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Optimization of Fixture Number in Large Thin-Walled Parts Assembly Based on IPSO

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 213-227页

作者： Changhui liu Jing Wang Ying zheng Ke Jin Jianbo Yu Jianfeng liu School of Mechanical Engineering Tongji UniversityShanghai 201804China Shanghai Jiaotong University Shanghai 200240China Shanghai Waigaoqiao Shipbuilding Co. Ltd.Shanghai 200137China

There are lots of researches on fixture layout optimization for large thin-walled *** researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of ***,how to determine the number of fixtures is *** most cases,the number of fixtures located on large thin-walled parts is determined based on engineering experience,which leads to huge fixture number and extra ***,this paper constructs an optimization model to minimize the number of *** constraints are set in the optimization model to ensure that the part deformation is within the surface profile *** addition,the assembly gap between two parts is also *** conduct the optimization,this paper develops an improved particle swarm optimization(IPSO)algorithm by integrating the shrinkage factor and adaptive inertia *** the algorithm,particles are encoded according to the fixture *** dimension of the particle is assigned to a sub-region by constraining the optional position range of each fixture to improve the optimization ***,a case study on ship curved panel assembly is provided to prove that our method can optimize the number of fixtures while meeting the assembly quality *** research proposes a method to optimize the number of fixtures,which can reduce the number of fixtures and achieve deformation control at the same time.

关键词： Assembly quality Large thin-walled parts Fixture layout PSO FEM

Hydration Behavior and Cementitious Properties of Calcium Carbonate-aluminate Minerals Composite

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 126-133页

作者：王冲周帅 ZOU Luyao liu Jiawen zheng Yalin College of Materials Science and Engineering Chongqing UniversityChongqing 400045China China West Construction Group Co. Ltd.Chengdu 610015China

The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The composite system of calcium carbonate and aluminate minerals is studied by measuring the component of hydration products, the hydration heat, setting time and compressive *** results prove that the composite system has certain cementitious properties and is feasible to prepare new low-carbon cement.

关键词： limestone hydrated calcium carboaluminate cementitious properties mechanical properties

Performance Enhancement of Parabolic Trough Collector by Using Homogenizer and Spiral

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Journal of Thermal Science 2024年第2期33卷 658-674页

作者： LI Peijing liu Taixiu QIN Yuanlong zheng Zhimei Zhao Kai liu Qibin School of Energy Powerand Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Science Beijing100049China Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei230027China Research Institute of Science and Technology of China Three Gorges Group Corporation Beijing100038China

In conventional parabolic trough collectors(PTCs),sunlight is concentrated at the bottom of the absorber tube,resulting in a significant circumferential temperature gradient across the absorber tube,heat loss and thermal deformation,which affects the safety and thermal performance of *** this study,a new receiver with homogenizer and spiral(RHS) is proposed,achieving the optical and thermal synergy to ameliorate the thermal deformation of the absorber tube and enhance thermal efficiency.A plane structure homogenizer is designed to improve uniformity of the concentrated solar flux of absorber tube through second *** combination with the spiral,it improves the optical-thermal efficiency of the PTC by enhancing heat exchange between the fluid and the backlight side of the absorber *** performance of the collector is numerically studied by building a three-dimensional coupled light-thermal-structure *** results show that the thermal deformation of the RHS is reduced by more than 96% and the optical-thermal efficiency is improved by 1.2%-0.63% compared with conventional receivers(CRs) under the same inlet temperature *** proposed receiver is validated to be effective in reducing thermal deformation and improving optical-thermal efficiency.

关键词： parabolic trough collector homogenizer thermal deformation spiral

Effect of Guanxin Danshen Dripping Pills on Coronary Heart Disease Comorbid with Depression or Anxiety: The ADECODE-Real World Study

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Chinese Journal of Integrative Medicine 2024年第5期30卷 443-448页

作者： WU Shi-hao SHI Wei-qi LI Yu-hang liu Ru-hui HU Da-yi zheng Li-qiang MA Wen-lin Department of Geriatric Medicine Tongji HospitalSchool of MedicineTongji UniversityShanghai 200065China Department of Cardiology Tongji HospitalSchool of MedicineTongji UniversityShanghai 200065China Department of Cardiology Peking University People's HospitalBeijing 100044China School of Public Health Shanghai Jiao Tong UniversityShanghai 200030China

