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Chinese Journal of Chemical Physics 2015年第4期28卷 -页

作者： Yuan-yuan Jing Kai Song shu-ming bai Qiang Shi Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190China

We employ the numerically exact hierarchical equations of motion (HEOM) method to perform benchmark tests for the popular modified Redfield method in calculating linear and nonlinear spectroscopic signals of molecular aggregates in photosynthetic light harvesting complexes. It is currently well known that the perturbative and Markovian approximations involved in the modified Redfield equation may give inappropriate description of the excitation energy transfer processes in the intermediate coupling regime. An interesting topic is thus to test the validity of the modified Redfield method in calculating various types of spectroscopic signals. By using model dimers with different sets of parameters and a model of the Fenna-Matthews-Olson complex, we calculate and compare the absorption, emission, and 2D spectra using the modified Redfield and HEOM methods. It is found that results from the modified Redfield method agree well with the HEOM ones in a wide range of parameter regimes. The comparison also helps to understand the quantum beating signals in the 2D spectra of the photosynthetic light harvesting complexes.

关键词： Linear spectra Nonlinear spectra Light harvesting complexes Modified Redfield method

CROWDING EFFECT INDUCED PHASE TRANSITION OF AMPHIPHILIC DIBLOCK COPOLYMER IN SOLUTION

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Chinese Journal of Polymer Science 2013年第11期31卷 1491-1500页

作者： Zhu Liu Zhi-Bin Jiang Hong Yang shu-ming bai 汪蓉薛奇 Department of Polymer Science and Engineering State Key Laboratory of Coordination ChemistryNanjing National Laboratory of MicrostructuresSchool of Chemistry and Chemical EngineeringNanjing University

The crowding agent induced phase transition of amphiphilic block copolymers in solution was explicitly considered. The influence of the size and the volume fraction of the crowding agent on the phase separation of ampbiphilic diblock copolymers is investigated by using self-consistent field theory （SCFT） method. The concentration of the disorder to order transition of the block copolymer decreases when the size of the crowding agent is larger than that of the solvent. The higher volume fraction of the crowding agent will induce the transition of the block copolymer from disorder to order state at a lower concentration. The relation between the size and the volume fraction of the crowding agent is elucidated. When the size of the crowding agent is larger, its volume fraction of the disorder to order transition of the block copolymer will be lower. The conformation of the crowding agent considered as a polymer chain is also studied and compared.

关键词： Crowding agent Disorder to order transition Block copolymer.

Synthesis and characterization of magnetic polymer microspheres with a core-shell structure

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China Particuology 2007年第1期5卷 180-185页

作者： ming Lu shu bai Kun Yang Yan Sun Department of Biochemical Engineering School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

Non-porous magnetic polymer microspheres with a core-shell structure were prepared by a novel micro-suspension polymerization technique. A stable iron oxide ferrofluid was used to supply the magnetic core, and the polymeric shell was made of glycidyl methacrylate （GMA monomer） and ethylene dimethacrylate （cross-linker）. In the preparation, polyvinyl alcohol was used as the stabilizer, and a lauryl alcohol mixture as the dispersant. The influence of various conditions such as aqueous phase volume, GMA and initiator amounts, reaction time and stirring speed on the character of the microspheres was investigated. The magnetic microspheres were then characterized briefly. The results indicate that the microspheres with active epoxy groups had a narrow size distribution range from 1 to 10 μm with a volume-weighted mean diameter of 4.5 μm. The saturation magnetization reached 19.9 emu/g with little coercivity and remanence.

关键词： Ferrofluid Micro-suspension polymerization Magnetic microspheres Particle size Magnetization

Analysis of Vanadium-Bearing Titanomagnetite Sintering Process by Dissection of Sintering Bed

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Journal of Iron and Steel Research International 2011年第6期18卷 8-15,36页

作者： bai Yong-qiang CHENG shu-sen bai Yan-ming School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing100083 Chinas Chenggang Company Hebei Iron and Steel Co Ltd Chengde 062001 Hebei China

Many problems appear in the sintering process of vanadium-bearing titanomagnetite, such as high energy consumption and low productivity; simer quality is also very poor for its low tumble strength and high reduction deg- radation. Sinter productivity and quality are dominated by bed permeability and mineralogy structure, which are highly influenced by the thermal state of sintering bed, so the sintering process of titanomagnetite is researched by bed dissection in this work. Temperature evolution curves of sinter materials were measured, and the results show that melting duration, peak temperature duration and sintering temperature of different layers differ greatly from each other; flame front speed and vertical sintering speed of bed lower region are much smaller than those of bed up- per region. Simultaneously, sinter samples were collected from different layers, and their mineralogy characteristics are analyzed; sinters from bed lower region have poor mineralogy structure, and the amounts of perovskite and dieM- cium silicate increase intensively, which are bad for sinter strength and reduction degradation property. Measures are proposed to improve the quality and productivity of titanomagnetite sinter.

