Author Keywords: Radiation detection; Long-lasting phosphor; Luminescence; Temperature dependence; Fade-out effect 相似文献
全文获取类型
收费全文 | 2563篇 |
免费 | 62篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 185篇 |
综合类 | 8篇 |
化学工业 | 689篇 |
金属工艺 | 51篇 |
机械仪表 | 82篇 |
建筑科学 | 60篇 |
能源动力 | 68篇 |
轻工业 | 199篇 |
水利工程 | 17篇 |
石油天然气 | 3篇 |
无线电 | 178篇 |
一般工业技术 | 418篇 |
冶金工业 | 378篇 |
原子能技术 | 73篇 |
自动化技术 | 224篇 |
出版年
2022年 | 19篇 |
2021年 | 26篇 |
2019年 | 21篇 |
2018年 | 25篇 |
2017年 | 18篇 |
2016年 | 45篇 |
2015年 | 36篇 |
2014年 | 64篇 |
2013年 | 105篇 |
2012年 | 83篇 |
2011年 | 113篇 |
2010年 | 77篇 |
2009年 | 94篇 |
2008年 | 111篇 |
2007年 | 97篇 |
2006年 | 95篇 |
2005年 | 84篇 |
2004年 | 93篇 |
2003年 | 83篇 |
2002年 | 81篇 |
2001年 | 62篇 |
2000年 | 56篇 |
1999年 | 70篇 |
1998年 | 168篇 |
1997年 | 128篇 |
1996年 | 74篇 |
1995年 | 54篇 |
1994年 | 38篇 |
1993年 | 41篇 |
1992年 | 34篇 |
1991年 | 32篇 |
1990年 | 23篇 |
1989年 | 36篇 |
1988年 | 38篇 |
1987年 | 30篇 |
1986年 | 33篇 |
1985年 | 27篇 |
1984年 | 19篇 |
1983年 | 23篇 |
1982年 | 35篇 |
1981年 | 28篇 |
1980年 | 29篇 |
1979年 | 22篇 |
1978年 | 17篇 |
1977年 | 24篇 |
1976年 | 23篇 |
1974年 | 12篇 |
1967年 | 13篇 |
1966年 | 11篇 |
1965年 | 13篇 |
排序方式: 共有2633条查询结果,搜索用时 421 毫秒
11.
Recently, a demand for small-capacity generators has been increasing as electric sources in small ships and automobiles or as portable electric sources driven by engines. It is desired that the structure of small-capacity generators be simple and robust, and that the generators be highly reliable, easily maintained and controlled. This paper describes an analysis of the original brushless synchronous generator without exciter. The output voltage can be adjusted in the wide range by controlling the stator dc current. To analyze the characteristics of this generator, the finite element method is applied. It is found that the results of theoretical analysis agree well with the experimental results. 相似文献
12.
H Midorikawa A Tsuda K Satoh K Akuzawa T Igari S Hoshino 《Canadian Metallurgical Quarterly》1997,50(13):1104-1107
This report describes a case in which a 68-year-old male underwent two operations simultaneously for left coronary ostial stenosis and gastric cancer. Successfully performed procedures were a single coronary artery grafting with the saphenous vein to the left anterior descending artery, and a subtotal gastrectomy using the Billroth II method. The postoperative course was uneventful and the patient was discharged from the hospital in good condition after 42 days. At present, one-year postoperative, the patient has been visiting the outpatient clinic in healthy condition. 相似文献
13.
Munehiko Kowatari Daisuke Koyama Yoshiyuki Satoh Kouichi Iinuma Shunsuke Uchida 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2002,480(2-3):431-439
The temperature dependence of luminescence from a long-lasting phosphor (LLP), SrAl2O4 : Eu2+,Dy3+, exposed to ionizing radiation has been measured to understand the LLP luminescence mechanism. Evaluation of the decay constants of the LLP exposed to -, β- or γ-rays at temperatures from 200 to 390 K showed that the decay constant is divided into four components ranging from 10−4 to 10−1 s−1 with activation energies of 0.02–0.35 eV.
Total luminous intensity from the LLP with changing irradiation temperature has its maximum value around the room temperature. Irradiation at elevated temperature (390 K) has the total luminescence pattern with monotonous decrease as temperature rises. As a result of evaluating the temperature dependence of luminescence, the luminescence mechanism is considered as follows:
14.
