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Jetting of a near-wall cavitation bubble induced by another tandem bubble

Journal of Hydrodynamics 2024年第3期36卷 444-456页

作者： Hui Han Jing-zhu Wang Jian-lin Huang peng-bo bai Yong-gang Chen Yi-wei Wang Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Guangdong Aerospace Research Academy Guangzhou511458China School of Future Technology University of Chinese Academy of SciencesBeijing100049China Jianghuai Advance Technology Center Hefei230088China

Double bubbles near a rigid wall surface collapse to produce a significant jet impact,with potential applications in surface cleaning and ultrasonic ***,the dynamic behaviors of near-wall bubbles remain *** this study,we investigate the jetting of a near-wall bubble induced by another tandem *** define two dimensionless standoff distances,γ_(1),γ_(2),to represent the distances from the center of the near-wall bubble to the rigid wall and the center of controlling bubble to the center of the near-wall bubble,*** observations reveal three distinct jetting regimes for the near-wall bubble:transferred jetting,double jetting,and directed *** further investigate the jetting mechanism,numerical simulations are conducted using the compressibleInterFoam solver in the open-source framework of OpenFOAM.A detailed analysis shows that the transferred jet flow is caused by the pinch-off resulting from the axial contraction velocity at the lower end of the near-wall bubble being greater than the vertical contraction velocity,leading to a maximum jet velocity of 682.58 m/*** the case of double jetting,intense stretching between the controlling bubble and the wall leads to a pinch-off and a double jetting with a maximum velocity of 1096.29 m/*** directed jet flow is caused by the downward movement of the high-pressure region generated by the premature collapse of the controlling bubble,with the maximum jet velocity reaching 444.62 m/s.

关键词： Jetting of near-wall bubble controlling bubble impact velocity

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Palladium-catalyzed relay C–H functionalization to construct novel hybrid-arylcyclophosphorus ligand precursors

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Chinese Chemical Letters 2022年第5期33卷 2397-2401页

作者： Juan Wang peng-bo bai Shang-Dong Yang State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

A new relay C–H functionalization of di([1,1'-biphenyl]-2-yl)phosphine oxide to obtain esterified and hy-droxylated products with different hypervalent iodines as oxidants under palladium catalysis is *** reaction provides a more effective and concise strategy for the synthesis of novel structural hybrid-arylcyclophosphorus ligand precursors with a wide range of substrates and good functional group toler-ance.

关键词： Palladium catalyst Cyclization Acetylation Hydroxylation Dibenzophosphorus oxide

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Phosphine oxide directing-group-enabled atroposelective C-H bond acyloxylation via an eight-membered palladacycle intermediate

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Chinese Chemical Letters 2023年第5期34卷 277-280页

作者： peng-bo bai Ming-Ying Wu Xin-Xin Yang Gang-Wei Wang Shang-Dong Yang State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Herein,we report the first atroposelective C(sp^(2))-H bond acyloxylation enabled by a phosphine oxide directing ***,this transformation is shown to proceed through an eight-membered palladacycle intermediate,as opposed to the kinetically and thermodynamically favored five-membered palladacycle ***,L-pGlu-OH,a cheap and abundant chiral amino acid derivative,was identified as the best chiral ligand to promote this atroposelective remote C-H functionalization reaction.

关键词： Palladiumcatalyst Axially chiral Acetylation Dibenzophosphorus oxide

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Solvent-controlled regioselective arylation of indoles and mechanistic explorations

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Organic Chemistry Frontiers 2022年第4期9卷 1023-1032页

作者： Yuan Niu Chao-Xian Yan Xin-Xin Yang peng-bo bai Pan-Pan Zhou Shang-Dong Yang State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

The ability to manipulate the site selectivity in C–H bond functionalization reactions is an important goal in modern ***,we report a new reaction strategy for the regioselective arylation of indoles at C2 or C3 posi... 详细信息

关键词： chemistry group indole

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Exploring the Interplay between Local Chain Structure and Stress Distribution in Polymer Networks

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Chinese Journal of Polymer Science 2024年第6期42卷 874-885页

作者： Jin-Tong Xue Yang bai Li peng Xian-bo Huang Zhao-Yan Sun School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China National-certified Enterprise Technology Center Kingfa Science and Technology Co.Ltd.Guangzhou510663China

The mechanical behavior of polymer networks is intrinsically correlated with the local chain topology and chain *** this study,we delve into this relationship through the lens of coarse-grained molecular dynamics(CG-MD)*** aim is to illuminate the intricate interplay between local topology and stress distribution within polymer monomers,cross-linkers,and various components with distinct cross-link connections,thereby elucidating their collective impact on the mechanical properties of polymer *** mainly focus on how specific local structures contribute to the overall mechanical response of the *** particular,we employ local stress analysis to unravel the mechanics of these *** findings reveal the diverse responses of individual components,such as junctions,strands,cross-linkers between junctions,and dangling chain ends,when subjected to ***,we observe that these components exhibit varying degrees of deformation tolerance,underscoring the significance of their roles in determining the mechanical characteristics of the *** investigations highlight junctions as primary contributors to stress accumulation,and particles with higher local stress showing a stronger correlation between stress and Voronoi ***,our results indicate that both strands and cross-linkers between junctions exhibit heightened stress levels as strand lengths *** study enhances our understanding of the multifaceted factors governing the mechanical attributes of cross-linked polymer systems at the microstructural level.

