Characterization of a polypropylene fibered cement composite using ESEM,FESEM and mechanical testing

The microstructure characterization and mechanical properties of a reinforced cement by the introduction of polypropylene fibres creating a composite material with a reduction of the weight and possible regulation of the times of setting has been carried out. A detailed microstructure determination has been made first time by environmental scanning electron microscopy and field emission scanning electron microscopy. The final surface of this composite after setting is different according to the contacts areas of mold, while the bulk microstructure is very homogeneous, depicting uniform distribution of fibres into the matrix.     

天麻素联合地塞米松保护缺糖缺氧诱导的H9C2细胞损伤

目的：探讨天麻素（gastrodin, GAS）联合地塞米松（dexamethasone, DEX）在缺糖缺氧诱导心肌细胞损伤中的作用及可能机制。方法：建立缺糖缺氧细胞（oxygen-glucose deprivation, OGD）模型,细胞分为5组,即正常对照组（normal group）,缺糖缺氧组（OGD group）,DEX组,GAS组,DEX+GAS组。利用CCK-8实验检测各组心肌细胞活性,利用比色法检测乳酸脱氢酶（LDH）的活性;利用TUNEL法检测各组心肌细胞的凋亡情况;利用ELISA实验检测各组心肌细胞培养液中炎性因子;利用Western blot检测各组心肌细胞中Notch1、Bax、Bcl-2及Beclin1的表达情况。结果：结果显示GAS与DEX联合使用可显著提高损伤心肌细胞的活性,减少心肌细胞的凋亡;降低促炎因子TNF-α、IL-6和IL-1β的产生及促进抑炎因子IL-10的产生,降低LDH的释放;Western blot结果显示GAS与DEX联合使用可促进Notch信号通路中Notch1的表达,显著降低受损心肌细胞中促凋亡蛋白Bax的表达,促进抑凋亡蛋白Bcl-2的表达,促进自噬相关基因Beclin1的表达。 结论：GAS与DEX联合使用,可能通过促进Notch信号通路的激活,促进其自噬,提高细胞的活性,抑制心肌细胞的凋亡,减轻炎症反应,从而减轻OGD诱导的心肌细胞损伤。     

基于刚度控制的起重机主梁设计理论

由于桥式起重机主梁受载不同而产生的挠度也不同。通过强度、刚度控制条件理论得出梁高的表达式,以25 t侧挂小车的桥式起重机为实例进行计算,最后运用ANSYS对分析结果进行验证,为设计人员提供一个借鉴的方法。     

The Mechanism of corrosion of MgOCaZrO3–calcium silicate materials by cement clinker

The chemical reactions involved in the corrosion of MgOCaZrO₃–calcium silicate materials by cement clinker were studied using a hot-stage microscope up to 1600 °C. The phases formed at 1500 °C were characterized by RLOM and SEM–EDS of the crystalline phases conducted near the reaction front and on unreacted refractory area.The general corrosion mechanism of attack on MgOCaZrO₃–calcium silicate materials involves a mechanism of matter diffusion of the liquid clinker phase through the grain boundaries and pores into the refractory substrate. The liquid phases in the clinker mainly enriched in calcium, iron and aluminium are rapidly diffused and preferentially react with magnesium spinel, calcium zirconate and magnesia, which are the major constituents in the refractory substrates. The dissolution of the CaZrO₃ refractory phase produces the enrichment with zirconium of the liquid phase increasing its viscosity and hindering the liquid phase diffusion.     

紫外线光照胶辊的工艺优化

以紫外线处理的三个光照工艺参数（时间、温度、距离）为因子,以纺纱质量和抗绕性能为指标,采用二次通用旋转组合设计试验和随机方向搜索法,求得最优工艺参数和各指标的等高线,讨论了各因子与指标的关系,提出了光照处理的基本原则。     

城市中压配电网辐射网络的优化布线研究

城市中压配电网规划是一个多目标、非线性、多阶段的复杂优化问题。随着我国城市化进程的加快,城市配电网建设存在供电范围、供电可靠性不能满足城市发展要求的现象。结合GIS提供的空间数据信息,给出了确定辐射网络初始布线集的方法;提出了基于改进最小生成树算法的辐射网络优化布线方法。该方法可以有效解决搜索过程中电能损耗费用对优化目标值的影响,以及交叉节点问题,通过算例的比较分析验证了该方法的有效性。     

Modeling and performance analysis of a hybrid driver model

For an effective simulation of vehicle motion a realistic driver model is as necessary as the dynamic vehicle model. In this paper, the human perception process is described by discrete event techniques that also allow human deficiencies to be addressed. When a human driver reaches his personal physical limits, his control performance rapidly deteriorates.     

106例支气管内膜结核临床分析

目的研究支气管内膜结核病理类型与治疗效果之间的关系。方法临床确诊的支气管内膜结核患者106例,结合临床、影像学及病理表现、治疗情况等进行总结、归纳。结果纤维狭窄型为支气管内膜结核晚期病理类型,是长时间误诊误治的结果,积极正规治疗后纤支镜下表现总有效率为18.2%,临床表现18.2%,X线表现27.3%,而非纤维狭窄型分别为82.1%、89.5%、77.9%。结论早期及时有效的化疗结合雾化吸入治疗支气管内膜结核,预后良好,长时间误诊误治导致气管支气管纤维狭窄,治疗效果不佳。     

Study of heavy metal removal from heavy metal mixture using the CCD method

The central composite design (CCD) technique was used to study the effect of the native species Lemna gibba on the removal heavy metals from the mixture of heavy metals, and understand their impact on the process. The effects of Cd, Cr, Cu, Zn, and Ni cations, incubation period and fronds number on heavy metals removal (Cd, Cr, Cu, Zn, and Ni) were studied, and the results were statistically analyzed using JMP 9.0.2 (SAS Institute) software. The analysis aimed at giving a mathematical model that shows the influence of each variable. Each factor has a distinct effect on heavy metal removal. High correlation was found between the experimental and predicted results, reflected by R² (coefficient of determination).     

Enhancing the sinterability and fracture toughness of Al2O3–TiN0.3 composites

We introduce a new and effective method for improving the fracture toughness of Al₂O₃-based composites through the addition of a nonstoichiometric material. Al₂O₃–TiN_0.3 composites were sintered by spark plasma sintering with different TiN_0.3 content at temperatures between 1300 and 1600 °C for 10 min and a micro-region diffusion phenomenon was observed at the Al₂O₃–TiN_0.3 interface. Ti atoms from TiN_0.3 diffused into Al₂O₃ to occupy Al sites, which led to the formation of Al vacancies that enabled the transport of aluminum by a vacancy mechanism. The optimal densification temperature of the Al₂O₃–30vol% TiN_0.3 composite was approximately 1400 °C. The maximum fracture toughness measured was 6.91 MPa m^1/2, from the composite with 30 vol% TiN_0.3 sintered at 1500 °C.