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Synthesis and formation mechanism of titanium lead carbide

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Journal of Advanced Ceramics 2018年第2期7卷 178-183页

作者： C. LING W. B. TIAN P. z.ANG W. z.ENG Y. M. z.ANG z. M. sun Jiangsu Key Laboratory of Advanced Metallic Materials School of Materials Science and Engineering Southeast University Nanjing 211189 China Jiangsu Key Laboratory of Construction Materials School of Materials Science and Engineering Southeast University Nanjing 211189 China

Ti：PbC was synthesiz.d for the first time by pressureless reaction synthesis using Ti/Pb/TiC as starting materials at a heating rate of 2 ℃/rain and holding at 1370 ℃ for 2 h in a tube furnace protected by Ar atmosphere. The effects of starting powders, heating rates, and holding temperatures on the formation of Ti2PbC were investigated. It was found that elementary mixture of Ti/Pb/C or higher heating rates fail to form Ti2PbC. The decreased lattice parameters in the synthesiz.d Ti2PbC indicated the existence of Pb vacancies in the compound. A reaction mechanism was proposed to explain the formation of Ti2PbC.

关键词： Ti2PbC MAX phase differential scanning calorimetry (DSC) thermal stability

THE MAGNETORESISTANT BEHAVIOR OF Ni_(85)Fe_(15) ALLOY FILM IMPLANTED BYCo^+

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Acta Metallurgica Sinica(English Letters) 1999年第4期12卷 562-565页

作者： G.Q. Li, S. z. sun , z. Xianyu , L.H. sun and D. R. Li Departmentof Physics, Northeastern University,Shenyang 110006 ,China

Implanting 1 ×1016 to1 ×1017 Co+/cm2 into Ni85 Fe15 alloy film anditschangesof mag netoresistantcharacters were researched . The results show that Co+ is very spectacular on modifying Ni85 Fe15 alloyfilm’s magnetoresistancecharacters. Atlower dose,theanisotrop ic magnetoresistivity ratio( AMR) and thesaturated magnetic field didn’tchange almost. ATmedium dose, the saturated magnetic field does not have great change either, butits AMRisraised from 1 % upto 3% . Thisiscomparabletothebest AMRvalueof permalloy based magnetoresistant material prepared by other methods. But the ion implantation tech niqueisrathersimpler. Whentheimplanting doseishigher,its AMRisalsoenhanced notice ably. However,theincreaseof saturated field saysthe material’sstructurecharacters have changed radically.

关键词： anisotropic magnetoresistivityratio, Ni85 Fe15 alloy, film ,ionimplanta tion

Special Column on Shear Failure Test and Analysis of Concrete Structures

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Frontiers of Structural and Civil Engineering 2014年第4期8卷 323-324页

作者： Y. L. MO J. G. NIE V. SIGRIST z. sun University of Houston USA Tsinghua University China Hamburg University of Technology (TUHH) Germany Research Fellow Tongji University China

Shear resistance capacity analysis is a traditional bottleneck problem for the analysis and design of reinforced concrete structures. Along with the use of high performance materials and the geometrical layout optimiz.tion of concrete, rebars and other additives, the performance of reinforced concrete components and structures are continuously improved. The testing, modelling and analyz.ng research works are continuously conducted for the accurate computation and conservative design of the improved concrete components and structures.

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Providing Wear Protection for Flat- Tappet （Sliding） Camshaft Followers in Rebuilt Engines

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润滑油 2007年第1期22卷 11-14页

作者： Larry M. Bendele Nian z. sun Southwest Research Institute San Antonio Texas USA

Rebuilt engine 'break-in' is the most critical period for long-term durability for a flat-tappet *** dialkyl dithio phosphate(z.DP) has proven to be a cost-effective engine oil additive for anti-wear protection and oxidation ***,tightening exhaust emission standards are requiring modern lubricants to have reduced levels of z.DP *** the valvetrain break-in is successfully completed,then modern low-phosphorus lubricants can be used with confidence at subsequent oil change service intervals.

