检索结果-南通市图书馆

内蒙古民族大学学报（哲学社会科学蒙古文版） 2024年第1期 67-71页

作者：乌·额尔很白乙拉阿拉坦塔娜不详

Structural and Electronic Properties of Lutetium Doped Germanium Clusters LuGen^((+/0/-))(n=6~19):A Density Functional Theory Investigation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2022年第3期41卷 155-165,I0011页

作者：杨兆峰曹珍珠 Aziz u Rehman 杨桔材 School of Chemical Engineering Inner Mongolia University of Technologyand Inner Mongolia Key Laboratory of Theoretical and Computational Chemistry SimulationHohhot 010051China School of Energy and Power Engineering Inner Mongolia University of TechnologyHohhot 010051China

Structural growth mechanism,energetics,and electronic properties of cationic,neutral,and anionic lutetium doped germanium cluster LuGen^((+/0/-))(n=6~19)were comprehensively studied by the ABCluster unbiased global search technique with a hybrid density functional theory *** to the experimental PES,the anion evolution of structure can be clearly defined as four-phase:from the adsorbed to the link structure,then to the half cage motif,and finally to the endohedral *** results revealed that the LuGe16-as Frank-Kasper structure with high symmetry of Td can greatly enhance the *** structures have shown thermodynamic stability and appropriate energy *** materials are suitable *** approaches,including quasi-spherical geometry with closed-shell model,aromaticity,uV-Vis spectra,density of states(DOS)and partial density of states(PDOS)were applied to further support the results.

关键词： lutetium doped germanium clusters the ground state structure density functional theory electronic property

Trace element geochemistry and stable isotopic(δ^(13)C andδ^(15)N)records of the Paleocene coals,Salt Range,Punjab,Pakistan

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2022年第3期32卷 551-561页

作者： Noshin Masood Tehseen Zafar Karen A.Hudson-Edwards Hafiz u.Rehman Abida Farooqi Environmental Geochemistry Laboratory Department of Environmental SciencesFaculty of Biological SciencesQuaid-i-Azam UniversityPO 45320Pakistan Institute of Geochemistry Chinese Academy of SciencesGuiyang 550081China Institute of Geology University of the PunjabLahore 54590Pakistan Environment&Sustainability Institute and Camborne School of Mines University of ExeterTR109EZUK Graduate School of Sciences and Engineering Kagoshima UniversityKagoshima 890-0065Japan

The Paleocene coals of the Salt Range in the Punjab Province of Pakistan have great economic potential;however,their trace element and stable isotopic characteristics have not been studied in detail except for a few sporadic *** this study,a total of 59 coal samples of which 14 are obtained from open cast mines have been investigated for elemental composition andδ^(13)C-δ^(15)N isotopic *** contents of trace elements such as Co,Cr,Cu,Pb,Sr,Th,u,V,and Zn are 7.4,41.7,11.2,12.5,90.2,4.0,1.9,128,and 31.1 mg/kg,*** values,when compared with the World Coal Clarke values,were relatively higher in low-rank coals in comparison with Clarke values for brown ***,As(20.4 mg/kg),Co(6.6 mg/kg),Cr(22.4 mg/kg),Cu(^(13).3 mg/kg),Pb(19.2 mg/kg),Sr(^(15)4.7 mg/kg),Th(2.5 mg/kg),V(47.8 mg/kg),and Zn(75.1 mg/kg)were significantly higher in the sub-bituminous to bituminous coals of the Salt *** analysis,based on X-ray diffraction and energy dispersive X-ray spectroscopy,revealed that the studied samples contain illite,kaolinite calcite,gypsum,pyrite,and *** affinity with organic and inorganic phases of coals calculated by an indirect statistical approach indicated a positive association of ash content with Ag,Al,Co,Cr,Cs,Cu,Mn,P,Rb,Pb,Th,u,and V,suggesting the presence of inorganic components in studied ***,As,Fe,Sr,and Zn exhibit negative correlations that imply their association with the organic ***δ^(13)C andδ^(15)N isotopic range and average−24.94‰to−25.86‰(−25.41‰)and−2.77‰to 3.22‰(0.96‰),respectively,reflecting 3C type modern terrestrial vegetation were common in the palaeomires of studied coal *** addition,the trivial variations of 0.92‰and 0.45‰among^(13)C and^(15)N values can be attributed to water level fluctuations and plant assemblies.

