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REAL-TIME FLOOD FORECASTING METHOD WITH 1-D UNSTEADY FLOW MODEL

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Journal of Hydrodynamics 2007年第2期19卷 150-154页

作者： MU jin-bin ZHANG Xiao-feng State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072China

A real-time forecasting method coupled with the I-D unsteady flow model with the recursive least-square method was developed. The 1-D unsteady flow model was modified by using the time-variant parameter and revising it dynamically through introducing a variable weighted forgetting factor, such that the output of the model could be adjusted for the real time forecasting of floods. The application of the new real time forecasting model in the reach from Yichang to Luoshan of the Yangtze River was demonstrated. Computational result shows that the forecasting accuracy of the new model is much higher than that of the original 1-D unsteady flow model. The method developed is effective for flood forecasting, and can be used for practical operation in the flood forecasting.

关键词： unsteady flow hydraulic model least squares,time variant forgetting factor real-time forecasting

Fabrication, annealing, and electrocatalytic properties of platinum nanoparticles supported on self-organized TiO_2 nanotubes

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Rare Metals 2008年第5期27卷 445-450页

作者： LEI bin XUE Jianjun jin Danping NIShougao SUN Haibo College of Materials Science and Technology Nanjing University of Aeronautics ＆ Astronautics Nanjing 210016 China

The platinum nanoparticles supported on self-organized TiO2 nanotubes （Pt-TiO2/Ti） were prepared using electrochemical anodic oxidation followed by cathodic reduction. The structure and chemical nature of the Pt-TiO2/Ti electrocatalyst were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Both XRD and SEM results indicate the presence of platinum on nanotubular TiO2. The stability of the Pt deposits was also investigated in 0.5 mol/L H2SO4 solution by cyclic voltammetry. The electrocatalytic activity of the Pt-TiO2/Ti catalyst exhibits enhancement effect during electro-oxidation of methanol when annealed to anatase. Successive cyclic voltam- mograms of methanol oxidation on the Pt-TiO2/Ti electrocatalyst shows unique electrocatalytic characteristics when compared to methanol oxidation on the bulk Pt catalyst. This is because of further quick oxidation of adsorbed CO by Pt （111） facets of Pt particles on self-organized TiO2 nanotubes when the formation of an electroactive film onto the working catalyst surface occurs.

关键词： platinum nanoparticles TiO2 nanotubes cyclic voltammetry methanol oxidation electrocatalytic properties

Broaching Performance of Superalloy GH4169 Based on FEM

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Journal of Materials Science & Technology 2011年第12期27卷 1178-1184页

作者： Xiangwei Kong bin Li Zhibo jin Wenran Geng. School-of Mechanical Engineering ＆ Automation Northeastern University Shenyang 110004 China

The nickel-based superalloy GH4169 is an important material for high temperature applications in the aerospace industry. However, due to its poor machinability, GH416g is hard to be cut and generates saw-tooth chips during high speed machining, which could significantly affect the dynamic cutting force, cutting temperature fluctuation, tool life, and the surface integrity of the parts. In this paper, the saw-tooth chip formation mechanism of superalloy GH4169 was investigated by the elasto-viscoplastic finite element method （FEM）. Using the finite element software of ABAQUS/Explicit, the deformation of the part during high speed machining was simulated. The effective plastic strain, the temperature field, the stress distribution, and the cutting force were analyzed to determine the influence of the cutting parameters on the saw-tooth chip formation. The study on broaching performance has great effect on selecting suitable machining parameters and improving tool life.

