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Nuclear Hexadecapole Deformation Effects on the Production of Super-Heavy Elements

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Chinese Physics Letters 2010年第6期27卷 66-69页

作者： WANG Nan DOU Liang ZHAO En-Guang werner Scheid College of Physics Shenzhen University Shenzhen 518060 Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 Center of Theoretical Nuclear Physics National Laboratory of Heavy ion Accelerator Lanzhou 730000 Institut fur Theoretisehe Physik Justus-Liebig-Universitat D-35392 Giessen Germany

We investigate the effects of the nuclear hexadecapole deformations on the interaction potentials between nuclei, the driving potentials and the fusion probabilities for some cold fusion reactions leading to super-heavy elements. It is found that nuclear hexadecapole deformations change significantly the structure of the driving potentials and the fusion probabilities for some reaction channels.

关键词： Nuclear Deformation Effects Elements

Three-dimensional structured on-chip stacked zone plates for nanoscale X-ray imaging with high efficiency

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Nano Research 2014年第4期7卷 528-535页

作者： Stephan werner Stefan Rehbein Peter Guttmann Gerd Schneider Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH Institute for Soft Matter and Functional Materials Albert-Einstein-Straβe15 12489 Berlin Germany

Fresnel zone plates are the key optical elements for nanoscale focusing of X-ray beams with high spatial resolution. Conventional zone plates manufactured by planar nanotechnology processes are limited by the achievable aspect ratios of their zone structures. Additionally, ultra-high resolution X-ray optics with high efficiency requires three-dimensional （3-D） shaped tilted zones. The combination of high spatial resolution and high diffraction efficiency is a fundamental problem in X-ray optics. Based on electrodynamical simulations, we find that the optimized zone plate profile for volume diffraction is given by zone structures with radially increasing tilt angles and decreasing zone heights. On-chip stacking permits the realization of such advanced 3-D profiles without significant loss of the maximum theoretical efficiency. We developed triple layer on-chip stacked zone plates with an overlay accuracy of sub-2 nm which fulfills the nanofabrication requirements. Efficiency measurements of on-chip stacked zone plates show significantly increased values compared to conventional zone plates.

关键词： X-ray optics Fresnel zone plates X-ray imaging X-ray microscopy volume diffraction

Leaching of rare Earth elements from an Illinois basin coal source

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Journal of Rare Earths 2019年第3期37卷 312-321页

作者： X.Yang J.werner R.Q.Honaker Department of Mining Engineering University of Kentucky

The existence of rare earth elements(REEs) in coal sources at elevated concentrations has been the focus of several studies over the past decade. However, limited research has been conducted on methods to recover and refine the REEs. This paper reports the results of a detailed study into the potential of selectively recovering REEs in an Illinois basin coal source by leaching. Leaching characteristics are obtained for several segments obtained from a core sample as well as three different reject materials collected at a coal processing plant. Using a 1.2 mol/L sulfuric acid solution at 75 ℃,over 60% REE recovery is achieved from the direct floor and an inner parting material as well as the coal-rich core segments that are pretreated by low-temperature plasma oxidation to obtain access to the microdispersed mineral matter. In the leachable parting material, fluorapatite is detected by XRD analysis,which is one of the more soluble phosphate minerals with a documented association with REEs. For the three plant reject samples, the leaching recovery values obtained for the heavy REEs are higher than those obtained for the light REEs under the standard leaching conditions and when 0.1 mol/L(NH_4)_2SO_4 was used to extract REEs by an ion exchange mechanism. Thermal activation by roasting or chemical activation by pretreatment using 8 mol/L NaOH solution increases the total REE recovery with significantly higher gains obtained for the light REEs. Leaching kinetics are relatively fast within the first 2 h and then slow to provide relatively low overall recovery values under the standard test conditions for the coarse and fine reject samples. However, significantly higher recovery values are realized when treating mixed-phase(middling) particles existing within the coarse reject material.

关键词： Leaching Coal Thermal activation Chemical activation Rare earth elements

Symmetry Adapted Block Diagonalisation in Equivariant Steady State Bifurcation Problems and its Numerical Application

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数学进展 1991年第4期 455-487页

作者： Peter Stork,Bodo werner Institut fur Angewandte Mathematik der Universitat Hamburg Bundesstr.55 D-2000 Hamburg 13 Federal Republic of Germany Institut fur Angewandte Mathematik der Universitat Hamburg Bundesstr.55 D-2000 Hamburg 13 Federal Republic of Germany

Considering steady state bifurcation of single parameter r-equivariant systemswhere Γ is a compact Lie group acting on X via a faithful orthogonal representation, we simultaneously block-diagonalise all jacobians of g along a solution path with respect to symmetry adapted subspaces and apply bifurcation groups to reduce symmetry breaking bifurcation points to simple bifurcation points. In generical situations this algorithm allows for numerically stable use of continuation methods and steady state bifurcation point detection and computation. The large scale decrease of computing efforts is demonstrated at computing the equilibria of a hexagonal lattice dome with 21 degrees of freedom, we present a great variety of solution arcs with symmetry from full D6 down to Z2 symmetry.

