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Study of PAPR mitigation in OFDM-VLC system by SCMA codebook design

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Optoelectronics Letters 2024年第9期20卷 543-548页

作者： YANG Ting li Ganggang liU tao WANG ping WANG Zhao School of Telecommunications Engineering Xidian UniversityXi'an 710071China

Traditional orthogonal frequency division multiplexing(OFDM)based visible light communication(VLC)system is susceptible to high peak-to-average power ratio(PAPR),thus leading to low power *** address this issue,a sparse code multiple access(SCMA)codebook design method has been proposed to lower the PAPR of the clipping based OFDM-VLC system.

关键词： OFDM SCMA code

Mutant rs189037 in ataxia-telangiectasia mutated gene had a negative association with metabolic syndrome but not cognitive decline in centenarians

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Genes & Diseases 2024年第3期11卷 106-108页

作者： Long Feng Hongqi Huo Qun li tao Yang Yali Zhao Pei Zhang ping ping Shihui Fu Department of Anesthesiology Hainan Hospital of Chinese People's Liberation Army General HospitalSanyaHainan 572013China Nuclear Medicine Department Handan Central HospitalHandanHebei056001China Department of Neurosurgery Hainan Hospital of Chinese People's Liberation Army General HospitalSanyaHainan 572013China Department of Oncology Hainan Hospital of Chinese People's Liberation Army General HospitalSanyaHainan 572013China Central Laboratory Hainan Hospital of Chinese People's Liberation Army General HospitalSanyaHainan 572013China School of life Science Beijing Institute of TechnologyBeijing 100081China General Station for Drug and Instrument Supervision and Control Joint Logistic Support Force of Chinese People's LiberationArmyBeijing 100071China Department of Cardiology Hainan Hospital of Chinese People's Liberation Army General HospitalSanyaHainan 572013China Department of Geriatric Cardiology Chinese People's Liberation Army General HospitalBeijing 100853China

Approximately 20%-25%of adults encounter metabolic syndrome(MetS)worldwide,and MetS is a riskfactorfor cognitive decline(CD)*** with MetS have an 11.48-fold increased incidence of CD compared with those without Mets.^(1) Ataxia-telangiectasia mutated(ATM)gene encodes ATM kinase,which belongs to the phosphatidylinositol 3-hydroxy kinase family.

关键词： ATM development cognitive

Internal limiting membrane peeling combined with silicone oil or air tamponade for highly myopic foveoschisis

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 1079-1085页

作者： Jin Deng Wen-tao Sun Ke Gong li-ping Wang Feng-Zhi li Xi’an People’s Hospital(Xi’an Fourth Hospital) Shaanxi Eye HospitalAffiliated People’s Hospital of Northwest UniversityXi’an 70004Shaanxi ProvinceChina

AIM:To compare the efficacy of pars plana vitrectomy(PPV)combined with internal limiting membrane(ILM)and silicone oil or sterile air tamponade for the treatment of myopic foveoschisis(MF)in highly myopic ***:This retrospective study included 48 myopic eyes of 40 patients with MF and axial lengths(ALs)ranging from 26-32 mm treated between January 2020 and January *** patients were underwent PPV combined with ILM peeling followed by sterile air or silicone oil tamponade and followed up at least *** on the features on spectral-domain optical coherence tomography(SD-OCT),the eyes were divided into the MF-only group(Group A,n=15 eyes),MF with central foveal detachment group(Group B,n=20 eyes),and MF with lamellar macular hole group(Group C,n=13 eyes).According to AL,eyes were further divided into three groups:Group D(26.01-28.00 mm,n=12 eyes),Group E(28.01-30.00 mm,n=26 eyes),and Group F(30.01-32.00 mm,n=10 eyes).The best-corrected visual acuity(BCVA),central foveal thickness(CFT),and complications were ***:The patients included 16 males and 24 females with the mean age of 56±*** BCVA and CFT improved in all groups after surgery(P0.05).The intergroup differences of BCVA and CFT postoperatively were statistically significant in Group D,E,and *** eyes were injected with sterile air,and 28 eyes were injected with silicone oil for tamponade based on the ***,there was no statistically significant difference among Groups D,E,and F in terms of the results of sterile air or silicone oil *** mean recovery time was 5.9mo for MF patients subjected to silicone oil tamponade and 7.7mo for patients subjected to sterile air tamponade,and the difference was not statistically ***:PPV and ILM peeling combined with silicone oil or sterile air tamponade can achieve good results for MF in highly myopic eyes with ALs

关键词： axial length myopic foveoschisis highly myopic internal limiting membrane pars plana vitrectomy

Study of the reaction mechanism for preparing powdered activated coke with SO_(2)adsorption capability via one-step rapid activation method under flue gas atmosphere

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Chinese Journal of Chemical Engineering 2024年第1期65卷 158-168页

作者： Binxuan Zhou Jingcai Chang Jun li Jinglan Hong tao Wang liqiang Zhang ping Zhou Chunyuan Ma School of Environmental Science and Engineering Shandong UniversityQingdao 266237China School of Energy and Power Engineering Shandong UniversityJinan 250061China Weihai Research Institute of Industrial Technology of Shandong University Weihai 264209China

