STRUCTURAL EFFECT IN FORKED CONJUGATIVE SYSTEMS——BIFURCATION-TYPE OF FORKED POLYENIC NITRILES,CARBOXYLIC ACIDS AND ESTERS

Five homologous series of bifurcate systems of aliphatic and aromatic polyenic cyano andcarboxylic compounds have been prepared and studied. The electronic absorption spectra forthe series and the NMR chemical shifts for the methyl-, methylene- and beta-protons havebeen found to conform very well to the rule of homologous linearity. The mass spectra forthe α-cyano polyenic ester series show strong peaks for the fragments of M-COOEt but noneof M-CN, indicating that the CN group seems to be in stronger conjugation with the poly-enic chain than the COOEt group does. In all the forked series studided, a red shift in electronic spectra is brought about upon theintroduction of an electron-attractive branching group, just like the case of introducing anelectron-repelling substituent. This has been taken as an indication of the predominance of themolecular integrality over the group characteristics. By means of the method of similar triangles between a homologous line for a linearseries and that for the corres     

QUANTITATIVE EXPLANATION ON STRUCTURE-CARCINOGENIC ACTIVITY RELATIONSHIP OF AROMATIC AMINES BY DI-REGION THEORY

Di-region theory, the theory for the mechanism of carcinogenesis, has been extendedsuccessfully on the quantitative Structure-carcinogenic activity relationship (QSCAR) of 63aromatic amines. A quantitative equation for the QSCAR of aromatic amines has been estab-lished by the mechanism conception of the specialized di- functional alkylation between thenitrenium ion of the amino group and the epoxide of the aromatic ring. The agreementbetween calculation and experiment comes up to 98%. Thus, it can now express the puzzlingvariation of the carcinogenicity of aromatic amines, as a comprehensible structure-chemicalreactivity relationship.     

Oxidizing mechanism of podophyllotoxin and its derivatives by sodium persulfate

The oxidizing mechanism of podophyllotoxin and its derivatives by sodium persulfate has been studied by laser flash photolysis and pulse radiolysis. The formation and decay processes of transient species of podophyllotoxin and its derivatives have been observed, and a series of rate constants for the formation and decay of transient species have been determined. It has been found that there is a light (UV) sensitive group on the C-4 of podophyllotoxin and two light (UV) sensitive groups on the C-4 and C-4' of 4'-demethylepipodophyllotoxin.     

STUDIES ON STRUCTURE AND PHASE BEHAVIOR OF MULTICOMPONENT POLYMERS THROUGH RHEOLOGICAL TESTS

Rheological measurement has been a preferred approach to the characterization of the structure and phase behaviors for multi-component/multi-phase polymer systems, due to its sensitive response to the changes of structure for these heterogeneous polymers. In the present article, recent progresses in the studies on rheology for heterogeneous polymer systems including phase-separated polymeric blends and block copolymers are reviewed, mainly depending on the results by the authors＇ research group. By means of rheological measurements, not only some new fingerprints responsible for the evolution of morphology and structure concerning these polymer systems are obtained, also the corresponding results are significant for design and preparation of novel polymeric structural materials and functional materials.     

Solid-phase Synthesis of a Novel Kind of Hydroxylated Heterocyclic Ketene Aminals

An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.     

RESEARCH AND DEVELOPMENT OF FUEL ALCOHOL SYNTHESIS FROM SYNGAS

The research and development of catalyst preparation and catalytic technology for fuel alcohol synthesis from syngas have been conducted. The laboratory research work includes the investigation on the effects of preparation method, the composition and K2O content on the catalyst performance. The influences of reaction temperature, pressure, GHSV and feed composition on higher alcohols synthesis have also been investigated. On the basis of laboratory results, the catalysts have been further tesied in micro-pilot reactor under the industrial condition to investigate the effects of commercial preparation of catalyst, the reactor scaling up and (he use of industrial coal based syngas on the fuel alcohol ( mixture of methanol and higher alcohols ) synthesis. The catalyst stability has been tested by a 1000 h continuous operation. These provide the fundamental for further commercial plant design.     

REFINEMENT OF THE STRUCTURE OF DESPENTAPEPTIDE (B26—30) INSULIN AT 1.5 RESOLUTION

The refinement of the structure of despentapeptide (B26-20) insulin (DPI) at 1.5 Aresolution is described in the present paper. Against the X-ray diffraction data of newlygrown crystals, the restrained parameter least-squares refinement of the structure alter-nated with model-rebuilding. The original 2.4A resolution model has been thoroughlyrefined and parts of it have been eonsiderably revised. The cadmium coordination struc-ture has been well determined, and appears to be a nearly ideal octahedron. After refine-ment 84 water oxygen atoms have been included in the final model; this gives us detailedinformation for studies on the water structure in the DPI crystal. The final crystal-lographic reliability index R value was 0.144 for 5678 unique observable reflexions (F_o great-er than 1.5σ (F_o)) in the 10-1.5A range; the refined model has a root-mean-squaredeviation from standard bond lengths of 0.04A.     

