1. 查找索引

查找当前元素在指定范围内的索引序号，示例：

$('.right_newestState_con').find('em').index($(this));

2. ie滤镜

利用ie的私有滤镜让低版本ie浏览器支持一些高级效果

2.1 透明度

#myElement {

    opacity: .4; /* other browsers */

    filter: progid: DXImageTransform.Microsoft.Alpha( opacity=40 ); /* IE6, IE7, and IE8 */

    -ms-filter : "progid:DXImageTransform.Microsoft.Alpha( opacity=40 )"; /* IE8 only */

}

2.2 PNG图片透明度

.transparent{

	_filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src=img/nav_bg.png);

	_background:none;

}

2.3 阴影

.box-shadow {

    -moz-box-shadow: 2px 2px 3px #969696; /* Firefox */

    -webkit-box-shadow: 2px 2px 3px #969696; /* Safari and Chrome */

    filter: progid:DXImageTransform.Microsoft.Shadow( color='#969696', Direction=145, Strength=3 );

}

2.4 渐变

#gradient {

	background-image: -moz-linear-gradient( top, #81a8cb, #4477a1 ); /* Firefox 3.6 */

	background-image: -webkit-gradient(linear , left bottom , left top , color-stop( 0, #4477a1 ) , color-stop( 1, #81a8cb )); /* Safari & Chrome */

	filter:  progid:DXImageTransform.Microsoft.gradient( GradientType= 0 , startColorstr = '#81a8cb', endColorstr = '#4477a1' ); /* IE6 & IE7 */

	-ms-filter: "progid:DXImageTransform.Microsoft.gradient( GradientType = 0,startColorstr = '#81a8cb', endColorstr = '#4477a1' )"; /* IE8 */

}

2.5 背景色透明(RGBA)

#rgba p {

    background: rgba( 98, 135, 167, .4 );  /* other browsers */

    filter: progid:DXImageTransform.Microsoft.gradient( GradientType = 0,startColorstr = '#886287a7', endColorstr = '#886287a7' );  /* IE */

}

2.6 多背景

#multi-bg {

	 /* other browsers */

	background: url(images/bg-image-1.gif) center center no-repeat, url(images/bg-image-2.gif) top left repeat;

	/* IE */

    background: transparent url(images/bg-image-1.gif) top left repeat;

    filter: progid:DXImageTransform.Microsoft.AlphaImageLoader (src = 'images/bg-image-2.gif', sizingMethod = 'crop'); /* IE6-8 */

    -ms-filter: "progid:DXImageTransform.Microsoft.AlphaImageLoader(src = 'images/bg-image-2.gif', sizingMethod = 'crop')"; /* IE8 only */

}

2.7 旋转

#rotate {

    -webkit-transform: rotate(180deg); /* Safari and Chrome */

    -moz-transform: rotate(180deg); /* Firefox */

    filter: progid:DXImageTransform.Microsoft.BasicImage(rotation = 2); /* IE */

}

2.8 其他

3. 动态背景

//流动背景

var offsetbg = 0;

var windowWidth = Number($(window).width());

setInterval(function bg() {

    if (offsetbg >= windowWidth) {

        offsetbg = -windowWidth;

    }

    offsetbg += 10;

    $(".section_footer_flow").css("background-position-x", -offsetbg + "px")

}, 90 );

参考链接：jquery实现动态背景效果