小电极体外心脏起搏成功抢救急性再发性心肌梗塞Ⅲ度房室传导阻滞1例

患者男性,63岁。1993年11月13日因咳嗽,胸闷,痰中带血4天入院诊治。既往有冠心病、广泛前壁心肌梗塞史8年,糖尿病史10年。体检:体温36.4℃,血压16/9.3kPa。双肺呼吸音粗,肺底可闻少许湿性罗音。心界无扩大,心率96/min,律齐,未闻及杂音。腹软,肝脾肋下未及。

恒流充电有限柱体电极浓度分布及扩散诱导应力解析分析

常见的柱状电极模型中,在轴向方向一般采用无限长假设广义平面应变分析方法,本文考虑恒流充电下有限柱形电极模型,基于力-化耦合一般方程,推导出位移与扩散诱导应力解析解.有限柱体电极中浓度分布由仅考虑径向扩散和仅考虑轴向扩散两部分叠加求解.将浓度函数代入力学方程,使用Boussinesq-Papkovich函数得到应力分量解析解.计算了表面自由柱状电极中浓度和应力场,并将其结果与有限元软件计算的结果进行对比计算.结果表明,理论解和数值解中浓度分布一致,应力分量趋势一致数值相差较小,在荷电状态为17.9%时径向应力在中心处相对误差最大约为4%.本文分析了不同长径比柱状电极中径向和轴向单向扩散对应力场的影响,结果表明,随着长径比的增大,轴向扩散对浓度分布影响下降,径向扩散对应力场影响上升.

视觉假体微电极经眶外侧壁入路植入视神经的应用解剖

目的为经眶外侧壁入路植入视神经视觉假体微电极提供解剖学依据。方法选用经4%甲醛固定及动脉灌注红色乳胶的成人头湿性标本30例,观测眶内眼动脉及相关分支的起始、数量和外径与穿入视神经鞘膜动脉的起始、外径和穿入部位、视神经外径等参数。结果泪腺动脉1～2支,经外直肌上缘上方(3.83±1.43)mm前行。外直肌-视神经间隙的深度为(8.14±0.90)mm,内有睫状短神经5～10条,颞侧睫状后动脉1～2支。穿入视神经鞘膜动脉的方位,内侧20%,上方29.3%,外侧6.7%,下方44%。视网膜中央动脉主要经下方穿入视神经,穿入处距球后(0.85±0.28)cm,该处动脉外径为(0.40±0.09)mm。眼动脉斜跨视神经处远侧端距球后(1.44±0.22)cm。在球后与总腱环中点处,视神经左右径(3.96±0.35)mm,上下径(4.18±0.33)mm。结论宜经眶外侧壁入路植入视神经视觉假体微电极,植入微电极的部位以视神经球后4～8mm处的外侧较好,植入深度应小于1.5mm。

硫酸亚汞电极的研制与电位滴定法分析测定青霉素类抗生素

目的 设计制备实用硫酸亚汞参比电极 ,测定其性能参数以及稳定性 ,探讨在分析测定青霉素类抗生素方面的应用。方法 制备硫酸亚汞、纯化汞 ,用聚丙烯塑料管作为电极体制备硫酸亚汞电极 ,测定在实验条件下电极电位对Hg2 + 的响应及相关参数 ,验证其用于分析测定青霉素类抗生素青霉素钠 (钾 )、氨苄西林钠、青霉素V钾、阿莫西林、苯唑西林钠、普鲁卡因青霉素以及氯唑西林钠等的可行性 ,探讨用电位滴定法测定哌拉西林钠和美洛西林钠的方法。结果 在汞离子浓度为 2 .0～5 3.0 μmol·L-1的范围内 ,实验电极的电极电位与汞离子浓度的对数值呈线性相关 (r =0 .9998,P <0 .0 0 1) ,平均响应斜率为37.0 0 ,与Nernst方程有良好的符合性 ,适用pH范围为 2 .8～ 9.0 ,检出限为 8.97× 10 -7mol·L-1,响应时间小于 18s ,温度系数为 - 1.39,电极电位的负性绝对值与温度呈正比 ,测定的标准电极电位与文献值基本一致 ,有效使用时间大于 5年 ;青霉素钠 (钾 )、氨苄西林 (钠 )、阿莫西林、苯唑西林钠、普鲁卡因青霉素、氯唑西林钠、青霉素V钾及美洛西林钠的电位滴定法测定结果与原方法一致 ,但哌拉西林钠的测定结果比HPLC的测定结果偏高。结论 制备的硫酸亚汞电极对汞离子有良好的线性响应 ,符合Nernst方程 。

