国有民办二级学院人才培养的实践与探讨

高等学校内部建立一校两制的国有民办二级学院,是高等教育管理模式、运行机制改革的有益探索。人才培养问题是国有民办二级学院面临的新课题。

A Kind of PWM Pneumatic Servo Control System——Modulation Methods and Dynamic Responses

Vibrations or dither's are features of the PWM servo control system in their steady outputs. On the grounds of analyses and experiments of a PWM pneumatic servo control system, the paper puts forward four varieties of PWM modulation methods, and concludes on the relationship between dithers and the different methods, and then discusses the influence of friction to the dithers. Results from experiments regarding the dynamic and static responses on the given system support the theories presented.

GUIDANCE AND CONTROL FOR AUTOMATIC LANDING OF UAV

A scheme of guidance and control is presented to meet the requirements for automatic landing of unmanned aerial vehicles (UAVs) based on the airborne digital flight control system and radio tracker on ground station. An automatic landing system is realized for an unmanned aerial vehicle. The results of real time simulation and flight test are given to illustrate the effectiveness and availability of the scheme. Results meet all the requirements for automatic landing of the unmanned aerial vehicle.

企业改制问题新探

以建立现代企业制度为中心的国企改革已经发展到了一个新的阶段,到目前为止,国有大中型企业普遍建立了现代企业制度,初步实现了"产权清晰、权责明确、政企分开、管理科学"的设定目标,同时,国家通过"债转股"、兼并破产、鼓励国企股票上市等有效政策,减轻了企业负担,增强了企业的竞争能力,使国企摆脱了困境,为国家经济持久稳定增长起了重要作用.

Distribution Orientation and Driving Mechanism of Geographical Pattern Change of China′s Banking Industry

By analyzing the relationship among government, market driving forces, distribution orientation of banking industry, service opportunity equality and spatial patterns, this paper proposes that it is distribution orientation that lead to the formation and evolution of spatial pattern of banking industry. The difference of the distribution orientation leads to the separation of the spatial pattern of banking industry, and the change of the distribution orientation leads to the change of spatial pattern. The degree of spatial pattern change is subject to the degree of change of distribution orientation, and the scale of bank resources in the regions, which supports the distribution orientation variation. Based on these theoretical frameworks, some indicators were designed to analyze the pattern change of China′s banking industry and its effects since 1995 under the change of the distribution orientation. This paper finds that the orientation of economic benefit maximization driven by market causes the banking industry to concentrate in economically developed regions.The government, which does not follow the orientation of economic benefit maximization, plays a role of stabilizer. Since the bank branches in the regions with the greatest change in bank branch distribution are too few, and regions with the greatest change in bank loan allocation are the regions with lots of loans, the pattern change of the banking industry in physical form is not as notable as that in economic form.

Control Strategies and Mechanisms for Active Control of Sound Transmission into a Vibro-acoustic Enclosure

An analytical study was presented on active control of sound transmission into a vibro-acoustic enclosure comprising two flexible plates. Two types of actuators were used, i.e. acoustic actuator and distributed lead zirconate titanate piezoelectric (PZT) actuator instead of point force actuator. Using the modal acoustic transfer impedance-mobility matrices, the excitation and interaction in the coupled sound transmission system can be described with clear physical significance. With the control system designed to globally reduce the sound field, different control system configurations were considered, including the structural actuator on the incident plate, actuator on the receiving plate, acoustic actuator on the cavity, and their combinations. The effectiveness and performance of the control strategy corresponding to each system configuration were compared and discussed. The role and control mechanism of each type of actuator were of particular interest. It was shown that the incident plate actuator is effective in controlling the cavity-dominated modes and the structural modes dominated by the incident plate and receiving plate. Two main control mechanisms are involved in this control configuration, i.e., modal suppressing and modal rearrangement. For control system configuration with only acoustic actuator in the enclosure, the mechanism involved in this arrangement is purely modal suppression. Desirable placements of structural actuators in terms of total potential energy reduction were also discussed.

Friction and wear of 7075 aluminum alloy induced by torsional fretting

The torsional fretting wear tests of 7075 aluminum alloy flat against 52100 steel ball in dry condition were carried out on a new high-precision torsional fretting-wear tester.The kinetics behaviors and damage mechanism of 7075 aluminum alloy under different angular displacement amplitudes were investigated in detail.The results show that the torsional fretting running behaviors of 7075 aluminum alloy can be defined by three fretting regimes(i.e.partial slip regime(PSR),mixed fretting regime(MFR) and slip regime(SR)) with the increase of angular displacement amplitudes.In PSR,the damage occurs at the lateral portion of the contact zone with a slight annular shape.However,in MFR and SR,more severe damages are observed and the debris layer covers the wear scars.Friction torque and dissipation energy which are strongly dependent upon the imposed angular displacement amplitudes and presented in three stages were discussed in detail.The mechanisms of torsional fretting wear of aluminum alloy are mainly oxidative wear,abrasive wear and delamination in the three fretting regimes.In addition,the oxidative debris plays an important role during the torsional fretting wear processes.

