当前工会劳动保护工作的研究与思考

随着建筑业的改革和中国加入WTO,传统的活动形式并不能完全适应新形式发展的要求,泛泛的群众性劳动保护其影响力及作用日趋下降,尤其是外包、分包的工程项目,更容易流于形式.为此,文章就影响企业劳动保护不能持续有效运行的成因进行了分析.     

水汽在细微颗粒表面异质核化数值分析

建立蒸汽在同时含有不溶物质与可溶成分的粗糙颗粒表面核化特性数值实验平台,对水汽异质核化晶核形成自由能、成核速率、成核几率、成核临界饱和度、平衡水汽饱和度进行数值分析.结果表明:可溶性盐含量对成核自由能势垒、成核临界饱和度无影响,但对晶核越过自由能势垒进一步长大过程自由能及平衡水汽饱和度影响显著.用自仿射分形理论描述粗糙颗粒表面,将表面粗糙程度与接触角联系起来,研究发现:颗粒表面粗糙度降低了成核自由能势垒,引起成核速率与成核几率迅速增大,成核临界饱和度降低,而对晶核进一步长大过程中水汽的平衡无明显影响.较高的可溶性盐含量有利于核化液滴的长大;颗粒表面越粗糙,越易于核化.     

基于结构层贡献率的沥青路面抗车辙措施

采用环道试验及德国汉堡车辙试验方法,研究在中面层使用改性沥青对路面结构和组合结构抗车辙性能的影响,包括对结构层贡献率和对沥青层剪切流动变形的影响;探讨在中面层添加纤维对路面结构抗车辙能力的影响.研究结果表明:中面层使用改性沥青,能提高路面结构的整体抗车辙性能;使剪切流动变形由95.2%下降至84.4%;中面层变形贡献率达到60%以上,应该重视提高中面层的抗车辙能力;对于中面层采用普通沥青的结构,在中面层添加纤维可明显减少整个结构车辙深度,但对于中面层已采用改性沥青的结构,添加纤维减少车辙的效果不明显.     

景观色彩研究初探

分析了景观色彩与基础色彩的异同点,在此基础上讨论了景观色彩与自然观、行为心理、地域文化、建筑材料的内在联系,借助有代表性的环境色彩案例加以论述,以期为建立规范系统的景观色彩研究体系提供借鉴。     

目标定位的分布式MIMO雷达资源分配算法

为了提高分布式多输入多输出(multiple input multiple output,MIMO)雷达的目标定位精度,分析了阵元、发射功率和信号带宽对定位精度的影响,进而提出一种将三者联合优化的资源分配算法。首先,以最小化目标的平方位置误差下限(squared position error bound,SPEB)为目标函数,建立了包含阵元、功率和带宽3个变量的优化模型;然后,通过推导最优功率分配矢量和带宽分配矢量的关系简化模型;最后利用凸松弛和循环最小化算法将优化问题转化成二阶锥形式,求解得到最优的资源分配策略。仿真结果表明,利用所提出的算法进行资源分配能明显提高目标的定位精度;信号有效带宽对目标定位精度的影响大于发射功率。     

黄大铁路黄河特大桥顶推施工分析与监控技术

针对黄大铁路黄河特大桥连续钢桁梁多点同步顶推施工,利用倒拆法建模计算顶推施工全过程,找出主桁杆件在支点处的最大应力值以及导梁悬臂端变形规律和最大变形值,确定出全过程施工中的最不利工况为M2工况;设置变形监测点,监控导梁前段竖向位移变形,实测值基本与理论值吻合,施工线形可控;在M2工况中,将主桁和导梁自重荷载乘以1.35的放大系数,计算主梁在导梁悬臂140m,悬臂160m和导梁上墩20m后的主桁杆件的应力值,并在主桁上设置24个监测点监测杆件应力值,对比发现实测值均略小于理论值,施工过程中材料强度储备是安全可靠的。作为国内最大跨度的平行弦桁架桥顶推成功,对其他同类大跨度桥梁顶推施工具有较高的参考价值。     

NaOH改性花生壳去除水中亚甲基蓝的吸附特性研究

利用亚甲基蓝水溶液进行实验,测定了NaOH改性处理的花生壳对其的吸附能力.运用单因素实验方法,探讨了改性花生壳的物理化学特性、吸附时间、吸附剂添加量、pH值、温度和离子强度等因素对吸附性能的影响以及等温吸附过程.结果表明,改性能够提高吸附剂的吸附效果.在低温碱性条件下,改性花生壳粉投加量为0.6 g·L~(-1),吸附时间为1 h时,亚甲基蓝的去除率可达94.43%,饱和吸附容量为294.12 mg·g~(-1),等温吸附过程遵循Langmuir方程.     

Melatonin and mitochondrial function during ischemia/reperfusion injury

Ischemia/reperfusion (IR) injury occurs in many organs and tissues, and contributes to morbidity and mortality worldwide. Melatonin, an endogenously produced indolamine, provides a strong defense against IR injury. Mitochondrion, an organelle for ATP production and a decider for cell fate, has been validated to be a crucial target for melatonin to exert its protection against IR injury. In this review, we first clarify the mechanisms underlying mitochondrial dysfunction during IR and melatonin’s protection of mitochondria under this condition. Thereafter, special focus is placed on the protective actions of melatonin against IR injury in brain, heart, liver, and others. Finally, we explore several potential future directions of research in this area. Collectively, the information compiled here will serve as a comprehensive reference for the actions of melatonin in IR injury identified to date and will hopefully aid in the design of future research and increase the potential of melatonin as a therapeutic agent.     

<Emphasis Type="Italic">Yersinia pseudotuberculosis</Emphasis> supports Th17 differentiation and limits de novo regulatory T cell induction by directly interfering with T cell receptor signaling

Adaptive immunity critically contributes to control acute infection with enteropathogenic Yersinia pseudotuberculosis; however, the role of CD4⁺ T cell subsets in establishing infection and allowing pathogen persistence remains elusive. Here, we assessed the modulatory capacity of Y. pseudotuberculosis on CD4⁺ T cell differentiation. Using in vivo assays, we report that infection with Y. pseudotuberculosis resulted in enhanced priming of IL-17-producing T cells (Th17 cells), whereas induction of Foxp3⁺ regulatory T cells (Tregs) was severely disrupted in gut-draining mesenteric lymph nodes (mLNs), in line with altered frequencies of tolerogenic and proinflammatory dendritic cell (DC) subsets within mLNs. Additionally, by using a DC-free in vitro system, we could demonstrate that Y. pseudotuberculosis can directly modulate T cell receptor (TCR) downstream signaling within naïve CD4⁺ T cells and Tregs via injection of effector molecules through the type III secretion system, thereby affecting their functional properties. Importantly, modulation of naïve CD4⁺ T cells by Y. pseudotuberculosis resulted in an enhanced Th17 differentiation and decreased induction of Foxp3⁺ Tregs in vitro. These findings shed light to the adjustment of the Th17-Treg axis in response to acute Y. pseudotuberculosis infection and highlight the direct modulation of CD4⁺ T cell subsets by altering their TCR downstream signaling.     

基于园林卓越人才培养的观赏植物组织培养课程实践改革

以园林专业卓越人才培养为目标,提出教学过程以应用与创新为导向,更新教学内容体系,探索引入项目式教学形式,调整考核方法.改革后的课程体系侧重学生实践动手能力与创新能力的培养,学生的学习主动性显著提高,在学生中反馈效果好,教学效果显著.