O(1D)+Si(CH3)3Cl反应生成振动激发的OH(ν≤3)

The vibrationally excited OH(v) from the reaction of O(~1D)+Si(CH_3)_3Cl was observed by UV laser photolysis/FTIR emission spectroscopy. The vibrational number was only up to 3 with a ratio of 1:0.8:0.1 for v=1:2:3. Comparing this result with the similar reaction of O(~1D)+Si(CH_3)_4 which OH(v) vibrational number was high up to 4 with a ratio of 1:1:1:0.3 for v=1:2:3:4 under the same experimental conditions, it was found that the substitution of Cl for CH_3 affected the extent of heavy Si atom blocking the energy migration in a molecule. This results identifies the prediction that the characteristic of electrons in central atom plays an important role in intramolecular energy transfer.     

Conductivity of LiBOB in various ternary solvent blends and the electrochemical performance of LiBOB-PC/EMC/DMC used in Li/MCMB and LiFePO4/Li cells

The solid-state reaction was employed to obtain LiBOB in vacuum dryer at 100°C, with the dryer of P₂O₅. The resulting LiBOB was employed in various ternary solvent blends to get the k, and its change with salt, solvent composition and temperature. 0.7 M LiBOB-PC/EMC/DMC (1: 1: 1, v: v: v) and 0.5 M LiBOB-EC/EMC/DMC (1: 1: 1, v: v: v) were observed to have better k at wide θ range, and the former was chosen to assemble Li/MCMB and LiFePO₄/Li cells. The results indicated that it can stabilize the MCMB anodes, and exhibit good stability in LiFePO₄/Li cell. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 10, pp. 1231–1236. The text was submitted by the authors in English.     

MgO/h-BN复合载体对Ba-Ru/MgO/h-BN氨合成催化剂性能的影响(英文)

采用浸渍法制备了系列不同质量比的MgO/h-BN复合载体负载的Ru基氨合成催化剂,采用X射线衍射、N2低温物理吸附、X射线荧光、扫描电镜、透射电镜、程序升温分析等手段对催化剂进行了详细的表征,并在固定床反应器上考察了它们在氨合成反应中的催化性能.结果表明,MgO/h-BN复合载体中h-BN含量对催化剂活性的影响较大,Ba-Ru[1:1](摩尔比)/MgO/h-BN[8:2](质量比),Ba-Ru[1:1]/MgO/h-BN[6:4]和Ba-Ru[1:1]/MgO/h-BN[5:5]催化剂上氨合成活性均高于Ba-Ru/MgO催化剂.在425°C,5.0MPa,N2/H2=1/3和5000h?1条件下,Ba-Ru[1:1]/MgO/h-BN[8:2]表现出最优催化活性,达506.9ml/(gcat·h).这可归因于MgO/h-BN复合载体上存在较高数量的碱性位,特别是弱碱性位和中等强度碱性位,而这些碱性位可能是由MgO和h-BN之间的相互作用造成.     

Egyptian heavy vacuum gas oil hydrotreating over Co-Mo/CNT and Co-Mo/γ-Al_2O_3 catalysts

The catalytic activity of CoMoS /CNT towards the Egyptian heavy vacuum gas oil hydrotreating was studied. The delivered CNT was functionalized with 6 mol /L HNO_3. The CNT were loaded with 12% MoO_3( by weight) and 0.7 Co /Mo atomic ratio with impregnation methods. The γ-Al_2O_3 catalyst was also prepared by impregnation method to compare both catalysts activities.The analysis tools such XRD,Raman spectroscopy,TEM,and BET were used to characterize the catalysts. The autoclave reactor was used to operate the hydrotreating experiments. The hydrotreating reactions were tested at various operating conditions of temperature 325-375 ℃,pressure 2-6 MPa,time 2-6 h,and catalyst /oil ratio( by weight) of 1 ∶75,1 ∶33 and 1 ∶10. The results revealed that the CoMoS /CNT was highly efficient for the hydrotreating more than the CoMoS /γ-Al_2O_3. Also, the hydrodesulfurization( HDS) increased with increasing catalyst /oil ratio. Additionally,results showed that the optimum condition was temperature 350℃,pressure 4 MPa,catalyst /oil ratio of 1 ∶75 for 2 h. Furthermore,even at low CoMoS /CNT catalyst /oil ratio of 1 ∶75,an acceptable HDS of 77.1% was achieved.     

