Feedforward Control of a 3-D Physiological Articulatory Model for Vowel Production

A three-dimensional (3-D) physiological articulatory model was developed to account for the biomechanical properties of the speech organs in speech production. Control of the model to investigate the mechanism of speech production requires an efficient control module to estimate muscle activation patterns, which is used to manipulate the 3-D physiological articulatory model, according to the desired articulatory posture. For this purpose, a feedforward control strategy was developed by mapping the articulatory target to the corresponding muscle activation pattern via the intrinsic representation of vowel articulation. In this process, the articulatory postures are first mapped to the corresponding intrinsic representations; then, the articulatory postures are clustered in the intrinsic representations space and a nonlinear function is approximated for each cluster to map the intrinsic representation of vowel articulation to the muscle activation pattern by using general regression neural networks (GRNN). The results show that the feedforward control module is able to manipulate the 3-D physiological articulatory model for vowel production with high accuracy both acoustically and articulatorily.     

广西保护区淡水鱼类的联系及分布

记录了广西木伦等6个保护区的鱼类72种,并应用弦距离系数比较了6保护区内水系的联系程度。6保护区的鱼类区系以老第三纪原始类群后裔种类为主,此外,还有东亚特有江河平原鱼类,南亚暖水性类群鱼类。云跺高原东部种类也有分布,除木伦保护区鱼类属东洋区南亚亚区的云贵高原鱼类外,其余的保护区属南东亚亚区华南小区。     

High-temperature ultrafast polariton parametric amplification in semiconductor microcavities.

Cavity polaritons, the elementary optical excitations of semiconductor microcavities, may be understood as a superposition of excitons and cavity photons. Owing to their composite nature, these bosonic particles have a distinct optical response, at the same time very fast and highly nonlinear. Very efficient light amplification due to polariton-polariton parametric scattering has recently been reported in semiconductor microcavities at liquid-helium temperatures. Here we demonstrate polariton parametric amplification up to 120 K in GaAlAs-based microcavities and up to 220 K in CdTe-based microcavities. We show that the cut-off temperature for the amplification is ultimately determined by the binding energy of the exciton. A 5-micrometer-thick planar microcavity can amplify a weak light pulse more than 5,000 times. The effective gain coefficient of an equivalent homogeneous medium would be 107 cm-1. The subpicosecond duration and high efficiency of the amplification could be exploited for high-repetition all-optical microscopic switches and amplifiers. 105 polaritons occupy the same quantum state during the amplification, realizing a dynamical condensate of strongly interacting bosons which can be studied at high temperature.     

含叠氮硝胺的低特征信号推进剂的热分解研究

应用高压ＤＳＣ（差示扫描量热法）、ＴＧ（热重法）和ＤＴＧ（差示热重法）了ＤＡＴＨ（１,７－二叠氮－２,４,６－三硝基氮杂庚烷）、ＲＤＸ（黑索金）单组分以脑ＲＤＸ－ＣＭＤＢ（复合改性双基推进剂）和ＣＤＡＴＨ－ＲＤＸ－ＣＭＤＢ推进剂样品的热分解,温度达２００℃时,首先暗ＤＡＴＨ中３个－ＮＯ２从主链上断裂分解,接着是一Ｎ３和其他残余分子在较短的时间剧烈地分解并释放出大量的热,在多组分体系中,ＤＡＴＨ与（     

基于Volterra基函数网络的自适应逆控制方法

提出了一种基于Ｖｏｌｔｅｒｒａ基函数（ＶＰＢＦ）网络的非线性系统自适应逆控制方法。对象和逆控制器各用一个ＶＰＢＦ网络表示,应用正交最小二乘算法进行离线网络结构确定和权值初始化,构造了一种动态归一化非线性最小均方（ＤＮＮＬＭＳ）权值更新算法,以进行网络权值的在线学习。仿真结果表明,该方法具有算法简单、学习速度快、鲁棒性能好等优点。     

华北板块北缘中段中元古代晚期花岗岩类特征及其构造意义

华北板块北缘出露的中元古代晚期花岗岩主要为黑云母花岗岩和二长花岗岩,化学上富SiO₂和K₂O, 贫FeO、CaO、MgO和TiO₂,A/CNK平均大于1.1,具过铝质花岗岩特征。微量元素Nb、Sr、P、Ti相对亏损,而Rb、K、Ta、Nd相对富集;轻重稀土较强分馏,其(La/Yb)_N=6.61～64.31,负铕异常明显,具有碰撞成因S型花岗岩特征。花岗岩呈东西向带状展布,并与北侧白乃庙（白乃庙群）和阜新旧庙（魏家沟岩群）中元古代古岛弧链及开原蛇绿混杂岩带平行,这表明该区中元古代晚期存在一个强烈的俯冲碰撞造山过程,这一碰撞造山事件为华北板块在Rodinia超大陆的拼合模式提供了最基本的制约条件。     

分层遗传算法在DC/DC变换器中的应用

DC／DC变换器为强非线性、时变及不确定系统．由于其自身的特点,使得DC／DC变换器的控制研究工作比较困难．文中提出一种用遗传算法优化的模糊控制器,控制DC／DC变换器．对传统的遗传算法进行改进．使之优化能力更好．由仿真和实际试验证明,经过改进的遗传算法优化的模糊控制器,对DC／DC变换器的控制效果更显著,动态特性和静态特性都得到进一步改善．同时说明所介绍的自适应遗传算法的寻优能力更好,收敛速度也更快．     

计算机多点温度实用检测系统的设计

设计一种以89C52为核心的实用新型计算机温度采集系统．它采用J类热电偶作为测温元件,利用集成电流的温度传感器AD590,实现热电偶冷端温度的有效补偿,从而提高系统的精度、稳定性和抗干扰性能．该系统主要从工程实际出发,对元件选择、电路设计等方面进行研究．在给出核心硬件电路的同时,提出可对多路数据作采集、处理并实现报警功能的可拓展电路．实现了低成本、远距离传输温度巡回检测。     

五台山晚太古代花岗岩的成因及其动力学意义

五台山晚太古代花岗岩（～2.540 Ga）,主要由花岗闪长岩、二长花岗岩、少量的英云闪长岩、奥长花岗岩组成,全岩化学分析表明它们具有中～高钾钙碱性花岗质岩浆性质,LILE富集和高的 w(Rb)/w(Sr) (即: Rb/Sr)比值,相对较低的 w(Sr)/w(Y)、w(La)_n/w(Yb)_n、w(Nb)/w(Ta) 和 w(Zr)/w(Hf) 比值,右斜式稀土配分模式,Nb、Ta、Ti亏损,但是它们均表现了Nd T_DM＝2.54～2.72 Ga和明显的正ε_Nd(t)值。这些地球化学特征表明其钙碱性花岗质岩浆形成于晚太古代大洋岛弧环境,来源于弧下玄武质初生地壳的部分熔融,并经历了一定程度的结晶分异。由于晚太古代洋壳向大洋岛弧俯冲、脱水,引起上覆地幔楔的部分熔融形成弧下初生地壳玄武质物质,这些弧下玄武质物质在少于37km环境下部分熔融形成五台山晚太古代钙碱性花岗质岩浆。     

轮胎垂直方向刚性环模型

为研究轮胎在中等频率时的垂向力学特性,建立了垂直方向上的刚性环模型,对1/4车模型进行了振型分析,说明刚性环模型能反映中频时的振动。简单介绍了模型输入和轮胎动态特性试验,并将模型和试验结果进行了对比,表明垂直方向刚性环模型能较好反映轮胎在典型短波长不平路面上垂直方向上的力学特性。