Synthesis and crystal structure of tetranuclear zinc benzoate

A tetranuclear zinc benzoate Zr4O(C6H5CO2)6 was synthesized and characterized by X-ray single crystal determination. It crystallizes in cubic, space group Ia-3d. Its crystal cell is very large, α=4.10063(18)nm, V=68.953(5)nm^3 and Z=48. The structure is composed of discrete Zr4O(C6H5CO2)6 molecules. In each molecule, four zinc atoms are held together by a central oxygen atom, which results in the formation of a regular tetrahedron. All benzoate ligands coordinate to zinc atoms in a bidentate bridging mode. Each zinc atom is in a slightly distorted tetrahedral geometry, coordinated by three benzoate oxygen atoms and the central oxygen atom. The intermolecular interactions result in the formation of a three-dimensional supramolecular framework, with non-intersecting parallel channels.     

A Novel Degradation Pathway of Zn（dmid） （ phen）2 in Pyridine

The light-oxidation degradation processes of Zn(dmid)(phen)2(dmid = 4, 5-dimercapto-1,3-dithiole-2 one, phen = 1,10-phenanthroaline) in pyridine solvent has been monitored, h has been found under the light, dmid^2- of Zn(dmid)(phen)2 in pyridine solution could generate NCS^- and NCS^-replaces dmid^2- to form Zn(NCS)2 (phen)2 simultaneously. The crystal structure of Zn(NCS)2 (phen)2 has been determined. In the crystal of Zn(NCS)2 (phen)2. two NCS^- ligands are arranged in syn-configuration, and there is strong π-π interaction between the two adjacent parallel phen.     

Low-heating solid state synthetic reactions of cyclopeantadienyl organolanthanide complexes

A novel and simple one-step,solid state reaction of multicomponent systems has been developed to synthesize cyclopentadienyl-containing organolanthanide complexes,in which the effects of the coordinated solvent molecules and the nature of the reactants were also studied.We also studied the solid state decomposition reaction of Cp2 YbPz(HPz),and the formation of [CpYb(Pz)2|2 may indicate that the constrained environment in solid state can lead to a novel chemical transformation,with product selectivity possibly different from that in the liquid phase.     

Mining Protein Complexes from PPI Networks Using the Minimum Vertex Cut

Evidence shows that biological systems are composed of separable functional modules. Identifying protein complexes is essential for understanding the principles of cellular functions. Many methods have been proposed to mine protein complexes from protein-protein interaction networks. However, the performances of these algorithms are not good enough since the protein-protein interactions detected from experiments are not complete and have noise. This paper presents an analysis of the topological properties of protein complexes to show that although proteins from the same complex are more highly connected than proteins from different complexes, many protein complexes are not very dense (density 0.8). A method is then given to mine protein complexes that are relatively dense (density 0.4). In the first step, a topology property is used to identify proteins that are probably in a same complex. Then, a possible boundary is calculated based on a minimum vertex cut for the protein complex. The final complex is formed by the proteins within the boundary. The method is validated on a yeast protein-protein interaction network. The results show that this method has better performance in terms of sensitivity and specificity compared with other methods. The functional consistency is also good.     

Multimedia Data Coding and its Development

The requirements of data coding in multimedia applications are presented, the current technique of coding and relative standards is introduced, then the work that have been doing is presented, i.e. the wavelet-based coding method and the VE (Visual Entropy)-based coding method. The experiment results prove that these methods have gained a better perceptual quality of a reconstructed image and a lower bit rate. Their performance evaluations are better than JPEG (Joint Photographic Experts Group) coding. Finally, the future topics of study are put forward.     

A Novel Method to SynthesizeP-phenylene-2,2＇ -bis （ 5-aminobenzoxazole ）

P-phenylene-2,2‘-bis(5-aminobenzoxazole) is synthesized by the condensation of 2,4-diaminophenol dihydrochloride and terephthalic acid with high yield of 98% in polyphosphoric acid through adding reductive agent SnC12 to suppress the oxidation of 2,4-diaminophenol dihydrochloride. The structure of the compound is characterized by using melting point, FT-IR,^1H NMR, and element analysis.     

Molecular complex 9,10-anthraquinone-(NO x ) y

9,10-Anthraquinone forms a series of molecular complexes with NO and NO 2,which are stable in solid state or in organic solutions at room temperature and will decompose to original anthraquinone and NO/NO 2 upon heating.The molecular complexes are formed via charge transfer,which is confirmed by a high-resolution mass spectroscopy.By means of reduction,the complexes can be converted to anthrahydroquinone.The mechanism of formation is investigated herein.     