关键词： sintering vanadium hearing titanomagnetite thermal state bed dissection mineralogy characteristic

Microstructure Characteristic and Phase Evolution of Refractory Siderite Ore during Sodium-carbonate-added Catalyzing Carbothermic Reduction

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Journal of Iron and Steel Research International 2016年第9期23卷 891-899页

作者： Shao-jun bai Meng WU Chao LU shu-ming WEN State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming 650093Yunnan China Faculty of Land Resource Engineering Kunming University of Science and Technology Kunming 650093 Yunnan China

Thermodynamic analysis of refractory siderite ore during carbothermic reduction was conducted. Micro- structure characteristics and phase transformation of siderite ore during sodium-carbonate-added catalyzing carboth- ermic reduction were investigated. X-ray diffraction （XRD）, scanning electron microscopy and energy-dispersive analysis of X rays were used to characterize the reduced samples. Results indicate that the solid reaction between FeO and SiO2 is inevitable during carbothermic reduction and the formation of fayalite is the main hindrance to the rapid reduction of siderite. The phase transformation of present siderite ore can be described as： siderite-magnetite-metallic iron, complying with the formation of abundant fayalite. Improving the reduction temperature （-1050 -C ） and duration is helpful for the formation and aggregation of metallic iron. The iron particle size in the reduced ore was below 20 l-m, and fayalite was abundant in the absence of sodium carbonate. With 5% Na2CO3 addition, the iron particle size in the reduced ore was generally above 50μm, and the diffraction intensity associated with metallic iron in the XRD pattern increased. The Na2O formed from the dissociation of Na2 CO3 can catalyze the carbothermie reduction of the siderite. This catalytic activity may be mainly caused by an increase in the reducing reaction activity of FeO.

关键词： siderite ore microstructure characteristic phase evolution catalyzing carbothermie reduction

Primary primitive neuroectodermal tumor in the pericardium-a focus on imaging findings:A case report

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World Journal of Clinical Cases 2021年第17期9卷 4336-4341页

作者： shu-ming Xu Juan bai Jin-Hua Cai Department of Radiology Children’s Hospital of ShanxiTaiyuan 030013Shanxi ProvinceChina Department of Medical Imaging Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Radiology Children’s HospitalChongqing Medical UniversityChongqing 400014China

BACKGROUND Primitive neuroectodermal tumors(PNETs)are rare,sporadic malignant tumors of the peripheral nervous system,bone,or soft ***,to the best of our knowledge,only three cases of PNET in the pericardium have been reported in the English literature,and their magnetic resonance imaging findings have not previously been *** SUMMARY A 3-year-old boy was hospitalized with a 1-wk history of recurrent vomiting and *** history-taking revealed no evidence of heart *** tomography demonstrated a soft tissue mass in the left pericardial cavity with heterogeneous contrast *** border between the mass and the heart was poorly *** revealed a mass invading the left ventricle,with a high risk of *** mass was considered inoperable.A biopsy was performed,and the histological and immunohistochemical findings confirmed the diagnosis of primary PNET of the *** patient received four cycles of standard *** magnetic resonance imaging 3 mo after the initiation of chemotherapy revealed that the tumor in the pericardium still existed,but its volume had slightly *** patient was lost to follow-up,and the final outcome was therefore *** Medical imaging plays an important role in defining the pericardial origin of PNET and understanding its *** resonance imaging can provide more information on the tumor than computed tomography and may thus aid therapeutic planning.

关键词： Primary primitive neuroectodermal tumors Pericardium Tumor Computed tomography Magnetic resonance imaging Case report

Effect of Ce addition on microstructures and mechanical properties of A380 aluminum alloy prepared by squeeze-casting

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International Journal of Minerals,Metallurgy and Materials 2018年第5期25卷 554-563页

作者： Xiao-hui Ao shu-ming Xing bai-shui Yu Qing-you Han School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Department of Mechanical Engineering Technology Purdue University

The effect of cerium(Ce)addition on the eutectic Si,β-Al_5Fe Si phase,and the tensile properties of A380 alloy specimens prepared by squeeze-casting were studied by optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).The experimental results showed that Ce more effectively modified the eutectic Si and refined theβ-Al_5Fe *** refinement effect significantly increased under a specific pressure of 100 MPa with the addition of Ce from 0.1wt%to 0.9wt%.In contrast,the average length and the aspect ratio of the eutectic Si andβ-Al_5Fe Si exhibited their optimal values when the content of the added Ce was greater than 0.5wt%.Needle-like Al_8Cu_4Ce was precipitated with the addition of excessive Ce;hence,the mechanical properties of A380 gradually decreased with increasing Ce content in the range from 0.3wt%to 0.9wt%.

关键词： cerium eutectic Si Fe-rich phases squeeze-casting mechanical properties

Plant Morphogenesis 123: a renaissance in modern botany?

