基于Jetson NANO的机器人智能码垛系统

随着工业自动化的快速发展,机器人智能码垛系统在物流和制造领域中扮演着越来越重要的角色。该文设计并实现一个基于NVIDIA Jetson NANO的机器人智能码垛系统,系统选用合适的传感器和执行器,集成机器视觉检测技术,能够实现对物块的自动识别、定位和码垛。测试结果表明,该系统在识别准确率、码垛速度以及稳定性方面均达到了预期目标,并在高负载下保持稳定运行,展现了良好的性能和较高的码垛效率。

Active Micro-Nano-Collaborative Bioelectronic Device for Advanced Electrophysiological Recording

The development of precise and sensitive electrophysiological recording platforms holds the utmost importance for research in the fields of cardiology and neuroscience.In recent years,active micro/nano-bioelectronic devices have undergone significant advancements,thereby facilitating the study of electrophysiology.The distinctive configuration and exceptional functionality of these active micro-nano-collaborative bioelectronic devices offer the potential for the recording of high-fidelity action potential signals on a large scale.In this paper,we review three-dimensional active nano-transistors and planar active micro-transistors in terms of their applications in electroexcitable cells,focusing on the evaluation of the effects of active micro/nano-bioelectronic devices on electrophysiological signals.Looking forward to the possibilities,challenges,and wide prospects of active micro-nano-devices,we expect to advance their progress to satisfy the demands of theoretical investigations and medical implementations within the domains of cardiology and neuroscience research.

The Influence of Carbon Nanotubes and Nano-Silica Fume on Enhancing the Damping and Mechanical Properties of Cement-Based Materials

This paper conducted experimental studies on the damping and mechanical properties of carbon nanotube-nanosilica-cement composite materials with different carbon nanotube contents. The damping and mechanical properties enhancement mechanisms were analyzed and compared through the porosity structure test, XRD analysis, and scanning electron microscope observation. The results show that the introduction of nanosilica significantly improves the dispersion of carbon nanotubes in the cement matrix. At the same time, the addition of nanosilica not only effectively reduces the critical pore size and average pore size of the cement composite material, but also exhibits good synergistic effects with carbon nanotubes, which can significantly optimize the pore structure. Finally, a rationalization suggestion for the co-doping of nanosilica and carbon nanotubes was given to achieve a significant increase in the flexural strength, compressive strength and loss factor of cement-based materials.

Leveraging Nanotechnology for Addressing COVID-19: Revealing Antiviral Approaches and Hurdles

The emergence of COVID-19 has caused extensive harm and is recognized as a significant threat to human life worldwide. Currently, the application of nanomedicine techniques in pre-clinical studies related to various infections, such as respiratory viruses, herpes viruses, human papillomavirus, and HIV, has demonstrated success. Nanoparticles, due to their specific attributes, have garnered considerable attention in combating COVID-19. Strategies employing nanomaterials for COVID-19 prevention encompass the development of rapid, precise diagnostic tools, the creation of effective disinfectants, the delivery of mRNA vaccines to the biological system, and the administration of antiretroviral medications within the body. This article focuses on recent research regarding the effectiveness of nano platforms as antiviral measures against coronaviruses. It delves into the molecular characteristics of coronaviruses and the affected target systems, highlighting challenges and limitations in combating SARS-CoV-2. Additionally, it explores potential nanotechnology-based treatments to confront current and future variants of coronaviruses associated with COVID-19 infections.

