The smart toolholder is the core component in the development of intelligent and precise manufacturing.It enables in situ monitoring of cutting data and machining accuracy evolution and has become a focal point in aca...The smart toolholder is the core component in the development of intelligent and precise manufacturing.It enables in situ monitoring of cutting data and machining accuracy evolution and has become a focal point in academic research and industrial applications.However,current table and rotational dynamometers for milling force,vibration,and temperature testing suffer from cumbersome installation and provide only a single acquisition signal,which limits their use in laboratory settings.In this study,we propose a wireless smart toolholder with multi-sensor fusion for simultaneous sensing of milling force,vibration,and temperature signals.We select force,vibration,and temperature sensors suitable for smart toolholder fusion to adapt to the cutting environment.Thereafter,structural design,circular runout,dynamic balancing,static stiffness,and dynamic inherent frequency tests are conducted to assess its dynamic and static performance.Finally,the smart toolholder is tested for accuracy and repeatability in terms of force,vibration,and temperature.Experimental results demonstrate that the smart toolholder accurately captures machining data with a relative deviation of less than 1.5%compared with existing force gauges and provides high repeatability of milling temperature and vibration signals.Therefore,it is a smart solution for machining condition monitoring.展开更多
Joule-heating reactors have the higher energy efficiency and product selectivity compared with the reactors based on radiative heating.Current Joule-heating reactors are constructed with electrically-conductive metals...Joule-heating reactors have the higher energy efficiency and product selectivity compared with the reactors based on radiative heating.Current Joule-heating reactors are constructed with electrically-conductive metals or carbon materials,and therefore suffer from stability issue due to the presence of corrosive or oxidizing gases during high-temperature reactions.In this study,chemicallystable and electrically-conductive(La_(0.80)Sr_(0.20))_(0.95)FeO_(3)(LSF)/Gd_(0.1)Ce_(0.9)O_(2)(GDC)ceramics have been used to construct Joule-heating reactors for the first time.Taking the advantage of the resistance decrease of the ceramic reactors with temperature increase,the ceramic reactors heated under current control mode achieved the automatic adjustment of heating to stabilize reactor temperatures.In addition,the electrical resistance of LSF/GDC reactors can be tuned by the content of the highconductive LSF in composite ceramics and ceramic density via sintering temperature,which offers flexibility to control reactor temperatures.The ceramic reactors with dendritic channels(less than 100μm in diameter)showed the catalytic activity for CO oxidation,which was further improved by coating efficient MnO_(2)nanocatalyst on reactor channel wall.The Joule-heating ceramic reactors achieved complete CO oxidation at a low temperature of 165℃.Therefore,robust ceramic reactors have successfully demonstrated effective Joule heating for CO oxidation,which are potentially applied in other high-temperature catalytic reactions.展开更多
This paper examines the development of labour markets and the evolution of a structure of wages in China, using household surveys for 1988, 1995, 2002 and 2007. It finds evidence of both provincial and sectoral segmen...This paper examines the development of labour markets and the evolution of a structure of wages in China, using household surveys for 1988, 1995, 2002 and 2007. It finds evidence of both provincial and sectoral segmentation in labour markets, with eastern regions and the state-controlled sector enjoying high wage premiums in the early reform period. During the reform, China has progressed slowly towards an integrated labour market with convergence in incomes between the rural non-agriculture sector and the urban market-based sector by 1995, when industry flourished in the rural areas. The wage gap between the rural non-agriculture sector and other sectors increased and the urban state-controlled sector remained segmented with respect to all other sectors up to 2002. However, the data from 2007 show there has been increasing sectoral and spatial integration.展开更多
To investigate the feasibility of intramuscular electro-acupuncture-mediated VEGF gene transfer on experimental limb ischemia, the transcription and expression of VEGF gene have been detected with RT-PCR and immunohis...To investigate the feasibility of intramuscular electro-acupuncture-mediated VEGF gene transfer on experimental limb ischemia, the transcription and expression of VEGF gene have been detected with RT-PCR and immunohistochemistry staining, and the biological effect of VEGF gene inside the nat limb has been observed through vascular angiography. Results from angiography show that the transfer of VEGF gene into the rat with experimental limb ischemia can stimulate the formation of neovessel, establish collateral circulation, augment blood perfusion, and ameliorate distal limb necrosis. These findings reveal that intramuscular electro acupuncture-mediated VEGF gene transfer may present a new therapeutic modality for treating tissue ischemia.展开更多
基金the National Key R&D Program of China(Grant No.2022YFB3206700)the Fundamental Research Funds for the Central Universities,China(Grant No.2022CDJKYJH060)the Graduate Research and Innovation Foundation of Chongqing,China(Grant No.CYB23017).
