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Service Function Chain Migration in LEO Satellite Networks

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China Communications 2024年第3期21卷 247-259页

作者： Geng Yuhui Wang Niwei Chen Xi Xu Xiaofan Zhou Changsheng Yang Junyi Xiao Zhenyu Cao Xianbin school of Electronic and information Engineering Beihang UniversityBeijing 100191China key laboratory of Advanced technology of Near Space information System Ministry of Industry and Information Technology of ChinaBeijing 100191China shanghai key laboratory of Satellite Network Shanghai 201204China shanghai Satellite Network Research Institute Co. Ltd.Shanghai 201204China

With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)satellite *** due to the scarcity of bandwidth resources and dynamic topology of LEO satellites,the static SFC placement schemes may cause performance degradation,resource waste and even service *** this paper,we consider migration and establish an online migration model,especially considering the dynamic *** the scarcity of bandwidth resources,the model aims to maximize the total number of accepted SFCs while incurring as little bandwidth cost of SFC transmission and migration as *** to its NP-hardness,we propose a heuristic minimized dynamic SFC migration(MDSM)algorithm that only triggers the migration procedure when new SFCs are *** results demonstrate that MDSM achieves a performance close to the upper bound with lower complexity.

关键词： network function virtualization(NFV) resource allocation satellite networks service function chain(SFC) SFC migration SFC placement soft-ware defined network(SDN)

On-chip ultra-high rejection and narrow bandwidth filter based on coherency-broken cascaded cladding-modulated gratings

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Photonics Research 2024年第5期12卷 979-985页

作者： JINZHAO WANG TING LI YANG FENG JIEWEN LI WANXIN LI LUWEI DING YONG YAO JIANAN DUAN WEI LIU FENG HE YI ZOU XIAOCHUAN XU Guangdong Provincial key laboratory of Integrated Photonic-Electronic Chip Guangdong Provincial Key Laboratory of Aerospace Communication and Networking TechnologyHarbin Institute of TechnologyShenzhenShenzhen 518055China school of information Science and technology ShanghaiTech UniversityShanghai 201210China

Bragg filters are of essential importance for chip-scale photonic ***,the implementation of filters with sub-nanometer bandwidth and rejection beyond 70 dB is hindered by the high index contrast of the siliconon-insulator platform,which makes filters prone to fabrication *** this paper,we propose to combine coherency-broken cascading architecture and cladding modulation to circumvent the intrinsic *** cascading architecture effectively prevents the accumulation of phase errors,while the cladding modulation offers additional design freedom to reduce the coupling coefficient.A bimodal Bragg filter with a testingequipment-limited rejection level of 74 dB and a 40 dB bandwidth of 0.44 nm is experimentally *** minimum feature size is 90 nm,which significantly relieves the fabrication constraints.

关键词： filter cladding narrow

CPT: a pre-trained unbalanced transformer for both Chinese language understanding and generation

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Science China(information Sciences) 2024年第5期67卷 43-55页

作者： Yunfan SHAO Zhichao GENG Yitao LIU Junqi DAI Hang YAN Fei YANG Zhe LI Hujun BAO Xipeng QIU school of Computer Science Fudan University shanghai key laboratory of Intelligent information Processing Fudan University Zhejiang Lab

In this paper, we take the advantage of previous pre-trained models(PTMs) and propose a novel Chinese pre-trained unbalanced transformer(CPT). Different from previous Chinese PTMs, CPT is designed to utilize the shared knowledge between natural language understanding(NLU) and natural language generation(NLG) to boost the performance. CPT consists of three parts: a shared encoder, an understanding decoder, and a generation decoder. Two specific decoders with a shared encoder are pretrained with masked language modeling(MLM) and denoising auto-encoding(DAE) tasks, *** the partially shared architecture and multi-task pre-training, CPT can(1) learn specific knowledge of both NLU or NLG tasks with two decoders and(2) be fine-tuned flexibly that fully exploits the potential of the model. Moreover, the unbalanced transformer saves the computational and storage cost, which makes CPT competitive and greatly accelerates the inference of text generation. Experimental results on a wide range of Chinese NLU and NLG tasks show the effectiveness of CPT.