关键词： Coal Salt Range Pakistan Geochemistry Trace elements δ^(13)C andδ^(15)N isotopes

在线全文

学校读者我要写书评

暂无评论

孔用弹性挡圈的数值模拟与优化

机械工程师 2024年第2期 67-69页

作者：徐小惠金成哲曹家斌沈阳理工大学机械学院沈阳110158 宜宾三江机械有限责任公司四川宜宾644000

针对小尺寸挡圈被压紧、放松后无法回到原始状态且易发生局部变形的问题,对孔用弹性挡圈的结构及装夹收缩动作进行研究,从挡圈结构方面结合虚位移原理开展力学分析,建立弹性挡圈受水平装夹力变形过程的力学模型,列出装夹力与偏心距、开... 详细信息

针对小尺寸挡圈被压紧、放松后无法回到原始状态且易发生局部变形的问题,对孔用弹性挡圈的结构及装夹收缩动作进行研究,从挡圈结构方面结合虚位移原理开展力学分析,建立弹性挡圈受水平装夹力变形过程的力学模型,列出装夹力与偏心距、开口角度的函数关系。以GB 893.2—1986 B型孔用弹性挡圈D42规格为研究对象,结合弹性试验技术条件数据参数,基于ANSYS Workbench软件对挡圈受力过程进行数值模拟,仿真结果与数学模型计算结果在小变形情况下吻合度较高。以挡圈结构强度为优化目标,对挡圈结构参数进行优化。以国标挡圈为例,绘制应力云图、位移云图、偏心距-应力、开口角度-应力曲线,开口角度对挡圈强度影响较小,偏心距与最大应力曲线图呈二次项关系。优化结果为提高自主设计挡圈结构强度提供改进方向。

关键词：轴用弹性挡圈能量法数值模拟优化设计

Implication of 14-3-3ζ-BDNF pathway in long-lasting memory enhancement and the rescue from memory deficits

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第12期17卷 2685-2686页

作者： Mariam Masmudi-Martín Irene Navarro-Lobato Zafar u.Khan Brain Metastasis Group National Cancer Research Centre(CNIO)MadridSpain Donders Institute for Brain Cognition and Behaviour Radboud UniversityNijmegenThe Netherlands Laboratory of Neurobiology CIMESUniversity of MalagaMalagaSpain Department of Medicine Faculty of MedicineUniversity of MalagaMalagaSpain CIBERNED Institute of Health Carlos ⅢMadridSpain

Intact memory function is critical for carrying out daily life activities,such as managing finances,remembering to take medications,driving in familiar environments,remembering a grandchild’s birthday,and learning to use a new ***,memory deficits not only accompany normal aging but are also comorbid with many psychiatric,neurological,and neurodegenerative *** disability,autism,attention deficit disorder,learning disability,schizophrenia,and depression all have memory deficit components,as do Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,and other neurodegenerative diseases(Khan et al.,2014).Therefore,a large proportion of the human population is affected by this brain disorder.

