46 research outputs found

    基于Android的SIP远程视频监控系统的设计

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    本文利用SIP协议建立组呼来控制监控摄像头,从而建立多路远程视频监控系统。论文介绍了基于AndrOId系统的SIP协议栈JAIn-SIP和远程视频监控系统架构,阐述了利用SIP扩展消息完成组呼控制,从而实现监控中心对远端监控摄像头的呼叫控制

    Development, fabrication, and applications of biomedical electrodes

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    生物医用电极作为一种能够有效地将生物体电化学活动产生的离子电位转换成测量系统电子电位的传感器,广泛应用于现代临床检测和生物医学测量.近年来,由于生物医用电极在心电图ECg、脑电图EEg、肌电图EMg以及电阻抗成像EIT等领域的迫切应用需求,新型生物医用电极结构及其高效低成本的制造方法不断涌现,生物医用电极制造技术获得飞速发展.本文通过对现有的生物医用体表电极进行了分类(包括传统银/氯化银电极、微针电极、纺织柔性电极、柔性衬底电极、泡沫结构电极、绝缘干电极),分别对其制造工艺过程与使用方法进行了综述,并对其已有或潜在的应用领域进行详细分析,最后对生物医用电极的应用前景进行了展望.Biomedical electrodes convert the ion potential generated by electrochemical activities into an electronic potential that can be measured by instrumentation systems; they are widely used as sensors in modern clinical detection and biomedical measurement.In recent years, with increasing applications in the fields of electrocardiography(ECG), electroencephalography(EEG), electromyography(EMG), and electrical impedance tomography(EIT), a great number of new biomedical electrodes with novel structural design and new material selection have been explored and developed; low-cost fabrication methods are also being intensively studied.In this paper, biomedical electrodes are classified into five types, including traditional silver/silver chloride electrodes, microneedle electrodes, flexible textile electrodes, foam electrodes, and insulated dry electrodes.The conversion mechanisms from ion potential to electronic potential of different biomedical electrodes described in the prior literature are firstly introduced, and then the latest research results concerning the fabrication processes for different biomedical electrodes, and the methods of using them, are reviewed.The advantages and disadvantages of each type of electrode for practical applications are discussed, based on the published literature.A general description of the current applications of biomedical electrodes in ECG, EEG, EMG, and EIT is presented.Typical results from researchers in various countries are reviewed to further introduce the detailed application of different biomedical electrodes.Emerging application fields for biomedical electrodes, such as electrooculography, electrogastrography, and the study of the nervous system, are also presented.Finally, the development and application prospects of biomedical electrodes are described briefly.With the rapid development of microelectronics, micro-nano manufacturing and signal processing technology, the related manufacturing technologies and signal processing methods for biomedical electrodes have achieved great progress; in particular, a much deeper understanding about the contact mechanism with human tissue and skin has been obtained.We believe that many new biomedical electrodes will be developed in the next few years to greatly improve the detection level of bioelectric information.国家自然科学基金(51475397); 厦门大学中央高校基本科研业务费(2013121017)资

    Manufacturing of Gradient Porosity Metal Cutting Fiber Materials and Its Comprehensive Performance Testing

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    多孔金属纤维烧结板是一种兼具结构与功能性的新型工程材料,因具有全连通的三维网状结构、比表面积大、孔隙率高等结构特点,以及良好导电导热性、耐磨耐腐蚀性、高弹性和高强度性能特征,在催化剂负载、换热与散热、吸声减噪、电磁屏蔽、过滤与分离等领域获得广泛应用。本文以多齿刀具车削加工的金属纤维为原材料,采用低温固相烧结技术制造出不同类型的多孔铜纤维烧结板。对多孔铜纤维烧结板抗拉强度、压降特性、导热系数、吸声系数等性能进行实验研究。论文主要研究内容如下: 1、连续型微细金属纤维的多齿切削加工成形及工艺研究 通过设计一种多齿切削刀具,在车床上实现连续型金属纤维的切削加工成形,建立其多齿刀具大刃倾角切削模型...Porous metal fiber sintered sheet (PMFSS) as a novel structural and functional engineering material has been widely carried out in many fields such as catalytic reaction, filtration and separation, heat transfer, noise control, electromagnetic shielding and so on. Because it possess the structural properties like tri-dimensional pore structure, large specific surface, high porosity and exhibits go...学位:工程硕士院系专业:航空航天学院_工程硕士(机械工程)学号:1992014115291

    Application of Electronic Money,Changes in Monetary Multiplier and Monetary Policy Validity

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    本文基于我国1990—2011年的数据,分析了使用电子货币对货币乘数变动、货币政策有效性的影响,结果显示:(1)在长期,我国货币乘数和电子货币使用率、存款准备金率以及现金漏损率之间存在均衡关系;电子货币使用率的提高对货币乘数具有双重作用,且使货币乘数下降的作用更强。(2)在短期,我国狭义货币乘数非均衡的自我纠正速度快于广义货币乘数;电子货币使用率的提高,使得现金漏损率与货币乘数出现了同向变化的情况,这与长期的结果相反。(3)电子货币的使用增强了我国货币乘数的内生性和不稳定性,降低了货币政策有效性。By the view of the using rate of electronic money,the estimated results based on the data from 1990 to 2011 shows:(1)In the long term,there is balanced relationship between monetary multiplier and the using rate of electronic money,deposit reserve ratio and cash leakage rate.The increasing of using rate of electronic money has double side effect on monetary multiplier,and the effect of declining the monetary multiplier is more effective.(2)In the short term,the speed of non-balanced self-correction of M1 is faster than M2;the increasing of using rate of electronic money make cash leakage and the monetary multiplier change in the same direction,which is opposite to long-term results.(3)The usage of electronic money enhances the endogenous and instability of monetary multiplier and reduces the effectiveness of monetary policy

