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Spatio-Temporal Service Analysis in Multi-Layer Non-Terrestrial Networks

Journal of Communications and Information Networks 2024年第1期9卷 43-55页

作者： qian chen Weixiao Meng Shuai Han cheng Li School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China School of Engineering Science Simon Fraser UniversityBurnabyBC V5A 1S6Canada Department of Electrical and Computer Engineering Memorial UniversitySt.John’sNL A1B 3X5Canada

In the advent of the 6G era, non-terrestrial networks (NTN) with expansive coverage are being increasingly recognized as a vital supplement to cellular networks for facilitating seamless communication. The intricate interplay between network performance and service quality necessitates a thorough investigation into the modeling and analysis of services for efficient construction of *** studies on service analysis, predominantly focused on terrestrial networks,fall short in addressing the unique challenges posed by NTN,particularly those related to platform distribution and antenna gain modeling. This deficiency in research,coupled with the varying preferences of users for different network types, forms the basis of this study. This paper explores the spatio-temporal characteristics of services within a multi-layered NTN *** this context,the spatial distribution of the platforms is modeled using a binomial point process, and the antennas are characterized by a sectorized beam pattern. We derive the closed-form expressions for the association probability,the number of accessed users, and the arrival rate of services with certain delay requirements towards different types of NTN. Simulation results are provided to evaluate the influence of various parameters on the association probability, the number of accessed users, and the total arrival rate of services. The number of satellites can be determined to achieve the optimal system utility,balancing the accessed services, offloading effects, and launching costs. This initial investigation lays the groundwork for further theoretical progress in the service analysis and platform deployment of NTN.

关键词： association strategy non-terrestrial networks service analysis stochastic geometry system utility

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First-principles calculations on the electronic structure and optical properties of BaSi_2

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Science China(Physics,Mechanics & Astronomy) 2009年第4期52卷 580-586页

作者： ZHAO FengJuan XIE Quan chen qian YANG ChuangHua Institute of New type Optoelectronic Materials and Technology Guizhou UniversityGuiyang 550025China College of Electronic Science and Information Technology Guizhou UniversityGuiyang 550025China

The electronic structure,densities of states and optical properties of the stable orthorhombic BaSi2 have been calculated using the first-principle density function theory and pseudopotential method. The results show that BaSi2 is an indirect semiconductor with the band gap of 1.086 eV,the valence bands of BaSi2 are mainly composed of Si 3p,3s and Ba 5d,and the conduction bands are mainly composed of Ba 6s,5d as well as Si 3p. The static dielectric function ε1(0) is 11.17,the reflectivity n0 is 3.35,and the biggest peak of the absorption coefficient is 2.15×105 cm-1.

关键词： BaSi_2 electronic structure optical properties first-principles

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Polymerization of methyl methacrylate catalyzed by mono-/bis-salicylaldiminato nickel(Ⅱ) complexes and methylaluminoxane

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Frontiers of Chemical Science and Engineering 2011年第1期5卷 19-25页

作者： Jihong LU Danfeng ZHANG qian chen Buwei YU School of Materials Science and Engineering East China University of Science and TechnologyShanghai 200237China Daqing Petrochemical Research Center of CNPC Daqing 163714China

Two types of salicylaldiminato-based nickel complexes,mono-ligated Ni(II)complexes([O-C_(6)H_(4)-o-C(H)=N-Ar]Ni(PPh_(3))(Ph)(5),[O-(3,5-Br_(2))C_(6)H_(2)-o-C(H)=N-Ar]Ni(PPh_(3))(Ph)(6),[O-(3-t-Bu)C_(6)H_(3)-o-C(H)=N-Ar]Ni(PPh_(3))(Ph)(7))and bis-ligated Ni(II)complexes([O-(3,5-Br_(2))C_(6)H_(2)-o-C(H)=N-Ar]_(2)Ni(8),[O-(3,5-Br_(2))C_(6)H_(2)-o-C(H)=N-2-C_(6)H_(4)(PhO)]_(2)Ni(9),Ar=2,6-C_(6)H_(3)(i-Pr)_(2))were synthesized and characterized by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance(NMR),mass spectrography(MS)and elemental analysis(EA).In the presence of methylaluminoxane(MAO)as cocatalyst,all the nickel complexes exhibited high activities for the polymerization of methyl methacrylate(MMA)and syndiotactic-rich poly(methyl methacrylate)(PMMA)was *** complexes with less bulky substituents on salicylaldiminato framework possessed higher activities,while with the same salicylaldiminato,the mono-ligated nickel complexes showed higher catalytic activity than bis-ligated ones.

