共查询到20条相似文献,搜索用时 15 毫秒
1.
Kh. Ya. Mulyukov Ya. A. Abzgil’din I. Z. Sharipov R. R. Mulyukov V. A. Popov 《Physics of the Solid State》2013,55(12):2608-2612
The results of the investigations of the temperature dependence of thermal expansion of nanostructured cobalt have been presented. It has been shown that deformation nanostructuring results in the nonlinear behavior of the cobalt thermal expansion curve, and the manifestation of a stepwise sample elongation in the phase transformation temperature range in this curve disappears. It has been found that the sample length at room temperature changes after cycles of heating to various temperatures. Based on the results obtained and X-ray diffraction data, it has been demonstrated that there is a correlation of these changes with recovery and recrystallization processes. 相似文献
2.
The amorphous carbon film/n-Si (a-C/n-Si) heterojunctions have been fabricated by direct current magnetron sputtering at room temperature, and their current-voltage characteristics have been investigated. The results show that these junctions have good rectifying properties in the temperature range 80-300 K. The interesting result is that the current-voltage curve changes dramatically with increasing applied voltage and temperature. For the forward bias voltages, the junction shows Ohmic mechanism characteristic in the temperature range 240-300 K. However, the conduction mechanism changes from Ohmic for the low bias voltages to space charge limited current for the high bias voltages in the temperature range 80-240 K. While for the reverse bias voltages, it changes from Schottky emission to breakdown with increasing voltage. Another important phenomenon is that the temperature dependence of the junction resistance shows a metal-insulator transition, whose transition temperature can be controlled by the bias voltage. 相似文献
3.
Esther M. Conwell 《Solid State Communications》1980,36(11):939-941
It has been reported that under pressure ? 10 kb, TMTSF-DMTCNQ shows at some temperature an S-shaped anomaly in the conductivity and a change in the slope of thermopower vs temperature. These changes have been taken to indicate a transition from one metallic phase to another. I give evidence that the transition these changes signal is from band to hopping conduction in the DMTCNQ chains. 相似文献
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Second-harmonic generation effects have been investigated in TlGaSe2 layered crystal over a temperature range where ferroelectric phase exists. Pronounced periodical changes of the second-harmonic signal with temperature have been discovered. The observed effect is explained within the phase synchronism condition which changes with the temperature. The main mechanism of the thermal expansion of the sample in the observed phenomenon is explained. 相似文献
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用磁控溅射法制备了GdFeCo/TbFeCo交换耦合两层薄膜,利用不同温度的克尔磁滞回线和VSM磁滞回线研究了读出层(GdFeCo)变温磁化方向变化过程.结果表明,随温度升高读出层从平面磁化转变为垂直磁化,交换耦合两层薄膜具有中心孔探测磁超分辨的基本性能.转变过程主要受饱和磁化强度(Ms)的影响,在GdFeCo的补偿温度附近,读出层的磁化强度较小,退磁场能也较小,在交换耦合的作用下,使读出层(GdFeCo)的磁化方向发生转变.磁化方向的转变在75℃~125℃的温度范围内变化较快. 相似文献
6.
Ralph T. Johnson Jr 《辐射效应与固体损伤》2013,168(1):21-27
Time dependent electrical resistivity changes at low temperature in fast-neutron irradiated CdS have been studied. The experiments were on low-resistivity single crystals, and the electrical changes result from radioactive decay effects induced by the fast-neutron irradiation. Results show that following neutron irradiation and upon lowering the sample temperature, the resistivity decreases with time and approaches a stable value. These effects are attributed to trapping phenomena, and can be erased by increasing the temperature. The time dependent electrical changes associated with radioactive decay provide a new means for neutron detection. 相似文献
7.
《Infrared Physics & Technology》2002,43(3-5):151-155
Temperature changes during tensile test and simple shear test of TiNi shape memory alloys loaded at various strain rates and at different temperatures have been presented. The temperature changes were measured by recording infrared radiation emitted by the surface of the specimen. It was found that the martensite transformation was accompanied by an increase in temperature while the reversible transformation––temperature decrease. 相似文献
8.
The temperature variation of the second order Raman spectra of RbI has been theoretically studied in three basic symmetries on the basis of the modified Born and Bradburn theory. The phonon frequencies and corresponding eigenvectors have been determined at the room temperature by employing a three body force shell model. It has been assumed that the major factor which governs the temperature dependence of Raman intensity is the occupation number and the changes in the phonon eigen data and the polarizability parameters with temperature have been ignored. Calculations have been made at three temperatures namely, 300,90 and 23 K and the theoretical results have been compared to the experimental Raman spectra. 相似文献
9.
