由STC89C51单片机来控制DHT11传感器采集的温湿度的转换、1602液晶屏的显示，以及蜂鸣器的报警。
上传时间： 2018-04-27
上传用户：luson
I saw the light of the future when I first read Ray Kurzweil’s best-seller book The Singularity Is Near: When Humans Transcend Biology. One cubic inch of nanotube cir- cuitry, once fully developed, would be up to one hundred million times more powerful than the human brain.
标签： Predictive Cognitive Warning System Early The
上传时间： 2020-05-26
上传用户：shancjb
Your Cisco Networking Academy Course Booklet is designed as a study resource you can easily read, high- light, and review on the go, wherever the Internet is not available or practical: ■ The text is extracted directly, word-for-word, from the online course so you can highlight important points and take notes in the “Your Chapter Notes” section. ■ Headings with the exact page correlations provide a quick reference to the online course for your class- room discussions and exam preparation. ■ An icon system directs you to the online curriculum to take full advantage of the images, labs, Packet Tracer activities, and dynamic Flash-based activities embedded within the Networking Academy online course interface.
标签： Switching Wireless LAN and
上传时间： 2020-05-27
上传用户：shancjb
An optical fiber amplifier is a key component for enabling efficient transmission of wavelength-divisionmultiplexed(WDM)signalsoverlongdistances.Eventhough many alternative technologies were available, erbium-doped fiber amplifiers won theraceduringtheearly1990sandbecameastandardcomponentforlong-haulopti- caltelecommunicationssystems.However,owingtotherecentsuccessinproducing low-cost, high-power, semiconductor lasers operating near 1450 nm, the Raman amplifiertechnologyhasalsogainedprominenceinthedeploymentofmodernlight- wavesystems.Moreover,becauseofthepushforintegratedoptoelectroniccircuits, semiconductor optical amplifiers, rare-earth-doped planar waveguide amplifiers, and silicon optical amplifiers are also gaining much interest these days.
标签： Propagation Light Media Gain in
上传时间： 2020-05-27
上传用户：shancjb
One of the prerequisites for the development of telecommunication services is the understanding of the propagation of the waves, either acoustic, electromagnetic, radio or light waves, which are used for the transmission of information. In this work, we shall limit ourselves to the study of radio waves: this term apply to the electromagnetic waves used in radio communications. Their frequency spectrum is very broad, and is divided into the following frequency bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves (300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub- EHF waves (300-3000 GHz).
标签： Propagation Radio Wave
上传时间： 2020-06-01
上传用户：shancjb
Before I can present design concepts or tactical wireless communications and network challenges, I feel the need to mention the challenges of writing for a field where some information is not available for public domain and cannot be included in this book’s context. Another challenge is the use of military jargon and the extensive number of abbreviations (and abbreviations of abbreviations!) in the field. Engineering books are naturally dry, and I have attempted to make it light by presenting the concepts in layman’s terms before diving into the technical details. I am structuring this book in such a way as to make it useful for a specialized graduate course in tactical communications and networking, or as a reference book in the field.
标签： Communications Tactical Networks Wireless and
上传时间： 2020-06-01
上传用户：shancjb
The use of light to send messages is not new. Fires were used for signaling in biblical times, smoke signals have been used for thousands of years and flashing lights have been used to communicate between warships at sea since the days of Lord Nelson. The idea of using glass fibre to carry an optical communications signal originated with Alexander Graham Bell. However this idea had to wait some 80 years for better glasses and low-cost electronics for it to become useful in practical situations.
标签： Communications Understanding Optical
上传时间： 2020-06-01
上传用户：shancjb
This is a book on wireless communication. That usually means communica- tion by radio, though ultrasound and infrared light are also used occasion- ally. The term “wireless” has come to mean nonbroadcast communication, usually between individuals who very often use portable or mobile equip- ment. The term is rather vague, of course, and there are certainly borderline applications that are called wireless without falling exactly into the above definition.
标签： Communication Technology Wireless
上传时间： 2020-06-01
上传用户：shancjb
This book was written by Michael Margolis with Nick Weldin to help you explore the amazing things you can do with Arduino. Arduino is a family of microcontrollers (tiny computers) and a software creation envi- ronment that makes it easy for you to create programs (called sketches) that can interact with the physical world. Things you make with Arduino can sense and respond to touch, sound, position, heat, and light. This type of technology, often referred to as physical computing, is used in all kinds of things, from the iPhone to automobile elec- tronics systems. Arduino makes it possible for anyone—even people with no program- ming or electronics experience—to use this rich and complex technology.
上传时间： 2020-06-09
上传用户：shancjb
在本书中，作者生动地讲述了相互联系的系统的历史：从瑞士数学家莱奥哈尔德·欧拉18世纪末对图论的开创性研究，至现代生物学家基于对细胞网络的了解而展开的治疗癌症药物的研究等。本书的思想核心是：链接是无处不在的，复杂网络的本质是无尺度网络。抓住复杂网络中的枢纽节点，是我们处理复杂数据的基本原则，也是人工智能背后的深度神经网络的重要基础。
标签： 互联网
上传时间： 2021-09-16
上传用户：清川澹如此
