THE PHENOMENON OF THE FLUORESCENCE PHOTOCHEMICAL ENHANCEMENT AND ITS KINETICS

This paper reports a fluorescence enhancement phenomenon concerning the 2-p-nitro-phenyl-5-biphenyloxazole (NPBO). Although the NPBO solution gives only a weak fluores-cence, yet by introducing some nonfluorescence organic amine, e.g. tri-n-butyl amine (TBA)into this solution, the fluorcscence will be enhanced tens or hundreds times through the ir-radiation. This phenomenon is a new one, different from that as stated by other authors.According to the spectral analysis and the kinetics research, its mechanism may be prelimi-narily suggested as follows: the NPBO may absorb the photons to form a certain intermediatewith less polarity, which might react with the amine to form a stronger fluorescence substance.Such a phenomenon may be called the fluorescence photochemical enhancement (FLPCE).In addition, the rate constants of this process are also dotermined.     

STUDIES ON THE PHOTOCHEMICAL REACTION OF TERTIARY AROMATIC AMINES AND ALIPHATIC HALIDES——STRUCTURE OF THE PRODUCT AND MECHANISM OF THE REACTION

The photochemical reaction of aromatic amines in the presence of aliphatic halides and molecular oxygen were studied. There is a very obvious structural effect of amines on the photoreactions, and the purple products, formed only in the tertiary aromatic amines system, were proved to be amiuium radical salts, e. g. CH_3—(CH_3)_2Cl-by moans of UV, NMR and ESR spectroscopies electronic conductivity and chemical analysis. The purple product can oxidize the adrenaline to adrenochrome. The mechanism of the photoreaction and the oxidation were discussed.     

THE ELECTRON SPIN RESONANCE STUDY ON PRIMARY PHOTOCHEMICAL REACTION OF HEMATOPORPHYRIN DERIVATIVE

The rate of oxygen consumption and the yield of free radical anion of hematoporphyrin derivative (HPD) in aqueous solutions of HPD and pyrocatechol were measured by the probe 2,2,6,6-tetramethyl4-piperidone-1-oxyl.It has been found that both singlet oxygen and free radical mechanisms exist simultaneously in primary photochemical reactions, and there is a competition between both mechanisms. When the oxygen concentration in solutions comes down to 12-14% of the stanting level, the predominant mechanism can be changed from the singlet oxygen to the free radical.Whether HPD exists in aggregation state is very important to photosensitization mechanisms.In the presence of the aggregation state of HPD, the predominant mechanism is the free radical,and photosensitization effects of HPD are all the better.     

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.     

A THEORETICAL STUDY OF MECHANISMS IN THE PHOTOCHEMICAL REACTIONS OF FORMING XETENE AFTER THE α-EOND RUPTURE IN CYCLCHEMANONE

ab initio,SCF+CI calculations of the potential energy surfaces and barries in the various paths are presented for the chemical reactions of forming ketene after the a-bond rupture in cyclohexanone,using acetaldehyde as model.The possibilities of the various paths and thansition states of the important paths are discussed.     

THE INFLUENCE OF HEAT TREATMENT ON STRUCTURES OF THE AGGREGATED STATE OF POLYAMIDE-1010

The structural parameters of the aggregated state of polyamide (PA)-1010 annealedat various temperatures were computed by means of the desmearing intensity from SmallAngle X-ray Scattering (SAXS) measurements and by using the concept of the distance dis-tribution function. The results indicated that the structural parameters of the aggregatedstate were strongly dependent upon heat treatment conditions and the maximum valuesof the structural parameters were obtained for the samples annealed at T = 175℃. Theparticle size Z annealed at different temperature was ranged between 8.1--12.8nm, and thevalues of the distance distribution function P_(max)(Z) were obtained when Z = 4.0--6.8nm.Using one dimension electron density correlation function (1D EDCF) method long period(L) and thickness of the lamellar (d_0) were estimated and were found to increase with theincrease of the degree of crystallinity.     

USE OF ANNULAR ARTIFICIAL PUPIL IN THE DETERMINATION OF MODULATION TRANSFER FUNCTION OF THE EYE

According to Bef. [1] primary spherical aberration of the schematic eye would be com-pletely absorbed by an annular aperture when its obstruetion ratio ∈≥0.60. Consequently thecontrast sensitivity function, T_(cs), determined with the use of such an annulus, T_(cs) (A), is theMTF of the retina-brain system, T_(rh), weighted by the MTF of the annulus, T_⊙.T_(rh) thus obtain-ed can be used to determine the MTF of the eye, T_e. Annular apertures of various sizes andobstruction ratios used for the determination of T_e have been analysed. It is shown that thereare several factors other than incomplete absorption of primary spherical aberration thatwould prevent the use of annular pupil to derive T_(rb) under unrestrained conditions. This is dueto the fact that the apparent T_⊙'s of annuli used in the actual determination of T_(cs)(A) usual-ly deviate from the theoretical T_⊙'s for the passive eye to different extents. However, it isfound that the T_⊙ for annulus of o.d.=2.7 mm and ∈= 0.60 conforms more or less to thetheoretical T_⊙ and can be used to derive reasonably accurate T_e(2.7). It is also possibleto estimate T_e(>2.7) from T_e(2.7) by some empirical correction.     

