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1.
Scanningtunnelingmicroscope(STM)hasrecentlybeenappliedtothestudyoftheadsorptionoforganicandbiologicalmoleculesinvariousenvironments,includingliquidcrystal(LC),onsurface.Inparticular,4_n_alkyl4′cyanobiphenyls(mCB,wheremisthenumberofcarbonsinthealkylgroup)on…  相似文献   

2.
Epimedium, one of representatives of traditional Chinese herb, is mainly composed of flavones and polysaccharide. It is famous for its antioxidant, antineoplastic and antiaging activities and has been widely used in the field of invigorating kidney and st…  相似文献   

3.
A stack of natural copper was bombarded with -particles. Cumulative cross-sections for65Ga,66Ga and65Zn production, and the excitation functions for68Ga and67Ga production, were measured using high resolution gamma-ray spectroscopy. The data are compared with the theoretical result provided by equilibrium and pre-equilibrium reaction model, for this purpose we used the code ALICE of Blann. The overall agreement with theory is good. Besides, we present the experimental data obtained by other authors.  相似文献   

4.
The substitution effect of fluorine on ethylene is investigated by means of studyingthe properties of the charge distribution at the bond critical points with the theory of atomsin molecules.It is found that fluorine atom acts not only as a σ electron acceptor,but also asa π electron donor,and these double effects are reflected in the quantity of ellipticity,Lap-lacian and the charge density of charge distribution at the bond critical points.For C—C,C—Fbonds,the major axis of elliptical contours is perpendicular to the molecular plane,but forC—H bond,it is parallel to the molecular plane.Other effects originating from the substi-tution have also been discussed.  相似文献   

5.
A systematic measurement of H2 adsorption on activated carbon over a wide scope of conditions was completed for the first time using a novel cryostat developed by the present authors. The equilibrium temperatures covered 77-298 K with the space of about 20 K, and the equilibrium pressures increased from 0 to about 7MPa. A set of adsorption/desorption isotherms was obtained by a standard volumetric method. This set of experimental data was fitted to all the well-known models of type-I isotherms, and Dubinin-Astakhov (D-A) equation was found to be the best-fit one On the basis of D-A model one can predict adsorption with relative error of ±4%. A 3-dimensional adsorption surface was also constructed, and the isosteric heat of adsorption was analytically determined. Except in the low pressure area, the calculated values agreed well with the experimental ones. Finally, the troubles encountered in applying D-A equation to supercritical adsorption is discussed.  相似文献   

6.
In this work,the influence of heat treatment on Polyamide-1010 structure ofaggregation state was studied by using WAXD and SAXS techniques.The results showedthat the best crystallinity was obtained nearby T=175℃ for Polyamide-1010 samples withvarious annealing treatment.Through extrapolating method,the Tg obtained wasapproximately 58℃.Based on the one-dimensional electron density correlation function ofpartially crystalline polymers,some structural parameters of Polyamide-1010 weredetermined by SAXS.  相似文献   

7.
IntroductionGlycolethersareimportantindustrialderivativesofepoxides .Polyethylene glycolethylethersandpolypropyleneglycolethylethersaretwoimportantseriesofproducts .Glycolethersaregoodsolventsduetothepresenceof—O—and—OH groups.Asare sult ,theyarewidelyuse…  相似文献   

8.
Synthesized macroporous cross-linked copolymers of methyl acrylate-divinyl benzene (MA-DVB), acrylamide-N,N'-methylenebisacrylamide (AAM-BIS) and their functionalized products were used for immobilization of aminoacylase from Aspergillus oryzae. Effects of the carrier properties on the activity of immobilized aminoacylase were investigated and effects of substrate concentration, pH, phosphate buffer concentration and temperature on the immobilized aminoacylase were compared with those of the soluble aminoacylase. A column of immobilized aminoaoylase was prepared and used for continuous resolution of N-acyl-DL-methionine; the operational stability of immobilized enzyme was also investigated.  相似文献   

9.
A novel polyquaternaryammonium cationic sulphur black dye was synthesized and its dyeing behavior on silk was studied. The dye exhibited excellent dyeing fixation of up to 98.2 %,as well as excellent dyeing fastness on silk.  相似文献   

