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Seacoast Digital Computers, Inc.
Motronics Circuits International Inc
We are an independent electronic component distributor. Our strength lies in locating obsolete parts and hard-to-find components that are often cirtical to our customers’ operations. We also are very strong in supplying load cells and strain gauges.
Networking for all engineering disciplines, groups and clubs.
Networking for all engineering disciplines, groups and clubs.
专业代理国际、国内往返特价机票，航空保险
datasheet
http://www.datasheet.ws/
Part No. Technical Notes
2743019447 SURFACE MOUNT BEAD, 5.1MM LG., (DIFFERENTIAL-MODE), BROADBAN
2743021447 SURFACE MOUNT BEAD, 9.6MM LG., (DIFFERENTIAL-MODE), BROADBAN
2944666671 WOUND FERRITE BEAD, 2 1/2 TURNS, BROADBAND FREQUENCIES 1-2
AMK105BJ225MV CAP, MLCC, 0402, 4V, X5R, 2.2UF, ¡À20%, T&R
AMK105BJ225MV-F CAP, MLCC, 0402, 4V, X5R, 2.2UF, ¡À20%, T&R
AMK105BJ475MV CAP, MLCC, 0402, 4V, X5R, 4.7uF, ¡À20%, T&R
AMK105BJ475MV-F CAP, MLCC, 0402, 4V, X5R, 4.7uF, ¡À20%, T&R
AMK107BJ106MA CAP, MLCC, 0603, 4V, X5R, 10UF, ¡À20%, T&R
AMK107BJ106MA-T CAP, MLCC, 0603, 4V, X5R, 10UF, ¡À20%, T&R
AMK107BJ226MA CAP, MLCC, 0603, 4V, X5R, 22uF ¡À20%, T&R
AMK107BJ226MA-T CAP, MLCC, 0603, 4V, X5R, 22uF ¡À20%, T&R
AMK107BJ475MK CAP, MLCC, 0603, 4V, X5R, 4.7UF, ¡À20%, T&R
AMK107BJ475MK-T CAP, MLCC, 0603, 4V, X5R, 4.7UF, ¡À20%, T&R
AMK316BJ107ML CAP, MLCC, 1206, 4V, X5R, 100UF, ¡À20%, T&R
AMK316BJ107ML-T CAP, MLCC, 1206, 4V, X5R, 100UF, ¡À20%, T&R
AMK316BJ476ML CAP, MLCC, 1206, 4V, X5R, 47UF, ¡À20%, T&R
AMK316BJ476ML-T CAP, MLCC, 1206, 4V, X5R, 47UF, ¡À20%, T&R
BK1005HM102 FERRITE BEAD, MULTILAYER CHIP, 0402, 1000 OHMS, ¡À25%, T&R
Directory web site http://www.siteforum.org
website forum
November 15th, 2008
Tecal Electronics, LLC
Franchised stocking distributor of Taiyo Yuden and Kamaya (Mitsubishi) passive electronic components including: capacitors, inductors, resistors, ferrite products, EMI/RFI filters, chokes, coils, thermistors, etc.
ic inventory
AZEGO Technology Services inventory file
November 14th, 2008
| Part No | Mfr | Date Code | Quantity | Comment |
|---|---|---|---|---|
| 1N4103-1JANTX | MSW | 488 | ||
| 1N4104-1JANTX | MSW | 1445 | ||
| 1N4108-1JANTX | MSW | 3961 | ||
| 1N4109-1JANTX | MSW | 2348 | ||
| 1N4110-1JANTX | MSW | 4550 | ||
| 1N4110UR-1JANTX | MSW | 426 | ||
| 1N4116-1JANTX | MSW | 104 | ||
| 1N4130-1JAN | MSW | 699 | ||
| 1N4148-1JANTXV | MSW | 12215 | ||
| 1N4148T/R | PHA | 2370000 | ||
| 1N4150-1JAN | MSW | 902 | ||
| 1N4153-1JANTXV | MSW | 589 | ||
| 1N4372A-1JANTX | MSW | 3564 | ||
| 1N4464JANTX | MSW | 190 | ||
| 1N4466USJANTXV | MSW | 37 | ||
| 1N4473JANTX | MSW | 207 | ||
| 1N4481JANTX | MSW | 2169 | ||
| 1N4487JAN | MSW | 299 | ||
| 1N4487JANTX | MSW | 3338 | ||
| 1N4490JANTX | MSW | 1024 | ||
| 1N4496JANTX | MSW | 556 |
vi usage
vi, the Unix visual editor, has two modes of operation:
- Command mode–This is vi’s initial and normal state. In this mode, most commands you type are not displayed. Only commands preceded by :, /, or ! are displayed on the status line, which also gives feedback about input, output, and large changes. Execute these commands with <Return> or <Esc>. Use <Esc> to change from text input mode to command mode (when in doubt, press <Esc>).
- Text input (Insert) mode–This mode is entered by pressing a, A, i, I, o, or O. Press <Esc> to end text input mode and return to command mode.
