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Uncertainty relations for general phase spaces

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Frontiers of physics 2016年第3期11卷 51-60页

作者： Reinhard F. werner Institut fiir Theoretische Physik Leibniz Universitiit Hannover Germany

We describe a setup for obtain!ing uncertainty relations for arbitrary pairs of observables related by a Fourier transform. The physical examples discussed here are the standard position and momentum, number and angle, finite qudit systems, and strings of qubits for quantum information applications. The uncertainty relations allow for an arbitrary choice of metric for the outcome distance, and the choice of an exponent distinguishing, e.g., absolute and root mean square deviations. The emphasis of this article is on developing a unified treatment, in which one observable takes on values in an arbitrary locally compact Abelian group and the other in the dual group. In all cases, the phase space symmetry implies the eciuality of measurement and preparation uncertainty bounds. There is also a straightforward method for determining the optimal bounds.

关键词： uncertainty relations phase space measurement uncertainty

A two-density approach to the general many-body problem and a proof of principle for small atoms and molecules

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Frontiers of physics 2019年第2期14卷 89-96页

作者： Thomas Pope werner Hofer School of Natural and Environmental Sciences Newcastle UniversityNewcastle NE1 7RUUnited Kingdom Institute of Physics & University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100190China

An extended electron model fully recovers many of the experimental results of quantum mechanics while it avoids many of the pitfalls and remains generally free of paradoxes. The formulation of the manybody electronic problem here resembles the Kohn Sham formulation of standard density functional theory. However, rather than referring electronic properties to a large set of single electron orbitals, the extended electron model uses only mass density and field components, leading to a substantial increase in computational efficiency. To date, the Hohenberg-Kohn theorems have not been proved for a model of this type, nor has a universal energy functional been presented. In this paper, we address these problems and show that the Hohenberg Kohn theorems do also hold for a density model of this type. We then present a proof^of^concept practical implementation of this method and show that it reproduces the accuracy of more widely used methods on a test-set of small atomic systems, thus paving the way for the development of fast, efficient and accurate codes on this basis.

关键词： many-body condensed matter Hartree-Fock density functional theory extended electrons

Single-mode and tunable VCSELs in the near-to mid-infrared Invited Paper

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Chinese Optics Letters 2008年第10期6卷 743-747页

作者： Markus-Christian Amann werner Hofmann Walter Schottky Institut Technische Universitt MnchenD-85748 GarchingGermany

Single-mode, long-wavelength vertical-cavity surface-emitting lasers （VCSELs） in the near- to mid-infrared covering the wavelength range from 1.3 to 2.3 μm are presented. This wide spectral emission range opens applications in gas sensing and optical interconnects. All these lasers are monolithically grown in the InGaAlAs-InP material system utilizing a buried tunnel junction （BTJ） as current aperture. Fabricated with a novel high-speed design with reduced parasitics, bandwidths in excess of 10 GHz at 1.3 and 1.55 μm have been achieved. Therefore, the coarse wavelength division multiplexing （CWDM） wavelength range of 1.3 to 1.6 μm at 10 Gb/s can be accomplished with one technology. Error-free data-transmission at 10 Gb/s over a fiber link of 20 km is demonstrated. One-dimensional arrays have been fabricated with emission wavelengths addressable by current tuning. Micro-electro-mechanical system （MEMS） tunable devices provide an extended tuning range in excess of 50 nm with high spectral purity. All these devices feature continuous-wave （CW） operation with typical single-mode output powers exceeding 1 mW. The operation voltage is around 1 - 1.5 V and power consumption is as low as 10 - 20 mW. Furthermore, we have also developed VCSELs based on GaSb, targeting functionality of tunable diode laser spectroscopy （TDLS） applying a 1.84-μm VCSEL. at the wavelength range from 2.3 to 3.0 μm. The systems is shown by presenting a laser hygrometer

关键词： mode VCSEL Single-mode and tunable VCSELs in the near-to mid-infrared Invited Paper

Heisenberg, uncertainty, and the scanning tunneling microscope

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Frontiers of physics 2012年第2期7卷 218-222页

作者： werner A. Hofer (1) 1. Department of Physics University of Liverpool L69 3BX Liverpool UK

We show by a statistical analysis of high-resolution scanning tunneling microscopy （STM） exper- iments, that the interpretation of the density of electron charge as a statistical quantity leads to a conflict with the Heisenberg uncertainty principle. Given the precision in these experiments we find that the uncertainty principle would be violated by close to two orders of magnitude, if this interpretation were correct. We are thus forced to conclude that the density of electron charge is a physically real, i.e., in principle precisely measurable quantity.

关键词： scanning tunneling microscope electron charge density functional theory uncertaintyrelations

Spin in the extended electron model

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Frontiers of physics 2017年第3期12卷 81-85页

作者： Thomas Pope werner Hofer School of Chemistry Newcastle University Newcastle NE1 7RU UK

It has been found that a model of extended electrons is more suited to describe theoretical simula- tions and experimental results obtained via scanning tunnelling microscopes, but while the dynamic properties are easily incorporated, magnetic properties, and in particular electron spin properties pose a problem due to their conceived isotropy in the absence of measurement. The spin of an electron reacts with a magnetic field and thus has the properties of a vector. However, electron spin is also isotropic, suggesting that it does not have the properties of a vector. This central conflict in the de- scription of an electron＇s spin, we believe, is the root of many of the paradoxical properties measured and postulated for quantum spin particles. Exploiting a model in which the electron spin is described consistently in real three-dimensional space - an extended electron model - we demonstrate that spin may be described by a vector and still maintain its isotropy. In this framework, we re-evaluate the Stern-Gerlach experiments, the Einstein-Podolsky-Rosen experiments, and the effect of consecutive ts and find in all cases a fairly intuitive explanation.