考虑到载流子和晶格的热容、热导率、弛豫时间等热力学参数随温度非线性变化因素的影响,利用有限差分算法,数值求解了半导体材料自相关热传导模型,讨论了2 m厚硅膜在波长和脉宽分别为775 nm和500 fs的脉冲激光辐照下的升温规律。数值结果表明:硅膜前表面载流子温度在激光辐照过程的0.69 ps时刻达到最大值,在4.8 ps时刻以后硅膜基本趋于总体热平衡;载流子热容的快速变化以及单光子吸收和由载流子浓度变化而引起的载流子能流变化是导致载流子温度变化的主要原因;超短脉冲激光辐照时,激光作用时间短,各扩散项及传导项不起主要作用,因此硅膜内各主要计算参数与硅膜的厚度及基体材料类型等的关系不大。 相似文献
10.
通过对柚子型微结构光纤Bragg光栅的多个反射峰的温度和应变传感特性进行的理论和实验 研究,得出柚子型微结构光纤Bragg光栅的反射波长与温度呈二次关系,且理论和实验二者 吻合较好; 同时发现每个反射峰的温度灵敏度不同.理论分析柚子型微结构光纤Bragg光栅的 反射波长与应变呈线性关系,实验得到了该种Bragg光栅的反射波长与应变的线性关系,实 验结果与理论分析相吻合.由于微结构光纤光栅反射谱中多个峰对温度和应变等物理量敏感 度不一致,这种Bragg光栅更适合应用到多参量传感领域.
关键词:
微结构光纤
光纤Bragg光栅
温度传感
应变传感 相似文献
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The temperature dependence of the light intensity emitted by the plasma layer generated at the surface of triglycine sulphate samples at alternating polarization has been investigated. The changes of intensity of the emitted light were found to correspond to the changes of the dielectric constant of triglycine sulphate. This phenomenon can be used to determine the ferroelectric phase-transition temperature and to investigate the changes of the dielectric constant of ferroelectrics by studying the light of plasma generated at their surfaces. 相似文献
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本文应用变温11B核磁共振技术研究了RNa2O·B2O3玻璃体系在室温和300℃时硼原子的配位情况。结果表明,当R>0.5时,四配位硼原子数随温度的上升而减少。因此,玻璃态结构也可能随温度变化而改变。 相似文献
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For commercialization of holographic storage drives, the effects of temperature changes on holographic medium is critical.
There has been no systematic study on the effect of temperature change on hologram recording properties. We believe that the
monomer-diffusion speed and polymerization rate changes are critical for hologram-recording properties and estimate those
parameters on each temperature using the photopolymer medium process simulation we have developed. We describe how these parameters
affect actual recording properties such as sensitivity, M=# and so on. Moreover, we propose a method for compensating temperature changes, and confirm the success of this. 相似文献
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N. V. Tokiy V. V. Tokiy A. N. Pilipenko N. E. Pismenova 《Physics of the Solid State》2014,56(5):1002-1005
The possibility of applying the two-component model of single-phase hybrid materials to the explanation of the anomalous temperature dependence of elastic moduli of copper with a submicrocrystalline structure has been discussed. An analysis has been performed based on new experimental data. A twin mechanism of changes in the crystallite orientation has been proposed. These changes cause the anomalous behavior of the elastic moduli of copper during deformation and subsequent heatings. 相似文献
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The photo (PL) and electro (EL) luminescence in ZnS: MnLa and ZnS: La have been studied. The enhancement and quenching of
emission bands have been observed on the simultaneous application of sinusoidal field and photons. The wave shape, voltage,
frequency and temperature dependence of EL brightness have been reported. A study of the phosphorescence and thermoluminescence
of these phosphors is also carried out and it is observed that the trap-depth changes slowly with temperature and activator
concentration. An attempt has been made to calculate the trap depth by studying temperature dependence of EL brightness. The
results are reported and discussed. 相似文献
20.
Abstract The temperature dependence of ice resistivity R has been investigated in the diamond anvil cell (DAC) of “rounded cone-plane” type. Mean pressure is about 20 GPa, temperature interval is 4,2–273 K. Measuring R it has been detected that ice changes to metallic conductivity type state between 220–260 K. At 25 K the temperature dependence of R shows the transport current dependence. 相似文献