diff --git a/apps/resm/tasks.py b/apps/resm/tasks.py
index 1507f80..06fe7a3 100644
--- a/apps/resm/tasks.py
+++ b/apps/resm/tasks.py
@@ -257,13 +257,17 @@ def get_pdf_from_elsevier(number_of_task=100):
     return f'{def_name}, {err_msg}, remaining {qs_count} papers'
 
 RUNNING_KEY = "download_pdf:running"
-MAX_RUNNING = 50
+
+def get_max_running():
+    return cache.get("download_pdf:max_running", 100)
 
 def can_send_more():
-    return cache.get(RUNNING_KEY, 0) < MAX_RUNNING
+    return cache.get(RUNNING_KEY, 0) < get_max_running()
 
 @shared_task(base=CustomTask)
-def send_download_fulltext_task(number_of_task=MAX_RUNNING):
+def send_download_fulltext_task(number_of_task=100):
+    if number_of_task != get_max_running():
+        cache.set("download_pdf:max_running", number_of_task)
     qs = Paper.objects.filter(is_oa=True, has_fulltext=False, fail_reason=None)
     if not qs.exists():
         return "done"
@@ -277,7 +281,7 @@ def send_download_fulltext_task(number_of_task=MAX_RUNNING):
         if paper.oa_url:
             # 发送任务前先增加计数，确保计数准确
             current_count = incr_running()
-            if current_count > MAX_RUNNING:
+            if current_count > number_of_task:
                 # 超过限制，回滚计数并停止
                 decr_running()
                 break
@@ -292,7 +296,7 @@ def send_download_fulltext_task(number_of_task=MAX_RUNNING):
                 countdown=countdown,
             )
             task_count += 1
-    return f"sent {task_count} download_pdf tasks, running {cache.get(RUNNING_KEY, 0)}/{MAX_RUNNING}"
+    return f"sent {task_count} download_pdf tasks, running {cache.get(RUNNING_KEY, 0)}/{number_of_task}"
 
 
 def incr_running():
@@ -391,5 +395,6 @@ def save_pdf_from_openalex(paper:Paper):
             cache.set("openalex_api_exceed", True, timeout=3600)
             return "Insufficient credits"
 
-
+def save_pdf_from_scihub(paper:Paper):
+    pass
 # https://sci.bban.top/pdf/10.1016/j.conbuildmat.2020.121016.pdf?download=true
\ No newline at end of file