Geology and mineralization of the Hongqiling large magmatic nickel-copper-cobalt deposit(22×10^(4)t)in Jilin Province,China:A review

The Hongqiling large nickel-copper-cobalt deposit(hereafter referred to as the Hongqiling deposit),a typical mafic-ultramafic copper-nickel deposit in China,boasts proven Ni(Ni)resources of approximately 22×10^(4)t,associated copper resources of 2×10^(4)t,and associated cobalt(Co)resources of 0.5×10^(4)t,with Ni reserves ranking 10th among China's magmatic nickel deposits.Geotectonically,the Hongqiling deposit is situated in the superimposed zone between the Xing'an-Mongolian orogenic belt and the circum-Western Pacific's active continental margin belt.Its ore-bearing plutons occur within the metamorphic rocks of the Ordovician Hulan Group,with the emplacement of plutons and the locations of orebodies governed by the deep-seated Huifahe fault and its secondary NW-trending Fujia-Hejiagou-Beixinglong-Changsheng fault zone.In the deposit,the rock assemblages of ore-bearing plutons predominantly encompass gabbro-pyroxenite-olivine pyroxenite-pyroxene peridotite(pluton No.1)and norite-orthopyroxenite-harzburgite(pluton No.7),with ore-bearing lithofacies consisting primarily of olivine pyroxenite and pyroxenite facies.The Hongqiling deposit hosts stratoid,overhanging lentoid,veined,and pure-sulfide veined orebodies.Its ores principally contain metallic minerals including pyrrhotite,pentlandite,chalcopyrite,violarite,and pyrite.Despite unidentified magma sources of ore-bearing mafic-ultramafic rocks,it is roughly accepted that the magmatic evolution in the Hongqiling deposit primarily involved fractional crystallization and crustal contamination.The ore-forming materials were primarily derived from the upper mantle,mixed with minor crustal materials.The ore-bearing mafic-ultramafic rocks in the deposit,primarily emplaced during the Indosinian(208-239 Ma),were formed in an intense extension setting followed by the collisional orogeny between the North China Plate and the Songnen-Zhangguangcai Range Block during the Middle-Late Triassic.From the perspective of the metallogenic geological setting,surrounding rocks,ore-controlling structures,and rock assemblages,this study identified one favorable condition and seven significant indicators for prospecting for Hongqiling-type nickel deposits and developed a prospecting model of the Hongqiling deposit.These serve as valuable references for exploring similar nickel deposits in the region,as well as the deep parts and margins of the Hongqiling deposit.

退役军人事务的国际研究进展及启示

当前,国际学界对退役军人事务较为关注与重视,但国内对这些研究缺乏系统的理论评介。论文基于SSCI数据库中社会学、政治学、经济学、法学、管理学与行政学6个学科的1397篇文献的数据分析,梳理了退役军人事务的国际研究概况和不同学科的研究进展,将退役军人事务的国际研究分为三类主题:一是医疗与健康保障,包括身体健康、心理健康、健康管理与医疗政策等议题;二是经济与社会保障,包括住房保障、教育保障、就业保障与人事行政等议题;三是政治与身份认同,包括政治参与、身份认同、家庭关系、种族与性别等议题。未来国内研究既要借鉴与吸收国际研究的思想成果,在共性研究领域中推动理论交流与对话,也要重视本土情境下的特色问题,积极推动理论探索与实践创新。公共管理学科需要重视和加强对退役军人事务的研究,重点围绕退役军人事务部的运行与退役军人的需求展开研究,为服务与保障退役军人群体贡献学科力量。

Translocality:A Re-recognition of Locality in Western Geography

Translocality,as a re-recognition of locality in western Geography,has gradually become an important theoretical framework for understanding the increasingly interconnected global world.By focusing on sorting out the context and main topics of current western geography on translocality research,it reached the following conclusions.(i)From the perspective of geography,translocality research can be roughly divided into initial development stage,stable development stage and high-speed development stage.(ii)Existing studies on migration,urbanization,and social resilience form the knowledge base for translocality research from the perspective of geography.Migration,mobility,and politics are hot topics of translocality research.(iii)Current issues mainly focus on the characteristics of translocal behavior,the impact of translocal behavior,translocal circular flow and gender research in translocal behavior.Based on this,it proposed the important trends that translocality research in China needs to pay attention.

