In the process of smart city construction, Beijing, Shanghai, Shenzhen and some other cities are facing many problems, among which the most essential one is the government' s leading role cannot give a better play du...In the process of smart city construction, Beijing, Shanghai, Shenzhen and some other cities are facing many problems, among which the most essential one is the government' s leading role cannot give a better play due to the constraints of the traditional government functions. Therefore, it is necessary to carry out a reasonable position for the government functions in the construction of smart city. This paper issues that the government should reflect functions in the construction of smart city, such as the planning function of top-level design and unified planning; the organizational function of providing funds and talent protection; the coordinating function of promoting multiple-subject cooperation; the controlling function of establishing technical standards and legal norms.展开更多
Global issues,just as the name implies,refer to the common threats and challenges facing the whole globe.Upon the backdrop of deepening globalization and increasing interdependence among all the countries,global issue...Global issues,just as the name implies,refer to the common threats and challenges facing the whole globe.Upon the backdrop of deepening globalization and increasing interdependence among all the countries,global issues feature diversification and complexity.Furthermore,without the so-called'world government'in place,all the countries should展开更多
Basic research features its indelible contribution to and energetic promotion of scientific cause and advancing social progress. This article explores its vital position and rewarding role in creating socio-economic b...Basic research features its indelible contribution to and energetic promotion of scientific cause and advancing social progress. This article explores its vital position and rewarding role in creating socio-economic benefits by reviewing the development and marketing success of a new drug, "Di’ aoxinxuekang".展开更多
"Removing English from the gaokao,China’s college entrance exam,might lower the Englishlearning fever in China but it helps build a fair and targeted college admission system,"said a national political advi..."Removing English from the gaokao,China’s college entrance exam,might lower the Englishlearning fever in China but it helps build a fair and targeted college admission system,"said a national political adviser.展开更多
Error modelling and compensating technology is an effective method to improve the processing precision.The position and orientation deviation of workpiece is caused by the fixing and manufacturing errors of the fixtur...Error modelling and compensating technology is an effective method to improve the processing precision.The position and orientation deviation of workpiece is caused by the fixing and manufacturing errors of the fixture.How to reduce the position and orientation deviation of workpiece has become a technical problem of improving the processing quality of workpiece.In order to increase machining accuracy,an implementation scheme of fixture system comprehensive errors(FSCE) compensation is proposed.A FSCE parameter model is established by analyzing the influence of contact points on the position and orientation of workpiece.Meanwhile,a parameter identification method for FSCE parameter model is presented by using the 3-2-1 deterministic positioning fixture,which determines the model parameters.Moreover,a FSCE compensation model is formulated to study the compensation value of the cutting position.By using RenishawOMP60 Probe and combining vertical machining centre(SKVH850) equipment with SKY2001 Open CNC System,on-machine verification system(OMVS) is built to measure FSCE successfully.The processing error can be reduced by analyzing the cutting position of the tool with the homogeneous transformation of space coordinate system.Finally,the compensation experiment of real time errors is conducted,and the cylindricality and perpendicularity errors of hole surface are reduced by 30.77% and 28.57%,respectively.This paper provides a new way of realizing the compensation of FCSE,which can improve the machining accuracy of workpiece largely.展开更多
文摘In the process of smart city construction, Beijing, Shanghai, Shenzhen and some other cities are facing many problems, among which the most essential one is the government' s leading role cannot give a better play due to the constraints of the traditional government functions. Therefore, it is necessary to carry out a reasonable position for the government functions in the construction of smart city. This paper issues that the government should reflect functions in the construction of smart city, such as the planning function of top-level design and unified planning; the organizational function of providing funds and talent protection; the coordinating function of promoting multiple-subject cooperation; the controlling function of establishing technical standards and legal norms.
文摘Global issues,just as the name implies,refer to the common threats and challenges facing the whole globe.Upon the backdrop of deepening globalization and increasing interdependence among all the countries,global issues feature diversification and complexity.Furthermore,without the so-called'world government'in place,all the countries should
文摘Basic research features its indelible contribution to and energetic promotion of scientific cause and advancing social progress. This article explores its vital position and rewarding role in creating socio-economic benefits by reviewing the development and marketing success of a new drug, "Di’ aoxinxuekang".
文摘"Removing English from the gaokao,China’s college entrance exam,might lower the Englishlearning fever in China but it helps build a fair and targeted college admission system,"said a national political adviser.
基金supported by National Natural Science Foundation of China (Grant No. 50975200)National Key Technologies R & D Programmer of China (Grant No. 2009ZX04014-021)
文摘Error modelling and compensating technology is an effective method to improve the processing precision.The position and orientation deviation of workpiece is caused by the fixing and manufacturing errors of the fixture.How to reduce the position and orientation deviation of workpiece has become a technical problem of improving the processing quality of workpiece.In order to increase machining accuracy,an implementation scheme of fixture system comprehensive errors(FSCE) compensation is proposed.A FSCE parameter model is established by analyzing the influence of contact points on the position and orientation of workpiece.Meanwhile,a parameter identification method for FSCE parameter model is presented by using the 3-2-1 deterministic positioning fixture,which determines the model parameters.Moreover,a FSCE compensation model is formulated to study the compensation value of the cutting position.By using RenishawOMP60 Probe and combining vertical machining centre(SKVH850) equipment with SKY2001 Open CNC System,on-machine verification system(OMVS) is built to measure FSCE successfully.The processing error can be reduced by analyzing the cutting position of the tool with the homogeneous transformation of space coordinate system.Finally,the compensation experiment of real time errors is conducted,and the cylindricality and perpendicularity errors of hole surface are reduced by 30.77% and 28.57%,respectively.This paper provides a new way of realizing the compensation of FCSE,which can improve the machining accuracy of workpiece largely.