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A Statistical Model for Phase Difference Spectrum of Ground-Motion and Its Application in Generating Non-Stationary Seismic Waves

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Computer Modeling in Engineering & Sciences 2020年第7期124卷 265-285页

作者： Dongsheng Du sheng shi Weizhi Xu Chen Kong Shuguang Wang Weiwei Li College of Civil Engineering Nanjing University of TechnologyNanjing210009China China Jiangsu International Group Architecture Design Institute Nanjing211816China

The intensity non-stationarity is one of the most important features of earthquake *** of this feature is significant to the generation of artificial earthquake *** on the theory of phase difference spectrum,an intensity non-stationary envelope function with log-normal form is *** a tremendous amount of earthquake records downloaded on Kik-net,a parameter fitting procedure using the genetic algorithm is conducted to obtain the value of model parameters under different magnitudes,epicenter distances and site conditions.A numerical example is presented to describe the procedure of generating fully non-stationary ground motions via spectral representation,and the mean EPSD(evolutionary power spectral density)of simulated waves is proved to agree well with the target *** results show that the proposed model is capable of describing the intensity non-stationary features of ground motions,and it can be used in structural anti-seismic analysis and ground motion simulation.

关键词： Intensity non-stationarity parameter fitting genetic algorithm phase

NaOH/Urea Swelling Treatment and Hydrothermal Degradation of Waste Cotton Fiber

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Journal of Renewable Materials 2020年第6期8卷 703-713页

作者： Lixia Gao sheng shi Wensheng Hou Shuhua Wang Zhifeng Yan Chao Ge College of Textile Engineering Taiyuan University of TechnologyJinzhong030600China Jihua 3542 Textile Company Limited Xiangyang441000China

In this study,waste cotton fabric was used as cellulose raw material and pretreated in aqueous NaOH/urea solution system to investigate the effect of NaOH/urea pretreatment solution on the hydrolysis of cotton *** cotton fiber was pretreated with different conditions of aqueous NaOH/urea solution,and the pretreated cotton fiber was hydrolyzed under the same conditions as the original cotton *** results of characterization analysis showed that water retention value of pretreated cotton fiber was higher than that of unpretreated ***,the cotton fiber presented both a convoluted structure and a coarser surface,XRD results suggested that the crystallinity degree of cellulose decreased dramatically,more cellulose II appeared,and the hydrogen bond is *** the different pretreatment conditions,the pretreatment effect was the best when the reaction temperature was 0°C,the solid-liquid ratio was 2:50,and the NaOH/urea ratio was 7:*** hydrolysis experiments of pretreated and unpretreated cotton fibers showed that when the hydrothermal temperature was 230°C,the heat preservation was 2 h,and the hydrochloric acid concentration was 5 wt.%,the glucose yield reached 29.99%.H+could catalyze the hydrolysis of cotton fiber more effectively due to damage to crystal structure and hydrogen bonds.

关键词： Waste cotton fibers NaOH/urea pretreatment hydrolyze recycling and reusing

A cellular mechanism underlying the restoration of thermo/photoperiod-sensitive genic male sterility

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Molecular Plant 2021年第12期14卷 2104-2114页

作者： Qiang-sheng shi Yue Lou shi-Yi Shen sheng-Hong Wang Lei Zhou Jun-Jie Wang Xing-Lu Liu Shuang-Xi Xiong Yu Han Hai-sheng Zhou Xue-Hui Huang Shui Wang Jun Zhu Zhong-Nan Yang Shanghai Key Laboratory of Plant Molecular Sciences College of Life SciencesShanghai Normal UniversityShanghai 200234China College of Resources&Environment Jiujiang UniversityJiujiangJiangxi 332005China Development Center of Plant Germplasm Resources College of Life SciencesShanghai Normal UniversityShanghai 200234China

