Studies on New Additions to 5-Methoxy-2 (5H)-Furanone: 1, 4-Addition of Grignard Reagents, and 1,3-Dipolar Cycloaddition of Silyl Nitronates

1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.

Theoretical Studies on the Mechanism of Mannich Reaction Involving Iminium Salt as Potential Mannich Reagent(1)--Use Acetaldehyde as Pseudo-acid Component

This paper is one of a series of reports of theoretical researches on the mechanism of the Mannich reaction using the iminium salt as the potential Mannich reagent. According to the results of AM1 dynamic calculations, the activation energies of key steps in conventional Mannich reactions between ammonia, formaldehyde and acetaldehyde in neutral and acidic media are 438 8 kJ/mol and 393 9 kJ/mol respectively. The activation energy of the rate controlling step of the Mannich reaction which contains the potential Mannich reagent is 274 7 kJ/mol. Therefore, it can be derived that the potential Mannich reagent can increase the rate of the reaction remarkably. The reasons for this have been discussed in terms of the orbital match and electrostatic interaction between the atoms of reactant complexes. In this paper another different conjectured mechanism of the potential Mannich reagent which can reduce the activation energy is considerably studied.

A Novel Palladium-Catalyzed Reaction and Its Application in Preparation of Derivatives of Stilbazols

A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it was found that reaction solvent is one of important factors in this catalytic system.

Pharmacological Study on Antitumor Activity of 5-Fluorouracil-1-Acetic Acid and Its Rare Earth Complexes

The antitumor activity of 5 fluorouracil 1 acetic acid(HFAA) and its lanthanide complexes(La(FAA) 3, Eu(FAA) 3) were studied. The results show that HFAA, La(FAA) 3 and Eu(FAA) 3 with the concentrations of 1 0×10 -5 ～1 0×10 -2 μg·ml -1 inhibit the colony formation of leukemia cells(L 1210 ) and the growth of transplanted tumor sarcoma 180(S 180 ), hepatic carcinoma(HEPA) and ehrlich ascites tumor(EC) as well. The maximum inhibitory rate of Eu(FAA) 3 for S 180 is 38 4%, that HFAA and La(FAA) 3 for EC are 22 4% and 43 4%, respectively. The life prolongation rate of Eu(FAA) 3 for HEPA bearing mice is as long as 284%.

Effect of Temperature Variation on the Separation of Sesamin and Sesamolin by Simulated Moving Bed

In this work, sesamin and sesamolin is separated and purified by SMB （simulated moving bed） chromatography. Purity of sesamin and sesamolin can reach 99.2% and 99.9 %, and they can be recovered by 99.9% and 99.4%, respectively. Concentrations of the extract and raffinate was monitored and periodical change of the concentration was observed on experiment. Effects of non-linear adsorption, dead volume, and temperature on the separation are reviewed by the triangle theory to explain the periodical change of concentration. It is found that dead volume has little effect, and temperature fluctuation significantly affects thc separation by SMB. The temperature seriously affects the robust operation of SMB due to the change of Henry＇s constant, which will change the selectivity and restrain the productivity. Although the productivity in this study is only 0.0416 g/L-hr, the cost of the stationary phase used in this study is much lower than that of packed in analytical column. By using this stationary phase, the authors are still able to separate the mixture of sesamin and sesmolin. This will economically attract attention for the application of SMB to purify bioactive compounds on developing botanical drugs.

THE ESTIMATION OF THE DENSE PHASE VOIDAGE OF A GAS FLUIDIZED BED

Dense phase voidage can be estimated by cutting gas flow and following the rate of bed collapse. Abrupt cessation of flow is not possible when excess gas in the windbox can only discharge through the bed. The magnitude of this problem is examined experimentally.

THE PARTICLE VELOCITY DISTRIBUTION IN A RISER OF DILUTE CIRCULATING FLUIDIZED BED

This paper presents an experimental study on the radial and axial profiles of local particle velocity of flu-idized catalyst(FCC)particles in a circulating fluidized bed of 8000mm in height and 186mm in inside diameterwith a Fiber-Optic Probe Laser Doppler Velocimetry.It has been found that the radial profiles of local particlevelocity are parabolic,even in the centre region and steep in the region near the bed wall,and that the length ofparticle acceleration along the bed height is longer than expected.The following formula has been recommended to correlate the 1 ocal particle velocity with dilute gas-solidflow in the bed:where a,b,c and e are functions of radial positions.

