Recognition for Frontal Emergency Stops Dangerous Activity Using Nano IoT Sensor and Transfer Learning

Currently,it is difficult to extract the depth feature of the frontal emergency stops dangerous activity signal,which leads to a decline in the accuracy and efficiency of the frontal emergency stops the dangerous activ-ity.Therefore,a recognition for frontal emergency stops dangerous activity algorithm based on Nano Internet of Things Sensor(NIoTS)and transfer learning is proposed.First,the NIoTS is installed in the athlete’s leg muscles to collect activity signals.Second,the noise component in the activity signal is removed using the de-noising method based on mathematical morphology.Finally,the depth feature of the activity signal is extracted through the deep transfer learning model,and the Euclidean distance between the extracted feature and the depth feature of the frontal emergency stops dangerous activity signal is compared.If the European distance is small,it can be judged as the frontal emergency stops dangerous activity,and the frontal emergency stops dangerous activity recognition is realized.The results show that the average time delay of activity signal acquisition of the algorithm is low,the signal-to-noise ratio of the action signal is high,and the activity signal mean square error is low.The variance of the frontal emergency stops dangerous activity recognition does not exceed 0.5.The difference between the appearance time of the dangerous activity and the recognition time of the algorithm is 0.15 s,it can accurately and quickly recognize the frontal emergency stops the dangerous activity.

基于Jetson Nano的智能双足人形机器人

针对人型机器人多样的使用需求及复杂的使用环境,本文设计出一款以高性能NVIDIA Jetson Nano为主控板,采用舵机驱动、搭载多个感知模块的智能双足人型机器人,通过ROS系统进行步态控制,依靠摄像头、多种传感器及配套算法实现姿态识别和空间位置计算,完成机器人整体的行动。

SURFACE-ENHANCED CANTILEVER SENSORS WITH NANO-POROUS FILMS

Developing surface-enhanced microcantilevers with improved sensitivities is of longstanding interest. In this paper, the design of surface-enhanced cantilever sensors using nano- （micro-） porous films as surface layers is proposed. The static deformation and resonance frequencies of these surface-enhanced sensors with the simultaneous effects of the eigenstrain, the surface stress and the adsorption mass are analyzed. It is shown that the sensitivities of these novel cantilever sensors for the static deformation and resonance frequencies can be tuned by the porosity, the size of the pores and the structure of the porous films. For the three kinds of cantilever consisting of solid films, films with aligned cylindrical micro-scale pores, and those with nano-scale pores, the nano-porous one has the highest static and dynamic sensitivities, whereas the solid one has the lowest.

A nano-metallic-particles-based CMOS image sensor for DNA detection

In this paper we report on a study of the CMOS image sensor detection of DNA based on self-assembled nano- metallic particles, which are selectively deposited on the surface of the passive image sensor. The nano-metallic particles effectively block the optical radiation in the visible spectrum of ordinary light source. When such a technical method is applied to DNA detection, the requirement for a special UV light source in the most popular fluorescence is eliminated. The DNA detection methodology is tested on a CMOS sensor chip fabricated using a standard 0.5 gm CMOS process. It is demonstrated that the approach is highly selective to detecting even a signal-base mismatched DNA target with an extremely-low-concentration DNA sample down to 10 pM under an ordinary light source.

Electrochemical Synthesis of Titanium Nano Particles at Carbon Paste Electrodes and Its Applications as an Electrochemical Sensor for the Determination of Acetaminophen in Paracetamol Tablets

Titania nano particles were synthesized at carbon paste electrode by cyclic voltammetry and then it was employed for the determination of acetaminophen in phosphate buffer at pH 7.4. Carbon paste electrode with titania nano particle displayed excellent electrochemically catalytic activities by shifting the oxidation potential of acetaminophen towards the negative side. The mass transfer process at electrochemical interface was diffusion controlled. Electrochemical techniques such as, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods were used to measure the resistance of the electrodes. The resistance of the titanium electrode decreased in two orders when compared to the bare carbon paste electrode;the decrease in the resistance of the electrode and increase in the surface area of the electrode are responsible for the negative shifting of the oxidation potential of acetaminophen. The present method was applied to the determination of actetaminophen in paracetamol tablet, urine and blood sample by using standard addition method and the obtained results were satisfactory with a good recovery of 98%.