关键词： Machining Superalloy Saw-tooth chip Finite element method (FEM)

Studies on Non-potentiometric Piezoelectric Sensor System for Determination of Vitamin B_1

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Chemical Research in Chinese Universities 2003年第3期19卷 280-285页

作者： YUAN jin bin NIE Li hua YAO Shou zhuo State Key Laboratory of Chemo/Biosensing&Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082P.R.China

A piezoelectric sensor responsive to vitamin B 1 was fabricated based on the vitamin B 1 tetraphenylborate ion pair. The general performance characteristics of the sensor are presented here. The proposed sensor showed a wide working pH range, a good sensitivity and selectivity. The response range is between 1 0×10 -7 -4 9×10 -5 mol/L with a detection limit of 8×10 -8 mol/L at pH 4 0. The selectivity should be attributed to the preferential adsorption of the component ion on the membrane/solution interface. The adsorption behavior of vitamin B 1 on the crystal surface was investigated with a quartz crystal impedance(QCI) system.

关键词： Piezoelectric sensor Vitamin B_(1) Ion-pair complex

Perioperative mortality of metastatic spinal disease with unknown primary: A case report and review of literature

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World Journal of Clinical Cases 2021年第2期9卷 379-388页

作者： Xiu-Mao Li Li-bin jin Department of Orthopedics The Second Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310009Zhejiang ProvinceChina

BACKGROUND Spinal metastases are common in patients with malignancies,but studies on those metastasized from unknown primaries are scarce due to the difficulty in treatment and the relatively poor *** of surgical complications,particularly perioperative mortality,in patients with spinal metastases from unidentified sources is still *** SUMMARY A 54-year-old man with chest-back pain was diagnosed with spinal metastasis in the seventh thoracic vertebra(T7).Radiographic examinations,as well as needle biopsy and immunohistochemical tests were performed to verify the characteristics of the lesion,resulting in an inconclusive diagnosis of poorly differentiated cancer from an unknown primary ***,spinal surgery was performed using the posterior approach to relieve symptoms and verify the *** histologic examination indicated that this poorly differentiated metastatic cancer was possibly sarcomatoid *** the patient experienced unexpectedly fast progression of the disease and died 16 d after surgery,the origin of this metastasis was *** discuss this case with respect to reported perioperative mortality in similar *** A comprehensive assessment prior to surgical decision-making is essential to reduce perioperative mortality risk in patients with spinal metastases from an unknown origin.

关键词： Hospital mortality Spine Neoplasm metastasis Unknown primary Carcinoma Case report

What is Discussed about COVID-19:A Multi-Modal Framework for Analyzing Microblogs from Sina Weibo without Human Labeling

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Computers, Materials & Continua 2020年第9期64卷 1453-1471页

作者： Hengyang Lu Yutong Lou bin jin Ming Xu School of Artificial Intelligence and Computer Science Jiangnan UniversityWuxi214122China National Key Laboratory for Novel Software Technology Department of Computer Science and TechnologyNanjing UniversityNanjing210023China

Starting from late 2019,the new coronavirus disease(COVID-19)has become a global *** the development of online social media,people prefer to express their opinions and discuss the latest news *** have witnessed the positive influence of online social media,which helped citizens and governments track the development of this pandemic in *** is necessary to apply artificial intelligence(AI)techniques to online social media and automatically discover and track public opinions posted *** this paper,we take Sina Weibo,the most widely used online social media in China,for analysis and *** collect multi-modal microblogs about COVID-19 from 2020/1/1 to 2020/3/31 with a web crawler,including texts and images posted by *** order to effectively discover what is being discussed about COVID-19 without human labeling,we propose a unified multi-modal framework,including an unsupervised short-text topic model to discover and track bursty topics,and a self-supervised model to learn image features so that we can retrieve related images about *** results have shown the effectiveness and superiority of the proposed models,and also have shown the considerable application prospects for analyzing and tracking public opinions about COVID-19.

