MICROSTRUCTURE OF Ti－B－NFILM AND INTERFACEFORMED BY N ION BOMBARDMENTON A Ti－B FILM

ＭＩＣＲＯＳＴＲＵＣＴＵＲＥＯＦＴｉ－Ｂ－ＮＦＩＬＭＡＮＤＩＮＴＥＲＦＡＣＥＦＯＲＭＥＤＢＹＮＩＯＮＢＯＭＢＡＲＤＭＥＮＴＯＮＡＴｉ－ＢＦＩＬＭＹＡＮＧＱｉａｏｑｉｎ;ＺＨＡＯＬｉｈｕａ;ＷＵＬｉｊｕｎ;ＬＩＸｕｅｑｉａｎａｎｄＤＵＨａｉｑｉｎｇ（Ｍ...     

铝靶电流对磁控溅射AlSn20镀层耐蚀性的影响

采用非平衡磁控溅射镀膜设备通过改变铝靶电流在铝基轴承合金表面制备了AlSn20镀层.并对镀层的交流阻抗谱和塔菲尔曲线进行了电化学研究,定量分析了镀层的耐蚀性,并用失重法进行了进一步验证.利用SEM研究了镀层表面微观结构.结果表明,铝靶电流为1.5 A时,轴承合金磁控溅射AlSn20镀层使合金的电化学阻抗提高5～6个数量级,可将镀层的自腐蚀电位提高到-1.12 V,改善轴承合金的耐蚀性.铝靶电流是影响AlSn20镀层耐蚀性的一个重要因素,铝靶电流越小,其耐蚀性越好.     

铸造Al-14Si-5Cu-3Ni-1Mg合金微弧氧化陶瓷层的结构与性能

采用显微硬度、XRD、SEM、极化曲线测量、DSC、TG等技术研究了铸造Al-14Si-5Cu-3Ni-1Mg微弧氧化陶瓷层的相组成、形貌、硬度、耐腐蚀性、耐热冲击性和热稳定性.结果表明,该合金微弧氧化陶瓷层由致密层和疏松层组成,致密层主要为αAl2O3相,疏松层主要为γ-Al2O3及无定型相,微弧氧化陶瓷层硬度(HV)高达2 400,合金的耐蚀性显著提高,抗热冲击性和热稳定性良好.     

基体偏压对磁控溅射类石墨镀层耐蚀性的影响

对铝合金表面非平衡磁控溅射沉积类石墨镀层,采用极化曲线测试和质量损失方法,分析了镀层的耐蚀性;利用扫描电子显微镜对镀层腐蚀前后的微观形貌进行了观察。结果表明,铝合金表面磁控溅射类石墨镀层由铬打底层和碳工作层组成。镀层组织细小,均匀致密,类石墨镀层可以提高铝合金的耐蚀性。随基体负偏压增大,铝合金试样的耐蚀性增加,当基体为-120 V偏压时,铝合金基体的自腐蚀电位由-0.452 V提高到-0.372 V,腐蚀电流由10.62 m A减小到3.67 m A。在Na Cl溶液中进行浸泡试验后,类石墨镀层仅发生了部分点蚀,可很好地保护铝合金基体。     

TEM STUDY OF C-B_4C-SiC COMPOSITES WITH SILICON ADDITIVE

ＴＥＭＳＴＵＤＹＯＦＣ－Ｂ_４Ｃ－ＳｉＣＣＯＭＰＯＳＩＴＥＳＷＩＴＨＳＩＬＩＣＯＮＡＤＤＩＴＩＶＥ￥ＺＨＡＯＬｉｈｕａ;ＷＵＬｉｊｕｎ;ＨＵＡＮＧＱｉｚｈｏｎｇ;ＹＡＮＧＱｉａｏｑｉｎ１）（ＭａｔｅｒｉａｌＲｅｓｅａｒｃｈａｎｄＴｅｓｔＣｅｎｔｅｒ,...     

