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New Mathematical Method for the Determination of Cutter Runout Parameters in Flat-end Milling

Chinese Journal of Mechanical Engineering 2012年第5期25卷 947-952页

作者： guo Qiang sun Yuwen guo Dongming ZHANG Chuantai Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024China

The cutting force prediction is essential to optimize the process parameters of machining such as feed rate optimization, etc. Due to the significant influences of the runout effect on cutting force variation in milling process, it is necessary to incorporate the cutter runout parameters into the prediction model of cutting forces. However, the determination of cutter runout parameters is still a challenge task until now. In this paper, cutting process geometry models, such as uncut chip thickness and pitch angle, are established based on the true trajectory of the cutting edge considering the cutter runout effect. A new algorithm is then presented to compute the cutter runout parameters for flat-end mill utilizing the sampled data of cutting forces and derived process geometry parameters. Further, three-axis and five-axis milling experiments were conducted on a machining centre, and resulting cutting forces were sampled by a three-component dynamometer. After computing the corresponding cutter runout parameters, cutter forces are simulated embracing the cutter runout parameters obtained from the proposed algorithm. The predicted cutting forces show good agreements with the sampled data both in magnitude and shape, which validates the feasibility and effectivity of the proposed new algorithm of determining cutter runout parameters and the new way to accurately predict cutting forces. The proposed method for computing the cutter runout parameters provides the significant references for the cutting force prediction in the cutting process.

关键词： flat end milling cutter runout cutting force five-axis machining

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Regulation of graphdiyne-based nanozymes with enhanced oxidaselike activity by cobalt and nitrogen codoping

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Nano Research 2025年第1期18卷 21-29页

作者： Jiali Liu Xiaoli Wang Yongfu Lian Xue Wang Xiuxiu Wang Xingfa Gao Baoyun sun Xihong guo CAS Key Laboratory for Biomedical Effects of Nanomaterial&Nanosafety Institute of High Energy PhysicsChinese Academy of ScienceBeijing 100049China Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080China Laboratory of Theoretical and Computational Nanoscience National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The development of nanozymes with excellent intrinsic oxidase-like activity and specificity has received increasing ***(GDY)could be a promising choice for designing nanozymes with enhanced oxidase(OXD)-like activity due to its unique structure and ***,Co-N-GDY with high OXD activity but no peroxidase(POD)activity was synthesized by codoping of cobalt(Co)and nitrogen(N)into GDY and compared with other GDY-based nanozymes(including GDY,Co-GDY,and N-GDY).Upon analyzing the doping effect of Co and N on the OXD-like and POD-like activities,we found that the combination of Co and N in GDY played a significant role in enhancing the OXD-like activity,and even reversed the POD-like activity of N-GDY to OXD-like activity of *** electrochemical experiment and the theoretical calculations provided an explanation for the mechanism and showed that the activity was closely linked to the reduction ability of O_(2) or H_(2)O_(2) on the nanozyme substrates,which was determined by the ratedetermining step of the catalytic reaction.

关键词： nanozymes oxidase-like activity graphdiyne heteroatom doping regulation

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Polymorphisms in HIF-1a gene are not associated with diabetic retinopathy in China

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World Journal of Diabetes 2021年第8期12卷 1304-1311页

作者： Yue-Hong Liu Chang guo yi-Qiong sun Qiang Li Department of Endocrinology Hainan Cancer HospitalHaikou 570312Hainan ProvinceChina Department of Endocrinology Shenzhen University General HospitalShenzhen 518055Guangdong ProvinceChina

