检索结果-南通市图书馆

Number of zero point for a polynomial in real field

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第11期42卷 886-890页

作者： LIN Liang and LIU Yirong1. guilin Institute of Technology, guilin 541004, {2. 2. Central South university of Technology, Changsha 410083, {2. guilin Institute of Technology Guilin 541004 China

IT is well known that for any real coefficient polynomial f(x) of degree n,how to determineits number of real zero points is a very important problem in theory of polynomial,as well as inapplications in mathematics,mechanics,physics and other *** way to solve thisproblem by using Euclidean mutual division as pointed out by Sturm is not simple and conve-nient for us to use the theoretic analyses for the above problem because the relation

关键词： polynomial real zero point coefficients.

Multi-layer quasi-zero-stiffness meta-structure for high-efficiency vibration isolation at low frequency

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1189-1208页

作者： Jiahao ZHOU Jiaxi ZHOU Hongbin PAN Kai WANG Changqi CAI guilin WEN college of Mechanical and Vehicle Engineering Hunan UniversityChangsha410082China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body The Ministry of Science and TechnologyChangsha410082China School of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou310018China School of Mechanical Engineering Yanshan UniversityQinhuangdao066004Hebei ProvinceChina

An easily stackable multi-layer quasi-zero-stiffness(ML-QZS)meta-structure is proposed to achieve highly efficient vibration isolation performance at low ***,the distributed shape optimization method is used to design the unit cel,i.e.,the single-layer QZS(SL-QZS)***,the stiffness feature of the unit cell is investigated and verified through static ***,the unit cells are stacked one by one along the direction of vibration isolation,and thus the ML-QZS meta-structure is ***,the dynamic modeling of the ML-QZS vibration isolation metastructure is conducted,and the dynamic responses are obtained from the equations of motion,and verified by finite element(FE)***,a prototype of the ML-QZS vibration isolation meta-structure is fabricated by additive manufacturing,and the vibration isolation performance is evaluated *** results show that the vibration isolation performance substantially enhances when the number of unit cells *** importantly,the ML-QZS meta-structure can be easily extended in the direction of vibration isolation when the unit cells are properly ***,the ML-FQZS vibration isolation meta-structure should be a fascinating solution for highly efficient vibration isolation performance at low frequency.

关键词： quasi-zero stiffness(QZS) meta-structure high efficiency low frequency vibration isolation

Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2.molecule

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 385-398页

作者： REN Weiyi1,2. SUN Weiguo1, HOU Shilin3 & FENG Hao4 1. Institute of physics, college of Chemical Engineering, Sichuan {2., Chengdu 610065, china 2. Institute of Theoretical physics, Xihua Normal {2., Nanchong 637002. china 3. Department of physics, china Oceanography {2., Qingdao 2.6003, china 4. college of physics, Sichuan {2., Chengdu 610065, china 1. Institute of physics College of Chemical Engineering Sichuan University 610065 Chengdu China 2. Institute of Theoretical physics Xihua Normal University 637002 Nanchong China 3. Department of physics China Oceanography University 266003 Qingdao China 4. college of physics Sichuan University 610065 Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2.molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

Application of Ice Pigging in a Drinking Water Distribution System:Impacts on Pipes and Bulk Water Quality

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第9期40卷 122-130页

作者： Yujing Huang Zhiwei Chen guilin He Yu Shao Shuang Song Feilong Dong Tuqiao Zhang college of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310027China Suzhou Wuzhong Water Co. Ltd.Suzhou 215128China School of Municipal and Environmental Engineering Shandong Jianzhu UniversityJi’nan 250101China college of Environment Zhejiang University of TechnologyHangzhou 310014China

Ice pigging is an emerging technique for pipe cleaning in drinking water distribution ***,substantial confusion and controversy exist on the potential impacts of ice pigging on bulk water *** study monitored the microstructural features and composition of sediments and microbial community structures in bulk water in eight multimaterial Chinese *** concentration analysis demonstrated that separate cleaning of pipes with different materials in complex networks could mitigate the risk of losing ice pigs and degrading water *** microstructural and trace element characterization results showed that ice pigs would scarcely disturb the inner surfaces of long-used *** bacterial richness and diversity of bulk water decreased significantly after ice ***,correlations were established between pipe service age,temperature,and chloride and total iron concentrations,and the 15 most abundant taxa in bulk water,which could be used to guide practical ice pigging operations.

关键词： Ice pigging Pipe cleaning Drinking water distribution system Bacterial community Sediments

Shell effect and capture cross sections in the synthesis of superheavy nuclei

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

Science china(physics,Mechanics & Astronomy) 2009年第10期52卷 1489-1493页

作者： DU SaiSai1,2.BIAN BaoAn1,2.3,LIU Min1,2.4,FENG ZhaoQing5,6 & ZHANG FengShou1,2.6 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,college of Nuclear Science and Technology,Beijing Normal university,Beijing 100875,{2. 2.Beijing Radiation Center,Beijing 100875,{2. 3 School of Science,Jiangnan university,Wuxi 2.412.,{2. 4 college of physics and Technology,guangxi Normal university,guilin 541004,{2. 5 Institute of Modern physics,Chinese Academy of Sciences,Lanzhou 730000,{2. 6 Center of Theoretical Nuclear physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 730000,{2. Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal University Beijing 100875 China Beijing Radiation Center Beijing 100875 China School of Science Jiangnan University Wuxi 214122 China college of physics and Technology Guangxi Normal University Guilin 541004 China Institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China Center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The shell effect is included in the improved isospin dependent quantum molecular dynamics model in which the shell correction energy of the system is calculated by using the deformed two-center shell model. A switch function is introduced to connect the shell correction energy of the projectile and the target with that of the compound nucleus during the dynamical fusion process. It is found that the calculated capture cross sections reproduce the experimental data quantitatively at the energy near the Coulomb barrier. The capture cross sections for reaction 35 80 Br + 82.2.8 Pb → 117 2.8 X are also calculated and discussed.

