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saturation efficiency for detecting 1550 nm photons with a 2×2 array of Mo0.8Si0.2 nanowires at 2.2 K

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Photonics Research 2021年第3期9卷 389-394页

作者： Feiyan Li Hang Han Qi Chen Biao Zhang Han Bao Yue Dai Rui Ge Shuya Guo Guanglong He Yue Fei Shuchao Yang Xiaohan Wang Hao Wang Xiaoqing Jia Qingyuan Zhao Labao Zhang Lin Kang Peiheng Wu School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China

Amorphous materials are attractive candidates for fabricating the superconducting nanowire single-photon detectors(SNSPDs) due to their superior tolerance and scalability over crystalline niobium nitride. However, the reduced superconducting transition temperature degenerates both operating temperature and saturation efficiency. Herein, the SNSPD(6.5 nm thickness and 50 nm width) based on the amorphous Mo0.8Si0.2 film with a high optical absorption coefficient demonstrates close-to-unity intrinsic detection efficiency for 1550 nm photons from 75 m K to 2.2 K. Further, a high-performance array SNSPD with optimized 90 nm-width wires is also demonstrated. As-fabricated uniform 4-pixel SNSPD exhibits a saturation plateau for the photon counts at 2.2 K,which overcomes the limitation of operation at low temperature(< 1 K) for traditional amorphous SNSPDs.Coupled with superior intrinsic quantum efficiency, highly efficient photon counts, and low dark count ratio, this detector paves a way for achieving high efficiency and superior yield for large array systems.

关键词： amorphous saturation intrinsic

saturation in wavelength-division multiplexing free-space optical communication systems

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Frontiers of Optoelectronics 2019年第2期12卷 197-207页

作者： Jeremiah O. BANDELE Malcolm WOOLFSON Andrew J. PHILLIPS Department of Electrical Electronics and Computer Engineering College of EngineeringAfe Babalola UniversityAdo-EkitiEkiti StateP.M.B 5454Nigeria Department of Electrical and Electronic Engineering Faculty of EngineeringUniversity of Nottingham University ParkNottinghamNG7 2RDUK

The performance of a wavelength-division multiplexing (WDM) free-space optical (FSO) commu-nication system in a turbulent atmosphere employing optical amplifiers to improve capacity is investigated, in the presence of amplified spontaneous emission noise, scintillation, beam spreading, atmospheric attenuation and interchannel crosstalk. Using on-off keying modulation, Monte Carlo simulation techniques are used to obtain the average bit error rate and system capability due to scintillation and the effect of introducing a power control algorithm (PCA) to the system is investigated. The PCA ensures that at any receiving instant, the same turbulence- free powers are received by all the receiving lenses. The performance of various WDM FSO communication system configurations such as non-amplified systems with an adaptive decision threshold (NOAADT), non- amplified systems with a non-adaptive decision threshold, fixed gain amplified systems with an adaptive decision threshold, fixed gain amplified systems with a non- adaptive decision threshold and saturated gain amplified systems with a non-adaptive decision threshold (SOA- NADT) are investigated. Results obtained show that the SOANADT is superior to the NOAADT and the PCA is only beneficial in amplified systems.

关键词： wavelength-division multiplexing (WDM) free-space optical (FSO) communication crosstalk optical amplifier (OA) gain saturation decision threshold

Effect of Skeleton Grain Size on the saturation of Gas Hydrate in Natural Sediments

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Journal of Ocean University of China 2024年第3期23卷 676-682页

作者： XU Zhenqiang LI Yang College of Marine Sciences Ocean University of ChinaQingdao 266100China China Petroleum&Chemical Corporation Beijing 100728China

Natural gas hydrate is prospected as a new and promising,highly clean energy resource that mainly occurs in perma-frost or at continental margins.Its formation is subject to many soil conditions,such as grain size,matrix materials,pore morphology,and permeability.In this study,we propose that grain size is the most decisive parameter that affects the saturation of gas hydrate in sediments based on data from Ocean Drilling Program Leg 164 and Mallik 5L-38,which represent marine sediments and terrestrial sediments,respectively.Our study reveals that high gas hydrate saturation generally occurs in coarse-grained sand,regardless of whether sediment formation is homogeneous or inhomogeneous,and the sorting of sediments may affect the hydrate saturation to a certain degree.Using grain size and sorting of sediments may be the most intuitive proxy method for a rough estimation of hydrate saturation.Further study is necessary to fully understand the relationship between hydrate morphology and sediment grain size,even though massive hydrates are typically found in fine clayey-rich sediments.

关键词： grain size saturation gas hydrates ODP Leg 164 Mallik 5L-38

Visual Feedback Disturbance Rejection Control for an Amphibious Bionic Stingray Under Actuator saturation

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IEEE/CAA Journal of Automatica Sinica 2023年第2期10卷 566-568页

作者： Haiyan Cheng Bin Fang Qing Liu Jinhua Zhang Jun Hong the Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China the School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China

Dear Editor,This letter is concerned with visual feedback disturbance rejection control for an amphibious bionic stingray subject to actuator saturation with internal and external disturbances. A visual feedback control method is designed for a dynamic nonlinear system on yaw angle of the amphibious bionic stingray via a finite-time extended-stateobserver,which is proved to achieve finite-time stability via a Lyapunov method. Finally, simulation results verify the effectiveness on the visual feedback control method.

