THE ANALYTICAL APPROACH FOR LARGE SCALE NON-CLASSICALLY DAMPED DYNAMIC SYSTEM

This paper gives a dynamic decoupling approach for the analysis of large scale non-classically damped system, in which the complex variable computations were completely avoided not only in solving for the eigenvalue problem but also in the calculation of the dynamic response. The analytical approaches for undamped gyroscopic system, non-classically damped system, including the damped gyroscopic system were unified. Very interesting and useful theoretical results, practical algorithms were obtained which are applicable to both non-defective and defective systems.

A method for stochastic seismic response analysis of non-classically damped structures

A method to calculate the stationary random response of a non-classically damped structure is proposed that features clearly-defined physical meaning and simple expression. The method is developed in the frequency domain. The expression of the proposed method consists of three terms, i.e., modal velocity response, modal displacement response, and coupled (between modal velocity and modal displacement response). Numerical results from the parametric study and three example structures reveal that the modal velocity response term and the coupled term are important to structural response estimates only for a dynamic system with a tuned mass damper. In typical cases, the modal displacement term can provide response estimates with satisfactory accuracy by itself, so that the modal velocity term and coupled term may be ignored without loss of accuracy. This is used to simplify the response computation of non-classically damped structures. For the white noise excitation, three modal correlation coefficients in closed form are derived. To consider the modal velocity response term and the coupled term, a simplified approximation based on white noise excitation is developed for the case when the modal velocity response is important to the structural responses. Numerical results show that the approximate expression based on white noise excitation can provide structural responses with satisfactory accuracy.

On precise time integration method for non-classically damped MDOF systems

In the complex mode superposition method, the equations of motion for non-classically damped multiple-degree-of-freedom （MDOF） discrete systems can be transferred into a combination of some generalized SDOF complex oscillators. Based on the state space theory, a precise recurrence relationship for these complex oscillators is set up; then a delicate general solution of non-classically damped MDOF systems, completely in real value form, is presented in this paper. In the proposed method, no calculation of the matrix exponential function is needed and the algorithm is unconditionally stable. A numerical example is given to demonstrate the validity and efficiency of the proposed method.

The Extended Non-Elementary Amplitude Functions as Solutions to the Damped Pendulum Equation, the Van der Pol Equation, the Damped Duffing Equation, the Lienard Equation and the Lorenz Equations

In this paper, we define some non-elementary amplitude functions that are giving solutions to some well-known second-order nonlinear ODEs and the Lorenz equations, but not the chaos case. We are giving the solutions a name, a symbol and putting them into a group of functions and into the context of other functions. These solutions are equal to the amplitude, or upper limit of integration in a non-elementary integral that can be arbitrary. In order to define solutions to some short second-order nonlinear ODEs, we will make an extension to the general amplitude function. The only disadvantage is that the first derivative to these solutions contains an integral that disappear at the second derivation. We will also do a second extension: the two-integral amplitude function. With this extension we have the solution to a system of ODEs having a very strange behavior. Using the extended amplitude functions, we can define solutions to many short second-order nonlinear ODEs.

Effect on Landau damping rates for a non-Maxwellian distribution function consisting of two electron populations

In many physical situations where a laser or electron beam passes through a dense plasma,hot low-density electron populations can be generated,resulting in a particle distribution function consisting of a dense cold population and a small hot population.Presence of such low-density electron distributions can alter the wave damping rate.A kinetic model is employed to study the Landau damping of Langmuir waves when a small hot electron population is present in the dense cold electron population with non-Maxwellian distribution functions.Departure of plasma from Maxwellian distributions significantly alters the damping rates as compared to the Maxwellian plasma.Strong damping is found for highly nonMaxwellian distributions as well as plasmas with a higher density and hot electron population.Existence of weak damping is also established when the distribution contains broadened flat tops at the low energies or tends to be Maxwellian.These results may be applied in both experimental and space physics regimes.

