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Synthesis and Crystal Structure of a Novel Manganese Coordination Polymer Constructed by 3,5-Dimethylbenzoic Acid with 4,4'-Bipyridine

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1213-1216页

作者： ZHANG Chun-Hua CHEN Man-sheng KUANG dai-Zhi Department of Chemistry and Materials Science Hengyang Normal University Hengyang 421008 China

A novel manganese coordination polymer [Mn（L）2（bipy）]n （HL = 3,5-dimethylbenzoic acid, 4,4＇-bipy = 4,4＇-bipyridine） has been synthesized by a hydrothermal method. The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 2.0996（8）, b = 1,1835（5）, c = 0.9958（4） nm, β = 110.161（5）°, V = 2,3229（16） nm^3, Z = 4, C28H26MnN2O4, Mr = 509.45, Dc= 1.457 g/cm^3,μ = 0.607 mm^-1, F（000） = 1060, Rim = 0.0566, R = 0.0334 and wR = 0.1078. In the crystal the manganese atom is six-coordinated by two nitrogen atoms from 4,4＇-bipy and four oxygen atoms from 3,5-dimethylbenzolate molecules, completing an octahedral geometry. The 4,4＇-bipy molecules bridge the infinite chain [Mn（L）2（bipy）]n to form a two-dimensional layer.

关键词： manganese coordination polymer hydrothermal synthesis crystal structure

Nucleosomal Context of Binding Sites Influences Transcription Factor Binding Affinity and Gene Regulation

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Genomics, Proteomics & Bioinformatics 2009年第4期7卷 155-162页

作者： Zhiming dai Xianhua dai qian Xiang Jihua Feng Electronic Department Sun Yat-Sen University Guangzhou 510006 China.

Transcription factor （TF） binding to its DNA target site plays an essential role in gene regulation. The location, orientation and spacing of transcription factor binding sites （TFBSs） also affect regulatory function of the TF. However, how nucleosomal context of TFBSs influences TF binding and subsequent gene regulation remains to be elucidated. Using genome-wide nucleosome positioning and TF binding data in budding yeast, we found that binding affinities of TFs to DNA tend to decrease with increasing nucleosome occupancy of the associated binding sites. We further demonstrated that nucleosomal context of binding sites is correlated with gene regulation of the corresponding TF. Nucleosome-depleted TFBSs are linked to high gene activity and low expression noise, whereas nucleosome-covered TFBSs are associated with low gene activity and high expression noise. Moreover, nucleosome-covered TFBSs tend to disrupt coexpression of the corresponding TF target genes. We conclude that nucleosomal context of binding sites influences TF binding affinity, subsequently affecting the regulation of TFs on their target genes. This emphasizes the need to include nucleosomal context of TFBSs in modeling gene regulation.

关键词： gene regulation nucleosome transcription factor binding site

Non-Gaussian feature of the output field from a double qubit-cavity ultrastrong coupling system

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Communications in Theoretical Physics 2024年第7期76卷 30-36页

作者： sheng-wen Xu Shi-yu dai Teng Zhao Center for Quantum Science and Technology Jiangxi Normal UniversityNanchang 330022China

We investigate the non-Gaussian feature of radiation in a circuit quantum electrodynamics(QED)system where two qubits are strongly coupled to a single-mode *** the regime of ultrastrong coupling(USC),the rotating-wave approximation is not valid,and the Rabi Hamiltonian contains counter-rotating wave terms,leading to level crossing and avoided crossings in the energy *** further analyze the intensity-amplitude correlation of the output field in these two novel *** the USC regime,the creation and annihilation operators in the correlation function are replaced,allowing for the identification of non-Gaussian features in the output *** findings reveal that despite the absence of squeezing effects in the output light,significant non-Gaussian characteristics are ***,we demonstrate that as the driving or coupling strength increases,the non-Gaussian features of the output field become more *** suggests that USC systems hold broad potential applications in the realms of nonlinear optics and the generation of non-Gaussian states.