Properties of electrospun PVDF/PMMA/CA membrane as lithium based battery separator

Poly vinylidene fluoride:poly methyl methacrylate:cellulose acetate (CA) at ratios of 100:0:0, 90:10:0, 90:5:5 and 90:0:10 respectively, were successfully electrospun. These membranes were mixed to form a 12 wt% solution prepared with volume ratio 7:3 of DMAc:acetone solvents. These membranes were then analyzed using differential scanning calorimetry, scanning electron microscopy, FTIR, WAXD, pore size, porosity% and electrolyte uptake (EU)%. It was observed that the best absorption results were obtained in the presence of CA. The electrospun membrane at ratio of 90:0:10 was observed with the highest porosity of 99.1 % and EU at 323 %. It also had a 43.6 % crystallinity and a 162 °C melting temperature. It was then concluded that addition of CA improved the separator properties.     

氟烷磺酰氟/双氧水/碱/丙酮体系与苄醇衍生物的氧化反应

研究了氟烷磺酰氟/双氧水/氢氧化钠/丙酮体系与6个苄醇衍生物的氧化反应, 其中氟烷磺酰氟包括HCF₂CF₂OCF₂CF₂SO₂F, n-C₄F₉SO₂F和n-C₈F₁₇SO₂F. 最优反应条件为n(苄醇衍生物): n(氟烷磺酰氟): n(双氧水): n(氢氧化钠)=1: 4: 8: 8, 溶剂为丙酮, 反应温度为20℃, 反应时间为24 h. 产物酮的收率为23% ~92%. 探讨了该氧化反应的机理, 原位生成的氟烷基过氧磺酸中间体可将丙酮氧化为二甲基二氧杂环丙烷, 进而将反应体系中共存的苄醇衍生物氧化成相应的产物酮. 氟烷磺酰氟/双氧水/氢氧化钠/丙酮体系原位生成的二甲基二氧杂环丙烷氧化苄位羟基的能力和传统的Oxone/CH₃COCH₃体系相当. 本研究提供了一种新颖的原位制备二甲基二氧杂环丙烷的方法.     

有机锡配合物{[(n-C8H17)2Sn(O2CCH2CS2NC4H8O)]2O}2的合成，表征及晶体结构

The title complex {[(n-C₈H₁₇)₂Sn(O₂CCH₂CS₂NC₄H₈O)]₂O}₂ has been synthesized by the reaction of (morpholinylthiocarbamoylthio)acetic acid with the di-n-octyltin oxide in 1∶1 molar ratio. The complex was characterized by elemental analysis, IR and ¹H NMR. The crystal and molecular structure of complex was determined by X-ray single crystal diffraction. The crystal belongs to triclinic system with space group P1 and unit cell dimensions: a=1.201 5(9) nm, b=1.481 8(11) nm, c=1.894 1(14) nm, α=72.485(10)°, β=88.586(10)°, γ=66.893(9)°, and Z=1, μ=1.034 mm^-1, V=2.941(4) nm³, D_c=1.295 g·cm^-3, F(000)=1 196, R₁=0.058 8, wR₂=0.155 8. The complex is a centrosymmetric structure with a four-membered central endo-cyclic Sn₂O₂ unit in which two bridged oxygen atoms both connect with an exo-cyclic tin atom. The endo-cyclic tin atoms and the exo-cyclic tin atom are all five-coordinate and have coordination geometry of distorted trigonal bipyramid with an additional weak coordination carboxylate oxygen. Four carboxylate ligands are divided into two types. And two of them are monodentate and connecting to each of exo-cyclic tin atoms by using one oxygen atom, whereas the others bridge to each pair of exo-and endo-cyclic tin atoms utilizing one oxygen atom. CCDC: 277048.     

