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A novel(Sm_(0.2)Eu_(0.2)Gd_(0.2)Ho_(0.2)Yb_(0.2))CrO_(3)high-entropy ceramic nanofiber as a negative temperature coefficient thermistor

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Journal of Rare Earths 2024年第10期42卷 1937-1942页

作者： Weijun Zhao Meng zhang Liyan Xue Kaixian Wang Fan yang Jiuping zhong Heng chen School of Materials Sun Yat-sen UniversityShenzhen518107China Xiamen Institute of Rare Earth Materials Haixi InstituteChinese Academy of SciencesXiamen361021China Xiamen key laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen361021China Fujian science&technology Innovation laboratory for Optoelectronic information of china Fuzhou350108China Advanced Energy science and technology Guangdong laboratory Huizhou516003China Sichuan Jcc Rare Earth Metals New Material Co. Ltd.Chengdu610000China

The electrical properties of high-entropy ceramics(HECs)have been extensively studied in recent years due to their unique structural characteristics and fascinating functional properties induced by entropy *** high-entropy(Sm_(0.2)Eu_(0.2)Gd_(0.2)Ho_(0.2)Yb_(0.2))CrO_(3)(HE-RECrO_(3))nanofibers were prepared by electro *** work demonstrates that HE-RECrO_(3)nanofibe rs were successfully synthesized at a low temperature(800℃),which is approximately 400℃lower than the temperatures at which chromate ceramics were synthesized via the sol-gel method and the solid-state reaction *** resistivity of HE-RECrO_(3)nanofibers decreases exponentially with increasing temperature from 25 to600℃.The logarithm of the resistivity is linearly related to the inverse of the temperature,confirming the negative temperature coefficient property of HE-RECrO_(3)*** B_(25/50)value of the HERECrO_(3)nanofibers reaches 4072 *** conclusion,HE-RECrO_(3)nanofibers are expected to be potential candidates for negative-temperature-coefficient(NTC)thermistors.

关键词： Rare earths High-entropy ceramics Ceramic fiber materials Negative temperature coefficient thermistors

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A state of art review on time series forecasting with machine learning for environmental parameters in agricultural greenhouses

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information Processing in Agriculture 2024年第2期11卷 143-162页

作者： Gedi Liu Keyang zhong Huilin Li Tao chen yang Wang national Innovation Center for Digital Fishery China Agricultural University100083 BeijingChina key laboratory of Smart Farming Technologies for Aquatic Animal and Livestock Ministry of Agriculture and Rural AffairsChina Agricultural University100083 BeijingChina beijing Engineering and technology Research Center for Internet of Things in Agriculture China Agricultural University100083 BeijingChina College of information and Electrical Engineering China Agricultural University100083 BeijingChina department of Chemical and Process Engineering University of SurreyGU27XH GuildfordUnited Kingdom

Agricultural greenhouse production has to require a stable and acceptable environment,it is therefore essential for future greenhouse production to obtain full and precisely internal dynamic environment *** modeling based on machine learning methods,e.g.,intelligent time series prediction modeling,is a popular and suitable way to solve the above *** this article,a systematic literature review on applying advanced time series models has been systematically conducted via a detailed analysis and evaluation of 61 pieces selected from 221 *** historical process of time series model application from the use of data and information strategies was first ***,the accuracy and generalization of the model from the selection of model parameters and time steps,providing a new perspective for model development in this field,were compared and ***,the systematic review results demonstrate that,compared with traditional models,deep neural networks could increase data structure mining capabilities and overall information simulation capabilities through innovative and effective structures,thereby it could also broaden the selection range of environmental parameters for agricultural facilities and achieve environmental prediction end-to-end optimization via intelligent time series model based on deep neural networks.

