Multibody system transfer matrix method:The past, the present, and the future

The multibody system transfer matrix method(MSTMM),a novel dynamics approach developed during the past three decades,has several advantages compared to conventional dynamics methods.Some of these advantages include avoiding global dynamics equations with a system inertia matrix,utilizing low‐order matrices independent of system degree of freedom,high computational speed,and simplicity of computer implementation.MSTMM has been widely used in computer modeling,simulations,and performance evaluation of approximately 150 different complex mechanical systems.In this paper,the following aspects regarding MSTMM are reviewed:basic theory,algorithms,simulation and design software,and applications.Future research directions and generalization to more applications in various fields of science,technology,and engineering are discussed.

Fault Estimation and Accommodation for Networked Control Systems with Transfer Delay

在这份报纸，差错评价和差错的一个方法为有转移延期和进程噪音的联网的控制系统(NCS ) 的容忍的控制被介绍。首先，联网的控制系统作为有转移的分离时间的系统推迟的 multiple-input-multiple-output (MIMO ) 被建模，处理噪音，并且为无常建模。在这个模型下面并且在一些条件下面，一个差错评价方法被建议估计系统差错。根据差错评价和滑动模式控制理论的信息，一个差错容忍的控制器被设计恢复系统性能。最后，模拟结果被用来验证方法的效率。

Survey on the Peasants' Will of Forest Land Transfer in the Reform of Collective Forest Right System——On the Case of 180 Peasant Households in Lishui City of Zhejiang Province

Taking sample survey in the eighteen villages of Yunhe, Longquan and Qingyuan County of Lishui City of Zhejiang Province, the results show that the forest land transfer of sample peasants is mainly transfer-out, the private treaty of forest land transfer is the main pattern of most peasant households, forest right trading market hasn't got wide approval in peasants, peasants' dependence on land is reducing, and so on. Through analysis, the reasons of influent transfer of forest land include peasant's subjective will, less type of transfer objects, dull information communication, big difference of expected price and imperfect development of intermediary organization. In order to promote a healthy development of forest land transfer, the paper puts forward proposals of strengthening policy publicity, improving system, identifying property right, pushing variety of transfer types, developing forest land market, cultivating subject of market and so on.

Dynamic Performance Analysis of the Coupling Shaft System in a Carpet Tufting Machine Utilizing the Transfer Matrix Method

The dynamic performance of the coupling shaft system in a carpet tufting machine is the most critical factor affecting the carpet tufting machine's efficiency,and the product quality of the tufted carpet. To determine how to avoid resonance produced by the coupling shaft system's vibration during the weaving process,the dynamic performance of a coupling shaft system in a carpet tufting machine was analyzed. Focusing on a DHGN801D-400 carpet tufting machine,a dynamic model of coupling shaft system was established by utilizing transfer matrix methodology. On the basis of this model,the natural frequencies and mode shapes of the coupling shaft system were obtained through simulations. The correctness of the theoretical model and the dynamic performance of the coupling shaft system were validated by experiments. The first order natural frequency of the coupling shaft system was close to 600 r / min. A conclusion can thus be drawn that operating the carpet tufting machine near this speed should be avoided as much as possible.

Spectrum Characteristics and Transfer Function of the Hydrograph of the Deep Aqueous System

The fluctuation of most of the hydrograph in the deep aqueous system records the fluid pulsation in lithosphere and variation of the earth's crust. Many observations have verified that groundwater is an ideal information carrier of the crust. In this paper, the series of input (precipitation, air pressure, Earth tide etc.) and output (water level, artesian flow) of the deep aqueous system are studied by using the spectrum analysis and system theory. The application concepts of transfer function and the spectral structure of the hydrograph enrich the knowledge of the deep aqueous system. Two typical spectral structures of the hydrograph of the deep aqueous system are obtained by comparing with many water-bearing systems of the Jizhong depression. One is from well Ma-17 and the other is from the well Xinze-5. Finally, the physical models of forming the spectrum of the hydrograph are constructed on the basis of the spectrum research on the deep aqueous system.

Transfer Function Description of Multirate Sampling Systems

Based on the sampler decomposition method and modified Z transform, this paper proposes a pulse transfer function matrix description of the multivariable multirate sampling systems. This multirate sampling system model has a simple structure, and can be used as a basis for the analysis and synthesis of the multirate sampling systems.