稀土固体超强酸SO42-/TiO2/La3+催化合成丁酸异戊酯

The synthesis of isoamyl butyrate with isoamyl alcohol and butyric acid as reactants and rare-earth solid superacid SO₄^2-/TiO₂/La³⁺ as catalyst had been studied.The influent actors of reaction were investigated.The results showed that the appropriate conditions should be: Weight of catalyst was 0.5g (weight of butyric acid if 0.2mol); molar ratio of isoamyl alcohol to butyric acid was 1.8: 1; reaction time was 2.0 h; the taking water reagent (Toluene) was 15mL.The yield of isoamyl butyrate was about 99.0%.     

Fluorocyclohexanes-III 1H:4H/2H- and 1H/2H:4H-nonafluorocyclohexane and derived compounds

Two nonafluorocyclohexanes of b.p. 92° and 101°, made by fluorination of benzene,¹ have each been dehydrofluorinated to give the same six unsaturated products. These were identified by oxidation and other studies as 3H:4H- and 4H:5H-octafluorocyclohexene, 1H-1:4-, 1H-1:3-, and 2H-1:3-heptafluorocyclohexadiene, and hexafluorobenzene,² thus indicating a 1H:2H:4H-structure for the saturated precursors. The stereochemistry of the adjacent> CHF groups was established by resolution, via the brucine salt, of the 3H:4H-hexafluoroadipic acid obtained by oxidation of the 4H:5H-mono-olefin, showing that the hydrogens were trans. The complete stereochemistry of the nonafluorides was suggested by the dehydrofluorinations and confirmed by further fluorination³ to give known decafluorocyclohexanes. Treatment of 4H/5H-octafluorocyclohexene with lithium aluminium hydride in diethyl ether gave 1H,4H/5H-heptafluorocyclohexene, a precursor of pentafluorobenzene.⁴     

Lysophosphatidylcholine—biomarker of Metformin action: studied using UPLC/MS/MS

An UPLC/MS/MS based metabonomic method was developed and applied to the elucidation of biomarker of metformin action. The plasma metabolite profiling in healthy volunteers before and after per os metformin was determined with UPLC/MS/MS and analyzed by using multivariate statistics. Significant difference in endogenous metabolite profiles was revealed before and after administration of metformin. Four biomarkers found were lysophosphatidylcholines (LPCs), and their structures were tentatively identified to be 16:0 LPC, 18:0 LPC, 18:1 LPC and 18:2 LPC according to the molecular ions information and corresponding fragments of product ion scan. Lysophosphatidylcholine in blood may be involved in metformin treatment. Copyright © 2009 John Wiley & Sons, Ltd.     

Preparation of MnxNi0.5-xZn0.5Fe2O4 Nanorods by the Co-precipitation Method

Mn_xNi_0:5-xZn_0:5Fe₂O₄ nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn²⁺, Ni²⁺, and Fe²⁺ in the lye. The phase, morphology, and particle diameter were examined by the X-ray diffrac-tion and transmission electron microscopy. The magnetic properties of the samples were stud-ied using a vibrating sample magnetometer. The results indicated that pure Ni_0:5Zn_0:5Fe₂O₄ nanorods with a diameter of 35 nm and an aspect ratio of 15 were prepared. It was found that the diameter of the Mn_xNi_0:5-xZn_0:5Fe₂O₄ (0≤x≤0.5) samples increased, the length and the aspect ratio decreased, with an increase in x value. When x=0.5, the diameter and the aspect ratio of the sample reached up to 50 nm and 7～8, respectively. The coercivity of the samples first increased and then decreased with the increase in the x value. The coer-civity of the samples again increased when the x value was higher than 0.4. When x=0.5,the coercivity of the Mn_xNi_0:5-xZn_0:5Fe₂O₄ sample reached the maximal value (134.3 Oe)at the calcination temperature of 600 oC. The saturation magnetization of the samples first increased and then decreased with the increase in the x value. When x=0.2, the satura-tion magnetization of the sample reached the maximal value (68.5 emu/g) at the calcination temperature of 800 oC.     

