一种DNA染料结合聚合酶链反应检测鉴别植物病原细菌死活细胞

建立了一种将DNA染料(EMA)结合PCR的新分析方法, 用于有效检测区分植物病原细菌死活细胞. 结果表明, 当用2.0 mg/L或更高浓度的EMA渗透处理含有106 cfu/mL的死细胞菌悬液后再曝光处理10 min, 其PCR结果呈阴性, 而未经过EMA渗透处理的对应样品PCR结果呈阳性; EMA渗透处理含有适当数量病菌活细胞的种子浸泡液后, 更有助于特异性检测混合体系中靶标菌活细胞. 分析认为, 该方法避免了传统PCR无法区分细菌死活细胞的弊端, 是一种快速、灵敏且能有效鉴别病原细菌死活细胞的新方法.     

Local existence and blow-up criterion of 3D ideal magnetohydrodynamics equations

We investigate the local existence of smooth solutions of a 3D ideal magnetohydrodynamics (MHD) equations in a bounded domain and give a blow-up criteria to this equations with respect to vorticists.     

三维有序SiC空心球的制备及表征

以三维有序多孔碳为模板, 以聚甲基硅烷(PMS)为前驱体, 经过前驱体的渗入、交联和陶瓷转化以及多孔碳模板的烧除, 制备了长程三维有序SiC空心球. 所制备的SiC空心球的外径(135-896 nm)、 球壳厚度(14-79 nm)、 BET比表面积(50.8～5.0 m2/g)及微孔体积(0.265～0.038 cm3/g)受不同孔径的多孔碳模板(150-1 000 nm)或不同前驱体浓度的控制. 所制备的SiC空心球以hcp结构排列成长程三维有序的序列.     

低温CO氧化中担载C0304催化剂失活的影响因素

This study focused on the influences of a variety of reaction parameters and guest molecules such as H2O and C3H8 on the deactivation of supported Co3O4 catalysts for CO oxidation.Additionally,the physical features of and carbon deposition on some samples after the reaction under the chosen conditions were determined by BET and X-ray diffraction as well as by carbon analyses to deduce the precursors associated with catalyst deactivation.Activity maintenance profiles of the catalysts for CO oxidation at 100°...     

Suppression of the Resonant Scattering in Imperfect Acoustic Cloaking with a Lossy Medium in R^3

It has been realized that resonance frequencies of imperfect the transformation acoustics in R^2 are located near Dirichlet acoustic cloaking based on a small perturbation of eigenvalues of the cloaked region [Chin. Phys. Lett. 26 （2009） 014301; 29 （2012） 124301]. In this work, we study the performance of the three-dimensional approximate cloaking system based on the transformation acoustics and show that the cloaking effect may be deteriorated at zeroth order Neumann eigenvalues of the concealed region. In particular, transmitted fields into the concealed region can be extremely resonated at frequencies corresponding to the zeroth-order Neumann eigenvalues while scattered fields are suppressed well for any frequency. To enhance the cloaking effect at resonance frequencies, we introduce a lossy medium inside the cloaked region and show that the new proposal can reduce the intensity of transmitted fields significantly due to the lossy medium.     

HF SAR image cross-correlation technique for high accuracy orbit positioning

A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an accuracy of ～ /4 or better, where is the wavelength of the HF radar pulse at its center frequency. The performance of the proposed technique was confirmed by simulation which was carried out under the condition of design facts of the SELENE LRS mission. The highly accurate orbit positioning ena...     

FREE VIBRATION ANALYSIS OF BAFFLED LIQUID-STORAGE TANKS BY THE STRUCTURAL-ACOUSTIC FINITE ELEMENT FORMULATION

In fluid-structure interaction systems, baffles as a dynamic damping device are being widely used to suppress the fluid sloshing motion. Meanwhile, natural and dynamic behaviors of such systems are significantly influenced by the baffle parameters, such as the baffle number, the installation location, the inner-hole diameter and the liquid fill height. This paper intends to numerically investigate the parametric eigen characteristics, by the coupled structural-acoustic finite element method (FEM), of baffled cylindrical liquid-storage tank. According to the symmetric two-field formulation, a test FEM program is developed, in which the reduced integration for avoiding the shear and membrane locking and the modified shear correction factor as well as degenerated 8- and 6-node shell elements and 3-D trilinear acoustic elements are used. Through the comparison with the available analytic solutions of no-baffled axisymmetric tank, the validity of the test program and theoretical work is verified. Next, with the verified test FEM program, various combinations of major baffle parameters are intensively examined, in order for the parametric baffle effects on the natural frequency of baffled tanks.     

ESTIMATES OF LOWER CRITICAL MAGNETICFIELD AND VORTEX PINNING BY INHOMO-GENEITIES IN TYPE II SUPERCONDUCTORS

The effect of an applied magnetic field on an inhomogeneous superconductor is studied and the value of the lower critical magnetic field HC1 at which superconducting vortices appear is estimated. In addition, the authors locate the vortices of local minimizers, which depends on the inhomogeneous term a(x).     

关于Triebel空间上的算子值傅里叶乘子

利用Str6mberg-Torchinsky分解,给出了Triebel空间FEp.q(Rn,X)上算子值傅里叶乘子的一个充分条件.在rl相似文献   

Guiding Properties of a Tapered Photonic Crystal Fiber Compared with Those of a Tapered Single-Mode Fiber

We have fabricated tapered photonic crystal fibers using a fusion splicer and experimentally observed the near-field mode distribution and the beam divergence of it. We have also compared characteristics of the tapered photonic crystal fiber with those of a tapered standard single-mode fiber. Unlike a tapered standard single-mode fiber, the mode field profile of a tapered photonic crystal fiber shows a good confinement of its field within the core region. The numerical apertures of tapered photonic crystal fibers are increased as the diameter of the fiber is decreased.