Microstructures and mechanical properties of Mg-8Gd-0.6Zr-xNd (x=0, 1, 2 and 3 mass%) alloys

Mg-8Gd-0.6Zr-xNd (x = 0, 1, 2 and 3 mass%) alloys were prepared by metal mould casting method, and the microstructures, age hardening responses and mechanical properties have been investigated. The microhardness of the as-cast alloys is increased with increasing Nd content. The age hardening behavior and mechanical properties are enhanced significantly by adding Nd element. The peak ageing hardness of the Mg-8Gd-0.6Zr-3Nd alloy is 103, it is about 1.3 times more than that of the Mg-8Gd-0.6Zr alloy. The aged Mg-8Gd-0.6Zr-3Nd alloy exhibits maximum ultimate tensile strength and yield strength, and the values are 271 and 205 MPa at room temperature, 205 MPa and 150 MPa at 250 degrees C, respectively. Which are about 2 times higher than those of Mg-8Gd-0.6Zr alloy. The improved hardness and strength are mainly attributed to the fine dispersiveness Of Mg5RE and Mg12RE precipitates in the alloy.

Effect of strontium substitution on the activity of La2-xSrxNiO4 (x=0.0-1.2) in NO decomposition

The aim of this work is to study the effect of Sr substitution on the redox properties and catalytic activity of La2-xSrxNiO4 (x = 0.0-1.2) for NO decomposition. Results suggest that the x = 0.6 sample shows the highest activity. The characterization (TPD, TPR, etc.) of samples indicates that the x = 0.6 sample possesses suitable abilities in both oxidation and reduction, which facilitates the proceeding of oxygen desorption and NO adsorption. At temperature below 700 degrees C, the oxygen desorption is difficult, and is the rate-determining step of NO decomposition. With the increase of reaction temperature (T > 700 degrees C), the oxygen desorption is favorable and, the active adsorption of NO on the active site (NO + V-o + Ni2+ -> NO--Ni3+) turns out to be the rate-determining step. The existence of oxygen vacancy is the prerequisite condition for NO decomposition, but its quantity does not relate much to the activity.

Electrosynthesis and characterization of 1,2-dibenzyl C-60: A revisit

A reinvestigation of the reaction between C-60(2-) and benzyl bromide in benzonitrile containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) has shown that there are more reaction products than previously reported. Use of a silica rather than a "Buckyclutcher I" column for HPLC purification led to isolation of two previously unattained products in the reaction mixture, one of which was identified as 1,2-(PhCH2)(2)C-60 by UV-vis and NMR. The earlier incorrectly assigned 1,2-(PhCH2)(2)C-60 was identified as the methanofullerene C61HPh by X-ray single-crystal diffraction. The electrochemistry of genuine 1,2-(PhCH2)(2)C-60 shows that its first reduction potential in PhCN containing 0.1 M TBAP is cathodically shifted by 100 mV with respect to E-1/2 for reduction of 1,4-(PhCH2)(2)C-60, indicating that the addition pattern significantly affects the electrochemistry of derivatized C-60. Visible and near-IR spectra of the monoanion and dianion of 1,2-(PhCH2)(2)C-60 are also reported.

Electrocatalytic reduction of 1,2-diiodoethane by anions of supramolecular complex of (beta-CD)(2)/C-60 in DMF solution

The homogeneous electrocatalytic reduction of 1,2-diiodoethane by anions of the supramolecular complex of (beta-CD)(2)/C-60 in DMF solution is reported. The results show that the trianion of (beta-CD)(2)/C-60 exhibits electrocatalytic behavior towards the reduction of 1,2-diiodoethane, whereas the diani on is unable to reduce the diiodoethane. The second-order catalytic rate constant in DMF solution was determined to be 3.1 x 10(5) M-1 s(-1) by analysis of voltammetric responses under pseudo-first-order conditions with respect to (beta-CD)(2)/C-60. The results suggest that the host beta-cyclodextrin molecules have little effect on the electrocatalytic ability of the encapsulated C-60 toward organic halides.

Effects of crystal growth conditions on morphology of crystalline syndiotactic 1,2-polybutadiene

The crystalline syndiotatic 1,2-polybutadiene was synthesized with a catalyst consisting of iron acetylacetonate (Fe(acac)(3))-triisobutylaluminum (Al(i-Bu)(3))-diethyl phosphite (DEP), and the effects of crystal growth conditions on morphology of thin films of the polymer were investigated by transmission electron microscopy (TEM) and electron diffraction (ED) techniques. The polymer with melting point 179 degreesC was found to have 89.3% 1,2-content and 86.5% syndiotacticity by C-13 NMR measurement. The results of electron microscopic studies indicate that the solution-cast thin films of the syndiotatic 1,2-polybutadiene consist of lath-like lamellae with the c-axis perpendicular to the film plane, while a- and b-axes are in the film plane. The morphology of isothermally crystallized thin films of the polymer is temperature dependent. At lower crystallization temperatures (130 degreesC), a spherulitic structure consisting of flat-on lamellae is formed. With an increase in the crystallization temperature (e.g., at 140 degreesC), the spherulites and single faceted crystals coexist. At higher crystallization temperatures (150 degreesC), single crystals with a hexagonal prismatic shape are produced.

