An explorative study on document type assignment of review articles in Web of Science,Scopus and journals’websites

Purpose:Accurately assigning the document type of review articles in citation index databases like Web of Science(WoS)and Scopus is important.This study aims to investigate the document type assignation of review articles in Web of Science,Scopus and Publisher’s websites on a large scale.Design/methodology/approach:27,616 papers from 160 journals from 10 review journal series indexed in SCI are analyzed.The document types of these papers labeled on journals’websites,and assigned by WoS and Scopus are retrieved and compared to determine the assigning accuracy and identify the possible reasons for wrongly assigning.For the document type labeled on the website,we further differentiate them into explicit review and implicit review based on whether the website directly indicates it is a review or not.Findings:Overall,WoS and Scopus performed similarly,with an average precision of about 99% and recall of about 80%.However,there were some differences between WoS and Scopus across different journal series and within the same journal series.The assigning accuracy of WoS and Scopus for implicit reviews dropped significantly,especially for Scopus.Research limitations:The document types we used as the gold standard were based on the journal websites’labeling which were not manually validated one by one.We only studied the labeling performance for review articles published during 2017-2018 in review journals.Whether this conclusion can be extended to review articles published in non-review journals and most current situation is not very clear.Practical implications:This study provides a reference for the accuracy of document type assigning of review articles in WoS and Scopus,and the identified pattern for assigning implicit reviews may be helpful to better labeling on websites,WoS and Scopus.Originality/value:This study investigated the assigning accuracy of document type of reviews and identified the some patterns of wrong assignments.

Large language models and scientific publishing

ChatGPT and similar large language models(LLMs)have rapidly caught the sci-entific and popular imagination,inviting reflections on their potential and risk for science(Grimaldi&Ehrler,2023;Nature,2023;Thorp,2023;van Dis et al.,2023).

Research on the Necessity of Building National-level Grape and Cherry Germplasm Resources Bank in Shandong Province

At present,the grape and cherry industries in Shandong are in the leading position in China and have driven the development of related high-end manufacturing industries such as wine,brandy,preserved fruit processing,fruit juice processing and health products. Therefore,vigorously developing the grape and cherry industries in Shandong Province and carrying out development and innovation are important parts of Shandong Province in responding to the strategy of national new and old kinetic energy conversion. However,currently the germplasm resources preserved in the fruit tree resources banks in China are only 45% of those in the US and 27. 2% of those in the EU. Moreover,the development of fruit trees resources banks in Shandong is relatively backward in China,and there is still no banks related with grape and cherry germplasm resources in Shandong. Therefore,importance can be attached to the agriculture,forestry,and animal husbandry to build germplasm resources banks for grape and cherry industries in Shandong Province. Building the national-level grape and cherry germplasm resources bank in Shandong Province can also promote the utilization of wild and farm germplasm resources in the future; advance the research on the genes related to disease resistance,stress resistance and quality of grapes and cherries; push forward the construction and development of cherry and grape mutants banks. It is conducive to the research on the agronomic traits of grapes and cherries,and can provide the parents resources for planting innovation and improving the quality of grapes and cherries,as well as promote the development and application of molecular markers of grapes and cherries,including the identification of lines and crossbreeding. Thereby,it cannot only promote the industry development,but also achieve the development of cultivation,breeding and basic research in an all-round way and the development of ＂ production,study and research＂ going side by side.

Editorial

For research assessment and for science communities,performance evaluation and resource allocatio n based on the evaluation are always comm on and heated concems.Although the controversy of how peer review and metrics working together has been long-standing,it is also widely recognized that metrics are significant and can provide useful information and necessary supports tor policy Citation:Liying Yang(2018).Editorial.making.

