扫描速度对半导体激光熔覆钴基合金涂层组织与性能的影响

采用2 kW半导体激光器在304不锈钢表面进行同轴送粉的激光熔覆Co基合金试验。通过扫描电镜（SEM）、X射线衍射仪（XRD）研究了不同扫描速度下熔覆层的显微组织和相结构;采用显微硬度计、摩擦磨损试验机和气蚀装置分别测试了不同扫描速度下熔覆层的显微硬度、耐磨性与抗气蚀性能。结果表明,不同激光扫描速度下合金涂层皆无裂纹与气孔,随着扫描速度增加,合金涂层的硬度、耐磨性能与抗气蚀性能则先增强后降低,在激光扫描速度为900 mm/min时,合金涂层具有较好的硬度、耐磨性和抗气蚀性能。     

Template-free hydrothermal synthesis of single-crystalline SnO<Subscript>2</Subscript> nanocauliflowers and their optical properties

Large-scale single-crystalline SnO₂ nanocauliflowers were successfully synthesized using a hydrothermal growth method without any template. The samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). FE-SEM images show that the as-grown SnO₂ nanocauliflowers are constructed of tetragonal prisms with a width of 500–600 nm. XRD, EDS, and SAED results indicate that the as-grown SnO₂ nanocauliflowers are single crystalline with the tetragonal rutile crystalline structure. The growth mechanism of SnO₂ nanocauliflowers is also preliminarily discussed on the basis of different Sn(OH)₆²⁻ concentrations, and it is found that Sn(OH)₆²⁻ concentration plays an important role in determining the shape of the prepared SnO₂. Room temperature photoluminescence was further carried out on SnO₂ nanocauliflowers to investigate their optical properties. An intense blue luminescence centered at a wavelength of 424 nm is observed in the as-grown SnO₂ nanocauliflowers.     

Ag-Ni复合材料界面的第一性原理研究

采用第一性原理方法分析了Ag(110)、(211)与Ni(110)、(211)的界面结合情况。通过对界面结合能、电荷布居以及界面处的电子结构等研究分析发现,在Ag与Ni界面的结合形式中,以Ag(110)/Ni(211)的界面结合能最高,界面处的电子杂化最为剧烈,其界面结合也是最稳定的     

微量稀土对Al-Zn-Mg-Cu-Zr合金力学性能与腐蚀性能的影响

采用慢应变速率拉伸试验、显微硬度和电导率测试、晶间腐蚀和剥落腐蚀试验、光学显微镜、扫描电镜、透射电镜等分析方法,研究微量稀土对7085铝合金（Al-7.5Zn-1.5Mg-1.4Cu-0.15Zr）力学性能和腐蚀性能的影响。研究结果表明,与未添加稀土的合金相比,添加微量稀土使合金组织细化,时效后强度、硬度提高,电导率略有降低。同时,合金的耐腐蚀性大大提高,其中抗晶间腐蚀性能由四级提高为二级、48 h下的剥落腐蚀性能由EB提高为PA、反映应力腐蚀性能的ISSRT值由65%提高到96%。     

地下柴油发电站机房的通风与降温设计

介绍了柴油发电机组的几种换热方式与发热量的构成。强调了采用通风降温时,换热器的热风不能排入机房,应直接排入排风道,再由耐高温风机排至室外。通过实例说明了这种降温方式最小进排风量的计算方法。介绍了目前工程中存在的几个共性问题,并提出了解决方法。     

路灯双侧交错布置方式和设计要求

道路照明灯具的布置方式与灯具的安装高度、间距等密不可分,采用双侧交错灯具布置方式应满足《城市道路照明设计标准》(CJJ 45—2015)的相关要求。为使相关照明值达到规范标准,分析此种布置方式的设计要求。     

带压堵漏作业防护探索与研究

本文分析了泄露现场的化学和物理危害因素及由此导致的各种后果,而且针对泄露事故对作业人员不同部位的伤害提出了相对应的个人防护用品,同时提供了与之相对应的国家行业标准.     

Glucose Metabolism,Neural Cell Senescence and Alzheimer’s Disease

Alzheimer’s disease (AD), an elderly neurodegenerative disorder with a high incidence and progressive memory decline, is one of the most expensive, lethal, and burdening diseases. To date, the pathogenesis of AD has not been fully illustrated. Emerging studies have revealed that cellular senescence and abnormal glucose metabolism in the brain are the early hallmarks of AD. Moreover, cellular senescence and glucose metabolism disturbance in the brain of AD patients may precede amyloid-β deposition or Tau protein phosphorylation. Thus, metabolic reprogramming targeting senescent microglia and astrocytes may be a novel strategy for AD intervention and treatment. Here, we recapitulate the relationships between neural cell senescence and abnormal glucose metabolism (e.g., insulin signaling, glucose and lactate metabolism) in AD. We then discuss the potential perspective of metabolic reprogramming towards an AD intervention, providing a theoretical basis for the further exploration of the pathogenesis of and therapeutic approach toward AD.     

Activation of TRPV4 Induces Exocytosis and Ferroptosis in Human Melanoma Cells

TRPV4 (transient receptor potential vanilloid 4), a calcium permeable TRP ion channel, is known to play a key role in endocytosis. However, whether it contributes to exocytosis remains unclear. Here, we report that activation of TRPV4 induced massive exocytosis in both melanoma A375 cell and heterologous expression systems. We show here that, upon application of TRPV4-specific agonists, prominent vesicle priming from endoplasmic reticulum (ER) was observed, followed by morphological changes of mitochondrial crista may lead to cell ferroptosis. We further identified interactions between TRPV4 and folding/vesicle trafficking proteins, which were triggered by calcium entry through activated TRPV4. This interplay, in turn, enhanced TRPV4-mediated activation of folding and vesicle trafficking proteins to promote exocytosis. Our study revealed a signaling mechanism underlying stimulus-triggered exocytosis in melanoma and highlighted the role of cellular sensor TRPV4 ion channel in mediating ferroptosis.     

电影频道节目传播工作的艰苦创业——纪念电影频道播出10周年

今年是中国电影百年华诞，也是电影频道CCTV-6开播并通过卫星向全国传送电影节目10周年。电影频道这10年的历史，是从无到有、发展壮大的历史，是电影频道的全体工作人员艰苦创业、努力奋斗的历史。10年来，全国收看电影频道节目的有线电视台、站已经超过6000余家；付费收视用户超过3500万户，实际收视用户近2亿户；收视人口约7．8亿；收视率名列CCTV前矛。