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Shape phase transitions in nuclei:Effective order parameters and trajectories

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Science china(Physics,Mechanics & Astronomy) 2011年第S1期54卷 88-97页

作者： ZHANG Yu1,2, HOU ZhanFeng2 & LIU YuXin2,3 1Department of Physics, Liaoning Normal University, Dalian 116029, china 2Department of Physics and the State key laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, china 3Center of Theoretical Nuclear Physics, national laboratory of Heavy Ion Accelerator, Lanzhou 720000, china Department of Physics Liaoning Normal University Dalian China Department of Physics and the State key laboratory of Nuclear Physics and Technology Peking University Beijing China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator Lanzhou China

We analyze systematically the effective order parameters in nuclear shape phase transition both in experiments and in the interacting boson model. We find that energy ratios and B(E2) ratios can distinguish the first from the second-order phase transition in theory above a certain boson number N (about 50), but in experiments, only those quantities, such as E(L1+)/E(02+) and B(E2; (L+2)1 → L1)/B(E2; 21 → 01), etc., of which the monotonous transitional behavior in the second-order phase transition is broken in the first order phase transition independent of N, are qualified as the effective order parameters. By implementing the originally proposed effective order parameters and the new ones, we find that the isotones with neutron number Nn = 62 are a trajectory of the second order phase transition. In addition, we predict that the transitional behavior of isomer shifts of Xe, Ba isotopes and Nn = 62 isotones is approximately monotonous due to the finiteness of nuclear system.

关键词： nuclear shape phase transition interacting boson model effective order parameter finite particle number effect transition trajectory

Effects of solidification parameters on microstructure and mechanical property of a Ni-based superalloy K35 blade

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Rare Metals 2007年第S1期26卷 274-279页

作者： XUE Xiang,and XU Lin national key laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology,Harbin 150001,china Harbin Inst Technol Natl Key Lab Precis Hot Proc Met Harbin 150001 Peoples R China

A gas turbine blade of Ni-based superalloy K35 was chosen as the test casting and the effects of solidification parameters on microstructure and mechanical property of the blade were investigated.A software package was used to numerically simulate the mold filling and solidification process of the blade casting in order to obtain the solidification parameters in the *** secondary dendrite arm spacing and grain size at different positions of the blade casting were *** relationships of secondary dendrite arm spacing and grain size versus cooling rate and solidification time were quantitatively *** relationships of Vickers-hardness versus solidification structures are also *** results show that Vickers-hardness decreases with the increase of both grain size and secondary dendrite arm *** offers a good basis to predict the microstructure and mechanical property of a gas turbine blade casting through numerical simulation in order to obtain a high-quality gas turbine blade casting.

关键词： superalloy microstructure dendrite arm spacing grain size hardness

Modeling Study on Stress Distribution as Effects of Temperature and TGO Thickness in ScYSZ/NiCrAlY TBCs System

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稀有金属材料与工程 2011年第S4期40卷 164-168页

作者： Liu Huaifei1,2,Li Qilian2,Li Songlin1,Li Yongming1 1State key laboratory of Powder Metallurgy,Central South University,Changsha 410083,china 2national key laboratory of Science and Technology on Power Beam Process,Beijing Aeronautical Manufacturing Technology Research Institute,Beijing 100024,china Cent S Univ State Key Lab Powder Met Changsha 410083 Peoples R China Beijing Aeronaut Mfg Technol Res Inst Natl Key Lab Sci & Technol Power Beam Proc Beijing 100024 Peoples R China

The effects of oxidation temperature and thickness of thermally grown oxide (TGO) on thermal stress distribution in thermal barrier coatings (TBCs) system are studied in the present paper.A typical TBC system is used:air plasma sprayed (APS) Scandia,yttria-stabilized zirconia (ScYSZ) top coat (TC) and NiCrAlY bond coat (BC) deposited on the nickel super-alloy *** behavior of BC oxidation was *** the Numerical model and Finite Element (FE) method were used to analyze the stress *** objective of this study is to provide important information for understanding the failure mechanism of TBCs at least in a qualitative way.