A MODEL EXPERIMENT OF THE PLATE MOVEMENT

Detailed analysis of some difficult aspects has been made from modeling the platemovement. A new method of using differential density of material (instead of differentialtemperature) has been developed in the experiments. The effect of convection of mantleon the plate movement has been studied using a centrifugal technique, and a patternshowing the recurrence of the plate movement has been successfully obtained. In this paper, a criterion De=Dm is presented for the similarity of the model to thecounterpart of the original mantle. According to the criterion, what happens in the modelin a span of ten minutes suggests a process of the "original model" going on in geologi-cal time of three million years.     

THE STRUCTURAL BASIS OF THE POOR FIBRIN SPECIFICITY OF UROKINASE(Ⅰ)——KNOWLEDGE-BASED PREDICTION OF KRINGLE STRUCTURES OF UROKINASE AND ITS RELATED PROTEINS

The Kringle-1 structure of plasminogen (PGK-1), the Kringle-2 structure of tissue plasminogen activator (PAK-2) and the Kringle structure of prourokinase (UKK) has been modeled on the basis of the three-dimensional structure of Kringle-1 of prothrombin (PTK-1) at 2.8 resolution. The predicted three-dimensional structure of these Kringles shows that the binding site of PGK-1 is characterized by an apparent dipolar site, the polar parts of which are separated by a hydrophobic region. PAK-2 possesses the anionic center but has not a cationic binding center which might be provided by a guanidinium group from Arg-69 located adjacent to the Arg-71 position. UKK possesses neither the anionic binding center nor the cationic center which are probably the main reason for the poor fibrin specificity of urokinase.     

Ab initio STUDIES ON NITROXYL RADICAL MODELS OF ORGANIC FERROMAGNETS

The magnetic coupling between the unpaired spin of nitroxyl group (>N--O) and itsneighbor sp~2 carbon atom has been studied in detail by UHF/6--31G and MP4/6-31G methods.and a number of conjugate nitroxyl diradicals have also been studied by ab initio UHFmethod. A simple topological rule about the ferromagnetic coupling between two nitroxylgroups has been revealed by our calculation. Based on this rule as well as ab initio cal-culation, some nitroxyl radical models of organic ferromagnets (OFM) have been proposed,and the possible way of synthesis has also been suggested. Moreover, the ab initio UHF-crystal orbital (UHF--CO) method has been used to characterize the electronic band struc-ture of one of the models. The ab initio UHF--CO results show that this model is a verypromising candidate of OFM,     

REVERSE VARIABLE-ANGLE SYNCHRONOUS SPECTROFLUORIMETRY FOR RAPID SIMULTANEOUS DETERMINATION OF CHLOROPHYLL A AND CHLOROPHYLL B

Rapid simultaneous determination of chlorophyll a and chlorophyll b by reversevariable-angle synchronous spectrofluorimetry has been studied on a laboratory-constructedmicrocomputer-controlled versatile spectrofluorimeter.A method in estimation of scanparameters for the determination of two-component system by variable-angle synchronousspectrofluorimetry has been suggested     

STUDY ON PHOTO-INDUCED ORIENTATION OF A NOVEL PHOTO-ALIGNMENT FILM WITH SURFACE ENHANCED RAMAN SCATTERING （SERS） SPECTROSCOPY

Surface enhanced Raman scattering (SERS) spectroscopy was first utilized to study the photo-orientation behaviour of the photoreactive groups on a novel photo-alignment film surface and elucidate the generation mechanism of pretilt angle. The novel photo-alignment film was prepared by spin-coating a solution of ladderlike polysiloxane (LPS) bearing dual photoreactive group on an ITO surface and by irradiation with linear-polarized ultraviolet (LPUV) light. A Si-H terminal compound (M) containing an identical photosensitive part has been used to fabricate a model film for SERS investigation.     

NEW LABELLING SCHEME OF ROTATION-VIBRATION STATES IN A LINEAR POLYATOMIC MOLECULE-LIE ALGEBRAIC POINT OF VIEW

THE results of a study on Clebsh-Gordan coefficients of polarharmonics have been reported.A labelling scheme has beenproposed.Under the new scheme,some rotation-vibration stateof a molecule will be labelled with half-integers.This doesnot mean they have double values.By using the concept ofspace-time symmetry and the dynamical symmetry of a doublydegenerate vibration-SU(2),the rotation and vibration inmolecular spectroscopy can be treated as one thing.Bothare realization of Lie group,and can be greatly simplifiedby use of Racah-Wigner algebra,as is done in atomic,nu-clear and molecular electronic spectroscopies.     

