Study of infrared spectrum of 3,3′-dichloroindanthrone

A complete calculation has been performed for the infrared spectrum of the molecule of 3,3-dichloroindanthrone, including vibration frequencies and intensities and the spectral curve. The satisfactory agreement that has been obtained between the calculated and experimental spectra has made it possible to interpret the spectrum in detail; to determine the characteristic spectral regions for manifestation of vibrations that pertain in form to such structural fragments of the molecule as the anthraquinone fragment, the nitrogen-containing ring, and the ring that embodies a hydrogen bond; and to obtain information on the sensitivity of vibrations to chlorination of indanthrone. The features that have been revealed have the character of a spectrum/structure correlation and can be used for analytical purposes.K. A. Timiryazev Agricultural Academy. Scientific-Research Institute of Physical Problems. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 1, pp. 190–196, January–February, 1993.     

Study of Preparation and Characteristics of Pyridoxalated Polyhemoglobin

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Ab Initio Study of the Dehydrogcnation of Methylenimine

The ab initio calculations were performed by the intrinsic reaction coordinated(IRC) method for the reaction paths of the dehydrogenations of methylenimine. We determined the geometries and energies of the transition states and obtained the activation energies, activation entropies and the statistical A factors on the RHF/4 -31G singlet potential energy surface. The mode selective study reveals the intrinsic reaction coordi-nates(URC) of 1 ,1 and 1 ,2 dehydrogenations of methylenimine to be related with the H2C= group symmetrical stretch mode and the =NH group stretch mode, respectively. The vibration coupling between the normal coordinates occurs in either of these two reaction paths.     

Calorimetric Study of Thermal Denaturation of Superoxide Dismutase

The thermal denaturation of superoxide dismutase (SOD) from bovine erythrocytes was studied at various pH values of different buffers and at various concentrations of solutions of two neutral salts by differential scanning calorimetry. The experiments performed indicate that the PIPES is a buffer non-coordinating with the SOD, and that the binding of the anions studied influences more or less the thermal denaturation of SOD, but the effect on the oxidation form of SOD is more apparent. A new conformer of SOD with lower thermostability was discovered by the experiments performed in different buffers at certain pH values higher than the isoelectric point of SOD, or at higher concentrations of neutral salt solutions. The new conformer may be converted irreversibly into the usual conformer with high thermostability during heating. Based on the thermodynamic parameters obtained in distilled water and by thermodynamic analysis using the Ooi's model, it is revealed that the large enthalpy △Hdc contributed by     

An XPS Study of Perovskite Oxides

An　XPS　Study　of　Perovskite　Oxides　...     

Spectrometric Study of α-Phenylcinnamic Acids

TheanalwisofMSdataofl4substitutalatwcbocacidsindicateSaclassofpeificfragmenpeakS(Tatrl)'fllcdevelopn1en1oftLhesefragmentPeaksistnggeredb)].3-shift[1J7-heMSIYapoenta[1onpattenlot'compotmdf;8belou'illustratesthegenera1mechanjs1nScbemc.lTbemajorMShagmentationpatternofa-phenysubstitutedcinnamicacidAstheSCheInshows,afterthel,3-shiftofhydr0xyinCOmpoUndE8-tberesultinginterInwhatewhllosetheRCX=0grOUfollowinthebondeq,chchleadstOtheformationofmlZl25anditscomPleInentaIyPeakYnlzl63,withthebo…     

Study on Stability of Nateglinide Polymorphism

The stability of three forms of nateglinide, especially S-form and H-form, was determined. S-form was a new crystal structure of nateglinide. Three forms of nateglinide were treated in different conditions, such as in various temperatures, humidity, light and so on.Analysis of their crystal structures was performed by X-ray powder diffraction ( XRD ) and their particle shapes were observed with scanning electron microscope ( SEM ). The results indicated that the stability of S-form of nateglinide is the best among the three forms and their particle shapes are quite difference. S-form is the sheet structure of layer upon layer, H-form looks like a hank of silk lines and B-form is the clubbed shape.     

