检索结果-南通市图书馆

Microstructure, porosity and mechanical properties of selective laser melted AlSi10Mg

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 Aeronautics 2020年第7期33卷 2043-2054页

作者： Jing CHEN Wei HOU Xiuzhuan WANG Songlin CHU Zhiyi YANG Joint Laboratory of 3d Enable R&d Technology AECC Aero Engine Control System InstituteWuxi 214063China

Finite element modeling(FEM),microscopy,X-ray computed tomography(CT)and mechanical property tests were used to study the microstructure,porosity and mechanical properties of an AlSi10Mg alloy produced by selective laser melting(SLM).The simulation of the melt pool and thermal history under different energy densities produced an optimized result with an energy density of 44.5 J·*** high cooling rate during the SLM process significantly refined the previous a-Al *** growth direction of the network-like Al-Si eutectic structure at different orientations confirmed the anisotropic nature of the ***,the microhardness,tensile testing and fracture analysis results proved that there were no obvious distinctions in the strength between the transverse and longitudinal directions,and that the ductility was anisotropic,possibly due to the shape and distribution of the *** pores measured by X-ray CT at different energy densities confirmed that the sphericity of the pores was inversely related to pores *** optimized processing conditions,the porosity of the selective laser melted sample decreased leading to the improved fabricated fuel system component via SLM.

关键词： AlSi10Mg Mechanical property Microstructure Porosity Selective laser melting

HOW TO SUCCESSFULLY IMPLEMENT LEEd:dOCUMENTATION CHALLENGES ANd solutions

在线全文

学校读者我要写书评

暂无评论

Journal of Green Building 2007年第4期2卷 3-13页

作者： Courtney France France Sustainable solutions France

INTROdUCTION Market Transformation The market’s attention to environmentally-related issues has drastically increased over the past *** over rising fuel costs,urban air quality,national security,and local development impacts have influenced a growing trend for improved environmental *** and commercial building expansion will continue,but balancing needs with resources,and infrastructure demand with capacity,proves to be a challenge for any scope of development.

关键词： LEEd Transformation continue

SOME ALMOST ALL RESULTS CONCERNINGTHE PJATECKII-SAPIRO PRIME NUMBERS

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 Annals of Mathematics,Series B 1996年第3期17卷 279-288页

作者： FISCHER,d. ZHANTAO InstituteofMathematics Albert-LudwigsUniversityAlbertstrasse23bD-W-7800FreiburgGermany. InstituteofMathematics ShandongUniversityJinan250100China.

The distribution of the Pjateckii-Sapiro prime numbers in arithmetic progressions is investigated, and a Bombier i- Vinogr adov typ e mean- value t heorem and anot her almost all resultconcerning this problem are esta... 详细信息

关键词： Pjateckii-Sapiro prime number Arithmetic progression Bombieri-Vinogradov type mean-value theorem

Surface area-volume ratios in insects

在线全文

学校读者我要写书评

暂无评论

Insect Science 2017年第5期24卷 829-841页

作者： Sara Kuhsel Adrian Bruckner Sebastian Schmelzle Michael Heethoff Nico Bluthgen department of Biology Technische Universitat Darmstadt Schnittspahnstrasse 3 D-64287 Darmstadt Germany

Body mass, volume and surface area are important for many aspects of the physiology and performance of species. Whereas body mass scaling received a lot of attention in the literature, surface areas of animals have not been measured explicitly in this context. We quantified surface area-volume （SA/V） ratios for the first time using 3d surface models based on a structured light scanning method for 126 species of pollinating insects from 4 orders （diptera, Hymenoptera, Lepidoptera, and Coleoptera）. Water loss of 67 species was measured gravimetrically at very dry conditions for 2 h at 15 and 30 ℃ to demonstrate the applicability of the new 3d surface measurements and relevance for predicting the performance of insects. Quantified SA/V ratios significantly explained the variation in water loss across species, both directly or after accounting for isometric scaling （residuals of the SA/V - mass2/3 relationship）. Small insects with a proportionally larger surface area had the highest water loss rates. Surface scans of insects to quantify allometric SA/Vratios thus provide a promising method to predict physiological responses, improving the potential of body mass isometry alone that assume geometric similarity.

关键词： body size body shape 3d surface imaging sphericity structured light water loss

News on the physics potential of the reaction e^+e^-→ Zγ

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2021年第2期64卷 27-28页

作者： Philipp Roloff CERN CH-1211Geneva 23Switzerland

The next large project in particle physics is widely expected to be a high-energy electron-positron *** a facility could be realised as a circular collider,like the Circular Electron Positron Collider(CEPC)and the Future e^+e^-Circular Collider(FCC-ee)[1],or as a linear collider,like the International Linear Collider(ILC)and the Compact Linear Collider(CLIC)[2].

