The configuration of information system security policy is directly related to the information asset risk, and the configuration required by the classified security protection is able to ensure the optimal and minimum...The configuration of information system security policy is directly related to the information asset risk, and the configuration required by the classified security protection is able to ensure the optimal and minimum policy in the corresponding security level. Through the random survey on the information assets of multiple departments, this paper proposes the relative deviation distance of security policy configuration as risk measure parameter based on the distance of information-state transition（DIT） theory. By quantitatively analyzing the information asset weight, deviation degree and DIT, we establish the evaluation model for information system. With example analysis, the results prove that this method conducts effective risk evaluation on the information system intuitively and reliably, avoids the threat caused by subjective measurement, and shows performance benefits compared with existing solutions. It is not only theoretically but also practically feasible to realize the scientific analysis of security risk for the information system.展开更多
This paper presents a cellular automaton model for single-lane traffic flow. On the basis of the Nagel-Schreckenberg （NS） model, it further considers the effect of headway-distance between two successive cars on the...This paper presents a cellular automaton model for single-lane traffic flow. On the basis of the Nagel-Schreckenberg （NS） model, it further considers the effect of headway-distance between two successive cars on the randomization of the latter one. In numerical simulations, this model shows the following characteristics. （1） With a simple structure, this model succeeds in reproducing the hysteresis effect, which is absent in the NS model. （2） Compared with the slow-tostart models, this model exhibits a local fundamental diagram which is more consistent to empirical observations. （3） This model has much higher efficiency in dissolving congestions compared with the so-called NS model with velocitydependent randomization （VDR model）. （4） This model is more robust when facing traffic obstructions. It can resist much longer shock times and has much shorter relaxation times on the other hand. To summarize, compared with the existing models, this model is quite simple in structure, but has good characteristics.展开更多
Spin glass system is a complex disordered system with a number of local minima separated by entropic barriers. Therefore, parallel tempering Monte Carlo simulation was used in order to get fast thermalisation （to min...Spin glass system is a complex disordered system with a number of local minima separated by entropic barriers. Therefore, parallel tempering Monte Carlo simulation was used in order to get fast thermalisation （to minimize the relaxation time）. Distance dependent interaction coupling in 2D is studied in order to show how a spin glass phase transition occurs when couplings between far away spins are permitted by considering Edwards-Anderson Ising spin glass model. The interaction coupling is a quenched random variable whose probability of being non-zero decays with distance between two spin sites rij = ｜i-j｜mod（L/2）.The interaction coupling is random and its probability distribution is decaying with the distance between the spins （p（Jij） αrij^-ρ）. The model is studied by changing p among three different regimes （p 〉 2D, 4/3 D〈 p 〈 2D, p 〈 4/3D）. A phase transition temperature for p = 2, 3, 4 is obtained.展开更多
The structural change in phase transition of hybrid （Cl2H25NH3）2MnCl4 was investigated. The temperature and the structures of the phase transition is investigated by thermal gravimetry （TG） and differential scanni...The structural change in phase transition of hybrid （Cl2H25NH3）2MnCl4 was investigated. The temperature and the structures of the phase transition is investigated by thermal gravimetry （TG） and differential scanning calorimetry （DSC）, infrared spectrum （IR） and X-ray diffraction （XRD）. The results suggest that the phase transition is reversible and the structural change arises from the conformation change of the organic chain. The interlayer distance increases when the hybrid transforms from low temperature phase to high temperature phase. This is explained by the diffusion of gauche-bond along the organic chains and they move away from each other when the phase transition occurs. Combining the experimental data with theoretical calculation, we propose that organic chain of the hybrid in high temperature phase is the conformation of gauche-bond alternating with trans bond （noted as GTG＇TGTG＇TGTG＇T）.展开更多
