SrFeO3-x可见光下降解亚甲基蓝的光催化性能研究

采用水热及柠檬酸法相结合的方法,制备了钙钛矿型复合氧化物SrFeO3-x(0＜x＜0.5)光催化剂.用X射线衍射(XRD)、紫外可见漫反射光谱(DRS-UV-Vis)、表面光电压谱(SPS)和场致表面光电压谱(EFISPS)表征制备的SrFeO3-x.以亚甲基蓝(MB)为模拟污染物,在可见光(λ≥430nm)照射下,首次考察了钙钛矿型复合氧化物SrFeO3-x的光催化性能,得到了较好的结果.     

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.     

超短脉冲强激光与固体靶相互作用中Kα射线的实验研究

在相对论激光强度下，对p偏振30 fs激光与固体Cu靶相互作用中产生的Kα射线进行了实验研究.采用刀边成像技术和单光子计数X射线CCD相结合的探测装置，在单发激光脉冲打靶时同时得到X射线源的尺寸、能谱以及Kα光子的转换效率等多种信息.实验结果与Reich等人的理论计算结果有明显的差异，Kα光子的能量转换效率在激光功率密度为1.6×10¹⁸W/cm²的条件下达到最大值7.08×10^-6/sr.根据这一结果并结合蒙特卡罗程序，推断出在这一聚焦光强下激光能量转换为前向超热电子的效率约为10%.     

The thermal properties of Al–Mg–TM (TM = Sc,Zr): Ab initio study

Ab initio density functional theory (DFT) and density function perturbation theory (DFPT) have been used to investigate the thermal properties of the Al–Mg–Sc, Al–Mg–Zr and Al–Mg–Sc–Zr alloys over a wide range of temperature and pressure. Phonon dispersions are obtained at equilibrium and strained configurations by DFPT. Using the quasiharmonic approximation (QHA) for the free energy, several physical quantities of interest such as thermal Grüneisen parameter, heat capacity at constant pressure and at constant volume, thermal expansion coefficient, entropy, adiabatic bulk modulus and isothermal bulk modulus as a function of temperature and pressure are calculated and discussed. The present results show that the thermal expansion coefficient of the Al–Mg–Sc–Zr is far lower than that of Al–Mg–Sc and Al–Mg–Zr, and the variation features in the adiabatic bulk modulus and isothermal bulk modulus for the Al–Mg–Sc–Zr are also very different from that of Al–Mg–Sc and Al–Mg–Zr.     

Analysis of fetal cortical complexity from MR images using 3D entropy based information fractal dimension

The fetal cortical complexity is a significant quantification for assessing the development of fetal brain. This study attempts to quantify the development of fetal cortical complexity using the concept of fractal dimension (FD) analysis. Thirty-two fetal MR images were selected from Taipei Veterans General Hospital at 27–37 weeks of gestational age (GA). To investigate the FD of fetal cortical complexity, the entropy based information fractal dimension method (FD _EBI), which is modified from Box-Counting method, was adopted and extended from 2D to 3D. The FD results from overall whole fetal brains show that the increase of cortical complexity is highly correlated with the gestational age of the fetus. Moreover, the FD values of right hemispheric brain are larger than those of left hemispheric brain, show that the development of right hemispheric fetal cortical complexity earlier than the left. These results are in good agreement with normal fetal brain development and suggest that the FD is an effective means for the quantification of fetal cortical complexity.     

Simulation of plasma doping process by using the localized molecular dynamics method

Plasma doping is the candidate for semiconductor doping. Accurate simulation of the doping technology is needed for the advanced integrated circuit manufacturing. In this paper, the plasma doping process simulation is performed by using the localized molecular dynamics method. Models that involve the statistics of the implanted compositions, angles and energies are developed. The effect of the model on simulation results is studied. The simulation results about the doping concentration profile are supported by experimental data.     

Regioselective reduction of 3-sulfonyl glutarimides to 3,4-dihydro-5-sulfonylpyridin-2-ones. Formal synthesis of the indolizidine 8a-epi-dendroprimine

Sodium borohydride regioselectively reduced various 3-sulfonyl glutarimides 1 to hydroxy piperidones 2, which were further dehydrated to 3,4-dihydro-5-sulfonylpyridin-2-ones 3 in the presence of boron trifluoride. Formal synthesis of 8a-epi-dendroprimine (4) possessing an indolizidine ring system has been accomplished via intramolecular radical cyclization of cyclic vinyl sulfone 5.     

Left ventricular 4D echocardiogram motion and shape analysis

The article describes the methodology and the processes of modeling the function and the motion of left ventricle using transesophageal echocardiograph. The parameters can be used in studying the functionality of left ventricle, the status of abnormality of myocardial, and the geometric and morphological of left ventricle in shape analysis. The parameters describes the motion of left ventricle are the left ventricular (LV) floating long axis, the morphological parameters. The LV morphological parameters describe the wall motion, the LV chamber cavity variation, the effective R-ratio of endomyocardial chamber of LV, the area surface curvature, and the global surface curvature circularity. The parameters such as stroke volume, ejection fraction used in evaluation of LV functions are also extracted.     

Talagrand＇s T2-transportation Inequality w.r.t, a Uniform Metric for Diffusions

Using the method of Girsanov transformation, we establish the Talagrand‘s T2-inequality for diffusion on the path space C([0, N], R^d) with respect to a uniform metric, with the constant independent of N. This improves the known results for the L2-metric.     

两种气液两相流模型的应用和比较

本文应用MUSIG模型[1]和均一直径模型对某溶液堆台架模型堆芯内气液流动传热进行了数值模拟.在MUSIG模型中堆芯内离散相气泡被分为5组不同直径的气泡,用于分析堆芯内气泡的流动变化和大小分布,采用Luo and Svendsen[2]和Prince and Blanch[3]模型描述不同直径气泡组间的破裂和聚合.在均一直径模型中,堆芯内的气体被考虑为同一直径的组分,并且不考虑其破裂与聚合现象.计算得到采用两个模型的模拟结果并且对其进行了对比研究.结果显示应用MUSIG模型的计算结果与台架实验结果吻合更好.