临时起搏器体外脉冲发生器充气减压固定装置的设计与应用

目前，临时起搏器体外脉冲发生器主要采用胶布或绷带固定于下肢。该方法存在以下弊端：（1）胶布固定可致部分患者因皮肤过敏发生皮炎，且因固定不牢固，导致起搏发生器与起搏导管电极脱位，致起搏失效。（2）绷带固定有致起搏器发生移位的可能，且遮盖起搏发生器上的起搏指数，不便于临床观察。

ADF4159的外脉冲触发扫频方式的实现

ADF4159作为一款高性能的频率合成器,可通过改变内部寄存器设置,实现多种频率输出方式。该文首先给出ADF4159的锁相环电路,而后介绍外部脉冲触发扫频方式下相关寄存器的配置,最后在FPGA的时序控制下完成扫频输出和数据采集。

复式脉冲体外冲击波碎石术联合通淋排石汤治疗肾结石术后残留结石的临床效果

研究复式脉冲体外冲击波碎石术联合通淋排石汤治疗肾结石术后残留结石的临床效果。方法 选择2022年4月-2023年10月我院收治的行复式脉冲体外冲击波碎石术后结石残留患者80例,随机分组。对照组复式脉冲体外冲击波碎石术联合常规治疗,观察组额外进行通淋排石汤治疗。结果 治疗后观察组排石效果高于对照组,P<0.05,症状消失和结石排净时间、中医证候积分、尿WBC、RBC、PCT、CRP、不良反应发生率低于对照组,P<0.05。结论 通淋排石汤在治疗复式脉冲体外冲击波碎石术后残留结石中具有良好效果。

改进型主成份分析外插脉冲响应滤波器设计

外插脉冲响应(EIR)滤波器设计技术是一种低复杂度有限冲击响应(FIR)滤波器设计技术,而基于主成份分析(PCA)的EIR(PCA-EIR)滤波器设计技术是一种有效(算法执行简单,效果较好)的EIR滤波器设计技术。PCA-EIR技术通过对由原型FIR滤波器系数组成的系数矩阵采用PCA技术进行降维来近似合成原型FIR滤波器,以达到降低原型滤波器硬件执行复杂度的目的。本文提出了一种简单有效的改进型PCA-EIR技术,其基本思想是将系数矩阵的前若干列向量保持不变,对剩余部分列向量组成的矩阵采用PCA技术进行降维来合成原型FIR滤波器。所提出改进型PCA-EIR技术的算法执行复杂度与传统PCA-EIR技术相当,且在滤波器频率响应指标基本相等的前提下,改进型PCA-EIR技术节省3.5%-17.5%乘法器和25.6%-51.6%加法器,从而进一步降低了FIR滤波器的硬件执行复杂度。

铝-铜外导槽式磁脉冲焊接接头组织与性能

目的对铝板和铜板进行外导槽式磁脉冲焊接,研究不同晶粒度的母材对焊接接头界面形貌和力学性能的影响。方法采用万能拉伸试验机、扫描电镜、EDS能谱以及显微硬度计等分析方法,观察焊接接头界面形貌,测试焊接接头的力学性能。结果在电压9 kV,间隙2 mm的条件下,获得了铝板和不同退火温度的紫铜板外导槽式磁脉冲焊接接头;铜母材的晶粒度大小会影响铝-铜板焊接接头界面形貌,经450℃退火处理的铜板与铝母材形成界面波形最明显且过渡区厚度最大;过渡区是铝铜元素的混合区,宽过渡区界面形成稳定的化合物,如CuAl和CuAl2;焊缝处的显微硬度值总是比两侧母材的硬度值高,远离焊缝的硬度值保持稳定,未热处理的铜板与铝板形成的焊缝硬度最高。结论铝-铜外导槽式磁脉冲焊接接头强度高于铝母材。

外插脉冲响应FIR滤波器系数敏感度参数研究

外插脉冲响应EIR(Extrapolated Impulse Response)FIR滤波器是诸多低复杂度FIR滤波器中的一种。如何在设计连续系数EIR滤波器时降低其实际硬件执行时的量化效应,具有重要的实际意义。已有研究者提出了添加系数敏感度参数约束的方法,用于降低EIR滤波器的量化效应。然而,关于该参数的严格理论推导以及实验分析未有报道。因此,对系数敏感度参数进行了严格理论推导,并进行了实验分析。实验结果表明,系数敏感度参数可以在一定程度上降低EIR滤波器的量化效应。

