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面向6G多维扩展的新型多址接入技术综述

电子与信息学报 2024年第6期46卷 2323-2334页

作者：逄小玮蒋旭卢华兵赵楠大连理工大学信息与通信工程学院大连116024 哈尔滨工业大学(威海)信息科学与工程学院威海264209

随着移动通信技术的不断演进,第6代移动通信(6G)将实现从万物互联到万物智联的跨越,满足更高的数据需求和更广泛的应用场景。新型多址接入技术和多维扩展技术将在6G中协同发挥作用,为构建高效、智能、可靠的通信网络提供关键支持,满足... 详细信息

随着移动通信技术的不断演进,第6代移动通信(6G)将实现从万物互联到万物智联的跨越,满足更高的数据需求和更广泛的应用场景。新型多址接入技术和多维扩展技术将在6G中协同发挥作用,为构建高效、智能、可靠的通信网络提供关键支持,满足未来通信的多重需求。该文旨在探讨新型多址接入技术在6G多维扩展通信网络中的应用潜力。首先,该文对比了传统多址接入技术与6G潜在新型多址接入技术,并重点阐述了非正交多址接入技术在提升频谱效率和系统容量方面的优势。然后,详细介绍了卫星通信、无人机(UAV)通信和智能反射面(IRS)等多维扩展技术在6G场景下的优势。进一步,讨论了新型多址技术与卫星通信、UAV以及IRS相结合的优势及协同应用。最后,探讨了基于新型多址接入技术的多维扩展网络中的关键技术挑战,包括大规模多入多出技术、太赫兹技术、通感算一体化、用户信息安全、不完美信道状态信息(CSI)估计,同时对新型编码技术、人工智能和机器学习等研究方向进行了展望。

关键词： 6G移动通信多维扩展新型多址接入技术卫星通信无人机智能反射面

Dawn of CAR-T cell therapy in autoimmune diseases

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Chinese Medical Journal 2024年第10期137卷 1140-1150页

作者： Yuxin Liu Minghao Dong Yunhui Chu Luoqi Zhou Yunfan You xiaowei pang Sheng Yang Luyang Zhang Lian Chen Lifang Zhu Jun Xiao Wei Wang Chuan Qin Daishi Tian Department of Neurology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei 430030China Hubei Key Laboratory of Neural Injury and Functional Reconstruction Huazhong University of Science and TechnologyWuhanHubei 430030China

Chimeric antigen receptor(CAR)-T cell therapy has achieved remarkable success in the treatment of hematological *** on the immunomodulatory capability of CAR-T cells,efforts have turned toward exploring their potential in treating autoimmune *** analysis of 210 records from 128 academic journals published by 372 institutions in 40 countries/regions indicates a growing number of publications on CAR-T therapy for autoimmune diseases,covering a range of subtypes such as systemic lupus erythematosus,multiple sclerosis,among ***-T therapy holds promise in mitigating several shortcomings,including the indiscriminate suppression of the immune system by traditional immunosuppressants,and non-sustaining therapeutic levels of monoclonal antibodies due to inherent pharmacokinetic *** persisting and proliferating in vivo,CAR-T cells can offer a tailored and precise *** paper reviewed preclinical experiments and clinical trials involving CAR-T and CAR-related therapies in various autoimmune diseases,incorporating innovations well-studied in the field of hematological tumors,aiming to explore a safe and effective therapeutic option for relapsed/refractory autoimmune diseases.

