首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 234 毫秒
1.
Positive electrode with uniform lead dioxide nanostructures directly synthesized by cyclic voltammetry (CV) method on the lead substrate in 1 M sulfuric acid solution including different concentration of barium sulfate. The effect of potential scan rate, sulfuric acid and barium sulfate concentration were studied on the morphology and particle size of lead dioxide using scanning electron microscopy (SEM) and X-ray diffraction techniques (XRD). The effect of barium sulfate was studied on the CV parameters including anodic peak current (I pa), cathodic peak current (I pc), anodic peak potential (E pa) and cathodic peak potential (E pc) during synthesis process. Finally, the effect of barium sulfate on the discharge capacity and cycle life of nanostructured positive electrodes and commercial positive plates was investigated. Both CV and battery test results showed that barium sulfate with concentration of 1 × 10−5 M can be used as suitable additive for positive paste of lead-acid batteries.  相似文献   

2.
《Electroanalysis》2003,15(1):40-48
The adsorptive accumulation of cercosporin (CER) at glassy carbon electrodes is studied by square‐wave voltammetry (SWV). The Freundlich adsorption isotherm resulted in being the best one to describe the specific interaction of CER with glassy carbon electrodes by using a fitting procedure of experimental fractional surface coverage vs. the CER bulk concentration (c*CER). SWV was also used to generate Q vs. c*CER and Ip, n. vs. c*CER calibration plots from pure commercial reagent solutions. Theoretical detection limits of 1.8×10?7 and 9.7×10?8 M were calculated from Q. vs. c*CER and Ip, n vs. c*CER plots, respectively. The lowest concentration value measured experimentally from calibration plots performed at a f =40 Hz for a signal to noise ratio of 2 : 1 was 3.7×10?8 M, being this value two orders of magnitude smaller than that obtained previously by us from the diffusion controlled CER reduction peak. Ip, n./f vs. f plots from SW voltammograms performed at different c*CER as well as different accumulation times showed the so‐called “quasi‐reversible maxima”. A splitting of the voltammetric peak was also observed by increasing the SW amplitude at a given frequency. A value of (?0.260±0.011) V was determined for the formal potential of the adsorbed redox couple from the split voltammetric peak. A full characterization of the surface redox process was obtained by applying the methods of the “quasi‐reversible maximum” and the “split SW peak”. In 1 M HClO4 aqueous solution, the formal rate constant and the anodic transfer coefficient were (3.5±0.5)×102 s?1 and (0.50±0.03), respectively. Besides, the number of electrons exchanged during the redox reaction was calculated as n≈1.  相似文献   

3.
This paper reports of a study on eutectic solidification of the quasi binary system of unfractionated isotactic polypropylene and the dentritic growing diluent pentacrythrityl tetrabromide. This system was characterized by a eutectic-type experimental phase diagram with a eutectic composition of 68% (w/w) of polypropylene. The eutectic temperature was found to depend on kinetics, and was established by differential scanning calorimetry to be 122 and 102°C at a cooling rate of 0.5 and 32°C/min, respectively. A remarkeable nucleating effect of the primary diluent crystals was observed in the solidification of diluted polypropylene solutions. Here the eutectic horizontal was located at a temperature which was 15°C higher than in the eutectic solutions exceeding the temperature at which the pure polymer crystallized from the melt by 8°C. The eutectic microstructures produced were found to depend on the rate of solidification, which was varied by pulling the polypropylene solutions through a fixed temperature gradient of 3°C/mm at different speeds ranging from 0.2 to 80 mm/hr. At rates lower than 3 mm/hr the polymer and the diluent crystallized simultaneously from the eutectic solution in a uncoupled mode of growth, forming a coarse structure of diluent crystals and isotactic polypropylene spherulites with dimensions of about 0.1 mm. At higher speeds the simultaneous crystallization of the macromolecules and solvent molecules proceeded in a co-operative manner with a nonplanar growth front. A rodlike eutectic microstructure was produced, in which diluent rods, lined up in the growth direction, were dispersed in a polypropylene matrix. The lateral dimension λ1 of these rods were found to depend on the growth rate R in the following way: λ12 R = 10?9 mm3/sec, and ranged from 0.3 to 1.0 μm. This was in accord with values calculated by using the current theory of rod eutectic growth of Jackson and Hunt.  相似文献   