Nonlinear Landau damping of high frequency waves in non-Maxwellian plasmas

Space plasmas often possess non-Maxwellian distribution functions which have a significant effect on the plasma waves. When a laser or electron beam passes through a dense plasma, hot low density electron populations can be generated to alter the wave damping/growth rate. In this paper, we present theoretical analysis of the nonlinear Landau damping for Langmuir waves in a plasma where two electron populations are found. The results show a marked difference between the Maxwellian and non-Maxwellian instantaneous damping rates when we employ a non-Maxwellian distribution function called the generalized （r, q） distribution function, which is the generalized form of the kappa and Maxwellian distribution functions. In the limiting case of r = 0 and q→∞, it reduces to the classical Maxwellian distribution function, and when r = 0 and q→k ＋1, it reduces to the kappa distribution function.

Non-Markovian Dynamics of an Open Two-Level System with Amplitude-Phase Damping

By use of the measure, the backflow of information presented recently, we study the non-Markovianity of the dynamics for a two-level system interacting with a zero-temperature structured environment via amplitude-phase coupling. In the limit of weak coupling between the system and its reservoir, the time-local non-Markovian master equation for the reduced state of the system is derived. Under the secular approximation, the exact analytic solution is obtained. Numerical simulations show that the amplitude and phase dampings can produce destructive interference to the backflow of information, leading to the weaker non-Markovianity of the compound dynamics compared with the dynamics of a single amplitude or phase damping model. We also study the characteristics of the initial-state pairs that maximize the backflow of information.

The Harmonic Oscillator with Random Damping in Non-Markovian Thermal Bath

In this paper, we define the harmonic oscillator with random damping in non-Markovian thermal bath. This model represents new version of the random oscillators. In this side, we derive the overdamped harmonic oscillator with multiplicative colored noise and translate it into the additive colored noise by changing the variables. The overdamped harmonic oscillator is stochastic differential equation driving by colored noise. We derive the change in the total entropy production (CTEP) of the model and calculate the mean and variance. We show the fluctuation theorem (FT) which is invalid at any order in the time correlation. The problem of the deriving of the CTEP is studied in two different examples of the harmonic potential. Finally, we give the conclusion and plan for future works.

清化方治疗湿热蕴结型非酒精性脂肪性肝病临床研究

目的:观察清化方治疗非酒精性脂肪性肝病(NAFLD)的临床疗效。方法:将66例NAFLD患者按随机数字表法分为对照组和观察组各33例,因研究过程中有脱落,对照组、观察组最终完成研究的患者例数分别为30例、32例。两组均给予生活方式干预,观察组在此基础上给予清化方干预。两组均以12周为1个疗程,共治疗2个疗程。观察两组患者干预前、干预12周、干预24周的受控衰减参数(CAP)、血脂代谢指标、肝功能指标、血糖代谢指标及体质量指数(BMI),并评价干预24周的腹部B超疗效和中医证候疗效。结果:①干预12周、24周后,两组CAP较干预前均降低(P<0.05);干预24周后,两组CAP较干预12周均降低(P<0.05)。干预12周、24周后,观察组CAP均低于对照组(P<0.05)。②干预24周后,观察组血清TG水平较干预前及干预12周降低(P<0.05),且低于同时点对照组(P<0.05)。③干预24周后,观察组空腹胰岛素(FINS)水平和HOMA胰岛素抵抗(HOMA-IR)指数较干预前降低(P<0.05),且低于同时点对照组(P<0.05)。④干预12周、24周后,两组BMI较干预前均降低(P<0.05)。干预24周后,观察组BMI较干预12周降低(P<0.05),且低于同时点对照组(P<0.05)。⑤干预24周后,观察组腹部B超疗效和中医证候疗效均优于对照组(P<0.05)。结论:清化方联合生活方式干预有助于改善NAFLD患者肝脏脂肪沉积,并可改善患者中医证候,疗效确切。

