Cyber-physical power system(CPPS)has significantly improved the operational efficiency of power systems.However,cross-space cascading failures may occur due to the coupling characteristics,which poses a great threat t...Cyber-physical power system(CPPS)has significantly improved the operational efficiency of power systems.However,cross-space cascading failures may occur due to the coupling characteristics,which poses a great threat to the safety and reliability of CPPS,and there is an acute need to reduce the probability of these failures.Towards this end,this paper first proposes a cascading failure index to identify and quantify the importance of different information in the same class of communication services.On this basis,a joint improved risk-balanced service function chain routing strategy(SFC-RS)is proposed,which is modeled as a robust optimization problem and solved by column-and-constraint generation(C-CG)algorithm.Compared with the traditional shortest-path routing algorithm,the superiority of SFC-RS is verified in the IEEE 30-bus system.The results demonstrate that SFC-RS effectively mitigates the risk associated with information transmission in the network,enhances information transmission accessibility,and effectively limits communication disruption from becoming the cause of cross-space cascading failures.展开更多
A generalized form of the error function, Gp(x)=pΓ(1/p)∫0xe−tpdt, which is directly associated with the gamma function, is evaluated for arbitrary real values of p>1and 0x≤+∞by employing a fast-converging power...A generalized form of the error function, Gp(x)=pΓ(1/p)∫0xe−tpdt, which is directly associated with the gamma function, is evaluated for arbitrary real values of p>1and 0x≤+∞by employing a fast-converging power series expansion developed in resolving the so-called Grandi’s paradox. Comparisons with accurate tabulated values for well-known cases such as the error function are presented using the expansions truncated at various orders.展开更多
A general technique to obtain simple analytic approximations for the first kind of modified Bessel functions. The general procedure is shown, and the parameter determination is explained through the applications to th...A general technique to obtain simple analytic approximations for the first kind of modified Bessel functions. The general procedure is shown, and the parameter determination is explained through the applications to this particular case I1/6(x)and I1/7(x). In this way, it shows how to apply the technique to any particular orderν, in order to obtain an approximation valid for any positive value of the variable x. In the present method power series and asymptotic expansion are simultaneously used. The technique is an extension of the multipoint quasirational approximation method, MPQA. The main idea is to look for a bridge function between the power and asymptotic expansion of the I1/6(x), and similar procedure for I1/7(x). To perform this, rational functions are combined with hyperbolic ones and fractional powers. The number of parameters to be determined for each case is four. The maximum relative errors are 0.0049 for ν=1/6, and 0.0047 for ν=7. However, these relative errors decrease outside of the small region of the variables, wherein the maximum relative errors are reached. There is a clear advantage of this procedure compared with any other ones.展开更多
In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate ...In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.展开更多
目的探讨关节镜联合C型臂X线机治疗胫骨平台骨折的效果。方法方便选择2017年1月—2022年12月丹阳市人民医院收治的78例胫骨平台骨折患者为研究对象,以随机双盲法分为两组,每组39例。对照组行常规切开复位内固定术,观察组行关节镜联合C型...目的探讨关节镜联合C型臂X线机治疗胫骨平台骨折的效果。方法方便选择2017年1月—2022年12月丹阳市人民医院收治的78例胫骨平台骨折患者为研究对象,以随机双盲法分为两组,每组39例。对照组行常规切开复位内固定术,观察组行关节镜联合C型臂X线机微创内固定术,对两组手术疗效、手术指标、膝关节功能恢复与并发症发生情况进行分析比较。结果观察组手术优良率(97.44%)明显高于对照组(82.05%),差异有统计学意义(χ^(2)=5.014,P<0.05);观察组手术治疗相关指标优于对照组,差异有统计学意义(P均<0.05)。术后6个月两组患者Lysholm、纽约特种外科医院(Hospital for Special Surgery,HSS)评分均升高,且观察组Lysholm、HSS评分明显高于对照组,差异有统计学意义(P均<0.05)。观察组术后并发症总发生率低于对照组,差异有统计学意义(P均<0.05)。结论胫骨平台骨折患者采用关节镜联合C型臂X线机治疗的疗效确切,患者创伤小、术后恢复快、并发症少,且对患者膝关节功能的恢复有着明显的促进作用。展开更多
文章对海上风电各国总体发展现状及未来发展趋势进行分析,表明各国都在加强对海上风电开发利用,但随着海上风电高速发展,有限的近海风电资源开发趋于饱和,深远海域风电成为海上风电未来发展的方向。然而水深离岸远,深远海风能开发困难,...文章对海上风电各国总体发展现状及未来发展趋势进行分析,表明各国都在加强对海上风电开发利用,但随着海上风电高速发展,有限的近海风电资源开发趋于饱和,深远海域风电成为海上风电未来发展的方向。然而水深离岸远,深远海风能开发困难,难于实现商业化。文章介绍了一种将新能源电力转换为其他能源载体的Power to X模式。氢作为1种可再生能源载体,可基于Power to X模式,通过将新能源电力电解水制氢的方式,有效降低深远海风电的成本。展开更多
