检索结果-南通市图书馆

Suppressing the disturbance in the transmission spectrum of Glan-Thompson-type prism polarizers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2010年第4期8卷 428-430页

作者：李红霞范吉阳苏富芳吴福全祝世宁 department of Applied physics Nanjing {2. of Science and Technology department of physics Nanjing University department of physics Southeast {2. Laser Research Institute Qufu normal university department of physics Nanjing {2.

We analyze the random disturbance in the transmission of light through a spinning Glan-Thompsontype prism *** disturbance makes the dependence of the transmission on the rotation angle significantly deviates from the Malus cosine-squared law and severely spoils the output light *** vibration of the polarizer as it rotates combing the multi-beam-interference effect raises the disturbance. Further analysis reveals the sensitive dependence of the disturbance on the composing material of the prism gap,and the appropriate selection of such material can make the disturbance minimize to very desirable *** model results show quite good agreement with experiments.

关键词： Light sources Optical instruments Prisms

The change of Morin transition temperature in nanocrystalline α-Fe_2._3

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第4期42卷 344-346页

作者： LI Haibo, GONG Jie, ZHENG Weitao, CHEN Gang and YU Ruihuang1. department of Materials Science, Jilin university, Changchun 13002.,{2. 2.department of physics, Siping normal ( lege, Siping 136000,{2. department of Materials Science Jilin University Changchun China department of physics Siping Normal College Siping China

THE magnetic property of the ultrafine particles differs from that ot the bulk materials and has a lot of applications. Because of the size effect, magnetically ordered materials exhibit both superparamagnetism and collective magnetic excitation, and the magnetic transition temperature changes in the ultrafine particles with respect to the bulk materials as well. Bulk α-Fe2./sub>O3 is weakly ferromagnetic above the Morin transition temperature TM

关键词： Morin transition ultrafine particles Mossbauer effect.

Quality evaluation for air plasma spray thermal barrier coatings with pulsed thermography

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2011年第4期21卷 301-306页

作者： Shi-bin ZHAO~1,Cun-lin ZHANG~2.Nai-ming WU~3,Hua-ming WANG~1 1.School of Materials Science and Engineering,Beihang university,Beijing 100191,china 2.{2. of physics,Capital normal university,Beijing 100048,china 3.School of Jet Propulsion,Beihang university,Beijing 100191,china School of Materials Science and Engineering Beihang University Beijing 100191 China department of physics Capital Normal University Beijing 100048 China School of Jet Propulsion Beihang University Beijing 100191 China

Pulsed thermography(PT) as a non-contact non-destructive evaluation(NDE) technique was employed to examine as-sprayed air plasma spray(APS) thermal barrier coatings(TBCs) for quality *** and micro-structural characteristics play a vital role in determining the *** this paper,PT logarithmic peak second-derivative method was adopted to measure the thickness of top *** dependent thermal images were used to characterize the microstructure which was confirmed by scanning electron microscope(SEM).The results showed that there was relationship between the temperature distribution of the surface and microstructure change in *** distribution in thermal images and measurement results of thickness were in fairly good agreement with the microstructure *** can be concluded that it was possible to employ these NDE methods as quality evaluation for as-sprayed TBCs.

关键词： thermal barrier coatings(TBCs) non-destructive evaluation(NDE) pulsed thermography microstructure thickness measurement

The principle of relativity, kinematics and algebraic relations

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第4期53卷 591-597页

作者： GUO HanYing1, HUANG ChaoGuang2.3, WU HongTu4 & ZHOU Bin5 1Institute of Theoretical physics, Chinese Academy of Sciences, Beijing 100190, china 2.nstitute of High Energy physics, Chinese Academy of Sciences, Beijing 100049, china 3Theoretical physics Center for Science Facilities, Chinese Academy of Sciences, Beijing 100049, china 4department of Mathematics, Capital normal university, Beijing 100048, china 5department of physics, Beijing normal university, Beijing 100875, china Institute of Theoretical physics Chinese Academy of Sciences Beijing China Institute of High Energy physics Chinese Academy of Sciences Beijing China Theoretical physics Center for Science Facilities Chinese Academy of Sciences Beijing China department of Mathematics Capital Normal University Beijing China department of physics Beijing Normal University Beijing China

Based on the relativistic principle and the postulate of universal invariant constants (c, l), all kinematic symmetries can be set up as the subsets of the Umov-Weyl-Fock-Hua transformations for the inertial motions. ... 详细信息

关键词： principle of relativity with (c l) Umov-Weyl-Fock-Hua transformations kinematics special relativity triple

Synthesis of superheavy nuclei with ^(2.8)U target

在线全文

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 1482-1488页

作者： LIU ZuHua1,3 & BAO JingDong2.4 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,Beijing normal university,Beijing 100875,{2. 2.department of physics,Beijing normal university,Beijing 100875,{2. 3 china Institute of Atomic Energy,Beijing 102.13,{2. 4 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 Beijing Normal University Beijing China china Institute of Atomic Energy Beijing China department of physics Beijing Normal University Beijing China Center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

The production of superheavy nuclei with Z=108-116 via hot fusion reactions of the neutron-rich projectiles with 2.8U target is systematically *** results show that the production cross sections of superheavy nuclei do not decrease monotonously as the atomic number Z *** cross sections of the superheavy nuclei at Z = 112.and 115 are enhanced as compared with the whole Z-trend in synthesis of the superheavy nuclei,which clearly illustrates that the reactions with large negative Q-value and shell correction are more favorable to synthesize superheavy nuclei.

