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Statistical Channel Modeling for Indoor VLC Communications Based on Channel Measurements

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China Communications 2024年第1期21卷 131-147页

作者： shuo liu Pan Tang Jianhua Zhang Yue Yin Yu Tong Baobao liu Guangyi liu Liang Xia State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China China Mobile Research Institute Beijing 100053China

Visible light communication(VLC)has attracted much attention in the research of sixthgeneration(6G)systems.Furthermore,channel modeling is the foundation for designing efficient and robust VLC systems.In this paper,we present extensive VLC channel measurement campaigns in indoor environments,i.e.,an office and a corridor.Based on the measured data,the large-scale fading characteristics and multipath-related characteristics,including omnidirectional optical path loss(OPL),K-factor,power angular spectrum(PAS),angle spread(AS),and clustering characteristics,are analyzed and modeled through a statistical method.Based on the extracted statistics of the above-mentioned channel characteristics,we propose a statistical spatial channel model(SSCM)capable of modeling multipath in the spatial domain.Furthermore,the simulated statistics of the proposed model are compared with the measured statistics.For instance,in the office,the simulated path loss exponent(PLE)and the measured PLE are 1.96and 1.97,respectively.And,the simulated medians of AS and measured medians of AS are 25.94°and 24.84°,respectively.Generally,the fact that the simulated results fit well with measured results has demonstrated the accuracy of our SSCM.

关键词： channel characteristics channel measurement channel modeling 6G spatial lobe VLC

Characteristics of atmospheric nitrous oxide observed at Mt.Waliguan GAW global station in the inland Eurasia during eighteen years

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Science China Earth Sciences 2024年第1期67卷 92-104页

作者： Miao LIANG Shuangxi FANG Lixin liu Yong ZHANG Jianqiong WANG shuo liu Hongyang WANG Liangchun DENG Meteorological Observation Centre(MOC) China Meteorological Administration(CMA)Beijing 100081China College of Environment Zhejiang University of TechnologyHangzhou 310014China Mt.Waliguan Background Station China Meteorological Administration(CMA)Xining 810001China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Center for Environmental Progress Wuhan 430070China

This study presents atmospheric N_(2)O mole fractions measured from discrete air samples from 2001 to 2018 at Mt.Waliguan(WLG)station(36°17′N,100°54′E,3816 m asl)in China,which is a global background station of the World Meteorological Organization/Global Atmosphere Watch Programme(WMO/GAW)in central Eurasia.Observed N_(2)O characteristics of annual means,interannual variability,and seasonal cycles were investigated.Our results show that N_(2)O at WLG possess a distinct increasing trend and a statistically significant seasonal cycle,with an average growth rate of 0.9±0.01 ppb yr^(−1)(1σ)(1ppb=10^(−9)),which is close to the global mean.The detrended seasonal cycle shows a trough of−0.25±0.04(1σ)ppb in June and a peak of 0.13±0.07(1σ)ppb in September,with an amplitude of 0.38 ppb.The pattern is due to combined effects of variation in surface sources,vertical convection within the boundary layer and stratosphere to troposphere transportation(STE).The interannual variability in growth rate was partly driven by quasi-biennial oscillation(QBO)of tropical zonal wind through stratospheric transport into the troposphere.According to a cluster analysis of back trajectories and the corresponding average N_(2)O load,most air masses cover arid and semi-arid areas in inner Asia with low N_(2)O emissions,indicating that the atmospheric N_(2)O at the WLG represents the background N_(2)O level in central Eurasia.

关键词： Nitrous oxide(N_(2)O) Observation Long-term trend Seasonal variation Interannual variability

Combining systemic inflammatory response index and albumin fibrinogen ratio to predict early serious complications and prognosis after resectable gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 732-749页

作者： Jing-Yao Ren Da Wang Li-Hui Zhu shuo liu Miao Yu Hui Cai School of Clinical Medicine Ningxia Medical UniversityYinchuan 750000Ningxia Hui Autonomous RegionChina General Surgery Clinical Medical Center Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina Key Laboratory of Molecular Diagnostics and Precision Medicine for Surgical Oncology in Gansu Province Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina NHC Key Laboratory of Diagnosis and Therapy of Gastrointestinal Tumor Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina Medical College of Jiangsu University Jiangsu UniversityZhenjiang 212013Jiangsu ProvinceChina The First Clinical Medical School Lanzhou UniversityLanzhou 730000Gansu ProvinceChina

