Photolyses of mammalian carboxy-hemoglobin studied by photoacoustic calorimetry

The enthalpy and conformational volume changes in the photolyses of carboxy-hemoglobin (HbCO) of human, bovine, pig, horse and rabbit are investigated by photoacoustic calorimetry. Considering the time scales of the exciting laser pulse and the receiving ultrasound transducers (PVDF films and PZT ceramics), as well as the reaction lifetimes in the photolysis processes of HbCO, the measured results are related to the geminate recombination and tertiary relaxation in photolyses of HbCO. Moreover, the quantum yields of the five mammals are also measured by laser pump-probe technique. The results show that the dynamic parameters, such as enthalpy and conformational volume changes, differ between the processes of the geminate recombination and tertiary relaxation. Also, the dynamic parameters differ among the five mammals although some of them may be consistent with each other.     

Catalytic enantioselective synthesis of optically active α-hydroxyl-β,γ-unsaturated acid esters as novel side chains of cerebrosides

Six optically active α-hydroxyl-β,γ-unsaturated acid esters 1a to 1f were synthesised, and they are significant moieties of the cerebrosides. The chiral intermediate alkynol 4 prepared by catalytic asymmetric addition had 99% ee, and which was converted into the target compounds 1a to 1f with high enantiomeric purity.     

Online Column Extraction Coupled with Double-Trap Column System for HPLC Determination of Valproic Acid in Human Plasma Without Derivatization

Chromatographia - An automated online column extraction coupled with high-performance liquid chromatography (HPLC) and equipped with a double-trap column system was developed to determine valproic...     

基于N-A型原子系统的1→N型分束器

分析N-A型原子系统的原子极化率,结果表明即使在全共振条件下,EIT效应并不一定产生,介质对信号场的色散和吸收关系与所有场的复拉比频率有关.信号场传播方程的解析分析表明,此系统可以把一束光分成不同频率的N束光,并且其强度和相位是可控的.暗态极化子分析表明它还可以用作1→N量子分束器,产生多体纠缠态.     

Synthesis of Cyclohexene Carbonate Catalyzed by Polymer-Supported Catalysts

A series of polystyrene-divinylbenzene cross-linked resin (PS)–supported zinc chloride catalysts were prepared in this study. They can efficiently catalyze the solventless cycloaddition of cyclohexene oxide with carbon dioxide in the presence of tetrabutylammonium bromide (TBAB) as cocatalyst under relatively mild reaction conditions. The catalyst is composed of carrier, connecting arm, ligand, and active ingredient. The connecting arms of different lengths can significantly affect the catalytic activity. Among these catalysts, the one using diethylene glycol as connecting arm and 2-aminopyridine as ligand, named PS-DEG-2ap-ZnCl₂, showed the optimal catalytic performance. The yield of cyclohexene carbonate was 95.18% calculated by gas chromatographic analysis under the optimal conditions (393 K, 5 MPa, 6 h). Moreover, the catalyst showed good stability and reusability. From the viewpoint of industrial application, the catalyst is attractive because of its excellent catalytic efficiency on the synthesis of cyclohexene carbonate.     

Simulating ion clustering in potassium thiocyanate aqueous solutions with various ion-water models

Using a molecular dynamics simulation technique,we compared several commonly used ion-water models to describe the microscopic structures and dynamics in KSCN aqueous solutions.Results are compared with observations of femtosecond infrared vibrational-energy transfer and anisotropy measurements.The Jorgensen/TIP4P model is found to provide the best reproduction of clustering properties such as percentage of clustered ions,cluster-size distribution,concentration dependence of the water,and ion-rotation time constants.     

Synthesis of a Pillar[5]arene with Both Hydroxyl and Methoxycarbonyl‐Methoxy Groups and Its Host‐Guest Complexation with a Bis(imidazolium) Salt

By the introduction of methoxycarbonyl‐methoxy groups and hydroxyl groups into a pillar structure, a pillararene entirely with two types of functional groups was successfully prepared, which can form a stable 1:1 complex with a bis(imidazolium) salt in CHCl₃/acetone solution (V:V=1:1).