特定益生元对内源性乳酸菌的富集作用

为明确小鼠粪便微生物生长所需的主要营养物质,以及粪便微生物的组成结构和多样性,通过体外模拟结合添加不同益生元或营养元素,探究这些物质对小鼠粪便中微生物的富集作用,以及小鼠粪便微生物的生长所需的营养物质。研究表明:氮源是粪便中微生物的生长限制性因子,乳酸细菌培养基(MRS)中的其它营养物质虽不是重要的限制因素,但添加氮源不适于肠道乳杆菌的富集工作。同时添加低聚果糖,乳杆菌数量增加,物种丰度和多样性均较好,适合粪便微生物的体外筛选。本研究结果可为益生元的应用和乳酸菌等菌株的筛选提供试验参考。

不同治疗对肺癌患者血液循环游离DNA检测EGFR基因突变的影响及预后分析

背景与目的表皮生长因子受体(epidermal growth factor receptor,EGFR)基因突变与肺腺癌患者TKI靶向治疗疗效和预后密切相关,常规组织分析其突变状态有诸多局限。本研究旨在探讨非小细胞肺癌(non-small cell lung cancer,NSCLC)患者血液循环游离DNA(cell-free DNA,cfDNA)检测EGFR基因突变在治疗前、传统化疗以及靶向治疗后的表达差异。分析血液cfDNA是否能准确检测EGFR基因突变并监测耐药基因T790M的变化,以及TKI在靶向治疗患者中的预后价值。方法应用ARMS(amplification refractory mutation system)法检测107例(50例治疗前、29例传统化疗和28例靶向治疗)肺癌患者配对血液和肿瘤组织样本的EGFR基因突变并比较其表达差异;计算检测的一致性、敏感性和特异性;分析血检对靶向治疗患者的预后价值。结果血浆cfDNA检测EGFR总突变率在107例肺癌患者中为56%(60例),而配对肿瘤组织样本检出率为77.6%(83例)。一一配对比较发现两者总体一致率为68.2%。血检的敏感性是72.3%,特异性为100%。依据治疗状态分组后发现治疗前组患者血液和肿瘤组织样本的检测一致率最高(74%,37/50),而靶向组一致率最低(57.1%,16/28),提示靶向治疗改变血浆cfDNA中EGFR基因状态。具体分析靶向组不一致病例发现50%新检出含T790M的双突变,提示靶向治疗后耐药基因出现。生存分析证实血检含T790M双突变组的无进展生存期(progression-free survival,PFS)和总生存期(overall survival,OS)均显著低于无T790M突变组。结论应用ARMS法检测血液循环游离DNA(circulating cell-free DNA,cfDNA)的EGFR基因突变是一种特异性高、敏感性好的检测方法。适用于治疗前晚期肺癌患者的EGFR基因突变状态检测。同时,适用于靶向治疗后监测T790M耐药突变状态及预测患者预后。

生计安全研究的可视化分析

以Web of science核心库中1991~2016年间收录主题为“livelihood security”的文献为基础,应用CiteSpace软件,采取突现词分析、关键词共现分析、文献共被引分析等方法对生计安全研究进行可视化分析。研究发现,干旱、健康、妇女、艾滋病、粮食安全、难民等是生计安全研究的前沿领域;生计安全研究热点主要包括生计结果类、生态环境类、生计策略类和重点地区类;生计安全研究的知识基础主要包括粮食安全、海洋资源、气候变化适应性等研究领域;从研究内容来看,中国生计安全研究主要包括自然资源与粮食安全、自然灾害与生计安全、快速城镇化与生计安全、气候变化与生计安全等4个方面。

DJ-1 Alters Epirubicin-induced Apoptosis via Modulating Epirubicin-activated Autophagy in Human Gastric Cancer Cells

Epirubicin,which is a conventional chemotherapeutic drug for gastric cancer,has innate and adaptive chemoresistance.Recent studies revealed that epirubicin could induce autophagy as a defensive mechanism in drug resistance of mammary carcinoma.Another study implied that D J-1 may be a chemoresistance-related gene.But the association between D J-1 and drug resistance of epirubicin in gastric cancer is still ambiguous.In the present report,we explored whether and how D J-1 conduced to epirubicin-induced apoptosis in gastric cancer.Epirubicin dose-dependently increased the expression of DJ-1 and induced autophagy.Knockdown of DJ-1 notably enhanced epirubicin-induced cell apoptosis,whereas overexpression of DJ-1 attenuated epirubicin-induced cell apoptosis.Further studies revealed that down-regulation of DJ-1 modulated epirubicin-activated autophagy which augmented epirubicin-induced apoptosis.In conclusion,our results validated that DJ-1 reduced epirubicin-induced apoptosis in gastric cancer cells via modulating epirubicin-activated autophagy.