关键词： Horticultural greenhouse environment Time series algorithms Prediction Deep neural networks

A Blind Batch Encryption and Public Ledger-Based Protocol for Sharing Sensitive Data

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china Communications 2024年第1期21卷 310-322页

作者： Zhiwei Wang Nianhua yang Qingqing chen Wei Shen Zhiying zhang School of Computer sciences Nanjing University of Posts and TelecommunicationsNanjing 210023China Dept.of intelligent science and information Law East China University of Political Science and LawShanghai 201620China key laboratory of Computational science and Application of Hainan Province Hainan Normal UniversityHaikou 571158China state key laboratory of Public Big Data Guizhou UniversityGuizhou 550025China Yunnan key laboratory of Blockchain Application technology Yunnan Innovation Research Institute of Beijing University of Aeronautics and AstronauticsKunming 650233

For the goals of security and privacy preservation,we propose a blind batch encryption-and public ledger-based data sharing protocol that allows the integrity of sensitive data to be audited by a public ledger and allows privacy information to be *** owners can tightly manage their data with efficient revocation and only grant one-time adaptive access for the fulfillment of the *** prove that our protocol is semanticallly secure,blind,and secure against oblivious requesters and malicious file *** also provide security analysis in the context of four typical attacks.

关键词： blind batch encryption data sharing onetime adaptive access public ledger security and privacy

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Efficient Spin-Flip between Charge-Transfer states for High-Performance Electroluminescence, without an Intermediate Locally Excited state

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Research 2024年第1期2023卷 339-349页

作者： Donghai zhang Shanshan Jiang Xiaodong Tao Fulin Lin Lingyi Meng Xu-Lin chen Can-zhong Lu state key laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China Fujian science and technology Innovation laboratory for Optoelectronic information of china FuzhouFujian 350108China Xiamen key laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian 361021China university of Chinese Academy of sciences Beijing 100049China

Thermally activated delayed fluorescence(TADF)materials with both high photoluminescence quantum yield(PLQY)and fast reverse intersystem crossing(RISC)are strongly desired to realize efficient and stable organic light-emitting diodes(OLEDs).Control of excited-state dynamics via molecular design plays a central role in optimizing the PLQY and RISC rate of TADF materials but remains ***,3 TADF emitters possessing similar molecular structures,similar high PLQYs(89.5%to 96.3%),and approximate energy levels of the lowest excited singlet states(S_(1)),but significantly different spin-flipping RISC rates(0.03×10^(6) s^(−1) vs.2.26×10^(6) s^(−1))and exciton lifetime(297.1 to 332.8μs vs.6.0μs)were systematically synthesized to deeply investigate the feasibility of spin-flip between charge-transfer excited states(^(3)CT–^(1)CT)transition.

关键词： transition lifetime desired

Wearable ultrasensitive and rapid human physiological monitoring based on microfiber Sagnac interferometer

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science china(information sciences) 2024年第3期67卷 281-290页

作者： Xin WANG Hongyou ZHOU Meihua chen Yongcheng HE Zhishen zhang Jiulin GAN zhongmin yang state key laboratory Luminescent Materials and Devices Institute of Optical Communication MaterialsSpecial Glass Fiber and Device Engineering Technology Research and Development Center of Guangdong ProvinceGuangdong Provincial Key Laboratory of Fiber Laser Materials and Applied TechniquesSouth China University of Technology Guangdong-Hong Kong-Macao Joint laboratory for intelligent Micro-Nano Optoelectronic technology Foshan University

High-sensitive and fast-responding flexible strain sensors are essential for the smart wearable devices that precisely and dynamically perceive the weak deformations induced by human physiological signals. Here, a flexible strain sensor via polydimethylsiloxane(PDMS)-encapsulated microfiber Sagnac interferometer was designed and prepared for monitoring the human pulse signals and sound vibrations. The sensor achieved a record-breaking sensitivity(gauge factor, GF = 9977) and an extremely low detection limit(0.00025%) due to the strong polarization-dependent coupling effect in the microfiber coupler and the polarization-mixing effect in the Sagnac loop. The relative intensity demodulation method also enabled a fast response time of 10 μs. The wearable pulse measurements were implemented by attaching this flexible strain sensor directly to human skin at various locations and the waveform details were accurately captured. Taking advantage of the ultra-high sensitivity and fast response performance of the prepared sensor, the real-time dynamic acquisition of the underwater weak signal, such as the hydro-acoustic waves with a wide range of 20 Hz–16.86 k Hz, has been demonstrated. These initial results pave the way for a new and innovative category of underwater wearable devices with rapid detection of human physiological signals and weak environmental vibrations.

