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周期加卸载条件在ABAQUS中的数值实施方法及验证

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周期加卸载条件在ABAQUS中的数值实施方法及验证

Mantle avalanches in a Venus-like stagnant lid planet

第五届中国水利水电岩土力学与工程学术讨论会

作者：陈勇杨贝贝韦双 dave.chan

水库运行期水位每年周期性涨落,岸坡土体在库水周期加卸载作用下发生不同程度的阶梯状变形。为探求变形的诱发机理、揭示变形的发展规律,本文以参数简单且意义明确的统一硬化模型(UH模型)为基础,建立了该模型的增量关系,并借用ABAQUS软... 详细信息

水库运行期水位每年周期性涨落,岸坡土体在库水周期加卸载作用下发生不同程度的阶梯状变形。为探求变形的诱发机理、揭示变形的发展规律,本文以参数简单且意义明确的统一硬化模型(UH模型)为基础,建立了该模型的增量关系,并借用ABAQUS软件的开发接口,添加该模型的UMAT子程序,从而建立土体在周期加卸载作用下的应力应变演化规律模拟方法。最后,对数值模拟方法和子程序进行了单元测试和试验成果验证,对比分析结论如下:开发的UH模型UMAT子程序是可行的,模拟结果与特殊应力路径下三轴试验中的有效应力变化与应变发展规律等吻合性较好。

关键词：周期加卸载统一硬化模型模型 UMAT子程序应力路径三轴试验

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Earth and Planetary Physics 2024年第5期8卷 686-702页

作者： Madeleine C.Kerr dave R.Stegman Institute of Geophysics and Planetary Physics Scripps Institution of Oceanography University of California

Stagnant lid planets are characterized by a globe-encircling, conducting lid that is thick and strong, which leads to reduced global surface heat flows. Consequently, the mantles of such planets can have warmer interiors than Earth, and interestingly, a pyrolitic mantle composition under warmer conditions is predicted to have a distinctly different mantle transition zone compared to the present-day Earth(Hirose, 2002; Stixrude and Lithgow-Bertelloni, 2011; Ichikawa et al., 2014; Dannberg et al, 2022). Instead of olivine primarily transforming into its higher-pressure polymorphs such as wadsleyite and then ringwoodite, at pressures corresponding to410 km and 520 km depth in Earth, respectively, it instead transforms into a mineral assemblage of wadsleyite, majorite, and ferropericlase(WMF), and then to majorite + ferropericlase(MF), before finally transforming into bridgmanite at pressures corresponding to 660 km depth in Earth(Stixrude and Lithgow-Bertelloni, 2011; Ichikawa et al., 2014). Convective motions in stagnant lid planets are dominated by small-scale instabilities(cold drips) forming within the mobile rheological sublayer under the rigid lid. Using ASPECT and a thermodynamic model of a pyrolitic mantle composition generated by HeFESTo, we show that under certain conditions, the small drips can pond atop the WMF-MF mineral phase transition. The barrier to convective flow arises from the WMF mineral phase assemblage having an effective negative thermal expansivity(Stixrude and Lithgow-Bertelloni, 2022). Although large-scale downwellings that typically occur within mobile lid planets are able to pass through the WMF zone without difficulty(Dannberg et al., 2022; Li RP et al.,2024), the smaller and less negatively buoyant nature of downwelling drips in stagnant lid planets are more susceptible to these effects,which leads to an ephemeral layering of the mantle. Our numerical models show that in stagnant lid planets with mantle potential temperatures that exceed

关键词： Venus mantle avalanches numerical modelling phase transitions

Global collaboration of eye research--personal experience

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 985-990页

作者： Chi-Chao chan Laboratory of Immunology National Eye InstituteNational Institutes of HealthBethesdaMD 20892-1858USA Zhongshan Ophthalmic Center Sun Yat-sen UniversityGuangzhou 5410060Guangdong ProvinceChina

On December 9,2023,I was privileged to be honored and participate in the *** Chao chan Symposium on Global Collaboration of Eye Research as the Global Eye Genetic Consortium(GEGC)session,which was held in the 16th Congress of the Asia-Pacific Vitreo-Retina Society(APVRS)in Hong *** with my talk on“Global collaboration of eye research:personal experience”,other prominent international speakers provided their own perspectives on opportunities for networking,collaboration,and exchange of ideas with global leaders and experts in ophthalmic practice,research,and education.

