检索结果-南通市图书馆

Mapping the Spinless Fermion-Boson Model onto a Luttinger Liquid Model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1996年第11期13卷 801-804页

作者： WANG Yu-peng PU fu-ke Cryogenic Laboratory Chinese Academy of SciencesBeijing 100080 Department of Physics Guangzhou Teacher’s CollegeGuangzhou 510400 Institute of Physics Chinese Academy of SciencesBeijing 100080

The spinless fermion-boson model in one-dimension is studied via the Bethe ansatz *** eigenstates of the model Hamiltonian are *** long distance correlation functions are calculated based on the prediction of the conformal field *** is shown that the low energy physics of the present model is equivalent to that of a Luttinger liquid model.

关键词： theory method Fermi

Exact Solution of a Backward Scattering Kondo Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 1996年第9期13卷 703-706页

作者： WANG Yu-peng PU fu-ke Cryogenic Laboratory Chinese Academy of SciencesBeijing 100080 Department of Physics Guangzhou Teachers’CollegeGuangzhou 510400 Institute of Physics Chinese Academy of SciencesBeijing 100080

To specify the difference between the one-dimensional Kondo problem and the three-dimensional Kondo problem,we consider a model which describes the interaction between one-dimensional free electrons and a magnetic *** ansatz exact results and scaling analysis show that if J_(F)>-|J_(B)|,the Kondo screening *** is no ferromagnetic Kondo screening in such a system but the long range antiferromagnetic Kondo coupling is *** soon as the Coulomb interaction is introduced,the crossovers between the scaling trajectories in the parameter region J_(F)<-|J_(B)|and the trajectories in other parameter regions arise and ferromagnetic Kondo screening may occur.

关键词： Kondo ferromagnetic scaling

Numerical simulation of polygonal particles moving in incompressible viscous fluids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2017年第2期15卷 140-151页

作者： Xiaowu fu Zhaohui yao Xiwen Zhang Department of Engineering Mechanics Tsinghua University Beijing 100084 China

A two-dimensional coupled lattice Boltzmann immersed boundary discrete element method is introduced for the simulation of polygonal particles moving in incompressible viscous fluids. A collision model of polygonal particles is used in the discrete element method. Instead of a collision model of circular particles, the collision model used in our method can deal with particles of more complex shape and efficiently simulate the effects of shape on particle–particle and particle–wall interactions. For two particles falling under gravity, because of the edges and corners, different collision patterns for circular and polygonal particles are found in our simulations. The complex vortexes generated near the corners of polygonal particles affect the flow field and lead to a difference in particle motions between circular and polygonal particles. For multiple particles falling under gravity, the polygonal particles easily become stuck owing to their corners and edges, while circular particles slip along contact areas. The present method provides an efficient approach for understanding the effects of particle shape on the dynamics of non-circular particles in fluids.

关键词： Polygonal particle Particle-fluid interaction Lattice Boltzmann method Immersed boundary method Discrete element method

Effective conversion of cellobiose and glucose to sorbitol using non-noble bimetallic NiCo/HZSM-5 catalyst

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2018年第9期61卷 1167-1174页

作者： Bakht Zada Long Yan yao fu Hefei National Laboratory for Physical Science at the Microscale Collaborative Innovation Center of Chemistry for Energy Materials (iChEM) CAS Key Laboratory of Urban Pollutant Conversion Anhui Province Key Laboratory for Biomass Clean Energy and Department of Chemistry University of Science and Technology of China

The tandem hydrolysis and hydrogenation of saccharides into sorbitol is an especially attractive reaction in the conversion of biomass. Here, an economical and efficient bimetallic catalyst for the transformation of glucose and cellobiose into sorbitol is reported. Non-precious metal based catalysts such as NiCo, Ni, and Co, were prepared via modified impregnation method, and NiCo/HZSM-5 showed superior performance for the synthesis of sorbitol(86.9% from cellobiose, 98.6% from D-glucose).Various characterizations, such as Brunner-Emmet-Teler(BET), X-ray diffraction(XRD), transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS), confirmed that NiCo alloy formed and highly dispersed in NiCo/HZSM-5 catalyst. The high performance of fabricated catalyst would be attributed to the formation of nickel-cobalt alloy over HZSM-5 zeolite surface. High temperature and H_2 pressure were favorable for the tandem hydrolysis and hydrogenation reaction. Besides,the reaction pathway was also proposed based on the kinetics study. Cellobitol was detected as the intermediate in the reaction mixture. furthermore, in the catalytic stability study, it was found that active metal species of NiCo/HZSM-5 were stable. The deactivation of catalyst would be due to the covering of acidic sites over NiCo/HZSM-5.

