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Effect of short-time low-temperature austenitizing on microstructure and mechanical properties of DT300 ultra-high strength steel fabricated by laser powder bed fusion

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Journal of Iron and Steel Research International 2024年第7期31卷 1763-1777页

作者： Chen-yang Jiang Xiao-qiang Li Jin-tao wang Hao Luo sheng-qing Gao sheng-guan Qu Chao Yang National Engineering Research Centre of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640GuangdongChina Institute of New Materials Guangdong Academy of ScienceGuangzhou 510650GuangdongChina

To address the inhomogeneous microstructure and improve the mechanical properties of DT300 ultra-high strength steel specimens fabricated by laser powder bed fusion,different post-heat treatment schedules are *** the increase in austenitizing temperature and time,the migration rate of austenite grain boundaries continuously increases with the dissolution of nano-carbides,and the formation of nano-oxides and twin martensite is also inhibited *** rapid growth in the size of prior austenite grains and martensite laths,as well as the decrease in the content of nano-oxides and twin martensite,led to a rapid decrease in the strength(yield strength and ultimate tensile strength)from HT2 to HTF *** HT1 specimens(austenitizing at 830℃for 30 min,then oil quenching and tempering at 300℃for 120 min and finally air cooling)display excellent mechanical properties of yield strength of 1572 MPa,ultimate tensile strength of 1847 MPa,elongation of 9.84%,and fracture toughness of 106 MPa m^(1/2),which are counterparts to those of conventional DT300 steel forgings after heat treatment.

关键词： DT300 ultra-high strength steel Laser powder bed fusion-Short-time low-temperature austenitizing Microstructure Mechanical property

Characteristics of Traditional Chinese Medicine Syndrome in Patients with Coronary Heart Disease at Different Disease Stages

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World Journal of Traditional Chinese Medicine 2022年第2期8卷 218-224页

作者： Yu-Mo Xia Hui Gao qing-sheng wang Xiao Feng Yi-Qin wang Zhao-Xia Xu Shanghai Key Laboratory of Health Identification and Assessment Basic Medical CollegeShanghai University of Traditional Chinese MedicineShanghaiChina

Coronary atherosclerotic heart disease(CHD)has a high incidence,disability rate,and mortality rate,which severely affect people’s health,work,and *** on its clinical manifestations,traditional Chinese medicine(TCM)has classified CHD as“chest impediment”and“heart pain”for the *** course of CHD is protracted,and the pathogenesis is complex and ***,different disease stages have different syndrome ***,this article aimed to summarize the classification and distribution characteristics of the TCM syndrome in various stages of CHD,such as before and after percutaneous coronary intervention therapy,disease progression,age,and complications,to provide references for the TCM clinical diagnosis and treatment of CHD.

关键词： Coronary heart disease different disease stages review traditional Chinese medicine syndromes

P-and SV-wave dispersion and attenuation in saturated microcracked porous rock with aligned penny-shaped fractures

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Petroleum Science 2024年第1期21卷 143-161页

作者： sheng-qing Li Wen-Hao wang Yuan-Da Su Jun-Xin Guo Xiao-Ming Tang School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Laoshan National Laboratory Qingdao 266071ShangdongChina Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology Southern University of Science and TechnologyShenzhen 518055GuangdongChina Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055GuangdongChina

P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned ***,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic ***,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the *** Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and *** then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy *** results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave *** coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV *** oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV *** a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.

关键词： Aligned fractures P-and SV-wave Dispersion and attenuation Microcracked porous background FB-WIFF Elastic scattering Squirt flow

Lessons from transulnar access for repeat percutaneous coronary intervention after radial artery occlusion

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Chinese Medical Journal 2020年第12期133卷 1497-1498页

作者： Xi-Le Bi qing-sheng wang Department of Cardiology The First Hospital of QinhuangdaoQinhuangdaoHebei 066000China

To the Editor:An 80-year-old man presented to the Cardiology Department with substernal pain of 20 minutes duration on August 13,*** reviewed the patient’s case history record,which included two transradial access interventions using 6F sheaths(11-cmlong,Cordis Corporation,FL,USA).On February 13,2009,the patient had presented with an acute inferior wall myocardial infarction and underwent percutaneous coronary intervention(PCI)via the right radial *** February 19,2009,the patient underwent a second intervention,also via right radial artery access,for an elective anterior descending branch *** patient ceased smoking after the first *** this admission,before the third intervention,the patient had a weak radial pulse,but his right hand was asymptomatic.