Characteristics of Nanoparticles-Based Chemical Sensors

Semiconducting nanoparticle tin oxide-based sensors have been prepared with a pressure load of 4, 6, 8, 10 tons and reinforced with carbon nanofibers (CNF) in SnO2 matrix. The SnO2/CNF sensor’s sensitivity for ethyl alcohol has in-creased by a factor of two, in compared with that of pure SnO2 8-ton pressed sensor with lower response time. These results open the way towards further optimized lower cost CNF nanocomposite sensors as compared with expensive tin oxide/carbon nanotubes sensors.

Simulation and analysis of phase-sensitive surface plasmon resonance sensor based on enhanced optical transmission through arrays of nanoholes in silver films

A high spatial resolution, phase-sensitive Surface Plasmon Resonance(SPR) sensor based on Extraordinary Optical Transmission(EOT) is proposed to monitor the binding of organic and biological molecules to the silver surface. The 2D nanohole-array configuration is well suited for dense integration in a sensor chip. The optical geometry is collinear, which simplifies the alignment with respect to the traditional Kretschmann arrangement for SPR sensing. Various design parameters of the device have been studied by simulation. The heterodyne technique is used to improve the sensitivity. The optimization results indicate that the sensor has the advantages of achieving high resolution and a wide dynamic range simultaneously.

基于纳米银/聚L-谷氨酸修饰玻碳电极的电化学传感器用于泡菜中亚硝酸钠含量的测定

采用电沉积和电聚合的方式,将纳米银和L-谷氨酸修饰在玻碳电极上,制得纳米银/聚L-谷氨酸修饰玻碳电极(Poly-L-Glu/Nano-Ag/GCE)。以0.2 mol·L^(-1)磷酸盐缓冲溶液(pH 7.0)为支持电解质,以Poly-L-Glu/Nano-Ag/GCE为工作电极,饱和甘汞电极为参比电极,铂电极为辅助电极,在最佳检测条件下,采用循环伏安法进行测定。结果表明:Poly-L-Glu/Nano-Ag/GCE对亚硝酸钠具有较好的选择性,亚硝酸钠的浓度在4.14×10^(-6)~1.35×10^(-3) mol·L^(-1)内与对应的氧化峰电流的绝对值呈线性关系,检出限(3s/k)为4.14×10^(-7) mol·L^(-1),并且该电极的制备方法具有较好的重复性。将PolyL-Glu/Nano-Ag/GCE用于泡菜样品中亚硝酸钠的测定,检出量为1.33×10^(-5) mol·L^(-1),加标回收率为98.9%~103%。

折/衍混合光学系统在纳型星敏感器中的应用

微纳卫星是一种新兴的微小卫星,与之适配的纳型星敏感器的光学系统应在小型化的同时实现大相对孔径、高成像质量。针对这一需求,由星敏感器的系统设计精度和探测星等分配了光学系统设计参数及指标,设计了一种全视场17°、焦距25 mm、相对孔径1∶1.086、光学系统总长36.4 mm的七片式折衍混合结构的星敏感器光学系统。根据衍射元件的负色散特性,用折衍混合透镜代替常规材料正负透镜组合的方式减少了镜片数量,缩短了光学系统长度,并提高了光学系统的成像质量,使点扩散函数趋于正态分布,有利于质心提取精度的提高。所设计的光学系统在3×3像元内的能量集中度超过90%;最大畸变仅0.013%;全视场垂轴色差小于0.6μm。通过标量衍射理论计算衍射元件在520~780 nm内衍射效率可以达80%以上,通过杂散光分析软件ASAP对系统进行了视场内鬼像分析,系统在多级衍射时探测目标成像光斑路径下的光通量与最亮鬼像光斑路径下的光通量之比大于3.17×10^(4),验证了在极限星等为6.5时满足信噪比大于8.1的结论。最后对所设计的系统进行了公差分析,结果表明加工后该光学系统可满足微纳卫星对星敏感器的使用要求。