体外大电极起搏的临床价值(附15例报告)

1993年以来我科采用美国Medical Research Laboratories简称(MRL)公司生产的心电监护～起搏器及随带的体外大电极为15例濒危患者做了体外临时心脏起搏，取得了较为满意的效果，特报告如下。

基于电火花加工方法的表面改性技术研究

研究了一种在普通电火花加工机床上实现金属工件表面改性的新方法。它是在传统电火花加工方法的基础上 ,采用TiC -Co半烧结体电极和普通煤油工作液 ,在工件表面形成一层硬质陶瓷层 ,从而达到改善工件表面性能的目的 ,这种新方法被称之为放电沉积。对放电沉积原理进行了探讨 ,在大量试验的基础上 ,总结了放电沉积的工艺方法。通过扫描电镜、电子探针、X射线衍射分析、摩擦磨损等试验 ,对形成的沉积层特性进行了定量和定性分析。最后利用该方法在普通的高速钢车刀上进行了初步应用。试验与分析表明 ,该方法是一种极具潜力的金属表面改性方法。

Effects of current density on preparation and performance of Al/conductive coating/α-PbO_2-Ce O_2-TiO_2/β-Pb O_2-MnO_2-WC-ZrO_2 composite electrode materials

Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy（EDXS）, anode polarization curves, quasi-stationary polarization（Tafel） curves, electrochemical impedance spectroscopy（EIS）, scanning electron microscopy（SEM）, and X-ray diffraction（XRD）. Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential（0.610 V at 500 A/m2） for oxygen evolution, the best electrocatalytic activity, the longest service life（360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2）, and the lowest cell voltage（2.75 V at 500 A/m2）. Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.

Ambient electrical conductivity of carbon cathode materials for aluminum reduction cells

The ambient electrical conductivity (AEC) of carbon cathode materials was investigated in respect to their open porosity, crystal structure and graphite content using hydrostatic method, four-probe technique and X-ray diffraction (XRD), respectively. The AEC is proportional to the specific conductivity (σ0) and the exponential of (1?ε) (ε is porosity) by a quasi-uniform formula based on the percolation theory. Theσ0 can reflect the intrinsic conductivity of the carbon cathodes free of pores, and it depends on the mean crystallite size parallel to the layer (002). The exponentn is dependent on the materials nature of the cathode aggregates, while an averaged value, 4.65, can practically work well with 5 types of cathode materials. The calculation ofσ0 can be extended to the graphitic cathodes containing different aggregates using the simple rule of mixture.

Preparation, characterization and electrochemical properties of boron-doped diamond films on Nb substrates

A series of boron-doped polycrystalline diamond films were prepared by hot filament （HF） chemical vapor deposition on Nb substrates. The effects of B/C ratio of reaction gas on film morphology, growth rate, chemical bonding states, phase composition and electrochemical properties of each deposited sample were studied by scanning electron microscopy, Raman spectra, X-ray diffraction, microhardness indentation, and electrochemical analysis. Results show that the average grain size of diamond and the growth rate decrease with increasing the B/C ratio. The diamond films exhibit excellent adhesion under Vickers microhardness testing （9.8 N load）. The sample with 2% B/C ratio has a wider potential window and a lower background current as well as a faster redox reaction rate in H2SO4 solution and KFe（CN）6 redox system compared with other doping level electrodes.

