Lithium–sulfur batteries are a promising energy-storage technology due to their relatively low cost and high theoretical energy density. However, one of their major technical problems is the shuttling of soluble polysulfides between electrodes, resulting in rapid capacity fading. Here, we present a metal–organic framework (MOF)-based battery separator to mitigate the shuttling problem. We show that the MOF-based separator acts as an ionic sieve in lithium–sulfur batteries, which selectively sieves Li+ ions while e ciently suppressing undesired polysulfides migrating to the anode side. When a sulfur-containing mesoporous carbon material (approximately 70 wt% sulfur content) is used as a cathode composite without elaborate synthesis or surface modification, a lithium–sulfur battery with a MOF-based separator exhibits a low capacity decay rate (0.019% per cycle over 1,500 cycles). Moreover, there is almost no capacity fading after the initial 100 cycles. Our approach demonstrates the potential for MOF-based materials as separators for energy-storage applications.
上傳時間： 2017-11-23
上傳用戶：653357637
壓縮包中有5篇論文，分別為《Data-driven analysis of variables and dependencies in continuous optimization problems and EDAs》這是一篇博士論文，較為詳細的介紹了各種EDA算法；《Anisotropic adaptive variance scaling for Gaussian estimation of distribution algorithm》《Enhancing Gaussian Estimation of Distribution Algorithm by Exploiting Evolution Direction with Archive》《Niching an Archive-based Gaussian Estimation of Distribution Algorithm via Adaptive Clustering》《Supplementary material for Enhancing Gaussian Estimation of Distribution Algorithm by Exploiting Evolution Direction with Archive》《基于一般二階混合矩的高斯分布估計算法》介紹了一些基于EDA的創新算法。
上傳時間： 2020-05-25
上傳用戶：duwenhao
This book provides technical information about all aspects of 3GPP LTE. The areas covered range from basic concepts to research-grade material, including future directions. The book captures the current state of 3GPP LTE technology and serves as a source of comprehensive reference material on this subject. It has a total of 12 chapters authored by 50 experts from around the world. The targeted audi- ence includes professionals who are designers or planners for 3GPP LTE systems, researchers (faculty members and graduate students), and those who would like to learn about this field.
標簽： Technology Cellular Radio 3GPP LTE and
上傳時間： 2020-05-26
上傳用戶：shancjb
This book is an entry-level text on the technology of telecommunications. It has been crafted with the newcomer in mind. The twenty-one chapters of text have been prepared for high-school graduates who understand algebra, logarithms, and the basic principles of electricity such as Ohm’s law. However, it is appreciated that many readers require support in these areas. Appendices A and B review the essentials of electricity and mathematics up through logarithms. This material was placed in the appendices so as not to distract from the main theme, the technology of telecommunication systems. Another topic that many in the industry find difficult is the use of decibels and derived units. Appendix C provides the reader a basic understanding of decibels and their applications. The only mathematics necessary is an understanding of the powers of ten
標簽： Telecommunications Fundamentals 2nd of ed
上傳時間： 2020-05-27
上傳用戶：shancjb
This book is intended for RF planners, to serve as a practical tool in their daily work designing indoor radio distribution systems. Based on feedback from readers of the first edition it was clear to me that I needed to add more material and in depth description of the basics of indoor systems based on using repeaters; this has grown into a new Section 4.7. There was also a strong demand to add more detail and dedicate a full chapter to radio planning in tunnels, for both rail and road tunnels; and redundancy principles in the design focus for solving the challenge of handover zones. An entire Chapter 11 is now dedicated to tunnel radio planning.
上傳時間： 2020-05-27
上傳用戶：shancjb
This books presents the research work of COST 273 Towards Mobile Broadband Multimedia Networks, hence, it reports on the work performed and on the results achieved within the project by its participants. The material presented here corresponds to the results obtained in four years of collaborative work by more than 350 researchers from 137 institutions (universities, operators, manufacturers, regulators, independent laboratories and others – a full list is provided in Appendix B) belonging to 29 countries (mainly European, but also from Asia and North America) in the area of mobileradio. Theobjectiveofpublishingtheseresultsasabookisessentiallytomakethemavailable to an audience wider than the project. In fact, it just follows a ‘tradition’ of previous COST Actions in this area of telecommunications, i.e. COST 207, 231 and 259.
標簽： Multimedia Techniques Broadband Networks Mobile
上傳時間： 2020-05-30
上傳用戶：shancjb
Before delving into the details of orthogonal frequency division multiplexing (OFDM), relevant background material must be presented first. The purpose of this chapter is to provide the necessary building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic and random process, discrete-time signals and systems, and the Discrete Fourier Transform (DFT). Tooled with the necessary mathematical foundation, we proceed with an overview of digital communication systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus OFDM.
上傳時間： 2020-05-31
上傳用戶：shancjb
The continuing vitality of spread-spectrum communication systems and the devel- opment of new mathematical methods for their analysis provided the motivation to undertake this new edition of the book. This edition is intended to enable readers to understand the current state-of-the-art in this field. Almost twenty percent of the materialinthiseditionisnew, includingseveralnewsections, anewchapteronadap- tive arrays and filters, and a new chapter on code-division multiple-access networks. The remainder of the material has been thoroughly revised, and I have removed a considerable amount of material that has been superseded by more definitive results.
標簽： Spread-Spectrum Communication Systems 3rd
上傳時間： 2020-06-01
上傳用戶：shancjb
The idea for this book was born during one of my project-related trips to the beautiful city of Hangzhou in China, where in the role of Chief Architect I had to guide a team of very young, very smart and extremely dedicated software developers and verification engineers. Soon it became clear that as eager as the team was to jump into the coding, it did not have any experience in system architecture and design and if I did not want to spend all my time in constant travel between San Francisco and Hangzhou, the only option was to groom a number of local junior architects. Logically, one of the first questions being asked by these carefully selected future architects was whether I could recommend a book or other learning material that could speed up the learning cycle. I could not. Of course, there were many books on various related topics, but many of them were too old and most of the updated information was either somewhere on the Internet dispersed between many sites and online magazines, or buried in my brain along with many years of experience of system architecture.
標簽： Telecommunication Gateways System Design for
上傳時間： 2020-06-01
上傳用戶：shancjb
Dear Reader, this book project brings to you a unique study tool for ESD protection solutions used in analog-integrated circuit (IC) design. Quick-start learning is combined with in-depth understanding for the whole spectrum of cross- disciplinary knowledge required to excel in the ESD field. The chapters cover technical material from elementary semiconductor structure and device levels up to complex analog circuit design examples and case studies.
標簽： Circuits Design Analog ESD for
上傳時間： 2020-06-05
上傳用戶：shancjb