During anther development,the transformation of the microspore into mature pollen occurs under the pro-tection of first the tetrad wall and later the pollen *** in genes involved in this wall transition often lead to microspore rupture and male sterility;some such mutants,such as the reversible male sterile(rvms)mutant,are thermo/photoperiod-sensitive genic male sterile(P/TGMS)*** studies have shown that slow development is a general mechanism of P/TGMS fertility *** this study,we iden-tified restorer of rvms-2(res2),which is an allele of QUARTET3(QRT3)encoding a polygalacturonase that shows delayed degradation of the tetrad pectin *** found that MS188,a tapetum-specific transcrip-tion factor essential for pollen wall formation,can activate QRT3 expression for pectin wall degradation,indicating a non-cell-autonomous pathway involved in the regulation of the cell wall *** as-says showed that a delay in degradation of the tetrad pectin wall is responsible for the fertility restoration of rvms and other P/TGMS lines,whereas early expression of QRT3 eliminates low temperature restoration of rvms-2 *** together,these results suggest a likely cellular mechanism of fertility restoration in P/TGMS lines,that is,slow development during the cell wall transition of P/TGMS microspores may reduce the requirement for their wall protection and thus support their development into functional pollens,leading to restored fertility.

关键词： thermo-sensitive male sterility pectin wall rvms-2 qrt

Isovector giant dipole resonances in proton-rich Ar and Ca isotopes

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Chinese Physics C 2021年第4期45卷 292-300页

作者： Ling Liu Shuai Liu shi-sheng Zhang Li-Gang Cao College of Physics Science and Technology Shenyang Normal UniversityShenyang 110034China School of Physics Beihang UniversityBejjing 100191China School of Mathematics and Physics North China Electric Power UniversityBeijig 102206China Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China

The isovector giant dipole resonances(IVGDR)in proton-rich Ar and Ca isotopes have been systematic-ally investigated using the resonant continuum Hartree-F ock+BCS(HF+BCS)and quasiparticle random phase ap-proximation(QRPA)*** Skyrme SLy5 and density-dependent contact pairing interactions are employed in the *** addition to the giant dipole resonances at energy around 18 MeV,pygmy dipole resonances(PDR)are found to be located in the energy region below 12 *** calculated energy-weighted moments of PDR in nuclei close to the proton drip-line exhaust about 4%of the TRK sum *** strengths decrease with in-creasing mass number in each isotopic *** transition densities of the PDR states show that motions of pro-tons and neutrons are in phase in the interiors of nuclei,while the protons give the main contribution at the *** analyzing the QRPA amplitudes of proton and neutron 2-quasiparticle configurations for a given low-lying state,we find that only a few proton configurations give significant *** contribute about 95%to the total QRPA amplitudes,which indicates that the collectivity of PDR states is not strong in proton-rich nuclei in the present study.

关键词： pygmy dipole resonances proton-rich nuclei Skyrme energy density functional

STOCHASTIC ANALYSIS OF GROUNDWATER FLOW SUBJECT TO RANDOM BOUNDARY CONDITIONS

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Journal of Hydrodynamics 2008年第5期20卷 553-560页

作者： shi Liang-sheng YANG Jin-zhong CAI Shu-ying LIN Lin State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China

A stochastic model was developed to simulate the flow in heterogeneous media subject to random boundary conditions. Approximate partial differential equations were derived based on the Karhunen-Loeve （KL） expansion and perturbation expansion. The effect of random boundary conditions on the two-dimensional flow was examined. It is shown that the proposed stochastic model is efficient to include the random boundary conditions. The random boundaries lead to the increase of head variance and velocity variance. The influence of the random boundary conditions on head uncertainty is exerted over the whole simulated region, while the randomness of the boundary conditions leads to the increase of the velocity variance in the vicinity of boundaries.

关键词： groundwater flow Karhunen-Loeve (KL) expansion hydraulic head random boundary variance

A New Iterative Method for Finding Common Solutions of Generalized Equilibrium Problem and Fixed Point Problem in Hilbert Spaces

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Journal of Mathematical Research and Exposition 2010年第6期30卷 1061-1070页

作者： Min LIU shi sheng ZHANG Department of Mathematics Yibin UniversitySichuan 644007P.R.China

In this paper,we introduce a new iterative scheme for finding a common element of the set of solutions for a generalized equilibrium problems and the set of fixed points for nonexpansive mappings in Hilbert *** suitab... 详细信息

关键词： nonexpansive mapping generalized equilibrium problem variational inequality continuous monotone mapping.