BACKGROUND Gastric cancer has a high incidence and fatality rate,and surgery is the preferred course of treatment.Nonetheless,patient survival rates are still low,and the incidence of major postoperative complications cannot be disregarded.The systemic inflammatory response,nutritional level,and coagulation status are key factors affecting the postoperative recovery and prognosis of gastric cancer patients.The systemic inflammatory response index(SIRI)and the albumin fibrinogen ratio(AFR)are two valuable comprehensive indicators of the severity and prognosis of systemic inflammation in various medical conditions.AIM To assess the clinical importance and prognostic significance of the SIRI scores and the AFR on early postoperative outcomes in patients undergoing radical gastric cancer surgery.METHODS We conducted a retrospective analysis of the clinicopathological characteristics and relevant laboratory indices of 568 gastric cancer patients from January 2018 to December 2019.We calculated and compared two indicators of inflammation and then examined the diagnostic ability of combined SIRI and AFR values for serious early postoperative complications.We scored the patients and categorized them into three groups based on their SIRI and AFR levels.COX analysis was used to compare the three groups of patients the prognostic value of various preoperative SIRI-AFR scores for 5-year overall survival(OS)and disease-free survival(DFS).RESULTS SIRI-AFR scores were an independent risk factor for prognosis[OS:P=0.004;hazards ratio(HR)=3.134;DFS:P<0.001;HR=3.543]and had the highest diagnostic power(area under the curve:0.779;95%confidence interval:0.737-0.820)for early serious complications in patients with gastric cancer.The tumor-node-metastasis stage(P=0.001),perioperative transfusion(P=0.044),positive carcinoembryonic antigen(P=0.014)findings,and major postoperative complications(P=0.011)were factors associated with prognosis.CONCLUSION Preoperative SIRI and AFR values were significantly associated with early postoperative

关键词： Inflammation Albumin fibrinogen ratio Gastric cancer Complications Prognosis

Instrumented oscillographic study on impact toughness of an axle steel DZ2 with different tempering temperatures

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1590-1598页

作者： shuo liu Peng Zhang Bin Wang Kaizhong Wang Zikuan Xu Fangzhong Hu Xin Bai Qiqiang Duan Zhefeng Zhang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Technology Center Ma'anshan Iron and Steel Co.Ltd.Ma'anshan 243000China

Compared with the conventional Charpy impact test method,the oscillographic impact test can help in the behavioral analysis of materials during the fracture process.In this study,the trade-off relationship between the strength and toughness of a DZ2 axle steel at various tempering temperatures and the cause of the improvement in impact toughness was evaluated.The tempering process dramatically influenced carbide precipitation behavior,which resulted in different aspect ratios of carbides.Impact toughness improved along with the rise in tempering temperature mainly due to the increase in energy required in impact crack propagation.The characteristics of the impact crack propagation process were studied through a comprehensive analysis of stress distribution,oscilloscopic impact statistics,fracture morphology,and carbide morphology.The poor impact toughness of low-tempering-temperature specimens was attributed to the increased number of stress concentration points caused by carbide morphology in the small plastic zone during the propagation process,which resulted in a mixed distribution of brittle and ductile fractures on the fracture surface.

关键词： axle steel DZ2 tempering process impact toughness oscillographic impact test impact crack propagation carbides

Challenges and countermeasures for developing countries in addressing loss and damage caused by climate change

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Advances in Climate Change Research 2024年第2期15卷 353-363页

作者： shuo liu Yu-E LI Bin WANG An-Dong CAI Chao FENG Hua LAN Ruo-Chen ZHAO Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China Key Laboratory of Agricultural Environment Ministry of Agriculture and Rural AffairsBeijing 100081China China Clean Development Mechanism Fund Management Center Beijing 100045China School of International Law China University of Political Science and LawBeijing 100088China

Loss and damage caused by extreme climate events have attracted increasing attention.The 28th Conference of the Parties to the United Nations Framework Convention on Climate Change(hereinafter referred to as the Convention)has agreed to adopt Loss and Damage Fund agreement,which identified the source of funding and the funds to be entrusted to the World Bank.However,there is still ambiguous that how to allocate the funds could accelerate the effectiveness of meeting the needs for developing countries.Pre-disaster prevention and preparedness is one of the most effective measures to deal with loss and damage,which closely related to adaptation.Previous studies rarely analyzed quantitatively the financial needs of pre-disaster prevention and preparedness relating to adaptation to reduce loss and damage.Based on the official reports submitted by countries under the Convention,this study analyzes the annual change in the total financial support provided by developed countries to developing countries,the proportion of pre-disaster prevention and preparedness in the adaptation needs of developing countries,and the progress in raising the current annual funding target of 100 billion USD for developed countries,to reveal the financial and technical challenges facing by developing countries on addressing loss and damage.The results show that by 2030,the total adaptation financial needs of developing countries are estimated to be about 3.8 trillion USD,of which pre-disaster prevention matters account for about 9%.Therefore,by 2030,developing countries will need about 342 billion USD in pre-disaster prevention and preparedness finance to withstand loss and damage.In addition,developing countries face a lack of technical methods to quantify information about their needs.Based on the above analysis,this study puts forward countermeasures and suggestions,including strengthening the allocation amount of loss and damage fund on pre-disaster warning,prevention and control actions,and establishing track modalities on the finance pr

