border-image-slice属性用于使用CSS对边界图像进行切片。您可以尝试运行以下代码来实现border-image-slice属性：
<html>
<head>
<style>
#borderimg1 {
border: 15px solid transparent;
padding: 15px;
border-image-source: url(https://nhooo.com/css/images/border.png);
border-image-repeat: round;
border-image-slice: 40;
}
</style>
</head>
<body>
<p id = "borderimg1">This is image border example.</p>
</body>
</html>