关键词： superheavy nuclei fusion reaction cross section 2.8U target

Travelling wave solutions of a generalized Camassa-Holm-Degasperis-Procesi equation

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2011年第3期54卷 555-572页

作者： DENG ShengFu1, GUO BoLing2.& WANG TingChun2.3 1department of Mathematics, Zhanjiang normal {2., Zhanjiang 52.048, china 2.nstitute of Applied physics and Computational Mathematics, Beijing 100088, china 3 College of Math and physics, Nanjing {2. of Information Science and Technology, Nanjing 2.0044, china department of Mathematics Zhanjiang Normal University Zhanjiang China Institute of Applied physics and Computational Mathematics Beijing China College of Math and physics Nanjing University of Information Science and Technology Nanjing China

The travelling wave solutions of a generalized Camassa-Holm-Degasperis-Procesi equation ut-uxxt + (1 + b)umux = buxuxx + uuxxx are considered where b > 1 and m are positive integers. The qualitative analysis methods of planar autonomous systems yield its phase portraits. Its soliton wave solutions, kink or antikink wave solutions, peakon wave solutions, compacton wave solutions, periodic wave solutions and periodic cusp wave solutions are obtained. Some numerical simulations of these solutions are also given.

关键词： homoclinic orbits heteroclinic orbits peakon wave solutions compacton wave solutions periodic cusp wave solutions

The formation and stability of Si_(1-x)C_x alloys in Si implanted with carbon ions

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第3期46卷 200-204页

作者： WANG Yinshu, LI Jinmin, JIN Yunfan, WANG Yutian, SUN Guosheng & LIN Lanying1. department of physics, Beijing {2. university, Beijing 100875, china 2. Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, china 3. Institute of Modern physics, Chinese Academy of Sciences, Lanzhou 730000, china department of physics Beijing Normal University Beijing China Institute of Semiconductors Chinese Academy of Sciences Beijing China Institute of Modern physics Chinese Academy of Sciences Lanzhou China

Si1-xCx alloys of carbon (C) concentration between 0.6%-1.0% were grown in Si by ion implantation and high temperature annealing. The formation of Si1-xCx alloys under different ion doses and their stability during annealing were studied. If the implanted dose was less than that for amorphizing Si crystals, the implanted C atoms would like to combine with defects produced during implantation and it was difficult to form Si1-xCx alloys after being annealed at 850℃. With the increment of implanted C ion doses, the lattice damage increased and it was easier to form Si1-xCx alloys. But the lattice strain would become saturate and only part of implanted carbon atoms would occupy the substitutional positions to form Si1-xCx alloys as the implanted carbon dose increased to a certain degree. Once Si1-xCx alloys were formed, they were stable at 950℃, but part of their strain would release as the annealing temperature increased to 1 000℃. Stability of the alloys became worse with the increment of carbon

关键词： ion implantation Si1-xCx alloys stability of Si1-xCx alloys.

Difference discrete connection and curvature on cubic lattice

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2006年第11期49卷 1458-1476页

作者： WU Ke, ZHAO Weizhong & GUO Hanying department of Mathematics, Capital normal {2., Beijing 100037, china Institute of Theoretical physics, Chinese Academy of Sciences, Beijing 100080, china department of Mathematics Capital Normal University Beijing China Institute of Theoretical physics Chinese Academy of Sciences Beijing China

In a way similar to the continuous case formally, we define in different but equivalent manners the difference discrete connection and curvature on discrete vector bundle over the regular lattice as base space. We deal with the difference operators as the discrete counterparts of the derivatives based upon the differential calculus on the lattice. One of the definitions can be extended to the case over the random lattice. We also discuss the relation between our approach and the lattice gauge theory and apply to the discrete integrable systems.

关键词： discrete connection, discrete curvature, noncommutative calculus, lattice gauge theory, discrete Lax pair.

Constraints on smoothness parameter and dark energy using observational H(z) data

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2011年第2期11卷 125-136页

作者： Hao-Ran Yu1,Tian Lan1,Hao-Yi Wan2.Tong-Jie Zhang1,3 and Bao-Quan Wang4 1 department of Astronomy,Beijing normal {2.,Beijing 100875,china 2.Business Office,Beijing Planetarium,Beijing 100044,china 3 Center for High Energy physics,Peking {2.,Beijing 100871,china 4 department of physics,Dezhou {2.,Dezhou 2.302.,china department of Astronomy Beijing Normal University Beijing 100875 China Business Office Beijing Planetarium Beijing 100044 China Center for High Energy physics Peking University Beijing 100871 China department of physics Dezhou University Dezhou 253023 China

With large-scale homogeneity,the universe is locally inhomogeneous,clustering into stars,galaxies and larger *** property is described by the smoothness parameter α which is defined as the proportion of matter in the form of intergalactic *** we consider the inhomogeneities over a small scale,there should be modifications of the cosmological distances compared to a homogenous *** and Roeder developed a second-order ordinary differential equation（D-R equation） that describes the angular diameter distance-redshift relation for inhomogeneous cosmological ***,we may obtain the D-R equation for observational H（z） data（OHD）.The density-parameter ΩM,the state of dark energy ω,and the smoothness-parameter α are constrained by a set of OHD in a spatially flat XCDM universe as well as a spatially flat XCDM *** using a χ2.minimization method,we get α = 0.81＋0.19-0.2. and ΩM = 0.32.0.12.0.06 at the 1σ confidence *** we assume a Gaussian prior of ΩM = 0.2. ± 0.1,we get α = 0.93＋0.07-0.19 and ΩM = 0.31＋*** the XCDM model,α is constrained to α≥ 0.80 but ω is weakly constrained around-1,where ω describes the equation of state of the dark energy（pX = ωρX）.We conclude that OHD constrains the smoothness parameter more effectively than the data of SNe Ia and compact radio sources.

关键词： cosmology -- dark energy -- cosmological parameters