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。

SiC-Ni60涂层中添加nano-Cu包覆MoS_(2)对其组织和摩擦磨损性能的影响

采用激光熔覆的方法在42CrMo钢基体上制备了nano-Cu/MoS_(2)镍基合金熔覆层,运用扫描电镜、XRD、显微硬度计以及摩擦磨损试验机等探究了不同含量nano-Cu/MoS_(2)熔覆层的组织及耐磨减摩性能.结果表明,采用激光熔覆技术制备的nano-Cu/MoS_(2)镍基合金熔覆层中上部为细密的等轴晶,中下部至靠近熔合线主要为条柱状晶,添加nano-Cu/MoS_(2)颗粒后覆层中部等轴晶粒部分转变为条带状,覆层中产生了金属硫化物CrS和软金属铜,晶界处分布一些细小MoS_(2)颗粒,受润滑相与部分晶粒粗化影响与C1(无nano-Cu/MoS_(2))相比,C2~C4(5%~15%nano-Cu/MoS_(2))熔覆层的硬度显著下降,但与基体相比有1.45~2.06倍,具有良好的力学性能,而摩擦质量损失增加最高达到0.0198 g,摩擦系数逐渐减小,熔覆层最低摩擦系数0.4430较C1明显降低,兼顾力学性能、摩擦系数和摩擦质量损失角度考虑,nano-Cu/MoS_(2)含量为10%,激光功率290 W、扫描速度6 mm/s时,其熔覆层力学及摩擦学性能为佳.

早期CO_(2)养护与Nano-TiO_(2)协同作用下低热水泥基浆体的力学性能

为探究早期CO_(2)养护和纳米TiO_(2)(nano-TiO_(2),NT)协同作用对低热硅酸盐水泥(low-heat portland cement, LHPC)力学性能的影响规律,测试了不同CO_(2)养护时间和NT掺量下LHPC的抗折、抗压强度,并结合扫描电镜、热重分析等测试结果分析其对力学性能的协同作用机制。结果表明:仅考虑掺入NT或CO_(2)养护,NT掺量或CO_(2)养护时间均存在最佳范围。CO_(2)养护与NT协同作用下,CO_(2)养护24 h内,LHPC浆体在14 d和28 d龄期的抗压、抗折强度分别在NT掺量为1%~1.5%和1.5%~2%时提升幅度大,这归因于试样中水化硅酸钙凝胶(C-S-H)、钙矾石(AFt)和CaCO_(3)质量增加,长径比较小的纤维状C-S-H细化了大于50 nm的孔径。而CO_(2)养护超过24 h、NT掺量大于2%时,试样中孔隙数量增加、较大长径比的晶须状文石和微观裂缝的产生降低了力学性能。综合力学强度和经济性,建议CO_(2)养护时间为12 h, NT掺量为1%。研究结果为提升LHPC早期力学性能提供一定的参考依据。

基于Jetson Nano的隐式场景表征重建方法

随着计算机视觉和边缘计算技术的不断发展,对于复杂场景的高效重建与表征成为了研究的热点之一。本研究提出了一种基于Jetson Nano的隐式场景表征重建方法,旨在通过深度学习和边缘计算技术的有机结合,实现对复杂场景的高效重建与表征。本研究是基于Jetson Nano边缘计算平台,将RGBD相机与其连接,通过网络传输将采集的数据存储于云端。本研究采用了一种创新性的隐式表示模型,通过函数对场景信息进行紧凑而高效的表征。该方法在Jetson Nano边缘计算平台上通过统一计算设备架构(Compute Unified Device Architecture,CUDA)和深度学习推理引擎(Turing Tensor R-Engine,TensorRT)优化,进一步提升了计算效率。结合隐式神经网络和同步定位与地图构建(Simultaneous Localization And Mapping,SLAM)技术,成功实现了三维场景的精准重建,相机追踪中绝对轨迹误差的均方根误差平均值达到了1.87,在各个场景的表现均具有鲁棒性。