关键词： pre-trained model transformer language model generation unified model

Four-dimensional direct detection receiver enabling Jones-space field recovery with phase and polarization diversity

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Photonics Research 2024年第3期12卷 399-410页

作者： QI WU YIXIAO ZHU XUEYANG LI HEXUN JIANG CHEN CHENG MENGFAN FU YIKUN ZHANG QUNBI ZHUGE ZHAOHUI LI WEISHENG HU Peng Cheng laboratory Shenzhen 518055China State key laboratory of Advanced Communication Systems and Networks Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghai 200240China school of Electronics and information technology and Guangdong Provincial key laboratory of Optoelectronic information Processing Chips and Systems Sun Yat-sen UniversityGuangzhou 510006China

Data centers,the engines of the global Internet,rely on powerful high-speed optical *** optical fiber communication,classic direct detection captures only the intensity of the optical field,while the coherent detection counterpart utilizes both phase and polarization diversities at the expense of requiring a narrow-linewidth and high-stability local oscillator(LO).Herein,we propose and demonstrate a four-dimensional Jones-space optical field recovery(4-D JSFR)scheme without an *** polarization-diverse full-field receiver structure captures information encoded in the intensity and phase of both polarizations,which can be subsequently extracted *** our knowledge,our proposed receiver achieves the highest electrical spectral efficiency among existing direct detection systems and potentially provides similar electrical spectral efficiency as standard intradyne coherent detection *** fully recovered optical field extends the transmission distance beyond the limitations imposed by fiber chromatic ***,the LO-free advantage makes 4-D JSFR suitable for photonic integration,offering a spectrally efficient and cost-effective solution for massively parallel data center *** results may contribute to the ongoing developments in the theory of optical field recovery and the potential design considerations for future high-speed optical transceivers.

关键词： polarization receiver phase

A Piezoelectrically Driven Microrobot Using a Novel Monolithic Spatial Parallel Mechanism as Its Hip Joint

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Journal of Bionic Engineering 2024年第2期21卷 803-820页

作者： Guangping Wu Ziyang Wang Jiaxin Zhao Feng Cui Xinghan Cai National key laboratory of Advanced Micro and Nano Manufacture technology Shanghai Jiao Tong UniversityShanghai200240China Department of Micro-Nano Electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai200240China

Inspired by the fast,agile movements of insects,we present a 1.9 g,4.5 cm in length,piezoelectrically driven,quadrupedal *** microrobot uses a novel spatial parallel mechanism as its hip joint,which consists of two spatially orthogonal slider-crank *** mechanism maps two inputs of two independent actuators to the decoupled swing and lift outputs of a leg,and each leg can produce the closed trajectories in the sagittal plane necessary for robot ***,the kinematics of the transmission are analyzed,and the parameters of the flexure hinges are designed based on geometrical constraints and yield *** hip joints,legs and exoskeletons are integrated into a five-layer standard laminate for monolithic fabrication which is composed of two layers of carbon fiber,two layers of acrylic adhesive and a polyimide *** measured output force(15.97 mN)of each leg is enough to carry half of the robot’s weight,which is necessary for the robot to move *** has been proven that the robot can successfully perform forward and turning *** to the microrobot fabricated with discrete components,the monolithically fabricated microrobot is more capable of maintaining the original direction of locomotion when driven by a forward signal and has a greater speed,whose maximum speed is 25.05 cm/s.

关键词： Insect-like Crawling microrobot Piezoelectric drive Parallel mechanism Monolithic fabrication

Rheological Behaviors of Polymers with Nanoparticles Tethered at Each End

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Chinese Journal of Polymer Science 2024年第3期42卷 400-406,I0009页

作者： Song-Qi Zhang Wen-Qing Wang Jia-Ping Lin Li-Quan Wang shanghai key laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

The polymer with nanoparticles tethered at each end is a unique model for unraveling the effect of chain ends on the polymer dynamics. We investigated the rheological behavior of this kind of polymer by using nonequilibrium molecular dynamics simulation. The effect of polymer lengths and nanoparticle radii on the complex moduli and viscosity was examined. The dependence of complex moduli on the frequency becomes less pronounced as the polymer is short or the nanoparticle is large. The shear thinning behavior was revealed for these systems, and the scaling exponent of complex viscosity with respect to the frequency was found to change from-1/2 to-3/4 as the polymer shortens or the nanoparticle enlarges. The rheological behavior was further explained by analyzing the mean square distance of nanoparticles. The simulation results were compared with the existing experimental finding, showing an agreement. The work provides information for understanding the chain end effect on polymer rheology.

