Lubrication characteristics of external return spherical hinge pair of axial piston pump or motor under combined action of inclination and offset distance

External return mechanism is a mechanical structure applied to axial piston pumps.To study its lubrication characteristics,the Reynolds equation applied to an external return spherical hinge pair was deduced based on the vector equation of relative-motion velocity of the external return spherical hinge pair under the influence of external swash plate inclination and offset distance.The results show that the total friction,axial leakage flow,and maximum value of the maximum oil-film pressure increase with increasing pump-shaft speed and decrease with increasing offset distance in one working cycle when the external-swash-plate inclination is constant.However,the varying offset distance has little effect on the axial leakage flow.The maximum value of the maximum oil-film pressure decreases with increasing external-swash-plate inclination and the total leakage flow increases with increasing external-swash-plate inclination in one working cycle when the offset distance is constant.It can be seen that the abovementioned parameters are important factors that affect the lubrication characteristics of external return spherical hinge pairs.Therefore,the complex effects of different coupling parameters should be comprehensively considered in the design of the external return mechanism.

The External Dimension of Europeanization and Social Conditionality： The Case of the Generalized System of Preferences

The aim of the paper is to clarify the mechanisms of external Europeanization. Studies so far claim that the more distant a country is from the EU core the more indirect the mechanisms of the external Europeanization are. The paper problematizes this claim. Empirically it focuses on the case of social conditionality （SC） as applied in the area of social trade policy. Theoretically it follows Normal Accident Theory, as adapted in the area of the EU studies. The paper focuses on the interactions of the web of actors found in this policy area. It distinguishes between complex and tightly linked interactions. It hypothesizes that the less complex and the more tightly linked actors are the more direct the mechanisms of external Europeanization. SC is a ＂social＂ trade policy instrument that the EU includes to its trade agreements with developing countries through the Generalized System of Preferences （GSP） in order to promote the ratification and application of basic human rights, and labor, sustainable development and good governance standards. The GSP is a trade policy program that allows the exemption of developing countries from exports tariffs as a way of assisting their growth and development. SC is a ＂hard＂ instrument in the sense that it consists of both a positive aspect （carrots） and a negative one （sticks）. Developing countries that ratify and apply basic human rights, and labor, sustainable development and good governance standards qualify for additional trade preferences （carrots）, while failure of compliance results to the withdrawal of the preferences （sticks）.

To improve the mechanical function of bovine jugular vein by external stent

Objective To increase the mechanic characteristic of bovine jugular veins conduit (BJVC) by combined knitted stent outside made of nylon fiber. Methods Got rid of the cells of BJVC by enzymolysis,then combined a fabric stent with a acellular bovine jugular vein

Mechanical behavior analysis of high power commercial lithium-ion batteries

In application,lithium-ion cells undergo expansion during cycling.The mechanical behavior and the impact of external stress on lithium-ion battery are important in vehicle application.In this work,18 Ah high power commercial cell with Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)/graphite electrode were adopted.A commercial compress machine was applied to monitor the mechanical characteristics under different stage of charge(SOC),lifetime and initial external force.The dynamic and steady force was obtained and the results show that the dynamic force increases as the SOC increasing,obviously.During the lifetime with high power driving mode,different external force is shown to have a great impact on the long-term cell performance,with higher stresses result in higher capacity decay rates and faster impedance increases.A proper initial external force(900 N)provides lower impedance increasing.Postmortem analysis of the cells with2000 N initial force suggests a close correlation between electrochemistry and mechanics in which higher initial force leads to higher direct current internal resistance(DCIR)increase rate.In addition,for the cell with higher external force,deformation of the cathode and thicker solid electrolyte interface(SEI)film on the surface of anode and separator are observed.Porosity reduction and closure was also verified after cycles which is an obstacle to the lithium ion transferring.The largest cause of the observed capacity decline was the loss of active lithium through autopsy analysis.In addition,for the cell with higher external force,deformation of the cathode and thicker SEI film on the surface of anode and separator are observed.Porosity reduction and closure was also verified after cycles which is an obstacle to the lithium ion transferring.The largest cause of the observed capacity decline was the loss of active lithium through autopsy analysis.

Study on Collision Characters for SPAR Platform

This paper presents the research on the external mechanism of collision characters for a SPAR platform. The collision characters of SPAR platform have not attracted so much attention as that of ships in the past, because short of this kind of collision accidents reported. But with the increasing number of SPAR platforms in the world, the possibility of such kind of accident also increases. Therefore, it is necessary to master the character of SPAR collision. Model test technique is employed to study the external mechanism. The collision scenario is a ship colliding with a SPAR platform moored in the site with 1500 meters water depth. The striking ship hits the SPAR platform on the hard tank near water surface in its longitudinal direction. The specifics of the SPAR＇s motions and the tension forces of the mooring lines are collected to summarize the hydrodynamic characters in the collision scenario. It is found that the maximal displacements and the maximal pitch angles of the SPAR platform, and the maximal tension forces of mooring lines are all linearly proportional to the initial velocity of the striking ship basically. Mooring lines play elastic roles in the collision course.