For more information about using vi, see the online help note (on Uniform Access Unix computers, enter help vi).
The following notations are used in this document (variables appear in italics):
| x | represents a single character | |
| <Control> x | control character: while holding down the <Control> key, press x | |
| text | one or more characters | |
| n | represents a number | |
| pat | text and pattern matching characters | |
| <Return> | Return key on your terminal | |
| <Esc> | Escape key on your terminal | |
| Entering and Leaving vi Files | ||
|---|---|---|
| vi filename(s) | edit a file or files | |
| vi -r filename | retrieve saved version of file after system or editor crash | |
| vi -x filename | edit encrypted file | |
| vi -wn filename | set default window size to n (useful for dial-ups) | |
| :wq | save (write) file and exit to system prompt | |
| ZZ | save file and exit to system prompt | |
| :q! | discard all changes and exit to system prompt | |
| Basic Cursor Movement | ||
| Use h, j, k, and l to move the cursor–using arrow keys may result in undesirable consequences | ||
| h | move cursor left one character | |
| j | move cursor down one line | |
| k | move cursor up one line | |
| l | move cursor right one character | |
| (Any of the above commands preceded by n will move the cursor n spaces or lines in the indicated direction.) | ||
| Inserting Text | ||
| (If n precedes an insert character, n copies of inserted text are added upon escape from insertion mode.) | ||
| a | begin insert at right of cursor | |
| A | begin insert at end of line | |
| i | begin insert at left of cursor | |
| I | insert at beginning of line | |
| o | open line below, ready for insertion | |
| O | open line above, ready for insertion | |
| S | replace text with blank line; begin insertion at beginning of that line | |
| <Control>i | insert tab | |
| <Control>v | insert non-printing character | |
| <Backspace> | erase character (invisible until over-typed or insert mode escaped) | |
| <Esc> | terminate insert mode; also terminates unwanted commands | |
| Deleting, Retrieving, and Undoing | ||
| dw | delete word | |
| dd | delete line | |
| yw | yank word into buffer | |
| yy | yank line into buffer | |
| x | delete character | |
| D | delete characters from cursor to end of line | |
| ndw | delete n words into buffer | |
| ndd | delete n lines into buffer | |
| nyw | yank n words into buffer | |
| nyy | yank n lines into buffer | |
| nx | delete n characters into buffer | |
| p | put buffer contents after cursor | |
| P | put buffer contents before cursor | |
| u | undo last single change | |
| U | restore current line | |
| Changing, Replacing, and Copying Text | ||
| . | repeat last change | |
| n. | repeat last change n times | |
| cwtext | mark end of a word with $ and change to text (press <Esc> to end) | |
| rx | replace character under cursor with character x | |
| nrx | replace n characters with character x | |
| Rtext | write over existing text, (<Esc> to end) | |
| J | join succeeding line to current cursor line | |
| :s/pat1/pat2 | on the current line, substitute the first occurence of pattern 1 with pattern 2 | |
| :s/pat1/pat2/ g | on the current line, substitute all occurences of pattern 1 with pattern 2 | |
| :& | ;repeat the last :s request | |
| :%s/pat1/pat2/ g | substitute all occurences of pattern 1 with pattern 2 throughout the file | |
| :.,$s/pat1/pat2/ g | substitute all occurences of pattern 1 with pattern 2 from cursor to end of file | |
| Moving Around in a File | ||
| <Control>g | ascertain line number of current line | |
| G | go to end of file | |
| nG | go to line n | |
| <Return> or + | move cursor to beginning of next line | |
| - | move to beginning of previous line | |
| w or nw | move one word or n words to the right | |
| b or nb | move one word or n words to the left | |
| ) | move to next sentence | |
| ( | move to previous sentence | |
| } | move to next paragraph | |
| { | move to previous paragraph | |
| <Control>d | scroll down one-half screen | |
| <Control>u | scroll up one-half screen | |
| <Control>l | clear and redraw the screen | |
| mx | mark cursor position with character x | |
| `x | move to position marked with x | |
| d`x | delete text from marked x to cursor | |
| y`x | yank text from marked x to cursor | |
| Note: If you precede the mark letter with ‘ (apostrophe) instead of ` (grave accent), the action will apply to the entire line the mark is in, not the exact marked location. | ||
| File Manipulation | ||
| :rfile | read in a file beginning on the line below the current line | |
| :w | save and remain in current file | |
| :wq | save file and quit | |
