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Handover improvement based on cost function and user fairness for cellular relay enhanced LTE networks

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High Technology Letters 2011年第3期17卷 299-304页

作者： Chen Muqiong ji Hong li Xi Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 P. R. China

In order to optimize handover target selection and achieve better handover performance in cellular relay networks under the long term evolution （LTE） system, a novel handover measurement and decision scheme based on cost function is proposed in the paper. The relay-enhanced network provides user equipment （UE） multiple handover choices from neighbor base stations or relays. This may result in different overhead, resource utility and traffic load which attaches importance to proper handover schemes. Compared with traditional handover measurement and decision schemes, the proposed scheme adopts reference signal receiving quality （RSRQ） in the measurement stage and uses a modified signal cost function considering signal overhead in different handover types and expected long-term throughput of UE. Besides, UE fairness and sector resource utilization are taken into account as well. Theory analysis and simulation results prove that the proposed scheme can enhance cell throughput, decrease handover delay and signal overhead, and improve UE fairness.

关键词： handover relay cost function fairness

Differentiation of retinal ganglion cells from induced pluripotent stem cells: a review

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International Journal of Ophthalmology(English edition) 2019年第1期12卷 152-160页

作者： Shang-li ji Shi-Bo Tang Aier Eye Institute Aier School of Ophthalmology Central South University

Glaucoma is a common optic neuropathy that is characterized by the progressive degeneration of axons and the loss of retinal ganglion cells(RGCs). Glaucoma is one of the leading causes of irreversible blindness worldwide. Current glaucoma treatments only slow the progression of RGCs loss. Induced pluripotent stem cells(iPSCs) are capable of differentiating into all three germ layer cell lineages. iPSCs can be patient-specific,making iPSC-derived RGCs a promising candidate for cell replacement. In this review, we focus on discussing the detailed approaches used to differentiate iPSCs into RGCs.

关键词： glaucoma retinal ganglion cells induced pluripotent stem cells differentiation

The synergy reduction and self-assembly of graphene oxide via gamma-ray irradiation in an ethanediamine aqueous solution

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Nuclear Science and Techniques 2016年第3期27卷 80-87页

作者： Ya-Lei He ji-Hao li lin-Fan li jing-Bo Chen jing-Ye li School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002China CAS Center for Excellence on TMSR Energy System Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China

Gamma-ray irradiation technique is an effective method for preparing graphene aerogel(GA).The effective reduction and self-assembly of graphene oxide(GO) sheets into 3D porous GA in ethylenediamine(EDA) aqueous solution under the protection of nitrogen have been achieved via γ-ray *** reduction degree and self-assembly process,which can be controlled by varying EDA dose and irradiation dose,are investigated by X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,X-ray diffractometer,and thermogravimetric analysis.A reduction mechanism is proposed for interactions among EDA molecules,active radicals from the radiolysis of water,and oxygen-containing groups on GO sheets.

关键词： γ射线照射氧化石墨乙二胺自组装协同还原溶液傅里叶变换红外光谱 X射线光电子能谱

Atom-pair tunneling and quantum phase transition in asymmetry double-well trap in strong-interaction regime

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Chinese Physics B 2019年第11期28卷 67-73页

作者： ji-li liu jiu-Qing liang College of Physics and Information Engineering Shanxi Normal UniversityLinfen 041004China Institute of Theoretical Physics Shanxi UniversityTaiyuan 030006China

The quantum effect of nonlinear co-tunnelling process, which is dependent on atom-pair tunneling and asymmetry of an double-well trap, is studied by using an asymmetrical extended Bose–Hubbard model. Due to the existence of atompair tunneling that describes quantum phenomena of ultracold atom-gas clouds in an asymmetrical double-well trap, the asymmetrical extended Bose–Hubbard model is better than the previous Bose–Hubbard model model by comparing with the experimental data cited from the literature. The dependence of dynamics and quantum phase transition on atom-pair tunneling and asymmetry are investigated. Importantly, it shows that the asymmetry of the extended Bose–Hubbard model,corresponding to the bias between double wells, leads to a number of resonance tunneling processes, which tunneling is renamed conditional resonance tunneling, and corrects the atom-number parity effect by controlling the bias between double wells.

