动画序列不能正常显示

(function($){
var seq=[
        {
            elements:$('#div1'),
            properties:{width:'300px'},
            options:{duration: 3000}
        },
        {
            elements:$('#div2'),
            properties:{width:'300px'},
            options:{duration: 3000}
        },
        {
            elements:$('#div3'),
            properties:{width:'300px'},
            options:{duration: 3000}

        }

    ];
    $.Velocity.RunSequence(seq);
})(jQuery);

这个并不能显示效果啊！为什么呢？