关键词：发动机磨损保护滑动凸轮轴机油添加剂二烷基二硫代磷酸锌润滑油

TcPO2 changes are more pronounced than SpO2 changes during simulated altitude changes in a hypobaric oxygen chamber: a nonrandomiz.d controlled trial

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Emergency and Critical Care Medicine 2024年第3期4卷 105-110页

作者： Li Y. Chen L. Fu z. Wang z. sun S. Luan X. Ma D. Hu T. School of Nursing and Rehabilitation Shandong University Shandong Jinan China Department of Emergency and Critical Care Medicine Qilu Hospital of Shandong University Shandong Jinan China Department of Pulmonary and Critical Care Medicine Qilu Hospital of Shandong University Shandong Jinan China Emergency Management Center of State Grid Shandong Electric Power Company Shandong Jinan China School of Nursing and Rehabilitation Cheeloo College of Medicine University of Shandong Department of Infection Control Qilu Hospital of Shandong University Shandong Jinan China School of Mechanical Engineering Shandong University Key Laboratory of the Ministry of Education for Efficient and Clean Machinery Manufacturing National Experimental Teaching Demonstration Center for Mechanical Engineering Shandong Jinan China

Background: Hypoxia is a significant risk factor of hypertension. However, no studies have used transcutaneous tissue partial pressure of oxygen (TcPO2) and partial pressure of carbon dioxide (TcPCO2) monitors to measure the respective partial pressures in healthy individuals. Oxygen saturation (SpO2) is often used for traditional monitoring of vital signs. This study investigated the changes in TcPO2 and SpO2 values during rapid changes in altitude. The trial was registered at *** (registration no. NCT06076057). Methods: Healthy adult volunteers were instructed to sit vertically in a hypobaric oxygen chamber, which ascended from 0 m to 2500 m at a uniform speed within 10 min. The Danish Radiometer TCM4 was used to measure TcPO2 and TcPCO2 with the ventral side of the upper arm as the measurement site. The Shenz.en Kerokan P0D-1 W pulse oximeter was used to measure heart rate and SpO2, with values recorded once every 500 m. Results: Altogether, 49 healthy volunteers were recruited between March 2023 and August 2023. With increasing altitude, TcPO2 and SpO2 decreased significantly (P 500 m, statistical significance was identified between TcPO2 in both sexes (P < 0.05). Statistical significance in TcPCO2 and heart rate was observed at the different elevations (P < 0.05). Conclusion: In acutely changing low-pressure hypoxic environments, TcPO2 changed more dramatically than SpO2 © Wolters Kluwer Health, Inc. All rights reserved.

关键词： Altitude change Low-pressure oxygen chamber Transcutaneous oxygen saturation Transcutaneous partial pressure of oxygen

Rational molecular design of efficient yellow-red dendrimer TADF for solution-processed OLEDs: a combined effect of substitution position and strength of the donors

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Science China Chemistry 2024年第5期67卷 1613-1623页

作者： Changfeng Si Dianming sun Tomas Matulaitis David B.Cordes Alexandra M.z.Slawin Eli z.sman-Colman Organic Semiconductor Centre EaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsKY169STUK

The development of high-performance solution-processed red organic light-emitting diodes(OLEDs) remains a challenge,particularly in terms of maintaining efficiency at high luminance. Here, we designed and synthesiz.d four novel orange-red thermally activated delayed fluorescence(TADF) dendrimers that are solution-processable: 2GCz.BP, 2DPACz.BP, 2FBP2GCz.and 2FBP2DPACz. We systematically investigated the effect of substitution position and strength of donors on the optoelectronic properties. The reverse intersystem crossing rate constant(kRISC) of the emitters having donors substituted at positions 11and 12 of the dibenz.[a,c]phenaz.ne(BP) is more than 10-times faster than that of compounds substituted having donors substituted at positions 3 and 6. Compound 2DPACz.BP, containing stronger donors than 2GCz.BP, exhibits a red-shifted emission and smaller singlet-triplet energy splitting, ΔE_(ST), of 0.01 e V. The solution-processed OLED with 10 wt% 2DPACz.BP doped in m CP emitted at 640 nm and showed a maximum external quantum efficiency(EQE_(max)) of 7.8%, which was effectively maintained out to a luminance of 1,000 cd m-2. Such a device's performance at relevant display luminance is among the highest for solution-processed red TADF OLEDs. The efficiency of the devices was improved significantly by using 4Cz.IPN as an assistant dopant in a hyperfluorescence(HF) configuration, where the 2DPACz.BP HF device shows an EQEmaxof 20.0% at λEL of 605 nm and remains high at 11.8% at a luminance of 1,000 cd m-2, which makes this device one of the highest efficiency orange-to-red HF SP-OLEDs to date.