关键词： atom-pair tunneling quantum phase transition

Resource allocation for load balancing and fairness improvement in relay-assisted OFDMA cellular

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High Technology Letters 2011年第4期17卷 377-382页

作者： Zhang Hailong ji Hong li Xi Key Lab of Universal Wireless Communications Ministry of EducationBeijing University of Posts and Telecommunications Beijing 100876 P.R.China

A resource allocation scheme with the considerations of user fairness and load balancing is proposed in orthogonal frequency division multiple access （OFDMA）-based relay networks. The optimal resource allocation scheme is formulated mathematically to maximize the minimum achievable rate among all user equipments （UEs） for fairnegs improvement. The optimal problem has been proved to be N-P-hard and it is prohibitive to find the optimal solution for its computational complexity. Accordingly, this paper proposes a suboptimal scheme which considers not only user fairness but also load balancing among base stations （BS） and relay stations （RSs） during resource allocation procedure. The suboptimal scheme takes the traffic load of access nodes （BS and RSs） into consideration to balance the system traffic load, which would prevent them from overloading and throughput degradation. Simulation results show that the suboptimal scheme performs similarly to the optimal solution and can enhance the system fairness and load balancing performance significantly compared with the traditional schemes.

关键词： radio resource allocation relay fairness load balancing orthogonal frequency division multiple access (OFDMA)

A local version of Hardy spaces associated with operators on metric spaces

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Science China Mathematics 2013年第2期56卷 315-330页

作者： GONG RuMing li ji YAN liXin School of Mathematics and Information Science Guangzhou University Key Laboratory of Mathematics and Interdisciplinary Sciences of Guangdong Higher Education Institutes Guangzhou University Department of Mathematics Sun Yat-sen University

Let （X, d, μ） be a metric measure space endowed with a distance d and a nonnegative Borel doubling measure μ. Let L be a second order self-adjoint positive operator on L^2（X）. Assume that the semigroup e-^tL generated by -L satisfies the Gaussian upper bounds on L2（X）. In this article we study a local version of Hardy space hi （X） associated with L in terms of the area function characterization, and prove their atomic characters. Furthermore, we introduce a Moser type local boundedness condition for L, and then we apply this condition to show that the space hzL（X） can be characterized in terms of the littlewood-Paley function. Finally, a broad class of applications of these results is described.

关键词： local Hardy space non-negative self-adjoint operator semigroups local (1 p)-atoms Moser typelocal boundedness condition space of homogeneous type

基于日尺度SPEI的黄土高原干旱时空变化特征及影响因素分析

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水土保持研究 2025年第2期32卷 244-254页

作者：杨广史海静姜艳敏吴友福王椰李冀西北农林科技大学水土保持科学与工程学院陕西杨凌712100 中国科学院水利部水土保持研究所陕西杨凌712100 中国科学院大学北京100049

[目的]探究黄土高原地区气象干旱的时空变化特征及其影响因素,以期为该地区的干旱监测、旱作农业粮食生产、水资源管理及生态恢复建设提供科学支撑。[方法]基于黄土高原地区119个站点1957—2019年逐日气象资料,使用FAO Penman-Monteith... 详细信息

[目的]探究黄土高原地区气象干旱的时空变化特征及其影响因素,以期为该地区的干旱监测、旱作农业粮食生产、水资源管理及生态恢复建设提供科学支撑。[方法]基于黄土高原地区119个站点1957—2019年逐日气象资料,使用FAO Penman-Monteith公式计算了日尺度潜在蒸散发及标准化降水蒸散指数(SPEI),并采用Theil-Sen Median斜率估计和Mann-Kendall趋势分析,探讨了干旱天数、干旱事件发生次数和强度的分布特征及变化趋势。同时,使用皮尔逊相关系数分析气象因子与干旱指标的关系,并结合土地利用类型转移矩阵探讨了人类活动对气象干旱的影响。[结果](1)日尺度SPEI在识别干旱天数、干旱事件发生次数和强度方面比月尺度SPEI更为精确;(2) 1957—2019年黄土高原西北地区干旱事件发生次数增加,大部分区域干旱强度呈现不断增加的趋势,不同类型干旱的天数有所降低;(3)黄土高原东南部和西北部地区存在明显的变干趋势,而北部和南部地区则呈现出湿润化趋势;(4)气象因子与干旱指标之间存在中等相关关系,土地利用/地表覆盖对黄土高原地区的气象干旱产生了一定程度的影响。[结论]黄土高原地区的气象干旱受气候因素和人类活动的双重影响,其时空变化特征复杂。研究结果为该地区的干旱监测与管理提供了重要的科学依据。

