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Molecular Dynamics Simulation of Microstructure Transitions in a Large-Scale Liquid Metal Al System During Rapid Cooling Processes

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Chinese Physics Letters 2002年第8期19卷 1144-1147页

作者： Liu Rang-Su, dong Ke-jun Department of Physics Hu"nan University Department of Chemistry Hu"nan University School of Materials Science and Engineering The University of New South Wales

We perform a molecular dynamics simulation of microstructure transitions in a large-scale system consisting of 400 000 atoms of liquid metal Al by the Clare supercomputer. A cluster-type index method is proposed to describe the structures of various short-range-order clusters in the liquid system. It is demonstrated that the icosahedron cluster (12 0 12 0) plays the most important role in the microstructure transition and that some larger clusters (containing more than 130 atoms) are formed in the system during the rapid cooling processes. It is obvious that the larger clusters are formed by means of combining some middle clusters, and that the middle clusters are formed with several smaller clusters. However, the larger clusters are not formed to be the multi-shell configuration as shown in the mass spectrum analysis of the cluster configurations of Al obtained by gaseous deposition, ionic spray methods and so on. This result can be used to explain the essential distinction between the cluster configurations of Al formed in two different ways

关键词： Molecular dynamics

Complications of common bile duct stones: A risk factors analysis

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Hepatobiliary & Pancreatic Diseases International 2021年第4期20卷 361-365页

作者： dong jun Oh Ji Hyung Nam dong Kee Jang jun Kyu Lee Department of Internal Medicine Dongguk University Ilsan HospitalGoyang 10326Korea

Background: The latest guidelines recommended that common bile duct stones(CBDSs) should be removed, preferably endoscopically, regardless of the presence of symptoms or complications. However, the removal of CBDSs may not be feasible in very old patients or those with co-morbidities. In these cases, it is important to understand the risk factors for the development of CBDSs-related complications to decide whether or not to treat high-risk patients. Herein, we aimed to identify the risk factors for the development of complications after the diagnosis of CBDSs. Methods: The medical records of patients with CBDSs between October 2005 and September 2019 were retrospectively analyzed. All patients with radiologically-diagnosed CBDSs, including those who received treatment and those who did not, were analyzed. Results: A total of 634 patients were included and 95(15.0%) patients had CBDS-related complications during the mean follow-up period of 32.6 months. Forty-four(6.9%) high-risk patients remained asymptomatic and did not receive treatment during the follow-up period. In multivariate analyses, size of CBDSs ≥ 5 mm and no treatment within 30 days were independent risk factors for the development of complications. The spontaneous passage of CBDSs was proved radiologically in 9 out of 81(11.1%) patients within 30 days. Conclusions: It is recommended treating CBDSs within 30 days from the diagnosis, even in high-risk patients, especially if the size is larger than 5 mm.

关键词： Common bile duct stone Risk factors Obstructive jaundice Pancreatitis Cholangitis

Organic/inorganic nanocomposite polymer electrolyte

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Chinese Chemical Letters 2007年第2期18卷 185-188页

作者： Li Qi Shao jun dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

The organic/inorganic nanocomposites polymer electrolytes were designed and synthesized. The organic/inorganic nanocomposites membrane materials and their lithium salt complexes have been found thermally stable below 200 °C. The conductivity of the organic/inorganic nanocomposites polymer electrolytes prepared at room temperature was at magnitude range of 10(?6) S/cm.

关键词： Organic/inorganic nanocomposites Polymer electrolyte Polymer lithium battery Conductivity Characterization Thermal stability

AN ANALYTICAL SOLUTION FOR THREE-DIMENSIONAL DIFFRACTION OF PLANE P-WAVES BY A HEMISPHERICAL ALLUVIAL VALLEY WITH SATURATED SOIL DEPOSITS

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Acta Mechanica Solida Sinica 2006年第2期19卷 141-151页

作者： Zhao Chenggang dong jun Gao Fuping School of Civil Engineering and Architecture Beijing Jiaotong University Beijing 100044 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

