Effect of Thermal Processing on the Metabolic Components of Black Beans on Ultra-High-Performance Liquid Chromatography Coupled with High-Field Quadrupole-Orbitrap High-Resolution Mass Spectrometry

An ultra-high-performance liquid chromatography coupled with high-field quadrupole-orbitrap mass spectrometry (UHPLC-QE-MS) histological platform was used to analyze the effects of two thermal processing methods (cooking and steaming) on the nutritional metabolic components of black beans. Black beans had the most amino acids, followed by lipids and polyphenols, and more sugars. Multivariate statistical analysis indicated that heat processing significantly affected the metabolic component content in black beans, with effects varying among different components. Polyphenols, especially flavonoids and isoflavones, were highly susceptible. A total of 197 and 210 differential metabolites were identified in both raw black beans and cooked and steamed black beans, respectively. Cooking reduced the cumulative content of amino acids, lipids, polyphenols, sugars, and nucleosides, whereas steaming reduced amino acid and lipid content, slightly increased polyphenol content, and significantly increased sugar and nucleoside content. Our results indicated that metabolic components were better retained during steaming than cooking. Heat treatment had the greatest impact on amino acids, followed by polyphenols, fatty acids, sugars, and vitamins, indicating that cooking promotes the transformation of most substances and the synthesis of a few. The results of this study provide a basis for further research and development of nutritional products using black beans.     

金催化乙炔氢氯化的密度泛函理论研究进展

乙炔氢氯化(AH)是生产氯乙烯的主要途径之一,传统上使用高毒性的汞催化剂,因此开发无汞催化剂迫在眉睫。金(Au)催化剂是最有潜力的替代催化剂之一,然而其活性Au物种、反应物的活化过程或反应过渡态结构等催化机理仍不够清晰。密度泛函理论（DFT）在研究由Au催化AH的反应机理中发挥了极其重要的作用。本文综述了DFT对金催化剂活性位点、反应物在催化剂上的吸附性质及反应机理的研究进展。重点讨论了DFT对阳离子金和金簇催化AH反应过程的模拟计算,包括Au电子状态、其它原子掺杂及金簇尺寸和形状对催化AH反应影响的模拟。结果表明DFT模拟计算在微观分子尺度上研究反应物的吸附、反应中间体及过渡态等方面发挥了关键作用,对理解Au催化AH反应机理做出了重要贡献。     

Synthesis,Structure and Theoretical Calculation of Metal Coordination Polymers with Pyrazine-2,3-dicarboxylic Acid and 3-(2-Pyridyl)pyrazole as Co-ligands

A new 2D metal coordination polymer(MCP),[Mn(pzdc)_(0.5)(L)]_n(1,pzdc=pyrazine-2,3-dicarboxylic acid,HL=3-(2-pyridyl)pyrazole),was synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction,powder XRD,FT-IR,TG,fluorescence and elemental analysis techniques.Pale yellow crystals crystallize in orthorhombic system,space group Fdd2 with a=11.2368(6),b=38.280(2),c=10.5682(6) A,V=4545.9(4) A~3,C_(11)H_7MnN_4O_2,M_r=282.15,D_c=1.649 g/cm~3,μ(MoKα)=1.159 mm~(-1),F(000)=2272,Z=16,the final R=0.0613 and wR=0.1773 for 2856 observed reflections(I 2σ(I)).It shows a two-dimensional network structure and is further assembled into a three-dimensional supramolecular framework via hydrogen bonds and abundant π-π interactions.In addition,we analyzed natural bond orbital(NBO) of 1 in using the PBE0/LANL2DZ method established in Gaussian 03 Program.There is obvious covalent interaction between the coordinated atoms and Mn(Ⅱ) ions.     

气相生长氮化铝单晶的新方法

通过在钨坩埚盖开小孔的方法改变氮化铝结晶衬底上的温度场分布,在开孔处形成局部低温区;由于孔的几何尺寸的限制和氮化铝晶体生长的各向异性,开孔处的氮化铝晶体单晶化;随后,开孔处的单晶起籽晶的作用,逐渐长成较大尺寸、较高质量的氮化铝单晶.目前用该方法已经制备出直径大于2mm的氮化铝单晶体.     

