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1.
The molecular weight distribution is an important factor that affects the properties of polymers. A control algorithm based on the moment-generating function was proposed to regulate the molecular weight distribution for polymerization processes in this work. The B-spline model was used to approximate the molecular weight distribution, and the weight state space equation of the system was identified by the subspace state space system identification method based on the paired date of B-spline weights and control inputs. Then, a new performance criterion mainly consisting of the moment-generating function was constructed to obtain the optimal control input. The effectiveness of the proposed control method was tested in a styrene polymerization process. The molecular weight distribution of the styrene polymers can be approximated by the B-spline model effectively, and it can also be regulated towards the desired one under the proposed control method.  相似文献   

2.
Nernst Theorem and Statistical Entropy of 5-Dimensional Rotating Black Hole   总被引:1,自引:0,他引:1  
In this paper, by using quantum statistical method, we obtain the partition function of Bose field and Fermi field on the background of the 5-dimensional rotating black hole. Then via the improved brick-wall method and membrane model, we calculate the entropy of Bose field and Fermi field of the black hole. And it is obtained that the entropy of the black hole is not only related to the area of the outer horizon but also is the function of inner horizon‘s area. In our results, there are not the left out term and the divergent logarithmic term in the original brick-wall method.The doubt that why the entropy of the scalar or Dirac field outside the event horizon is the entropy of the black hole in the original brick-wall method does not exist. The influence of spinning degeneracy of particles on entropy of the black hole is also given. It is shown that the entropy determined by the areas of the inner and outer horizons will approach zero,when the radiation temperature of the black hole approaches absolute zero. It satisfies Nernst theorem. The entropy can be taken as the Planck absolute entropy. We provide a way to study higher dimensional black hole.  相似文献   

3.
In this paper, by using quantum statistical method, we obtain the partition function of Bose field and Fermi field on the background of the 5-dimensional rotating black hole. Then via the improved brick-wall method and membrane model, we calculate the entropy of Bose field and Fermi field of the black hole. And it is obtained that the entropy of the black hole is not only related to the area of the outer horizon but also is the function of inner horizon‘s area. In our results, there are not the left out term and the divergent logarithmic term in the original brick-wall method.The doubt that why the entropy of the scalar or Dirac field outside the event horizon is the entropy of the black hole in the original brick-wall method does not exist. The influence of spinning degeneracy of particles on entropy of the black hole is also given. It is shown that the entropy determined by the areas of the inner and outer horizons will approach zero,when the radiation temperature of the black hole approaches absolute zero. It satisfies Nernst theorem. The entropy can be taken as the Planck absolute entropy. We provide a way to study higher dimensional black hole.  相似文献   

4.
Increased reactive oxygen species (ROS) contribute to numerous brain disorders, and ROS generation has been examined in diverse experimental models of lipopolysaccharide (LPS)-induced inflammation. The in vivo electron paramagnetic resonance (EPR)/nitroxide spin probe method has been used to analyze the redox status in animal models modulated by ROS generation. In this study, a blood–brain barrier (BBB)-permeable nitroxide spin probe, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (HMP), was used as a redox-sensitive nitroxide probe. Magnetic resonance images of mouse head after the injection of HMP showed that HMP was distributed throughout all regions of the mouse head including the brain, suggesting that HMP can reveal redox information in all regions of the mouse head. After the injection of HMP through the mouse tail vein 6 h after the injection of LPS, three-dimensional (3D) EPR images were obtained each minute under a field scanning of 0.3 s and with 81 projections. The reduction reaction of HMP in septic mouse heads was remarkably accelerated compared to that in control mice, and this accelerated reaction was inhibited by aminoguanidine and allopurinol, which inhibit enzymatic activities of induced nitric oxide synthase and xanthine oxidase, respectively. Based on the pharmacokinetics of HMP in mouse heads, the half-life mapping of HMP was performed in LPS-treated mouse head. Half-life maps clearly show a difference in the redox status induced by ROS generation in the presence or absence of inhibitors of ROS-generating enzymes. The present results suggest that a 3D in vivo EPR imaging system combined with BBB-permeable HMP is a useful noninvasive tool for assessing changes in the redox status in rodent models of brain disease under oxidative stress.  相似文献   

