弦振泛频分析及演奏中的泛音

根据弦振驻波的规律,证明了弦乐器振动中各次振动的振幅递减之规律,给出了演奏中准确的泛音触弦位置,揭示了拉弦类乐器泛音的物理本质,是设计扩展音域、增加自然泛音的理论根据。     

套管外压挤毁强度分析与计算

在对大量的套管全尺寸挤毁试验结果分析的基础上，提出套管外压失稳机理：实际工程中的套管截面不是理想圆，在外压作用下的非圆套管圆周方向上环向应力分布不均匀，有附加弯矩效应；随外压增加，在最大压缩环向应力处达到屈服；当屈服逸到一定程度时，材料由于强度承载力不足而失效，导致套管发生失稳挤毁。基于上述套管强度挤毁准则，分析了理想弹塑性套管在轴向载荷作用下的抗挤强度计算方法，得到较保守的套管挤毁压力计算公式。与试验结果对比表明：导出的计算公式偏差较小，计算精度满足工程要求，失稳强度准则是适用的。     

Efficient preparation of mesocarbon microbeads by pyrolysis of coal-tar pitch in the presence of rosin

Mesocarbon microbeads (MCMB) were prepared by pyrolysis of coal-tar pitch in the presence of rosin, and characteristics of the pitch-rosin mixtures and the MCMB were studied. Pyrolysis behavior of the pitch-rosin mixtures was investigated by thermogravimetric analysis (TGA), and chemical structures of the pyrolysated pitch-rosin mixtures were studied using Fourier transform infrared spectroscopy (FTIR) technique. Optical textures of the pyrolysated pitch-rosin mixtures were characterized by polarized-light microscopy. In addition, morphologies and microstructures of the MCMB, extracted from the pyrolysated pitch-rosin mixtures, were studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Results show that the rosin addition contributes to a notable increase of MCMB yield as well as a decrease in the aromaticity index of the pyrolysated pitch-rosin mixtures. Moreover, the pyrolysis conditions have great effect on the morphologies and yields of MCMB. When the pitch-rosin mixtures are pyrolysated at 450 °C for 1.5-2.5 h, the MCMB yields arrive at 33.8-54.6 wt.% of the pyrolysated pitch-rosin mixtures.     

交联萘沥青的组成与结构特征

萘与硫在较低温度下交联聚合，制得了可溶性好、残炭值高、软化点较低，流动性良好的交联萘沥青。结构分析发现，此沥青分子量分布较窄，主要由三到四个萘分子交联而成，推测其反应机理，估计聚合物经萘环侧位交联成环而形成长链状硫杂环类结构。     

Irreversible helix rearrangement from Cis‐transoid to Cis‐cisoid in poly(p‐n‐hexyloxyphenylacetylene) induced by heat‐treatment in solid phase

Polymerization of p‐n‐hexyloxyphenylacetylene (pHPA) by using a [Rh(norbornadine)Cl]₂‐triethylamine catalyst was carried out at room temperature to afford stereoregular helical poly(p‐n‐hexyloxyphenylacetylene)s (PpHPAs). When ethanol and n‐hexane were used as polymerization solvents, a bright yellow PpHPAs, poly( Y ) with M_n = 8.5 × 10⁴ and its purple red polymer, poly( R ) with M_n = 5.3 × 10⁴ were obtained in 95% yields and 84% yields, respectively. Diffuse reflective UV–vis spectra of poly( Y ) and poly( R ) in solid phase showed different broad absorption peaks at 445 and 575 nm, respectively. X‐Ray diffraction patterns of poly( Y ) and poly( R ) showed typical columnar structures assignable to cis‐transoid and cis‐cisoid structures, respectively, which were also supported by molecule mechanics calculation. Poly( Y ) was irreversibly transformed to a reddish‐black polymer, poly( Y‐B ), which columnar diameter was nearly the same as that of poly( R ). Further, poly( Y ) showed an exothermic peak in the differential scanning calorimetry trace at 80 °C for 1 h in N₂ gas. Thus, these findings suggest a thermally irreversible rearrangement from an unstable cis‐transoid form, poly( Y ) with a stretched cis‐transoid helix to a stable cis‐cisoid form, poly( R ), with a contracted cis‐cisoid helix in the solid phase to give poly( Y → B ) with the cis‐cisoid form. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

奥里乳化油与孤岛油掺炼生产重交通道路沥青技术

将奥里乳化油与孤岛原油混炼生产重交通道路沥青，既缓和了乳化油的破乳脱水条件，又改善了所生产沥青的性质。实验室及工业试验研究结果表明，两种原油以不同比例混合可以生产符合ＳＨ０５２２９２的１００号道路沥青和ＧＢ／Ｔ１５１８０及ＪＴＪ０５２９３的重交通道路沥青系列产品，产品质量达到国际同类产品先进水平。     

煤沥青改质非等温动力学研究

The non-isothermal kinetics for mesophase transformation of Baogang-I coal tar pitch (I-CTP), soft pitch consisted of I-CTP and 18% phenanthrene residue oil (PRO) or I-CTP and 30% PRO have been studied in a thermal conversion unit. Kinetic parameters were calculated by using an integral method. Results showed that the process of mesophase pitch transformation could be described in first order reaction. The activation energy of I-CTP is 175.36kJ/ mol. But adding 30% PRO, which improved the reactivity of I-CTP with activation energy is 138.07kJ/mol, is not beneficial to mesophase transformation.     

四辊中板轧机钢板波浪生成与抑制之六--辊系偏移距的确定

首次考虑摩擦弯矩和附加弯矩对辊系稳定性的影响，建立了四辊轧机辊系最佳偏移距模型。     

四辊中板轧机钢板波浪生成与抑制之四--确定影响辊系稳定性的附加弯矩

建立了附加弯矩模型．该模型提出，在确定辊系偏移距时，应考虑附加弯距的影响；减少万向接轴的倾角，可以提高辊系的稳定性，从而给确定辊系最佳偏移距提供了理论基础．     

基于FIR滤波器的基音提取预处理

基音周期是语音信号的重要参数，在语音分析、语音合成和语音识别中，估计基音周期都是一个重要任务。基于MATLAB设计的FIR滤波器，可以随时对比设计要求和滤波器特性调整参数，直观简便，极大的减轻了工作量，使滤波器设计最优化，在语音信号基音提取预处理方面具有精度高、稳定性好、灵活性强等优点，滤波效果较好。把其应用于基音提取预处理将为基音提取后继工作打下良好基础。