THE EFFECT OF LIQUID PHYSICAL PROPERTIES ON DRIFT VELOCITY

Drift velocity is a very important paramcter for predictirg the pool volumetric void fraction. Two-phase system of gas and high viscous liquids pool is encountered in various engineering applications. A review of the literature shows no data for explaining the effect of highly viscous liquids on the drift velocity. This paper’s analysis shows that there is a considerable influence. It is shown that the foaming behaviour of liquids is dependent on the surface properties. For some highly viscous liquids at a given superficial gas velocity, the viscosity changes with time. The effect of "foam" and "time" on drift velocity is clearly elucidated.

EXTENSION OF SOAVE EQUATION OF STATE TO LIQUID DENSITY

On the basis of vapor pressures, volumes of saturated vapor and liquid, both parameters "a" and "b" in Soave equation of state are treated as temperature dependent and an extended Soave equation is proposed in this work. The VLE for 38 pure components including polar substances have been calculated. The comparison of calculated results with experimental data shows the prediction of liquid density is improved over Soave equation without losing the accuracy of prediction in vapor pressure and vapor density.

PREPAKATION OF THERMALLY REVERSIBLE HYDROGELS AND THEIR USE FOR THE IMMOBILIZATION OF CHYMOTRYPSIN

A series of hydrogels with lower critical solution temperature (LCST) were prepared and used for the immobilization of chymotrypsin. The activities of the immobilized enzyme decrease when the temperatures are raised above their LCST and recover below their LCST. This property is reversible.

CRYSTAL STRUCTURE OF DI - NITRATOBIS(ETHYLCAPROLACTAM)URANYL(Ⅱ) UO_2[CH_2(CH_2)_4CONC_2H_5]_2(NO_3)_2

The crystal structure of Di-nitratobis(ethylcaprolactam)uranyl(Ⅱ) UO_2[CH_2(CH_2)_4CONC_2H_5]_2(NO_3)_2 was established by a single-crystal X-ray diffraction study.It is triclinie, space group P1, with a=7.171(2), b=8.655(3), c=10.182(5)A, α=78.27(3), β=70.63(3), γ=81.76(3)°, V=581.7(4)A^3, Z=l, Dc=1.94 g.cm^(-3).Final R value is 0.0218.The result reveals that uranyl ion is coordinated to six oxygen atoms, two of them are from two carbonyl groups of ethylcaprolactam and the other four are from two nitrate groups.

Adsorption of Cd（II） on Zn-AI LDHs （Layered Double Hydroxides） Intercalated with Chelating Agents EDTA

The hydrotalcite-like compound [Zn2AI（OH）6]NO3-mH20 （shorted as ZnAI-NO3） was intercalated with the chelating agent EDTA （ethylene diamine tetraacetic acid） by anion exchange to uptake cadmium ion from aqueous solutions. The materials synthesized in this work were characterized by chemical analysis, FT-IR （fourier transform infrared spectroscopy）, XRD （X-ray powder diffraction） to confirm their properties. In order to investigate the optimum conditions for Cd（II） adsorption, the amount of Cd（ll） adsorbed by Zn-AI LDHs intercalated with EDTA （ZnAI-EDTA） under different conditions （i.e., adsorbent dosage, temperature and contact time） were determined by ICP-AES （inductively coupled plasma-atomic emission spectrometry）. Adsorption isotherms of Cd（II） onto ZnA1-EDTA were measured at varying initial Cd concentrations （0.05 mg/L to 1 mg/L） under optimized conditions. The data were applied to Langmuir and Freundlich isotherms model, and well fitted by the Freundlich isotherms model. The pseudo-second-order kinetic model was more adequate to describe the kinetic in this case.

CRYSTAL STRUCTURE OF DI-CHLORO-BIS-(P-METHYLPHENYLBUTYLSULFIDE) PALLADIUM(Ⅱ)

The title complex was obtained by repeatly extracting the 0.1 mol/L HCI solution of PdCl2 with the petroleum ether in which p-CH3C6H4SC4H9 was previously dissolved at room temperature. The resulting precipitate, after washed With deionized water and petroleum ether respectively,

SYNTHESIS OF 1H，1＇H BIS（BENZ－△~4－IMIDAZOLINE）2，2＇－SPIRO－TITANIUM DICHLORIDE

New model compound 1H, 1' H-Bis (benz-△￣4-imidazoline) 2,2'-spiro-titanium dichloride was prepared and the structure of the compound was determined by 1R, us and elementary analysis.

