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A Dual-Cluster-Head Based Medium Access Control for Large-Scale UAV Ad-Hoc Networks

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China Communications 2024年第5期21卷 123-136页

作者： Zhao Xinru Wei Zhiqing Zou Yingying ma hao Cui Yanpeng Feng Zhiyong Key Laboratory of Universal Wireless Communications Ministry of EducationSchool of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing100876China

Unmanned Aerial Vehicle(UAV)ad hoc network has achieved significant growth for its flexibility,extensibility,and high deployability in recent *** application of clustering scheme for UAV ad hoc network is imperative to enhance the performance of throughput and energy *** conventional clustering scheme,a single cluster head(CH)is always assigned in each ***,this method has some weaknesses such as overload and premature death of CH when the number of UAVs *** order to solve this problem,we propose a dual-cluster-head based medium access control(DCHmaC)scheme for large-scale UAV *** DCHmaC,two CHs are elected to manage resource allocation and data forwarding ***,two CHs work on different *** of CH is used for intra-cluster communication and the other one is for inter-cluster communication.A markov chain model is developed to analyse the throughput of the *** result shows that compared with FM-maC(flying ad hoc networks multi-channel maC,FM-maC),DCHmaC improves the throughput by approximately 20%~50%and prolongs the network lifetime by approximately 40%.

关键词： dual cluster head medium access control UAV swarm

Experimental research on the launching system of auxiliary charge with filter cartridge structure

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Defence Technology（防务技术） 2024年第1期31卷 41-48页

作者： Zi-Jun Chen Ze He Hong-hao ma Lu-Qing Wang Zhao-Wu Shen CAS Key Laboratory of Mechanical Behavior and Design of materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefeiAnhui230027PR China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefeiAnhui230026PR China

A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the *** combustion chamber of the launching system is divided into two fixed chambers,one is located in the breech chamber,and the other is arranged in the *** breech chamber charge was ignited first,and the charges in the auxiliary chambers were ignited by the high-temperature,highpressure combustible gas trailing the *** this way,the combustible gas in the auxiliary chambers could compensate for the pressure drop caused by the movement of the *** proposed device features the advantage of launching a projectile with high muzzle velocity without exceeding the maximum pressure in the *** order to obtain some internal ballistic characteristics of the launch system,some critical structure,such as the length of the filter cartridge auxiliary charge,the combustion degree of the propellant in the chamber,and the length of the barrel,are *** experimental results show that with the increased auxiliary charge length,a pressure plateau or even a secondary peak pressure can be formed,which is less than the peak *** projectile velocity increased by 23.57%,14.64%,and 7.65%when the diaphragm thickness was 0 mm,1 mm,and2 mm,*** muzzle velocity of the projectile can be increased by 13.42%by increasing the length of the *** the same charge condition,with the increase of barrel length,the energy utilization rate of propellant increases by 28.64%.

关键词： Interior ballistics Charge structures Launch system Charge design

Enhanced red luminescence of Ca_(3)Si_(2−x)M_(x)O_(7):Eu^(3+)(M=Al,P)phosphors via partial substitution of Si^(4+) for applications in white light-emitting diodes

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Rare Metals 2024年第2期43卷 736-748页

作者： Yu-hao ma Xi Gao Wen-Tao Zhang Zhen-Rui Yang Zhou Zhao Chen Qu College of materials and Chemistry and Chemical Engineering Chengdu University of TechnologyChengdu610059China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China International Advanced Energy Science Research and Education Center Graduate School of Energy ScienceKyoto UniversityYoshida-HonmachiKyoto606-8501Japan