Current perspectives of nanoparticles in medical and dental biomaterials

Nanotechnology is gaining tremendous impetus due to its capability of modulating metals into their nanosize, which drastically changes the chemical, physical and optical properties of metals. Nanoparticles have been intro- duced as materials with good potential to be extensively used in biological and medical applications. Nanoparticles are clusters of atoms in the size range of 1-100 nm. Inorganic nanoparticles and their nano-composites are applied as good antibacterial agents. Due to the outbreak of infectious diseases caused by different pathogenic bacteria and the development of antibiotic resistance, pharmaceutical companies and researchers are searching for new antibacterial agents. The metallic nanoparticles are the most promising as they show good antibacterial properties due to their large surface area to volume ratios, which draw growing interest from researchers due to increasing microbial resistance against metal ions, antibiotics and the development of resistant strains. Metallic nanoparticles can be used as effective growth inhibitors in various microorganisms and thereby are applicable to diverse medical devices. Nanotechnology discloses the use of elemental nanoparticles as active antibacterial ingredient for dental materials. In dentistry, both restorative materials and oral bacteria are believed to be responsible for restoration failure. Secondary caries is found to be the main reason to restoration failure. Secondary caries is primarily caused by invasion of plaque bacteria （acid-producing bacteria） such as Streptococcus mutans and lactobacilli in the presence of fermentable carbohydrates. To make long-lasting restorations, antibacterial materials should be made. The potential of nanoparticles to control the formation of biofilms within the oral cavity is also coming under in- creasing scrutiny. Possible uses of nanoparticles as topically applied agents within dental materials and the appli- cation of nanoparticles in the control of oral infections are also reviewed.

一种基于Jetson Nano的智能辅助导盲装置设计

为解决中国视障人群出行困难的问题,设计了一种基于Jetson Nano的智能辅助导盲装置,使视障人群能够安全出行。采用摄像头帮助视障人群探测周围环境,将Jetson Nano作为主控板,通过视觉算法将摄像头捕捉的画面信息提取后,结合TFmini Plus激光测距雷达对视障人群前方物体进行测距,视觉算法采用基于CNN卷积神经网络的YOLOv4目标检测算法,语音转化模块采用科大讯飞出品的六麦克风阵列模块。当物体靠近视障人群前方一定距离时,智能辅助导盲装置会将摄像头识别到的物体名称通过语音形式反馈给视障人群。设计的智能辅助导盲装置可以实现对周围环境的实时检测和识别,对常见的物体如车辆等都能够准确识别,提醒视障人士及时避让,有效提高他们的出行安全。该装置还有很大的发展空间和应用前景,可以进一步完善其功能,为更多视障人士服务。

Nano-Fe_(3)O_(4)强化牛粪厌氧发酵及抗性基因削减

为提高牛粪高浓度厌氧发酵产气性能,考察了不同浓度纳米四氧化三铁(Nano-Fe_(3)O_(4))对底物水解及产气效率的强化效果,探究其对发酵系统中微生物群落结构变化以及抗生素抗性基因(ARGs)归趋的影响.结果表明,添加500mg/L的Nano-Fe_(3)O_(4)可以提高牛粪高浓度厌氧发酵底物水解程度,增强系统稳定性,提高沼气产量12.36%.与对照相比,发酵系统中水解产酸菌厚壁菌门(Firmicutes)、纤维杆菌门(Fibrobacteres)的丰度分别显著增加了37.39%和75.86%.属水平上尤其是梭菌属(Clostridium)和瘤胃球菌(Ruminofilibacter)丰度是原来的3.50倍和8.69倍.产甲烷菌中甲烷八叠球菌(Methanosarcina)占主导地位,其丰度达2.55%,比对照显著增加27.50%.此外,潜在致病菌密螺旋体属(Treponema)和不动杆菌属(Acinetobacter)的丰度分别显著降低72.14%和93.69%;ARGs中四环素类(tetA、tetG、tetH、tetJ)、氨基糖苷类(aph(3)、aph(6))削减率达100%.磺胺酰胺类(sul1、sul2)平均削减率达74.41%~96.55%.研究表明添加适量的Nano-Fe_(3)O_(4)对稳定发酵系统、提高微生物活性、增加沼气产量、抗性基因削减等方面有多重促进作用,研究结果可为畜禽粪污沼气工程中Nano-Fe_(3)O_(4)等导电性外源调控添加剂的使用提供参考.

