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正博士后[德国]Max Planck InstituteMax Planck Institute for Biophysical Chemistry in Gttingen(Germany)invites applications for positions as Postdoc orPh D student(Code-Number 22-14).You should have a strongbackground in physics,chemistry,computer science and/ormathematics and hold a Ph D or a Masters degree(or equivalent)in any of these or a related field,be highly interactive and willingto collaborate efficiently with experts from all natural sciences.     

Design optimization of a C-band traveling-wave accelerating structure for a compact X-ray Free Electron Laser facility

The research and development of a C-band (5712 MHz) high gradient traveling-wave accelerating structure has been in progress for some years at the Shanghai Institute of Applied Physics, Chinese Academy of Sciences. Conceptual design of the accelerating structure has been accomplished, and verified by cold testing an experimental model. The first prototype structure is now ready for high RF power tests. To develop a robust high gradient C-band accelerating structure, an optimized constant gradient structure with a 4 /5 operating mode for future X-ray Free Electron Laser facilities is proposed in this paper. This scheme can improve the breakdown stability and beam quality. The high power RF system, four operating modes and disk iris shape are analyzed and optimized.     

New insights into the properties of high-manganese steel

In the Collaborative Research Centre 761’s“Steel ab initio-quantum mechanics guided design of new Fe based materials,”scientists and engineers from RWTH Aachen University and the Max Planck Institute for Iron Research conducted research on mechanism-controlled material development with a particular focus on high-manganese alloyed steels.From 2007 to 2019,a total of 55 partial projects and four transfer projects with industrial participation(some running until 2021)have studied material and process design as well as material characterization.The basic idea of the Collaborative Research Centre was to develop a new methodological approach to the design of structural materials.This paper focuses on selected results with respect to the mechanical properties of high-manganese steels,their underlying physical phenomena,and the specific characterization and modeling tools used for this new class of materials.These steels have microstructures that require characterization by the use of modern methods at the nm-scale.Along the process routes,the generation of segregations must be taken into account.Finally,the mechanical properties show a characteristic temperature dependence and peculiarities in their fracture behavior.The mechanical properties and especially bake hardening are affected by short-range ordering phenomena.The strain hardening can be adjusted in a never-before-possible range,which makes these steels attractive for demanding sheet-steel applications.     

Mechanism of the Greenland-Scotland Ridge overflow variation under different atmospheric CO2 scenarios

Baroclinic transport and the barotropic effect are two different viewpoints for understanding the mechanism of the Greenland-Scotland Ridge overflow. The mechanism of this overflow, being an important deep branch of thermohaline circulation, deserves research discussion, especially against the background of global warming. Using the newly developed ECHAM5/MPI-OM, of the Max Planck Institute for Meteorology, which is an advanced atmospheresea iceocean coupled climate model, the mechanism of the Greenland-Scotland Ridge overflow variation under different atmospheric CO2 scenarios is studied. First, a control experiment is forced by a fixed CO2 concentration of 280 ppmv, which is the pre-industrial level before 1860. Three sensitive experiments are carried out under different scenarios of increased atmospheric CO2 concentrations, which are listed in the Intergovernmental Panel on Climate Change (IPCC) assessment report (B1, A1B and A2). In the control run, more water with higher salinity intruding into the Greenland-Icelandic-Norwegian Seas results in greater barotropic transport and greater overflow because of the baroclinic effect. Therefore, the barotropic effect and baroclinic effect on the overflow are unified. Under the atmospheric CO2 scenarios, the strength of overflow across the Faro-Bank Channel is controlled by the baroclinic effect and the increase in Denmark Strait overflow is attributed to the barotropic effect.     

The Kavli Institute for Theoretical Physics China at the Chinese Academy of Sciences

KITPC is a platform for the sharing of knowledge at the frontiers of physics. Founded in 2006 and in operation since May 2007, the Institute has quickly established itself as a center for world-class interdisciplinary work. KITPC     

Editor's note

Yoshiyuki （Yoshi） Tatsumi is currently the Program Director of the Institute for Research on Earth Evolution of Japan Agency for Marine-Earth Science and Technology （IFREE/JAMSTEC）. He received a BSc in Geology with honors （1978） and an MS （1980） from Kyoto University, and a PhD in Earth Sciences from the University of Tokyo in 1983. He held research/visiting positions at the University of Manchester, UK （1983--1984） and the University of Tasmania, Australia （1989--1990） while holding Assistant and Associate Professorships at Kyoto University （1983--1996）. He has been full Professor of School of Earth Sciences, Institute of Geothermal Sciences at the Kyoto University, and Ocean Research Institute at the University of Tokyo since 1996. Yoshi is a world-renowned igneous petrologist and authority on magma generation and evolution associated with subduction zones. He uses magmatism as a tool to understand the evolution of the solid Earth. He has published over 120 research papers in leading journals such as Nature, Science, Geology, Earth and Planetary Science Letters, Journal of Geophysical Research, Journal of Petrology, Contributions to Petrology and Mineralogy, Chemical Geology, etc. Every igneous petrologist today, in particular those who study the petro- genesis of subduction-zone igneous rocks, is impressed with and influenced by Yoshi＇s classic book 《Subduction Zone Magmatism》 （Tatsumi Y. and Eggins S., Blackwell Publishing, 1995, 1--224）, which has been widely cited in research papers and used in classrooms. His thinkina goes bevond magmatism.     