4.
In nitroxide‐mediated radical polymerization, the polymerization times decrease with the increasing re‐formation rate constant of the C? ON bond (→ alkoxyamine) between the growing polymer chain and the nitroxide radical. The factors influencing the re‐formation rate constant are of considerable interest, but up to now, the polar/stabilization effects have not been addressed thoroughly. The combination of new data with previously reported data now showed that the re‐formation rate constant kc increases with the increasing polar character of the substituents attached to the nitroxide moiety. The polar/stabilization effects are weaker for the re‐formation than for the homolysis of the C? ON bond, and may be mainly attributed to the relocation of the odd electron onto the O‐atom of the N? O moiety, i.e., the stabilization of the nitroxide moiety. Hence, it is possible to predict the values of kc by combining both the polar/stabilization (σI) and steric effects (E ), i.e., log(kc/M ?1 s?1) = 9.86 + 0.57 ? σI + 0.40 ? Es.  相似文献   

5.
The non-isothermal crystallisation kinetics of Se90?xIn10Sbx (x = 0, 1, 2, 4, 5) chalcogenide glasses prepared by a conventional melt quenching technique was studied using the differential scanning calorimetry (DSC) measurement at different heating rates 5, 7, 10 and 12 °C min?1. The values of the glass transition temperature T g and the crystallisation temperature T c are found to be composition and heating rate dependent. The activation energy of glass transition E g, Avrami index n, dimensionality of growth m and activation energy of crystallisation E c have been determined from different models.  相似文献   

6.
7.
In a previous study, we have investigated the structure, crystallization, and morphology of poly(aryl ether ketone ketone), PEKK, copolymers prepared from diphenyl ether (DPE), terephthalic acid (T), and isophthalic acid (I) with T/I ratios from 100/0 to 50/50. These materials were considered as having -DPE-T-DPE-T- (TT) and/or -DPE-T-DPE-I- (TI) “phthalate diads.” In this work, we continue the study of this copolymer series with six different T/I ratios (40/60, 30/70, 20/80, 15/85, 10/90, and 0/100), which are viewed as having TI and/or -DPE-I-DPE-I- (II) “diads.” The I moieties (1,3-linked isomers) were always found to be incorporated in the crystals and acted as “entropy or symmetry” defects that effectively decreased the equilibrium melting temperature Tmo and the rate of crystallization. However, the retardation of crystallization in PEKK 0/100 (the homopolymer with pure II diads) was significantly less than expected, which was attributed to the segregation of I moieties between the chains leading to a reduction of total entropy in the unit cells. The evidence of segmental segregation in PEKK 0/100 was seen in x-ray diffraction patterns, where several extra reflections were seen that could only be indexed by the published unit cell modified with a larger c-axis dimension (3.048 nm, corresponding to the length of six phenyl residues or 1.524 nm, the length of three phenyl residues). The composition of 15/85 was found to have the lowest value of Tmo and the slowest crystallization rate. Upon heating, the “II” crystals (T/I from 30/70 to 0/100) exhibited the conventional double-melting behavior rather than the triple-melting behavior as in the “TI” crystals (50/50 to 40/60). No indication of the second polymorph form 2 was found in “II” crystals. © 1994 John Wiley & Sons, Inc.  相似文献   

