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Chinese Physics Letters 2001年第2期18卷 205-207页

作者： LI Yun-Jing zhan chuan-lang ZHAO Li-Zeng WANG Duo-Yuan LU Zhen-Zhong NIE Yu-Xin Laboratory of Optical Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080 The Center for Molecular Science Institute of ChemistryChinese Academy of SciencesBeijing 100080

Large two-photon absorption cross section of a novel compound trans-1,3,5-tri-(4-N,N-dimethylaminobenzylstyryl)-acetylacetone is measured to beσ_(2)=8.4×10^(-20)cm^(4)/GW orσ'_(2)=1.594×10^(-47)cm^(4)/(photon.s)by using a 1064 nm Nd:YAG laser with 35 ps pulse width based on the intensity-dependent transmissivity *** frequency upconversion fluorescence is observed by two-photon laser *** material is an ideal candidate for optical limiting and upconversion fluorescence.

关键词： measurement benzyl Fluorescence

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分子第一超极化率的分子结构效应研究

化学学报 2001年第2期59卷 213-219页

作者：詹传郎王夺元中国科学院化学研究所分子科学中心北京100080

以 (类 )杂芪染料等十种有机分子为例 ,研究了分子结构效应对有机分子第一超极化率的影响规律 .将分子结构效应归为五类 ,即 :正负电荷效应、共轭π -电子数效应、共轭π -原子效应、联接效应和电子给 /受体效应 ,得到了用简单的分子跃... 详细信息

以 (类 )杂芪染料等十种有机分子为例 ,研究了分子结构效应对有机分子第一超极化率的影响规律 .将分子结构效应归为五类 ,即 :正负电荷效应、共轭π -电子数效应、共轭π -原子效应、联接效应和电子给 /受体效应 ,得到了用简单的分子跃迁波数νa 来表示分子结构效应对第一超极化率影响的线性方程组和网状关系图 ,该图不仅反映了每种结构因素对 β值的影响规律及其所能给出的最高第一超极化率 ,更反映了这五种结构因素对第一超极化率的不同影响规律间的关系 ,指出了最能增大第一超极化率的结构因素是正电荷效应。

关键词：杂芪染料分子第一超极化率溶致变色分子结构效应线性相关有机分子

溴代苝二酰亚胺衍生物的光谱及其在溶液中的聚集

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化学试剂 2011年第11期33卷 966-970页

作者：庞树峰曾文峰詹传郎北京理工大学物理化学研究所北京100081 北京理工大学理学院北京100081 中国科学院化学研究所分子科学中心北京100190

设计合成了一种新型的苝二酰亚胺衍生物1,6,7,12-四溴代-N,N-丙酸2-(2-氨基乙氧基)乙醇酯苝四羧酸酐。研究了在不同有机溶剂中的紫外、荧光光谱性能以及相应的聚集行为。光谱研究表明,在4种不同的溶剂中,临界聚集浓度不同。随着溶液浓... 详细信息

设计合成了一种新型的苝二酰亚胺衍生物1,6,7,12-四溴代-N,N-丙酸2-(2-氨基乙氧基)乙醇酯苝四羧酸酐。研究了在不同有机溶剂中的紫外、荧光光谱性能以及相应的聚集行为。光谱研究表明,在4种不同的溶剂中,临界聚集浓度不同。随着溶液浓度的增加,化合物分子呈斜线发生面-面堆积。SEM观察了在有机溶液中的聚集形貌,受分子-分子作用与分子-溶剂相互作用之间平衡关系的影响,在4种溶剂中化合物表现出了不同的聚集行为。

关键词：苝二酰亚胺紫外荧光扫描电镜聚集体

Tailoring the photophysical and photovoltaic properties of boron-difluorodipyrromethene dimers

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Chinese Chemical Letters 2017年第4期28卷 875-880页

作者： Wen-Xu Liu Jian-Nian Yao chuan-lang zhan Beijing National Laboratory of Molecular Science CAS Key Laboratory of PhotochemistryInstitute of ChemistryChinese Academy of SdencesBeijing 100190China

Five boron-difluorodipyrromethene（BODIPY） dimers have been designed and synthesized successfully via acid-catalysed condensation and Pd-catalysed cross-coupling *** structural modification,including verifying the structures of the π-bridges,altering the positions the bridges link（meso-or β-positions）,and regulating the molecular planarity,can modulate the photophysical properties and the aggregation behaviors of the five dimers ***-processed organic solar cells were fabricated to evaluate the photovoltaic properties of these molecules further either as acceptors or *** using as nonfullerene acceptor and blended with the polymer donor of PTB7,an opencircuit voltaic（V_（oc）） of 1.12 and 1.08 V was achieved from the thiophene and benzodithiophene bridged BODIPY dimers,*** V_（oc） is among the top values achieved from the non-fullerene organic solar cells so far.

