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Sharp lower bound of spectral gap for Schrodinger operator and related results

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Frontiers of Mathematics in China 2015年第6期10卷 1283-1312页

作者： yue HE Institute of Mathematics School of Mathematics Sciences Nanjing Normal UniversityNanjing 210023 China

We give an easy proof of Andrews and Clutterbuck＇s main results [J. Amer. Math. Soc., 2011, 24（3）： 899-916], which gives both a sharp lower bound for the spectral gap of a Schr5dinger operator and a sharp modulus of concavity for the logarithm of the corresponding first eigenfunction. We arrive directly at the same estimates by the ＇double coordinate＇ approach and asymptotic behavior of parabolic flows. Although using the techniques appeared in the above paper, we partly simplify the method and argument. This maybe help to provide an easy way for estimating spectral gap. Besides, we also get a new lower bound of spectral gap for a class of SchSdinger operator.

关键词： SchrSdinger operator Laplace operator spectral gap ground state,strictly convex domain diameter of domain

Complete solutions for elastic fields induced by point load vector in functionally graded material model with transverse isotropy

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Applied Mathematics and Mechanics(English Edition) 2023年第3期44卷 411-430页

作者： Sha XIAO Zhongqi yue Key Laboratory of Urban Security and Disaster Engineering of China Ministry of Education Beijing University of TechnologyBeijing 100124China Department of Civil Engineering The University of Hong KongHong KongChina

The paper develops and examines the complete solutions for the elastic field induced by the point load vector in a general functionally graded material(FGM)model with transverse *** FGMs are approximated with n-layered *** of the n-layered materials is homogeneous and transversely *** complete solutions of the displacement and stress fields are explicitly expressed in the forms of fifteen classical Hankel transform integrals with ten kernel *** ten kernel functions are explicitly expressed in the forms of backward transfer matrices and have clear mathematical *** singular terms of the complete solutions are analytically isolated and expressed in exact closed forms in terms of elementary harmonic *** results show that the computation of the complete solutions can be achieved with high accuracy and efficiency.

关键词： functionally graded material(FGM) transverse isotropy elasticity closedform singular solution Green's function point load vector

Morphology and contact mechanics influence adhesive characteristics of Dung Beetle's bristle and Gecko's setae

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Progress in Natural Science:Materials International 2007年第9期17卷 1074-1081页

作者： yue David China Institute of Bio-Inspired Structure and Surface Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016

Geckos(Gekko gecko)use their hairy setae to adhere on various solid surfaces and dung beetles(Copris ochus Motschulsky)use their hairy bristles to anti-adhere in sticky *** study why two hairy systems express a conflict in functions by using SEM,histological approaches and functional *** models and various parameters were collected and *** on the morphological data and functional experimental results carried out by natural and denatured gecko setae and beetle bristles,we first demonstrated that the stiffness along the hair is 1000 to 30000 times that perpendicular to the *** stiffness difference is the key factor leading to the two hairy systems’ functional *** of gecko setae reduces contact stiffness,increases contact points and real contact area that results in amazing adhesive *** the other hand,stiff bristles in a beetle have higher contact stiffness,which reduces the real contact area and decreases the adhesion between two contact *** of gecko setae destroys the hierarchical structure,increases the contact stiffness and results in a decrease of adhesion ***,deformation of beetle bristles destroys the erect structure of the hair,interconnects the separated bristles and thus decreases the anti-adhesive *** observations inspire us in designing anti-adhesive and adhesive biomimetic systems

关键词： Adherence Morphology Contact stiffness Beetle bristles Gecko setae Contact mechanics

Switching,explosion,and chaos of multi-wavelength soliton states in ultrafast fiber lasers

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 82-90页

作者： Zhi-Zeng Si yue-yue Wang Chao-Qing Dai College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityLin’an 311300China

Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are *** this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are *** generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three *** and negative dispersion lead to different group velocities of *** presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an *** an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental *** work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.