关键词： flexible strain sensor microfiber Sagnac interferometer underwater detection

Chiral transmission by an open evolution trajectory in a non-Hermitian system

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Light(science & Applications) 2024年第4期13卷 628-636页

作者： Xiaoqian Shu Qi zhong Kai Hong Oubo You Jian Wang Guangwei Hu Andrea Alù Shuang zhang Demetrios N.Christodoulides Lin chen Wuhan national laboratory for Optoelectronics and School of Optical and Electronic information Huazhong University of Science and TechnologyWuhan 430074China. Zhejiang Lab Hangzhou 311121China. CREOL College of Optics and PhotonicsUniversity of Central FloridaOrlandoFlorida 32816USA. department of Physics The University of Hong KongHong KongChina. School of Electrical and Electronic Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore. Photonics Initiative Advanced Science Research CenterCity University of New YorkNew YorkNY 10031USA. Shenzhen Huazhong university of science and technology Research Institute Shenzhen 518063China

Exceptional points(EPs),at which two or more eigenvalues and eigenstates of a resonant system coalesce,are associated with non-Hermitian Hamiltonians with gain and/or loss *** encircling of EPs has received significant interest in recent years,as it has been shown to lead to highly nontrivial phenomena,such as chiral transmission in which the final state of the system depends on the encircling ***,chiral transmission for a pair of eigenmodes has been realized by establishing a closed dynamical trajectory in parity-time-(PT-)or anti-PT-symmetric *** chiral transmission of symmetry-broken modes,more accessible in practical photonic integrated circuits,has been realized by establishing a closed trajectory encircling EPs in anti-PTsymmetric systems,the demonstrated transmission efficiency is very low due to path-dependent ***,we demonstrate chiral dynamics in a coupled waveguide system that does not require a closed ***,we explore an open trajectory linking two infinite points having the same asymptotic eigenmodes(not modes in PT-and anti-PT-symmetric systems),demonstrating that this platform enables high-efficiency chiral transmission,with each eigenmode localized in a single *** concept is experimentally implemented in a coupled silicon waveguide system at telecommunication *** work provides a new evolution strategy for chiral dynamics with superior performance,laying the foundation for the development of practical chiral-transmission devices.

关键词： chiral system symmetric

Predicting influenza-like illness trends based on sentinel surveillance data in china from 2011 to 2019:A modelling and comparative study

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Infectious Disease Modelling 2024年第3期9卷 816-827页

作者： Xingxing zhang Liuyang yang Teng chen Qing Wang Jin yang Ting zhang Jiao yang Hongqing Zhao Shengjie Lai Luzhao Feng Weizhong yang School of Population Medicine and Public Health Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing100073China state key laboratory of Respiratory Health and Multimorbidity China key laboratory of Pathogen Infection Prevention and Control(Peking Union Medical College) Ministry of EducationChina national key laboratory of intelligent Tracking and Forecasting for Infectious Diseases National Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionChina department of Management science and information System Faculty of Management and EconomicsKunming University of Science and TechnologyKunming650506China department of Applied Mathematics&Statistics Stony Brook UniversityStony BrookNY11794-3600USA WorldPop School of Geography and Environmental ScienceUniversity of SouthamptonSouthamptonSO171BJUK

Background Influenza is an acute respiratory infectious disease with a significant global disease ***,the coronavirus disease 2019 pandemic and its related non-pharmaceutical interventions(NPIs)have introduced uncertainty to the spread of ***,comparative studies on the performance of innovative models and approaches used for influenza prediction are ***,this study aimed to predict the trend of influenza-like illness(ILI)in settings with diverse climate characteristics in china based on sentinel surveillance data using three approaches and evaluate and compare their predictive *** The generalized additive model(GAM),deep learning hybrid model based on Gate Recurrent Unit(GRU),and autoregressive moving average-generalized autoregressive conditional heteroscedasticity(ARMA—GARCH)model were established to predict the trends of ILI 1-,2-,3-,and 4-week-ahead in beijing,Tianjin,Shanxi,Hubei,Chongqing,Guangdong,Hainan,and the Hong Kong Special Administrative Region in china,based on sentinel surveillance data from 2011 to *** relevant metrics,namely,Mean Absolute Percentage Error(MAPE),Root Mean Squared Error(RMSE),and R squared,were calculated to evaluate and compare the goodness of fit and robustness of the three *** Considering the MAPE,RMSE,and R squared values,the ARMA—GARCH model performed best,while the GRU-based deep learning hybrid model exhibited moderate performance and GAM made predictions with the least accuracy in the eight settings in ***,the models’predictive performance declined as the weeks ahead ***,blocked cross-validation indicated that all models were robust to changes in data and had low risks of *** Our study suggested that the ARMA—GARCH model exhibited the best accuracy in predicting ILI trends in china compared to the GAM and GRU-based deep learning hybrid ***,in the future,the ARMA—GARCH model may be used

