检索结果-南通市图书馆

Magnetic properties of melt-spun MM-Fe-B ribbons with different wheel speeds and mischmetal contents

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2017年第12期36卷 992-996页

作者： Xue-Feng Zhang Wen-Kai Zhang yong-Feng Li Yan-Li Liu Zhu-bai Li Qiang Ma Meng-fei Shi fei Liu Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science andTechnology Baotou 014010 China Schools of Mathematics Physics and Biological EngineeringInner Mongolia University of Science and TechnologyBaotou 014010 China

In this study, the effect of wheel speed and mischmetal（MM） content on the magnetic properties of MMFeB ribbons was investigated. The samples were prepared via direct solidification technique. The nominal composition of the alloy ingots is MM;Fe;B;with x varying from 9 to 15 in steps of 2. Experimental results show the overall magnetic properties of the *** of the results shows that the magnetic properties first improve and then degrade with the wheel speed and MM content increasing. Increase in MM content leads to better formation of crystal texture in the ribbons, indicating that the a-Fe phase might undermine the formation of crystal texture. Magnetic properties results show that the coercivity of the ribbons rises with an appropriate increase in both MM content and wheel speed during melt-spun process. The strongest magnetic properties of the ribbons(remanence of M;= 0.72 T, intrinsic coercivity of H;= 352.58 kA·m;, and maximum energy product of（BH）;=72.14 kJ·m;) are obtained for compositions where x = 13 and a wheel speed of v = 20 m·s;.

关键词： Mischmetal MMFeB Magnetic properties Melt spun

MODIFIED BERNOULLI ITERATION METHODS FOR QUADRATIC MATRIX EQUATION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2007年第5期25卷 498-511页

作者： Zhong-Zhi bai yong-Hua Gao LSEC ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China

We construct a modified Bernoulli iteration method for solving the quadratic matrix equation AX^2 ＋ BX ＋ C = 0, where A, B and C are square matrices. This method is motivated from the Gauss-Seidel iteration for solving linear systems and the ShermanMorrison-Woodbury formula for updating matrices. Under suitable conditions, we prove the local linear convergence of the new method. An algorithm is presented to find the solution of the quadratic matrix equation and some numerical results are given to show the feasibility and the effectiveness of the algorithm. In addition, we also describe and analyze the block version of the modified Bernoulli iteration method.

关键词： Quadratic matrix equation Quadratic eigenvalue problem Solvent Bernoulli's iteration Newton's method Local convergence.

Applying physics informed neural network for flow data assimilation

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2020年第6期32卷 1050-1058页

作者： Xiao-dong bai yong Wang Wei Zhang Ministry of Education Key Laboratory of Coastal Disaster and Defence Hohai UniversityNanjing210098China Max Planck Institute for Dynamics and Self-Organization GöttingenGermany Science and Technology on Water Jet Propulsion Laboratory Marine and Research Institute of ChinaShanghai200011China

Data assimilation(DA)refers to methodologies which combine data and underlying governing equations to provide an estimation of a complex *** informed neural network(PINN)provides an innovative machine learning technique for solving and discovering the physics in *** encoding general nonlinear partial differential equations,which govern different physical systems such as fluid flows,to the deep neural network,PINN can be used as a tool for *** to its nature that neither numerical differential operation nor temporal and spatial discretization is needed,PINN is straightforward for implementation and getting more and more attention in the *** this paper,we apply the PINN to several flow problems and explore its potential in fluid *** the mesoscopic Boltzmann equation and the macroscopic Navier-Stokes are considered as physics *** first introduce a discrete Boltzmann equation informed neural network and evaluate it with a one-dimensional propagating wave and two-dimensional lid-driven cavity *** laminar cavity flow is also considered as an example in an incompressible Navier-Stokes equation informed neural *** parameterized Navier-Stokes,two turbulent flows,one within a C-shape duct and one passing a bump,are studied and accompanying pressure field is *** examples end with a flow passing through a porous *** in this paper show that PINN provides a new way for intelligent flow inference and identification,ranging from mesoscopic scale to macroscopic scale,and from laminar flow to turbulent flow.