In this study,the impact of different reaction times on the preparation of powdered activated carbon(PAC)using a one-step rapid activation method under flue gas atmosphere is investigated,and the underlying reaction mechanism is *** indicate that the reaction process of this method can be divided into three stages:stage I is the rapid release of volatiles and the rapid consumption of O_(2),primarily occurring within a reaction time range of 0-0.5 s;stage II is mainly the continuous release and diffusion of volatiles,which is the carbonization and activation coupling reaction stage,and the carbonization process is the main in this *** stage mainly occurs at the reaction time range of 0.5 -2.0 s when SL-coal is used as material,and that is 0.5-3.0 s when JJ-coal is used as material;stage III is mainly the activation stage,during which activated components diffuse to both the surface and interior of *** stage mainly involves the reaction stage of CO_(2)and H2O(g)activation,and it mainly occurs at the reaction time range of 2.0-4.0 s when SL-coal is used as material,and that is 3.0-4.0 s when JJ-coal is used as ***,the main function of the first two stages is to provide more diffusion channels and contact surfaces/activation sites for the diffusion and activation of the activated components in the third *** the reaction mechanism would serve as a crucial reference and foundation for designing the structure,size of the reactor,and optimal positioning of the activator nozzle in PAC preparation.

关键词： Reaction mechanism Powdered activated coke preparation SO_(2)adsorption One-step rapid activation Flue gas atmosphere

Heat Transfer and Friction Characteristics of Printed Circuit Heat Exchangers with Different Channel Structures for S-CO_(2) Power System

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Journal of Thermal Science 2024年第3期33卷 1132-1147页

作者： JIANG tao li Mingjia Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

Printed circuit heat exchanger(PCHE)has been widely used in supercritical carbon dioxide(S-CO_(2))power systems because of its high heat transfer efficiency and good ***,due to the large variety of PCHE configurations,channel selection in practical applications lacks a ***,this paper discussed the heat transfer and friction characteristics and the synergy of three fields in the channel under the guidance of the field synergy principle for four typical PCHE ***,the comprehensive performance of four channels was ***,the heat transfer and friction factor correlations for S-CO_(2)in four channels were *** findings demonstrate that the synergy of velocity and pressure fields of the straight channel PCHE is better(β≈180°),so its resistance loss is relatively *** zigzag and sinusoidal wavy channels and the airfoil fins can reduce the angle a between the temperature gradient and velocity,thus enhancing the heat *** sinusoidal wavy channel can reduce flow resistance compared to the zigzag channel due to the rounded *** streamlined airfoil structure can guide the flow and reduce backflow,thus reducing resistance *** the range of Re studied in this paper,the maximum error of the proposed heat transfer and friction factor correlations of PCHE is 7.0%,which shows good fitting *** research in this paper can provide a reference for the selection and design of PCHE with different channel configurations.

关键词： printed circuit heat exchanger supercritical carbon dioxide typical channel structure field synergy analysis

Formation mechanism of fault accommodation zones under combined stress in graben basin:Implications from geomechanical modeling

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Petroleum Science 2024年第1期21卷 54-76页

作者： Qi-Qiang Ren Jin-liang Gao Rong-tao Jiang Jin Wang Meng-ping li Jian-Wei Feng Institute of Sedimentary Geology Chengdu University of TechnologyChengdu 610059SichuanChina PetroChina Research Institute of Petroleum Exploration and Development Beijing100083China Jianghan Oilfield Oil and Gas Production Capacity Construction Management Center Chongqing408000China Sinopec Chongqing Fuling Shale Gas Exploration and Development Company Chongqing408000China College of Energy Chengdu University of TechnologyChengdu 610059SichuanChina School of Geoscience China University of Petroleum(East China)Qingdao 266580ShandongChina

A fault accommodation zone is a type of structure that is defined as regulating displacement and strain between faults *** numbers of fault accommodation zones are being identified in graben basins,indicating the potential exploration target and petroleum accumulation *** study aims to analyze the formation mechanism and development of fault accommodation zones under combined stress by a numerical simulation method considering geomechanical *** three-dimensional(3-D)seismic interpretation and fractal dimension method,exampled with the Dongxin fault zone,the fault activity and fault combination pattern were conducted to quantitatively characterize the activity difference in fault accommodation *** with mechanical experiment test,a geomehcanical model was established for fault accommodation zones in a graben *** the paleostress numerical simulations and structural physical simulation experiment,the developmental characteristics and genetic mechanism of fault accommodation zones were *** by multi movements and combined stresses,three significant tectonic evolution stages of the Dongxing Fault Zone(DXFZ)were distinguished:During the E_(s)^(3)sedimentary period,the large difference in the stress,strain,and rupture distribution in various faults were significant,and this stage was the key generation period for the prototype of the DXFZ,including the FAZ between large-scale *** the E_(s)^(2)sedimentary period,the EW-trending symmetric with opposite dipping normal faults and the NE-SW trending faults with large scale were furtherly *** junction area of two secondary normal faults were prone to be ruptured,performing significant period for inheriting and developing characteristics of fault accommodation *** the Es1 sedimentary period,the high-order faults in the DXFZ exhibited the obvious fault depressions and strike-slip activity,and the fault accommodation zones were