Large numbers of basic transceiver stations,where the telecommunication room is one of the main components,comprise an important part of the telecommunication system.After earthquakes,considerable economic loss from t...Large numbers of basic transceiver stations,where the telecommunication room is one of the main components,comprise an important part of the telecommunication system.After earthquakes,considerable economic loss from telecommunication systems is often associated with seismic damage and functional loss of the telecommunication room.However,research related to this has been limited.In this study,shaking table tests were conducted for a full-scale typical telecommunication room,including a light-steel house and the necessary communication and power supply equipment.The tests not only focused on the seismic damage to all the structures but also considered the functions of the communication and power supply of the equipment.The interactions between these facilities and their effects on communication function were also investigated.Compared with the damage to structures,the interruption of the power supply due to earthquakes is a weak link.Finally,the damage indexes,together with their threshold values of different damage states for the communication and power supply equipment,were derived from the test results.The results of this research can contribute to the literature gaps regarding seismic performance studies of telecommunication rooms,and can serve as a valuable reference for future research on its seismic fragility and economic losses evaluation.展开更多
The analytic solution of the radial Schrodinger equation is studied by using the tight coupling condition of several positive-power and inverse-power potential functions in this article. Furthermore, the precisely ana...The analytic solution of the radial Schrodinger equation is studied by using the tight coupling condition of several positive-power and inverse-power potential functions in this article. Furthermore, the precisely analytic solutions and the conditions that decide the existence of analytic solution have been searched when the potential of the radial Schrodinger equation is V（r） =α1r^8 ＋α2r^3 ＋ α3r^2 ＋β3r^-1 ＋β2r^-3 ＋β1r6-4. Generally speaking, there is only an approximate solution, but not analytic solution for SchrSdinger equation with several potentials＇ superposition. However, the conditions that decide the existence of analytic solution have been found and the analytic solution and its energy level structure are obtained for the Schrodinger equation with the potential which is motioned above in this paper. According to the single-value, finite and continuous standard of wave function in a quantum system, the authors firstly solve the asymptotic solution through the radial coordinate r → ∞ and r →0; secondly, they make the asymptotic solutions combining with the series solutions nearby the neighborhood of irregular singularities; and then they compare the power series coefficients, deduce a series of analytic solutions of the stationary state wave function and corresponding energy level structure by tight coupling among the coefficients of potential functions for the radial SchrSdinger equation; and lastly, they discuss the solutions and make conclusions.展开更多
基金funded by the National Natural Science Foundation of China under Grant 52177074.
文摘Cyber-physical power system(CPPS)has significantly improved the operational efficiency of power systems.However,cross-space cascading failures may occur due to the coupling characteristics,which poses a great threat to the safety and reliability of CPPS,and there is an acute need to reduce the probability of these failures.Towards this end,this paper first proposes a cascading failure index to identify and quantify the importance of different information in the same class of communication services.On this basis,a joint improved risk-balanced service function chain routing strategy(SFC-RS)is proposed,which is modeled as a robust optimization problem and solved by column-and-constraint generation(C-CG)algorithm.Compared with the traditional shortest-path routing algorithm,the superiority of SFC-RS is verified in the IEEE 30-bus system.The results demonstrate that SFC-RS effectively mitigates the risk associated with information transmission in the network,enhances information transmission accessibility,and effectively limits communication disruption from becoming the cause of cross-space cascading failures.
文摘A generalized form of the error function, Gp(x)=pΓ(1/p)∫0xe−tpdt, which is directly associated with the gamma function, is evaluated for arbitrary real values of p>1and 0x≤+∞by employing a fast-converging power series expansion developed in resolving the so-called Grandi’s paradox. Comparisons with accurate tabulated values for well-known cases such as the error function are presented using the expansions truncated at various orders.