关键词： Data assimilation(DA) deep learning physics informed neural network hydrodynamics

Kernel Estimators of the ROC Curve with Censored Data

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

Acta Mathematicae Applicatae Sinica 2013年第1期29卷 43-54页

作者： Fang-fang bai yong Zhou Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Statistics and Management Shanghai University of Finance and Economics

Receiver operating characteristic （ROC） curves are often used to study the two sample problem in medical studies. However, most data in medical studies are censored. Usually a natural estimator is based on the Kaplan-Meier estimator. In this paper we propose a smoothed estimator based on kernel techniques for the ROC curve with censored data. The large sample properties of the smoothed estimator are established. Moreover, deficiency is considered in order to compare the proposed smoothed estimator of the ROC curve with the empirical one based on Kaplan-Meier estimator. It is shown that the smoothed estimator outperforms the direct empirical estimator based on the Kaplan-Meier estimator under the criterion of deficiency. A simulation study is also conducted and a real data is analyzed.

关键词： ROC curve smoothed estimator censored data Kaplan-Meier estimator deficiency

Seismological challenges in earthquake hazard reductions:reflections on the 2008 Wenchuan earthquake

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2018年第17期63卷 1159-1166页

作者： yong Chen Jiupeng Hu fei Peng School of Earth Sciences and Engineering Nanjing University Institute of Geophysics China Earthquake Administration Seismic Observation and Geophysical Imaging Laboratory Institute of Earthquake Forecasting China Earthquake Administration

The Wenchuan earthquake is a natural disaster. Its occurrence and aftermath have demonstrated the critical roles of seismology and earthquake engineering in reducing seismic hazards and damages. However,their existing limitations should also be underscored. This article summarized and reviewed the current scientific understanding of earthquake ruptures, and new insights gained since the Wenchuan event. This study focused on the related challenges to seismology and earthquake engineering as follows:(1) The under-estimation of earthquake risks before occurrences.(2) The current limited data regarding large earthquakes in continental thrust fault systems.(3) The causal relationship between the Wenchuan earthquake and the reservoir impoundment in its vicinity.(4) The identification of low-velocity zone in the crust and its seismogenical role.(5) The casualties and economic losses from a cascade of diverse natural hazards triggered by the ruptures, and the excellent earthquake resistance associated with tunnels in mountainous terrain.

关键词： Wenchuan earthquake Hazard reduction Low-velocity zone Secondary hazard

General Galois Processor for Transmitters in 5G/6G Base Stations

在线全文

学校读者我要写书评

暂无评论

China Communications 2021年第10期18卷 129-134页

作者： Qingbo Zhai yong bai Dake Liu State Key Laboratory of Marine Resource Utilization in South China Sea College of Information and Communication EngineeringHainan UniversityHaikou 570228Hainan ProvinceChina

This paper proposes a flexible eight-mode high parallel Galois SIMD ASIP(Application Specific Instruction Set Processor).It supports parallel executions of Gold,Scrambling,CRC,CC,Turbo,RM,PSS,SSS encoding LFSR(linear feedback shift registers)algorithms with high performance and *** can perform also general bit processing and *** design is based on proposed table conversion and a datapath for unified eight-mode *** on 28 nm digital CMOS technology,the total area is 0.177 mm2 and the clock frequency can be up to 1 *** throughputs of Gold,Scrambling,CRC32,CRC24,CRC16,CRC8,CC,Turbo are 64 Gb/s,64 Gb/s,128 Gb/s,168 Gb/s,256 Gb/s,512 Gb/s,3×80 Gb/s,and 72 Gb/s,respectively.

