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81.
We have produced a multilayer transmission filter with 100 periods of Cr/C to achieve a significant phase retardation while maintaining good transmission for photon energies just below the carbon K edge. This device was installed into a polarimeter behind the SX700/3 monochromator at the Berlin synchrotron radiation laboratory, BESSY. The phase-retardation properties were observed as theoretically predicted. Agreement between experiment and calculation could be obtained by introduction of a rather small interface roughness in the simulation code (σ = 0.65 nm rms). An observed phase retardation of 5° was sufficient to permit, for the first time we believe, a complete and unambiguous polarization analysis of soft-x-ray synchrotron radiation (265-eV photon energy) with primary standards. 相似文献
82.
Schäfer M 《Applied optics》1994,33(28):6591-6596
The optical properties of highly chirped gratings of broadband reflection-type volume phase holograms are evaluated by a ray-tracing approach. The deformation of the fringes as well as the change of refractive index is attributed to swelling during processing. For high-efficiency holograms the problem can be reduced to geometric optics. The power density distribution in the focus of an on-axis mirror is calculated by a Monte Carlo integration. The results are discussed for replay conditions that are relevant for photovoltaic applications. 相似文献
83.
Hendrik Voigt Aaron Rigoni Evgeniy Boltynjuk Mohammed Reda Chellali Bonnie Tyler Harald Rösner Sergiy Divinski Horst Hahn Gerhard Wilde 《Advanced functional materials》2023,33(44):2302386
Comprehensive analyses of the atomic structure using advanced analytical transmission electron microscopy-based methods combined with atom probe tomography confirm the presence of distinct glass–glass interfaces in a columnar Cu-Zr nanoglass synthesized by magnetron sputtering. These analyses provide first-time in-depth characterization of sputtered film nanoglasses and indicate that glass–glass interfaces indeed present an amorphous phase with reduced mass density as compared to the neighboring amorphous regions. Moreover, dedicated analyses of the diffusion kinetics by time-of-flight secondary ion mass spectroscopy (ToF SIMS) prove significantly enhanced diffusivity, suggesting fast transport along the low density glass–glass interfaces. The present results further indicate that sputter deposition is a feasible technique for reliable production of nanoglasses and that some of the concepts proposed for this new class of glassy materials are applicable. 相似文献
84.
Lukas Schäfer Konstantin Skokov Fernando Maccari Iliya Radulov David Koch Andrey Mazilkin Esmaeil Adabifiroozjaei Leopoldo Molina-Luna Oliver Gutfleisch 《Advanced functional materials》2023,33(4):2208821
Permanent magnets based on neodymium-iron-boron (Nd-Fe-B) alloys provide the highest performance and energy density, finding usage in many high-tech applications. Their magnetic performance relies on the intrinsic properties of the hard-magnetic Nd2Fe14B phase combined with control over the microstructure during production. In this study, a novel magnetic hardening mechanism is described in such materials based on a solid-state phase transformation. Using modified Nd-Fe-B alloys of the type Nd16Febal-x-y-zCoxMoyCuzB7 for the first time it is revealed how the microstructural transformation from the metastable Nd2Fe17Bx phase to the hard-magnetic Nd2Fe14B phase can be thermally controlled, leading to an astonishing increase in coercivity from ≈200 kAm−1 to almost 700 kAm−1. Furthermore, after thermally treating a quenched sample of Nd16Fe56Co20Mo2Cu2B7, the presence of Mo leads to the formation of fine FeMo2B2 precipitates, in the range from micrometers down to a few nanometers. These precipitates are responsible for the refinement of the Nd2Fe14B grains and so for the high coercivity. This mechanism can be incorporated into existing manufacturing processes and can prove to be applicable to novel fabrication routes for Nd-Fe-B magnets, such as additive manufacturing. 相似文献
85.
