Contributions of qqqq(q)over-bar Components to Axial Charges of Proton and N(1440)

The axial charges of the proton and N(1440) are studied in the framework of an extended constituent quark model (CQM) including qqqq (q) over bar components. The cancellation between the contributions of qqq components and qqqq (q) over bar components gives a natural explanation to the experimental value of the proton axial charge, which can not be well reproduced in the traditional CQM even after the SU (6) circle times O(3) symmetry breaking is taken into account. The experimental value of axial charge pins down the proportion of the qqqq (q) over bar component in the proton to about 20%, which is consistent with the ones given by the strong decay widths and helicity amplitudes. Besides, an axial charge for N(1440) about 1 is predicted with 30% qqqq (q) over bar component, which is obtained by the strong and electromagnetic decays.

Alternating copolymerization of carbon dioxide and propylene oxide by single-component cobalt salen complexes with various axial group

A series of single-component cobalt salen complexes, N,N'-bis(salicylidene)-1,2phenylenediamino cobaltIII X(X = Cl (1a), Br (1b), NO3 (1c), CF3COO (1d), BF4 (le), and N3 (If)) (SalphCoX), were prepared for alternating copolymerization of carbon dioxide and propylene oxide(PO) under mild condition. The axial anion X group of the SalenphCoX played important role in tailoring the catalytic activity, polymeric/cyclic carbonate selectivity, as well as stereochemistry of carbonate unit sequence in the polymer chain. SalenphCoX with an electron-withdrawing axial X group (complex 1c) was an ideal catalyst for the copolymerization of CO2 and PO to selectively produce polycarbonate with similar to 99% carbonate linkage and over 81% head-to-tail structure.

Comparison of wavelet transform methods - The compression of IR spectral data

In this paper, an introduction of wavelet transform and multi-resolution analysis is presented. We describe three data compression methods based on wavelet transform for spectral information,and by using the multi-resolution analysis, we compressed spectral data by Daubechies's compactly supported orthogonal wavelet and orthogonal cubic B-splines wavelet, Using orthogonal cubic B-splines wavelet and coefficients of sharpening signal are set to zero, only very few large coefficients are stored, and a favourable data compression can be achieved.

Axial coordination effects of pyridine on the electrochemistry of (TPP)Co in 1,2-dichloroethane solution

The electrochemistry of (TPP)Co in the presence of pyridine was investigated in dichloroethane solution by cyclic voltammetry. With the addition of pyridine to the solution, the reduction peaks of the axial complex compounds, (TPP)Co(III)(Py) and (TPP)Co(III)(Py)(2) were observed. It was found that the reduction peak of Co(II)/Co(I) shifted to about -1.20V (SCE) with the increase of added pyridine. The new reduction peak may be attributed to the direct reduction of the axially complex (TPP)Co(II)(Py).

Effect of F- axial coordination on the electrochemistry of (TPP)Co

The axial coordination effect of F- on the redox behavior of (TPP)Co was investigated and spectroeletrochemistry in dichloroethane. It was verified that mono(F-) axial adduct (TPP)Co(II)(F-) could be reduced at 0.1 V(SCE). and bis(F-) axis adduct (TPP)Co(II)(F-)(2) formed with added F- molar ratio>1 could be reduced at the potential <-0.6 V(SCE). The equilibrium between (TPP)Co(II)(F-) and (TPP)Co(II)(F-)(2) was demonstrated.

Studies on porphyrin and phthalocyanine monolayers by means of compression-recompression isotherms and BAM

Monolayers of porphyrin and phthalocyanine at the air-water interface were studied by means of film balance and Brewster angle microscopy (BAM). Results showed that the final point of compression isotherm and that of recompression isotherm were coincident or not coincident depending on the target pressures. Results were discussed in terms of the morphology of monolayers observed by BAM.