关键词： multi-wavelength fiber laser soliton explosion chaos state switching real-time dynamics

Improvement of Urban Impervious Surface Estimation in Shanghai Using Landsat7 ETM+ Data

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Chinese Geographical Science 2009年第3期19卷 283-290页

作者： yue Wenze Department of Land Management Zhejiang University Hangzhou 310029 China

This paper explores the potential to improve the impervious surface estimation accuracy using a multi-stage approach on the basis of vegetation-impervious surface-soil (V-I-S) model. In the first stage of Spectral Mixture Analysis (SMA) process, pixel purity index, a quantitative index for defining endmember quality, and a 3-dimensional endmember selection method were applied to refining endmembers. In the second stage, instead of obtaining impervious surface fraction by adding high and low albedo fractions directly, a linear regression model was built between impervious surface and high/low albedo using a random sampling method. The urban impervious surface distribution in the urban central area of Shanghai was predicted by the linear regression model. Estimation accuracy of spectral mixture analysis and impervious surface fraction were assessed using root mean square (RMS) and color aerial photography respectively. In comparison with three different research methods, this improved estimation method has a higher overall accuracy than traditional Linear Spectral Mixture Analysis (LSMA) method and the normalized SMA model both in root mean square error (RMSE) and standard error (SE). However, the model has a tendency to overestimate the impervious surface distribution.

关键词： vegetation-impervious surface-soil model spectral mixture analysis impervious surface Shanghai

Spatio-temporal Distributions of Tropospheric NO_2 over Oases in Taklimakan Desert, China

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Chinese Geographical Science 2015年第5期25卷 561-568页

作者： QI yue Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Max Planck Institute for Chemistry University of Chinese Academy of Sciences

Soil biogenic NO emission is one of the most important sources of atmospheric nitrogen oxides(NOx) worldwide. However, the estimation of soil source, especially in arid areas presents large uncertainties because of the substantial lack of measurements. In this study, we selected the Ruoqiang oases on the southeastern edge of the Taklimakan Desert, China as the study area and applied Ozone Monitoring Instrument(OMI) NO2 retrievals(DOMINO v2.0, 2005–2011) to investigate the spatial distribution and seasonal variations in tropospheric NO2 vertical column density(VCD). High NO2 VCDs were observed over the oases(farmlands and natural vegetation), with the highest value obtained during summer, and lowest during winter. Pulses were observed during spring. We conducted in-situ measurements in June 2011 in Milan oasis and employed ground-based multi-axis differential optical absorption spectroscopy(MAX-DOAS) instruments to validate satellite NO2 retrievals. The findings are as follows: 1) in the study area soil biogenic NO emission is the dominant source of tropospheric NO2; 2) oases(farmlands) are hotspots of tropospheric NO2, and a higher increase in tropospheric NO2 is found in oases from winter to summer; and 3) enhancement of soil biogenic NO emission due to soil managements is predictable. Given the rapid agricultural development in the southern Uygur Autonomous Region of Xinjiang, researches on soil biogenic NO emission and increase in tropospheric NOx should be given more importance.

关键词： NO2 vertical column density ozone monitoring instrument (OMI) soil biogenic NO emission arid area agricultural management

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家族性高胆固醇血症国内外诊疗异同

中国全科医学 2025年第6期28卷 655-665页

作者：马弘阳岳岸娜孙康云南京医科大学附属苏州市立医院心血管内科江苏省苏州市215000

家族性高胆固醇血症(FH)是一种常见的遗传代谢性疾病,主要特征是低密度脂蛋白胆固醇(LDL-C)异常升高,可表现为角膜弓、黄色瘤等症状。长期高水平的LDL-C会增加动脉粥样硬化性心血管疾病(ASCVD)的风险。FH患者早发ASCVD的风险较高,纯合型... 详细信息

