划痕 CD 修复指南

指南的原作者是 theRadDept（逝者安息）。

本指南将向你展示如何修复一张因带有划痕，而会给你带来 CRC 不匹配、读取错误、同步错误和可疑位置等问题的 CD。

在正确修复之后，你的划痕 CD 应向你提供 CRC 匹配的完美翻录。即使是严重划伤的 CD，只要反射层（印有图案的一面）没有被损坏，也是一样能被修复的。

在你尝试修复一张原版碟片之前，我建议你先拿一张又旧又烂的 CD-R 练习一下。

不管怎样，不要购买 CD 修复套装。它们的成本远远高于本方法，但结果却很差。

在你完成修复之后，你会看到 CD 上仍有细微的划痕。不用担心，这点儿瑕疵小到不足以影响播放或抓轨。如果你处于美学上的追求想要把这点儿瑕疵也抹除干净，细砂纸会是不错的工具。

材料明细

为写这篇指南，我使用了一张我女朋友买来希望我修复的 CD，是 Tom Jones 的《This is Tom Jones》。它实际上是一盒三张 CD，全都划花了，在 CD 机播放时，它们会疯狂跳转，抓轨就更不可能了。在修复后，全部三张 CD（74 首歌）都可以被 CRC 匹配地完美抓轨。

我使用的光驱和软件是 TOSHIBA ODD-DVD SD-R6372 和 EAC V0.99 prebeta 4。安全模式抓轨、正确设置的偏移值、测试并抓取、高纠错质量。

准备清单

1 张划痕 CD
3 到 10 分钟
一瓶 Meguiar’s PlastX（透明塑料清洁抛光剂）参考购买链接
砂纸：1500 和 2000 目（我使用的是 3M 车漆水砂纸）参考购买链接，店家是 10 张一起卖的，你可以请店家两种目数各 5 张卖给你。
一块布（我用的是一块旧围巾；你可以用旧 T 恤、袜子、毛巾等）
面巾纸
温水

砂纸和抛光剂你可以在万能的淘宝买到。我是在 Canadian Tire 花了 $10.49 买了一瓶 296 ml 的抛光剂，以及 $2.99 买了五张 9×23 cm 的砂纸。这些材料足以修复逾百张 CD。

修复

首先，切一小张砂纸（一张 2.5 cm 见方的砂纸足够几次修复了，你只需要切买来的整张砂纸的 1/64 就差不多是这个大小）。

将砂纸在水中浸泡，然后用手指稍微湿润 CD。

按如下图所示的动作打磨 CD。这个方法适用于严重划伤的 CD；如果只有少量瑕疵，打磨整张 CD 就没必要了，打磨有瑕疵的地方即可。

在打磨时稍稍用点力，在你觉得差不多且划痕消失的时候，继续不施力地打磨一会儿。在用力打磨时我使用了 1500 目的砂纸，轻轻打磨时我使用了 2000 目。

用温水冲洗碟片然后轻轻用纸巾吸干水分。

然后，在 CD 上滴几滴抛光剂，使用小块布抛光它直到抛光剂被布完全吸收。要抛光整个碟片的表面大约需要 6 滴，这已经很足够了。

再一次用温水冲洗 CD 然后轻轻用纸巾吸干水分。

现在，你的 CD 的反光面应当已经重新闪耀了起来。小心检查看看还有没有划痕剩下。如果还有，说明你打磨得还不够，重复打磨和抛光的过程即可。

现在，CD 应该已经能被正确抓轨了。

示例

下面展示了一张严重划伤的 CD-ROM 修复前后的对比图。

实测

作为一个实事求是的 Wiki 译者，我必须要实测一下修复的实际效果。

修复确实很快，所消耗的材料也非常的少，但抛光后的光滑程度还是比不上未经打磨的区域，显得有些雾蒙蒙。当然了，最重要的还是它对于抓轨是否有帮助，我实测这个方法的主要目的也正是为了正确地抓取一张 CD。下面是三份不同处理的同一 CD 的抓轨 LOG：

