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Electronic Structures and Chemical Bonding of NbS6^(-/0)Clusters

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Chinese Journal of Structural Chemistry 2016年第2期35卷 175-184页

作者： WANG Bin li qian-qian WANG Jian-Fu HUANG Xin ZHANG Yong-Fan Department of Chemistry Fuzhou UniversityFuzhou 350116China Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry Xiamen 361005China

Density functional theory（DFT） and coupled cluster theory（CCSD（T）） calculations were employed to investigate the structural and electronic properties of Nb S6^- and Nb S6 clusters. Generalized Koopmans＇ theorem was applied to predict the vertical detachment energies and simulate the photoelectron spectra（PES）. The current study indicated that various types of sulfur ligands（i.e., S^（2-）, S^（2-）, S2^（2-） and S3^（2-）） were presented in the lowest-energy structures of Nb S6^（-/0）. The ground-state structure of Nb S6^- is shown to be Cs（~1A＇） symmetry with a terminal S^（2-）, a side-on bound S2^（2-） and a S3^（2-） ligands. Molecular orbital analyses were performed to analyze the chemical bonding in NbS6^（-/0） clusters and elucidate their structural and electronic properties.

关键词： niobium sulfide cluster density functional theory(DFT) simulated photoelectron spectroscopy chemical bonding

Mechanical and tribological performance of AlCr_(0.5)NbTa_(x)Ti_(4-x)(x=0,0.5,1)refractory high-entropy alloys

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Journal of Materials Science & Technology 2023年第25期156卷 241-253页

作者： Haozhe li Xiaolin li Chi Jin qian li qiang Ma Ke Hua Haifeng Wang Weimin liu State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

The tribological behavior of AlCr_(0.5)NbTa_(x)Ti_(4-x)(x=0,0.5,and 1)refractory high-entropy alloys was systematically investigated from room temperature to 800℃.The relationship between the alloy composition,microstructure,mechanical properties,and tribological performance was *** results show that all three alloys have a body-centered cubic(bcc)single-phase *** Ta addition enhances solid solution strengthening and increases the melting point that would resist high-temperature thermal *** a result,high-temperature strength is enhanced considerably,the coefficients of friction(COF)and wear rates of the alloys are reduced considerably at elevated temperatures,demonstrating excellent friction-reducing and anti-wear properties,e.g.,the COF and wear rate of AlCr_(0.5) NbTaTi_(3) alloy at 800℃ are 0.34 and 4.40×10^(-7) mm^(3) N^(-1) m^(-1),*** excellent wear resistance at high temperatures can be attributed to the formation of an oxide-tribo layer(Ta_(2)O_(5) and TiO_(2))with ultrafine-grained layers and good high-temperature mechanical properties.

关键词： Refractory high entropy alloys High temperature Mechanical properties Wear resistance Oxide-tribo layer

Drosophila Ortholog of Mammalian Immediate-Early Gene Npas4 is Specifically Responsive to Reversal Learning

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Neuroscience Bulletin 2021年第1期37卷 99-102页

作者： Tingting liu linghan Wang qian li School of life Sciences Tsinghua UniversityBeijing 100084China

Dear Editor,In dynamic environments,the memory system of the brain must be able to perceive and process conflicting experiences to reach an adaptive *** Drosophila,in contrast to consistent experiences,conflicting experiences trigger significantly increased Rac1 activity which mediates active forgetting [1].The ability to cope with conflicting experiences but not simple learning experiences is impaired in mutants of multiple autism-risk genes [2].

关键词： Drosophila Ortholog of Mammalian Immediate-Early Gene Npas4 is Specifically Responsive to Reversal Learning

Theoretical Study on the Structural and Electronic Properties of the Reduced SnO_2 (110) Surface

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Chinese Journal of Structural Chemistry 2007年第5期26卷 606-612页

作者： ZHANG Yong-Fan liN Wei WANG Qi-Wei li Yi li Jun-qian Department of Chemistry Fuzhou University Fuzhou Fujian 350002 China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China

The reduced SnO2（110） surface has been investigated by using first-principles method with a slab model. By examining the vacancy formation energy of three kinds of reduced SnO2（110） surfaces, the most energetically favorable defect surface is confirmed to be the surface with the coexistence of bridging and in-plane oxygen vacancies, which is different with the traditional model by only removing bridging oxygen. The results of band structure calculations indicate that the electronic structure of this defect surface is similar to the SnO surface.

关键词： SnO2(110) surface band structure defect state

A review on recent progress of non-stoichiometric SiOx anodes based on lithium ion batteries

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Progress in Natural Science:Materials International 2023年第1期33卷 47-54页

作者： Gengchen Yu Jiayi Jing Chengzhe li qian li Zhikai Yang Shuyu Yao Tao li Xue Bai School of Materials Science and Engineering Shandong University of Science and Technology Key Laboratory for liquid–Solid Structural Evolution & Processing of Materials(Ministry of Education) Shandong University

SiOxanode has attracted more and more attention due to its rich reserves and high theoretical capacity. However,the disadvantages of low initial Coulombic efficiency and large volume change limit its application. Therefore in this review, the research progress of SiOxanode will be summarized in detailed to demonstrate the various strategies adopted by researchers. Systematically introduction of the progress on preparation methods and modification strategies would be discussed, and the merits and challenges of various approaches will be highlighted as well, which provides valuable insights into the rational design and development of techniques to deal with the promising practical application of SiOxanode.