An analytical solution for the three-dimensional scattering and diffraction of plane P-waves by a hemispherical alluvial valley with saturated soil deposits is developed by employing Fourier-Bessel series expansion technique. Unlike previous studies, in which the saturated soil deposits were simulated with the single-phase elastic theory, in this paper, they are simulated with Biot＇s dynamic theory for saturated porous media, and the half space is assumed as a single-phase elastic medium. The effects of the dimensionless frequency, the incidence angle of P-wave and the porosity of soil deposits on the surface displacement magnifications of the hemispherical alluvial valley are investigated. Numerical results show that the existence of a saturated hemispherical alluvial valley has much influence on the surface displacement magnifications. It is more reasonable to simulate soil deposits with Biot＇s dynamic theory when evaluating the displacement responses of a hemispherical alluvial valley with an incidence of P-waves.

关键词： Biot's dynamic theory three-dimensional scattering hemispherical alluvial valley,analytical solution

Invariant Hyperbolic Tori for Gevrey-smooth Hamiltonian Systems Under Rfissmann's Non-degeneracy Condition

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Acta Mathematica Sinica,English Series 2008年第10期24卷 1625-1636页

作者： dong Feng ZHANG jun Xiang XU Department of Mathematics Southeast University Nanjing 210096 P. R. China

In this paper, we prove the persistence of hyperbolic lower dimensional invariant tori for Gevrey-smooth perturbations of partially integrable Hamiltonian systems under Riissmann＇s nondegeneracy condition by an improved KAM iteration, and the persisting invariant tori are Gevrey smooth, with the same Gevrey index as the Hamiltonian.

关键词： hyperbolic invariant tori KAM iteration Gevrey-smooth non-degeneracy condition

Neighbor Sum Distinguishing Total Colorings of Graphs with Bounded Maximum Average Degree

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Acta Mathematica Sinica,English Series 2014年第4期30卷 703-709页

作者： Ai jun dong Guang Hui WANG School of Science Shandong Jiao Tong University School of Mathematics Shandong University

A proper [h]-total coloring c of a graph G is a proper total coloring c of G using colors of the set [h] ={1, 2,..., h}. Let w（u） denote the sum of the color on a vertex u and colors on all the edges incident to u. For each edge uv ∈ E（G）, if w（u） ≠ w（v）, then we say the coloring c distinguishes adjacent vertices by sum and call it a neighbor sum distinguishing [h]-total coloring of G. By tndi∑ （G）, we denote the smallest value h in such a coloring of G. In this paper, we obtain that G is a graph with at least two vertices, if mad（G）〈 3, then tndi∑ （G） ≤k ＋ 2 where k = max{△（G）, 5}. It partially confirms the conjecture proposed by Pilgniak and Wolniak.

关键词： Total coloring neighbor sum distinguishing total colorings average degree

Reduced graphene oxide-nano zero value iron(rGO-nZVI) micro-electrolysis accelerating Cr(Ⅵ) removal in aquifer

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Journal of Environmental Sciences 2018年第11期30卷 96-106页

作者： Liming Ren jun dong Zifang Chi Huazheng Huang Key Lab of Groundwater Resources and Environment Ministry of Education Jilin University Changchun 130021 China

Nanoscale zero-valent iron （nZVI） assembled on graphene oxide （GO）（rGO-nZVI） composites were synthesized by reduction of GO and ferrous ions with potassium borohydride, for use in Cr（VI） removal from aqueous solution. The results showed that the two-dimensional structure of GO could provide a skeleton support for Fe0, thus overcoming the bottleneck of aggregation for nZVI. Also, rGO-nZVI would form a ferric-carbon micro-electrolysis system in Cr（VI）-contaminated aquifers, enhancing and accelerating electron transfer, exhibiting high rate and capacity for Cr（VI） removal. The optimum dosage of the applied rGO-nZVI was linearly correlated with the initial Cr（VI） concentration. Characterization of rGO-nZVI before and after reaction with Cr（VI） revealed the process of Cr（VI） removal： rGO-nZVI firstly transferred electrons from Fe0 cores via their Fe（II）/Fe（III） shells to the GO sheet; there, negatively charged Cr（VI） received electrons and changed into positively charged Cr（III）, which was adsorbed by the negatively charged GO sheet, avoiding the capping and passivating of nZVI rGO-nZVI formed a good electrically conductive network, and thus had long-term electron releasing properties, which was important for groundwater remediation.

