Periodic oscillation and fine structure of wedge-induced oblique detonation waves

An oblique detonation wave for a Mach 7 inlet flow over a long enough wedge of 30 turning angle is simulated numerically using Euler equation and one-step rection model.The fifth-order WENO scheme is adopted to capture the shock wave.The numerical results show that with the compression of the wedge wall the detonation wave front structure is divided into three sections：the ZND model-like strcuture,single-sided triple point structure and dual-headed triple point strucuture.The first structure is the smooth straight,and the second has the characteristic of the triple points propagating dowanstream only with the same velocity,while the dual-headed triple point structure is very complicated.The detonation waves facing upstream and downstream propagate with different velocities,in which the periodic collisions of the triple points cause the oscillation of the detonation wave front.This oscillation process has temporal and spatial periodicity.In addition,the triple point trace are recorded to obtain different cell structures in three sections.

HEATING CHARACTERISTICS OF BLUNT SWEPT FIN-INDUCED SHOCK WAVE TURBULENT BOUNDARY LAYER INTERACTION

An experimental study was conducted on shock wave turbulent boundary layer interactions caused by a blunt swept fin-plate configuration at Mach numbers of 5.0, 7.8, 9.9 for a Reynolds number range of (1.0.similar to 4.7) x 10(7)/m. Detailed heat transfer and pressure distributions were measured at fin deflection angles of up to 30 degrees for a sweepback angle of 67.6 degrees. Surface oil flow patterns and liquid crystal thermograms as well as schlieren pictures of fin shock shape were taken. The study shows that the flow was separated at deflection of 10 degrees and secondary separation were detected at deflection of theta greater than or equal to 20 degrees. The heat transfer and pressure distributions on flat plate showed an extensive plateau region followed by a distinct dip and local peak close to the fin foot. Measurements of the plateau pressure and heat transfer were in good agreement with existing prediction methods, but pressure and heating peak measurements at M greater than or equal to 6 were significantly lower than predicted by the simple prediction techniques at lower Mach numbers.

Adequate Closed Form Wave Solutions to the Generalized KdV Equation in Mathematical Physics

In this paper, we consider the generalized Korteweg-de-Vries (KdV) equations which are remarkable models of the water waves mechanics, the shallow water waves, the quantum mechanics, the ion acoustic waves in plasma, the electro-hydro-dynamical model for local electric field, signal processing waves through optical fibers, etc. We determine the useful and further general exact traveling wave solutions of the above mentioned NLDEs by applying the exp(−τ(ξ))-expansion method by aid of traveling wave transformations. Furthermore, we explain the physical significance of the obtained solutions of its definite values of the involved parameters with graphic representations in order to know the physical phenomena. Finally, we show that the exp(−τ(ξ))-expansion method is convenient, powerful, straightforward and provide more general solutions and can be helping to examine vast amount of travelling wave solutions to the other different kinds of NLDEs.

WAVE1、MMP-2及MMP-9在卵巢癌组织中的表达及意义

目的探讨WASP家族富含脯氨酸同源蛋白1(WASP-family verprolin-homologous protein 1,WAVE1)及基质金属蛋白酶-2(matrix metalloproteinases-2,MMP-2)和基质金属蛋白酶-9(MMP-9)在卵巢癌的表达及临床意义。方法采用免疫组化SABC三步法检测47例卵巢癌、30例卵巢良性肿瘤和21例正常卵巢组织中WAVE1、MMP-2、MMP-9的表达,并对卵巢癌组织WAVE1与MMP-2、MMP-9的表达进行相关性分析。结果①WAVE1、MMP-2及MMP-9在卵巢癌中的表达均高于在正常卵巢组织及卵巢良性组织中的表达,差异有统计学意义(P<0.05);Spearman相关分析显示,WAVE1和MMP-2、MMP-9两两表达成正相关(r=0.773,r=0.664,P<0.05)。②WAVE1的表达与卵巢癌的临床分期、组织分化及Ca-125水平有关(P<0.05),与年龄、肿瘤的直径无关(P>0.05)。MMP-2、MMP-9表达与卵巢癌的临床分期有关(P<0.05),与年龄、组织分化、Ca-125水平及肿瘤直径无关(P>0.05)。结论 WAVE1和MMP-2、MMP-9在卵巢癌中呈现高表达,早期联合筛查WAVE1和MMP-2、MMP-9指标对卵巢癌病情演变和预后评估有着重要的临床意义。

Measurements of non-equilibrium and equilibrium temperature behind a strong shock wave in simulated martian atmosphere