5.
Quantum Statistical Entropy of Black Hole   总被引:1,自引:0,他引:1  
By using the method of quantum statistics, we derive the partition function of bosonic and fermionic field in various coordinates and obtain the integral expression of the entropy of a black hole. Then via the improved brick-wall method, membrane model, we obtain that if we choose proper parameter, the entropy of black hole is proportional to the area of horizon. In our result, the stripped term and the divergent logarithmic term in the original brick-wall method no longer exist. We offer a new simple and direct way of calculating the entropy of black holes in various coordinates.  相似文献   

6.
Quantum Statistic Entropy of Three-Dimensional BTZ Black Hole   总被引:1,自引:0,他引:1  
Using the new equation of state density motivated by the generalized uncertainty relation in the quantum gravity, we investigate entropy of a black line on the background of the three-dimensional BTZ. In our calculation, we need not introduce cutoff and can remove the divergent term in the original brick-wall method via the new equation of state density. And it is obtained that the entropy of the black line is proportional to the area of the horizon (perimeter). Further it is shown the entropy of black line is the entropy of quantum state on the surface of horizon (perimeter). The black line entropy is the intrinsic property of the black hole. The entropy is a quantum effect. By using quantum statistical method, we directly obtain the partition function of Bose field and fermi field on the background of the black line. The difficulty to solve wave equation of various particles is avoided. We offer a new simple and direct way for calculating the entropy of various spacetime black holes (black plane, black line and black column). PACS 04.20.Dw; 97.60.Lf  相似文献   

7.
By making use of the method of quantum statistics,we directly derive the partition function of bosonic and fermionic fields in Reissner-Nordstrom-De Sitter black Hole and obtain the integral expression of black hole‘s entropy and the entropy to which the cosmic horizon surface corresponds.It avoids the difficulty in solving the wave equation of various particles.Then via the improved brick-wall method,i.e.the membrane model,we calculate black hole‘s entropy and cosmic entropy and find out that if we let the integral upper limit and lower limit both tend to the horizon,the entropy of black hole is proportional to the area of horizon and the entropy to which cosmic horizon surface corresponds is proportional to the area of cosmic horizon.In our result,the stripped term and the divergent logarithmic term in the original brick-wall method no longer exist.In the whole process,the physical idea is clear and the calculation is simple.We offer a new simple and direct way for calculating the entropy of different complicated black holes.  相似文献   

8.
Sen黑洞熵与能斯特定理   总被引:3,自引:0,他引:3       下载免费PDF全文
张丽春  赵仁 《物理学报》2004,53(2):362-366
避开求解黑洞背景下波动方程的困难,应用量子统计方法,直接求解轴对称Sen黑洞背景下Bose场和Fermi场的配分函数.然后利用改进的 brick-wall 方法-膜模型,计算黑洞背景下Bose场和Fermi场的熵.得到黑洞熵不但与黑洞的外视界面积有关,而且也是内视界面积的函数.在所得结论中不存在对数发散项与舍去项,也不存在黑洞视界外标量场或Dirac场为什么是黑洞熵疑难,并且给出粒子的自旋简并度对黑洞熵的影响. 当黑洞的辐射温度趋于绝对零度时,由黑洞内外视界面积决定的黑洞熵也趋于零,它满足能斯特定理,可视 关键词: 膜模型 黑洞熵 能斯特定理  相似文献   

