无约束层激光冲击薄板的疲劳寿命

探讨激光冲击对无约束层铝合金薄板试样疲劳寿命的影响。结果表明 ,无约束层磷化薄板试样冲击后的疲劳寿命与未磷化未冲击处理的比较 ,寿命提高 62 .8% ;与有约束层经磷化冲击处理的比较 ,寿命也提高51 .2 %。说明在本试验条件下 ,激光冲击处理用于提高材料疲劳寿命 ,无需在冲击部位表面覆盖约束层     

营养元素调控热休克蛋白研究进展

热休克蛋白(Heat Shock Protein,HSP)是生物体在受热或其他不利环境因素刺激下应激合成的一组特殊蛋白质.HSP的生物学功能广泛,不仅表现在热应激条件下参与细胞的抗损伤、修复和热耐受过程,保护细胞生命活动,而且在蛋白质折叠、跨膜运输、细胞骨架及核骨架稳定等方面发挥重要作用.由于机体的营养状况与应激能力密切相关,本文主要综述了营养元素对HSP合成的调控作用.     

Dissection of the molecular mechanisms that control the nuclear accumulation of transport factors importin-α and CAS in stressed cells

The physiological state of eukaryotic cells controls nuclear trafficking of numerous cargos. For example, stress results in the inhibition of classical protein import, which is characterized by the redistribution of several transport factors. As such, importin-alpha and cellular apoptosis susceptibility protein (CAS) accumulate in nuclei of heat-shocked cells; however, the mechanisms underlying this relocation are not fully understood. We now show that heat upregulates the initial docking of importin-alpha at the nuclear envelope and stimulates the translocation of CAS into the nuclear interior. Moreover, heat exposure compromises the exit of importin-alpha from nuclei and drastically increases its retention in the nucleoplasm, whereas CAS nuclear exit and retention are less affected. Taken together, our results support the idea that heat shock regulates importin-alpha and CAS nuclear accumulation at several levels. The combination of different stress-induced changes leads to the nuclear concentration of both transport factors in heat-stressed cells.     

开放式电子技术实验教学——激光图案控制电路的焊接安装和调试

通过“激光图案控制电路的焊接安装和调试”这一开放式电子技术实验的教学，使理科学生在经过“电子线路”等课程及其相应电子技术基础实验学习后，进一步培养综合分析和设计电路的能力，锻炼动手能力，并切实提高实验技能，为以后深造或相关工作打下基础。     

电脑控制三相矢量差触、漏电保护器

电脑控制三相矢量差触、漏电保护器能灵活地解决一、二次保护问题,完全克服了脉冲型保护器所谓死区问题.     

Maintenance of multi-state production systems deteriorated by random shocks and production

We consider the preventive maintenance of a production system that is deteriorated by random shocks and the production process itself. The degree of deterioration is modeled by discrete and finite states. Shocks arrive according to a Poisson process and deteriorate the system by random amounts. The system may deteriorate whenever it produces an item. The system is continuously monitored and repaired if the system state is at or above a predetermined level for maintenance. We analyze the lifetime, product quantity, average cost, and average profit considering revenue from the product and cost due to setup, operation, and repair. Assuming a structure of system parameters and costs, using numerical examples, we investigate the impact of production and shock arrivals on the average profit and the optimal maintenance level that maximizes the average profit. The proposed model is applicable to manufacturing tasks in which machines wear due to production, for example, press processes, milling, turning, punching, and drilling.     

激光加工多孔端面机械密封性能参数的计算与分析

通过建立激光加工多孔端面机械密封性能参数的数学模型,应用有限差分法求解,获得在给定工况下泄漏量、摩擦功耗等密封性能参数数值,并分析不同微孔深度hp和面积密度sp对其密封性能参数的影响规律,得到微孔深度和面积密度的最佳值.研究结果表明:当微孔深度hp为20~40μm和面积密度sp为0.2~0.4时,可获得最佳的机械密封性能.     

HSP60在大肠腺瘤和大肠癌中表达的临床病理研究

选择大肠癌手术切除癌组织标本56份及同组病例距癌组织外缘 3cm内的癌旁组织标本20份,采用免疫组织化学Elivision Plus二步法检测正常大肠黏膜、癌旁组织、大肠腺瘤和大肠癌中热休克蛋白60(HSP60)的表达.结果HSP60在正常大肠黏膜、癌旁组织、大肠腺瘤、大肠癌中表达阳性率分别为27.78%,40%,77.78%,80.36%.各组间比较,HSP60表达的阳性率具有显著性差异(χ2＝23.314,P＝0.000).HSP60在大肠癌中的表达可能在大肠癌发生发展中发挥作用,特别在大肠癌恶性演进中以及预后预测中具有重要意义,其可能可以作为独立的生物标志物.     

Albumin resuscitation protects against traumatic/hemorrhagic shock-induced lung apoptosis in rats

Objective： To determine the effects of albumin administration on lung injury and apoptosis in traumatic/hemorrhagic shock （T/HS） rats. Methods： Studies were performed on an in vivo model of spontaneously breathing rats with induced T/HS; the rats were subjected to femur fracture, ischemia for 30 min, and reperfusion for 20 min with Ringer＇s lactate solution （RS） or 5% （w/v） albumin （ALB）, and the left lower lobes of the lungs were resected. Results： Albumin administered during reperfusion markedly attenuated injury of the lung and decreased the concentration of lactic acid and the number of in situ TdT-mediated dUTP nick-end labelling （TUNEL）-positive cells. Moreover, immunohistochemistry performed 24 h after reperfusion revealed increases in the level of nuclear factor κB （NF-κB）, and phosphorylated p38 mitogen-activated protein kinase （MAPK） in the albumin-untreated group was down-regulated by albumin treatment when compared with the sham rats. Conclusion： Resuscitation with albumin attenuates tissue injury and inhibits T/HS-induced apoptosis in the lung via the p38 MAPK signal transduction pathway that functions to stimulate the activation of NF-κB.     

多光子康普顿效应下的自由电子激光中电子与光子碰撞截面的特性

籍助电子与光子的碰撞，计算了在多光子康普顿效应条件下光子的散射截面的表示式，得出在多光子康普顿效应下，电子对光子的散射截面随因子ｎω１／ｍ而迅速减小的结论。