Non-equilibrium radiation measurements behind strong shock wave for simulated Martian atmosphere are presented in this paper. The shock wave is established in a hydrogen oxygen combustion driven shock tube. Time- resolved spectra of the Av = 0 sequence of the B^2∑^＋ → X^2∑^＋ electronic transition of CN have been observed through optical emission spectroscopy （OES）. A new method, which is based on fitting high resolution spectrum for rotational and vibrational temperatures measurement, is proposed to diag- nose temperature distribution behind the shock wave. It is estimated that the current scheme has the maximum deviation less than 8% （lσ） for vibrational temperature measurement through detailed analysis of the influence of the uncertainties of spectroscopic constants and spectral resolution. Radiation structure of the shock layer, including induction, relaxation and equilibrium process, and corresponding rotational and vibrational temperatures are obtained through time gating OES diagnostics with sub-microsecond temporal resolution. The present extensive results will strongly benefit the reaction rate estimation and computational fluid dynamics （CFD） code validation in high enthalpy Mars reentry chemistry.

3D v_P and v_S models of southeastern margin of the Tibetan plateau from joint inversion of body-wave arrival times and surface-wave dispersion data

A new 3D velocity model of the crust and upper mantle in the southeastern （SE） margin of the Tibetan plateau was obtained by joint inversion of body- and sur- face-wave data. For the body-wave data, we used 7190 events recorded by 102 stations in the SE margin of the Tibetan plateau. The surface-wave data consist of Rayleigh wave phase velocity dispersion curves obtained from ambient noise cross-correlation analysis recorded by a dense array in the SE margin of the Tibetan plateau. The joint inversion clearly improves the Vs model because it is constrained by both data types. The results show that at around 10 km depth there are two low-velocity anomalies embedded within three high-velocity bodies along the Longmenshan fault system. These high-velocity bodies correspond well with the Precambrian massifs, and the two located to the northeast of 2013 Ms 7.0 Lushan earthquake are associated with high fault slip areas during the 2008 Wenchuan earthquake. The aftershock gap between 2013 Lushan earthquake and 2008 Wenchuan earthquake is associated with low-velocity anomalies, which also acts as a barrier zone for ruptures of two earthquakes. Generally large earthquakes （M 〉 5） in the region occurring from 2008 to 2015 are located around the high-velocity zones, indicating that they may act as asperities for these large earthquakes. Joint inversion results also clearly show that there exist low-velocity or weak zones in the mid-lower crust, which are not evenly distributed beneath the SE margin of Tibetan plateau.

A novel type of transverse surface wave propagating in a layered structure consisting of a piezoelectric layer attached to an elastic half-space

The existence and propagation of transverse surface waves in piezoelectric coupled solids is investigated, in which perfect bonding between a metal/dielectric substrate and a piezoelectric layer of finite-thickness is assumed. Dis- persion equations relating phase velocity to material con- stants for the existence of various modes are obtained in a simple mathematical form for a piezoelectric material of class 6mm. It is discovered and proved by numerical examples in this paper that a novel Bleustein-Gulyaev （B-G） type of transverse surface wave can exist in such piezoelectric cou- pled solid media when the bulk-shear-wave velocity in the substrate is less than that in the piezoelectric layer but greater than the corresponding B-G wave velocity in the same pie- zoelectric material with an electroded surface. Such a wave does not exist in such layered structures in the absence of pie- zoelectricity. The mode shapes for displacement and electric potential in the piezoelectric layer are obtained and discussed theoretically. The study extends the regime of transverse sur- face waves and may lead to potential applications to surface acoustic wave devices.

Numerical study on wave loads and motions of two ships advancing in waves by using three-dimensional translating-pulsating source

A frequency domain analysis method based on the three-dimensional translating-pulsating （3DTP） source Green function is developed to investigate wave loads and free motions of two ships advancing on parallel course in waves. Two experiments are carried out respectively to mea- sure the wave loads and the free motions for a pair of side-by- side arranged ship models advancing with an identical speed in head regular waves. For comparison, each model is also tested alone. Predictions obtained by the present solution are found in favorable agreement with the model tests and are more accurate than the traditional method based on the three dimensional pulsating （3DP） source Green function. Numer- ical resonances and peak shift can be found in the 3DP pre- dictions, which result from the wave energy trapped in the gap between two ships and the extremely inhomogeneous wave load distribution on each hull. However, they can be eliminated by 3DTP, in which the speed affects the free sur- face and most of the wave energy can be escaped from the gap. Both the experiment and the present prediction show that hydrodynamic interaction effects on wave loads and free motions are significant. The present solver may serve as a validated tool to predict wave loads and motions of two ves- sels under replenishment at sea, and may help to evaluate the hydrodynamic interaction effects on the ships safety in replenishment operation.

