SYNTHESIS AND CHARACTERIZATION OF AN ORDERED LADDER POLYESTER

An ordered ladder polyester （LPE） was first synthesized through the ladder superstructure （LS） constructed by concerted interactions of hydroxyl- and aramide-based H-bonding and p-terphenyl （TP）-based π-stacking by dehydrochlorination condensation using phosgene （COCl2） as coupling agent. LPE was characterized by GPC, FTIR, NMR, XRD, DSC and AFM. Among them, a distinct image of regularly linear alignment corresponding to the ladder main chain of LPE was first revealed by high-resolution AFM.     

A STUDY OF ACYLATION OF AN ENAMINE AND A NOVEL SYNTHESIS OF 4-PYRONES

The acylation of 3-pentanone enamine was studied and a novelformation of 4-pyrones from β-diketone enol esters was found involvingan intramolecular O- to C-acyl shift followed by cyclization.     

SYNTHESIS AND SPECTROSCOPIC PROPERTIES OF AN AMINO ACID MODIFIED PHTHALOCYANINE

ＳＹＮＴＨＥＳＩＳＡＮＤＳＰＥＣＴＲＯＳＣＯＰＩＣＰＲＯＰＥＲＴＩＥＳＯＦＡＮＡＭＩＮＯＡＣＩＤＭＯＤＩＦＩＥＤＰＨＴＨＡＬＯＣＹＡＮＩＮＥ￥ＲｕｎＡｎＤＯＮＧ；ＷｏｎｇＱＩＵ；ＸｉｎＱｉＳＯＮＧ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，Ｔｓｉｎ...     

THE COKING PROPERTIES AND STATES OF AN INDUSTRIAL W-Ni USED CATALYST

PASCA, ESR and Microreactor, have been used to study the states and properties of coking deposits on catalyst. The results indicate that the C exists as three types of states on catalyst surface. The first and second types of carbon are the main reason of the catalyst deactivation, but the third type has a promoting role in n-C_7 hydrocracking reaction. The S_s-C interacts strongly with catalyst, forming metal-carbon-support interaction (MCSI).     

SYNTHESIS AND PHOTOLUMINESCENCE OF AN ANTHRACENE-CONTAINING HYPERBRANCHED POLY（ARYLENEETHYNYLENE）

A hyperbranched poly（aryleneethynylene） containing anthracene chromophore was synthesized by palladiumcatalyzed cross-coupling reaction of 2,4,6-triiodophenyl 9-anthracenylcarboxylate with 9,9-bis[4-（2-propynyloxy）phenyl]- 9H-fluorene. The structure and properties of the polymer are characterized and evaluated by NMR, IR, UV, PL and TGA analyses. The polymer is soluble in common organic solvents, possesses high thermal stability （Td 〉 330℃）, and emits a strong blue light of 465 nm in both solution and solid states.     

AN EFFICIENT AND PRACTICAL SYNTHESIS OF α-(1→3)-LINKED MANNOHEXAOSE AND MANNOOCTAOSE

α-(1→3)-Linked mannohexaose and mannooctaose as their methyl glycosides were synthesized from condensation of the corresponding α-(1→3)-linked di- (9) and tetrasaccharide donor (21) with the tetrasaccharide acceptor (23), respectively, followed by deacylation. The donor 21 and acceptor 23 were prepared readily from activation of C-1 of the tetrasaccharide 20 and deallylation of the tetrasaccharide 22, respectively. The tetrasaccharide 20 was prepared from oxidative cleavage of 1-O-p-methoxyphenyl of 19, which was obtained from coupling of 9 with 11. The tetrasaccharide 22 was obtained from condensation of the donor 13 with the acceptor 18. These disaccharides 9, 11, 13, and 18 were produced easily by simple chemical transformation using p-methoxyphenyl 3-O-allyl-α-d-mannopyranoside (1) and 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl trichloroacetimidate (6), and methyl 3-O-allyl-α-d-mannopyranoside (14) as the synthons.     

SYNTHESIS AND CHARACTERIZATION OF POLYPROPYLENE/MONTMORILLONITE NANOCOMPOSITES VIA AN in-situ POLYMERIZATION APPROACH

Polypropylene/montmorillonite (PP/MMT)nanocomposites were prepared by in-situ polymerization using aMMT/MgCl_2/TiCl_4-EB Ziegler-Natta catalyst activated by triethylaluminum(TEA). The enlarged layer spacing of MMT wasconfirmed by X-ray wide angle diffraction (WAXD), demonstrating that MMT were intercalated by the catalyst components.X-ray photoelectron spectrometry (XPS) analysis proved that TiCl_4 was mainly supported on MgCl_2 instead of on the surfaceof MMT The exfoliated structure of MMT layers in the PP matrix of PP/MMT composites was demonstrated by WAXDpatterns and transmission electron microscopy (TEM) observation. The higher glass transition temperature and higher storage modulus of the PP/MMT composites in comparison with pure PP were revealed by dynamic mechanical analysis (DMA).     