关键词： Symmetry Adapted Block Diagonalisation in Equivariant Steady State Bifurcation Problems and its Numerical Application

High precision magnetometer for geomagnetic exploration onboard of the China Seismo-Electromagnetic Satellite

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Science China(Technological Sciences) 2018年第5期61卷 659-668页

作者： CHENG BingJun ZHOU Bin MAGNES werner LAMMEGGER Roland POLLINGER Andreas National Space Science Center Chinese Academy of Sciences Space Research Institute Austrian Academy of Sciences Institute of Experimental Physics Graz University of Technology

The China Seismo-Electromagnetic Satellite(CSES) is the first platform of China's earthquake observation system in space and the first satellite of China's geophysical field detection missions. The high precision magnetometer(HPM), which contains two fluxgate sensors and a coupled dark state magnetometer(CDSM), measures the vector of the Earth's magnetic field with a bandwidth from DC to 15 Hz. The two fluxgate sensors are in a gradiometer configuration in order to reduce satellite interferences. Additionally, the CDSM sensor measures the scalar value of the magnetic field with higher accuracy and *** data processing and calibration methods have been prepared to get accurate vector magnetic field data. This includes the calibration of each of the three sensors, the absolute vector correction algorithm, the spacecraft magnetic interference elimination and the coordinate transformation method. Also the instrument performances based on ground calibration activities are shown in this article.

关键词： magnetometer fluxgate magnetometer CPT magnetometer magnetometer calibration data processing

On Radar Signatures of Upwelling

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Journal of Geodesy and Geoinformation Science 2021年第1期4卷 17-23页

作者： werner ALPERS Kan ZENG Institute of Oceanography University of HamburgHamburg 20146Germany Ocean Remote Sensing Institute Ocean University of ChinaQingdao 266003China

In studies of upwelling,usually data from infrared and optical sensors is used which provides information on the sea surface temperature(SST)and the chlorophyll-a(Chl-a)*** this paper,we show that also synthetic aperture radars(SAR)images can give valuable contribution to such *** regions become detectable by SAR because they are associated with a reduction of the radar backscatter due to(1)the change of the stability of the air-sea interface or/and(2)the presence of biogenic ***,the boundary of upwelling regions consists of a line of increased radar backscatter due to the presence of convergent surface flow.

关键词： upwelling synthetic aperture radar cyclonic eddies Agulhas Return Current biogenic surface films chlorophyll concentration air-sea interface sea surface temperature

AGN: The Gamma-Ray Status after CGRO

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天文研究与技术 2003年第S1期 121-125页

作者： werner Collmar Max-Planck-Institut für extraterrestrische Physik Giessenbachstr.D 85748 Garching Germany

By detecting more than 100 AGN at γ ray energies, the experiments aboard CGRO finally opened the field of extragalactic γ ray astronomy. A general picture has developed which is briefly summarized.

关键词： AGN The Gamma-Ray Status after CGRO Long

Impactless biped walking on a slope

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Theoretical & Applied Mechanics Letters 2013年第1期3卷 25-31页

作者： Lulu Gong werner Schiehlen School of Life Sciences and Technology Tongji University Institute of Eng. Comput. Mechanics University of Stuttgart

Walking without impacts has been considered in dynamics as a motion/force control problem. In order to avoid impacts, an approach for both the specified motion of the biped and its ground reaction forces was presented yielding a combined motion and force control problem. As an application, a walker on a horizontal plane has been considered. In this paper, it is shown how the control of the ground reaction forces and the energy consumption depend on the gradient of a slope. The biped dynamics and the constraints within the biped system and on the ground are discussed. A motion control synthesis is developed using the inverse dynamics principle proven to be most efficient for human walking research, too. The impactless walking with controlled legs is illustrated by a seven-link biped. The ＂flying＂ biped has nine degrees of freedom, with six control inputs. During locomotion, the standing leg has three scleronomic constraints, and the trunk has three rheonomic constraints. However, there are three rheonomic constraints for the prescribed leg motion or three scleronomic constraints for reaction forces of the trailing leg, respectively. The nominal control action for impactless walking can be precomputed and stored. The model proposed allows the investigation of several problems： uphill and downhill walking, optimization of step length,stiction of the feet on the slope and many more. All these findings are also of interest in biomechanics. C 2013 The Chinese Society of Theoretical and Applied Mechanics. [doi：10.1063/2.1301302]

关键词： biped impactless walking motion/force control slope

Evaluation of coarse-grained CFD-DEM models with the validation of PEPT measurements

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Particuology 2023年第11期82卷 48-63页

作者： Hanqiao Che Dominik werner Jonathan Seville Tzany Kokalova Wheldon Kit Windows-Yule School of Chemical Engineering University of BirminghamB152TTUK School of Physics and Astronomy University of BirminghamBirminghamB152TTUK

Computational Fluid Dynamics coupled with Discrete Element Method (CFD-DEM) is a commonly used numerical method to model gas-solid flow in fluidised beds and other multiphase systems. A significant limitation of CFD-DEM is the feasibility of the realistic simulation of large numbers of particles. Coarse-graining (CG) approaches, through which groups of multiple individual particles are represented by single, larger particles, can substantially reduce the total number of particles while maintaining similar system dynamics. As these three CG models have not previously been compared, there remains some debate, however, about the best practice in the application of CG in CFD-DEM simulations. In this paper, we evaluate the performance of three typical CG methods based on simulations of a bubbling fluidised bed. This is achieved through the use of a numerical validation framework, which makes full use of the high-resolution 3D positron emission particle tracking (PEPT) measurements to rigorously validate the outputs of CFD-DEM simulations conducted using various different coarse-graining models, and various different degrees of coarse-graining. The particle flow behaviours in terms of the particle occupancy field, velocity field, circulation time, and bubble size and velocity, are comprehensively analysed. It is shown that the CG simulation starts to fail when the size ratio between the bed chamber and the particles decreases to approximately 20. It is also observed, somewhat surprisingly, that the specific CG approach applied to interparticle contact parameters does not have a substantial effect on the simulation results for the bubbling bed simulations across a wide range of CG factors.

关键词： Coarse-graining Discrete element method Computational fluid dynamics CFD-DEM Positron emission particle tracking(PEPT) Bubbling fluidised bed