四株野生酵母菌株耐受性的研究

酿酒酵母对于葡萄酒风味形成起着重要的作用,使用产区酵母酿造葡萄酒可以突出产区的典型特色,从而避免我国葡萄酒在品种和风格上的单一。本实验利用WL培养基从采自攀枝花的葡萄自然发酵液中分离了酿酒酵母,结合显微镜下的细胞形态,及26S r DNA D1/D2区的序列分析和比对,成功分离得到四株酿酒酵母。进一步对这四株菌株的耐受性(高渗透压、高温、营养饥饿、高糖浓度、高浓度酒精、低p H)进行了研究,结果发现四株菌在上述耐受性方面有一定差异,以菌株C1和M1相对较佳。      

用统一强度理论的多层预应力组合凹模强度设计和应用

运用统一强度理论,对用于加工废油资源化装备部件,以及由不同材料构成的3层预应力组合凹模的分层半径、过盈量和弹性极限内压进行分析,得到了组合凹模的分层半径、过盈量和弹性极限内压的表达式。运用该文所推导的公式对挺柱体冷挤压组合凹模在考虑和不考虑拉压异性的两种情况下,计算出组合凹模的分层半径、过盈量和弹性极限内压。结果表明,在考虑拉压异性情况下,组合凹模的分层半径、过盈量有较小差异,而弹性极限内压有较大提高。     

添加铜箔中间层的NiTi形状记忆合金超声波焊接

采用超声波焊接方法对添加铜箔中间层的NiTi形状记忆合金进行搭接焊,研究接头的表面形貌、界面形貌、相变行为、抗拉性能和断裂特点. 结果表明,超声波焊接能实现添加铜箔中间层的薄片状NiTi形状记忆合金的有效连接. NiTi焊缝表面存在明显压痕,界面处结合良好,无金属间化合物生成. NiTi形状记忆合金超声波焊缝呈可逆单相转变过程,接头强度达到母材的65%,断裂位置在母材区,断口形貌呈现韧性断裂特征. 超声波焊接方法将有效解决NiTi形状记忆合金采用传统熔焊方法时产生脆性金属间化合物的这一问题,为NiTi记忆合金的连接提供了新的解决途径.     

Exploring the attenuation mechanisms of <i>Dalbergia odorifera</i> leaves extract on cerebral ischemia-reperfusion based on weighted gene co-expression network analysis

Background: The attenuation function of Dalbergia odorifera leaves on cerebral ischemia-reperfusion (I/R) is little known. The candidate targets for the Chinese herb were extracted from brain tissues through the high-affinity chromatography. The molecular mechanism of D. odorifera leaves on cerebral I/R was investigated. Methods: Serial affinity chromatography based on D. odorifera leaves extract (DLE) affinity matrices were applied to find specific binding proteins in the brain tissues implemented on C57BL/6 mice by intraluminal middle cerebral artery occlusion for 1 h and reperfusion for 24 h. Specific binding proteins were subjected to mass-spectrometry to search for the differentially expressed proteins between control and DLE-affinity matrices. The hub genes were screened based on weighted gene co-expression network analysis (WGCNA). Then, predictive biology and potential experimental verification were performed for the candidate genes. The protective role of DLE in blood-brain barrier damage in cerebral I/R mice was evaluated by the leakage of Evans blue, western blotting, immunohistochemistry, and immunofluorescent staining. Results: 952 differentially expressed proteins were classified into seven modules based on WGCNA under soft threshold 6. Based on WGCNA, AKT1, PIK3CA, NOS3, SMAD3, SMAD1, IL6, MAPK1, TGFBR2, TGFBR1, MAPK3, IGF1R, LRG1, mTOR, ROCK1, TGFB1, IL1B, SMAD2, and SMAD5 18 candidate hub proteins were involved in turquoise module. TGF-β, MAPK, focal adhesion, and adherens junction signaling pathway were associated with candidate hub proteins. Gene ontology analysis demonstrated that candidate hub proteins were related to the TGF-β receptor signaling pathway, common-partner SMAD protein phosphorylation, etc. DLE could significantly reduce the leakage of Evans blue in mice with cerebral I/R, while attenuating the expression of occludin, claudin-5, and zonula occludens-1. Western blotting demonstrated that regulation of TGF-β/SMAD signaling pathway played an essential role in the protective effect of DLE. Conclusion: Thus, a number of candidate hub proteins were identified based on DLE affinity chromatography through WGCNA. DLE could attenuate the dysfunction of blood-brain barrier in the TGF-β/SMAD signaling pathway induced by cerebral I/R.     