纳米银修饰ITO电极快速测定水中吡虫啉

利用恒电压沉积纳米银制备了对吡虫啉响应良好的电化学传感器。采用扫描电镜(SEM)、电化学阻抗谱(EIS)对电极进行了表征。探讨了缓冲液pH、扫描速率、干扰物质对实验结果的影响。研究表明,最佳实验条件(0.01 mol/L、pH=7的PBS缓冲液,扫描速率100 mV/s)下,在10~100μmol/L浓度范围内含吡虫啉线性伏安扫描的还原峰电流与其浓度呈线性关系(R2=0.980 0),LOD值为0.04μmol/L。该修饰电极具有电稳定性良好、可重复使用等一系列优点。对河水的添加回收率为90.05%~103.1%,与液相色谱测定的结果相符,表明该传感器在实际样品检测和环境保护中具有良好的应用前景。

纳米电化学传感器快速检测藜麦多酚的方法研究

以Nafion、多壁碳纳米管(MWCNTs)、纳米铜(Nano-copper)为复合修饰材料制备纳米电化学传感器,建立快速检测藜麦多酚的电化学分析方法,并采用循环伏安法研究多酚的电化学反应过程。结果表明:最佳测定条件为以磷酸氢二钠-柠檬酸溶液(pH 3.5)为电解质缓冲液,以Nafion-MWCNTs修饰量5μL、纳米铜富集量为循环伏安扫描15圈、Nafion和MWCNTs体积比1∶1。在此条件下,多酚氧化峰电流与浓度在5~60μmol/L范围内线性关系良好,检出限为3.7×10^(-8)mol/L,加标回收率为105.8%~112.4%。建立的方法可用于藜麦多酚的快速检测分析。

载银聚乳酸纳米纤维复合面料传感器的制备与表征

聚乳酸(PLA)纳米纤维摩擦电材料具有良好的生物相容性和可降解性,但其驻极后易吸附细菌等微生物,影响面料耐久性和穿戴者健康安全。以PLA为保护剂原位合成纳米银溶液,所制备纳米银粒径集中于0~5 nm和10~25 nm。将上述溶液经静电纺丝得到载银PLA纳米纤维膜,纤维膜直径由纯PLA纳米纤维的0.7~1.4μm降至0.4~0.7μm。载银PLA纳米纤维膜与导电织物复合后,面料的抗菌性能随PLA纳米银含量的增加而提高,最佳银质量分数为300 mg/kg,对E.coli和S.aureus的抑菌率均大于99.9%。复合面料摩擦电性能随纳米银含量增加先增加后降低,银质量分数为300 mg/kg,开路电压(VOC)峰值提高15.33%。研究表明摩擦电最佳条件为:接触频率2.0 Hz、接触压力12250 N/m^(2),相应VOC最高为99.47 V,短路电流(ISC)峰值最高为1.17μA,最高输出功率为129.35 mW/m^(2)。复合面料在监测人体运动信号方面具有良好的灵敏度。

针灸领域应用纳米技术的现状及思考

此文阐明纳米技术在针灸中目前的应用和未来的潜力,分别从纳米技术结合针灸针、穴位贴敷与穴位注射、穴位埋线3个方面进行论述。首先,纳米技术与针具制作方面相结合研制出的纳米针灸传感针在实时检测活体活性分子方面提供了新的解决方案;其次,纳米中药与穴位注射、穴位贴敷等针灸特色疗法上的结合也具有很大的潜力;最后,依据纳米技术研发的高抗菌力、低过敏性的纳米银线,应用于临床,为临床穴位埋线治疗疾病提供更优的材料。但从纳米技术在针灸领域的应用现状来看,仍存在着一些待解决的问题,我们需要在不断思考中进一步探索,从而为今后临床治疗提供更多的选择。

