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Synthesis of Aldehydes by Organocatalytic Formylation Reactions of Boronic Acids with Glyoxylic Acid

Angewandte Chemie 2017年第28期129卷

作者： He Huang Chenguang Yu Xiangmin Li Yongqiang Zhang Yueteng Zhang Xiaobei Chen Patrick S. Mariano Hexin Xie Wei Wang Department of Chemistry & Chemical Biology University of New Mexico Albuquerque NM 87131 USA State Key Laboratory of Bioengineering Reactor and Shanghai Key Laboratory of New Drug Design School of Pharmacy East China University of Science & Technology 130 Mei-Long Road Shanghai 200237 P.R. China

Reported herein is a conceptually novel organocatalytic strategy for the formylation of boronic acids. New reactivity is engineered into the α‐amino‐acid‐forming Petasis reaction occurring between aryl boronic acids, amines, and glyoxylic acids to prepare aldehydes. The operational simplicity of the process and its ability to generate structurally diverse and valued aryl, heteroaryl, and α,β‐unsaturated aldehydes containing a wide array of functional groups, demonstrates the practical utility of the new synthetic strategy.

关键词： Arene Bor Formylierungen Organokatalyse Synthesemethoden

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Study on key Technologies in Product Lifecycle Data Management system for Spindle Bearings of Numerically Controlled Machine Tool

Study on Key Technologies in Product Lifecycle Data Manageme...

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2016 6th International Conference on Machinery,Materials,Environment,Biotechnology and Computer(MMEBC 2016)

作者：崔咏 Jishun LI Xin SUI Wei MA 河南省洛阳市河南科技大学西苑校区 Henan Key Laboratory for Machinery Design and Transmission System Henan University of Science and Technology

In order to fulfil the lifecycle data management for the spindle bearings of CNC machine tool, this paper firstly presented a bearings-lifecycle-oriented data management model, in which the bearings' code re-factoring methods and a ontology-based entity relationship(E-R) model are discussed in detailSecondly, the key technologies of the data management system that utilized the presented data models, including the architecture, database design and integration schemas are described as wellFinally, a component-based system framework is presented to solve the heterogeneous problem in the process of XML-based bearing data extraction, transformation, cleaning and loadingAn application demo will also be given to demonstrate the unity of management, integration, tracking and feedback for the lifecycle data management for spindle bearing.

关键词： Machine Tool Bearings Production Lifecycle Management Data Model Integration technology

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Pressure Effect Due to Arcing Faults of Shipboard MV Switchboard

Pressure Effect Due to Arcing Faults of Shipboard MV Switchb...

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2016 5th International Conference on Environment, Materials, Chemistry and Power Electronics(EMCPE 2016)

作者： Shuang Cao Lijun Fu Ling Zhang Zhihao Ye He Gong Yuzhou Hu National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Shanghai Marine Equipment Research Institute Wuhan Ordnance N.C.O. Academy

In this paper, the pressure effects of arcing faults in the shipboard MV switchboard are analyzed. First the estimated method of arcing fault energy is discussed. Then the pressure model of the MV switchboard due to arcing fault is put forward. And based on Simulink platform, simulations are processed according to a shipboard switchboard example. The results of this paper are helpful to the design on new switchboard products and can supply scientific basis to the research of equipment possibly having arcing faults.

关键词： Shipboard MV Switchboard Arcing Pressure Effect

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H-plane Loaded and Phase Velocity Tapered SWS for Improved Performance of TWT THz Sources

H-plane Loaded and Phase Velocity Tapered SWS for Improved P...

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2016 IEEE 9th UK-Europe-China Workshop on Millimetre Waves and Terahertz Technologies

作者： Xuyuan Chen Laxma R.Billa Xianbao Shi M.Nadeem Akram Department of Micro- and Nano-System Technology University College of Southeast Norway State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi University Vacuum Electronics National Laboratory School of Physical ElectronicsUniversity of Electronic Science and Technology of China

The design optimization and simulation for high performance of two types of slow wave structures(SWS) for micro-electro-mechanical system(MEMS) terahertz(THz)sources are presented,e.g.,THz staggered double vane(SDV)traveling wave tube(TWT) working at center frequency of 220 GHz,H-plane and E-plane loaded(HEL) rectangular TWT working at center frequency of 400 *** structures are able to realize a larger interaction impedance,thereby resulting in higher gain and improved output power of the *** further enhance the energy transferring between the electron beam and THz wave,the maximum length of the interaction section can be extended using the phase velocity tapering technique,where the spent electron beam energy can be reused by resynchronizing the phase velocity of the THz signal with electron velocity at the second section of the *** an achievement,improved power of more than 50%is achieved over the operated bandwidth for both *** designs have considered the LIGA fabrication for these vacuum MEMS THz sources.

