Forward gated-diode Recombination-Generation(R-G) current method is applied to an NMOSFET/SOI to measure the stress-induced interface traps in this letter. This easy but accurate experimental method can directly give ...Forward gated-diode Recombination-Generation(R-G) current method is applied to an NMOSFET/SOI to measure the stress-induced interface traps in this letter. This easy but accurate experimental method can directly give stress-induced average interface traps for characterizing the device’s hot carrier characteristics. For the tested device, an expected power law relationship of △Nit-t0.787 between pure stress-induced interface traps and accumulated stressing time is obtained.展开更多
Using sequential DEA methodology, this paper has measured the variations in the technological gaps of China＇s industrial sectors compared with the world frontiers of technology. From a temporal dimension, variations ...Using sequential DEA methodology, this paper has measured the variations in the technological gaps of China＇s industrial sectors compared with the world frontiers of technology. From a temporal dimension, variations in the technological gaps of China＇s industrial sectors can be divided into the following four stages： slight abatement of technological gaps between 1985 and 1992, and between 1999 and 2007; stagnation in the variation of technological gaps between 1994 and 1999; and continuous abatement of technological gaps between 2008 and 2009. From the industry dimension, by 2009, 58.8% of China＇s industrial sectors had gradually reached or approached the world frontiers of technology; 29.4% of industrial sectors had experienced technological improvements but still lagged far behind the world frontiers of technology; 11.8% of industrial sectors significantly lagged behind the world frontiers of technology.展开更多
This paper discusses the relations between mass media and urban tribes, by Stafford Beer＇s viable system model （VSM）. During 1950-2010, the influence of media and advertising over individual decision-making process...This paper discusses the relations between mass media and urban tribes, by Stafford Beer＇s viable system model （VSM）. During 1950-2010, the influence of media and advertising over individual decision-making processes has deepened of age range to which have targeted advertising and expanded for Western world, leading the culture diversity, naturally given, toward only one standardized culture prevailing nowadays. In the 1960s they were the women, then the young people during 1970s, and then children in the 1980s and during the 1990s over early childhood, when we learnt to speak （3 years old）, achieving brand loyalty among very young children and the brands of products for this age group. From this perspective, urban tribes have taken control of the lives of young people, offering a false freedom, at the moment of choosing ＂How to be yourself＂ from options given in the market as a ＂catalogue of predesigned identities＂. A phenomenon is so complex, so it requires a holistic framework able to make explicit its components and relations between them and the relationship with internal and external environment. In particular, the VSM provides a way to analyze communication＇s problems thus clarifying： how, when and where, repair and controlling into the organization, identifying strategies to improve decision-making. Given the recursive nature of the VSM, it is possible to navigate within the phenomenon, through different recursions＇ levels. It will help to define more assertive and effective policies by health authorities, education and government in general, and also help someone among young people to see themselves inside of a dynamic consumption and thus can leave the domain and enter into a recta-domain, with more wisdom and consciousness.展开更多
The layout features of unit shafting and their effects on vibration, as well as evaluation criteria, were introduced for a 1000-MW ultra-supercritical turbine-generator unit with Simens technology. Based on vibration ...The layout features of unit shafting and their effects on vibration, as well as evaluation criteria, were introduced for a 1000-MW ultra-supercritical turbine-generator unit with Simens technology. Based on vibration diagnosis and treatment for more than 10 units, some typical vibration faults were summarized, such as the vibration fluctuation of the high pressure (HP) rotor, abnormal vibration increases of the No.3 bearing pedestal and large vibration of the exciter rotor during its critical speed range. The vibration characteristics and the causes of faults and countermeasures were analyzed. Three applications for further illustration were given. The vibration fault identification method, control measures, and applications can provide a reference for vibration diagnoses and treatment of same type units.展开更多