关键词： speakers collaboration Global

Tetradentate Pt(Ⅱ)complex as a singlet exciton sensitizing host for highly efficient green fluorescent organic light-emitting diodes

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Science China Materials 2024年第8期67卷 2618-2627页

作者： Unhyeok Jo Seung chan Kim chan Hee Ryu Kang Mun Lee Jae-Min Kim Jun Yeob Lee School of Chemical Engineering Sungkyunkwan University2066Seobu-roJangan-guSuwon-siGyeonggi-do 16419Republic of Korea Department of Chemistry Institute for Molecular Science and Fusion TechnologyKangwon National UniversityChuncheonGangwon 24341Republic of Korea Department of Advanced Materials Engineering Chung-Ang University4726Seodong-daeroDaedeok-myeonAnseong-siGyeonggi-do 17546Republic of Korea SKKU Advanced Institute of Nano Technology Sungkyunkwan University2066Seobu-roJangan-guSuwonGyeonggi 16419Republic of Korea SKKU Institute of Energy Science and Technology Sungkyunkwan University2066Seobu-roJangan-guSuwonGyeonggi 16419Republic of Korea

Efficient green fluorescent organic light-emitting diodes were designed with a phosphorescent metal complex as a singlet exciton sensitizing host(SESH)for achieving high efficiency and low efficiency roll-off through exciton and polaron *** Pt(Ⅱ)complex(Pt-Trz)possessing a tetradentate ligand with a bulky blocking group not only suppresses the severe formation of excimer or dimer itself but also transfers radiative excitons to fluorescent dopant *** SESH assisted fluorescence(SESHF)device with Pt-Trz as the host exhibits the maximum external quantum efficiency of 13.3%and a lower efficiency roll-off compared with exciplex host device which is a general approach for harvesting triplet *** exciton dynamics modeling unravels that the SESHF device effectively utilizes triplet excitons in the host by intersystem crossing and resonance energy transfer from the triplet state of the host to the singlet state of the terminal *** quenching rates of the SESHF device are reduced by 11 times for triplet-triplet annihilation and 1.8 times for tripletpolaron annihilation compared with the exciplex device,which demonstrates that Pt-Trz could be a platform to be used as an efficient host for fluorophores.

关键词： singlet annihilation polaron

Interplay of laser power and pore characteristics in selective laser melting of ZK60 magnesium alloys:A study based on in-situ monitoring and image analysis

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Journal of Magnesium and Alloys 2024年第4期12卷 1346-1366页

作者： Weijie Xie Hau-Chung Man Chi-Wai chan Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong KongChina School of Mechanical and Aerospace Engineering Queen’s UniversityBelfast BT95AHUK Research Institute for Advanced Manufacturing The Hong Kong Polytechnic UniversityHong KongChina

This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)***-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 *** morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore *** laser power led to increased pore coverage,whereas a denser structure was observed at higher laser *** laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the *** increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore *** laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher *** interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys.

关键词： Selective laser melting(SLM) Magnesium(Mg)alloys Biodegradable implants Porosity In-situ monitoring

An Overview of Chemical Constituents, Medicinal Properties, Clinical Trials, and Patents of Twigs of Morus alba(Ramulus Mori)

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World Journal of Traditional Chinese Medicine 2024年第2期10卷 149-158页

作者： Eric Wei Chiang chan Hung Tuck chan Siu Kuin Wong Department of Food Science and Nutrition Faculty of Applied SciencesUCSI UniversityCherasKuala LumpurMalaysia Secretariat of International Society for Mangrove Ecosystems Faculty of AgricultureUniversity of the RyukyusOkinawaJapan School of Foundation Studies Xiamen University MalaysiaSepangSelangorMalaysia

The rich chemical constituents and diverse pharmacological properties of Ramulus Mori(RM) or the twig of Morus alba with evidence supported by clinical trials and patents are reviewed. Known as Sangzhi in Chinese, RM is widely used in traditional Chinese medicine to treat gout, arthritis, and rheumatism. Chemical constituents include flavonoids, benzofurans, alkaloids, stilbenes, chalcones, phenolic acids, and coumarins. Bioactivities of RM include antidiabetic, anti-obesity, anti-inflammatory, antityrosinase, neuroprotective, antioxidant, hepatoprotective, cytoprotective, renoprotective, antihyperuricemic, analgesic, antifungal, DNA protective, anticancer, gastroprotective, cardioprotective, anti-hair aging, anti-arthritic, and antiplatelet aggregation properties. The most active compounds from RM are mulberrin, oxyresveratrol, and mulberroside A. All four clinical trials on RM are focused on the treatment of diabetes. The patents entail using RM extracts as cosmetics for skin whitening and as agents for hypoglycemia. Topics for further research on RM are suggested.