关键词： COVID-19 public opinion microblog topic model self-supervised learning

Effect of Surface Mechanical Attrition Treatment on Tribological Behavior of the AZ31 Alloy

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Journal of Materials Science & Technology 2016年第12期32卷 1245-1252页

作者： Shuangwu Xia Yong Liu Dongming Fu bin jin Jian Lu Key Laboratory of Near Net Forming of Jiangxi Province Nanchang University Department of Mechanical and Biomedical Engineering City University of Hong Kong Centre for Advanced Structural Materials Shenzhen Research InstituteCity University of Hong Kong

By surface mechanical attrition treatment（SMAT）,a gradient nano structure（GNS） from the surface to center was generated in the AZ31 alloy *** tribological behavior of AZ31 alloy with GNS was systematically investigated by using dry sliding tests,a 3D surface profile-meter and a scanning electron microscope equipped with an energy-dispersive *** experimental results indicate that the Mg alloy with GNS exhibits better wear resistance comparing to the as-received sample,which is associated to the alteration of wear mechanism at different sliding *** Mg alloy with GNS presents the wear mechanism of the abrasive wear at 0.05 m/s and the oxidative wear at 0.5 m/s,***,the GNS can effectively promote the reaction between the oxygen and worn surface,which leads to a compact oxidation layer at 0.5 m/*** effect of oxidation layer on the wear resistance of the Mg alloy was also discussed.

关键词： Magnesium alloy Surface mechanical attrition treatment Wear mechanism Oxidation layer

Microstructure Evolution and Mechanical Properties of a SMATed Mg Alloy under In Situ SEM Tensile Testing

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Journal of Materials Science & Technology 2017年第3期33卷 224-230页

作者： Xiaowei Liu Yong Liu bin jin Yang Lu Jian Lu 1 CentreforAdvanced Structural Materials(CASM) Department of Mechanical and Biomedical EngineeringCity University ofHong KongKowloonHong KongChina Key Laboratory of Near Net Forming of Jiangxi Province Nanchang UniversityNanchang 330031China Shenzhen Research Institute City University of HongKongShenzhen 518057China

Surface mechanical attrition treatment（SMAT） has been recently applied to bulk polycrystalline magnesium（Mg） alloys with gradient grain size distribution from the impact surface to inside matrix, hence effectively improving the alloys＇ mechanical performances. However, in-depth understanding of their mechanical property enhancement and grain size-dependent fracture mechanism remains unclear. Here,we demonstrated the use of in situ micro-tensile testing inside a high resolution scanning electron microscope（SEM） to characterize the microstructure evolution, in real time, of SMATed Mg alloy AZ31 samples with different grain sizes of ~10 μm（＇coarse-grain sample＇） and ~5 μm（＇fine-grain sample＇）, respectively, and compared the results with those of a raw Mg alloy AZ31. The quantitative tensile tests with in situ SEM imaging clearly showed that fracture of ‘fine-grain sample＇ was dominated by intergranular cracks,while both trans-granular and intergranular cracks led to the final failure of the ‘coarse-grain samples＇.It is expected that this in situ SEM characterization technique, coupled with quantitative tensile testing method, could be applicable for studying other grain-refined metals/alloys, allowing to optimize their mechanical performances by controlling the grain sizes and their gradient distribution.

关键词： Surface mechanical attrition treatment(SMAT) Mg alloy Mechanical property In situ SEM Microstructure characterization

Pd(OAc)2 catalyzed synthesis of heteroaryl-substituted 1,8-naphthyridine derivatives via C-N-coupling reactions of chloronaphthyridines

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Chinese Chemical Letters 2007年第4期18卷 383-386页

作者： Shou Wen jin bin Liu Wan Zhi Chen Department of Chemistry Zhejiang University Xixi Campus Hangzhou 310028 China

An efficient route to synthesize the heteroaryl-substituted 1,8-naphthyridine derivatives was described. Eight 2-heteroaryl- and 2,7-diheteroaryl-1,8-naphthyridine derivatives were obtained through palladium-catalyzed C-N-coupling reactions of chloronaphthyridines with imidazole, benzimidazole, morpholine, 3,5-dimethylpyrazole, and phthalimide in moderate to good yields.

关键词： Palladium Naphthyridine C-N-coupling reaction Catalyst