镍基单晶高温合金界面位错网在剪切载荷作用下的演化

运用分子动力学方法,研究了镍基单晶高温合金γ/γ' 相界面错配位错网在剪切载荷作用下的演化特征.结果表明:(100),(110) 和 (111) 三种相界面形成的位错网在载荷作用下有不同形式和不同程度的损伤,其变形和损伤随温度的增加而增加.在相同的剪切载荷和温度作用下,(100) 相界面形成的正方形位错网最稳定. 关键词： 镍基单晶高温合金 界面位错网 分子动力学     

Potential Distribution and Transmission Characteristics in a Curved Quadrupole Ion Guide

The potential distribution in the curved quadrupole is exactly characterized by the Laplace equation, and an approximate solution to the Laplace equation is calculated. We represent the Laplace equation under the coordinates named minimal rotation frame (MRF) and derive an expression on the hexapole and octopole superposition. Our conclusion is in agreement with the results by the numerical (SIMION) method. Based on the Poincare-Lighthill-Kuo (PLK) method reported in our previous work, the nonlinear effects of ion motion are investigated in detail. The frequency shift of ion motion can be well eliminated by coupling the hexapole component with a positive octopole component, and the transmission efficiency of ions is found to decrease dramatically with the increase of the ionic kinetic energy in the z-direction. Furthermore, the transmission characteristics of ions are discussed with regards to the phase-space theory. The results show that the centrifugally introduced axis shift is mainly responsible for the ion losses. A modified direct current (dc) voltage supply pattern is hence proposed to compensate for this effect.     

The development of charge detection-quadrupole ion trap mass spectrometry driven by rectangular and triangular waves

In this article, the charge detection quadrupole mass spectrometry (CD-ITMS) driven by rectangular and triangular waveforms (rect-CD-ITMS and tri-CD-ITMS) was developed for the characterization of microparticles. Since the frequency scan of rectangular and triangular waveform could be realized easier than that of sinusoidal waveform, this research intends to provide simpler operation modes for CD-ITMS. In order to demonstrate the feasibility of rect-CD-ITMS and tri-CD-ITMS, the discharge onset voltage, ejection point of analyzed particles, and the achieved mass resolution were analyzed and compared with the case in conventional sinusoidal CD-ITMS (sin-CD-ITMS). The results indicated that the rect-CD-ITMS and tri-CD-ITMS can work well for the mass measurement of microparticles by using frequency scan. Identical mass resolutions were achieved under the same root mean square (RMS) voltage of different waveforms. The mass resolution was further improved by increasing the applied voltage and signal-to-noise ratio (S/N) of charge detector. Moreover, the rect-CD-ITMS and tri-CD-ITMS were applied to characterize red blood cells (RBCs). According to the obtained mean masses and mass distributions, normal and anemic RBCs were distinguished successfully.     

受激布里渊散射的线宽压缩及时间相干性

首先从实验上研究了受激布里渊散射(SBS)的线宽压缩效应. 发现线宽压缩直接受到脉宽压缩的影响. 进而提出了一种通过测量SBS脉宽来测量SBS线宽的新方法. 在此基础上, 详细讨论了SBS的时间相干性, 指出 SBS的时间相干性不是固定不变的, 而是随线宽压缩的程度发生变化. 最后指出 SBS的脉宽压缩率和时间相干性不能同时达到最佳值.     

不同趋势对滑动移除近似熵的影响

许多观测资料中存在着各种各样的趋势,如季节变化引起的周期性趋势、全球变暖所造成的线性趋势、多项式趋势等.鉴于此,本文研究了各种趋势对滑动移除近似熵的影响.数值试验结果表明,周期性趋势、线性趋势及非线性趋势均对滑动移除近似熵的突变检测结果影响较小,论证了滑动移除近似熵方法检测突变的可靠性,为该方法在实际观测资料中的广泛应用提供了实验基础.     

旱涝预测的演化建模方法

发展了一种旱涝预测的演化建模方法, 数值试验结果表明, 该方法能够从历史资料中准确地挖掘出气候要素演化的主要动力学特征, 所建立的模型不仅能够较好地模拟要素的历史演变情况, 而且还能够对未来的演变趋势进行准确的预测. 对于演化建模所得到的误差较大的模型, 对其预测误差序列进行二次演化建模可明显提高模型的预测精度.     

A Blind Quantum Signature Scheme with χ-type Entangled States

A blind quantum signature scheme with χ-type entangled states is proposed, which can be applied to E-voting system. In this scheme, the particles in χ-type state sequence are used for quantum key distribution first, and then for quantum signature. Our scheme is characterized by its blindness, impossibility of forgery, impossibility of disavowal. In addition, our scheme can perform an audit program with respect to the validity of the verification process in the light of actual requirements. The security of the scheme is also analyzed.     

2′-(2-噻吩亚甲基)-2-羟基苯甲酰腙钴(Ⅲ)配合物的合成、表征及晶体结构

In ethanol, a mononuclear cobalt(Ⅱ) complex incorporating 2′-(2-Thienylidene)-2-Hydroxybenzoylhydra-zide has been synthesized and characterized by IR, UV-Vis, elemental analysis and X-ray crystal structure analysis. The crystal belongs to triclinic system, space group P1 with cell constant, a=1.230 69(10) nm, b=1.329 18(11) nm, c=1.330 56(11) nm, α=113.702(2)°, β=91.590(2)°, γ=100.846(2)°, V=1.944 4(3) nm³, Z=2, μ=0.662 mm^-1, D_c=1.482 g·cm^-3, F(000)=896, R_int=0.048 7. The crystal structure shows an anionic didentate ligand O and N donors in this work. The cobalt(Ⅲ) atom is hexacoordinated with oxygen atom from keto group and nitrogen atom from amide to form a cobalt atom for the core octahedral structure. CCDC: 748882.     

机翼后缘噪声预测研究

机翼后缘噪声是飞机重要的机体噪声源之一。本文基于CFD(Computational Fluid Dynamic)数值模拟和Ffcows Williams-Hall理论,研究应用了一种预测干净机翼后缘气动噪声的方法。采用Menter’s SSTκ-ω湍流模型对翼型和机翼进行N-S方程数值模拟得到后缘附近的湍流特征速度和特征长度,再利用Serhat Hosder的预估方法计算后缘噪声强度级。本文首先计算了NACA0012翼型在7种不同状态的后缘噪声,计算结果与实验值比较,符合很好,从而证明了本文采用的方法的可行性和正确性;然后研究了两个亚音速翼型(NACA 0009,NACA 0012),两个超临界翼型(SC(2)- 0710,SC(2)-0714),EET机翼的不同参数对后缘噪声强度级的影响,得出了对降低后缘噪声有参考意义的结论。     

特殊三反射镜太赫兹波段准光腔回旋管的动力学理论

基于回旋管线性理论,运用Laplace变换和留数定理的方法,在线性Vlasov-Maxwell方程组的框架下,研究了特殊三反射镜准光腔回旋管的动力学理论.导出了注-波互作用功率、频偏和起振电流公式,运用MATLAB进行了数值运算.结果表明,这种回旋管工作于高次谐波状况下能有较高的互作用功率,具有工作于太赫兹波段的潜力. 关键词： 三反射镜准光腔 太赫兹 回旋动力学理论