Analysis of microbial adaptation at enzyme level for enhancing biodegradation rate of BTX

Catechol was found to be a common intermediate in the degradation of benzene and toluene byAlcaligenes xyhsoxidans Y234, and the ring cleavage of the catechol mediated by catechol 1,2-dioxygenase was a rate-determining step. Since benzene induced higher level of catechol 1,2-dioxygenase than toluene, the cells pre-adapted to benzene showed higher degradation rate of benzene and toluene. The degradation rate ofm-xylene was also increased significantly when benzene-adapted cells were inoculated.m-Xylene was metabolized via 3-methyl catechol which was effectively cleaved by catechol 1,2-dioxygenase.     

对改进重轨全长淬火质量的探讨

结合国内外重轨生产发展态势，对攀钢重轨的全长淬火工艺进行了分析与探讨，并对提高全长淬火质量提出了一定的看法。     

热装轴管中频感应加热设备的设计与研制

介绍了一种新型的车桥轴管热装配感应加热设备 分析了该设备中频电源电路的工作原理 ,提供了主要设计参数 ,运用CAD技术对主电路进行运算 ,绘出仿真图并对比实验结果验证了设计方案 为推广节能环保型的热装工艺提供参考     

涡轮流量计的原理,应用及其测井曲线的解释

本文研究了涡轮流量计的工作原理、适用条件，并指出，涡轮流量计适合于单相流、高流量的井眼环境。对于低流量、多相流的井限，测量误差较大，此时要提高测量精度应采用集流式涡轮流量计进行测量。本文还研究了，在各种井眼条件下正确使用涡轮流量计，以便提高测井线的解释精度。     

去上皮羊膜及其浸提液体外诱导骨髓间充质干细胞的分化

目的观察去上皮羊膜及其浸提液体外诱导骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMSCs)向上皮细胞的分化,并探讨其机制。方法从胎儿四肢长骨分离BMSCs,扩增后采用流式细胞术分析第3代(P3)细胞表面抗原(CD29、CD34、CD71和HLA-DR)的表达,并用4,6-乙酰基-2-苯基吲哚(DAPI)标记第4代BMSCs(P4-BMSCs)。机械法去除正常胎盘羊膜上皮,制成去上皮羊膜,并制备去上皮羊膜浸提液。将DAPI标记的BMSCs接种于羊膜上,设加或不加表皮细胞生长因子(Epidermal growth factor,EGF)、类胰岛素1号生长因子(Insulin-like growth factor 1,IGF-1)、羊膜浸提液诱导组及细胞爬片对照组,体外诱导培养后,采用免疫荧光组织(细胞)化学染色学法检测各组细胞角蛋白(Cytokeratin,CK)、EGF-R和IGF-1-R的表达,并于诱导后第10天计算CK阳性细胞率。结果原代BMSCs呈典型旋涡状生长,P3细胞表达CD29和CD71,不表达CD34和HLA-DR。羊膜组和细胞爬片组BMSCs在加入EGF或IGF-1诱导后,表达EGF-R和IGF-1-R的时间较未加生长因子的对照组提前2～4 d,表达CK的时间提前2～6 d,单用羊膜组或羊膜浸提液组的表达时间差异无统计学意义(P>0.05);诱导第10天,单用羊膜或羊膜浸提液诱导组的CK阳性细胞表达率明显高于细胞爬片对照组(P<0.05);羊膜与EGF、IGF-1联合诱导组高于单用羊膜组(P<0.05);EGF诱导组高于IGF-1诱导组(P<0.05)。结论羊膜及羊膜浸提液、外源性EGF和IGF-1在体外均可诱导BMSCs向上皮细胞分化,羊膜可能主要通过其所含的细胞因子诱导BMSCs向上皮分化。     

Effects of aggregate microstructure on slag resistance of lightweight Al2O3-MgO castable

Corundum-spinel castables using lightweight aggregate have drawn much attention due to their energy-saving potential, in particular when they are applied in high-temperature areas, such as the work lining of refining ladle. One of the main issues which hinder their application is their relatively poor slag corrosion performance. In this study, one type of dense tabular corundum and three types of lightweight corundum were chosen as aggregates to prepare four different model corundum-spinel castables. Their slag resistance was evaluated by an induction furnace corrosion test method. As well as SEM, EDS, and XRD characterizations, thermodynamic and kinetic analyses were carried out to assist understanding the corrosion mechanism. Results indicated that size and shape of crystalline grain in aggregate were important for the slag corrosion (dissolution) resistance of lightweight corundum-spinel castables under dynamic condition (enforced convection), whereas the effects of pore characteristics were not significant. Use of aggregates having large average crystal size and flake-shaped crystals led to a thicker diffusion boundary layer and lowered dissolution rate, i.e., good corrosion resistance, whereas use of aggregates with small and spherical crystals and larger pores led to poor slag resistance.     

基于DD-DWT和Log-Logistic参数回归的癫痫脑电自动识别方法

针对现有癫痫脑电(EEG)识别算法分类模式单一、普适性不强的问题,提出了一种新的基于双密度离散小波变换(DDDWT)和Log-Logistic参数回归(LLPR)的脑电信号自动识别方法。不仅利用了DD-DWT算法的分解特性,还建立了脑电信号的LLPR模型,并将二者有机的结合,从而更好的发挥算法的优势。滤波后脑电信号由DD-DWT进行6层分解,提取各子频带系数的小波域能量波形,并结合LLPR模型计算尺度参数α和形状参数β以表征信号,将构成的特征向量送入遗传算法(GA)优化的支持向量机(SVM)得出识别结果,从而实现脑电信号的自动识别。所提方法在处理A\D\E与AB\CD\E两种多模式脑电分类问题时,识别率分别为98.90%和97.75%。实验结果表明,所提算法更符合实际应用需求,可以较好地解决多类脑电信号识别问题,具有良好的普适能力和分类性能。     

感应加热技术在钢管热处理工艺中的应用

介绍了利用中频电流感应加热原理进行钢管热处理的工艺技术。由于其设备投资不大、没有环境污染,且便于进行工艺控制和组织生产,与燃气加热(天然气或发生炉煤气)方式的钢管热处理工艺比较,具有明显的技术优势。经过生产证明,采用中频感应加热方法对钢管进行热处理的工艺技术是完全可行的。     

川气东送管道工程用Φ1016mm×26.2mm感应加热弯管的性能分析

从对国内某弯管厂生产的川气东送管道工程用Φ1016mm×26.2mm感应加热弯管及其母管的主要理化性能进行的分析比较中发现,感应加热弯管及其母管的主要性能均值明显高于该管道工程技术标准的要求;所制得的弯管较母管强度下降,韧性上升,塑性略有增加;弯管不同部位的性能变化也有一定的差异。