diff --git a/docs/notes/数据库系统原理.md b/docs/notes/数据库系统原理.md
index cdf1d97c..8e062a5e 100644
--- a/docs/notes/数据库系统原理.md
+++ b/docs/notes/数据库系统原理.md
@@ -47,7 +47,7 @@
 
 事务指的是满足 ACID 特性的一组操作，可以通过 Commit 提交一个事务，也可以使用 Rollback 进行回滚。
 
-<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/731a5e8f-a2c2-43ff-b8dd-6aeb9fffbe26.jpg" width="400px"> </div><br>
+<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/f74144be-857a-40cd-8ec7-87626ef4e20b.png" width="400px"> </div><br>
 
 ## ACID
 
@@ -80,7 +80,7 @@
 - 在并发的情况下，多个事务并行执行，事务不仅要满足原子性，还需要满足隔离性，才能满足一致性。
 - 事务满足持久化是为了能应对数据库崩溃的情况。
 
-<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/de2740c2-c1b5-413d-b6d5-9680d3485c02_200.png" width="450px"> </div><br>
+<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/417bc315-4409-48c6-83e0-59e8d405429e.jpg" width="400px"> </div><br>
 
 ## AUTOCOMMIT
 
@@ -94,27 +94,25 @@ MySQL 默认采用自动提交模式。也就是说，如果不显式使用`STAR
 
 T<sub>1</sub> 和 T<sub>2</sub> 两个事务都对一个数据进行修改，T<sub>1</sub> 先修改，T<sub>2</sub> 随后修改，T<sub>2</sub> 的修改覆盖了 T<sub>1</sub> 的修改。
 
-<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/26a7c9df-22f6-4df4-845a-745c053ab2e5.jpg" width="350"/> </div><br>
+<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/75184b58-c627-4edc-8dcf-605762ebb733.png" width="320px"> </div><br>
 
 ## 读脏数据
 
 T<sub>1</sub> 修改一个数据，T<sub>2</sub> 随后读取这个数据。如果 T<sub>1</sub> 撤销了这次修改，那么 T<sub>2</sub> 读取的数据是脏数据。
 
-<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/bab0fba6-38e4-45f7-b34d-3edaad43810f.jpg" width="400"/> </div><br>
+<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/af0e94d9-502d-4531-938f-d46dd29de52d.png" width="360px"> </div><br>
 
 ## 不可重复读
 
 T<sub>2</sub> 读取一个数据，T<sub>1</sub> 对该数据做了修改。如果 T<sub>2</sub> 再次读取这个数据，此时读取的结果和第一次读取的结果不同。
 
-<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/43bf0957-0386-4c09-9ad7-e163c5b62559.jpg" width="400"/> </div><br>
-
+<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/66ae164c-ad47-4905-895e-51fe38ce797a.png" width="360px"> </div><br>
 
 ## 幻影读
 
 T<sub>1</sub> 读取某个范围的数据，T<sub>2</sub> 在这个范围内插入新的数据，T<sub>1</sub> 再次读取这个范围的数据，此时读取的结果和和第一次读取的结果不同。
 
-<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/2959e455-e6cb-4461-aeb3-e319fe5c41db.jpg" width="400"/> </div><br>
-
+<div align="center"> <img src="https://gitee.com/CyC2018/CS-Notes/raw/master/docs/pics/8fdc577d-552d-4b43-b5e4-a8f98bc2cb51.png" width="340px"> </div><br>
 
 ----
 
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