采用超小型封装读卡芯片，如图 1所示；
z 符合 ISO14443 标准；
z 可选择 5V或 3.3V供电；
z 能接双天线，能识别是哪一个天线上有卡；
z 有I
2
C从机接口，也有UART接口或RS-232 接口；
z 可主动检测卡进入，检测到卡时可产生中-采用超小型封装读卡芯片，如图 1所示；
z 符合 ISO14443 标准；
z 可选择 5V或 3.3V供电；
z 能接双天线，能识别是哪一个天线上有卡；
z 有I
2
C从机接口，也有UART接口或RS-232 接口；
z 可主动检测卡进入，检测到卡时可产生中
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.002221s ]
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:0.092926s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.002104s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.002223s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.002504s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003847s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002181s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003292s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014894s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.002726s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 131046 [ RunTime:0.001445s ]
