胆小管超微细胞酶学研究

以电镜细胞化学的方法,观察了小鼠胆小管酶的分布。观察的12种酶中,NDPase和G6Pase三种酶分布于胆小管微绒毛;AlPase、Na~+-K~+ATPase、Mg~(++)-ATPase、Ca~(++)-ATPase、CMPase、ACase和5＇-Nase等7种酶分布于胆小管微绒毛,也分布于肝细胞邻接面细胞膜和Disse间隙微绒毛;ACPase、细胞色素氧化酶以及线粒体ATPase不分布胆小管微绒毛,也不分布Disse间隙微绒毛和肝细胞膜。据信,胆小管微绒毛上的酶参与胆汁成份的转运,提供转运所需能量以及还可能与某些代谢过程有关。本实验中磷酸水解酶类使用的铈基法及亚铁氰化钾半还原的锇酸后固定法,效果优于铅法。     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

小信号多腔速调管主要性能指标简化分析

介绍了速调管在我国的发展现状和小信号条件下速调管的各种主要性能指标的简化分析方法。在这种简化分析方法中,首先不考虑非线性和相对论效应等带来的影响,并把多腔速调管看作是几个双腔速调管的级联,得出了增益、效率、带宽和输出功率等重要参数的计算公式。然后通过给出部分参数的修正系数说明了这种简化分析方法的实用价值及理论指导意义。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

无源器件辅助换流的单相全桥软开关逆变器

为提高单相全桥逆变器的转换效率,提出了一种无源器件辅助换流的单相全桥软开关逆变器拓扑结构,通过在逆变器桥臂上增加辅助谐振电路,实现了开关器件的软开关动作.辅助谐振电路中无辅助开关器件,只含有电感、电容和二极管等少量无源器件,这有利于降低辅助电路的成本,而且不会使逆变器的控制策略复杂化.此外,在逆变器处于死区状态时,负载电流能通过辅助谐振电路续流,可以改善逆变器输出电流波形的畸变率,减小了死区的不利影响.文中详细分析了电路的工作过程,在功率为4kW的单相实验样机上进行了实验验证,获得的实验结果表明在轻载和满载时逆变器的开关器件都能实现软开关,逆变器输出电流波形的畸变率都得到了改善.因此,该无源器件辅助换流的单相全桥软开关拓扑结构对于提高逆变器的性能具有重要意义.     

Improvement of the accuracy of the In-situ ellipsometric measurements of temperature and alloy composition for MBE grown HgCdTe LWIR/MWIR structures

Spectroscopic ellipsometry (SE) has proven to be a very reliable technique for the in-situ monitoring of the substrate temperature and alloy composition during the HgCdTe epitaxy. In this work, the influence of the variations in the angle of incidence and the spectral wavelength shift on the measured accuracy of the growth temperature and alloy composition are studied, and a method for precisely determining these variations independent of the modeling of the SE data has been developed. It is shown that the stability of the fittings of the optical models for in-situ applications increases and that the couplings between model parameter decreases upon either eliminating the angle of incidence as an independent model parameter or correcting for the shifts of the wavelength offset. The variations in the angle of incidence and wavelength shift, which arise in the M88 ellipsometer from reflected beam deflections, were precisely calibrated in two dimensions as a function of alignment parameters, using a thick thermally grown SiO₂/Si sample and were parameterized for our experimental geometry. A new extension of theWVASE software was developed to correct the raw SE data in real time for wavelength shift and the angle of incidence drift. A comparison of the corrected and uncorrected results of in-situ temperature measurements for HgCdTe and CdZnTe(211) B/Si(211) clearly demonstrates that the proposed method significantly enhances the accuracy of temperature and composition readings over a broad range of values in these parameters.     

二硫化钼纳米薄片分散液的剥离制备

文中采用液相超声剥离粉末二硫化钼制备了纳米薄片分散液,通过紫外可见吸收光谱测定分散液的浓度,并探索了超声功率、超声时间以及二硫化钼初始浓度对纳米薄片分散液浓度的影响。实验结果表明,当超声功率为350 W,超声时间为48 h,二硫化钼初始浓度为10 mg/mL时,所制备的纳米薄片分散液浓度可达0.16 mg/mL。在剥离过程中加入聚乙烯吡咯烷酮,可以有效避免由于纳米薄片自身团聚而导致的分散液稳定性差的问题,所得到的二硫化钼纳米薄片分散液可稳定存放超过两个月;同时,PVP的加入可将二硫化钼纳米薄片分散液浓度提高至0.42 mg/mL。     

CDMA核心网络的演进路线

CDMA核心网的发展面临着路线选择的问题,本文详细讨论了核心网电路域和核心网分组域的演进路线.核心网电路域有两种路线可以选择,本文对每一种路线需要考虑的问题进行了分析.分组域作为IMS的承载网络,需要解决安全、QoS以及业务感知等问题,本文对分组域演进的需求和目标进行了分析,讨论了未来分组网络需要重点解决的问题.针对未来CDMA核心网络采用IMS还是分组演进网络的问题,从技术、标准、设备的角度分析了IMS的成熟性,最终得出了CDMA核心网络演进的总体路线.     

Molecular dynamics study on compressive strength of monocrystalline, nanocrystalline and amorphous Si mold for nanoimprint lithography

Molecular dynamics studies are carried out to investigate the compressive strengths and the failure mechanisms of monocrystalline, nanocrystalline and amorphous Si molds for nanoimprint lithography. The stress-strain characteristics and the stress distributions are analyzed for the three types of Si molds. The stress-strain characteristics show that the strength of the monocrystalline Si mold is the greatest among the three types of Si molds. The strength of the nanocrystalline Si mold decreases as the grain size decreases. This shows the Hall-Petch effect does not hold true in the grain size of nanometer order. The visualization of the stress distribution shows that the monocrystalline, nanocrystalline and amorphous Si mold fail due to the slipping of the specific atomic plane, the sliding in the grain boundaries and the nonlocal plastic deformation, respectively. As a result, the monocrystalline Si mold is the most suitable for nanoimprint lithography among the three types of Si molds in the nanoscale regime.     

MANETs在军事通信中的应用

MANETs是目前通信技术领域的焦点之一,它具有极强的适应和生存能力,其应用前景十分广阔。首先介绍了MANETs的概念、结构和特点,阐述了MANETs在军事通信中的重要作用,并提出了一种应用阶段的过渡结构。最后指出了MANETs应用于军事通信中的关键技术和研究方向。