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Elastodynamic analysis of synergistic oscillation system driven by double servomotors for continuous casting mold

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Journal of Iron and Steel Research International 2022年第1期29卷 115-123页

作者： Da-wei Liu Chen lv Jin-ming Zhang Xin Jin College of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina National Engineering Technology Research Center of Cold Rolling Strip Equipment and Technology Yanshan UniversityQinhuangdao 066004HebeiChina

Based on the principle of speed superposition,the oscillation system for continuous casting mold synchronously driven by double servomotors can adjust all parameters online with high reliability and high bearing *** elastodynamic model of the oscillation system was presented to analyze the oscillation characteristics affected by multiple ***,the working principle of the system was illustrated,with the kinematic model of the system *** the elastic deformation of mechanical components,the lumped parameter method was used to establish the equivalent component and elastodynamic model of the oscillation *** on Runge–Kutta method,the oscillation response of the system was *** validity of the elastodynamic model was validated by comparing the simulated solution and experimental data,and the oscillation characteristics of the system were analyzed emphatically with model *** results showed that the first three harmonic frequencies of the eccentric shafts are the main cause of harmonic resonance,which has a strong relationship with the system *** increase in the fluctuation coefficients and the decrease in the phase difference enhanced the elastic oscillation of the *** elastic error tends to show linear growth with the increase in the friction force of the slab.

关键词： Continuous casting Mold Non-sinusoidal oscillation Elastic response

Effects of minor Nd and Er additions on the precipitation evolution and dynamic recrystallization behavior of Mg-6.0Zn-0.5Mn alloy

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Journal of Magnesium and Alloys 2021年第3期9卷 840-852页

作者： Bin-Jiang lv Sen Wang Tie-wei Xu Feng Guo School of Mechanical and Automotive Engineering Qingdao University of Technology266520China Key Lab of industrial Fluid Energy Conservation and Pollution Control Qingdao University of Technology266520China

A new wrought magnesium(Mg)alloy based on Mg-6.0Zn-0.5Mn(ZM60)is developed,which performs excellent combination of high tensile yield strength and good *** investigate the effects of micro-alloying on dynamic precipitation,dynamic recrystallization(DRX)and mechanical properties of ZM60 *** co-addition of minor(0.6 wt%)neodymium(Nd)and(0.3 wt%)erbium(Er)can accelerate the twinning and DRX process of ZM60 alloy at the initial compression deformation *** dynamic precipitation process is also accelerated due to Nd and Er *** accumulation disappears and a higher density of rodβ_(1) precipitates and some thick β_(2) precipitates in matrix and fine twins,which inhibits the growth of DRX grains in compressed ZM60-0.6Nd-0.3Er *** as-extruded ZM60-0.6Nd-0.3Er alloy has a yield strength(YS)of 245.8 MPa,ultimate tensile strength(UTS)of 347.2 MPa and elongation(EL)of 16.3%.The yield strength and tensile strength are improved via minor Nd and Er additions due to fine complete DRX grains,second phase particles and high density of *** grain refinement,weakened reserved working hardening and weakened basal fiber texture improve the elongation of ZM60-0.6Nd-0.3Er alloy.

关键词： Nd and Er Hot deformation Dynamic precipitation Dynamic recrystallization Texture

Optimization of the End Effect of Hilbert-Huang transform(HHT)

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 732-745页

作者： Chenhuan lv jun ZHAO Chao WU Tiantai GUO Hongjiang CHEN College of Metrology&Measurement Engineering China Jiliang UniversityHangzhou 310018China Hunan Institute of Metrology and Test Changsha 410014China

In fault diagnosis of rotating machinery, Hil- bert-Huang transform （HHT） is often used to extract the fault characteristic signal and analyze decomposition results in time-frequency domain. However, end effect occurs in HHT, which leads to a series of problems such as modal aliasing and false IMF （Intrinsic Mode Func- tion）. To counter such problems in HHT, a new method is put forward to process signal by combining the general- ized regression neural network （GRNN） with the bound- ary local characteristic-scale continuation （BLCC）. Firstly, the improved EMD （Empirical Mode Decompo- sition） method is used to inhibit the end effect problem that appeared in conventional EMD. Secondly, the gen- erated IMF components are used in HHT. Simulation and measurement experiment for the cases of time domain, frequency domain and related parameters of Hilbert- Huang spectrum show that the method described here can restrain the end effect compared with the results obtained through mirror continuation, as the absolute percentage of the maximum mean of the beginning end point offset and the terminal point offset are reduced from 30.113% and 27.603% to 0.510% and 6.039% respectively, thus reducing the modal aliasing, and eliminating the false IMF components of HHT. The proposed method caneffectively inhibit end effect, reduce modal aliasing and false IMF components, and show the real structure of signal components accuratelX.

