检索结果-南通市图书馆

Effects of diurnal adjustment on biases and trends derived from inter-sensor calibrated AMSU-A data

Frontiers of Earth Science 2018年第1期12卷 1-16页

作者： H. chen x. ZOU Z. QIN Department of Atmospheric and Oceanic Sciences University of Colorado Boulder Colorado CO 80309 USA Earth System Science Interdisciplinary Center (ESSIC) University of Maryland College Park Maryland MD 20742 USA Joint Center for Data Assimilation Research and Applications Nanjing University of Information Science and Technology Nanjing 210044 China

Measurements of brightness temperatures from Advanced Microwave Sounding Unit-A （AMSU-A） temperature sounding instruments onboard NOAA Polar- orbiting Operational Environmental Satellites （POES） have been extensively used for studying atmospheric temperature trends over the past several decades. Inter- sensor biases, orbital drifts and diurnal variations of atmospheric and surface temperatures must be considered before using a merged long-term time series of AMSU-A measurements from NOAA- 15, - 18, - 19 and MetOp-A. We study the impacts of the orbital drift and orbital differences of local equator crossing times （LECTs） on temperature trends derivable from AMSU-A using near-nadir observa- tions from NOAA-15, NOAA-18, NOAA-19, and MetOp-A during 1998 - 2014 over the Amazon rainforest. The double difference method is firstly applied to estimation of inter-sensor biases between any two satellites during their overlapping time period. The inter-calibrated observations are then used to generate a monthly mean diurnal cycle of brightness temperature for each AMSU-A channel. A diurnal correction is finally applied each channel to obtain AMSU-A data valid at the same local time. Impacts of the inter-sensor bias correction and diurnal correction on the AMSU-A derived long-term atmospheric temperature trends are separately quantified and compared with those derived from original data. It is shown that the orbital drift and differences of LECT among different POESs induce a large uncertainty in AMSU-A derived long-term warming/cooling trends. After applying an inter-sensor bias correction and a diurnal correction, the warming trends at different local times, which are approximately the same, are smaller by half than the trends derived without applying these corrections.

关键词： AMSU-A diurnal adjustment decadal tem-perature trend

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses

引用

Acta Mechanica Sinica 2015年第4期31卷 558-569页

作者： H.Wu x.W.chen Q.Fang x.Z.Kong L.L.He Institute of Systems Engineering China Academy of Engineering Physics State Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact PLA University of Science and Technology

During the high-speed penetration of projectiles into concrete targets （the impact velocity ranges from 1.0 to 1.5 km/s）, important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic tra- jectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differ- ential Area Force Law （DAFL） method and semi-empirical resistance function, a finite differential approach was pro- grammed （PENTRA2D） for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed pene- trators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of ter- minal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.

关键词： Projectile Penetration Concrete Massabrasion Terminal ballistic trajectory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Harmonic balance-based approach for optimal time delay to control unstable periodic orbits of chaotic systems

引用

Acta Mechanica Sinica 2020年第4期36卷 918-925页

作者： Y.M.chen Q.x.Liu J.K.Liu Department of Mechanics Sun Yat-sen UniversityGuangzhou 510275China

As a classical technique for chaos suppression,the time-delayed feedback controlling strategy has been widely developed by stabilizing unstable periodic orbits(UPOs)embedded in chaotic systems.A critical issue for achieving high controlling precision is to search for an appropriate time *** paper proposes a simple yet effective approach,based on incremental harmonic balance method,to determine the optimal time delay in the delayed feedback *** time delay is adjusted within the iterative scheme provided by the proposed method,and finally converges to the period of the target *** long as the optimal time delay is fixed,moreover,the attained solution makes it quite convenient to analyze its stability according to the Floquet theory,which further provides the effective interval of the feedback gain.

关键词： Chaos control Unstable periodic orbit Delayed feedback Optimal time delay Incremental harmonic balance method

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microstructure,oxidation behavior and tribological properties of AlCrN/Cu coatings deposited by a hybrid PVD technique

引用

Journal of Materials Science & Technology 2022年第5期100卷 150-160页

作者： Dongsen Geng Haiqing Li Ziliang chen Yu.x.xu Qimin Wang School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China