非堆积型多颗粒阻尼器等效力学模型及其减振性能分析

为考虑颗粒群碰撞过程中时间效应对非堆积型多颗粒阻尼器(non-packed particle damper, NPPD)减振性能的影响,在现有考虑惯容的等效单颗粒力学模型(equivalent inertia single-particle model, EISM)研究基础上,提出了基于接触单元法的等效单颗粒力学模型(equivalent inertia single-particle model based on contact element method, EISM-CE),并基于Runge-Kutta算法建立了NPPD单自由度结构运动状态求解算法。设计进行附加NPPD单层钢框架结构振动台试验,探究不同填充率对结构顶层位移频响曲线的影响规律,提出了EISM-CE参数取值原则,进而进行力学模型试验验证及模型对比分析。在模型验证合理性基础上,基于EISM-CE依次进行了自由振动、简谐激励及记录强震动下减振性能及能量变化规律分析。研究结果表明,与现有EISM相比,提出的基于接触单元法的EISM-CE模型及参数取值原则更加合理有效。减振性能数值分析结果表明,不同激励下NPPD均具有较好的减振性能;考虑碰撞时间效应后EISM-CE与EISM对应减振性能及机理分析结果存在一定的差异。

升阳泻湿法治疗非酒精性脂肪性肝病初探

非酒精性脂肪性肝病是目前的多发病,为多因素所致,严重影响公共健康,目前对于该病的证治报道较多。该病的临床表现多数不典型,病机证候复杂,笔者汲取李东垣理论思想中升发脾之清气,以及黄元御理论思想中泻湿疏木的治法,把二者进行优化组合,拟定了升阳化湿,培土疏木为治疗大法运用于临床,立足于“湿”,分为“湿浊内蕴”和“脾虚湿困”2个证型,驭繁就简,取得了理想的临床疗效。

清热渗湿降浊法联合水飞蓟宾葡甲胺片治疗湿热蕴结型非酒精性脂肪性肝炎临床疗效观察

【目的】探讨清热渗湿降浊法联合水飞蓟宾葡甲胺片治疗丙氨酸氨基转移酶(ALT)异常的湿热蕴结型非酒精性脂肪性肝炎(NASH)患者的临床疗效。【方法】采用回顾性研究方法,根据用药情况将80例ALT异常的湿热蕴结型NASH患者分为对照组和观察组,每组各40例。对照组给予水飞蓟宾葡甲胺片治疗,观察组在对照组的基础上联合清热渗湿降浊法治疗,疗程为12周。观察2组患者治疗前后肝功能指标[丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、γ-谷氨酰转肽酶(GGT)]、血脂指标[总胆固醇(CHOL)、甘油三酯(TRIG)]以及肝脂肪度的变化情况,并评价2组患者的临床疗效及安全性。【结果】(1)经治疗12周后,观察组的总有效率为95.00%(38/40),对照组为77.50%(31/40);组间比较,观察组的疗效明显优于对照组,差异有统计学意义(P<0.05)。(2)治疗后,2组患者的肝功能指标ALT、AST、GGT水平均较治疗前明显下降(P<0.05),且观察组对肝功能指标ALT、AST、GGT水平的下降作用均明显优于对照组(P<0.05)。(3)治疗后,2组患者的血脂指标CHOL、TRIG水平均较治疗前明显下降(P<0.05),且观察组对血脂指标CHOL、TRIG水平的下降作用均明显优于对照组(P<0.05)。(4)治疗后,2组患者的肝脂肪度均较治疗前明显下降(P<0.05),且观察组对肝脂肪度的下降作用明显优于对照组(P<0.05)。(5)治疗过程中,2组患者均未发生明显不良反应,具有较高的安全性。【结论】清热渗湿降浊法联合水飞蓟宾葡甲胺片治疗ALT异常的湿热蕴结型NASH患者疗效确切,联合清热渗湿降浊法治疗能显著提高临床疗效。

