A reagentless and disposable electronic genosensor: from multiplexed analysis to molecular logic gates

Reagentless, sensitive and multiplexed analysis of gyrB and K-ras gene biomarkers is achieved based on the proximity changes of two different redox-tags to the electrode surface upon DNA hybridizations, and the presence of the two gene biomarkers also acts as inputs and activates the logic gate.     

Modules of the Intermediate Series over Not-finitely Graded Lie Algebras W(Γ)

Let W(Γ)be a class of not-finitely graded Lie algebras related to gener-alized Virasoro algebras with basis{Lα,i,C | α ∈ Γ,i ∈ Z+},which satisfies relations[Lα,i,Lβ,j]=(β-α)Lα+β,i+j+(j-i)Lα+β,i+j+1+δα+β,0δi+j,0α3-α/12C and[C,Lα,i]=0.In this paper,W(Γ)-modules of the intermediate series satisfying some conditions are con-structed and classified.We also obtain modules of the intermediate series over the related Lie superalgebra.     

Study on the Interaction Between Water-Soluble CdTe Quantum Dots and Ovalbumin by Optical Spectroscopy

ABSTRACT

CdTe quantum dots (QDs) modified by 2-mercaptoethylamine hydrochloride (CA) and thioglycolic acid (TGA), respectively, were synthesized in aqueous medium. The interaction of CdTe QDs with ovalbumin has been investigated in depth by Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption, fluorescence-quenching spectrometry, and resonance Rayleigh scattering spectroscopy (RRS). Fluorescence data show that the quenching type of ovalbumin by CA-CdTe QDs is static quenching with the binding constant being 10^?4 M^?1, and the number of binding sites being one. The calculated thermodynamic parameters demonstrate that the main binding forces are hydrophobic interaction and electrostatic attraction. In contrast, the quenching style of ovalbumin by TGA-CdTe QDs is verified to be dynamic quenching. Under suitable acidity conditions, the interaction of CA-CdTe QDs or TGA-CdTe QDs with ovalbumin leads to the remarkable enhancement of RRS, and the increments are found to be proportional to the concentration of ovalbumin in a certain range. A simple and highly sensitive RRS approach for determining ovalbumin is developed. In addition, the causes for the enhancement of RRS and the quenching of fluorescence are investigated to shed light on the quenching mechanism.     

A development on approximation by monotone sequences of polynomials

Recently people proved that every f∈C[0,1] can be uniformly approximated by polynomial sequences {P_n}, {Q_n} such for any x∈[0,1] and n=1,2,… that {fx98-1}. For example, Xie and Zhou^[2] showed that one can construct such monotone polynomial sequences which do achieve the best uniform approximation rate for a continuous function. Actually they obtained a result as {fx98-2}, which essentially improved a conclusion in Gal and Szabados^[1]. The present paper, by optimal procedure, improves this inequality to {fx98-3}, where ɛ is any positive real number.     

单纵模Nd∶YAG激光抽运CH_4中强后向受激拉曼散射

用单纵模Nd∶YAG二倍频激光[波长532 nm,线宽Δνp<100 MHz,脉宽(半峰全宽)6.5 ns]抽运CH4气体,观察到很强的后向一级斯托克斯(BS1)受激拉曼散射,这与前人采用脉宽30 ns的单纵模抽运激光得到的绝大部分为后向受激布里渊散射(SBS)完全不同,其原因是脉宽6.5 ns与本实验条件下CH4的受激布里渊散射声子寿命接近,受激布里渊散射处于瞬态。理论计算表明,这时的受激布里渊散射瞬态增益系数已略小于后向一级斯托克斯的增益系数,而被其竞争抑制。当脉冲重复频率为2 Hz,抽运能量为95 mJ时,在1.1 MPa CH4中,后向一级斯托克斯的量子转换效率高达73%,其时间波形出现张弛振荡,脉宽被压窄到1.2 ns,从而使后向一级斯托克斯峰值功率达到了抽运激光功率的2.7倍,而且其光束质量要大大优于抽运激光的光束质量。用编制的准二维计算机模型程序相当好地再现了实验中后向一级斯托克斯的时间波形张弛振荡。     

Research of Asymmetric Y-Branching Total Internal Reflection All-Optical Switch

Y-branching TIR all-optical switch have been fabricated. When the switching optical intensity is 149.9W/mm2, the extinction ratio is 18dB. A theoretical model was also proposed which provided a good fit to the experimental data.     

用于检测油膜厚度的光纤传感器系统

非接触式光纤传感器因其抗干扰性强、灵敏度高、电绝缘性好等特点在某些场合占有不可替代的位置.本文介绍了一种用于检测大型涡轮机液压轴承运动状态及其周围油膜厚度分布情况的光纤传感器系统.详细讨论了传感器的结构及数据模型,并着重介绍了系统的几个重要组成部分,其中包括双光路、调制解调和并行数据采集等,最后给出了传感器的特性测试数据.