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Mathematical modelling study for water uptake of steadily growing plant root

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Science China(Physics,Mechanics & Astronomy) 2008年第2期51卷 184-205页

作者： CHU JiaQiang jiao weiping XU JianJun School of Mathematical Sciences Nankai UniversityTianjin 300071China Department of Mathematics and Statistics McGill UniversityMontreal H3A 2K6Canada

The root system of plant is a vitally important organ for living plant. One of the major functions of the root system is uptaking water and nutrients from the soil. The present paper analyzes the whole process of water uptake from soil by a steadily growing plant with a single slender root. We start from the basic principles of physics and fluid-dynamics, consider the structure characteristics of the water transport channel formed by the tiny xylems tubes inside plant, and establish a simplified coherent mathematical model to describe the water transport in the complete system consisting of soil, individual plant, including root, stem and leaves-atmosphere, on the basis of the plant physiology. Moreover, we resolve the proposed mathematical model for a simple artificial plant model under a variety of conditions, in terms of the numerical approach as well as analytical approach. It is shown that the results obtained by both approaches are in very good agreement; the theoretical predictions are qualitatively consistent with the practical experi-ences very well. The simplified mathematical model established in the present pa-per may provide a basis for the further investigations on the more sophisticated mathematical model.

关键词： plant root water uptake Poiseuille flow asymptotic expansion solution

Cadmium uptake and speciation changes in the rhizosphere of cadmium accumulator and non-accumulator oilseed rape varieties

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Journal of Environmental Sciences 2009年第8期21卷 1125-1128页

作者： SU Dechun XING Jianping jiao weiping WONG Woonchung College of Resources and Environmental Sciences China Agricultural University Beijing 100193 China Department of Biology Hong Kong Baptist University Kowloon Tong Hong Kong SAR China

Characteristics of cadmium （Cd） uptake kinetics and distribution of Cd speciation in the rhizosphere for Cd accumulator and nonaccumulator oilseed rape varieties were investigated under nutrient solution and rhizobox soil culture conditions. The results showed that the maximal influx （Vmax） for Cd^2＋ and Km were significantly different for the two oilseed rape varieties. The value of Vmax for Cd accumulator oilseed rape Zhucang Huazi was two-fold greater than that for oilseed rape Chuan you Ⅱ-93. The exchangeable Cd concentration in the rhizosphere was significantly lower than in non-rhizospheric soils supplemented with CdSO4 for both the varieties. Carbonate-bound Cd in the rhizosphere of Cd accumulator oilseed rape was significantly higher than that in the rhizosphere of nonaccumulator oilseed rape and non-rhizospheric soil. Cd accumulator oilseed rape had a higher Cd^2＋ affinity and more ability to uptake insoluble Cd in the soil than the non-accumulator oilseed rape.

关键词： cadmium oilseed rape rhizosphere uptake kinetics

C—F Bond Insertion into Indoles with CHBr_(2)F:An Efficient Method to Synthesize Fluorinated Quinolines and Quinolones

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Chinese Journal of Chemistry 2024年第10期42卷 1128-1132页

作者： Chao Li Lei Chen Hongye Wang Zixi Yan Bin Lyu weiping Lyu Changwei Jiang Dehua Lu Jiaxing Li Ning jiao Song Song State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityXue Yuan Rd.38Beijing 100191China

A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharmaceuticals,materials,and organic synthesis,was described through C—F bond insertion into indoles using CHBr_(2)*** simple conditions,readily availability of CHBr_(2)F,as well as the versatility of the transformations make this strategy very powerful in synthesizing 3-fluoroquinoline and *** mechanistic studies reveal that bromofluorocarbene generated in-situ under basic condition was the key intermediate.

关键词： Skeleton edit Fluorocarbene Ring expansion Quinoline Quinolone

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良性周围性神经鞘瘤的超声诊断价值

中华医学杂志 2016年第7期96卷 551-552页

作者：焦卫平陈述王萍首都医科大学宣武医院超声诊断科北京100053

目的探讨周围性神经鞘瘤的声像图特点。方法回顾分析首都医科大学宣武医院2011年3月至2014年11月经手术病理证实的31例周围性神经鞘瘤的超声图像及临床表现。结果31例患者中14例具有触压疼痛等临床症状，17例表现为无痛性浅表肿物。超... 详细信息

目的探讨周围性神经鞘瘤的声像图特点。方法回顾分析首都医科大学宣武医院2011年3月至2014年11月经手术病理证实的31例周围性神经鞘瘤的超声图像及临床表现。结果31例患者中14例具有触压疼痛等临床症状，17例表现为无痛性浅表肿物。超声表现为低回声结节30例，平均大小（2．9±1．6）cm；包膜完整，边界清，其中1例出现部分囊性变；彩色多普勒超声血流显像：70％（21／30例）病变内无血流信号，30％有少量血流信号（9／30例）；2例为多发病变。另1例术前超声检查显示为无回声，误诊为腱鞘囊肿。结论低回声，包膜完整，边界清，少或无血流信号是超声诊断神经鞘瘤的主要依据，部分病例超声可出现囊性变，少数为多发病变。

关键词：神经鞘瘤超声检查诊断

Stochastic resonance of spinor condensates in optical cavity

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 80-87页

作者： Zheng-Chun Li Bixuan Fan Lu Zhou weiping Zhang School of Physics and Astronomy and Tsung-Dao Lee InstituteShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Precision Spectroscopy School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China Shanghai Branch Hefei National LaboratoryShanghai 201315China Shanghai Research Center for Quantum Sciences Shanghai 201315China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Stochastic resonance is a phenomenon in which adding random noise to a system enhances the detection or transmission of a weak signal. It occurs when the noise interacts with the system's nonlinearity, thus improving signal-to-noise ratio and increasing sensitivity. Although parametric resonances in an atomic spinor Bose-Einstein condensate have been investigated, the question of whether one can observe stochastic resonance in such a system persists. In this study we propose a scheme for generating stochastic resonance in a cavity-spinor Bose-Einstein condensate coupling system. We demonstrate stochastic resonance through numerical calculations using the mean-field theory and truncated Wigner approximation methods. Furthermore, the characteristics of the system's response to noise and periodic signals are studied in detail. This study unravels a new scheme for observing stochastic resonance via linking atomic many-body physics with cavity quantum electrodynamics.