Achieving high hardness and low friction at elevated temperatures for nitride-based hard coatings has substantial scientific interest and application *** this study,AlCrN/Cu coatings were deposited by a hybrid PVD technique combining arc evaporation from an Al_(60)Cr_(40) target and magnetron sputtering from a Cu target in a mixed Ar and N_(2) *** microstructure,oxidation behavior,and tribological properties of the coatings were ***/Cu coatings show a dual-phase structure of(Al,Cr)N solid solution and Cu metallic *** sputtering power of the Cu target induces the disintegration of interlayer interfaces of the nano-multilayered geometry,accompanied by a decline in hardness from above 30 GPa to 22.7 ***,the formation of fine CuO grains on the coating surface is conducive to reducing the friction coefficient of AlCrN/Cu when exposed to air at high *** AlCrN/Cu coating with a sputtering power of 0.5 kW obtains a friction coefficient of 0.39±0.05 after pre-oxidation at 800℃,distinctly lower than that of AlCrN,which exhibits a friction coefficient of~*** further transformation of CuO to cubic Cu(Al,Cr)_(2)O_(4),which stems from the solid-state reaction of CuO,Al_(2)O_(3),and Cr_(2)O_(3),would cause a rise in friction coefficient and wear *** mechanism of oxidation and tribological behavior of the AlCrN/Cu coatings related to the temperature and Cu content was discussed.

关键词： AlCrN/Cu coatings Microstructure Oxidation Friction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Emergent Z2 topological invariant and robust helical edge states in two-dimensional topological metals

引用

Science China(Physics,Mechanics & Astronomy) 2020年第10期63卷 105-110页

作者： Chui-Zhen chen Hua Jiang Dong-Hui xu x.C.xie Institute for Advanced Study and School of Physical Science and Technology Soochow UniversitySuzhou 215006China Department of Physics Hubei UniversityWuhan 430062China International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China Beijing Academy of Quantum Information Sciences Beijing 100193China

In this work,we study the effects of disorder on topological metals that support a pair of helical edge modes deeply embedded inside the gapless bulk ***,we predict that a quantum spin Hall(QSH)phase can be obtained from such topological metals without opening a global band *** be specific,disorder can lead to a pair of robust helical edge states which is protected by an emergent Z2 topological invariant,giving rise to a quantized conductance plateau in transport *** results are instructive for solving puzzles in various transport experiments on QSH materials that are intrinsically *** work also will inspire experimental realization of the QSH effect in disordered topological metals.

关键词： topological metal disorder Z2 topological invariant

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Alternative Strategy for Development of Dielectric Calcium Copper Titanate‑Based Electrolytes for Low‑Temperature Solid Oxide Fuel Cells

引用

Nano-Micro Letters 2025年第1期17卷 310-332页

作者： Sajid Rauf Muhammad Bilal Hanif Zuhra Tayyab Matej Veis MAKYousaf Shah Naveed Mushtaq Dmitry Medvedev Yibin Tian chen xia Martin Motola Bin Zhu College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Department of Inorganic Chemistry Faculty of Natural SciencesComenius University BratislavaIlkovicova684215 BratislavaSlovakia Energy Storage Joint Research Center School of Energy and EnvironmentSoutheast UniversityNanjing 210096People’s Republic of China Hydrogen Energy Laboratory Ural Federal University620002 EkaterinburgRussia Laboratory of Electrochemical Devices Based on Solid Oxide Proton Electrolytes Institute of High Temperature Electrochemistry620066 EkaterinburgRussia School of Microelectronics Hubei UniversityWuhan 430062People’s Republic of China

The development of low-temperature solid oxide fuel cells(LT-SOFCs)is of significant importance for realizing the widespread application of *** has stimulated a substantial materials research effort in developing high oxide-ion conductivity in the electrolyte layer of *** this context,for the first time,a dielectric material,CaCu_(3)Ti_(4)O_(12)(CCTO)is designed for LT-SOFCs electrolyte application in this *** individual CCTO and its heterostructure materials with a p-type Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ)(NCAL)semiconductor are evaluated as alternative electrolytes in LT-SOFC at 450–550℃.The single cell with the individual CCTO electrolyte exhibits a power output of approximately 263 mW cm^(-2) and an open-circuit voltage(OCV)of 0.95 V at 550℃,while the cell with the CCTO–NCAL heterostructure electrolyte capably delivers an improved power output of approximately 605 mW cm^(-2) along with a higher OCV over 1.0 V,which indicates the introduction of high hole-conducting NCAL into the CCTO could enhance the cell performance rather than inducing any potential short-circuiting *** is found that these promising outcomes are due to the interplay of the dielectric material,its structure,and overall properties that led to improve electrochemical mechanism in CCTO–***,density functional theory calculations provide the detailed information about the electronic and structural properties of the CCTO and NCAL and their heterostructure CCTO–*** study thus provides a new approach for developing new advanced electrolytes for LT-SOFCs.