关键词： Huntington remember finance

Load dependent microstructural evolution in an as-cast 26%Cr high chromium cast iron during unlubricated sliding

在线全文

学校读者我要写书评

暂无评论

Friction 2022年第8期10卷 1258-1275页

作者： u.Pranav NAYAK Sebastian SuÁREZ Valentin PESNEL Frank MÜCKLICH María Agustina GuITAR Department of Materials Science Saarland UniversitySaarbrücken 66123Germany Materials Engineering Center Saarland Saarbrücken 66123Germany Ecole Européenne d’ingénieurs en Génie des Matériaux Universitéde LorraineNancy 54000France

In the current study,an as-cast 26%Cr high chromium cast iron(HCCI)alloy was subjected to dry-sliding linear wear tests,under different *** loads were selected based on analytically computing the critical load(PC)i.e.,the load necessary to induce plastic *** PC was calculated to be 15 N and accordingly,a sub-critical load(5 N)and an over-critical load(20 N)were *** influence of increasing the load during the wear test was investigated in terms of the matrix microstructural behaviour and its ability to support the surrounding *** morphological aspects of the wear tracks,and the deformed matrix microstructure adjacent and underneath the track was analysed by confocal laser scanning microscope(CLSM)and scanning electron microscope(SEM),*** evidence of plastic deformation of the matrix was observed below *** the contrary,at loads equal to and higher than PC,the austenitic matrix plastically deformed as evidenced by the presence of slip *** backscattered diffraction(EBSD)measurements in terms of grain reference orientation deviation,and micro-Vickers hardness of the austenitic matrix indicated a deformation depth of about 40μm at the maximum applied load of 20 *** active wear mechanisms during sliding were a combination of both adhesive and abrasive wear,although increasing the load shifted the dominant mechanism towards *** was primarily attributable to the increased propensity for carbide cracking and fracturing,combined with the inability of the hardened austenitic matrix surface and sub-surface to adequately support the broken carbide ***,the shift in the dominant wear mechanism was also reflected in the wear volume and subsequently,the wear rate.

关键词： high chromium cast iron unlubricated sliding plastic deformation wear resistance carbide spallation matrix hardness

Analysis of a Stagnation Point Flow with Hybrid Nanoparticles over a Porous Medium

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第2期19卷 541-567页

作者： u.S.Mahabaleshwar T.Anusha M.Hatami Department of Mathematics Davangere UniversityShivagangothriDavangereIndia Department of Mechanical Engineering Ferdowsi University of MashhadMashhadIran

The unsteady stagnation-point flow of a hybrid nanofluid over a stretching/shrinking sheet embedded in a porous medium with mass transpiration and chemical reactions is *** momentum and mass transfer problems are combined to form a system of partial differential equations,which is converted into a set of ordinary differential equations via similarity *** ordinary differential equations are solved analytically to obtain the solution for velocity and concentration profiles in exponential and hypergeometric forms,*** concentration profile is obtained for four different cases namely constant wall concentration,uniform mass flux,general power law wall con-centration and general power law mass *** effect of different physical parameters such as Darcy number Da^(1-1),mass transpiration parameter V_(C),stretching/shrinking parameter (d),chemical reaction parameter(β)and Schmidt number (Sc)on velocity and concentration profile is *** show that,the axial velocity will decreases as the shrinking sheet parameter increases,regardless of whether the suction or injection case is *** concentration decreases with an increase in the shrinking sheet parameter and the chemical reaction rate parameter.

关键词： Chemical reaction parameter mass transpiration hybrid nanofluid porous medium Schmidt number

四种典型球墨铸铁应变释放系数及其塑性修正研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

铸造 2024年第7期73卷 1017-1023页

作者：汪友路钱冬冬刘爱军解明国张学斌合肥工业大学材料科学与工程学院安徽合肥230009 安徽合力股份有限公司合肥铸锻厂安徽合肥230601

盲孔法是工程中测量残余应力最普遍的方法,其中材料的应变释放系数是该方法中的关键参数,目前国内外对球墨铸铁的应变释放系数研究相对较少。本文采用盲孔法对四种常用球墨铸铁QT450-10、QT550-6、QT600-3和QT700-4的应变释放系数进行... 详细信息

