高温超导8mm波介质谐振器的设计

高温超导８ｍｍ 谐振器是毫米波应用的重要部件之一．本文研究了在确定频率下的介质谐振器的设计,给出了设计计算结果和实验结果,表明了采用园柱形超导谐振器可以获得稳定的毫米波高Ｑ（４５００） 谐振．实验中采用的是ＧｄＢａ２Ｃｕ３Ｏ７ － δＨＴＳ薄膜     

ICP-AES法测定高温质子导体中的五种元素

研究用ICP-AES法测定高温质子导体中的钡、铈、锶、钇和镱，选定了适宜的溶解方法及分析条件，在溶解酸中加入盐酸羟胺，获得了较为满意的分析结果，相对标准差小于10%。     

四氢呋喃阳离子聚合向丁二酸酐链转移反应的研究

四氢呋喃阳离子聚合向丁二酸酐链转移反应的研究魏斌，赵庆香，栗方星（南开大学化学系天津３０００７１）关键词聚四氢呋喃，五氯化锑，表现链转移速率常数，表现聚合反应速率常数前言在用ＣＨ３ＣＯＳｂＣｌ５引发的四氢呋喃阳离子聚合［１］过程中，我们发现存在着活性...     

固载β-环糊精吸附剂对胆红素吸附机理的探讨

胆红素是血红蛋白的降解产物．当肝脏组织受到损伤或发生病变时,会导致血液中游离胆红素含量增高,人体无法依靠自身代谢排出过高浓度的胆红素．过高浓度的胆红素可以对机体产生严重的神经毒性作用,使胃肠道、脾、肾、性腺、骨髓和呼吸道粘膜等处出现渐进性坏死,其中,未结合胆红素的毒性尤其明显［１］．梗阻性黄疸患者中,１０％左右发生急性肾功能衰竭,其死亡率也较高［２］．因此人们试图合成胆红素吸附剂,通过血液灌流方法,将浓度过高的胆红素清除掉［３,４］．胆红素分子内含有４个毗咯环（见图１）,呈脂溶性,它可自由透过脂…     

BaF radical: A promising candidate for laser cooling and magneto-optical trapping

Recently, there have been great interest and advancement in the field of laser cooling and magneto-optical trapping of molecules. The rich internal structure of molecules naturally lends themselves to extensive and exciting applications. In this paper, the radical~(138)Ba~(19) F, as a promising candidate for laser cooling and magneto-optical trapping, is discussed in detail.The highly diagonal Franck–Condon factors between the X~2Σ~+_(1/2)and A~2Π_(1/2) states are first confirmed with three different methods. Afterwards, with the effective Hamiltonian approach and irreducible tensor theory, the hyperfine structure of the X~2Σ~+_(1/2)state is calculated accurately. A scheme for laser cooling is given clearly. Besides, the Zeeman effects of the upper(A~2Π_(1/2)) and lower(X~2Σ~+_(1/2)) levels are also studied, and their respective g factors are obtained under a weak magnetic field.Its large g factor of the upper state A~2Π_(1/2) is advantageous for magneto-optical trapping. Finally, by studying Stark effect of Ba F in the X~2Σ~+_(1/2), we investigate the dependence of the internal effective electric field on the applied electric field. It is suggested that such a laser-cooled Ba F is also a promising candidate for precision measurement of electron electric dipole moment.     

光弹性分组环节点光分组的组装及时延分析

分析了光弹性分组环(ORPR)网络中流量成型时光分组组装算法,提出一种适合ORPR网络的基于控制发送时间的光分组组装算法,并给出了该算法的算法结构.该算法在混合门限组装算法的基础上,通过增加一个控制分组发送间隔的参数,使得光分组单位时间内流量的突发性被平滑,并可以保证ORPR网络的服务质量(QoS)性能,适合于使用容量有限光缓存的ORPR网络.对ORPR节点光分组平均组装时延进行了详细的分析,新算法通过对分组发送间隔的调整,使在不同负载条件下,组装时延的概率分布基本相同.在ORPR中,平均组装时延的稳定对ORPR网络的QoS性能和公平性调度有重要意义,而发送时机的合理选择,可以保证ORPR网络的QoS性能以及公平性.仿真结果表明,新算法使得ORPR网络中的光分组平均组装时延相对稳定,在大多数情况下,可以保证ORPR网络的调度要求.     

一种高温超导介质滤波器的研制

本文提出了采用单个屏蔽腔设计超导介质滤波器的方法,在腔内并列摆放多个圆柱形介质谐振器,在谐振器上下两个端面均采用一片超导薄膜作为短路面,滤波器结构紧凑,制备工艺简单.根据此方法设计并制作了一个两节超导介质滤波器,实测滤波器中心频率为18.13 GHz,带宽为70 MHz,带内插损小于0.4 dB.测试结果与设计指标相符合,更高节数的高温超导介质滤波器正在研制中.     

High-performance n-channel organic thin-film transistors based on the dual effects of heterojunction and surface modification

This paper presents two n-channel organic heterojunction transistors with modified insulator by using hexadecafluorophthalocyaninatocopper (F₁₆CuPc)/copper phthalocyanine (CuPc) and F₁₆CuPc/pentacene as the active layers. Compared with a single-layer device, it reports that an improved field-effect mobility and a 6-fold higher drain current are observed. The highest mobility of 0.081~cm²/(V.s) was obtained from F₁₆CuPc/CuPc heterojunction devices. This result is attributed to the dual effects of the organic heterojunction and interface modification. Furthermore, for two heterojunction devices, the performance of the F₁₆CuPc/CuPc-based transistor is better than that of F₁₆CuPc/pentacene. This is attributed to the morphologic match of two organic components.     

清华大学H5数值仿真物理实验建设

清华大学物理系自2020年10月开始HTML5数值仿真物理实验(Numerical Simulation Experiment of Physics,简称NuSEP系统)建设工作,已经建成32个仿真实验,覆盖物理学多个方向。首期目标是全面支持清华基础课课堂教学、实验教学与对外科普宣传。建设过程得到多所院校、专业科研机构的支持。本文首先回顾了NuSEP系统建设背景,之后重点介绍NuSEP系统建设目标、建设思路、建设流程、建设要点与难点以及初步应用体验。期望与国内国际同行探讨合作开发与开放模式。