Dynamical coupling between gradients and transport in fusion plasmas

The dynamical coupling between density gradients and particle transport has been investigated using similar experimental tools in the plasma boundary of different tokamak (JET, ISTTOK) and stellarator (TJ-II) devices, showing that the size of turbulent events is minimum in the proximity of the most probable density gradient. Experimental results were found to be consistent with results from two very different models of plasma turbulence and transport. The present findings, common to several plasma devices, suggest the importance of self-regulation mechanisms between plasma transport and gradients in fusion devices.     

Microrheological consequences of attractive colloid-colloid potentials in a two-dimensional Brownian fluid

By using microrheological methods commonly employed in videomicroscopy experiments, we study the rheology of a two-dimensional computational fluid formed by Brownian disks with the aim of exploring the influence of some effective colloid-colloid attractive interactions. The model of fluid is developed by Brownian dynamics simulations without hydrodynamical interactions, and it is characterized by calculating its equation of state from the pair distribution function. Micromechanical properties, relative and intrinsic viscosity and freezing are discussed. Then, we include attractive forces such a Asakura-Oosawa depletion force or an empiric expression proposed by Grier and Hal (GH) for an anomalous electrostatic potential observed in confined and charged colloids. By using both potentials, viscosity is clearly increased, but when the GH potential is included, viscoelastic gel state is reached for intermediate values of surface concentration. Finally, we analyse the influence of the attractive potentials in the breaking-up by thermal fluctuations of linear chains formed by 2D particles, finding that the GH potential reduces the characteristical time at which the disks can be considered as disaggregated. In this work, we employ an experimental-like methodology for the study of a Brownian hard-disk fluid, providing a very useful link with experimental procedures.     

水相中磷钼酸催化三组分合成烯丙基胺

以磷钼酸作为催化剂，芳香醛、胺和三丁基烯丙基锡三组分在水作为溶剂，室温下高产率的得到相应的烯丙基胺。     

Synthesis and Crystal Structure of Chiral Spiro{1-bromo-4-hydroxy-5-N-cyclohexyl-butyrolactam-6-oxo-dirings[3.1.0]hexane-2,3′-(4′-diphenylcarbinol-5′-menthyloxy-butyrolatone)}

A novel compound of chiral spiro{1-bromo-4-hydroxy-5-N-cyclohexyl-butyro-lactam-6-oxo-dirings3.1.0hexane-2,3′-(4′-diphenylcarbinol-5′-menthyloxy-butyrolatone)} was synthesized via tandem nucleophilic substitution reaction under mild conditions=and its structure was determined by IR =1H NMR=elemental analysis and X-ray diffraction.The crystal structure of this compound is of monoclinic system=space group P21 with a=9.7356(9)=b=12.2760(12)=c=14.9577(14)=β=101.0300(10)°=Mr=680.66=Z=2=V=1754.6(3)3=Dc=1.288 g/cm3=μ(MoKα)=1.216 mm-1=F(000)=716=the final R=0.0434 and wR=0.0996.     

钯-碳/NaHCO3催化下2,4-二氯嘧啶的区域选择性脱氯反应：一种合成2-氯嘧啶的有效方法

本文报道了一种合成2-氯嘧啶的有效方法。易得原料2,4-二氯嘧啶在钯-碳/NaHCO3作用下可以区域选择性地脱除2位氯原子得到2-氯嘧啶。2-氯嘧啶可以用作多种复杂嘧啶衍生物的有效合成砌块。     

Photochemical degradation of environmentally persistent perfluorooctanoic acid （PFOA） in the presence of Fe（Ⅲ）

Environmentally persistent and bioaccumulative perfluorooctanic acid （PFOA） was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe（Ⅲ）, 80% of PFOA with initial concentration of 48μmol/L （20 mg/L） was effectively degraded and 47.8% of fluorine atoms in PFOA molecule were transformed into inorganic fluoride ion after 4 h reaction. Shorter chain perfluorocarboxylic acids bearing C3-C7 and fluoride ion were detected and identified by LC/MS and IC as the degradation products in the aqueous solution. It was proposed that complexes of PFOA with Fe（Ⅲ） initiated degradation of PFOA irradiated with 254 nm UV light.     

