根据砝码磁性参数的测量原理,针对磁性测量中示值稳定性的影响量进行分析,提出影响砝码磁性参数测量中示值稳定性的关键影响量.采用最大称量5.1 g、分辨率0.1μg的磁化率计进行砝码磁性测量,测量过程中分别同步测试振动的变化和环境磁...根据砝码磁性参数的测量原理,针对磁性测量中示值稳定性的影响量进行分析,提出影响砝码磁性参数测量中示值稳定性的关键影响量.采用最大称量5.1 g、分辨率0.1μg的磁化率计进行砝码磁性测量,测量过程中分别同步测试振动的变化和环境磁场的变化,通过实验数据分析,验证了环境磁场的波动是影响砝码磁性测量的关键影响量.
Abstract：
According to the measurement principle of weight magnetic parameter, the influence of reading stability for measuring magnetism is analyzed, and the key influence of reading stability is presented in the measurement process. The magnetism of weight is measured by the magnetic susceptometer with capacity of 5.1 g and resolution of O. 1 μg. At the same time the change of environmental vibration in the laboratory and the fluctuating of ambient magnetic field are measured respectively. The experimental results show the fluctuating of ambient magnetic field that is the key influence of weight magnetism measurement.展开更多
The finite-temperature Pauli paramagnetic susceptibility of a three-dimensional ideal anyon gas obeying Haldane fractional exclusion statistics is studied analytically.Different from the result of an ideal Fermi gas,t...The finite-temperature Pauli paramagnetic susceptibility of a three-dimensional ideal anyon gas obeying Haldane fractional exclusion statistics is studied analytically.Different from the result of an ideal Fermi gas,the susceptibility of an ideal anyon gas depends on a statistical factor g in Haldane statistics model.The low-temperature and high-temperature behaviors of the susceptibility are investigated in detail.The Pauli paramagnetic susceptibility of the two-dimensional ideal anyons is also derived.It is found that the reciprocal of the susceptibility has the similar factorizable property which is exhibited in some thermodynamic quantities in two dimensions.展开更多
Magnetophoresis is one of the most important separation methods in biological and chemical engineering. In this paper,a novel impact parameter on separation efficiency,i.e.,the angle between the vectors of magnetic fo...Magnetophoresis is one of the most important separation methods in biological and chemical engineering. In this paper,a novel impact parameter on separation efficiency,i.e.,the angle between the vectors of magnetic force and fluid velocity,was derived from the basic equation describing the motion of magnetic beads in microchannels. It is proposed that one of the most important approaches for separation efficiency enhancement is to improve the coordination of magnetic force field and fluid flow field. A T-shaped microchannel magnetophoretic separator was designed based on the angle. And then a two-dimensional dynamic model of magnetic beads moving in microchannels was established to study the separation efficiency of T-shaped microseparator by combined use of finite element method and Runge-Kutta method. The results show that the capture effi-ciency of T-shaped microseparator is much higher than that of the straight microseparator at the same conditions. For small magnetic beads at high fluid velocities,the designed T-shaped microseparator could still keep high separation efficiency whereas the conventional straight microseparator fails to separate the magnetic beads. Further analysis shows that the mechanism of separation efficiency enhancement lies in the synergy of magnetic force field and flow field,which directly leads to large deflected velocity of the magnetic beads from the main stream,and thus increasing the separation efficiency. It is anticipated that the results in this paper are theoretically helpful for the optimum design of highly efficient magnetophoretic separators.展开更多
文摘根据砝码磁性参数的测量原理,针对磁性测量中示值稳定性的影响量进行分析,提出影响砝码磁性参数测量中示值稳定性的关键影响量.采用最大称量5.1 g、分辨率0.1μg的磁化率计进行砝码磁性测量,测量过程中分别同步测试振动的变化和环境磁场的变化,通过实验数据分析,验证了环境磁场的波动是影响砝码磁性测量的关键影响量.
Abstract：
According to the measurement principle of weight magnetic parameter, the influence of reading stability for measuring magnetism is analyzed, and the key influence of reading stability is presented in the measurement process. The magnetism of weight is measured by the magnetic susceptometer with capacity of 5.1 g and resolution of O. 1 μg. At the same time the change of environmental vibration in the laboratory and the fluctuating of ambient magnetic field are measured respectively. The experimental results show the fluctuating of ambient magnetic field that is the key influence of weight magnetism measurement.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 11275082 and 11178001
文摘The finite-temperature Pauli paramagnetic susceptibility of a three-dimensional ideal anyon gas obeying Haldane fractional exclusion statistics is studied analytically.Different from the result of an ideal Fermi gas,the susceptibility of an ideal anyon gas depends on a statistical factor g in Haldane statistics model.The low-temperature and high-temperature behaviors of the susceptibility are investigated in detail.The Pauli paramagnetic susceptibility of the two-dimensional ideal anyons is also derived.It is found that the reciprocal of the susceptibility has the similar factorizable property which is exhibited in some thermodynamic quantities in two dimensions.
基金supported by the National Natural Science Foundation of China (Grant No.50925624)the National Basic Research Program of China ("973" Project) (Grant No.2012CB720404)the Science and Technology Commission of Shanghai Municipality (Grant No.11XD1403100)
文摘Magnetophoresis is one of the most important separation methods in biological and chemical engineering. In this paper,a novel impact parameter on separation efficiency,i.e.,the angle between the vectors of magnetic force and fluid velocity,was derived from the basic equation describing the motion of magnetic beads in microchannels. It is proposed that one of the most important approaches for separation efficiency enhancement is to improve the coordination of magnetic force field and fluid flow field. A T-shaped microchannel magnetophoretic separator was designed based on the angle. And then a two-dimensional dynamic model of magnetic beads moving in microchannels was established to study the separation efficiency of T-shaped microseparator by combined use of finite element method and Runge-Kutta method. The results show that the capture effi-ciency of T-shaped microseparator is much higher than that of the straight microseparator at the same conditions. For small magnetic beads at high fluid velocities,the designed T-shaped microseparator could still keep high separation efficiency whereas the conventional straight microseparator fails to separate the magnetic beads. Further analysis shows that the mechanism of separation efficiency enhancement lies in the synergy of magnetic force field and flow field,which directly leads to large deflected velocity of the magnetic beads from the main stream,and thus increasing the separation efficiency. It is anticipated that the results in this paper are theoretically helpful for the optimum design of highly efficient magnetophoretic separators.
