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Debris classification method based on photometric series

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Journal of Beijing Institute of Technology 2016年第S2期25卷 161-165页

作者：秦记东彭华峰王斌 National Digital Switching System Engineering & technological R&D center

Space debris classification is significant for debris catalog and early warning.A space debris classification method using photometric sequence obtained from ground based optical telescopes was ***,the photometric data was analyzed and the debris size was estimated from *** 2 characteristic values could be obtained,namely the size mean value and *** motion attitude was divided into three-axis-stabilized,spin-stabilized and random-tumbling by frequency-domain characteristics of estimated size,and it was used as the 3 rd ***,the normalization and credibility methods were introduced to equalize 3 characteristics when constructing characteristic ***,debris was classified using maximum probably criterion with Gaussian mixture models,due to the debris’ variety of observation arcs with different *** simulation shows that success rate is more than 90% in classification of 4 kinds of debris.

关键词： space debris photometric series debris classification size estimation motion attitude

Controllable single accumulated state-sequential acquisition with low signal noise ratio

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Science in China(Series F) 2009年第5期52卷 858-866页

作者： JI Jiang HUANG KaiZhi JIN Liang ZHANG LiZhi ZHANG Meng National Digital Switching System Engineering & technological Research center Zhengzhou 450002 China

The sequential estimation （SE） algorithm has a poor performance in the environment with a low signalto-noise ratio （SNR） and a high bit error rate （BER）, especially for unknown initial acquisition sequence. This paper summarizes the conventional sequence acquisition model, and discovers its several problems, which are caused by accumulating sequence innovation to all of the received sequences dispersedly. To solve these problems, the paper presents a new algorithm, CSAS-SA （controllable single accumulated state-sequential acquisition）. This algorithm accumulates the sequence innovation to a single appointed sequence state and makes the useful information accumulated effectively. Through simulation, CSAS-SA has a higher probability of success acquisition. When SNR equals -3 dB, the performance can be improved by 70%.

关键词： pseudo-noise (PN) sequence single accumulated state sequential acquisition control state

Preparation and upconversion luminescence of YAG(Y_3Al_5O_(12)):Yb^(3+),Ho^(3+) nanocrystals

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Journal of Rare Earths 2009年第1期27卷 66-70页

作者：刘敏王士维唐定远陈立东马建 Structural Ceramics Engineering Research center Energy Materials Research Center Shanghai Institute of Ceramics Chinese Academy of Sciences School of Electrical & Electronic Engineering Nanyang Technological University Energy Materials Research center Shanghai Institute of Ceramics Chinese Academy of Sciences School of Materials Science and Engineering Nanyang Technological University

Cubic YAG：Yb3＋, Ho3＋ pure phase nanocrystals were synthesized by using coprecipition nitrate and ammonium hydrogen carbonate as raw *** calcining the precipitates at 800 °C, the resultant YAG：Yb3＋, Ho3＋ nanocrystals were nearly spheric and the particle size was about 40 *** upconversion spectra were observed on the powder compact pumped by a 980 nm continuous wave diode laser, and green emission centered at 549 nm, red emission centered at 667 nm, and NIR centered at 760 nm were all due to two photons process, which originated from 5S2（5F4）→5I8, 5F5→5I8, and 5S2（5F4）→5I7 transitions, respectively.

关键词： chemical synthesis nanoparticle upconversion luminescence rare earths 1

Minimizing treatment complexity of combat-related soft tissue injuries using a dedicated tension relief system and negative pressure therapy augmented by high-dose in situ antibiotic therapy and oxygen delivery: a retrospective study

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Burns & Trauma 2021年第1期9卷 454-463页

作者： Moris Topaz Itamar Ashkenazi Oren Barzel Seema Biswas Dan Atar Nurit Shadmi Itzhak Siev-Ner Sheba Medical center Ramat GanIsrael Hillel Yaffe Medical center HaderaIsrael Rambam Medical center HaifaIsrael galilee Medical center NahariyaIsrael Soroka Medical center Beer ShevaIsrael Adi Negev Rehabilitation Hospital MerhavimIsrael