未经处理

Exact Audio Copy V1.3 from 2. September 2016 EAC extraction logfile from 2. November 2019, 18:35 刘嘉卓 / 新的一天 Used drive : ATAPI CDRW 52X32 Adapter: 1 ID: 0 Read mode : Secure Utilize accurate stream : Yes Defeat audio cache : Yes Make use of C2 pointers : No Read offset correction : 738 Overread into Lead-In and Lead-Out : Yes Fill up missing offset samples with silence : Yes Delete leading and trailing silent blocks : No Null samples used in CRC calculations : Yes Used interface : Native Win32 interface for Win NT & 2000 Gap handling : Appended to previous track Used output format : User Defined Encoder Selected bitrate : 896 kBit/s Quality : High Add ID3 tag : No Command line compressor : D:\Tools\foobar2000\encoders\flac.exe Additional command line options : -8 -e -p -V -T “ARTIST=%artist%” -T “TITLE=%title%” -T “ALBUM=%albumtitle%” -T “DATE=%year%” -T “TRACKNUMBER=%tracknr%” -T “GENRE=%genre%” -T “COMMENT=%comment%” -T “BAND=%albuminterpret%” -T “ALBUMARTIST=%albuminterpret%” -T “COMPOSER=%composer%” %haslyrics%–tag-from-file=LYRICS="%lyricsfile%"%haslyrics% -T “DISCNUMBER=%cdnumber%” -T “TOTALDISCS=%totalcds%” -T “TOTALTRACKS=%numtracks%” %hascover%–picture="%coverfile%"%hascover% %source% -o %dest% TOC of the extracted CD Track | Start | Length | Start sector | End sector --------------------------------------------------------- 1 | 0:00.00 | 2:55.58 | 0 | 13182 2 | 2:55.58 | 3:12.68 | 13183 | 27650 3 | 6:08.51 | 1:56.39 | 27651 | 36389 4 | 8:05.15 | 3:21.42 | 36390 | 51506 5 | 11:26.57 | 3:50.62 | 51507 | 68818 6 | 15:17.44 | 3:00.35 | 68819 | 82353 7 | 18:18.04 | 2:36.02 | 82354 | 94055 8 | 20:54.06 | 3:03.71 | 94056 | 107851 9 | 23:58.02 | 1:59.14 | 107852 | 116790 10 | 25:57.16 | 3:41.18 | 116791 | 133383 11 | 29:38.34 | 2:03.54 | 133384 | 142662 12 | 31:42.13 | 3:58.02 | 142663 | 160514 Track 1 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\01. 跳跃.wav Pre-gap length 0:00:02.00 Peak level 95.4 % Extraction speed 4.1 X Track quality 100.0 % Test CRC 5CA448B4 Copy CRC 5CA448B4 Track not present in AccurateRip database Copy OK Track 2 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\02. 境.wav Peak level 95.4 % Extraction speed 3.7 X Track quality 99.9 % Test CRC 24444B5B Copy CRC 24444B5B Track not present in AccurateRip database Copy OK Track 3 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\03. 东京喰种.wav Peak level 95.5 % Extraction speed 3.2 X Track quality 99.9 % Test CRC C77660FE Copy CRC C77660FE Track not present in AccurateRip database Copy OK Track 4 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\04. 独角犀.wav Peak level 95.5 % Extraction speed 4.3 X Track quality 100.0 % Test CRC 3FF2E76E Copy CRC 3FF2E76E Track not present in AccurateRip database Copy OK Track 5 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\05. 飘雪.wav Peak level 95.5 % Extraction speed 4.8 X Track quality 100.0 % Test CRC C38D6D0A Copy CRC C38D6D0A Track not present in AccurateRip database Copy OK Track 6 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\06. 青鸟.wav Peak level 95.5 % Extraction speed 4.7 X Track quality 100.0 % Test CRC 64DAB3A9 Copy CRC 64DAB3A9 Track not present in AccurateRip database Copy OK Track 7 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\07. 轨迹.wav Peak level 95.4 % Extraction speed 4.2 X Track quality 99.9 % Test CRC BF684EFA Copy CRC BF684EFA Track not present in AccurateRip database Copy OK Track 8 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\08. 时间飞逝.wav Peak level 95.4 % Extraction speed 4.5 X Track quality 99.9 % Test CRC F2C125EA Copy CRC F2C125EA Track not present in AccurateRip database Copy OK Track 9 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\09. 公爵之舞.wav Peak level 95.5 % Extraction speed 3.7 X Track quality 99.9 % Test CRC C300ABF5 Copy CRC C300ABF5 Track not present in AccurateRip database Copy OK Track 10 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\10. 比利・金.wav Peak level 95.5 % Extraction speed 5.5 X Track quality 100.0 % Test CRC 47DC07F2 Copy CRC 47DC07F2 Track not present in AccurateRip database Copy OK Track 11 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\11. 力量.wav Peak level 95.5 % Extraction speed 5.2 X Track quality 100.0 % Test CRC 7598767F Copy CRC 7598767F Track not present in AccurateRip database Copy OK Track 12 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\12. 真棒！.wav Suspicious position 0:02:59 Suspicious position 0:03:06 Peak level 95.5 % Extraction speed 1.8 X Track quality 99.3 % Test CRC 888D95C5 Copy CRC 92F839A1 Track not present in AccurateRip database Copy finished None of the tracks are present in the AccurateRip database There were errors End of status report —- CUETools DB Plugin V2.1.6 [CTDB TOCID: 1acgnZj5CNzt_.Jxj3tN2mk.PaU-] disk not present in database Submit result: insufficient quality