文摘A general technique to obtain simple analytic approximations for the first kind of modified Bessel functions. The general procedure is shown, and the parameter determination is explained through the applications to this particular case I1/6(x)and I1/7(x). In this way, it shows how to apply the technique to any particular orderν, in order to obtain an approximation valid for any positive value of the variable x. In the present method power series and asymptotic expansion are simultaneously used. The technique is an extension of the multipoint quasirational approximation method, MPQA. The main idea is to look for a bridge function between the power and asymptotic expansion of the I1/6(x), and similar procedure for I1/7(x). To perform this, rational functions are combined with hyperbolic ones and fractional powers. The number of parameters to be determined for each case is four. The maximum relative errors are 0.0049 for ν=1/6, and 0.0047 for ν=7. However, these relative errors decrease outside of the small region of the variables, wherein the maximum relative errors are reached. There is a clear advantage of this procedure compared with any other ones.
文摘In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.
文摘目的探讨关节镜联合C型臂X线机治疗胫骨平台骨折的效果。方法方便选择2017年1月—2022年12月丹阳市人民医院收治的78例胫骨平台骨折患者为研究对象,以随机双盲法分为两组,每组39例。对照组行常规切开复位内固定术,观察组行关节镜联合C型臂X线机微创内固定术,对两组手术疗效、手术指标、膝关节功能恢复与并发症发生情况进行分析比较。结果观察组手术优良率(97.44%)明显高于对照组(82.05%),差异有统计学意义(χ^(2)=5.014,P<0.05);观察组手术治疗相关指标优于对照组,差异有统计学意义(P均<0.05)。术后6个月两组患者Lysholm、纽约特种外科医院(Hospital for Special Surgery,HSS)评分均升高,且观察组Lysholm、HSS评分明显高于对照组,差异有统计学意义(P均<0.05)。观察组术后并发症总发生率低于对照组,差异有统计学意义(P均<0.05)。结论胫骨平台骨折患者采用关节镜联合C型臂X线机治疗的疗效确切,患者创伤小、术后恢复快、并发症少,且对患者膝关节功能的恢复有着明显的促进作用。
文摘文章对海上风电各国总体发展现状及未来发展趋势进行分析,表明各国都在加强对海上风电开发利用,但随着海上风电高速发展,有限的近海风电资源开发趋于饱和,深远海域风电成为海上风电未来发展的方向。然而水深离岸远,深远海风能开发困难,难于实现商业化。文章介绍了一种将新能源电力转换为其他能源载体的Power to X模式。氢作为1种可再生能源载体,可基于Power to X模式,通过将新能源电力电解水制氢的方式,有效降低深远海风电的成本。
基金Key Project of the Key Laboratory of Earthquake Engineering and Engineering Vibration,China Earthquake Administration under Grant Nos.2020EEEVL0502 and 2019EEEVL0304。
文摘Large numbers of basic transceiver stations,where the telecommunication room is one of the main components,comprise an important part of the telecommunication system.After earthquakes,considerable economic loss from telecommunication systems is often associated with seismic damage and functional loss of the telecommunication room.However,research related to this has been limited.In this study,shaking table tests were conducted for a full-scale typical telecommunication room,including a light-steel house and the necessary communication and power supply equipment.The tests not only focused on the seismic damage to all the structures but also considered the functions of the communication and power supply of the equipment.The interactions between these facilities and their effects on communication function were also investigated.Compared with the damage to structures,the interruption of the power supply due to earthquakes is a weak link.Finally,the damage indexes,together with their threshold values of different damage states for the communication and power supply equipment,were derived from the test results.The results of this research can contribute to the literature gaps regarding seismic performance studies of telecommunication rooms,and can serve as a valuable reference for future research on its seismic fragility and economic losses evaluation.
基金supported by the National Natural Science Foundation of China under Grant No.10575140the Basic Research of Chongqing Education Committee under Grant No.KJ060813
文摘The analytic solution of the radial Schrodinger equation is studied by using the tight coupling condition of several positive-power and inverse-power potential functions in this article. Furthermore, the precisely analytic solutions and the conditions that decide the existence of analytic solution have been searched when the potential of the radial Schrodinger equation is V（r） =α1r^8 ＋α2r^3 ＋ α3r^2 ＋β3r^-1 ＋β2r^-3 ＋β1r6-4. Generally speaking, there is only an approximate solution, but not analytic solution for SchrSdinger equation with several potentials＇ superposition. However, the conditions that decide the existence of analytic solution have been found and the analytic solution and its energy level structure are obtained for the Schrodinger equation with the potential which is motioned above in this paper. According to the single-value, finite and continuous standard of wave function in a quantum system, the authors firstly solve the asymptotic solution through the radial coordinate r → ∞ and r →0; secondly, they make the asymptotic solutions combining with the series solutions nearby the neighborhood of irregular singularities; and then they compare the power series coefficients, deduce a series of analytic solutions of the stationary state wave function and corresponding energy level structure by tight coupling among the coefficients of potential functions for the radial SchrSdinger equation; and lastly, they discuss the solutions and make conclusions.