关键词： coronary acute radial

Improving mathematical model of burden distribution and correcting chute angle to cope with fluctuation of stock line

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Journal of Iron and Steel Research International 2024年第2期31卷 342-356页

作者： Jian-sheng Chen Wen-guo Liu Hao Guo wang Ding qing-guo Xue Jing-song wang Hai-bin Zuo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China MCC Capital Engineering&Research Incorporation Limited Beijing100176China Hunan Valin Xiangtan Iron and Steel Co. Ltd.Xiangtan411101HunanChina

Accurate evaluations of the burden distribution are of critical importance to stabilize the operation of blast *** mathematical model and discrete element method(DEM)are two attractive methods for predicting burden *** on DEM,the initial velocities of the pellet,sinter,and coke were calculated,and the velocity attenuations of the above three particles between the burden and the chute were *** initial velocity and velocity attenuation were applied to a mathematical model for improving the ***,based on the improved model,a scheme for rectifying the chute angles was proposed to address the fluctuation of the stock line and maintain a stable burden *** validity of the scheme was confirmed via a stable burden distribution under different stock *** mathematical model has been successfully applied to evaluate the online burden distribution and cope with the fluctuation of the stock line.

关键词： Burden distribution Mathematical model Discrete element method Velocity attenuation Stock line fluctuation

CD8＋ Tc-lymphocytes immunodeviation in peripheral blood and airway from patients of chronic obstructive pulmonary disease and changes after short-term smoking cessation

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Chinese Medical Journal 2013年第19期 3608-3615页

作者： YU Mu-qing LIU Xian-sheng wang Jian-miao XU Yong-jian Department of Respiratory and Critical Care Medicine TongjiHospital of Yongji Medical College Huazhong University of Scienceand Technology Wuhan Hubei 430030 China

Background Cigarette smoke induces an acute but persisting inflammation in peripheral blood and airway in chronic obstructive pulmonary disease （COPD）,and CD8＋ Tc-lymphocytes are considered as a key role in this *** aimed to investigate the Tc-lymphocytes immunodeviation in system and local airway of COPD patients and changes of the immunodeviation after short-term smoking *** Peripheral blood （PB） and bronchoalveolar lavage fluid （BALF） were collected from 42 patients （14 COPD patients,16 smokers with normal lung function and 12 nonsmokers）,while PB and induced sputum （IS） were obtained from other 19 patients （10 quitting smokers and 9 continuing smokers） at baseline and follow-up respectively of 4-week smoking *** of CD8＋ Tc-lymphocytes （%CD3＋） and Tc1/Tc2 ratios were measured by flow *** Percentages of CD8＋ Tc-lymphocytes were higher in COPD patients than those in smokers and nonsmokers in both PB and ***1/Tc2 ratio in PB and in BALF from COPD patients was greater than that from smokers and nonsmokers and negatively correlated with FEV1%*** comparing the ratios between PB and BALF,significantly positive correlation was found in COPD ***,after 4-week smoking cessation,percentages of CD8＋ Tc-lymphocytes in PB and IS in quitting smokers were decreased compared to that in baseline and continuing smokers,whereas Tc1/Tc2 ratios were not *** CD8＋ Tc1-trend immunodeviation profiles occurred in both system and local airway of COPD *** exceptional immunodeviation could not be relieved by short-term smoking cessation.

关键词： pulmonary disease, chronic obstructive smoke CD8-positive T-lymphocytes smoking cessation

Design parameter optimization method for a prestressed steel structure driven by multi-factor coupling

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1066-1083页

作者： Guo-Liang SHI Zhan-sheng LIU De-Chun LU qing-Wen ZHANG Majid DEZHKAM Ze-Qiang wang Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China The Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education Beijing University of TechnologyBeijing 100124China Beijing Building Construction Research Institute Co. Ltd.Beijing 100039China