关键词： multi-mode parallel encoding ASIP SIMD URLLC 5G base station

Jitter Enhanced Full Digital RF Transmitter and PWM RFPA for 5G Broadband Communications

在线全文

学校读者我要写书评

暂无评论

China Communications 2022年第5期19卷 69-86页

作者： Linxin Yin Dake Liu yong bai The State Key Laboratory of Marine Resources Utilization in South China Sea Hainan UniversityHaikou 570228China School of Information and Communication Engineering Hainan UniversityHaikou 570228China

RFPA(radio frequency power amplifier)based on PWM(pulse width modulation)can be perfect linear without using complicated DPD(digital pre-distortion)***,PWM RFPA need ultra-high PWM time resolution(less than 10 ps)for wide-band 5G,which is limited by CMOS technologies(can reach 40 ps).It limits the complexity of modulation so that PWM RFPA cannot be really commercialized so far in wideband radio/mobile *** paper presents our contribution by introducing jitter into *** the first time,we demonstrate that jitter can improve the PWM time resolution equivalently reaching less than 2.6 *** PWM RFPA can be used in 5G supporting 256QAM OFDM modulation based on currently available digital CMOS *** demonstrate that jitter can refine the inherent resolution of PWM hardware circuit *** jitter makes the MCS(modulation and coding scheme)of the bandwidth OFDM system improved from 16QAM to 256QAM in the band n28 of 3GPP *** also verified that 5G 256QAM OFDM modulation is achievable in the 3GPP band n20,Softbank band28 and NTT Docomo *** RMS EVM(root mean square error vector magnitude)of 256QAM OFDM modulation is about-44 dB.

关键词： PWM RFPA OFDM jitter 256QAM EVM

Integrating remote sensing and 3-PG model to simulate the biomass and carbon stock of Larix olgensis plantation

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2024年第4期11卷 543-555页

作者： Yu bai yong Pang Dan Kong Key Laboratory of National Forestry and Grassland Administration on Forestry Remote Sensing and Information System Institute of Forest Resource Information

Accurate estimations of biomass and its temporal dynamics are crucial for monitoring the carbon cycle in forest ecosystems and assessing forest carbon sequestration *** studies have shown that integrating process-based models(PBMs)with remote sensing data can enhance simulations from stand to regional scales,significantly improving the ability to simulate forest growth and carbon stock ***,the utilization of PBMs for large-scale simulation of larch carbon storage distribution is still *** this study,we applied the parameterized 3-PG(Physiological Principles Predicting Growth)model across the Mengjiagang Forest Farm(MFF)to make broad-scale predictions of the biomass and carbon stocks of Larix olgensis *** model was used to simulate average diameter at breast height(DBH)and total biomass,which were later validated with a wide range of observation data including sample plot data,forest management inventory data,and airborne laser scanning *** results showed that the 3-PG model had relatively high accuracy for predicting both DBH and total biomass at stand and regional scale,with determination coefficients ranging from 0.78 to *** on the estimation of total biomass,we successfully produced a carbon stock map of the Larix olgensis plantation in MFF with a spatial resolution of 20 m,which helps with relevant management *** findings indicate that the integration of 3-PG model and remote sensing data can well predict the biomass and carbon stock at regional and even larger *** addition,this integration facilitates the evaluation of forest carbon sequestration capacity and the development of forest management plans.

关键词： 3-PG model Larch Biomass Carbon stock ALS

Special issue on recent progress in organic electronics and photonics

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2017年第4期60卷 431-432页

作者： fei Huang yong Cao Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510641 China

Organic electronic and photonic devices have received tre- mendous attention from both academia and industry be- cause of their great promise for practical use as organic light-emitting diodes （OLEDs）, organic solar cells （OSCs）, organic field-effect transistors （OFETs）, and chemical and biological sensors. During the past decade, remarkable pro- gress has been achieved in this cutting-edge research field, which has opened numerous opportunities for the fabrica- tion of advanced organic electronic devices. For instance, solution-processable OSCs with a power conversion effi- ciency （PCE） exceeding 12% have been achieved, which meets the basic requirements for commercialization. Re- cently, active-matrix OLEDs that can be used in smart phones, televisions, and as flexible displays for portable devices have been commercialized.

关键词：电子学有机发光二极管光子学有机太阳能电池场效应晶体管有机电子器件功率转换效率生物传感器