全文获取类型
收费全文 | 347篇 |
免费 | 4篇 |
专业分类
电工技术 | 17篇 |
综合类 | 1篇 |
化学工业 | 100篇 |
金属工艺 | 22篇 |
机械仪表 | 10篇 |
建筑科学 | 4篇 |
能源动力 | 19篇 |
轻工业 | 31篇 |
石油天然气 | 1篇 |
无线电 | 17篇 |
一般工业技术 | 74篇 |
冶金工业 | 35篇 |
原子能技术 | 8篇 |
自动化技术 | 12篇 |
出版年
2023年 | 2篇 |
2021年 | 2篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 16篇 |
2012年 | 15篇 |
2011年 | 13篇 |
2010年 | 14篇 |
2009年 | 15篇 |
2008年 | 13篇 |
2007年 | 10篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 12篇 |
1997年 | 12篇 |
1996年 | 9篇 |
1995年 | 13篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1967年 | 3篇 |
1927年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有351条查询结果,搜索用时 6 毫秒
91.
The changes in the mechanical properties accompanying the reduction of disulfide (SS) linkages in hair were studied. A variety of extents of thiol groups were introduced into hair by treatments with thioglycolic acid and tri-n-butyl phosphine. The reduced fibers swollen with an aqueous 11M LiBr solution containing N-ethylmaleimide showed typical rubberlike elasticity in a solution composed of equal volumes of 8M LiBr and diethylene glycol mono-n-butyl ether. The crosslink density was determined from the shear modulus of the swollen fiber. It was found that the SS linkages can be divided into two groups: the intermolecular linkages group (SS1 and SS2) and the intramolecular linkages group (SS3). The effect of the SS bond scission on the shear modulus of the reduced fibers in water was also studied. It was further found that intermolecular SS1 linkages do not respond to the shear modulus of fiber in water, and the amounts of SS1, SS2, and SS3 are about 35, 18, and 47% of the total cystine content in hair (623 μmol/g), respectively. With respect to the location of SS linkages in hair, important suggestions were obtained: the intermolecular SS1 and SS2 linkages are located in the microfibril and the matrix, and the former are more accessible to water than the latter; and SS3 linkages are localized within the hydrophobic region of the matrix. © 1996 John Wiley & Sons, Inc. 相似文献
92.
Koji Watari Kiyoshi Hirao Motohiro Toriyama Kozo Ishizaki 《Journal of the American Ceramic Society》1999,82(3):777-779
Polycrystalline Si3 N4 samples with different grain-size distributions and a nearly constant volume content of grain-boundary phase (6.3 vol%) were fabricated by hot-pressing at 1800°C and subsequent HIP sintering at 2400°C. The HIP treatment of hot-pressed Si3 N4 resulted in the formation of a large amount of ß-Si3 N4 grains ∼10 µm in diameter and ∼50 µm long, and the elimination of smaller matrix grains. The room-temperature thermal conductivities of the HIPed Si3 N4 materials were 80 and 102 Wm−1 K−1 , respectively, in the directions parallel and perpendicular to the hot-pressing axis. These values are slightly higher than those obtained for hot-pressed samples (78 and 93 Wm−1 K−1 ). The calculated phonon mean free path of sintered Si3 N4 was ∼20 nm at room temperature, which is very small as compared to the grain size. Experimental observations and theoretical calculations showed that the thermal conductivity of Si3 N4 at room temperature is independent of grain size, but is controlled by the internal defect structure of the grains such as point defects and dislocations. 相似文献
93.
Kozo Taguchi Kaname Fukushima Atsuyuki Ishitani Masahiro Ikeda 《Electrical Engineering in Japan》2000,132(4):73-78
Semiconductor ring lasers have many capabilities of realizing new functional devices. In this paper, we propose a novel optical inertial rotation sensor using a semiconductor ring laser. If a semiconductor ring laser operates as an optical inertial rotation sensor, a very small and simple optical gyroscope can be realized. To our knowledge this is the first demonstration of a semiconductor ring laser gyroscope (S‐RLG). Experimental results are as follows. (1) The Sagnac frequency shift can be detected as a beat note by the terminal voltage change of the semiconductor ring laser without branching the circulating optical power. Therefore, the S‐RLG system can be constructed very simply as compared with already proposed optical gyroscopes. (2) The detected beat frequency between two counterpropagating lasers in the S‐RLG is directly proportional to the applied rotation rate. (3) Furthermore, we present data demonstrating the injection locking phenomenon around low rotation rate. These results verify that the proposed S‐RLG operates as an optical inertial rotation sensor based on the Sagnac effect. © 2000 Scripta Technica, Electr Eng Jpn, 132(4): 73–78, 2000 相似文献
94.
