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51.
A direct measurement of the dynamics of electrons in the X6 valley for a GaAs crystal by time-resolved absorption spectroscopy is reported for the first time. IR picosecond probe pulses were used to monitor the growth and decay of the population in the X6 valley subsequent to excitation by a 527 nm pump pulse. The intervalley X6→Γ6, L6 scattering time tx of 0.70 ± 0.50 ps is determined and the crossection for the X6→X7 transition is estimated to be 1.8 × 10−16 cm2. 相似文献
52.
叙述了体吸收激光能量计的特点,介绍了其标定方法,给出了其技术参数。体吸收激光地的推广应用取得了广泛的社会效益。 相似文献
53.
T. R. Guilinger M. J. Kelly J. R. Scully T. M. Christensen D. Ingersoll J. A. Knapp R. I. Ewing W. H. Casey S. S. Tsao 《Journal of Fusion Energy》1990,9(3):299-304
We describe several electrochemical methods used to investigate the possibility of cold fusion phenomena in palladium and titanium tritide cathodes. We performed long-term (up to 77 days) electrolysis experiments with electrochemical cells of the University of Utah type at current densities as high as 1 A/cm2, while monitoring neutron and tritium levels. With some cells, we pulsed the current to determine if neutron bursts would result. In another cell, we used titanium tritide as the cathode to determine if D-T reactions yielding neutrons would occur. In no instance were levels of neutrons or tritium significantly above background except in the titanium tritide cell where isotopic exchange, occcurring between the electrode and the electrolyte, resulted in significant tritium levels. We also combined x-ray photoelectron spectroscopy (XPS) and electrochemical hydrogen permeation experiments to determine the effectiveness of various Pd surface treatment procedures on the resultant electrochemical hydrogen absorption efficiency. Electroanalytical and thermal desorption/gas analysis techniques indicated the maximum loading of H in Pd was to a ratio of HPd=0.8. 相似文献
54.
55.
提出了利用直拉硅中与氮有关的特征红外吸收峰963、996、1081-1及1027cm-1确定直拉硅中氮含量的计算公式,并进行了多种样品实测。该法克服了只用963cm-1峰测定直拉硅中氮使结果偏低的弊病,方法相对偏差为5%~20% 相似文献
56.
Shilin Liu Jing Lin Qiyuan Chen Zili Liu Lishuang Gui Liwei Chen Shilin Huang Xuelin Tian 《大分子材料与工程》2021,306(10):2100242
Crude oil spill accidents pose a worldwide environmental threat. Oleophilic and hydrophobic absorbents that can selectively absorb oil from water have shown promising application potential in oil spill remediation. Simultaneous optimization of the absorption and desorption speed of absorbents towards oil is highly desirable for their recyclable usage, but remains a great challenge, because these two properties are generally conflicting. Here, a facile and ingenious strategy is proposed to tackle the above challenge via surface modification of porous sponges with highly flexible linear polydimethylsiloxane (LPDMS) brushes. The LPDMS brushes feature liquid-like properties at room temperature owing to its extremely low glass transition temperature, and act as a covalently-grafted lubrication layer throughout the 3D network channels of the sponge, which can minimize contact angle hysteresis and reduce friction between oil and sponge channel. Compared to the prevalent cross-linked polydimethylsiloxane (CPDMS) modification strategy, sponges modified with LPDMS brushes not only shows significantly enhanced absorption speed, but also exhibits superior desorption dynamics towards viscous crude oils. The design strategy of slippery sponges with liquid-like molecules may open a new avenue for developing advanced absorbents with simultaneously enhanced absorption and desorption performances for liquid separation and purification applications. 相似文献
57.
58.
红外辐射吸收法测量火焰温度 总被引:3,自引:0,他引:3
简述了几种温度测量的方法,介绍了红外辐射吸收法测温原理及实验装置,并对稳定的煤气火焰进行温度测量,试图在此基础上测量固体推进剂火焰的温度。 相似文献
59.
1 INTRODUCTION Mass transfer across free interface of gas-liquid flow is of extensive importance and is encountered in most industrial applications. A close investigation of concentration distribution near the interface is helpful to understand mass transfer phenomena, to guide the development of transport theories, and to optimize the design of gas-liquid contact equipment. Laser holographic interference technique provides a precise and noncontact measurement method for measuring the tran… 相似文献
60.
磷酸浓缩氟吸收问题的探讨 总被引:1,自引:0,他引:1
将我国现有的几种磷酸浓缩流程和实际应用效果进行比较 ,并从氟吸收机理分析探讨氟吸收级数与吸收效率的关系 ;氟硅酸浓度、温度与吸收效率的关系 ;吸收设备和雾沫分离器选型等 相似文献