THE CRYSTALLOGRAPHIC STRUCTURE OF THE PHOTOOXIDIZED PRODUCT OF HYPOCRELLIN A AND THE STUDY OF THE PHOTODYNAMIC ACTION MECHANISM

In attempting to study the phototherapeutic action and the photosensitized oxygenation mechanism, we have determined the crystal structure of the main oxidized product of hypocrellin A (HA). It was crystallized in monoclinic system with space group P2_1. The cell data are: a=10.030(3), b=8.877(3), c=15.764(5), β=104.50(2)°, Z=2. The crystal structure has been determined by direct method and refined to a final R of 0.055 based on the 1408 observed reflections with l>2.5σ(Ⅰ). The photooxidized product is composed of a heptacyclic aliphatic hydrocarbon connecting with two α-naphthoquinone derivatives as its skeletal molecule. No peroxidic linkage has been found. On the basis of the crystal structure determined, we have deduced part of the process of formation of the oxide, ⅰ. e. firstly, the peroxide was formed by photocycloaddition of oxygen molecule to Hypocrellin A, then thermodissociation took place to form a stable oxide.     

THE STUDY OF THE NON-STEADY KINETICS OF THE OXYDEHYDROGENATION OF ETHANE TO ETHYLENE OVER THE CATALYST OF Mo-V-Nb/Al_2O_3 BY THE TECHNIQUE OF TEMPERATURE PROGRAMMED TRANSIENT RESPONSE AND ELECTRIC CONDUCTIVITY

In this paper, instead of with the more expensive Fourier Transform Infrared Spectrometer(FTIR) a new technique of Temperature Programmed Transient Response(TP-TR) has been used with gas chromatography. Therefore, the TP-TR will be applied more widespreadly than ever before. With the technique of TP-TR and electric conductivity, the study is on the reaction mechanism and the adsorption behavior of the reactants and products to the present catalyst Mo-V-Nb/Al_2O_3 in the reaction from ethane through oxydehydrogenation to ethylene as the product. By Range-Kutta-Gill and Margarat methods, the kinetic parameters of the reaction elementary steps (i.e. rate constants, active energies and frequency factors) have been evaluated. The mathematical treatment coincides with the experimental results.     

THE EFFECT OF MODIFICATION OF COORDINATING GROUPS ON THE CATALYTIC BEHAVIORS OF POLYMER CATALYSTS

Several polymer-supported palladium complex catalysts containing two different coordinatinggroups were prepared and the cooperative effect of the coordinating groups on the catalytic behaviorsof polymer catalysts was studied. It was found that poly(acrylic acid-co-acrylonitrile)-Pd complex(PAA-AN-Pd) is a more active and stable catalyst for hydrogenation than both poly(acrylic acid)-Pd and poly(acrylonitrile)-Pd complexes. A marked change of catalytic behaviors of poly(N-substituted maleamic acid-co-styrene)-Pd complexes was observed in comparison with poly(maleicacid-co-styrene)-Pd complex. Acetophenone was reduced to 1-phenyl ethanol by poly(N-phenylmaleamic acid-Co-styrene)-Pd complex (N-1-Pd), but ethylbenzene was obtained using poly(maleicacid-co-styrene)-Pd complex as a catalyst. The influence of solvents, additives and N/Pd gramatomic ratio on the catalytic behaviors of the polymer complexes was investigated.     

THE COURSE OF THE POLYPEPTIDE CHAIN OF TRICHOSANTHIN MOLECULE

The course of the polypeptide chain of Trichosanthin has been determined from the electron density map at 4 resolution. The structure belongs to α+β type. It contains eight α-helices (39% of total residues) and four β-sheets (32% of total residues) which are made up of thirteen β-strands. The α-helices are relatively in the centre of the molecule and surrounded by β-sheets. This is the characteristic feature of Trichosanthin structure. This kind of structural arrangement has not been reported before. The transformation matrix and translation vector, which superpose two molecules in one asymmetric unit, were obtained. The root mean square error is 1.31 for this superposition.     

THE RESEARCHES OF GLACIER LAKE OUTBURST FLOODS OF THE YARKANT RIVER IN XINJIANG

The Jokulhlaup of the Yarkant River (Yarkant He) is usually csused by the sudden discharge of the glacier-dammed lake and the mode of the discharge is the rapid expansion of the subglacial channel. Keyajir (Kyagar) Glacier and Telamukanli Glacier are on the upper reaches of the Keleqin (Shaksgam) River, the chief birthplaces of this kind of flood. Up to the end of this century, since the global climate has become warmer, the glaciers have accordingly shrunk and become thinner, with the result that the size and dimensions of the glacier-dammed lakes and their outburst floods have diminished. All these simply reveal the mystery of the Jokulhlaups of the Yarkant River in Xinjiang.     

