金属塑性变形的表面光反射率测量方法研究

本文在讨论了弹性和塑性变形对表面衍射谱的不同影响后,研究了激光衍射谱变化测量金属塑性变形的表面光反射率方法,并对不同光路布置进行了比较,提出了最佳光路布置。对45~#钢、40CrNiMoA合金钢、LY12-CZ和LD10铝合金进行了实测。结果表明:用这种方法测量金属材料的塑性变形是可行的;提出用光强比—对数应变曲线的拐点作为材料是否产生塑性变形的判据;为用表面光学特征表征金属材料的塑性损伤做了测试方法的准备。     

氨法脱硫装置存在的问题及解决方案

介绍氨法脱硫装置运行中暴露出的问题,分析目前大多数燃煤电厂氨法脱硫所存在的缺陷,通过优化脱硫工艺条件和实施相关设备改造,解决了脱硫装置不能够实现长周期稳定运行的难题。     

氨-硫酸铵法烟气脱硫工艺研究进展

介绍了氨-硫酸铵法脱硫工艺的原理和大致流程,论述氨-硫酸铵法脱硫关键环节,这些关键环节是塔内传质、氨逃逸、氧化、结晶。说明了影响氨-硫酸铵法工艺应用的关键是经济性,与经济性相关的是工艺的先进性、氨水来源和硫酸铵销售。指出了氨-硫酸铵法脱硫工艺发展方向是提高吸收剂利用率,降低物料消耗、节能。     

NK Cells Lose Their Cytotoxicity Function against Cancer Stem Cell-Rich Radiotherapy-Resistant Breast Cancer Cell Populations

Cancer stem cells (CSCs) can be induced from differentiated cancer cells in the tumor microenvironment or in response to treatments and exhibit chemo- and radioresistance, leading to tumor recurrence and metastasis. We previously reported that triple negative breast cancer (TNBC) cells with acquired radioresistance exhibited more aggressive features due to an increased CSC population. Therefore, here, we isolated CSCs from radiotherapy-resistant (RT-R)-TNBC cells and investigated the effects of these CSCs on tumor progression and NK cell-mediated cytotoxicity. Compared to MDA-MB-231 and RT-R-MDA-MB-231 cells, CD24^−/low/CD44⁺ cells isolated from RT-R-MDA-MB-231 cells showed increased proliferation, migration and invasion abilities, and induced expression of tumor progression-related molecules. Moreover, similar to MDA-MB-231 cells, CD24^−/low/CD44⁺ cells recruited NK cells but suppressed NK cell cytotoxicity by regulating ligands for NK cell activation. In an in vivo model, CD24^−/low/CD44⁺ cell-injected mice showed enhanced tumor progression and lung metastasis via upregulation of tumor progression-related molecules and altered host immune responses. Specifically, NK cells were recruited into the peritumoral area tumor but lost their cytotoxicity due to the altered expression of activating and inhibitory ligands on tumors. These results suggest that CSCs may cause tumor evasion of immune cells, resulting in tumor progression.     

Vaccination strategies when vaccines are scarce: on conflicts between reducing the burden and avoiding the evolution of escape mutants

When vaccine supply is limited but population immunization urgent, the allocation of the available doses needs to be carefully considered. One aspect of dose allocation is the time interval between the first and the second injections in two-dose vaccines. By stretching this interval, more individuals can be vaccinated with the first dose more quickly, which can be beneficial in reducing case numbers, provided a single dose is sufficiently effective. On the other hand, there has been concern that intermediate levels of immunity in partially vaccinated individuals may favour the evolution of vaccine escape mutants. In that case, a large fraction of half-vaccinated individuals would pose a risk—but only if they encounter the virus. This raises the question whether there is a conflict between reducing the burden and the risk of vaccine escape evolution or not. We develop an SIR-type model to assess the population-level effects of the timing of the second dose. Trade-offs can occur both if vaccine escape evolution is more likely or if it is less likely in half-vaccinated than in unvaccinated individuals. Their presence or absence depends on the efficacies for susceptibility and transmissibility elicited by a single dose.     

水下机器人最优逃生线路规划研究与仿真

水下机器人最优逃生路线规划方法在海洋资源探测方面发挥巨大作用;水下环境较为复杂,机器人在逃生过程中规划逃生路线需要考虑复杂的水下环境,建立过多的约束条件;传统的机器人路径规划模型应用到水下时,会导致建模较慢,规划耗时;为了避免上述缺陷,提出基于贪婪遗传算法的水下机器人最优逃生线路规划方法;将自适应遗传算法与贪婪算法相结合,针对水下机器人最优逃生路线规划问题求解,获取最合理的逃生线路,保证水下机器人的安全运行;实验结果表明,利用改进算法进行水下机器人最优逃生路线规划,能够在大量的逃生路线中选取满足逃生约束条件的最优路线,缩短逃生时间,保证逃生效率,最终保证水下机器人的安全逃生。     

六分量天平在救生伞空投试验中的应用研究

针对飞行员救生伞高速空投试验开伞力测试不真实的问题,通过分析拉力传感器和过载传感器测试方法影响高速试验开伞力测试结果的机理,提出了含有六分量天平的测试布局,并研制了专用的杆式六分量天平,经过空投试验实际应用表明,该方案可以显著减小外界因素对测试结果的影响,能够更真实的反应测试假人承受开伞力的状态.     

老纽约、规训、失败的逃离——解读《纯真年代》所蕴含的时代主题

美国女作家伊迪丝
华顿在小说《纯真年代》中深刻表达了老纽约规训之下“失败的逃离” 的时代主题, 即面对环境的制约力量, 个人企图逃脱却注定失败。小说展现了19 世纪70 年代纽约上流社会强调规则和体面, 崇尚表象上的愉悦而残酷压制个人真实情感的虚伪特质。结合19 世纪老纽约的时代背景与社会现实, 解读小说所蕴含的规训、体面、逃离等时代主题, 剖析处于时代变迁中的贵族习俗规范与个人情感追求之间的对抗, 以及这种破坏性对抗所导致的徒劳的逃离悲剧。     

Julia分形

近年来分形理论和它的构造方法受到极大关注。Julia集是使用非线性复映射f（z）=zm＋c为迭代函数生成的一类著名分形,而逃逸时间算法是生成Julia集最常用的算法。本文在给出逃逸时间算法的算法步骤之后,针对迭代函数fm.c（z）=zm＋c中参数m,c变化的不同情况,给出了Julia集的实验图例,并分析了二次表达式的常规Julia集（m=2）和高阶的广义Julia集（m〉2）的一些特点。     

井下火灾中逃生人员健康度评价模型

在井下火灾逃生过程中,矿井人员在有害环境影响下的身体状况对其逃生的成功与否具有决定性作用。提出了井下火灾中逃生人员健康度的概念,综合分析了热辐射、有毒气体、烟尘颗粒及缺氧等危害因素对井下人员健康度的影响。基于模糊综合评价方法,建立了上述危害因素对逃生人员健康度的影响评价模型,并建立了人员在逃生过程中的健康度的动态评价方法。利用火灾模拟软件FDS对井下火灾实例进行了简单模拟,模拟结果验证了该评价方法的实用性和有效性。人员健康度能够对复杂灾害环境中的逃生人员状态进行综合评价,为井下灾害中的逃生路径决策提供量化的标准。