关键词： lithium ion batteries SiOx anode Preparation methods Modification strategies

Bi-large Neutrino Mixing See-Saw Mass Matrix with Texture Zeros and Leptogenesis

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Communications in Theoretical Physics 2006年第6期45卷 1073-1084页

作者： CHAO Wei HE Xiao-Gang li Xue-qian Department of Physics Nankai University Tianjin 300071 China NCTS/TPE Department of Physics National Taiwan University Taipei China

We study constraints on neutrino properties for a class of bi-large mixing See-Saw mass matrices with texture zeros and with the related Dirac neutrino mass matrix to be proportional to a diagonal matrix of the form diag （e, 1, 1）. Texture zeros may occur in the light （class a）） or in the heavy （class b）） neutrino mass matrices. Each of these two classes has 5 different forms which can produce non-trivial three generation mixing with at least one texture zero. We tind that two types of texture zero mass matrices in both class a and class b can be consistent with present data on neutrino masses and mixing. None of the neutrinos can have zero masses and the lightest of the light neutrinos has a mass larger than about 0.046 eV for class a and 0.0027 eV for class b. In these models although the CK.M CP violating phase vanishes, the non-zero Majorana phases can exist and can play an important role in producing the observed baryon asymmetry in our universe through leptogenesis mechanism. The requirement of producing the observed baryon asymmetry can further distinguish different models and also restrict the See-Saw scale to be in the range of 10^12- 10^15 GeV. We also discuss RG effects on V^13.

关键词： neutrino neutrino mass matrix neutrino masses and mixing bi-large mixing matrix

Equation of State for Neutralino Star as a Form of Cold Dark Matter

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Communications in Theoretical Physics 2008年第1期49卷 212-216页

作者： REN Jie li Xue-qian SHEN Hong Department of Physics Nankai University Tianjin 300071 China

In order to study the structure of neutralino star and dark galaxy, we consider dynamical interactions due to boson-exchange in the neutralino matter. Taking into account interactions of neutralinos with bosons, we derive the equation of state （EOS） of neutralino stars in terms of the relativistic mean-field approach. Then we apply the resulting EOS to investigate properties of the neutralino star such as its density profile and mass limit. For example, if the neutralino mass is around 1 TeV, the Oppenheimer mass limit of the neutralino star is obtained as 6.06 ×10^-7 M⊙, and the corresponding radius is about 7.8 mm. Actually, due to an increasing annihilation rate as indicated by our calculation, this dense state can never be realized in practice. Our results also show that the low-density neutralino star may be a possible aggregation of the cold dark matter.

关键词： neutralino star equation of state dark matter

Restudy on Dark Matter Time-Evolution in the littlest Higgs Model with T-Parity

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Communications in Theoretical Physics 2008年第11期50卷 1211-1218页

作者： QIAO Qing-Peng TANG Jian li Xue-qian Department of Physics Nankai University Tianjin 300071 China

Following previous study, in the littlest Higgs model （LHM）, the heavy photon is supposed to be a possiL dark matter candidate and its relic abundance of the heavy photon is estimated in terms of the Boltzman- Lee-Weinba time-evolution equation. The effect of the T-parity violation is also considered. Our calculations show that when Higmass MH taken to be 300 GeV and do not considering T-parity violation, only two narrow ranges 133 〈 MAH 〈 135 Ge and 167 〈 MAH〈 169 GeV are tolerable with the current astrophysical observation and if 135 〈 MAH 〈 167 GeV there must at least exist another species of heavy particle contributing to the cold dark matter. As long as the T-pari; can be violated, the heavy photon can decay into regular standard model particles and would affect the dark matt abundance in the universe, we discuss the constraint on the T-parity violation parameter based on the present dat Direct detection prospects are also discussed in some detail.

关键词： little Higgs dark matter time evolution

Ultrasound-assisted Extraction of Kamebakaurin from Rabdosia excisa by Response Surface Methodology

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Chemical Research in Chinese Universities 2013年第6期29卷 1072-1077页

作者： TANG Jian MA Rui-li li qian-qian JIANG Chun-bao CHEN Rui OUYANG Zhen CHEN Hai-sheng School of Pharmacy Jiangsu University Zhenjiang 212013 P.R.China School of Pharmacy Second Ministry Medical University Shanghai 200433 R R. China College of Material Chemistry and Chemical Engineering Hangzhou Normal University Hangzhou 310036 P. R. China

For the efficient extraction of kamebakaurin（KA）, the ultrasound-assisted extraction（UAE） of KA from Rabdosia excisa（R, excisa） via response surface methodology（RSM） was investigated with high-performance liquid chromatography（HPLC）. Effects of the experimental parameters such as extraction solvent, ratio of liquid to plant material, extraction time and extraction temperature on the extracting efficiency of KA from R. excisa were evaluated, and the purity of KA in residual was calculated. The optimized conditions were 65.5%（volume fraction） acetone, 35 ℃, time of 24.6 min with ultrasound of 80 W/L, 40 kHz, ratio of liquid to plant material at 30：1（mL/g）. The maximum yield of KA is 0.708 mg/kg, with mean purity of 6.09%, indicating that ultrasound-assisted extraction is a feasible and useful method for extracting KA from R. excisa.

关键词： Ultrasound-assisted extraction Kamebakaurin Rabdosia excisa Response surface methodology