On Properties of p-critical Points of Convex Bodies

Properties of the p-measures of asymmetry and the corresponding affine equivariant p-critical points, defined recently by the second author, for convex bodies are discussed in this article. In particular, the continuity of p-critical points with respect to p on （1, ＋∞） is confirmed, and the connections between general p-critical points and the Minkowski-critical points （∞-critical points） are investigated. The behavior of p-critical points of convex bodies approximating a convex bodies is studied as well.

On the Artificial Equilibrium Points in a Generalized Restricted Problem of Three Bodies

The present article studies the stability conditions of central control artificial equilibrium generalized restricted problem of three bodies. It is generalized in the sense that here we have taken the larger primary body to be in shape of an oblate spheroid. The equilibrium points are sought by the application of the propellant for which it would just balance the gravitational forces. The launching flight of such a satellite is seen to be applicable for having arbitrary space stations for these different missions. Specialty of the result of the investigation lies in the fact that an arbitrary space station can be formed to attain any specified mission.

SUPPORTING AND SEPARATING SUBSETS FOR INVEX BODIES

Invex bodies represent an important class of bodies which are considered as a generalization of convex bodies.In this article,the author studies the supporting for this class of bodies as well as the separating subsets of two bodies.

Effect of Resonance on the Motion of Two Cylindrical Rigid Bodies

The effect of resonance on the motion of two cylindrical rigid bodies has been studied in the light of Bhatnagar [1] [2] [3] and under some defined axiomatic restrictions. Here we have calculated variation in Eulerian angles due to resonance in terms of orbital elements and unperturbed Eulerian angles.

经“O”点穿刺与传统单侧入路治疗L_(5)椎体骨质疏松性压缩性骨折

背景:单侧穿刺入路经皮穿刺球囊扩张椎体后凸成形治疗骨质疏松性椎体压缩骨折优于双侧穿刺入路,由于L_(5)特殊解剖形态和位置特殊,传统单侧穿刺入路治疗L_(5)椎体骨质疏松性椎体压缩骨折适用性差,因此提出“O”点穿刺入路来解决该问题。目的:比较经横突基底部-椎弓根后上部-关节突外侧交点(“O”点)入路与传统单侧入路经皮穿刺球囊扩张椎体后凸成形治疗L_(5)椎体骨质疏松性压缩骨折的疗效差异。方法:回顾性分析西南医科大学附属医院2020年1月至2022年12月收治的54例L_(5)椎体骨质疏松性压缩骨折行经“O”点入路或传统经皮穿刺球囊扩张椎体后凸成形治疗的患者,根据手术方式分为2组,“O”点入路组(A组)29例,传统入路组(B组)25例。术前在X射线正位片测量A组“O”点与髂棘位置及穿刺角度;比较两组术前与术后第2天、末次随访的局部Cobb角、椎体前缘、中部高度及骨水泥分布情况;术前、术后第2天及末次随访采用疼痛目测类比评分、Oswestry功能障碍指数评估患者疼痛缓解情况与日常生活能力,记录手术相关并发症。结果与结论:①A组手术时间、术中透视次数均少于B组,差异有显著性意义(P<0.05);两组术中出血量及骨水泥注射量差异无显著性意义;②两组患者术后第2天及末次随访疼痛目测类比评分、Oswestry功能障碍指数较术前明显降低,且A组降低比B组更明显(P<0.05);③“O”点位于双侧髂棘最高点连线之下平均距离1.23 cm;“O”点到髂棘平均横向距离2.89 cm;④两组患者末次随访Cobb角较术前明显改善(P<0.05),但两组间比较差异无显著性意义(P>0.05);⑤术后骨水泥分布,A组分布良好占97%(28/29),B组分布良好占88%(22/25),A组明显优于B组(P<0.05);⑥提示经“O”点穿刺入路与传统入路经皮穿刺球囊扩张椎体后凸成形治疗L_(5)椎体骨质疏松性压缩骨折疗效满意,但“O”点穿刺入路经皮穿刺球囊扩张椎体后凸成形治疗骨水泥分布更满意,还可避免高髂棘对L_(5)椎体穿刺入路的影响。