CISK-rossby wave and the 30-60 Day Oscillation in the Tropics

The 30-60 day oscillation is an important aspect of the atmospheric variance in the tropical area. A number of works have been done on this phenomenon, this article is a further one. A quasi-geostrophic linear model that consists of a two-layer free atmosphere and a well-mixed boundary layer is used to investigate the instability of intraseasonal oscillation, its propagation and vertical structures. Results show that the dynamical coupling and interaction between the barotropic and baroclinic components via boundary layer convergence / divergence are responsible for the appearance of a new kind of low-frequency wave. Such wave is very different from the traditional tropical Rossby wave. It can propagate westward and eastward. Some behaviours of it appear to resemble the observed 30-60 day oscillation mode in many aspects, such,as vertical structures, zonal and meridional propagations. Now many researchers emphasize the direct relationship between CISK-Kelvin mode and the tropical atmospheric 30-60 oscillation. It is considered that CISK-Rossby mode should not be neglected.

Analytical and Traveling Wave Solutions to the Fifth Order Standard Sawada-Kotera Equation via the Generalized exp(-Φ(ξ))-Expansion Method

In this article, we propose a generalized exp(-Φ(ξ))-expansion method and successfully implement it to find exact traveling wave solutions to the fifth order standard Sawada-Kotera (SK) equation. The exact traveling wave solutions are established in the form of trigonometric, hyperbolic, exponential and rational functions with some free parameters. It is shown that this method is standard, effective and easily applicable mathematical tool for solving nonlinear partial differential equations arises in the field of mathematical physics and engineering.

STUDY ON DYNAMICS OF TROPICAL CISK-ROSSBY WAVES AND MECHANISM OF 30-50 DAY OSCILLATIONS

To add to the growing mature research on the tropical 30-50 day oscillations from a new prospective, the current work bases on dynamic analysis of baroclinic quasi-geostrophic models to discuss dynamic mechanisms for the generation and propagation of CISK-Rossby waves, and to understand restraints and effects of different wave structures and thermodynamic forcing on the 30-50 day oscillations in the tropical atmosphere. Some important properties of the oscillation propagation have been explained and, in detail, with respect to its meridional propagation and vertical "baroclinic" structure. The work has come up with some new opinions and viewpoints. New opinions about the propagation and energy dispersion are to be proved by more observations and study.

Nonlinear Three-Wave Interaction among Barotropic Rossby Waves in a Large-scale Forced Barotropic Flow

In this paper. the coupling equations describing nonlinear three-wave interaction amongRossby waves including the forcing of an external vorticity source are obtained. Under certainconditions, the coupling equations with a constant amplitude forcing, the stability analysis indicates that when the amplitude of the external forcing increases to a certain extent, a pitchforkbifurcation occurs. Also. it is shown fi-o m numerical results that the bifurcation can lead to chaoticbehavior of' strange' attractor. For the obtained three-variable equation, when the amplitude ofmodulated external forcing gradually increases, a Period-doubling bifurcation is found to lead tochaotic behavior. Thus, in a nonlinear three-wave coupling model in the large-scale forcedbarotropic atmospheric flow, chaotic behavior can be observed. This chaotic behavior can explainin part 30-60-day low-flequency oscillations observed in mid-high latitudes.

Exact Traveling Wave Solutions of Nano-Ionic Solitons and Nano-Ionic Current of MTs Using the exp(-φ (ξ ))-Expansion Method

In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to be special values, the solitary wave solutions are derived from the exact traveling wave solutions. The validity and reliability of the method are tested by its applications to Nano-ionic solitons wave’s propagation along microtubules in living cells and Nano-ionic currents of MTs which play an important role in biology.

Novel traveling wave solutions and stability analysis of perturbed Kaup-Newell Schrodinger dynamical model and its applications

We study the traveling wave and other solutions of the perturbed Kaup-Newell Schrodinger dynamical equation that signifies long waves parallel to the magnetic field.The wave solutions such as bright-dark(solitons),solitary waves,periodic and other wave solutions of the perturbed Kaup-Newell Schrodinger equation in mathematical physics are achieved by utilizing two mathematical techniques,namely,the extended F-expansion technique and the proposed exp(-φ(ξ))-expansion technique.This dynamical model describes propagation of pluses in optical fibers and can be observed as a special case of the generalized higher order nonlinear Schrodinger equation.In engineering and applied physics,these wave results have key applications.Graphically,the structures of some solutions are presented by giving specific values to parameters.By using modulation instability analysis,the stability of the model is tested,which shows that the model is stable and the solutions are exact.These techniques can be fruitfully employed to further sculpt models that arise in mathematical physics.