9.
平面对称黑洞的统计熵   总被引:1,自引:0,他引:1       下载免费PDF全文
赵仁  张丽春 《物理学报》2002,51(1):21-24
避开求解各种粒子波动方程的困难,直接应用量子统计的方法,计算平面对称黑面背景下玻色场与费米场的配分函数,得到黑面熵的积分表达式.然后应用改进的brickwall方法膜模型,计算黑面视界所对应的统计熵.在所得结果中当所取的积分下限和上限都趋于视界上时,可得到黑面熵与相应黑面视界面积成正比的关系,不存在原brickwall方法中的舍去项与对数发散项.整个计算过程,物理图像清楚,计算简单,为研究黑洞熵提供了一条简捷的新途径 关键词: 量子统计 膜模型 黑面熵  相似文献   

10.
By using the method of quantum statistics, we directly derive the partition function of bosonic and fermionic fields in black cylinder. Then via the improved brick-wall method, membrane model, we obtain that if we choose the proper parameter, the entropy of black cylinder is proportional to the area of the horizon. In our result, the stripped term and the divergent logarithmic term in the original brick-wall method no longer exist. In the whole process, we do not take any approximation. We offer a new simple and direct way of calculating the entropy of different complicated black holes.  相似文献   

11.
By using the method of quantum statistics, we directly derive the partition function of bosonic and fermionic field in dilatonic black hole and obtain the integral expression of the black hole's entropy, which avoids the difficulty in solving the wave equationof various particles. Then via the improved brick-wall method, membrane model, we obtain that we can choose proper parameter in order to let the thickness of film tend to zero and have it approach the surface of its horizon. Consequently the entropy of the black hole is proportional to the area of its horizon. In our result, the stripped term and the divergent logarithmic term in the original brick-wall method no longer exist. In the whole process, physics idea is clear; calculation is simple. We offer a new simple and direct way of calculating the entropy of different complicated black holes.  相似文献   

12.
By using the method of quantum statistics, we directly derive the partition function of bosonic and fermionic field in Reissner-Nordström-anti-de Sitter black hole and obtain the integral expression of black hole's entropy. It avoids the difficulty in solving the wave equation of various particles. Then via the improved brick-wall method, membrane model, we calculate the statistical entropy of a film with the thickness of (N – 1) around the outside of horizon. In our result we can choose proper parameter in order to let the thickness of film tend to zero and have it approach the surface of horizon. Consequently, the entropy of black hole is proportional to the area of horizon. The stripped term and the divergent logarithmic term in the original brick-wall method no longer exist. In the whole process, physics idea is clear; calculation is simple. We offer a new simple and direct way of calculating the entropy of different complicated black holes.  相似文献   

13.
The time dependent entropy (or Leipnik’s entropy) of harmonic and damped harmonic oscillator systems is studied by using time dependent wave function obtained by the Feynman path integral method. The Leipnik entropy and its envelope change as a function of time, angular frequency and damping factor. Our results for simple harmonic oscillator are in agreement with the literature. However, the joint entropy of damped harmonic oscillator shows remarkable discontinuity with time for certain values of damping factor. The envelope of the joint entropy curve increases with time monotonically. These results show the general properties of the envelope of the joint entropy curve for quantum systems.  相似文献   

14.
The Hawking radiation from charged Kerr black hole via the method beyond semi-classical approximation is studied. In our work, we apply the WKB approximation method and the quantum tunneling method, then calculate the tunneling rate and further correct Hawking entropy to charged Kerr black hole. It is shown that the result is still in agreement with the unitary theory, the entropy of the black hole contains three parts: the usual Bekenstein-Hawking entropy, the logarithmic term and the inverse area term. Apart from coefficients, our correction to the charged Kerr black hole entropy is consistent with results of loop quantum gravity.  相似文献   

