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Numerical Study on the Stress–Strain Cycle of Thermal Self-Compressing Bonding

Chinese Journal of Mechanical Engineering 2018年第4期31卷 140-147页

作者： Yun-Hua Deng qiao guan Jun Tao Bing Wu Aeronautical Key Laboratory for Welding and Joining Technologies AVIC Beijing Aeronautical Manufacturing Technology Research Institute School of Mechanical Engineering and Automation Beihang University Science and Technology on Power Beam Process Laboratory AVIC Beijing Aeronautical Manufacturing Technology Research Institute

Thermal self-compressing bonding(TSCB) is a new solid-state bonding method pioneered by the authors. With electron beam as the non-melted heat source, previous experimental study performed on titanium alloys has proved the feasibility of TSCB. However, the thermal stress–strain process during bonding, which is of very important significance in revealing the mechanism of TSCB, was not analysed. In this paper, finite element analysis method is adopted to numerically study the thermal elasto-plastic stress–strain cycle of thermal self-compressing bonding. It is found that due to the localized heating, a non-uniform temperature distribution is formed during bonding, with the highest temperature existed on the bond interface. The expansion of high temperature materials adjacent to the bond interface are restrained by surrounding cool materials and rigid restraints, and thus an internal elasto-plastic stress–strain field is developed by itself which makes the bond interface subjected to thermal compressive action. This thermal self-compressing action combined with the high temperature on the bond interface promotes the atom diffusion across the bond interface to produce solid-state joints. Due to the relatively large plastic deformation, rigid restraint TSCB obtains sound joints in relatively short time compared to diffusion bonding.

关键词： Thermal self-compressing bonding Locally non-melted heating Thermal elasto-plastic stress–strain Atom diffusion Solid-state bonding Finite element analysis

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Design and Dynamic Analysis of the Recirculating Planetary Roller Screw Mechanism

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 240-255页

作者： guan qiao Rong Liao Shijie Guo Zhenghong Shi Shangjun Ma Inner Mongolia Key Laboratory of Advanced Manufacturing Technology Inner Mongolia University of TechnologyHohhot 010051China University of Cincinnati CincinnatiOH 45221USA Shaanxi Engineering Laboratory for Transmissions and Controls Northwestern Polytechnical UniversityXi’an 710072China

The recirculating planetary roller screw mechanism(RPRSM)is a transmission mechanism that engages the screw and nut threaded by multiple grooved *** this paper,frstly,the design method of RPRSM nut threadless area is proposed,and the equations related to the structural parameters of nut threadless area are *** this basis,the cross-section design method of roller,screw and nut is constructed according to the actual situation of engagements between the screw/nut and the *** adjusting the gap between the two beveled edges and that between the arc and the beveled edge,the accuracy of the thread engagements between the screw/nut and the roller can be ***,to ensure the engagements of the screw/nut and the roller,the distance equation from the center surface of the diferent rollers to the end surface of cam ring is ***,combined with the working principle and structural composition of RPRSM,the component model is established according to its relevant structural parameters,and the virtual assembly is ***,the 3D model is imported into the ADAMS simulation software for multi-rigid body *** dynamic characteristic is analyzed,and the simulated values are compared with the theoretical *** results show that the contact forces between the screw/nut and the roller are sinusoidal,mainly due to the existence of a small gap between the roller and the *** maximum collision forces between the roller and cam ring are independent from load ***,the collision force between the roller and the carrier increases as the load *** RPRSM is in the transmission process,the roller angular speed in nut threadless area begins to appear abruptly,and the position of the maximum change is at the contact between the roller and the convex platform of cam *** design of the nut threadless area and the proposed virtual assembly method can provide a theoretical guidance for RPRSM research,as well as

关键词： Recirculating planetary roller screw mechanism Nut threadless area Virtual assembly method Motion relationship Dynamic analysis

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Microstructure and performance of AZ80D magnesium alloy by purification of chloride flux containing Er

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Rare Metals 2014年第5期33卷 541-546页