关键词： End effect Hilbert-Huang transform (HHT)Modal aliasing Boundary local characteristic-scalecontinuation (BLCC) Generalized regression neuralnetwork (GRNN)

Self-organized Criticality Behavior in Bulk Metallic Glasses

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Journal of Iron and Steel Research International 2016年第1期23卷 7-13页

作者： jun-wei QIAO Zhong WANG Laboratory of Applied Physics and Mechanics of Advanced Materials College of Materials Science and EngineeringTaiyuan University of Technology

Serrated flows are known as repeated yielding of bulk metallic glasses（BMGs）during plastic deformation under different loading conditions,which are associated with the operation of shear *** to the statistics of some parameters,the shear avalanches can display a self-organized critical state,suggesting a large ductility of *** emergence of the self-organized criticality（SOC）behavior in different BMGs is due to the temperature,strain rate,and chemical *** SOC behavior is accompanied with the following phenomena：the interactions occur in the shear bands;the incubation time is longer than the relaxation time;the time interval is lacking of typical time scale;and the spatial or temporal parameters should display apower-law distribution.

关键词： self-organized criticality behavior bulk metallic glass serrated flow power-law distribution

Morphological Control of Gold Nanoparticles by Green Synthesis Using L-Tryptophan and Other Additives

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Transactions of Tianjin University 2018年第1期24卷 16-24页

作者： Jinsheng Sun Dongmei wei Hao lv School of Chemical Engineering and Technology Tianjin University

This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent L-Tryptophan(L-Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV-Vis spectrophotometer and X-ray diffraction(XRD) for size and morphological information. The effects of the specific additives of PVP((C_6 H_9 NO)_n), CTAB(C_(16)H_(33)(CH_3)_3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.

关键词： Gold nanoparticles L-Tryptophan Morphology control Binary exogenous additives

Hybrid Flowshop Scheduling with Interstage Job Transportation

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Journal of the Operations Research Society of China 2014年第1期2卷 109-121页

作者： wei-ya Zhong Long-hua lv Department of Business Administration School of ManagementShanghai University200444 ShanghaiPeople’s Republic of China Department of Mathematics Shanghai University200444 ShanghaiPeople’s Republic of China

There are a variety of joint job production and transportation scheduling problems that arise in modern manufacturing *** this paper,we study one of such problems that arises in a flowshop environment where there are two processing stages and a single transporter that is available to deliver the finished jobs from the first stage to the *** is a single machine in the first stage and two parallel machines in the second *** transporter can carry only one job in each *** job is first processed on the single machine at stage one,then transported to and processed on one of the two parallel machines at stage *** objective is to minimize the makespan,i.e.,the completion time of the last job in the second *** this problem is strongly NP-hard,we propose a fast heuristic and show that the heuristic has a worst-case bound of 5/*** also conduct1 numerical experiments to evaluate the average performance of this heuristic.

关键词： Hybrid flowshop scheduling Transportation Approximation heuristic

Amiodarone-induced hepatotoxicity-quantitative measurement of iodine density in the liver using dual-energy computed tomography:Three case reports

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World Journal of Clinical Cases 2020年第20期8卷 4958-4965页

作者： Hai-Juan lv Hong-wei Zhao Department of Radiology The Second Affiliated Hospital of Jiaxing UniversityJiaxing 314000Zhejiang ProvinceChina

BACKGROUND Amiodarone is the drug most commonly used to manage ***-term amiodarone administration causes hepatotoxicity due to iodine accumulation in the ***,we present three cases of amiodarone-induced hepatotoxicity in patients on long-term oral amiodarone therapy who underwent dual-energy computed tomography(DECT).CASE SUMMARY We report the clinical and iodine density in the liver using DECT in three patients with amiodarone-induced *** enzymes were increased in these three patients,and abdominal DECT without contrast medium showed highly increased attenuation in the ***,the iodine concentration in the liver was *** first patient with amiodarone-induced reversible hepatotoxicity,showed a reversible course of liver function and a decrease in CT values after discontinuation of *** second patient on long-term oral amiodarone had increased iodine concentration in the liver and liver damage,the patient eventually developed rapidly progressive pneumonia and died of multiple organ *** third patient,showed an increased iodine concentration in the liver and elevated liver ***,the patient refused radiofrequency ablation for atrial fibrillation and continued oral amiodarone to control atrial fibrillation,and routine liver function tests were required every 3-6 mo in this *** DECT is a potentially noninvasive diagnostic tool for quantifying iodine concentration in the liver and monitoring adverse reactions due to amiodarone.