Facilitated ion-transfer of sodium cation by (anthraquinone-1-yloxy) methane-15-crown-5 across the water/1,2-dichloroethane microinterface

The transfer of sodium cation facilitated by (anthraquinone-1-yloxy) methane-15-crown-5(L) has been investigated at the water/1,2-dichloroethane microinterface supported at the tip of a micropipette. The diffusion coefficient of (anthraquinone-1-yloxy) methane-15-crown-5 obtained was (3.42 +/- 0.20) x 10(-6) cm(2) s(-1). The steady-state voltammograms were observed for forward and backward scans due to sodium ion transfer facilitated by L with 1:1 stoichiometry. The mechanism corresponded to an interfacial complexation (TIC) and interfacial dissociation (TID) process. The association constant was calculated to be log beta(o) = 11.08 +/- 0.03 in the DCE phase. The association constant of other alkali metals (Li+, K+, Rb+) were also obtained.

Crystal structures of EtEDTB center dot 1.4C(2)H(5)OH center dot 5H(2)O and H4EtEDTB(ClO4)(4)center dot C2H5OH (EtEDTB=N, N, N ', N '-tetrakis[2-(1-ethylbenzimidazolyl)methyl]-1,2-ethanediamine)

The crystal structures of EtEDTB.1.4C(2)H(5)OH.5H(2)O 1 and H4EtEDTB(ClO4)(4).C2H5OH 2 (EtEDTB = N, N,N',N'-tetrakis[2-(1-ethylbenzimidazolyl)methyl]-1,2-ethanediamine) have been determined by single-crystal X-ray diffraction method. Compound 1 crystallizes in the space group P(1) over bar with a = 11.489(2), b = 11.866(3), c = 12.002(3) Angstrom, alpha = 97.47(2), beta = 114.564(13), gamma = 114.11(2)degrees, V = 1266.6(5) Angstrom(3), Z = 1, M-r = 847.48, D-c = 1.111 g/cm(3), F(000) = 456 and mu(MoKalpha) = 0.076 mm(-1). A total of 5207 reflections were measured for 1, of which 4323 were independent. The structure of 1 was solved by direct methods and refined by full-matrix least-squares technique to the final R = 0.0706 and wR = 0.1802 for 1318 observed reflections with I > 2sigma(I). In the structure of 1, centrosymmetric EtEDTB molecules are linked by hydrogen bonds through water and ethanol to form 2-dimensional network. Compound 2 crystallizes in the space group C2/c with a = 24.260(5), b = 13.040(3), c = 17.680(4) Angstrom, beta = 97.50(3)degrees, V = 5545.2(2) Angstrom(3), Z = 4, M-r = 1140.80, D-c = 1.366 g/cm(3), F(000) = 2384 and mu(MoKalpha) = 0.289 mm(-1).

Synthesis and properties of polyimides derived from cis- and trans-1,2,3,4-cyclohexanetetracarboxylic dianhydrides

Cis-1,2,3,4-cyclohexanetetracarboxylic dianhydride (cis-1,2,3,4-CHDA) was synthesized. It was found that under such conditions as heating or boiling in acetic anhydride, cis-1,2,3,4-CHDA could be converted to its trans-isomer. The process of thermal isomerization was monitored by H-1 NMR spectra and the mechanism of conversion was proposed. Their absolute structures of cis- and trans-1,2,3,4-CHDAs were elucidated by single crystal X-ray diffraction. The polycondensations of cis- and trans-1,2,3,4-CHDAs with aromatic diamines such as 4,4'-oxydianiline (ODA), 4,4'-methylenedianiline (MDA), 4,4'-diamino-3,3'-dimethyldiphenylmethane (DMMDA), 4,4'-bis(4-aminophenoxy)benzene (TPEQ), 2,2-bis[4-(4-aminophenoxy)phenyl] propane (BAPP) were studied. It is easy to obtain higher molecular weight polyimides from trans-1,2,3,4-CHDA using conventional one-step or two-step methods. However, higher molecular weight polyimides derived from cis-1,2,3,4-CHDA could not be prepared by the usual methods (solid content ca. 10%) owing to the trend of forming cyclic oligomers.

医药-护肤品中氯霉素和1,2-丙二醇的分析方法

医药－护肤品中氯霉素和１，２－丙二醇的分析方法是先进行氯霉素和１，２－丙二醇的富集，再用高效液相色谱、元素分析、质谱分析、红外光谱分析、无机金属离子测定对氯霉素富集物定性分析，用高效液相色谱分析、红外光谱分析、无机金属离子测定对１，２－丙二醇富集物定性分析，色谱外标法完成氯霉素和１，２－丙二醇的定量分析。本发明解决了未知成分的被浓缩富集问题，对被检测的物品可定性、定量分析，应用领域的广泛性。

Crystallization and phase behavior of crystalline syndiotactic 1,2-polybutadiene/isotactic polypropylene blends in solution-cast thin films