关键词： spinor condensate stochastic resonance optical cavity

Joint Transmit and Reflective Beamforming Design for Active IRS-Aided SWIPT Systems

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Chinese Journal of Electronics 2024年第2期33卷 536-548页

作者： weiping SHI Qingqing WU Di WU Feng SHU Jiangzhou WANG School of Electronic and Optical Engineering Nanjing University of Science and Technology Department of Electronic Engineering Shanghai Jiao Tong University School of Information and Communication Engineering Hainan University Department of Automation Shanghai Jiao Tong University School of Engineering University of Kent

To further improve the performance of passive intelligent reflecting surface(IRS)-assisted communication systems and mitigate the serious path loss due to “double-fading ” of IRS-assisted links, an active IRS-aided simultaneous wireless information and power transfer(SWIPT) system is investigated. This paper jointly optimizes the transmit beamforming at the base station(BS) and the phase shifts at the active IRS in order to maximize the power collected by the energy harvesting receiver under both perfect and imperfect channel state information(CSI)states, subject to the signal-to-interference-noise ratio constraint of the information decoding receiver, and the power constraints of the BS/IRS. Under perfect CSI, the alternating optimization algorithm is utilized for obtaining the transmit beamforming at the BS and the phase shifts at the active IRS. For each subproblem, we first transform nonconvex objective function and constraints into convex ones by performing a first-order Taylor expansion. Then, each subproblem is solved by using the interior point method. Given that obtaining perfect CSI is impractical, two robust beamforming designs are proposed for imperfect CSI case. Under the bounded CSI error model, we first transform the non-convex optimization problem into two semidefinite programming subproblems, and then solve each subproblem based on S-procedure and sequential rank-one constraint relaxation(SROCR) techniques. Under the stochastic CSI error model, the alternating optimization method is applied in an iterative manner based on Bernstein-type inequality and SROCR technique. Simulation results show that both robust and non-robust schemes for active IRS-assisted SWIPT systems can achieve extremely superior performance over conventional passive IRS-assisted systems under the same overall power budget.

关键词： Wireless communication Semidefinite programming Array signal processing Simulation Stochastic processes Transforms Receivers

A review of ^(17)O isotopic labeling techniques for solid-state NMR structural studies of metal oxides in lithium-ion batteries

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Magnetic Resonance Letters 2024年第2期4卷 46-53页

作者： Xiaoli Xia Lei Zhu weiping Tang Luming Peng Junchao Chen School of Chemistry and Chemical Engineering Shanghai Jiao Tong University800 Dongchuan RoadShanghai200240China Key Laboratory of Mesoscopic Chemistry of Ministry of Education and Collaborative Innovation Center of Chemistry for Life Sciences School of Chemistry and Chemical EngineeringNanjing University163 Xianlin RoadNanjing210023China State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power-SourcesShanghai200245China

Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structural and dynamic ***,we commence with a brief introduction to recent research on lithium-ion battery oxide materials studied using ^(17)O solid-state NMR *** we delve into a review of ^(17)O isotopic labeling methods for tagging oxygen sites in both the bulk and surfaces of metal *** last,the unresolved problems and the future research directions for advancing the ^(17)O labeling technique are discussed.

关键词： ^(17)O solid-state NMR ^(17)O isotopic labeling methods Bulk and surfaces of metal oxides DFT calculation

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铁路通信中的数字调度系统的应用探析

信息与电脑 2017年第20期29卷 125-126,130页

作者：焦伟平神华包神铁路有限责任公司内蒙古包头014010

随着我国社会经济的不断发展,各地经济文化交流更加频繁,很大程度上促进了我国铁路运输事业的发展。铁路调度通信系统是连接行车调度员与各车站的通信体系,在铁路运输过程中能够及时了解实时信息,是保证铁路运输统一指挥的关键。在现代... 详细信息

随着我国社会经济的不断发展,各地经济文化交流更加频繁,很大程度上促进了我国铁路运输事业的发展。铁路调度通信系统是连接行车调度员与各车站的通信体系,在铁路运输过程中能够及时了解实时信息,是保证铁路运输统一指挥的关键。在现代通信技术不断发展的今天,铁路调度通信系统也向着数字化、信息化方向发展,使得铁路运输系统更加精确,保障了列车的运行和调度,极大提高了铁路运输调度的工作效率。笔者简要阐述了铁路通信的数字调度系统及其结构特点,重点对数字调度系统的应用进行研究,同时对包神铁路集团的现有数字调度系统进行分析并提出建议。

关键词：铁路通信数字调度系统包神铁路集团

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无序就医下医保总额控制刍议

中国医院 2013年第9期17卷 41-42页

作者：焦卫平首都医科大学宣武医院北京市西城区长椿街45号100053

总额控制是医保基金预算管理的基本要求。无序就医存在诸多的表现和成因,增加了医疗机构费用补偿测算的难度。医保、卫生等政府行政部门应该加强合作,给医疗机构的运营和管理创造稳定和谐的政策环境。

关键词：总额控制无序就医医疗保险