A Potential Flow Based Flight Simulator for an Underwater Glider

Underwater gliders are recent innovative types of autonomous underwater vehicles （AUVs） used in ocean exploration and observation. They adjust their buoyancy to dive and to return to the ocean surface. During the change of altitude, they use the hydrodynamic forces developed by their wings to move forward. Their flights are controlled by changing the position of their centers of gravity and their buoyancy to adjust their trim and heel angles. For better flight control, the understanding of the hydrodynamic behavior and the flight mechanics of the underwater glider is necessary. A 6-DOF motion simulator is coupled with an unsteady potential flow model for this purpose. In some specific cases, the numerical study demonstrates that an inappropriate stabilizer dimension can cause counter-steering behavior. The simulator can be used to improve the automatic flight control. It can also be used for the hydrodynamic design optimization of the devices.

Improved Behaviour Control on Laser Cruise of Autonomous Mobile Robot

The software of behaviour-based algorithm~ was parted to several functional modules which represented different behaviours with different priorities. A basic algorithm with S-type arbiter and an improved algorithm with I-type arbiter were compared. The improved algorithm can reduce judging time and avoid some mistakes of the basic one. In mapping obstacles, the robot adjusted the spread angle according to different distances to obstacles in scaled vector field histogram （SVFH） algorithm, and then the robot turned more sharply in near obstacles than in far obstacles, which made the robot move more safely and smoothly in a cluttered room.

Development and control of flexible pneumatic wall-climbing robot

A new kind of flexible pneumatic wall-climbing robot,named WALKMAN-I,was proposed. WALKMAN-I is basically composed of a flexible pneumatic actuator (FPA),a flexible pneumatic spherical joint and six suction cups. It has many characteristics of low-cost,lightweight,simple structure and good flexibility. Its operating principle was introduced. Then three basic locomotion modes,which are linear motion,curvilinear motion and crossing the orthogonal planes,were presented. The safety conditions of WALKMAN-I were discussed and built. Finally,the control system was designed and experiments were carried out. Experimental results show that WALKMAN-I is able to climb on the vertical wall surface along a straight line or a curved path,and has the ability of crossing orthogonal planes and obstacles. The maximum rotation angle reaches 90°,the maximum velocity reaches 5 mm/s,and the rotation angle and the moving velocity of WALKMAN-I can be easily controlled.

Limestone mechanical deformation behavior and failure mechanisms： a review

In this paper, several mechanical deformation curves of limestone are reviewed, and the effects of temperature, confining pressure, and fluid are discussed. Generally, Mohr–Coulomb is used for limestone brittle fracture. The characteristic of low temperature cataclastic flow and the conditions and constitutive equations of intracrystal plastic deformation such as dislocation creep,diffusion creep, and superplastic flow are discussed in detail. Specifically, from the macroscopic and microscopic view, inelastic compression deformation(shear-enhanced compaction) of large porosity limestone is elaborated.Compared with other mechanics models and strength equations, the dual porosity(macroporosity and microporosity) model is superior and more consistent with experimental data. Previous research has suffered from a shortage of high temperature and high pressure limestone research; we propose several suggestions to avoid this problem in the future:(1) fluid-rock interaction research;(2) mutual transition between natural conditions and laboratory research;(3) the uniform strength criterion forshear-enhanced compaction deformation;(4) test equipment; and(5) superplastic flow mechanism research.

Prediction of Planing Craft Motion Based on Grey System Theory

In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM（1,N） model in grey system theory to predict planing craft motion and carried out the numerical simulation experiment. According to the characteristics of planing craft motion, a recurrence formula was proposed of the parameter matrix of an MGMfl,N） model. Using this formula, data can be updated in real-time without increasing computational complexity significantly. The results of numerical simulation show that using an MGM（1,N） model to predict planing motion is feasible and useful for prediction. So the method proposed in this study can reflect the planing craft motion mechanism successfully, and has rational and effective functions of forecasting and analyzing trends.

Theory and experiment of observer based magnetostrictive self-sensing actuator

Giant magnetostrictive actuators (GMAs) often work in a close-loop feedback system. This system needs independent sensors which may be difficult to be fixed, besides, excessive sensors may cause more unpredicted problems in a large system. This paper aims to develop a self-sensing GMA. An observer based on piezomagnetic equations is constructed to estimate the stress and strain of the magnetostrictive material. The observer based self-sensing approach depends on the facts that the magnetic field is controllable and that the magnetic induction is measurable. Aiming at the nonlinear hysteresis in magnetization, a hys- teresis compensation observer based on Preisach model is developed. Experiment verified the availability of the observer approach, and the hysteresis compensation observer has higher tracking precision than linear observer for dynamic force sensing.

