Coherence and Quantum Phase Transition in Spin Models

Based on quantum renormalization group (QRG) method, we investigated quantum coherence and quantum phase transition (QPT) in XXZ chain and XY chain, respectively. The results show that both the geometric quantum coherence and entropic coherecne can accurately indicate the QPT at critical point after enough iteration steps. Moreover, the increasing anisotropy parameter destroys the coherence in the XXZ chain, while enhances it in the XY chain. In addition, focused on the XXZ chain we analyzed the nonanalytic phenomena and scaling behaviors with different theoretical exponents in detail.

     

Distributed high-temperature pressure sensing using air-hole microstructural fibers

We present spatially resolved Rayleigh scattering measurements in different polarization-maintaining (PM) fibers for high-temperature pressure sensing. The pressure-induced birefringence in the fiber cores is interrogated using polarization-resolved frequency-swept interferometry. The pressure responses of a PM photonic crystal fiber and a twin-air-hole PM fiber are investigated for a pressure range of 0 to 13.8 MPa (0-2000 psi) at room temperature and at temperatures as high as 800 °C. The proposed sensing system provides, for the first time to our knowledge, a truly distributed pressure-sensing solution for high-temperature applications.     

DNA四面体结构纳米材料及其应用

基于DNA纳米技术自组装的DNA四面体纳米材料,由于结构稳定、机械性能优越、分子修饰位点丰富等特点,逐渐成为DNA纳米材料领域的研究热点。此外,该DNA四面体纳米材料只需一步热变性即可自组装形成,具有合成方法简单、产率高的优点。可通过不同的设计,利用自组装方法将功能分子修饰在DNA四面体的顶点处,包裹在其笼状孔隙结构内,镶嵌或悬挂在双螺旋的边上,甚至通过引入发卡环结构等方式智能控制其结构变化。本文综述了DNA四面体结构纳米材料的设计和自组装原理、功能化修饰方法和结构的智能化,同时介绍了DNA四面体纳米材料在分子诊断、生物成像、分子输送和靶向给药等方面的应用研究,并探讨了此类纳米材料在今后应用研究中应关注的方面。     

超声波对多孔介质中两相流动的影响

近年来，超声技术已被应用于采油工程中，在油井解堵，水井增注等方面发挥了重要的作用。     

Regenerated gratings in air-hole microstructured fibers for high-temperature pressure sensing

We present thermally regenerated fiber Bragg gratings in air-hole microstructured fibers for high-temperature, hydrostatic pressure measurements. High-temperature stable gratings were regenerated during an 800 °C annealing process from hydrogen-loaded Type I seed gratings. The wavelength shifts and separation of grating peaks were studied as functions of external hydrostatic pressure from 15 to 2400 psi, and temperature from 24 °C to 800 °C. This Letter demonstrates a multiplexible pressure and temperature sensor technology for high-temperature environments using a single optical fiber feedthrough.