含稀土元素和Al贝氏体钢的相变和组织性能

研究了微量稀土（ＲＥ）和Ａｌ对贝氏本钢在７００～５６０℃和３８０～３２０℃区域相变动力学及其组织性能的影响。研制的贝氏体钢锻后正火回火获得以贝氏体／马氏体为主、含碳化物和少量列岛奥氏体的组织、在光学显微镜下难以区分贝氏体（包括马淬透性。加入ＲＥ使贝氏体钢组织细化,冲击韧度提高;加入ＲＥ元素并不加速珠光体墨迹,而是少许推迟珠光体转变,有利于提高钢的淬透性。加入ＲＥ使贝氏体钢组织细化,冲击韧度提高;加     

Microstructure of explosively compacted Nd-Fe-B magnet by TEM

The microstructure of an explosively compacted Nd-Fe-B permanent magnet(Nd-Fe-B) was investigated by means of TEM and XRD. It is shown that there are three kinds of phases: Nd2 Fe14 B matrix phase, O-rich phases and Nd-rich phase with different structures and compositions in the magnet. The hard magnetic phase Nd2Fe14 B is tetragonal, which lattice parameters are determined to be a=0.88 nm and c=1.22 nm. The O-rich phase locates at the grain boundaries and the triple junctions has fcc structure whose lattice parameter is a=0. 559 nm. A dislocation is observed in this phase. It is also found that a large number of the block-shaped Nd-rich phases with hcp structure are embedded in the Nd2 Fe14 B matrix or at grain boundary. Their lattice parameters are determined to be a= 0. 395 nm and c=0. 628 nm.     

废旧轮胎热解及热解产物研究展望

热解作为废旧轮胎处置的重要技术手段,可以有效实现其减量化、无害化和资源化利用。本文综述了废旧轮胎热解的影响因素以及热解产物的研究进展,对废旧轮胎热解的经济、环境和社会效益进行了说明,指出当前工业化热解废旧轮胎存在的问题,并展望了未来节能环保式热解工艺的应用前景。结合现有的工业化热解设备,优化工艺条件和反应器结构型式,进一步分析了热解产物即热解气、热解油及热解炭的成分结构与应用,通过对热解产物改性活化与提质处理,创造更大的经济效益。提出应基于环境法规要求和绿色发展理念,糅合多种处理技术,研制适合废旧轮胎热解的工艺装备,开发集收集/预处理/热解/产物回收与提质于一体的废旧轮胎处置技术,实现废旧轮胎高效清洁转化和高值利用。     

水玻璃激发下HBSS-PG-AC复合胶凝材料水化性能分析

以磷石膏(PG)、热焖钢渣(HBSS)、硅酸盐水泥和铝酸盐水泥(AC)为主原料,水玻璃为碱激发剂制备复合胶凝材料。在养护龄期0~28 d内,测试了该材料的抗压强度与膨胀率,并通过X射线衍射(XRD)、扫描电子显微镜(SEM)和比表面积及孔隙率(BET)测试,分析了磷石膏、热焖钢渣和铝酸盐水泥间的水化协同机理。结果表明,过0.300 mm筛孔的钢渣微粉同时具备良好的骨架填充作用和水化胶凝性能。水化过程中水玻璃可提高钢渣表面玻璃体网络结构的溶解速率,促使钢渣与铝酸盐水泥生成C-A-S-H。同时,铝酸盐水泥与磷石膏反应生成的钙矾石可抑制C-A-H水化过程中的相变收缩。此外,若铝酸盐水泥比例过高,大量钙矾石和C-A-H会迅速生成并覆盖于钢渣表面,阻碍Na₂SiO₃促进钢渣玻璃网络结构的溶解。本文可为磷石膏和钢渣协同资源化利用提供理论依据。     

锰质量分数和压缩比对中碳钢相变组织的影响

采用光学显微镜和电子探针观察了中碳钢显微组织形貌,分析了不同锰质量分数和轧制压缩比对相变组织的影响。研究表明：试验钢显微组织为形态不同的铁素体+珠光体;增加Mn质量分数抑制晶界铁素体形核和长大,同时细化铁素体晶粒,促进退化珠光体的形成;提高轧制压缩比有利于原奥氏体晶内蜂窝状铁素体的形成,该铁素体均匀的分割原奥氏体晶粒,与晶界铁素体具有相同的方向性;MnS或其复合夹杂物是铁素体在原奥氏体晶粒内部形核的有效位置。     

基于TMS320F2812振动信号采集系统的设计与开发

文章对机械振动信号采集的方法进行了研究,提出了一种基于TMS320F2812振动信号采集系统的设计与开发方案.该系统是一种快速、实时性高、稳定高效的振动信号采集系统.它采用DSP芯片TMS320F2812实现对振动信号实时采集处理,文章主要包括该系统的组成与结构、振动信号调理电路的设计、控制参数的设置和实现A/D采样的程序流程等,通过串口将数据传到上位机,由上位机用MATLAB对数据进行处理分析.最后通过实例表明了该系统是成功可行的.