Bose-Einstein condensates in an eightfold symmetric optical lattice

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Chinese Physics B 2020年第5期29卷 400-405页

作者： Zhen-Xia Niu Yong-Hang Tai Jun-sheng shi Wei Zhang Department of Physics Renmin University of ChinaBeijing 100872China Yunnan Key Laboratory of Optoelectronic Information Technology Yunnan Normal UniversityKunming 650500China Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China

We investigate the properties of Bose-Einstein condensates(BECs)in a two-dimensional quasi-periodic optical lattice(OL)with eightfold rotational symmetry by numerically solving the Gross-Pitaevskii *** a stationary external harmonic trapping potential,we first analyze the evolution of matter-wave interference pattern from periodic to quasiperiodic as the OL is changed continuously from four-fold periodic to eight-fold *** also investigate the transport properties during this evolution for different interatomic interaction and lattice depth,and find that the BEC crosses over from ballistic diffusion to ***,we focus on the case of eightfold symmetric lattice and consider a global rotation imposed by the external trapping *** BEC shows vortex pattern with eightfold symmetry for slow rotation,becomes unstable for intermediate rotation,and exhibits annular solitons with approximate axial symmetry for fast *** results can be readily demonstrated in experiments using the same configuration as in ***.122110404(2019).

关键词： quasicrystals Bose-Einstein condensates quantum transport vortex and soliton

Potentials of classical force fields for interactions between Na^+ and carbon nanotubes

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Chinese Physics B 2018年第9期27卷 639-644页

作者： De-Yuan Li Guo-sheng shi Feng Hong Hai-Ping Fang Department of Physics and Shanghai Applied Radiation Institute Shanghai UniversityShanghai 200444China Division of Interfacial Water and Key Laboratory of Interracial Physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China

Carbon nanotubes （CNTs） have long been expected to be excellent nanochannels for use in desalination membranes and other bio-inspired human-made channels owing to their experimentally confirmed ultrafast water flow and theoretically predicted ion rejection. The correct classical force field potential for the interactions between cations and CNTs plays a cru- cial role in understanding the transport behaviors of ions near and inside the CNT, which is key to these expectations. Here, using density functional theory calculations, we provide classical force field potentials for the interactions of Na＋/hydrated Na＋ with （7,7）, （8,8）, （9,9）, and （10,10）-type CNTs. These potentials can be directly used in current popular classical soft- ware such as nanoscale molecular dynamics （NAMD） by employing the tclBC interface. By incorporating the potential of hydrated cation-g interactions to classical all-atom force fields, we show that the ions will move inside the CNT and accu- mulate, which will block the water flow in wide CNTs. This blockage of water flow in wide CNTs is consistent with recent experimental observations. These results will be helpful for the understanding and design of desalination membranes, new types of nanofluidic channels, nanosensors, and nanoreactors based on CNT platforms.

关键词： carbon nanotube density functional theory force field molecular dynamics simulation

Microstructural evolution in Al–Zn–Mg–Cu–Sc–Zr alloys during short-time homogenization

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International Journal of Minerals,Metallurgy and Materials 2015年第5期22卷 516-523页

作者： Tao Liu Chun-nian He Gen Li Xin Meng Chun-sheng shi Nai-qin Zhao Department of Materials Science and Engineering Tianjin University Tianjin Key Laboratory of Composite and Functional Materials Collaborative Innovation Center of Chemical Science and Engineering

Abstract： Microstructural evolution in a new kind of aluminum （A1） alloy with the chemical composition of AI-8.82Zn-2.08Mg- 0.80Cu-3.31Sc-0.3Zr was investigated. It is found that the secondary phase MgZn2 is completely dissolved into the matrix during a short homogenization treatment （470℃, 1 h）, while the primary phase A13（Sc,Zr） remains stable. This is due to Sc and Zr additions into the A1 al- loy, high Zn/Mg mass ratio, and low Cu content. The experimental findings fit well with the results calculated by the homogenization diffusion kinetics equation. The alloy shows an excellent mechanical performance after the short homogenization process followed by hot-extrusion and T6 treatment. Consequently, a good combination of low energy consumotion and favorable mechanical properties is obtained.

关键词： aluminum alloys microstructural evolution short-time ,homogcnization grain refinement