A red-emitting phosphor Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) with partial Al^(3+)/P^(5+) substitution on Si^(4+) was synthesized via a simple solid-state method,and the effects of the introduction of the M^(3+/5+)(M=Al,P)ions on the crystal structure and photoluminescence performance of Ca_(2.91)Si_(2−x)M_(x)O_(7):0.09Eu^(3+) phosphors were *** X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy(EDS),and X-ray photoelectron spectroscopy(XPS)results revealed that the structure of Ca_(3)Si_(2)O_(7) remained the same after the introduction of Al^(3+) and P^(5+) *** characteristic emission of Eu^(3+)-doped Ca_(3)Si_(2−x)M_(x)O_(7) phosphors exhibited two main peaks at 617 nm(red)and 593 nm(orange)under excitation at 394 nm,which originated from the^(5)D_(0)→^(7)F_(2)and^(5)D_(0)→^(7)F_(1) electron transitions of Eu^(3+) *** the partial substitution of Al^(3+) and P^(5+),the red emission intensities of the Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) phosphors were significantly enhanced by 1.88-and 1.42-fold,respectively,which is attributed to the crystal-field effect around Eu^(3+).Meanwhile,the luminescence intensities of the Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+) and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) phosphors at 210℃ were 79.36%and 77.53%of those at 30°C,respectively,indicating their excellent thermal ***,the as-prepared Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+)and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) red-emitting phosphors were combined with a near-ultraviolet chip of 395 nm to fabricate red-light-emitting diode(LED)and white(w)-LED devices with excellent chromaticity *** summary,Al^(3+)/P^(5+)-substituted Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) can serve as red-emitting phosphors for applications in w-LEDs.

关键词： Ca_(3)Si_(2)O_(7) Red-emitting phosphor Structure substitution Luminescence enhancement Crystal-field effect White light-emitting diode

Force model in electrostatic atomization minimum quantity lubrication milling GH4169 and performance evaluation

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Frontiers of Mechanical Engineering 2024年第4期19卷 55-72页

作者： Min YANG hao ma Zhonghao LI Jiachao hao Mingzheng LIU Xin CUI Yanbin ZHANG Zongming ZHOU Yunze LONG Changhe LI School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China College of Physics QingdaoUniversityQingdao 266071China Hanergy Lubrication Technology Co. Ltd.Qingdao 266200China

The nickel-based high-temperature alloy GH4169 is the material of choice for manufacturing critical components in aeroengines,and electrostatic atomization minimum quantity lubrication(EMQL)milling represents a fundamental machining process for ***,the effects of electric field parameters,jet parameters,nozzle position,and milling parameters on milling performance remain unclear,which constrains the broad application of EMQL in aerospace *** study evaluated the milling performance of EMQL on nickel-based alloys using soybean oil as the lubrication *** revealed that compared with conventional pneumatic atomization MQL milling,EMQL reduced the milling force by 15.2%-15.9%,lowered the surface roughness by 30.9%-54.2%,decreased the average roughness spacing by 47.4%-58.3%,and decreased the coefficient of friction and the specific energy of cutting by 55%and 19.6%,*** optimization experiments using orthogonal arrays demonstrated that air pressure most significantly affected the milling force and specific energy of cutting,with a contribution rate of 22%,whereas voltage had the greatest effect on workpiece surface roughness,contributing 36.71%.Considering the workpiece surface morphology and the potential impact of droplet drift on environmental and health safety,the optimal parameter combination identified were a flow rate of 80 mL/h,an air pressure of 0.1 MPa,a voltage of 30 kV,a nozzle incidence angle of 35°,an elevation angle of 30°,and a target distance of 40 *** research aimed to provide technical insights for improving the surface integrity of aerospace materials that are difficult to machine during cutting operations.

关键词： electrostatic atomization MQL nickel-based alloys milling force surface roughness force model

Single-gait crawling robot: A solution for improving mobility and payload of soft locomotor via simple structure and easy control

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Science China Technological Sciences 2024年

作者： ma hao hao TianZe ma JiChao SUN Zhenhao LI Xiang LIU YiBo XIAO HuaPing LIU ShuHai College of Mechanical and Transportation Engineering China University of Petroleum-Beijing Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology National Demonstration Center for Experimental Mechanical and Electrical Engineering Education (Tianjin University of Technology)