| :q | quit (leave unedited file) | |
| :q! | quit and do not save changes | |
| :!command | run single Unix command while editing (press <Return> to return to file) | |
| :sh | obtain temporary shell (<Control>D to return to file being edited) | |
| :n,mm l | move lines numbered n through m after line l | |
| :n,mt l | make a copy of lines numbered n through m and put after line l | |
| :n,mw file | write lines numbered n through m to file | |
| :n,mw>> file | append lines numbered n through m to end of file | |
| :’a,’ bwfile | write block, marked with a and b, to file | |
| Searching For Text | ||
| /pat | go to pattern pat (forward in file from current cursor position) | |
| ?pat | go to pattern pat (backward in file from current cursor position) | |
| n | repeat last search, looking in direction of initial search | |
| N | repeat last search, looking in reverse direction of initial search | |
| % | find matching ( ) or { } or [ ] (can be used in combination with /,?,n, or N to search for matching brackets throughout file) | |
| Setting Options | ||
| Options are either toggled on and off, or given values. When editing, set options for a file with the set command. If you want options to be permanent in a particular directory, create a .exrc file in that directory and set options in that file: set option option option=n. (For example, set ai sm sw=4.) If you want certain option settings to apply throughout your Unix environment, edit your .login file by entering setenv EXINIT’set option option option=n’ (for example, setenv EXINIT’set ai sw wm=10′). | ||
| The values in a .exrc file for a directory will override the values of EXINIT in the .login file. If no .exrc file exists, any option values set in the .login are used. If some option values are set in the .exrc file and others are set in the .login file, values from both files are used. | ||
| :set all | displays all option settings on your terminal | |
| :set | displays settings set by EXINIT, the .exrc file, and any current changes | |
| :set option | sets option | |
| :set option=n | sets option and assigns it the value of n | |
| :set nooption | unsets option | |
| :set option? | displays setting of option on screen status line | |
| Common Option Selections | ||
| (To see a complete list of options, enter :set all.) | ||
| Option Name | Default | What Option Does | |
| autoindent (ai) | noai | provides automatic indentation during text entry | |
| autowrite (aw) | noaw | automatically saves file (write) before searches, control codes, escapes to shell | |
| ignorecase (ic) | noic | ignore case during searchs | |
| lisp | nolisp | modify )( }{ ][ to be compatible with lisp | |
| list | nolist | show tabs (^I) and ends of lines ($) | |
| magic | magic | allows metacharacters; with nomagic, these only include <Control> and $ | |
| number (nu) | nonu | show line numbers | |
| readonly (ro) | noro | make file status read only | |
| redraw (re) | nore | simulate smart terminal on dumb | |
| shell | sh=/bin/sh | pathname of new shell for ! and :sh (default from $SHELL if present) | |
| showmatch (sm) | nosm | show matching ( or { when ) or } is entered | |
| term | $TERM | name of terminal being used; set by Unix $TERM | |
| terse | noterse | provide shorter error diagnostics | |
| wrapmargin (wm) | wm=0 | cause lines to be broken at least n spaces from right edge of screen |
craiglist mysql schematics
Craigslist 的数据库架构 每月超过 1000 万人使用该站服务，月浏览量超过 30 亿次，(Craigslist每月新增的帖子近 10 亿条??)网站的网页数量在以每年近百倍的速度增长。Craigslist 至今却只有 18 名员工(现在可能会多一些了)。Tim O’reilly 采访了 Craigslist 的 Eric Scheide ，于是通过这篇 Database War Stories #5: craigslist 我们能了解一下 Craigslist 的数据库架构以及数据量信息。
数据库软件使用 MySQL 。为充分发挥 MySQL 的能力，数据库都使用 64 位 Linux 服务器, 14 块 本地磁盘(72*14=1T ?), 16G 内存。
不同的服务使用不同方式的数据库集群。
论坛
1 主(master) 1 从(slave)。Slave 大多用于备份. myIsam 表. 索引达到 17G。最大的表接近 4200 万行。
分类信息
1 主 12 从。 Slave 各有个的用途. 当前数据包括索引有 114 G , 最大表有 5600 万行(该表数据会定期归档)。 使用 myIsam。分类信息量有多大? “Craigslist每月新增的帖子近 10 亿条”，这句话似乎似乎有些夸张，Eric Scheide 说昨日就超过 330000 条数据，如果这样估计的话，每个月的新帖子信息大约在 1 亿多一些。
归档数据库
1 主 1 从. 放置所有超过 3 个月的帖子。与分类信息库结构相似但是更大， 数据有 238G， 最大表有 9600 万行。大量使用 Merge 表，便于管理。
搜索数据库
4 个 集群用了 16 台服务器。活动的帖子根据 地区/种类划分，并使用 myIsam 全文索引，每个只包含一个子集数据。该索引方案目前还能撑住，未来几年恐怕就不成了。
Authdb
1 主 1 从，很小。
目前 Craigslist 在 Alexa 上的排名是 30，上面的数据只是反映采访当时(April 28, 2006)的情况，毕竟，Craigslist 数据量还在每年 200% 的速度增长。
Craigslist 采用的数据解决方案从软硬件上来看还是低成本的。优秀的 MySQL 数据库管理员对于 Web 2.0 项目是一个关键因素。
http://www.diybl.com/course/7_databases/mysql/myxl/2007614/52429.html
如何将Access和Excel导入到Mysql中
http://info.codepub.com/2008/08/info-21401.html
构建支持Master/Slave读写分离的数据库操作类
PHP+MYSQL 简单实现中文分词全文索引
http://info.codepub.com/2008/07/info-20442.html
http://unix-cd.com/vc/www/26/2008-07/10189.html