铝基复合材料高速干摩擦行为的遗传神经网络预测模型

对4种SiC颗粒增强铝基复合材料在5种速度和4种压力条件下进行了销-盘摩擦磨损试验,运用遗传神经网络技术建立了铝基复合材料在高速干滑动过程中的摩擦行为预报模型,并用该模型对铝基复合材料进行预报.结果表明,蓄热能力较大的铝基复合材料在服役条件下具有较高的摩擦系数,与实际情况相一致.用遗传神经网络建立的铝基复合材料摩擦行为预测模型为服役条件下提供了简便、可靠的优选材料方法.     

激光多普勒测速技术在气液两相流中的应用

本文采用激光颗粒动态分析仪(PDA)测量了钢包底部喷吹气液两相流中气泡的直径和气泡上升速度的分布;采用激光多普勒测速仪(LDA)测量了气液两相区和液体单相循环区液体速度场的分布。测量结果表明:气泡在脱离喷嘴上浮一定距离后,其大小基本保持不变;在气液两相区中,气泡速度和液体速度的分布均服从高斯分布;液体在单相区作循环流动,在侧壁与底部交接处,存在液体流动的“死区”。     

一个二维锰配位聚合物[Mn2(L)2(1,3-BDC)2]·0.25H2O的合成、结构和表征

The title complex, [Mn₂(L)₂(1,3-BDC)₂]·0.25H₂O 1 (L=2-(2-chloro-6-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline and 1,3-H₂BDC=1,3-benzenedicarboxylic acid) has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P2₁/n with a=1.751 68(6) nm, b=1.160 14(4) nm, c=2.585 30(8) nm, β=104.331(4)°, V=5.090 3(3) nm³, Z=4, C₅₄H_28.50Cl₂F₂Mn₂N₈O_8.25, M_r=1 140.13, D_c=1.488 g·cm^-3, F(000)=2 306, μ(Mo Kα)=0.673 mm^-1, R=0.060 5 and wR=0.161 6. The compound 1 exhibits two-dimensional wavy layer structures, which are further stacked through π-π interactions to form three-dimensional supramolecular architectures. CCDC: 760201.     

99mTc-AMD3100: A novel potential receptor-targeting radiopharmaceutical for tumor imaging

<正>The chemokine CXCR4 receptor is over-expressed in a wide variety of tumors.In this study,AMD3100,which was a prototype non-peptide antagonist of CXCR4 receptor,was labeled with ~(99m)Tc.~(99m)Tc-AMD3100 was verified by thin layer radio chromatography(TLRC).The tumor-localizing properties of ~(99m)Tc-AMD3100 were evaluated and proved in mice bearing Hep-G2 tumor xenograft.~(99m)Tc-AMD3100 was a promising,novel receptor-specific radiopharmaceutical with potential application in the imaging of human tumors.     

Synthesis and structure determination of pyrazine-containing macrocyclic polyazomethines

<正>Two pyrazine-contairting macrocyclic polyazomethines 2 and 3 were synthesized by direct[2 + 2]and[3 + 3]condensation reactions between 2,2'-[pyrazine-2,3-diylbis(oxy)]dibenzaldehyde(1) and hydrazine.Both 2 and 3 were characterized by NMR, HRMS,and their structures were determined via X-ray crystal diffraction studies.     

Synthesis and CDK2 kinase inhibitory activity of 7/7′-azaindirubin derivatives

A series of novel 7′-azaindirubin (1a-g) and 7-azaindirubin (2a, 2c, 2e and 2f) derivatives were designed and synthesized. Their structures were characterized by 1H NMR and MS spectroscopy as well as by elemental analysis. Their inhibitory properties against CDK2/cylinA were evaluated in vitro. In contrast to indirubin, some of the described azaindirubins emerged as potent inhibitors of CDK2/cylinA and compound 2b had more potent activity. Biological tests also showed that nitrogen atom at 7-position of azaindirubin was more beneficial to enhance the kinase inhibitory activity.     

微量钛掺杂的纳米二氧化锆相变过程中的光学性质

微量钛掺杂的纳米氧化锆由于纳米“小尺寸效应”的影响,在材料中产生了过量的氧空位缺陷,这些氧空位缺陷使得氧化锆在室温下呈现出高温的四方相。这种晶相的变化对氧化锆的光学性质产生了很大的影响。在氧化锆从四方相向单斜相的转变过程中,位于470 nm位置的Ti发光中心的宽带发光以及相同位置的余辉发光得到了增强。     

PMMA/PVDF共混对PVDF的β相构型影响的研究

采用溶液法制备了不同含量的聚甲基丙烯酸甲酯/聚偏二氟乙烯(PMMA/PVDF)共混薄膜,利用傅立叶变换红外光谱(FTIR)、X射线衍射谱(XRD)、和差热分析法(DSC)对共混薄膜的结晶行为进行了分析。结果表明,共混物中PMMA的含量对PVDF的β相构型有明显影响:PMMA/PVDF=30/70共混物中β相含量最高。为提高PVDF薄膜的铁电性能提供了新的研究方法。     

橡胶及橡胶制品中4种酚类防霉剂的高效液相色谱法测定

建立了橡胶及其制品中硝基苯酚(PNP)、2,3,5,6-四氯苯酚(TeCP)、五氯苯酚(PCP)、邻苯基苯酚(OPP)4种酚类防腐剂的高效液相色谱测定方法。样品冷冻粉碎后,经甲醇超声提取,在Venusil-XBP C18色谱柱(250 mm×4.6 mm,5μm)上以10 mmol/L醋酸铵和甲醇为流动相梯度洗脱,采用二极管阵列检测器,PCP、TeCP、OPP的检测波长为220 nm,PNP的检测波长为320 nm。4种酚类防霉剂的质量浓度在0.5~250mg/L范围内与峰面积呈良好的线性关系,相关系数大于0.999 4。丁苯橡胶、硅橡胶基体的加标回收实验结果表明:TeCP、PCP、OPP、PNP在不同基质中的平均加标回收率分别为82%~95%、68%~90%、85%~98%、87%~98%,相对标准偏差小于5%。     

用酰胺缩醛法合成单(双)长链烷基脒基化合物

在氮气保护下,以N,N-二甲基甲酰胺二甲缩醛和初级长链脂肪胺为原料,采用酰胺缩醛法合成了单(双)长链烷基脒基化合物--N′-烷基-N,N-二甲基甲脒和N,N′-双烷基甲脒,产率高于83%,其结构经NMR,IR和MS表征.