THE EFFECT OF HOT DRAWN ON THE PHYSICAL AGING OF ATACTIC POLYSTYRENE

The physical aging behavior of atactic polystyrene (aPS) films achievedunder different drawing conditions has been studied by optical birefringence and modulatedifferential scanning calorimeter (m.d.s.c.). The results show that on annealing at specifictemperature below glass transition temperatue (T_g), the enthalpy relaxation (△H) and T_gdecrease with increasing of birefringence (△n). On the other hand, the effect of moleculardraw ratio (MDR) is confusing: △H and T_g decrease with increasing of MDR in the earlystage of aging, but the MDR's effect become unobvious with the development of aging.It may be concluded that the ordered domain generated by the drawing below or aboveglass transition temperature will affect the development of physical aging behavior. Theviewpoint of cohesional entanglement is used to account for the above observations.     

APPLICATION OF SIMPLEX-DEVIATION-PATTERN RECOGNITION TO THE CONFIRMATION OF THE ELECTRODE REACTION MECHANISM

Three hypotheses of the electrochemical reaction mechanism of theDy(III)-ALC complex were put forward,based on the experimental results.Thenit has been confirmed by simplex-deviation-pattern reoognition that the pola-rographic wave of the Dy(III)-ALC complex was an adsorptive-complex wave.     

THE SPECTRA OF BAROTROPIC QUASIGEOSTROPHIC MODEL AND THE EVOLUTION OF DISTURBANCES

The spectra of linearized barotropic quasigeostrophic model is one of classical but not yet completelysolved problems in dynamic meteorology. This paper is devoted to a detailed investigation of this problem.It is obtained that in the case of zonal basic flow μ(y), there exist two types of spectra, the discrete andcontinuous. Each discrete spectrum (eigenvalue) gives an eigenfunction (normal mode); and the real num-bers in the interval [μ_(min), μ_(max)] are the continuous spectra; every point c ? [μ_(min), μ_(max)] gives a spectralfunction which is bounded and whose derivative is unbounded but integrable. Every disturbance can berepresented as a linear combination of two parts, ψ'(x, y, t) and ψ'(x, y, t), the former is expressed bythe discrete spectra, and the latter by the continuum. ψ'_d can be easily derived from the initial conditionby the use of the generalized "weighted orthogonality" of normal modes. It is also proved that ψ'_c as wellas its energy E'_c and mean y-direction scale l_c a     

THE PROPERTY OF PERIPHERAL INPUT OF PROJECTION NEURONS IN THE SPINAL CORD DORSAL HORN

Antidromic and orthodromic responses of the projection neurons in the dorsal horn ofthe spinal cord have been recorded by a glass microelectrode in anesthetized and paralyz-ed cats. Furthermore, the effect of cervical segment antidromic stimulation to orthodromicresponse of the projection neurons has been observed by way of conditioning-test stimulation. Among all the spinocervical tract neurons (SCT), the dorsal column postsynaptic neu-rons (DCPS) and the spinocervical tract-dorsal column postsynaptic neurons (SCT-DCPS),which were identified by cervical segment antidromic stimulation, 46% are low-thresholdmechanoreceptive (LTM) and 54% are wide-dynamic-range (WDR) neurons. Most LTMneurons can evoke the same response to both 10 times (10 T) and 50 times (50 T) the thresh-old stimulation on the peroneal nerve. Most WDR neurons to 50 T intensity stimulation arestronger than the 10 T stimulation. Under the antidromic-cervical segment conditioningstimulation, the amount of orthodromic-discharging in most WD     

THE REFINEMENT OF CRYSTAL STRUCTURE OF BALIPHOLITE

Balipholite is a new mineral discovered in China. Its space group is C cca with the lattice parameters a=13.587(6), b=20.164(10), c=5.144(1). The structure was refined to an R value of 0.047 for 949 independent reflections with (|F_0|>3σ|F_0|). Balipholite has the simailar structure as that of the carpholite group but with large cations Ba occupying the caves of the structure. It is very interesting to point out that the additional anions F and OH occupy different crystallographic positions. Formula of balipolite can he written a BaMg_2LiAl_3(Si_2O_6)_2(OH)_4F_4.     

THE PROCESS OF THE EMULSIFIER-FREE POLYMERIZATION IN THE PRESENCE OF BARIUM SULFATE POWDER

The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K_sS_sO_s-water in thepresence of Barium Sulfate(BS)powder was investigated under varied conditions within the range of BSpowder quantity,initiator concentration and reaction temperature.Experimental results showed thatthe rate of polymerization is proportional to 0.3-power of the BS quantity and 1.3-power of theinitiator concentration.There is a linear relationship of 2/3-power for the conversion and time.Aprocess for the polymerization is propose to explain the experimental results.     

THE POLYMERIZATION THERMOKINETICS OF PYRROLE IN THE PRESENCE OF IRON TRICHLORIDE

The polymerization thermokinetics of pyrrole in the presence of iron trichloride art studied by using a Calvet microcalorimoter. The apparent activation energy, the pre-exponential constant and reaction order of this reaction in the temperature range of 25.2—37℃are 34.5 KJ·mol~(-1), 10~(2.74)S~(-1) and 1 respectively. The activation free-energies of this reaction at 25.2°, 30°and 37℃are 91.8, 92.9 and 94.2 KJ·mol~(-1) respectively.