8.
Preparation and Structure of the Compounds Ba2Pb4F10Br2–xIx (x = 0–2) with Related Structure Motifs of the Fluorites and Matlockites Colourless single crystals of Ba2Pb4F10Br2–xIx (x = 0–2) have been obtained under hydrothermal conditions (T = 250 °C, 10 d), starting from stoichiometric amounts of BaF2, PbF2, PbBr2 and PbI2. The compounds crystallize in the tetragonal space group P4/nmm (No. 129). A complete miscibility in the region x = 0–2 has been observed. The mixed crystals follow Vegard's rule. For the compounds with the composition Ba2Pb4F10Br2 (a = 5.9501(2) Å, c = 9.6768(10) Å, R[F2 > 2σ(F2)] = 0.022, wR(F2 all reflections) = 0.059), Ba2Pb4F10Br1.1I0,9 (a = 5.9899(3) Å, c = 9.7848(5) Å, R[F2 > 2σ(F2)] = 0.014, wR(F2 all reflections) = 0.035) and Ba2Pb4F10I2 (a = 6.6417(3) Å, c = 9.9216(10) Å, R[F2 > 2σ(F2)] = 0.023, wR(F2 all reflections) = 0.049) complete structure analyses have been performed on the basis of single crystal diffractometer data. Microcrystalline single phase compounds Ba2Pb4F10Br2–xIx (x = 0–2) have been obtained by coprecipitation from aqueous solutions of KF, KBr (KI) and Ba(CH3COO)2, Pb(NO3)2 in acetic acid medium. For Ba2Pb4F10Br1.5I0.5 and Ba2Pb4F10Br0.5I1.5 powder data of microcrystalline samples were used for the Rietveld analyses (RBragg = 0.077 for Ba2Pb4F10Br1,5I0,5 and RBragg = 0.065 for Ba2Pb4F10Br0.5I1.5). The crystal structure comprises alternating structural features of fluorite related type (CaF2) around Ba and matlockite related type (PbFCl) around Pb1 and Pb2 along the c axis. Barium shows a {8 + 4} cuboctahedral coordination of fluorine. The coordination polyhedron around the two crystallographically independent lead atoms is a monocapped quadratic antiprism built of {4 + 1} fluorine and {4} bromine or iodine atoms, respectively.  相似文献   

9.
Uranyl complexes with acetylenedicarboxylic acid, K(H5O2)[UO2L2H2O] · 2H2O (I) and Cs2[UO2L2H2O] · 2H2O (II), L2− = C4O 4 2− were prepared for the first time. The composition and structure of the complexes were determined by X-ray diffraction. The crystal data are as follows: a = 16.254(12) ?, b = 13.508(8) ?, c = 7.683(6) ?, β = 90.91(7)°, space group C2/c, V = 1687(2) ?3 (I); a = 7.0745(10), b = 18.4246(10), c = 13.1383(10) ?, space group Abm2, V = 1712.5(3) ?3 (II). The structures of I and II are based on [UO2L2H2O] n 2− anionic chains stretched along the [101] direction (I) or [010] direction (II). In I and II, the uranium coordination polyhedron is a pentagonal bipyramid in which the equatorial environment of the uranyl ions is formed by the oxygen atoms of the four L2− anions and the water molecule. The L2− anions in I and II are bidentate bridging ligands connecting two uranium atoms that are next to each other in the anionic chain; their coordination capacity is equal to 2. In I, the K+ and H5O 2 + cations are outer-sphere species. The latter form hydrogen bonds combining the anionic chains shifted by translation b with respect to each other. The [UO2L2H2O] n 2− chains in I are surrounded by the potassium and oxonium cations; in II, these are combined by hydrogen bonds into anionic layers between which Cs+ cations are arranged. The IR spectrum of compound II was measured and interpreted. Original Russian Text ? I.A. Charushnikova, A.M. Fedoseev, N.A. Budantseva, I.N. Polyakova, Ph. Moisy, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 1, pp. 63–69.  相似文献   

10.
The Na6[Gd2III(Ttha)2] · 8H2O (I) (H6Ttha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid) and (H2En)3[GdIII(Ttha)]2 · 11H2O (II) (En = ethylenediamine) complexes were prepared with heat-refluxing and acidity-adjusting methods, respectively. Their composition and structures were determined by elemental analysis and single-crystal X-ray diffraction techniques. Complex I shapes a binuclear and nine-coordinated structure and crystallizes in the orthorhombic crystal system with space group Pccn. The central Gd3+ ion is coordinated with one Ttha ligand by three N atoms and four O atoms and with one adjacent Ttha ligand by two O atoms. The crystal data are as follows: a = 26.036(13) ?, b = 21.007(10) ?, c = 22.694(12) ?, V = 12412(11) ?3, Z = 8, c = 1.699 g/cm3, μ = 2.254 mm−1, F(000) = 6368, R = 0.0602, and wR = 0.1146 for 3434 observed reflections with I ≥ 2σ(I). The GdN3O6 part in the [Gd2III(Ttha)2]6− complex anion forms a pseudo-tricapped trigonal prismatic geometry. Complex II is also nine-coordinate, but mononuclear and crystallizes in the monoclinic crystal system with space group P21/n. While the central Gd3+ ion is coordinated by four nitrogen atoms and five oxygen atoms from the same Ttha ligand. The crystal data are as follows: a = 17.7726(17) ?, b = 19.2942(17) ?, c = 20.6045(19) ?, β = 111.4600(10)°, V = 6575.6(10) ?3, Z = 8, c = 1.693 g/cm3, μ = 2.102 mm−1, F(000) = 3428, R = 0.0333 and wR = 0.0827 for 14792 observed reflections with I ≥ 2σ(I). Otherwise, the GdN4O5 part in each [GdIII(Ttha)]3− complex anion adopts a pseudo-monocapped square antiprismatic polyhedron.  相似文献   