==== Log checksum E09D5061403F4A27152B2E122CBFF5033F8AB4E83BB645A6EC0037D7B0838262 ====

眼镜布擦拭

Exact Audio Copy V1.3 from 2. September 2016 EAC extraction logfile from 2. November 2019, 20:18 刘嘉卓 / 新的一天 Used drive : ATAPI CDRW 52X32 Adapter: 1 ID: 0 Read mode : Secure Utilize accurate stream : Yes Defeat audio cache : Yes Make use of C2 pointers : No Read offset correction : 738 Overread into Lead-In and Lead-Out : Yes Fill up missing offset samples with silence : Yes Delete leading and trailing silent blocks : No Null samples used in CRC calculations : Yes Used interface : Native Win32 interface for Win NT & 2000 Gap handling : Appended to previous track Used output format : User Defined Encoder Selected bitrate : 896 kBit/s Quality : High Add ID3 tag : No Command line compressor : D:\Tools\foobar2000\encoders\flac.exe Additional command line options : -8 -e -p -V -T “ARTIST=%artist%” -T “TITLE=%title%” -T “ALBUM=%albumtitle%” -T “DATE=%year%” -T “TRACKNUMBER=%tracknr%” -T “GENRE=%genre%” -T “COMMENT=%comment%” -T “BAND=%albuminterpret%” -T “ALBUMARTIST=%albuminterpret%” -T “COMPOSER=%composer%” %haslyrics%–tag-from-file=LYRICS="%lyricsfile%"%haslyrics% -T “DISCNUMBER=%cdnumber%” -T “TOTALDISCS=%totalcds%” -T “TOTALTRACKS=%numtracks%” %hascover%–picture="%coverfile%"%hascover% %source% -o %dest% TOC of the extracted CD Track | Start | Length | Start sector | End sector --------------------------------------------------------- 1 | 0:00.00 | 2:55.58 | 0 | 13182 2 | 2:55.58 | 3:12.68 | 13183 | 27650 3 | 6:08.51 | 1:56.39 | 27651 | 36389 4 | 8:05.15 | 3:21.42 | 36390 | 51506 5 | 11:26.57 | 3:50.62 | 51507 | 68818 6 | 15:17.44 | 3:00.35 | 68819 | 82353 7 | 18:18.04 | 2:36.02 | 82354 | 94055 8 | 20:54.06 | 3:03.71 | 94056 | 107851 9 | 23:58.02 | 1:59.14 | 107852 | 116790 10 | 25:57.16 | 3:41.18 | 116791 | 133383 11 | 29:38.34 | 2:03.54 | 133384 | 142662 12 | 31:42.13 | 3:58.02 | 142663 | 160514 Track 1 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\01. 跳跃.wav Pre-gap length 0:00:02.00 Peak level 95.4 % Extraction speed 3.3 X Track quality 100.0 % Test CRC 5CA448B4 Copy CRC 5CA448B4 Track not present in AccurateRip database Copy OK Track 2 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\02. 境.wav Peak level 95.4 % Extraction speed 5.4 X Track quality 99.9 % Test CRC 24444B5B Copy CRC 24444B5B Track not present in AccurateRip database Copy OK Track 3 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\03. 东京喰种.wav Peak level 95.5 % Extraction speed 4.7 X Track quality 99.9 % Test CRC C77660FE Copy CRC C77660FE Track not present in AccurateRip database Copy OK Track 4 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\04. 独角犀.wav Peak level 95.5 % Extraction speed 7.5 X Track quality 100.0 % Test CRC 3FF2E76E Copy CRC 3FF2E76E Track not present in AccurateRip database Copy OK Track 5 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\05. 飘雪.wav Peak level 95.5 % Extraction speed 7.1 X Track quality 100.0 % Test CRC C38D6D0A Copy CRC C38D6D0A Track not present in AccurateRip database Copy OK Track 6 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\06. 青鸟.wav Peak level 95.5 % Extraction speed 7.0 X Track quality 100.0 % Test CRC 64DAB3A9 Copy CRC 64DAB3A9 Track not present in AccurateRip database Copy OK Track 7 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\07. 轨迹.wav Peak level 95.4 % Extraction speed 5.8 X Track quality 99.9 % Test CRC BF684EFA Copy CRC BF684EFA Track not present in AccurateRip database Copy OK Track 8 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\08. 时间飞逝.wav Peak level 95.4 % Extraction speed 6.3 X Track quality 99.9 % Test CRC F2C125EA Copy CRC F2C125EA Track not present in AccurateRip database Copy OK Track 9 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\09. 公爵之舞.wav Peak level 95.5 % Extraction speed 5.7 X Track quality 99.9 % Test CRC C300ABF5 Copy CRC C300ABF5 Track not present in AccurateRip database Copy OK Track 10 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\10. 比利・金.wav Peak level 95.5 % Extraction speed 7.9 X Track quality 100.0 % Test CRC 47DC07F2 Copy CRC 47DC07F2 Track not present in AccurateRip database Copy OK Track 11 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\11. 力量.wav Peak level 95.5 % Extraction speed 7.5 X Track quality 100.0 % Test CRC 7598767F Copy CRC 7598767F Track not present in AccurateRip database Copy OK Track 12 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\12. 真棒！.wav Suspicious position 0:02:59 Suspicious position 0:03:06 Suspicious position 0:03:13 Peak level 95.5 % Extraction speed 1.9 X Track quality 99.2 % Test CRC 542E83CA Copy CRC 502E7CD7 Track not present in AccurateRip database Copy finished None of the tracks are present in the AccurateRip database There were errors End of status report —- CUETools DB Plugin V2.1.6 [CTDB TOCID: 1acgnZj5CNzt_.Jxj3tN2mk.PaU-] disk not present in database Submit result: insufficient quality