关键词： Terahetz TWT Phase velocity tapered technology H-loaded and E-loaded corrugation

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Balance compensation study of electromagnetic active balancer for motorized spindle

Balance compensation study of electromagnetic active balance...

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International Conference on Ubiquitous Robots and Ambient Intelligence (URAI)

作者： Bijia Shi Minqing Jing Hongwei Fan Heng Liu Qian Wang Key Laboratory of Education Ministry for Modern Design & Rotor-bearing System Xi'an China School of Mechanical Engineering Xi'an Jiaotong University Xi'an China School of Mechanical Engineering Xi'an University of Science and Technology Xi'an China

ISBN: (纸本)9781509008223

With the increase of rotating speed, the rotor unbalance of the modern rotating machinery becomes more sensitive. The on-line active balance is an ideal balancing mode for precision machines. Electromagnetic balancer is a non-contact new-structure balancing device in the on-line balancing field, as it can reliably work in high-speed condition and keep the position balanceable after turning down. Balance ability is an important indicator evaluating the performance of a balancer. This paper studies a new electromagnetic balancer carrying permanent magnet for the motorized spindle. Because the counterweight disk is the primary moving element of the balancer, its balance compensation value and distribution are mainly discussed in this paper. Based on the existing disk structure, the balance ability of disks with different structure is researched. The two counterweight disks with the same compensation value and distribution angle, the two disks have the same compensation value and different distribution angles, the two disks have different compensation values and the same distribution angle are analysed. The calculation results demonstrate that the first scheme is proven better in the balance ability and can be easily developed.

关键词： Magnetic analysis

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design and simulation of corrugated diaphragm applied to the MEMS fiber optic pressure sensor

Design and simulation of corrugated diaphragm applied to the...

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IEEE International Conference on Nano/Micro Engineered and Molecular systems (NEMS)

作者： Yiming Gui Yangxi Zhang Guandong Liu Yilong Hao Chengchen Gao Institute of Microelectronics Peking University China National Key Laboratory of Science and Technology on Micro/Nano Fabrication China Innovation Center for Micro-Nano-electronics and Integrated System China Device and System Collaborative Innovation Center for Micro/Nano Fabrication Beijing China

ISBN: (纸本)9781509019489

In this paper, we propose a corrugated diaphragm applied to the fiber optic pressure sensor which needs a wide sensing range and a large deflection. The corrugated diaphragm can effectively improve the sensitivity of the sensor has been proved by ANSYS simulation. The stress concentration is weakened after the silicon is chamfered into corrugated diaphragm by isotropic etching process. The sensitivity of the corrugated diaphragm can reach to 0.44μ m/MPa which is two times larger than that of the same size planar diaphragm. The maximum sensing stress is up to 14MPa.

关键词： Stress Pressure sensors Sensitivity Optical fibers Micromechanical devices Silicon

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Research on Post Nonlinear Geometric Algorithm for BSS of Mixed Vibration Simulation Signals from the Impeller Pumps

Research on Post Nonlinear Geometric Algorithm for BSS of Mi...

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The second International Symposium on Socially and Technically Symbiotic systems (STSS2015);The 7th International Symposium on Symbiotic Nuclear Power systems (ISSNP2015)

作者： Sun Shi-yan XIA Hong CHEN Zhi-hui YANG Bo LIU Mei-ru Fundamental Science on Nuclear Safety and Simulation Technology Laboratory College of Nuclear Science and TechnologyHarbin Engineering University Science and Technology on Reactor System Design Technology Laboratory Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China

In nuclear power plants,for rotating equipment,a normal method for monitoring the modes and diagnosing its fault is monitoring and analyzing its vibration or noise ***,the detected signals are usually the non-linear mixed signals produced by multiple pieces of equipment or their different *** order to distinguish equipment's status,Blind Source Separation technique need to be applied to separate the mixed signals,then equipment's mode can be distinguished *** existing mature BSS algorithms are based on the assumption of the linear *** it to the nonlinear mixed problem directly may cause failure or result in totally wrong *** this paper,we apply geometric algorithm to separate the mixed vibration simulation *** method follows the post-nonlinear mixing model assumption,and develops its separating measure exploiting the difference between a linear mixture and a nonlinear one from their distributions in a three-dimensional *** impeller pump,which is a typical rotating machinery in nuclear power plants,is chosen as the study *** build a three-dimensional model of a kind of impeller pump,use Finite Element Analysis method to create some correlative stress and mode analysis,decorate appropriate monitoring points to get the most intense vibration simulation signal in the pump,and then construct the mixed *** using the post-nonlinear geometric algorithm,the mixed vibration simulation signals of the pump are *** with correlation coefficient,the algorithm performs *** can obtain the same vibration peak frequency from the result as that from the source signals.