关键词： BODIPY Nonfullerene acceptor Small molecule donor Photovoltaic cell Solution-processed

Reducing energy barriers of chemical reactions with a nanomicrocell catalyst consisting of integrated active sites in conductive matrices

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Science Bulletin 2019年第6期64卷 385-390页

作者： Guo-Peng zhan chuan-De State Key Laboratory of Silicon Materials Center for Chemistry of High-Performance&Novel MaterialsDepartment of ChemistryZhejiang University

Reducing energy barriers of chemical reactions is the never-ending endeavor of *** by the high reactivity of primary cells,we develop a nanosized fuel cell catalyst(denoted as nanomicrocell catalyst),consisting of integrated electrode pairs,conductive matrices and electrolytes,to improve the chemical ***,the anodes are Pd species which is combining with the electron-rich N atoms in B-and-N co-doped carbon dots;the cathodes are electron-deficient B atoms;and the conductive matrices are B-and-N co-doped carbon dots which are connecting with the electrode *** to the reactivity of primary cells,the catalytic properties of the nanomicrocell catalyst in hydrogenation of benzaldehyde are depending on the properties of electrode pairs,conductive matrices and *** unique catalytic properties are attributed to the different substrate adsorption capability and catalytic properties of paired electrodes,and the easy migration of electrons and charge carriers,which could improve the synergetic effect between paired active ***,this work may open up a new window for designed synthesis of advanced catalysts which could highly lower the energy barriers of chemical reactions.

关键词： Nanomicrocell catalysts Conductive matrices Electrode pairs Electrolytes Primary cells

Generation of global 1-km daily top-of-atmosphere outgoing longwave radiation product from 2000 to 2021 using machine learning

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International Journal of Digital Earth 2023年第1期16卷 2002-2012页

作者： chuan zhan Shunlin Liang School of Resources and Environmental Engineering Wuhan University of Science and TechnologyWuhanPeople's Republic of China Department of Geography The University of Hong KongPokfulamPeople's Republic of China

Top-of-atmosphere(TOA)outgoing longwave radiation(OLR),a key component of the Earth’s energy budget,serves as a diagnostic of the Earth’s climate system response to incoming solar ***,existing products are typically estimated using broadband sensors with coarse spatial *** paper presents a machine learning method to estimate TOA OLR by directly linking Moderate Resolution Imaging Spectroradiometer(MODIS)TOA radiances with TOA OLR determined by Clouds and the Earth’s Radiant Energy System(CERES)and other information,such as the viewing geometry,land surface temperature and cloud top temperature determined by Modern-Era Retrospective analysis for Research and Applications,Version 2(MERRA-2).Models are built separately under clear-and cloudy-sky conditions using a gradient boosting regression *** test results show that the root mean square errors(RMSEs)of the clear-sky and cloudy-sky models for estimating instantaneous values are 4.1 and 7.8 W/m^(2),***-time conversion ratios derived from CERES daily and hourly OLR data are used to convert the instantaneous MODIS OLR to daily ***-comparisons of the daily results show that the RMSE of the estimated MODIS OLR is 8.9 W/m^(2) in East *** developed high resolution dataset will be beneficial in analyzing the regional energy budget.

关键词： TOA outgoing longwave radiation MODIS CERES machine learning Earth’s energy budget

Tuning the type of charge carriers in N-heterocyclic carbene-based molecular junctions through electrodes

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Chinese Physics B 2020年第11期29卷 290-296页

作者： Ming-lang Wang chuan-Kui Wang School of Physics and Electronics Shandong Normal UniversityJinan 250358China

