13.56 MHz/2 MHz柱状感性耦合等离子体参数的对比研究

通过Langmuir双探针和发射光谱诊断方法,对比研究了驱动频率为13.56 MHz和2 MHz柱状感性耦合等离子体中电子密度和电子温度的径向分布规律.结果表明:在高频和低频放电中,输入功率的增加对等离子体参数产生了不同的影响,高频放电中主要提升了电子密度,低频放电中则主要提升了电子温度.固定气压为10 Pa,分别由高频和低频驱动时,电子密度的径向分布均为"凸型".而电子温度的分布差异比较明显,高频驱动时,电子温度在腔室中心较为平坦,在边缘略有上升;低频驱动时,电子温度随径向距离的增加而逐渐下降.为了进一步分析造成这种差异的原因,在相同放电条件下采集了氩等离子体的发射光谱图,利用分支比法计算了亚稳态粒子的数密度,发现电子温度的径向分布始终与亚稳态粒子的径向分布相反.继续升高气压到100 Pa,发现不论高频还是低频放电,电子密度的径向分布均从"凸型"转变为"马鞍形",较低气压时电子密度的均匀性有了一定的提升,但低频的均匀性更好.     

ComBn(m+n≤6)团簇的结构，电子特性和磁性研究

基于密度泛函理论和卡里普索结构预测方法,系统研究了ComBn(m+n≤6)团簇的结构,电子特性和磁性。首先,通过卡里普索结构预测方法获得了体系的基态和亚稳态结构。基于基态结构,利用HOMO-LUMO能隙,垂直电离势,垂直电子亲和势和化学硬度分析了掺杂体系的稳定性。最后,研究了基态结构对应的自然布局分布,自然电子组态等电子特性和磁性。     

一种新的基于频域有限差分方法的小周期有机太阳能电池的光电特性

由MoO₃/Ag/MoO₃ （MAM）组成的多层膜结构非常有希望替代ITO作为有机太阳能电池中的透明阳极.然而,基于MAM结构的有机太阳能电池光吸收能力较弱.为此,引入了一种小周期短节距金属光栅,利用表面等离子激元增强活性层的光吸收.借助于频域有限差分方法求解麦克斯韦方程和半导体方程,探讨了有机太阳能电池结构的光学和电学性质.分析结果表明：与平面结构相比,活性层中的光吸收大大提高;同时,当凹槽宽度为4 nm,能量转换效率提高了49%.相关结果有助于更好地开发和利用无ITO层的有机太阳能电池.     

Vertical assembly of carbon nanotubes for via interconnects

The via interconnects are key components in ultra-large scale integrated circuits(ULSI).This paper deals with a new method to create single-walled carbon nanotubes(SWNTs) via interconnects using alternating dielectrophoresis(DEP).Carbon nanotubes are vertically assembled in the microscale via-holes successfully at room temperature under ambient condition.The electrical evaluation of the SWNT vias reveals that our DEP assembly technique is highly reliable and the success rate of assembly can be as high as 90%.We also propose and test possible approaches to reducing the contact resistance between CNT vias and metal electrodes.     

Two localized CO2 laser treatment methods for mitigation of UV damage growth in fused silica

Two methods：high-power,short-time,single-shot irradiation（Method A） and low-power,long-time,multi-shot irradiation（Method B） are investigated to mitigate the UV damage growth in fused silica by using a 10.6-μm CO2 laser.To verify the mitigation effect of the two methods,the laser induced damage thresholds（LIDTs） of the mitigated sites are tested with a 355-nm,6.4-ns Nd：YAG laser,and the light modulation of the mitigation sites are tested with a 351-nm continuous Nd：YLF laser.The mitigated damaged sites treated with the two methods have almost the same LIDTs,which can recover to the level of pristine material.Compared with Method A,Method B produces mitigated sites with low crater depth and weak light modulation.In addition,there is no raised rim or re-deposited debris formed around the crater edge for Method B.Theoretical calculation is utilized to evaluate the central temperature of the CO2 laser beam irradiated zone and the radius of the crater.It is indicated that the calculated results are consistent with the experimental results.     

Topological aspect of Chern--Simons p-branes

By generalizing the topological current of Abelian Chern--Simons (CS) vortices, we present a topological tensor current of CS p-branes based on the \phi -mapping topological current theory. It is revealed that CS p-branes are located at the isolated zeros of the vector field \phi(x), and the topological structure of CS p-branes is characterized by the winding number of the \phi-mappings. Furthermore, the Nambu--Goto action and the equation of motion for multi CS p-branes are obtained.     

甲醇在γ-Al2O3,CeO2及其负载Pd催化剂上吸附和分解的原位红外光谱研究

利用原位傅里叶变换红外光谱 (FTIR)技术对甲醇在γ Al2 O3,CeO2 以及Pd/Al2 O3,Pd/CeO2 催化剂上的吸附和分解行为进行了研究。综合考虑了载体和活性组分的作用 ,分析了甲醇在不同载体负载Pd催化剂上可能的分解途径。在Pd/CeO2 催化剂上 ,活性组分和载体对甲醇分解的过程表现出了一种协同效应。     

A snapback suppressed reverse-conducting IGBT with uniform temperature distribution

A novel reverse-conducting insulated-gate bipolar transistor(RC-IGBT) featuring a floating P-plug is proposed. The P-plug is embedded in the n-buffer layer to obstruct the electron current from flowing directly to the n-collector, which achieves the hole emission from the p-collector at a small collector size and suppresses the snapback effectively. Moreover, the current is uniformly distributed in the whole wafer at both IGBT mode and diode mode, which ensures the high temperature reliability of the RC-IGBT. Additionally, the P-plug acts as the base of the N-buffer/P-float/N-buffer transistor, which can be activated to extract the excessive carriers at the turn-off process. As the the simulation results show, for the proposed RC-IGBT, it achieves almost snapback-free output characteristics with a uniform current density and a uniform temperature distribution, which can greatly increase the reliability of the device.     

Theoretical description of improving measurement accuracy for incoherence Mie Doppler wind lidar

For the nonlinearity of Fabry-Perot interferometer(FPI) transmission spectrum,the measurement uncertainty of incoherent Mie Doppler wind lidar based on it increases evidently with the increase of backscattering signal Doppler shift.A method of repeating the use of the approximate linear part of FPI transmission spectra for reducing the high uncertainty of a big Doppler shift is proposed.One of the ways of realizing this method is discussed in detail,in which the characteristics of FPI transmission spectrum changing with thickness and incident angle are utilized simultaneously.Under different atmosphere conditions,it has been proved theoretically that the range of measurement uncertainty drops to one-sixth while its minimum has no serious change.This method can be used not only to guide the new system design,but also as a new working way for the fabricated system.     

荞麦花多糖的提取及含量测定

采用热水提取、乙醇沉淀的方法从荞麦花中提取出了水溶性多糖,采用硫酸-苯酚法在波长为497nm处进行了糖含量的测定,求得其校准曲线的回归方程为y=0.00508x 0.0294,相关系数为r=0.9978.平均回收率为99%-103%,RSD为0.74%.结果显示:荞麦花多糖的产率为2.5%.糖含量为41.63%.