To achieve efficient structural design,it is crucial to reduce the cost of materials while ensuring structural *** study proposes an optimization method for design parameters(DPs)in a prestressed steel structure driven by multi-factor *** accomplish this,a numerical proxy model of prestressed steel structures is established with integration of DPs and mechanical parameters(MPs).A data association-parameter analysis-optimization selection system is established.A correlation between DPs and MPs is established using a back propagation(BP)neural *** correlation provides samples for parameter analysis and optimization *** are used to characterize the safety of the *** on the safety grade analysis,the key DPs that affect the mechanical properties of the structure are obtained.A mapping function is created to match the MPs and the key *** optimal structural DPs are obtained by setting structural materials as the optimization objective and safety energy as the constraint *** theoretical model is applied to an 80-m-span gymnasium and verified with a scale test physical *** MPs obtained using the proposed method are in good agreement with the experimental *** with the traditional design method,the design cycle can be shortened by more than 90%.Driven by the optimal selection method,a saving of more than 20% can be achieved through reduction of structural material ***,the cross-sectional dimensions of radial cables have a substantial influence on vertical *** initial tension and cross-sectional size of the upper radial cable exhibit the most pronounced impact on the stress distribution in that *** initial tension and cross-sectional size of the lower radial cable hold the greatest sway over the stress distribution in that cable.

关键词： structure design association relationship performance analysis optimum selection experimental verification

Early changes in corneal densitometry after FS-LASIK combined with accelerated corneal cross-linking for correction of high myopia

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1307-1312页

作者： qing-Bao wang Hong-sheng Bi Xiao-Fan wang Hua Fan Li Li Peng Ji Shandong University of Traditional Chinese Medicine Jinan 250014Shandong ProvinceChina Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine Shandong Clinical Medicine Research CenterJinan 250002Shandong ProvinceChina Shandong Academy of Eye Disease Prevention and Therapy Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular DiseasesJinan 250002Shandong ProvinceChina

AIM:To observe the effects of femtosecond laserassisted excimer laser in situ keratomileusis combined with accelerated corneal cross-linking(FS-LASIK Xtra)on corneal densitometry after correcting for high ***:In this prospectively study,130 patients underwent FS-LASIK or FS-LASIK Xtra for high *** right eyes were selected for inclusion in the study,of which 65 cases of 65 eyes in the FS-LASIK group,65 patients with 65 eyes in the FS-LASIK Xtra *** were evaluated for corneal densitometry at 1,3,and 6mo postoperatively using Pentacam Scheimpflug ***:Preoperative differences in corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups in different ranges were not statistically significant(P>0.05).Layer-by-layer analysis revealed statistically significant differences in the anterior(120μm),central,and total layer corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups at 1 and 3mo postoperatively(all P0.05).CONCLUSION:There is an increase in internal corneal densitometry during the early postoperative period after FS-LASIK Xtra for correction of high ***,the densitometry values decreased to the level of conventional FS-LASIK at 6mo after surgery,with the most significant changes observed in the superficial central zone.

关键词： femtosecond laser accelerated corneal cross-linking corneal densitometry high myopia femtosecond laser in situ keratomileusis

Day-ahead P2P Energy Sharing Strategy Among Energy Hubs Considering Flexibility of Energy Storage and Loads

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1105-1118页

作者： Penghua Li Wanxing sheng qing Duan Jun Liang Cunhao Zhu China Electric Power Research Institute Beijing 100192China School of Engineering Cardiff UniversityUK IEEE

Multi-energy systems are one of the key technologies to tackle energy crisis and environmental *** energy hub(EH)is a minimum multi-energy *** of multiple EHs through energy routers(ERs)can realize mutual energy *** paper proposes a peer-to-peer(P2P)energy sharing strategy between EHs including ERs in an interconnected system,which is divided into two *** the lower level,a method of determining the charging/discharging constraints of energy storage devices is *** on the Lyapunov optimization method,virtual queues are used to model the energy storage devices and flexible loads in the *** objective is to minimize the overall operating cost of the interconnected *** the upper level,a non-cooperative game model is introduced to minimize the cost of purchasing power from other EHs for each EH.A best response-based method is adapted to find the Nash *** simulation outcomes demonstrate that application of the proposed strategy can reduce operating costs of an interconnected system and each *** basis of a real-world dataset of interconnected EHs,both analytical and numerical results show the effectiveness of the proposed strategy.

关键词： Energy hub energy router Lyapunov optimization non-cooperative game peer to peer virtual queue