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Autonomous aeroamphibious invisibility cloak with stochastic-evolution learning

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Advanced Photonics 2024年第1期6卷 64-72页

作者： chao qian Yuetian Jia Zhedong Wang Jieting Chen Pujing Lin Xiaoyue Zhu Erping Li Hongsheng Chen Zhejiang University ZJU-UIUC InstituteInterdisciplinary Center for Quantum InformationState Key Laboratory of Extreme Photonics and InstrumentationHangzhouChina Zhejiang University ZJU-Hangzhou Global Science and Technology Innovation CenterKey Laboratory of Advanced Micro/Nano Electronic Devices and Smart Systems of ZhejiangHangzhouChina Zhejiang University Jinhua Institute of Zhejiang UniversityJinhuaChina

Being invisible ad libitum has long captivated the popular imagination,particularly in terms of safeguarding modern high-end instruments from potential *** ago,the advent of metamaterials and transformation optics sparked considerable interest in invisibility cloaks,which have been mainly demonstrated in ground and waveguide ***,an omnidirectional flying cloak has not been achieved,primarily due to the challenges associated with dynamic synthesis of metasurface *** demonstrate an autonomous aeroamphibious invisibility cloak that incorporates a suite of perception,decision,and execution modules,capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external *** physical breakthrough lies in the spatiotemporal modulation imparted on tunable metasurfaces to sculpt the scattering field in both space and frequency *** intelligently control the spatiotemporal metasurfaces,we introduce a stochastic-evolution learning that automatically aligns with the optimal solution through maximum probabilistic *** a fully self-driving experiment,we implement this concept on an unmanned drone and showcase adaptive invisibility in three canonical landscapes-sea,land,and air-with a similarity rate of up to 95%.Our work extends the family of invisibility cloaks to flying modality and inspires other research on material discoveries and homeostatic meta-devices.

关键词： intelligent metasurfaces optical materials and structures deep learning

Group Contribution Method Supervised Neural Network for Precise Design of Organic Nonlinear Optical Materials

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Precision Chemistry 2024年第6期2卷 263-272页

作者： Jinming Fan Bowei Yuan chao qian Shaodong Zhou College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang UniversityHangzhou 310027P.R.China Zhejiang Provincial Innovation Center of Advanced Chemicals Technology Institute of Zhejiang University-QuzhouQuzhou 324000P.R.China

To rationalize the design of D-π-A type organic small-molecule nonlinear optical materials,a theory guided machine learning framework is *** an approach is based on the recognition that the optical property of the molecule is predictable upon accumulating the contribution of each component,which is in line with the concept of group contribution method in *** realize this,a Lewis-mode group contribution method(LGC)has been developed in this work,which is combined with the multistage Bayesian neural network and the evolutionary algorithm to constitute an interactive framework(LGC-msBNN-EA).Thus,different optical properties of molecules are afforded accurately and efficientlyby using only a small data set for ***,by employing the EA model designed specifically for LGC,structural search is well *** origins of the satisfying performance of the framework are discussed in *** that such a framework combines chemical principles and data-driven tools,most likely,it will be proven to be rational and efficient to complete mission regarding structure design in related fields.

关键词： supervised Bayesian neural network Lewis-type group contribution method nonlinear optical material molecule design evolutionary algorithm

Computed tomography-based radiomics diagnostic approach for differential diagnosis between early-and late-stage pancreatic ductal adenocarcinoma

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1256-1267页

作者： Shuai Ren Li-chao qian Ying-Ying Cao Marcus J Daniels Li-Na Song Ying Tian Zhong-Qiu Wang Department of Radiology Jiangsu Province Hospital of Chinese MedicineAffiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina Department of Geratology Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese MedicineNanjing 210022Jiangsu ProvinceChina Department of Radiology NYU Langone HealthNew YorkNY 10016United States

BACKGROUND One of the primary reasons for the dismal survival rates in pancreatic ductal adenocarcinoma(PDAC)is that most patients are usually diagnosed at late *** is an urgent unmet clinical need to identify and develop diagnostic methods that could precisely detect PDAC at its earliest *** A total of 71 patients with pathologically proved PDAC based on surgical resection who underwent contrast-enhanced computed tomography(CT)within 30 d prior to surgery were included in the *** staging was performed in accordance with the 8th edition of the American Joint Committee on Cancer staging *** features were extracted from the region of interest(ROI)for each patient using Analysis Kit *** most important and predictive radiomics features were selected using Mann-Whitney U test,univar-iate logistic regression analysis,and minimum redundancy maximum relevance(MRMR)*** forest(RF)method was used to construct the radiomics model,and 10-times leave group out cross-validation(LGOCV)method was used to validate the robustness and reproducibility of the *** A total of 792 radiomics features(396 from late arterial phase and 396 from portal venous phase)were extracted from the ROI for each patient using Analysis Kit *** most important and predictive features were selected using Mann-Whitney U test,univariate logistic regression analysis,and MRMR *** method was used to construct the radiomics model with the nine most predictive radiomics features,which showed a high discriminative ability with 97.7%accuracy,97.6%sensitivity,97.8%specificity,98.4%positive predictive value,and 96.8%negative predictive *** radiomics model was proved to be robust and reproducible using 10-times LGOCV method with an average area under the curve of 0.75 by the average performance of the 10 newly built *** The radiomics model based on CT could serve as a promising non-invasive method in differential diag