Mathematical Modeling of Hemoglobin Release under Hypotonic Conditions

Mathematical model is developed to estimate hemoglobin release under hypotonic conditions at microscopic level. The phenomenon of hemoglobin (Hb) release depends on: 1) the dynamics of repeated opening of hemolytic holes and 2) the radial fluctuations of lipid membrane. Both processes are sensitive to the rate of ionic strength decrease within the surrounding medium. Influence of the rate of ionic strength decrease on hemoglobin release is quantified by the model parameters: 1) the specific decrease of erythrocyte radius and 2) the specific decrease of hole radius during single opening time period of hemolytic hole. The prediction of released amount of Hb influenced by the conductive mechanism is equal to 2.9 %. The prediction of total released amount of Hb influenced by the conductive and convective mechanisms is approximately equal to 4 % of the initial amount of Hb within erythrocyte.

THEORETICAL ANALYSIS OF HYDROGENATION MECHANISM CATALYZED BY Pd-Fe_2O_3/D_(3520)

The mechanism of catalytic hydrogenation of styrene is analyzed by catalysis theory and frontier molecular orbital theory.

STUDIES ON SYNTHESIS AND PROPERTIES OF BIS（β－ALKOXYCARBONYALKYL）TIN POLYTHIOETHERS

Bib(β--alkoxycarbonylalkyl)tin dichlorides were interfacial condensed with organic dithio--alcohols to give a series of new organo--tin polymers. Experimental parameters were discussed. The polymers synthesized were tested for their effect on the heat--stabilization of PVC resins. The results are of interest in this area of application

Sorption Properties of a Bentonite Based Material for Removal of Uranium from Alum Shale Leachate

A dynamic sorption experiment was performed for removal of uranium （VI or 6＋） from a leachate from an alum shale landfill with a diatomite-bentonite based sorbent in a laboratory scale. Such material was grounded and treated chemically with H3PO4 （phosphoric acid） and thermally for improving its porosity and resistance to water flow. A specific surface area of 209 m2·g-1 was determined by the BET method. A sorption capacity of 30 μg·gl and 0.6 μg·g-1 was obtained at a pH of 7.5 and 4 respectively by means of Langmuir and Freundlich isotherm models. The flow rate was 3 mL·min-1 was effective for controlling the pH inside of the column. The sorption mechanism was investigated along with desorption of the element of interest for further process design considerations for a treatment unit on the landfill site.

STUDIES ON THE LB FILM OF 2-HEPTADECYL IMIDAZOLECOORDINATING METAL IONS

The surface pressure—area isotherms(π—A curves) of 2—heptadecyl imidazole (HIM) Langmuir films at the subphases of deionized water and solutions containing metal ions such as Cu^(2+), Cd^(2+), Ca^(2+), Co^(2+), Ag^+ etc. have been studied. It was formed Langmuir film at the subphase containing Cu^(2+) or Ag^+ ions and its LB film was successfully deposited. The molecular and ionic total energies (E) and stabil. ity energies (△E) forming complexes were computed by CNDO/2 method. The computational results agreed with the experiments.

KINETIC STUDY OF THE CATALYTIC STEAM REFORMING OF PARAFFINS

Kinetics of the steam reformig of n-butane,n-hexane,n-heptane,n-nonane and i-octane on Z409 catalystwere studied at atmospheric pressure by using an internal recycle gradientless reactor.The reaction temperaturewas varied in the range of 743-853K,the steam carbon molar ratio 3-5.The experimental results showed thatthe reforming products contained no hydrocarbon other than methane.In addition,the product distributionof different n-paraffins were similar,but the product distribution of i-octane was different from that of n-paraffins.A reaction scheme for the steam reforming of paraffin has been proposed and the hyperbolic type rateequations were derived.It is clear that the obtained kinetic model could simulate the experimental results ofi-octane as well as different n-paraffins satisfactorily.