RETENTION RULE IN THE LIQUID CHROMATOGRAPHY——SELECTION OF THE OPTIMUM ELUTION COMPOSITION OF SOME PTH AMINO ACIDS ON SILICA GEL

The minimal relative retention α' and the required relative retention α'_(min) of the pair of substances being most difficult to separate in a multicomponent mixture have been discussed on the basis of the fundametal retention equation ln k'=b_0 b_1C_B b_2ln C_B and resolution criterion. The selection principle to optimize elution composition means that selected a value must be greater than α'_(min) and that the capacity factor of last peak should be held to a minimum. A rapid method to select optimum elution composition has been established in which it is necessary to do a few experiments. An example for the 5 pairs of phenylthiohydantion amino acids (PTH-AA) using the ternary mobile phase of methanol, ether and hexane is also demonstrated in this paper. The results show that theoretical prediction is good in agreement with the experiments.     

CHARACTERIZATION OF BLEND ACRYLIC FIBER''''S STRUCTURES

The fine structures, paracrystal, porous and phase structures of blend acrylic fibers have bencharacterized using techniques based on X-ray diffraction, gas adsorption, density, electron and opticalmicroscopy, mercury penetration method and IR spectroscopic analysis. The existence of a fibril-void structure, with voids and fibrils of the order of 10~2.to 10~3A diameter has been confirmed for thewet-spun blend fibers. It was found that the blend acrylic fiber in the present work is a kind of ma-trix-fibril fiber; phase separation takes place in it. Further studies about the effects of composition andsequence distribution of copolymers on structure of the blend fibers were made; and it was discoveredthat void volume in the blend fibers largely depends on the interface area between two polymer phases,and pore size and number on the particle size and number of the dispersing phase. An appropriatestructural model about the blend fibers has been described.     

STUDY OF CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE OVER A BIDENTATE POLYMER BOUND CIS-DICARBONYLRHODIUM COMPLEX AS CATALYST

Copolymer of 2-vinylpyridine and vinylacetate coordinated with dicarbonylrhodiumused as a catalyst for carbonylation of methanol to acetic acid and anhydride has beenstudied. The structural characteristics of the copolymer ligand and complex, and the in-fluences of the reaction conditions on the carbonylation catalyzed by this polymer complexhave been investigated. In comparison with small molecule catalyst of Rh complex, thebidentate copolymer coordinated complex has better thermal stability. The reactionmechanism of the carbonylation reaction is also illustrated.     

THE STUDY OF HUMAN TRANSFER FACTOR

In this paper, the study of human transfer factor is reported. We established a negative pressure dialysis method instead of ordinary dialysis for treatment of the crude leukocyte extract. Dialysate is rapidly obtained in only 5h so that a large volume of preparation is easier to handle and the chance of contamination avoided. When humau TF was incubated With human cord blood T-lymphocytes and pig lymphocytes, a very high biological activity on SRBC rosette enhancement and an increase in electrophoresis rate appeared. It suggests that these assays may be used as in vitro method of evaluation of TF activity. In our clinic, TF has been in clinical trials for 5 years and has now been administered to a large number of patients with a variety of diseases, in which cell-mediated immune responses have been compromised. We observe that TF has served an efficient immunopotentiating or immunemodulation agent.     

RHEOLOGICAL CHARACTERIZATION OF PROCESSABILITY OF UNVULCANIZED POLYBUTADIENE

Rheological investigation on a series ot unvulcamzed polybutadiene elastomers of different processability has been carried out by means of a capillary extrusion rheometer. It is found that the processability of unvulcanized polybutadiene can be correlated with the occurrence of unsteady flow and the wall stress, dependence of the dimensionless number e characterizing the entrance elongational elasticity which has been found to be sensitive to the branching structure and the molecular weight distribution of the samples. Interpretations based on the structural data of unvulcanized polybutadiene were discussed.     

Spectroscopic Properties of Methyl Ketone Bridged Electrochromic Materials: a Quantum Chemical and Experimental Study

Tuning accurately the color of electrochromic materials has been considered as a crucial step to achieve successful electrochromic display. In this paper, the effect of substitution on the color of methyl ketone bridged electrochromic materials has been investigated systematically by experimental and TDDFT methods. By screening 15 functional and 11 basis sets, a statistical method based on M052 X data is developed to estimate the maximum absorption wavelengths(λ_(max)) of electrochromic materials, based on analyzing λ_(max) of 18 molecules. For methyl ketone bridged electrochromic materials, the color from yellow to green and λ_(max) from 400 to 690 nm can be adjusted by electron-withdrawing functional group on Ar2 and electron-donating functional group on Ar1. This work not only exhibits the suitable method to predict the maximum absorption wavelength and color of electrochromic materials, but also inspires and accelerates further development of electrochromic materials for future displays.     

INDUCTION—POLYMERIZATION OF PREPARING POLYMERS OF REGULAR STRUCTURE

Induction-Polymerization is a novel method for preparing polymers of regular structure. In the presence of a special macromolecular compound, monomer molecules are aggregeted regularly around one or more growth points and polymerized to polymer of regular structure. Regularity of structure of the polyacrylamide prepared by this means has been verified with electron diffractograms, DSC curve and IR spectrum of the polymer.