Motion performance, including movement speed, adaptability to various environments, and load-carrying capability, is crucial for soft crawling robots, tasked with field exploration and the transporting material in often complex and unstructured environments. A wide variety of soft crawling robots, which are driven by electricity [1], chemical power [2], and pressurized fluid [3] to move forward via cyclic deformation, have thus far been inspired by the mobile patterns of soft-bodied animals, such as worms [4],snake [5], octopus [6], etc. The performance of soft robots in terms of speed and load has developed impressively in recent years. Notably, there have been crawling robots with morphological adaptability [7], multimodality,and amphibious locomotion [8,9]. Despite impressive progress, there is still substantial work that remains in creating true systems that can match the speed, adaptability to various environments, and load-carrying capability, of natural organisms or motorized machines.

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Optical responses of metallic plasmonic arrays under the localized excitation

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Nano Research 2024年第3期17卷 1571-1577页

作者： Sen Yan hao ma Yi-Fan Bao maofeng Cao Chuan Liu Kaifeng Zhang Xiaowei Wu Jianbo He Xiang Wang Bin Ren State Key Laboratory of Physical Chemistry of Solid Surfaces Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy materials of Fujian Province(IKKEM) Xiamen 361005China Research&Development Group HitachiLtd.Yokohama 244-0817KanagawaJapan Department of Electronic Science and Engineering Kyoto UniversityKyoto 615-8510Japan

The metallic plasmonic array that can support both propagating surface plasmon polaritons(PSPPs)and localized surface plasmon resonance(LSPR)possesses rich optical properties and remarkable optical performance,making it a powerful platform for applications in photonics,chemistry,and *** practical applications,the excitation spot is usually smaller than the area of metal *** is thus imperative to address“how many array units are enough?”towards a rational design of plasmonic ***,we employed focused ion beam(FIB)to precisely fabricate a series of plasmonic array structures with increased unit *** utilizing photoluminescence(PL)and surface-enhanced Raman spectroscopy(SERS),we found that the array units outside the excitation spot still have a significant impact on the optical response within the *** with the numerical simulation,we found that the boundary of the finite array leads to the loss of PSPP outside the excitation point,which subsequently affects the coupling of PSPP and LSPR in the excitation spot,leading to variations in PL and SERS *** on the findings,we further tuned the LSPR mode of the metal arrays by electrodeposition to obtain strong near-field enhancement without any influence on the PSPP *** work advances the understanding of near-field and far-field optical behavior in finite-size array structures and provides guidance for designing highly-efficient photonic devices.

关键词： plasmonic periodic array finite-size effects dark field scattering surface-enhanced Raman spectroscopy(SERS)

Loneliness,social isolation and incident chronic kidney disease among patients with diabetes

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General Psychiatry 2024年第3期37卷 440-448页

作者： Rui Tang Jian Zhou Xuan Wang hao ma Xiang Li Yoriko Heianza Lu Qi Epidemiology Tulane University School of Public Health and Tropical MedicineNew OrleansLouisianaUSA The Second Xiangya Hospital of Central South University ChangshaHunanChina Nutrition Harvard University T H Chan School of Public HealthBostonMassachusettsUSA

Background Individuals with diabetes have a significantly higher risk of developing chronic kidney disease(CKD)and higher levels of social isolation and loneliness compared with those without ***,the American Heart Association highlighted the importance of considering social determinants of health(SDOH)in conjunction with traditional risk factors in patients with *** To investigate the associations of loneliness and social isolation with incident CKD risk in patients with diabetes in the UK *** A total of 18972 patients with diabetes were included in this prospective *** and Social Isolation Scales were created based on self-reported *** adjusted Cox proportional hazard model was used to investigate the associations of loneliness and social isolation with CKD risk among patients with *** relative importance in predicting CKD was also calculated alongside traditional risk *** During a median follow-up of 10.8 years,1127 incident CKD cases were reported.A higher loneliness scale,but not social isolation,was significantly associated with a 25%higher risk of CKD,independent of traditional risk factors,among patients with *** the individual loneliness factors,the sense of feeling lonely emerged as the primary contributing factor to the elevated risk of *** with individuals not experiencing feelings of loneliness,those who felt lonely exhibited a 22%increased likelihood of developing *** addition,feeling lonely demonstrated greater relative importance of predicting CKD compared with traditional risk factors such as body mass index,smoking,physical activity and *** This study indicates the significant relationship between loneliness and CKD risk among patients with diabetes,highlighting the need to address SDOH in preventing CKD in this population.