10.
11.
IwrR0DUCTl0NThedeveloPmentofllthjuxnrechargeablebatteneshasattratedagreatdeal0finterestinrecentyearsduet0advancesinmicrotechnologyandPOrtabIeeleCtromceewpmenLC0nunerciaiaPPllcallonofthistechn01ogr'hasaJreadybeenrealizedwiththeintredchonofliffoum-ionrechargcablecellsbySOW'JutiliamgcarbonanodesSndlarceUtechnologyhasbeenreportedbysomeresearchersI2]usingacarb0nanodeandadifferentmetaloxide(ie.LixCoO2,LixNO2,Li.Mn204)cathodematerial.ButthecaPamtyofthecarbonandthereversibility0flithiuminc…  相似文献   

12.
Mononuclear copper phthalocyanine (CuPc) and binuclear copper phthalocyanine (Cu2Pc2) were synthesized by the phenylanhydride-urea route, and their catalytic oxidation activity on 2-mercaptoethanol was studied. Based on the experimental results, a catalytic mechanism of Cu2Pc2 on 2-mercaptoethanol has been proposed. Furthermore, the effects of pH, Cu2Pc2 concentration, and temperature on the catalytic oxidation activity were evaluated. The results showed that CuPc has no catalytic activity, while Cu2Pc2 has high catalytic oxidation activity towards 2-mercaptoethanol with the optimal activity at pH 11. The reaction can further be enhanced by increasing Cu2Pc2 concentration and temperature, due to its endothermic characteristics.  相似文献   

13.
14.
There is a common hypothesis for the presently popular mild-slope equations that wave particle motion is irrotational. In this paper, an attempt is made to abandon the irrotational assumption and to set up new sea wave packet equations on slowly varying topography by use of the WKBJ method. To simplify the deduction, the two-dimensional shallow water equations are used to describe the sea wave particle motion in the very shallow nearshore area. The established equations can give some characteristics of wave propagation near shore.  相似文献   

15.
The adsorption and diffusion of N atoms on the three low-index Cu planes were studied using 5-parameter Morse potential (5-MP) method, and the best theory-experiment agreement was obtained. N atoms of Cu(100) surface sit on the fourfold hollow site with the vertical height of 0.018 nm closely coplanar with the topmost copper layer, and the four Cu-N bond lengths are 0.182 nm and the fifth Cu-N distance is 0.199 nm. For Cu(111) system, the existence of aberrant Cu(100) reconstructed structure is approved at higher coverage, and at low coverage the structure is almost an ideal Cu(111) surface structure. With respect to Cu(110) system, the N atoms are adsorbed at LB and H3 sites, not at SB site. The diffusion passage and diffusion barrier of adsorbed N atoms were also studied.  相似文献   

16.
IntroductionIt is well known that ZnO, a wide band-gap semi-conductor, is a promising material because of its wideband gap of 3.37 eV at room temperature(RT) and itslarge excitonic binding energy of about60 meV; it canbe used to prepare high-efficiency ul…  相似文献   

17.
1 INTRODUCTION Pyrazoline compounds have been widely used in industry due to their good photoconductivity and high fluorescence quantum productivity[1]. In recent years, pyrazoline derivatives with high vitrification temperature Tg have been found to act as hole trans- fer materials in the electroluminescence device, which has captured the intensive interest of che- mists[2]. But so far, the electron transfer mechanism of these compounds is still unclear[3~7]. Some resear- ches have attr…  相似文献   

18.
Exergy analysis on eco-industrial systems   总被引:1,自引:0,他引:1  
1 Introduction Ecological industry is to realize the harmony de- velopment between economy and environment by planning industrial systems according to material cy- cle in the natural ecological system. It got grown rap- idly both in theories and practices since the 1990s[1,2]. Many countries including China have applied indus- trial ecology to industrial practices. It is deeply recog- nized that developing ecological industry and advanc- ing on a new industrialization mode is an important way…  相似文献   

19.
Oscillographic chronopotentiometry is a type of current-controlled electroanalytical technique founded by J.Heyrovsky in19411and developed by Hung Kao after19632-5.In this technique,a constant-amplitude of alternating current j=j0sin(ωt)as well as a less direct current,passed through the electrolytic cell and the change of potential of the polarizable electrode exhibited on the oscillograph directly as a function of time during a continuous potential scan from zero to–2V.Generally,quantita…  相似文献   

20.
Twenty years of aggregation-induced emission(AIE)research has witnessed the flourishing development of aggregate-related disciplines(ie,solid-state emitters).From photophysical mechanisms to structural frameworks and thence to functional applications,AIE systems possess many unique and superior characteristics compared to the traditional structures with detrimental aggregation-caused quenching(ACQ)effct.  相似文献   

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