANS) was applied to investigate the molecular origin of the mechanical properties observed in DN-gels. We present SANS results in both deformed and undeformed conditions for a tough DN-gel made of poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (PAMPS) and polyacrylamide (PAAm). The SANS measurements indicate that deformation of DN-gels results in periodic and mesoscale (1.5 μm) compositional fluctuations in both PAMPS and PAAm. In addition, SANS measurements also indicate that the DN-gel constituents interact favorably with each other while in water. This favorable interaction between PAMPS and PAAm is consistent with the rheological results on solution mixtures of these two polymers. The implications of the above observations to toughening mechanisms are discussed. 相似文献
70.
We propose a fast surface-profiling algorithm based on white-light interferometry by use of sampling theory. We first provide a generalized sampling theorem that reconstructs the squared-envelope function of the white-light interferogram from sampled values of the interferogram and then propose the new algorithm based on the theorem. The algorithm extends the sampling interval to 1.425 microm when an optical filter with a center wavelength of 600 nm and a bandwidth of 60 nm is used. The sampling interval is 6-14 times wider than those used in conventional systems. The algorithm has been installed in a commercial system that achieved the world's fastest scanning speed of 80 microm/s. The height resolution of the system is of the order of 10 nm for a measurement range of greater than 100 microm. 相似文献