关键词： Local chain structure Local stress Molecular dynamics simulation

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Response of runoff and its components to climate change in the Manas River of the Tian Shan Mountains

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Advances in Climate Change Research 2024年第1期15卷 62-74页

作者： Ze-Long YANG peng bai Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 10010lChina University of Chinese Academy of Sciences Beijing 100049China

A warming-wetting climate trend has led to increased runoff in most watersheds in the Tian Shan Mountains over the past few ***,it remains unclear how runoff components,that is,rainfall runoff(Rrain),snowmelt runoff(Rsnow),and glacier meltwater(Rglacier),responded to historical climate change and how they will evolve under future climate change ***,we used a modified Hydrologiska Byrans Vattenbalansavdelning(HBV)model and a detrending method to quantify the impact of precipitation and temperature changes on runoff components in the largest river(Manas River)on the northern slope of the Tian Shan Mountains from 1982 to 2015.A multivariate calibration strategy,including snow cover,glacier area,and runoff was implemented to constrain model parameters associated with runoff *** downscaled outputs of 12 general circulation models(GCMs)from the Sixth Coupled Model Intercomparison Project(CMIP6)were also used to force the modified HBV model to project the response of runoff and its components to future(2016-2100)climate change under three common socio-economic pathways(SSP126,SSP245,and SSP585).The results indicate that Rrain dominates mean annual runoff with a proportion of 42%,followed by Rsnow(37%)and Rglacier(21%).In terms of inter-annual variation,Rrain and Rsnow show increasing trends(0.93(p0.05)mm per year),while Rglacier exhibits an insignificant(p>0.05)decreasing trend(-0.12 mm per year),leading to an increasing trend in total runoff(1.12 mm per year,p>0.05).The attribution analysis indicates that changes in precipitation and temperature contribute 8.16 and 10.37 mm,respectively,to the increase in runoff at the mean annual *** wetting(increased precipitation)increases Rrain(5.03 mm)and Rsnow(3.19 mm)but has a limited effect on Rglacier(-0.06 mm),while warming increases Rrain(10.69 mm)and Rglacier(5.79 mm)but decreases Rsnow(-6.12 mm).The negative effect of glacier shrinkage on Rglacier has outweighed the

关键词： Tian Shan Rainfall runoff Snowmelt runoff Glacier meltwater Warming-wetting Tipping point

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Simple preparation of C(CS)/g-C_(3)N_(4)/Co carbon aerogel and its catalytic performance for ammonium perchlorate

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Defence Technology（防务技术） 2024年第3期33卷 186-196页

作者： Yujie Yan bo Jin Rufang peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

Biomass chitosan(CS)was used as a template,graphitic phase carbon nitride(g-C_(3)N_(4))with high nitrogen content and certain catalytic activity was used as a dopant,and nano-transition metal cobalt(Co)was used as a catalytic center *** carbon aerogel(C(CS)/g-C_(3)N_(4)/Co)with a three-dimensional network-like structure was prepared by assembling the three materials through experimental operations such as freeze-drying and high-temperature *** was demonstrated by scanning and transmission characterization that the CS in the carbon aerogel could provide more active sites for the cobalt nanoparticles,and the doping of graphite-phase carbon nitride as a template dispersed the cobalt nanoparticles and changed the conductivity of the *** investigate the catalytic effect of carbon aerogel on ammonium perchlorate(AP),it was investigated by differential thermal analyzer and TG thermal *** carbon aerogel was very effective in catalyzing AP,and the 10 wt% content of the catalyst reduced the AP pyrolysis peak from 703.9 to 595.5 *** to further investigate the synergistic effect of the three materials,further carbon aerogels such as C(CS)/Co,g-C_(3)N_(4)/Co were prepared and applied to catalyze AP,and the same ratio reduced the AP pyrolysis peak by 98.1℃ and 97.7℃.This result indicates a synergistic effect of the assembly of the three materials.

