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Efficient fully blade-coated perovskite solar cells in air with nanometer-thick bathocuproine buffer layer

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Nano Research 2021年第4期14卷 1034-1042页

作者： Sergio Castro-Hermosa Luana Wouk Izabela Silva Bicalho Luiza de Queiroz Correa Bas de Jong Lucio Cina Thomas M.Brown Diego Bagnis CSEM Brasil Avenida Jose Candido da Silveira200031035-536 Belo HorizonteBrazil CHOSE(Centre for Hybrid and Organic Solar Energy) Department of Electronic EngineeringUniversity of Rome Tor VergataVia del Politecnico 100133 RomeItaly Hydro Engineering and Agricultural Development Research Group(GHIDA) Faculty of EngineeringUniversidad SurcolombianaAvenida Pastrana Borrero-Carrera 1410001 NeivaColombia Cicci Research srl via Giordania 227 58100 GrossetoItaly Department of Biotechnology Chemistry and PharmacyUniversity of SienaVia A.Moro 253100 SienaItaly

Fully printed perovskite solar cells(PSCs)were fabricated in air with all constituent layers,except for electrodes,deposited by the blade coating technique.The PSCs incorporated,for the first time,a nanometer-thick printed bathocuproine(BCP)hole blocking buffer using blade coating and deposited at relative humidity up to 50%.The PSCs with a p-i-n structure(glass/indium tin oxide(ITO)/poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS)/CH_(3)NH_(3)Pbl_(3)/[6,6]-phenyl-C_(61)-butyric acid methyl ester(PCBM)/BCP/Ag)delivered a maximum power conversion efficiency(PCE)of 14.9%on an active area of 0.5 cm^(2)when measured under standard test conditions.The PSCs with a blade coated BCP delivered performance of 10%and 63%higher(in relative terms)than those incorporating a spin coated BCP or without any BCP film,respectively.The atomic force microscopy(AFM)showed that blade coated films were more homogeneous and acted also as a surface planarizer leading to a reduction of roughness which improved BCP/Ag interface lowering charge recombination.The demonstration of 15%efficient devices with all constituent layers,including nanometer-thick BCP(〜10 nm),deposited by blade coating in air,demonstrates a route for industrialization of this technology.

关键词： perovskite buffer bathocuproine(BCP) blade coating printed electronics

GekkoFS—A Temporary Burst buffer File System for HPC Applications

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Journal of Computer Science & Technology 2020年第1期35卷 72-91页

作者： Marc-AndréVef Nafiseh Moti Tim Süβ Markus Tacke Tommaso Tocci Ramon Nou Alberto Miranda Toni Cortes AndréBrinkmann Zentrum für Datenverarbeitung Johannes Gutenberg University MainzMainz 55128Germany Barcelona Supercomputing Center Barcelona 08034Spain Computer Architecture Department Universitat Politècnica de CatalunyaBarcelona 08034Spain

Many scientific fields increasingly use high-performance computing(HPC)to process and analyze massive amounts of experimental data while storage systems in today's HPC environments have to cope with new access patterns.These patterns include many metadata operations,small I/O requests,or randomized file I/O,while general-purpose parallel file systems have been optimized for sequential shared access to large files.Burst buffer file systems create a separate file system that applications can use to store temporary data.They aggregate node-local storage available within the compute nodes or use dedicated SSD clusters and offer a peak bandwidth higher than that of the backend parallel file system without interfering with it.However,burst buffer file systems typically offer many features that a scientific application,running in isolation for a limited amount of time,does not require.We present GekkoFS,a temporary,highly-scalable file system which has been specifically optimized for the aforementioned use cases.GekkoFS provides relaxed POSIX semantics which only offers features which are actually required by most(not all)applications.GekkoFS is,therefore,able to provide scalable I/O performance and reaches millions of metadata operations already for a small number of nodes,significantly outperforming the capabilities of common parallel file systems.

关键词： distributed file system high-performance computing(HPC) burst buffer POSIX(portable operating system interface)

Contract theory based incentive mechanism design for buffer resource in wireless caching networks

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High Technology Letters 2020年第2期26卷 152-159页

作者：刘婷婷 Tang Lei Zhu Hao Bao Yongqiang Guo Yajuan School of Information and Communication Engineering Nanjing Institute of TechnologyNanjing 211167P.R.China Institute of Electric Power Science Jiangsu Electric Power Co.Ltd.Nanjing 210024P.R.China

Evidences indicate that,due to the limited caching capacity or inaccurate estimation on users’preferences,the requested files may not be fully cached in the network edge.The transmissions of the un-cached files will also lead to duplicated transmissions on backhaul channels.buffer-aided relay has been proposed to improve the transmission performance of the un-cached files.Because of the limited buffer capacity and the information asymmetric environment,how to allocate the limited buffer capacity and how to incentivize users in participating buffer-aided relay have become critical issues.In this work,an incentive scheme based on the contract theory is proposed.Specifically,the backlog violation probability,i.e.,the buffer overflow probability,is provided based on the martingale theory.Next,based on the backlog violation probability,the utility functions of the relay node and users are constructed.With the purpose to maximize the utility of the relay node,the optimal contract problem is formulated.Then,the feasibility of the contract is also demonstrated,and the optimal solution can be obtained by the interior point method.Finally,numerical results are presented to demonstrate effectiveness of the proposed contract theory scheme.