Crystallization and phase behavior in solution-cast thin films of crystalline syndiotactic 1,2-polybutadiene (s-1,2-PB) and isotactic polypropylene (i-PP) blends have been investigated by transmission electron microscopy (TEM), atomic force microscopy (AFM) and field-emission scanning electron microscopy (FESEM) techniques. Thin films of pure s-1,2-PB consist of parallel lamellae with the c-axis perpendicular to the film plane and the lateral scale in micrometer size, while those of i-PP are composed of cross-hatched and single-crystal-like lamellae. For the blends, TEM and AFM observations show that with addition of i-PP, the s-1,2-PB long lamellae become bended and i-PP itself tends to form dispersed convex regions oil a continuous s-1,2-PB phase even when i-PP is the predominant component, which indicates a strong phase separation between the two polymers during film formation. FESEM micrographs of both lower and upper surfaces of the films reveal that the s-1,2-PB lamellae pass through i-PPconvex regions from the bottom, i.e. the dispersed i-PP regions lie on the continuous s-1,2-PB phase. The structural development is attributed to an interplay of crystallization and phase separation of the blends in the film forming process.

Syntheses, structures and near-IR luminescent studies on ternary lanthanide (Er-III, Ho-III, Yb-III, Nd-III) complexes containing 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)hexane-1,3-dionate

The ligand Hhfth [4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)hexane-1,3-dione], which contains a heptafluoropropyl group, has been used to synthesize several new ternary lanthanide complexes (Ln = Er, Ho, Yb, Nd) in which the synergistic ligand is 1,10-phenanthroline (phen) or 2,2'-bipyridine (bipy). The two series of complexes are [Ln(hfth)(3)phen] [abbreviated as (Ln)1, where Ln = Er, Ho, Yb] and [Ln(hfth)(3)bipy] [abbreviated as (Ln)2, where Ln = Er, Ho, Yb, Nd]. Members of the two series have been structurally characterized. The growth morphology, diffuse reflectance (DR) spectra, thermogravimetric analyses, and photophysical studies of these complexes are described in detail. After ligand-mediated excitation of the complexes, they all show the characteristic near-infrared (NIR) luminescence of the corresponding Ln(3+) ions (Ln = Er, Ho, Yb, Nd). This is attributed to efficient energy transfer from the ligands to the central Ln(3+) ions, i.e. an antenna effect. The heptafluorinated substituent in the main hfth sensitizer serves to reduce the degree of vibrational quenching. With these NIR-luminescent lanthanide complexes, the luminescent spectral region from 1300 to 1600 nm, which is of particular interest for telecommunication applications, can be covered completely.

Fe(2-EHA)(3)/Al(i-Bu)(3)/hydrogen phosphite catalyst for preparing syndiotactic 1,2-polybutadiene

Polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene with art iron(III) catalyst system has been investigated. Activity of the catalyst was affected by the type of cocatalyst alkylaluminum and the phosphorus compound as an electron donor, molar ratio of catalyst components, and their aging sequence and aging time of the catalyst. The microstructure and configuration of the polymer was decided by the catalyst components, the higher [Al]/[Fe] molar ratio tending to yield syndiotactic 1,2-polybutadiene, while the higher [P]/[Fe] molar ratio favors the formation of amorphous 1,2-polybutadiene.

Poly[di-mu(3)-chloro-mu(2)-trans-1,2-di-4-pyridylethylene-dicopper(I)]: a two-dimensional organic-inorganic hybrid constructed from linear CuCl clusters and bridging ligands

The structure of the title compound, [Cu2Cl2(C12H10N2)](n), contains infinite CuCl staircase-like chains, which lie about inversion centres. The trans-1,2-di-4-pyrid-ylethyl-ene mol-ecules also lie about inversion centres and connect the CuCl chains through Cu-N coordination bonds into a two-dimensional organic-inorganic hybrid network. The planar sheets are stacked along the c axis and associated through weak C-H center dot center dot center dot Cl inter-actions. The results show a reliable structural motif with controllable separation of the CuCl chains by variation of the length of the ligand.

catena-Poly[[[2-(2-furyl)-1H-imidazo[4,5-f][1,10]phenanthroline]zinc(II)]-mu-benzene-1,2-dicarboxylato]

In the title compound, [Zn(C8H4O4)(C17H10N4O)](n), the Zn-II atom is five-coordinated by two N atoms from the phenanthro-line-derived ligand and three O atoms from one bidentate and one monodentate benzene-1,2-dicarboxylate (1,2-BDC) dianions in a distorted trigonal-bipyramidal geometry. The Zn-II atoms are bridged by the 1,2-BDC ligands to form a single-chain structure. Neighboring chains interact through pi-pi interactions, leading to a two-dimensional network.

用核磁共振方法表征6(8)氨基-3H苯[1,2]氧嗪-1,4-二酮

用一维1HNMR、13CNMR方法研究了6(8)氨基-3H苯[1,2]氧嗪-1,4二-酮的结构,并通过二维1H-1H同核相关谱(COSY)、13C-1H异核相关谱(HMQC)及13C-1H异核远程相关谱(HMBC)进一步确定了该类化合物的1H谱和13C谱中各谱峰的归属,为研究同类化合物表征提供了依据。