新型高速加工工具系统研究进展

综述了新型高速加工工具系统的发展过程、特点及应用情况,着重分析了NC5工具系统的刚度和承载能力、夹紧力、抗颤振能力及刀柄清洁等关键问题,展望了高速加工工具系统的发展趋势。     

SiO2矿化剂对钛酸铝材料结构与性能的影响

以铝型材厂污泥为主原料合成Al2TiO5材料,在合成的Al2TiO5中添加少量SiO2矿化剂,与Al2TiO5形成固溶体,抑制Al2TiO5的分解,达到提高Al2TiO5热稳定性的目的.采用XRD法和SEM法表征各试样的晶相结构和显微结构;用Rietveld Quantification 法确定各试样中各晶相的含量;测试各试样的性能.结构与性能分析结果表明较佳SiO2矿化剂添加量为2%,较佳烧结温度为1450 ℃,对应抗折强度为44.3 MPa,体积密度为3.28 g/cm3,气孔率为6.3%,吸水率为1.9%,热震后抗折强度保持率为84.2%.     

Genome-Wide Identification of TaSAUR Gene Family Members in Hexaploid Wheat and Functional Characterization of TaSAUR66-5B in Improving Nitrogen Use Efficiency

Excessive input of nitrogen fertilizer not only causes a great waste of resources but brings about a series of ecological and environmental problems. Although Small Auxin Up-regulated RNAs (SAURs) participate in diverse biological processes, the function of SAURs in the nitrogen starvation response has not been well-studied. Here, we identified 308 TaSAURs in wheat and divided them into 10 subfamilies. The promoter regions of most TaSAURs contain hormone responsive elements, and their expression levels change under the treatment of different hormones, such as IAA, MeJA, and ABA. Interestingly, overexpression of one of the TaSAUR family members, a nitrogen starvation responsive gene, TaSAUR66-5B, can promote the growth of Arabidopsis and wheat roots. In addition, overexpression of TaSAUR66-5B in Arabidopsis up-regulates the expression levels of auxin biosynthesis related genes, suggesting that overexpression TaSAUR66-5B may promote root growth by increasing the biosynthesis of auxin. Furthermore, overexpression of TaSAUR66-5B in wheat can increase the biomass and grain yields of transgenic plants, as well as the nitrogen concentration and accumulation of both shoots and grains, especially under low nitrogen conditions. This study provides important genomic information of the TaSAUR gene family and lays a foundation for elucidating the functions of TaSAURs in improving nitrogen utilization efficiency in wheat.     

Downregulation of miR-122-5p Activates Glycolysis via PKM2 in Kupffer Cells of Rat and Mouse Models of Non-Alcoholic Steatohepatitis

Non-alcoholic steatohepatitis (NASH) has pathological characteristics similar to those of alcoholic hepatitis, despite the absence of a drinking history. The greatest threat associated with NASH is its progression to cirrhosis and hepatocellular carcinoma. The pathophysiology of NASH is not fully understood to date. In this study, we investigated the pathophysiology of NASH from the perspective of glycolysis and the Warburg effect, with a particular focus on microRNA regulation in liver-specific macrophages, also known as Kupffer cells. We established NASH rat and mouse models and evaluated various parameters including the liver-to-body weight ratio, blood indexes, and histopathology. A quantitative phosphoproteomic analysis of the NASH rat model livers revealed the activation of glycolysis. Western blotting and immunohistochemistry results indicated that the expression of pyruvate kinase muscle 2 (PKM2), a rate-limiting enzyme of glycolysis, was upregulated in the liver tissues of both NASH models. Moreover, increases in PKM2 and p-PKM2 were observed in the early phase of NASH. These observations were partially induced by the downregulation of microRNA122-5p (miR-122-5p) and occurred particularly in the Kupffer cells. Our results suggest that the activation of glycolysis in Kupffer cells during NASH was partially induced by the upregulation of PKM2 via miR-122-5p suppression.     

Assessing the reliability of the M5-120 on Amazon’s mechanical Turk

Amazon’s online service, Mechanical Turk (MTurk) has become a popular option for data collection among social scientists. Early work (Buhrmester, Kwang, & Gosling, 2011) indicated that data collection through MTurk was faster and less expensive than traditional collection methods (undergraduate human subject pool), as well as being reliable when administered at different dates. Building on their work, we sought to extend this investigation of reliability to a larger measure. For the current research we chose a 120-item measure of personality. After collecting data through MTurk, it was determined that our MTurk sample had strong test–retest reliability, indicating that they did not significantly change between administration dates.     

2,5-二巯基-1,3,4-噻二唑的电化学性能

以二硫化碳和水合肼为原料合成了2,5-二巯基-1,3,4-噻二唑(DMcT),并通过元素分析、Raman光谱和红外(IR)光谱对DMcT的结构进行了表征。DMcT的两对氧化还原峰电位差分别为0.96V和1.33V,这表明在室温下氧化还原反应速度很慢。酸碱对DMcT氧化还原反应有很大的影响:加入三乙胺之后,DMcT的氧化反应更加容易,还原峰电流增加,但对还原峰电位影响不大;相反,甲磺酸存在时,DMcT的氧化反应更难进行,而还原反应变得更加容易。     

LED的寿命,你真正理解了吗?

LED技术起始于半导体行业,却带给照明行业应用上的大发展。作为一个新兴事物,有很多问题都在探索当中。LED一个显著的特点就是超长寿命。但没有确切的试验,这超长寿命是如何得来的?它与传统照明理解的寿命有什么不同吗?本文将从LED寿命这个看似简单的问题作为出发点,来系统的分析和梳理LED元件及系统的寿命问题。通过比较与传统照明的异同点,分析当今最新标准来帮助LED的使用者和系统制造商理解和推导真正的LED的寿命。     

浅谈T5荧光灯支架质量问题和性价比

根据标准要求和实际应用,讨论T5荧光灯支架几个应注意的质量问题并分析其性价比。     

V_2O_5/DBSA-PANI复合材料的制备及电容性能研究

制备了V2O5/DBSA-PANI复合材料,用XRD、IR及SEM对材料进行了表征.结果表明,复合材料为片状,V2O5和DBSA-PANI之间有化学键形成;材料的恒流充放电性能测试结果表明.当电流密度为0.2～0.8 mA.电压范围为-0.2-0.8 V(vs.SCE),电解液为1 mol/L KNO3溶液时,所得材料具有良好的电容特性,复合材料的比电容比单独的V2O5明显提高,而循环性能比单独的DBSA-PANI好.电压范围为-0.2～0.8 V(vs.SCE),以2～10 mV/s扫描速率进行循环伏安测试,该复合材料均表现出良好的赝电容性能.     

基于以太网的103通信规约在微机馈线保护装置中的研究与实现

IEC60870-5-103通信规约是电力系统通信常用的通信规约,许多继电保护设备的通信模块都是基于这个规约设计制造的,但详细的通信流程却大不相同.首先在分析研究了微机馈线保护装置硬件结构的基础上,重点论述了基于以太网的103规约的实现方案,然后提出了一种有限状态机的软件设计方法,并利用Linux环境下的Socket编程,实现了基于以太网的103通信规约的软件编程.