A portable 4-channel electrochemical noise(EN) test system with high precision was developed.The modular instrument cRIO was used as its core and the signal conditioning module included zero resistance ammeter(ZRA),fl...A portable 4-channel electrochemical noise(EN) test system with high precision was developed.The modular instrument cRIO was used as its core and the signal conditioning module included zero resistance ammeter(ZRA),fly line,screening box and shielded wire.The EN data were acquired from two Q235 carbon steel specimens placed in 0.5 mol/L H2SO4 solution and 0.1 mol/L NaCl solution.The experimental result shows that this system can achieve an accuracy of 10 pA and 10 μV,and it can be applied to on-site multi-channel EN test.展开更多
Al-11%Si(mass fraction)alloy was transformed into a ductile material by equal-channel angular pressing(ECAP)with a rotary die.Two mechanisms at impact test,slip deformation by dislocation motion and grain boundary sli...Al-11%Si(mass fraction)alloy was transformed into a ductile material by equal-channel angular pressing(ECAP)with a rotary die.Two mechanisms at impact test,slip deformation by dislocation motion and grain boundary sliding,were discussed.The ultrafine grains with modified grain boundaries and the high content of fine particles(<1μm)were necessary for attaining high absorbed energy.The results contradict the condition of slip deformation by dislocation motion and coincide with that of grain boundary sliding.Many fine zigzag lines like a mosaic were observed on the side surface of the tested specimens.These observed lines may show grain boundaries appeared by the sliding of grains.展开更多
AIM:To explore the possibility of using the Non-invasive Micro-test Technique(NMT)to investigate the role of Transient Receptor Potential Canonical 1(TRPC1) in regulating Ca 2+ influxes in HL-7702 cells,a normal human...AIM:To explore the possibility of using the Non-invasive Micro-test Technique(NMT)to investigate the role of Transient Receptor Potential Canonical 1(TRPC1) in regulating Ca 2+ influxes in HL-7702 cells,a normal human liver cell line.METHODS:Net Ca 2+ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces,non-invasively.The expression levels of TRPC1 were increased by liposomal transfection,whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction. RESULTS:Ca 2+ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells.They were enhanced by addition of 20μmol/L noradrenalin and inhibited by 100μmol/L LaCl3(a non-selective Ca 2+ channel blocker);5μmol/L nifedipine did not induce any change.Overexpression of TRPC1 caused increased Ca 2+ influx.Five micromoles per liter nifedipine did not inhibit this elevation,whereas 100μmol/L LaCl3 did.CONCLUSION:In HL-7702 cells,there is a type of TRPC1-dependent Ca 2+ channel,which could be detected via NMT and inhibited by La3+.展开更多
With the development of wireless communication technology,the fifth generation mobile communications system(5 G) emerges at a historic moment and devotes itself to open the curtain of the information age.Recently,in o...With the development of wireless communication technology,the fifth generation mobile communications system(5 G) emerges at a historic moment and devotes itself to open the curtain of the information age.Recently,in order to satisfy the requirement of different applications,various advanced 5 G technologies have been developed in full swing.However,before applying these 5 G related technologies in practical systems,effective testing methods are needed to evaluate these technologies in a real,comprehensive,rapid and flexible manner.However,the testing methods are faced with new challenges along with the continuous development of the new 5 G technologies.In this paper,we present a survey of 5 G testing,including solutions and opportunities.In particular,two cases are considered,i.e.,channel modelling and overthe-air(OTA) testing of antenna systems.Specifically,a non-stationary channel model is proposed to characterize and test massive multiple-input multiple-output(MIMO) channel.In addition,we propose two probe subset selection algorithms for three-dimensional(3 D) OTA testing,which minimizes the number of probe antennas while ensuring the accuracy of the target channel emulation.Finally,future research directions and challenges on 5 G testing are given.展开更多
基金Supported by the National Basic Research Program of China("973"Program,No.2011CB610505)National Natural Science Foundation of China(No.61240038)
文摘A portable 4-channel electrochemical noise(EN) test system with high precision was developed.The modular instrument cRIO was used as its core and the signal conditioning module included zero resistance ammeter(ZRA),fly line,screening box and shielded wire.The EN data were acquired from two Q235 carbon steel specimens placed in 0.5 mol/L H2SO4 solution and 0.1 mol/L NaCl solution.The experimental result shows that this system can achieve an accuracy of 10 pA and 10 μV,and it can be applied to on-site multi-channel EN test.
文摘Al-11%Si(mass fraction)alloy was transformed into a ductile material by equal-channel angular pressing(ECAP)with a rotary die.Two mechanisms at impact test,slip deformation by dislocation motion and grain boundary sliding,were discussed.The ultrafine grains with modified grain boundaries and the high content of fine particles(<1μm)were necessary for attaining high absorbed energy.The results contradict the condition of slip deformation by dislocation motion and coincide with that of grain boundary sliding.Many fine zigzag lines like a mosaic were observed on the side surface of the tested specimens.These observed lines may show grain boundaries appeared by the sliding of grains.
基金Supported by The National Natural Science Foundation of China,No.30270532 and No.30670774Tsinghua-Yue-Yuen Medical Science Foundation,No.20240000531 and No.20240000547
文摘AIM:To explore the possibility of using the Non-invasive Micro-test Technique(NMT)to investigate the role of Transient Receptor Potential Canonical 1(TRPC1) in regulating Ca 2+ influxes in HL-7702 cells,a normal human liver cell line.METHODS:Net Ca 2+ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces,non-invasively.The expression levels of TRPC1 were increased by liposomal transfection,whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction. RESULTS:Ca 2+ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells.They were enhanced by addition of 20μmol/L noradrenalin and inhibited by 100μmol/L LaCl3(a non-selective Ca 2+ channel blocker);5μmol/L nifedipine did not induce any change.Overexpression of TRPC1 caused increased Ca 2+ influx.Five micromoles per liter nifedipine did not inhibit this elevation,whereas 100μmol/L LaCl3 did.CONCLUSION:In HL-7702 cells,there is a type of TRPC1-dependent Ca 2+ channel,which could be detected via NMT and inhibited by La3+.
基金supported by the National Natural Science of Foundation for Creative Research Groups of China(No.61421061)
文摘With the development of wireless communication technology,the fifth generation mobile communications system(5 G) emerges at a historic moment and devotes itself to open the curtain of the information age.Recently,in order to satisfy the requirement of different applications,various advanced 5 G technologies have been developed in full swing.However,before applying these 5 G related technologies in practical systems,effective testing methods are needed to evaluate these technologies in a real,comprehensive,rapid and flexible manner.However,the testing methods are faced with new challenges along with the continuous development of the new 5 G technologies.In this paper,we present a survey of 5 G testing,including solutions and opportunities.In particular,two cases are considered,i.e.,channel modelling and overthe-air(OTA) testing of antenna systems.Specifically,a non-stationary channel model is proposed to characterize and test massive multiple-input multiple-output(MIMO) channel.In addition,we propose two probe subset selection algorithms for three-dimensional(3 D) OTA testing,which minimizes the number of probe antennas while ensuring the accuracy of the target channel emulation.Finally,future research directions and challenges on 5 G testing are given.