11.
The binding of mixed surfactants of cationic cetyltrimethylammonium bromide (CTAB) and nonionic octaethylene glycol monododecyl ether (C 12E 8) on anionic polyelectrolyte poly[2-acrylamido-2-methylpropanesulfonic acid (PAMPS)] and fluorophore-labeled copolymers containing about 40 mol% of AMPS was investigated at different mole fractions, Y , of CTAB in the surfactant mixture. The excimer emission of the cationic probe 1-pyrenemethylamine hydrochloride (PyMeA·HCl), nonradiative energy transfer (NRET) between pyrene and naphthalene labels and I 1/ I 3 of the pyrene label were determined by varying the total surfactant concentration, c Surf. The I E/ I M value of PyMeA·HCl firstly increases and then decreases to 0 with c Surf, showing a maximum on every curve. The critical aggregation concentration of the mixed surfactants determined from the I E/ I M maximum decreased from 5×10 -5 to 1×10 -5 mol/l as Y increased from 0.1 to 0.50, and then leveled off as Y increased up to unity. And at least 5×10 -6 mol/l CTAB was required for the mixed surfactants to bind on the PAMPS cooperatively. Equimolar binding of CTAB on AMPS was formed at I E/ I M=0 when Y =0.25, while at Y =0.1 some CTAB molecules in the mixed micelle were directed to the water phase without binding with AMPS. Both the intramolecular and the intermolecular NRET increased and then decreased with c Surf, having a maximum on each curve corresponding to the equimolar binding of CTAB and AMPS so long as Y >0, indicating the coiling of the chain and interchain aggregation upon bound surfactants. The I Py/ I Np value at the maximum decreased with decreasing Y because more nonionic surfactant C 12E 8 participated into the polyelectrolyte-mixed surfactant complexes together with bound CTAB.  相似文献   

12.
A simple adsorptive cathodic stripping voltammetry method has been developed for antimony (III and V) speciation using 4‐(2‐thiazolylazo) – resorcinol (TAR). The methodology involves controlled preconcentration at pH 5, during which antimony(III) – TAR complex is adsorbed onto a hanging mercury drop electrode followed by measuring the cathodic peak current (Ip,c) at ?0.39 V versus Ag/AgCl electrode. The plot of Ip,c versus antimony(III) concentration was linear in the range 1.35×10?9–9.53×10?8 mol L?1.The LOD and LOQ for Sb(III) were found 4.06×10?10 and 1.35×10?9 mol L?1, respectively. Antimony(V) species after reduction to antimony(III) with Na2SO3 were also determined. Analysis of antimony in environment water samples was applied satisfactorily.  相似文献   

13.
Absolute rate constants for H-atom abstraction by OH radicals from cyclopropane, cyclopentane, and cycloheptane have been determined in the gas phase at 298 K. Hydroxyl radicals were generated by flash photolysis of H2O vapor in the vacuum UV, and monitored by time-resolved resonance absorption at 308.2 nm [OH(A2Σ+X2Π)]. The rate constants in units of cm3 mol−1 s−1 at the 95% confidence limits were as follows: k(c C3H6) = (3.74 ± 0.83) × 1010, k(c C5H10) = (3.12 ± 0.23) × 1012, k(c C7H14) = (7.88 ± 1.38) × 1012. A linear correlation was found to exist between the logarithm of the rate constant per C H bond and the corresponding bond dissociation energy for several classes of organic compounds with equivalent C H bonds. The correlation favors a value of D(c C3H5–H) = (101 ± 2) kcal mol−1.  相似文献   