Analysis and Optimization of the Characteristics of a New IEC-GTO Thyristor

Based on a short anode GTO structure （SA-GTO）,a novel GTO structure called an injection efficiency controlled gate turn off thyristor （IEC-GTO） is proposed,in which the injection efficiency can be controlled via an additional thin oxide layer located in the short anode contact region. The forward blocking, conducting, and switching characteristics are analyzed and compared with an SA-GTO and conventional GTO. The results show that the IEC-GTO can obtain a better trade-off relation between on-state and turn-off characteristics. Additionally,the width of the oxide layer covering the anode region and the doping concentration of the anode region are optimized, the process feasibility is analyzed, and a realization scheme is given. The results show that the introduction of an oxide layer would not increase the complexity of process of the IEC-GTO.

Non-Destructive Parameters Extraction for a Novel IGBT SPICE Model and Verified with Measurements

An IGBT subcircuit model is proposed and optimized,which is fully SPICE compatible.Based on analytical equations describing the semiconductor device physics,the model parameters are extracted accurately from the measured data without device destruction.The IGBT n - layer conductivity modulated resistor is effectively modeled as a voltage controlled resistor.The proposed model can be used to accurately predict the IGBT output I-V characteristics and low current gain etc.The simulation results are verified by the comparison with measurements and found to be in good agreement with them.The error in average is within 8%,which is better than the results of semi-mathematical models reported previously.

基于电火花加工方法的表面涂层技术研究

研究了一种可在普通电火花加工机床上实现的金属工件表面涂层新方法。对其原理进行了探讨,并在实验基础上对涂层的特性进行了详细的分析。结果表明,用电火花加工的方法进行表面涂层可以明显改善金属工件的性能。在普通车刀上初步应用此种新方法,切削实验结果表明,涂层车刀的寿命较未涂层车刀的寿命提高一倍以上。

Study and Fabrication of a Au/n-ZnO/p-Si Structure UV-Enhanced Phototransistor

The fabrication and characterization of a Schottky-emitter heterojunction-collector UV-enhanced bipolar phototransistor （SHBT） are presented. The luminescence peak of the ZnO film is observed at 371nm in the PL spectrum. The sensitivity of the ultraviolet response from 200 to 400nm is enhanced noticeably, and the spectrum response at wavelengths longer than 400nm is also retained, The experiments show that the Au/n-ZnO/p-Si SHBT UV enhanced phototransistor enhances the sensitivity of the ultraviolet response noticeably. The UV response sensitivity at 370nm of the phototransistor is 5-10 times that of a ZnO/Si heterojunction UV enhanced photodiode.

OTFT with Bilayer Gate Insulator and Modificative Electrode

An organic thin-film transistor （OTFT） with an OTS/SiO2 bilayer gate insulator and a MoO3/AI electrode configuration between gate insulator and source/drain electrodes has been investigated. A thermally grown SiO2 layer is used as the OTFT gate dielectric and copper phthalocyanine（CuPc） is used as an active layer. This OTS/SiO2 bilayer gate insulator configuration increases the field-effect mobility, reduces the threshold voltage, and improves the on/off ratio simultaneously. The device with a MoO3/Al electrode has shown similar Ids compared to the device with an Au electrode at the same gate voltage. Our results indicate that using a double-layer of electrodes and a double-layer of insulators is an effective way to improve OTFT performance.

SnO_2-based gas(hydrogen) anodes for aluminum electrolysis

A novel SnO2-based gas anode was developed for aluminum electrolysis in molten cryolite at 850 ＆#176;C to reduce energy consumption and decrease CO2 emissions. Hydrogen was introduced into the anode, participating in the anode reaction. Carbon and aluminum were used as the cathode and reference electrodes, respectively. Cyclic voltammetry was applied in the cell to investigate the electrochemical behavior of oxygen ion on platinum and SnO2-based materials. The potential for oxygen evolution on these electrode materials was determined. Then, galvanostatic electrolysis was performed on the gas anode, showing a significant depolarization effect （a decrease of ~0.8 V of the anode potential） after the introduction of hydrogen, compared with no gas introduction or the introduction of argon. The results indicate the involvement of hydrogen in the anode reaction （three-phase-boundary reaction including gas, electrolyte and electrode） and give the possibility for the utilization of reducing gas anodes for aluminum electrolysis.