Bacterial biota in reflux esophagitis and Barrett's esophagus

AIM: To identify the bacterial flora in conditions such as Barrett's esophagus and reflux esophagitis to determine if they are similar to normal esophageal flora.METHODS: Using broad-range 16S rDNA PCR,esophageal biopsies were examined from 24 patients [9with normal esophageal mucosa, 12 with gastroesophageal reflux disease (GERD), and 3 with Barrett's esophagus].Two separate broad-range PCR reactions were performed for each patient, and the resulting products were cloned.In one patient with Barrett's esophagus, g9 PCR clones were analyzed.RESULTS: Two separate clones were recovered from each patient (total = 48), representing 24 different species, with 14 species homologous to known bacteria,5 homologous to unidentified bacteria, and 5 were not homologous (<97% identity) to any known bacterial 16S rDNA sequences. Seventeen species were found in the reflux esophagitis patients, 5 in the Barrett's esophagus patients, and 10 in normal esophagus patients.Further analysis concentrating on a single biopsy from an individual with Barrett's esophagus revealed the presence of 21. distinct bacterial species. Members of four phyla were represented, including Bacteroidetes,Firmicutes, Proteobacteria, and Actinobacteria.Microscopic examination of each biopsy demonstrated bacteria in intimate association with the distal esophageal epithelium, suggesting that the presence of these bacteria is not transitory.CONCLUSION: These findings provide evidence for a complex, residential bacterial population in esophageal reflux-related disorders. While much of this biota is present in the normal esophagus, more detailed comparisons may help identify potential disease associations.

Node2vec Representation for Clustering Journals and as A Possible Measure of Diversity

Purpose: To investigate the effectiveness of using node2 vec on journal citation networks to represent journals as vectors for tasks such as clustering, science mapping, and journal diversity measure.Design/methodology/approach: Node2 vec is used in a journal citation network to generate journal vector representations. Findings: 1. Journals are clustered based on the node2 vec trained vectors to form a science map. 2. The norm of the vector can be seen as an indicator of the diversity of journals. 3. Using node2 vec trained journal vectors to determine the Rao-Stirling diversity measure leads to a better measure of diversity than that of direct citation vectors.Research limitations: All analyses use citation data and only focus on the journal level.Practical implications: Node2 vec trained journal vectors embed rich information about journals, can be used to form a science map and may generate better values of journal diversity measures.Originality/value: The effectiveness of node2 vec in scientometric analysis is tested. Possible indicators for journal diversity measure are presented.

Bacteria,inflammation,and colon cancer

Our relationship with the colonic bacterial flora has long been viewed as benign, but recent studies suggest that this symbiosis has risks as well as benefits. This relationship requires that the host not only provide a supportive environment for the symbiotic bacteria, but also actively maintain intact mechanisms for properly managing the physiologic stresses that are closely associated with the symbiont’s essential survival functions. Failure to do so breaches the host- symbiont contract, and can result in serious effects on the health of the host. Recent investigations that employ several knockout mouse models reveal the consequences of genetic deficiency in the host regarding these mechanisms, and the latent, pro-inflammatory, tumorigenic nature of normal bacterial flora. Further study of the interactions between normal bacterial flora and hosts could shed light on the etiologies and pathogenesis of inflammatory diseases and related cancers, with implications for human health.

A Comparison of Citation Disciplinary Structure in Science between the G7 Countries and the BRICS Countries

Purpose： This study aims to compare the characteristics of citation disciplinary structure between the G7 countries and the BRICS countries.Design/Methodology/Approach： In this contribution, which uses about 1 million Web of Science publications and two publications years（1993 and 2013）, we compare the G7 countries and the BRICS countries with regard to this type of structure. For the publication year 2013, cosine similarity values regarding the citation disciplinary structures of these countries（and of nine other countries） were used as input to cluster analysis. We also obtained cosine similarity values for a given country and its citation disciplinary structures across the two publication years. Moreover, for the publication year 2013, the within-country JeffreysMatusita distance between publication and citation disciplinary structure was measured. Research limitations： First, the citation disciplinary structures of countries depend on multiple and complex factors. It is therefore difficult to completely explain the formation and change of the citation disciplinary structure of a country. This study suggests some possible causes, whereas detailed explanations might be given by future research. Second, the length of the citation window used in this study is three years. However, scientific disciplines differ in their citation practices. Comparison between citations across disciplines using the same citation window length may affect the citation discipline structure results for some countries.Practical limitations： First, the results of this study are based on the WoS database. However, in this database some fields are covered to a greater extent than others, which may affect the results for the citation discipline structure for some studied countries. In future research, we might repeat this study using another database（like Scopus） and, in that case, we would like to make comparisons between the two outcomes. Second, the use of a constant journal setyielded that a large share of the journals covered by WoS year 2013 is ignored in the study. Thus, disciplinary structure is studied based on a quite restricted set of publications. The three mentioned limitations should be kept in mind when the results of this study are interpreted.Originality/value： Disciplinary structure on country level is a highlighted topic for the S＆T policy makers, especially for those come from developing countries. This study observes the disciplinary structure in the view of academic impact, and the result will provide some evidence to make decision for the discipline strategy and funding allocation. Besides, JeffreysMatusita distance is introduced to measure the similarity of citation disciplinary structure and publication disciplinary structure. By applying this measure, some new observations were drawn, for example, ＂Based on the comparison of publication disciplinary structure and citation disciplinary structure, the paper finds most BRICS counties have less impact with more publications＂.Findings： The outcome of the cluster analysis indicates that the G7 countries and BRICS countries are quite heterogeneous regarding their citation disciplinary structure. For a majority of the G7 countries, the citation disciplinary structure tend to be more stable compared to BRICS countries with regard to the years 1993 and 2013. Most G7 countries, with United States as an exception, turned out to have lower values on the Jeffreys-Matusita distance than BRICS countries, indicating a higher degree of heterogeneity between the publication and the citation disciplinary structure for the latter countries. In other words, BRICS countries still receive much less citations in most disciplines than their publication output would suggest. G7 countries can still expect more citations than is to be expected based on their publication output, thereby generating relatively more impact than BRICS countries.