Expression of Stanniocalcin 2 in Breast Cancer and Its Clinical Sigmiicance

This study aims to explore the expression of stanniocalcin 2(STC2)gene in breast cancer and its clinical significance.Female patients with breast cancer from Zhongnan Hospital of Wuhan University admitted during March 2014 to October 2014 were enrolled in this study.All the tissues used in this experiment included 50 cases of breast cancer tissues and corresponding 50 cases of paracancer normal breast tissues with complete patients'information.The real-time quantitative polymerase chain reaction(qPCR)was applied to detect the expression of STC2 gene in 50 cases of breast cancer and paracancer normal breast tissues.The results showed that the expression level of STC2 gene in 50 cases of breast cancer tissues was significantly higher than that in paracancer normal breast tissues(P<0.001).The expression of STC2 gene was correlated with lymph node metastasis,distant metastasis,TNM stage and histological grade(P<0.001).The expression level of STC2 gene was significantly higher in breast cancer tissues with higher expression of Ki-67(P<0.001).The expression level of STC2 gene was significantly higher in estrogen receptor(ER)positive breast cancer tissues than in ER negative ones(P<0.001).However,different groups of age,pathological type,tumor size,PR expression and human epidermal growth factor receptor-2(HER2)expression did not show significant differences in STC2 expression(P>0.05).In conclusion,the abnormal overexpression of STC2 gene may play a role in the development and progression of breast cancer,and it can be used as an independent metastasis and prognostic factor of breast cancer.In addition,STC2 gene probably promotes the development and metastasis of breast cancer by interacting with estrogen and ER,and it may become a new direction for breast cancer endocrine therapy.

乳酸菌在肠道内黏附定殖的研究进展

乳酸菌是一类无芽孢的革兰氏阳性菌,能利用碳水化合物发酵产酸。由于其具有安全高效,易获取的优势,在食品、医疗及动物生产方面得到广泛运用。在动物肠道内,它利用糖类物质,生成酸性代谢物,降低肠道pH,改善肠道微生物环境。要实现乳酸菌在动物体内的良好定殖,首先要实现黏附,而黏附过程主要分为特异性结合与非特异性结合。黏附机制的相关研究中黏附素理论被普遍认可,包含了粘附蛋白学说、磷璧酸学说及细菌表面分子学说。本文就乳酸菌的黏附相关因子,体外黏附模型及黏附的影响因素做了阐述。

Bioinformatics Analysis and Identification of Potential Genes Associated with Pathogenesis and Prognosis of Gastric Cancer

Objective Gastric cancer(GC)is a deadly cancer and a challenging public health problem globally.This study aimed to analyze potential genes associated with pathogenesis and prognosis of gastric cancer.Methods This work selected the overlapping differentially expressed genes(DEGs)in GC from four datasets,the GSE29272,GSE29998,GSE54129 and GSE118916 Gene Expression Omnibus databases.These DEGs were used to carry out comprehensive bioinformatic analysis to analyze the related functions and pathways enriched,the relative expression levels and immune infiltrates,the prognostic characteristics and the interaction network.Results In total,55 DEGs increased while 98 decreased in their expression levels.For those DEGs with increased expression,they were mostly concentrated on“focal adhesion”and“ECM-receptor interaction”,whereas DEGs with decreased expression were mostly associated with“gastric acid secretion”and“drug metabolism cytochrome P450”.MCODE and ClueGO results were then integrated to screen 10 hub genes,which were FN1,COL1A1,COL3A1,BGN,TIMP1,COL1A2,LUM,VCAN,COL5A2 and SPP1.Survival analysis revealed that higher expression of the ten hub genes significantly predicted lower overall survival of GC patients.TIMP1 was most significantly related to neutrophils,CD8+T cells,as well as dendritic cells,while LUM was most significantly related to macrophages.Conclusion Immunohistochemistry results and functional testing showed that the expression of COL5A2 was elevated in GC and that it might be a key gene in GC tumorigenesis.

