To study the diagnostic problem of Wire-OR （W-O） interconnect fault of PCB （Printed Circuit Board）, five modified boundary scan adaptive algorithms for interconnect test are put forward. These algorithms apply Glo...To study the diagnostic problem of Wire-OR （W-O） interconnect fault of PCB （Printed Circuit Board）, five modified boundary scan adaptive algorithms for interconnect test are put forward. These algorithms apply Global-diagnosis sequence algorithm to replace the equal weight algorithm of primary test, and the test time is shortened without changing the fault diagnostic capability. The descriptions of five modified adaptive test algorithms are presented, and the capability comparison between the modified algorithm and the original algorithm is made to prove the validity of these algorithms.展开更多
The fractal curve is proposed as a novel scanning path used in Layered Manufacturing. Aiming at a limitation that the fractal curve can only fill a square region, a method is developed to realize the trimming of frac...The fractal curve is proposed as a novel scanning path used in Layered Manufacturing. Aiming at a limitation that the fractal curve can only fill a square region, a method is developed to realize the trimming of fractal curve in arbitrary boundary layer by means of judging intersection points between parameterized arbitrary boundary and a FASS (space filling, self avoiding, simple and self similar) fractal curve. Accordingly, the related algorithm concerning with determining intersection points has been investigated according to the recursion feature of the fractal curve, and in the process of the fractal curve traversed, the rule of judging intersection points is ascertained as well, so that the laser scanning beam can “walk” along the fractal curve inside the desired boundary, and arbitrary contour components are fabricated.展开更多
The IEEE Standard 1149.1 boundary scan (BS) implementation provides the internal access required for testing the digital printed circuit board (PCB). However, the integrity of the boundary scan test infrastructure sh...The IEEE Standard 1149.1 boundary scan (BS) implementation provides the internal access required for testing the digital printed circuit board (PCB). However, the integrity of the boundary scan test infrastructure should be tested first to guarantee the validation of the results of the rest functional test and diagnosis. This paper describes the fault models and test principles of the BS test access port (TAP) lines on PCBs. A test algorithm with high fault coverage and short time is then presented for the PCB on which all ICs are BS ones.展开更多
The boundary scan architecture and its basic principle of board level built in test(BIT) technology are presented. A design for board level built in test and the method to implement test tool are brought forward.
本文利用电子背散射衍射(electron backscatter d iffraction,EBSD)技术研究了YUS701奥氏体不锈钢ROF内罩在高温服役前后的显微组织和晶界特征分布。研究结果表明,服役前后YUS701奥氏体不锈钢ROF内罩在显微组织和晶界特征分布上有明显...本文利用电子背散射衍射(electron backscatter d iffraction,EBSD)技术研究了YUS701奥氏体不锈钢ROF内罩在高温服役前后的显微组织和晶界特征分布。研究结果表明,服役前后YUS701奥氏体不锈钢ROF内罩在显微组织和晶界特征分布上有明显的差异,这种差异是ROF内罩超高温运行失效的重要原因。展开更多
An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, clo...An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.展开更多
Creep of squeeze-cast Mg-3Y-2Nd-1Zn-1Mn alloy was investigated at the constant load in the stress range of 30-80 MPa. Tensile creep tests were performed at 300℃up to the final fracture.Several tests at 50 MPa were in...Creep of squeeze-cast Mg-3Y-2Nd-1Zn-1Mn alloy was investigated at the constant load in the stress range of 30-80 MPa. Tensile creep tests were performed at 300℃up to the final fracture.Several tests at 50 MPa were interrupted after reaching the steady state creep;and another set of creep tests was interrupted after the onset of ternary creep.Fraction of cavitated dendritic boundaries was evaluated using optical microscopy.Measurement of grain boundary sliding by observation of the offset of marker lines was carried out on the surface of the crept specimens after the test interruption by scanning electron microscopy and by confocal laser scanning microscopy.The results show that the dominant creep mechanism in this alloy is dislocation creep with minor contribution of the grain boundary sliding.Creep failure took place by the nucleation,growth and coalescence of creep cavities on the boundaries predominantly oriented perpendicular to the applied stress.Increasing amount of cavitated boundaries with time of creep exposure supports the mechanism of continuous cavity nucleation and growth.展开更多
文摘To study the diagnostic problem of Wire-OR （W-O） interconnect fault of PCB （Printed Circuit Board）, five modified boundary scan adaptive algorithms for interconnect test are put forward. These algorithms apply Global-diagnosis sequence algorithm to replace the equal weight algorithm of primary test, and the test time is shortened without changing the fault diagnostic capability. The descriptions of five modified adaptive test algorithms are presented, and the capability comparison between the modified algorithm and the original algorithm is made to prove the validity of these algorithms.
文摘The fractal curve is proposed as a novel scanning path used in Layered Manufacturing. Aiming at a limitation that the fractal curve can only fill a square region, a method is developed to realize the trimming of fractal curve in arbitrary boundary layer by means of judging intersection points between parameterized arbitrary boundary and a FASS (space filling, self avoiding, simple and self similar) fractal curve. Accordingly, the related algorithm concerning with determining intersection points has been investigated according to the recursion feature of the fractal curve, and in the process of the fractal curve traversed, the rule of judging intersection points is ascertained as well, so that the laser scanning beam can “walk” along the fractal curve inside the desired boundary, and arbitrary contour components are fabricated.
文摘The IEEE Standard 1149.1 boundary scan (BS) implementation provides the internal access required for testing the digital printed circuit board (PCB). However, the integrity of the boundary scan test infrastructure should be tested first to guarantee the validation of the results of the rest functional test and diagnosis. This paper describes the fault models and test principles of the BS test access port (TAP) lines on PCBs. A test algorithm with high fault coverage and short time is then presented for the PCB on which all ICs are BS ones.
文摘The boundary scan architecture and its basic principle of board level built in test(BIT) technology are presented. A design for board level built in test and the method to implement test tool are brought forward.
文摘本文利用电子背散射衍射(electron backscatter d iffraction,EBSD)技术研究了YUS701奥氏体不锈钢ROF内罩在高温服役前后的显微组织和晶界特征分布。研究结果表明,服役前后YUS701奥氏体不锈钢ROF内罩在显微组织和晶界特征分布上有明显的差异,这种差异是ROF内罩超高温运行失效的重要原因。
基金Project(51274250)supported by the National Natural Science Foundation of ChinaProject(2012BAK09B02-05)supported by the National Key Technology R&D Program during the 12th Five-year Plan of China
文摘An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.
基金Project(106/06/0252)supported by the Czech Science FoundationProject(CTU0810412)supported by the Grant Agency of the CzechTechnical University in Prague
文摘Creep of squeeze-cast Mg-3Y-2Nd-1Zn-1Mn alloy was investigated at the constant load in the stress range of 30-80 MPa. Tensile creep tests were performed at 300℃up to the final fracture.Several tests at 50 MPa were interrupted after reaching the steady state creep;and another set of creep tests was interrupted after the onset of ternary creep.Fraction of cavitated dendritic boundaries was evaluated using optical microscopy.Measurement of grain boundary sliding by observation of the offset of marker lines was carried out on the surface of the crept specimens after the test interruption by scanning electron microscopy and by confocal laser scanning microscopy.The results show that the dominant creep mechanism in this alloy is dislocation creep with minor contribution of the grain boundary sliding.Creep failure took place by the nucleation,growth and coalescence of creep cavities on the boundaries predominantly oriented perpendicular to the applied stress.Increasing amount of cavitated boundaries with time of creep exposure supports the mechanism of continuous cavity nucleation and growth.