关键词： Sc2O3-Y2O3-ZrO2 thermal barrier coating stress analysis finite element TGO

Coupling the hydrological and ecological process to implement the sustainable water resources management in Hanjiang River Basin

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Science china(Technological Sciences) 2009年第11期52卷 3240-3248页

作者： ZHANG Xiang1 & XIA Jun2 1 State key laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, china 2 key laboratory of Water Cycle and Related Land Surface Processes, IGSNRR, Chinese Academy of Sciences, Beijing 100101, china State key laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan China key laboratory of Water Cycle and Related Land Surface Processes IGSNRR Chinese Academy of Sciences Beijing China

Research on the combination of hydrological variation and ecological demands plays an important role in water availability assessment and sustainable management on basin scale. An integrative frame, consisting of hydrological regime modelling, ecological water demands estimation and renewable resources management, is given in this paper in order to support the implementation of the sustainable water resources management. The suggested integrative frame has been used to study the integrated water resources management in southern Hanjiang River Basin which is the water source of South-toNorth Water Transportation Project in china. SWAT (soil and water assessment tool) model was used to simulate the monthly averaging streamflow and the amounts of ecological water demands in stream were also estimated in order to evaluate the available water resources for the local users and the transportation project. Then we formed the developing scenarioes by coupling the available water resources, the recovering rate of water resources in natural water cycle, the local water use rate and the amounts of the water transported to North, and used the Scheafer model to analyze their evolving trajectories. Eventually, the sustainable water resources management measures were assembled by the comprehensive evaluation of the scenarioes. The research indicates that the integrative frame provided a new way for the integrated water resources management in river basin.

关键词： SWAT (soil and water assessment tool) Scheafer model ecological water demands water resources availability sustainable water resources management

Microstructure modification by La_2O_3 and its effect on wear resistance properties of as-cast ZL107 alloy

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Rare Metals 2010年第5期29卷 460-464页

作者： WAN Diqing key laboratory of the Ministry of Education of china for Conveyance and Equipment,East china Jiaotong University,Nanchang 330013,china key laboratory of the Ministry of Education of china for Conveyance and Equipment East China Jiaotong University Nanchang China

Modification of ZL107 aluminum alloy has been successfully achieved by using La2O3. The different casting parameters, including casting temperature as well as holding time and modifier content, were carried out to investigate the modification effects. The results show that the best modifier content is 1.0 wt.%, and the casting temperature has little effect. In addition, the wear behavior of modified and unmodified ZL 107 has been compared. The wear resistance of as-cast ZL 107 aluminum alloy can be significantly improved after modification.

关键词： aluminum alloys lanthanum oxides modification microstructure wear resistance

LEAFY HEAD2,which encodes a putative RNA-binding protein,regulates shoot development of rice

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Cell Research 2006年第3期16卷 267-276页

作者： Guo Sheng Xiong~(1,3) Xing Ming Hu~2 Yong Qing Jiao~1 Yan Chun Yu~1 Cheng Cai Chu~1 Jia Yang Li~1 Qian Qian~2 Yong Hong Wang~11 State key laboratory of Plant Genomics and national Center for Plant Gene Research,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing 100101,china 2 State key laboratory of Rice Biology,china national Rice Research Institute,Chinese Academy of Agricultural Sciences,Hangzhou 310006,china 3 Graduate University of Chinese Academy of Sciences,Beijing 100049,china State key laboratory of Plant Genomics and national Center for Plant Gene Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China State key laboratory of Rice Biology China National Rice Research Institute Chinese Academy of Agricultural Sciences Hangzhou China

During vegetative development,higher plants continuously form new leaves in regular spatial and temporal *** with abnormal leaf developmental patterns not only provide a great insight into understanding the regulatorymechanism of plant architecture,but also enrich the ways to its modification by which crop yield could be ***,we reported the characterization of the rice leafy-head2 (lhd2) mutant that exhibits shortened plastochron,dwarfism,reduced tiller number,and failure of phase transition from vegetative to reproductive *** and histologicalstudy revealed that the rapid emergence of leaves in lhd2 was resulted from the rapid initiation ofleafprimordia whereasthe reduced tiller number was a consequence of the suppression of the tiller bud *** molecular and geneticanalysis showed that LHD2 encodes a putative RNA binding protein with 67% similarity to maize *** ofgenome-scale expression profiles between wild-type and lhd2 plants suggested that LHD2 may regulate rice shoot devel-opment through KNOXand hormone-related *** similar phenotypes caused by LHD2 mutation and the conservedexpression pattern of LHD2 indicated a conserved mechanism in controlling the temporal leaf initiation in grass.

