检索结果-南通市图书馆

improving toughness of medium-Mn steels after friction stir welding through grain morphology tuning

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第23期118卷 243-254页

作者： Mun Sik Jeong Tak Min park Dong-Il Kim Hidetoshi Fujii Hye Ji im Pyuck-pa Choi Seung-Joon Lee Jeongho Han Division of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea Department of Advanced Materials Engineering Korea Polytechnic UniversitySiheung 15073Republic of Korea Joining and Welding Research Institute Osaka UniversityOsaka 567-0047Japan Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Department of Materials Science and Engineering Northwestern UniversityEvanstonIL 60208USA

This work demonstrated the viability of friction stir welding for the welding of medium-Mn steels when used as cryogenic vessel materials for liquefied gas storage.We used an intercritically annealed Fe-7 Mn-0.2 C-3 Al(wt.%)steel with a dual-phase(α'martensite andγ_(R) retained austenite)nanolaminate structure as a base material and systematically compared its microstructure and impact toughness after friction stir and tungsten inert gas welding.The friction stir welded specimen exhibited a large amount ofγ_(R) phase owing to a relatively low temperature during welding,whereas the tungsten inert gas welded specimen comprised only theα'phase.Furthermore,the friction stir welded steel exhibited a tuned morphology of nanoscale globular microstructure at the weld zone and did not exhibit any prior austenite grain boundary due to active recrystallization caused by deformation during welding.The preserved fraction ofγ_(R) and morphological tuning in the weldment improved the impact toughness of the friction stir welded steel at low temperatures.In the steel processed by tungsten inert gas welding,the notch crack propagated rapidly along the prior austenite grain boundaries-weakened by Mn and P segregations-resulting in poor impact toughness.However,the friction stir welded steel exhibited a higher resistance against notch crack propagation due to the slow crack propagation along the ultrafine ferrite/ferrite(α/α)interfaces,damage tolerance by the active transformation-induced plasticity from the large amount ofγR,and enhanced boundary cohesion by suppressed Mn and P segregations.

关键词： Charpy impact test Transformation-induced plasticity Friction stir welding Phase stability Medium-Mn steel

From occupants to occupants:A review of the occupant information understanding for building HVAC occupant-centric control

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2022年第6期15卷 913-932页

作者： Tao Yang Arkasama bandyopadhyay Zheng O’Neill Jin Wen Bing Dong mike walker’66 department of mechanical engineering texas a&m universitycollege stationtx77843usa department of civil architectural&environmental engineeringdrexel universityphiladelphiapa19104usa department of mechanical and aerospace engineering syracuse universitysyracuseny13244usa

Occupants are the core of the built environment.Traditional heating,ventilation,and air-conditioning(HVAC)systems operate with predefined schedules and maximum occupancy assumptions with no consideration of specific occupant information.These generalized assumptions usually do not align with the actual demand and result in over-conditioning and occupant discomfort.In recent years,with the aid of Information&Communication Technology(ICT)and Computer Science(CS),it is possible to acquire real-time and accurate occupant information to satisfy the exact thermal requirement through specific HVAC control in one particular built environment.This mechanism is called HVAC“Occupant-centric Control(OCC).”HVAC OCC strategy starts with collecting the occupant’s information(e.g.,presence/absence)and then applies it to meet the occupant’s requirement(e.g.,thermal comfort).However,even though some research studies and field pilot demonstrations have been devoted to the field of OCC,there is a lack of systematic knowledge about occupant data,which is the principal component of OCC for HVAC researchers and practitioners.To fill this gap,this review paper discusses OCC with a particular emphasis on occupant information and investigates how this information can assist HVAC operation in providing an acceptable built environment in required spaces during the required time.We provide a fine-grained,comprehensive picture of occupant information,discuss its features,the modalities of information feed-in into the HVAC control,and the application of commonly utilized occupant information for OCC.