椎间盘外靶点脉冲射频治疗与联合使用盘内热凝射频治疗腰椎间盘突出症的临床疗效比较

目的：探讨椎间盘外靶点脉冲射频治疗与联合使用盘内热凝射频治疗腰椎间盘突出症的临床疗效比较。方法：我院2010年1月－2012年10月收治的腰椎间盘突出症126例，分别采用采用小关节内侧缘入路穿刺单独椎间盘外靶点脉冲射频治疗与联合使用盘内热凝射频治疗腰椎间盘突出症治疗的临床疗效比较，按照临床疗效评定标准进行临床疗效评定，并进行优良率比较。结果：2种手术方式比较P〈0．05，显著差异性。结论：腰椎间盘突出症患者采用椎间盘外靶点射频脉冲同时合椎间盘内射频热凝治疗能取得较单独椎间盘外靶点射频脉冲更好的临床效果。

外滤式布袋脉冲除尘脉冲反吹控制系统的改进探讨

在分析原脉冲反吹控制系统的基础上提出了一改进方法,给出了具体程序框图和程序。PLC大部分输入采用分时复用技术,输出采用矩阵输出的方法,大大减少了I/O点数。本系统应用于内滤式闭路加压反吹系统改造为处滤式脉冲反吹系统可减少投资,降低控制系统的施工难度。

复式脉冲低能量体外冲击波碎石治疗尿路结石的效果观察及护理

目的：探讨复式脉冲低能量体外冲击波碎石治疗尿路结石的效果和护理方法。方法：2003年7～6月采用广东湛江海滨医疗器械有限公司生产的复式脉冲HB-ESWL-VG型低能量碎石机治疗各种尿路结石130例。结果：结石排净率和粉碎率高，疗效满意，并发症轻微。结论：国产复式脉冲低能量ESWL治疗尿路结石，具有成功率高，复打率低，副作用少和无严重并发症等优点，既保证了碎石效果，又降低了组织损伤。

Ultra-soft Desorption Assisted Mass Spectrometry using Picosecond Infrared Laser for the Detection of lons in the Liquid Surface

To identify the species in liquid surface using mass spectrometry,we must eliminate or reduce interferences during the vaporization or desorption of the species from the liquid surface.It is much more challenging to isolate the ionic,larger species from the liquid surface,because of the frangible structures and the higher solvation energies of those species.Here we demonstrate a new mass spectrometry in which the ionic species at the liquid surface can be desorbed with ultrasoft infrared picosecond laser pulses while the liquid surface is not breached.This laser desorption assisted mass spectrometry is not only a powerful tool to detect the fragile species but also promising to investigate vibrational energy transfer dynamics in the liquid surface.

两强震涡中点的“拍涡”引发致洪暴雨初探

两个强震震涡中心连线的中点处，因为共振和“拍”的作用，会形成“地热涡”，它使得位于其上的地幔与地壳抬升，地温升高（3．2m地温亦升高），因此将其称为“拍地热涡”（简称“拍涡”）．本文对近30年出现在我国的“拍涡”进行了统计，结果表明：凡两个强震符合下述条件者：1）两强震的震级差≤1．5级，其最强地震≥6．5级（除1982年12月6．4级例外）；2）两强震的震中距相差1500-6000km；3）两强震的时间差≤2个月．半年之内在其“拍涡”的数百公里范围内会出现一块R’％〉100％的强大多雨区，这为水灾预测提供了依据．同时对少数不符合上述条件的个例进行了成因解释．

复式脉冲低能量体外冲击碎石术治疗上尿路结石(附717例报告)