15.
Background: For the kinetic models used in contrast-based medical imaging, the assignment of the arterial input function named AIF is essential for the estimation of the physiological parameters of the tissue via solving an optimization problem. Objective: In the current study, we estimate the AIF relayed on the modified maximum entropy method. The effectiveness of several numerical methods to determine kinetic parameters and the AIF is evaluated—in situations where enough information about the AIF is not available. The purpose of this study is to identify an appropriate method for estimating this function. Materials and Methods: The modified algorithm is a mixture of the maximum entropy approach with an optimization method, named the teaching-learning method. In here, we applied this algorithm in a Bayesian framework to estimate the kinetic parameters when specifying the unique form of the AIF by the maximum entropy method. We assessed the proficiency of the proposed method for assigning the kinetic parameters in the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), when determining AIF with some other parameter-estimation methods and a standard fixed AIF method. A previously analyzed dataset consisting of contrast agent concentrations in tissue and plasma was used. Results and Conclusions: We compared the accuracy of the results for the estimated parameters obtained from the MMEM with those of the empirical method, maximum likelihood method, moment matching (“method of moments”), the least-square method, the modified maximum likelihood approach, and our previous work. Since the current algorithm does not have the problem of starting point in the parameter estimation phase, it could find the best and nearest model to the empirical model of data, and therefore, the results indicated the Weibull distribution as an appropriate and robust AIF and also illustrated the power and effectiveness of the proposed method to estimate the kinetic parameters.  相似文献   

16.
王传艺  赵柳 《中国物理C(英文版)》2019,43(9):095103-095103-8
f(Ricci) gravity is a special kind of higher curvature gravity whose bulk Lagrangian density is the trace of a matrix-valued function of the Ricci tensor. It is shown that under some mild constraints, f(Ricci) gravity admits Einstein manifolds as exact vacuum solutions, and can be ghost-free and tachyon-free around maximally symmetric Einstein vacua. It is also shown that the entropy for spherically symmetric black holes in f(Ricci) gravity calculated via the Wald method and the boundary Noether charge approach are in good agreement.  相似文献   

17.
A method is proposed to calculate the Boltzmann non equilibrium entropy as a Taylor series expansion in terms of the successive moments of the velocity distribution function. As a first application, the entropy of the BKW solution of the Boltzmann equation is calculated for both even and odd dimensions. The properties of the entropy of the Tjon Wu modeld=2) are studied and a quantitative condition is derived, showing that the McKean conjecture is incorrect. As a second application of the method, the entropy of one of the solutions of the very hard particle model for the Boltzmann equation is also derived.  相似文献   

18.
二维广义模糊熵图像阈值分割法   总被引:1,自引:1,他引:0  
雷博  范九伦 《光子学报》2014,39(10):1907-1914
针对一维广义模糊熵不能有效处理含噪图像的分割问题,在二维灰度直方图上定义了图像的二维隶属度函数,提出了二维广义模糊熵阈值分割法.该方法不仅考虑了图像的点灰度值,同时考虑了图像像素的邻域平均灰度值,能更好地利用图像中的信息.为了提高二维广义模糊熵阈值法的运行速度、解决参量选取问题,结合粒子群优化搜索方法,设计了嵌套式的优化过程.实验表明,二维广义模糊熵阈值分割法对噪音图像有更好的适应性.  相似文献   

19.
The entropy spectrum of a spherically symmetric black hole was derived without the quasinormal modes in the work of Majhi and Vagenas. Extending this work to rotating black holes, we quantize the entropy and the horizon area of a Kerr anti-de Sitter black hole by two methods. The spectra of entropy and area are obtained via the Bohr–Sommerfeld quantization rule and the adiabatic invariance in the first way. By addressing the wave function of emitted (absorbed) particles, the entropy and the area are quantized in the second one. Both results show that the entropy and the area spectra are equally spaced.  相似文献   

20.
The entanglement entropy of an acoustic black hole in a Bose-Einstein condensates (BEC) is derived, which is associated with the phonons generated via the Hawking mechanism in a sonic hole. Considering the dispersion relation of a BEC, we recalculate the entanglement entropy of the acoustic black hole by means of statistical method in two limits. We find that the entropy is still proportional to the area of event horizon, but with a coefficient dependent on the infrared cutoff.  相似文献   

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