Progress in magnetic couple system of nitroxidemetal complexes

Metal_radical method is an effective approach to synthesizing magnetic molecular materials. With the development in decades, the study of nitroxide_metal complexes has made great progress in model, theoretical treatment and design of molecules. Several mechanisms of the metal_radical magnetic coupling are discussed. Molecular magnetic project of nitroxide_metal complexes has made fruitful achievements, but crystal magnetic project is difficult to be controlled, and it is a challenge to chemists. The studies on nitronyl nitroxide_metal complexes are summarized. At present, there are three major approaches to increasing the T c of the metal_radical compounds: (ⅰ) Searching for nitronyl nitroxide ligands that can yield 3_D ferro_ or ferrimagnetic structures; (ⅱ) decorating the structure of radicals with the aim to enhance the coordinate capability of radicals; (ⅲ) grafting polynitroxide radicals as a versatile bridge. The third approach, namely searching for polynitroxide ligand, will serve as a hopeful strategy for exploring higher T c radical molecule_based magnets.     

Research progress in synthesis and catalysis of polyoxometalates

Recent progress in the synthetic chemistry and catalysis of polyoxometalates (POMs) is reviewed. The novel POMs and their derivatives emerging in nearly three years (2002—2004) are introduced, including POMs with novel structure, POMs-organic hybrid compounds and host-guest complexes. Our review is focused on the elaboration of POMs' supramolecular chemistry.     

Treatment of Wastewater Containing Polyacrylamide Using Three Dimensional Electrodes

A method using three-dimensional electrode is applied to treat wastewater in oil fields, which contains polyacrylamide (PAM), for analogue. A best condition for electrolysis (I=1.0 A, t=90 min, c=0.1%, m=980 g,φ =5 mm, d=5.0 cm) has been determined, under which the COD removal efficiency reached 96.0%, COD containing in wastewater reduced to 64.3 mg/L from 1 622.9 mg/L, the figure before treatment. Three categories of PAM-containing wastewater in production practice have been treated with the COD removal ratios being 87.5%, 82.4% and 84.7% respectively. Presence of H_2O_2 and·OH are detected by means of Ti(Ⅳ)-5-Br-PADAP technique and colorimetry respectively. The concentration is positively proportional to the COD removal ratio and increases in accordance with increment of time of electrolysis and current.     

Structure and internal stress of Au films deposited on SiO2/Si(100) and mica by dc sputtering

Au films with a thickness of about 300 nm were deposited on SiO₂/Si(100) and mica substrates by dc sputtering. X-ray diffraction spectroscopy and field emission scanning electron microscopy were used to analyze the structure and internal stress of the Au films. The films grown on SiO₂/Si(100) show a preferential orientation of [111] in the growth direction. However the films grown on mica have mixture crystalline orientations of [111], [200], [220] and [311] in the growth direction and the orientations of [200] and [311] are slightly more than those of [111] and [220]. An internal stress in the films grown on SiO₂/Si(100) is tensile. For Au films grown on mica the internal stresses in the [111]- and [311]-orientation grains are compressive while those in the [200]- and [220]-orientation grains are tensile. Au films grown SiOJSi(100) have some very large grains with a size of about 400 nm and have a wider grain size distribution compared with those grown on mica.     

Estimating the Willingness-to-Pay for Urban Housing in Chinese Cities

The housing market, an important component of the urban economy, is closely integrated with urban development. Urban development attracts labor inflows which then increase the housing demand in the cities. Urban dwellers’ willingness-to-pay (WTP) for housing, as part of their living costs, depends on their incomes they can earn in the cities and the quality of life (QOL) they want to enjoy. Urban wage growth and quality of life improvements are always accompanied by increased demand and increased WTP. This ...     

Behavior of Non-metallic Inclusions in Centrifugal Induction Electroslag Castings

In order to know the behavior of non-metallic inclusions in centrifugal induction electroslag castings (CIESC), non-metallic inclusions in 5CrMnMo and 4Cr5MoSiV1 were qualitatively and quantitatively analyzed. The largest size of inclusions in the casting and the thermodynamic possibility of TiN precipitation in steel were also calculated. The results show that sulfide inclusions are evenly distributed and the content is low. The amount of oxide inclusions in CIESC: 4Cr5MoSiV1 steel is close to the ESR steel and lower than that in the EAF steel, and there are some differences along radial direction. Nitride inclusions are fine and the diameter of the largest one is 3-4 μm. With the increase of the centrifugal machine's rotational speed, the ratio of round inclusions increases and the ratio of sharp inclusions decreases. According to the experiment and the calculation results, it is pointed out that the largest diameter of non-metallic inclusions in the CIESC 4Cr5MoSiV1 casting is only 6.6 mum, and [N%][Ti%] in 4Cr5MoSiV1 steel should be controlled less than 4.4×10-5 in order to further reduce the amount and size of TiN inclusions.     