BACKGROUND It has been reported that vascular endothelial growth factor(VEGF)is a susceptibility gene for both type 2 diabetes mellitus(T2DM)and diabetic retinopathy(DR).In response to hypoxia,VEGF mRNA levels are increased,which is mainly mediated by the binding of hypoxia-inducible factor-1(HIF-1)and hypoxia response element upstream of the transcriptional start site of ***,HIF-1a is supposed to be involved in pathology of *** To investigate whether the polymorphisms in HIF-1a gene are associated with *** Two hundred and ninety-nine type 2 diabetic patients(128 males and 171 females)and 144 healthy volunteers were *** age was 56.04±21.05 *** to the results of fundus fluorescein angiography and examination of ophthalmoscopy,patients were divided into two groups,DNR group(diabetes without retinopathy)and DR group(diabetes with retinopathy).There are 150 cases in DNR group and 149 cases in DR *** single nucleotide polymorphisms(SNP)of the HIF-1a gene were tested using matrix-assisted laser desorption/Ionization time of flight mass *** frequency of genotypes and alleles,and odds ratio were *** The mean age of the cases with diabetes was 55.84±3.66 years,the mean age of the cases with DR was 55.97±4.66 years and that of controls was 56.32±4.70 *** variations were found in 76 ***11549465 is the change of C-T base,rs11549467 is the change of G-A *** rs11549467 G/A genotype was 5.33%in diabetes and 6.04%in DR patients,*** rs11549465 C/T genotype was 10%and 12.75%in patients with diabetes and *** rs11549467 A allele frequencies and rs11549465 T frequencies was similar to that of *** SNP linkage disequilibrium analysis indicated that rs11549467 was in linkage disequilibrium with *** association analysis denoted that the haplotype association exhibited similar distribution in the patients compared to the normal *** This s

关键词： Diabetic retinopathy Single nucleotide polymorphisms HIF1a Vascular endothelial growth factor Diabetes Mutation

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Redesigned Surface Based Machining Strategy and Method in Peripheral Milling of Thin-walled Parts

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Chinese Journal of Mechanical Engineering 2010年第3期23卷 282-287页

作者： JIA Zhenyuan guo Qiang sun Yuwen guo Dongming Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of Technology Dalian 116024 China

Currently, simultaneously ensuring the machining accuracy and efficiency of thin-walled structures especially high performance parts still remains a challenge. Existing compensating methods are mainly focusing on 3-aixs machining, which sometimes only take one given point as the compensative point at each given cutter location. This paper presents a redesigned surface based machining strategy for peripheral milling of thin-walled parts. Based on an improved cutting force/heat model and finite element method（FEM） simulation environment, a deflection error prediction model, which takes sequence of cutter contact lines as compensation targets, is established. And an iterative algorithm is presented to determine feasible cutter axis positions. The final redesigned surface is subsequently generated by skinning all discrete cutter axis vectors after compensating by using the proposed algorithm. The proposed machining strategy incorporates the thermo-mechanical coupled effect in deflection prediction, and is also validated with flank milling experiment by using five-axis machine tool. At the same time, the deformation error is detected by using three-coordinate measuring machine. Error prediction values and experimental results indicate that they have a good consistency and the proposed approach is able to significantly reduce the dimension error under the same machining conditions compared with conventional methods. The proposed machining strategy has potential in high-efficiency precision machining of thin-walled parts.

关键词： redesigned surface tool path part deflection error prediction finite element method

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Analytical modeling of geometric errors induced by cutter runout and tool path optimization for five-axis flank machining

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Science China(Technological Sciences) 2011年第12期54卷 3180-3190页

作者： guo Qiang sun YuWen guo DongMing Key Laboratory for Precision and Non-Traditional Machining Technology of the Ministry of Education Dalian University of Technology Dalian 116024 China

The cutter runout effect has significant influence on the shape of cutter swept surface and the machining surface quality. Hence,it is necessary to integrate the cutter runout effect in cutter swept surface modeling,geometric error prediction and tool path optimization for five-axis flank machining. In this paper,an envelope surface model considering cutter runout effect is first established,and geometric errors induced by runout effect are derived based on the relative motion analysis between the cutter and part in machining. In the model,the cutter runout is defined by four parameters,including inclination angle,location angle,offset value and the length of cutter axis. Then the runout parameters are integrated into the rotation surface of each cutting edge that is used to form the final cutter envelope surface for the five-axis machining process. Thus,the final resulting geometric errors of the machined surface induced by cutter runout can be obtained through computing the deviations from the nominal cutter swept surface. To reduce these errors,an iterative least square method is used to optimize the tool paths for five-axis flank machining. Finally,a validation example is given for a specific ruled surface. Results show the effectiveness and feasibility of the analytical model of geometric errors induced by cutter runout,and also show that the geometric errors can be reduced significantly using the proposed tool path planning method.