Exercise Training Alleviates Cardiac Fibrosis through Increasing Fibroblast Growth Factor 21 and Regulating TGF-β1-Smad2/3-MMP2/9 Signaling in Mice with Myocardial Infarction

Exercise training has been reported to alleviate cardiac fibrosis and ameliorate heart dysfunction after myocardial infarction (MI), but the molecular mechanism is still not fully clarified. Fibroblast growth factor 21 (FGF21) exerts a protective effect on the infarcted heart. This study investigates whether exercise training could increase FGF21 protein expression and regulate the transforming growth factor-β1 (TGF-β1)-Smad2/3-MMP2/9 signaling pathway to alleviate cardiac fibrosis following MI. Male wild type (WT) C57BL/6J mice and Fgf21 knockout (Fgf21 KO) mice were used to establish the MI model and subjected to five weeks of different types of exercise training. Both aerobic exercise training (AET) and resistance exercise training (RET) significantly alleviated cardiac dysfunction and fibrosis, up-regulated FGF21 protein expression, inhibited the activation of TGF-β1-Smad2/3-MMP2/9 signaling pathway and collagen production, and meanwhile, enhanced antioxidant capacity and reduced cell apoptosis in the infarcted heart. In contrast, knockout of Fgf21 weakened the cardioprotective effects of AET after MI. In vitro, cardiac fibroblasts (CFs) were isolated from neonatal mice hearts and treated with H₂O₂ (100 μM, 6 h). Recombinant human FGF21 (rhFGF21, 100 ng/mL, 15 h) and/or 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR, 1 mM, 15 h) inhibited H₂O₂-induced activation of the TGF-β1-Smad2/3-MMP2/9 signaling pathway, promoted CFs apoptosis and reduced collagen production. In conclusion, exercise training increases FGF21 protein expression, inactivates the TGF-β1-Smad2/3-MMP2/9 signaling pathway, alleviates cardiac fibrosis, oxidative stress, and cell apoptosis, and finally improves cardiac function in mice with MI. FGF21 plays an important role in the anti-fibrosis effect of exercise training.     

原位合成层状双氢氧化物去除水溶液中重金属氰化物络合物

以铁氰络合物作为重金属氰化物络合物替代物,通过在含Fe(CN)63-水溶液中加入Mg2 ,Al3 ,研究了原位合成层状双氢氧化物(layered double hydroxide,LDH)去除废水中重金属氰化物络合物的可行性.详细探讨了pH值、反应时间、摩尔比n(Mg2 )/n(Al3 )和Fe(CN)63-初始浓度对Fe(CN)63-去除率的影响,结合X射线衍射探讨了去除机理.结果表明:利用原位合成LDH处理废水中重金属氰化物络合物是可行的.实验条件下,影响去除率的最主要的因素是pH值,在pH=9.5时达到最佳效果.通过X射线衍射谱可知:所得固体为LDH,Fe(CN)63-是嵌入到LDH层间被去除的.     

基体偏压对磁控溅射AlSn20镀层组织形貌与性能的影响

采用非平衡磁控溅射在铝基轴承合金表面制备了AlSn20镀层,分析不同基体偏压对AlSn20镀层的组织形貌、硬度、膜基结合力、摩擦因数等的影响.结果表明,非平衡磁控溅射AlSn20镀层,基体偏电压在-60～-120 V范围内,镀层呈层状生长,随着基体偏电压增大,镀层由粗大结构向细晶结构变化,镀层硬度与基体偏电压成反比,当偏电压为-120 V时,镀层硬度(HV0.025)最高为80,镀层与基体结合力最高可达35 N,镀层的摩擦因数最低为O.15.     

55CrSi弹簧钢失效分析与研究

本文利用扫描电镜对弹簧钢的金相组织、断口及表面进行观察分析,研究其失效原因,结果表明此弹簧钢断裂为早期疲劳断裂,裂纹源萌生于并圈处,由于该处间隙过小,一则不能保证喷丸的效果,二则增加疲劳过程的接触疲劳应力及加重表面损伤,另外该处喷丸微细粒子未清洗干净,相当于表面有一夹杂在运行时遗留在并圈处表层,导致表面损伤,并诱发微裂纹而导致弹簧早期疲劳断裂。     

C-SiC-TiC-TiB_2复合材料等温氧化行为研究

对原位合成的（Ｃ－ＳｉＣ－ＴｉＣ－ＴｉＢ２）碳／陶复合材料的等温抗氧化性能进行了研究。结果表明，该材料的氧化增重和失重主要取决于碳相和陶瓷相的氧化速率和氧化层的结构特征。该材料表现出优良的抗氧化能力，这归结于在８００℃时ＴｉＢ２优先氧化，８００～１０００℃时其表面生成了一层致密的硼硅酸盐玻璃，以及在１２００℃下ＴｉＯ２晶粒包裹在其表面。