A further development of exclusively inverse frequency domain method for leak detection in pipelines is presented and validated.The location and leakage can be determined by analyzing the difference of transient water...A further development of exclusively inverse frequency domain method for leak detection in pipelines is presented and validated.The location and leakage can be determined by analyzing the difference of transient water head response between the simulated and measured data in frequency domain.The transient signals are generated by portion sharp closure of a valve from the small constant opening and it needs only a few meters of water.The discrete boundary conditions and observation data are both transformed in frequency domain by Laplace transform.Example in numerical simulation is studied for demonstration of this approach.The application of the method to an experimental pipeline confirms the analysis and illustrates successful detection of the single pipeline leak.The precalibration approach is presented to minimize the effect of data and model error and it splits the method into two parts.One uses data from a known state to fit the parameters of the model and the other uses data from the current state for the fitting of leak parameters using the now calibrated model.Some important practical parameters such as wave speed,friction in steady and unsteady state and the adaptability of the method are discussed.It was found that the nonlinearity errors associated with valve boundary condition could be prevented by consideration of the induced flow perturbation curve shape.展开更多
In a world in which, according to public health authorities and the media, everyone seems to be getting fatter, what does fat mean when we look across cultures？ Is being fat the same in China as in the USA？ How does...In a world in which, according to public health authorities and the media, everyone seems to be getting fatter, what does fat mean when we look across cultures？ Is being fat the same in China as in the USA？ How does obesity map onto culture in a world in which there are multiple, competing models for understanding illness？展开更多
In 2011, Buhrman et al. proved that it is impossible to design an unconditionally secure quantum position verification(QPV)protocol if the adversaries are allowed to previously share unlimited entanglements. Afterward...In 2011, Buhrman et al. proved that it is impossible to design an unconditionally secure quantum position verification(QPV)protocol if the adversaries are allowed to previously share unlimited entanglements. Afterwards, people started to design secure QPV protocols in practical settings, e.g. the bounded-storage model, where the adversaries' pre-shared entangled resources are supposed to be limited. Here we focus on another practical factor that it is very difficult for the adversaries to perform attack operations with unlimitedly high frequency. Concretely, we present a new kind of QPV protocols, called non-simultaneous QPV.And we prove the security of a specific non-simultaneous QPV protocol with the assumption that the frequency of the adversaries' attack operations is bounded, but no assumptions on their pre-shared entanglements or quantum storage. Actually, in our nonsimultaneous protocol, the information whether there comes a signal at present time is also a piece of command. It renders the adversaries "blind", that is, they have to execute attack operations with unlimitedly high frequency no matter whether a signal arrives, which implies the non-simultaneous QPV is also secure in the bounded-storage model.展开更多
Gas diffusion layer(GDL) plays a great important role in proton exchange membrane fuel cell(PEMFC).Water transport mechanism in GDL is still not clear.In the present study,an ex-situ transparent setup is built to visu...Gas diffusion layer(GDL) plays a great important role in proton exchange membrane fuel cell(PEMFC).Water transport mechanism in GDL is still not clear.In the present study,an ex-situ transparent setup is built to visualize the transport phenomena and to measure the threshold pressure of water in GDL at different temperatures.It is found that the relationship between the breakthrough pressure and the temperature is nearly linear(i.e.the pressure decreases linearly with the increase of temperature).To avoid the problems faced by the continuum models,the pore network model is developed to simulate the liquid water transport through the carbon paper.A uniform pressure boundary condition is used in simulation and the results are similar to the ones obtained in the experiment.The reason is that the contact angle and surface tension coefficient of water in GDLs change accordingly with the change of temperature.展开更多
基金Sponsored by Motorola-Peking University Joint Project.Contract No.:MSPSDDLCHINA-0004
文摘Forward gated-diode Recombination-Generation(R-G) current method is applied to an NMOSFET/SOI to measure the stress-induced interface traps in this letter. This easy but accurate experimental method can directly give stress-induced average interface traps for characterizing the device’s hot carrier characteristics. For the tested device, an expected power law relationship of △Nit-t0.787 between pure stress-induced interface traps and accumulated stressing time is obtained.
文摘Using sequential DEA methodology, this paper has measured the variations in the technological gaps of China＇s industrial sectors compared with the world frontiers of technology. From a temporal dimension, variations in the technological gaps of China＇s industrial sectors can be divided into the following four stages： slight abatement of technological gaps between 1985 and 1992, and between 1999 and 2007; stagnation in the variation of technological gaps between 1994 and 1999; and continuous abatement of technological gaps between 2008 and 2009. From the industry dimension, by 2009, 58.8% of China＇s industrial sectors had gradually reached or approached the world frontiers of technology; 29.4% of industrial sectors had experienced technological improvements but still lagged far behind the world frontiers of technology; 11.8% of industrial sectors significantly lagged behind the world frontiers of technology.
