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21.
Rongli Xu Da Bian Yongwu Zhao Xiaoyan Xu Yaxuan Liu Wenlei Zhou 《International Journal of Applied Ceramic Technology》2020,17(3):1010-1016
To improve the wear resistance of the chemically bonded phosphate ceramic coatings, MWCNTs are selected as the reinforcement after the modification. The high temperature wear experiment is carried out to investigate the wear behavior of the coatings with different temperatures. The results suggest that, when the temperature is below 500℃, MWCNTs can decrease friction coefficient, and the lowest friction coefficient is about 0.28, but MWCNTs lose the lubricant function at 500℃ and the friction coefficient keeps at the level of ~ 0.68. In addition, the wear resistance of coatings is improved with the introduction of MWCNTs at 100℃ and 300℃ (the wear rate is below 15X10-3mm3/Nm), but keeps similar level at 500℃ (the wear rate is ~ 22 × 10−3mm3/Nm). Besides, the wear mechanism of the coatings reinforced by MWCNTs is also investigated based on the wear behavior and microstructural characterizations. MWCNTs improve the fracture toughness by preventing the crack generation and forming the bridge when crack occurs, which leads to smooth wear tracks and good wear resistance of coatings. The coatings with MWCNTs achieve poor wear resistance at 500℃ because MWCNTs lose their strength and resistance to fatigue by oxidizing. 相似文献
22.
通过显微组织观察与力学性能测试研究了氮含量(0.08%~0.22%,质量分数)对HPD-1双相不锈钢硬度、拉伸性能、低温冲击性能及疲劳性能的影响。结果表明,氮含量变化可显著影响试验钢γ/α相比例,当氮含量由0.08%升高到0.22%,γ相含量由38.1%提高至56.5%。α相的硬度由273 HV10提高到343 HV10,γ相的硬度由238 HV10提高到299 HV10,试验钢强度明显提升。氮元素对两相比例和奥氏体相韧性的双重影响导致试验钢低温冲击性能呈先上升后下降的趋势;更高的氮含量抑制疲劳裂纹萌生与拓展,是影响HPD-1双相不锈钢室温疲劳性能的主要因素。撕裂棱是疲劳断口的显著特征。 相似文献
23.
Prof. Chiara Brullo Dr. Federica Rapetti Prof. Silvana Alfei Dr. Irena Maric Dr. Francesca Rizzelli Dr. Marina Mapelli Dr. Camillo Rosano Dr. Maurizio Viale Prof. Olga Bruno 《ChemMedChem》2020,15(11):961-969
Even though immunotherapy has radically changed the search for anticancer therapies, there are still many different pathways that are open to intervention with traditional small molecules. To expand our investigation in the anticancer field, we report here a new series of compounds in which our previous pyrazole and imidazopyrazole scaffolds are linked to a differently decorated phenyl ring through an acylhydrazone linker. Preliminary tests on the library were performed at the National Cancer Institute (USA) against the full NCI 60 cell panel. The best compounds among the imidazopyrazole series were then tested by immunofluorescence staining for their inhibition of cell proliferation, apoptosis induction, and their effect on the cell cycle and on microtubules. Two compounds, in particular 4-benzyloxy-3-methoxybenzyliden imidazopyrazole-7-carbohydrazide showed good growth inhibition, with IC50 values in the low-micromolar range, and induced apoptosis. Both compounds altered the cell-cycle phases with the appearance of polyploid cells. Immunofluorescence analysis evidenced microtubules alterations; tubulin polymerization assays and docking studies suggested the tubulin system to be the possible, although not exclusive, target of the new acylhydrazone series reported here. 相似文献
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ASME标准钢板对于短时高温抗拉数据无规定,但设备设计人员在校核时又要用到此数据,于是有些设计文件在技术要求中将ASME II卷表U的数据作为材料验收的标准。针对此种做法引发的争议及涉及的主要问题进行试验验证和分析探讨。研究结果表明,ASME II卷D篇表U中的数据是基于室温抗拉强度保证值,并根据拟合曲线将室温保证值提高了10%得到的,实测数据与ASME规范数据不一致,部分材料在250~350℃存在动态应变时效现象,但仍不满足设计要求。材料经模拟焊后热处理后性能下降,难以到达交货态的要求。给出了短时高温抗拉强度的选用建议。 相似文献
27.
目前国内外地层压力测井解释方法较多,但大多数方法基于欠压实沉积理论并局限于单一的地层岩性,尤其是针对盆地边缘山前深层构造,单一测井参数确定地层压力误差较大,且无法解释沉积压实机制以外的异常高压。为此,将多种异常高压机制相关的测井参数进行综合解释,建立适合山前复杂构造的地层压力测井多参数计算模型,评价准噶尔盆地南缘高泉背斜高探1井的地层压力剖面,其计算结果与钻井实测数据吻合,相对误差小于3.00%.同时,基于原始沉积加载—卸载过程力学原理,利用地层压力测井多参数分析判别出高泉背斜深层各层系异常高压的形成机制。 相似文献
28.
《等离子体科学和技术》2020,22(1):15402
Laminar plasma jet(LPJ) generated by laminar plasma torch(LPT) has a favorable temperature and velocity distribution. Thus, it is superior to the turbulent plasma jet in material processing.However, most of the reported LPTs usually operate at a relatively low output power with a relatively low arc voltage and thermal efficiency, which limits its capabilities. In this context, this paper attempts to design a new type of high-power LPT with a relatively low arc current and a high thermal efficiency. In the first section, the design principle of the main components is studied and discussed in detail, and a new high-power LPT is proposed. Then, the experimental characteristics of the proposed high-power LPT are examined. Experimental results reveal the following characteristics of the proposed LPT.(1) The max jet length of the proposed LPT reaches at 540 mm.(2) Its mean arc voltage is higher than 290 V when the LPT works with arc currents lower than 200 A, leading to an output power greater than 50 kW.(3) The mean thermal efficiency is higher than 50%. Lastly, the proposed LPT has been applied to spheroidize the aluminum oxide powers. The experiment results for the production of spherical powders show that the proposed LPT has a good characteristic for material processing. 相似文献
29.
The incorporation of viscoelastic materials represents an effective strategy to reduce the vibratory level of structural components. Thermoplastic vulcanizates (TPVs) are a special type of viscoelastic material that combines the elastomeric properties of rubbers with the easy processing of thermoplastics. In the present work, we propose innovative ways to improve the damping properties of high‐performance TPVs by using rubbers with carboxylic functionalities. For that, TPVs from physical blends of carboxylated hydrogenated acrylonitrile butadiene rubber (XHNBR) and polyamide 6 (PA6) were prepared. The chain dynamics of different mixed crosslink systems containing peroxide, metal oxides and hindered phenolic antioxidants were investigated in order to find the most suitable strategy to design a high‐performance TPV system with upgraded damping properties. The results indicate that the damping performance of the TPV system can be tailored by controlling the type and magnitude of the bonding interactions between the mixed crosslink system and the XHNBR rubber phase. Therefore, this study demonstrates the potential of TPV systems containing carboxylic rubbers as high‐performance damping materials. © 2020 Society of Chemical Industry 相似文献
30.
本文以神达朝凯煤矿正在开采的台阶为工程背景,针对该矿在台阶爆破过程中存在着大块率高、根底多的现象,通过改变装药结构的方式对爆破参数进行优化。实践证明,优化后大块率和根底问题的治理效果明显。 相似文献