$the_query = new WP_Query( array( 'author_name' => 'isim' ,'post_type'=>'post','posts_per_page'=>10,'orderby'=>'date') );

if ( $the_query->have_posts() ) {
	echo '<ul>';
	while ( $the_query->have_posts() ) {
		$the_query->the_post();
		echo '<li>' . get_the_title() . '</li>';
	}
	echo '</ul>';
} else {
	// no posts found
}