A method was developed for determination of chlorine and bromine in plant materials by ion chromatography using temperature programing-semi molten for sample preparation. Values of detection limits of the method found...A method was developed for determination of chlorine and bromine in plant materials by ion chromatography using temperature programing-semi molten for sample preparation. Values of detection limits of the method found were 1.0×10^-5 for CI and 1.3×10^-6 for Br. The measuring range of the method found were 0.3-20.0 mg/L for CI and 4,0-120,0 μg/L for Br. The results obtained agreed quite well with those reference values.展开更多
Let A∈N,B∈Z with gcd(A,B)=1,B{-1,0,1}. For the binary recurrence (Lucas sequence) of the form u 0=0, u 1=1, u n+2 =Au n+1 +Bu n, let N 1(A,B,k) be the number of the terms n of |u n|=k, where k∈N. In this paper, usi...Let A∈N,B∈Z with gcd(A,B)=1,B{-1,0,1}. For the binary recurrence (Lucas sequence) of the form u 0=0, u 1=1, u n+2 =Au n+1 +Bu n, let N 1(A,B,k) be the number of the terms n of |u n|=k, where k∈N. In this paper, using a new result of Bilu, Hanrot and Voutier on primitive divisors, we proved that N 1(A,B,k)≤1 except N 1(1,-2,1)=5[n=1,2,3,5,13], N 1(1,-3,1)=3, N 1(1,-5,1)=3,N 1(1,B,1)=2(B{-2,-3,-5}), N 1(12,-55,1)=2, N 1(12,-377,1)=2, N 1(A,B,1)=2(A 2+B=±1, A>1), N 1(1,-2,3)=2, N 1(A,B,A)=2(A 2+2B=±1,A>1. For Lehmer sequence, we got a similar result. In addition, we also obtained some applications of the above results to some Diophantime equations.展开更多
Many improved authentication solutions were put forward, on purpose of authenticating more quickly and securely.However, neither the overuse of hash function,or additional symmetric encryption, can truly increase the ...Many improved authentication solutions were put forward, on purpose of authenticating more quickly and securely.However, neither the overuse of hash function,or additional symmetric encryption, can truly increase the overall security. Instead,extra computation cost degraded the performance.They were still vulnerable to a variety of threats, such as smart card loss attack and impersonation attack, due to hidden loopholes and flaws. Even worse, user's identity can be parsed in insecure environment, even became traceable. Aiming to protect identity, a lightweight mutual authentication scheme is proposed. Redundant operations are removed,which make the verification process more explicit. It gains better performance with average cost compared to other similar schemes.Cryptanalysis shows the proposed scheme can resist common attacks and achieve user anonymity.Formal security is further verified by using the widely accepted Automated Validation of Internet Security Protocols and Applications(AVISPA) tool.展开更多
In this paper the authors describe the design, prototyping and evaluation of SIMpliLife, a framework for mobile phones with the aim of making people＇s life easier, providing day-to-day services such as payment, ticke...In this paper the authors describe the design, prototyping and evaluation of SIMpliLife, a framework for mobile phones with the aim of making people＇s life easier, providing day-to-day services such as payment, ticketing and information retrieval by means of NFC （Near Field Communication） technology. It was developed via the collaboration between two research labs of Sapienza University of Rome： the RFID （Radio Frequency Identification） Lab and the Usability and Accessibility Lab （LUA）, both belonging to CATTID （Centre for Applications of Teleservices and of Technologies for Innovation in Digital world） research centre. Technically, SIMpliLife is a SIM-based platform for NFC mobile phones that interfaces several applications able to manage the abovementioned services. The high-level User Interface has been developed by means of Smart Card Web Server （SCWS） technology, thus providing enhanced user experience if compared to traditional SIM-based implementations based on SIM Toolkit.展开更多
Feature screening plays an important role in ultrahigh dimensional data analysis.This paper is concerned with conditional feature screening when one is interested in detecting the association between the response and ...Feature screening plays an important role in ultrahigh dimensional data analysis.This paper is concerned with conditional feature screening when one is interested in detecting the association between the response and ultrahigh dimensional predictors(e.g.,genetic makers)given a low-dimensional exposure variable(such as clinical variables or environmental variables).To this end,we first propose a new index to measure conditional independence,and further develop a conditional screening procedure based on the newly proposed index.We systematically study the theoretical property of the proposed procedure and establish the sure screening and ranking consistency properties under some very mild conditions.The newly proposed screening procedure enjoys some appealing properties.(a)It is model-free in that its implementation does not require a specification on the model structure;(b)it is robust to heavy-tailed distributions or outliers in both directions of response and predictors;and(c)it can deal with both feature screening and the conditional screening in a unified way.We study the finite sample performance of the proposed procedure by Monte Carlo simulations and further illustrate the proposed method through two real data examples.展开更多