纳米羟基磷灰石/羧甲基壳聚糖多孔生物复合材料的制备与性能研究

采用化学沉淀法合成了纳米羟基磷灰石粉体(HAP),以无水乙醇为沥滤剂,以16.7%(质量分数)的柠檬酸水溶液作粘结剂,通过粒子沥滤法制备了HAP/CMCS多孔材料,并对其进行了IR、XRD、SEM、孔隙率及抗压强度的测试。结果表明HAP/CMCS复合材料复合前后两组份的化学组成未发生显著变化,但两相间发生了相互作用。多孔材料孔隙率高,孔径分布范围宽,其尺寸分布大约从几微米到600微米,以圆形为主,具有良好的贯通性,非常有利于组织在其中的长入与扩展。当复合材料中CMCS含量为40%,复合材料/造孔剂的质量比为1:1时,多孔材料的孔隙率接近75%,其抗压强度可达21MPa以上,可以满足骨组织工程支架材料的要求。     

半导体单晶生长过程中的位错研究

阐述了现有的半导体单晶位错模型,即临界切应力模型和粘塑性模型的基本理论及应用状况.分析了熔体法单晶生长过程中影响位错产生、增殖的各种因素,以及抑制位错增殖的措施.与熔体不润湿、与晶体热膨胀系数相近的坩埚材料,低位错密度的籽晶可有效地抑制生长晶体的位错密度;固液界面的形状及晶体内的温度梯度是降低位错密度的关键控制因素,而两因素又受到炉膛温度梯度、长晶速率、气体和熔体对流等晶体生长工艺参数的影响.最后,对熔体单晶生长过程的位错研究进行了展望.     

钾明矾蓄热性能的研究与改善

钾明矾(KAl(SO4)2·12H2O)有较高的潜热和良好的导热性(熔化热232.4kJ/kg,导热系数为0.55W/m·K),熔点为91℃,是中低温相变材料中较有开发价值的一种.但是它的过冷度高达19.8℃,并且由于相变过程伴随着结晶水的蒸发使无机盐的使用寿命大大降低.本文通过冷指法及添加成核剂的方法对硫酸铝钾的过冷现象进行了研究,结果表明成核剂NiSO4·6H2O、MgCl2·6H2O能较好的改善过冷现象,当MgCl2·6H2O的添加量为2;时可使过冷度降为零,且能保持钾明矾的相变温度而不使其降低.利用MgCl2·6H2O具有很强的吸湿性,可以补充相变过程中损失的水分,使相变材料的使用寿命大大提高.     

兆巴高压下c向蓝宝石的冲击辐射研究

采用三层夹心靶结构,利用铜箔与抛光蓝宝石之间良好的接触条件,使用辐射式高温计在1.30～1.72兆巴压力范围内观测到c向蓝宝石的强冲击辐射。在1.30和1.72兆巴的冲击压力下,得到蓝宝石在0.633μm波长处的不透明系数为1.7 cm-1和5.0 cm-1。实验显示蓝宝石的冲击辐射随着冲击压力的增加而急剧增强。     

工作气压对磁控溅射ITO薄膜性能的影响

工作气压在ITO薄膜的制备过程中是一个重要的工艺参数,直接决定着薄膜的性能.本文利用射频磁控溅射方法,采用氧化铟锡陶瓷靶材,在衬底温度为175℃,工作气压范围为0.45～1.0 Pa条件下,制备了氧化铟锡透明导电薄膜.研究了工作气压对其微观结构、表面形貌和光电特性的影响.在衬底温度为175℃、纯氩气中制备的氧化铟锡薄膜电阻率为3.04 ×10-4 Ω·cm、可见光波段(400～800 nm)透过率为91.9;,适合用作异质结太阳电池的前电极和减反射膜.     

CTAB与SDBS对碳酸锶粒子生长形态调控及机理研究

以表面活性剂CTAB和SDBS为化学添加剂,采用化学共沉淀法对碳酸锶晶体的生长形态进行调控,成功地制备出了实心的树枝状和花瓣为空心的花状碳酸锶粉体,并用X射线衍射(XRD)、扫描电子显微镜(SEM)和傅里叶变换红外光谱(FT-IR)等分析手段对样品进行了表征;最后重点对化学添加剂可能产生的影响机理进行了初步的探讨.结果表明,CTAB和SDBS在晶体生长的过程中能起到显著的影响作用,两者对粒子分散性能的作用效果相反,而且后者对晶体(013)和(213)晶面表面能降低的贡献明显大于前者.