缝洞型油藏致密基质灰岩的压力敏感性规律的NMR研究

相比于常规储层,缝洞型油藏灰岩储具有集体结构复杂、缝洞尺度差异大、裂缝起主要沟通作用等特点,使用常规方法研究其流动特性和流体分布规律异常困难．该文采用自行研制的核磁共振（NMR）在线驱替装置对塔河奥陶系油藏15块致密基质灰岩岩芯进行了压力敏感性实验,获得了高压及流动状态下岩芯的横向弛豫时间（T₂）谱变化情况．在此基础上分析了灰岩在压敏实验过程中微裂缝尺寸、孔隙度及渗透率的变化规律,并与常规测试分析结果进行了对比．结果表明：NMR在线检测技术可以定量测量岩芯孔隙及微裂缝的变化,为岩芯渗透率变化规律提供微观解释．     

Highly Efficient Continuous-Wave Mid-Infrared Intracavity Singly Resonant Optical Parametric Oscillator Based on MgO:PPLN

We present a compact all-solid-state cw mid-infrared intracavity singly resonant optical parametric oscillator （OPO） that is based on a self-fabricated 1-mm-thick 40-mm-long doped MgO periodically poled lithium niobate （MgO：PPLN）. At a diode pump power of 15.6 W, the compact intracavity Nd：YVO4/MgO：PPLN OPO produced 1.9 W output power at 3.19μm, corresponding to conversion efficiency of 12.2% from the laser diode pump to OPO idler output.     

Modeling,simulations,and optimizations of gallium oxide on gallium-nitride Schottky barrier diodes

With technology computer-aided design(TCAD)simulation software,we design a new structure of gallium oxide on gallium-nitride Schottky barrier diode(SBD).The parameters of gallium oxide are defined as new material parameters in the material library,and the SBD turn-on and breakdown behavior are simulated.The simulation results reveal that this new structure has a larger turn-on current than Ga2O3 SBD and a larger breakdown voltage than Ga N SBD.Also,to solve the lattice mismatch problem in the real epitaxy,we add a Zn O layer as a transition layer.The simulations show that the device still has good properties after adding this layer.     

大屏幕激光投影与激光电视

作为下一代的全色显示技术,激光投影显示技术与传统的显示技术相比,有很多明显优势,这是由激光本身的固有特点所决定的,比如高饱和度、低功耗以及潜在的寿命长等.文章介绍了激光显示技术的历史背景以及国内外的研究现状,介绍并分析了激光光源、基于数字光学引擎(DLP)及反射式硅基液晶光学引擎(LCOS)的激光显示系统和颜色管理技术.文章还对激光投影显示的优势进行了归纳,并对激光显示的产业化前景和整体市场进行了分析和预测.     

Optical phase conjugation by resonant degenerate four-wave mixing in liquid phase medium

In this paper, frequency-doubled Nd:YAG laser's phase conjugation has been investigated experimentally using resonant degenerate four-wave mixing (DFWM). The iodine solution was used as resonant medium. In this way, the energy of the DFWM phase conjugation beam arrived at 43μJ/pulse while the total pump beam's energy reached 8mJ/pulse. The relation between the pulse energy of the DFWM phase conjugation beam and that of the pump beam was investigated. We also measured the optical field distributions of pump beam and DFWM phase conjugation beam, from which it can be noticed that the DFWM phase conjugation can improve the laser beam quality. At the same time, we observed the influence of the pump beam's disturbance on the DFWM signal.