AN IMPROVED SYNTHESIS OF NIMBIDIOL

ＡＮＩＭＰＲＯＶＥＤＳＹＮＴＨＥＳＩＳＯＦＮＩＭＢＩＤＩＯＬ￥ＲｏｎｇＺＨＯＵ；ＸｉａｏＦｅｎｇＷＡＮＧ；ＹｕａｎＴＩＡＮ；ＸｉｎＦｕＰＡＮ（ＮａｔｉｏｎａｌＬａｂｏｒａｔｏｒｙｏｆＡｐｐｌｉｅｄＯｒｇａｎｉｃＣｈｅｍｉｓｔｒｙ，ＬａｎｚｈｏｕＵｎｉ...     

AN SCF-CI STUDY OF HIGHLY EXCITED VIBRATIONAL STATES OF BENT TRIATOMIC MOLECULES AND ITS APPLICATION TO O_3

A self-consistent-field—configuration interaction(SCF-CI)procedure of studying highlyexcited vibrational states of bent triatomic molecules is suggested and its application to O_3 is investigated.     

CHEMISTRY OF DENUDATINE.Ⅳ.AN UNUSUAL REARRANGEMENT BY CONTRACTION OF RING C IN DENUDATINE AND DIACETYLDENUDATINE

An unusual rearrangement by contraction of the ring C in denudatine 1 and di-acetyldenudatine 2 is presented.     

AN ESR STUDY OF ELECTROCHEMICAL REDUCTION OF NITROBENZENE

By means of a highly sensitive electrolytic cell installed in the ESR cavity, the authors investi-gated in situ the kinetic behavior of the primary electroreduction product (a radical anion) in a sol-vent mixture of water and ethanol over a wide range of pH. For the first time they observed somefurther complex kinetic behaviors of the electroreduction process of nitrobenzene. Through a study ofthe behavior of the radical anion (φ-NO_2~-.) with variations of pH, concentration of nitrobenzene(φ-NO_2) and electroreduction potential, they advanced a reaction scheme of the electroreduction ofnitrobenzene and simulated the experimental curves in order to evaluate the kinetic parameters of thereaction steps concerned.     

AN INVESTIGATION OF THE PROBLEM OF OCCURRENCE OF THE ATMOSPHERIC TURBULENCE

Using the truncated-spectrum model of Burger's-Chao Jiping equation, in which thetemperature advection is involved, we investigated the role of three parameters (Ri number, Renumber, Pr number) in occurrence of turbulence. It is shown that the turbulence may oc-cur only in the case of Ri<0.25 and Rc>2π~2. If Pr is too small (Pr = 0.7 for the atmos-phere), then the turbulence may occur only in the case of introducing interaction betweenbasic field and perturbation field or adding "viscosity" to the model. It is emphasized thatthe temperature advection plays an important role in turbulence occurrence. On the parame-ter plane (Ri, Re), the atmospheric motion states can be divided into the O-region (basicstate), the P-region (periodic state), the T-region (chaotic state), and the T-P region (cha-otic-periodic transition state). In fact, this is appropriate. Finally, the physical reason of turbu-lence occurrence is discussed.     

AN ANOMALOUS MOSSBAUER SPECTRUM OF SCHORLOMITE

The characteristics of Mossbauer spectra for a sample of schorlomite are described in this paper. There are 7 fitting doublets, three of which are considered as anomalous absorptions and their origin may come front complex electronic processes occurring in the schor]omite. It has been found that the isomer shift (IS) of Fe~(3 ) exhibits an apparent temperature effectin the mineral studied.     

AN ELECTRON MICROSCOPE STUDY OF MINERAL GROUP OF FRANCKEITE

Franckeite and cylindrite of franckite mineral group were examined in the transmission electron microscope. Selected-area electron diffraction indicated that in the structure exists a long period, belonging to an incommensurate modulation period. The incommensurate modulation in this kind of minerals results from sine undular structure sheets. The excellent correspondence between high resolution simulated computer image and observed image was obtained on the basis of the structure of franckeite and cylindrite which was put forward in this paper. First, the fact that in the structures of franckeite and cylindrite exist two kinds of structure sheets whose lattices are different has been proved by experiment, i. e. false tetragonal symmetrical galena structure sheets(t sheets)and false hexagonal SnS_2 sheets(h sheets). The two kinds of sheets are packed in order of htht…     

