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Transient stimulated Raman scattering spectroscopy and imaging

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Light(Science & Applications) 2024年第4期13卷 654-663页

作者： Qiaozhi yu Zhengjian Yao Jiaqi Zhou Wenhao yu Chenjie Zhuang Yafeng Qi hanqing Xiong National Biomedical Imaging Center College of Future TechnologyPeking UniversityBeijing 100871China Biomedical Engineering Department College of Future TechnologyPeking UniversityBeijing 100871China

Stimulated Raman scattering(SRS)has been developed as an essential quantitative contrast for chemical imaging in recent ***,while spectral lines near the natural linewidth limit can be routinely achieved by state-of-the-art spontaneous Raman microscopes,spectral broadening is inevitable for current mainstream SRS imaging *** is because those SRS signals are all measured in the frequency *** is a compromise between sensitivity and spectral resolution:as the nonlinear process benefits from pulsed excitations,the fundamental time-energy uncertainty limits the spectral ***,the spectral range and acquisition speed are mutually *** we report transient stimulated Raman scattering(T-SRS),an alternative time-domain strategy that bypasses all these fundamental conjugations.T-SRS is achieved by quantum coherence manipulation:we encode the vibrational oscillations in the stimulated Raman loss(SRL)signal by femtosecond pulse-pair sequence excited vibrational wave packet *** Raman spectrum was then achieved by Fourier transform of the time-domain SRL *** all Raman modes are impulsively and simultaneously excited,T-SRS features the natural-linewidth-limit spectral line shapes,laser-bandwidth-determined spectral range,and improved ***~150-fs laser pulses,we boost the sensitivity of typical Raman modes to the sub-mM *** all-plane-mirror high-speed time-delay scanning,we further demonstrated hyperspectral SRS imaging of live-cell metabolism and high-density multiplexed imaging with the natural-linewidth-limit spectral resolution.T-SRS shall find valuable applications for advanced Raman imaging.

关键词： scattering excited mutually

Enhancement and Removal of PM_(2.5)by Cold and Warm Air Masses Accompanying Certain Synoptic Weather Systems across Hangzhou,China during 2014-2020

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Journal of Meteorological Research 2024年第3期38卷 620-634页

作者： Bu yu Feng CHEN hanqing KANG Bin ZHU Hongnian LIU Hangzhou Meteorological Bureau Hangzhou310051China Hangzhou International Urbanology Research Center for Urban Governance Studies Hangzhou311121China Zhejiang Institute of Meteorological Sciences Hangzhou310008China Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science&TechnologyNanjing210044China School of Atmospheric Sciences Nanjing UniversityNanjing210023China

Local air pollution is strongly affected by synoptic weather systems,such as fronts,troughs,low-altitude vortices,or high-altitude ***,few studies have analyzed the meteorological properties of cold or warm air masses associated to these systems and their impact on local air *** this study,hourly observations of fine particulate matter(diameter of up to 2.5µm,i.e.,PM_(2.5)),wind(V),temperature(T),pressure(P),and precipitation(R),acquired in Hangzhou in 2014-2020,were *** this analysis,weather patterns were categorized into 27 types;89 and 94 cases illustrating the passage of warm and cold air masses over Hangzhou were identified,respectively;the influence of air mass temperature,wind speed,and wind direction on PM_(2.5) concentrations and local accumulation or removal was *** main results are as follows.(1)Pollution events occurred more frequently for cold than for warm air masses,but average pollutant concentration was lower for cold air masses;(2)48%of the cold air mass cases corresponded to PM_(2.5) decreases and 52%to PM_(2.5) increases,with strong cold air masses(ΔT_(24h)>4°C;∣V∣_(average)>4 m s^(−1))markedly reducing local pollution,but weak cold air masses(ΔT24h4°C)reduced the PM_(2.5) concentration whereas weaker winds(∣V∣_(average)<2 m s^(−1))increased it;and(4)PM_(2.5) concentration decreased sharply within 4 h after the passage of strong cold air masses,but more gradually within 14 h after the passage of strong warm air *** results considerably improve the current understanding of the influence of cold and warm air masses on local pollution patterns.