关键词： cutter runout tool path optimization envelope surface five-axis machining geometric errors

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Investigation on Active Thermal Control Method with Pool Boiling Heat Transfer at Low Pressure

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Journal of Thermal Science 2018年第3期27卷 277-284页

作者： sun Chuang guo Dong WANG Zhengyu sun Fengxian School of Energy Science and Engineering Harbin Institute of Technology School of Power and Energy Engineering Harbin Engineering University

In order to maintain a desirable temperature level of electronic equipment at low pressure, the thermal control performance with pool boiling heat transfer of water was examined based on experimental measurement. The total setup was designed and performed to accomplish the experiment with the pressure range from 4.5 kPa to 20 kPa and the heat flux between 6 kW/m^2 and 20 kW/m^2. The chosen material of the heat surface was alu- minium alloy and the test cavity had the capability of varying the direction for the heat surface from vertical to horizontal directions. Through this study, the steady and transient temperature of the heat surface at different pressures and directions were obtained. Although the temperature non-uniformity of the heat surface from the centre to the edge could reach 10℃ for the aluminium alloy due to the varying pressures, the whole temperature results successfully satisfied with the thermal control requirements for electronic equipment, and the temperature control effect of the vertically oriented direction was better than that of the borizontally oriented direction. Moreover, the behaviour of bubbles generating and detaching from the heat surface was recorded by a high-resolution camera, so as to understand the pool boiling heat transfer mechanism at low-load heat flux. These pictures showed that the bubbles departure diameter becomes larger, and departure frequency was slower at low pressure, in contrast to 1.0 atm.

关键词： Pool Boiling Heat Transfer Water Low Pressure Low-load Heat Flux Experiment Measurement

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Reliability modeling of the bivariate deteriorating product with both monotonic and non-monotonic degradation paths

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Journal of Systems Engineering and Electronics 2021年第4期32卷 971-983页

作者： sun Fuqiang guo Hongxuan LIU Jingcheng School of Reliability and Systems Engineering Beihang UniversityBeijing 100191China Science and Technology on Reliability and Environmental Engineering Laboratory Beihang UniversityBeijing 100191China Wuhan Maritime Communication Research Institute Wuhan 430079China

Fiber optical gyroscope(FOG)is a highly reliable navigation element,and the degradation trajectories of its two accuracy indexes are monotonic and non-monotonic *** this paper,a flexible accelerated degradation testing(ADT)model is used for analyzing the bivariate dependent degradation process of *** time-varying copulas are employed to consider the dynamic dependency structure between two marginal degradation processes as the Wiener process and the inverse Gaussian *** statistical inference is implemented by utilizing an inference function for the margins(IFM)*** is demonstrated that the proposed method is powerful in modeling the joint distribution with various margins.

关键词： fiber optical gyroscope bivariate accelerated degradation testing Wiener process inverse Gaussian process time-varying copulas dependence

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Using FEM to predict tree motion in a wind field

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第7期9卷 907-915页

作者： Xiao-yi HU Wei-ming TAO yi-mu guo Department of Mechanical Engineering Zhejiang University Hangzhou 310027 China School of Engineering Zhejiang Forestry University Hangzhou 311300 China

In this paper we propose a finite element(FE) simulation method to predict tree motion in a wind field. Two FE tree models were investigated:One model was generated based on a realistic nature-looking geometric tree model,and the other was a symmetric model to investigate the influence of asymmetric material properties on tree motion. The vortex-induced vibration(VIV) theory is introduced to estimate the fluctuating wind force being exerted on tree stems and the fluid-structure interaction(FSI) analysis is also included in the simulation. The results indicate that asymmetric material properties result in the crosswind displacement of the investigated node and the main swaying direction deviation. The simulation reveals that under wind loading,a tree with leaves has much larger swaying amplitude along the wind direction and longer swaying period than a tree without leaves. However,the crosswind swaying amplitude is mainly due to branch interaction. The numerical simulation proved that the inter-action of tree branches can prevent dangerous swaying motion developing.

