铈对中铝耐热铸铁抗氧化性能的影响

采用氧化增重法测定了含Ce中铝耐热铸铁在850℃时氧化动力学曲线，用SEM，X－ray对氧化膜表面的形貌，结构及氧化层－基体界面进行了观察分析，结果表明：Ce改变了中铝耐热铸铁氧化膜的结构和组成，提高了中铝耐热铸铁的抗氧化性能。     

WAVE FIELD EXTRAPOLATION IN VISCOELASTIC MEDIUM AND VARIABLE FOCUS METHOD TO SEPARATE SEISMIC COMPOUND WAVE

ＷＡＶＥＦＩＥＬＤＥＸＴＲＡＰＯＬＡＴＩＯＮＩＮＶＩＳＣＯＥＬＡＳＴＩＣＭＥＤＩＵＭＡＮＤＶＡＲＩＡＢＬＥＦＯＣＵＳＭＥＴＨＯＤＴＯＳＥＰＡＲＡＴＥＳＥＩＳＭＩＣＣＯＭＰＯＵＮＤＷＡＶＥ￥ＳｏｎｇＳｈｏｕｇｅｎ；ＹｕａｎＸｉｕｇｕｉ；ＨｅＪｉｓｈａｎ...     

数据机房送风孔板处空气流动的数值模拟

以数据中心机房某一孔板及其相邻机柜为研究对象,采用ANSYS有限元分析方法,对孔板和机柜建立3种不同的有限元模型:几何实体模型、缩小送风孔板风口面积的基础模型、将孔板视为多孔介质面并添加源项的优化模型。根据实测数据确定3种模型的边界条件,通过有限元仿真计算获得它们的压力、速度云图,将基础模型和优化模型分别与几何实体模型进行对比。结果表明,优化模型与几何实体模型的速度场和压力场的大小误差在5%以内,同时优化模型的计算时间相较于几何实体模型可以减少60%。     

Functional and Molecular Properties of DYT-SGCE Myoclonus-Dystonia Patient-Derived Striatal Medium Spiny Neurons

Myoclonus-dystonia (DYT-SGCE, formerly DYT11) is characterized by alcohol-sensitive, myoclonic-like appearance of fast dystonic movements. It is caused by mutations in the SGCE gene encoding ε-sarcoglycan leading to a dysfunction of this transmembrane protein, alterations in the cerebello-thalamic pathway and impaired striatal plasticity. To elucidate underlying pathogenic mechanisms, we investigated induced pluripotent stem cell (iPSC)-derived striatal medium spiny neurons (MSNs) from two myoclonus-dystonia patients carrying a heterozygous mutation in the SGCE gene (c.298T>G and c.304C>T with protein changes W100G and R102X) in comparison to two matched healthy control lines. Calcium imaging showed significantly elevated basal intracellular Ca²⁺ content and lower frequency of spontaneous Ca²⁺ signals in SGCE MSNs. Blocking of voltage-gated Ca²⁺ channels by verapamil was less efficient in suppressing KCl-induced Ca²⁺ peaks of SGCE MSNs. Ca²⁺ amplitudes upon glycine and acetylcholine applications were increased in SGCE MSNs, but not after GABA or glutamate applications. Expression of voltage-gated Ca²⁺ channels and most ionotropic receptor subunits was not altered. SGCE MSNs showed significantly reduced GABAergic synaptic density. Whole-cell patch-clamp recordings displayed elevated amplitudes of miniature postsynaptic currents and action potentials in SGCE MSNs. Our data contribute to a better understanding of the pathophysiology and the development of novel therapeutic strategies for myoclonus-dystonia.     

