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Chinese Journal of Mechanical En.ineering 2021年第6期34卷 51-62页

作者： M.nuño J.Bühring M.n.Rao K.-U.Schröder Institute of Structural Mechanics and Lightweight Design RWTH Aachen UniversityWüllnerstraβe 752072 AachenGermany

Sandwich structures possess a high ben.ing stiffness compared to monolithic structures with a similar *** makes them very suitable for lightweight applications,where high stiffness to weight ratios are *** common manufacturing methods of sandwich structures involve adhesive bon.ing of the core material with the ***,adhesive bon.ing is prone to delamination,a failure mode that is often difficult to *** paper presents the results of delamination testing of fully additive manufactured(AM)AlSi10Mg sandwich structures with pyramidal lattice truss core using Laser Powder Bed Fusion(LPBF).The faces and struts are 0.5 mm thick,while the core is 2 mm *** inclination of the struts is 45°.To characterise the bon.ing strength,climbing drum peel tests and out-of-plane tensile tests are *** formulas are derived to predict the expected failure loads and *** analytics and tests are supported by finite element(FE)*** the analytic approach,design guidelines to avoid delamination.in AM sandwich structures are *** study presents a critical face sheet thickness to strut diameter ratio for which the structure can *** ratio is mainly influenced by the inclination of the *** peel tests resulted in face yielding,which can also be inferred from the analytics and *** out-of-plane tensile tests didn’t damage the structure.

关键词： Additive Manufacturing Sandwich Structures Pyramidal Lattice Core

Efficient DnA-assisted synthesis of trans-membrane gold nanowires

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Microsystems & nanoen.ineering 2018年第1期4卷 490-497页

作者： Maoxiang Guo Iván Hernández-neuta narayanan Madaboosi Mats nilsson Wouter van der Wijngaart Department of Micro and nanosystems KTH Royal Institute of TechnologyOsquldas väg 10Stockholm 10044Sweden Science for Life Laboratory Department of Biochemistry and BiophysicsStockholm UniversityTomtebodavägen 23 ASolna SE-17165Sweden

Whereas electric circuits and surface-based(bio)chemical sensors are mostly constructed in-plane due to ease of manufacturing,3D microscale and nanoscale structures allow denser integration of electronic components and improved mass transport of the analyte to(bio)chemical sensor *** work reports the first out-of-plane metallic nanowire formation based on stretching of DnA through a porous *** use rolling circle amplification(RCA)to generate long single-stranded DnA concatemers with one end anchored to the *** DnA strands are stretched through the pores in the membrane during liquid removal by forced *** the liquid–air interface movement across the membrane occurs in every pore,DnA stretching across the membrane is highly *** stretched DnA molecules are transformed into trans-membrane gold nanowires through gold nanoparticle hybridization and gold enhancement chemistry.A 50 fM oligonucleotide concentration,a value two orders of magnitude lower than previously reported for flat surface-based nanowire formation,was sufficient for nanowire *** observed nanowires in up to 2.7% of the membrane pores,leading to an across-membrane electrical conductivity reduction from open circuit to nal-to-noise ratio and can also be extended for use as a biosensor due to the high specificity and scope for multiplexing offered by RCA.

关键词： DnA stretching DnA detection gold nanowires nanowire synthesis membrane

Landslide Loss and Damage in Sindhupalchok District, nepal:Comparing Income Groups with Implications for Compensation and Relief

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International Journal of Disaster Risk Science 2018年第2期9卷 157-166页

作者： Kees van der Geest United nations University Institute for Environment and Human Security

The 2014 Jure landslide in Sindhupalchok District, nepal, caused significant loss and damage to ecosystems and livelihoods in the area. In the direct aftermath of the landslide, several disaster loss assessments were conducted, with the aim of coun.ing casualties,injured people, and damaged houses and *** useful and necessary in their own right, such rapid assessments do not reveal the true extent and significance of the losses and damages that people in disaster areas face, including their monetary value. We address this gap, based on a comprehensive household survey(n = 234), as well as other, qualitative research tools. Our results highlight the importance of differentiating between loss and damage in absolute monetary terms as opposed to losses relative to annual income. We find a stark contrast between the high absolute losses incurred by nonpoor households, and the high relative losses—up to 14 times their annual income—experienced by poor *** results have important implications for policy that addresses loss and damage, not only of landslides but also of other disasters. Loss and damage assessments need to take the livelihood characteristics of affected households into account to identify and support those most in need of compensation and relief.

