使用phpexcel导出excel乱码

<?php
header('Cache-Control: No-cache');  
      
error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);
date_default_timezone_set('Europe/London');
set_time_limit(0);
require "E:\www\Classes\PHPExcel.php";//引入PHPExcel$objPHPExcel=new PHPExcel();//实例化PHPExcel类， 等同于在桌面上新建一个excel
$link = mysql_connect('127.0.0.1','root','root');
mysql_select_db('wsyy',$link);
mysql_query("set name gbk");
$sql = "select hospital.id,hospital.name as hosname from wsyy_hospital inner join wsyy_hospitalspecialtyill on wsyy_hospital.id=wsyy_hospitalspecialtyill.hosid limit 100;";
$result = mysql_query($sql);$objPHPExcel->getActiveSheet()->setTitle('Simple');
// Set active sheet index to the first sheet, so Excel opens this as the first sheet
$objPHPExcel->setActiveSheetIndex(0);
$objPHPExcel->getProperties()->setCreator("Maarten Balliauw")
 ->setLastModifiedBy("Maarten Balliauw")
 ->setTitle("PHPExcel Test Document")
 ->setSubject("PHPExcel Test Document")
 ->setDescription("Test document for PHPExcel, generated using PHP classes.")
 ->setKeywords("office PHPExcel php")
 ->setCategory("Test result file");
$objPHPExcel->setActiveSheetIndex(0)
->setCellValue("A1","编号")
->setCellValue("B1","医院名称")
->setCellValue("C1","省")
->setCellValue("D1","市")
->setCellValue("E1","区")
->setCellValue("F1","简介");//填充数据$res=array();
while(($row=mysql_fetch_assoc($result))!=false){
$res[]=$row;
}$j=2;
foreach($res as $key=>$vo){

$objPHPExcel->setActiveSheetIndex(0)
->setCellValue("A".$j,$vo['id'])
->setCellValue("B".$j,$vo['hosname'])
->setCellValue("C".$j,$vo['province'])
->setCellValue("C".$j,$vo['city'])
->setCellValue("C".$j,$vo['area'])
->setCellValue("D".$j,$vo['name']);

$j++;
}$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');var_dump($objWriter);die;
$objWriter->save(str_replace('.php', '.xlsx', __FILE__));