On a mutualism model with feedback controls

We propose and study a mutualism model with feedback controls. By applying a new differential inequality, we show that the conditions which ensure the permanence of the system are the same as that of the model without feedback controls, which means that the feedback control variables have no influence on the persistent property of the system. Our results not only improve but also complement some existing ones.     

Studies on the formation of hierarchical zeolite T aggregates with well-defined morphology in different template systems

In this paper, the disk-like and pumpkin-like hierarchical zeolite T aggregates consisted of primary nano-grains have been hydrothermally synthesized with and without the aid of the second template. The first template is used with tetramethylammonium hydroxide (TMAOH) and the second template is used with triethanolamine (TEA) or polyving akohol (PVA). A combination of characterization techniques, including XRD, SEM, TEM and N₂ adsorption–desorption to examine the crystal crystallinity, morphology and surface properties of hierarchical zeolite T aggregates. In the single-template preparation process, the two-step varying-temperature treatment has been used to improve the meso-porosity of zeolite T aggregates. In the double-template preparation process, the amounts of PVA or TEA on the crystallinity, morphology and meso-porosity of zeolite T aggregates have been studied. It has been proved that the interstitial voids between the primary grains of aggregates are the origin of additional mesopores of samples. The micro- and meso-porosities of samples prepared with and without the second template have been contrasted in detail at last. In particular, the sample synthesized with the addition of PVA presents a hierarchical pore structure with the highest S_ext value of 122 m²/g and V_meso value of 0.255 cm³/g.     

V型原子与光场拉曼相互作用传送未知原子态

未知量子态从一个地方到另一个地方的隐形传送在量子信息领域中有非常重要的作用,提出了一种利用简并V型三能级原子与振幅很大的单模相干态腔场的拉曼相互作用来传送未知原子态的方案。     

利用Raman型的Jaynes-Cummings模型传送光场的福克叠加态

提出了一种利用Λ型三能级原子与光场Raman相互作用来传送光场的福克叠加态的方案.     

Singular perturbation of first boundary value problem for higher order elliptic equations (II)

In this paper we discuss singular perturbations of first boundary value problem for higher order elliptic equations of two parameter and obtain the asymptotic expression for the formal solution containing two-parameter as well as the estimation of its remainder term. These results are the extensions of (2) and (3).     

An extremal problem on potentially Kr,s-graphic sequences

We consider a variation of a classical Turán-type extremal problem (F. Chung, R. Graham, Erd s on Graphs: His Legacy of Unsolved Problems, AK Peters Ltd., Wellesley, 1998, Chapter 3) as follows: Determine the smallest even integer σ(K_r,s,n) such that every n-term graphic sequence π=(d₁,d₂,…,d_n) with term sum σ(π)=d₁+d₂++d_nσ(K_r,s,n) is potentially K_r,s-graphic, where K_r,s is a r×s complete bipartite graph, i.e., π has a realization G containing K_r,s as its subgraph. In this paper, we first give sufficient conditions for a graphic sequence being potentially K_r,s-graphic, and then we determine σ(K_r,r,n) for r=3,4.     

YVO4晶体及其掺Nd的喇曼光谱

本文报道了对YVO4晶体及其掺Nd的喇曼光谱的测量结果,用这些结果可以了解到这种材料的声子能谱情况,在与其它基质材料比较中可以看出它的特点是：分立的低声子在500－800cm^-1之间有一个间隙,主要部分分布在800－900cm^-1附近,根据群论分析可以得出各喇曼谱线相应的对称性,而且可看出这些喇曼谱线主要来源于VO4^3-的振动,对这种不均匀分布的声子能变对于其光谱性能可能产生的影响也作了分析讨论,测量结果还发现掺杂能抑制原有的高能声子。     

利用V型三能级原子与光场Raman相互作用制备Schrdinger猫态

提出了一种制备光场具有可控制的权重因子和相位的相干态的叠加态的方案 .它是基于 V型三能级原子与初始处于相干态的光场 Raman相互作用中对通过腔中原子进行选态测量来制备 Schro　　　¨ dinger猫态 .     

Laser-Induced Fluorescence Bronchoscopy for Detection and Localization of Early Lung Cancer

Experimenatal results on the development of a Laser-Induced Fluorescence Bronchoscopy(LIFB) for the detection and localization of early lung cancer are reported in this paper. The system utilizes fluorescence of photosensitizer drug to provide real time video imaging for the examined lung tissue. Color filters are used to differentiate signal from background and a computer image processing technique is also applied to subtract the background. Moreover, a pseudocolor contrast enhancement method was developed to enhance the fluorescence image displayed on the vidio monitor. Suspicious areas are identified by pseudocolor image to guide biopsy, and several clinical trials show that sensitivity and contrast capability of the system should permit the detection and localization of early lung cancer.     

聚丙烯酸/聚(苯乙烯-丙烯酸)二苯酰基甲烷铕(Ⅲ)配合物的合成及其荧光性能

铕(Ⅲ)和二苯甲酰甲烷(HDBM)形成的有机配合物与聚丙烯酸(PAA)(M_n=5000)、聚(苯乙烯-丙烯酸)(PSAA)(M_n=3000)发生配位反应,分别得到配位聚合物Eu(Ⅲ)-DBM-PAA和NaEu(Ⅲ)-DBM-PSAA,产率分别为89.7%和87.3%.红外光谱、紫外光谱、X光电子能谱测试表明,Eu³⁺分别与PAA,PSAA和DBM-发生配位,元素分析和电导率测定结果证明,1个Eu³⁺分别与PAA中2个链节或PSAA中3个链节的羧基和1个DBM-发生配位.Eu³⁺离子在配位聚合物Eu(Ⅲ)-DBM-PAA和Eu(Ⅲ)-DBM-PSAA中的含量分别为28.46%和12.23%.荧光光谱表明,常温下配位聚合物在紫外光下发出强的红光,主要是Eu³⁺离子的5D0→7F2的能级跃迁.