SnO2/SiO2 and Sn/Sb-oxide/SiO2 gel-derived composites. Part 1: Structural evolution from a Mössbauer study

The lasing photostability of the red perylimide dye (RPD) in various solid matrices was measured under frequency-doubled Nd:YAG laser excitation. The RPD: composite glass laser intensity decayed to 50% of its initial value after approximately 20,000 pump pulses of 13 mJ/pulse. The output of RPD:ormosil glass and RPD:PMMA glass lasers decayed to 50% of their initial value after 1,200 and 1,000 pump pulses of the same energy, respectively. For rhodamine-6G:silica-gel and rhodamine-6G:ormosil glass lasers, the 50% decay occurred already after 1,000 and 300 pulses, respectively. The decay was non-exponential, suggesting that the dye bleaching was not a single-photon process. The average laser output decay rates increased linearly with the pump energy. Singlet-singlet excited state absorption of the RPD dye in the solid matrices was also measured between 550 and 730 nm. At ～600 nm the cross section was ～2×10^?16 cm²/molecule. The excited-state absorption competes with the lasing, and is a main factor that limits the laser efficiency.     

国产航空煤油裂解催化剂Pt/ZrxTixAl1-2xO2的性能

采用共沉淀法制备了一系列Zr_xTi_xAl_1-2xO₂复合氧化物载体材料,考察了其作为裂解催化剂载体对航空煤油裂解反应的影响.?采用全自动吸附仪、X射线衍射、扫描电镜/能谱仪联用、NH₃-程序升温脱附等手段对催化剂进行了表征.?结果表明,当ZrO₂：TiO₂：Al₂O₃质量比为1：1：3时催化剂具有最大的比表面积和孔容;具有最强的表面酸性和最集中的强酸中心密度,且具有良好的再生功能.?实验结果表明,载体ZrO₂：TiO₂：Al₂O₃质量比为1：1：3时催化剂上650?℃裂解产气量较热裂解提高了2.1倍,700?℃时提高1.4倍.?另外,该系列载体材料经1000?℃焙烧5?h后,所制得的催化剂几乎失去了催化活性.     

Rheology of concentrated multi-sized poly(St/BA/MMA) latices

 Four monodisperse latices with particle size of 75, 135, 340 and 477 nm were synthesized. The rheo-logical properties of mixture of the monodisperse latices were inves-tigated as a function of blending ratio, and compared with those of multi-modal latices, in a range of shear rate from 0.2 to 100 s^-1. The maximum packing (highest solid contents) was observed at a weight fraction 80% of large particles with respect to total solids contents for both bimodal and trimodal latices, and the lowest viscosity was obtained when the ratio of large to medium to small particles was approximately 80/10/10 (by wt.). It was also demonstrated that this minimum in the viscosity is not strongly dependent on the actual size of each kind of particles present in the multimodal latices. Received: 22 November 1996 Accepted: 26 November 1997     

The Al stabilized phase Li3−3xAlxBO3

The structure of an Al³⁺ stabilized phase Li_3−3xAl_xBO₃ (x≈0.18) was determined by means of single crystal X-ray diffraction. This phase crystallizes in space group P6₁22 or P6₅22, with lattice constants , and Z=6. The unit cell consists of six layers of BO₃ groups with Li⁺ cations distributing statistically on five crystallographic sites, none of which is fully occupied. The Li sites are close to each other and a three-dimensional network results when Li sites only within 1.65 Å are connected. Significant ionic conductivity was observed for this phase.     

Simultaneous propane dehydrogenation andco2hydrogenation overCrOx/SiO2catalyst

Summary Single reverse water-gas shift (RWGS) and dehydrogenation of propane with CO₂(DH-CO₂) reactions in the presence and absence of the CrO_x/SiO₂ catalyst have been studied between 673 and 873 K. It was found that the CrO_x/SiO₂ catalyst is active both in the dehydrogenation of propane and in the RWGS reactions. The obtained results suggest that the dehydrogenation of propane to propene in the presence of CO₂on CrO_x/SiO₂can be facilitated by the RWGS reaction.</o:p>     

Formation of water-in-oil (W/O) nano-emulsions in a water/mixed non-ionic surfactant/oil systems prepared by a low-energy emulsification method