关键词： Pancreatic ductal adenocarcinoma Radiomics Computed tomography American Joint Committee on Cancer staging

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质谱技术在新能源领域的应用

质谱学报 2024年第5期45卷 587-599页

作者：栗世涵钱超周少东浙江大学化学工程与生物工程学院浙江省化工高效制造技术重点实验室浙江杭州310058

当前,全球能源短缺、气候变化问题日益严重,开发和利用环境友好型能源迫在眉睫。质谱技术能够快速识别多组分物质、鉴定未知化合物结构,在光催化反应、电催化反应以及电化学储能装置开发等能源研究领域得到了广泛应用。本文介绍了液相色... 详细信息

当前,全球能源短缺、气候变化问题日益严重,开发和利用环境友好型能源迫在眉睫。质谱技术能够快速识别多组分物质、鉴定未知化合物结构,在光催化反应、电催化反应以及电化学储能装置开发等能源研究领域得到了广泛应用。本文介绍了液相色谱-质谱(LC-MS)、气相色谱-质谱(GC-MS)、基质辅助激光解吸电离质谱(MALDI-MS)、微分电化学质谱(DEMS)和电喷雾电离质谱(ESI-MS)等技术在反应瞬态中间体、产物检测和反应机理推测方面的应用,并对质谱技术在光催化降解、光催化合成、电催化还原、电催化合成、锂离子电池以及锂硫电池等领域面临的挑战和发展趋势进行展望。

关键词：质谱产物检测反应中间体反应机理光催化电催化储能装置

Formation,evolution,reconstruction of black shales and their influence on shale oil and gas resource

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China Geology 2024年第3期7卷 551-585页

作者： Shi-zhen Li Qiu-chen Xu Mu Liu Guo-heng Liu Yi-fan Li Wen-yang Wang Xiao-guang Yang Wei-bin Liu Yan-fei An Peng Sun Tao Liu Jiang-hui Ding qian-chao Li chao-gang Fang State Key Laboratory of Continental Shale Oil Beijing 100083China The Key Laboratory of Unconventional Oil and Gas Geology China Geological SurveyBeijing 100083China Oil and Gas Survey China Geological SurveyMinistry of Natural ResourcesBeijing 100083China State Key Laboratory of Lithospheric and Environmental Coevolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Geosciences China University of Petroleum(East China)Qingdao 266580China School of Energy Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Petroleum Resources Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Resource and Environment Engineering Anhui UniversityHefei 230601China Yangtze University Wuhan 430100China Nanjing Center China Geological SurveyNanjing 210016China National Elite Institute of Engineering CNPCBeijing 100096China

Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and *** are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human *** also record the evolution process of the earth and improve the understanding of the *** review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and *** terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional *** formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom *** a geological perspective,the formation of black shales is often closely related to global or regional major geological *** enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation *** terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore *** terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore *** activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black *** resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales wou

关键词： Black shales Shale oil and gas Resource effects Sedimentary environment Sedimentary process Organic matter accumulation Diagenetic evolution Thermal evolution Organic matter and inorganic minerals Tectonic reconstruction Oil and gas exploration engineering Veins Fluid activity

中国ETF期权Delta对冲收益的日夜特征研究

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管理科学学报 2024年第2期27卷 136-158页

作者：刘彦初汤昊文钱潮阳中山大学岭南学院广州510275 华宝基金管理有限公司上海200120

期权市场是现代金融市场的重要组成部分,研究期权市场Delta对冲收益的日夜特征,对于理解期权市场运行机制以及降低金融市场风险具有重要意义.本文使用我国2015年—2021年股票ETF期权数据,研究了期权Delta对冲收益的日夜特征.研究结果表... 详细信息

期权市场是现代金融市场的重要组成部分,研究期权市场Delta对冲收益的日夜特征,对于理解期权市场运行机制以及降低金融市场风险具有重要意义.本文使用我国2015年—2021年股票ETF期权数据,研究了期权Delta对冲收益的日夜特征.研究结果表明,总体上Delta对冲的隔夜收益为负、日内收益不显著;认购期权和认沽期权的Delta对冲收益具有非对称性,即认购期权日内为负、隔夜为正,而认沽期权恰好相反.即使替换为基于波动率和标的资产价格关系的对冲模型,非对称性异象仍然存在.这些发现不同于美国期权市场的Delta对冲收益日内为正、隔夜为负的特征.本文进一步探讨了可能的成因:从风险溢价看,波动率风险溢价可以解释总体上负的隔夜对冲收益,但是不能解释Delta对冲收益的非对称性;从模型误差看,模型误差与标的资产收益共同作用影响了Delta对冲收益;从交易制度看,T+1交易制度约束造成了标的资产日夜收益反转,进而导致了对冲收益的非对称性,并且T+1交易制度约束越强,对冲收益的非对称性越明显.本文将丰富我国期权市场Delta对冲效率、交易制度对金融市场影响的相关研究,有利于提高投资者的风险管理水平、增进监管者对市场行为的理解,从而推动中国多层次资本市场的高质量发展.