关键词： Compensation and relief Impact assessment Landslides Loss and damage analysis nepal

Laguerre calculus and Paneitz operator on the Heisenberg group

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Science China Mathematics 2009年第12期52卷 2549-2569页

作者： CHAnG der-Chen Department of Mathematics Georgetown University

Laguerre calculus is a powerful tool for harmonic analysis on the Heisenberg group. Many sub-elliptic partial differential operators can be inverted by Laguerre calculus. In this article, we use Laguerre calculus to find explicit kernels of the fundamental solution for the Paneitz operator and its heat equation. The Paneitz operator which plays an important role in CR geometry can be written as follows: $$ {\mathcal{P}_\alpha} = {\mathcal{L}_\alpha} \bar {\mathcal{L}_\alpha} = \frac{1} {4}\left[ {\sum\limits_{j = 1}^n {\left( {Z_j \bar Z_j + \bar Z_j Z_j } \right)} } \right]^2 + \alpha ^2 T^2 $$ Here “Z j ” j=1 n is an orthonormal basis for the subbundle T (1,0) of the complex tangent bundle T ?(H n ) and T is the “missing direction”. The operator $ \mathcal{L}_\alpha $ is the sub-Laplacian on the Heisenberg group which is sub-elliptic if α does not belong to an exceptional set Λ α . We also construct projection operators and relative fundamental solution for the operator $ \mathcal{L}_\alpha $ while α ∈ Λ α .

关键词： Paneitz operator Heisenberg group Laguerre calculus fundamental solution heat kernel spectrum 35H20 53C44

Laguerre expansion on the Heisenberg group and Fourier-Bessel transform on C^n Dedicated to Professor Sheng GOnG on the occasion of his 75th birthday

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Science China Mathematics 2006年第11期49卷 1722-1739页

作者： CHAnG der-Chen GRIEnER Peter Department of Mathematics Georgetown University Washington DC 20057USA Department of Mathematics University of Toronto TorontoON M5S 3G3Canada

Given a principal value convolution on the Heisenberg group Hn = Cn × R, we study the relation between its Laguerre expansion and the Fourier-Bessel expansion of its limit on Cn. We also calculate the Dirichlet kerne... 详细信息

关键词： Heisenberg group, Fourier transform, Laguerre expansion, Bessel functions,Poisson sum, Dirichlet kernel.

Selective expansion of human natural killer cells leads to enhanced alloreactivity

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Cellular & Molecular Immunology 2014年第2期11卷 160-168页

作者： Diana n Eissens Clive M Michelo Frank WMB Preijers Bram van Cranenbroek Houwelingen Arnold van der Meer Irma Joosten Department of Laboratory Medicine--Laboratory of Medical Immunology Radboud University Nijmegen Medical Centre Nijmegen The Netherlands and Department of Laboratory Medicine--Laboratory of Hematology Radboud University Nijmegen Medical Centre Nijmegen The netherlands These authors contributed equally to this work.

In allogeneic stem cell transplantation （SCT）, natural killer （nK） cells lacking their cognate inhibitory ligand can.induce graft-versus-leukemia responses, without the induction of severe graft-versus-host disease （GVHD）. This feature can be exploited for cellular immunotherapy. In this study, we examined selective expansion of nK cell subsets expressing distinct killer immunoglobulin-like receptors （KIRs） within the whole human peripheral blood nK cell population, in the presence of HLA-Cw3 （C1） or Cw4 （C2） transfected K562 stimulator cells. Coculture of KIR＋ nK cells with C1 or C2 positive K562 cells, in the presence of IL-2＋ IL-15, triggered the outgrowth of nK cells that missed their cognate ligand. This resulted in an.increased frequency of alloreactive KIR＋ nK cells within the whole nK cell population. Also, after preculture with K562 cells lacking their cognate ligand, we observed that this alloreactive nK population revealed higher numbers of CD107~ cells when cocultured with the relevant K562 HLA-C transfected target cells, as compared to coculture with untransfected K562 cells. This enhanced reactivity was confirmed using primary leukemic cells as target. This study demonstrates that HLA class I expression can mediate the skewing of the nK cell repertoire and enrich the population for cells with enhanced alloreactivity towards leukemic target cells. This feature may support future clinical applications of nK cell-based immunotherapy.