关键词： occupant information occupant-centric control smart building HVAC energy efficiency

关于帕竹政权时期大司徒绎曲坚赞修建的“十三大宗”考述

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

攀登（藏文版） 2024年第1期 70-78页

作者：拉巴次仁卓嘎西藏自治区日喀则市第一高级中学西藏自治区拉萨市墨竹工卡县第二双语幼儿园

根据《西藏王臣记》等史书记载,帕竹政权的第一任第悉大司徒绛曲坚赞为了稳固政权,促进发展,采取了减轻差税、改定法律、在各冲要地点兴建以内邬栋孜为首的城堡(宗)、设立宗谿等一系列制度。关于他所修建的城堡(宗),后人习惯称之为“大... 详细信息

根据《西藏王臣记》等史书记载,帕竹政权的第一任第悉大司徒绛曲坚赞为了稳固政权,促进发展,采取了减轻差税、改定法律、在各冲要地点兴建以内邬栋孜为首的城堡(宗)、设立宗谿等一系列制度。关于他所修建的城堡(宗),后人习惯称之为“大司徒的十三大宗”,但相关文献资料中几乎找不到“十三大宗”这样确切数字的表述。因此,对所谓“大司徒的十三大宗”的说法有待进一步考证,并且对于一些史书及论文中出现的琼杰宗、白朗伦珠孜宗、江噶尔达孜宗等类属于“大司徒的十三大宗”的说法更有待于进一步商榷。

关键词：帕竹政权大司徒绛曲坚赞 “十三大宗”

Generating oligodendroglia from adult mesenchymal cells for transplantation:cell reprogramming or direct lineage conversion?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第7期18卷 1493-1494页

作者： Jorge pascual-Guerra JoséA.Rodríguez-Navarro Carlos L.paíno Service of Neurobiology-Research Ramón y Cajal University Hospital-IRYCISMadridSpain Department of Cellular Biology Complutense UniversityMadridSpain

Cell replacement therapy has long been proposed as a treatment for the damaged nervous system.One of the most challenging aspects of such a strategy,however,is finding sources of donor cells for transplantation.Autologous neural cells are rarely an option as every cell in the nervous system has a defined function that would be lost if that cell was to be removed.One possibility would be sourcing precursor or differentiated cells from fetal tissues;however,aside from ethical issues,heterologous cells are at risk of immunological rejection in the long term.Methodological improvements over the past 15 years have led to the possibility that autologous non-neural cells could be used for cell transplantation through their conversion into neural derivatives.

关键词： neural programming removed

Ultra-low temperature cofired ceramics based on Li_(2)WO_(4)as perspective substrate materials for terahertz frequencies

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2023年第3期12卷 526-538页

作者： Dorota Szwagierczak Beata Synkiewicz-Musialska Jan Kulawik Elżbieta Czerwińska Norbert pałka Kraków Division Łukasiewicz Research Network-Institute of Microelectronics and PhotonicsKraków 30-701Poland Institute of Optoelectronics Military University of TechnologyWarszawa 00-908Poland

With the development of low dielectric permittivity materials having an ultra-low sintering temperature,testing their dielectric properties at terahertz frequencies suitable for 6G communication systems and implementation of the fabricated materials in ultra-low temperature cofired ceramics(ULTCC)were the main goals of the research.Lithium tungstate Li_(2)WO_(4)was synthesized by a solid-state reaction and used for the preparation of green tapes and test structures with cofired internal conductive layers,which are destined for substrates of microwave and submillimeter wave circuits.Sintering behavior,thermal effects,and mass changes of the green tapes during heating were studied using a hot-stage microscope,differential thermal analysis,and thermogravimetry.A single-phase composition was revealed for being undoped and doped with AlF3–CaB_(4)O_(7)ceramics.The impact of frequency,temperature,the addition of AlF3–CaB_(4)O_(7)and CuBi_(2)O_(4)dopants,and sintering temperature was the subject of in-depth characterization of dielectric properties in a terahertz region.A glass-free composition,ultra-low sintering temperature of 590–630℃,low roughness of the green tapes,dense microstructure,compatibility with Ag conductors,low and stable dielectric permittivity of 5.0–5.8 in a broad range of 0.2–2 THz,and low dielectric loss of 0.008–0.01 at 1 THz are the main advantages of the developed ULTCC substrates.