关键词： weather type air mass enhancement removal meteorological condition

Facile synthesis of a tumor microenvironment-responsive nanomaterial with metallic polyphenol-encapsulated for enhanced synergistic therapy

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Journal of Rare Earths 2024年第10期42卷 1895-1902页

作者： Kaige yu Nuo Kou Shouqiang Zhang Tianqi Cao hanqing Wu Jing Zhou Department of Chemistry Capital Normal UniversityBejing100048China College of Teacher Education Capital Normal University Beijing100048China

The tumor microenvironment(TME)differs from normal tissue cells in its physiological and biochemical *** construction of TME-responsive nanoplatforms requires a tedious preparation process and complex multicomponent *** this work,Er@EGCG-Cu,a TME-responsive nanoplatform,was simply and rapidly synthesized by combining rare earth-doped nanomaterials(NaLuF_(4):Yb,Er)with EGCG-Cu which is based on the ability of metal ions to coordinate with polyphenols to form a metal-phenolic network(MPN)*** MPN structure is then destroyed under an acidic TME,releasing the chemotherapy(CT)drug EGCG,which can cause apoptosis,Cu_(x)S_(y)is generated by combining Cu^(2+)with H_2S overexpressed in human colorectal cancer cells and can be used for photothermal therapy(PTT).Cell experiments show that laser irradiation improves the CT/PTT synergistic effect of Er@*** study has significance for the construction of TME-responsive nanomedicines with simple and rapid preparation for synergistic therapy.

关键词： Tumor microenvironment Metal-polyphenol networks Synergistic therapy Rare earths Nanomaterials

Concise synthesis of NaTi_2(PO_4)_3 nanocrystals with size and morphology control

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Chinese Chemical Letters 2019年第2期30卷 517-520页

作者： hanqing Dai Wenqian Xu Kehan yu Wei Wei School of Electronic and Optical Engineering Nanjing University of Posts and Telecommunications

NaTi_2 (PO_4)_3 (NTP) nanocrystals with high room-temperature ionic conductivity of 1.1×10~3 S/cm were prepared by a concise solvothermal method at 140 ℃ for 3 h, and the aspect ratios of all the NTP nanocrystals are the closest to 0.7. It implies a moderate size-distribution of NTP nanocrystals obtained at 140 ℃ for 3 h is helpful for increasing packing density, and the packing density is the larger, so its conductivity is the higher. The controllability over size and morphology of the NTP nanocrystals via solvothermal temperature and time were investigated. The results suggest that our method is of great potential in synthesizing NTP nanocrystals with high room-temperature ionic conductivity at low cost.

关键词： Nanocrystal Morphology Aspect ratio Size-distribution Ionic conductivity

Flow softening and dynamic recrystallization behavior of a Mg-Gd-Y-Nd-Zr alloy under elevated temperature compressions

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Journal of Magnesium and Alloys 2023年第8期11卷 2891-2900页

作者： Yiping WU yuzhen JIA Sha Zhang yu Liu hanqing Xiong Gang Chen Department of Mechanical and Electrical Engineering Changsha UniversityChangsha 410003China Bichamp Cutting Technology(Hunan)Co. LtdChangsha 410200China College of Material Science and Engineering Hunan UniversityChangsha Hunan 410082China

Flow softening behavior of a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy under compression to a final strain of∼1.8 at elevated temperatures of 450∼550℃ and a constant strain rate of 2s^(−1) has been investigated by optical microscopy,scanning electron microscopy,electron back-scattered diffraction and transmission electron *** results show that true stress first rises to the peak point and then drops to the bottom value and increases again with further increasing strain at each *** dynamic recrystallization(DRX)and continuous DRX contribute to the formation of new fine grains at temperatures 450∼475℃ when the restoration is caused by both DRX and texture change due to extension twinning,resulting in the larger softening degrees compared with the softening effects owing to continuous DRX and discontinuous DRX at 500∼550℃ when twinning activation is suppressed.500℃ is the transition temperature denoting a significant decline in the contribution of twinning and TDRX to the strain with increasing *** cuboid-shape phase exists in both homogenized and compressed samples,while the compositions are varied.

关键词： Mg-Gd-Y alloy Elevated temperature compression Flow softening Dynamic recrystallization

Field Modeling Method for Identifying Urban Sphere of Influence:A Case Study on Central China

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Chinese Geographical Science 2010年第4期20卷 353-362页

作者： DENG yu LIU Shenghe WANG Li MA hanqing WANG Jianghao Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Institute of Policy and Management Chinese Academy of Sciences Beijing 100190 China Center for Interdisciplinary Studies of Natural and Social Sciences Chinese Academy of Sciences Beijing 100190 China

With rapid development of urbanization and regional interaction and interdependence, regional urban agglomeration planning becomes more and more important in China, in order to promote integrated development of various cities with close interrelationship. However, it is still arguable academically on how to define the boundary or which cities to be included for the urban agglomeration of a region. This paper aims to shed lights on how to identify urban spheres of influence scientifically by introducing field modeling method and by practicing a case study on 168 cities in Central China. In our field modeling method, the influence intensities of cities were measured by a compre-ensive index and urban spheres of influence were represented spatially by field intensity. Then, their classification and spatial distribution characteristics of study area in 2007 were identified and explored by using GIS and statistical methods. The result showed that： 1） Wuhan is the absolute dominant city in Central China; 2） the provincial capital cities dominate their own provinces and there are no other lower grade agglomeration centers; and 3） the basic types of organization form of urban sphere of influence are single-polar type, agglomeration type, close-related group type and loose-related group type.