Are Contributions from Chinese Physicists Undercited?

Purpose:In this work,we want to examine whether or not there are some scientific fields to which contributions from Chinese scholars have been un der or over cited.Design/methodology/approach:We do so by comparing the number of received citations and the IOF of publications in each scientific field from each country.The IOF is calculated from applying the modified closed system input–output analysis(MCSIOA)to the citation network.MCSIOA is a PageRank-like algorithm which means here that citations from the more influential subfields are weighted more towards the IOF.Findings:About 40% of subfields in physics in China are undercited,meaning that their net influence ranks are higher(better)than the direct rank,while about 75% of subfields in the USA and German are undercited.Research limitations:Only APS data is analyzed in this work.The expected citation influence is assumed to be represented by the IOF,and this can be wrong.Practical implications:MCSIOA provides a measure of net influences and according to that measure.Overall,Chinese physicists’publications are more likely overcited rather than being undercited.Originality/value:The issue of under or over cited has been analyzed in this work using MCSIOA.

Genome-wide Identification and Analysis of DNA Methyltransferases in Grape

DNA methylation is an important epigenetic regulation mechanism, which is catalyzed by DNA methyltransferases. In this study, eight DNA methyltransferase genes were identified in grape genome to analyze the selective pressure, gene expression and codon usage bias. The results showed grape DNA methyltransferase MET subfamily underwent relatively strong purifying selection during evolution, while chromomethylase CMT subfamily underwent positive selection during evolution. Under different abiotic(heat, drought or cold) stresses, the expression level of many grape DNA methyltransferase genes changed significantly. The expression level of these genes might be related with cis-regulatory elements of their promoters. The results of codon usage bias analysis showed that synonymous codon bias existed in grape DNA methyltransferase gene family, which might be affected by mutation pressure. These results laid a solid foundation for in-depth study of DNA methyltransferases in grape.

Characterization and expression analysis of genes encoding Taxol biosynthetic enzymes in Taxus spp.

Taxol(Paclitaxel),an important anticancer drug,is derived at very low yields from Taxus(yew)species that grow very slowly.In the present study,thirteen genes that encode enzymes involved in Taxol biosynthesis in Taxus spp.were analyzed with bioinformatics methods,and their expression levels in different tissues and after cold and hormone treatments were also analyzed.The results indicated that many cis-elements related to abiotic stresses and hormones were found in the promoter sequences of the 8 genes involved in Taxol biosynthesis.Moreover,the 13 enzymes encoded by the target genes were located in different organelles and had many phosphorylation sites in the response proteins.The 13 genes were expressed highly either in roots or in stems,with lower transcripts in needles,and they were highly expressed after treatment with cold,gibberellin,methyl jasmonate or coronatine,consistent with predictions based on the bioinformatics analysis.These results suggest that the factors such as hormones and abiotic stresses stimulate taxane biosynthesis in yews,providing an important way to sustainably generate taxanes from yew trees or their cell cultures to improve Taxol yields.