高黏附罗伊氏乳杆菌的筛选及其益生特性评价

通过对28株不同罗伊氏乳杆菌(Lactobacillus reuteri)菌株的粘附力、细胞表面疏水性、与大肠杆菌的共聚合等指标的测定及相关性分析,成功筛选出粘附力最高的菌株R28。研究了该菌株的耐酸性和耐胆盐能力。结果表明,R28与其它菌株相比具有良好的粘附能力。该菌株的自聚集能力和疏水性分别为26.25%和75.53%。与大肠杆菌的共聚合能力可高达36.84%。细胞粘附数可达约43个细菌/每个杆菌细胞。菌株R28具有良好的耐酸性(pH=3)和耐胆盐性(0.1%),其能够很好的粘附于宿主肠道细胞发挥益生作用。罗伊氏乳杆菌R28作为一株优良的益生菌在食品和医药领域具有广阔的应用前景。

Identification of Prognostic Genes for Colon Cancer through Gene Coexpression Network Analysis

Objective:The present study was aimed to identify novel key genes,prognostic biomarkers and molecular pathways implicated in tumorigenesis of colon cancer.Methods:The microarray data GSE41328 containing 10 colon cancer samples and 10 adjacent normal tissues was analyzed to identify 4763 differentially expressed genes.Meanwhile,another microarray data GSE17536 was performed for weighted gene co-expression network analysis(WGCNA).Results:In present study,12 co-expressed gene modules associated with tumor progression were identified for further studies.The red module showed the highest association with pathological stage by Pearson's correlation analysis.Functional enrichment analysis revealed that genes in red module focused on cell division,cell proliferation,cell cycle and metabolic related pathway.Then,a total of 26 key hub genes were identified,and GEPIA database was subsequently selected for validation.Holliday junction-recognizing protein(HJURP)and cell division cycle 25 homolog C(CDC25C)were identified as effective prognosis biomarkers,which were all detrimental to prognosis.Gene set enrichment analyses(GSEA)found the two hub genes were enriched in“oocyte meiosis”,“oocyte maturation that are progesterone-mediated”,“p53 signaling pathway”,and“cell cycle”.Furthermore,the immunohistochemistry and western blotting showed that HJURP was highly expressed in colon cancer tissue.Conclusion:HJURP was identified as a key gene associated with colon cancer progression and prognosis by WGCNA,which might influence the prognosis by regulating cell cycle pathways.

Analysis on medication rule of traditional Chinese medicine treating chemotherapy-induced diarrhea based on traditional Chinese medicine(TCM) inheritance computing platform system

Objective:To dig deeper into the traditional Chinese medicine treatment rules of chemotherapy-induced diarrhea with traditional Chinese medicine(TCM)inheritance computing platform system.Methods:Taking“traditional Chinese medicine”,“chemotherapy”and“diarrhea”as the theme words,comprehensive search of the database of CNKI,Wanfang and VIP from its inception to November 2020 was conduct-ed.The formulas of external treatment of traditional Chinese medicine for chemotherapy-induced diarrhea were included and the association rule,clustering and factor analysis were carried out.Results:A total of 145 papers,57 prescriptions meeting the inclusion criteria were collected,among which high-frequency drugs including Baizhu(Atractylodis macrocephalae rhizoma),Fuling(Poria),Dangshen(Codonopsisradix),Huanglian(Coptidis rhizoma),Zhigancao(Glycyrrhizae radix et rhizoma praeparata cum melle)were the most commonly used.The confidence level was set as 0.7 and the support level was set as 10,12 core compatibility groups were obtained,and 6 categories were cluster analyzed.Conclusion:The principle of external treatment of chemotherapy-induced diarrhea is mainly“restore deficiency and benefiting qi”,“benefiting water infiltration and dampness”,“clearing heat”and“inducing astringency”.Prescription combination and new prescription combination based on traditional Chinese medicine(TCM)inheritance computing platform system can be used as reference for clinicians and applied in primary hospitals.

