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Research on the nanometric machining of a single crystal nickel via molecular dynamics simulation

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Science China(Technological Sciences) 2016年第12期59卷 1837-1846页

作者： gong ya Dong ZHU Zong Xiao ZHOU Yun Guang SUN yao School of Mechanical Engineering & Automation Northeastern University

Molecular dynamics simulations are employed to study the nanometric machining process of single crystal nickel. Atoms from different machining zones had different atomic crystal structures owing to the differences in the actions of the cutting tool. The stacking fault tetrahedral was formed by a series of dislocation reactions, and it maintained the stable structure after the dislocation reactions. In addition, evidence of crystal transition and recovery was found by analyzing the number variations in different types of atoms in the primary shear zone, amorphous region, and crystalline region. The effects of machining speed on the cutting force, chip and subsurface defects, and temperature of the contact zone between the tool and workpiece were investigated. The results suggest that higher the machining speed, larger is the cutting force. The degree of amorphousness of chip atoms and the depth and extent of subsurface defects increase with the machining speed. The average friction coefficient first decreases and then increases with the machining speed because of the temperature difference between the chip and machining surface.

关键词： molecular dynamics simulation nanometric machining single crystal nickel crystal transition and recovery machining speed

Progress in application and preparation of silver nanowires

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Rare Metals 2016年第4期35卷 289-298页

作者： Xiong-Zhi Xiang Wen-ya gong Ming-Sheng Kuang Lei Wang Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen University

Silver nanowires have attracted wide research attention for their excellent optical, electrical and chemical properties. Many researches were performed toward syn- thesizing and application of silver nanowires. The appli- cation of silver nanowires such as transparent conductive film electrode, conductive silver adhesive and nanowelding technology was introduced herein. Principles and charac- teristics of different synthesizing methods of silver nano- wires were reviewed in this paper, including template method, liquid polyol method, self-assembly method, ultrasonic reduction method and wet chemical method. The liquid polyol method was the most available one to achieve efficient large-scale production.

关键词： Silver nanowires Applications Synthesizingtechnologies

Impact of ventilation design on the precooling effectiveness of horticultural produce-a review

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Food Quality and Safety 2020年第1期4卷 29-40页

作者： Yuhui Cao ya-Fang gong Xin-Rong Zhang College of Engineering Sciences University of Chinese Academy of SciencesBeijingChina Department of Energy and Resource Engineering College of EngineeringPeking UniversityBeijingChina

Optimizing the ventilation design of packaging system is of crucial importance for improving the efficiency of the forced-air precooling process to maintain the quality of horticultural produce and extend the shelf life in food cold *** efforts had been devoted to the study about the impact of ventilation design on airflow and temperature distribution inside ventilated *** paper reviews relevant research methods,commonly used quantities for the measurement of precooling effectiveness,attractive design parameters,and their impact on precooling *** allow us to know exactly the characteristic and deficiency of each research method,identify dominant design parameters,and seek a promising way for the future improvement of the ventilated packaging system.

关键词： horticultural produce precooling effectiveness ventilation design forced-air precooling technique packaging system

Some Special Properties of Singular Integral Operators

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Wuhan University Journal of Natural Sciences 1999年第3期4卷 269-274页

作者： gong ya-fang Du Jin-yuan Wuhan Univ China

In this paper, we have proved some special properties of singular integral operators which are transformed from the singular integral equation defined in the interval (?1, 1), i.e., the properties of singular intergra... 详细信息

关键词： singular integral canonical function generalized Jacobi weight

Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels——Elasto-plastic analysis of stress field of enclosing rock mass

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Mining Science and Technology 2009年第3期19卷 84-90页

作者： WU Hao FANG Qin ZHANG ya-dong gong Zi-ming Engineering Institute of Engineering Corps PLA University of Science and Technology Nanjing Jiangsu 210007 China

The zonal disintegration phenomenon （ZDP） is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constitutive model of rock mass were used to analyze the elasto-plastic stress field of the enclosing rock mass around a deep round tunnel. The radius of the plastic region and stress of the enclosing rock mass were obtained by introducing dimensionless parameters of radial distance. The results show that tunneling in deep rock mass causes a maximum stress zone to appear in the vicinity of the boundary of the elastic and the plastic zone in the surrounding rock mass. Under the compression of a large tangential force and a small radial force, the rock mass in the maximum stress zone was in an approximate uniaxial loading state, which could lead to a split failure in the rock mass.

关键词： enclosing rock mass around deep tunnels zonal disintegration equivalent material Hoek-Brown strength criterion

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Structures and Properties of 1,2,3-Triazoles and 1,2,4-Triazoles

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Chinese Journal of Structural Chemistry 2006年第5期25卷 582-588页

作者： LU ya-Lin gong Xue-Dong JU Xue-Hai JI Guang-Fu XIAO He-Ming School of Chemical Engineering Nanjing University of Science and Technology Nanjing 210094 China

In this paper, the fully optimized molecular geometries and electronic structures of six 1,2,3- and 1,2,4-triazoles were calculated using density functional theory B3LYP/6-311G^＊＊ method. The salvation energies were obtained by SCRF in THF. The results show that the total energies of F are the lowest both in gas and liquid phases, and the order of thermodynamic stabilities of the title compounds is F〉D〉C〉B〉E〉A. Their frontier orbital energy gaps and electron delocalization also support that F is the most stable. All the computed conclusions are in good agreement with the experiments. Vibrational frequencies of the title compounds were computed. The thermodynamic properties and their temperature curves of six compounds were obtained by using the statistical thermodynamic method with the temperature ranging from 200 to 1000 K.