作者： Zhong-Jun Wang guan-qiao Su Wei-Ping Jia Qing-Xiang Yang School of Material and Metallurgy University of Science and Technology Liaoning Key Laboratory of Materials Forming and Microstructure and Properties Control Education Department in Liaoning Province State Key Laboratory of Metastable Materials Science and Technology College of Materials Science and EngineeringYanshan University

The purification effects of Er addition in chloride flux during smelting on microstructure, tensile properties, and corrosion resistance of as-cast AZ80 D magnesium alloy were carried out. The results show that Er addition in the flux can eliminate the MgO inclusions and improve the tensile properties and corrosion resistance of the alloy. Using chloride flux mixed with 8.0 wt% Er, σb and δ of the as-cast AZ80 D magnesium alloy can be improved from 150 MPa and 2.1 % to the maximum value of 230 MPa and 4.8 %, respectively. Meanwhile, the corrosion rate decreases from 1.10 to 0.12 mg·（cm^2·d）^-1 in 5 wt% NaCl solution. However, with increasing Er content in chloride flux further, φ-（Al7ErMn5） and τ-（Al66.7Mg23.3Er10） phase are formed, and the morphology of γ-（Mg17Al12） phase is modified. The coarse φ-（Al7ErMn5）phase along dendrite boundaries decreases cohesion force between dendrites, which results in the worse of tensile properties.

关键词： Er Chloride flux AZ80D Microstructure Magnesium alloy

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Rehabilitation care for pain in elderly knee replacement patients

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World Journal of Clinical Cases 2024年第4期12卷 721-728页

作者： Li Liu qiao-Zhen guan Li-Fang Wang Wuhan Fourth Hospital Wuhan 430033Hubei ProvinceChina Department of Orthopaedics Wuhan Third HospitalWuhan 430074Hubei ProvinceChina

BACKGROUND Total knee arthroplasty(TKA)is recognized as the most effective surgical intervention for relieving pain and improving joint mobility and deformity in patients with knee osteoarthritis and other synovial *** application of accelerated postoperative rehabilitation(enhanced recovery after surgery)has demonstrated its efficacy in improving patient outcomes,and early postoperative joint function exercise has become a key prognostic factor in knee *** unexpected appearance of limb pain and swelling hindered the patient’s tendency for early mobilization,leading in prolonged hospitalization,delayed functional recovery and negative psychological responses.A retrospective analysis was conducted on a cohort of 116 patients who under-went TKA at our hospital between July 2019 and July *** patients were divided into two groups:A control group(n=58)receiving programmatic nur-sing,and an observed group(n=58)receiving programmed nursing combined with a collaborative nursing model.A pain management team consisting of attending physicians,head nurses,and responsible nurses was *** measures included visual analogue scale(VAS)scores,activities of daily living(ADL)scale scores,and functional *** ADL scores of patients in both groups exhibited a continuous ***,there was no statistically significant difference in the ADL scores between the two groups at 48 h and the 7th d post-surgery(P>0.05).Upon reexamination at the 3rd mo,the observation group demonstrated higher ADL scores compared to the control group(67.48±14.69 vs 59.40±16.06,P0.05).The functional status of patients in both groups exhibited a gradual increase prior to intervention and at the 1st,2nd,and 3rd month following discharge(P<0.05).There was no statistically significant difference in knee joint function scores b

关键词： Programmed pain nursing Collaborative nursing Total knee arthroplasty

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Skeletal phenotypes and molecular mechanisms in aging mice

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Zoological Research 2024年第4期45卷 724-746页

作者： qiao guan Yuan Zhang Zhi-Kun Wang Xiao-Hua Liu Jun Zou Ling-Li Zhang School of Exercise and Health Shanghai University of SportShanghai 200438China College of Athletic Performance Shanghai University of SportShanghai 200438China

Aging is an inevitable physiological process,often accompanied by age-related bone loss and subsequent bone-related diseases that pose serious health *** on skeletal diseases caused by aging in humans is challenging due to lengthy study durations,difficulties in sampling,regional variability,and substantial ***,mice are preferred for such studies due to their similar motor system structure and function to humans,ease of handling and care,low cost,and short generation *** this review,we present a comprehensive overview of the characteristics,limitations,applicability,bone phenotypes,and treatment methods in naturally aging mice and prematurely aging mouse models(including SAMP6,POLG mutant,LMNA,SIRT6,ZMPSTE24,TFAM,ERCC1,WERNER,and KL/KL-deficient mice).We also summarize the molecular mechanisms of these aging mouse models,including cellular DNA damage response,senescence-related secretory phenotype,telomere shortening,oxidative stress,bone marrow mesenchymal stem cell(BMSC)abnormalities,and mitochondrial ***,this review aims to enhance our understanding of the pathogenesis of aging-related bone diseases.