关键词： CAR-T cell therapy Autoimmune disease Immunotherapy Multiple sclerosis Neuromyelitis optica spectrum disorder Systemic lupus erythematosus

Energy-efficient design for mmW ave-enabled NOMA-UAV networks

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Science China(Information Sciences) 2021年第4期64卷 40-53页

作者： xiaowei pang Jie TANG Nan ZHAO Xiuyin ZHANG Yi QIAN School of Information and Communication Engineering Dalian University of Technology School of Electronic and Information Engineering South China University of Technology Department of Electrical and Computer Engineering University of Nebraska-Lincoln

Owing to the recent advances of non-orthogonal multiple access(NOMA) and millimeter-wave(mmWave), these two technologies are combined in unmanned aerial vehicle(UAV) networks in this ***, energy efficiency has become a significant metric for UAVs owning to their limited energy. Thus, we aim to maximize the energy efficiency for mmWave-enabled NOMA-UAV networks by optimizing the UAV placement, hybrid precoding and power allocation. However, the optimization problem is complicated and intractable, which is decomposed into several sub-problems. First, we solve the UAV placement problem by approximating it into a convex one. Then, the hybrid precoding with user clustering is performed to better reap the multi-antenna gain. Particularly, three schemes are proposed, where the cluster head selection algorithm is adopted while considering different equivalent channels of users. Finally, the power allocation is optimized to maximize the energy efficiency, which is converted to convex and solved via an iterative algorithm. Simulation results are provided to evaluate the performance of the proposed schemes.

关键词： energy efficiency hybrid precoding millimeter-wave non-orthogonal multiple access placement optimization power allocation unmanned aerial vehicle

Time and energy efficient data collection via UAV

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Science China(Information Sciences) 2022年第8期65卷 182-196页

作者： Tianhao WANG xiaowei pang Jie TANG Nan ZHAO Xiuyin ZHANG Xianbin WANG School of Information and Communication Engineering Dalian University of Technology Department of Electrical and Computer Engineering Western University School of Electronic and Information Engineering South China University of Technology

Using unmanned aerial vehicles(UAVs) for data collection has emerged as a promising technique to achieve both time-and energy-efficient data gathering while keeping data fresh. In this study, two schemes are proposed for flight cycle minimization and energy efficiency maximization to collect data from ground sensors. We first minimize the flight cycle by jointly optimizing the wake-up scheduling of sensors, the trajectory,and the time slot, which is a mixed-integer non-convex problem and difficult to solve directly. To this end,we propose an iterative algorithm based on block coordinate descent and successive convex approximation to decouple the original non-convex problem into two sub-problems and the constraints are turned to be convex approximately. Furthermore, the energy efficiency is maximized since the limited energy is a critical issue in UAV communication systems. We approximate the two subproblems as convex optimizations by introducing slack variables and applying SCA. The approximate energy efficiency is a fractional expression, and we use Dinkelbach’s method to solve it. Numerical results show that the flight cycle is minimized in the first scheme with the data requirement satisfied, while in the second scheme, the energy efficiency is maximized with the trade-off between the transmission data and the propulsion power consumption.

关键词： data collection energy efficiency maximization time minimization trajectory optimization unmanned aerial vehicle (UAV)

Tungsten separation behavior on preparation of high-purity cerium by combined vacuum gravity sedimentation-directional solidification

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Journal of Rare Earths 2024年第6期42卷 1182-1186,I0007页

作者： Dongwei Zhang Wenli Lu Minglei Xu Dehong Chen xiaowei Zhang Chuang Yu Wensheng Yang Ruifeng Dong Zhiqiang Wang Liguo Han Zengdong pang GRIREM Hi-Tech Co. Ltd.Langfang065201China National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China GRIREM Advanced Materials Co. Ltd.Beijing100088China

In light of the difficult removal of harmful impurity tungsten(W)in Ce metal,in this paper a combined vacuum gravity sedimentation-directional solidification method was innovatively designed and the W separation behavior was *** reducing the electron beam power instantly and gradually at reduction rates of 1,3 and 5 kW/min,it is found that W is enriched at the bottom of ingots as the melt *** enrichment effect is much better than that of single purification method and the enrichment degree increases as the beam reduction rate decreases,attributed to the k0(W)>1 andρ(W)>ρ(Ce).Overall,the minimum content of W impurity can decrease from 630 to 0.1 ppm at the top of the ingot,and the purity of Ce increases from 99.932 wt%to 99.995 wt%by this combined ***,this paper provides a new method for the removal of high density and low evaporation coefficient impurities in low vapor pressure rare earth metals.