目的 探讨复式脉冲HB V型低能量体外冲击碎石术 (ESWL)治疗各种上尿路结石的效果。 方法 采用复式脉冲HB ESWL VG型低能量碎石机治疗符合ESWL适应证的上尿路结石 717例 ,工作电压 3～ 9kV。其中直径≤ 2 .0cm肾结石 4 6 7例 ,平均冲击次数 2 30 0次 ;直径≤ 1.0cm输尿管结石 2 5 0例 ,平均冲击次数 2 80 0次。 结果 上中盏结石排净率 89.5 % (170 / 190 ) ,复打率 13.2 %(2 5 / 190 ) ;下盏结石排净率 81.6 % (16 9/ 2 0 7) ,复打率 17.4 % (36 / 2 0 7) ;肾盂结石排净率 92 .9% (6 5 / 70 ) ,复打率 5 .7% (4 / 70 ) ;输尿管结石总排净率 95 .2 % (2 38/ 2 5 0 ) ,总复打率 6 .4 % (16 / 2 5 0 )。碎石过程中出现轻度疼痛者 10 7例 (14 .9% ) ,治疗后出现肉眼血尿者 6 87例 (95 .8% ) ,1～ 3d后血尿消失。无肾周血肿等严重并发症。 结论 复式脉冲低能量ESWL治疗上尿路结石成功率高 ,复打率低 ,副作用少 ,无严重并发症。

Ultraviolet Source Assisted Enhancement of Attosecond Pulse

A promising method to improve the attosecond pulse intensity has been theoretically pre- sented by properly adding an ultraviolet pulse into the orthogonal two-color field. The results show that by properly adding a 125 nm ultraviolet pulse to the orthogonal two-color field, not only the harmonic yield is enhanced by 2 orders of magnitude compared with the original orthogonal two-color field case, but also the single short quantum path, which is selected to contribute to the harmonic spectrum, results in an ultrabroad 152 eV bandwidth. Moreover, by optimizing the laser parameters, we find that the harmonic enhancement is not very sen- sitive to the pulse duration and the polarized angle of the assisted ultraviolet pulse, which is much better for experimental realization. As a result, an isolated pulse with duration of 38 as can be obtained, which is 2 orders of magnitude improvement in comparison with the original two-color orthogonal field case.

基于一维PCA-EIR技术的二维SVD-FIR滤波器设计

为了减少2D有限冲击响应(FIR)滤波器的硬件执行复杂度,采用基于主成分分析(PCA)的1D外插脉冲响应(PCA-EIR)滤波器设计技术,合成了基于奇异值分解(SVD)的2D FIR(2DSVD-FIR)滤波器系统中的所有1D FIR子滤波器.在不影响2D FIR滤波器频率响应指标的前提下,如果1D EIR技术所合成的1D FIR子滤波器的硬件执行复杂度低于原型1D FIR子滤波器的硬件执行复杂度,则前者可替代后者;反之,原型1D FIR子滤波器保持不变.仿真结果表明,在不影响2D FIR滤波器频率响应性能的前提下,与传统的2D SVD-FIR滤波器设计相比,采用1DPCA-EIR技术设计2D冲击响应矩阵SVD-FIR滤波器和2D频率响应矩阵SVD-FIR滤波器,可使其硬件执行分别减少8.85%和7.37%的乘法器,而加法器则分别减少13.15%和13.19%.由此可知,1D PCA-EIR技术可用于合成任意1D FIR滤波器.

A NEW MODULATION SCHEME FOR IR-UWB COMMUNICATION SYSTEMS

Since the poor performance of orthogonal binary Pulse Position Modulation (PPM) compared with binary Pulse Amplitude Modulation (PAM), this paper presents a new modulation scheme named Pulse Width Modulation (PWM) for Impulse Radio Ultra-WideBand (IR-UWB) communication systems. This modulation scheme uses pulses with equal amplitude and different widths to carry different information. The receiver employs differences between similarity coefficients among these pulses to distinguish different information. Both theoretical analysis and simulation results verify that this novel scheme has a Signal to Noise Ratio (SNR) gain of about 1.75 dB compared with or- thogonal binary PPM, and has an SNR loss of about 1.4 dB compared with binary PAM. Although both the theoretical analysis and simulations are based on time-hopping multiple access, this modulation scheme can also be applied to other accessing techniques of UWB communication systems.

