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A Novel Peak-to-Average Power Ratio Reduction Scheme via Tone Reservation in OFDM Systems

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China Communications 2017年第11期14卷 279-290页

作者： Jurong Bai Yong Li Wei Cheng huimin du Yanben Wang School of Electronics and Information Northwestern Polytechnical University School of Electronic Engineering Xi'an University of Posts and Telecommunications

In this paper, a novel signal-to-clipping noise ratio and least squares approximation tone reservation scheme(SCR-LSA TR) is proposed to reduce the peak-to-average power ratio for orthogonal frequency division multiplexing systems. during the SCR procedure, only the element with the maximal amplitude is picked for processing, which not only decreases the algorithm complexity, but also helps to overcome the BER deterioration. With the LSA method, the amplitude of the peak-cancelling signals can approximate to that of the original clipping noise as much as possible. Through the combination of the optimization factor in the LSA method, the classic SCR method can achieve better PAPR reduction with faster convergence. Simulation results show that the proposed SCR-LSA TR scheme has less in-band distortion and smaller out-of-band spectral radiation. The BER of the proposed scheme shows a better performance especially under the 16-QAM over the additive white Gaussian noise channel.

关键词： orthogonal frequency division multiplexing peak-to-average power ratio tone reservation signal to clipping noise ratio

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面向密集场景的空天地网络资源分配算法

电子与信息学报 2024年第5期46卷 1968-1976页

作者：张鸿廖彧歆王汝言吴大鹏杜慧敏重庆邮电大学通信与信息工程学院重庆400065 先进网络与智能互联技术重庆市高校重点实验室重庆400065 泛在感知与互联重庆市重点实验室重庆400065

空天地网络具有覆盖范围大、吞吐量高、弹性强等优点。该文针对大量用户并发接入、网络负载不均衡所引发的网络拥塞、服务质量恶化等问题,提出一种面向密集场景的资源分配算法。首先以用户需求为中心,根据不同类型用户任务的偏好来构建... 详细信息

空天地网络具有覆盖范围大、吞吐量高、弹性强等优点。该文针对大量用户并发接入、网络负载不均衡所引发的网络拥塞、服务质量恶化等问题,提出一种面向密集场景的资源分配算法。首先以用户需求为中心,根据不同类型用户任务的偏好来构建用户效用函数,然后基于匹配博弈的网络选择算法和结合对偶上升法的功率控制算法来实现负载均衡,优化资源分配方案。实验表明,相较于传统策略,所提策略整体用户接入率至少提高35%,时延和吞吐量方面性能提升超过50%;在密集场景下,能更有效地均衡负载,提升网络性能。

关键词：空天地一体化网络资源分配博弈论密集场景

京广高铁沿线武汉乌龙泉镇生境质量演变特征研究

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风景园林 2024年第2期31卷 102-110页

作者：殷利华杜慧敏姚忠勇华中科技大学建筑与城市规划学院华中科技大学湖北省城镇化工程技术研究中心武汉林业集团

【目的】高铁作为中国重要的交通基础设施,其建设和运营不可避免对沿线环境造成不同程度的影响,如土地利用变化、生境质量变化、生物多样性干扰等,但其影响程度、范围等科学问题亟待深入研究。【方法】以京广高铁武汉江夏区生态本底良... 详细信息

