1. Rails commends line: Example: rails new blog --skip-test-unit --database=postgresql…

Google : Op-Amp Level Shifter Level shifting a +/- 2.5V signal to 0 - 5V I have a front end module that generates an (ECG) signal that varies from +/-2.5 V. I want to shift this signal to 0 - 5V. What is the best way to do this? First thing to try is…

Leveling Ground 题目连接: https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=4925 Description It is important to first level the ground before you build anything on top of it (e.g., new house, sh…

http://electronicdesign.com/boards/non-inverting-level-shifter-requires-only-one-op-amp-one-supply-voltage With portable battery-operated devices continuing to add functionality while shrinking in size, printed-circuit-board real estate becomes incre…

来源:http://podlipensky.com/2012/06/choosing-web-framework-asp-net-mvc-vs-django-python-vs-ruby-on-rails/ How often do you emerge from you cubicle to look around, note new faces or new facial expression on old ones? How often do you emerge from you tec…

日常英语---十一.MapleStory/Monsters/Level 201-210(Dark Demon Eagle Rider) 一.总结 一句话总结:骑着鹰的快速飞行的恶魔,进入地图后跟着你.发现于黑暗世界树中上茎附近.这些将自动跟随你进入地图,并造成10%的HP作为触摸伤害,以及锁定你的能力使用药水,所以不要去AFK!失败5分钟后再次出现. rider-['raɪdə]-n.骑手 A fast-flying demon riding an eagle, that follows you…

日常英语---十.MapleStory/Monsters/Level 191-201(Sad Erda:向你发射炮弹进行攻击) 一.总结 一句话总结:一种悲伤的精神,形成于奥术之河,一个黑法师能够融合枫叶世界.格兰迪斯和友谊故事的维度.发现于消失之旅的遗忘之湖,一个需要30点奥术力量才能造成全部伤害的区域.向你发射炮弹进行攻击. firing-['faɪərɪŋ]-v.开火 projectile-[prə(ʊ)'dʒektaɪl]-n.射弹 Attacks_by_firing_a_project…

http://www.daycounter.com/Circuits/Level-Translators/Level-Translators.phtml Interfacing 5V and 3V logic circuits is a common task.  3V logic is preferred to 5V logic because it consumes less power, so most microcontrollers and peripheral devices use…

Installing RSpec In this level we'll start by getting you setup on a regular Ruby project, then move onto using RSpec within Rails. Let's start by installing the rspec gem from the console. gem install rspec Command Line With the RSpec gem installed,…

接触ruby on rails 已经有一段时间了,想记录一下自己的rails历程.自己写一些小例子来帮助学习.  Rails 适用于那些以数据为中心的应用,很多应用的核心部分包括一个数据库,这些引用的存在的主要原因是为了让客户可以通过它们来操作数据库,而不是直接使用SQL. Rails应用的组成部分: (1)ActionPack的应用框架.用来负责帮助生成数据驱动的交互页面来访问和修改数据库. (2)Web服务器.可以是rails内置的web服务器也可以用apache等. (3)数据库.可以是r…