按照惯例，JCR每年警告一些期刊，不公布影响因子，主要是自引或互引吧，今年继续，而且有2种中国期刊。详见原文和名单，标红的为中国期刊：

http://help.incites.clarivate.com/incitesLiveJCR/JCRGroup/titleSuppressions.html

Title Suppressions

Editorial Expression of Concern

Investigation following on the editorial expression of concern for 2017 data has been completed. Please see the results here.

Journals Suppressed from 2018 JCR Data (2019 release)

Metrics for the titles listed below are not published due to anomalous citation patterns found in the 2018 citation data. These patterns result in a significant distortion of the Journal Impact Factor and rank that does not accurately reflect the journal’s citation performance in the literature. The Journal Impact Factor provides an important and objective measure of a journal’s contribution to scholarly communication. In the interest of fairness and accuracy for all journals, the distortion of the Journal Impact Factor by an excessive concentration of citations gives rise to the need for suppression. JCR staff will monitor these journals going forward and the titles will be included in a future edition of JCR when the anomalous patterns are resolved. Coverage of these journals in Web of Science and other Clarivate Analytics products is not immediately affected by suppression from the JCR. However, the titles may be subject to review to determine if they continue to meet the quality and publication standards necessary for inclusion in Web of Science Core Collection flagship indexes (Science Citation Index Expanded and Social Science Citation Index). For more information, review our suppression policy.

A list of title suppression for previous years can be downloaded here.

Self Citation Suppressed Titles with Key Data Points*

This table lists the categories for each journal (note that each journal may be included in multiple categories), the percentage of citations in the Journal Impact Factor numerator that are self cites, and the distortion in category rank due to self cites. The distortion in category rank is based on analysis of all journals in all categories of the JCR ranked both with and without the inclusion of self cites. Here distortion equals the percentage shift in rank with self cites included versus excluded.

Citation Stacking Suppressed Titles with Key Data Points* 

This table lists the recipient and donor journal pairs along with the percentage of citations in the Journal Impact Factor numerator that are from the donor to the recipient (x% of the JIF Numerator cites to Recipient journal from Donor journal). The percentage exchange to the Journal Impact Factor years is the proportion of all citations from donor to recipient (all years) that reference the two years considered in the Journal Impact Factor calculation (x% of all citations from Donor to Recipient were concentrated in the Journal Impact Factor years).