Design Concept for Key Parameters of Reverse Conducting GCT

Presented is design concept for key parameters o f the reverse conducting gate commutated thyristor (RC-GCT),such as the thickness and concentration of n-base region and the transparent anode region,and the wi dth of separation region between asymmetric GCT and PIN diode.A structure model of the RC-GCT is set up based on the design concept and its characteristics are analyzed.The simulation results show the design concept is reasonable.

A monolithic InGaP/GaAs HBT power amplifier for W-CDMA applications

A monolithic microwave integrated circuit （MMIC） power amplifier （PA） is proposed. It adopts a new on-chip bias circuit, which not only avoids the instability of the direct current bias caused by the change in the power supply and temperature, but also compensates deviations caused by the increase in input power. The bias circuit is a current-mirror configuration, and the feedback circuit helps to maintain bias voltage at a constant level. The gain of the feedback circuit is improved by the addition of a non-inverting amplifier within the feedback circuit. A shunt capacitor at the base node of the active bias transistor enhances the linearity of the PA. The chip is fabricated in an InGaP/GaAs heterojunction bipolar transistor （HBT） process. Measured results exhibit a 26. 6-dBm output compression point, 33.6% power-added efficiency （PAE） and - 40.2 dBc adjacent channel power ratio （ACPR） for wide-band code division multiple access （W-CDMA） applications.

Dependence of R-G Currenton Bulk Traps Characteristics and Silicon Film Structure in SOI Gated-Diode

The dependence of the Recombination- Generation( R- G) current on the bulk trap characteristics and sili- con film structure in SOI lateral p+ p- n+ diode has been analyzed num erically by using the simulation tool,DESSIS- ISE.By varying the bulk trap characteristics such as the trap density and energy level spectrum systematically,the dependence of the R- G current on both of them has been dem onstrated in details.Moreover,the silicon film doping concentration and thickness are changed to make silicon body varies from the fully- depletion m ode into the partial- ly- depletion one.The influence of the transfer of silicon body characteristics on the R- G currenthas also been care- fully examined.A better understanding is obtained of the behavior of bulk trap R- G current in the SOI lateral gat- ed- diode.

希浦系统起搏在缓慢性心律失常中的应用

目的探讨希浦系统起搏在缓慢性心律失常患者中运用的安全性和有效性。方法选择2018年5-8月在本院诊治的19例符合起搏器植入指征的缓慢性心律失常患者作为研究对象。若3830电极标记到希氏束电位并能稳定起搏者行希氏束起搏(His组,希氏束组),若失败,3830电极若能拧过室间隔到达左室内膜下并能稳定起搏,起搏心电图呈右束支图形者行左束支区域起搏(LBBB组,左束支组),若3830电极不能拧过间隔部到达左室内膜面,起搏心电图呈左束支图形者行右室间隔部起搏(RVS组,间隔组)。采用起搏系统分析仪测量植入即刻、3月的起搏阈值、振幅和阻抗等参数,观察起搏电极导线有无移位等并发症。结果本研究中19例患者均成功地植入了永久心脏起搏器,9例完成希氏束(旁)起搏,6例完成左束支(旁)起搏,希浦系统植入成功率78.9%。植入即刻和3个月测试程控参数三组间无统计学差异。截止随访期末未出现心肌穿孔、感染等并发症,无死亡病例,患者预后良好。结论在缓慢性心律失常患者中采用希浦系统起搏是安全的和有效的,术后起搏参数较为稳定。