14.
The ADSC (Alternating DSC [1]) technique superimposes upon the conventional constant heating rate a periodically varying modulation [2–8]. The modulation creates high instantaneous heating rates which increases sensitivity. The low underlying constant heating rate is used to get better resolution. With ADSC it is possible to separate overlapping thermal effects without loss of sensitivity and to determine heat capacities under quasi-isothermal conditions. It has been reported that there are also some limitations for the use of the modulation techniques, i.e. that the accuracy of cp determination is reduced at higher modulation frequencies due also to thermal diffusivity within the sample itself [9, 10]. In this contribution, the limitations given by the measuring system itself will be discussed. A key value is the limit frequency of the sensor arrangement. In the Mettler Toledo DSC821c this frequency is approximately 1/3 Hz. From these findings the following recommendations amongst others can be given: for light mass crucibles, 30 s periods are reasonable with amplitudes not exceeding the heating/cooling rates possible. A blank and a calibration measurement will eliminate cell asymmetry and will enhance the accuracy of cp measurements even at higher modulation frequencies. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

15.
Kinetics of oxidation of semicarbazide (SC) by iodamine-T (IAT), iodine monochloride and aqueous iodine has been studied in aqueous perchloric acid medium. The rate laws followed by the oxidation of SC were determined. The rates decreased slightly with increase in ionic strength of the medium in IAT and ICI oxidations, while the reverse trend was observed with I2. Decrease in dielectric constant of the medium increased the rates with IAT and ICI, while it decreased the rate in I2 oxidations. Addition of the reduced product,p-toluene-sulphonamide had no effect on the rate with IAT. Addition of I had slight negative and positive effects on the rates of oxidations with IAT and ICI, respectively, but the negative effect was considerable in I2 oxidations. Mechanisms consistent with the observed rate laws have been proposed and discussed. Rate determining steps have been identified and their coefficients calculated. These constants were used to predict the rate constants from the deduced rate laws as [SC], [H+] and [I] varied. Reasonable agreement between the calculated constants and experimental values provide support for the suggested mechanisms.  相似文献   

16.
A novel optically active amphiphilic diblock copolymer bearing quinine pendants poly(ethylene oxide)‐b‐poly(glycidyl triazolyl‐L ‐quinine) (MPEO‐b‐PGTQ) was synthesized by “click” reaction of alkyne‐modified diblock copolymer poly(ethylene oxide)‐b‐poly(glycidyl propargyl ether) (MPEO‐b‐PGPE) and 9‐N3‐quinine. The structure and composition of copolymers were characterized by gel permeation chromatography, 1H nuclear magnetic resonance spectroscopy (1H NMR), elemental analysis and optical rotation measurements, which showed that the synthetic route could provide the copolymer with well‐defined composition and with similar optical activity compared to its parent quinine. The micellization behavior of this chiral copolymer was investigated in different solvent systems. The results from fluorescence spectroscopy, UV spectroscopy, dynamic light scattering, transmission electron microscopy, 1H NMR and circular dichroism (CD) spectroscopy indicated that the MPEO‐b‐PGTQ could form regular chiral spherical micelles in H2O and Tetrahydrofuran‐H2O (10:90, V/V) systems, and the state of aggregated chiral micelles depended on the nature of the medium. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3640–3650, 2009  相似文献   

17.
The experimental temperature/composition phase diagram of the binary system decanedioic acid (C10H18O4)/dodecanedioic acid (C12H22O4) was established by combining X‐ray powder diffraction (XRD), differential‐scanning calorimetry (DSC), infrared spectroscopy (IR), scanning electron microscopy (SEM), and thermo‐optical microscopy (TOM). Both compounds crystallize in the same ordered form, C (P21/c), which is the phase that melts in both cases. The C form melts in C12H22O4 earlier than in C10H18O4, in contrast to other unbranched‐chain compounds (alkanes, alkanols, and alkanoic acids) in which the melting temperatures increase as the C‐atom number rises. Contrary to what might be expected, total solid‐state miscibility is not observed. The C10H18O4/C12H22O4 binary system shows a complex phase diagram. At low temperatures, a new monoclinic form, Ci (P21/c), stabilizes as a result of the disorder of composition in the mixed samples; two [C+Ci] domains appear. Upon heating, four solid–solid and seven solid–liquid domains appear related by eutectic and peritectic invariants. All the crystallographic forms observed are isostructural.  相似文献   