Objective: To evaluate the efficacy of Guanxin Danshen Dripping Pill(GXDSDP) in treating anxiety and depression in patients with coronary heart disease(CHD). Methods: A total of 1,428 patients diagnosed with CHD screened for anxiety, depression, and quality of life(QOL) at baseline received 0.4 g of GXDSDP treatment 3 times per day and returned for monthly reassessment. Patients were recruited after stable treatment for CHD and received assessment of General Anxiety Disorder-7(GAD-7), Patient Health Questionnaire-9(PHQ-9), and Seattle Angina Questionnaire(SAQ) for evaluating anxiety, depression, and *** were followed up 3 times, once every 4 weeks, during outpatient visits for 12 weeks. Results: At the third follow-up(F3), the anxiety symptom of 63.79%(673/1,055) of the patients improved to sub-clinical level, and the GAD-7 score improved significantly(8.11 vs. 3.87, P<0.01);57.52%(585/1,017) patients' depressive symptoms improved to sub-clinical level, with a significant improvement in PHQ-9 score(8.69 vs. 4.41, P<0.01) at F3. All aspects of QOL significantly improved at the end of treatment compared to those at baseline(all P<0.01) as assessed by SAQ: physical limitation(31.17 vs. 34.14), anginal stability(2.74 vs. 4.14), anginal frequency(8.16vs. 9.10), treatment satisfaction(13.43 vs. 16.29), and disease perception(8.69 vs. 11.02). Conclusions: A fixed dosage of GXDSDP may be a potential treatment option for CHD patients comorbid with anxiety or depression.(Registration No. ChiCTR2100051523)

关键词： Guanxin Danshen Dripping Pill coronary heart disease depression anxiety quality of life Chinese medicine

Scenario Modeling-Aided AP Placement Optimization Method for Indoor Localization and Network Access

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China Communications 2024年第3期21卷 37-50页

作者： Pan hao Chen Yu Qi Xiaogang liu Meili School of Mathematics and Statistics Xidian UniversityXi’an 710126China Science and Technology on Near-Surface Detection Laboratory Wuxi 214035China School of Software Nanchang Hangkong UniversityNanchang 330063China

Owing to the ubiquity of wireless networks and the popularity of WiFi infrastructures,received signal strength(RSS)-based indoor localization systems have received much *** placement of access points(APs)significantly influences localization accuracy and network ***,the indoor scenario and network access are not fully considered in previous AP placement optimization *** study proposes a practical scenario modelingaided AP placement optimization method for improving localization accuracy and network *** order to reduce the gap between simulation-based and field measurement-based AP placement optimization methods,we introduce an indoor scenario modeling and Gaussian process-based RSS prediction *** that,the localization and network access metrics are implemented in the multiple objective particle swarm optimization(MOPSO)solution,Pareto front criterion and virtual repulsion force are applied to determine the optimal AP ***,field experiments demonstrate the effectiveness of the proposed indoor scenario modeling method and RSS prediction model.A thorough comparison confirms the localization and network access improvement attributed to the proposed anchor placement method.

关键词： indoor localization MOPSO network access RSS prediction

Rational design multi-color-emissive chemiluminescent carbon nanodots in a single solvothermal reaction

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Nano Research 2024年第6期17卷 4651-4660页

作者： Guang-Song zheng Cheng-Long Shen Yuan Deng Kai-Kai liu Jin-hao Zang Lin Dong Qing Lou Chong-Xin Shan Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Materials PhysicsMinistry of Educationand School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China

Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission ***,the difficulty of synthesizing chemiluminescent CDs with full-spectrum emission severely hinders the further regulation of the CL emission ***,the multi-color-emissive chemiluminescent CDs are rational designed and further synthesized by regulating the sp2-hybrid core and sp3-hybrid surface from the citrate-ammonia molecular in a single solvothermal *** experimental characterizations and density functional theory calculations reveal that the higher temperature can promote the crosslinking polymerization/carbonization of carbon core and the higher protonation of solvent can determine the core size of final CDs,resulting in the variant CL emission from molecular-,crosslinking-and ***,the CL emission of the CDs can be further synthesized by tuning the luminescence chromophores in the formation process via regulating the temperature and solvent,enabling the applications of the CL CDs in illumination and information *** study paves a new technology to understand the luminescence of CDs and affords an industry translational potential over traditional chemiluminescent molecular.