Background:Following combat-related,extensive soft tissue injury from gunshot wounds or blasts,prolonged duration from injury to full wound closure is associated with infection,increased morbidity and mortality,failure to mobilize,poor functional outcome and increased *** purpose of this study was to evaluate a novel treatment enabling early primary closure of combat ***:This was a retrospective study of 10 soldiers and civilians with extensive combat-related soft tissue limb injuries(5 gunshot wounds,5 blasts)treated using the TopClosure^(■)Tension Relief System(TRS)with simultaneous administration of regulated oxygen-enriched and irrigation negative pressure-assisted wound therapy(ROINPT)via the Vcareα^(■)***:Nine patients were treated during the acute phase of injury and one was treated following removal of a flap due to deep infection 20 years after injury and flap *** patients had upper limb injury and the rest lower limb *** the aid of the TRS and/or ROINPT,immediate primary closure during reconstruction was achieved in 6 patients and delayed primary closure in *** one patient required a skin graft to close a small area of the wound after most of the wound had been closed by delayed primary *** closure was achieved within 0–37 days(median:12.5 days,interquartile range:2.75–19.75)from ***:The TRS is a novel device for effective,early skin stretching and secure wound closure through the application of stress relaxation and mechanical creep,achieving primary closure of large defects using a simplified surgical technique and reducing the need for closure using skin grafts and flaps and the use of tissue *** supplemental oxygen to the wound by ROINPT reverses the reduced oxygen levels inherent in conventional negative pressure-assisted wound therapy,mitigating anaerobic contamination and reducing *** may accelerate the evacuation of infectious materia

关键词： Soft tissue injury Combat injuries Limb injuries Stress relaxation Mechanical creep Tension relief systems

Strain-Modulated Photoelectric Responses from a Flexibleα-In_(2)Se_(3)/3R MoS_(2)Heterojunction

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Nano-Micro Letters 2021年第7期13卷 1-11页

作者： Weifan Cai Jingyuan Wang Yongmin He Sheng Liu Qihua Xiong Zheng Liu Qing Zhang center for Micro-and Nano-Electronics School of Electrical and Electronic EngineeringNanyang Technological UniversitySingapore 639798Singapore School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 639798Singapore

Semiconducting piezoelectricα-In_(2)Se_(3) and 3R MoS_(2) have attracted tremendous attention due to their unique electronic *** van der Waals(vdWs)hetero-structures constructed withα-In_(2)Se_(3)and 3R MoS_(2)flakes have shown promising applications in optoelectronics and ***,we present the first flexibleα-In_(2)Se_(3)/3R MoS_(2)vdWs p-n heterojunction devices for photodetection from the visible to near infrared *** heterojunction devices exhibit an ultrahigh photoresponsivity of 2.9×10^(3)A W^(−1) and a substantial specific detectivity of 6.2×10^(10) Jones under a compressive strain of−0.26%.The photocurrent can be increased by 64%under a tensile strain of+0.35%,due to the heterojunction energy band modulation by piezoelectric polarization charges at the hetero-junction *** work demonstrates a feasible approach to enhancement of α-In_(2)Se_(3)/3R MoS_(2) photoelectric response through an appropriate mechanical stimulus.

关键词： α-In_(2)Se_(3)/3R MoS_(2)heterojunction Flexible Self-powered photodetector Strain modulation Piezoelectric charge

A secure routing model based on distance vector routing algorithm

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Science China(Information Sciences) 2014年第1期57卷 137-149页

作者： WANG Bin WU ChunMing YANG Qiang LAI Pan LAN JuLong GUO YunFei College of Computer Science Zhejiang University College of Electrical Engineer Zhejiang University School of Computer Engineering Nanyang Technological University National Digital Switching System Engineering and technological Research center

Distance vector routing protocols have been widely adopted as an efcient routing mechanism in current Internet,and many wireless ***,as is well-known,the existing distance vector routing protocols are insecure as it lacks of efective authorization mechanisms and routing updates aggregated from other *** a result,the network routing-based attacks become a critical issue which could lead to a more deteriorate performance than other general network *** efciently address this issue,this paper,through analyzing the routing model and its security aspect,and presents a novel approach on guaranteeing the routing *** on the model,we present the security mechanism including the message exchange and update message security authentication *** suggested approach shows that the security mechanism can efectively verify the integrity and validate the freshness of routing update messages received from neighbor *** comparison with exiting mechanisms(SDV,S-RIP etc),the proposed model provides enhanced security without introducing significant network overheads and complexity.