An improved algorithm for blind carrier frequency estimation with burst MPSK transmissions

This paper presents an improved non-data-aided algo-rithm for carrier frequency estimation for burst M-ary PSK signals when modulation order M and training symbols are unknown. Unlike data-aided estimation, a phase clustering algorithm is used first to estimate M and modulated information is removed by a vari-able interval linear phase unwrapping. Then, a high-order correlation algorithm with proper correction is present, which reduces the probability of phase ambiguity and promotes anti-noise capability of the estimation. Simulations are given to analyze the unbiased esti-mation range, and the asymptotic performance and symbol number are needed to compare with the former algorithms. The new algo-rithm has a large estimation range close to the theoretical maximum value for non-data-aided estimation and has a better performance than earlier non-data-aided techniques for large frequency offset, low signal-to-noise ratio, and limited symbol numbers.     

Preface from Guest Editor

Max Lu has been serving as Deputy Vice-Chancellor and Vice President (Research) since 2009 at the University of Queensland,Australia.He was also the Foundation Director of the ARC Centre of Excellence for Functional Nanomaterials from 2003 to 2009. Professor Lu's research expertise is in the areas of materials chemistry and nanotechnology.He is known for his work on nanoparticles and nanoporous materials for clean energy and environmental technologies.With over 500 journal publications in high impact journals including Nature,Journal of the American Chemical Society,Angewandte Chemie,and Advanced Materials;he is also co-inventor of 20 international patents.Professor Lu is an Institute for Scientific Information (ISI) Highly Cited Author in Materials Science with over 17,500 citations (h-index of 63).He has received numerous prestigious awards nationally and internationally including the Chinese Academy of Sciences International Cooperation Award,China International Science and Technology Cooperation Award,Orica Award,RK Murphy Medal,Le Fevre Prize,ExxonMobil Award,Chemeca Medal (2011),and Top 100 Most Influential Engineers in Australia (2004,2010,2012).He is an elected Fellow of ATSE and Fellow of Institution of Chemical Engineers (IChemE).He is an editor and editorial board member of 12 major international journals including Colloid and Interface Science and Carbon.     

An Order-oriented Procedure Model for A Robust and Agile Production System

The manufacturing industry in 1990's is faced with se-vere challenge among the global competition for mar-kets.Production for a small quantity and high varietyeven lot-sizes of one-digit numbers products has be-come a main trend today.Traditional production proce-dure limits the flexibility of the production system.Inthis paper,based on the analysis of the procedure charac-teristics,a design strategy for re-usage of informationand resource is introduced,and an order-oriented pro-cedure model with concurrent,hierarchical and micro-cycle structure for a robust and agile production systemis proposed in order to realize flexible and adaptive pro-duction for dynamically-changing orders.     

Algorithm of Dynamic Operation Process of Hydraulic Automatically Operated Canals with Constant-Downstream Level Gates

On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed with AVIO and AVIS gates is presented, the main point of this rnathematical model is firstly applying a set of unsteady flow equations （St. Venant equations here） and treating the condition of gate movement as its dynamic boundary, and then deeoupling this interaction of gate movement with the change of canal flow. In this process, it is necessary to give the gateg open-loop transfer function whose input is water level deviation and output is gate discharge. The result of this simulation for a practical reach has shown it has satisfactory accuracy.     

An Intelligent Agent Approach to Adaptive Project Management

This paper presents the initial steps to integrating a distributed discrete event simulation system with a framework for intelligent software agents. The resulting system has a simulation component that is based on the high-level architecture (HLA) and an agent component that implements the belief-desire-intention (BDI) approach to agent modelling. The architecture is connected to a real-time information source. The framework was successfully applied to a real-life monitoring system for a tunnel-boring machine excavation project that helped with forecasting and managing the project timelines in response to the changes in the uncertain excavation environment. This project is presented as a test case and demonstrates encouraging results for integrative modelling of large-scale problems with elements of uncertainty.     

一种新的考虑启动压力梯度产能方程的建立

The flowing mechanism of a low permeability gas reservoir is different from a conventional gas reservoir,especially for that with higher irreducible water saturation the threshold pressure gradient exists. At present,in all the deliverability equation,the additional pressure drop caused by the threshold pressure gradient is viewed as constant,but this method has big error in the practical application. Based on the non-Darcy steady flow equation,the limited integral of the additional pressure drop is solved in this paper and it is realized that the additional pressure drop is not a constant but has something to do with production data,and a new deliverability equation is derived,with the relevant processing method for modified isochronal test data. The new deliverability equation turns out to be practical through onsite application.     

