MasterCAM后置处理钻孔循环参数页面关系对应研究

研究MasterCAM中后置处理器与主体钻孔循环页面参数,对比分析出文本显示TXT、后置处理PST文件与主体页面之间的关系。以西门子802D的钻孔循环为例,解决用户在使用后置处理器进行二次开发时的数据输入图形接口的对应关系,方便用户进行后置处理二次开发。     

核电汽轮机焊接低压转子1∶1模拟件接头高周疲劳性能及门槛值预测

测试了25Cr2Ni2Mo V百万千瓦级核电汽轮机焊接低压转子1∶1模拟件埋弧焊接头的高周疲劳性能,高周疲劳断口分析表明,内部启裂源多为气孔,且有明显的分区现象.已有文献计算启裂区应力强度因子幅的公式多应用于内部夹杂物启裂的情况,文中针对模拟件埋弧焊接头高周疲劳裂纹椭球形气孔裂纹源,提出裂纹源形状影响因子对已有公式进行修正,建立了通过高周疲劳测试和断口观察预测疲劳裂纹扩展门槛值的方法.该方法通过白光干涉形貌仪确定启裂区的面积、采用对数拟合确定启裂源形状影响因子等手段,预测出埋弧焊接头焊缝区的疲劳裂纹扩展门槛值,并进行了模拟件埋弧焊接头的疲劳裂纹扩展门槛值的测试,结果一致,进一步验证了方法的合理性.     

2-甲基呋喃对锂硫电池性能的影响

采用2-甲基呋喃作为锂硫电池电解液添加剂,并通过充放电测试考察了2-甲基呋喃的含量对锂硫电池的循环性能、库伦效率、放电中压的影响。结果表明,与空白锂硫电池相比,添加2wt%的2-甲基呋喃的电解液的锂硫电池的性能较好,在电流密度为200 m A/g下,前50次的电池放电容量保持率由42.8%提高到53.3%,首次循环的库伦效率由60.2%提高到82.6%。     

安全仪表系统在化工装置中的设计与应用

随着石油化工生产向大型化、一体化和智能化方向发展,安全生产受到人们越来越多的关注,从而使得安全仪表系统越来越多地得到研究和应用。本文介绍了安全仪表系统的基本概念、安全生命周期和保护层的概念,安全完整性等级及其确定方法,并详细说明了安全仪表系统的设计原则和方法,以及安全仪表系统的实施步骤。     

盐冻融和重复荷载作用下沥青混凝土开裂的细观分析

选用普通沥青混凝土、玄武岩纤维沥青混凝土、SBS改性沥青混凝土、玄武岩纤维+SBS改性沥青混凝土为研究样本,采用数字图像相关(DIC)技术,从细观角度对重复荷载作用下4种沥青混凝土小梁试件进行全局位移、应变测量,并对其裂缝发展进行时间及空间上的分析;以融雪剂(盐溶液)冻融循环作用下裂纹稳定发展阶段的应变集中速率为指标,采用正交试验极差分析和方差分析,研究玄武岩纤维、冻融循环次数、盐溶液(NaCl、CH3 COOK、CaCl2)对沥青混凝土小梁试件应变集中速率的影响.结果 表明:玄武岩纤维沥青混凝土的寿命与应变集中程度有很大关联;SBS改性剂与玄武岩纤维的加强方式有互补性;在相同盐冻融循环条件下,玄武岩纤维的加入可以减小沥青混凝土的应变集中速率;盐溶液对沥青混凝土应变集中速率的影响大小依次为CaCl2、NaCl、CH3 COOK;盐冻融的主要作用方式依旧是冰冻结晶刺入.     

教学生命周期视角下课程质量生态环境构建

按照课程启动、质量计划、质量保证、质量控制、课程结束的教学生命周期,建立教学共同体责任矩阵,构建课程质量生态环境,对课程质量施以保证服务。课程启动沿用迈阿密大学课程教学过程规划模式,说明和定义课程的需求,将布卢姆教育目标分类法运用于识别课程目标,围绕教学目标开展教学活动和学习过程评价,提供课程质量计划,采用价值链分析法了解教学行为的“增值”和“贬值”,评估教学行为对教学价值的贡献。在课程质量控制阶段,制定多元化评价模式和实践策略,通过“促进学习的评价”和“做为学习的评价”两种形成性评价关注学生的学习过程。在课程结束时,通过师师反馈、师生反馈及第三方反馈进行课程质量改进。将学习投入作为衡量课程质量的重要因素,数据分析表明,学生在课程满意度和学习绩效等方面具有较高认同度。     

