要求：从x(t)=sin(2*pi*5*t)+sin(2*pi*200*t)+sin(2*pi*50*t)信号中滤出频率为5Hz的信号-Requirements: from x (t) = sin (2* pi* 5* t)+ sin (2* pi* 200* t)+ sin (2* pi* 50* t) signal to filter out the signal frequency of 5Hz
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001467s ]
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:0.113487s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001450s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.002057s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001313s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.004560s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001441s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003523s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015713s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001639s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 26889 [ RunTime:0.001622s ]