关键词： circular positron potential

Secretome of polarized macrophages:potential for targeting inflammatory dynamics in spinal cord injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第11期20卷 3231-3232页

作者： Andreia Monteiro Susana Monteiro Nuno A.Silva Life and Health Sciences Research Institute(ICVS) School of MedicineUniversity of MinhoBragaPortugal ICVS/3B’s Associate Lab PT Government Associated LabBraga/GuimaraesPortugal

Spinal cord injury(SCI)involves an initial traumatic phase,followed by secondary events such as ischemia,increased blood-spinal cord barrier permeability,ionic disruption,glutamate excitotoxicity,and metabolic alterations.A pe rsistent and exagge rated inflammato ry response within the spinal cord accompanies these events(Lima et al.,2022).The complexity and interplay of these mechanisms exacerbate the initial injury,leading to a degenerative process at the injury *** the initial trauma is unavoidable,the secondary injury begins within minutes and can last for months,creating an optimal window for therapeutic intervention.

关键词： alterations injury companies

Rapid directionally solidified microstructure characteristic and fracture behaviour of laser melting deposited Nb–Si–Ti alloy

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2021年第1期31卷 113-120页

作者： Wei Liu Xinyu Ren Neng Li Chao Gao Huaping Xiong 3d Printing Research and Engineering Technology Center Beijing Institute of Aeronautical Materials

Aiming at achieving fine and directionally-solidified microstructure of Nb-Si based alloy,Nb,Si and Ti powder particles were utilized as the raw materials,and laser melting deposition（LMd） experiments were conducted with1500 W and 2000 W laser power,*** microstructure characteristic,micro-hardness,and indentation fracture toughness were examined by scanning electron microscope（SEM）,X-ray energy dispersive spectrometer（XEdS） and X-ray diffraction（XRd）.The results showed that the two kinds of as-deposited Nb-17 Si-23 Ti alloy samples were mainly composed of Nbss,（Nb,Ti）3 Si and Ti-rich Nbss,and the microstructure presents rapid directionally-solidified characteristic,in which the crystallographic direction of Nbss and crystallographic direction of（Nb,Ti）3 Si tend to be parallel to the LMd building *** the laser power increasing from 1500 W to 2000 W,the microstructure became more oriented and *** the sample at 2000 W,the dendrite spacing was only about 1-2 μm,and Nbss and（Nb,Ti）3 Si couples grow alternately and they are parallel to the building direction *** the meantime the micro-hardness and indentation fracture toughness reached 1075 HV and 20.3 MPa·m1/2,respectively,indicating significant improvement by the directional growth of fine Nbss and（Nb,Ti）3 Si phases,and the dimple fracture mode of the Nbss dendrites.

关键词： Nb–Si based Alloy Laser melting deposition directional solidification Microstructure characteristic Fracture behaviour

Long-term monitoring data reveal effects of age,population density,and environmental aspects on hatching success of Common Cranes(Grus grus)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Avian Research 2022年第3期13卷 347-355页

作者： Isabel Barwisch Wolfgang Mewes Angela Schmitz Ornes AG Vogelwarte Zoological Institute and MuseumUniversity of GreifswaldSoldmannstr.23GreifswaldGermany Grüner Weg 3 19395Plau Am SeeOT KarowGermany

Facing climate and land use change,a species’ability to successfully adapt to changing environments is crucial for its *** drainage and intensification of agriculture and forestry set wetlands and associated species at risk of population *** population of Common Cranes(Grus grus)has experienced considerable fluctuations over the last *** increasing population numbers,hatching success seemed to have decreased over the last *** aim of this study was to identify factors influencing hatching success and nest survival of Common Cranes based on analyses of long-term individual-based monitoring data from northeastern Germany and evaluate the species ability to adapt to changing *** success decreased over the course of the study period from 0.75 to ***,nest survival and hatching success did not vary across different nesting habitats,whereas factors such as female age,timing of nest initiation and breeding pair density were found to have significant effects on hatching *** females showed higher hatching success,even though the proportion of unhatched eggs was highest in females aged 20 years or *** nest initiation had a positive effect on hatching *** levels are more favorable early in the nesting season,whereas increasing evaporation with time causes water levels to decrease,granting easier access for *** of female age,hatching success decreased with increasing numbers of breeding pairs within a 2-km radius around a nesting *** population densities intensify competition for resources and promote intraspecific interactions,affecting reproductive outcome *** study gives first insights into mechanisms behind population regulation in Common Cranes,highlighting the importance of population dynamics and individual *** suggest to further investigate density dependent effects including landscape and habitat features as well as reproduct

关键词： Adaptation Age Cranes Grus grus Habitat Nest survival Population density Reproduction

Serrated Plastic Flow in a Zr-based Bulk Metallic Glass during Nanoindentation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2004年第8期21卷 1593-1595页

作者：戴兰宏刘龙飞阎敏魏炳忱 ECKERTJürgen StateKeyLaboratoryofNonlinearMechanics(LNM) InstituteofMechanicsChineseAcademyofSciencesBeijing100080 NationalMicrogravityLaboratory InstituteofMechanicsChineseAcademyofSciencesBelting100080 departmentofMaterialsandGeosciences PhysicalMetallurgyDivisionDarmstadtUniversityofTechnologyPetersenstr23D-64287DarmstadtGermany

We investigate plastic deformation of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass using depth sensing nanoindentation. Numerous serrations in the load–displacement curves during indentation, shear bands and pile-ups around the indent were observed. The results revealed that the serrated plastic flow behaviour in this alloy depends strongly on the indentation strain rate.

关键词： Strain rate