Novel Operation Mechanism of Capacitorless DRAM Cell Using Impact Ionization and GIDL Effects

A novel operation mechanism of capacitorless SOl-DRAM （silicon on insulator dynamic random access memory） cell using impact ionization and GIDL （gated-induce drain leakage） effects for write ＂1＂ operation was proposed. The conventional capacitorless DRAM cell with single charge generating effect is either high speed or low power, while the proposed DG-FinFET （double-gate fin field effect transistor） cell employs the efficient integration of impact ionization and GIDL effects by coupling the front and back gates with optimal body doping profile and proper bias conditions, yielding high speed low power performance. The simulation results demonstrate ideal characteristics in both cell operations and power consumption. Low power consumption is achieved by using GIDL current at 0. luA when the coupling between the front and back gates restrains the impact ionization current in the first phase. The write operation of the cell is within Ins attributed to significant current of the impact ionization effect in the second phase. By shortening second phase, power consumption could be further decreased. The ratio of read ＂1＂ and read ＂0＂ current is more than 9.38E5. Moreover, the cell has great retention characteristics.

The Enlightenment and Reference of American Medical Insurance Operation Mechanism to the Modernization of Medical Insurance in China

The United States is unique in terms of health insurance, supplemented by commercial health insurance, supplemented by government medical care and medical assistance, and the United States has been criticized for being the only developed country that has failed to achieve universal health insurance. Although the United States in the health insurance operation also encountered a variety of problems, but its health insurance operation mechanism in the commercial insurance model and legislation first, democratic participation and other experience, it is worth in China＇s medical insurance management in the modernization of learning to learn from.

A Study on Dimension Synthesis for the Peaucellier Mechanism

Straight-line motion, albeit simple, manifests itself in numerous applications, from running steam engines and oil wells to manufacturing parts with straight edges and sides. The drive to maximize production creates a need for continuously running assembly-line manufacturing comprised of precise, individually optimized components. While there are many so-called straight-line generating mechanisms, few actually produces a true straight-line, most generate only approximate straight-line. Featured an eight-link rhomboidal system with length constraints,, the Peaucellier mechanism is one that actually produces a true straight line intrinsically. This paper presents a study on the dimension synthesis of the Peaucellier mechanism, namely by identifying the correct ratio of linkage lengths to produce the longest straight line stroke. In addition to designing for stroke, another objective of interest is to attain a desired velocity profile along the path. Kinematic analysis of the velocity profile on the mechanism will render the creation of input angular velocity standards based on desired stroke speed. Given the stroke and velocity specifications, specific steps to size the dimensions of the mechanism developed as result of this study will be presented.

Review of actuators for high speed active flow control

Actuators are one of the key points for the development of active flow control technology.Efficient methods of high speed flow control can provide enhanced propulsive efficiency and at the same time enable safe and maneuverable high speed flight.The development of high speed flight technology promotes the emergence of novel and robust actuators.This review introduces the state of the art in the development of actuators that can be used in high speed active flow control.The classification and different operation criteria of the actuators are discussed.The specifications,mechanisms and applications of various popular actuator types including fluidic,mechanical,and plasma actuators are described.Based on the realistic need of high speed flow control and the existing results of actuators,a new actuator design method is proposed.At last,the merits and drawbacks of the actuators are summarized and some suggestions on the development of active flow control technology are put forward.

The potential of natural products for targeting PPARα

Peroxisome proliferator activated receptors(PPARs) α,-γ and-β/δ are ligand-activated transcription factors and members of the superfamily of nuclear hormone receptor. These receptors play key roles in maintaining glucose and lipid homeostasis by modulating gene expression. PPARs constitute a recognized druggable target and indeed several classes of drugs used in the treatment of metabolic disease symptoms, such as dyslipidemia(fibrates, e.g. fenofibrate and gemfibrozil) and diabetes(thiazolidinediones, e.g. rosiglitazone and pioglitazone) are ligands for the various PPAR isoforms. More precisely, antidiabetic thiazolidinediones act on PPARγ, while PPARα is the main molecular target of antidyslipidemic fibrates. Over the past few years, our understanding of the mechanism underlying the PPAR modulation of gene expression has greatly increased. This review presents a survey on terrestrial and marine natural products modulating the PPARα system with the objective of highlighting how the incredible chemodiversity of natural products can provide innovative leads for this "hot" target.

Displacement manifold method for type synthesis of lower-mobility parallel mechanisms

Type synthesis of lower-mobility parallel mechanisms is a hot and frontier topic in international academic and industrial field. Based on the Lie group theory, a displacement manifold synthesis method is proposed. For all the nine kinds of lower-mobility parallel mechanisms, the mechanism displacement manifold, limb displacement manifold and the geometrical conditions which guarantee that the intersection of the limb displacement manifold is the desired mechanism displacement manifold are enumerated. Various limb kinematic chains can be obtained using the product closure of displacement subgroup. Parallel mechanisms can be constructed with these limbs while obeying the geometrical conditions. Hence, all the nine kinds of lower-mobility parallel mechanisms can be synthesized using this method. Since displacement manifold deals with finite motion, the result mechanism of synthesis have full-cycle mobility. Novel architectures of lower-mobility parallel mechanisms can be obtained using this method.