关键词： ETF期权 Delta对冲收益日内和隔夜风险溢价模型误差 T+1交易制度

Comparison between solid pseudopapillary neoplasms of the pancreas and pancreatic ductal adenocarcinoma with cystic changes using computed tomography

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World Journal of Radiology 2024年第6期16卷 211-220页

作者： Shuai Ren Li-chao qian Xiao-Jing Lv Ying-Ying Cao Marcus J Daniels Zhong-Qiu Wang Li-Na Song Ying Tian Department of Radiology Jiangsu Province Hospital of Chinese MedicineThe Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina Department of Geratology Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese MedicineNanjing 210022Jiangsu ProvinceChina Department of Radiology NYU Langone HealthNew YorkNY 10016United States

BACKGROUND Solid pseudopapillary neoplasms of the pancreas(SPN)share similar imaging findings with pancreatic ductal adenocarcinoma with cystic changes(PDAC with cystic changes),which may result in unnecessary *** To investigate the value of computed tomography(CT)in differentiation of SPN from PDAC with cystic *** This study retrospectively analyzed the clinical and imaging findings of 32 patients diagnosed with SPN and 14 patients diagnosed with PDAC exhibiting cystic changes,confirmed through pathological *** and qualitative analysis was performed,including assessment of age,sex,tumor size,shape,margin,density,enhancement pattern,CT values of tumors,CT contrast enhancement ratios,“floating cloud sign,”calcification,main pancreatic duct dilatation,pancreatic atrophy,and peripancreatic invasion or distal *** logistic regression analysis was used to identify relevant features to differentiate between SPN and PDAC with cystic changes,and receiver operating characteristic curves were obtained to evaluate the diagnostic performance of each variable and their *** When compared to PDAC with cystic changes,SPN had a lower age(32 years vs 64 years,P0.05).The area under the receiver operating characteristic curve of the combination was 0.833(95%confidence interval:0.708-0.957)with 78.6%sensitivity,81.3%specificity,and 80.4%accuracy in differentiation of SPN from PDAC with cystic *** A larger tumor size,“floating cloud sign,”and peri

关键词： Solid pseudopapillary neoplasm Pancreas Pancreatic ductal adenocarcinoma Computed tomography Differential diagnosis

Homogeneous Einstein-like metrics on symmetric spaces

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Science China Mathematics 2021年第5期64卷 1045-1060页

作者： chao qian Ail Wu School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 102488China

In this paper, we study homogeneous Einstein-like metrics on the compact irreducible symmetric space M, which is not isometric to a compact Lie group and has rank greater than 1. Whenever there exists a closed proper subgroup G′ of G = Isom_0(M) acting transitively on M, we find all the G′-invariant A-metrics and B-metrics on M. More precisely, we prove that G′-invariant metrics on M must be A-metrics, and G′-invariant B-metrics on M are always Einstein.

关键词： homogeneous space symmetric space Einstein-like metric A-metric B-metric

On the robustness of median sampling in noisy evolutionary optimization

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Science China(Information Sciences) 2021年第5期64卷 32-44页

作者： chao BIAN chao qian Yang YU Ke TANG State Key Laboratory for Novel Software Technology Nanjing University Shenzhen Key Laboratory of Computational Intelligence Department of Computer Science and EngineeringSouthern University of Science and Technology

Evolutionary algorithms(EAs) are a sort of nature-inspired metaheuristics, which have wide applications in various practical optimization problems. In these problems, objective evaluations are usually inaccurate, because noise is almost inevitable in real world, and it is a crucial issue to weaken the negative effect caused by noise. Sampling is a popular strategy, which evaluates the objective a couple of times, and employs the mean of these evaluation results as an estimate of the objective value. In this work, we introduce a novel sampling method, median sampling, into EAs, and illustrate its properties and usefulness theoretically by solving OneMax, the problem of maximizing the number of 1 s in a bit string. Instead of the mean, median sampling employs the median of the evaluation results as an estimate. Through rigorous theoretical analysis on OneMax under the commonly used onebit noise, we show that median sampling reduces the expected runtime exponentially. Next, through two special noise models, we show that when the 2-quantile of the noisy fitness increases with the true fitness, median sampling can be better than mean sampling; otherwise,it may fail and mean sampling can be better. The results may guide us to employ median sampling properly in practical applications.

关键词： evolutionary algorithms noisy optimization median sampling computational complexity runtime analysis