关键词： Aging Premature aging Mice Bone Gene knockout

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Preliminary Studies on Thickness of Nondestructive Rice (Oryza sativa L.) Leaf Blade

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Agricultural Sciences in China 2007年第7期6卷 802-807页

作者： CHEN You-ding ZHANG Xu ZHOU Xin-qiao CHEN guan-hua Rice Research Institute Guangdong Academy of Agricultural Sciences Guangzhou 510640 P.R. China

Two varieties, Yuexinzhan and guangchao 3, were used to study leaf thickness in rice in this experiment. The thickness of the leaf blade was measured by the nondestructive leaf thickness instrument, which was modified from the thickness instrument for steel objects （John Bull, England）. The contacting area between the leaf and the probe of the instrument was 0.5 cm^2. There was no significant difference between the thickness of steel materials measured by the nondestructive rice leaf thickness instrument and the micrometer. The correlation between the thickness of the rice leaf blade measured by the nondestructive rice leaf thickness instrument and the specific leaf weight （SLW） was significant （P 〈 0.05 or P〈 0.01）. The results also showed that the rice leaf thickness was uneven and asymmetric. The thickness and SLW of flag leaf tended to increase from the base to the tip of the leaf blade. The middle part of the second and third top leaf was the thickest, but no significant difference in thickness between the basal part and the fore part was found. Drawing a line on the main vein in the top three leaves, the left part was thinner than the right part. The thickness of the lower leaves （6/0-9/0） on the main culm tended to increase with increasing positions of the leaves in the early and middle stages, but the tendency was not the same for the higher leaves （10/0 upwards）, although the higher leaves （10/0 upward） were thicker than the lower leaves （9/0 or downward）. Furthermore, different CO2 concentrations （550±30, 460 ± 30 μmol mol^-1） in the growth boxes had no effect on the thickness of rice leaf blades. It can be concluded that the measurement of rice leaf thickness using the nondestructive rice leaf thickness instrument is simple, precise, and nondestructive.

关键词： paddy rice leaf thickness nondestructive rice leaf thickness instrument

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Progress of welding technology in aviation industry

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China Welding 1994年第2期3卷 97-104页

作者： guan qiao and SHAO Yichen(Beijing Aeronautical Manufacturing Technology Research Institute (100024 ))

Welding in aviation industry has become one of the dominate processing technologies for manufacturing flying *** percentage of welded structures in designs of new flying apparatus has been continuously growing *** technology provides a freedom and guarantee to new structure design and new material application. Technical and economic benefits have been obtaining in application of newly developed welding technologies and achievements in research, such as, SPF/DB,electron beam welding, breezing,low stress nondistortion welding etc.

关键词： Progress of welding technology in aviation industry

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Thermal Tensioning Effects to Prevent Welding Buckling Distortions in Manufacturing of Thin-Walled Aerospace Shells and Panels

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工程科学（英文版） 2006年第3期4卷 1-10页

作者： guan qiao Beijing Aeronautical Manufacturing Technology Research Institute P. O. Box 863 Beijing 100024

To prevent buckling distortions of thin-walled elements, Low Stress No Distortion welding techniques have been pioneered and developed for product engineering and component manufacturing of aerospace structures with material thickness less than 4 mm. In this paper, the nature of Low Stress No Distortion (LSND) welding techniques using thermal tensioning effects is described and special emphases are given to the mechanism of localized thermal tensioning effect. The fundamental principle of Low Stress No Distortion welding is to create active in-process control of incompatible (inherent) plastic strains and stresses formation during welding to achieve distortion-free results implying that no post weld costly reworking operations for distortion correction is required. Finite element analysis is applied to predict and optimize the localized thermal tensioning technique with a trailing spot heat sink coupled to the welding heat source. Comparisons of the thermal elastic-plastic stress-strain cycles are given between conventional gas tungsten arc welding and GTAW with a trailing spot heat sink.