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Science China(Life Sciences) 2019年第4期62卷 453-466页

作者： shu-Nong bai College of Life Sciences Peking University

Plants are a group of multicellular organisms crucial for the biosphere on the Earth. In the 17 th century, the founding fathers of modern botany viewed the bud as the basic unit undergoing the plant life cycle. However, for many understandable reasons, the dominant conceptual framework evolved away from the "bud-centered" viewpoint to a "plant-centered" viewpoint that treated the whole plant, consisting of numerous buds, as a unit and considered the entire plant to be the functional equivalent of an animal individual. While this "plant-centered" viewpoint is convenient and great progress has been made using this conceptual framework, some fundamental problems remain logically unsolvable. Previously, I have proposed a new conceptual framework for interpretation of plant morphogenesis, called Plant Morphogenesis 123, which revives a "bud-centered" viewpoint. The perspective of Plant Morphogenesis 123 allows us to address new questions regarding to the mechanisms of plant morphogenesis that are important, and technically accessible, but previously neglected under the "plant-centered" conceptual framework. In addition to describing these questions, I address a more fundamental question for further discussion: why do people study plants?

关键词： Plant Morphogenesis 123 bud-centered viewpoint developmental unit life cycle renaissance

Unravelling the metal borides evolution in the transient liquid phase bonding of Ni-based alloys via high-throughput transmission electron microscopy and first-principles thermo-kinetic calculations

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Journal of Materials Science & Technology 2021年第26期85卷 118-128页

作者： Kewu bai ming Lin Institute of High Performance Computing Agency for ScienceTechnology and ResearchFusionopolis Way#16-16 ConnexisSingapore 138632Singapore Institute of Materials Research and Engineering(IMRE) Fusionopolis WayInnovis#08-03Singapore 138634Singapore

The understanding of temperature and time-dependent metal borides precipitation/dissolution is crucial for the design of the transient liquid phase(TLP)bonding process of Ni-based *** however remains elusive despite substantial research efforts for many years mainly owing to the uncertainty on the precipitated metal borides and the complex thermo-kinetics in the *** this paper,we have unambiguously constructed the micro/nano scale map of the precipitated metal borides in the TLP bonded Ni-based Inconel 718 superalloy via a high-throughput transmission electron microscopy(TEM)*** types of metal borides were found to precipitate in the diffusion affected zone(DAZ)when the isothermal solidification is *** are the M_(5)B_(3)with stacking faults,Ti-rich M_(3)B4,and Nb-rich M_(3)B4 at the grain boundaries as well as single-crystalline M_(5)B_(3)and M_(3)B2 inside the ***,the crystal structure of the faulted M_(5)B_(3)was rationalized by a hybrid modelling approach integrating firstprinciples calculation and TEM *** sublattice model,with the optimized thermodynamic model parameters,was used to reproduce the metal borides precipitation map in the TLP process using DICTRA *** with multiscale simulation and experimental data,the present work built a modified thermo-kinetic model,which enables the design of the TLP bonding process of Ni-based alloys that often involves complicated time-tempe rature schedules and the precipitation/dissolution of a variety of diffe rent *** strategy can be applied to the design of the brazing process of other alloys or hybrid materials such as ceramics and metal.

关键词： Ni-based superalloy Transmission electron microscopy Transient liquid bonding Precipitation Kinetics

First-principle study on the surface atomic relaxation properties of sphalerite

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International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 775-781页

作者： Jian Liu shu-ming Wen Yong-jun Xian Shao-jun bai Xiu-min Chen Faculty of Land Resource Engineering Kunming University of Science and Technology Kunming 650093 China National Engineering Laboratory of Vacuum Metallurgy Kunming University of Science and Technology Kunming 650093 China

The surface properties of sphalerite （ZnS） were theoretically investigated using first principle calculations based on the density functional theory （DFT）. DFT results indicate that both the （110） and the （220） surfaces of sphalerite undergo surface atom relaxation after geometry optimization, which results in a considerable distortion of the surface region. In the normal direction, i.e., perpendicular to the sur- face, S atoms in the first surface layer move outward from the bulk （dl）, whereas Zn atoms move toward the bulk （d2）, forming an S-enriched surface. The values of these displacements are 0.003 nm for dl and 0.021 nm for d2 on the （110） surface, and 0.002 nm for dl and 0.011 nm for d2 on the （220） surface. Such a relaxation process is visually interpreted through the qualitative analysis of molecular mechanics. X-ray photoelectron spectroscopic （XPS） analysis provides the evidence for the S-enriched surface. A polysulphide （S n^2- ） surface layer with a bind- ing energy of 163.21 eV is formed on the surface of sphalerite after its grinding under ambient atmosphere. This S-enriched surface and the S 2- surface layer have important influence on the flotation properties ofsphalerite. Keywords：

关键词： sphalerite surface relaxation density fimctional theory froth flotation