Investigation of charge effects on poling and stability for corona-poled polymer films

The optimal corona-poling temperature of polymer films was accurately determined by measuring the temperature dependence of the in situ second-harmonic (SH) intensity profile under the applied poling electric field. The in situ SH intensity profile was first measured by probing both the surface voltages and the poling currents induced by surface/space charges for the corona-poled polymer films. Moreover, charge effects on the stability of the chromophore orientation were first studied by using the thermally stimulated discharge-current technique. PACS 72.20.Jv; 42.65.Ky; 73.61.Ph; 81.40.Tv     

MULTIPLICATION OF WEAK FUNCTIONS

This paper is a contionuation of [1] and is concerned with multiplication of weak functions. Here the weak functions are treated as generalized expansions in Hermite functions in [2].     

Imprinting by hot embossing in polymer substrates using a template of silica glass surface-structured by the ablation of LIBWE method

Laser-induced backside wet etching (LIBWE) of silica glass plates was performed to fabricate an imprinting template for hot embossing in polymer substrates such as polystyrene and silicone resin. Well-defined inverse surface-micropatterns of gratings and grid arrays on the substrates were produced by the hot embossing using a surface-structured silica glass as the template. These results indicate that the LIBWE method allows us to generate robust glass molding tools that exhibit the inverse shapes of the intended microstructures. PACS 52.38.Mf; 68.47.Mn; 81.05.Kf; 81.05.Lg; 83.50.Uv     

HL－1装置辅助加热等对能量约束的影响

在ＨＬ－１托卡马克上进行了辅助加热、加料、电流驱动的物理实验研究。在改善等离子体约束方面，某些实验取得了较好的结果。在适当的稳定放电条件下，低杂波电流驱动和弹丸注入辅助加料，均能使等离子体能量约束得到一定程度的改善，与相同密度条件下的欧姆加热放电相比，能量约束时间提高了约３０％。在电子回旋共振加热等离子体实验中，等离子体总能量明显增加，但与相同密度条件下的欧姆加热放电相比，能量约束时间减少了约２０％。     

X-ray absorption spectra of plasmas

In this paper we present a theoretical method to calculate the absorption spectra of hot dense plasmas. Based on our fully relativistic treatment incorporated with the quantum defect theory to handle the huge number of transition arrays from many configurations with high principal quantum number, we can calculate the absorption spectra for any element or multi-element plasmas with little computational efforts. We calculate the absorption spectra of C10H1605 plasmas, which are in good agreement with the experimental spectra. We can then provide diagnostic analysis for plasmas in relevant inertial confinement fusion (lCF) experiments; namely not only to determine plasmas' temperatures and densities, but also to provide the population densities of various ionic stages. Our theoretical method verified by "benchmark experiments" will be a basic tool to provide "precise" opacity data for the ICF research.``     

Boiling heat transfer characteristics of nanofluids in a flat heat pipe evaporator with micro-grooved heating surface

An experimental study was performed to understand the nucleate boiling heat transfer of water–CuO nanoparticles suspension (nanofluids) at different operating pressures and different nanoparticle mass concentrations. The experimental apparatus is a miniature flat heat pipe (MFHP) with micro-grooved heat transfer surface of its evaporator. The experimental results indicate that the operating pressure has great influence on the nucleate boiling characteristics in the MFHP evaporator. The heat transfer coefficient and the critical heat flux (CHF) of nanofluids increase greatly with decreasing pressure as compared with those of water. The heat transfer coefficient and the CHF of nanofluids can increase about 25% and 50%, respectively, at atmospheric pressure whereas about 100% and 150%, respectively, at the pressure of 7.4 kPa. Nanoparticle mass concentration also has significant influence on the boiling heat transfer and the CHF of nanofluids. The heat transfer coefficient and the CHF increase slowly with the increase of the nanoparticle mass concentration at low concentration conditions. However, when the nanoparticle mass concentration is over 1.0 wt%, the CHF enhancement is close to a constant number and the heat transfer coefficient deteriorates. There exists an optimum mass concentration for nanofluids which corresponds to the maximum heat transfer enhancement and this optimum mass concentration is 1.0 wt% at all test pressures. The experiment confirmed that the boiling heat transfer characteristics of the MFHP evaporator can evidently be strengthened by using water/CuO nanofluids.     

Convergence of the fractional step Lax-Friedrichs scheme and Godunov scheme for the isentropic system of gas dynamics

A convergence theorem of the fractional step Lax-Friedrichs scheme and Godunov scheme for an inhomogeneous system of isentropic gas dynamics (1<5/3) is established by using the framework of compensated compactness. Meanwhile, a corresponding existence theorem of global solutions with large data containing the vacuum is obtained.Partially supported by U.S. NSF Grant # DMS-850403     

新显色剂对羧基苯基重氮氨基偶氮苯的合成及与镉显色反应的研究

本文报道了新色剂对羟基苯基重氮氨基偶氮苯的合成。