Wavelet Analysis of Average

The identification method in the CurveExpert-1.40 software environment revealed asymmetric wavelets of changes in the average monthly temperature of New Delhi from 1931 to 2021.The maximum increment for 80 years of the average monthly temperature of 5.1℃was in March 2010.An analysis of the wave patterns of the dynamics of the average monthly temperature up to 2110 was carried out.For forecasting,formulas were adopted containing four components,among which the second component is the critical heat wave of India.The first component is the Mandelbrot law(in physics).It shows the natural trend of decreasing temperature.The second component increases according to the critical law.The third component with a correlation coefficient of 0.9522 has an annual fluctuation cycle.The fourth component with a semi-annual cycle shows the influence of vegetation cover.The warming level of 2010 will repeat again in 2035-2040.From 2040 the temperature will rise steadily.June is the hottest month.At the same time,the maximum temperature of 35.1℃in 2010 in June will again reach by 2076.But according to the second component of the heat wave,the temperature will rise from 0.54℃to 16.29°C.The annual and semi-annual cycles had an insignificant effect on the June temperature dynamics.Thus,the identification method on the example of meteorological observations in New Delhi made it possible to obtain summary models containing a different number of components.The temperature at a height of 2 m is insufficient.On the surface,according to space measurements,the temperature reaches 55°C.As a result,in order to identify more accurate asymmetric wavelets for forecasting,the results of satellite measurements of the surface temperature of India at various geographical locations of meteorological stations are additionally required.

鳍形浮子多自由度水动力性能研究

[目的]为优化摇臂式波浪能装置的能量俘获(俘能)效果,针对平台支柱分流方案与浮子形状对装置俘能效果影响进行研究。[方法]首先,建立浮子运动的水动力学模型;然后,利用AQWA仿真软件,对平台支柱不同分流方案的多种鳍形浮子的水动力特性进行计算分析,得到鳍形浮子的波浪合力、幅值响应算子、附加质量及辐射阻尼等频域参数,以及位移、速度、加速度及激振力等时域参数;最后,研究平台支柱不同分流方案的各鳍形浮子的俘能宽度比。[结果]结果表明:不同平台支柱分流方案对鳍形浮子的频域参数影响较小,对时域参数的浮子运动位移影响较小,但对运动周期影响较大;双柱分流方案的100°时鳍形浮子的俘能效果最优。[结论]基于所建立的仿真数值模型能够准确模拟多自由度鳍形浮子在波浪运动中的水动力学响应,可为振荡浮子式波浪能发电平台浮子形状的优化设计提供参考。

新型仿鳐鱼水陆两栖机器人的结构设计、运动学建模与运动规划

跨介质作业机器人在灾害救援、环境探测、军事侦查等方面具有显著优势,但现有水陆两栖机器人依赖于两套或多套驱动系统,结构复杂、维护成本高,且额外的驱动系统切换将增加控制难度与作业时间.为此,本文设计了一种新型的行波驱动仿鳐鱼水陆两栖机器人(Wave-inspired actuated ray-inspired amphibious robot,WARAR).首先,设计了一种具有高越障能力的行波驱动机构.基于此,设计了一种仿鳐鱼柔性鳍,将行波机构驱动力转换为水中游动的推进力,从而实现单一驱动系统同时满足陆地和水中运动的双重目标.随后,建立了WARAR的运动学模型,并提出了一种跨水陆介质轨迹规划方法.最后,自主搭建了WARAR的实验平台,并对所设计机器人的移动、爬坡、转向、游动等性能进行了充分测试.此外,验证了所设计跨水陆介质作业轨迹规划方法的有效性.

Design and Mechanics of a Composite Wave-driven Soft Robotic Fin for Biomimetic Amphibious Robot

Bionic amphibious robots have important prospects in scientific, commercial, and military fields. Compared with traditional amphibious robots which use propellers/jets for aquatic medium and wheels/tracks for terrestrial medium, bionic propulsion method has great advantages in terms of manoeuvrability, efficiency, and reliability, because there is no need to switch between different propulsion systems. To explore the integrated driving technology of amphibious robot, a novel bio-inspired soft robotic fin for amphibious use is proposed in this paper. The bionic fin can swim underwater and walk on land by the same undulating motion. To balance the conflicting demands of flexibility underwater and rigidity on land, the undulating fin adopts a special combination of a membrane fin and a bending spring. A periodic longitudinal wave in horizontal direction has been found generating passively in dynamic analysis. To find the composite wave-driven mechanics, theoretical analysis is conducted based on the walking model and swimming model. A virtual prototype is built in ADAMS software to verify the walking mechanics. The simulation result reveals that the passive longitudinal wave is also periodical and the composite wave contributes to land walking. Finally, an amphibious robot prototype actuated by a pair of undulating fins has been developed. The experiments show that the robot can achieve multiple locomotion, including walking forward/backward, turning in place, swimming underwater, and crossing medium, thus giving evidence to the feasibility of the newly designed undulating fin for amphibious robot.