关键词： routing security distance vector auxiliary trustable model authentication metric

A Novel 1×2 Thermo-Optic Multimode Interference Switch Structure Based on Photodefinable Benzocyclobutene （BCB 4024-40） Polymer on Silica

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Chinese Physics Letters 2006年第10期23卷 2796-2798页

作者： M.H.Ibrahim Mee-Koy Chin N.M.Kassim A.B.Mohammad Photonics Research Croup Universiti Teknologi Malaysia Johor Malaysia Photonics Research center Nanyang Technological University Singapore

A novel 1× 2 multimode interference photonics switch structure based on thermal controlling effect is proposed. A ridge waveguide of photosensitive polymer, benzocyclobutene （BCB 4024-40） on silica clad is used as a design structure. A temperature changes as a result of electrode heating are analysed by employing a two-dimensional finite difference thermal model considering both conduction and convection mechanisms. The switching characteristics due to changes in effective index are analysed by the two-dimensional finite difference beam propagation method with transparent boundary condition. The proposed structure works well with low crosstalk level of -28 dB and low switching power relatively to the structural upper cladding thickness.

关键词： WAVE-GUIDES

Synthesis of ZrSiN composite films using a plasma focus device

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Chinese Physics B 2014年第6期23卷 381-386页

作者： R.Ahmad T.Hussain I.A.Khan R.S.Rawat center for Advanced Studies in Physics GC University Physics Department GC Universit National Institute of Education Nanyang Technological University

ZrSiN thin films are synthesized by using plasma focus through various numbers of focus shots （10, 20, and 30）, with samples placed at 9 cm away from the tip of the anode. Crystal structures, surface morphologies, and elemental compositions of ZrSiN films are characterized by an X-ray diffractometer （XRD） and scanning electron microscope （SEM） attached with energy dispersive X-ray spectroscopy （EDS）. XRD patterns confirm the formations of polycrystalline ZrSiN films. Crystallinity of nitride increases with the increase of focus shot number. The average crystallite size of zirconium nitride increases from 27 ± 3 nm to 73±8 nm and microstrain decreases from 2.28 to 1.0 with the increase of the focus shot number. SEM results exhibit the formations of granular and oval-shaped microstructures, depending on the number of focus shots. EDS results confirm the presences of silicon, zirconium, nitrogen, and oxygen in the composite films. The content values of Zr and N in the composite films increase with the increase of the focus shot number.

关键词： DPF ZrSiN thin films XRD SEM

High-precision magnetic field measurement system based on a coherent population trapping magnetometer onboard the SATech-01 satellite

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Science China technological Sciences 2025年

作者： Hongbo XUE Wei SONG Haoran ZHAO Yiteng ZHANG Shanzhi YE Jindong WANG Ran TAO Peng SANG Keli CHEN Xingzi BI Bingjun CHENG Bin ZHOU Yongliang XUE Yingying TANG Liu LIU Jinsong LI Xiaocheng ZHU Baoquan LI Jinguo LIU Wen CHEN Xiaofeng ZHANG Yonghe ZHANG Lei LI State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences Key Laboratory of Solar Activity and Space Weather National Space Science Center Chinese Academy of Sciences Key Laboratory of Electronics and Information Technology for Space Systems National Space Science Center Chinese Academy of Sciences State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Innovation Academy for Microsatellites Chinese Academy of Sciences

On July 27, 2022, a high-precision system for measuring the magnetic field based on a coherent population trapping magnetometer（referred to as the CPT system） was launched onboard the Space Advanced Technology demonstration satellite（SATech-01） by a ZK-1A rocket. The payload comprises a scalar coherent population trapping magnetometer（CPTM）, triaxial anisotropic magnetoresistance magnetometer（AMRM）, and nano star tracker mounted on a non-magnetic telescopic tubular mast. This configuration enables synchronized measurement of scalar and vector geomagnetic fields, as well as the attitude,making the payload with its compact sensors suitable for applications on miniature satellite platforms. On November 7, 2022,the novel telescopic tubular mast was deployed in orbit, extending to a length of 5.28 m. The CPTM, an absolute scalar magnetometer with an omnidirectional sensor, is the first China-developed quantum/atomic magnetometer successfully operating in space. In orbit, the CPTM has sensitivity of ～10 pT/Hz1/2and can automatically operate under complex magnetic field variations. The difference between the scalar fields obtained using the CPTM and CHAOS model has a mean deviation of–3.73 n T and a standard deviation of 26.11 nT（1σ）, without on-orbit calibration or correction. The miniaturized AMRM has a sensitivity of ～0.3 n T/Hz1/2and maintains stable and reliable operation in orbit. The low-power and miniaturized nano star tracker has a measurement uncertainty of 14.23″（1σ） in orbit. The mission has realized the on-orbit technical verification of the integrated and synchronized detection of the vector magnetic field and attitude and fully validated the system's performance,automation level, and reliability.

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