We study the global pressure of a one-dimensional polydisperse granular gases system for the first time, in which the size distribution of particles has the fractal characteristic and the inhomogeneity is described by...We study the global pressure of a one-dimensional polydisperse granular gases system for the first time, in which the size distribution of particles has the fractal characteristic and the inhomogeneity is described by a fractal dimension D. The particles are driven by Gaussian white noise and subject to inelastic mutual collisions. We define the global pressure P of the system as the impulse transferred across a surface in a unit of time, which has two contributions, one from the translational motion of particles and the other from the collisions. Explicit expression for the global pressure in the steady state is derived. By molecular dynamics simulations, we investigate how the inelasticity of collisions and the inhomogeneity of the particles influence the global pressure. The simulation results indicate that the restitution coefficient e and the fractal dimension D have significant effect on the pressure.展开更多
We present a model of non-uniform granular gases in one-dimensional case, whose granularity distribution has the fractal characteristic. We have studied the nonequilibrium properties of the system by means of Monte Ca...We present a model of non-uniform granular gases in one-dimensional case, whose granularity distribution has the fractal characteristic. We have studied the nonequilibrium properties of the system by means of Monte Carlo method. When the typical relaxation time T of the Brownian process is greater than the mean collision time To, the energy evolution of the system exponentially decays, with a tendency to achieve a stable asymptotic value, and the system finally reaches a nonequilibrium steady state in which the velocity distribution strongly deviates from the Gaussian one. Three other aspects have also been studied for the steady state： the visualized change of the particle density, the entropy of the system and the correlations in the velocity of particles. And the results of simulations indicate that the system has strong spatial clustering; Furthermore, the influence of the inelasticity and inhomogeneity on dynamic behaviors have also been extensively investigated, especially the dependence of the entropy and the correlations in the velocity of particles on the restitute coefficient e and the fractal dimension D.展开更多
目的研究P波高尖与青年肺结核患者右心房负荷的相关性。方法选择60例肺结核合并右心房负荷患者(合并右心房负荷组),其中男性29例,女性31例;年龄30~38岁,平均年龄35.96岁。另选取单纯性肺结核患者60例(单纯性肺结核组),其中男性30例,女...目的研究P波高尖与青年肺结核患者右心房负荷的相关性。方法选择60例肺结核合并右心房负荷患者(合并右心房负荷组),其中男性29例,女性31例;年龄30~38岁,平均年龄35.96岁。另选取单纯性肺结核患者60例(单纯性肺结核组),其中男性30例,女性30例;年龄31~37岁,平均年龄35.90岁。分别对两组患者开展心电图及心脏超声检测,分析两组患者的P波电压值、心电图改变情况、右心室负荷情况之间的差异,分析合并右心房负荷患者的P波电压值与患者右心房负荷情况相关性。结果合并右心房负荷组P波电压值显著高于单纯肺结核组患者[(0.35±0.05) mV vs(0.25±0.03) mV;t=13.284,P=0.000]。合并右心房负荷组电轴偏移、窦性心动过速发生率、ST-T改变及P波高尖发生率显著高于单纯肺结核组(χ2=6.541、4.681、5.261、15.912,P <0.05);合并右心房负荷组患者的RAVImax、RAVImin、RAVIt显著高于单纯肺结核组患者[RAVImax:(32.33±1.09) m L/m2vs (28.25±1.27) m L/m2;RAVImin:(13.42±1.03) m L/m2vs(11.88±1.22) m L/m2;RAVIt:(20.22±3.22) m L/m2vs (17.33±5.33) m L/m2](t=20.971、8.297、3.992,P <0.05),RAVIpre、RAVIp、RAVIa、Tei指数显著低于单纯肺结核组患者[RAVIpre:(3.01±0.22) mL/m2vs (17.51±5.33) mL/m2;RAVIp:(7.41±1.02) m L/m2vs (10.36±1.13) mL/m2;RAVIa:(38.25±2.63) mL/m2vs (44.51±2.16) m L/m2;Tei指数:0.25±0.13 vs0.39±0.11](t=23.382、16.670、15.823、6.368,P <0.05)。患者的P波电压值与RAVImax、RAVImin、RAVIt呈现正相关(r=0.339、0.441、0.497,P <0.05),与患者的RAVIpre、RAVIp、RAVIa、Tei指数呈现负相关(r=-0.449、-0.552、-0.559、-0.367,P <0.05)。结论 P波与患者的右心房的负荷显著相关,可作为心脏功能发生改变的有效指标。展开更多
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10675048 and 10604017 and Natural Science Foundation of Xianning College under Grant No. KZ0627
文摘We study the global pressure of a one-dimensional polydisperse granular gases system for the first time, in which the size distribution of particles has the fractal characteristic and the inhomogeneity is described by a fractal dimension D. The particles are driven by Gaussian white noise and subject to inelastic mutual collisions. We define the global pressure P of the system as the impulse transferred across a surface in a unit of time, which has two contributions, one from the translational motion of particles and the other from the collisions. Explicit expression for the global pressure in the steady state is derived. By molecular dynamics simulations, we investigate how the inelasticity of collisions and the inhomogeneity of the particles influence the global pressure. The simulation results indicate that the restitution coefficient e and the fractal dimension D have significant effect on the pressure.