关键词： spin extended electron model geometric algebra Stern-Gerlach experiment Einstein-Podolsky-Rosen magnetism

Case studies of high-sensitivity monitoring of natural and engineered slopes

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Journal of Rock Mechanics and Geotechnical Engineering 2015年第4期7卷 379-384页

作者： werner Lienhart Graz University of Technology

High-sensitivity monitoring solutions are crucial for early warning systems of earth structures. In this paper, we discuss the design and implementation of such systems for natural and engineered slopes using two case studies. At the Gradenbach Observatory, one key element of the monitoring system is a large fiber optic strain rosette embedded in the slope. We demonstrate that the strain rosette can depict landslide deformations much earlier than geodetic sensors like GPS or total stations and is therefore well suitable for an early warning system. In a second application we report the construction of a reinforced earth structure using geogrids. A distributed fiber optic measurement system was installed to measure the current operating grade of the geogrids within the earth structure. About 2 km of Brillouin sensing cables were installed in the project area. It is demonstrated that the developed monitoring system is well suited for assessing the current state of health of reinforced earth structures.

关键词： Structural health monitoring Fiber optic sensors Brillouin optical frequency domain analyzer(BOFDA) SOFO sensors Reinforced eart

Quenching Simulation of PM Coated Tools

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材料热处理学报 2004年第5B期25卷 752-757页

作者： Axel Htter werner Theisen Christoph Broeckmann Chair of Materials Technology Ruhr University Bochum GermanyChair of Materials Technology Ruhr University Bochum GermanyKoppern Entwicklungs-GmbH Hattingen Germany

HIP cladding is a powder metallurgical coating technique used in the production of wear parts and tools. In many cases the composite components consist of carbide-free hot-work steel as base material and wear resistant carbide-rich PM cold-work steel as coating material. To ensure operativeness a heat treatment matched to the substrate and coating material is required. Dissimilar phase transformation behaviour and different thermal expansion coefficients of layer and substrate entail inner stresses affecting the transformation kinetics in turn. In order to get a deeper insight into these effects Finite Element simulation tools are used. On the one hand, the transient heat conduction problem of the quenching process has to be solved. Non-linear boundary conditions and phase transformation of both, substrate and layer are considered. On the other hand, the mechanical response is calculated. The overall aim of the investigation is an improvement of common heat treatment techniques used for HIP cladded wear parts.

关键词：数值模拟淬火 HIP包覆磨损工具钢

Moonlighting PPKL1 reveals a role of cytokinin in regulating rice grain size

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Molecular Plant 2022年第2期15卷 216-218页

作者： Tomas werner Thomas Schmülling Institute of Biology University of GrazNAWI GrazSchubertstrasse 518010 GrazAustria Institute of Biology/Applied Genetics Dahlem Centre of Plant Sciences(DCPS)Freie Universitat BerlinAlbrecht-Thaer-Weg 614195 BerlinGermany

Rice is the staple food of more than half of the world's population,and major efforts are being made to improve rice *** yield is mainly determined by three components:number of panicles per plant,number of grains per panicle,and grain weight,which is positively associated with grain ***,grain size is an important agricultural trait for yield improvement in rice,and it is controlled by multiple genetic factors and environmental cues(Li et al.,2018).The final size of rice grains is largely determined by cell proliferation and cell expansion in the spikelet hull(husk),which sets the storage capacity of the grain and limits grain filling(Li et al.,2018).A number of quantitative trait loci for grain size have been identified and their underlying molecular functions *** include,for example,protein ubiquitination,chromatin modifications,transcription factors,RNA-mediated regulatory networks,and multiple plant hormones(Li and Li,2016).Among the plant hormones,brassinosteroids and cytokinin play pivotal roles in grain size ***,Liu et al.(2021)reported the discovery of an unexpected novel link between the brassinosteroid and the cytokinin signaling pathways with a major impact on rice grain size.

关键词： grain size lighting

亚苄基乙酰苯的液相加氢：溶剂、催化剂载体、金属种类及反应条件的影响(英文)

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Chinese Journal of Catalysis 2011年第8期32卷 1312-1322页

作者： Achim STOLLE Christine SCHMGER Bernd ONDRUSCHKA werner BONRATH Thomas F. KELLER klaus D. JANDT Institute for Technical Chemistry and Environmental Chemistry (ITUC) Friedrich-Schiller University Jena Institute for Technical Chemistry and Environmental Chemistry (ITUC) Friedrich-Schiller University Jena R&D Chemical Process Technology DSM Nutritional ProductsP.O. Box 2676 Institute of Materials Science and Technology (IMT) Friedrich-Schiller University Jena

Innovative catalysts based on a "porous glass" support material were developed and investigated for the reduction of benzalace-tophenone. The easy preparation conditions and possibility to use different metals (e.g. Pd, Pt, Rh) for impregnation gave a broad variety of these catalysts. Hydrogenation experiments with these supported catalysts were carried out under different hydrogen pressures and temperatures. Porous glass catalysts with Pd as the active component gave chemoselective hydrogenation of benzalacetophenone, while Pt- and Rh-catalysts tended to further reduce the carbonyl group, especially at elevated hydrogen pressures and temperatures. Kinetic analysis of the reactions revealed these had zero order kinetics, which was independent of the type of porous glass support and solvent used.

关键词： chalcone hydrogenation porous glass supported catalyst