Bridging of Calixarenes with N, N＇-Bis（Chloroacetyl） Propylenediamine

A new bridging reagent, N, N‘-bis (chloroacetyl) propylenediamine was used to explore the relativeactivity and bridging pattern of p-ten-bury lcalix [4] arene, p-tert-butylcalix [6] arene and butylcalix [8] arene. It wasfound that the bridging reaction is selectively, at least, preferably at 1, 3-position for p-tert-butylcalix [4] arene and p-tert-butylcalix [6] arene, 1,5-position for p-tert-butylcalix [8] arene. Taking the yield of bridged calixarene as a compar-sion standard, the activity decreases with the increasing of the number of phenolic units in calixarene.     

Evaluation of the Photo-Protection of Eye-Patch Protectors Used in Phototherapy

An evaluation method for the practical photo-protection of eye-patch protectors (EPs) used in phototherapy for neonatal jaundice is developed.The protecting condition of neonatal eyes using EPs under typical phototherapy light is simulated.The simulation system consists of a neonatal head manikin,an International Light ILT 900 wideband rapid portable spectroradiometer,a standard Air Shields Isolette incubator,and a Medela fluorescent phototherapy unit.The results show that the practical protection of neonatal eyes,provided by EPs which are affected by the material characteristic,shape design,and wearing condition,is comprehensively illustrated using the indices of illuminance (Ev in lux unit) and the spectral irradiance (E in μW/(cm2·nm) unit).     

Propagation Characteristics of Surface Acoustic Waves on LGT and Quartz Substrates

Langatate （LGT） is a novel piezoelectric crystal; its structure is similar to quartz. A numerical analysis of the most important propagation characteristics of surface acoustic waves （ SAW） on LGT and quartz is presented in this paper. The results show that the phase velocity on LGT is slower than that on quartz. Similar to quartz. there are zero temperature cuts and pure module orientations on LGT. The electro-mechanical coupling constant （k2 ） of LGT is larger than that of quartz. The characteristics of SAW on LGT with different material constants are calculated and compared. The results show that there are somewhat deviations with different material constants. Especially. the temperature coefficient of frequency （ TCF） shows a relatively high difference.     

An electrochemical method for evaluating the resistance to cathodic disbondment of anti-corrosion coatings on buried pipelines

Methods for evaluating the resistance to cathodic disbondment (RCD) of anti-corrosion coatings on buried pipelines were reviewed. It is obvious that these traditional cathodic disbondment tests (CDT) have some disadvantages and the evaluated results are only simple figures and always rely on the subjective experience of the operator. A new electrochemical method for evaluating the RCD of coatings, that is, the potentiostatic evaluation method (PEM), was developed and studied. During potentiostatic anodic polarization testing, the changes of stable polarization current of specimens before and after cathodic disbonding (CD) were measured, and the degree of cathodic disbondment of the coating was quantitatively evaluated, among which the equivalent cathodic disbonded distance △D was suggested as a parameter for evaluating the RCD. A series of testing parameters of the PEM were determined in these experiments.     

Review on aggregation of acid extractants in solvent extraction of metal ions: remark on the general model

The aggregation behavior of various acid extractants in the solvent extraction systems of metal ions is re-examined and explained according to knowledge obtained in recent work. The conclusions are as follows. (1) Complexes formed by the extractants and metal ions can form reversed micelles in organic diluents, depending on the microstructures of the complexes. The dimers of the acid extractant cannot percolate to the metal-extractant aggregates, and the acid-salt complexes are always formed in the aggregates. The reversed micelles or the W/O microemulsions formed by different species cannot be associated with each other to form a unified aggregate. (2) In solvent extraction systems, hydration of the extractants and metal ions can be considered as the driving force of forming reversed micelles. (3) Information of the first approach to the insight of the bicontinuous microemulsion of NaDEHP shows that various components in the aqueous phase behave confined and very similar to the typical AOT/n-heptane W/O microemulsions. (4) In the extraction of lanthanide ions by the W/O microemulsion of sodium naphthenate, the saponification is a process of forming reversed micelle or W/O microemulsion, while the extraction step is a process of destroying reversed micelles or W/O microemulsion droplets.     

Coordination polymer based on （1,2-bis（2-picolinamido） phenyl）copper

( 1,2-bis(2-pyridinecarboxamido)benzene copper Cu(bpb) was synthesized and employed as a building block to construct supramolecular coordination polymer based on intermolecular coordination and hydrogen bonding interactions. X-ray single-crystal diffraction characterization revealed that intermolecular coordination interactions lead to the formation of one-dimensional infinite molecular columns, which array along the same direction in the crystal resulting in the three-dimensional network. The molecular columns are linked together by hydrogen-bonding interactions, which infinitely extend in bc plane. The one-dimensional coordination bonding and two-dimensional hydrogen-bonding interactions result in the formation of supramolecular coordination polymer.