The paper gives a new approach to statistical simulation and resampling by the use of numbertheoretic methods and representative points. Resempling techniques take samples from an approximate population. The bootstrap...The paper gives a new approach to statistical simulation and resampling by the use of numbertheoretic methods and representative points. Resempling techniques take samples from an approximate population. The bootstrap suggests to use a random sample to form an approximate population. We propose to construct some approximate population distribution by the use of two kinds of representative points, and samples are taken from these approximate distributions. The statistical inference is based on those samples. The statistical inference in this paper involves estimation of mean, variance, skewness, kurtosis, quantile and density of the population distribution. Our results show that the new method can significantly improve the results by the use of Monte Carlo methods.展开更多
Betavoltaic radioisotope microbatteries have gradually become the research direction of micro-power sources because of their several advantages,including small scale,stable output performance,long service life,high en...Betavoltaic radioisotope microbatteries have gradually become the research direction of micro-power sources because of their several advantages,including small scale,stable output performance,long service life,high energy density,strong anti-jamming capability,and so on.Based on the theory of semiconductor physics,the current paper presented a design scheme of isotope microbattery with wide-gap semiconductor material GaN and isotope 147Pm.In consideration of the isotope's self-absorption effect,the current paper studied and analyzed the optimization thickness of semiconductor and isotope source,junction depth,depletion region thickness,doping concentration,and the generation and collection of electron hole pairs with simulation of transport process of beta particles in semiconductor material using Monte Carlo simulation program MCNP.In the proposed design scheme,for a single decay,an average energy of 28.2 keV was deposited in the GaN,and the short circuit current density,open circuit voltage,and efficiency of a single device were 1.636 μA/cm2,3.16 V,and 13.4%,respectively.展开更多
文摘A method was developed for determination of chlorine and bromine in plant materials by ion chromatography using temperature programing-semi molten for sample preparation. Values of detection limits of the method found were 1.0×10^-5 for CI and 1.3×10^-6 for Br. The measuring range of the method found were 0.3-20.0 mg/L for CI and 4,0-120,0 μg/L for Br. The results obtained agreed quite well with those reference values.
文摘Let A∈N,B∈Z with gcd(A,B)=1,B{-1,0,1}. For the binary recurrence (Lucas sequence) of the form u 0=0, u 1=1, u n+2 =Au n+1 +Bu n, let N 1(A,B,k) be the number of the terms n of |u n|=k, where k∈N. In this paper, using a new result of Bilu, Hanrot and Voutier on primitive divisors, we proved that N 1(A,B,k)≤1 except N 1(1,-2,1)=5[n=1,2,3,5,13], N 1(1,-3,1)=3, N 1(1,-5,1)=3,N 1(1,B,1)=2(B{-2,-3,-5}), N 1(12,-55,1)=2, N 1(12,-377,1)=2, N 1(A,B,1)=2(A 2+B=±1, A>1), N 1(1,-2,3)=2, N 1(A,B,A)=2(A 2+2B=±1,A>1. For Lehmer sequence, we got a similar result. In addition, we also obtained some applications of the above results to some Diophantime equations.
基金supported by the National Key Research and Development Program of China (No. 2017YFC0820603)
文摘Many improved authentication solutions were put forward, on purpose of authenticating more quickly and securely.However, neither the overuse of hash function,or additional symmetric encryption, can truly increase the overall security. Instead,extra computation cost degraded the performance.They were still vulnerable to a variety of threats, such as smart card loss attack and impersonation attack, due to hidden loopholes and flaws. Even worse, user's identity can be parsed in insecure environment, even became traceable. Aiming to protect identity, a lightweight mutual authentication scheme is proposed. Redundant operations are removed,which make the verification process more explicit. It gains better performance with average cost compared to other similar schemes.Cryptanalysis shows the proposed scheme can resist common attacks and achieve user anonymity.Formal security is further verified by using the widely accepted Automated Validation of Internet Security Protocols and Applications(AVISPA) tool.