Application of Calcite Veins to Study of Newly-activated Faulting

The study of period and chronology of fault activity in major worksites in an area with exposed basement rocks is quite difficult. The authors have applied the combinative techniques of field investigation, microscopic observation and isotopic dating to studying the calcite veins filled in the fault zones in several major engineering regions and got successful results. The following conclusions are reached: (i) The last period of strong activity of fault F8 in the Tianshengqiao Hydropower Station, Nanpan River is 200 ka B. P. , and there has been, no obvious activity since 150 ka. (ii) The last period of strong activity for 5 faults in Shixiali Reservoir, Yangyuan County, Hebei Province is 200-300 ka B. P. , and there has been no obvious activity since 200 ka. The research results provide a sound basis of engineering geology for project designers.     

Thermodynamic Study of the Three Isomers of Bromobenzoic Acid

The enthalpies of sublimation and fusion and triple-point temperatures of 2-bromo-. 3-bro-mo- and 4-bromobenzoic acids have been determined precisely by sublimation calorimetry, drop calorimetry and differential thermal analysis. The measurements of sublimation enthalpy of the three acids were made at 333, 348 and 363 K, respectively, using a Tian-Calvet microcalorimeter equipped with Knudsen effusion cells. The derived standard molar enthalpies of sublimation at 298.15 K are (95. 94±0. 41), (99. 20± 0.18), and (103. 08±0. 59) kJ · mol-1for the 2-bromo-, 3-bromo- and 4-bromobenzoic acids, respectively. In addition, the saturated vapour pressure of these compounds was also calculated on the basis of the sublimation experiments. The enthalpy of fusion, the triple-point temperatures and the mole fraction purities of the samples of the investigated substances were measured using the mean temperature version DTA apparatus developed by the CTM of the CNRS in Marseille. The triple-point temperature and the     

Study of Intramolecular Cyclization of N-styryl-oxo-cinnamides (Ⅱ)

lnthepreviouspaper',wereportedtheintramolecularcyclizationsofamide4anditscis-eneisomerinanattempttosynthesizehomoclausenamideandzetaclausenamide2.Inordertostudytherelationshipbetweenthestereochemistryandtheilltramolecularcyclizationofthisseriesofcompounds,theamides5(cis-oxirane,trans-ene)and8(cis-oxirane,cis-ene)wereprepared,andtheirintramolecularcyclizationswerereportedinthispaper.Theamide5withm.p.152.O-l54.O"CwasobtainedfromDarzen'scondensationofcompound3withPhCHOinMeOHatl5-2OoCwithMeO…     

PCM Study of Bond Dissociation Energies of the S–NO Bond: A DFT Study

Quantum chemical calculations are used to estimate the equilibrium S–NO bond dissociation energies (BDEs) for seven S-nitro-N-acetyl-d,l-penicillamine dipeptides (SNAP-two peptides) in acetonitrile solution. These compounds were studied by employing the hybrid density functional theory (B3LYP, B3P86 and B3PW91) methods together with the 6-31G** basis set. The obtained results are compared with available experimental results. It is demonstrated that B3PW91 method is the best method to compute the bond dissociation energies of SNAP-two peptides. The substituent and solvent effects of the S–NO BDEs are further analyzed. The results show that S–NO BDE increases with the increment of isoelectric points of substituted groups. In addition, the S–NO BDE decreases due to the inclusion of solvent effects. Furthermore, SNAP-two peptides and the other NO-donors are compared.     

Study of Methanol Conversion over Fe-Zn-Zr Catalyst

The methanol conversion over Fe-Zn-Zr catalyst was studied at 0.1 MPa and 280-360℃. The experimental results indicate that the main products of methanol conversion are methane and butane, and that other hydrocarbons are scarcely produced.All results show that propylene is most probably the olefin formed first in methanol conversion rather than ethene over Fe-Zn-Zr catalyst.Methane is formed from methoxy group,and C_4 is possibly yielded on the surface from propylene through binding with a methoxy group.     