关键词： Fault accommodation zone Graben basin Fault activity Tectonic physical simulation experiment Finite element numerical simulation Dongxin fault zone

High-precision analytical solutions for Earth coverage of constellation equipped with reentry glide vehicles

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 385-398页

作者： Ma, ping Sun, Weibo Gao, Jie Chao, tao Harbin Inst Technol Control & Simulat Ctr Harbin 150001 Peoples R China Beijing Inst Spacecraft Syst Engn Beijing 100094 Peoples R China

To efficiently and accurately design satellite constellations equipped with Reentry Glide Vehicles (RGVs), new analytical solutions are developed for calculating their coverage performance. Specifically, a new coverage model is established by approximating the Reentry Reachable Domain (RRD). However, the computation of real-time relative distances between satellites and targets, which is essential for coverage analysis based on this model, imposes a significant computational burden. To address this challenge, a coverage analysis method based on two-dimensional map theory is proposed. This method represents the coverage conditions of a target as a fixed area on a two-dimensional map and transforms the satellite trajectory into a series of parallel lines. By determining the intersection points between these lines and the area boundaries, the coverage analytical solutions for a target point are derived. On this basis, coverage theorems are presented for rapid calculation of the constellation coverage performance for an area. Simulation results demonstrate the effectiveness and high precision of the proposed analytical solutions. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： Analytical solutions Reentry glide vehicle Reentry reachable domain Two-dimensional map Constellation GENERAL-ANALYSIS METHOD SATELliTE CONSTELLATION ROUTE THEORY DISCONTINUOUS COVERAGE GEOMETRIC ANALYSIS DESIGN FUNDAMENTALS ORBITS

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中国番荔枝科植物三新异名

植物分类学报 2007年第3期45卷 369-375页

作者：侯学良李秉滔厦门大学生命科学学院华南农业大学林学院广州510642

报道了3个新异名,即西藏暗罗Polyalthia chinensis *** & ***、Enicosanthellum plagioneurum *** Ban和桂南瓜馥木Fissistigma guinanense ***,分别并入疣叶暗罗*** *** ex ***、云桂暗罗*** Merr.和凹叶瓜馥木Fissistigma retusum(Lé... 详细信息

关键词：番荔枝科暗罗属瓜馥木属新异名中国

Mechanical characteristics and reservoir stimulation mechanisms of the Gulong shale oil reservoirs, the northern Songliao Basin

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Petroleum Science 2024年第3期21卷 2023-2036页

作者： Si-Wei Meng Jia-ping tao Tian-Jiao li Dong-Xu li Su-ling Wang liu Yang Xin liu li-Hao liang He liu PetroChina Research Institute of Petroleum Exploration Development Beijing100083China National Key Laboratory of Continental Shale Oil Daqing 163002HeilongjiangChina Dalian University of Technology Dalian116024LiaoningChina PetroChina Daqing Oilfield Co.Ltd. Daqing163002HeilongjiangChina Northeast Petroleum University Daqing163002HeilongjiangChina China University of Mining and Technology(Beijing) Beijing100083China

Shale oil of the Qingshankou Formation of the Gulong Sag,the northern Songliao Basin,represents the first attempt at large-scale development of pure-shale-type shale oil in *** integrating the multiscale refined reservoir characterization with macro-micro-scale mechanical testing,it is clarified that the Gulong shale is characterized by high clay mineral content,high rock plasticity,highly-developed bedding,and prominent mechanical anisotropy.A three-dimensional(3D)fracture propagation model of hydraulic fracturing was built for the Gulong shale,which fully captures the hydraulic fracture distribution pattern affected by the high bedding density,in-situ stress,and fracturing treatment *** research showed that due to influences of bedding,hydraulic fracturing in the Gulong shale forms a complex fracture morphology featuring the main fracture with multiple perpendicular branches that have different lengths(like the outdoor directional TV antenna);however,the vertical propagation of fractures is inhibited,and the fracture height is commonly less than 10 *** limited stimulated reservoir volume(SRV)is the main problem facing the fracturing stimulation of the Gulong shale *** density has vital effects on fracture morphology,so case-specific fracturing designs shall be developed for shale intervals with different bedding development *** reservoirs with welldeveloped bedding,it is suggested to properly increase the perforation cluster spacing and raise the volume and proportions of viscous fluids of the pad,so as to effectively promote vertical fracture propagation and improve reservoir stimulation *** study integrates multi-scale fine reservoir characterization and macro-micro-scale mechanical testing,as well as the construction and numerical simulation of hydraulic fracturing models for high-density layered shale reservoirs,providing a new approach and methodological framework for the fracturing research of high-density layer

关键词： Shale oil Hydraulic fracturing High bedding density Fracture propagation model