文摘In this paper the authors describe the design, prototyping and evaluation of SIMpliLife, a framework for mobile phones with the aim of making people＇s life easier, providing day-to-day services such as payment, ticketing and information retrieval by means of NFC （Near Field Communication） technology. It was developed via the collaboration between two research labs of Sapienza University of Rome： the RFID （Radio Frequency Identification） Lab and the Usability and Accessibility Lab （LUA）, both belonging to CATTID （Centre for Applications of Teleservices and of Technologies for Innovation in Digital world） research centre. Technically, SIMpliLife is a SIM-based platform for NFC mobile phones that interfaces several applications able to manage the abovementioned services. The high-level User Interface has been developed by means of Smart Card Web Server （SCWS） technology, thus providing enhanced user experience if compared to traditional SIM-based implementations based on SIM Toolkit.
基金supported by National Science Foundation of USA (Grant No. P50 DA039838)the Program of China Scholarships Council (Grant No. 201506040130)+6 种基金 National Natural Science Foundation of China (Grant No. 11401497)the Scientific Research Foundation for the Returned Overseas Chinese ScholarsState Education Ministry, the National Key Basic Research Development Program of China (Grant No. 2010CB950703)the Fundamental Research Funds for the Central UniversitiesNational Institute on Drug AbuseNational Institutes of Health (Grants Nos. P50 DA036107 and P50 DA039838)National Science Foundation of USA (Grant No. DMS 1512422)
文摘Feature screening plays an important role in ultrahigh dimensional data analysis.This paper is concerned with conditional feature screening when one is interested in detecting the association between the response and ultrahigh dimensional predictors(e.g.,genetic makers)given a low-dimensional exposure variable(such as clinical variables or environmental variables).To this end,we first propose a new index to measure conditional independence,and further develop a conditional screening procedure based on the newly proposed index.We systematically study the theoretical property of the proposed procedure and establish the sure screening and ranking consistency properties under some very mild conditions.The newly proposed screening procedure enjoys some appealing properties.(a)It is model-free in that its implementation does not require a specification on the model structure;(b)it is robust to heavy-tailed distributions or outliers in both directions of response and predictors;and(c)it can deal with both feature screening and the conditional screening in a unified way.We study the finite sample performance of the proposed procedure by Monte Carlo simulations and further illustrate the proposed method through two real data examples.
基金supported by the Special Research Foundation from the Chinese Academyof Sciencesthe Beijing Normal University-Hong Kong Baptist University United International College Research(Grant No.R201409)National Natural Science Foundation of China(Grant No.11261016)
文摘The paper gives a new approach to statistical simulation and resampling by the use of numbertheoretic methods and representative points. Resempling techniques take samples from an approximate population. The bootstrap suggests to use a random sample to form an approximate population. We propose to construct some approximate population distribution by the use of two kinds of representative points, and samples are taken from these approximate distributions. The statistical inference is based on those samples. The statistical inference in this paper involves estimation of mean, variance, skewness, kurtosis, quantile and density of the population distribution. Our results show that the new method can significantly improve the results by the use of Monte Carlo methods.
基金supported by the China Postdoctoral Science Foundation Funded Project (Grant No. 20100481140)the Nanjing University of Aeronautics and Astronautics Basic Research Funded Project (Grant No. Y1065-063)
文摘Betavoltaic radioisotope microbatteries have gradually become the research direction of micro-power sources because of their several advantages,including small scale,stable output performance,long service life,high energy density,strong anti-jamming capability,and so on.Based on the theory of semiconductor physics,the current paper presented a design scheme of isotope microbattery with wide-gap semiconductor material GaN and isotope 147Pm.In consideration of the isotope's self-absorption effect,the current paper studied and analyzed the optimization thickness of semiconductor and isotope source,junction depth,depletion region thickness,doping concentration,and the generation and collection of electron hole pairs with simulation of transport process of beta particles in semiconductor material using Monte Carlo simulation program MCNP.In the proposed design scheme,for a single decay,an average energy of 28.2 keV was deposited in the GaN,and the short circuit current density,open circuit voltage,and efficiency of a single device were 1.636 μA/cm2,3.16 V,and 13.4%,respectively.