关键词： Influenza-like illness Influenza Sentinel surveillance china Predicting Modeling

Playdough-like carbon electrode: A promising strategy for high efficiency perovskite solar cells and modules

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escience 2024年第2期4卷 101-107页

作者： Aodong Zhu Lin chen Ao zhang chenpu Zhu Xinxin zhang Jie zhong Fuzhi Huang Yi-Bing cheng Junyan Xiao School of Materials science and Engineering Wuhan University of Technology122 Luoshi RoadWuhanHubeiChina state key laboratory of Advanced Technologies for Materials Synthesis and Processing Wuhan University of Technology122 Luoshi RoadWuhanHubeiChina School of Chemistry and Chemical Engineering Huazhong University of Science and Technology1037 Luoyu RoadWuhanHubeiChina Research Centre for Advanced Thin Film Photovoltaics Wuhan University of Technology122 Luoshi RoadWuhanHubeiChina Jinan Municipal Bureau of Industry and information technology JinanShandongChina

Carbon-based perovskite solar cells(C-PSCs)are promising candidates for large-scale photovoltaic applications due to their theoretical low cost and high ***,the fabrication of high-performance C-PSCs with large-area electrodes remains *** this work,we propose a novel playdough-like graphite putty as top electrode in the perovskite *** electrode with soft nature can form good contact with the holetransporting layer and the conductive substrate at room temperature by a simple pressing technique,which facilitates the fabrication of both small-area devices and perovskite solar *** this preliminary research,the corresponding small devices and modules can achieve efficiencies of 20.29%(~0.15 cm^(2))and 16.01%(~10 cm^(2)),***,we analyze the limitations of the optical and electrical properties of this playdough-like graphite electrode on the device performance,suggesting a direction for further improvement of C-PSCs in the future.

关键词： Perovskite solar cells Large-area module Carbon electrode Conductive playdough

Fiber optical parametric oscillator based on photonic crystal fiber pumped with all-normal-dispersion mode-locked Yb:fiber laser

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Chinese Physics B 2014年第11期23卷 332-338页

作者：苟斗斗杨四刚张磊王小建陈宏伟陈明华谢世钟陈伟罗文勇 tsinghua national laboratory for information science and technology (TNList) Department of Electronic EngineeringTsinghua University FiberHome Telecommunication Technologies CO. Ltd

We demonstrate a cost effective, linearly tunable fiber optical parametric oscillator based on a home-made photonic crystal fiber pumped with a mode-locked ytterbium-doped fiber laser, providing linely tuning ranges from 1018 nm to 1038 nm for the idler wavelength and from 1097 nm to 1117 nm for the signal wavelength by tuning the pump wavelength and the cavity length. In order to obtain the desired fiber with a zero dispersion wavelength around 1060 rim, eight sam- ples of photonic crystal fibers with gradually changed structural parameters are fabricated for the reason that it is difficult to accurately customize the structural dimensions during fabrication. We verify the usability of the fabricated fiber experimen- tally via optical parametric generation and conclude a successful procedure of design, fabirication, and verification. A seed source of home-made all-normal-dispersion mode-locked ytterbium-doped fiber laser with 38.57 ps pulsewidth around the 1064 nm wavelength is used to pump the fiber optical parametric oscillator. The wide picosecond pulse pump laser enables a larger walk-off tolerance between the pump light and the oscillating light as well as a longer photonic crystal fiber of 20 m superior to the femtosecond pulse lasers, resulting in a larger parametric amplification and a lower threshold pump power of 15.8 dBm of the fiber optical parametric oscillator.

关键词： fiber optical parametric oscillator photonic crystal fiber mode-locked fiber laser

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