Micellar-enhanced photochemically induced fluorescence detection of chlorophenoxyacid herbicides. Flow injection analysis of mecoprop and 2,4-dichlorophenoxyacetic acid

In this paper, a combination of a flow injection analysis (FIA) system with micellar-enhanced photochemically induced fluorescence (MEPIF) detection is presented as a powerful alternative for the rapid and sensitive analysis of chlorophenoxyacid herbicides. These compounds do not show native fluorescence but they can be photolysed into strongly fluorescence photoproducts after direct irradiation with ultraviolet light. The use of a cationic surfactant such as cetyltrimethylammonium chloride (CTAC) provides a considerable enhancement of photochemically induced fluorescence intensity and the nature of the technique allows a possible and easy adaptation to a FIA system. In this sense, parameters related to the nature of the analytical signal (pH, irradiation times, surfactant concentration) and to the FIA manifold (injection volume, flow rate and reactor length) have been optimised. Linear calibration graphs, with three replicates for each concentration value were established in the range of 0.2-5.0 mug ml(-1) for 2,4-Dichlorophenoxyacetic acid (2,4-D) and 0.1-5.0 mug ml(-1) for Mecoprop (MCPP). The IUPAC detection limits were 73.2 and 33.5 ng ml(-1) for 2,4-D and MCPP, respectively. Satisfactory recoveries were obtained in the analysis of these herbicides in spiked waters.     

HETEROAROMATIC POLYMERS—HIGH TEMPERATURE POLYPYRROLONES DERIVED FROM 2,6-BIS(3'''',4''''-DIAMINOPHENYL)-4-BIPHENYLPYRIDINE AND VARIOUS AROMATIC DIANHYDRIDES

A new type of aromatic tetraamine containing biphenyl moiety in the side chain was synthesized via a modified Chichibabin's reaction.3-Nitro-4-acetamidoacetophenone was reacted with 4-phenyl benzaldehyde in the presence of ammonium acetate to obtain 2,6-bis(3',4'-diaminophenyl)-4-biphenyl pyridine(DPPA).A series of polypyrrolones(PPys) were prepared using tetraamine and various aromatic dianhydrides via a two-step cyclization procedure.All the PPys show excellent high temperature stabilities with the initial decomposition temperatures of 530-549℃ and residual weight ratio of 49%-80% at 750℃ in nitrogen.The polymers exhibit no apparent glass transition temperatures(T_gs)except PPy-1 (T_g=327℃),which is derived from tetraamine DPPA and 2,2-bis[4-(3',4'-dicarboxyphenoxy)-phenyl]propane dianhydride (BPADA).In addition,the polymers have acceptable mechanical properties with the tensile strength of 65-94 MPa.The PPy films show excellent hydrolysis-resistance in alkaline aqueous medium and could maintain most of the properties even after boiling in 10% aqueous sodium hydroxide solution for a week.     

Investigation of the interaction of DNA and neutral red by?uorescence spectroscopic analysis

The binding characteristics of neutral red (NR) with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition (SVD) was used to evaluate the number of spectral species in the drug-DNA binding process, and then the intrinsic binding constant of 1.6 104 in base pairs and the binding site number of 0.97 were obtained from the Scatchard plot.     

Synthesis, Structure and DFT Investigation into a Copper(II) Compound Consisting of 4,7-diphenyl-1,10-phentheanthroline

1 INTRODUCTION terested in the unique effects associated with substituents at 4- and 7-positions of the phenan- The coordination chemistry of 1,l0-phenanthroline throline ring. Thus, when phenyl groups are present, and its derivatives has captured the attention of che- the absorptivities of the CT transitions are increased mists for years. The reports on biological importance[1~4], markedly due to the extension of the dipole moment supramolecular chemistry[5], electronic spectra[6], conne…