基于肠道菌群探讨艾滋病免疫重建不良“气虚湿阻”的病机与治法

肠道菌群紊乱与艾滋病免疫重建不良(INR)的发病关系密切,中医理论和现代研究表明“气虚湿阻”为艾滋病INR的核心病机,且肠道菌群失调为中医气虚证和湿证的生物学基础之一,与“气虚湿阻”病机相通,故可从“气虚湿阻”和肠道菌群两方面为艾滋病INR的中医治疗提供理论依据。根据中医扶正祛邪原则,提出益气祛湿的治疗大法,并可通过调节肠道菌群,促进艾滋病INR患者免疫重建,改善临床症状。

基于声阻抗匹配理论的弹性吸收体研究

基于时域耦合模型理论的吸收体研究,不适用于所有模型,且基于此理论的设计过程复杂,难以在工业工程得到广泛应用。因此提出一种基于声阻抗匹配理论的弹性吸收体的研究方法,并通过理论计算、数值仿真以及实验对吸收体的吸收曲线进行验证。结果表明:本文提出的方法能够快速、简便地实现弹性吸收体的结构设计,无需额外附加阻尼材料,更有利于满足航空工程中对于结构轻量化的要求,为振动波吸收领域,尤其是弯曲波的高效吸收和减振设计研究带来了新的可能性。

非马尔科夫环境中Werner态的量子非局域关联检验研究

以量子信息领域中常使用的Werner态为研究对象,详细地研究了其在两种非马尔科夫相位阻尼环境,即Random-Telegraph(RT)噪声环境、Ornstein-Uhlenbeck(OU)噪声环境,以及非马尔科夫振幅阻尼(AD)环境中演化后的量子非局域关联检验情况.分别推导了Werner态在RT,OU以及AD环境中密度矩阵随时间的演化结果.基于Clauser-Horne-Shimony-Holt(CHSH)不等式,对演化后的量子态进行了详细的量子非局域关联检验研究.结果表明,Werner态在RT噪声环境和AD环境中存在信息回流现象,导致其量子非局域关联特性存在周期性振荡变化的现象,即随演化时间的增加,量子态能够从不具备量子非局域关联特性重新回到具有量子非局域关联特性的情况.而在OU噪声环境中,由于不存在信息回流现象,量子非局域关联检验值将随演化时间的增加而降低.同时,本文还详细给出了Werner的保真度、量子态与非马尔科夫环境的耦合强度、OU噪声环境和AD环境的线宽、RT环境噪声的翻转率等参数与成功进行量子非局域关联检验的演化时间之间的关系.

基于16sRNA测序技术探讨不同体质腹型肥胖者肠道菌群特征

目的:探讨痰湿体质与非痰湿体质腹型肥胖人群肠道菌群的丰度及物种差异。方法:共纳入91例不同体质腹型肥胖受试者,收集了91例大便样本,其中痰湿体质受试者44例,非痰湿体质受试者47例。使用NovaSeq6000基因测序仪,对痰湿体质与非痰湿体质受试者肠道菌群相对丰度、物种多样性进行分析。结果:痰湿体质与非痰湿体质腹型肥胖受试者的肠道菌群门纲目科属五个层级菌群相对丰度的差异显著。痰湿体质与非痰湿体质相比门纲目科属五个层级菌群相对丰度以及差别较大,其中拟杆菌、类杆菌、毛螺菌、肠杆菌相对丰度差异有统计学意义(P<0.05)。结论:痰湿体质与非痰湿体质腹型肥胖受试者肠道菌群存在差异,二者间菌群差异可能是形成体质差异的内在因素。