W/O nano-emulsion formation by a low-energy emulsification method is described for the first time. The nano-emulsions have been formed in water/mixed Cremophor EL:Cremophor WO7 surfactant/isopropyl myristate systems at Cremophor EL:Cremophor WO7 ratios between 1:2 and 1:9, by slow addition of isopropyl myristate to surfactant/water mixtures. Phase behaviour studies have showed that the compositions giving rise to W/O nano-emulsions belong to multiphase regions, one of the phases being a lamellar liquid crystalline phase. The droplet size of the nano-emulsions at a fixed oil concentration of 85% and mixed surfactants/water ratio of 70/30 ranged from 60 to 160 nm as Cremophor EL:Cremophor WO7 ratio increased from 1:8 to 1:2. These nano-emulsions showed high kinetic stability. No phase separation was observed during 5 months in nano-emulsions of the water/Cremophor EL:Cremophor WO7 1:8/isopropyl myristate system with 85% oil concentration, although droplet size experienced an increase with time.     

半夹芯16电子化合物CpCo(S_2C_2B_(10)H_(10))与乙炔基二茂铁在甲醇中的反应性

半夹芯16电子化合物CpCo(S2C2B10H10)(1)(Cp:cyclopentadienyl)与过量乙炔基二茂铁(FcC≡CH)(Fc:ferrocenyl)在甲醇中反应,分离得到了化合物(CHCFc)(CH=CFc)(S2C2B9H10)(8)和2个乙炔基二茂铁环三聚产物1,2,4-三二茂铁基苯和1,3,5-三二茂铁基苯。在8中,2个乙炔基二茂铁分子以"头对头"方式聚合连接到CpCo(S2C2B10H10)分子中的2个S原子上,导致CpCo结构单元的丢失。碳硼烷笼体B(3)位上的BH键发生活化,该B原子与1个乙炔基二茂铁分子的乙炔基末端C原子连接生成C-B键;同时,B(6)位的BH碎片在甲醇作用下失去,从而closo-C2B10闭式结构转变成nido-C2B9巢式结构。化合物8用单晶X-射线衍射分析方法进行了表征。     

Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry of polychlorinated biphenyls

A sample mixture of polychlorinated biphenyls (PCBs) was measured by gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) using four types of laser sources. When a fourth harmonic emission (266 nm) of a picosecond Nd:YAG laser (1064 nm) was utilized, highly chlorinated PCBs larger than hepta-CBs were not observed. A fifth harmonic emission (213 nm) of the picosecond Nd:YAG laser allowed the measurement of PCBs from di-CBs to octa-CBs, and the limit of detection (LOD) was several pg for each component of PCBs. The LOD for the total amount of PCBs, which was calculated using the protocol provided by the Ministry of the Environment, Japan, was 1000 pg. The signal intensity of the congeners with chlorine atoms at the ortho positions (non-coplanar PCBs) was enhanced by using the fifth harmonic emission. When the fourth harmonic emission remaining after fifth harmonic generation was simultaneously used, the LOD for total PCBs was improved to 667 pg. The PCB sample was also measured using a third harmonic emission (267 nm) of a femtosecond Ti:sapphire laser (800 nm), providing an LOD of 677 pg. Thus, the two-color beam (266/213 nm) of a picosecond Nd:YAG laser had a comparable, or even slightly superior, performance to the more expensive femtosecond Ti:sapphire laser.     

Application of TiO2/Er3+:Y3Al5O12 composite to photo-degrade acid red B dye under sun light irradiation

In this work, an upconversion luminescence agent, Er³⁺:Y₃Al₅O₁₂, was synthesized and its absorption and fluorescent spectra was determined. By calculation, the upconversion efficiency of the emission peak at 320 nm was estimated to be about 3.4%. And then, TiO₂/Er³⁺:Y₃Al₅O¹² composite was prepared by simple ultrasonic dispersion and liquids boil methods. The obtained composite was characterized by X-ray diffrac-tion. The effect of TiO₂/Er³⁺:Y₃Al₅O₁₂ composite with different Er³⁺:Y₃Al₅O₁₂ doping amount, heat-treated temperature and heat-treated time on photodegradation of acid red B under sun light was investigated in detail. It was found that the photocatalytic activity of TiO₂/Er³⁺:Y₃Al₅O₁₂ composite was much higher than that for the similar system with only TiO₂ powder. These results support the usefulness of TiO₂/Er³⁺:Y₃Al₅O₁₂ composite in the process of photodegrading dye wastewater and using the sun light.