关键词： triazoles DFT stabilities IR thermodynamic properties

Theoretical Studies on Intermolecular Interactions of 4-Amino-5-nitro-1,2,3-triazole Dimers

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Chinese Journal of Structural Chemistry 2006年第8期25卷 1004-1010页

作者： LU ya-Lin gong Xue-Dong JU Xue-Hai MA Xiu-Fang XIAO He-Ming School of Chemical Engineering Nanjing Universityof Science and Technology Nanjing 210094 China

Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory （DPT） method at the B3LYP/6-311＋＋G＊＊ level. The maximum intermolecular interaction energy is -35.42 kJ/mol via the basis set superposition error-correction （BSSE） and zero point energy-correction （ZPE）. Charge transfers between the two subsystems are small. The vibration analysis of optimized configurations was performed, and the thermodynamic property changes from monomer to dimer have been obtained with the temperature ranging from 200 to 800 K on the basis of statistical thermodynamics. It is found that the hydrogen bonds contribute to the dimers dominantly, and the extent of intermolecular interaction is mainly determined by the hydrogen bonds＇ strength rather than their number. The dimerization processes of Ⅳ, Ⅴand Ⅵ can occur spontaneously at 200 K.

关键词： 4-amino-5-nitro-1,2,3-triazole intermolecular interaction density functional theory thermodynamic properties

Syntheses and Crystal Structures of Cobalt(II) Chloride Complexes of 1,3-Bis(pyridyl-4-ylthio)propan-2-one

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Chinese Journal of Structural Chemistry 2006年第5期25卷 511-516页

作者： WU Ben-Lai WU Ming-yan gong ya-Qiong CHEN Bai-Quan HONG Mao-Chun State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China

Reactions of 1,3-bis（pyridyl-4-ylthio）propan-2-one L and COCl2·6H2O under different conditions gave two new cobalt（Ⅱ）-chloride-L complexes with distinct structures. Complex [Co（L）2Cl2]·0.5CH3OH}n 1 prepared by solvothermal treatment is a 3D network, whereas complex {[Co3（L）2Cl6（DMF）4]·2CH3OH·H2O} 2 obtained in DMF-diethyl ether system is a discrete acyclic trimer. Crystal data for 1： space group lbca, a = 15.993（4）, b = 18.454（5）, c = 21.506（6）A, V= 6347（3） ,A^3, Z = 8, Dc = 1.462 g/cm^3,μ = 1.005 mm^-1, F（000） = 2864, C26.5H26Cl2CoN4O2.5S4, Mr = 698.58, the final R = 0.0499 and wR = 0.1024. Crystal data for 2： space group P1^-, a = 9.9177（6）, b = 11.0871 （4）, c = 15.5490（12） ,A, α = 83.1834（14）,β = 88.910（13）, γ = 71.096（ 11 ）°, V = 1605.8（2） A^3, Z = 1, Dc = 1.362 g/cm^3,μ= 1.194 mm^-1, F（000） = 677, C40H62Cl6Co3N8O9S4, Mr = 1316.71, the final R = 0.0666 and wR =0.1575.

关键词： cobalt chloride complex 1,3-bis(pyridyl-4-ylthio)propan-2-one crystal structure

Developing new SSR markers from ESTs of pea(Pisum sativum L.)

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第9期11卷 702-707页

作者： ya-ming gong Sheng-chun XU Wei-hua MAO Qi-zan HU Gu-wen ZHANG Ju DING ya-dan LI Institute of Vegetables Zhejiang Academy of Agricultural Science Hangzhou 310021 China Center of Analysis and Measurement Zhejiang University Hangzhou 310029 China

The development of expressed sequence tags(ESTs) from pea has provided a useful source for mining novel simple sequence repeat(SSR) *** the present research,in order to find EST-derived SSR markers,18 552 pea ESTs from the National Center for Biotechnology Information(NCBI) database were downloaded and assembled into 10 086 unigenes.A total of 586 microsatellites in 530 unigenes were identified,indicating that merely 5.25% of sequences contained *** most abundant SSRs within pea were tri-nucleotide repeat motifs,and among all the tri-nucleotide repeats,the motif GAA was the most abundant *** total,49 SSRs were used for primer ***-SSR loci were subsequently screened on 10 widely adapted varieties in *** these,nine loci showed polymorphic profiles that revealed two to three alleles per *** polymorphism information content value ranged from 0.18 to 0.58 with an average of ***,transferable analysis revealed that some of these loci showed transferability to faba *** of their polymorphism and transferability,these nine novel EST-SSRs will be valuable tools for marker-assisted breeding and comparative mapping of pea in the future.

关键词： Pea Expressed sequence tag(EST) Simple sequence repeat(SSR) Microsatellite