基金The project supported by National Natural Science of China under Grant No. 10675408 and Natural Science Foundation of Xianning College under Grant No. KZ0627
文摘We present a model of non-uniform granular gases in one-dimensional case, whose granularity distribution has the fractal characteristic. We have studied the nonequilibrium properties of the system by means of Monte Carlo method. When the typical relaxation time T of the Brownian process is greater than the mean collision time To, the energy evolution of the system exponentially decays, with a tendency to achieve a stable asymptotic value, and the system finally reaches a nonequilibrium steady state in which the velocity distribution strongly deviates from the Gaussian one. Three other aspects have also been studied for the steady state： the visualized change of the particle density, the entropy of the system and the correlations in the velocity of particles. And the results of simulations indicate that the system has strong spatial clustering; Furthermore, the influence of the inelasticity and inhomogeneity on dynamic behaviors have also been extensively investigated, especially the dependence of the entropy and the correlations in the velocity of particles on the restitute coefficient e and the fractal dimension D.
文摘目的研究P波高尖与青年肺结核患者右心房负荷的相关性。方法选择60例肺结核合并右心房负荷患者(合并右心房负荷组),其中男性29例,女性31例;年龄30~38岁,平均年龄35.96岁。另选取单纯性肺结核患者60例(单纯性肺结核组),其中男性30例,女性30例;年龄31~37岁,平均年龄35.90岁。分别对两组患者开展心电图及心脏超声检测,分析两组患者的P波电压值、心电图改变情况、右心室负荷情况之间的差异,分析合并右心房负荷患者的P波电压值与患者右心房负荷情况相关性。结果合并右心房负荷组P波电压值显著高于单纯肺结核组患者[(0.35±0.05) mV vs(0.25±0.03) mV;t=13.284,P=0.000]。合并右心房负荷组电轴偏移、窦性心动过速发生率、ST-T改变及P波高尖发生率显著高于单纯肺结核组(χ2=6.541、4.681、5.261、15.912,P <0.05);合并右心房负荷组患者的RAVImax、RAVImin、RAVIt显著高于单纯肺结核组患者[RAVImax:(32.33±1.09) m L/m2vs (28.25±1.27) m L/m2;RAVImin:(13.42±1.03) m L/m2vs(11.88±1.22) m L/m2;RAVIt:(20.22±3.22) m L/m2vs (17.33±5.33) m L/m2](t=20.971、8.297、3.992,P <0.05),RAVIpre、RAVIp、RAVIa、Tei指数显著低于单纯肺结核组患者[RAVIpre:(3.01±0.22) mL/m2vs (17.51±5.33) mL/m2;RAVIp:(7.41±1.02) m L/m2vs (10.36±1.13) mL/m2;RAVIa:(38.25±2.63) mL/m2vs (44.51±2.16) m L/m2;Tei指数:0.25±0.13 vs0.39±0.11](t=23.382、16.670、15.823、6.368,P <0.05)。患者的P波电压值与RAVImax、RAVImin、RAVIt呈现正相关(r=0.339、0.441、0.497,P <0.05),与患者的RAVIpre、RAVIp、RAVIa、Tei指数呈现负相关(r=-0.449、-0.552、-0.559、-0.367,P <0.05)。结论 P波与患者的右心房的负荷显著相关,可作为心脏功能发生改变的有效指标。