教育学习工具灵活和有效的瘦客户部署方式

Given today's dynamic and fast paced world of Information Technology(IT),it has become more challenging for an IT manager to provide students with the most flexible and innovative learning environment.The requirement to provide these facilities must be balanced against constraints such as capital spending within budgets,maintenance costs and staffing issues.This paper discusses how a server-centric IT solution,such as thin clients,is capable of meeting these demands in a more efficient manner particularly in relation to Financial Management,Infrastructure Management and Security Management.The flexibility and efficiency of server-centric technology as an education tool is overviewed as experienced by several departments within the Dublin Institute of Technology.     

Reflection and phase of left-handed metamaterials at microwave frequencies

We experimentally investigated the reflection and phase of the left-handed metamaterials (LHMs) in a rectangular waveguide for the normally incident microwave. The samples are constructed by periodically arraying the copper split ring resonators (SRRs) and wires. It is found that for the LHMs with one-layered SRRs, a reflection peak with a depth of -3.3 dB (i.e. with the reflectivity of 47%) occurs in the left-handed range. The dependence of reflection phase on the frequency is different from that of the transmission phase, and the reflection phase has an inflexion at the reflection peaks. For the LHMs with three-layered SRRs, the depth of reflection peak increases with the row number, i.e. reflection is weakened, and the reflection peak has a shift with respect to the left-handed transmission peak. It is thought that the interaction between different layers of SRRs is the reason of the shift.     

A Novel Design of Power management integrated circuit with 90 plus efficiency used in AC/DC converter

Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So，a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.     

Image Reconstruction Using a Genetic Algorithm for Electrical Capacitance Tomography

Electrical capacitance tomography （ECT） has been used for more than a decade for imaging dielectric processes. However, because of its ill-posedness and non-linearity, ECT image reconstruction has always been a challenge. A new genetic algorithm （GA） developed for ECT image reconstruction uses initial results from a linear back-projection, which is widely used for ECT image reconstruction to optimize the threshold and the maximum and minimum gray values for the image. The procedure avoids optimizing the gray values pixel by pixel and significantly reduces the search space dimension. Both simulations and static experimental results show that the method is efficient and capable of reconstructing high quality images. Evaluation criteria show that the GA-based method has smaller image error and greater correlation coefficients. In addition, the GA-based method converges quickly with a small number of iterations.     

Development of a continuum robot for colonoscopy

A novel continuum robot for colonoscopy is presented.The aim is to develop a robot for colonoscopywhich can provide the same functions as conventional colonoscope,but much less pain and discomfort forpatient.In contrast to traditional rigid-link robot,the robot features a continuous backbone with nojoints.The continuum robot is 300 mm in total length and 12 mm in diameter that is less than the averagediameter of human colon(20 mm).The robot has a total of 4 DOF(degrees of freedom)and is actuatedremotely...     

New Magnetic Effect of Electricity in Unified Field Theory (Continued)——Solutions of Unified Field Equations

Starting from unified field equations we obtain two solutions and an expres-sion for Planck constant: U=32πe~2/v, it has two values as when v=0.731c, U=h; when v=c. U_(min)=0.731h. to gether with the derivationsfor Planck particle, Einstein photon and Dirac spin from such theory etc.     

Synthesizing and editing dynamic flames with color temperature

Generating computer animated flames is a difficult and computationally expensive problem. Dynamic textures provide an effective means for extrapolating and synthesizing dynamic flames, but aggravates color distortion due to the high correlation of RGB components. A novel method for dynamic flame texture synthesis using color temperature is proposed in this paper. Firstly, the colortemperature mapping is calculated by using the Planck’s law and two-color pyrometric technique to avoid color distortion. Secondly, a novel dynamic texture model is presented to transform the RGB space into temperature space. Finally,the dynamic flames editing is presented to support physical temperature adjustment. Experimental results illustrate that our approach is effective to synthesize visually plausible dynamic flames without color distortions and to edit dynamic flames with intuitive physical interpretation.     

Rapid Manufacturing of Non-Assembly Complex Micro-Devices by Microstereolithography

This paper introduces a non-assembly manufacturing case with microstereolithography technology. The design and manufacturing process of a pneumatic thrust bearing is described, and a special tessellation method is developed to further improve the capability of the manufacturing system thus bigger products can also be easily manufactured. Implemented in a layer-by-layer fashion, stereolithography has been used for the rapid manufacturing of complex devices, and it avoids the expensive assembly process in the traditional manufacturing. This paper presents that microstereolithography can produce high-resolution products with intricate details, small openings, and smooth surfaces. The potential of the microstereolithograhy technique is explored for the rapid manufacturing of small and complex objects.