Design equations for the assessment and FRP-strengthening of reinforced rectangular concrete columns under combined biaxial bending and axial loads

A simple procedure is proposed for the assessment of reinforced rectangular concrete columns under combined biaxial bending and axial loads and for the design of a correct amount of FRP-strengthening for underdesigned concrete sections. Approximate closed-form equations are developed based on the load contour method originally proposed by Bresler for reinforced concrete sections. The 3D failure surface is approximated along its contours, at a constant axial load, by means of equations given as the sum of the acting/resisting moment ratio in the directions of principal axes of the sections, raised to a power depending on the axial load, the steel reinforcement ratio, and the section shape. The method is extended to FRP-strengthened sections. Moreover, to make it possible to apply the load contour method in a more practical way, simple closed-form equations are developed for rectangular reinforced concrete sections with a two-way steel reinforcement and FRP strengthenings on each side. A comparison between the approach proposed and the fiber method (which is considered exact) shows that the simplified equations correctly represent the section interaction diagram. Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 44, No. 3, pp. 443–462, May–June, 2008.     

Specific interaction of jacalin with phycocyanin, a fluorescent phycobiliprotein

Recent research has shown that, like porphyrins, phycocyanin (PC) too can produce singlet oxygen upon excitation with the appropriate radiation and hence could be useful in photodynamic therapy (PDT) for cancer. Unlike porphyrins, PC has the advantage of being a non-toxic, non-carcinogenic, soluble protein. However, the challenge would be to target the fluorescent phycobiliprotein to malignant cells. We report here that the tumor-specific lectin, jacalin, binds PC specifically in a carbohydrate-independent manner and with affinities better than that for porphyrins. Hence the lectin could prove to be a useful carrier for targeted delivery of PC. The interaction involves both ionic and hydrophobic interactions and more than one contact site.     

Pseudo-non-contact AFM imaging?

Recent non-contact atomic force microscopy studies have demonstrated that imaging of single atom defects is possible. However, the imaging mechanism was unclear. Long-range forces of attraction, which are normally associated with non-contact mode, are not known to produce sufficient lateral resolution to image atoms. In this study, we suggest a mechanism that could be responsible for the resolution achieved. We use realistic interatomic interaction parameters to do numerical simulations. These simulations are in good agreement with experimental data. As a result, we are able to ‘separate' the attractive and repulsive forces acting between the AFM tip and the sample surface. Calculations indicate that the force responsible for image contrast in the experimental studies mentioned above, is in most cases the repulsive contact force, and not the long-range attractive force. We check our conclusions against a variety of interatomic interaction parameters and our results remain valid for any reasonable set of such parameters, including the power law of the attractive potential N<9.     

Null Controllability in a Heat–Solid Structure Model

A model representing a coupling between a heat conducting medium and a solid structure is considered. We establish a Carleman inequality for this model. Next we deduce a null controllability result with an internal control in the conducting medium and there is no control in the solid part.     

智能建筑通信平台集约系统研究——制冷设备信号的底层通信

文中为智能建筑设计了一个通信网络系统,以实现建筑物内的低温信号采集处理和信息交换。在已有硬件设施基础上,利用基于FPGA的SOC设计技术,通过需求分析、算法设计,再到硬件开发、系统集成,实现对低温信号的处理完善,使之从系统的底层开始,为动平衡过程的所有信息交互提供服务。该系统可以满足BACNet标准和LONMARK标准,为智能建筑自控提供一套有效的信息处理模式。     

Preparing of coherent superposition state in serial multi-A-type system by stimulated Raman adiabatic passage

A scheme for creating an arbitrary coherent superposition of two atomic states in serial multi-A-type system is proposed.This technique with the application of a control field is based on the existence of two degenerate dark states and their interaction.The mixing of the dark states can be controlled by changing the relative delay time of the control pulse.One can get any desired superposition by changing the delay time of the control pulse.     

非线性单模光纤中源啁啾孤子相互作用

本文采用分步傅氏变换法对非线性单模光纤中源啁啾孤子相互作用进行了详细的数值研究.所得结果揭示了先源啁啾对孤子相互作用影响的本质,为设计光源啁啾情况下的孤子传转系统提供了依据.     

Hamilton operator and the semiclassical limit for scalar particles in an electromagnetic field

We successively apply the generalized Case-Foldy-Feshbach-Villars (CFFV) and the Foldy-Wouthuysen (FW) transformation to derive the Hamiltonian for relativistic scalar particles in an electromagnetic field. In contrast to the original transformation, the generalized CFFV transformation contains an arbitrary parameter and can be performed for massless particles, which allows solving the problem of massless particles in an electromagnetic field. We show that the form of the Hamiltonian in the FW representation is independent of the arbitrarily chosen parameter. Compared with the classical Hamiltonian for point particles, this Hamiltonian contains quantum terms characterizing the quadrupole coupling of moving particles to the electric field and the electric and mixed polarizabilities. We obtain the quantum mechanical and semiclassical equations of motion of massive and massless particles in an electromagnetic field. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 156, No. 3, pp. 398–411, September, 2008.