α-Fe2O3/煤矸石复合光催化剂的制备及其降解五氯酚性能的研究

以Fe（NO₃）₃、煤矸石和NaOH为原料,采用沸腾回流法制得了一系列不同质量比的α-Fe₂O₃/煤矸石复合光催化剂。采用场发射扫描电子显微镜（FESEM）、X射线衍射仪（XRD）及紫外-可见漫反射光谱（UV-Vis DRS）等多种手段对产物做了表征。以五氯酚为目标降解物,考察了模拟太阳光照下样品的光催化效果。结果表明,将球形α-Fe₂O₃负载于改性煤矸石表面可有效提高其光催化活性,且α-Fe₂O₃/煤矸石复合光催化剂的性能与α-Fe₂O₃的含量有关,当α-Fe₂O₃与煤矸石的质量比为30∶100时,样品的光催化效果最佳,180 min内即可将五氯酚降解完全。此外,α-Fe₂O₃/煤矸石复合光催化剂还具有可重复使用的特点。     

Cell-Based Optimization of Covalent Reversible Ketoamide Inhibitors Bridging the Unprimed to the Primed Site of the Proteasome β5 Subunit

The ubiquitin-proteasome system (UPS) is an established therapeutic target for approved drugs to treat selected hematologic malignancies. While drug discovery targeting the UPS focuses on irreversibly binding epoxyketones and slowly-reversibly binding boronates, optimization of novel covalent-reversibly binding warheads remains largely unattended. We previously reported α-ketoamides to be a promising reversible lead motif, yet the cytotoxic activity required further optimization. This work focuses on the lead optimization of phenoxy-substituted α-ketoamides combining the structure-activity relationships from the primed and the non-primed site of the proteasome β5 subunit. Our optimization strategy is accompanied by molecular modeling, suggesting occupation of P1′ by a 3-phenoxy group to increase β5 inhibition and cytotoxic activity in leukemia cell lines. Key compounds were further profiled for time-dependent inhibition of cellular substrate conversion. Furthermore, the α-ketoamide lead structure 27 does not affect escape response behavior in Danio rerio embryos, in contrast to bortezomib, which suggests increased target specificity.     

温控相分离纳米Ir催化α，β-不饱和醛、酮选择加氢

将温控相分离Ir纳米催化剂用于α,β-不饱和醛、酮的选择性加氢反应中,系统考察了其催化加氢性能。在优化的反应条件下,Ir纳米催化剂对α,β-不饱和醛的C═O键加氢选择性大于99%,对α,β-不饱和酮的C═C键加氢选择性大于99%。 Ir纳米催化剂经简单分离可直接循环使用5次,选择性均大于99%。TEM表征结果显示反应四次后的Ir纳米催化剂的平均粒径变为(1.9 ± 0.2) nm,比新制备的Ir纳米催化剂的平均粒径（1.3 ± 0.1）nm有所增大。ICP-AES测试结果表明Ir流失低于仪器检测下限（检测下限为5 μg/L）。     

基于局部样本增益优化的α-shape曲面拓扑重建

在曲面重建中,提高棱边特征重建精度是逆向工程和计算机辅助设计制造等领域的难点问题。采用样点的近似拓扑近邻点集作为曲面局部样本,对α-shape算法进行优化,使α-shape尺度阈值能更为准确地反映样点分布密度,从而提高α-shape曲面拓扑重建结果的正确性。样点的近似拓扑近邻点集的获取本质上是欧氏近邻点集的增益优化,使后者向邻近的稀疏区域适度延伸,从而弥补因数据分布不均匀而导致的拓扑邻域信息缺失。基于增益优化后的样点近邻点集并结合曲面重建先验知识可确定α-shape尺度阈值,使α-shape曲面拓扑重建过程中尺度阈值可自适应调整。试验表明:该算法使所得网格曲面基本不含孔洞和棱边凹痕,能更好保持棱边特征的形位精度,可减少初次过滤结果中的非流形面片,同时具有与主流Delaunay网格过滤算法相近的重建效率。     

Semisolid casting with ultrasonically melt-treated billets of Al-7mass%Si alloys

The demand for high performance cast aluminum alloy components is often disturbed by increasing impurity elements,such as iron accumulated from recycled scraps.It is strongly required that coarse plate-like iron compound of β-Al5FeSi turns into harmless form without the need for applying refining additives or expensive virgin ingots.The microstructural modification of Al-7mass%Si alloy billets with different iron contents was examined by applying ultrasonic vibration during the solidification.Ultrasonically melt-treated billets were thixocast right after induction heating up to the semisolid temperature of 583 oC,the microstructure and tensile properties were evaluated in the thixocast components.Globular primary α-Al is required to fill up a thin cavity in thixocasting,so that the microstructural modification by ultrasonic melt-treatment was firstly confirmed in the billets.With ultrasonic melt-treatment in the temperature range of 630 oC to 605 oC,the primary α-Al transforms itself from dendrite into fine globular in morphology.The coarse plate-like β-Al5FeSi compound becomes markedly finer compared with those in non-treated billets.Semisolid soaking up to 583 oC,does not appreciably affect the size of β-Al5FeSi compounds;however,it affects the solid primary α-Al morphology to be more globular,which is convenient for thixocasting.After thixocasting with preheated billets,eutectic silicon plates are extremely refined due to the rapid solidification arising from low casting temperature.The tensile strength of thixocast samples with different iron contents does not change much even at 2mass% of iron,when thixocast with ultrasonically melt-treated billets.However,thixocast Al-7mass%Si-2mass%Fe alloy with non-treated billets exhibits an inferior strength of 80MPa,compared with 180MPa with ultrasonically melt-treated billets.The elongation is also improved by about a factor of two in thixocastings with ultrasonically melt-treated billets for all iron contents of Al-7mass%Si alloys,for example,the elongation of 11% in thixocast of Al-7mass%Si-0.5mass%Fe alloy with ultrasonically melt-treated billets,5% in that with non-treated billets.     