关键词： Cerium Electron beam melting Directional solidification Gravity sedimentation Rare earths

Comparing the effects of dual-task training and single-task training on walking,balance and cognitive functions in individuals with Parkinson’s disease:A systematic review

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Chinese Medical Journal 2024年第13期137卷 1535-1543页

作者： Xiaoying Lin Yanming Zhang xiaowei Zhang Xi Chen Jianhua Liu Lei Yang Marco Yiu Chung pang Department of Rehabilitation Medicine the First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anShaanxi 710061China Department of Rehabilitation Medicine The Second People’s Hospital of KunmingKunmingYunnan 650051China Department of Rehabilitation Medicine Xuanwu HospitalCapital Medical UniversityBeijing 100000China Department of Physical Therapy China Rehabilitation Research CenterBeijing 100000China Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHong Kong 999077China

Background:This systematic review aimed to examine whether dual-task(DT)training was superior to single-task(ST)training in improving DT walking,balance and cognitive functions for individuals with Parkinson’s disease(PD).Methods:Literature search was performed in the following electronic databases:PubMed,the Cochrane Library,Web of Science,and Metstr covering inception to May 10,*** in order to facilitate comparison across trials,we calculated the effect size(Hedges’g)of gait,balance,cognitive,and other parameters under both ST and DT conditions,using the mean change score and standard deviation(SD)of change score of the experimental and control *** controlled trials that examined the effects of DT motor and cognitive training in individuals with Parkinson’s disease were included for this systematic ***:A total of 214 participants recruited from six articles(actually five trials)were involved in this *** terms of walking ability,only double support time and stride time variability showed significant between-group difference(Hedges’g=0.34,0.18,respectively).Compared to ST training group,DT training group had a more improvement effect in laboratory balance measurement(Hedges’g=0.18,1.25),but no significant improvement in clinical balance *** significant between-group differences were observed,thus its training effect on cognitive function was ***:The DT training failed to achieve promising results better than ST training in improving DT walking and balance functions for individuals with *** firm conclusion cannot be drawn at present,due to the limited number of eligible *** sample size and high-quality studies are needed to investigate the effectiveness of DT training in individuals with PD.

关键词： Parkinson’s disease Dual-task training Mobility Cognition Systematic review

数字经济、创新螺旋与产业链关键环节控制能力研究

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科技进步与对策 2024年第9期41卷 1-12页

作者：庞磊阳晓伟云南师范大学经济与管理学院云南昆明650500 宁波大学法学院浙江宁波315211

数字经济改变了现有产业模式,促使产业链由传统生产者主导向新兴消费者主导逆向转变,重构产业链新格局。基于2017—2022年投入产出表、中经网统计数据库和国泰安数据库,结合《数字经济及其核心产业统计分类(2021)》对数字产业化和产业... 详细信息

数字经济改变了现有产业模式,促使产业链由传统生产者主导向新兴消费者主导逆向转变,重构产业链新格局。基于2017—2022年投入产出表、中经网统计数据库和国泰安数据库,结合《数字经济及其核心产业统计分类(2021)》对数字产业化和产业数字化进行统计分类,采用PSM、渐进DID方法,聚焦数字经济、创新螺旋与产业链关键环节控制能力进行分析,得出如下结论:一是数字经济能够有效提升产业链中心度和中介度,促进关键环节控制能力提升;二是数字产业化与产业数字化能够显著提升产业链关键环节控制能力,数字产业化的推动作用强于产业数字化;三是数字经济提升产业链关键环节控制能力存在区域异质性、时段异质性和“卡脖子”行业异质性;四是数字技术“创新螺旋”效应承担部分中介作用,数字经济通过“创新螺旋”效应有效提升产业链关键环节控制能力。据此,提出数字经济驱动产业链关键环节控制能力提升的实践路径。