    北斗星基增强系统性能评估

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    以实际广播星历、精密星历和北斗星基增强系统(BDSBAS)增强报文为实验数据,通过计算BDSBAS轨道误差、卫星钟差、空间信号测距误差和BDSBAS格网电离层有效点、播发时间和电离层延迟误差6个指标,评估分析了BDSBAS空间信号的性能。结果显示:BDSBAS增强后的GPS卫星轨道误差在切向、法向、径向分别降低了34.57%,40.57%,30.90%;卫星钟差均方根降低了24.31%,卫星钟差标准差降低了16.8%;空间信号测距误差相比增强前降低了32.75%;BDSBAS格网电离层有效点覆盖了中国及周边地区;BDSBAS各点电离层延迟播发间隔均达到ICAO对精确差分定位的要求;电离层延迟在0°-5°N范围内误差在0.4 m以上,可信度均达到99.9%,在5°-55°N范围内误差小于0.4 m,可信度均为100%;BDSBAS水平定位误差提升超过25%,垂直定位误差提升超过50%,完好性均在99.9%以上

    新型轻质阻尼基座设计与隔振性能研究

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    为了减少船体振动与辐射噪声,采用声子玻璃和弧形衔接结构设计了一种新型轻质阻尼基座。然后用加速度振级落差表征其隔振性能,开展了水泵电机激励下的基座隔振性能试验研究,结果表明阻尼基座在20~10 000 Hz的频率范围具有显著的隔振效果,相较于同尺寸钢制基座,其振动落差总级可达12.93 dB。研究结果充分验证了本文设计的轻质阻尼基座具备高强度、高阻尼、宽频隔振的特点,在舰船机械设备等减振降噪领域具有广泛的潜在应用价值

    齿面摩擦对双圆弧齿轮动力学特性影响的研究与试验

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    由于双圆弧齿轮设计的特殊性,在以往研究双圆弧齿轮的动态特性时,经常忽略齿面摩擦对其传动的影响。通过参数化设计精确双圆弧齿轮模型,并以Adams软件为平台,结合多体动力学分析理论,在双圆弧齿轮传动动力学性能仿真过程中,通过设置齿面之间的不同摩擦因数,分析了齿面摩擦对双圆弧齿轮传动的动态性能影响,并通过双圆弧齿轮传动试验进一步验证了仿真结果,为研究双圆弧齿轮传动与齿面摩擦的相关性提供一定的参考

    齿轮接触疲劳极限Locati快速测定法的研究

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    对齿轮进行寿命和可靠性设计时,其材料的疲劳极限起着至关重要的作用。由于罗卡提(Locati)快速测定法具有时间短、数据少并且试验结果较可靠的优点,成为齿轮疲劳试验常用的方法,但该方法必须参照相关试验资料确定参考曲线。探讨了一种更为可靠的数据处理方法,与传统的方法相比,既不需要预先确定参考曲线,也不需要计算疲劳损伤累积和,而是通过直接求解疲劳曲线方程得出相应的疲劳极限。改进后的方法只是单纯地求解方程,计算过程简单,结果更为可信准确。通过疲劳试验验证该方法是可行的,为疲劳试验快速测定法获得相关材料的疲劳极限提供了理论依据

    用于复合极棒电化水处理装置的电极结构

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    本实用新型涉及一种用于复合极棒电化水处理装置的电极结构,该电极结构包含一管状主体,在该管状主体内沿管路方向贯穿设置一个线性阳极,且管状主体的内壁上沿轴向依次设置多于一个的环状阴极,各环状阴极在管状结构内彼此间隔绝缘设置,而在管状结构外相互电连接,所述线性阳极采用金属银、铁、铜、铝和非金属碳中的任意一种制成。本实用新型采用了管状主体式电极设计,电传输效率高,结构简单,易于组装维护,成本低廉,易于操作,且可实现对待处理水的连续处理,高效快捷;同时,通过采用不同材质的阳极,可产生不同的水处理功效,因此适应更宽范围的水质处理,尤其是若同时采用不同材质阳极的组合,更可对成分复杂的水体进行近乎一步化的净化处理,大大简化了工艺

    一种聚吡咯纳米微球的制备方法及应用

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    本发明涉及一种聚吡咯纳米微球的制备方法及应用,是以FeCl2/H2O2/H2O复合体系作为氧化体系,使用化学氧化法合成聚吡咯纳米微球,步骤依次为:按摩尔比为1∶0.01~1∶5量取吡咯单体和FeCl2;将1份吡咯单体和相应比例的FeCl2加入含有1~100份水的反应容器中,充分混合均匀;再加入一定量的H2O2,在反应温度-30℃~35℃之间进行氧化反应,反应时间6~48h;最后将反应后得到的产物进行过滤、洗涤、干燥。所述的聚吡咯纳米微球作为储能系统中超级电容器的电极材料,或者作为催化剂的负载媒介。本发明不仅工艺条件简单、路线绿色,而且所制备的聚吡咯微球结构完美,尺寸均一,可实现大规模商业化生产
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