.fix_3 li{
    width: 32%;
    margin-bottom: 70px;
    margin-right: 1%;
    float: left;
    height: 400px;
}

.fix_3 ul{
    width: 100%;
}

.fix_3 li .pic{
    max-height: 300px;
}

.fix_3 li .word h6{
    overflow: hidden;
    white-space: nowrap;
}

@media screen and (max-width:480px){
    .research_book_list .pic img{
        height: 186px ;
    }

    .research_book_list{
        height: 306px;
    }

    .fix_3 li{
        height: 320px;
        margin-bottom: 5px;
    }
}

@media screen and (max-width: 640px) and (min-width: 480px) {
    .research_book_list .pic img{
        height: 295px;
    }

    .research_book_list{
        height: 360px;
    }

    .fix_3 li{
        height: 380px;
        margin-bottom: 50px;
    }
}

@media screen and (max-width: 780px) and (min-width: 640px) {
    .research_book_list .pic img{
        height: 355px;
    }

    .research_book_list{
        height: 423px;
    }

    .fix_3 li{
        margin-bottom: 50px;
    }
}

@media screen and (max-width: 980px) and (min-width: 780px) {
    .research_book_list .pic img{
        height: 432px;
    }

    .research_book_list{
        height: 453px;
    }

    .fix_3 li{
        margin-bottom: 50px;
    }
}

@media screen and (max-width: 1200px) and (min-width: 980px) {
    .research_book_list .pic img{
        height: 432px;
    }

    .research_book_list{
        height: 453px;
    }
}