关键词： ultrastrong coupling non-Gaussian intensity-amplitude correlation

Advanced Transmission Electron Microscopy for Identification of Atomic-Scale Configurations of Zeolite-Supported Metal Catalysts

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Chinese Journal of Chemistry 2022年第19期40卷 2371-2373页

作者： Xuan Tang Jiajie Ye Yun Guo sheng dai Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center Frontiers Science Center for Materiobiology and Dynamic ChemistryEast China University of Science and TechnologyShanghai200237 China Key Laboratory for Advanced Materials Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and Technology130 Meilong RoadShanghai200237 China

Zeolite-supported metal catalysts have important applications in various catalytic reactions,but unveiling their atomic-scale structures is always a grand *** developed transmission electron microscopy(TEM)characterization techniques,e.g.,integrated differential-phase contrast(iDPC)scanning transmission electron microscopy(STEM)is emerging as a powerful tool for visualizing the electron beam-sensitive materials at atomic resolution,thus,providing new opportunities for imaging the exact configurations of metal species in the various channels of *** emerging topic summarizes recent progress utilizing iDPC-STEM-related technique for determination of the structures of metal species in zeolites that should offer insights into the structure-property relationships of zeolite-supported metal catalysts.A brief perspective about the new TEM technique is also presented,showing prospects in this field that will stimulate further scientific research in zeolite-supported metal catalysts.

关键词： Metal-zeolite Catalyst structure Heterogeneous catalysis TEM characterization Electron microscopy

Strong quartic anharmonicity,ultralow thermal conductivity,high band degeneracy and good thermoelectric performance in Na_(2)TlSb

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npj Computational Materials 2023年第1期9卷 2167-2175页

作者： Tongcai Yue Yinchang Zhao Jun Ni sheng Meng Zhenhong dai Department of Physics Yantai UniversityYantai 264005P.R.China Department of Physics Tsinghua UniversityBeijing 100084P.R.China Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190P.R.China Collaborative Innovation Center of Quantum Matter Beijing 100084P.R.China

We employ first-principles calculations combined with self-consistent phonon theory and Boltzmann transport equations to investigate the thermal transport and thermoelectric properties of full-Heusler compound Na_(2)*** findings exhibit that the strong quartic anharmonicity and temperature dependence of the Tl atom with rattling behavior plays an important role in the lattice stability of Na_(2)*** find that soft Tl-Sb bonding and resonant bonding in the pseudocage composed of the Na and Sb atoms interaction is responsible for ultralowκ***,the multi-valley band structure increases the band degeneracy,results in a high power factor in p-type Na_(2)*** coexistence of ultralowκL and high power factor presents that Na_(2)TlSb is a potential candidate for thermoelectric ***,these findings help to understand the origin of ultralowκL of full-Heusler compounds with strong quartic anharmonicity,leading to the rational design of full-Heusler compounds with high thermoelectric performance.

关键词： harmonic bonding thermal

The noise matrix theory of two-port network--The noise analysis of a feedback amplifier

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Chinese Science Bulletin 1997年第19期42卷 1665-1669页

作者： dai, YS qian, ZH Li, YQ Department of Electronics Engineering Jilin University of Technolsgy Changchun China

THE low-noise preamplifier, as one of the major circuits in signal detection system, consists ofthe low noise amplifier and the feedback network. The low noise amplifier design aims both tocalculate the optimal source impedance and minimum noise figure, and to compare the noiseperformance and other characteristics of variant circuits and components. The conventional ap-proach to noise analysis of an electronic circuit is to calculate the output noise power of the

关键词： two-port network noise spectral density matrix feedback amplifier.

