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991.
992.
With the advantages of transmitting energy from multiple directions to one direction and transforming vibration from one source to multiple directions, the two-dimensional vibra?tion direction converter has important applications in power ultrasonic technology. However, for the complexity of using the wave equation to design and analysis the two-dimensional vibration direction converter, a concise equivalent circuit for the converter is investigated. By introducing the two-dimensional mechanical coupling coefficient and the longitudinal force transform coef?ficient, and using the electromechanical analogy principle, the equivalent circuit and resonance frequency equation of the two-dimensional vibration direction converter vibrating in anti-phase and in-phase two-dimensional coupled vibration are deduced. The resonance frequencies of the vibration direction converters of two different materials are calculated by using the proposed frequency equation, which are in agreement with the results from the finite element method and the experimental test. It provides a concise method for the design and applications of such ultrasonic vibration system. 相似文献
993.
994.
ZHAO JinYu LI JiaHuang ZHANG Zheng ZHANG ShuYi QU Min FANG JianWen HUA ZiChun 《中国科学:物理学 力学 天文学(英文版)》2013,(7):1301-1309
The enthalpy and conformational volume changes in the photolyses of carboxy-hemoglobin (HbCO) of human, bovine, pig, horse and rabbit are investigated by photoacoustic calorimetry. Considering the time scales of the exciting laser pulse and the receiving ultrasound transducers (PVDF films and PZT ceramics), as well as the reaction lifetimes in the photolysis processes of HbCO, the measured results are related to the geminate recombination and tertiary relaxation in photolyses of HbCO. Moreover, the quantum yields of the five mammals are also measured by laser pump-probe technique. The results show that the dynamic parameters, such as enthalpy and conformational volume changes, differ between the processes of the geminate recombination and tertiary relaxation. Also, the dynamic parameters differ among the five mammals although some of them may be consistent with each other. 相似文献
995.
CHENG Dan JIN Hua LI Ben-xian WANG Xiao-feng CHU Qing-xin L Yang LIU Xiao-yang ZHAO Xu-dong 《高等学校化学研究》2012,28(2)
High-quality needle-like CuTaS3 single crystals have been synthesized through a chemical vapor transport(CVT)process.Crystallographic data show the special double chains of edge-sharing TaS6 octahedra.... 相似文献
996.
铈基催化剂催化氧化燃煤烟气中汞的实验及机理研究 总被引:1,自引:0,他引:1
采用超声波增强的浸渍法合成了CeO2-TiO2催化剂,并采用BET,XRD,XPS等分析手段对催化剂进行了表征。利用固定床反应器,在模拟燃煤烟气条件下研究了CeO2-TiO2催化剂对单质汞的催化氧化行为及机理。结果表明:CeO2-TiO2催化剂在低温范围(150~250°)具有很强的催化氧化汞的能力;最佳的CeO2/TiO2质量比在1.5左右,此时汞的氧化效率可高达90%以上;P25,Evonik TiO2比锐钛矿TiO2更适合做铈基催化剂载体;CeO2-TiO2催化剂上汞的催化氧化符合Langmuir-Hinshelwood机理,即吸附态的汞与其邻近的活性物质反应生成氧化态汞。 相似文献
997.
998.
Surfaces of three types of CuZr-based bulk metallic glasses (BMGs) were modified by laser surface treatment (LST), and the influence of the treatment on structure and mechanical properties of these alloys was investigated. The phase structure of as-cast and laser-treated samples was characterized by XRD and the morphology of the alloys after fracture was examined by SEM. The compressive plasticity of treated Cu47.5Zr47.5Al5 and Cu46.5Zr47.5Al5Co1 BMGs can be improved from 0.5% to 2.0% and from 1.2% to 5.7% respectively compared with the as-cast ones, while (Cu0.55Zr0.40Al0.05)99Er1 BMG shows insignificant change of plasticity. The improvement in plasticity is attributed to induced crystallization of B2 CuZr phase in the treated surface zone of selected metallic glasses. 相似文献
999.
Using a molecular dynamics simulation technique,we compared several commonly used ion-water models to describe the microscopic structures and dynamics in KSCN aqueous solutions.Results are compared with observations of femtosecond infrared vibrational-energy transfer and anisotropy measurements.The Jorgensen/TIP4P model is found to provide the best reproduction of clustering properties such as percentage of clustered ions,cluster-size distribution,concentration dependence of the water,and ion-rotation time constants. 相似文献
1000.
In conventional research on beam gas coulomb scattering(BGCS), only the related beam lifetime using the analytical method is studied. In this paper, using the particle-in-cell Monte Carlo collisions(PIC-MCC) method,we not only simulated the beam lifetime but also explored the effect of BGCS on the beam distribution. In order to better estimate the effect on particle distribution, we study the ultra-low emittance electron beam. Here we choose the He Fei Advanced Light Source. By counting the lost particles in a certain time, the corresponding beam lifetime we simulated is 4.8482 h/13.8492 h in x/y, which is very close to the theoretic value(5.0555 h /13.7024 h in x/y).By counting the lost particles relative to the collided particles, the simulated value of the loss probability of collided particles is 1.3431e-04, which is also very close to the theoretical value(1.3824e-04). Besides, the simulation shows there is a tail in the transverse distribution due to the BGCS. The close match of the simulation with the theoretic value in beam lifetime and loss probability indicates our simulation is reliable. 相似文献