家族性高胆固醇血症(FH)是一种常见的遗传代谢性疾病,主要特征是低密度脂蛋白胆固醇(LDL-C)异常升高,可表现为角膜弓、黄色瘤等症状。长期高水平的LDL-C会增加动脉粥样硬化性心血管疾病(ASCVD)的风险。FH患者早发ASCVD的风险较高,纯合型的FH病情更为严重。全球FH的流行率逐渐受到重视,但诊断和治疗仍存在不足。借着《2023年中国血脂管理指南》的发布,本文主要比较了国内外关于FH筛查、诊断的不同,用于强调筛查血脂情况的重要性,并建议早期识别FH患者。同时,基因检测也被推荐,不仅限于少数基因,还应包含其他相关基因或全基因组检测。此外,本文也比较了不同指南对于FH患者LDL-C控制管理水平的差异,以及对于不同LDL-C划分的ASCVD危险因素新要素;比较了不同指南在饮食、生活方式、药物控制等方面的差别,指出国内外一致认为他汀类药物是主要的降脂药物,联合应用尤为重要,但对于最大剂量后LDL-C控制未达标的患者国际血脂护理指南有一定更新。同时,对于纯合型FH(HoFH)患者,高强度他汀类药物联合其他药物治疗是首选,早期的治疗更为关键,适当提早脂蛋白单采术与前蛋白转换酶枯草溶菌素9(PCSK9)抑制剂的应用有助于降低ASCVD的发病率和死亡率。

关键词：高胆固醇血症分子基础诊断诊疗方案指南差异

A novel(2+1)-dimensional integrable KdV equation with peculiar solution structures

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Chinese Physics B 2020年第8期29卷 176-181页

作者： Sen-yue Lou School of Physical Science and Technology Ningbo UniversityNingbo 315211China

The celebrated(1+1)-dimensional Korteweg de-Vries(KdV)equation and its(2+1)-dimensional extension,the Kadomtsev-Petviashvili(KP)equation,are two of the most important models in physical *** KP hierarchy is explicitly written out by means of the linearized operator of the KP equation.A novel(2+1)-dimensional KdV extension,the cKP3-4 equation,is obtained by combining the third member(KP3,the usual KP equation)and the fourth member(KP4)of the KP *** integrability of the cKP3-4 equation is guaranteed by the existence of the Lax pair and dual Lax *** cKP3-4 system can be bilinearized by using Hirota's bilinear operators after introducing an additional auxiliary *** solutions of the cKP3-4 equation possess some peculiar and interesting properties which are not valid for the KP3 and KP4 *** instance,the soliton molecules and the missing D'Alembert type solutions(the arbitrary travelling waves moving in one direction with a fixed model dependent velocity)including periodic kink molecules,periodic kink-antikink molecules,few-cycle solitons,and envelope solitons exist for the cKP3-4 equation but not for the separated KP3 equation and the KP4 equation.

关键词： (2+1)-dimensional KdV equations Lax and dual Lax pairs soliton and soliton molecules D’Alembert type waves

Co_(4)^(Ⅱ)O_(4)立方烷簇的合成、结构、质谱学和电催化性质研究

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湖北大学学报（自然科学版） 2025年第1期47卷 146-152页

作者：张越胡泉源湖北大学化学化工学院湖北武汉430062

以2-甲基-2-(1 H-苯并咪唑基)-1,3丙二醇配体与3d过渡金属Co离子通过溶剂热法配位合成配合物,借助X-射线单晶衍射仪进行晶体结构检测。结果表明:中心离子C_(O)(Ⅱ)以六配位形成八面体构型,该晶体属于单斜晶系,其中a(nm)=1.25579(3),b(nm... 详细信息

以2-甲基-2-(1 H-苯并咪唑基)-1,3丙二醇配体与3d过渡金属Co离子通过溶剂热法配位合成配合物,借助X-射线单晶衍射仪进行晶体结构检测。结果表明:中心离子C_(O)(Ⅱ)以六配位形成八面体构型,该晶体属于单斜晶系,其中a(nm)=1.25579(3),b(nm)=1.88920(8),c(nm)=2.39851(5),α(°)=90,β(°)=95.379(2),γ(°)=90(2),ESI-MS、XRD、TG-MS等常规测试手段研究了此配合物的基本结构、固液性质和物化性能,同时电催化氧化表征测试结果表明在电流密度为10 mA^(-2)时,其催化过电位为344 mV。

关键词：配合物晶体结构质谱电催化