关键词： biomass sorbitol glucose cellobiose bimetallic catalyst

On Gorenstein coalgebras

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2016年第4期11卷 845-867页

作者： Xuerong fu Hailou yao College of Applied Sciences Beijing University of Technology Beijing 100124 China

We investigate the comodule representation category over the Morita-Takeuchi context coalgebra F and study the Gorensteinness of F. Moreover, we determine explicitly all Gorenstein injective comodules over the Morita-Takeuchi context coalgebra F and discuss the localization in Gorenstein coalgebras. In particular, we describe its Gabriel quiver and carry out some examples when the Morita-Takeuchi context coalgebra is basic.

关键词： Gorenstein coalgebra Gorenstein injective comodule Gabriel quiver

Polyoxometalates based nanocomposites for bioapplications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2023年第11期42卷 3570-3600页

作者： yao Cheng ke-Jie Qin De-Jin Zang School of Pharmacy and Pharmaceutical Sciences&Institute of Materia Medica National Key Laboratory of Advanced Drug Delivery and SystemShandong First Medical University&Shandong Academy of Medical SciencesNHC Key Laboratory of Biotechnology Drugs(Shandong Academy of Medical Sciences)Key Lab for Rare&Uncommon Diseases of Shandong ProvinceJinan250117China

Health care and medical care have always been dominant topics in human *** field of precision medicine,iatrotechnics revolution and timely on-demand detection have continued to evolve in response to increasing demands from the ***,the emergence of innovative materials and their applications offer promising prospects for advancing global ***(POMs)are negatively-charged molecular metal oxides with well-defined structures,beautiful geometries and nanoscale *** to their vast diversity in composition,structure,nuclearity and charge,they constitute a significant subcategory of inorganic clusters that contain bridging oxygen atoms between two or more metal ***,POMs based nanocomposites have been widely applied in the field of disease diagnosis,anticancer therapy and antibacterial therapy as new generation bioactive *** this review,the recent advances of POMs based nanocomposites in bioapplications are summarized and the future perspectives are discussed.

关键词： Polyoxometalates(POMs) Disease diagnosis Anticancer therapy Antibacterial therapy Biological imaging

Parallel exploration via negatively correlated search

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2021年第5期15卷 123-135页

作者： Peng YANG Qi YANG ke TANG Xin yao Guangdong Provincial key Laboratory of Brain-inspired Intelligent Computation Department of Computer Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China

Effective exploration is key to a successful search *** recently proposed negatively correlated search(NCS)tries to achieve this by coordinated parallel exploration,where a set of search processes are driven to be negatively correlated so that different promising areas of the search space can be visited *** successful applications of NCS,the negatively correlated search behaviors were mostly devised by intuition,while deeper(e.g.,mathematical)understanding is *** this paper,a more principled NCS,namely NCNES,is presented,showing that the parallel exploration is equivalent to a process of seeking probabilistic models that both lead to solutions of high quality and are distant from previous obtained probabilistic *** learning,for which exploration is of particular importance,are considered for empirical *** proposed NCNES is applied to directly train a deep convolution network with 1.7 million connection weights for playing Atari *** results show that the significant advantages of NCNES,especially on games with uncertain and delayed rewards,can be highly owed to the effective parallel exploration ability.

关键词： evolutionary computation reinforcement learning exploration

Analysis of the dominant frequency in a subsonic compressor stator at near stall condition

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2014年第1期59卷 23-28页

作者： ke Shi Song fu School of Aerospace Tsinghua University

IDDES method was applied to investigate the highly unsteady flow in a subsonic compressor stator with very large hub clearance and high incidence *** blade loading variation frequency was found close to the rotating instability(RI)frequency f RI&333 Hz observed in the *** analysis of the flow physics shows that the loading variation is caused by the periodic swing of the large scale separated flow on the blade suction side *** breakdown of the leakage vortex has no significant dominant frequencies,thus cannot be the cause of RI in this compressor stator as normally ***,the vortex shedding and vortex breakdown due to shear layer instability at the outer edge of the blade suction surface separation region excite high frequency unsteadiness that can form the sources of noise.

关键词：压气机亚音速静子非定常流动频分状态失速优势频率

A user requirements-oriented privacy policy self-adaption scheme in cloud computing

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2023年第2期17卷 33-44页

作者： Changbo ke fu XIAO Zhiqiu HUANG Fangxiong XIAO School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210003China College of computer science and technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Software Engineering Jinling Institute of TechnologyNanjing 210000China

In an ever-changing environment,Software as a Service(SaaS)can rarely protect users'*** able to manage and control the privacy is therefore an important goal for *** the participant of composite service is substituted,it is unclear whether the composite service satisfy user privacy requirement or *** this paper,we propose a privacy policies automatic update method to enhance user privacy when a service participant change in the composite ***,we model the privacy policies and service variation ***,according to the service variation rules,the privacy policies are automatically generated through the negotiation between user and service ***,we prove the feasibility and applicability of our method with the *** the service quantity is 50,ratio that the services variations are successfully checked by monitor is 81%.Moreover,ratio that the privacy policies are correctly updated is 93.6%.

关键词： cloud computing SaaS service privacy protec-tion privacy policies update