微波消解-电感耦合等离子体原子发射光谱(ICP-AES)法测定蒙药材文冠木中16种元素

文冠木为常用蒙药材之一。实验采用微波消解-电感耦合等离子体原子发射光谱法测定蒙药文冠木中Cd,Zn,Mn,Fe,Mg,Cu,Hg等16种元素。用微波加热技术消解样品,随后在选定的仪器工作条件下进行测定,测定方法的加标回收率为90.9%~109%,相对标准偏差均小于3.5%,检出限小于0.005 1!g/mL。方法简便、准确、可靠,可作为文冠木中多种元素含量的测定方法。     

具不同分数阶扩散趋化模型的衰减估计

研究了生物学中具有分数阶扩散的Keller-Segel模型.该模型是由两个分数阶抛物方程和一个经典抛物方程组成.在小初值条件下,利用[李大潜,陈韵梅.非线性发展方程[M].北京:科学出版社,1999.]中的能量方法,作者建立了该模型古典解的全局存在性及最优的衰减估计,得到了u,v及▽Ψ高阶导数的衰减估计.     

白光有机发光二极管的研究进展

由于白光有机发光二极管(WOLED)具有效率高、亮度高、功耗低、视角广、响应速度快、主动发光、超薄超轻以及可柔性化等优异性能, 并在显示和照明领域有广阔的应用前景, 受到学者和业界的广泛重视而成为研究热点. 本文首先介绍了实现WOLED的不同方法, 然后从发光材料种类的角度, 阐述了全荧光WOLED、全磷光WOLED、基于荧光/磷光杂化WOLED以及延迟荧光WOLED近年来的研究进展, 并结合我们研究团队最近的工作详细地介绍了不同高性能WOLED的器件结构、设计思想、工作原理、物理机制以及发光过程; 接着, 简单介绍了柔性WOLED最近研究进展; 最后探讨了WOLED目前存在的问题及其未来的发展趋势.     

High efficiency grating couplers based on shared process with CMOS MOSFETs

Grating couplers are widely investigated as coupling interfaces between silicon-on-insulator waveguides and optical fibers.In this work,a high-efficiency and complementary metal-oxide-semiconductor(CMOS) process compatible grating coupler is proposed.The poly-Si layer used as a gate in the CMOS metal-oxide-semiconductor field effect transistor(MOSFET) is combined with a normal fully etched grating coupler,which greatly enhances its coupling efficiency.With optimal structure parameters,a coupling efficiency can reach as high as ～ 70% at a wavelength of 1550 nm as indicated by simulation.From the angle of fabrication,all masks and etching steps are shared between MOSFETs and grating couplers,thereby making the high performance grating couplers easily integrated with CMOS circuits.Fabrication errors such as alignment shift are also simulated,showing that the device is quite tolerant in fabrication.     

Impact of back-gate bias on the hysteresis effect in partially depleted SOI MOSFETs

The hysteresis effect in the output characteristics, originating from the floating body effect, has been measured in partially depleted (PD) silicon-on-insulator (SOI) MOSFETs at different back-gate biases. I_D hysteresis has been developed to clarify the hysteresis characteristics. The fabricated devices show the positive and negative peaks in the I_D hysteresis. The experimental results show that the I_D hysteresis is sensitive to the back gate bias in 0.13-μm PD SOI MOSFETs and does not vary monotonously with the back-gate bias. Based on the steady-state Shockley--Read--Hall (SRH) recombination theory, we have successfully interpreted the impact of the back-gate bias on the hysteresis effect in PD SOI MOSFETs.     

Self-Collimation in Planar Photonic Crystals Fabricated by CMOS Technology

We report a self-collimating demonstration in planar photonic crystals （PhCs） fabricated in silicon-on-insulator （SOI） wafers using 0.18 μm silicon complimentary metal oxide semiconductor （CMOS） techniques. The emphasis was on demonstrating the self-collimation effect by using the standard CMOS equipment and process development of an optical test chip using a high-volume manufacturing facility. The PhCs are designed on the 230-nm-top-Si layer using a square lattice of air holes 280 nm in diameter. The lattice constant of the PhCs is 380 nm. The experimentally obtained wavelengths for self-collimation are in excellent agreement with theory.     

脲和盐酸胍诱导过氧化氢酶去折叠的研究

用荧光相图法分别研究了脲和盐酸胍诱导牛肝过氧化氢酶去折叠的过程。当脲 浓度从0依次增大至0.50,4.5和8.0 mol/L时,过氧化氢酶从天然四聚体依次转变 为蓬松的四聚体、部分折叠的无活性二聚体和去折叠态,而当盐酸胍浓度从0依次 变化至0.65,2.5和6.0 mol/L时,过氧化氢酶则从天然四聚体集资转变为部分折叠 的激活二聚体、部分折叠的单体和去折叠态,这表明无论是用脲还是用盐酸胍作为 变性剂,该蛋白的变性过程都符合“四态模型”,但这两种变性剂诱导该蛋白去折 叠的途径和机制有较大差异。实验结果表明荧光相图法可以检测蛋白质去折叠的中 间态。用等温滴定量去热法研究了盐酸胍诱导过氧化氢酶去折叠过程的热力学, 25.0 ℃时低浓度盐酸胍诱导该蛋白从天然四聚体转变为部分折叠的激活二聚体的 本征摩尔构象变化焓、Gibbs自由能和熵分别为-69.2 kJ·mol~(-1),6.43 kJ· mol~(-1)和-254 J·K~(-1)·mol~(-1),据此推断盐酸胍通过熵效应和静电效应来 稳定和激活该二聚体。     

SiOxNy薄膜高场电子陷阱和释放特性的研究

本文研究热氮氧化硅(SiO_xN_y)薄膜在高场下的电子陷阱和被陷电子的释放。发现:当样品被氮化的程度较轻时,膜中的有效电子陷阱表面浓度随着样品被氮化时间的增加而迅速增加,被陷电子的释放率近于零,与样品被短路的时间及外加反向电场的持续时间和大小(直到8MV/cm)无关,电子陷阱能级是较深的;当样品被氮化的程度较重时,随着对样品氮化时间的进一步增加,膜中的有效电子陷阱表面浓度逐渐减小,电子陷阱能级深度逐渐变浅,被陷电子的释放率逐渐增加,并与外加反向电场和外加反向电场的 关键词：     

THE ROLE OF HYPERBARIC OR HIGHLY CONCENTRATED OXYGEN IN PREVENTION AND TREATMENT OF NOISE-INDUCED HEARING DAMAGE

In this paper we presented the effect of breathing oxygen at 2 atm or 1 atm before or after exposure on noise-induced hearing damage.The noise exposure was made with a 1/3 octave bandnoise(1000 Hz,136 dB,1 hour).The inhalation of 2 atm-oxygen before or after exposure couldreduce noise-induced permanent threshold shift.The role of breathing 2 atm-oxygen correspondedto reduce the noise level by 10 dB.The effect of prophylactic inhalation of oxygen was much betterthan that of therapeutic inhalation of oxygen,and the effect was better at 2 atm than at 1 atm.Somemechanisms concerning inhalation of hyperbaric or high concentration oxygen were discusscd inprevention and treament of noise-induced hearing damage.     

元素分析仪测定土壤氮、碳含量的不确定度评定

用实例对元素分析仪测定土壤氮、碳含量不确定度进行评定.分析讨论了测定过程中不确定度的来源、不确定度分量的计算.结果表明,影响土壤碳、氮含量测定不确定度的主要因素是标准物质的引入和标准曲线的绘制.