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On stability of elastic domain during isothermal solid-solid phase transformationin a tube configuration

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Acta Mechanica Sinica 2012年第3期28卷 683-694页

作者： Liang dong Qing-ping Sun Department of Mechanical Engineering The Hong Kong University of Science and TechnologyClear Water Bay Hong Kong China

Under isothermal quasi-static stretching the phase transition of a superelastic NiTi tube involves the formation （during loading） and vanishing （in unloading） of a high strain （martensite） domain. The two events are accompanied by a rapid stress drop/rise due to the formation/vanishing of do- main fronts. From a thermodynamic point of view, both are instability phenomena that occur once the system reaches its critical state. This paper investigates the stability of a shrink- ing cylindrical domain in a tube configuration during unload- ing. The energetics and thermodynamic driving force of the cylindrical domain are quantified by using an elastic inclu- sion model. It is demonstrated that the two domain fronts ex- hibit strong interaction when they come close to each other, which brings a peak in the total energy and a sign change in the thermodynamic driving force. It is proved that such domain front interaction plays an important role in control- ling the stability of the domain and in the occurrence of stress jumps during domain vanishing. It is also shown that the pro- cess is governed by two nondimensional length scales （the normalized tube length and normalized wall-thickness） and that the length scale dependence of the critical domain length and stress jump for the domain vanishing can be quantified by the elastic inclusion model.

关键词： Cylindrical elastic domain Stability of domain Domain front Critical domain length Stress jump ~ Ther-modynamic driving force

Energy Spectra, g Factors and Their Pressure-Induced and/or Thermal Shifts of SrTiO3:Cr3+ and SrTiO3:Mn4+ Ⅲ: R-Line Thermal Shifts of SrTiO3:Mn4+

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Communications in Theoretical Physics 2001年第11期36卷 463-468页

作者： MA dong-ping ZHANG Ji-ping Department of Applied Physics Sichuan University Chengdu 610065 China International Centre for Materials Physics The Chinese Academy of Sciences Shenyang 110015 China Department of Applied Physics Sichuan University Chengdu 610065 China

By taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as all the levels and the admixtures of basic wavefunctions within d3 electronic configuration,the values of the parameters in the expressions of thermal shift (TS) from EPI for the ground level, R level and R line of SrTiO3:Mn4+ have been evaluated; the R-line TS and various contributions to it have been calculated in the low-temperature region. It is found that all the three terms of R-line TS from EPI relevant to the lattice vibration are red shifts. The Raman term is the largest, the neighbor-level term is the second, and the optical-branch term is very small over the range of T ≤ 80 K. The contribution to R-line TS from thermal expansion has been approximately neglected in this work. The very strong EPI relevant to its lattice vibration for SrTiO3:Mn4+ causes its R-line TS to be an unusually large red-shift. Only by taking into account the strong softening of the low-frequency acoustic modes of the lattice vibration at low temperatures, can we successfully explain the variation of R-line TS of SrTiO3:Mn4+ with temperature.

关键词： crystal fields, optical properties, electron-phonon interaction, thermal shift, softening of acoustic modes

The oldest known larva and its implications for the plesiomorphy of metazoan development

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Science Bulletin 2015年第22期60卷 1947-1953页

作者： Huaqiao Zhang Xi-ping dong Key Laboratory of Economic Stratigraphy and Palaeogeography Chinese Academy of Sciences (Nanjing Institute of Geology and Palaeontology) School of Earth and Space Sciences Peking University

There has been a century-long debate in evolutionary developmental biology about whether the ancestral metazoan was a larva or an adult. Two competing hypotheses have been proposed: the ‘‘terminal addition''theory, which assumes the primitiveness of larvae, and the‘‘intercalation'' theory, which assumes the primitiveness of adults. A consensus has not yet been reached, but the‘‘terminal addition'' theory appears to be more widely accepted. However, in contrast to the majority of larvae among living metazoans, all currently known fossil invertebrate embryos such as Markuelia and Olivooides are direct developers. Here, we describe Eolarva kuanchuanpuensis gen. et sp. nov., the oldest known larva, from the early Cambrian(*535 Ma) of South China. Eolarva kuanchuanpuensis lacks a mouth or any other type of feeding apparatus, which is non-feeding or *** possesses a distinct body plan and might represent a cnidarian-grade animal. This is the first fossil evidence indicating that indirect development is the plesiomorphy of metazoan development.

关键词： Oldest known larva Indirectdevelopment Plesiomorphy of metazoandevelopment Cambrian South China

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文化的生死问题探源

河北学刊 2025年第1期45卷 91-97页

作者：韩东屏华中科技大学哲学学院

文化的生死作为既成事实,只能是指群体文化的生死。学术界专门研究过文化生死的学者,有斯宾格勒和汤因比。但这二人无论是对文化之生死的指认,还是对文化生死之因的解释,都存在谬误,不能成立。文化作为人类创造力的果实,从生物性意义的... 详细信息

文化的生死作为既成事实,只能是指群体文化的生死。学术界专门研究过文化生死的学者,有斯宾格勒和汤因比。但这二人无论是对文化之生死的指认,还是对文化生死之因的解释,都存在谬误,不能成立。文化作为人类创造力的果实,从生物性意义的现代人类算起,其生即起点是晚期智人的原始群文化,其后相继演变为氏族文化和国家文化,而其死即终点则是文化的主人不复存在之时。其生的成因是人为了满足自身需求所进行的创造,死的原因是群体文化的创造者和使用者被外部力量消灭或打散。

关键词：文化生死群体文化民族文化

Polycyclic Structure Synthesis via a Three-step "[2+n]" Annulation

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Chinese Journal of Chemistry 2019年第5期37卷 529-530页

作者： Qian He dong-ping Wu Department of Chemistry Fujian Provincial Key Laboratory of Chemical Biology College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China

Carbocycles are ubiquitous in natural organic molecules and medicinal agents. Therefore, developing methodologies for the efficie nt con struction of car bo cycles constitutes an importa nt goal in organic synthesis. In this regard, for the construction of sixmembered rings, the Diels-Alder [4+2] cycloaddition reaction (Figure 1, eq 1) and Robinson annulation (Figure 2, eq 1) represent two paradigms in terms of efficiency, selectivity, and versatility.