文摘The smart toolholder is the core component in the development of intelligent and precise manufacturing.It enables in situ monitoring of cutting data and machining accuracy evolution and has become a focal point in academic research and industrial applications.However,current table and rotational dynamometers for milling force,vibration,and temperature testing suffer from cumbersome installation and provide only a single acquisition signal,which limits their use in laboratory settings.In this study,we propose a wireless smart toolholder with multi-sensor fusion for simultaneous sensing of milling force,vibration,and temperature signals.We select force,vibration,and temperature sensors suitable for smart toolholder fusion to adapt to the cutting environment.Thereafter,structural design,circular runout,dynamic balancing,static stiffness,and dynamic inherent frequency tests are conducted to assess its dynamic and static performance.Finally,the smart toolholder is tested for accuracy and repeatability in terms of force,vibration,and temperature.Experimental results demonstrate that the smart toolholder accurately captures machining data with a relative deviation of less than 1.5%compared with existing force gauges and provides high repeatability of milling temperature and vibration signals.Therefore,it is a smart solution for machining condition monitoring.
基金Prof.Dehua DONG acknowledges the financial support by the National Natural Science Foundation of China(51872123)Jinan Science and Technology Bureau(2020GXRC033).
文摘Joule-heating reactors have the higher energy efficiency and product selectivity compared with the reactors based on radiative heating.Current Joule-heating reactors are constructed with electrically-conductive metals or carbon materials,and therefore suffer from stability issue due to the presence of corrosive or oxidizing gases during high-temperature reactions.In this study,chemicallystable and electrically-conductive(La_(0.80)Sr_(0.20))_(0.95)FeO_(3)(LSF)/Gd_(0.1)Ce_(0.9)O_(2)(GDC)ceramics have been used to construct Joule-heating reactors for the first time.Taking the advantage of the resistance decrease of the ceramic reactors with temperature increase,the ceramic reactors heated under current control mode achieved the automatic adjustment of heating to stabilize reactor temperatures.In addition,the electrical resistance of LSF/GDC reactors can be tuned by the content of the highconductive LSF in composite ceramics and ceramic density via sintering temperature,which offers flexibility to control reactor temperatures.The ceramic reactors with dendritic channels(less than 100μm in diameter)showed the catalytic activity for CO oxidation,which was further improved by coating efficient MnO_(2)nanocatalyst on reactor channel wall.The Joule-heating ceramic reactors achieved complete CO oxidation at a low temperature of 165℃.Therefore,robust ceramic reactors have successfully demonstrated effective Joule heating for CO oxidation,which are potentially applied in other high-temperature catalytic reactions.
文摘This paper examines the development of labour markets and the evolution of a structure of wages in China, using household surveys for 1988, 1995, 2002 and 2007. It finds evidence of both provincial and sectoral segmentation in labour markets, with eastern regions and the state-controlled sector enjoying high wage premiums in the early reform period. During the reform, China has progressed slowly towards an integrated labour market with convergence in incomes between the rural non-agriculture sector and the urban market-based sector by 1995, when industry flourished in the rural areas. The wage gap between the rural non-agriculture sector and other sectors increased and the urban state-controlled sector remained segmented with respect to all other sectors up to 2002. However, the data from 2007 show there has been increasing sectoral and spatial integration.
文摘To investigate the feasibility of intramuscular electro-acupuncture-mediated VEGF gene transfer on experimental limb ischemia, the transcription and expression of VEGF gene have been detected with RT-PCR and immunohistochemistry staining, and the biological effect of VEGF gene inside the nat limb has been observed through vascular angiography. Results from angiography show that the transfer of VEGF gene into the rat with experimental limb ischemia can stimulate the formation of neovessel, establish collateral circulation, augment blood perfusion, and ameliorate distal limb necrosis. These findings reveal that intramuscular electro acupuncture-mediated VEGF gene transfer may present a new therapeutic modality for treating tissue ischemia.