关键词： patients diabetes kidney

基于外差相敏色散光谱技术的宽动态范围甲烷气体检测

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中国光学（中英文） 2024年第4期17卷 789-800页

作者：周晨马柳昊王宇武汉理工大学汽车工程学院湖北武汉430070 中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室吉林长春130033

为实现痕量甲烷气体的宽动态范围高灵敏度检测,本文开展了双边带拍频抑制模式的外差相敏色散光谱技术研发,研究了电光调制器工作特性以及偏置电压调控方法,对比了抑制与非抑制模式下的色散相位谱轮廓与信噪比,并对检测性能(如线性动态... 详细信息

为实现痕量甲烷气体的宽动态范围高灵敏度检测,本文开展了双边带拍频抑制模式的外差相敏色散光谱技术研发,研究了电光调制器工作特性以及偏置电压调控方法,对比了抑制与非抑制模式下的色散相位谱轮廓与信噪比,并对检测性能(如线性动态检测范围)进行了系统研究。基于近红外分布式反馈激光器和电光调制器,搭建了外差相敏色散甲烷气体检测系统,通过探索和分析电光调制器的最佳工作区间,实现了双边带拍频抑制进而得到了大幅值、高信噪比的色散相位信号。测量了典型高频(1.2 GHz)强度调制下甲烷/氮气标气的色散相位信号,获取了色散相位信号峰峰值随气体浓度的变化规律。同时开展了波长调制光谱技术实验,对两种技术的线性度、检测动态范围和对光功率波动的抗干扰性能进行对比研究。最后,通过测量不同浓度的标气验证了该系统在宽动态、快速时间响应下的性能。所开发的基于外差相敏色散光谱技术的甲烷检测系统具有线性度高(R^(2)=0.9999),动态检测范围宽(38.5 ppm~40%),且对光功率波动免疫性高的显著优势。本文研发的基于外差相敏色散光谱技术的气体检测技术在宽动态范围检测和实际现场检测应用领域具有广阔的前景。

关键词：相敏检测色散光谱双边带拍频抑制甲烷检测宽动态范围

双有源桥串联欠谐振变换器的最小回流电流控制

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电工技术学报 2024年第14期39卷 4480-4494页

作者：高祎韩周子航张欣马皓浙江大学电气工程学院杭州310027 浙江大学杭州国际科创中心杭州310027 浙江大学伊利诺伊大学厄巴纳香槟校区联合学院海宁311200

该文采用时域分析法对双有源桥串联欠谐振电路进行了分析,得到电感电流在稳态时的表达式并推导所有开关管实现软开关的条件。由于电压增益偏离1时仅采用移相控制难以实现所有开关管的软开关,因此,该文在传统移相控制的基础上,引入额外... 详细信息

该文采用时域分析法对双有源桥串联欠谐振电路进行了分析,得到电感电流在稳态时的表达式并推导所有开关管实现软开关的条件。由于电压增益偏离1时仅采用移相控制难以实现所有开关管的软开关,因此,该文在传统移相控制的基础上,引入额外的变频控制策略,使得电路在不同的电压增益和负载条件下都能有较好的软开关性能。然而,软开关的实现会增加电路的回流电流,影响电路的传输效率。该文对所提出的变频移相控制进行了进一步的优化,使其可以在确保电路实现软开关的同时产生最小的回流电流和电感电流有效值。所提出的控制策略在一台2 kW的样机中进行了验证。

关键词：双有源桥串联欠谐振变换器软开关最小回流电流控制变频控制