Study on polymerization and structure of polydiphenylamine

The electrochemical oxidation of diphenylamine in acetonitrile produces an adherent uniform polymer film which exhibits mutiple colour variation(yellow-green-blue) in a wide range of potential scan. The polymerization mechanism and the structure of the polymer were studied by cyclic voltammetry, FT-IR and in situ ESR. The results indicate that the electrochemical polymerization of diphenylamine belongs to a cationic radical polymerization process. During electrolysis, only oligomers were initialy produced, then polymer film was formed on the electrode surface. The electropolymerization performs via the 4,4' C-C phenyl-phenyl coupling mechanism.     

Absorption Study of Norfloxacin – DNA Interaction

Summary: Norfloxacin, a quinolone antibacterial reagent, has been studied with respect to its binding to calf thymus DNA using absorption spectroscopy. We examined the self-association of the norfloxacin, in order to determine the molar absorption coefficient of the monomer, the molar absorption coefficient of the dimer and the dimerization constant. We also examined the interaction of norfloxacin with DNA by measuring the number of binding sites per DNA segment and the binding constant. Hypochromism, broadening of the envelope and a red-shift in the drug absorption region are apparent for the norfloxacin that bound to DNA. The results were rationalized taking into account both self-association of the drug and the cooperatively effects, in terms of several literature models, Benesi-Hildebrand, Scott, Scatchard, Schwarz and Watanabe-Schwarz.     

UV Photoionization Study of the Ethyl Radical

Introduction Ashighlyreactivebuildingblocksandfundamen talreactionintermediatesinorganicsynthesis,thealkyl radicalfamilyplaysacentralroleinadiversearrayof importantprocessesrangingfromcombustion[1]toat mosphericchemistry[2].Amongalkylradicals,theeth ylrad…     

Catalyst Kinetics Analytical Method Study of Ruthenium

Color reactions are used to determine ruthenium utilizing spectrophotometer, but the process need high temperature, long time pyrogenation and miscellaneous extraction and it contaminates the enviroment. As the sensitive degree and simple apparatus of catalyst kinetics analytical method, it was extensively attented. The fundmental principle means to determinn a certain chemistry reaction rate accelerated by homogeneous catalyst and determine substantial content using the function of the numeri…     

An ab Initio Study of Tetrathiosquaric Acid

Inthepastfewdecades,sincetheoxocarbonanionsC.O.'-wererecognizedasmembersofanewclassofstabilizedcarbocyclicnonbenzenoidaromaticcompounds"',theknowledgeoftheirchemicalandphysicalpropertieshasbeendevelopingrapidly'Theiruniqueelectronicstructures,highdegreeofsymmetry,andestheticallybeauti-fulgeometrygeneratedafreshimpetustostudytheeffectofreplacingtheoxygensbyvariousfunctionalgroups,suchassulfur',andselenium[11.Analogoustotheoxocar-bondianions,thethioxocarbondianionscanbecharacterizedbythegeneralf…     

Mössbauer Study of El-Bahrain Meteorite

Procedures for the determination of traces of rare earth elements (REE) in geological samples by instrumental neutron activation analysis (INAA) and high resolution liquid chromatography (HPLC) are presented. The international standard reference materials AGV-1, GSP-1 and G-2 (USGS) were tested for the determination of REE concentrations using both techniques. The results obtained showed good agreement with certified values, giving relative errors less than 10%. By using INAA, the REE La, Ce, Nd, Sm, Eu, Tb, Yb and Lu were determined. All the REE, except Dy and Y, were determined when HPLC was employed. The application of INAA and HPLC to the determination of REE in geological samples is also discussed.