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Recent advances in asymmetric reactions catalyzed by chiral phosphoric acids

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Chinese Chemical Letters 2018年第8期29卷 1181-1192页

作者： Xin Li Qiuling Song institute of next generation Matter Transformation College of Chemical Engineering at Huaqiao University

This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids（CPAs）, a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral molecules. In the past years, different kinds of chiral phosphoric acids have been designed and developed into a privileged class of catalysts in asymmetric synthesis. A number of remarkable achievements have been made by many groups around the world. Due to length limitation, this review only summarizes those works published from January 2016 to November 2017. Meanwhile, catalytic systems which combine metal catalysts and chiral phosphoric acids will not be discussed in this review.

关键词： Chiral phosphoric acids Asymmetric reactions Organocatalysis Conjugate addition Cycloaddition Mannich reaction Friedel–Crafts reactions

Public Charging Infrastructure in Germany–A Utilization and Profitability Analysis

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Journal of Modern power systems and Clean Energy 2022年第6期10卷 1750-1760页

作者： Benedict J.Mortimer Amandus Dominik Bach Christopher Hecht Dirk Uwe Sauer Rik W.De Doncker institute for power generation and Storage systems at the E.ON Energy Research Center RWTH Aachen UniversityAachenGermany

The current increase in the number of electric vehicles in Germany requires an adequately developed charging *** numbers of public and semi-public charging stations are necessary to ensure sufficient coverage of charging *** order to make the installation worthwhile for the mostly private operators as well as public ones,a sufficient utilization is *** paper gives an overview of the differences in the utilization across the public charging infrastructure in *** this end,a dataset on the utilization of 21164 public and semi-public charging stations in Germany is *** installation and operating costs of various charging stations are modeled and economically evaluated in combination with the utilization *** is shown that in 2019-2020,the average utilization in Germany was rather low,albeit with striking regional *** consider future scenarios allowing the regional development forecasting of economic *** is demonstrated that a growth in electric mobility of 20%-30%per year leads to a large number of economically feasible charging parks in urban agglomeration areas.

关键词： Charging infrastructure charging station utilization electromobility economic analysis

Design and engineering implementation of non-supplementary fired compressed air energy storage system: TICC-500

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Science China(Technological Sciences) 2015年第4期58卷 600-611页

作者： MEI Sheng Wei WANG Jun Jie TIAN Fang CHEN Lai Jun XUE Xiao Dai LU Qiang ZHOU Yuan ZHOU Xiao Xin State Key Laboratory of Control and Simulation of power systems and generation Equipment Department of Electrical EngineeringTsinghua University Key Laboratory of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences Department of power systems China Electric Power Research Institute

The integration and accommodation of the wind and solar energy pose great challenges on today’s power system operation due to the intermittent nature and volatility of the wind and solar *** efficient large-scale electrical energy storage is one of the most effective and economical solutions to those *** the comprehensive review of the existing storage technologies,this paper proposes an overall design scheme for the Non-supplementary Fired Compressed Air Energy Storage(NFCAES)system,including system design,modeling and efficiency assessment,as well as protection and ***,the design principles of the multistage regenerative,*** recovery system which is used to fully recycle and utilize the waste heat from compression are provided,so as the overall system efficiency evaluation *** paper theoretically ascertains the storage decoupling rules in the potential and internal energy of molecular compressed air and reveals the conversion mechanism of gas,heat,power,electricity and other forms of *** this basis,a 500-k W physical simulation system of CAES system(TICC-500,Tsinghua-IPCCAS-CEPRI-CAES)is built,which passed a system-wide 420-k W load power generation test with less pollution and zero carbon ***,the multi-form energy conversion of multi-stage regenerative CAES and storage efficiency is verified,especially its incomparable superiority in solving the uncertainty problem in wind and solar power ***,the propaganda and application scenario of the CAES system in China is introduced.