Ti-6.5Al-3.5Mo-1.5Zr-0.3Si合金中α′相和α″相的组织演变与力学性能

对Ti-6.5Al-3.5Mo-1.5Zr-0.3Si合金进行固溶时效处理,随后使用光学显微镜、扫描电镜、XRD衍射仪、拉伸试验以及冲击性能试验,分析固溶时效对合金中α′相和α″相的组织演变与力学性能的影响。结果表明,固溶处理后的微观组织中发生初生α相尺寸变小并趋于等轴化,尺寸较小的初生α相发生溶解并消失,其β转变组织变得不明显,经时效后的微观组织中析出大量α_s相,β转变组织更加明显。经固溶处理后,组织均由α+α′+α″相构成,经时效处理后,组织由α相和β相构成。合金经固溶处理后,其抗拉强度为1336 MPa,屈服强度为1070 MPa,断后伸长率为6%,断面收缩率为22%,冲击吸收能量为16 J。经时效处理后,强度随时效温度升高而升高,塑性趋势与之相反,其冲击性能几乎没有变化。合金经固溶处理后的拉伸与冲击断口微观形貌均由韧窝构成,为典型的韧性断裂。经时效处理后,拉伸和冲击断口的微观形貌有明显的高低起伏,随着时效温度的升高,韧窝的尺寸和数量减少,并出现撕裂棱以及空洞,断裂类型有向脆性断裂转变的趋势,但仍以韧性断裂为主。     

卷柏酸性成分提取工艺及活性研究

用碱提酸沉法,以HPLC法测定穗花衫双黄酮的质量分数为指标,设计单因素和正交实验,确定了从卷柏中提取酸性成分的最佳工艺条件:ρ(NaOH)=2mg/mL水溶液为提取溶液、m(提取溶液):m(卷柏)=40:1、提取温度50℃、提取时间30min、沉降pH=3、提取1次,所得提取物中穗花衫双黄酮的质量分数稳定为10～12。该文首次报道了卷柏具有体内降血脂和体外抑制α-葡萄糖苷酶活性的功效。与模型组比较,酸性提取物能显著降低高脂血症小鼠的TC和LDL,极显著升高HDL;体外抑制α-葡萄糖苷酶活性(IC50=154.49μg/mL)高于对照阿卡波糖(IC50=1081.27μg/mL)。该文报告工作的新颖性已为河南大学图书馆2008年7月2日出具的第CX2008004号《科技查新报告》所证实。     

苯乙烯在HDPE-g-TMI接枝共聚物制备中的作用

以2,5-二甲基-2,5-二（叔丁基过氧基）己烷（DHBP）为引发剂,3-异丙基-α,α-二甲基异氰酸酯（TMI）为接枝单体,苯乙烯（St）为共聚单体,与高密度聚乙烯（HDPE）在HAAKE转矩流变仪中进行熔融混合共聚反应,制备了一种新型相容剂HDPE-g-TMI。研究讨论了St在HDPE-g-TMI接枝共聚物制备中的作用。结果表明,TMI成功接到HDPE分子链上。适当的St可以作为共单体加入到共混体系中抑制HDPE分子链的降解和提高接枝率,当w（St）含量为7．5％时接枝率达最高值为0．4050mmol／g,与HDPE相比,HDPE-g-TMI的熔融温度tm和熔融焓△Hm、拉伸屈服强度、断裂强度和断裂伸长率均有所降低。     

Analysis of the Active Au Species on Au/α-Fe2O3 Catalyst

采用沉积沉淀法制备了CO低温氧化 Au/α-Fe2O3催化剂,利用 X 射线衍射(XRD)、X 射线光电子能谱(XPS)、BET 比表面测定、程序升温还原(H2-TPR)等表征技术,对比了制备过程 pH 值的微小变化、焙烧及光线照射对催化剂结构及催化性能的影响,探明了 Au/α-Fe2O3催化剂的活性物种。结果表明,110 ℃处理的 Au/α-Fe2O3催化剂表面同时存在 Au3+、Au0以及过渡态 Auδ+(0<δ<1),它们对 CO 氧化的活性顺序为 Au3+>Auδ+>Au0;pH 值为 8 条件下制备的催化剂 Au3+含量高、比表面积大,催化性能最好;高温焙烧使氧化态金还原的同时也使载体比表面积严重缩小,催化活性显著下降;紫外线照射可以引起 Au3+的逐渐还原以及 Au0 颗粒的生长,其催化失活作用弱于高温焙烧。