盲孔法是工程中测量残余应力最普遍的方法,其中材料的应变释放系数是该方法中的关键参数,目前国内外对球墨铸铁的应变释放系数研究相对较少。本文采用盲孔法对四种常用球墨铸铁QT450-10、QT550-6、QT600-3和QT700-4的应变释放系数进行了标定,得到应变释放系数与应力的关系曲线,发现低牌号的球墨铸铁由于铁素体含量多,对应力集中更为敏感,在标定试验中易产生局部的塑性变形。使用基于形状改变比能S的修正方法对四种球墨铸铁的应变释放系数进行修正,发现和其他均质金属材料不同,球墨铸铁应变释放系数与■之间存在良好的线性关系,因此提出了球墨铸铁应变释放系数关于■的修正公式,可直接应用于盲孔法测量球墨铸铁的残余应力。

关键词：球墨铸铁应变释放系数盲孔法残余应力塑性修正

维普期刊数据库博看期刊

Solar Supergranular Fractal Dimension Dependence on the Solar Cycle Phase

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第4期22卷 55-61页

作者： G.Rajani G.M.Sowmya u.Paniveni R.Srikanth PES College of Engineering Mandya-571401KarnatakaIndia GSSS Institute of Engineering and Technology for Women KRS RoadMetagalli Mysuru-570016KarnatakaIndia Bangalore university JnanabharathiBengaluru-560056India Poornaprajna Institute of Scientific Research DevanahalliBangalore-562110KarnatakaIndia

We study the complexity of the supergranular network through fractal dimension by using the Ca II K digitized data archive obtained from the Kodaikanal Solar *** data consist of 326 visually selected supergranular cells spread across the 23rd solar *** cells that were well-defined were chosen for the analysis and we discuss the potential selection effect thereof,mainly that it favors cells of a smaller size(upergranules across the solar cycle and find that it is anticorrelated with the activity level.

关键词： Sun:chromosphere Sun:granulation Sun:activity

Bioavailability and Solubility of Different Calcium-Salts as a Basis for Calcium Enrichment of Beverages

在线全文

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2010年第2期1卷 53-58页

作者： gaby Kressel 不详

Background: When usual calcium consumption patterns were analysed most people in the u.S. and Europe consume less than the recommended daily allowance. Supplements and fortified foods offer alternative and additional sources of calcium to traditional food. Calcium carbonate is the most common supplement but it is less soluble in water and, therefore, not suitable for enrichment of beverages. New organic calcium salts have a better solubility but less is known about their bioavailability. In the present study, we assessed the solubility and bioavailability of the new organic calcium salts, calcium lactate citrate and calcium lactate malate, in comparison to the traditional supplements, calcium carbonate and calcium gluconate. Design: Randomized, single-blind, four way cross-over study comparing single doses of 500 mg calcium in the form of four different calcium-salts. Subjects were advised to consume 25 μg vitamin D3 daily two weeks prior to the start of the study and during the whole study period. Subjects: 20 healthy young men, Methods: Blood samples were drawn immediately before and 2, 4, 6, 8, 12 and 24 h after ingestion of the calcium preparation. Concentration of total calcium and intact parathyroid hormone were measured in the serum. urine was collected at baseline and during the intervals 0-3, 3-6, 9-15 and 15-24 h and excretion of calcium, sodium and creatinine was examined. Results: The tested new salts were easily water soluble, significantly better than calcium gluconate. Calcium carbonate is almost insoluble. The bioavailability of the four different calcium salts was found to be almost identical. The maximum total serum calcium increased by 7.6 % two hours after ingestion calcium lactate citrate, by 7.4 % after calcium lactate malate, by 5.5 % after calcium carbonate, and by 5.8 % after calcium gluconate. Intact parathyroid hormone concentration showed the expected depression for calcium lactate citrate, calcium lactate malate and calcium carbonate, wh

关键词： Calcium Salt Bioavailability Solubility Enrichment of Beverages