关键词： late transition metal catalyst methyl methacrylate polymerization salicylaldiminato nickel complexes methylaluminoxane syndiotactic structure

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Successful treatment of a case of COVID-19 pneumonia following kidney transplantation using paxlovid and tocilizumab

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World Journal of Clinical Cases 2023年第25期11卷 6012-6018页

作者： qian chen Yu-Lin Niu Department of Organ Transplantation Affiliated Hospital of Guizhou Medical UniversityGuiyang 550000Guizhou ProvinceChina

BACKGROUND Since its initial detection in 2019,coronavirus disease 2019(COVID-19)pneumonia has rapidly spread throughout the world in a global ***,reports of COVID-19 pneumonia among patients following kidney transplantation have been limited and no uniform treatment guidelines for these patients have yet to be *** SUMMARY Here,we report the case of a 39-year-old patient recovering from kidney transplantation who contracted perioperative COVID-19 pneumonia that was successfully controlled with oral paxlovid and a single intravenous drip infusion of tocilizumab following the discontinuation of immunosuppressive *** Given the rapid spread of severe acute respiratory syndrome coronavirus 2 infections,clinicians should be aware of the potential for more cases of COVID-19 among patients following kidney transplantation and be familiar with appropriate treatment options and likely clinical outcomes.

关键词： Clinical research Kidney transplantation Coronavirus disease 2019 pneumonia Paxlovid Tocilizumab Case report

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Quantitation of camellianin A in HepG2 cells using a high performance liquid chromatography-electrospray ionization tandem mass spectrometric method

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Chinese Journal of Natural Medicines 2017年第3期15卷 234-240页

作者： chen qian-qian XI Hai-Ling WANG Cai-Yun XU Feng-Guo ZHANG Wei State Key Laboratory of Quality Research in Chinese Medicine Macao University of Science and Technology School of Public Health Baotou Medical College Key Laboratory of Drug Quality Control and Pharmacovigilance(Ministry of Education) China Pharmaceutical University

The present study was designed to develop a sensitive and selective high performance liquid chromatography-tandem mass spectrometric method for the determination of Camellianin A in HepG2 *** extraction of Camellianin A was achieved using 15% trichloroacetic acid and then separated on a C_(18) column interfaced with a triple quadrupole tandem mass spectrometer in multiple reaction monitoring *** mobile phase was consisted of methanol-water(0.1% formic acid)(55:45,V/V).The total run time was 5.0 *** method was linear in the concentration range of 0.25-250.0 ng·mL^(-1).The lower limit of quantification was 0.25 ng·mL^(-1).The intra-and inter-day relative standard deviations of entire concentration range were less than 9.3%.The proposed HPLC-MS/MS method was successfully applied to detect the intracellular concentration of Camellianin A in HepG2 cells.

关键词： Camellianin A HepG2 cells HPLC-MS/MS

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Quantitation of ligupurpurosides B and C in rat plasma using HPLC-MS/MS

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Chinese Journal of Natural Medicines 2016年第6期14卷 473-480页

作者： chen qian-qian GUO Jian-Ru FENG Suo-Ming WANG Cai-Yun ZHANG Wei State Key Laboratory of Quality Research in Chinese Medicine Macao University of Science and Technology College of Pharmacy Xi'an Medial University

The present study was designed to develop a sensitive and selective specific high performance liquid chromatography(HPLC)-tandem mass spectrometric method(MS/MS) for the determination of ligupurpurosides B and C in rat plasma. The samples were prepared after protein precipitation and analyzed by liquid chromatography equipped with a C18 column interfaced with a triple quadrupole tandem mass spectrometer using ESI as the ionization source in the negative ion mode. The mobile phase consisted of water(0.01 % formic acid)–methanol(57 : 43, V/V) at the flow rate of 0.3 m L·min-1. The analytes and internal standard acteoside were both detected by use of multiple reaction monitoring mode. The total run time was 6.0 min. The method was linear in the concentration range of 2.5–500.0 ng·m L-1 and the lower limit of quantification(LLOQ) was 2.5 ng·m L-1. The intra-day and inter-day relative standard deviations across three validation runs over the entire concentration range were less than 9.8 %. The accuracy determined at three concentrations was within ± 6.1% in terms of relative error. In conclusion, this assay offers advantages in terms of expediency and suitability for the analysis of ligupurpuroside B and ligupurpuroside C in various biological fluids.

关键词： Ligupurpuroside B Ligupurpuroside C HPLC-MS/MS Pharmacokinetics Quantitation

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Optical Bistability in Ag/Dielectric Multilayers

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Chinese Physics Letters 2012年第5期29卷 100-103页

作者： LI Heng SHENG Chuan-Xiang chen qian School of Electronic Engineering and Optoelectronics Technology Nanjing University of Science and TechnologyNanjing 210094

We numerically study the optical bistability (OBIS) in periodic multilayers of Ag/SiO_(2).The calculated dependence of the output on the input intensity shows two possible OBIS states at the test *** is due to the field localization effects in silver layers with nonlinear refractive index modifying resonant tunneling of electromagnetic waves;the other,with about a three times lower threshold input intensity,is attributed to the intensity dependence change of the Ag/SiO_(2) composite's effective dielectric constant from metallic-like (negative) to dielectric-like (positive).With appropriate design engineering the Ag/SiO2 multilayers could find broad applications in all-optical information processes.