==== Log checksum F8FE6C494FC1A6FECE4BCD5DBC1A7A18B5FCB3C6C91AAEBC0661BA712A24388B ====

打磨抛光

Exact Audio Copy V1.3 from 2. September 2016
EAC extraction logfile from 5. November 2019, 14:24
刘嘉卓 / 新的一天
Used drive : ATAPI CDRW 52X32 Adapter: 1 ID: 0
Read mode : Secure
Utilize accurate stream : Yes
Defeat audio cache : Yes
Make use of C2 pointers : No
Read offset correction : 738
Overread into Lead-In and Lead-Out : Yes
Fill up missing offset samples with silence : Yes
Delete leading and trailing silent blocks : No
Null samples used in CRC calculations : Yes
Used interface : Native Win32 interface for Win NT & 2000
Gap handling : Appended to previous track
Used output format : User Defined Encoder
Selected bitrate : 896 kBit/s
Quality : High
Add ID3 tag : No
Command line compressor : D:\Tools\foobar2000\encoders\flac.exe
Additional command line options : -8 -e -p -V -T “ARTIST=%artist%” -T “TITLE=%title%” -T “ALBUM=%albumtitle%” -T “DATE=%year%” -T “TRACKNUMBER=%tracknr%” -T “GENRE=%genre%” -T “COMMENT=%comment%” -T “BAND=%albuminterpret%” -T “ALBUMARTIST=%albuminterpret%” -T “COMPOSER=%composer%” %haslyrics%–tag-from-file=LYRICS="%lyricsfile%"%haslyrics% -T “DISCNUMBER=%cdnumber%” -T “TOTALDISCS=%totalcds%” -T “TOTALTRACKS=%numtracks%” %hascover%–picture="%coverfile%"%hascover% %source% -o %dest%
TOC of the extracted CD
 Track |   Start  |  Length  | Start sector | End sector
---------------------------------------------------------
    1  |  0:00.00 |  2:55.58 |         0    |    13182
    2  |  2:55.58 |  3:12.68 |     13183    |    27650
    3  |  6:08.51 |  1:56.39 |     27651    |    36389
    4  |  8:05.15 |  3:21.42 |     36390    |    51506
    5  | 11:26.57 |  3:50.62 |     51507    |    68818
    6  | 15:17.44 |  3:00.35 |     68819    |    82353
    7  | 18:18.04 |  2:36.02 |     82354    |    94055
    8  | 20:54.06 |  3:03.71 |     94056    |   107851
    9  | 23:58.02 |  1:59.14 |    107852    |   116790
   10  | 25:57.16 |  3:41.18 |    116791    |   133383
   11  | 29:38.34 |  2:03.54 |    133384    |   142662
   12  | 31:42.13 |  3:58.02 |    142663    |   160514