PREPARATION OF PERFLUOROOCTANOYL-MODIFIED POLY(VINYL-ALCOHOL)S AND THEIR ADSORPTION AT AN AIR-WATER INTERFACE

Perfluorooctanoyl modified poly(vinyl alcohol)s (FPVA) were prepared by means of substituting a small amountof hydroxyl groups on the backbone of poly(vinyl alcohol), for which the initial degree of polymerization is equal to 1750.The substitution extent, defined by the number of substituting units in a chain, for the four FPVA samples was in the range of0.5-5 perfluorooctanoyl groups per chain. The FPVA samples with the highest substitution extent still had good solubility inwater. It was shown by experimental measurement at 30.0±0.1℃ that the surface tension of the aqueous solution of thehighest substituted FPVA decreased to 16.6 mN/In at a higher concentration, e.g about 0.1 g/mL. Obviously,macromolecules of FPVA exhibit a very strong tendency to adsorb at the air-water interface, because the hydrophobicperfluorooctanoyl groups in FPVA have a very high surface activity as they are in small molecular fluorinated surfactants.The chain conformation of such a model polymer adsorbed on the air-water interface was also discussed.     

AN ALTERNATE SYNTHESIS OF 4,6-DIHYDROXYQUINAZOLINE

ＡＮＡＬＴＥＲＮＡＴＥＳＹＮＴＨＥＳＩＳＯＦ４，６－ＤＩＨＹＤＲＯＸＹＱＵＩＮＡＺＯＬＩＮＥ￥ＹｉＱａｎｇＺＨＵ；ＨｕｉＴｏｎｇＴＡＮＧ；ａｎｄＰａｎｇＺＨＡＮＧ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＰｅｎｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊ...     

AN EXPERIMENTAL STUDY ON THE FORCING OF LARGE-SCALE HEAT SOURCES AND TOPOGRAPHY ON BAROCLINIC FLOW

The experiments show that the travelling waves strongly vacillate with time due to the topographic forcing. Otherwise in the experiments with the same imposed external conditions but without topography, the baroclinic waves would travel regularly with almost no vacillation. It was found that a prominent feature in the flow with the topographic forcing is large-scale wave vacillation with a period of 127 annulus rotations, which is equivalent to approximately 26 days in the Earth's atmosphere. The experiments also show that the role of topography is to modulate the unstable baroclinic waves both in space and in time.In the second part of this paper, a series of comparative experiments is introduced to study the influences of heat sources and topography on the large-scale baroclinic background flows defined as the flow patterns determined by Ω, the angular velocity of the annulus rotation and △T, the radial temperature difference between the inner and outer walls of the annulus. The flow patterns depend     

THE FORMATION AND CRYSTAL STRUCTURE OF DIHYDRONITIDINE AND DISCUSSION OF ANTICANCER MECHANISM OF NITIDINE CATION

The paper reports the formation and crystal structure of dihydronitidine, expounds thereasons and conditions of easily formed oxynitidine, and discusses anticancer mechanism ofnitidine (cation). The crystallographic parameters of dihydronitidine are: space group P2_(1/n),a= 12.54(1), b = 9. 148(5), c = 14.748(8)A, β= 92. 12(6)°,Z =4. 4108 independent reflec-tions were collected within the range of 3°≤2θ≤54°, of which 2137 intensity data with I≥3σ(I) were used in the structural determination. The crystal structure has been refined byfull matrix least-square method to a final R of 0.050.     

CALCULATION OF THE YOUNG''''S MODULUS OF AN ADSORBED POLYMER LAYER

Polymer layers adsorbed to a surface or in a confined environment often change their mechanical properties. There is even the possibility of solidification of the confined layer. To judge the stiffness of such a layer, we used the Hertz model to calculate the Young's modulus of the polymer layer in the confinement of AFM experiments with silicon nitride tip with a radius of curvature of R≈50 nm and a glass sphere attached to the cantilever R = 5μm. Since there is no visible indentation of the layer in the AFM experiments, the layer is either penetrated very easily, or the indentation is too small to be seen in a force curve. The latter would be the case for a polymer layer with a Young's modulus above 4×108 Pa in case of an experiment with a silicon nitride tip and 4×105 Pa in case of a glass sphere.     

SYNTHESIS OF MACROPOROUSCOPOLYMER OF VCA AND DVB

1.INTRODUCTIONVinylacetate(VAc)isacommonandcheapmonomeLUsuallyitisusedtopreparelinearhomopolymerorcopolymeLHowever,becauseoftheusefulestergrouppresentinVAc,italsoat'tractsthegreatinterestsofsomescientistswhoworkintheareaoffunctionalpolymers.Recently,alotofreporthaveappearedusingVAcasamainmonomertopreparecrosslinkedpolymersII~sl.ThesereportsmainlyfocustheinterestsonthesynthesisandapplicationoftheVAccontainingcrosslinkedpolymers.Noreportshavebeenfoundtostudythekineticsofthesynthesisofc…