Research on fine Spatial Quantitative Model about vulnerability of hazard-affected bodies

The seriousness of losses caused by disaster dependent on the hazard degree of environment,vulnerability of hazard-affected bodies,and emergency response capacity of the region is studied in this article.The study on hazard-affected bodies is of importance to disaster risk management,regional hazard prevention,reduction,and investment in disaster insurance.With summarizing of various assessment methods of vulnerability of hazard-affected bodies,this paper presents a refined Spatial Quantification Model of regional vulnerability which combines refined spatial geographic data and land-use type data.A quantitative study on regional vulnerability was carried out by defining fine spatial grid as the basic evaluation unit based on GIS.

Fine anatomy of reservoir architecture of point bar in meandering river: a case study of Minghuazhen Formation in northern block of Q oilfield,Bohai Sea

In order to solve dynamic Problems caused by the internal structure of fluvial reservoir,it is necessa-ry to study the fine anatomy of Point bar. Taking Minghuazhen Formation in the northern block of Q oilfield, Bohai Sea as an examPle,the authors studied identification marks,distribution Pattern and scale of Point bar based on coring,logging and dynamic data. The results show that the length of Point bar and the width of lateral accretion body are 713-911 m and 71-111m,resPectively;the diP angle and the thickness of lateral accretion bedding are 3. 5o-5. 9o and 0. 1-0. 5 m. The lateral accretion beddings are the key factor affecting the seePage velocity of the tracer.

Analysis for the Deployment of Single-Point Mooring Buoy System Based on Multi-Body Dynamics Method

Deployment of buoy systems is one of the most important procedures for the operation of buoy system. In the present study, a single-point mooring buoy system which contains surface buoy, cable segments with components, anchor and so on is modeled by applying multi-body dynamics method. The motion equations are developed in discrete node description and fully Cartesian coordinates. Then numerical method is used to solve the ordinary differential equations and dynamics simulations are achieved while anchor is casting from board. The trajectories and velocities of different nodes without current and with current in buoy system are obtained. The transient tension force of each part of the cable is analyzed in the process of deployment. Numerical results indicate that the transient payload increases to a peak value when the anchor is touching the seabed and the maximum tension force will vary with different floating configuration. This work is helpful for design and deployment planning of buoy system.

Numerical solutions for point masses sliding over analytical surfaces: Part 2

This paper is the second of two companion papers addressing the dynamics of two coupled masses sliding on analytical surfaces and interacting with one another. The motion occurs under the effect of gravity, the reaction force of the surface and basal friction. The interaction force maintains the masses at a fixed distance and lies on the line connecting them. The equations of motion form a system of ordinary differential equations that are solved through a fourth-order Runge–Kutta numerical scheme. In the first paper we considered an approximate method holding when the line joining the masses is almost tangent to the surface at the instant mass positions. In this second paper we provide a general solution. Firstly, we present special cases in which the system has exact solutions. Second, we consider a series of numerical examples where the interest is focused on the trajectories of the masses and on the intensity and changes of the interaction force.

A new control law based on characteristic exponent assignment for libration point orbit maintenance

A new method is developed for stabilizing motion on collinear libration point orbits using the formalism of the circular restricted three body problem. Linearization about the collinear libration point orbits yields an unstable linear parameter-varying system with periodic coefficients. Given the variational equations, an innovative control law based on characteristic exponent assignment is introduced for libration point orbit maintenance. A numerical simulation choosing the Richardson＇s third order approximation for a halo orbit as a nominal orbit is conducted, and the results demonstrate the effectiveness of this control law.