从痰湿论治非酒精性脂肪性肝病的用药规律及作用机制分析

目的:挖掘从痰湿论治非酒精性脂肪性肝病(NAFLD)的处方用药规律,分析核心处方药物发挥作用的潜在机制。方法:搜集从痰湿论治NAFLD的临床研究文献,对处方药物的性味、归经进行系统聚类与关联规则分析。得出从痰湿论治NAFLD的核心处方后,检索数据库获取药物有效成分作用靶点及疾病靶点,二者取交集后在STRING数据库构建蛋白质-蛋白质相互作用关系网络,并在Cytoscape中对所有交集靶点进行评分以获取核心靶点。对关键靶点进行基因本体功能富集分析、京都基因和基因组百科全书通路富集分析,并将分析结果导入Cytoscape软件构建中药活性成分-靶点-疾病通路网络图。结果:筛选后共得到119首方药,涉及153味药物,多为甘味、温性,以归肝、脾经多见。关联规则分析结果显示,山楂、茯苓、泽泻、白术、丹参、半夏和陈皮是治疗NAFLD的核心药物。聚类分析得到核心处方组合“山楂、决明子、泽泻、丹参、柴胡、郁金”,网络药理学分析结果显示,核心处方与NAFLD交集靶点有248个,信号转导及转录激活因子3和细胞外基质致癌基因是从痰湿论治NAFLD最核心的靶点。叉头框O、肿瘤坏死因子和磷脂酰肌醇3激酶-蛋白激酶B信号通路等是从痰湿论治NAFLD的主要信号通路。甲基庚烯酮、槲皮素及山柰酚等是核心处方发挥作用的主要有效成分。结论:从痰湿论治NAFLD以甘味、温性药物为主,离不开对肝、脾的调理,山楂、茯苓、泽泻、白术、丹参、半夏和陈皮是从痰湿论治NAFLD的常用药物;从痰湿论治NAFLD的核心处方主要通过参与调节脂质代谢、炎症反应和氧化应激等生物学过程,发挥对NAFLD的治疗作用。

非比例阻尼结构动态响应的时间同步分析

针对在结构动态响应采集过程中出现的时间异步问题,基于相位与时间的映射关系,通过计算动态响应之间的相位偏差估算其相对时滞;利用相位偏差的周期性缩小相对时滞的搜索范围,减少计算时间。同时,利用多阶模态的平均相位偏差解决因相位偏差周期性造成的相对时滞估算结果不唯一的问题;提出了一种非比例阻尼结构异步动态响应的时间同步算法;通过一个非比例阻尼结构模型的实测位移数据验证该算法的有效性,并在不同阻尼比大小的情况下与其他时间同步算法进行比较。结果表明:该算法无须假设比例阻尼,在阻尼比大小不同情况下均适用,且相较于其他算法具有较高的准确性。

基于非比例阻尼模态叠加的阻尼合金动力学拓扑优化研究

针对阻尼合金在动力学拓扑优化中的非比例阻尼特征,基于实模态进行非比例阻尼结构响应的迭代模态叠加算法,结合移动渐近线方法,构建了一种考虑非比例阻尼特性的阻尼合金动力学拓扑优化模型。案例分析结果表明:该模型较传统的基于比例阻尼的拓扑优化方法对阻尼合金的形状和布局优化具有更佳效果,可为类似阻尼合金在应用中的形状和布局设计提供思路借鉴和方案参考。

可恢复功能复合结构体系基于复模态叠加法的响应分析和应用

可恢复功能复合结构体系利用黏滞阻尼等耗能机制可显著提高抗震韧性水平,同时导致其非比例阻尼特征更加突出,采用传统振型叠加法进行响应计算会产生较大误差。为建立该类体系面向抗震韧性的设计方法,该文在前期研究基础上,推导得到可恢复功能复合结构体系分布参数模型复模态正交性条件,建立了该类体系基础激励下动力响应的复模态叠加计算方法。在验证推导正确性后,将该方法应用于两个方面:传统振型叠加法响应计算误差分析和复合体系的设计参数选择。结果表明:相比于振型叠加法只在非比例阻尼不显著的情况具备较好的计算精度,复模态叠加法不仅可以更加准确地计算地震响应,而且可以量化黏滞阻尼对结构响应的控制效果,对于指导该类体系的设计具有参考价值。