瞬态平面热源法测量硅胶混合吸附剂导热系数

利用瞬态平面热源法对制冷吸附剂的导热性能进行测试.所研究的吸附剂包括:硅胶颗粒、硅胶-水、硅胶-氯化钙混合多孔介质、硅胶-氯化钙-膨胀石墨固化混合吸附剂.实验结果表明:硅胶颗粒的孔隙率对其导热性能的影响比较大;此外,当硅胶的吸水量增大时,导热系数呈线性增大.当氯化钙质量分数大于0.2时,混合多孔介质的导热系数随氯化钙质量分数的增大而显著增加.利用膨胀石墨可以明显地提高硅胶颗粒的导热系数,固化的混合吸附剂的导热系数可以达到2.942W/mK,相对于硅胶颗粒的导热系数提高约30倍.     

利用宇宙线对BESⅢ量能器CsⅠ（Tl）晶体探测器单元的测量

利用宇宙射线进行探测器模型的性能测试是高能物理普遍采用的方法，其中最重要的步骤之一就是确定宇宙线入射的准确位置和径迹．多数采用丝室探测器来进行宇宙线的精确定位，需要很高的造价和复杂的电子学系统．本文介绍一种简单的定位方法，采用塑料闪烁体条加波移剂光纤编码读出的方式，可以实现精度为1cm的定位．据此建立了一套实验装置，对BESⅢ电磁量能器CsⅠ（Tl）晶体探测器单元的光输出强度和不均匀性进行了测量．     

皮肤晚期糖基化终末产物的自体荧光光谱特性

在分析晚期糖基化终末产物(Advanced glycation end products,AGEs)标准品三维荧光光谱和皮肤中AGEs自体荧光光谱的基础上,确定了皮肤中AGEs的最佳激发波长为370 nm.使用自行设计的皮肤荧光光谱检测装置对正常人和糖尿病患者皮肤AGEs的荧光光谱进行了检测,结果表明:在418,450...     

一种适于小角度测量的旋光角度测量方法研究

通过对输出信号的分析,提出了一种适于小角度测量的旋光角度测量方法,此方法通过检测经过旋光物质并经法拉第磁光调制的信号与不加旋光物质而仅经法拉第磁光调制的信号的波形宽度来实现对旋光物质旋光角度的测量.同时,利用搭建的测试系统,配置不同浓度的白砂糖溶液进行了验证性实验.实验结果表明,旋光角度与溶液浓度之间成很好的线性关系,...     

双模最小关联混态的量子统计性质

研究了双模最小关联混态在不同参数情况下的量子统计性质.发现在一定的参数范围内双模最小关联混态的二阶相干性违反经典的Cauchy-Schwartz不等式,呈现非经典性相关;同时对双模最小关联混态的压缩特性、亚泊松分布等非经典性质进行了分析,通过数值计算得出,每模光子的压缩性及其亚泊松分布均与参数d的取值密切相关.     

负P表示非经典光场的Wehrl熵和Shannon熵

研究了负P表示非经典光场的Wehrl熵和Shannon熵与场参数m和平均光子数(-n)的关系,结果显示,负P表示的非经典光场的Wehrl熵随着场参数m和平均光子数的增大而减小,当(-n)增大到一定程度时Wehrl熵趋向于一个不变的常数.用数值计算的方法研究了负P表示光场的Shannon熵与平均光子数(-n)的关系,结果表明,Shannon熵随着场参数m和平均光子数(-n)的增大而增大.同时发现,Wehrl熵随光场总噪声的增大而减小,Shannon熵随力学量起伏的减小而减小.     

Tesla微混合器结构参数对混合强度的影响

针对Tesla微混合器混合原理,利用计算流体力学(CFD)模拟与分析软件对其进行了三维数值模拟.模型采用有限体积法离散、SIMPLEC算法进行层流计算.分析了结构参数的改变对该混合器混合效果的影响,并采用混合强度值作为衡量指标.分析结果显示,不同通道高宽比和分离通道入流角度等结构参数对该微混合器的混合效果有重要影响.模...     

Stochastic Momentum Cooling——Palmer Cooling at HIRFL-CSRm

The Palmer cooling is always used for large dispersion momentum cooling in storage ring. So it will be used during the stripping injection of HIRFL-CSRm. Here the Palmer cooling is described. The optimum cooling time, optimum gain and optimum cooling bandwidth are obtained in the simulation with Palmer method. Using the Fokker-Planck equation, the particle distribution with respect to the momentum dispersion is also obtained numerically during the stochastic cooling process. This is useful for analysis of experimental data and for design of the cooling system, i.e, optimization of the system passband and gain, specification of accuracy of the signal transmission, etc.     

Quantum Bidirectional Secure Direct Communication via Entanglement Swapping

In light of a quantum secure direct communication （QSDC） scheme using entanglement swapping [Chin. Phys. Lett. 22 （2005）18], by introducing additional local operations for encoding, we propose a bidirectional QSDC （BQSDC） protocol, in which two legitimate users can simultaneously exchange their respective messages. The rule for the users to retrieve his/her partner＇s messages is derived explicitly in the most general case. Eve＇s commonly used attack method has been discussed and can be detected with the security checking process.     

Experimental Study on Electrostatic with Two Guiding of Supersonic D20 Molecular Beam Charged Wires

We demonstrate the guiding of a supersonic heavy-water （D2O） molecular beam using a hollow electrostatic field generated by the combination of two parallel charged-wires and two grounded metal-plates, and report some new and preliminary experimental results. In the experiment, we detect the guiding signals by using the method of time-of-flight mass spectrum and study the dependence of the relative transmission of the beam guide on the guiding voltage. Our study shows that the relative transmission of the beam guide is increased linearly with increasing guiding voltage Vguid, and the number of the guided D20 molecules is at least increased by 89.4% when the guiding voltage is ＋20.0k V. Finally, some potential applications of our guiding scheme in the molecule optics are briefly discussed.