Wanwan Qiu Jenny Gehlen Margherita Bernero Christian Gehre Gian Nutal Schädli Ralph Müller Xiao-Hua Qin 《Advanced functional materials》2023,33(20):2214393
Tomographic volumetric bioprinting (VBP) enables fast photofabrication of cell-laden hydrogel constructs in one step, addressing the limitations of conventional layer-by-layer additive manufacturing. However, existing biomaterials that fulfill the physicochemical requirements of VBP are limited to gelatin-based photoresins of high polymer concentrations. The printed microenvironments are predominantly static and stiff, lacking sufficient capacity to support 3D cell growth. Here a dynamic resin based on thiol–ene photo-clickable polyvinyl alcohol (PVA) and thermo-sensitive sacrificial gelatin for fast VBP of functional ultrasoft cell-laden hydrogel constructs within 7–15 s is reported. Using gelatin allows VBP of permissive hydrogels with low PVA contents of 1.5%, providing a stress-relaxing environment for fast cell spreading, 3D osteogenic differentiation of embedded human mesenchymal stem cells and matrix mineralization. Additionally, site-specific immobilization of molecules-of-interest inside a PVA hydrogel is achieved by 3D tomographic thiol–ene photopatterning. This technique may enable spatiotemporal control of cell-material interactions and guides in vitro tissue formation using programmed cell-friendly light. Altogether, this study introduces a synthetic dynamic photoresin enabling fast VBP of functional ultrasoft hydrogel constructs with well-defined physicochemical properties and high efficiency. 相似文献
86.
S. Matthiesen T. Gwosch T. Schäfer P. Dültgen C. Pelshenke H.-J. Gittel 《Forschung im Ingenieurwesen》2016,80(1-2):17-27
This article shows by experimental studies on angle grinders, how application-equivalent stresses on the components can be determined. For this purpose a distance measurement technique is applied with which the movement of the shaft is detected while the angle grinder is in operation. The research results support validation activities in product development and contribute to early validation. It helps to analyzing the dynamic and working life of the power tool and therefore construction targets are derived. The related applications are considered and power tools with measuring equipment in the lab are tested. The measurement results are presented and possible causes and effects on the life of the components are discussed. With the method of investigation it is possible to study the behavior of subsystems already in development phases in which the overall system is not physically present. 相似文献
87.
R. Strauss G. Angloher A. Bento C. Bucci L. Canonica X. Defay A. Erb F. v. Feilitzsch N. Ferreiro Iachellini P. Gorla A. Gütlein D. Hauff J. Jochum M. Kiefer H. Kluck H. Kraus J. C. Lanfranchi J. Loebell A. Münster C. Pagliarone F. Petricca W. Potzel F. Pröbst F. Reindl K. Schäffner J. Schieck S. Schönert W. Seidel L. Stodolsky C. Strandhagen A. Tanzke H. H. Trinh Thi C. Türkoglu M. Uffinger A. Ulrich I. Usherov S. Wawoczny M. Willers M. Wüstrich A. Zöller 《Journal of Low Temperature Physics》2016,184(3-4):866-872
88.
T. Dubberstein M. Schürmann H. Chaves H.-P. Heller C. G. Aneziris 《International Journal of Thermophysics》2016,37(10):100
A novel vibrating finger viscometer for high-temperature measurement in liquid metals and alloys up to 1823 K was constructed. The dynamic viscosity (\(\eta \)) of the liquid fluid is measured as a product of \((\rho \cdot \eta )^{0.5}\) and the relative change of the field coil input for a constant amplitude recording at the resonant frequency of the oscillator. The viscometer was calibrated at 298 K using reference silicon oils with varying kinematic viscosities (\(\nu \)), \((0.79\hbox { to } 200)\times 10^{-6}\hbox { m}^{2}\cdot \hbox {s}^{-1}\). In the present study, the viscosity of liquid gold (\(99.99\,\%\) Au), silver (\(99.9\, \%\) Ag), and tin (\(99.9\,\%\) Sn) was measured. The viscosities expressed as an Arrhenius function of temperature are: The viscosity values are consistent within the range of available literature data.
相似文献
$$\begin{aligned} \hbox {for Au:}\quad \quad \hbox {ln }\eta= & {} -0.1990+\frac{2669}{T}\\ \hbox {for Ag:} \quad \quad \hbox {ln }\eta= & {} -0.4631+\frac{2089}{T}\\ \hbox {for Sn:} \quad \quad \hbox {ln }\eta= & {} -0.5472+\frac{671}{T} \end{aligned}$$
89.
90.
High Efficiency Poly(acrylonitrile) Electrospun Nanofiber Membranes for Airborne Nanomaterials Filtration
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Riyadh Al‐Attabi Ludovic F. Dumée Lingxue Kong Jürg A. Schütz Yosry Morsi 《Advanced Engineering Materials》2018,20(1)