High-Resolution Infrared-Vacuum Ultraviolet Photoion and Pulsed Field Ionization-Photoelectron Methods for Spectroscopic Studies of Neutrals and Cations

We show that by scanning the frequency of a single mode infrared （IR） optical parametric oscillator （IR- OPO） laser to excite the molecular species of interest and fixing the frequency of a vacuum ultraviolet （VUV） laser to photoionize the IR excited species, high-resolution IR spectra of polyatomic neutrals can be obtained with high sensitivity. The fact that this IR-VUV-photoion （IR-VUV-PI） method is based on VUV photoionization probe, and thus, allows the identification of the neutral IR absorber, makes it applicable for IR spectroscopy measurements of isotopemers, radicals, and clusters, which usually exist as impure samples. The highly resolved IR-VUV-PI measurements achieved using the single mode IR-OPO laser have made possible the selection of single rovibrational states of CH3X （X=Br and I）, C2H4, and C3H4 for VUV-pulsed field ionization-photoelectron （VUV-PFI-PE） measurements, resulting in rovibrationally resolved photoelectron spectra for these polyatomic molecules. These experiments show that the signal- to-noise ratios of the IR-VUV-PI and IR-VUV-PFI-PE spectra obtained by employing the high-resolution IR-OPO laser are significantly higher than those observed in previous IR-VUV-PI and IR-VUV-PFI-PE studies using a low-resolution IR-OPO laser. Further improvement in sensitivity of IR-VUV-PI and IR- VUV-PFI-PE measurements by using the collinear arrangement of IR-VUV lasers and molecular beam is discussed.

Cytogenetic Effects of Pulsing Electromagnetic Field on Domestic Pig Lymphocytes in Vitro

The effects of pulsing electromagnetic fields(PEMFs)on cells are very important subjects in the field of bioelectromagnetics.In this experiment,the cytogenetic effects of PEMF on domestic pig lymphocytes were tested in vitro.Pig lymphocytes in RPMI 1640 medium were exposed to PEMFs of 100 kHz and 200 kHz for 12,24 and 48 hours.Chromosomal aberrations(aneuploidy,breaks,gaps,et al)were significantly increased in exposed cultures,and of these aberrations,56%chromosomal or chromatid breaks and 42%gaps induced by PEMFs were the points of pig chromosomal fragile sites.The baseline frequency of sister chromatid exchange(SCE)increased after exposing lymphocytes continuously to PEMFs of 100 kHz and 200 kHz for 48 hours.These results suggested that the exposure to PEMFs might induce a type of DNA lesion and chromosomal aberrations.

Pulse modulated microwave and infrared thermography for superficial hyperthermia

A 3D temperature field distribution of biological tissue for superficial hyperthermia using a pulse modulated microwave （PMMW） was presented. A 3D sliced homogeneous phantom was radiated by the PMMW and an infrared thermal imager was applied to image temperature distribution throughout the phantom. The period of the PMMW is 3 s and the output power is 35 W. The temperature rises by at least 3 ℃ in the phantom when the duty cycle varies from 1/3, 1/2, 2/3 to 1 （denoted by scenarios 1-4）. Both the accumulative temperature-volume histogram and the relative depth-area ratio histogram show that the maximum temperature rise （MTR） is 6.6 and 8 ℃ in scenarios 2 and 3, and they are superior to scenarios 1 and 4. Furthermore, the PMMW can control temperature field distribution of biological tissue. It provides both preliminary basis for thermal volume control and new technology for temperature control and monitor in superficial hyperthermia.

Effects of transmitter-related parameter settings on ranging accuracy for IR-UWB systems

For impulse radio ultra-wideband (IR-UWB) ranging systems,effects of the settings of transmitter-related parameters, which include the pulse shape, the bandwidth and the pulse repetition interval (PRI), on ranging accuracy were studied through theoretical analysis and simulations. Both the match-filtering based coherent TOA estimation algorithm and the energy-detection based non-coherent algorithm were used during simulations. Results show that the pulse shape has the least effect on the ranging accuracy. Increasing the pulse bandwidth can improve the ranging performance, but the performance is hardly improved any more when the bandwidth is increased beyond a certain level. PRI should be set long enough to guarantee the accurate ranging, because when PRI is shorter than the maximum excess delay of the channel, the ranging accuracy will be deteriorated by inter-pulse interference.