关键词： Case report Amiodarone Hepatotoxicity Iodine density Computed tomography Dual energy Arrhythmias

Poor oral health was associated with higher risk of gastric cancer: Evidence from 1431677 participants

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 585-595页

作者： Fei Liu Shi-jun Tang Zi-wei Li Xu-Rui Liu Quan lv wei Zhang Dong Peng Department of Gastrointestinal Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Pediatric Dentistry Stomatological Hospital of Guizhou Medical UniversityGuizhou 550000Guizhou ProvinceChina

BACKGROUND In recent years,the association between oral health and the risk of gastric cancer(GC)has gradually attracted increased ***,in terms of GC incidence,the association between oral health and GC incidence remains *** is reported to increase the risk of ***,some studies have shown that periodontitis has no effect on the risk of ***,the present study aimed to assess whether there is a relationship between oral health and the risk of *** To assess whether there was a relationship between oral health and the risk of *** Five databases were searched to find eligible studies from inception to April 10,***-Ottawa Scale score was used to assess the quality of included *** quality of cohort studies and case-control studies were evaluated separately in this *** of GC were described by odds ratio(OR)and 95%confidence interval(CI).Funnel plot was used to represent the publication bias of included *** performed the data analysis by StataSE *** A total of 1431677 patients from twelve included studies were enrolled for data analysis in this *** to our analysis,we found that the poor oral health was associated with higher risk of GC(OR=1.15,95%CI:1.02-1.29;I2=59.47%,P=0.000.01),gingivitis(OR=1.19,95%CI:0.71-1.67;I2=0.00%,P>0.01),dentures(OR=1.27,95%CI:0.63-1.19;I2=68.79%,P>0.01),or tooth brushing(OR=1.25,95%CI:0.78-1.71;I2=88.87%,P>0.01)had no influence on the risk of ***,patients with periodontitis(OR=1.13,95%CI:1.04-1.23;I2=0.00%,P<0.01)had a higher risk of *** Patients with poor oral health,especially periodontitis,had a higher risk of *** should be concerned about their oral *** oral health might reduce the risk of GC.

关键词： Oral health Tooth loss Periodontitis Gastric cancer Risk factor

Corrosion behavior of laser-clad coatings fabricated on Ti6Al4V with different contents of TaC addition

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Rare Metals 2020年第4期39卷 436-447页

作者： Lie-Feng Hu jun Li Ying-Hao lv Yang-Feng Tao School of Materials Engineering Shanghai University of Engineering ScienceShanghai 201620China

The coatings were produced on Ti6A14V by lasercladding the mixture of Ni-based alloy and different contents of TaC(0 wt%,5 wt%,10 wt%,20 wt%,30 wt%,40 wt%).The microstructure and corrosion behavior of the coatings were investigated in *** coating without TaC is composed of TiNi/Ti2Ni(matrix)and TiC/TiB/TiB2(reinforcement).Moreover,TaC is precipitated again and TiC/TiB/TiB2 solid solutions containing Ta are formed in the *** potential of the coatings(-0.639,-0.636,-0.547,-0.534,-0.471 and-0.348 V)increases,and passive current density(1×10-5.4,1×10-5.6,1×10-6.4,1×10-6.8,1×10-6.7 and 1×10-6.9 A·cm-2)*** passive films are more difficult to break down(breakdown potential of 0.003,0.080,0.204 and 0.605 V).When the content of TaC exceeds 20 wt%,no breakdown phenomenon is *** passive film on the surface of coating without TaC is mainly composed of TiO2,Al2O3,Cr2O3,CrO3,NiO,Ni2O3 and *** the addition of TaC,Ta2O5 is formed in the passive *** content of Ta2O5 presents an increasing trend with the increase in the content of *** addition of TaC has a positive effect on corrosion resistance of the coatings.

关键词： Laser cladding Coating Microstructural evolution Corrosion resistance