关键词：黄土高原日尺度SPEI 气象干旱 Theil-Sen Median斜率估计

Distribution,characteristics and daily fluctuations of microplastics throughout wastewater treatment plants with mixed domestic-industrial influents in Wuxi City,China

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Frontiers of Environmental Science & Engineering 2022年第1期16卷 107-115页

作者： Wei Shan Bingbing li Haichuan Zhang Zhenghao Zhang Yan Wang Zhiyang Gao ji li School of Environment and Civil Engineering Jiangnan UniversityWuxi 214122China jiangsu Key Laboratory of Anaerobic Biotechnology Jiangnan UniversityWuxi 214122China jiangsu College of Water Treatment Technology and Material Collaborative Innovation Centre Suzhou 215009China jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology Jiangnan UniversityWuxi 214122China Wuxi Puhui Environmental Protection Technology Co. Ltd.Wuxi 214122China Wuxi Hi-Tech Water Co. Ltd.Wuxi 214028Chin

In wastewater treatment plants(WWTPs),microplastics(MPs)are complex,especially with mixed domestic–industrial *** random grab sampling can roughly depict the distribution and characteristics of MPs but can not accurately reflect their daily *** this study,the concentration,shape,polymer type,size,and color of MPs were analyzed by micro-Raman spectroscopy(detection limit of 0.05 mm)throughout treatment stages of three mixed domestic–industrial WWTPs(W1,W2,and W3)in Wuxi City,China,and the daily fluctuations of MPs were also obtained by dense grab sampling within 24 *** influent samples,the average MP concentration of 392.2 items/L in W1 with 10%industrial wastewater was much higher than those in W2(71.2 items/L with 10%industrial wastewater)and W3(38.3 items/L with 60%industrial wastewater).White polyethylene granules with a diameter less than 0.5 mm from plastic manufacturing were the most dominant MPs in the influent of W1,proving the key role of industrial sources in MPs *** addition,the daily dense sampling results showed that MP concentration in W1 influent fluctuated widely between 29.1 items/L and 4617.6 items/L within a ***,few MPs(less than 4.0 items/L)in these WWTPs effluents were attributed to the effective removal of wastewater treatment ***,further attention should be paid to regulating the primary sources of MPs.

关键词： Microplastic Wastewater treatment plant Mixed domestic-industrial influent Characteristic Daily fluctuation

Simple synthesis of silver nanocluster composites AgNCs@PE-g-PAA by irradiation method and fluorescence detection of Cr^(3+)

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Nuclear Science and Techniques 2023年第5期34卷 101-111页

作者： Fei Han Wen-Rui Wang Dan-Yi li Mou-Hua Wang ji-Hao li lin-Fan li Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Wuwei Institute of New Energy Wuwei 733000China

Silver nanoclusters(AgNCs)are a new type of nanomaterials with similar properties to molecules and unique *** applications of AgNCs can be significantly expanded by combining them with different matrix materials to obtain AgNC *** irradiation techniques,we developed a simple two-step method for preparing silver nanocluster ***,polyacrylic acid(PAA)chains were grafted onto the surface of a PE film as templates(PE-g-PAA).Subsequently,silver ions were reduced in situ on the surface of the template material to obtain the AgNC composites(AgNCs@PE-g-PAA).The degree of AgNC loading on the composite film was easily controlled by adjusting the reaction *** loaded AgNCs were anchored to the carboxyl groups of the PAA and wrapped in the graft *** particle size of the AgNCs was only 4.38±0.85 nm,with a very uniform particle size *** AgNCs@PE-g-PAA exhibited fluorescence characteristics derived from the *** fluorescence of the AgNCs@PE-g-PAA was easily quenched by Cr^(3+)*** composite can be used as a fluorescence test paper to realize visual detection of Cr^(3+).

关键词： Silver nanoclusters Irradiation grafting Irradiation reduction In situ preparation Fluorescence detection