关键词： organic agents versatility

Improved Ligand-Field Calculation of Energy Spectrum and R-Line Thermal Shift of MgO：Cr^3＋

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Communications in Theoretical Physics 2007年第5期47卷 937-943页

作者： ZHANG Zheng-Jie MA dong-ping College of Information Engineering Chengdu University of Technology Chengdu 610059 China Department of Applied Physics Sichuan University Chengdu 610065 China

Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R-line, t^3 2^2 T1 lines, t^2 2（^3 T1）e^4 T2, and t^2 2（^3T1）e^4T1 bands, ground-state g factor, four strain-induced level- splittings, and R-line thermal shift of MgO：Cr^3＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：Cr^3＋, the contributions due to electron-phonon interaction （EPI） come from the first-order term. In thermal shift of R-line of MgO：Cr^3＋, the temperature-dependent contribution due to EPI is dominant.

关键词： improved ligand-field theory electron-phonon interaction energy spectrum strain-induced splitting thermal shift g factor

Energy Spectrum of La3Lu2Ga3O12：Cr^3＋ and Its Pressure-Induced R-Line-Shift Reversal

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Communications in Theoretical Physics 2005年第6X期44卷 1103-1114页

作者： MA dong-ping CHEN Ju-Rong Department of Applied Physics Sichuan University Chengdu 610065 Chinat International Centre for Materials Physics the Chinese Academy of Sciences Shenyang 110015 China

By means of both the theory for pressure-induced Shifts （PS） of energy spectra and the theory for shifts of energy spectra due to electron-phonon interaction （EPI）, the normal-pressure energy spectra of α and β centers of Cr^3＋ ions for LLGG：Cr^3＋ and the PS＇s of R1 lines and U band of these centers have been calculated at 10 K, respectively. The total calculated results are in very good agreement with the experimental data. For LLGG：Cr^3＋, the pressureinduced low-high crystal-field transition and the reversal of R1-line PS take place. The pressure-dependent variation of Rmix^ei （2E - 4T2） [mixing-degree of （t2^2 （^3T1）e^4T2） and （t2^3 E） base-wavefunctions in the wavefunction of R1 state without EPI] plays a key role for the reversal of R1-line PS. The behavior of the pure electronic PS of R1 line is quite different from that of the PS of R1 line due to EPI. It is the combined effect of them that gives rise to the total PS of R1 line. The comparison between R1-line PS＇s of GSGG：Cr^3＋ and LLGG：Cr^3＋ has been made. It is found that a peak of R1-line PS appears at Rmix^ei （^2E - ^4T2） ≈ 0.08.

关键词： pressure-induced reversal of Rl-line shift low high crystal-field transition electron-phonon interaction mixing of base-wavefunctions

Remaining Useful Life Prediction for Aero-Engines Combining Sate Space Model and KF Algorithm

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第3期34卷 265-271页

作者： Cai Jing Zhang Li dong ping College of Civil Aviation Nanjing University of Aeronautics and Astronautics

The key to failure prevention for aero-engine lies in performance prediction and the exhaust gas temperature margin(EGTM)is used as the most important degradation parameter to obtain the operating performance of the *** of the complex environment interference,EGTM always has strong randomness,and the state space based degradation model can identify the noisy observation from the true degradation state,which is more close to the actual ***,a state space model based on EGTM is established to describe the degradation path and predict the remaining useful life(RUL).As one of the most effective methods for both linear state estimation and parameter estimation,Kalman filter(KF)is ***,with EGTM degradation data,state space model approach is used to set up a state space model for ***,RUL of aero-engine is analyzed,and expected RUL and distribution of RUL are ***,the sate space model and KF algorithm are applied to an example of *** expected RUL is predicted,and corresponding probability density distribution(PDF)and cumulative distribution function(CDF)are *** result indicates that the accuracy of RUL prediction reaches 7.76%ahead 580 flight cycles(FC),which is more accurate than linear regression,and therefore shows the validity and rationality of the proposed method.

关键词： Prediction remaining noisy situations exhaust ahead rationality validity cumulative Bayesian

Improved Ligand-Field Theoretical Calculation of R-Line Pressure-Induced Shift of MgO:V^(2+)

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Communications in Theoretical Physics 2008年第9期50卷 781-786页

作者： ZHANG Zheng-Jie MA dong-ping Department of Physics Chengdu University of Technology Chengdu 610059 China Department of Applied Physics Sichuan University Chengdu 610065 China

By means of an improved ligand-field theory, the ＂pure electronic＂ PS and the PS due to EPI of R line of MgO： V^2＋ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. The behaviors of the pure electronic PS of R line of MgO：V^2＋ and the PS of its R line due to EPI are different. It is the combined effect of them that gives rise to the total PS of R line, which has satisfactorily explained the experimental results. The mixing-degree of ｜t2^2（^3T1）e^4T2〉 and ｜t2^3 ^2E〉 in the wavefunetion of R level and its variation with pressure have been calculated and analyzed. The comparison between the feature of R-line PS of MgO：V^2＋ and that of MgO：Cr^3＋ has been made.

关键词： high-pressure effect electron-phonon interaction R line improved ligand-field theory the admix-ture of |t2^2(^3T1)e^4T2〉 and |t2^3 2E〉