Experimental Study on Denitrification Using Coated Electrode of Immobilized Denitrifying Bacteria

Objective To develop a coated electrode of immobilized denitrificants and to evaluate the performance of a bioelectrochemical reactor to enhance and control denitrification, Methods Denitrifying bacteria were developed by batch incubation and immobilized with polyvinyl alcohol （PVA） on the surface of activated carbon fiber （ACF） to make a coated electrode. Then the coated electrode （cathode） and graphite electrode （anode） were transferred to the reactor to reduce nitrate. Results After acclimated to the mixtrophic and autotrophic denitrification stages, the denitrifying bacteria could use hydrogen as an electron donor to reduce nitrate, When the initial nitrate concentration was 30.2 mg NO3-N/L, the denitrification efficiency was 57.3% at an applied electric current of 15 mA and a hydraulic retention time （HRT） of 12 hours. Correspondingly, the current density was 0.083 mA / cm^2. The nitrate removal rate of the reactor was 34,4 g NO3-N / m^3,d, and the surface area loading was 1.34 g NO3-N / m^2.d. Conclusion The coated electrode may keep high quantity of blomass, thus achieving a high denitrification rate. Denitrification efficiencies are related to HRT, current density, oxidation reduction potential （ORP）, dissolved oxygen （DO）, pH value, and temperature,

New-generation Migrant Workers' Urban Adaptation: A Case Study of Jianggan District in Hangzhou City

New-generation migrant workers are the " elite" among migrant workers,and whether they can really adapt to the city is one of the real problems to be urgently solved during China's new urbanization,related to the success of new urbanization construction. From the perspective of livelihood capital,this paper uses the measuring indicators in line with the new-generation migrant workers' livelihood characteristics,to analyze the typical characteristics and causes of new-generation migrant workers' urban adaptation in Jianggan District of Hangzhou City based on field survey data. In the study,it is found that the new-generation migrant workers' urban adaptation characteristics are focused on life adaptation,work adaptation and cultural adaptation,but the adaptation in the three areas is not good and there is a big room for improvement.

Estrogen Receptor β of Host Promotes the Progression of Lung Cancer Brain Metastasis of an Orthotopic Mouse Model

Estrogen receptors (ERα and ERβ) in the brain play critical roles in maintaining brain tissue homeostasis and in tissue repair after injury. Growth of cancer metastasis in the brain is a constant damaging process. The role of ERs of the host in the progression of cancer brain metastasis is unknown. To determine the role of ERβ of host in the progression of lung cancer brain metastasis, we used an isogenic murine lung cancer cell line, Lewis lung carcinoma cells (3LL), to produce orthotopic lung cancer brain metastases in wild type and ERβ knockout (ERβ-/-) mice. In the wild type mice, we found that ERα and ERβ appeared in the tumor associated reactive astrocytes at 24hr after injection of tumor cells, and ERβ remained thereafter while ERα disappeared after 1 week. The metastasis bearing ERβ-/- mice survived significantly longer than the wild type mice. To further test the role of ERβ of reactive astrocytes in the survival of cancer cells, we knocked down ERβ in cultured actrocytes using shRNA and performed 3D co-culture with 3LL cells in the presence/absence of chemotherapeutic agents, oxaliplatin and 5-fluorouracil. We found that loss of ERβ in astrocytes significantly reduced the survivability of 3LL cells co-cultured with astrocytes. It is concluded that ERβ of host, especially ERβ in reactive astrocytes, promotes the progression of lung cancer brain metastasis and ERβ might be a potential therapeutic target for lung cancer brain metastasis.

Knockout of miR396 genes increases seed size and yield in soybean

Yield improvement has long been an important task for soybean breeding in the world in order to meet the increasing demand for food and animal feed.mi R396 genes have been shown to negatively regulate grain size in rice,but whether mi R396 family members may function in a similar manner in soybean is unknown.Here,we generated eight soybean mutants harboring different combinations of homozygous mutations in the six soybean mi R396genes through genome editing with clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated nuclease(Cas)12SF01 in the elite soybean cultivar Zhonghuang 302(ZH302).Four triple mutants(mir396aci,mir396acd,mir396adf,and mir396cdf),two quadruple mutants(mir396-abcd and mir396acfi),and two quintuple mutants(mir396abcdf and mir396bcdfi)were characterized.We found that plants of all the mir396 mutants produced larger seeds compared to ZH302 plants.Field tests showed that mir396adf and mir396cdf plants have significantly increased yield in growth zones with relatively high latitude which are suited for ZH302 and moderately increased yield in lower latitude.In contrast,mir396abcdf and mir396bcdfiplants have increased plant height and decreased yield in growth zones with relatively high latitude due to lodging issues,but they are suited for low latitude growth zones with increased yield without lodging problems.Taken together,our study demonstrated that loss-of-function of mi R396 genes leads to significantly enlarged seed size and increased yield in soybean,providing valuable germplasms for breeding high-yield soybean.