关键词： LT-SOFCs Dielectric CaCu_(3)Ti_(4)O_(12) Semiconductor Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ) Ionic conductivity Heterostructure electrolyte

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High Fe‑Loading Single‑Atom Catalyst Boosts ROS Production by Density Effect for Efficient Antibacterial Therapy

引用

Nano-Micro Letters 2025年第2期17卷 187-203页

作者： Si chen Fang Huang Lijie Mao Zhimin Zhang Han Lin Qixin Yan xiangyu Lu Jianlin Shi Department of Cardiology Shanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200092People’s Republic of China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050People’s Republic of China Shanghai Frontiers Science Center of Nanocatalytic Medicine School of MedicineTongji UniversityShanghai 200092People’s Republic of China

The current single-atom catalysts(SACs)for medicine still suffer from the limited active site ***,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of SACs by exchanging zinc with *** constructed iron SACs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A exhibit excellent oxidase-like catalytic performance without significant activity decay after being stored for six months and promising antibacterial ***,a“density effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly boosted intrinsic activity of single-atomic iron sites in h^(3)-FNCs by 2.3 times compared to low-and medium-loading ***,the overall catalytic activity of h^(3)-FNC is highly improved,with mass activity and metal mass-specific activity that are,respectively,66 and 315 times higher than those of commercial Pt/*** addition,h^(3)-FNCs demonstrate efficiently enhanced capability in catalyzing oxygen reduction into superoxide anion(O_(2)·^(−))and glutathione(GSH)*** in vitro and in vivo assays demonstrate the superior antibacterial efficacy of h^(3)-FNCs in promoting wound *** work presents an intriguing activity-enhancement effect in catalysts and exhibits impressive therapeutic efficacy in combating bacterial infections.

关键词： Nanocatalytic medicine Single-atom catalysts Reactive oxygen species(ROS) High metal loading Oxidase catalysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Achieving Reliable CoSb_(3) based thermoelectric joints with low contact resistivity using a high-entropy alloy diffusion barrier layer

引用

Journal of Materiomics 2022年第4期8卷 882-892页

作者： Z.Sun x.chen Juncheng Zhang Huiyuan Geng L.x.Zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China

Skutterudite(SKD)thermoelectric materials have high conversion efficiency,great mechanical proper-ties,and economical practicability in the medium temperature range(500e550C).They need to bejoined with metal electrodes to form a thermoelectric power generation device during ***,high contact resistivity,severe element diffusion,and large coefficient of thermal expansionmismatch are main obstacles for their *** address these issues,a FeCoNiCrMo high-entropyalloy diffusion barrier layer was designed and prepared using an arc smelting method in this *** heating temperatures on the microstructure and properties of the bonded joints were *** maximum shear strength was 21.6 Mpa and the corresponding reaction layer thickness,contactresistivity were 3.77 mm,1.8 mUcm2 respectively at 600C,40 MPa,10 *** strength dropped downto 18.8 MPa and the contact resistivity increased to 4.2 mU cm2 after aging for 640 *** modelwas established and it predicted that the contact resistivity would keep lower than 6.5 mU cm2(300 h,100 days)and 11 mU cm2(8760 h,1 year)and the reaction layer thickness would not exceed 25 mm(2400 h,100 days)and 45 mm(8760 h,1 year).

关键词： High-entropy diffusion barrier layer Skutterudite Diffusion bonding Microstructure Shear strength Contact resistivity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Spherical cavity-expansion model for penetration of reinforced-concrete targets

引用

Acta Mechanica Sinica 2019年第4期35卷 535-551页

作者： Y.J.Deng W.J.Song x.W.chen Institute of Systems Engineering China Academy of Engineering PhysicsP.O.Box 919-416Mianyang 621999China Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province Mianyang 621000China Department of Civil Engineering and Architecture Southwest University of Science and TechnologyMianyang 621000China Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China Advanced Research Institute for Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China State Key Lab of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

The feature of reinforcing bars is introduced into dynamic cavity-expansion theory. Based on the elastic-plastic response penetration model of plain (i.e., unreinforced) concrete (Forrestal and Tzou, 1997), a dynamic spherical cavity-expansion penetration model for reinforced-concrete targets is developed with consideration of the circumferential restriction effect derived from reinforcing bars in the crushed region. The theoretical solution and simplified calculation formula for the cavity radial stress in incompressible and compressible reinforced concrete are obtained by introducing a reinforcement ratio as the volume fraction of rebars in the concrete target. A damping function is presented to describe the restriction effect of a single layer of reinforcing bars on the surrounding concrete, thus establishing a model to calculate the penetration resistance of multilayer reinforced-concrete targets. Compared with test data for the penetration depth, this model considering the circumferential restriction effect produces better results compared with the existing theory.

关键词： Dynamic cavity-expansion theory Reinforced concrete Penetration resistance Reinforcement ratio

来源：

维普期刊数据库

维普期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2) thin films

引用

Chinese Physics B 2024年第9期33卷 637-643页

作者： S x chen M M chen Y Liu D W Cao G J chen Department of Microelectronics Jiangsu UniversityZhenjiang 212013China Department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong Kong–Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CMOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：