关键词：焊接残余应力热源冷源弯曲变形加热张拉薄壁航空材料

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Effect of heating time on bonding interface, atom diffusion and mechanical properties of dissimilar titanium joints produced by thermal self-compressing bonding

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Transactions of Nonferrous Metals Society of China 2018年第4期28卷 662-668页

作者： Yun-hua DENG qiao guan Jun TAO Aeronautical Key Laboratory for Welding and Joining Technologies AVIC Beijing Aeronautical Manufacturing Technology Research InstituteBeijing 100024China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China

Solid-state bonding between pure titanium and Ti6Al4V(TC4)alloy was conducted by a new bonding method named as rigid restraint thermal self-compressing *** of heating time on bonding interface,atom diffusion and mechanical properties of the joints were *** show that atom diffusion between pure titanium and TC4 alloy significantly takes place during *** diffusion depths of Al and V in pure titanium side are increased with increasing heating *** to the enhancement of atom diffusion,bond quality of the bonding interface is improved along with the increase of heating *** heating time seems to have little effect on microhardness distribution across the ***,the tensile strength and ductility of the joint have close relation to heating *** heating time can improve the tensile strength and ductility of the joint,especially the *** the heating time increases to 450 s,solid-state joint with good combination of strength and ductility is attained.

关键词： dissimilar titanium alloys joining rigid restraint thermal self-compressing bonding atom diffusion,mechanical properties

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Validated preoperative computed tomography risk estimation for postoperative hepatocellular carcinoma recurrence

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World Journal of Gastroenterology 2017年第35期23卷 6467-6473页

作者： Wei Zhang Shao-Lv Lai Jie Chen Dong Xie Fei-Xiang Wu guan-qiao Jin Dan-Ke Su Departments of Radiology Affiliated Tumor Hospital of Guangxi Medical University Hepatobiliary Surgery Affiliated Tumor Hospital of Guangxi Medical University

AIM To develop and validate a risk estimation of tumor recurrence following curative resection of operable hepatocellular carcinoma(HCC).METHODS Data for 128 patients with operable HCC(according to Barcelona Clinic Liver Cancer imaging criteria) who underwent preoperative computed tomography(CT) evaluation at our hospital from May 1, 2013 through May 30, 2014 were included in this study. Follow-up data were obtained from hospital medical records. Follow-up data through May 30, 2016 were used to retrospectively analyze preoperative multiphasic CT findings, surgical histopathology results, and serum α-fetoprotein and thymidine kinase-1 levels. The χ~2 test, independent t-test, and Mann-Whitney U test were used to analyze data. A P-value of < 0.05 was considered statistically *** During the follow-up period, 38 of 128 patients(29.7%) had a postoperative HCC recurrence. Microvascular invasion(MVI) was associated with HCC recurrence(χ~2 = 13.253, P < 0.001). Despite postoperative antiviral therapy and chemotherapy, 22 of 44 patients with MVI experienced recurrence after surgical resection. The presence of MVI was 57.9% sensitive, 75.6% specific and 70.3% accurate in predicting postoperative recurrence. Of 84 tumors without MVI, univariate analysis confirmed that tumor margins, tumor margin grade, and tumor capsule detection on multiphasic CT were associated with HCC recurrence(P < 0.05). Univariate analyses showed no difference between groups with respect to hepatic capsular invasion, Ki-67 proliferation marker value, Edmondson-Steiner grade, largest tumor diameter, necrosis, arterial phase enhanced ratio, portovenous phase enhanced ratio, peritumoral enhancement, or serum α-fetoprotein *** Non-smooth tumor margins, incomplete tumor capsules and missing tumor capsules correlated with postoperative HCC recurrence. HCC recurrence following curative resection may be predicted using CT.

关键词： Hepatocellular carcinoma Microvascular invasion Computed tomography Recurrence Tumor margin Tumor capsule

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