1．据估计，地球上的绿色植物通过光合作用每年能结合来自CO2中的碳1500亿吨和来自水中 的氢250亿吨，并释放4000亿吨氧气。光合作用的过程一般可用下式表示： CO2 + H2O + 微量元素(P、N等) (蛋白质、碳水化台物、脂肪等)+O2 SHAPE \* MERGEFORMAT 光能 叶绿素 下列说法不正确的是 A．某些无机物通过光合作用可转化为有机物 B．碳水化合物就是碳和水组成的化合物
上传时间： 2019-09-11
上传用户：hnjhnjhnj
Device-to-device(D2D) communications are now considered as an integral part of future 5G networks which will enable direct communication between user equipment (UE) without unnecessary routing via the network infrastructure. This architecture will result in higher throughputs than conventional cellular networks, but with the increased potential for co-channel interference induced by randomly located cellular and D2D UEs.
标签： Device-to-Device Communications Analysis of
上传时间： 2020-05-26
上传用户：shancjb
Ultra-wideband (UWB) technology enables high data-rate short-range communica- tion, in excess of hundredmegabit-per-secondsand up to multi-gigabit-per-seconds, over a wide spectrum of frequencies, while keeping power consumption at low lev- els. This low power operation results in a less-interfering co-existence with other existed communication technologies (e.g., UNII bands). In addition to carrying a huge amount of data over a distance of up to 230 feet at very low power (less than 0.5mW), the UWB signal has the ability to penetrate through the doors and other obstacles that tend to reflect signals at more limited bandwidths and higher power densities.
标签： Silicon-Based Front-Ends RF
上传时间： 2020-06-01
上传用户：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.
标签： Telecommunication Gateways System Design for
上传时间： 2020-06-01
上传用户：shancjb
n the first part of this book, we give an introduction to the basic applications of wireless com- munications, as well as the technical problems inherent in this communication paradigm. After a brief history of wireless, Chapter 1 describes the different types of wireless services, and works out their fundamental differences. The subsequent Section 1.3 looks at the same problem from a different angle: what data rates, ranges, etc., occur in practical systems, and especially, what combination of performance measures are demanded (e.g., what data rates need to be transmitted over short distances; what data rates are required over long distances?) Chapter 2 then describes the technical challenges of communicating without wires, putting special emphasis on fading and co-channel interference. Chapter 3 describes the most elementary problem of designing a wireless system, namely to set up a link budget in either a noise-limited or an interference-limited system. After studying this part of the book, the reader should have an overview of different types of wireless services, and understand the technical challenges involved in each of them. The solutions to those challenges are described in the later parts of this book.
标签： Communications Wireless Edition 2nd
上传时间： 2020-06-01
上传用户：shancjb
Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data in the Marconi age, they have transformed, thanks to substantial advances in electronic technology, into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia communications. This, however, would not have been possible unless significant progress had been made in recent decades in the field of signal processing algorithms for baseband and passband signals. In fact, the core of any modern digital radio consists of a set of algorithms running over programmable electronic hardware. This book stems from the research and teaching activities of its co-authors in the field of algorithmic techniques for wireless communications. A huge body of technical literature has accumulated in the last four decades in this area, and an extensive coverage of all its important aspects in a single textbook is impossible. For this reason, we have selected a few important topics and, for ease of reading, organized them into two parts.
标签： Communications Algorithmic Techniques Wireless
上传时间： 2020-06-01
上传用户：shancjb
This paper reviews key factors to practical ESD protection design for RF and analog/mixed-signal (AMS) ICs, including general challenges emerging, ESD-RFIC interactions, RF ESD design optimization and prediction, RF ESD design characterization, ESD-RFIC co-design technique, etc. Practical design examples are discussed. It means to provide a systematic and practical design flow for whole-chip ESD protection design optimization and prediction for RF/AMS ICs to ensure 1 st Si design success.
标签： ESD_protection_for_RF_and_AMS_ICs
上传时间： 2020-06-05
上传用户：shancjb
stract With global drivers such as better energy consumption, energy efficiency and reduction of greenhouse gases, CO 2 emission reduction has become key in every layer of the value chain. Power Electronics has definitely a role to play in these thrilling challenges. From converters down to compound semiconductors, innovation is leading to breakthrough technologies. Wide BandGap, Power Module Packaging, growth of Electric Vehicle market will game change the overall power electronic industry and supply chain. In this presentation we will review power electronics trends, from technologies to markets.
标签： Electronics Materials Power WBG for
上传时间： 2020-06-07
上传用户：shancjb
Instrukcja programowania trójosiowego sterownika ruchu „przemysłowego wyświetlania ekranugo” V2.0 Model kontrolera : HYCNC-WPRS232-P3 , Wersja oprogramowania : V2.0 , Data : 2020-7-12 Autor : Guilin Hengyuan Technology Co., Ltd. ( Pan Lee )
标签： programowania Instrukcja HYCNC-WPRS sterownika 232 PLC ver P3 PL
上传时间： 2021-06-23
上传用户：DawidoCezaro
The Verilog Hardware Description Language (HDL) is defined in this standard. Verilog HDL is a formal notation intended for use in all phases of the creation of electronic systems. Because it is both machine readable and human readable,it supports the development,verification, synthesis,and testing of hardware designs; the communication of hardware design data; and the maintenance,modification,and procurement of hardware. The primary audiences for this standard are the implementors of tools supporting the language and advanced users of the language.
上传时间： 2021-11-09
上传用户：
