固定光路可变焦宽调角表面等离子共振成像装置

设计了一种折反式棱镜耦合单元, 用于简化表面等离子共振系统的角度调节操作, 并基于此单元构建了固定光路可变焦宽调角表面等离子共振成像装置. 该装置通过旋转折反式棱镜耦合单元即可实现角度调节, 调节范围可达40°~80°, 结合1~2倍的变焦成像系统, 可对1~4 cm²传感芯片成像, 且可分辨至少3600 Point/cm². 以蔗糖溶液为研究对象, 考察了该装置的灵敏度, 结果表明其灵敏度可达7×10^-6 RIU(Refractive index unit), 共振角与折射率的线性相关系数为0.99953. 将该装置用于研究抗牛血清白蛋白抗体与其它蛋白的实时相互作用, 所得结果与理论相符. 该表面等离子共振成像装置将在实时并行分析方面具有广阔的应用前景.     

DYNAMIC BUCKLING OF DOUBLE-WALLED CARBON NANOTUBES UNDER STEP AXIAL LOAD

An approximate method is presented in this paper for studying the dynamic buckling of double-walled carbon nanotubes （DWNTs） under step axial load. The analysis is based on the continuum mechanics model, which takes into account the van der Waals interaction between the outer and inner nanotubes. A buckling condition is derived, from which the critical buckling load and associated buckling mode can be determined. As examples, numerical results are worked out for DWNTs under fixed boundary conditions. It is shown that, due to the effect of van der Waals forces, the critical buckling load of a DWNT is enhanced when inserting an inner tube into a single-walled one. The paper indicates that the critical buckling load of DWNTs for dynamic buckling is higher than that for static buckling. The effect of the radii is also examined. In addition, some of the results are compared with the previous ones.     

1,3-氧氮杂环戊烷类化合物在Chiralcel OD上的对映异构体拆分

2位取代的5-氯甲基-1,3-氧氮杂环戊烷衍生物具有两个手性中心,有多种生理和生物活性.利用Chiralcel OD手性柱,首次对通过非手性选择性合成的2,3-二苯基-5-氯甲基-1,3-氧氮杂环戊烷和2-(4′-硝基苯)-3-苯基-5-氯甲基-1,3-氧氮杂环戊烷进行手性拆分研究.考察了流动相中极性添加剂以及柱温对拆分的影响.初步探讨了其手性识别的作用机理.发现在正相体系下溶质的4个对映异构体都获得了很好的拆分.     

FORMULATION AND EVALUATION OF AN ANALYTICAL STUDY FOR CYLINDRICAL HELICAL SPRINGS

The free vibration analysis of cylindrical helical springs is carried out by means of an analytical study.In the governing equations of the motion of the springs,all displacement functions are defined at the centroid axis and also the effects of the rotational inertia,axial and shear deformations are included in the proposed model.Explicit analytical expressions which give the vibrating mode shapes are derived by rigorous application of the symbolic computing package MATHEMATICA and a process of searching is used to determine the exact natural frequencies.Numerical examples are provided for fixed-fixed boundary conditions.The free vibrational parameters are chosen as the number of coils(n=4 ～ 14),the helix pitch angle(α=5 ～ 30?) and as the ratio of the diameters of the cylinder and the wire(D/d=4 ～ 18) in a wide range.Validation of the proposed model has been achieved through comparison with a finite element model using two-node standard beam elements and the results available in published literature,which in these cases indicates a very good correlation.     

基于Q-R分解的平滑算法在惯导参数标定中应用

针对舰船中低精度惯性导航设备参数标定维护费用高、过程周期长等问题,采用测姿型DGPS作为测定误差的基准平台搭建导航设备性能测试系统,利用组合导航方式获取的高精度导航参数对惯导设备性能进行评估。为此,利用Q-R分解中上三角矩阵求逆计算的快速性和稳定性特点,建立基于Q-R矩阵分解的区间平滑滤波器,取代滤波误差方差阵P阵的计算为R阵的迭代,避免P阵在计算过程中失去正定性和对称性导致滤波发散。仿真分析结果表明:结合导航设备性能测试系统的Q-R分解区间平滑算法能有效提高系统位置、速度、姿态等数据的估计精度和数据平滑度,可以作为一种中低精度惯导参数性能事后评估方法。     

Quasinormal modes of a stationary axisymmetric EMDA black hole

The massless scalar quasinormal modes (QNMs) of a stationary axisymmetric Einstein--Maxwell dilaton--axion (EMDA) black hole are calculated numerically using the continued fraction method first proposed by Leaver. The fundamental quasinormal frequencies (slowly damped QNMs) are obtained and the peculiar behaviours of them are studied. It is shown that these frequencies depend on the dilaton parameter $D$, the rotational parameter $a$, the multiple moment $l$ and the azimuthal number $m$, and have the same values with other authors at the Schwarzschild and Kerr limit.     

New infinite-dimensional symmetry groups for the stationary axisymmetric Einstein--Maxwell equations with multiple Abelian gauge fields

The so-called extended hyperbolic complex (EHC) function method is used to study further the stationary axisymmetric Einstein--Maxwell theory with $p$ Abelian gauge fields (EM-$p$ theory, for short). Two EHC structural Riemann--Hilbert (RH) transformations are constructed and are then shown to give an infinite-dimensional symmetry group of the EM-$p$ theory. This symmetry group is verified to have the structure of semidirect product of Kac--Moody group $\widehat{SU(p+1,1)}$ and Virasoro group. Moreover, the infinitesimal forms of these two RH transformations are calculated and found to give exactly the same infinitesimal transformations as in previous author's paper by a different scheme. This demonstrates that the results obtained in the present paper provide some exponentiations of all the infinitesimal symmetry transformations obtained before.     

Physical design and cooling test of C-band standing wave accelerating tube

The physical design and cooling test of a C-band 2MeV standing wave (SW) accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section with a total length of about 163mm,excited with 1MW magnetron. Dynamic simulation presents that about 150mA beam pulse current and 30{\%} capture efficiency can be achieved. By means of nonlinear Gauss fit on electron transverse distribution, the diameter of beam spot FWHM (full width at half maximum of density distribution) is about 0.55mm. Cooling test results of the accelerating tube show that frequencies of cavities are tuned to 5527MHz and the field distribution of bunching section is about 3:9:10.     

Luminescent Bacterial Sensors Made from Immobilized Films of Photobacterium Phosphoreum

A kind of luminous bacterial sensors that can quickly detect the acute toxicity of environmental pollutants were developed. The method is based on the detection of the cellular light of bright luminous bacillus by means of fixing cells so as to detect acute toxicity of luminous bacillus. The bacterial sensor is composed of immobilized film of photobacterium phosphoreum. These bacterial films are sensitive to detecting the toxicolds, which are difficult or even impossible to be measured by traditionaL analyticaL chemistry methods. The films should be stored at 4℃ and the stability of the sensors exceeds 1 month with no measurable deterioration of the signal. These results demonstrate that the immobilized film of P. phosphreum can be used to develop the on-line environmental contamination monitor.     

固定刚果红的交联聚乙烯醇光化学pH敏感膜

固定刚果红的交联聚乙烯醇光化学pH敏感膜;聚乙烯醇; pH敏感膜; 刚果红