In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 ℃ were characterized by XRD, TEM and elect...In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 ℃ were characterized by XRD, TEM and electron diffraction(ED), respectively. The results show that titania powders calcined below 500 ℃ are almost composed of anatase, rutile appears below 500 ℃ and its ratio increases gradually with increase of calcin temperature; nano-titania particles are smaller than 40 nm mostly and the dispersion is related to calcining temperature; the inter-planar distances of nano-anatase single crystalline change gradually when calcing temperature increases to 500 ℃; so do that of nano-rutile single crystalline when calcining temperature charges from 600 to 700 ℃. The conclusions can be drawn that the temperature of transformation from anatase to rutile is below 500 ℃ and the process carries on gradually. Both inter-planar distances and the structure of nano-titania transform gradually with increasing calcing temperature.展开更多
Two-photon laser-induced fluorescence spectrum (TP-LIF) of NO is obtained with a Nd:YAG pumped optical parametric generator and amplifier as radiation source. Spectral intensity distribution shows that the electronic ...Two-photon laser-induced fluorescence spectrum (TP-LIF) of NO is obtained with a Nd:YAG pumped optical parametric generator and amplifier as radiation source. Spectral intensity distribution shows that the electronic transition moment for NO (A2 X2II) transition varies significantly with inter-nuclear distance. The variation relationship of the electronic transition moment versus inter-nuclear distance is deduced with polyminal fit procedure. The spontaneous radiative coefficients for NO (A2X2II) transition from v' = 0,1 are obtained by combing this transition moment variation with the measurements of spontaneous radiative lifetime.展开更多
近年来随着3D打印技术的飞速发展,材料挤出成型工艺制备功能梯度材料成为研究热点。材料之间的过渡是影响最终成型质量的关键因素。目前,国内外学者只研究了两种独立材料之间相互转变的过渡距离,对不同组分材料之间的转变研究较少。采...近年来随着3D打印技术的飞速发展,材料挤出成型工艺制备功能梯度材料成为研究热点。材料之间的过渡是影响最终成型质量的关键因素。目前,国内外学者只研究了两种独立材料之间相互转变的过渡距离,对不同组分材料之间的转变研究较少。采用双料筒打印机研究了不同组分材料之间的过渡距离,并通过实验探究不同进给量对过渡距离的影响,在保证打印质量的前提下得到了过渡距离最小的进给量。以Visual Studio 2019为开发平台提出一种新的进料策略缩短过渡距离,在路径规划中对切片得到点的材料信息进行判断,对组分增大的材料根据变化值计算其进给量并输出生成新型G代码。最终,采用新型G代码进行打印实验,缩短了材料过渡距离得到了理想的材料过渡曲线。展开更多
基金Supported by the National Natural Science Foundation of China(61662009)the Education Reform Project in Guizhou Province(SJJG201404)the Natural Science Foundation of Guizhou Province Education Department(KY(2015)367)
文摘The configuration of information system security policy is directly related to the information asset risk, and the configuration required by the classified security protection is able to ensure the optimal and minimum policy in the corresponding security level. Through the random survey on the information assets of multiple departments, this paper proposes the relative deviation distance of security policy configuration as risk measure parameter based on the distance of information-state transition（DIT） theory. By quantitatively analyzing the information asset weight, deviation degree and DIT, we establish the evaluation model for information system. With example analysis, the results prove that this method conducts effective risk evaluation on the information system intuitively and reliably, avoids the threat caused by subjective measurement, and shows performance benefits compared with existing solutions. It is not only theoretically but also practically feasible to realize the scientific analysis of security risk for the information system.
基金supported by the National Basic Research Program of China (973 Program No 2006CB705500)the National Natural Science Foundation of China (Grant Nos 10635040, 10532060, 10472116 and 70271070)+2 种基金the Special Research Funds for Theoretical Physics Frontier Problems (NSFC Nos 10547004 and A0524701)the President Funding of Chinese Academy of Sciencethe Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘This paper presents a cellular automaton model for single-lane traffic flow. On the basis of the Nagel-Schreckenberg （NS） model, it further considers the effect of headway-distance between two successive cars on the randomization of the latter one. In numerical simulations, this model shows the following characteristics. （1） With a simple structure, this model succeeds in reproducing the hysteresis effect, which is absent in the NS model. （2） Compared with the slow-tostart models, this model exhibits a local fundamental diagram which is more consistent to empirical observations. （3） This model has much higher efficiency in dissolving congestions compared with the so-called NS model with velocitydependent randomization （VDR model）. （4） This model is more robust when facing traffic obstructions. It can resist much longer shock times and has much shorter relaxation times on the other hand. To summarize, compared with the existing models, this model is quite simple in structure, but has good characteristics.
