高温超导体Josephson阵列在磁场中的微波响应与磁通涡旋激发

本文从分析相变电阻率 ρP 和磁通蠕动电阻率 ρF 出发 ,指出当T小于某一温度T0 时 ,ρF>ρP,而当T >T0 时 ,ρF 远小于 ρP,并进一步分析了 ρF 与 ρP 随温度的变化率分布图 ,得出磁通蠕动电阻率 ρF 随温度的变化率分布图跟微波响应曲线具有相似的分布特征 ,结果表明 :高温超导体的非平衡微波响应机制可能与磁通涡旋的激发有关 .     

激光诱导间质肿瘤热疗的数值模拟和实验研究

本文在考虑生物组织物性动态变化的情况下建立了激光诱导间质肿瘤热疗(LITT)的物理数学模型,采用MonteCarlo方法数值模拟了LITT中激光能量在生物组织内的传输过程,基于Pennes生物传热方程和Arrhenius方程数值求解了组织内的温度分布和热损伤体积的变化,分析了热物性及血液灌注率的动态变化对LITT过程的影响,并与相应的离体实验结果进行了对比。数值模拟结果表明,组织的热物性及血液灌注率的动态变化对于热损伤体积的变化具有重要的影响。因此在激光诱导间质肿瘤热疗的数值模拟中应该考虑热物性及血液灌注率的动态变化以期为临床治疗方案的制定提供更为准确的依据。     

宇宙具有十二面体形状

 在从观测宇宙微波背景的Wilkinson微波各向异性探测器(WMAP)获得的数据基础上,美国数学家计算出,宇宙多半最终会具有十二面体形状。进行的是反证法:如果宇宙是无限的,则在微波背景上应观察到任何大小的波,但是实际上不是这样:Wilkinson微波各向异性探测器确实一次也没有观测到巨大的波。根据以杰弗里·威克斯(JeffreyWeeks)博士为首的数学家小组的计算,在宇宙微波背景上的波看上去完全像从规则几何形状十二面体内部看到的一样。其实,其他专家也证实,在其他几何形状内部也能产生类似的波结构。     

Microwave Synthesis, Characterization and DNA-binding Properties of a New Cobalt（ Ⅱ ） Complex with 2,6-Bis（benzimidazol-2-yl）pyridine

A new cobalt(Ⅱ) complex with tridentate ligand 2, 6-bis (benzimidazol-2-yl)pyridine has been synthesized by microwave irradiation method and characterized by elemental analysis,electrochemical and spectral methods. The binding of the complex with calf thymus DNA has also been investigated by absorption and fluorescence spectra.     

Fabrication of Zeolite A Rods with Irregular Macropores by Self-assembly of Zeolite A Microcrystals Using Microwave-assisted Hydrothermal Synthesis

Zeolite A rods by self-assembly of zeolite A microcrystal were successfully synthesized by microwave-assisted hydrotherrnal synthesis. The average size of zeolite crystals consisting of self-assembling materials was about 300 nm and the length of zeolite rods was in the range of 15--30μm.     

Microwave-promoted Palladium Catalyzed Suzuki Cross-coupling Reaction in WaterI

A simple, rapid and environmental friendly method for the synthesis of biaryl compounds under microwave irradiation is reported.     

Structure and Photoluminescence of Nano-ZnO Films Grown on a Si （100） Substrate by Oxygen- and Argon-Plasma-Assisted Thermal Evaporation of Metallic Zn

Nano-ZnO thin films were prepared by oxygen- and argon-plasma-assisted thermal evaporation of metallic Zn at low temperature, followed by low-temperature annealing at 300℃ to 500℃ in oxygen ambient. X-ray diffraction patterns indicate that the nano-ZnO films have a polycrystalline hexagonal wurtzite structure. Raman scattering spectra demonstrate the existence of interface layers between Zn and ZnO. Upon annealing at 400℃ for i h, the interface mode disappears, and photoluminescence spectra show a very strong ultraviolet emission peak around 381 nm. The temperature-dependent PL spectra indicate that the UV band is due to free-exciton emission.     

微波反馈振荡器分析与设计

利用小信号S参数对串联反馈微波振荡器进行了分析,并给出设计方法。该方法对微波点频式压控振荡器的设计十分有效,且便于工程应用。实验表明,此方法简单有效,对工程技术人员有参考价值。     

YBa2Cu3O7—δ高温超导薄膜微桥结在微波辐照下的响应特性

采用偏轴直流磁控溅射原位生长ＹＢａ２Ｃｕ３Ｏ７－δ高温超导薄膜，以Ｈ３ＰＯ４为腐蚀液，采用化学湿刻工艺制作ＹＢａ２Ｃｕ３Ｏ７－δ高温超导薄膜微桥，微桥长１０μｍ，宽５μｍ，在８ｍｍ微波源的辐照下，除观察到整数常压台阶外，还观察到ｎ＝１／２，１／５，６／５，９／５等分数常压台阶，分数台阶的高度随微波功率的变化较整数台阶更敏感。     

新型微波有源滤波器综合方法

本文给出了一种新颖的微波有源滤波器的拓扑结构及综合方法，并对有源滤波电路进行了计算机模拟，结果表明本文给出的微波有源滤波器电路具有优良的的窄带滤波特性，通带内正向增益大于１０ｄＢ，带外抑制大于３０ｄＢ。