关键词： phyllotaxy plastochron LHD2 RNA-binding protein stem elongation plant architecture Oryza sativa L

Speckle Noise Suppressing Based on a Generalized Parallel Weighted-Average Multidirectional Morphological Filtering Algorithm

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Chinese Journal of Lasers 2000年第2期9卷 182-186页

作者： JIANG Lihui WANG Chunhui WANG Qi SHANG Tieliang (national key laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin 150001, china ) 哈尔滨工业大学可调谐(气体)激光技术国防科技重点实验室黑龙江哈尔滨

In this paper, a generalized parallel weighted-average multidirectional morphological filtering algorithm is presented to suppresing speckle noise. Simulation shows the algorithm can not only effectively suppress speckle noise but also preserve the geometrical features of images. Through comparison, it is proved that the algorithm is superior to F. Safa algoritm.

关键词： speckle noise morphological filter weighted averages parallel processing

Transition Temperature of Bi_2Sr_2CaCu_2O_(8+x) Superconducting Films Prepared from Commercial Precursors

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稀有金属材料与工程 2011年第S3期40卷 368-371页

作者： Bi Yue1, Wang Sansheng1, Hao Qingbin2 1 Inertial technology key laboratory of Fundamental Science for national Defense, Beihang University, Beijing 100191, china 2 Northwest Institute for Nonferrous Metal Research, Xi,an 710016, china Beihang Univ Sch Instrument Sci & Optoelect Engn Inertial Technol Key Lab Fundamental Sci Natl Def Beijing 100191 Peoples R China NW Inst Nonferrous Met Res Xian 710016 Peoples R China

This paper have made a systematic study of the superconducting Bi-2212 phase transition temperature, which has a transition temperature (Tc) around 80-93 K, and depends on precise control of synthesis conditions, mainly including heat treatment parameters, oxygen partial pressure, and annealing temperature. Partial melting of the sample during preparation helps to raise its Tc. To elucidate the origin of this strong effect, the samples were heated with different melting process. The rapid changes in Tc value are associated with small changes in oxygen content, which depends on the annealing temperature and the oxygen partial pressure. We have optimized the above mentioned parameters for Bi-2212 film, and Tconset was improved to 93 K.

关键词： Bi-2212 phase partial melt process transition temperature

TTT Diagram Used to Control Phase Structure of 2/4 Functional Epoxy Blends for Advanced Composites

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Chinese Journal of Aeronautics 2009年第4期22卷 449-452页

作者： Zhang Ming,An Xuefeng,Tang Bangming,Yi Xiaosu national key laboratory of Advanced Composites Materials,Beijing Institute of Aeronautical Materials,Beijing,100095,china national key laboratory of Advanced Composites Materials Beijing Institute of Aeronautical Materials Beijing 100095 China

This article uses a 2/4 functional epoxy blend system （E-54/AG-80） cured with diaminodiphenyl sulphone（DDS） as a raw material and develops a methodological procedure to establish a cure kinetic model with isothermal and dynamic differential scanning calorimeter（DSC） method and a gelation model with round-disk compression mode dynamic mechanical analyzer（DMA）, thus acquiring a series of experimental data. Characteristic temperatures such as initial glass transition temperature Tg0, gelation glass transition temperature gelTg, and infinite glass transition temperature Tg∞ are determined. The cure degree at gelation is turned out to be 0.45, while ge1Tg is found to be 70.2 ℃. The data are then used to form time-temperature-transition（TTT） diagram of the system, which serves to be a tool for process optimization of epoxy-matrix composites. A new cure processing is therefore derived from the TTT diagram. The final phase structure obtained from a controllable method is identified through scanning electron microscope（SEM） photographs to be of＂ex-situ＂ phase morphology.

关键词： composites epoxy resins TTT diagram phase structure