Therapeutic Effects of hiPSC-Derived Glial and Neuronal Progenitor Cells-Conditioned Medium in Experimental Ischemic Stroke in Rats

Transplantation of various types of stem cells as a possible therapy for stroke has been tested for years, and the results are promising. Recent investigations have shown that the administration of the conditioned media obtained after stem cell cultivation can also be effective in the therapy of the central nervous system pathology (hypothesis of their paracrine action). The aim of this study was to evaluate the therapeutic effects of the conditioned medium of hiPSC-derived glial and neuronal progenitor cells in the rat middle cerebral artery occlusion model of the ischemic stroke. Secretory activity of the cultured neuronal and glial progenitor cells was evaluated by proteomic and immunosorbent-based approaches. Therapeutic effects were assessed by overall survival, neurologic deficit and infarct volume dynamics, as well as by the end-point values of the apoptosis- and inflammation-related gene expression levels, the extent of microglia/macrophage infiltration and the numbers of formed blood vessels in the affected area of the brain. As a result, 31% of the protein species discovered in glial progenitor cells-conditioned medium and 45% in neuronal progenitor cells-conditioned medium were cell type specific. The glial progenitor cell-conditioned media showed a higher content of neurotrophins (BDNF, GDNF, CNTF and NGF). We showed that intra-arterial administration of glial progenitor cells-conditioned medium promoted a faster decrease in neurological deficit compared to the control group, reduced microglia/macrophage infiltration, reduced expression of pro-apoptotic gene Bax and pro-inflammatory cytokine gene Tnf, increased expression of anti-inflammatory cytokine genes (Il4, Il10, Il13) and promoted the formation of blood vessels within the damaged area. None of these effects were exerted by the neuronal progenitor cell-conditioned media. The results indicate pronounced cytoprotective, anti-inflammatory and angiogenic properties of soluble factors secreted by glial progenitor cells.     

薄规格取向硅钢电磁特性及在中低频率电力装备中的应用#br#

针对工频配电网中节能变压器、兆瓦级DC/DC变换器中频隔离变压器、柔性低频交流输电领域低频变压器等电力装备对高性能取向硅钢的应用需求,采用任意波形磁场激励软磁测量系统,研究了0.10~0.27 mm不同牌号取向硅钢在不同工作频率下的电磁特性,探讨了薄规格取向硅钢在中低频电力装备中的应用前景。与0.10 mm超薄取向硅钢相比,0.18 mm高磁感取向硅钢在15~400 Hz中低频率范围具有更低的损耗特征。0.18 mm产品不仅在轧向的铁损低于0.23 mm和0.27 mm产品,在横向也具有最低损耗优势;但对于相同厚度材料,轧向低损耗并不意味着横向同样具有低损耗。分析了不同厚度取向硅钢电磁特性差异及原因,结果可支撑各类型变压器铁心材料选型。结合工频、中频和低频领域电力装备技术发展对铁心材料性能要求,展望了薄规格取向硅钢未来的发展趋势。     

热管空冷器在淬火介质控温过程中的应用

针对连续淬火介质在工作中存在的冷却问题，提出由空气冷却代替水冷系统，研制出的热管空冷器可以精确控制连续淬火介质温度，保证热处理工件的金相组织和力学性能，在实际应用中取得较大成效。     

冷却介质对ZG30CrMn2Si2NiMo组织和力学性能的影响

研究了不同冷却介质对ZG30CrMn2Si2NiMo铸钢力学性能及组织的影响.试验结果表明,奥氏体化后空冷ZG30CrMn2Si2NiMo组织为板条贝氏体型铁素体和残余奥氏体组织,奥氏体化后淬火ZG30CrMn2Si2NiMo组织为板条马氏体、贝氏体型铁素体和残余奥氏体组织.ZG30CrMn2Si2NiMo获得板条马氏体、贝氏体型铁素体和残余奥氏体组织时,具有良好的力学性能.     

利用"正火液"作为高铬铸铁磨球淬火介质的生产实践

高铬铸铁件在没有添加贵重元素的条件下,利用"正火液"配入适量的水作为淬火介质进行了试验和生产.实践证明,产品在热处理淬火时从未发生炸裂现象,同时完全达到了要求的力学性能指标.生产的锤头其使用寿命为高锰钢的6～8倍,为低铬白口铸铁的4～6倍.     

采用中频炉冶炼LCC低温钢的实践与应用

介绍了中频炉炼LCC钢时 ,通过选择合适的炉衬和包衬材料 ,严谨的操作工艺 ,降低钢水中的气体和夹杂 ,从而使LCC钢低温性能合格率大大提高