ADJOINT SYSTEM INTEGRALS FOR OPTIMAL SPACE N-IMPULSE TRANSFER

The adjoint system integrals for time free, optimal N-impulse transfer during a firing period in 5-phase selected are derived.

Transfer alignment of shipborne inertial-guided weapon systems

The transfer alignment problem of the shipborne weapon inertial navigation system （INS） is addressed. Specifically, two transfer alignment algorithms subjected to the ship motions induced by the waves are discussed. To consider the limited maneuver level performed by the ship, a new filter algorithm for transfer alignment methods using velocity and angular rate matching is first derived. And then an improved method using integrated velocity and integrated angular rate matching is introduced to reduce the effect of the ship body flexure. The simulation results show the feasibility and validity of the proposed transfer alignment algorithms.

Protection of Collective Rights of Rural Members in the Process of Land Transfer under Shareholding Cooperative Systems

According to the legal definitions of land transfer under shareholding cooperative systems,rural groups,collective rights of members,and this paper discloses the necessity of protecting the collective rights of members.In terms of qualification definition of members,rights of fetus,married daughters and sons in law cannot be guaranteed.In terms of rights protection,partial rights cannot be assured,power of personal stake inthe collective members is imperfect which results in inadequate,unbalanced,shaky and unpunctuated benefits.Based on objective and subjectivecauses,the democratic management rights of members in land transfer process have been weakened or even deprived,the protection of the basiclife is hard to realize.The paper proposes that it is necessary to build the social protection mechanisms of rural land shareholding cooperative sys-tems.The first is to treat those members that own land,attending the shareholding cooperation but having not taken part in the land transfer proces-sion as the protection objects.The second is in the procession of land transfer,making it clear the compensation standards of land transfer,estab-lishing the intermediate agencies of land transfer and performing the collective economic organizing functions.The third is that the account capital ofsocial protection is contributed together by personal member,the land users(shareholding cooperative companies) and government.The fourth isto pay more attention to the added value and safety management of capital operation.

NEW INITIATION SYSTEMS FOR ATOM TRANSFER RADICAL POLYMERIZATION

This review summarizes our achievements in designing new initiation systems for atom transfer radical polymerization (ATRP). First-order kinetics and extension experiments revealed the living nature of these reactions. Tailor- made vinyl polymers with functional end groups were characterized by 1H-NMR and UV-vis spectroscopic analyses. Replacing traditional radical initiators AIBN and BPO, carbon-carbon bond compounds, 1,1,2,2-tetraphenyl-1,2-ethanediol, diethyl 2,3-dicyano-2,3-diphenylsuccinate and diethyl 2,3-dicyano-2,3-di(p-tolyl)succinate, were utilized in reverse ATRP to produce the initiating radical. Sulfur-sulfur bond iniferter, tetraethylthiuram disulfide (TD), in conjunction with CuBr/bpy or NiCl2/PPh3 complex could control the styrene polymerization via redox reaction. Pseudo-halogen transfer reaction was demonstrated to maintain the dormant-active species equilibrium in normal and reverse ATRP with Cu(S2CNEt2), Cu(S2CNEt2)Cl and Fe(S2CNEt2)3 as catalysts. The organic halide initiator and reduced transition metal compound that started the living polymerization were produced in situ from the components of TD/FeCl3/PPh3, TD/CuBr2/bpy and Fe(S2CNEt2)3/FeCl3/PPh3 systems. Accurate control of UV irradiation time favored the radical generation process in photo ATRP with the 2,2-dimethoxy-2-phenylacetophenone/Fe(S2CNEt2)3 initiation system.

Design of control sequence of pulses for the population transfer of high dimensional spin 1/2 quantum systems

On the basis of the relationship between the Hamiltonian of spin 1/2 quantum system under control and the energy level structure and transitions, a radio frequency pulse sequence is designed using intuitive and half counter-intuitive sequences of pulse to transfer the population of the 3-qubit system coherently. The effectiveness of the designed control sequence is verified through the system simulation experiment of the evolution of state. In principle, the design method of the control pulse sequence proposed can be generalized to use in the quantum systems of higher dimension.

Energy transfer in double plate system dynamics

The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component.