关键词： Polymer rheology Modulus Viscosity Molecular dynamics

ChatGPT: potential, prospects, and limitations

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Frontiers of information technology & Electronic Engineering 2024年第1期25卷 6-11页

作者： Jie ZHOU Pei KE Xipeng QIU Minlie HUANG Junping ZHANG school of Computer Science Fudan UniversityShanghai 200433China Department of Computer Science and technology Tsinghua UniversityBeijing 100084China shanghai key laboratory of Intelligent information Processing Shanghai 200433China

Recently,OpenAI released Chat Generative Pre-trained Transformer(ChatGPT)(Schulman et al.,2022)(https://***),which has attracted considerable attention from the industry and academia because of its impressive *** is the first time that such a variety of open tasks can be well solved within one large language *** better understand ChatGPT,we briefly introduce its history,discuss its advantages and disadvantages,and point out several potential ***,we analyze its impact on the development of trustworthy artificial intelligence,conversational search engine,and artificial general intelligence.

关键词： artificial limitations intelligence

Enhanced electrochemical performance of Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3) solid electrolyte by anion doping

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Nano Research 2024年第3期17卷 1465-1472页

作者： Jingrui Kang Xu Guo Rui Gu Honglei Hao Yi Tang Jiahui Wang Li Jin Hongfei Li Xiaoyong Wei Electronic Materials Research laboratory Key Laboratory of the Ministry of Education&International Center for Dielectric ResearchSchool of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049China school of Energy and Materials Shanghai Key Laboratory of Engineering Materials Application and EvaluationShanghai Polytechnic UniversityShanghai 201209China

Nowadays,the majority of the studies on the substitution are focused on cations(such as Y^(3+),Ti^(4+),P^(5+),etc.)in Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP),while there are few studies on the substitution of anion O^(2-).In this work,the modified LATP with a series of LiCl(LATPClx,x=0.1,0.2,0.3,0.4)additives is prepared to enhance ionic *** successful introduction of Cl-makes the length of the c axis decrease from 20.822(2)to 20.792(1)Å,and the bulk conductivity of 2.13×10^(-3) S·cm^(-1) is achieved in LATPCl_(0.3).Moreover,the Al/Ti-O1/Cl1 and Al/Ti-O_(2)/Cl_(2) distance decrease,while the Li1-O_(2)/Cl_(2) distance *** ions migrate more easily in the nanochannel of *** addition,the LiCl additive increases the relative density and the grain boundary conductivity of LATPClx ***,a higher ionic conductivity of 2.12×10^(–4) S·cm^(-1) and a low activation energy of 0.30 eV are obtained in LATPCl_(0.3).Correspondingly,the symmetric cell exhibits a low overpotential of±50 mV for over 200 h in LATPCl_(0.3).The solid-state Li|LATPCl_(0.3)|NCM811(NCM811=LiNi0.8Co0.1Mn0.1O_(2))battery exhibits high initial capacity 185.1 mAh·g^(-1) with a capacity retention rate of 95.4%after 100 cycles at 0.5 *** result suggests that LiCl additive is an effective strategy to promote electrochemical properties of LATP solid electrolyte and can be considered for reference to other inorganic solid electrolytes systems.

关键词： Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)solid electrolyte anion doping ionic conductivity cyclic performance

Multistep continuous flow synthesis of Erlotinib

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Chinese Chemical Letters 2024年第4期35卷 371-375页

作者： Hui Jin Qin Cai Peiwen Liu Yan Chen Derong Wang Weiping Zhu Yufang Xu Xuhong Qian State key laboratory of Bioreactor Engineering Shanghai Key Laboratory of Chemical BiologySchool of PharmacyEast China University of Science and TechnologyShanghai 200237China

Erlotinib is an orally administered, highly effective, specific epidermal growth factor receptor tyrosine kinase inhibitor, used to treat non-small cell lung cancer and pancreatic cancer. The traditional synthetic methods for Erlotinib exhibit long reaction time and safety concern. Herein, we describe a novel five-step route for the synthesis of Erlotinib in flow. These five steps comprise etherification, nitration, reduction,addition and cyclization reactions. All steps were optimized and converted to continuous flow process,which drastically reduces the reaction time and considerably improves the process safety as well as the total yield. Enabled by five continuous flow units, Erlotinib is efficiently afforded with an E-factor of 38,an overall yield of 83%, and a total residence time of 25.1 min. Majority steps in this process have been optimized for quantitative conversion, which offers the possibility of telescoping the entire process.

关键词： Erlotinib Continuous flow synthesis Microchannel flow reactor Process optimization Continuous nitration Continuous hydrogenation