关键词： Li_(2)WO_(4) ultra-low temperature cofired ceramics(ULTCC) tape casting dielectric properties terahertz frequency range

Long-term records of glacier evolution and associated proglacial lakes on the Tibetan Plateau(1976‒2020)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Big Earth Data 2022年第4期6卷 435-452页

作者： Drolma Lhakpa Yubao Qiu pa Lhak Lijuan Shi Maoce Cheng Bin Cheng Tibet Institute of Plateau Atmospheric and Environmental Sciences Tibet Meteorological BureauLhasaChina Key Laboratory of Atmospheric Environment of Tibet Autonomous Region LhasaTibet Autonomous RegionChina School of Geography and Ocean Science Nanjing UniversityNanjingChina International Research Center of Big Data for Sustainable Development Goals BeijingChina Aerospace Information Research Institute Chinese Academy of SciencesBeijingChina FMI-AIR Joint Research Center for Arctic Observations Finnish Meteorological Institute and Aerospace Information Research InstituteChinese Academy of SciencesSodankyläFinland Climate Center of Tibet Autonomous Region Tibet Meteorological BureauLhasaTibet Autonomous RegionChina School of Earth Resources China University of GeosciencesWuhanChina Finnish Meteorological Institute HelsinkiFinland

The glaciers on the Tibetan Plateau(TP)constitute critical sources of water for the proglacial lakes and many rivers found downstream.To better understand the evolution of glaciers and the impact of this on proglacial lakes,seven glaciers corresponding to continenṅtal,sub-continental,and marine climate types that are influenced by wester-lies and the Indian summer monsoon were selected for study.The evolution of the edges of these glaciers and their associated progla-cial lakes were identified based on the visual interpretation of Landsat TM/ETM+/OLI images.A dataset covering the period 1976-2020 that included the glacier and proglacial lake edge vectors was then created.The relative errors in the areas of the individual glaciers were less than 3%,and for the proglacial lakes these errors were in the range 0%-7%.The dataset was used to effectively compare the changes in glaciers and proglacial lakes that have occurred over the past four decades.The most striking changes that were found were the retreat of glaciers and the formation of small proglacial lakes.This dataset could also be used as a proxy to support research on changes in mountain glaciers,particularly their response to climate change and water resources.This response is of great scientific significance and is important in many applications,including assessments of the ecological problems caused by melting glaciers.The dataset can be downloaded from http://***/10.57760/sciencedb.j00076.00131.

关键词： Glacier and proglacial lake long-term changes Landsat Tibetan Plateau

Elucidating the evolution of long-period stacking ordered phase and its effect on deformation behavior in the as-cast Mg-6Gd-1Zn-0.6Zr alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第8期11卷 2801-2810页

作者： Sangwon Lee Yejun park Jongbin Go Young Mok Kim Seok Su Sohn Jiehua Li Pyuck-pa Choi Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon34141Republic of Korea Department of Materials Science and Engineering Kyoto UniversityKyoto606-8501Japan Department of Materials Science and Engineering Korea UniversitySeoul02841Republic of Korea Institute of Casting Research Montanuniverstät LeobenLeobenA-8700Austria

Herein,the evolution of long-period stacking ordered(LPSO)phases in the as-cast Mg-6Gd-1Zn-0.6Zr(wt.%)alloy are investigated via transmission electron microscopy(TEM)and atom probe tomography(APT).The TEM results reveal that two types of LPSO phase(a bulky interdendritic phase and a plate-like matrix LPSO phase)are formed in the as-cast sample.Most of the LPSO phases are confirmed to be of the 14H type,with a smaller proportion being of the 18R LPSO.Further,the APT results reveal that the composition of the interdendritic LPSO phase is closer to that of the ideal 14H phase compared to the matrix LPSO phase,and both the interdendritic and matrix LPSO phases exhibit a Gd/Zn ratio of 2.5,thereby indicating a deficient Zn content compared to the ideal 14H phase(i.e.,1.3).In addition,the influence of the LPSO phases on the deformation behavior is investigated at different compressive plastic strains using electron backscatter diffraction(EBSD)analysis to reveal twinning and slip behavior during deformation.The results indicate that the LPSO phase induces additional work hardening in the late stage of deformation via the suppression of{1011}compressive twinning and the activation of non-basal slip systems.

