不同层显式格式及在微尺度热传导中的应用

基于指数拟合和牛顿插值多项式构造了用于数值计算偏微分方程的不同层显式格式,应用不同层显式格式可获得不同精度的数值计算结果,并将该算法应用于微结构热传导方程和薄膜强瞬态热传导方程中.

基于动态压力检测模块的高精度医用微量注射泵的研制

目的为解决对病人影响较大的药物在注射过程中存在的阻塞问题,消除低速微量输液时的风险,研制了一款带有动态压力监测功能的高精度微量注射泵。方法针对临床使用患者的特点,在FC1型微量注射泵的基础上,增加动态压力检测功能和快速启动功能。结果成功研制高精度微量注射泵,其阻塞报警的精度较之前的FC1泵提高了173.5倍。结论新型高精度医用微量注射泵的研制解决了患者给药中断或长时间不给药及非预期Bolus的问题,消除低速微量输液的风险,为微量注射泵的临床应用提供更安全的技术保障,有广泛的应用前景。

Interface waves between two piezoelectric half-spaces with a semiconductor film

In this work propagation of anti-plane (SH) waves in two piezoelectric ceramic half-spaces with a thin layer of a semiconducting material between the half-spaces is studied, and wave attenuation and dispersion caused by semiconduction as well as wave amplification by a biasing electric field are examined. Key words Piezoelectricity - Semiconductor - Wave - Attenuation - Dispersion Document code A CLC number TH11

Combining the Radiative, Conductive and Convective Heat Flows in and around a Skylight

Normal skylights bring light into the spaces located below them. By the use of IR （infrared radiation） transmissive polymer films and IR-emitting and absorbing gases, an advanced version of the skylight may supply passive cooling and thermal insulation to the room located below it. This novel radiative skylight can, in its cooling mode, lead heat from the room below, to the cool skies located above the skylight. When cooling is no longer needed or attainable, the skylight will in its cooling mode provide the room with an optimal amount of thermal resistance. This article is a progress reporting on the modeling of the skylight. The main work is done to combine the different heat transfer methods into one single model by the use of the commercial program Comsol 4.1. The results show that a cooling effect of 100 W/ma is achievable when the skylight is compared with a similar skylight containing only air.

Dropwise Condensation Heat Transfer of Steam on a Polytethefluoroethylene Film

Excellent dropwise condensation of steam was observed on a polytethefluoroethylene (PTFE) coated plate. The experimental results indicated that the condensation heat transfer performance was increased by 30 to 47 times when compared with film condensation values at the same surface subcooling degrees. The random fluctuation of the surface temperature was resulted from the high thermal conductivity of the copper substrate and the ultra thin coated polymer film with lower surface free energy. The effect of the steam temperature for pressures near atmospheric pressure on the dropwise condensation heat transfer characteristics was investigated as well.

Experimental and theoretical study of the charge transport property of 4,4′-N,N′-dicarbazole-biphenyl

The hole and electron mobilities of the amorphous films of the organic semiconductor 4,4′-N,N′-dicarbazole-biphenyl (CBP) at different electric fields were measured through the time of flight (TOF) method. Based on its crystalline structure, the hole and electron mobilities of CBP were calculated. A detailed comparison between experimental and theoretical results is necessary for further understanding its charge transport properties. In order to do this, charge mobilities at zero electric field, μ(0), were deduced from experimental data as a link between experimental and theoretical data. It was found that the electron transport of CBP is less affected by traps compared with its hole transport. This unusual phenomenon can be understood through the distributions of frontier molecular orbitals. We showed that designing materials with frontier molecular orbitals localized at the center of the molecule has the potency to reduce the influence of traps on charge transport and provide new insights into designing high mobility charge transport materials.

Numerical Study of Heat Transfer Enhancement by Liquid Film on the Walls

The mechanism of heat transfer enhancement by liquid film on the channel walls has been investigated in laminar mixed convective flows. The temperature distribution, velocity and mass fraction distributions, and the effects of the wetted wall temperatures and the Reynolds number on the momentum,heat and mass transfer were examined in details. Results show that the liquid film can enhance heat transfer along the wetted walls by 5-10 times.

Non-Fourier heat conduction in a thin gold film heated by an ultra-fast-laser

Based on the dual-phase-lagging(DPL)heat conduction model,the Cattaneo-Vernotte(CV)model and the improved CV model we investigate the one-dimensional heat conduction in gold films with nano-scale thickness exposed to an ultra-fast laser heating.The influence of system parameters on the temperature field is explored.We find that for all the non-Fourier heat conduction models considered in this work,a larger Knudsen number normally leads to a higher temperature.For the DPL model,the large ratio of the phase lag of temperature gradient to the phase lag of heat flux reduces the maximum temperature and shortens the time for the system to reach its steady state.The CV model and the improved CV model lead to the similar thermal wave behavior of the temperature field,but the thermal wave speeds for these two models are different,especially for large Knudsen numbers.When the phase lag of temperature gradient is smaller,the difference between the DPL model and the improved CV model is not significant,but for the large phase lag of temperature gradient the difference becomes quite significant,especially for the large Knudsen number.In addition,the effect of the surface accommodation coefficient,which is a parameter in the slip boundary condition,on the temperature field of the gold film heated by ultra-fast laser pulses is investigated based on the DPL model.