关键词： Reduced graphene oxide-nano zero value iron (rGO-nZVI) Micro-electrolysis Cr(VI) removal Groundwater remediation

Effects of pH and particle size on kinetics of nitrobenzene reduction by zero-valent iron

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Journal of Environmental Sciences 2010年第11期22卷 1741-1747页

作者： jun dong Yongsheng Zhao Ran Zhao Rui Zhou College of Environment and Resources Jilin University Changchun 130026 China. College of Chemistry Jilin University Changchun 130026 China

Nitrobenzene has been considered as a significant groundwater contaminant due to its wide usage in explosives, insecticides, herbicides, pharmaceuticals and dyes. Nitrobenzene is of environmental concern because of its toxicity. In the presence of zero-valent iron （ZVI）, reduction of the nitro group is the dominant transformation process for nitrobenzene. A series of experiments were carried out to investigate the kinetics of nitrobenzene reduction by ZVI and the effects of pH and ZVI particle size on nitrobenzene removal in groundwater. The results indicated that nitrobenzene could be reduced to aniline by ZVI; the reduction of nitrobenzene by ZVI followed a pseudo first-order kinetics; the observed nitrobenzene reduction rate constant （k obs ） was 0.0006 min^-1 and the half-life of nitrobenzene （t 1/2 ） was 115.5 min; the mass balance achieved 87.5% for nitrobenzene reduction by the 1 mm ZVI particle and the final removal efficiency was 80.98%. In addition, the pH and ZVI particle size were found to exhibit significant influences on the nitrobenzene reduction. The observed nitrobenzene reduction rate constant linearly decreased with increase pH and the data fitted on polynomial regression equation for the observed nitrobenzene reduction rate constant and ZVI particle size. Therefore, use of ZVI based permeable reactive barrier technology to remedy nitrobenzene contaminated groundwater was feasible.

关键词： zero-valent iron nitrobenzene reduction aniline formation particle size

Evaluation of a risk factor scoring model in screening for undiagnosed diabetes in China population

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第10期12卷 846-852页

作者： Jian-jun dong Neng-jun LOU Jia-jun ZHAO Zhong-wen ZHANG Division of Endocrinology Department of Medicine Qilu Hospital of Shandong University Jinan 250012 China Division of Endocrinology Department of Medicine the Second Hospital of Shandong University Jinan 250033 China Division of Endocrinology Department of Medicine Shandong Provincial Qianfoshan Hospital Jinan 250014 China Division of Endocrinology Department of Medicine Provincial Hospital Affiliated to Shandong University Jinan 250021 China

Objective:To develop a risk scoring model for screening for undiagnosed type 2 diabetes in Chinese ***:A total of 5348 subjects from two districts of Jinan City,Shandong Province,China were *** A (2985) included individuals from east of the city and Group B (2363) from west of the *** questionnaires and a standard oral glucose tolerance test (OGTT) were completed by all *** on the stepwise logistic regression analysis of Group A,variables were selected to establish the risk scoring *** validity and effectiveness of this model were evaluated in Group ***:Based on stepwise logistic regression analysis performed with data of Group A,variables including age,body mass index (BMI),waist-to-hip ratio (WHR),systolic pressure,diastolic pressure,heart rate,family history of diabetes,and history of high glucose were accepted into the risk scoring *** risk for having diabetes increased along with aggregate *** Youden index was closest to 1,the optimal cutoff value was set up at *** this point,the diabetes risk scoring model could identify diabetes patients with a sensitivity of 83.3% and a specificity of 66.5%,making the positive predictive value 12.83% and negative predictive value 98.53%.We compared our model with the Finnish and Danish model and concluded that our model has superior validity in Chinese ***:Our diabetes risk scoring model has satisfactory sensitivity and specificity for identifying undiagnosed diabetes in our population,which might be a simple and practical tool suitable for massive diabetes screening.

关键词： Diabetes mellitus Screening Questionnaire Risk factor score