关键词： Blind Source Separation post-nonlinear model geometric algorithm the impeller pump vibration simulation signal

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design of a graphene capacitive pressure sensor for ultra-low pressure detection

Design of a graphene capacitive pressure sensor for ultra-lo...

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IEEE International Conference on Nano/Micro Engineered and Molecular systems (NEMS)

作者： Yangxi Zhang Yiming Gui Fanrui Meng Chengchen Gao Yilong Hao Institute of Microelectronics Peking University Beijing China National Key Laboratory of Science and Technology on Micro/Nano Fabrication Beijing China Device and system Collaborative Innovation Center for Micro/Nano Fabrication Beijing China Innovation Center for MicroNanoelectronics and Integrated System Beijing China

ISBN: (纸本)9781509019489

This paper reports the design and theoretical calculation of a capacitive ultra-low pressure sensor, which is based on circular suspend graphene diaphragm array. The atom scale thickness and high mechanical strength of suspend graphene diaphragm both contribute to ultra-low pressure measure range. As the size of single suspend graphene diaphragm is limited by fabrication process, a parallel connected sensor array is designed to achieve detectable capacitance change and redundancy. In calculation, a sensor array with 40,000 5μm radius suspend graphene diaphragm cells in 4mm×4mm size can provide 288fF/Pa sensitivity to pressure load.

关键词： Graphene Capacitance Pressure sensors Sensor arrays Films Electrodes Sensitivity

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Transmission Line Monitoring Network design in Smart Grid

Transmission Line Monitoring Network Design in Smart Grid

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2016 International Conference on Applied Mechanics, Mechanical and Materials Engineering(AMMME 2016)

作者： Yan ZHEN Hai-jun WANG Qing-hai OU Ling-kang ZENG Jia-yong FENG State Grid Information & Telecommunication Co. Ltd.the Future of Science and Technology City National Grid Park Changping District Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

In this paper, we provide a cost optimized algorithm to design a real-time data transmission network architecture and realize real-time monitoring of transmission line in smart grid. How to deliver this real-time data to the control center efficiently is a critical challenge to build an intelligent smart grid. We formulate a three-layer network structure that can provide cost effective data transmission by the meantime, the bandwidth, delay, and connectivity constraints can be well met. Furthermore, the optimal placement of the LTE transceivers is studied aiming at maximizing the bandwidth and minimizing the delay in information delivery. The results we present in the paper individually analyze the effect of variation in each of the constraint on the cost of the network while other constraints are assumed to take up average values. Our analysis shows that three-layer wireless network used in smart grids can solve the problem of real-time data transmission and reduce the overall cost of transmission line monitoring network by the algorithm proposed in this paper.

关键词： Smart grid Transmission line monitoring Network design Optimal deployment algorithm

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Adapting Memory Hierarchies for Emerging Datacenter Interconnects

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Journal of Computer science & technology 2015年第1期30卷 97-109页

作者：江涛侯锐董建波柴琳 Sally A. McKee 田斌张立新孙凝晖 State Key Laboratory of Computer Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Computer Science and Engineering Chalmers University of Technology Gothenburg 41296 Sweden National High Performance Integrated Circuit Design Center (Shanghai) Shanghai 201204 China

Efficient resource utilization requires that emerging datacenter interconnects support both high performance communication and efficient remote resource sharing. These goals require that the network be more tightly coupled with the CPU chips. designing a new interconnection technology thus requires considering not only the interconnection itself, but also the design of the processors that will rely on it. In this paper, we study memory hierarchy implications for the design of high-speed datacenter interconnects particularly as they affect remote memory access -- and we use PCIe as the vehicle for our investigations. To that end, we build three complementary platforms： a PCIe-interconnected prototype server with which we measure and analyze current bottlenecks; a software simulator that lets us model microarchitectural and cache hierarchy changes; and an FPGA prototype system with a streamlined switchless customized protocol Thunder with which we study hardware optimizations outside the processor. We highlight several architectural modifications to better support remote memory access and communication, and quantify their impact and ]imitations.

关键词： high-speed interconnect memory hierarchy time shared memory datacenter network

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