Contrast-enhanced fluorescence microscope by LED integrated excitation cubes

Fluorescence microscopy is a powerful tool for scientists to observe the microscopic world,and the fluorescence excitation light source is one of the most critical components.To compensate for the short operation lifetime,integrated light sources,and low excitation efficiency of conventional light sources such as mercury,halogen,and xenon lamps,we designed an LED-integrated excitation cube(LEC)with a decentralized structure and high optical power density.Using a Fresnel lens,the light from the light-emitting diode(LED)was effectively focused within a 15 mm mounting distance to achieve high-efficiency illumination.LEC can be easily designed in the shape of fluorescence filter cubes for installation in commercial fluorescence microscopes.LECs’optical efficiency is 1–2 orders of magnitude higher than that of mercury lamps;therefore,high-quality fluorescence imaging with spectral coverage from UV to red can be achieved.By replacing conventional fluorescence filter cubes,LEC can be easily installed on any commercial fluorescence microscope.A built-in LEC driver can identify the types of LEDs in different spectral bands to adopt the optimal operating current and frequency of pulses.Moreover,high-contrast images can be achieved in pulse mode by time-gated imaging of long-lifetime luminescence.

Impact history and origin of lunar meteorite Northwest Africa 15528

No samples from the Moon’s far side have been returned to Earth.Thus,lunar meteorite study can deepen the understanding of the Moon’s far side(if we can identify which lunar meteorites came from the Moon’s far side).The Northwest Africa(NWA)15528 meteorite is a lunar feldspathic regolith breccia meteorite and we speculated it might originate from the Feldspathic Highlands Terrane(FHT)on the far side of the Moon.Here,we report detailed petrography,major and trace elements,and noble gas(He,Ne,and Ar)isotopes for the clasts and matrix,respectively.The results show that the NWA 15528 lunar meteorite contains diverse clasts,including anorthosite,granulite,basalt,and impact melt clasts.The coarse,wellcrystallized,uniform chemical composition minerals may come from intrusive plutonic rocks.Among the anorthosite clasts,the norite/olivine clasts originate from the deep lunar crust,whereas the other anorthosite clasts are from lunar highlands.The Sm concentrations in NWA 15528 were similar to those in the fourth group of Apollo 16 melt samples,demonstrating that NWA 15528 has a typical plagioclase highland meteorite composition.Compared with the Apollo sample data and remote sensing results,the chemical composition of NWA 15528 indicated strong affinities with the FHT area and ferroan anorthosite(FAN)material from the far side of the Moon.The noble gas isotopic composition of NWA 15528 is consistent with a binary mixture of solar wind and cosmogenic components;during stepwise pyrolytic extractions,we observed that the abundance of cosmogenic components decreased,whereas that of solar wind components increased with increasing temperature.The average cosmic-ray exposure(CRE)age of the matrix and granulite is 42±6 Ma,with a shielding depth in the same range of 10-20 g cm^(−2).The gas retention age of NWA 15528 is 2.14 Ga,and the antiquity age of NWA 15528 is(0.69-0.74)±0.2 Ga(considering 50%40Arm is 40Artrap)which indicates the different clasts of NWA 15528 are assembled after 0.69-0.74 Ga.

碳纤维增强树脂复合材料齿槽加工中分层缺陷的形成机制

针对碳纤维增强树脂复合材料(Carbon fiber-reinforced plastic,CFRP)齿槽加工中易产生分层缺陷的问题,尤其以切出侧最严重。根据齿槽加工中分层缺陷的形成过程,重点构建CFRP齿槽加工切出侧最表层材料分层形成的临界切削力模型,并以平纹编织CFRP为研究对象,采用T型铣刀进行试验,从力学角度揭示齿槽加工中分层缺陷的形成机制。结果表明:齿槽上下两侧的经向纤维分层缺陷较小;A情形(有支撑)、B情形(无支撑)下纬向纤维分层缺陷产生的临界切削力均较小,因此,齿槽加工中分层缺陷均易产生,尤其是B情形;A、B两种情形下单束纤维临界力均在边缘附近呈较大值,中间部位临界力变化较小及纤维的变形均以中间部分较大,边缘部位变形小,由此导致A、B两种情形下的分层缺陷均以单束纤维为边界形成半月弧形"波峰";随着每齿进给量f;和切削速度V;的增大,两种情形下的分层缺陷均呈增大趋势。试验结果与临界力理论推导结果基本一致。