关键词： Clinical trials mulberrin mulberroside A oxyresveratrol patents Sangzhi

Construction of a High‑Performance Composite Solid Electrolyte Through In‑Situ Polymerization within a Self‑Supported Porous Garnet Framework

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Nano-Micro Letters 2024年第5期16卷 56-70页

作者： An‑Giang Nguyen Min‑Ho Lee Jaekook Kim chan‑Jin Park Department of Materials Science and Engineering Chonnam National University77 Yongbong‑roBuk‑guGwangju 61186South Korea

Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).However,concurrently achieving exceptional ionic conductivity and interface compatibility between the electrolyte and electrode presents a significant challenge in the development of high-performance CSEs for *** overcome these challenges,we present a method involving the in-situ polymerization of a monomer within a self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZT)to produce the *** synergy of the continuous conductive LLZT network,well-organized polymer,and their interface can enhance the ionic conductivity of the CSE at room ***,the in-situ polymerization process can also con-struct the integration and compatibility of the solid electrolyte–solid electrode *** synthesized CSE exhibited a high ionic conductivity of 1.117 mS cm^(-1),a significant lithium transference number of 0.627,and exhibited electrochemical stability up to 5.06 V ***/Li+at 30℃.Moreover,the Li|CSE|LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cell delivered a discharge capacity of 105.1 mAh g^(-1) after 400 cycles at 0.5 C and 30℃,corresponding to a capacity retention of 61%.This methodology could be extended to a variety of ceramic,polymer electrolytes,or battery systems,thereby offering a viable strategy to improve the electrochemical properties of CSEs for high-energy–density SSLMBs.

关键词： Scalable tape-casting method Self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12) Composite solid electrolyte LiF-and B-rich interphase layers

In situ infrared, Raman and X-ray spectroscopy for the mechanistic understanding of hydrogen evolution reaction

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Journal of Energy Chemistry 2024年第3期90卷 632-651,I0014页

作者： Andi Haryanto Kyounghoon Jung chan Woo Lee Dong-Wan Kim Department of Chemistry Kookmin UniversitySeoul 02707Republic of Korea School of Civil Environmental and Architectural EngineeringKorea UniversitySeoul 02841Republic of Korea

Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy *** methods have been widely used to study the reaction mechanism of the hydrogen evolution reaction(HER),but the calculation results need to be supported by experimental results and direct evidence to confirm the mechanistic *** this review,we discuss the fundamental principles of the in situ spectroscopic strategy and a theoretical model for a mechanistic understanding of the *** addition,we investigate recent studies by in situ Fourier transform infrared(FTIR),Raman spectroscopy,and X-ray absorption spectroscopy(XAS) and cover new findings that occur at the catalyst-electrolyte interface during *** spectroscopic strategies provide practical ways to elucidate catalyst phase,reaction intermediate,catalyst-electrolyte interface,intermediate binding energy,metal valency state,and coordination environment during HER.

关键词： Hydrogen evolution reaction Infrared spectroscopy Raman spectroscopy X-ray absorption spectroscopy Reaction mechanism

Detection of Turbulence Anomalies Using a Symbolic Classifier Algorithm in Airborne Quick Access Record(QAR)Data Analysis

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Advances in Atmospheric Sciences 2024年第7期41卷 1438-1449页

作者： Zibo ZHUANG Kunyun LIN Hongying ZHANG Pak-Wai chan Flight Academy Civil Aviation University of ChinaTianjin 300300China School of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China Aviation Weather Services Hong Kong ObservatoryHong KongChina

As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation *** eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil *** study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)*** detection of atmospheric turbulence is approached as an anomaly detection *** evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence ***,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently *** summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning *** finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.

关键词： turbulence detection symbolic classifier quick access recorder data