文摘This paper discusses the relations between mass media and urban tribes, by Stafford Beer＇s viable system model （VSM）. During 1950-2010, the influence of media and advertising over individual decision-making processes has deepened of age range to which have targeted advertising and expanded for Western world, leading the culture diversity, naturally given, toward only one standardized culture prevailing nowadays. In the 1960s they were the women, then the young people during 1970s, and then children in the 1980s and during the 1990s over early childhood, when we learnt to speak （3 years old）, achieving brand loyalty among very young children and the brands of products for this age group. From this perspective, urban tribes have taken control of the lives of young people, offering a false freedom, at the moment of choosing ＂How to be yourself＂ from options given in the market as a ＂catalogue of predesigned identities＂. A phenomenon is so complex, so it requires a holistic framework able to make explicit its components and relations between them and the relationship with internal and external environment. In particular, the VSM provides a way to analyze communication＇s problems thus clarifying： how, when and where, repair and controlling into the organization, identifying strategies to improve decision-making. Given the recursive nature of the VSM, it is possible to navigate within the phenomenon, through different recursions＇ levels. It will help to define more assertive and effective policies by health authorities, education and government in general, and also help someone among young people to see themselves inside of a dynamic consumption and thus can leave the domain and enter into a recta-domain, with more wisdom and consciousness.
文摘The layout features of unit shafting and their effects on vibration, as well as evaluation criteria, were introduced for a 1000-MW ultra-supercritical turbine-generator unit with Simens technology. Based on vibration diagnosis and treatment for more than 10 units, some typical vibration faults were summarized, such as the vibration fluctuation of the high pressure (HP) rotor, abnormal vibration increases of the No.3 bearing pedestal and large vibration of the exciter rotor during its critical speed range. The vibration characteristics and the causes of faults and countermeasures were analyzed. Three applications for further illustration were given. The vibration fault identification method, control measures, and applications can provide a reference for vibration diagnoses and treatment of same type units.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51109230, 50679085)the Special Funds of IWHR (Grant No. 0912)
文摘A further development of exclusively inverse frequency domain method for leak detection in pipelines is presented and validated.The location and leakage can be determined by analyzing the difference of transient water head response between the simulated and measured data in frequency domain.The transient signals are generated by portion sharp closure of a valve from the small constant opening and it needs only a few meters of water.The discrete boundary conditions and observation data are both transformed in frequency domain by Laplace transform.Example in numerical simulation is studied for demonstration of this approach.The application of the method to an experimental pipeline confirms the analysis and illustrates successful detection of the single pipeline leak.The precalibration approach is presented to minimize the effect of data and model error and it splits the method into two parts.One uses data from a known state to fit the parameters of the model and the other uses data from the current state for the fitting of leak parameters using the now calibrated model.Some important practical parameters such as wave speed,friction in steady and unsteady state and the adaptability of the method are discussed.It was found that the nonlinearity errors associated with valve boundary condition could be prevented by consideration of the induced flow perturbation curve shape.
文摘In a world in which, according to public health authorities and the media, everyone seems to be getting fatter, what does fat mean when we look across cultures？ Is being fat the same in China as in the USA？ How does obesity map onto culture in a world in which there are multiple, competing models for understanding illness？
基金supported by the National Natural Science Foundation of China(Grant Nos.61272057 and 61572081)the Fundamental Research Funds for the Central Universities(Grant No.106112016CDJXY180001)
文摘In 2011, Buhrman et al. proved that it is impossible to design an unconditionally secure quantum position verification(QPV)protocol if the adversaries are allowed to previously share unlimited entanglements. Afterwards, people started to design secure QPV protocols in practical settings, e.g. the bounded-storage model, where the adversaries' pre-shared entangled resources are supposed to be limited. Here we focus on another practical factor that it is very difficult for the adversaries to perform attack operations with unlimitedly high frequency. Concretely, we present a new kind of QPV protocols, called non-simultaneous QPV.And we prove the security of a specific non-simultaneous QPV protocol with the assumption that the frequency of the adversaries' attack operations is bounded, but no assumptions on their pre-shared entanglements or quantum storage. Actually, in our nonsimultaneous protocol, the information whether there comes a signal at present time is also a piece of command. It renders the adversaries "blind", that is, they have to execute attack operations with unlimitedly high frequency no matter whether a signal arrives, which implies the non-simultaneous QPV is also secure in the bounded-storage model.
基金supported by the National Natural Science Foundation of China (No.50976011)Fundamental Research Funds for the Central Universities of China (No. 2009JBM090)
文摘Gas diffusion layer(GDL) plays a great important role in proton exchange membrane fuel cell(PEMFC).Water transport mechanism in GDL is still not clear.In the present study,an ex-situ transparent setup is built to visualize the transport phenomena and to measure the threshold pressure of water in GDL at different temperatures.It is found that the relationship between the breakthrough pressure and the temperature is nearly linear(i.e.the pressure decreases linearly with the increase of temperature).To avoid the problems faced by the continuum models,the pore network model is developed to simulate the liquid water transport through the carbon paper.A uniform pressure boundary condition is used in simulation and the results are similar to the ones obtained in the experiment.The reason is that the contact angle and surface tension coefficient of water in GDLs change accordingly with the change of temperature.