关键词：数字经济创新螺旋数字产业化产业数字化产业链

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煤矿倾斜地层瞬变电磁加权横向约束反演

吉林大学学报（地球科学版） 2024年第1期54卷 310-322页

作者：高小伟苏超庞少东中煤科工西安研究院(集团)有限公司西安710077 吉林大学地球探测科学与技术学院长春130026

传统的单点一维反演是煤矿瞬变电磁数据处理与解释应用最广泛的技术方法,然而,实际地层往往存在一定倾角,当地层倾角较大时,基于单点水平层状模型的一维反演方法将不再适用,无法准确还原倾斜地层的电性分布特征。为此,针对煤矿瞬变电磁... 详细信息

传统的单点一维反演是煤矿瞬变电磁数据处理与解释应用最广泛的技术方法,然而,实际地层往往存在一定倾角,当地层倾角较大时,基于单点水平层状模型的一维反演方法将不再适用,无法准确还原倾斜地层的电性分布特征。为此,针对煤矿瞬变电磁探测点距小、沉积地层地下电性结构相对连续的特点,本文采用加权横向约束反演(weighted laterally-constrained inversion,WLCI)方法,将相邻测点地电参数的差异作为约束项加入目标函数,对层界面的深度进行约束,同时引入加权因子控制约束强度,反演过程尽可能使相邻测点反演剖面具有横向的连续性以及纵向的光滑性。首先,阐述了瞬变电磁一维正、反演原理,并对WLCI计算过程进行了详细介绍。然后,建立了2组不同倾斜角度的H型与K型模型进行测试,分析加权因子对反演结果的影响。与传统的一维反演结果相比,WLCI通过建立层参数和深度加权约束方程并合成总的反演方程,是一种拟二维的反演方法,反演的电阻率剖面横向及纵向连续性好,与实际模型的吻合度较高,验证了反演方法的有效性。最后,实测数据的反演结果显示,WLCI可以准确还原倾斜地层的电性分布,反演结果与实际地质资料吻合。

关键词：倾斜地层瞬变电磁一维反演加权横向约束反演拟二维反演

玛多7.4级地震野马滩大桥桥台纵桥向破坏机理分析

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土木工程学报 2024年第5期57卷 53-64页

作者：周成叶爱君王晓伟庞于涛包绍伦同济大学土木工程防灾减灾全国重点实验室上海200092 中国地质大学(武汉) 湖北武汉430074 中交第一公路勘察设计研究院有限公司陕西西安710068

针对2021年青海玛多7.4级地震中野马滩大桥的桥台震害,开展基于Pushover分析的桥台纵桥向破坏机理研究。提出土-桩-桥台精细化有限元模拟方法,以及基于地勘资料的模型土体参数确定实用方法,建模方法和加载模式要点为:(1)适用于土-桥台... 详细信息

针对2021年青海玛多7.4级地震中野马滩大桥的桥台震害,开展基于Pushover分析的桥台纵桥向破坏机理研究。提出土-桩-桥台精细化有限元模拟方法,以及基于地勘资料的模型土体参数确定实用方法,建模方法和加载模式要点为:(1)适用于土-桥台相互作用的分布式p-y弹簧修正模型;(2)可识别背墙弯曲、剪切或弯-剪多种破坏模式的背墙非线性梁柱单元-墙底非线性剪切单元串联模型;(3)土-搭板和土-翼墙摩擦弹簧;(4)基于分布式间隙单元的可捕捉地震中主梁与背墙接触位置变化的Pushover加载模式,从而实现了桥台纵桥向地震损伤破坏全过程模拟。结果表明:野马滩桥台在水平地震作用下,背墙底截面先发生屈服,随后背墙剪力达到抗剪能力峰值,桥台整体水平承载力开始退化,直至背墙底完全剪断,而桩基础并不发生明显损伤。总体而言,桥台破坏模式为背墙弯-剪破坏,数值分析结果与桥台实际震害相符。

关键词：玛多地震桥台纵桥向破坏机理土-桩-桥台精细化有限元模型 Pushover分析地勘资料