一篇讲解OFDM技术的PDF文档，里面详细讲解了OFDM原理，希望对初学者有帮助。-One explain the OFDM technology, PDF documents, which gave a detailed OFDM principle, want to be helpful for beginners.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001096s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.059773s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.000989s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001093s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000988s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003019s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000845s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003859s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014321s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001259s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 242892 [ RunTime:0.017152s ]