关键词： alloreactivity cytotoxicity immunotherapy KIR nK cells stem cell transplantation

Efficient photon coupling from a diamond nitrogen vacancy center by integration with silica fiber

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Light(Science & Applications) 2016年第1期5卷 671-676页

作者： Rishi n Patel Tim Schröder noel Wan Luozhou Li Sara L Mouradian Edward H Chen Dirk R Englund Department of Electrical En.ineering and Computer Science Massachusetts Institute of Technology77 Massachusetts AveCambridgeMA 02139USA Department of Applied Physics Stanford University348 Via Pueblo MallStanfordCA 94305USA

A central goal in quantum information science is to efficiently interface photons with single optical modes for quantum networking and distributed quantum ***,we introduce and experimentally demonstrate a compact and efficient method for the low-loss coupling of a solid-state qubit,the nitrogen vacancy(nV)center in diamond,with a single-mode optical *** this approach,single-mode tapered diamond waveguides containing exactly one high quality nV memory are selected and integrated on tapered silica *** optimization of an adiabatic coupler indicates that near-unity-efficiency photon transfer is possible between the two ***,we find an overall collection efficiency between 16%and 37%and estimate a single photon count rate at saturation above 700 *** integrated system enables robust,alignment-free,and efficient interfacing of single-mode optical fibers with single photon emitters and quantum memories in solids.

关键词： diamond nanophotonics fiber optics nitrogen vacancy center quantum optics single photon source

A note on Hermite and Subelliptic Operators

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Acta Mathematica Sinica,English Series 2005年第4期21卷 803-818页

作者： der Chen CHAnG Jing Zhi TIE Department of Mathematics Georgetown University Washington DC 20057-1233. USA Department of Mathematics University of Georgia Athens GA 30602-7403 USA

In this note, we compute the fundamental solution for the Hermite operator with singularity at an arbitrary point y∈R^n. We also apply this result to obtain the fundamental solutions for the Grushin operator in R^2 a... 详细信息

关键词： Hermite operator Heisenberg group Sub-Laplacian Gruhsin operator Heat kernel Laguerre function

Fourier transform of anisotropic mixed-norm Hardy spaces

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Frontiers of Mathematics in China 2021年第1期16卷 119-139页

作者： Long HUAnG der-Chen CHAnG Dachun YAnG Laboratory of Mathematics and Complex Systems(Ministry of Education of China) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875China Department of Mathematics and Statistics Georgetown UniversityWashingtonDC 20057USA Graduate Institute of Business Adminstration College of ManagementFu Jen Catholic UniversityNew Teipei City 242China

Let a:=(a1,…,an)∈[1,∞)n,p:=(p1,…,pn)∈(0,1]n,Hpa(R^(n))be the anisotropic mixed-norm Hardy space associated with adefined via the radial maximal function,and let f belong to the Hardy space Hpa(R^(n)).In this article,we show that the Fourier transform fcoincides with a con.inuous function g onℝn.in the sense of tempered distributions and,moreover,this con.inuous function g,multiplied by a step function associated with a,can be pointwisely controlled by a constant multiple of the Hardy space norm of *** proofs are achieved via the known atomic characterization of Hpa(R^(n))and the establishment of two uniform estimates on anisotropic mixed-norm *** applications,we also conclude a higher order convergence of the con.inuous function gat the ***,a variant of the Hardy-Littlewood inequality in the anisotropic mixed-norm Hardy space setting is also *** these results are a natural generalization of the well-known correspon.ing conclusions of the classical Hardy spaces Hp(R^(n))with p∈0,1],and are even new for isotropic mixed-norm Hardy spaces on∈n.

关键词： Anisotropic(mixed-norm)Hardy space Fourier transform Hardy-Littlewood inequality

Lin.ing electronic structure calculations to generalized stacking fault energies in multicomponent alloys

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npj Computational Materials 2020年第1期6卷 989-997页

作者： Anirudh Raju natarajan Anton Van der Ven Materials Department University of CaliforniaSanta BarbaraCA 93106USA

The generalized stacking fault energy is a key ingredient to mesoscale models of *** we develop an approach to quantify the dependence of generalized stacking fault energies on the degree of chemical disorder in multicomponent *** introduce the notion of a“configurationally-resolved planar fault”(CRPF)energy and extend the cluster expansion method from alloy theory to express the CRPF as a function of chemical occupation variables of sites surroun.ing the *** apply the approach to explore the composition and temperature dependence of the unstable stacking fault energy(USF)in binary Mo–nb ***-principles calculations are used to parameterize a formation energy and CRPF cluster *** Carlo simulations show that the distribution of USF energies is significantly affected by chemical composition and *** formalism is broadly applicable to arbitrary crystal structures and alloy chemistries and will enable the development of rigorous models for deformation mechanisms in high-entropy alloys.

关键词： alloy alloys fault