The Physics of Rotational Flattening and the Point Core Model

The effect of rotation on the shape (figure) and gravitational quadrupole of astronomical bodies is calculated by using an approximate point core model: A point mass at the center of an ellipsoidal homogeneous fluid. Maclaurin’s analytical result for homogenous bodies generalizes to this model and leads to very accurate analytical results connecting the three observables: oblateness (ò), gravitational quadrupole (J2), and angular velocity parameter (q). The analytical results are compared to observational data for the planets and a good agreement is found. Oscillations near equilibrium are studied within the model.

Effect of intradermal needle at five-zang Back-Shu points on treatment of chronic fatigue syndrome

Objective:To observe the effect of intradermal needle therapy on back-shu points of five zang organs in treating chronic fatigue syndrome(CFS)and provide evidence for the usage of unilateral back-shu point.Methods:Patients were randomly divided into bilateral back-shu point group,unilateral back-shu point group and non-acupoint group,remove shedding cases,each group remaining 30 patients.In bilateral back-shu point group,both sides of back-shu points of five zang organs were selected.In unilateral back-shu point group,only one side was selected,left or right alternately.The location where non-acupoint group inserted by intradermal needles were outward from the back-shu points,left or right alternately.Fatigue Scale-14(FS-14)was used to evaluate the fatigue level and the scores’improvement of physical fatigue and mental fatigue revealed the therapeutic effect on body constituents and spirits of CFS patient.Results:After the 8-week intradermal needle therapy,the total effective rate was 83.33%in the bilateral back-shu point group,which was 76.67%in the unilateral back-shu point group and 50.00%in the non-acupoint group.The curative effects of the two groups whose back-shu points of five zang organs were inserted by intradermal needles were better than the non-acupoint group(P<0.05).There was no significant difference in clinical efficacy between the bilateral back-shu point group and the unilateral back-shu point group(P>0.05).There were statistical differences in FS-14 questionnaires including total,physical and mental scores between before and after the treatment in both the two back-shu point groups(P<0.05).Only the scores of total and physical fatigue in decreased in non-acupoint group(P<0.05),which means it couldn’t help to alleviate mental fatigue statistically(P>0.05).Conclusions:(1)The intradermal needle therapy on back-shu points of five zang organs for CFS has a satisfying clinical efficacy in curing tiredness.It can help to reduce both physical and mental fatigue for the patients.Hence,it can regulate both body constituents and spirits simultaneously.(2)Needling the unilateral acupoints can get similar clinical efficacy to the bilateral points.It reveals that we can cut cost by reducing the consumption of the amount of intradermal needles used on one side.(3)Both the groups of back-shu points get better clinical efficacy than the non-acupoint group dramatically.The reason of why the intradermal needle can treat CFS maybe that back-shu points of five zang organs can regulate the functions of five zang organs characteristically.

A Measure System of Zero Moment Point Using Wearable Inertial Sensors

Keeping balance is the premise of human walking. ZMP(zero moment point) is a point where total torque achieves balance. It is an important evaluation parameter of balance ability in walking, since it can be used to better reflect the dynamic balance during walking. ZMP can be used in many applications, such as medical rehabilitation, disease diagnosis, treatment and etc. In this paper, wearable inertial sensors system based on MEMS is used to measure ZMP(zero moment point) during walking, which is cheap, convenient, and free from the restriction of lab. Our wearable ZMP measurement system consists of inertial measurement subsystem and PC real-time monitoring station. Inertial measurement subsystem includes 9-axis inertial sensing nodes, the body communication network and the central node. Inertial sensing nodes are mounted on different parts of the body to collect body posture information in real-time, and then the best estimation of current posture are obtained by Kalman filter. The data from sensors is aggregated to the central node through the CAN bus, and then ZMP is calculated. Finally, it can be showed in the PC monitoring station. Experiments prove the system can achieve real-time ZMP detection during walking.