睡前服用二甲双胍缓释片对2型糖尿病患者空腹血糖、胰岛素样生长因子-1的影响

目的观察睡前服用二甲双胍缓释片对2型糖尿病患者空腹血糖、胰岛素样生长因子-1(IGF-1)水平的影响。方法选取医我院收治的2型糖尿病患者80例,随机分为观察组和对照组,每组40例。2组均予管理饮食、运动疗法、健康教育,其中对照组仅予生活方式干预,观察组同时睡前口服二甲双胍缓释片治疗,抽取空腹静脉血液检测各项生化指标并对比分析。结果观察组治疗后空腹血糖(FPG)、空腹胰岛素(FINS)较治疗前及对照组有明显下降,差异有统计学意义(P <0. 05);观察组经治疗后IGF-1水平亦较治疗前及对照组明显下降,差异有统计学意义(P <0. 05)。结论睡前服用二甲双胍缓释片治疗2型糖尿病,可改善患者葡萄糖代谢,减轻胰岛素抵抗,抑制IGF-1水平,具有较高的临床应用价值。

代谢综合证中医证型与白介素-6相关性研究

目的:探讨代谢综合征(METABOLIC SYNDROME)不同的中医辨证分型患者与细胞因子-白细胞介素-6IL(IL-6)及血脂、体重指数、胰岛素等相关指标的关系,为中医的证型的研究提供一定的依据。方法:将符合入选标准的107例代谢综合征患者按中医辨证分型分为四个证型组,即肝胃郁热型组、痰湿瘀滞型组、气阴两虚型组、阴阳两虚型组。其中肝胃郁热组29例、痰湿瘀滞组27例、气阴两虚组29例、阴阳两虚组22例,选取21例健康体检作为正常对照组。检测患者的血脂、空腹胰岛素(FINS)、白介素-6水平,血脂用酶法,FINS用酶联免疫方法,其它指标用放射免疫法,并测量体重、身高、腰围、臀围、计算体重指数、腰臀围值。结果:(1)各证型白细胞介素-6(IL-6)均高于正常组(P<0.05),即痰湿瘀滞组>肝胃郁热组>气阴两虚组>阴阳两虚组,均有差异,差别有统计学意义,而痰湿瘀滞组MS的患者白细胞介素-6(IL-6)较其他各证型组及正常对照组均明显增高;以痰湿瘀滞组>肝胃郁热组>气阴两虚组>阴阳两虚组>正常对照组的顺序增高。(2)各证型的代谢综合征患者的甘油三酯(TG)和低密度脂蛋白(LDL)、高密度脂蛋白(HDL)较正常组有明显增高(P<0.05),差别有统计学意义,以痰湿瘀滞组>肝胃郁热组>气阴两虚组>阴阳两虚组>正常对照组的顺序增高,以痰湿瘀滞型为著;各组证型中胆固醇(TC)与正常对照组无明显差异(P>0.05),差别无统计学意义。(3)与正常对照组比较,各证型MS患者的胰岛素抵抗指数明显增加,四组证候按次序递增即痰湿瘀滞型>肝胃郁热型>阴阳两虚型>阴阳两虚型(P>0.05);与正常对照比较,各证型MS患者的胰岛素敏感指数均明显降低,四组证候按顺序递减即痰湿瘀滞型>肝胃郁热型>气阴两虚型>阴阳两虚型,均有差异(P>0.05),差别有统计学意义。结论:(1)MS患者中医证型中白细胞介素-6(IL-6)的变化有一定关系,中医证型表现不同客观指标亦变化各异,临床可根据客观指标变化,结合临床表现为MS患者证型确定提供依据。在MS患者的证型中白细胞介素-6(IL-6)水平以痰湿瘀滞型为最高,表明痰湿瘀病邪加重MS患者胰岛素抵抗。(2)各代谢综合征患者的证型与血脂紊乱的变化水平,表明以痰湿瘀滞型为主,更易导致血脂紊乱,痰湿瘀滞可能为代谢综合征的基本病机,从而为代谢综合征的中医药治疗提供依据。(3)各代谢综合征患者的证型中胰岛素敏感指数由低到高;而胰岛素抵抗指数随着各型的代谢综合征患者病情的发展由高到低。