垂直轴阻力差型风力机驱动水输运过程的功率匹配

以垂直轴阻力差型风力机和水泵之间的配合为对象,试验研究了风力机驱动水输运过程的功率匹配问题,并提出了理论预测方法。通过测试同一风力、不同传动比情况下水泵的工作状况,研究了风力机驱动水泵的最高循环效率及相应的最佳传动比。结果显示:对于风轮半径为1.2 m的半圆弧形5叶片风车,以及小型螺纹拖泵BPZ-18,在2组鼓风情况下,风车叶片处风速为6 m/s和传动比为37.8时,水泵的水流量也达到最大,风力机动力与水泵之间达到了最佳的配合,与理论预测结果比较接近。结果对风能系统的开发应用具有重要意义。     

Caffeic Acid Phenethyl Ester Is a Potential Therapeutic Agent for Oral Cancer

Head and neck cancers, which affect 650,000 people and cause 350,000 deaths per year, is the sixth leading cancer by cancer incidence and eighth by cancer-related death worldwide. Oral cancer is the most common type of head and neck cancer. More than 90% of oral cancers are oral and oropharyngeal squamous cell carcinoma (OSCC). The overall five-year survival rate of OSCC patients is approximately 63%, which is due to the low response rate to current therapeutic drugs. In this review we discuss the possibility of using caffeic acid phenethyl ester (CAPE) as an alternative treatment for oral cancer. CAPE is a strong antioxidant extracted from honeybee hive propolis. Recent studies indicate that CAPE treatment can effectively suppress the proliferation, survival, and metastasis of oral cancer cells. CAPE treatment inhibits Akt signaling, cell cycle regulatory proteins, NF-κB function, as well as activity of matrix metalloproteinase (MMPs), epidermal growth factor receptor (EGFR), and Cyclooxygenase-2 (COX-2). Therefore, CAPE treatment induces cell cycle arrest and apoptosis in oral cancer cells. According to the evidence that aberrations in the EGFR/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling, NF-κB function, COX-2 activity, and MMPs activity are frequently found in oral cancers, and that the phosphorylation of Akt, EGFR, and COX-2 correlates to oral cancer patient survival and clinical progression, we believe that CAPE treatment will be useful for treatment of advanced oral cancer patients.     

A Natural Triterpene Derivative from Euphorbia kansui Inhibits Cell Proliferation and Induces Apoptosis against Rat Intestinal Epithelioid Cell Line in Vitro

Kansenone is a triterpene from the root of the traditional Chinese medicine, Euphorbia kansui. However, kansenone exerts serious toxicity, but the exact mechanism was not clear. In this work, the effects of kansenone on cell proliferation, cell cycle, cell damage, and cell apoptosis were investigated. The suppression of cell proliferation was assessed via the colorimetric MTT assay, and cell morphology was visualized via inverted microscopy after IEC-6 cells were incubated with different concentrations of kansenone. Reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA) content were detected for evaluating cell damage. RNase/propidium iodide (PI) labeling for evaluation of cell cycle distribution was performed by flow cytometry analysis. Annexin V-fluorescein isothiocyanate (FITC)/PI and Hoechst 33342/Annexin V-FITC/PI staining assay for cell apoptosis detection were performed using confocal laser scanning microscopy and high content screening. Moreover, apoptosis induction was further confirmed by transmission electron microscope (TEM) and JC-1 mitochondrial membrane potential, western blot and RT-PCR analysis. The results demonstrated that kansenone exerted high cytotoxicity, induced cell arrest at G0/G1 phase, and caused mitochondria damage. In addition, kansenone could up-regulate the apoptotic proteins Bax, AIF, Apaf-1, cytochrome c, caspase-3, caspase-9, caspase-8, FasR, FasL, NF-κB, and TNFR1 mRNA expression levels, and down-regulate the anti-apoptotic Bcl-2 family proteins, revealing that kansenone induces apoptosis through both the death receptor and mitochondrial pathways.     

液化天然气接收站保冷循环工艺分析

为了研究液化天然气接收站两种常见保冷工艺的特点及优劣,为旧站的工艺变更和新站的设计方向提供依据。从运行能耗、操控性能、应急操作、最小外输量四个方面入手进行对比分析,得出两种工艺各有优劣的结论,故应针对具体情况选择适合的保冷工艺,才能有效实现平稳运行、节能降耗等目标。