Document Type Profiles in Nature, Science, and PNAS： Journal and Country Level

Purpose： In this contribution, we want to detect the document type profiles of the three prestigious journals Nature, Science, and Proceedings of the National Academy of Sciences of the United States （PNAS） with regard to two levels： journal and country. Design/methodology/approach： Using relative values based on fractional counting, we investigate the distribution of publications across document types at both the journal and country level, and we use （cosine） document type profile similarity values to compare pairs of publication years within countries. Findings： Nature and Science mainly publish Editorial Material, Article, News Item and Letter, whereas the publications of PNAS are heavily concentrated on Article. The shares of Article for Nature and Science are decreasing slightly from 1999 to 2014, while the corresponding shares of Editorial Material are increasing. Most studied countries focus on Article and Letter in Nature, but on Letter in Science and PNAS. The document type profiles of some of the studied countries change to a relatively large extent over publication years. Research limitations： The main limitation of this research concerns the Web of Science classification of publications into document types. Since the analysis of the paper is based on document types of Web of Science, the classification in question is not free from errors, and the accuracy of the analysis might be affected.Practical implications： Results show that Nature and Science are quite diversified with regard to document types. In bibliometric assessments, where publications in Nature and Science play a role, other document types than Article and Review might therefore be taken into account. Originality/value： Results highlight the importance of other document types than Article and Review in Nature and Science. Large differences are also found when comparing the country document type profiles of the three journals with the corresponding profiles in all Web of Science journals.

The Intrauterine Bigatti Shaver for Endometrial Lesions: Our Experience and Modifications

Background: Removal of endometrial polyps and submucosal fibroids by blind avulsion or excision with resectoscope is associated with risks such as fluid imbalance and uterine perforation. This review describes our centre’s experience with the intrauterine Bigatti shaver (IBS), a new method for resecting these lesions. Methods: All procedures performed between August 2015 and June 2016 were included. Patient demographics and operation details (set-up time, resection time, operative findings and complications) were collected at time of surgery using a standardised form. Results: 21 cases were performed between August 2015 and June 2016 by two senior gynaecologists. The majority (18, 86%) were performed for polyps associated with menstrual abnormalities or subfertility. Mean operating time was 9.6 minutes (range 3 - 25), median fluid input 1450 mls (range 700 - 3000) and median fluid deficit 100 mls (range 50 - 300). There were no cases of infection, perforation or fluid overload. The IBS blade was bent after resection of an anterior wall polyp in an anteverted uterus. A 3 mm grade 1 submucosal fibroid could not be resected as it was too hard in consistency. Conclusions: The constant clear visualisation provided by the continuous flow of fluid enabled fast and complete resection of sizeable polyps with minimal fluid deficit. No serious complications occurred despite this being the initial series performed by both surgeons. Bending of the blade may be avoided by rotating the camera such that the operating channel is situated just next to the lesion. A drainage sock was fashioned out of ribbon gauze and attached to the end of the suction tubing for collection of small polyp fragments. The IBS is a valuable addition to current methods for resection of endometrial polyps. Further study is required to determine its utility for submucosal fibroids, particularly those with a hard consistency.

Fighting Against Academic Misconduct:What Can Scientometricians Do?

As the number of published papers being retracted is increasing dramatically and is higher than ever before, the phenomenon of retraction has aroused widespread concern in the research community all over the world. It has been mentioned that large-scale retracted papers from China appeared in journals of major publishers(Tang, 2019). After we classified these retracted papers published between 2011 and 2021 based on their retraction reasons(1), we see that 8,594 cases are retracted because of academic misconduct. The “academic misconduct” problem has become a common issue faced by academic communities worldwide, including China.