关键词： Loss and damage Funding mechanism Pre-disaster warning and preparedness Convention negotiations Countermeasures

A Priori Error Analysis for NCVEM Discretization of Elliptic Optimal Control Problem

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Engineering（科研） 2024年第4期16卷 83-101页

作者： Shiying Wang shuo liu School of Mathematics and Statistics Shandong Normal University Jinan China

In this paper, we propose the nonconforming virtual element method (NCVEM) discretization for the pointwise control constraint optimal control problem governed by elliptic equations. Based on the NCVEM approximation of state equation and the variational discretization of control variables, we construct a virtual element discrete scheme. For the state, adjoint state and control variable, we obtain the corresponding prior estimate in H1 and L2 norms. Finally, some numerical experiments are carried out to support the theoretical results.

关键词： Nonconforming Virtual Element Method Optimal Control Problem a Priori Error Estimate

Amoeba-inspired magnetic microgel assembly assisted by engineered dextran-binding protein for vaccination against lifethreatening systemic infection

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Nano Research 2023年第1期16卷 938-950页

作者： shuo liu Yan Zhao Linpei Guo Qilin Yu Key Laboratory of Molecular Microbiology and Technology Ministry of EducationDepartment of MicrobiologyCollege of Life SciencesNankai UniversityTianjin 300071China Research Center for Infectious Diseases Nankai UniversityTianjin 300350China College of Environmental Science and Engineering Tianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China Department of Urology The Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical UniversityWuxi 214002China

Vaccination is critical for population protection from pathogenic infections.However,its efficiency is frequently compromised by a failure of antigen retention and presentation.Herein,we designed a dextran-binding protein DexBP,which is composed of the carbohydrate-binding domains of Trichoderma reesei cellobiohydrolases Cel6A and Cel7A,together with the sequence of the fluorescent protein mCherry.DexBP was further prepared by engineered Escherichia coli cells and grafted to magnetic nanoparticles.The magnetic nanoparticles were integrated with a dextran/poly(vinyl alcohol)framework and a reactive oxygen species-responsive linker,obtaining magnetic polymeric microgels for carrying pathogen antigen.Similar to amoeba aggregation,the microgels self-assembled to form aggregates and further induced dendritic cell aggregation.This step-by-step assembly retained antigens at lymph nodes,promoted antigen presentation,stimulated humoral immunity,and protected the mice from lifethreatening systemic infections.This study developed a magnetic microgel-assembling platform for dynamically regulating immune response during protection of the body from dangerous infections.

关键词： magnetic nanoparticle engineered protein dextran microgel vaccination systemic infection

An integer programming formulation and iterative scheme algorithm for the block relocation problem

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Journal of Control and Decision 2023年第3期10卷 338-347页

作者： shuo liu Shixin liu Chao Lu College of Information Science and Engineering Northeastern UniversityShenyangPeople’s Republic of China

In this paper, we deal with the unrestricted block relocation problem. We present a new integerprogramming formulation for solving the problem. The initial formulation is improved by tighteningconstraints and a pre-processing step to fix several variables. We design a exact iterativescheme algorithm based on a fast heuristic for the integer programming formulation (ISA-FH).Computational results show the effectiveness of the improved formulation and algorithm.

关键词： Block relocation problem integer programming iterative scheme algorithm

Rational design strategies of Cu-based electrocatalysts for CO_(2) electroreduction to C_(2) products

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Journal of Energy Chemistry 2022年第8期31卷 63-82,I0003页

作者： shuo liu Baoshan Zhang Lihong Zhang Jie Sun Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China

Electrochemical reduction of CO_(2)(CO_(2)RR)to high value-added chemicals is an effective way to remove excess CO_(2) from the atmosphere.Due to the unique propensity of Cu for valuable hydrocarbons,Cu-based electrocatalysts are the most potential catalysts that allow the conversion of CO_(2) into a variety of C_(2) products such as ethylene and ethanol.Rational design of Cu-based catalysts can improve their directional selectivity to C_(2) products.Hence,in this review,we summarize the recent progress in the mechanistic studies of Cu-based catalysts on reducing CO_(2) to C_(2) products.We focus on three key strategies for efficiently enhancing electrocatalytic performance of Cu-based catalysts,including tuning electronic structure,surface structure,and coordination environment.The correlation between the structural characteristics of Cu-based catalysts and their activity and selectivity to C_(2) products is discussed.Finally,we discuss the challenges in the field of CO_(2) electroreduction to C_(2) products and provide the perspectives to design efficient Cu-based catalysts in the future.

关键词： Carbon dioxide Cu-based catalysts Mechanisms Active site regulation