关键词： carbon nanodots chemiluminescence regulation energy level alignment mechanism

Preparing cyclic polymers at high concentrations via self-folding cyclization technique by adjusting the contents of hydrophilic units in linear precursors

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Chinese Chemical Letters 2024年第2期35卷 283-288页

作者： hao Zha Zuowei Wang Chao liu Chunyan Hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Cyclic polymers are a class of polymers that feature endless topology,and the synthesis of cyclic polymers has attracted the attention of many ***,cyclic polymers were efficiently constructed by self-folding cyclization technique at high *** poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate))(P(OEGA-co-DDA))precursors with different ratios of hydrophilic and hydrophobic moieties were synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization using a bifunctional chain transfer agent with two anthryl end *** amphiphilic linear precursors underwent the self-folding process to generate polymeric nanoparticles in *** irradiating the aqueous solution of the nanoparticles with 365 nm UV light,cyclic polymers were synthesized successfully via coupling of anthryl *** effects of the ratios of hydrophilic and hydrophobic moieties in linear P(OEGA-co-DDA)copolymers and polymer concentration on the purity of the obtained cyclic polymers were explored in detail via ^(1)H nuclear magnetic resonance(^(1)H NMR),dynamic light scattering(DLS),UV‒visible(vis)analysis,three-detection size exclusion chromatography(TD-SEC)and transmission electron microscopy(TEM).It was found that by adjusting the content of the hydrophilic segments in linear precursors,single chain polymeric nanoparticles(SCPNs)can be generated at high polymer ***,cyclic polymers with high purity can be constructed *** method overcomes the limitation of traditional ring-closure method,which is typically conducted in highly dilute conditions,providing an efficient method for the scalable preparation of cyclic polymers.

关键词： Cyclic polymers Self-folding cyclization technique Single chain polymeric nanoparticles RAFT polymerization Direct visualization

Effects of orientation on the fatigue crack growth behaviors of the ZK60 magnesium alloy in air and PBS

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Journal of Magnesium and Alloys 2024年第1期12卷 281-294页

作者： Jiaqi Hu zheng liu Zuoliang Ning Hong Gao School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology Tianjin 300072China

Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium *** investigate the influences of specimen orientation,the corrosion tests and(corrosion)fatigue crack growth tests were *** rolled and transverse surfaces of the materials show distinct corrosion rate differences in the stable corrosion stage,but the truth is the opposite for the initial stage of *** air,specimen orientations have a significant influence on the plastic deformation mechanisms near the crack tip,which results in different fatigue fracture surfaces and cracking *** with R-T specimens,N-T specimens show a slower fatigue crack growth(FCG)rate in air,which can be attributed to crack closure effects and deformation twinning near the crack *** corrosion environment will not significantly change the main plastic deformation mechanisms for the same type of ***,the FCG rate in phosphate buffer saline(PBS)is one order of magnitude higher than that in air,which is caused by the combined effects of hydrogen-induced cracking and anodic *** to the similar corrosion rates at crack tips,the specimens with different orientations display close FCG rates in PBS.

关键词： Magnesium alloy Orientation Corrosion Fatigue crack growth

Strategic regulation of nitrogen-containing intermediates for enhanced nitrate reduction over Co_(3)O_(4)/SiC catalyst having multiple active centers

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Journal of Energy Chemistry 2024年第9期96卷 291-299页

作者： Ming-hao Guan hao-Nan Xu Jin liu Tao Wu An-Hui Lu State Key Laboratory of Fine Chemicals Liaoning Key Laboratory for Catalytic Conversion of Carbon ResourcesSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina

Regulating the intermediates involved in the electrocatalytic nitrate reduction reaction(NO_(3)RR)is crucial for the enhancement of reaction ***,it remains a great challenge to regulate the reaction intermediates through active site manipulation on the surface of the ***,a family of n%-Co_(3)O_(4)/SiC(n=5,8,12,20)catalysts with a delicate percentage of Co^(2+)and Co^(3+)were prepared for NO_(3)*** found that Co^(3+)primarily acts as the active site for NO_(3)^(−)reduction to NO_(2)^(−),while Co^(2+)is responsible for the conversion of NO_(2)^(−)to NH_(3).Moreover,the conversion of these intermediates over the active sites is autonomous and separately *** processes synergistically accomplish the reduction of nitrate ions to synthesize *** the experimental studies and density functional theory(DFT)calculations,it is discovered the pathway(^(*)NHO→^(*)NHOH→^(*)NH_(2)OH→^(*)NH_(2)→^(*)NH_(3))is more favorable due to the lowerΔG value(0.25 eV)for the rate-limiting step(^(*)NO→^(*)NHO).The NH_(3)yield rate of 8%-Co_(3)O_(4)/SiC reached 1.08 mmol/(cm^(2)h)with a Faradaic efficiency of 96.4%at−0.89 V versus the reversible hydrogen electrode(RHE),surpassing those of most reported non-noble NO_(3)RR *** strategy not only provides an efficient catalyst for NO_(3)RR but also serves as an illustrative model for the regulation of multi-step reaction intermediates through the design of distinct active sites,thereby presenting a new approach to enhance the efficiency of intricate reactions.

关键词： Electrocatalysis Nitratereduction Co_(3)O_(4)/SiC catalysts Intermediates control