Heat Transfer Process of Bubble during the Occurrence of Cavitation in Hydraulic System

Thermal characteristic of cavitation has great influence on the process of occurrence,development and collapse of bubble in hydraulic system. By choosing the stage of bubble growth as the research object,combining with the characteristic of the process of bubble occurrence and development in hydraulic system, and ignoring the impact of thermal radiation,the heat transfer situation of bubble growth was analyzed under appropriate assumptions of thermodynamic conditions in the bubble generation and development process. The mathematical expression of the temperature change of bubble was deduced using thermodynamic principle. Through combining the expression with classic Rayleigh-Plesset Equation,numerical calculation was carried out and the temperature variation over time( or bubble radius) was obtained. The influences of convective heat transfer coefficient of bubble and polytropic exponent on the thermodynamic process of bubble were analyzed. Finally,the thermal characteristic of bubble growth after cavitation occurrence was summarized.

Discrete time transfer matrix method for dynamics of multibody system with flexible beams moving in space

In this paper, by defining new state vectors and developing new transfer matrices of various elements mov- ing in space, the discrete time transfer matrix method of multi-rigid-flexible-body system is expanded to study the dynamics of multibody system with flexible beams moving in space. Formulations and numerical example of a rigid- flexible-body three pendulums system moving in space are given to validate the method. Using the new method to study the dynamics of multi-rigid-flexible-body system mov- ing in space, the global dynamics equations of system are not needed, the orders of involved matrices of the system are very low and the computational speed is high, irrespec- tive of the size of the system. The new method is simple, straightforward, practical, and provides a powerful tool for multi-rigid-flexible-body system dynamics.

体系化构造:美国保密基础设施立法及启示

数字技术高速发展态势下,国家保密法律制度需要树立符合时代特征的保密基础设施概念,充分考虑设置、维护、管理和销毁保密信息的端点、系统环境、人员的安全及相应的能力,以积极应对网络信息技术运用带来的环境变化和挑战。第二次世界大战后美国保密立法历程表明,美国通过法律法规推动保密基础设施的现代化和改革,逐步完成了系统架构下的涉密信息安全保障;而立法后紧跟的标准、手册等规范文件对贯彻实施其保密基础设施法律法规也起到了非常重要的作用。美国保密基础设施立法一直以国家安全战略为遵循,并不断加强与企业合作,如今则更加重视与网络安全的衔接。研究美国保密基础设施立法现状与趋势,为中国从立法理念、规范内容和形式等方面完善保密法律制度提供了新思路。

Exciton transfer dynamics in a trimer system

We study exciton transfer dynamics in a trimer system by investigating excitation transfer probability （ETP）. We calculate ETP in the zero-temperature limit and theoretically predict the environment-assisted quantum critical effect, in which ETP exhibits a sudden change at the critical point of quantum phase transition for the trimer. In particular, we find that the steady-state ETP can be observed in the presence of the environment interaction.

Energy transfer and correlation dynamics in a three-quasi-spin-pigment system

In this paper, the effects of quantum and classical correlations on the excitation energy transfer in a three-quasi- spin-pigment system are investigated. We first study the dependence of the energy transfer efficiency on various initial correlations of the donor pigments, and find that the initial concurrence is crucial to the efficiency no matter whether the initial states are pure or mixed. We then demonstrate the dynamics of correlations of the system and observe the appearance of sudden death of quantum correlations in the donor pigments. The relation between the energy transfer efficiency and the dynamics of correlations in the donor pigments is also discussed.

Design of low-energy transfer from lunar orbit to asteroid in the Sun-Earth-Moon system

Asteroid exploration trajectories which start from a lunar orbit are investigated in this work.It is assumed that the probe departs from lunar orbit and returns to the vicinity of Earth,then escapes from the Earth by performing a perigee maneuver.A low-energy transfer in Sun-EarthMoon system is adopted.First,the feasible region of lowenergy transfer from lunar orbit to perigee within 5 000 km height above the Earth surface in Sun-Earth-Moon system is calculated and analyzed.Three transfer types are found,i.e.,large maneuver and fast transfers,small maneuver and fast transfers,and disordered and slow transfers.Most of feasibility trajectories belong to the first two types.Then,the lowenergy trajectory leg from lunar orbit to perigee and a heliocentric trajectory leg from perigee to asteroid are patched by a perigee maneuver.The optimal full-transfer trajectory is obtained by exploiting the differential evolution algorithm.Finally,taking 4179 Toutatis asteroid as the target,some low-energy transfer trajectories are obtained and analyzed.