具有多孔双微结构层的柔性电容式压力传感器

电极和介电层的材料性能和表面结构是决定柔性电容式压力传感器性能的关键因素。将碳纳米管(CNT)与硅橡胶结合制备出拉伸性能优良的斜线型微结构电极层。以聚二甲基硅氧烷(PDMS)/BaTiO_(3)/SrTiO_(3)复合材料制备多孔砂纸微结构介电层。电极与介电层交界面构成双重微结构以提升电荷携带能力。场发射扫描电子显微镜与光学显微镜观测结果验证了上述微结构的存在。基于电容模型的分析表明,传感器灵敏度主要取决于多孔介电层的形变量。所制备的多孔双微结构层柔性电容式压力传感器最高灵敏度为2.681 kPa^(-1),在3~5 kPa的压力区间仍具有0.412 kPa^(-1)的灵敏度,响应时间和释放时间分别约为39和61 ms。该传感器能够检测出吞咽时咽部运动的微小压力,实验中测得的最小电容变化率为0.13%,能够识别0.53 Pa的微小压力,具有较低的检测限。进行6000次以上的压缩循环测试后,传感器加载-卸载曲线重合性好,同时对不同频率压力的响应良好,验证了传感器良好的可重复性。总之,所提出的传感器具有良好的压力感知性能,在生理信号监测、人机交互等领域具有广阔的应用前景。

纳米材料在食品检验鉴定中的应用研究进展

食品安全直接影响到国家安全稳定和人民群众的身心健康。食品检验鉴定技术在食品领域的违法犯罪案件中发挥着重要证据固定作用。近年来,运用纳米材料可以使食品检测更加简便、灵敏、高效。本文主要从纳米材料修饰的电化学传感器、荧光纳米材料和荧光染料修饰的适配体传感器和纳米表面增强拉曼光谱分析技术三方面介绍了纳米材料在食品检测鉴定中的应用研究,并对纳米技术在食品检测方面的发展趋势进行了总结和展望。

光学波前传感技术研究进展

光学波前是光波相位面的几何表示,光学波前传感技术通过检测光波传播路径中的相位变化来分析物体的性质。该技术广泛应用于大气湍流检测、光学元件缺陷分析、生物样品研究等领域,在天文学、自适应光学、显微成像、激光系统和生物医学等方面具有重要作用。然而,常见探测器仅对光强度敏感,为了探测光学波前,通常需要在探测前端使用一系列复杂的光学元件,这导致系统体积庞大、成本高昂且结构复杂。近年来,随着微纳光学和人工智能等领域的不断进展,涌现出一系列基于新原理、新器件和新算法的集成化、小型化和高性能的光学波前传感技术。该论文系统综述了近期光学波前传感技术的研究进展,并根据其原理将其分为干涉型和非干涉型两大类,具体包括剪切干涉型、光栅干涉型、近场干涉型、算法重构型和维度关联型等技术。最后,总结了当前领域尚存的挑战,并展望了未来可能的研究方向。

基于差热式原理的液体微/纳流量计设计与开发

基于MEMS技术的差热式超微小液体流量传感器具有测试流量极低、体积小、精度高、可实时监测等特点,近年来在现代精密分析科学仪器和微流控技术等领域获得广泛应用。本工作基于差热式液体流量传感器成功设计了满足μL/min~nL/min级液体流量准确测量的5款微纳流量计,输出流量数据稳定且准确性高,精度均小于0.5%。另外,开发了配套流量监控软件,可以实时采集流量数据,记录保存,实现平均流量、流量脉动率等定量计算功能。