关键词： index terms-compressed air energy storage non-supplementary fired regenerative/heat recovery multi-stage expansion TICC-500

A Centralized Algorithm for Assigning MDC Video Application in Virtual Network

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China Communications 2016年第S1期13卷 158-166页

作者： ZHU Kai WU Chunming ZHOU Boyang CHEN Fei WANG Haoxue next generation Network Laboratory College of Computer Science and Technology Zhejiang University Henan Electrical power Research institute State Grid Corporation of China Information Engineering University

Providing services on demand is a major contributing factor to drive the increasingly development of the software defined network. However, it should supply all the current popular applications before it really attains widespread development. Multiple Description Coding(MDC) video applications, as a popular application in the current network, should be reasonably supported in this novel network virtualization environment. In this paper, we address this issue to assign MDC video application into virtual networks with an efficient centralized algorithm(CAMDV). Since this problem is an NP-hard problem, we design an algorithm that can effectively balance the user satisfaction and network resource cost. Previous work just builds a global multicast tree for each description to connect all the destination nodes by breadth-first search strategy or shortest path tree algorithm. But those methods could not achieve an optimal balance or a high-level user satisfaction. By introducing the hierarchical clustering scheme, our algorithm decomposes the whole mapping procedure into multicast tree construction and multipath description distribution. A serial of simulation experiments show that our centralized algorithm could achieve a better performance in balancing the user satisfaction and average mapping cost in comparison with its rivals.

关键词： multiple description coding video multipath programming hierarchical clustering scheme multicast tree construction network virtualization

Lanthanide NIR luminescence for telecommunications, bioanalyses and solar energy conversion

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Journal of Rare Earths 2010年第6期28卷 824-842页

作者： Jean-Claude G. Bünzli Svetlana V. Eliseeva cole Polytechnique Fédérale de Lausanne Institute of Chemical Sciences and Engineering WCU Professor Korea University Center for Next Generation Photovoltaic Systems Katholieke Universiteit Leuven Department of Chemistry Laboratory of Coordination Chemistry

Present-day advanced technologies heavily rely on the exciting magnetic and spectroscopic properties of lanthanide ions. In particular, their ability to generate well-characterized and intense near-infrared (NIR) luminescence is exploited in any modern fiber-optic telecommunication network. In this feature article, we first summarize the whereabouts underlying the design of highly luminescent NIR molecular edifices and materials. We then focus on describing the main trends in three applications related to this spectral range: telecommunications, biosciences, and solar energy conversion. In telecommunications, efforts concentrate presently on getting easily processable polymer-based waveguide amplifiers. Upconversion nanophosphors emitting in the visible after NIR excitation are now ubiquitous in many bioanalyses while their application to bio-imaging is still in its early stages; however, highly sensitive NIR-NIR systems start to be at hand for both in vitro and in vivo imaging, as well as dual probes combining magnetic resonance and optical imaging. Finally, both silicon-based and dye-sensitized solar cells benefit from the downconversion and upconversion capabilities of lanthanide ions to harvest UV and NIR solar light and to boost the overall quantum efficiency of these next-generation devices.

关键词： lanthanide luminescence near-infrared luminescence telecommunications bioanalysis solar energy conversion solar cell upconversion downconversion

Measurement-based solution for low frequency oscillation analysis

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Journal of Modern power systems and Clean Energy 2016年第3期4卷 406-413页

作者： Chen SHEN Zhi AN Xianzhong DAI Wei WEI Lijie DING Department of Electrical Engineering Tsinghua UniversityBeijingChina State Key Laboratory of Control and Simulation of power systems and generation Equipments Tsinghua UniversityBeijingChina Electric power Research institute of Sichuan Electric power Company ChengduChina

This paper presents a measurement-based solution for low frequency oscillation(LFO) analysis in both real time monitoring and off-line case study. An online LFO property discrimination method is developed first,which alternately uses empirical mode decomposition(EMD)/Hilbert transform(HT) and square calculation to process the measurement data. The method magnifies the variation trend of oscillating variables to accurately discriminate the property of the oscillation. Subsequently, an oscillation source locating method for the forced oscillation(FO) and a strongly correlated generator identification method for the weak damping oscillation(WDO) are proposed. Finally, numerical study results on a test system of the isolated Changdu grid in Tibet validate the proposed methods.

关键词： Low frequency oscillation Oscillation property discrimination Oscillation source location Strongly correlated generator identification

Review and prospect of NiCo_(2)O_(4)-based composite materials for supercapacitor electrodes

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Journal of Energy Chemistry 2019年第4期28卷 54-78页

作者： Yanmei Li Xiao Han Tingfeng Yi Yanbing He Xifei Li School of Chemistry and Chemical Engineering Anhui University of Technology School of Resources and Materials Northeastern University at Qinhuangdao Engineering Laboratory for the next generation power and Energy Storage Batteries Graduate School at Shenzhen Tsinghua University institute of Advanced Electrochemical Energy Xi'an University of Technology