关键词： thermally activated delayed fluorescence solution-processing red OLEDs dibenz.[a,c]phenaz.ne dendrimers

Climate Changes and Sustainability

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Open Journal of Ecology 2024年第1期14卷 17-53页

作者： Kholoud z. Ghanem Department of Biological Science College of Science & Humanities Shaqra University Riyadh Saudi Arabia

Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variables are the main contributors to this cyclical adjustment of the Earth’s climate. Such changes may be induced purposefully, because of burning fossil fuels, clearing forests, and raising animals, or they may be natural, brought on by significant volcanic eruptions or variations in the sun’s activity. By significantly increasing the amount of greenhouse gases already in the atmosphere, this heightens the greenhouse effect and contributes to global warming. This work includes several additional theoretical and practical explanations of sustainable development. The theoretical work encompasses hundreds of researches that identify requirements for how development routes might satisfy sustainable development (SD) criteria using economic theory, complex systems approach, ecological science, and other techniques. The agreements made by the Parties in various nations across the world will consider a wide range of perspectives about what would be considered undesirable effects on the environment, the climate system, sustainability, economic growth, or food production.

关键词： Earth System Ancient Climatic Changes Causes of Climatic Changes Ecological Risk Assessment Ecosystem Abrupt Climate Change of Earth Sustainability

Compressive property and energy absorption characteristic of interconnected porous Mg-z.-Y alloys with adjusting Y addition

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Journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： J.A.Liu S.J.Liu B.Wang W.B.sun X.J.Liu z.W.Han College of Materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of Bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics-Jilin University Weihai 264205PR China

In this study,interconnected porous Mg-2z.-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characteriz.tion methods were then applied to identify the microstructure of the porous Mg-z.-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-z.-Y ternary phases appear:I-phase(Mg_(3)z._(6)Y),W-phase(Mg_(3)z._(3)Y_(2)),and LPSO phase(Mg_(12)z.Y).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 MJ/m^(3)to 10.97 MJ/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-z.-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-z.-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

Graphene-Semiconductor Quantum Well with Asymmetric Energy Gaps

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World Journal of Condensed Matter Physics 2013年第1期3卷 67-72页

作者： J. T. Wang D. S. Guo G. L z.ao J. C. Chen z. W. sun A. Ignatiev Department of Physics Southern University and A & M College Baton Rouge USA Department of Physics University of Houston Houston USA Department of Physics Xiamen University Xiamen China Institute of Mechanics Chinese Academy of Sciences Beijing China

Semiconductor solar cell (PV cell) has been widely used for generating solar electricity. However, the high cost and severe pollution limits its application. Recently the discovery of graphene may open a door to fabricate a novel solar cell with lower cost and more environmentally friendly. Our proposed solar cell device consists of a graphene strip and two semiconductor strips with different energy gaps attached to the two edges of the graphene strip on a flat plane. This structure is a two-dimensional quantum well. The energy bands of graphene can be described by a two-dimensional Dirac equation centered on hexagonal corners (Dirac points) of the honeycomb lattice Brillouin z.ne. The 2 D Dirac equation has been solved numerically in this paper. The results indicate that the graphene quantum well possesses very dense quantum energy states which imply that quantum well of this type can absorb sun light with more different frequencies. If we use graphene quantum well to fabricate the photo voltaic cell, the efficiency of converting solar energy to electricity will be enhanced.

关键词： Graphene Quantum Well Dirac Equation PV Cell Energy Levels