关键词： superheavy nuclei transport theory shell effect cross sections

A POISSON-GAUSSIAN MODEL TO PRICE EUROPEAN OPTIONS ON THE EXTREMUM OF SEVERAL RISKY ASSETS WITHIN THE HJM FRAMEWORK

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2010年第4期23卷 769-783页

作者： Guohe DENG Lihong HUANG School of Mathematics Guangxi Normal University Guilin 541004 China. college of Mathematics and Econometrics Hunan University Changsha 410082 China

This paper generalizes European call options on the extremum of several risky assets in a Poisson-Gaussian model which allows both the risky assets and stochastic interest rates moving randomly with jump risks. The stochastic interest rate is assumed to follow an extended multi-factor HJM model with jumps. The authors provide explicitly the closed-form solutions of these options through the change of numeralre technique and examine the effects of both jump risks and stochastic interest rate on the option price with numerical experiment. The model can be seen as an extension of Stulz （1982., Johnson （1987） and Lindset （2.06）.

关键词： Extremum options jump-diffusion model stochastic interest rate.

Magnetic Field Controllable Photocurrent Properties in BiFe_(0.9)Ni_(0.1)O_(3)/La_(0.7)Sr_(0.3)MnO_(3) Laminate Thin Film

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第2期7卷 381-388页

作者： Guanzhong Huo Ke Wang Qingying Ye Shuiyuan Chen Chao Su Yuxiang Zhang guilin Chen Zhigao Huang Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials College of Physics and EnergyFujian Normal UniversityFuzhou 350117China Fujian Provincial Engineering Technology Research Center of Solar Energy Conversion and Energy Storage Fuzhou 350117China

This paper reports a multifunctional magnetic-photoelectric laminate device based on the integration of spintronic material(La_(0.7)Sr_(0.3)MnO_(3))and multiferroic(Ni-doped BiFeO_(3)),in which the repeatable modulation effect on the photoelectric properties were achieved by applying external magnetic *** obviously,photocurrent density(J)of the laminate was largely enhanced,the change rate of J up to 2.7.6%is *** sensing function effect should be attributed to the low-field magnetoresistance effect in perovskite manganite and the scattering of spin photoelectron in multiferroic *** laminate perfectly combines the functions of sensor and controller,which can not only reflect the intensity of environmental magnetic field,but also modulate the photoelectric conversion *** work provides an alternative and facile way to realize multi-degree-of-freedom control for photoelectric conversion performances and lastly miniaturize multifunction device.

关键词： bismuth ferrite low-field magnetoresistance effect magnetic field modulation perovskite manganite photocurrent

Preparation of Nanosized AlOOH and Its Application in Polymer-inorganic Nanocomposites

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials Science) 2008年第5期23卷 638-643页

作者：廖海达 State Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology college of Chemistry and Ecological Engineering Guangxi University for Nationalities Key Lab of Nonferrous Materials and New Processing Technology (guangxi university Guilin University of Technology) Ministry of Education

With industrial grade Al（OH）3 as raw materials, the self dispersion nanosized AlOOH crystal powder were prepared by the sol-hydrothermal method. The results of XRD and TEM show that the nanosized AlOOH could automatically disperse to a single-dispersing state in water without surface modification, dispersant, additive and accessional conditions （ultrasonic wave dispersing, ball-mill dispersing）. The application results of the product indicate that the nanosized AlOOH can be composed into a toughened nanocomposites without surface modification. Accordingly, the self dispersion characteristic and mechanism of hydrothermal crystallization and charging composite dispersion of nanosized AIOOH are found, and a new technique of preparing polymer/inorganic nanocomposites is proposed, which is called blending compositing new techniques of sol even dispersing at auasi-homogeneous phase.

关键词： self dispersion nanosized AlOOH peptizing-hydrothermal method nanocomposites

Virtualities of quark and gluon in QCD vacuum

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2008年第10期51卷 1439-1447页

作者： ZHOU LiJuan1, QIN SongMei2. WU Qing3 & MA WeiXing4 1 Collaboration Group of Hadron physics and Non-perturbative QCD Study, guangxi {2. of Tech- nology, Liuzhou 545006, china 2.Department of physics, guangxi {2., Nanning 540003, china 3 Department of physics, Qingdao {2., Qingdao 2.6071, china 4 Institute of High Energy physics, Chinese Academy of Sciences, Beijing 100049, china 1. Collaboration Group of Hadron physics and Non-perturbative QCD Study Guangxi University of Technology Liuzhou 545006 China 2. Department of physics Guangxi University Nanning 540003 China 3. Department of physics Qingdao University Qingdao 266071 China 4. Institute of High Energy physics Chinese Academy of Sciences Beijing 100049 China

The non-local vacuum condensates of quantum chromodynamics (QCD) describe the distributions of quarks and gluons in the non-perturbative QCD vacuum state. Physically, this means that vacuum quarks and gluons have a nonzero mean-squared momentum in the vacuum, called virtuality. The quark virtuality is given by the ratio of the local quark-gluon mixed vacuum condensate to the quark local vacuum condensate. The gluon virtuality is expressed by gluon vacuum condensates and four-quark vacuum condensates. We study the two virtualities by solving Dyson-Schwinger Equations and calculating quark and gluon vacuum condensates. Our theoretical results for quark virtuality are in good agreement with many other theoretical model predictions such as QCD sum rules and lattice QCD calculations. Our calculation on gluon virtuality is initial and the results are quite interesting.

关键词： quark gluon virtuality QCD vacuum condensate non-perturbative QCD