关键词： contract theory buffer resource allocation wireless caching network incentive mechanism design

A buffer Scheduling Method Based on Message Priority in Delay Tolerant Networks

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Journal of Computer Science & Technology 2016年第6期31卷 1228-1245页

作者： En Wang Yong-Jian Yang Jie Wu Wen-Bin Liu Department of Computer Science and Technology Jilin University Changchun 130012 China Department of Computer and Information Sciences Temple University Philadelphia 19122 U.S.A. Department of Software Jilin University Changchun 130012 China

Routing protocols in delay tolerant networks usually utilize multiple message copies to guarantee the message delivery, in order to overcome unpredictable node mobility and easily-interrupted connections. A store-carry-and-forward paradigm was also proposed to further improve the message delivery. However, excessive message copies lead to the shortage of buffer and bandwidth. The spray and wait routing protocol has been proposed to reduce the network overload caused by the buffer and transmission of unrestricted message copies. However, when a node＇s buffer is quite constrained, there still exist congestion problems. In this paper, we propose a message scheduling and drop strategy on spray and wait routing protocol （SDSRP）. To improve the delivery ratio, first of all, SDSRP calculates the priority of each message by evaluating the impact of both replicating and dropping a message copy on delivery ratio. Subsequently, scheduling and drop decisions are made according to the priority. In order to further increase delivery ratio, we propose an improved message scheduling and drop strategy on spray and wait routing protocol （ISDSRP） through enhancing the accuracy of estimating parameters. Finally, we conduct extensive simulations based on synthetic and real traces in ONE. The results show that compared with other buffer management strategies, ISDSRP and SDSRP achieve higher delivery ratio, similar average hopcounts, and lower overhead ratio.

关键词： delay tolerant network spray and wait buffer scheduling priority

Performance of the(BMAP_1, BMAP_2 )/(PH_1, PH_2 )/N Retrial Queueing System with Finite buffer

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Acta Mathematicae Applicatae Sinica 2014年第2期30卷 429-446页

作者： Zong-hao ZHOU Shi-xing LI Yi-jun ZHU School of Mathematics and Statistics Huangshan University School of Mathematics and Statistics Zhejiang University of Finance and Economics Faculty of Science Jiangsu University

This paper consider the （BMAP1, BMAP2）/（PH1, PH2）/N retrial queue with finite-position buffer. The behavior of the system is described in terms of continuous time multi-dimensional Markov chain. Arriving type I calls find all servers busy and join the buffer, if the positions of the buffer are insufficient, they can go to orbit. Arriving type II calls find all servers busy and join the orbit directly. Each server can provide two types heterogeneous services with Phase-type （PH） time distribution to every arriving call （including types I and II calls）, arriving calls have an option to choose either type of services. The model is quite general enough to cover most of the systems in communication networks. We derive the ergodicity condition, the stationary distribution and the main performance characteristics of the system. The effects of various parameters on the system performance measures are illustrated numerically.

关键词： retrial queue batch Markov arrival process PH distribution buffer

Regulation of hepatic blood flow:The hepatic arterial buffer response revisited

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World Journal of Gastroenterology 2010年第48期16卷 6046-6057页

作者： Christian Eipel Kerstin Abshagen Brigitte Vollmar Institute for Experimental Surgery Medical FacultyUniversity of Rostock

The interest in the liver dates back to ancient times when it was considered to be the seat of life processes. The liver is indeed essential to life,not only due to its complex functions in biosynthesis,metabolism and clearance,but also its dramatic role as the blood volume reservoir. Among parenchymal organs,blood flow to the liver is unique due to the dual supply from the portal vein and the hepatic artery. Knowledge of the mutual communication of both the hepatic artery and the portal vein is essential to understand hepatic physiology and pathophysiology. To distinguish the individual importance of each of these inflows in normal and abnormal states is still a challenging task and the subject of on-going research. A central mechanism that controls and allows constancy of hepatic blood flow is the hepatic arterial buffer response. The current paper reviews the relevance of this intimate hepatic blood flow regulatory system in health and disease. We exclusively focus on the endogenous interrelationship between the hepatic arterial and portal venous inflow circuits in liver resection and transplantation,as well as inflammatory and chronic liver diseases. We do not consider the hepatic microvascular anatomy,as this has been the subject of another recent review.