18.
Measurements of the thermal expansion coefficients (TECs) of cellulose crystals in the lateral direction are reported. Oriented films of highly crystalline cellulose Iβ and IIII were prepared and then investigated with X‐ray diffraction at specific temperatures from room temperature to 250 °C during the heating process. Cellulose Iβ underwent a transition into the high‐temperature phase with the temperature increasing above 220–230 °C; cellulose IIII was transformed into cellulose Iβ when the sample was heated above 200 °C. Therefore, the TECs of Iβ and IIII below 200 °C were measured. For cellulose Iβ, the TEC of the a axis increased linearly from room temperature at αa = 4.3 × 10?5 °C?1 to 200 °C at αa = 17.0 × 10?5 °C?1, but the TEC of the b axis was constant at αb = 0.5 × 10?5 °C?1. Like cellulose Iβ, cellulose IIII also showed an anisotropic thermal expansion in the lateral direction. The TECs of the a and b axes were αa = 7.6 × 10?5 °C?1 and αb = 0.8 × 10?5 °C?1. The anisotropic thermal expansion behaviors in the lateral direction for Iβ and IIII were closely related to the intermolecular hydrogen‐bonding systems. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1095–1102, 2002  相似文献   

19.
Thermal properties of glasses from the system Bi x (As2S3)100−x were studied by differential scanning calorimetry of a representative series of samples with x = 0.5, 2, 4, 6, 8, and 10 at.% Bi by determining the characteristic temperatures (T g, T onset, T c, T m) and enthalpies (H c, H m) of the processes taking place in the samples during their thermal treatment. Analysis of DSC recordings for the samples at the same heating rate allowed characterization of the phase transition temperature T g as a function of the content of doping atoms in accordance with the criteria of chemical bonds formation in amorphous materials. Samples with 4 and 6 at.% Bi were thermally treated at different heating rates with the aim of determining, among the others, the parameters of their thermal stability. The assessment was done based on three different criteria. A higher tendency toward crystallization was observed with the glasses having a higher Bi content. Also, a trend of T g shifting toward higher values, observed with increase in the heating rate, is in concordance with the Lasocka equation.  相似文献   

20.
In this work, the title complexes, NH4[ErIII(Cydta)(H2O)2] · 4.5H2O (I) (H4Cydta = trans-1,2-cyclo-hexanediamine-N,N,N′,N′-tetraacetic acid) and (NH4)2[Er2III(Pdta)2(H2O)2] · 2H2O (II) (H4Pdta= propylene-diamine-N,N,N′,N′-tetraacetic acid), were prepared, respectively, and their composition and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques. Complex I selects a mononu-clear structure with pseudosquare antiprismatic geometry crystallized in the triclinic crystal system with space group $ P\bar 1 $ P\bar 1 and the central Er3+ ion is eight-coordinated by the hexadentate Cydta ligand and two water molecules. The crystal data are as follows: a = 8.568(3), b = 10.024(3), c = 14.377(4) ?, α = 88.404(4)°, β = 75.411(4)°, γ = 88.332(4)°, V = 1194.2(6) ?3, Z = 1, ρ c = 1.793 g/cm3, μ = 3.586 mm−1, F(000) = 648, R = 0.0257, and wR = 0.0667 for 4169 observed reflections with I ≥ 2σ(I). Complex II is eight-coordinated as well, which selects a binuclear structure with two pseudosquare antiprismatic geometry and crystallizes in the monoclinic crystal system with space group P21/n. The central Er3+ ion is coordinated by two nitrogens and four oxygens from one hexadentate Pdta ligand. Besides, two oxygens come from one carboxylic group of the neighboring Pdta ligand and one water molecule, respectively. The crystal data are as follows: a = 12.7576(8), b = 9.3151(6), c = 14.3278(9) ?, β = 96.1380(10)°, V = 1692.93(19) ?3, Z = 4, ρ c = 2.054 g/cm3, μ = 5.015 mm−1, F(000) = 1028, R= 0.0228, and wR = 0.0534 for 2984 observed reflections with I ≥ 2σ(I).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号