关键词： Central China urban sphere of influence urban influence index field intensity urban influence intensity

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微波脉冲孔缝线性耦合的数值与实验研究

微波学报 1995年第4期11卷 244-251页

作者：王建国刘国治陈雨生范如玉俞汉清周金山屈华民西北核技术研究所西安710024

本文讨论了微波脉冲与孔缝耦合在电磁兼容研究中的重要性,并用实验方法和数值模拟方法研究了微波脉冲与腔体上孔缝的线性耦合过程,给出了部分数值模拟结果和初步的实验结果.分析了耦合对入射波载频、入射场偏振方向和孔缝尺寸的依赖关系... 详细信息

本文讨论了微波脉冲与孔缝耦合在电磁兼容研究中的重要性,并用实验方法和数值模拟方法研究了微波脉冲与腔体上孔缝的线性耦合过程,给出了部分数值模拟结果和初步的实验结果.分析了耦合对入射波载频、入射场偏振方向和孔缝尺寸的依赖关系,得出了微波脉冲与孔缝耦合的共振效应和增强效应等规律,同时也给出了共振发生的条件.

关键词：微波脉冲线性耦合时域有限差分电磁兼容

特发性肾病综合征患儿尿液外泌体miR-194-5p水平及其临床价值

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临床检验杂志 2019年第5期37卷 321-324页

作者：陈婷婷王成于汉卿宋琳珠张春妮南方医科大学南京临床医学院东部战区总医院临床检验科南京210002 南京大学生命科学学院南京210046 南京医科大学附属儿童医院检验科南京210008 广东省广雅中学广州510160

目的探讨特发性肾病综合征(idiopathic nephrotic syndrome,INS)患儿尿液外泌体miR-194-5p水平及其作为辅助诊断标志物的临床价值。方法收集101例INS患儿和98例性别、年龄相匹配的健康儿童尿液标本,采用实时荧光定量PCR(qRT-PCR)检测miR... 详细信息

目的探讨特发性肾病综合征(idiopathic nephrotic syndrome,INS)患儿尿液外泌体miR-194-5p水平及其作为辅助诊断标志物的临床价值。方法收集101例INS患儿和98例性别、年龄相匹配的健康儿童尿液标本,采用实时荧光定量PCR(qRT-PCR)检测miR-194-5p在尿液外泌体中的含量;ROC曲线、相关性分析等评估其对INS患儿的诊断价值。结果 INS组尿液外泌体miR-194-5p水平明显高于健康人对照组[2.420(0.650,9.515)fmol/L vs 0.360(0.220,0.653)fmol/L,U=1 552,P<0.01],且其中44例患者在治疗缓解后明显下降[0.975(0.375,4.358)fmol/L vs 0.320(0.145,0.523)fmol/L,W=708,P<0.01];伴有高尿蛋白的INS患儿miR-194-5p水平明显高于伴有低尿蛋白患儿[8.430(7.225,13.070)fmol/L vs 2.130(1.180,3.090)fmol/L,U=0,P<0.01];miR-194-5p诊断INS的ROC曲线下面积(AUCROC)为0.843(95%CI:0.789~0.897)。相关性分析显示,INS患儿尿液外泌体miR-194-5p与血清清蛋白(r=-0.300)水平呈负相关,与血清总胆固醇(r=0.278)、24 h尿蛋白(r=0.296)呈正相关(P均<0.01)。结论 INS患儿尿液外泌体miR-194-5p含量明显升高,与24 h尿蛋白、血清清蛋白和胆固醇水平密切相关,有望作为辅助诊断儿童INS的非侵入性分子标志物。

关键词：特发性肾病综合征尿液外泌体 miR-194-5p 分子标志物

一种仪表运放与高通滤波相融合的前置放大器増强方案

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电子测量技术 2014年第7期37卷 10-13页

作者：汪瑞余晗卿司峻峰黄晓林肇莹刘红星南京大学电子科学与工程学院南京210046

提出了一种将仪表运放与二阶高通滤波相融合的生物电前置放大器增强解决方案,进行了幅频响应的仿真,讨论了该增强方案与前置级参考电极电路相结合的方式。实验验证了该方案幅频响应仿真结果的正确性和其与几种参考电极电路相结合的可行... 详细信息

提出了一种将仪表运放与二阶高通滤波相融合的生物电前置放大器增强解决方案,进行了幅频响应的仿真,讨论了该增强方案与前置级参考电极电路相结合的方式。实验验证了该方案幅频响应仿真结果的正确性和其与几种参考电极电路相结合的可行性。提出的方案较现有方案具有更好的阻带衰减特性,更有利于前置放大器抗饱和性的提高。

关键词：前置放大器抑制饱和高通滤波