关键词： Visual concerned saturation

saturation AND RELIABLE HIERARCHICAL A POSTERIORI MORLEY FINITE ELEMENT ERROR CONTROL

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Journal of Computational Mathematics 2018年第6期36卷 833-844页

作者： Carsten Carstensen Dietmar Gallistl Yunqing Huang Humboldt-Universitat zu Berlin Institut fiir Mathematik Unter den Linden 6 10099 Berlin Germany Department of Applied Mathematics University of Twente P.O. Box 217 7500 AE Enschede Institute for Computational and Applied Mathematics and Hunan Key Laboratory for Computation & Simulation in Science & Engineering Xiangtan University Xiangtan 411105 China

This paper proves the saturation assumption for the nonconforming Morley finite ele- ment discretization of the biharmonic equation. This asserts that the error of the Morley approximation under uniform refinement is strictly reduced by a contraction factor smaller than one up to explicit higher-order data approximation terms. The refinement has at least to bisect any edge such as red refinement or 3-bisections on any triangle. This justifies a hierarchical error estimator for the Morley finite element method, which simply compares the discrete solutions of one mesh and its red-refinement. The related adaptive mesh-refining strategy performs optimally in numerical experiments. A remark for Crouzeix-Raviart nonconforming finite element error control is included.

关键词： saturation Hierarchical error estimation Finite element Nonconforming Biharmonie Morley Kirchhoff plate Crouzeix-Raviart

Path Following of Underactuated Autonomous Surface Vessels With Surge Velocity Constraint and Asymmetric saturation

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IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1343-1345页

作者： Yalei Yu Chen Guo Tieshan Li the School of Marine Electrical Engineering Dalian Maritime UniversityDalian 116026China the Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughborough LE113RHUK the School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731 the School of Navigation Dalian Maritime UniversityDalian 116026China

Dear Editor, This letter is concerned with the path following of underactuated autonomous surface vessels(ASV) in the presence of surge velocity constraint and asymmetric saturation as well as unknown dynamics.To cope with velocity constraints both magnitude and rate and asymmetric saturation as well as unknown dynamics, an adaptive finitetime sliding mode control scheme(AFTSM) is designed.

关键词： dynamics saturation asymmetric

Gas hydrate saturation model and equation for logging interpretation

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Petroleum Exploration and Development 2022年第6期49卷 1243-1250页

作者： LI Ning SUN Wenjie LI Xintong FENG Zhou WU Hongliang WANG Kewen PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China Peking University Beijing 100871China

Since gas hydrate exists in three different forms at the same time such as pore filling,particle support and separate stratification,the calculation method of hydrate saturation using traditional shaly sand formation interpretation models is equivalent to considering only the simple case that hydrate exists as pore filling,and does not consider other complex states.Based on the analysis of hydrate resistivity experimental data and the general form of the resistivity-oil(gas)saturation relationship,the best simplified formula of hydrate saturation calculation is derived,then the physical meaning of the three items are clarified:they respectively represent the resistivity index-saturation relationship when hydrate particles are completely distributed in the pores of formation rocks,supported in the form of particles,and exist in layers,corresponding quantitative evaluation method of hydrate saturation is built.The field application shows that the hydrate saturation calculated by this method is closer to that obtained by sampling analysis.At the same time,it also provides a logging analysis basis for the effective development after hydrate exploration.

关键词： unconventional oil and gas hydrate resistivity index saturation non-Achie well logging interpretation

saturation phenomenon of Ce and Ti in the modification of Al–Zn–Si filler metal

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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 184-189页

作者： Jin-long Yang Song-bai Xue Wei Dai Peng Xue College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Zhejiang Xinrui Welding Material Co. Ltd.

Cerium and titanium were added to an A1-42Zn-5.5Si brazing alloy, and the subsequent microstructures of the brazing alloy and the 6061 AI alloy brazing seam were investigated. The microstructures of filler metals and brazed joints were characterized by scanning elec- tron microscopy and X-ray energy dispersion spectrometry. A new Ce-Ti phase formed around the silicon phase in the modified filler metal and this saturation phenomenon was analyzed. Interestingly, following brazing of the 6061 alloy, there is no evidence of the Ce--Ti phase in the brazing seam. Because of the mutual solubility of the brazing alloy and base metal, the quantity of the solvent increases, and the solute Ce and Ti atoms assume an undersaturated state.

关键词： filler metals aluminum alloys brazing cerium titanium saturation

Simplified calculation of bile cholesterol saturation index

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Hepatobiliary & Pancreatic Diseases International 2022年第3期21卷 293-294页

作者： Fen-Ming Zhang Xin Jiang Sha Li Long-Gui Ning Fang-Fang Guo Guo-Qiang Xu Department of Gastroenterology the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

>Gallstones (cholelithiasis) are masses in the gallbladder or biliary tract that are caused by abnormally high levels of either cholesterol or bilirubin in bile [1]. It is a multifactorial disease and the main pathogenesis is the increased secretion of bile cholesterol,which can increase the cholesterol saturation index (CSI) of bile.Patients with CSI greater than 1 are more likely to develop gallstones.Bile is a kind of dark green to yellowish-brown liquid containing> 90% water.Cholesterol,lecithin and bile salts are the three main lipid species in bile and combined to form the main components of gallstones[1].

关键词： bile cholesterol saturation