关键词： composite intensity dielectric

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Diagnostic values of questionnaires of Convergence Insufficiency Symptom Survey and College of Optometrists Vision Development Quality of Life in the screening of convergence insufficiency

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 904-908页

作者： Ling Xiong qian chen Ye Wu Department of Ophthalmology West China HospitalSichuan University/Laboratory of Optometry and Vision ScienceWest China School of MedicineChengdu 610041Sichuan ProvinceChina Department of Clinical Research Management Center of BiostatisticsDesignMeasurement and EvaluationWest China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

AIM:To compare and analyse the diagnostic efficacy of the College of Optometrists Vision Development Quality of Life Questionnaire(COVD-QOL)and the Convergence Insufficiency Symptom Survey(CISS)in detecting convergence insufficiency and to compare their diagnostic value in clinical ***:Using the diagnostic test method,62 adult patients with convergence insufficiency(age:24.74±3.75y)and 62 normal participants(age:23.61±3.13y)who visited the Optometry Clinic of West China Hospital of Sichuan University from April 2021 to January 2023 were *** subjects completed the CISS and *** analysis of the sensitivity and specificity of the CISS and COVD-QOL and comparison and joint experimental analysis of their diagnostic efficacy were ***:The sensitivity of the CISS and COVD-QOL for convergence insufficiency was 64.5%and 71.0%,respectively,while the specificity was 96.8%and 67.7%,*** to the CISS alone,the combination of the CISS and COVD-QOL demonstrated lower sensitivity and *** areas under the receiver operating characteristic curve of CISS,COVD-QOL and CISS combined with COVD-QOL were 0.806,0.694 and 0.782,***:Considering the low sensitivity of the CISS and the low specificity of the COVD-QOL,it is recommended to supplement these questionnaires with other screening tests for the detection of convergence insufficiency.

关键词： convergence insufficiency symptom survey College of Optometrists Vision Development Quality of Life Questionnaire convergence insufficiency asthenopia

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Nonlinear control of spacecraft formation flying with disturbance rejection and collision avoidance

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Chinese Physics B 2017年第1期26卷 250-259页

作者： Qing Ni Yi-Yong Huang Xiao-qian chen College of Aerospace Science and Engineering National University of Defense Technology Changsha 410073 China

A nonlinear controller for disturbances rejection and collision avoidance is proposed for spacecraft formation *** formation flying is described by a nonlinear model with the J2 perturbation and atmospheric drag. Based on the theory of the state-dependent Riccati equation（SDRE）, a finite time nonlinear control law is developed for the nonlinear dynamics involved in formation flying. Then, a compensative internal mode（IM） control law is added to eliminate *** two control laws compose a finite time nonlinear tracking controller with disturbances rejection. Moreover, taking safety requirements into account, the repulsive control law is incorporated in the composite controller to perform collision avoidance manoeuvres. A numerical simulation is presented to demonstrate the effectiveness of the proposed *** to the conventional control method, the proposed method provides better performance in the presence of the obstacles and external disturbances.

关键词： nonlinear control disturbances rejection collision avoidance formation flying

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Transient receptor potential-related risk model predicts prognosis of hepatocellular carcinoma patients

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World Journal of Gastrointestinal Oncology 2023年第12期15卷 2064-2076页

作者： Xiao-Cai Mei qian chen Shi Zuo Department of Hepatobiliary Surgery Affiliated Hospital of Guizhou Medical UniversityGuiyang 550000Guizhou ProvinceChina Department of Organ Transplantation Affiliated Hospital of Guizhou Medical UniversityGuiyang 550000Guizhou ProvinceChina

BACKGROUND Members of the transient receptor potential(TRP)protein family shape oncogenic development,but the specific relevance of TRP-related genes in hepatocellular carcinoma(HCC)has yet to be *** To investigate the role of TRP genes in HCC,their association with HCC development and treatment was *** HCC patient gene expression and clinical data were downloaded from The Cancer Genome Atlas database,and univariate and least absolute shrinkage and selection operator Cox regression models were employed to explore the TRP-related risk *** on these analyses,clinically relevant TRP family genes were selected,and the association between the key TRP canonical type 1(TRPC1)gene and HCC patient prognosis was *** In total,28 TRP family genes were screened for clinical relevance,with multivariate analyses ultimately revealing three of these genes(TRPC1,TRP cation channel subfamily M member 2,and TRP cation channel subfamily M member 6)to be significantly associated with HCC patient prognosis(P<0.05).These genes were utilized to establish a TRP-related risk *** were separated into low-and high-risk groups based on the expression of these genes,and high-risk patients exhibited a significantly poorer prognosis(P=0.001).Functional analyses highlighted pronounced differences in the immune status of patients in these two groups and associated enriched immune ***1 was identified as a candidate gene in this family worthy of further study,with HCC patients expressing higher TRPC1 levels exhibiting poorer survival ***,quantitative,immunohistochemistry,and western blot analyses revealed increased TRPC1 expression in *** These three TRP genes help determine HCC patient prognosis,providing insight into tumor immune status and immunological *** findings will help design combination therapies including immunotherapeutic and anti-TRP agents.

关键词： Transient receptor potential family genes Hepatocellular carcinoma Transient receptor potential canonical type 1 Novel oncogene

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