Supercapacitors known as typical electrochemical capacitors have been considered as one of the most promising candidates of energy storage systems owing to their advantages such as high-power density,long life span and lower production *** electrode materials play a crucial role on properties of ***,many researches have been focused on the development of novel electrode materials for high-performance ***_2O_4as supercapacitor electrode material has drawn more and more attentions in recent years due to its outstanding advantages,such as high theoretical capacity,low cost,natural abundance and easy of ***,the NiCo_2O_4always suffer from severe capacity deterioration because of the low electrical conductivity and small surface ***,it is necessary to systematically and comprehensively summarize the progress in understanding and modifying NiCo_2O_4-based materials from various *** this review,the structure and synthesis method of NiCo_2O_4-based materials are discussed in *** then,the major goal of this review is to highlight new progress in using proposed strategies to improve the cycling stability and rate capacity of NiCo_2O_4-based materials,including synthesis,control of special morphologies and design of composite ***,an insight into the future research and development of Ni Co_2O_4-based materials for supercapacitors is prospected.

关键词： NiCo_(2)O_(4) Electrochemical performance Synthesis Morphology Supercapacitors

Standardizing and Centralizing Datasets for Efficient Training of Agricultural Deep Learning Models

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Plant Phenomics 2023年第4期5卷 689-702页

作者： Amogh Joshi Dario Guevara Mason Earles Department of Viticulture and Enology University of CaliforniaDavisDavisCAUSA Department of Biological and Agricultural Engineering University of CaliforniaDavisDavisCAUSA AI institute for next-generation Food systems(AIFS) University of CaliforniaDavisDavisCAUSA

In recent years,deep learning models have become the standard for agricultural computer *** models are typically fine-tuned to agricultural tasks using model weights that were originally fit to more general,non-agricultural *** lack of agriculture-specific fine-tuning potentially increases training time and resource use,and decreases model performance,leading to an overall decrease in data *** overcome this limitation,we collect a wide range of existing public datasets for 3 distinct tasks,standardize them,and construct standard training and evaluation pipelines,providing us with a set of benchmarks and pretrained *** then conduct a number of experiments using methods that are commonly used in deep learning tasks but unexplored in their domain-specific applications for *** experiments guide us in developing a number of approaches to improve data efficiency when training agricultural deep learning models,without large-scale modifications to existing *** results demonstrate that even slight training modifications,such as using agricultural pretrained model weights,or adopting specific spatial augmentations into data processing pipelines,can considerably boost model performance and result in shorter convergence time,saving training ***,we find that even models trained on low-quality annotations can produce comparable levels of performance to their high-quality equivalents,suggesting that datasets with poor annotations can still be used for training,expanding the pool of currently available *** methods are broadly applicable throughout agricultural deep learning and present high potential for substantial data efficiency improvements.

关键词： weights overcome shorter

Multi-Time-Scale Resource Allocation Based on Long-Term Contracts and Real-Time Rental Business Models for Shared Energy Storage systems

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Journal of Modern power systems and Clean Energy 2024年第2期12卷 454-465页

作者： Yuxuan Zhuang Zhiyi Li Qipeng Tan Yongqi Li Minhui Wan College of Electrical Engineering Zhejiang UniversityHangzhouChina China Southern power Grid power generation Company Energy Storage Research institute GuangzhouChina IEEE

The push for renewable energy emphasizes the need for energy storage systems(ESSs)to mitigate the unpre-dictability and variability of these sources,yet challenges such as high investment costs,sporadic utilization,and demand mismatch hinder their broader *** response,shared energy storage systems(SESSs)offer a more cohesive and efficient use of ESS,providing more accessible and cost-effective energy storage solutions to overcome these *** enhance the profitability of SESSs,this paper designs a multi-time-scale resource allocation strategy based on long-term contracts and real-time rental business *** initially construct a life cycle cost model for SESS and introduce a method to estimate the degradation costs of multiple battery groups by cycling numbers and depth of discharge within the ***,we design various long-term contracts from both capacity and energy perspectives,establishing associated models and real-time rental ***,multi-time-scale resource allocation based on the decomposition of user demand is *** analysis validates that the business model based on long-term contracts excels over models operating solely in the real-time market in economic viability and user satisfaction,effectively reducing battery degradation,and leveraging the aggregation effect for SESS can generate an additional increase of 10.7%in net revenue.

关键词： Capacity allocation long-term contracts shared energy storage system stochastic programming