Amend:An integrated platform of retracted papers and concerned papers

Purpose:The notable increase in retraction papers has attracted considerable attention from diverse stakeholders.Various sources are now offering information related to research integrity,including concerns voiced on social media,disclosed lists of paper mills,and retraction notices accessible through journal websites.However,despite the availability of such resources,there remains a lack of a unified platform to consolidate this information,thereby hindering efficient searching and cross-referencing.Thus,it is imperative to develop a comprehensive platform for retracted papers and related concerns.This article aims to introduce“Amend,”a platform designed to integrate information on research integrity from diverse sources.Design/methodology/approach:The Amend platform consolidates concerns and lists of problematic articles sourced from social media platforms(e.g.,PubPeer,For Better Science),retraction notices from journal websites,and citation databases(e.g.,Web of Science,CrossRef).Moreover,Amend includes investigation and punishment announcements released by administrative agencies(e.g.,NSFC,MOE,MOST,CAS).Each related paper is marked and can be traced back to its information source via a provided link.Furthermore,the Amend database incorporates various attributes of retracted articles,including citation topics,funding details,open access status,and more.The reasons for retraction are identified and classified as either academic misconduct or honest errors,with detailed subcategories provided for further clarity.Findings:Within the Amend platform,a total of 32,515 retracted papers indexed in SCI,SSCI,and ESCI between 1980 and 2023 were identified.Of these,26,620(81.87%)were associated with academic misconduct.The retraction rate stands at 6.64 per 10,000 articles.Notably,the retraction rate for non-gold open access articles significantly differs from that for gold open access articles,with this disparity progressively widening over the years.Furthermore,the reasons for retractions have shifted from traditional individual behaviors like falsification,fabrication,plagiarism,and duplication to more organized large-scale fraudulent practices,including Paper Mills,Fake Peer-review,and Artificial Intelligence Generated Content(AIGC).Research limitations:The Amend platform may not fully capture all retracted and concerning papers,thereby impacting its comprehensiveness.Additionally,inaccuracies in retraction notices may lead to errors in tagged reasons.Practical implications:Amend provides an integrated platform for stakeholders to enhance monitoring,analysis,and research on academic misconduct issues.Ultimately,the Amend database can contribute to upholding scientific integrity.Originality/value:This study introduces a globally integrated platform for retracted and concerning papers,along with a preliminary analysis of the evolutionary trends in retracted papers.

Two indicators rule them all:Mean and standard deviation used to calculate other journal indicators based on log-normal distribution of citation counts

Two journal-level indicators,respectively the mean(mi)and the standard deviation(vi)are proposed to be the core indicators of each journal and we show that quite several other indicators can be calculated from those two core indicators,assuming that yearly citation counts of papers in each journal follow more or less a log-normal distribution.Those other journal-level indicators include journal index,journal one-by-one-sample comparison citation success index S_(j)^(i),journal multiple-sample K^(i)-K^(j) comparison success rate S_(j,k^(j)^(i,k^(i))),and minimum representative sizes k_(j)^(i) and k_(i)^(j),the average ranking of all papers in a journal in a set of journals(R^(t)).We find that those indicators are consistent with those calculated directly using the raw citation data({C^(i)=(c_(1)^(i),c_(2)^(j),...c_(N)^(i),■i})of journals.In addition to its theoretical significance,the ability to estimate other indicators from core indicators has practical implications.This feature enables individuals who lack access to raw citation count data to utilize other indicators by simply using core indicators,which are typically easily accessible.

结合滤波与优化的无人机多传感器融合方法

高精度实时状态估计是无人机安全飞行及执行各种任务的首要条件.多传感器(如视觉、惯性测量单元(IMU)和GPS等)融合可提高状态估计精度,并实现信息冗余,当其中某些传感器出现故障时,仍具有较好的鲁棒性.因此,本文提出结合滤波与优化的无人机多传感器融合方法,从而得到局部高精度、全局无漂移的状态估计.该方法主要分为卡尔曼(Kalman)滤波和全局优化两部分.卡尔曼滤波器作为主体融合框架,融合局部传感器(IMU)和全局传感器(经优化后的视觉、GPS、磁力计和气压计)信息得到全局位姿估计.由于卡尔曼滤波算法计算量较小,可以保证融合估计的实时性.全局优化则负责将有漂移的视觉惯性里程计信息与全局传感器(GPS,磁力计和气压计)融合对齐后,得到高精度的全局视觉估计.但优化输出会出现不连续且视觉处理存在延迟的问题.因此,将优化后的里程计再输入到卡尔曼滤波器中,从而得到高精度、实时无漂移的状态估计.最后结合具体无人机平台,进行了实际的飞行测试与定位实验,实验结果表明了本文方法的有效性和鲁棒性.