Improved semi-analytical computation of center manifolds near collinear libration points

In the framework of the circular restricted three-body problem, the center manifolds associated with collinear libration points contain all the bounded orbits moving around these points. Semianalytical computation of the center manifolds and the associated canonical transformation are valuable tools for exploring the design space of libration point missions. This paper deals with the refinement of reduction to the center manifold procedure. In order to reduce the amount of calculation needed and avoid repetitive computation of the Poisson bracket, a modified method is presented. By using a polynomial optimization technique, the coordinate transformation is conducted more efficiently. In addition, an alternative way to do the canonical coordinate transformation is discussed, which complements the classical approach. Numerical simulation confirms that more accurate and efficient numerical exploration of the center manifold is made possible by using the refined method.

Three-dimensional analysis of pedicle screw channel,screw entry point and lateral surface of cervical vertebral body

Objective To explore three-dimensional relations of pedicle screw channel (PSC) ,screw entry point and lateral surface of cervical vertebral body by digital techniques. Methods CT scan images of cervical

Lissajous Orbits at the Collinear Libration Points in the Restricted Three-Body Problem with Oblateness

In the present work, the collinear equilibrium points of the restricted three-body problem are studied under the effect of oblateness of the bigger primary using an analytical and numerical approach. The periodic orbits around these points are investigated for the Earth-Moon system. The Lissajous orbits and the phase spaces are obtained under the effect of oblateness.

Existence of Equilibrium Points in the R3BP with Variable Mass When the Smaller Primary is an Oblate Spheroid

The paper deals with the existence of equilibrium points in the restricted three-body problem when the smaller primary is an oblate spheroid and the infinitesimal body is of variable mass. Following the method of small parameters;the co-ordinates of collinear equilibrium points have been calculated, whereas the co-ordinates of triangular equilibrium points are established by classical method. On studying the surface of zero-velocity curves, it is found that the mass reduction factor has very minor effect on the location of the equilibrium points;whereas the oblateness parameter of the smaller primary has a significant role on the existence of equilibrium points.

高校生理学课程思政建设路径的探索与实践

以生理学课程为例,在教学中充分挖掘生理学知识中蕴含的思政元素,把案例故事与专业知识有机结合,以案例故事作为支撑“点”,其中贯穿爱国情怀与责任、科学精神、敬畏生命、医学人文素养、中医药文化自信等育人主“线”,再映射到“理、法、情”3个层“面”中的对应思政元素。采用以点带线、以线扩面、多维结合的模式构筑“教师—课程—学生”一体化生理学课程思政建设路径,增强课程育人效果。

Libration Points in the R3BP with a Triaxial Rigid Body as the Smaller Primary and a Variable Mass Infinitesimal Bod

The paper deals with the existence of the coplanar libration points in the restricted three-body problem when the smaller primary is a triaxial rigid body and the infinitesimal body is of variable mass. Following small parameter method, the coordinates of collinear libration points are established whereas the coordinates of triangular libration points are established by classical method. It is found that the mass reduction factor has small effect but triaxiality parameters of the smaller primary have great effects on the coordinates of the libration points.

Artificial Equilibrium Points in the Low-Thrust Restricted Three-Body Problem When Both the Primaries Are Oblate Spheroids

This paper studies the existence and stability of the artificial equilibrium points (AEPs) in the low-thrust restricted three-body problem when both the primaries are oblate spheroids. The artificial equilibrium points (AEPs) are generated by canceling the gravitational and centrifugal forces with continuous low-thrust at a non-equilibrium point. Some graphical investigations are shown for the effects of the relative parameters which characterized the locations of the AEPs. Also, the numerical values of AEPs have been calculated. The positions of these AEPs will depend not only also on magnitude and directions of low-thrust acceleration. The linear stability of the AEPs has been investigated. We have determined the stability regions in the xy, xz and yz-planes and studied the effect of oblateness parameters A1(0A1?and ?A2(0A2<1) on the motion of the spacecraft. We have found that the stability regions reduce around both the primaries for the increasing values of oblateness of the primaries. Finally, we have plotted the zero velocity curves to determine the possible regions of motion of the spacecraft.