【目的】高铁作为中国重要的交通基础设施,其建设和运营不可避免对沿线环境造成不同程度的影响,如土地利用变化、生境质量变化、生物多样性干扰等,但其影响程度、范围等科学问题亟待深入研究。【方法】以京广高铁武汉江夏区生态本底良好的乌龙泉镇为研究区域,运用InVEST 3.2模型,分析2000—2010年、2010—2020年、2000—2020年研究区域生境质量的时空演变,探讨京广高铁建设对两侧生境质量的影响特征。【结果】1)研究区域用地类型转化有时段差异:2000—2010年主要是林地、湿地和水体转化为耕地,2010—2020年则是耕地向其他类转化。2)镇域生境质量先差后优:建设用地扩张使生境质量较差区域的面积持续增加,生境质量优良的林地和水体面积为先减后增。3)核心区域的生境质量变化特征与镇域表现一致。2000—2020年,高铁建设对沿线核心区生境质量的影响明显,生境质量整体变差,部分水域湿地生境质量提高。【结论】京广高铁沿线土地利用方式的改变很大程度影响了沿线的生境质量。高铁两侧用地类型及结构不同,对两侧生境质量的影响程度各不同:高铁沿线西侧随远离高铁距离的增加,生境质量呈现“先降后升”特点,而东侧则相反。分析高铁不同时间对沿线乡镇生境质量影响特征,可为沿线生物多样性保护和受损生境修复以及美丽乡村建设等提供参考依据。

关键词：风景园林绿色基础设施生境修复生物多样性保护可持续发展 InVEST模型

高铁对沿线野生动物空间分布的影响特征及生境适宜性评价——以京广高铁武汉乌龙泉段为例

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中国园林 2024年第5期40卷 97-103页

作者：殷利华杜慧敏余田姚忠勇万敏华中科技大学建筑与城市规划学院武汉430074 华中科技大学湖北省城镇化工程技术研究中心武汉430074 武汉林业集团武汉430056 华中科技大学建筑与城市规划学院景观学系武汉430074) 本刊

高铁作为中国重要的交通基础设施,其建设和运营不可避免会对沿线环境造成不同程度的影响。解析高铁对沿线生境的干扰特征,是实现沿线野生动物保护的重要途径。基于京广高铁武汉乌龙泉段乡野样本地的长期红外相机监测结果,分析高铁对沿... 详细信息

高铁作为中国重要的交通基础设施,其建设和运营不可避免会对沿线环境造成不同程度的影响。解析高铁对沿线生境的干扰特征,是实现沿线野生动物保护的重要途径。基于京广高铁武汉乌龙泉段乡野样本地的长期红外相机监测结果,分析高铁对沿线野生动物空间分布的影响特征,并筛选出当地陆地野生动物代表物种小麂,提取其分布点数据,利用最大熵(MaxEnt)模型预测小麂生境适宜区分布,分析气候、地形、人类干扰和水源4类环境变量的影响程度。结果表明:1)高铁对狗獾和黄鼬造成空间阻隔效应显著;2)小麂、白鹇、黄鼬、狗獾和貉均对高铁产生回避效应;3)代表物种小麂的适宜生境主要分布于核心区的中部,距离高铁的远近是影响小麂生境适宜性的主要因素,且高铁对小麂生境的最大影响距离约为1500m。根据野生动物生境区因高铁建设而受到干扰的情况,通过增加水源点、营造适宜动物生存的植被空间等措施促进其受损生境修复。研究结果可为高铁沿线受损生境的空间识别和修复提供参考。

关键词：风景园林生境干扰高铁建设生境修复生物多样性保护

变步长CMA和DD-LMS双模式切换盲均衡算法

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西安邮电大学学报 2024年第1期29卷 53-63页

作者：杜慧敏刘洋马元中西安邮电大学电子工程学院陕西西安710121 烽火通信科技股份有限公司湖北武汉430205

针对经典盲均衡算法收敛速度较慢和稳态误差较大的问题,提出了一种基于变步长恒模算法(Constant Modulus Algorithm, CMA)和判决引导的最小均方(Decision Directed Least Mean Square, DD-LMS)算法的双模式切换盲均衡算法。在算法收敛... 详细信息

