糖与氨基酸反应产物结构的EPR和~(13)C NMR研究(英文)

应用EPR和~(13)C NMR技术系统地研究了糖与氨基酸反应的产物。EPR波谱分析表明,反应产物的结构主要取决于氨基酸的结构。~(13)C NMR波谱的化学位移表明、反应产物的结构应该是2,5-哌嗪二酮,糖是作为1,4位取代的配位基。本文还提出了一种可能的反应机制。     

Photosensitive,self‐assembled ultrathin films based on diazoresin and phosphate‐containing polyanions

Photosensitive ultrathin films with phosphate‐containing polyanions and diazoresin (DR) as a polycation were fabricated with a self‐assembly technique. The phosphate‐containing polyanions were poly(sodium phosphate), phosphorylated poly(vinyl alcohol), and DNA. The fabrication process was monitored by the determination of the absorbance from DR. The surface morphology of the multilayer films was observed with atomic force microscopy. Under ultraviolet irradiation, the linkage between the layers of the films changed from being ionic to being covalent; as a result, the stability of the films toward polar solvents increased. This kind of film may have applications for biosensor devices. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 222–228, 2002     

N参数Ornstein-Uhlenbeck过程的点常返性

本文得到了Ｎ参数 Ｏｒｎｓｔｅｉｎ－Ｕｈｌｅｎｂｅｃｋ过程的点常返性准则，我们证明了：若 ｄ＜ ２Ｎ，则ｄ－维 ＯＵＰＮ，Ｘｚ是点常返的；若 ｄ ≥２Ｎ，则Ｘｚ以概率 １不击中点。     

A postbeamformer adaptive noise cancelling system

I.IntroductionApostbeamformernoisecancel1erisasing1e-channeladaptiveprocessorinbeamspace['l.Ithasnotonlysimplerstructure,buta1sobetterpropertiesthane1ementspaceprocessorinimp1ementation.L.C.GodaraandA.Conto1ihavestudiedthesignaltonoiseratioofthebroadbandPIC[1].Theauthorshavesolvedtheprob1emofapplicationconditionsofnarrowbandPIC['],andproposedthatRMGSEFa1gorithmistheoptimuma1gorithminthenarrowbandPICadaptiveprocessing['1.Atpresent,thepfob1emofadaptivecance11ingofbroadbandtowing-shipnoi…     

Local Unstable Entropy and Local Unstable Pressure for Partially Hyperbolic Endomorphisms*

In this paper, local unstable metric entropy, local unstable topological entropy and local unstable pressure for partially hyperbolic endomorphisms are introduced and investigated. Specially, two variational principles concerning relationships among the above mentioned numbers are formulated.     

Iridium(III)‐Catalyzed Regioselective Intermolecular Unactivated Secondary Csp3−H Bond Amidation

For the first time, a highly regioselective intermolecular sulfonylamidation unactivated secondary Csp³?H bond has been achieved using Ir^III catalysts. The introduced N,N’‐bichelating ligand plays a crucial role in enabling iridium–nitrene insertion into a secondary Csp³?H bond via an outer‐sphere pathway. Mechanistic studies and density functional theory (DFT) calculations demonstrated that a two‐electron concerted nitrene insertion was involved in this Csp³?H amidation process. This method tolerates a broad range of linear and branched‐chain N‐alkylamides, and provides efficient access to diverse γ‐sulfonamido‐substituted aliphatic amines.     

VPO,VPO／Al2O3催化剂前身物的热分解过程

本文应用差热、热重分析技术并结合Ｘ射线衍射和红外光谱法对水相，有机相制备的ＶＰＯ催化剂及水相制备的ＶＰＯ／Ａｌ_２Ｏ_３催化剂前身物在空气中的热分解过程进行了考察，由红外光谱证明，ＶＰＯ催化剂前身物的主要组成成分为ＶＯＨＰＯ４·０．５Ｈ２Ｏ．不同制备方法和制备条件对ＶＰＯ催化剂的热分解行为和最终产物有很大影响，随着Ｐ／Ｖ比的改变，ＶＰＯ催化剂前身物在焙烧过程中转变为不同的活性相，并且过量的磷酸抑制Ｖ（Ⅳ）的氧化过程。在ＶＰＯ／Ａｌ_２Ｏ_３催化剂上，ＶＰＯ前身物和载体发生了化学作用，这种作用促进了催化剂的热分解。     

硫化态Ru-Co-Mo/Al2O3加氢脱硫催化剂的表征

应用程序升温还原和化学吸附考察了硫化态Mo/Al_2O_3, Co-Mo/Al_2O_3, Ru-Mo/Al_2O_3, Ru-Co-Mo/Al_2O_3系列催化剂中的钴与钌的助剂作用. 实验结果发现, TPR谱图中Co-Mo/Al_2O_3上的Co 中心的还原峰强度比Co/Al_2O_3上的大大降低, 并且氧在Co-Mo/Al_2O_3上化学吸附量少于分别在Co/Al_2O_3和Mo/Al_2O_3上的吸附量之和, 说明钴和钼发生了相互作用, 可能生成了所滑的CoMoS相, 减少了独立的钴或钼中心. 与Co不同, 在Ru-Mo/Al_2O_3催化剂上助剂钌使得部分高温还原的Mo中心位移到中温区还原, 并且还增加了H_2和O_2在Mo中心上的吸附量, 这表明在硫化和还原过程中Ru促进了Mo中心的还原, 生成了更多的配位不饱和铝中心, 在Ru-Co-Mo/Al_2O_3催化剂上也发现了类似的钌助还原现象, 钉的这种助还原功能可以用氢溢流机理来解释.