Track 1
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\01. 跳跃.wav

 Pre-gap length  0:00:02.00

 Peak level 95.4 %
 Extraction speed 3.5 X
 Track quality 100.0 %
 Test CRC 5CA448B4
 Copy CRC 5CA448B4
 Track not present in AccurateRip database
 Copy OK

Track 2
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\02. 境.wav

 Peak level 95.4 %
 Extraction speed 3.0 X
 Track quality 99.9 %
 Test CRC 24444B5B
 Copy CRC 24444B5B
 Track not present in AccurateRip database
 Copy OK

Track 3
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\03. 东京喰种.wav

 Peak level 95.5 %
 Extraction speed 2.4 X
 Track quality 99.9 %
 Test CRC C77660FE
 Copy CRC C77660FE
 Track not present in AccurateRip database
 Copy OK

Track 4
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\04. 独角犀.wav

 Peak level 95.5 %
 Extraction speed 3.4 X
 Track quality 100.0 %
 Test CRC 3FF2E76E
 Copy CRC 3FF2E76E
 Track not present in AccurateRip database
 Copy OK

Track 5
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\05. 飘雪.wav

 Peak level 95.5 %
 Extraction speed 3.3 X
 Track quality 100.0 %
 Test CRC C38D6D0A
 Copy CRC C38D6D0A
 Track not present in AccurateRip database
 Copy OK

Track 6
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\06. 青鸟.wav

 Peak level 95.5 %
 Extraction speed 3.2 X
 Track quality 100.0 %
 Test CRC 64DAB3A9
 Copy CRC 64DAB3A9
 Track not present in AccurateRip database
 Copy OK

Track 7
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\07. 轨迹.wav

 Peak level 95.4 %
 Extraction speed 2.8 X
 Track quality 99.9 %
 Test CRC BF684EFA
 Copy CRC BF684EFA
 Track not present in AccurateRip database
 Copy OK

Track 8
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\08. 时间飞逝.wav

 Peak level 95.4 %
 Extraction speed 3.0 X
 Track quality 99.9 %
 Test CRC F2C125EA
 Copy CRC F2C125EA
 Track not present in AccurateRip database
 Copy OK

Track 9
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\09. 公爵之舞.wav

 Peak level 95.5 %
 Extraction speed 2.7 X
 Track quality 99.9 %
 Test CRC C300ABF5
 Copy CRC C300ABF5
 Track not present in AccurateRip database
 Copy OK

Track 10
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\10. 比利・金.wav

 Peak level 95.5 %
 Extraction speed 3.2 X
 Track quality 100.0 %
 Test CRC 47DC07F2
 Copy CRC 47DC07F2
 Track not present in AccurateRip database
 Copy OK

Track 11
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\11. 力量.wav

 Peak level 95.5 %
 Extraction speed 2.0 X
 Track quality 100.0 %
 Test CRC 07F7EF81
 Copy CRC 7598767F
 Track not present in AccurateRip database
 Copy OK

Track 12
 Filename E:\EAC\刘嘉卓 - 新的一天 (2019) [FLAC]\12. 真棒！.wav

 Peak level 95.5 %
 Extraction speed 2.6 X
 Track quality 99.9 %
 Test CRC 622C0907
 Copy CRC 622C0907
 Track not present in AccurateRip database
 Copy OK

None of the tracks are present in the AccurateRip database
No errors occurred
End of status report
—- CUETools DB Plugin V2.1.6
[CTDB TOCID: 1acgnZj5CNzt_.Jxj3tN2mk.PaU-] found
Submit result: already submitted
Track | CTDB Status
1 | (1/1) Accurately ripped
2 | (1/1) Accurately ripped
3 | (1/1) Accurately ripped
4 | (1/1) Accurately ripped
5 | (1/1) Accurately ripped
6 | (1/1) Accurately ripped
7 | (1/1) Accurately ripped
8 | (1/1) Accurately ripped
9 | (1/1) Accurately ripped
10 | (1/1) Accurately ripped
11 | (1/1) Accurately ripped
12 | (1/1) Accurately ripped
==== Log checksum B069FF9F9EEBF6DBFD257170B7D361D5647A706AD34E331F70B551C82EED3731 ====

事实证明，这个方法是有效的。根据我个人的经验来看，除非划痕很深，否则打磨的时候几乎不需要花什么力气，蹭几下就可使划痕不明显，诸位在尝试时请勿太大力。

另外，也不要抱有太大的希望，我也遇到过这个方法不好使的情况，有些碟子本身的制作工艺就有问题，打磨往往毫无改善作用。