针对经典盲均衡算法收敛速度较慢和稳态误差较大的问题,提出了一种基于变步长恒模算法(Constant Modulus Algorithm, CMA)和判决引导的最小均方(Decision Directed Least Mean Square, DD-LMS)算法的双模式切换盲均衡算法。在算法收敛初期采用CMA算法,以确保算法可以较快收敛。在收敛之后切换至DD-LMS算法,以进一步降低稳态误差。通过设定阈值来切换算法,取相邻多次迭代误差的平均值作为算法的切换值,以确保算法切换时机的合理性。另外,引入Softsign变步长函数并加入3个参数对该函数进行改进,使得Softsign变步长函数可以依据不同信道环境设定最佳参数,同时提高算法的收敛速度。仿真结果表明,在卫星通用信道条件下,所提算法的收敛迭代次数约为1 000次,稳态误差为-12 dB,在信噪比为15 dB时,误码率为1×10~(-6)。与相关算法对比,所提算法的收敛速度较高,误码率和稳态误差较低。

关键词：变步长盲均衡误码率均方误差双模式算法

Yb^(3+)/Ho^(3+)共掺杂Sc^(2)W_(3)O_(12)荧光粉的上转换发光和温度传感特性

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聊城大学学报（自然科学版） 2024年第2期37卷 42-49页

作者：杜慧敏杨骏胡珊珊西南大学化学化工学院重庆北碚400715

利用水热法结合煅烧制备Sc^(2)W_(3)O_(12):Yb 3+/Ho 3+荧光粉,用X射线衍射仪、扫描电子显微镜和荧光光谱仪对样品进行表征。在980 nm的激光激发下,Sc^(2)W_(3)O_(12):Yb 3+/Ho 3+表现出了542、657和752 nm三个特征峰,分别对应于Ho^(3+)... 详细信息

利用水热法结合煅烧制备Sc^(2)W_(3)O_(12):Yb 3+/Ho 3+荧光粉,用X射线衍射仪、扫描电子显微镜和荧光光谱仪对样品进行表征。在980 nm的激光激发下,Sc^(2)W_(3)O_(12):Yb 3+/Ho 3+表现出了542、657和752 nm三个特征峰,分别对应于Ho^(3+)的^(5)F_(4)/^(5)S_(2)-^(5)I_(8),^(5)F_(5)-^(5)I_(8) 和 ^(5)F_( 4)/^(5)S_( 2)-^(5)I_(7)能级跃迁,分别发射出绿光、红光和弱红光。讨论了荧光粉的上转换发光机理,得出绿色和红色上转换发射均为双光子过程。基于荧光强度比技术,在323~523 K温度范围内研究了^(5)F_(4)/^(5)S_(2)与^(5)F_(5)这对非热耦合能级的上转换发光强度与温度的关系,得出在523 K时荧光粉的最大绝对灵敏度达到1%K-1,结果表明Sc^(2)W_(3)O_(12):Yb ^(3+)/Ho^( 3+)荧光粉可以作为温度传感器的候选材料。

关键词：上转换发光能量传递荧光强度比温度传感器

Trogocytosis of CAR molecule regulates CAR-T cell dysfunction and tumor antigen escape

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Signal Transduction and Targeted Therapy 2024年第1期9卷 326-337页

作者： You Zhai Yicong du Guanzhang Li Mingchen Yu huimin Hu Changqing Pan Di Wang Zhongfang Shi Xu Yan Xuesong Li Tao Jiang Wei Zhang Department of Molecular Neuropathology Beijing Neurosurgical InstituteCapital Medical UniversityBeijingPR China Department of Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijingPR China Department of Urology Peking University First HospitalInstitute of UrologyPeking UniversityNational Urological Cancer CenterBeijingPR China Department of Pathophysiology Beijing Neurosurgical InstituteCapital Medical UniversityBeijingPR China China National Clinical Research Center for Neurological Diseases BeijingPR China Center of Brain Tumor Beijing Institute for Brain DisordersBeijingPR China Research Unit of Accurate Diagnosis Treatmentand Translational Medicine of Brain TumorsChinese Academy of Medical SciencesBeijingPR China Chinese Glioma Genome Atlas Network(CGGA)and Asian Glioma Genome Atlas Network(AGGA) BeijingPR China