The roller drawing of ultrahigh molecular weight polyethylene (UHMW-PE) sheets were carried out in the roller temperature Tr range of 100–140°C. In addition to the roller drawing in the solid state (Tr = 100°C), we attempted to crystallize the molten UHMW-PE sheet under the roller-drawing process (Tr = 100–140°C). The tensile and dynamic viscoelastic properties, the molecular orientation, and the microstructure of the roller-drawn UHMW-PE sheets were investigated. The mechanical properties of UHMW-PE sheets were much improved by crystallization during the roller drawing process at Tr = 140°C. The sheets roller-drawn at Tr = 135 and 140°C exhibited c-axis orientation to the draw direction and (100) alignment in the sheet plane. However, at Tr = 100°C the elastic motion of the amorphous chains induces the twinnings of lattice, which enhances the transition to the (110) alignment in the sheet plane. The dynamic storage modulus below γ-dispersion temperature showed good correlation with crystallinity and orientation functions, while taut tie molecules and thick crystallites play an important role in the storage modulus above γ-dipersion temperature. 相似文献
15.
16.
Tetsuya Suemitsu Yoshino K. Fukai Hiroki Sugiyama Kazuo Watanabe Haruki Yokoyama 《Microelectronics Reliability》2002,42(1):47-52
The reliability of InP-based HEMTs is studied, focussing on how it is affected by the doped layer material and gate recess structure. Bias-and-temperature stress tests reveal that fluorine-induced donor passivation in the recess region, formed adjacent to the gate electrode, causes the source resistance (Rs) to increase at large drain bias voltages. The increase in Rs can be prevented by using InP or InAlP as the carrier supply layer material instead of InAlAs. On the other hand, the increase in the drain resistance (Rd) does not depend on the material of the carrier supply layer, which suggests that a mechanism different from that in the case of Rs should be considered. It is also found that a deep gate recess suppresses the increase in Rd after long-term stressing. 相似文献
17.
Dr. Kazuo Ishihara 《Computing》1987,38(2):117-132
In this paper, we consider the successive overrelaxation method with projection for obtaining the finite element solutions under the nonlinear radiation boundary conditions. In particular we establish the convergence of the successive overrelaxation method with projection. Some numerical results are also given to illustrate the usefulness. 相似文献
18.
Swelling degrees of poly(N-vinyl-2-pyrrolidone) (PVP) gel were measured in aqueous salt solutions and in water/organic solvent mixtures to find marked ion- and solvent-specificities. In order to investigate any correlation of those specificities with hydration or solvation of PVP, IR spectra band of the CO group was monitored by means of ATR method both for PVP gel and the relevant solution systems. Dependence of the peak frequency on the swelling ratio suggested that hydration of PVP carbonyl group in deswollen gel systems is different from that in the corresponding solution systems. In the solution systems, PVP carbonyl band showed a high-wavenumber shift for deswollen systems, which can be well correlated with changes in water proton charge through ionic hydration and with Gutmann's acceptor number of organic solvents. In the deswollen gel systems, the CO band showed a low-wavenumber shift, suggesting a strong hydration or doubly hydrated state. This unexpected behavior was interpreted by assuming an intermolecular hydrogen bond of two carbonyl groups intermediated by water molecules. 相似文献
19.
T Yoshida M Satoh Y Nakagaito H Kuno M Takeuchi 《Canadian Metallurgical Quarterly》1993,76(1):147-150
The effects of various cytokines on survival and differentiation of an astrocyte progenitor cell line (AP-16) were examined. Epidermal growth factor (EGF) deprivation caused death of AP-16 cells by apoptosis. Transforming growth factor-alpha (TGF-alpha) and basic fibroblast growth factor (bFGF) prevented the apoptosis occurring in the absence of EGF. Leukemia inhibitory factor (LIF) and ciliary neurotrophic factor (CNTF) induced glial fibrillary acidic protein (GFAP) and decreased A2B5 antigen in AP-16 cells, indicating that these cytokines induced AP-16 cells to differentiate into astrocytes. 相似文献
20.
Ken Kato Yasuhiro Kasuga Masanori Fujiwara Kazuo Onda 《Electrical Engineering in Japan》1996,116(4):94-108
Laboratory-scale and parametric experiments of SO2 and NOx removal from the simulated combustion gas by pulsed corona discharge have been performed by changing the combustion gas composition and temperature, the electrode configuration of plasma reactor, and the polarity of high-voltage electrode. The following results are obtained: 1) the higher the concentration of H2O and O2, the higher the efficiency of desulfurization and denitrification at the same specific input; 2) the pulsed corona discharge with a voltage pulsewidth as short as 200 ns of negative polarity shows the possibility to attain almost 90 percent deSOx and deNOx efficiency at the specific discharge input of 20 J/g, which is almost the same as the specific input in the electron-beam process; 3) the deNOx characteristics show a little temperature dependence in the range of 70 to 130°C, but the deSOx efficiency increases rapidly in the temperature region below 100°C suggesting the thermochemical dependence of deSOx reaction; 4) when desulfurization and denitrification proceed, the white dendritic powder deposits on the plasma reactor whose composition is identified to be 49 mol% (NH4)2SO4 and 47 mol% of 2NH4NO3 · (NH4)2SO4, and the ratio of SO2, NO and NH3 of the deposit is almost equal to that of supplied gas. 相似文献