Four-year dynamic observation and study on standardized management of elderly patients with type 2 diabetes in Beijing Yongding Road Community

Purpose:This study aimed to understand the joint standard of blood glucose,blood li-pids,and blood pressure in elderly patients>60 years of age with type 2 diabetes in the Beijing Yongding Road Community.Methods:One hundred ninety-two elderly patients>60 years of age who were diagnosed with type 2 diabetes in Yongding Road Community served as the investigation subjects,under-went standard management,and the dynamic changes in blood glucose,blood lipids,and blood pressure were monitored for 48 months.Results:At the end of the observation period,the standard rates of fasting blood glucose and postprandial blood glucose were 72.55%and 80.00%,respectively,which were increased compared with 55.73%and 56.08%at baseline(P<0.01).The standard rate of HbA1c was 59.81%,which was increased compared with 53.44%at baseline(P>0.05).The standard rates of TG and LDL-C were 76.71%and 60.38%,respectively,which were increased compared with 54.69%and 34.74%at base-line,and the standard rate of HDL-C was 13.64%,which was decreased compared with 40.10%at baseline(P<0.01).The standard rate of BP was 58.33%,which was increased compared with 38.54%at baseline(P<0.01).The optimal control rate of blood glucose for 48 months(the standard times of the total measurement times in 48 months≥75%)was higher;the fasting blood glucose was 52.17%,the 2-h postprandial blood glucose was 60.22%,and the HbA1c was 46.45%.The optimal control rate of blood lipids was lower;LDL-C was 17.49%and HDL-C was 13.59%.The optimal control rate of BP was 9.13%.At the end of the observation period,the levels of fasting blood glucose and postprandial blood glucose were decreased by 0.7 mmol/L and 1.48 mmol/L,respectively,compared with the base-line(P<0.01).The level of HbA1c was decreased by 0.18%compared with the baseline(P<0.05).The levels of LDL-C and HDL-C were decreased by 0.4 mmol/L and 0.23 mmol/L,respectively,compared with the baseline(P<0.01).The levels of SBP and DBP were decreased by 4 mmHg compared with the baseline(P<0.01).At the end of the observation period,the joint standard rate of the three indices of HbA1c,LDL-C,and BP was 24.72%,which was increased compared with 6.25%at baseline(P<0.01).Conclusion:Standardized management of elderly patients with diabetes in the Community can improve the joint standard rate of blood glucose,blood lipids,and blood pressure.The op-timal control rate and joint standard rate are the important indices for evaluating the quality of diabetes management.

Performance comparisons between cellular-only and cellularfWLAN integrated systems based on analytical models

To solve the traffic load imbalance issue in cellular networks, which is often in the form of hot-spots caused by the different user mobility levels, one of the good solutions at present is to construct heterogeneous integrated wireless networks that combine cellular networks and wireless local area networks （WLANs） together. In general, the traffic volume is significantly heavier in the hot-spots of cellular networks and a higher data transferring rate can be provided by introducing a WLAN so as to raise the utilization of the channel and achieve a good balance between user satisfaction and the efficiency of the network. In this paper, we provide a comprehensive performance comparison of the systems both before and after the integration, based on an existing mathematical model, focusing on both the qualitative and the quantitative analysis of changes in the performance of the system to validate the efficiency and superiority of the cellular/WLAN integrated systems over cellular-only systems.

Wear Behavior of Cold Pressed and Sintered Al_2O_3/TiC/CaF_2-Al_2O_3/TiC Laminated Ceramic Composite

A novel laminated Al2O3/TiC/CaF2-Al2O3/TiC sandwich ceramic composite was fabricated through cold pressing and sintering to achieve better anti-wear performance, such as low friction coefficient and low wear rate. Al2O3/TiC/CaF2 and Al2O3/TiC composites were alternatively built layer-by-layer to obtain a sandwich structure. Solid lubricant CaF2 was added evenly into the Al2O3/TiC/CaF2 layer to reduce the friction and wear. Al2O3/TiC ceramic was also cold pressed and sintered for comparison. Friction analysis of the two ceramics was then conducted via a wear-and-tear machine. Worn surface and surface compositions were examined by scanning electron microscopy and energy dispersion spectrum, respectively. Results showed that the laminated Al2O3/TiC/CaF2-Al2O3/TiC sandwich ceramic composite has lower friction coefficient and lower wear rate than those of Al2O3/TiC ceramic alone because of the addition of CaF2 into the laminated Al2O3/TiC/CaF2-Al2O3/TiC sandwich ceramic composite. Under the friction load, the tiny CaF2 particles were scraped from the Al2O3/TiC/CaF2 layer and spread on friction pairs before falling off into micropits. This process formed a smooth, self-lubricating film, which led to better anti-wear properties. Adhesive wear is the main wear mechanism of Al2O3/TiC/CaF2 layer and abrasive wear is the main wear mechanism of Al2O3/TiC layer.