关键词： Magnesium alloy Long-period stacking ordered phase Transmission electron microscopy Atom probe tomography Work hardening behavior

Effective tool design of three-rank form as precision removal-process of ITO thin-films

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2009年第B9期19卷 232-237页

作者： pai-shan pa Digital Content Design Graduate School of Toy and Game DesignNational Taipei University of Education

A new effective tool design of three-rank form of electroremoval was present using a precision recycle system offering faster performance in removing the indium-tin-oxide(ITO) thin-films on color filter surface of displays. Higher electric power is not required since the three-rank form tool is adopted as a feeding mode to reduce the response area. The low yield of ITO persists throughout the entire semiconductor production process. By establishing a recycle process of ultra-precise removal of the thin-film nanostructure, defective products in the optoelectronic semiconductors industry can be effectively recycled, decreasing both production costs and pollution. A 5th generation TFT-LCD was used. The design features of the removal processes for the thin-films and the tool design of three-rank form were of major interest. For the precision removal processes, a pulsed current can improve the effect of dreg discharge and contributes to the achievement of a fast workpiece (displays' color filter) feed rate, but raises the current rating. High flow velocity of the electrolyte with a high rotational speed of the tool electrodes elevates the ITO removal effect. A displays' color filter with a fast feed rate is combined with enough electric power to provide highly effective removal. A small thickness of the rank and a small arc angle of the negative-electrode correspond to a higher removal rate for ITO-film. An effective three-rank form negative-electrode provides larger discharge mobility and better removal effect. It only needs a short period of time to remove the ITO easily and cleanly.

关键词：工具设计薄膜材料 ITO

同型半胱氨酸、低密度脂蛋白胆固醇及糖化血红蛋白在2型糖尿病视网膜病变的影响研究

在线全文

学校读者我要写书评

暂无评论

齐齐哈尔医学院学报 2024年第2期45卷 124-128页

作者：帕里杂·赛力克侯志梅舒哈尔新疆医科大学第二临床医学院新疆乌鲁木齐830000 克拉玛依市中心医院新疆克拉玛依834000

目的探讨血清同型半胱氨酸(Hcy)、低密度脂蛋白胆固醇(LDL-C)及糖化血红蛋白(HbA1c)在2型糖尿病视网膜病变(DR)中的影响。方法回顾性分析2019年4月—2022年6月本院内分泌科住院的2型糖尿病患者有糖尿病视网膜病变组(DR组)患者150例和非... 详细信息

目的探讨血清同型半胱氨酸(Hcy)、低密度脂蛋白胆固醇(LDL-C)及糖化血红蛋白(HbA1c)在2型糖尿病视网膜病变(DR)中的影响。方法回顾性分析2019年4月—2022年6月本院内分泌科住院的2型糖尿病患者有糖尿病视网膜病变组(DR组)患者150例和非糖尿病视网膜病变(NDR组)患者150例的临床资料,包括每位患者的一般资料、生化指标。比较两组间的一般信息;分析DR组与NDR组的影响因素;多元素回归分析DR的危险因素。结果DR及NDR组患者年龄、病程方面差距具有统计学意义(P<0.05)。DR组患者Hcy、FBG、TG、LDL-C、HbA1c水平明显高于NDR组(P<0.05)。Pearson相关系数分析,DR组患者的Hcy与年龄,病程FBG、TG、TC、LDL-c、HbA1c呈正相关关系(P<0.05)。Logistics回归分析结果显示病程、TG、LDL-c、Hcy、HbA1c均是影响2型糖尿病视网膜病变的独立因素(P<0.05)。结论Hcy、LDL-c、HbA1c水平在DR患者中远高于NDR患者,三者与DR发生、发展存在一定联系,临床可根据其表达水平对患者病情变化进行有效评估。

关键词：糖尿病视网膜病变同型半胱氨酸 2型糖尿病低密度脂蛋白糖化血红蛋白