关键词： g-C_(3)N_(4) Chitosan Co Ammonium perchlorate Pyrolysis kinetics

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Identifying the effective combination of acupuncture and traditional Chinese medicinal herbs for postmenopausal osteoporosis therapy through studies of their molecular regulation of bone homeostasis

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Journal of Traditional Chinese Medicine 2024年第1期44卷 212-219页

作者： REN Ping WANG Quanwu bai Wei SUN Miao LIU Zheling GAO Ming WANG Liang peng bo XU Liguang Department of Health Management the Third Affiliated Clinical Hospital of Changchun University of Chinese MedicineChangchun 130117China Department of Dirty Tuina the affiliated Hospital to Changchun University of Chinese MedicineChangchun 130117China Department of Acupuncture the affiliated Hospital to Changchun University of Chinese MedicineChangchun 130117China Department of Rehabilitation Medicine the 924th Hospital of the PLA Joint Logistic Support ForceFoshan 528226China Department of College of Acupuncture and Massage Changchun University of Chinese MedicineChangchun 130117China

Worldwide,as the population age,osteoporosis is becoming increasingly common,and osteoporotic fractures have a significant economic *** women are the most susceptible to developing osteoporosis and the most critical time to prevent it is during the perimenopausal and early menopausal *** this regard,we hypothesize rational combination of acupuncture and Traditional Chinese Medicine(TCM)in the form of herbal extract could prevent osteoporosis in *** deficiency during menopause causes low-level inflammation that stimulates the formation of osteoclasts,the boneresorbing cells,and simultaneously inhibits the viability and function of osteoblasts,the bone-forming *** most potent inflammatory cytokine in skeletal homeostasis is the receptor activator of nuclear factor kappa B ligand(RANKL)that stimulates osteoclast ***,the canonical Wnt pathway is essential for osteoblastogenesis and bone formation,and estrogen deficiency leads to diminished functioning of this *** and acupuncture could target the RANKL and the Wnt pathway in favorable ways to prevent the accelerated bone loss experienced during the early menopausal stage and promote the gain in bone mass in postmenopausal *** this review,we propose a rational combination of specific TCM and acupuncture targeting those signaling molecules/pathways by the drugs that are in clinical use for the treatment of postmenopausal *** rational approach revealed that Danshen(Radix Salviae Miltiorrhizae)could exert a synergistic effect with *** then propose a translational path for developing the putative combination in women with postmenopausal osteoporosis to curtail the risk of osteoporotic fractures.

关键词： medicine traditional osteogenic anti-resorptive review

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Angiotensin-converting enzyme 2 alleviates liver fibrosis through the renin-angiotensin system

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World Journal of Gastroenterology 2024年第6期30卷 607-609页

作者： bai-Wei Zhao Ying-Jia Chen Ruo-peng Zhang Yong-Ming Chen bo-Wen Huang Department of Gastric Surgery Sun Yat-sen University Cancer CenterState Key Laboratory of Oncology in South ChinaGuangdong Provincial Clinical Research Center for CancerGuangzhou 510060Guangdong ProvinceChina Health Science Center Peking UniversityBeijing 100191China

The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.

关键词： Angiotensin-converting enzyme 2 Hepatic stellate cells Liver fibrosis Angiotensin II Angiotensin 1-7 Renin-angiotensin system

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Machining dynamics and chatters in micro-milling:A critical review on the state-of-the-art and future perspectives

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Chinese Journal of Aeronautics 2024年第7期37卷 59-80页

作者： Qingshun bai peng WANG Kai CHENG Liang ZHAO Yabo ZHANG School of Mechanical and Electrical Engineering Harbin Institute of TechnologyHarbin 150001China Department of Mechanical and Aerospace Engineering Brunel University LondonUxbridge UB83PHUK

Micro-milling technology is widely applied in micro manufacturing,particularly for the fabrication of miniature and micro ***,the chatters and machining dynamics related issues in micro-milling are often the main challenges restricting its machining quality and *** research works have rendered that the machining dynamics and chatters in micro-milling are more complex compared with the conventional macro-milling process,likely because of the size effect and rigidity of the micro-milling system including the tooling,workpiece,process variables,materials involved,and the high-speed milling machines,and further their collective dynamic ***,in this paper,the state of the art focusing on micro-milling chatters and dynamics related issues over the past years are comprehensively and critically reviewed to provide some insights for potential researchers and ***,typical applications and the problems caused by the machining dynamics and chatters in micro-milling have been put forward in this ***,the research on the underlying micro-cutting mechanics and dynamics,stability analysis,chatters detection,and chatter suppression are summarized ***,the underlying scientific and technological challenges are discussed particularly against typical precision engineering ***,the possible future directions and trends in research and development of micro-milling have been discussed.

关键词： Micro-milling Machining dynamics Micro-cutting mechanics Stability lobe diagram(SLD) Chatters suppression Digital twin

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