关键词： Finite element method (FEM) Fluid-structure interaction (FSI) Vortex-induced vibration (VIV) Asymmetric Wind field

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QUASICONTINUUM SIMULATION OF NANOINDENTATION OF NICKEL FILM

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Acta Mechanica Solida Sinica 2006年第4期19卷 283-288页

作者： Zeng Fanlin sun yi Department of Astronautic Science and Mechanics Harbin Institute of Technology Harbin 150001 China

A large-scale atom simulation of nanoindentation into a thin nickel film using the quasicontinuum method was performed. The initial stages of the plasticity deformation of nickel were studied. Several useful results were obtained as follows：（1） The response of the load versus indentation depth on the load versus indentation depth curve, besides the straight parts corresponding to the elastic property of nickel, the sudden drop of the load occurred several times; （2） The phenomena of dislocation nucleation -- the dislocation nucleation took place when the load descended, which makes it clear that dislocation nucleation causes the drop of the load; （3） The mechanism of the dislocation emission - the Peierls-Nabarro dislocation model and a pow- erful criterion were used to analyze the dislocation emission. And the computational value was in good agreement with the predict value; （4） The density of geometrically necessary dislocations. A simple model was used to obtain the density of geometrically necessary dislocations beneath the indenter. Furthermore, the influence of the boundary conditions on the simulation results was discussed.

关键词： quasicontinuum method nanoindentation dislocation nucleation density of geometrically necessary dislocation

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Functional characterization of SAG/RBX2/ROC2/RNF7, an antioxidant protein and an E3 ubiquitin ligase

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Protein & Cell 2013年第2期4卷 103-116页

作者： yi sun Hua Li Division of Radiation and Cancer Biology Department of Radiation OncologyUniversity of Michigan4424B Medical Science-I1301 Catherine StreetAnn ArborMI 48109USA.

SAG(Sensitive to Apoptosis Gene),also known as RBX2(RING box protein 2),ROC2(Regulator of Cullins 2),or RNF7(RING Finger Protein 7),was originally cloned in our laboratory as a redox inducible antioxi-dant protein and later characterized as the second member of the RBX/ROC RING component of the SCF(SKP1-CUL-F-box Proteins)E3 ubiquitin *** acting alone,SAG scavenges oxygen radicals by forming inter-and intra-molecular disulfide bonds,whereas by forming a complex with other components of the SCF E3 ligase,SAG promotes ubiquitination and degradation of a number of protein substrates,includ-ing c-JUN,DEPTOR,HIF-1α,IκBα,NF1,NOXA,p27,and procaspase-3,thus regulating various signaling path-ways and biological ***,SAG pro-tects cells from apoptosis,confers radioresistance,and plays an essential and non-redundant role in mouse embryogenesis and ***,stress-inducible SAG is overexpressed in a number of human cancers and SAG overexpression correlates with poor patient ***,SAG transgenic expression in epidermis causes an early stage inhibi-tion,but later stage promotion,of skin tumorigenesis triggered by DMBA/*** its major role in pro-moting targeted degradation of tumor suppressive proteins,leading to apoptosis suppression and accel-erated tumorigenesis,SAG E3 ligase appears to be an attractive anticancer target.

关键词： antioxidant angiogenesis apoptosis Cullin-RING ligases radiation resistance reactive oxygen species SAG/RBX2/ROC2/RNF7 SCF E3 ligases tumori-genesis ubiquitin ligase vasculogenesis

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