Designing tunable molecular devices with different charge carriers in single-molecule junctions is crucial to the nextgeneration electronic ***,it has been demonstrated that the type of charge carriers depends on and can be tuned by controlling the molecular length and the number of interfacial covalent *** this study,we show that the type of charge carriers can also be tuned by controlling the material and shape of electrodes.N-heterocyclic carbenes(NHCs)have attracted attention because of their ability to form strong,substitutional inert bonds in a variety of ***,NHCs are more stable than the widely used thiol ***,we use electrodes to tune the type of charge carriers in a series of NHCs with different side *** ab initio calculations based on non-equilibrium Green’s formalism combined with density functional theory show that the dominant charge carrier switches from electrons to holes when gold electrodes are changed into platinum *** nature of the charge carriers can be identified by variations in the transport spectra at the Fermi level(EF),which are caused by the side *** projections of transport spectra onto the central molecules further validate our *** addition,the transmission coefficient at EF is found to be dependent on the atomic interface *** particular,for the NHC without methyl or ethyl side groups,connecting a protruding atom on the electrode surface significantly enhances the transportability of both electrode ***,this study presents an effective approach to modifying transport properties,which has potential applications in designing functional molecular devices based on NHCs.

关键词： molecular electronics charge carriers side groups non-equilibrium Green’s function

Deep multiple instance selection

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Science China(Information Sciences) 2021年第3期64卷 18-32页

作者： Xin-Chun LI De-chuan zhan Jia-Qi YANG Yi SHI State Key Laboratory for Novel Software Technology Nanjing University

Multiple instance learning(MIL) assigns a single class label to a bag of instances tailored for some real-world applications such as drug activity prediction. Classical MIL methods focus on figuring out interested instances, that is, region of interests(ROIs). However, owing to the non-differentiable selection process, these methods are not feasible in deep learning. Thus, we focus on fusing ROIs identification with deep MILs in this paper. We propose a novel deep MIL framework based on hard selection, that is, deep multiple instance selection(DMIS), which can automatically figure ROIs out in an end-to-end *** be specific, we propose DMIS-GS for instance selection via gumbel softmax or gumbel top-k, and then make predictions for this bag without the interference of redundant instances. For balancing exploration and exploitation of key instances, we apply a cooling down approach to the temperature in DMIS-GS, and propose a variance normalization method to make this hyper-parameter tuning process much easier. Generally, we give a theoretical analysis of our framework. The empirical investigations reveal the proposed frameworks' superiorities against classical MIL methods on generalization ability, positioning ROIs, and comprehensibility on both synthetic and real-world datasets.

关键词： multiple instance learning instance selection gumbel softmax variance normalization hard attention

MECHANISM DESIGN AND MOTION ANALYSIS OF A SPHERICAL MOBILE ROBOT

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Chinese Journal of Mechanical Engineering 2005年第4期18卷 542-545页

作者： zhan Qiang Jia chuan Ma Xiaohui Zhai Yutao Robot Research Institute Beihang University Beijing 100083 China China Aerospace Science ＆ Industry Academy of Technology Beijing 100037 China

A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is developed with Lagrange method and factors affecting the driving torque of two motors are analyzed. The relationship between the turning radius of the robot and the length of two links is discussed in order to optimize its mechanism design. Simulation and experimental results demonstrate the good controllability and motion performance of BHQ-1.

关键词： Spherical mobile robot Mechanism design Motion analysis

Wave height forecast method with uncertainty quantification based on Gaussian process regression

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Journal of Hydrodynamics 2024年第5期36卷 817-827页

作者： Zi-lu Ouyang Chao-fan Li Ke zhan chuan-qing Li Ren-chuan zhu Zao-jian Zou School of Ocean and Civil Engineering Shanghai Jiao Tong UniversityShanghai200240China State Key Laboratory of Navigation and Safety Technology Shanghai Ship and Shipping Research Institute CO.LtdShanghai200135China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai200240China

Wave height forecast(WHF)is of great significance to exploit the marine renewables and improve the safety of ship navigation at *** the development of machine learning technology,WHF can be realized in an easy-to-operate and reliable way,which improves its engineering *** paper utilizes a data-driven method,Gaussian process regression(GPR),to model and predict the wave height on the basis of the input and output *** the help of Bayes inference,the prediction results contain the uncertainty quantification *** comparative studies are carried out to evaluate the performance of GPR based on the simulation data generated by high-order spectral method and the experimental data collected in the deep-water towing tank at the Shanghai Ship and Shipping Research *** results demonstrate that GPR is able to model and predict the wave height with acceptable accuracy,making it a potential choice for engineering application.

关键词： Wave height forecast data-driven modeling Gaussian process regression(GPR) bayes inference covariance function