文摘Spin glass system is a complex disordered system with a number of local minima separated by entropic barriers. Therefore, parallel tempering Monte Carlo simulation was used in order to get fast thermalisation （to minimize the relaxation time）. Distance dependent interaction coupling in 2D is studied in order to show how a spin glass phase transition occurs when couplings between far away spins are permitted by considering Edwards-Anderson Ising spin glass model. The interaction coupling is a quenched random variable whose probability of being non-zero decays with distance between two spin sites rij = ｜i-j｜mod（L/2）.The interaction coupling is random and its probability distribution is decaying with the distance between the spins （p（Jij） αrij^-ρ）. The model is studied by changing p among three different regimes （p 〉 2D, 4/3 D〈 p 〈 2D, p 〈 4/3D）. A phase transition temperature for p = 2, 3, 4 is obtained.
基金the National Natural Science Foundation of China(No.NSFC90206047)the Natural Science Foundation of Hubei Province(No.2006ABA306)
文摘The structural change in phase transition of hybrid （Cl2H25NH3）2MnCl4 was investigated. The temperature and the structures of the phase transition is investigated by thermal gravimetry （TG） and differential scanning calorimetry （DSC）, infrared spectrum （IR） and X-ray diffraction （XRD）. The results suggest that the phase transition is reversible and the structural change arises from the conformation change of the organic chain. The interlayer distance increases when the hybrid transforms from low temperature phase to high temperature phase. This is explained by the diffusion of gauche-bond along the organic chains and they move away from each other when the phase transition occurs. Combining the experimental data with theoretical calculation, we propose that organic chain of the hybrid in high temperature phase is the conformation of gauche-bond alternating with trans bond （noted as GTG＇TGTG＇TGTG＇T）.
文摘In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 ℃ were characterized by XRD, TEM and electron diffraction(ED), respectively. The results show that titania powders calcined below 500 ℃ are almost composed of anatase, rutile appears below 500 ℃ and its ratio increases gradually with increase of calcin temperature; nano-titania particles are smaller than 40 nm mostly and the dispersion is related to calcining temperature; the inter-planar distances of nano-anatase single crystalline change gradually when calcing temperature increases to 500 ℃; so do that of nano-rutile single crystalline when calcining temperature charges from 600 to 700 ℃. The conclusions can be drawn that the temperature of transformation from anatase to rutile is below 500 ℃ and the process carries on gradually. Both inter-planar distances and the structure of nano-titania transform gradually with increasing calcing temperature.
基金This work was supported by the Natural Science Foun-dation of Hebei Province,China (Grant No,102090)
文摘Two-photon laser-induced fluorescence spectrum (TP-LIF) of NO is obtained with a Nd:YAG pumped optical parametric generator and amplifier as radiation source. Spectral intensity distribution shows that the electronic transition moment for NO (A2 X2II) transition varies significantly with inter-nuclear distance. The variation relationship of the electronic transition moment versus inter-nuclear distance is deduced with polyminal fit procedure. The spontaneous radiative coefficients for NO (A2X2II) transition from v' = 0,1 are obtained by combing this transition moment variation with the measurements of spontaneous radiative lifetime.
文摘近年来随着3D打印技术的飞速发展,材料挤出成型工艺制备功能梯度材料成为研究热点。材料之间的过渡是影响最终成型质量的关键因素。目前,国内外学者只研究了两种独立材料之间相互转变的过渡距离,对不同组分材料之间的转变研究较少。采用双料筒打印机研究了不同组分材料之间的过渡距离,并通过实验探究不同进给量对过渡距离的影响,在保证打印质量的前提下得到了过渡距离最小的进给量。以Visual Studio 2019为开发平台提出一种新的进料策略缩短过渡距离,在路径规划中对切片得到点的材料信息进行判断,对组分增大的材料根据变化值计算其进给量并输出生成新型G代码。最终,采用新型G代码进行打印实验,缩短了材料过渡距离得到了理想的材料过渡曲线。
