A novel way towards CdS sensitized TiO_2 nanoparticles

<正>Polymethyl methacrylate cadmium was grafted on TiO_2 surface via the surface initiated atomic transfer radical polymerization of methyl methacrylate cadmium from a surface tether initiator.The coordinated cadmium as the source precursor reacts with H_2S generates CdS nanoscrystal on TiO_2 surface.The grain size of CdS is about 5 nm and stabilized by tether polymer chains.The light absorption of CdS/TiO_2 is expanded to visible light region.     

Investigation on very large scale motions(VLSMs) and their influence in a dust storm

Based on the real-time synchronous measurements of the wind velocity,temperature,the PM10 concentration at 16 m and 47 m during a dust storm event,in which Reynolds number Re exceeds 6×106,this study reveals the existence of the very large scale motions(VLSMs) during the stable stage both in the stream velocity and the temperature field at the two heights,whose streamwise scales reach up to 10 times the thickness of the boundary layer.The streamwise velocity and the PM10 concentration display a similar frequency corresponding to the peaks of their energy spectra,which implies that the VLSMs of streamwise flow have a significant role in dust transportation.In contrast,the salient deviations of the PM10 concentration at 47 m from the Gaussian distribution are revealed,which means that 47 m is not in the dust transportation layer,but is a region where the dust transportation layer and the outer flow intersect each other.Analysis demonstrates that the energy spectra of the PM10 concentrations at 16 m and 47 m display the "-1" scaling law feature,which has the same frequency range(0.001-0.1 Hz) as that of the wind velocity.This provides a new paradigm for the existence of the self-similarity scaling region in turbulent flow.     

代数连续映象的零点定理及其应用

在Hausdorff拓扑线性空间X及其超1维线性子空间V中，提出并证明了代数连续映象F：X→V^#的一个零点定理，作为应用，讨论了一类广义保号的散度型二阶椭圆方程和一类退化的Fichera-Keldys型二阶抛物方程的弱解存在的问题，推广和改进了现有的结论和现有的证法。     

Highly efficient oxidation of alcohols using Oxone~ as oxidant catalyzed by ruthenium complex under mild reaction conditions

Aromatic and alkyl alcohols were oxidized to the corresponding aldehydes or ketones at room temperature with high conversion and selectivity using Oxone(?)(2KHSO_5·KHSO_4·K_2SO_4)as oxidant catalyzed by ruthenium complex Quin-Ru-Quin(where Quin = 8-hydroxyquinoline).The reaction time is very short and the preparation of complex is simple.     

Two New Compounds from Melanosciadum pimpinelloideum H. Boiss

Melanosciadum pimpinelloideum H. Boiss (Umbelliferae), an indigenous plant，is the unique representative of species Melanosciadum1. Anomalin and 3(-angeloyl-4(-hydroxy-trans-khellactone were isolated from this plant2. In this investigation, from the whole plants two new compounds, melanochromone 1 and 2-ethoxyl-2-(4-hydroxyphenyl)ethanol 2 were isolated with known compounds 1-(4-hydroxyphenyl)-1,2-ethanediol 33, tymine (5-methyluracil) 44, cimifugin 55, umtatin 65, bergenin 76, daucosterol 87…     

Theoretical study of the mechanism for C-H bond activation in spin-forbidden reaction between Ti~+ and C_2H_4

The mechanism of the spin-forbidden reaction Ti+(4F, 3d24s1) + C2H4 → TiC2H2+ (2A2) + H2 on both doublet and quartet potential energy surfaces has been investigated at the B3LYP level of theory. Crossing points between the potential energy surfaces and the possible spin inversion process are discussed by means of spin-orbit coupling (SOC) calculations. The strength of the SOC between the low-lying quartet state and the doublet state is 59.3 cm-1 in the intermediate complex IM1-4B2. Thus, the changes of its ...     

Oxidation of 3,4-dihydropyrimidin-2（1H）-ones with nitrosonium （NO^＋）

3,4-Dihydropyrimidin-2(1H)-ones (DHPMs) were oxidized with 1.2 equiv. of nitrosonium tetrafluoroborate (NO⁺BF₄⁻) to pyrimidin-2(1H)-ones in acetonitrile at room temperature in high yields.     

An Efficient Cationic Cyclization Approach for the Construction of Labdane Diterpenoid Decalin Ring Skeleton

An effective approach for the construction of the decalin ring skeleton of labdane diterpenoids was developed based on a key biomimetic cationic polyene cyclization of an epoxy allylsilane precursor. The synthetic approach demonstrated here would be useful in the enantioselective and diastereoselective total synthesis of natural labdane diterpenoids in general.     

A new phenolic lactone from the bark of Phellodendron chinense

A new phenolic lactone,named phellolactone(1) was isolated from the bark ofPhellodendron chinense Schneid and its structure was elucidated by means of extensively spectroscopic methods,including IR,UV,HRESI-MS and NMR techniques.     

β-DDB及其衍生物的结构与红外光谱特征

总结归属了肉豆寇醚酸甲酯、6－Br肉豆寇醚酸甲酯、β-DDB（6,6′－二甲氧基－4,5,4′,5′－二次甲二氧基－2,2′－二甲氧羰基联苯）及其5种衍生物的主要红外吸收谱带和特征,讨论了其红外吸收频率随化合物结构变化的规律。 结果表明分子中酯基的改变主要对羰基的伸缩振动频率有较大的影响,而对苯环的骨架振动影响较小;当苯环上H原子被其他取代基取代时,羟基及苯环的骨架吸收均发生显著变化。