Chimeric antigen receptor(CAR)T-cell therapy has demonstrated clinical response in treating both hematologic malignancies and solid tumors.Although instances of rapid tumor remissions have been observed in animal models and clinical trials,tumor relapses occur with multiple therapeutic resistance mechanisms.Furthermore,while the mechanisms underlying the long-term therapeutic resistance are well-known,short-term adaptation remains less understood.However,more views shed light on short-term adaptation and hold that it provides an opportunity window for long-term resistance.In this study,we explore a previously unreported mechanism in which tumor cells employ trogocytosis to acquire CAR molecules from CAR-T cells,a reversal of previously documented processes.This mechanism results in the depletion of CAR molecules and subsequent CAR-T cell dysfunction,also leading to short-term antigen loss and antigen masking.Such type of intercellular communication is independent of CAR downstream signaling,CAR-T cell condition,target antigen,and tumor cell type.However,it is mainly dependent on antigen density and CAR sensitivity,and is associated with tumor cell cholesterol metabolism.Partial mitigation of this trogocytosis-induced CAR molecule transfer can be achieved by adaptively administering CAR-T cells with antigen density-individualized CAR sensitivities.Together,our study reveals a dynamic process of CAR molecule transfer and refining the framework of clinical CAR-T therapy for solid tumors.

关键词： Together instance depletion

On the Application of Mixed Models of Probability and Convex Set for Time-Variant Reliability Analysis

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1981-1999页

作者： Fangyi Li Dachang Zhu huimin Shi Center for Research on Leading Technology of Special Equipment School of Mechanical and Electric EngineeringGuangzhou UniversityGuangzhou510006China

In time-variant reliability problems,there are a lot of uncertain variables from different sources.Therefore,it is important to consider these uncertainties in engineering.In addition,time-variant reliability problems typically involve a complexmultilevel nested optimization problem,which can result in an enormous amount of computation.To this end,this paper studies the time-variant reliability evaluation of structures with stochastic and bounded uncertainties using a mixed probability and convex set model.In this method,the stochastic process of a limit-state function with mixed uncertain parameters is first discretized and then converted into a timeindependent reliability problem.Further,to solve the double nested optimization problem in hybrid reliability calculation,an efficient iterative scheme is designed in standard uncertainty space to determine the most probable point(MPP).The limit state function is linearized at these points,and an innovative random variable is defined to solve the equivalent static reliability analysis model.The effectiveness of the proposed method is verified by two benchmark numerical examples and a practical engineering problem.

关键词： Mixed uncertainty probability model convex model time-variant reliability analysis

Selenium-oxidizing Agrobacterium sp.T3F4 decreases arsenic uptake by Brassica rapa L.under a native polluted soil

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Journal of Environmental Sciences 2024年第4期138卷 506-515页

作者： Lijin An Chunzhi Zhou Lipeng Zhao Ao Wei Yiting Wang huimin Cui Shixue Zheng State Key Laboratory of Agricultural Microbiology College of Life Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China

Toxic arsenic(As)and trace element selenium(Se)are transformed by microorganisms but their complex interactions in soil-plant systems have not been fully understood.An Asand Se-oxidizing bacterium,Agrobacterium sp.T3F4,was applied to a native seleniferous As-polluted soil to investigate As/Se uptake by the vegetable Brassica rapa L.and As-Se interaction as mediated by strain T3F4.The Se content in the aboveground plants was significantly enhanced by 34.1%,but the As content was significantly decreased by 20.5% in the T3F4-inoculated pot culture compared to the control(Pduced by increasing Se(IV)concentrations.The 50% growth inhibition concentration(IC50)values for As in plants were increased about one-fold and two-fold under co-exposure with 5 and 10μmol/L Se(IV),respectively.In conclusion,strain T3F4 improves Se uptake but decreases As uptake by plants via oxidation of As and Se,resulting in decrease of soil As bioavailability and As/Se competitive absorption by plants.This provides a potential bioremediation strategy for Se biofortification and As immobilization in As-polluted soil.

关键词： Selenium oxidation Selenium biofortification Arsenite-oxidizing bacteria Arsenic immobilization Brassica rapa L