Kozo Ikegami Yo Shirasawa Tomohito Yokotsuka Yasushi Niitsu 《Metals and Materials International》1998,4(4):899-903
Cyclic plastic deformation of stainless steel SUS 304 is experimentally investigated at low temperature of liquid nitrogen
(77 K) under various cyclic loading conditions Thin walled tubular specimens are subjected to cyclic loading under constant
strain ranges. At low temperature, the material shows remarkable hardening by cyclic loading comparing with cyclic loading
at room temperature. The hysteresis curves of stress-strain relations by cyclic loading are saturated by increasing the cycle
numbers. The saturation tendency depends on loading direction. The saturated stress values are related with cumulative plastic
strain of cyclic loading. The prestraining is given at 77 K by axial and torsional loadings, and subsequent cyclic loading
under constant strain range is conducted at 77 K. The cyclic stress-strain curves are saturated by increasing cyclic numbers.
At small cyclic numbers, cyclic plastic deformation depends on the prestrain direction. The directional effect of pre-strain
on cyclic loading becomes small with increasing number of cycles. 相似文献
95.
96.
Yasushi Niitsu
Akinori Horigushi
Kozo Ikegami 《International Journal of Pressure Vessels and Piping》1993,53(3):511-523Plastic behavior of S25C mild steel was investigated at constant and variable temperatures in the range from room temperature to 400°C. The combined loading tests were carried out with the thin walled tubular specimens by applying the axial and torsional loads. The initial yield condition of the material obeyed Tresca's law, but the stress-strain relation after yielding followed neither Tresca's nor Mises's laws. Bauschinger's curves in the torsional loading conditions were different from those in the axial loading conditions. The stress-strain relations subsequent to the tensile pre-strain were obtained at various temperatures. The experimental results were compared with the isothermal stress-strain relation. 相似文献
97.
Rho-associated kinase (Rho-kinase), which is activated by the small GTPase Rho, phosphorylates moesin at Thr558 in vitro. Here, using a site- and phosphorylation state-specific antibody, we found that the expression of dominant active RhoA in COS7 cells induced moesin phosphorylation and the formation of microvilli-like structures at apical membranes where the Thr558-phosphorylated moesin accumulated, whereas the expression of dominant negative Rho-kinase inhibited both of these processes. The expression of dominant active Rho-kinase also induced moesin phosphorylation. When COS7 cells expressing moesin or moesinT558A (substitution of Thr by Ala) were cultured under serum-depleted conditions, there were few microvilli-like structures, whereas microvilli-like structures remained in the cells expressing moesinT558D (substitution of Thr by Asp). The expression of moesinT558A inhibited the dominant active RhoA-induced formation of microvilli-like structures. These results indicate that Rho-kinase regulates moesin phosphorylation downstream of Rho in vivo and that the phosphorylation of moesin by Rho-kinase plays a crucial role in the formation of microvilli-like structures. 相似文献
98.
Makoto Imanaka Waichiro Kishimoto Kozo Okita Hideaii Nakayama Hiroyoshi Nagai 《International Journal of Fracture》1989,41(3):223-234
Fatigue tests and analytical investigation of adhesive bonded shaft joints were conducted to propose the estimation method of fatigue strength. Two kinds of adhesive bonded joints were studied: one, shaft joints connected with adhesive coupling, the other, adhesive joints of thin wall tubes to obtain standard fatigue strength. Both pulsating tensile and torsional fatigue tests were conducted with each adhesive joint. Furthermore, the stress distributions under tensile and torsional load conditions were analyzed by finite element method. Based on the analytically computed maximum normal shear stress in the adhesive layer, fatigue strength of the shaft joints was tandardized and compared with that of adhesive joints of thin wall tubes. As a result, it is confirmed that the maximum normal and shear stresses are key parameters for estimating fatigue strength under pulsating tensile and forsional load conditions, respectively. Furthermore, this study indicates an improved method of estimating fatigue strength by using tapered coupling order to reduce the stress concentration at the end of the adhesive layer. 相似文献
99.
100.
Chemical reactions to increase thermal conductivity by decreasing oxygen contents during AlN sintering with an Y2O3 additive in a reducing nitrogen atmosphere with carbon were investigated. They were: Al2O3 + N2 + 3CO ⇋ 2AlN + 3CO2, Al2Y4O9 + N2 + 3CO ⇋ 2AlN + 2Y2O3 + 3CO2 and Y2O3 + N2 + 3CO ⇋ 2YN + 3CO2. Some of the CO2 gas reduced to CO gas in the presence of carbon by a chemical reaction: CO2 + C ⇋ 2CO. These reactions were confirmed by examining oxygen contents, the grain boundary phases of the sintered AlN, and
the trapped CO and CO2 gases in the sintered bodies. These reducing reactions proceed with increasing sintering temperature and periods, and hence
the thermal conductivity is increased. 相似文献