A critical review of ferritin as a drug nanocarrier:Structure,properties,comparative advantages and challenges

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Particuology 2022年第5期20卷 65-84页

作者： Shuang Yin Kenneth Davey sheng dai Yongdong Liu Jingxiu Bi School of Chemical Engineering&Advanced Materials Faculty of EngineeringComputer and Mathematical Sciences.University of AdelaideAdelaideAustralia Department of Chemical Engineering Brunei University LondonUxbridge UB83PHUnited Kingdom State Key Laboratory of Biochemistry Engineering.Institute of Process Engineering Chinese Academy of Sciences.BeijingChina

Ferritin stores and releases iron ions in *** is globally important as a drug *** is because of its unique hollow-spherical structure,desirable stability and biological *** drug-loading approaches plus various functionalization approaches have been developed to improve ferritin in response to differing demands in disease ***,we critically review ferritin drug delivery and evaluate its diverse drug-loading and functionalization approaches,we:(1)Introduce basic structural and property information related to ferritin as a drug nanocarrier;(2)Contrast in detail the different means to load drugs and the selection of drug loading means;(3)Discuss multiple ferritin functionalization approaches,together with related advantages and potential risks;and,(4)Compare ferritin with alternative,commonly-used drug *** conclude that despite that no drugs based on ferritin are commercially available,the market potential for it is significant,and evaluate future research *** from this work will be of immediate benefit and interest to a wide range of researchers and manufacturers for drug delivery using ferritin.

关键词： Ferritin Drug delivery Drug nanocarrier Protein functionalization

Ore-blending optimization model for sintering process based on characteristics of iron ores

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 217-224页

作者： sheng-li Wu Dauter Oliveira Yu-ming dai Jian Xu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China VALE Shanghai Office Shanghai 200070 China

An ore-blending optimization model for the sintering process is an intelligent system that includes iron ore characteristics, expert knowledge and material balance. In the present work, 14 indices are proposed to represent chemical composition, granulating properties and high temperature properties of iron ores. After the relationships between iron ore characteristics and sintering performance are established, the ＂two-step＂ method and the simplex method are introduced to build the model by distinguishing the calculation of optimized blending proportion of iron ores from that of other sintering materials in order to improve calculation efficiency. The ore-blending optimization model, programmed by Access and Visual Basic, is applied to practical production in steel mills and the results prove that the present model can take advantage of the available iron ore resource with stable sinter yield and quality performance but at a lower cost.

关键词： ore-blending optimization mathematical model sintering process iron ores

Preparation and Acid Catalytic Activity of TiO2 Grafted Silica MCM-41 with Sulfate Treatment

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Chinese Journal of Chemical Physics 2008年第1期21卷 21-26页

作者： dai-shi Guo Zi-feng Ma Chun-sheng Yin Qi-zhong Jiang Department of Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China School of Environmental Science and Engineering Shanghai Jiao Tong University Shanghai 200240China

TiO2 grafted silica MCM-41 catalyst with and without sulfate treatment were prepared. The structural and acid properties of these materials were investigated by XRD, N2 adsorption-desorption, element analysis, thermal analysis, Raman and FTIR measurements. Their acid-catalytic activities were evaluated using the cyclization reaction of pseudoionone. It was found that the obtained materials possess well-ordered mesostructure, and the grafted TiO2 components were in highly dispersed amorphous form. T/MCM41 without sulfation contained only Lewis acid sites, while Brφnsted and Lewis acidities were remarkably improved for the sulfated materials ST/MCM41 and d-ST/MCM41. T/MCM-41 was not active for the cyclization reaction of pseudoionone, but ST/MCM-41 and d-ST/MCM-41 possessed favorable catalytic activities. The catalytic performance of ST/MCM-41 was comparable with that of the commercial solid acid catalyst of Amberlyst-15, and better than that of d-ST/MCM-41, although the latter underwent a second TiO2 grafting process and accordingly had higher Ti and S content. The specific surface structure of Si-O-Ti-O-S=O in ST/MCM-41 and the bilateral induction effect of Si and S=O on Si-O-Ti bonds were speculated to account for its higher acid catalytic activity.

关键词： TiO2 grafting Sulfate treatment Silica MCM-41 Acid catalytic activity Cyclization of pseudoionone