关键词： Hepatic blood flow Hepatic arterial buffer response Liver

TWO-DIMENSIONAL FINITE ELEMENT MODEL TO STUDY CALCIUM DISTRIBUTION IN ASTROCYTES IN PRESENCE OF VGCC AND EXCESS buffer

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International Journal of Modeling, Simulation, and Scientific Computing 2013年第2期4卷 1-15页

作者： BRAJESH KUMARJHA NEERU ADLAKHA M.N.MEHTA Department of Applied Mathematicsand Humanities S.V.NationalInstitute of Technology Surat Gujarat 395007India Department of Mathematics&Humanities Institute of TechnologyNirma UniversityAhmedabadIndia Department of Mathematics M.A.National Institute of TechnologyBhopalIndia.

Astrocyte plays a pivotal role in synaptic transmission with neuron.It maintains the ionic concentration in synapse to regulate signals from one cell to another.Calcium known as second messenger plays an important role in signal transduction.There are so many physiological processes that affect the cytosolic calcium concentration[Ca2+]i like calcium buffering,flow of calcium ion through channels,etc.The modeling of calcium signaling in astrocytes has become more sophisticated.The modeling effort has provided insight to understand the cell contraction.Main objective of this work is to study the effect of voltage-gated calcium channel on calcium profile under excess buffer approximation in the form of diffusion equation.A mathematical model is developed in the form of diffusion equation for the calcium profile.The model incorporates the important physiological parameter like diffusion coefficient association rate constant,etc.Appropriate boundary conditions have been framed.Finite element method is employed to solve the problem.A MATLAB program has been developed for the entire problem and simulated to compute the numerical results.

关键词： [Ca2+] buffer VGCC FEM.

buffer单元单粒子效应及其若干影响因素研究

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电子器件 2014年第2期37卷 186-189页

作者：杜明邹黎李晓辉邱恒功邓玉良深圳市国微电子有限公司广东深圳518057

基于标准0.13μm工艺使用Sentaurus TCAD软件采用3D器件/电路混合模拟方式仿真了buffer单元的单粒子瞬态脉冲。通过改变重离子的入射条件,得到了一系列单粒子瞬态电流脉冲(SET)。分析了LET值、入射位置、电压偏置等重要因素对SET峰值和... 详细信息

基于标准0.13μm工艺使用Sentaurus TCAD软件采用3D器件/电路混合模拟方式仿真了buffer单元的单粒子瞬态脉冲。通过改变重离子的入射条件,得到了一系列单粒子瞬态电流脉冲(SET)。分析了LET值、入射位置、电压偏置等重要因素对SET峰值和脉宽的影响。研究发现,混合模式仿真中的上拉补偿管将导致实际电路中SET脉冲的形状发生明显的变化。

关键词： buffer 电荷收集单粒子瞬态脉冲 TCAD仿真

Engineering Design of High Quality GaN Epitaxy on Silicon Substrate Using Varying GaN/AlGaN Composite buffer Structures

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稀有金属材料与工程 2012年第S1期41卷 57-60页

作者： Wu, G. M. Tu, K. N. Kuo, C. C. Univ Calif Los Angeles Dept Mat Sci & Engn Los Angeles CA 90095 USA Chang Gung Univ Inst Electroopt Engn Tao Yuan 333 Taiwan

High quality GaN epitaxy thin films have been desired for the energy-efficient,solid-state semiconductor illuminating devices.Silicon substrates offer high crystal quality,low wafer cost,large wafer size,and potential integration with the well-established silicon processing technologies.However,due to the large mismatch in lattice constants and thermal expansion coefficients,it is still challenging to grow high quality GaN on silicon substrates.In this study,high quality GaN epitaxy has been engineering designed to grow on Si(111)substrate using varying GaN/AlGaN composite buffer structures by an Axitron 200 metal-organic vapor phase epitaxy deposition system.A thin AlN seed layer of 25 nm was firstly grown at 720℃.AlGaN layer of different thickness was then grown at 1050℃with subsequent GaN thin film until the total thickness reached 500 nm.The thickness of the subsequent GaN thin film could be increased by reducing the AlGaN thickness in the composite buffer structures.The results have shown that the lower GaN/AlGaN thickness ratio would decrease the dislocation density and provide crack-free,mirror-like upper GaN crystal thin film.On the other hand,the GaN/AlGaN thickness ratio could be designed to be 2-6 to balance the processing cost and the thin film quality for engineering applications.The dislocation density has been about 2×10 9 cm-2.In addition,dislocation close loop was observed near the GaN/AlGaN interface.The annihilation mechanism could be depicted by the reduction in dislocation strain energy.

关键词： gallium nitride dislocation density silicon substrate buffer layer