function _x(STR_XPATH) {
    
    var xresult = document.evaluate(STR_XPATH, document, null, XPathResult.ANY_TYPE, null);
    var xnodes = [];
    var xres;
    while (xres = xresult.iterateNext()) {
        // 获取元素
        xnodes.push(xres);
      	// 获取指定元素的值
        //xnodes.push(xres.getAttribute('data-cgt-code'));
    }

    return xnodes;
}

// 使用
console.log(_x('//ul[@id="newul"]/li'));