Axial growth of hexactinellid spicules: Formation of cone-like structural units in the giant basal spicules of the hexactinellid Monorhaphis

The glass sponge Monorhaphis chuni (Porifera: Hexactinellida) forms the largest bio-silica structures on Earth; their giant basal spicules reach sizes of up to 3 m and diameters of 8.5 mm. Previously, it had been shown that the thickness growth proceeds by appositional layering of individual lamellae; however, the mechanism for the longitudinal growth remained unstudied. Now we show, that the surface of the spicules have towards the tip serrated relief structures that are consistent in size and form with the protrusions on the surface of the spicules. These protrusions fit into the collagen net that surrounds the spicules. The widths of the individual lamellae do not show a pronounced size tendency. The apical elongation of the spicule proceeds by piling up cone-like structural units formed from silica. As a support of the assumption that in the extracellular space silicatein(-like) molecules exist that associate with the external surface of the respective spicule immunogold electron microscopic analyses were performed. With the primmorph system from Suberites domuncula we show that silicatein(-like) molecules assemble as string- and net-like arrangements around the spicules. At their tips the silicatein(-like) molecules are initially stacked and at a later stay also organized into net-like structures. Silicatein(-like) molecules have been extracted from the giant basal spicule of Monorhaphis. Applying the SDS-PAGE technique it could be shown that silicatein molecules associate to dimers and trimers. Higher complexes (filaments) are formed from silicatein(-like) molecules, as can be visualized by electron microscopy (SEM). In the presence of ortho-silicate these filaments become covered with 30-60 nm long small rod-like/cuboid particles of silica. From these data we conclude that the apical elongation of the spicules of Monorhaphis proceeds by piling up cone-like silica structural units, whose synthesis is mediated by silicatein(-like) molecules. (C) 2008 Elsevier Inc. All rights reserved.

填土边坡水文作用机理与破坏过程研究—以深圳羊宝地填土滑坡为例

A full understanding of failure mechanism, critical hydrological condition, and process of mobilization and deposition of a landslide is essential for optimal design of stabilization measure and forecasting of landslide hazard. This requires a quantitative study of hydrological response of a slope to rainfall through field monitoring, laboratory test and numerical modelling. At 13:40 on September 18, 2002, a fill slope failed following a period of prolonged rain in Shenzhen, resulting in 5 fatalities and 31 injuries. The failed mass with a volume about 2.5×104m3 traveled about 140m on level ground. Field monitoring, laboratory test, theoretical analysis and numerical modelling were carried out to undestand the hydrological response and failure mechanism of this fill slope. This thesis mainly focuses on the following aspects: (1) The hydrological responses and failure processes of slopes under rainfall infiltration were reviewed. Firstly, the factors influencing on the hydrological responses of slopes were analysed. Secondly, the change of stress state of slope soil and modelling methods of slope failure under rainfall infiltration were reviewed. (2) The characteristics of the Yangbaodi landslide and associated rainfall triggering the failure were presented. The failure was characterized by shallow flowslide, due to an increase of ground water table caused by rainfall infiltration. (3) A fully automated instrumentation was carried out to monitor rainfall, and saturated – unsaturated hydrological response of the fill slope, using a raingauge, piezometers, tensiometers and moisture probes. A conceptual hydrogeological model was presented based on field monitoring and borehole data. Analysis of monitoring data showed that the high pore water pressure in fill slope was caused by upward flow of semiconfined groundwater in the moderately decomposed granite. (4) Laboratory and in-situ testing was performed to study the physical and mechanical properties of fills. Isotropically consolidated undrained compression tests and anisotropically consolidated constant shear stress tests were carried out to understand the failure mechanism of the fill slope. It is indicated that loosely compacted soil is of strain-softening behaviour under undrained conditions, accompanied with a rapid increase in excess pore water pressure. In anisotropically consolidated constant shear stress tests, a very small axial strain was required to induce the failure and the excess pore water pressure increased quickly at failure. This indicated that static liquefaction caused by rise in groundwater table due to rainfall infiltration occurred. (5) The hydraulic conductivity of the highly and moderately decomposed granite was estimated using monitering data of pore water pressure. A saturated – unsaturated flow was modeled to study the hydrological response of the fill slope using rainfall records. It was observed that the lagged failure was due to the geological conditions and the discrepancy of hydraulic conductivity of slope soils. The hydraulic conductivity of moderately decomposed granite is relatively higher than the other materials, resulting in a semiconfied groundwater flow in the moderately decomposed granite, and subsequent upward flow into the upper fill layer. When the ground water table in the fill layer was increased to the critical state, the fill slope failed. (6) Numerical exercises were conducted to replay the failure process of the fill slope, based on field monitoring, laboratory and in-situ testing. It was found that the fill slope was mobilized by a rapid transfer of the concentrated shear stress. The movement of failure mass was characterized by viscosity fluid with a gradual increase in velocity. The failure process, including mobilization and subsequent movement and deposition, was studied using numerical methods.