Energy-Efficient Implementation of BCD to Excess-3 Code Converter for Nano-Communication Using QCA Technology

Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique was adopted to investigate integration with other complicated circuits.Using a unique XOR gate,the recommended circuit’s cell complexity has been decreased.The findings produced using the QCADesigner-2.0.3,a reliable simulation tool,prove the effectiveness of the current structure over earlier designs by considering the number of cells deployed,the area occupied,and the latency as design metrics.In addition,the popular tool QCAPro was used to estimate the energy dissipation of the proposed design.The proposed technique reduces the occupied space by∼40%,improves cell complexity by∼20%,and reduces energy dissipation by∼1.8 times(atγ=1.5EK)compared to the current scalable designs.This paper also studied the suggested structure’s energy dissipation and compared it to existing works for a better performance evaluation.

Mechanical behavior of nanorubber reinforced epoxy over a wide strain rate loading

Nanorubber/epoxy composites containing 0,2,6 and 10 wt%nanorubber are subjected to uniaxial compression over a wide range of strain rate from 8×10^(-4) s^(-1) to~2×10^(4) s^(-1).Unexpectedly,their strain rate sensitivity and strain hardening index increase with increasing nanorubber content.Potential mechanisms are proposed based on numerical simulations using a unit cell model.An increase in the strain rate sensitivity with increasing nanorubber content results from the fact that the nanorubber becomes less incompressible at high strain,generating a higher hydro-static pressure.Adiabatic shear localization starts to occur in the epoxy under a strain rate of 22,000 s^(-1) when the strain exceeds 0.35.The presence of nanorubber in the epoxy reduces adiabatic shear localization by preventing it from propagating.

Effect of Sintering Temperature on the Microstructure and Mechanical Properties of Nanocrystalline Cemented Carbide

WC-Co nanocrystalline nitrogen-containing cemented carbides were prepared by vacuum sintering and low pressure sintering.The sintering processes of Cr_(2)(C,N)doped nano WC-Co powders were studied by using thermogravimetric analysis(TGA)and differential scanning calorimetry(DSC).The effect of sintering temperature on the microstructure and mechanical properties of nanocrystalline cemented carbide was studied by scanning electron microscope(SEM),high resolution transmission electron microscope(HRTEM)and mechanical property test.The results showed that the nano WC grains began to grow in the solid phase sintering stage.A high-performance nano-nitrogen-containing cemented carbide with uniform microstructure and good interfacial bonding can be obtained by increasing the sintering temperature to 1380℃.It has a transverse rupture strength(TRS)of 5057 MPa and a hardness of 1956 HV30.

Recent advances in zwitterionic nanoscale drug delivery systems to overcome biological barriers

Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.

On-Chip Micro Temperature Controllers Based on Freestanding Thermoelectric Nano Films for Low-Power Electronics

Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.

Ignition processes and characteristics of charring conductive polymers with a cavity geometry in precombustion chamber for applications in micro/nano satellite hybrid rocket motors

The arc ignition system based on charring polymers has advantages of simple structure,low ignition power consumption and multiple ignitions,which bringing it broadly application prospect in hybrid propulsion system of micro/nano satellite.However,charring polymers alone need a relatively high input voltage to achieve pyrolysis and ignition,which increases the burden and cost of the power system of micro/nano satellite in practical application.Adding conductive substance into charring polymers can effectively decrease the conducting voltage which can realize low voltage and low power consumption repeated ignition of arc ignition system.In this paper,a charring conductive polymer ignition grain with a cavity geometry in precombustion chamber,which is composed of PLA and multiwall carbon nanotubes(MWCNT)was proposed.The detailed ignition processes were analyzed and two different ignition mechanisms in the cavity of charring conductive polymers were revealed.The ignition characteristics of charring conductive polymers were also investigated at different input voltages,ignition grain structures,ignition locations and injection schemes in a visual ignition combustor.The results demonstrated that the ignition delay and external energy required for ignition were inversely correlated with the voltages applied to ignition grain.Moreover,the incremental depth of cavity shortened the ignition delay and external energy required for ignition while accelerated the propagation of flame.As the depth of cavity increased from 2 to 6 mm(at 50 V),the time of flame propagating out of ignition grain changed from 235.6 to 108 ms,and values of mean ignition delay time and mean external energy required for ignition decreased from 462.8 to 320 ms and 16.2 to 10.75 J,respectively.The rear side of the cavity was the ideal ignition position which had a shorter ignition delay and a faster flame propagation speed in comparison to other ignition positions.Compared to direct injection scheme,swirling injection provided a more favorable flow field environment in the cavity,which was beneficial to ignition and initial flame propagation,but the ignition position needed to be away from the outlet of swirling injector.At last,the repeated ignition characteristic of charring conductive polymers was also investigated.The ignition delay time and external energy required for ignition decreased with repeated ignition times but the variation was decreasing gradually.

An Investigation into Forced Convection of a Nanofluid Flowing in a Rectangular Microchannel under the Influence of a Magnetic Field

In line with recent studies,where it has been shown that nanofluids containing graphene have a stronger capacity to boost the heat transfer coefficient with respect to ordinary nanofluids,experiments have been conducted using water with cobalt ferrite/graphene nanoparticles.In particular,a circular channel made of copper subjected to a constant heatflux has been considered.As nanoparticles are sensitive to the presence of a magneticfield,different conditions have been examined,allowing both the strength and the frequency of such afield to span relatively wide ranges and assuming different concentrations of nanoparticles.According to thefindings,the addition of nanoparticles to thefluid causes its rotation speed to increase by a factor of two,whereas ultraviolet radiation plays a negligible role.The amount of time required to attain the maximum rotation speed of the nanofluid and the Nusselt number have been measured under both constant and alternating magneticfields for a ferrofluid with a concentration of 0.5%and atflow Reynolds number of 550 and 1750.

ZnO Influence on Thermophysical Characteristics of Natural Polymer-Based Nanofluids

This thesis investigates the influence of zinc oxide (ZnO) on the thermophysical characteristics of natural polymer-based nanofluids. The focus is on pectin nanofluids with incorporated ZnO nanoparticles. In this experiment, varying concentrations of zinc oxide (ZnO) were combined with a constant amount of pectin to study their effects on the final solution’s characteristics. Initially, ZnO and pectin solutions were prepared individually and subjected to magnetic stirring and sonication. The experiment involved three different concentrations of ZnO: 0.1 g, 0.02 g, and 0.03 g, while the weight of pectin remained constant at 0.05g throughout. After individual preparation, the solutions were mixed, further stirred, and subjected to sonication. Two analysis techniques, Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA), were employed to characterize the samples. SEM provided insights into surface morphology and chemical composition, while TGA analyzed mass changes over temperature variations, offering valuable information on material properties. The significance and applications of these techniques in material characterization and analysis were discussed, highlighting their roles in understanding physical and chemical phenomena. The presence of ZnO nanoparticles enhanced the thermal stability of the pectin nanofluids. Contact angle measurements were performed to evaluate the hydrophilicity of the nanofluids. The contact angle trend indicated an increase in hydrophobicity with an increasing concentration of ZnO in the pectin nanofluids. The measured contact angles supported the high stability of the synthesized nanofluids. Overall, this study provides valuable insights into the incorporation of ZnO nanoparticles into pectin nanofluids and their impact on the thermophysical characteristics. The findings contribute to the development of nanofluids for potential applications in drug release and biomedical fields.

Chemically Radiative MHD Flow of a Micropolar Nanofluid over a Stretching/ Shrinking Sheet with a Heat Source or Sink

This study examines the behavior of a micropolar nanofluidflowing over a sheet in the presence of a transverse magneticfield and thermal effects.In addition,chemical(first-order homogeneous)reactions are taken into account.A similarity transformation is used to reduce the system of governing coupled non-linear partial differ-ential equations(PDEs),which account for the transport of mass,momentum,angular momentum,energy and species,to a set of non-linear ordinary differential equations(ODEs).The Runge-Kutta method along with shoot-ing method is used to solve them.The impact of several parameters is evaluated.It is shown that the micro-rota-tional velocity of thefluid rises with the micropolar factor.Moreover,the radiation parameter can have a remarkable influence on theflow and temperature profiles and on the angular momentum distribution.