Diacetonediperoxide (DADP) derivatives were investigated with density functional theory (DFT) methods at the DFT-B3LYP and M06-2X/6-311++G (d, p) levels and were also compared with other multi-peroxidic compounds. The investigated derivatives were 3,6-dimethyl-3,6-diamine-1,2,4,5-tetraoxane (DADPNH2), 3,6-dimethyl-3,6-dinitro-1,2,4,5-tetraoxane (DADPNO2), and 3,6-dimethyl-3,6-bis(trifluoromethyl)-1,2,4,5-tetraoxane (DADP3F). The investigations were focused on detonation performance and stability which were determined according to geometrical and electronic structure. The results of the simulation revealed that DADP derivatives are less sensitive than some other organic peroxidic compounds. In addition, detonation performance, including explosion heat (Q), detonation velocity (D), and detonation pressure (P), was estimated according to density and heat of formation using EXPLO 5 software. The results revealed that DADPNO2 has better detonation performance (Q = 5543 kJ kg-1, P = 23.7 GPa, D = 7631 m s-1) compared with traditional explosive 2,4,6-trinitrotoluene (TNT; Q = 5418 kJ kg-1, P = 19.0 GPa, D = 6950 m s-1). Therefore, it is a novel candidate for use as an energetic material.

Present paper deals with the preparation (by sol-gel method) and characterization (by H-2-TPR, XPS, XRD, IR, SEM, TEM) of the Pt substituted LaMn1-xPtxO3 (x = 0,0.05,0.1,0.2,0.3) perovskite oxides and their activities towards the diesel soot oxidation at simulated atmosphere. The results show platinum enters the perovskite crystal structure when x < 0.1. With the increase of platinum doping amount, the oxygen vacancy concentration on the catalyst surface increases, and H-2-TPR shows that the low-temperature oxidation-reduction performance of the catalyst is improved with the increase of platinum doping amount. Catalytic oxidation of soot was studied under tight contact with soot/catalyst ratio of 1/10 under a flow rate of air at 100 ml/min. LaMn0.8Pt0.2O3 perovskite catalyst was found to give the best result for soot oxidation with the light off temperatures T-10 = 339 degrees C, T-50 = 370 degrees C, T-90 = 405 degrees C. The might reaction mechanism is also presented.

In this paper, we propose a novel method based on the plate theory to simultaneously predict retention times and peak shapes under gradient elutions and different flow rates by reversed-phase high-performance liquid chromatography. The proposed method yielded excellent retention prediction results in experiments with 16 common sulfonamides under 18 gradient conditions and four different flow rates, including 0.7, 1.0, 1.3, and 1.5 mL/min. The mean absolute deviation was 0.70%, which indicates accurate prediction. Moreover, the proposed method predicts the change well in peak shapes caused by the expansion or compression of peaks under different gradient conditions.

In this paper, a new concept of calibration hold-up time was defined. On the basis of the concept, a novel method was proposed to predict retention times in temperature programmed (isothermal) under constant flow and constant pressure mode each other, and the method also researched in simultaneous pressure and temperature programmed. The prediction results show that average relative errors are 1.33% (0.64%) in temperature programmed (isothermal) under constant pressure mode by using isothermal dates in constant flow mode, and the other way around, average relative errors are 0.62% (−0.62%). For simultaneous pressure and temperature programmed, retention times were predicted by using isothermal dates in constant flow and constant pressure mode, average relative errors are −0.24% and −0.16%; and retention times were predicted by using isothermal dates directly, average relative errors are −0.62%.

Hollow silica spheres possessing excellent mechanical properties were successfully prepared through a layer-by-layer process using uniform polystyrene (PS) latex fabricated by dispersion polymerization as template. The formation of hollow SiO2 micro-spheres, structures and properties were observed in detail by zeta potential, SEM, TEM, FTIR, TGA and nitrogen sorption porosimetry. The results indicated that the hollow spheres were uniform with particle diameter of 1.6 μm and shell thickness of 150 nm. The surface area was 511 m2/g and the pore diameter was 8.36 nm. A new stationary phase for HPLC was obtained by using C18-derivatized hollow SiO2 micro-spheres as packing materials and the chromatographic properties were evaluated for the separation of some regular small molecules. The packed column showed low column pressure, high values of efficiency (up to about 43 000 plates/m) and appropriate asymmetry factors.

Witnessed by X-ray powder diffraction (XRD), Raman, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies, BiVO4 nanofibers and porous nanostructures were successfully fabricated by electrospinning method using NH4VO3 and Bi(NO3)(3) as starting materials. Polyvinylpyrrolidinone (PVP) was used to tune the viscosity and spinnability of the electrospinning sol. The slow decomposition and combustion of PVP matrix prevented rapid crystal growth of BiVO4 nanostructures leading to considerably small crystallite size (approximately 19.1-28.3 nm) with less surface defects after two hours calcination at varying temperatures. This paid great tributes to the superior visible light photocatalytic activity when compared to the submicron sized BiVO4 prepared in the absence of PVP. (C) 2015 Elsevier Ltd. All rights reserved.

采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术建立了烟草中硒的形态分析方法.烟草样品采用0.10 mol/L HCl超声提取30 min,经离心、过膜后引入HPLC-ICP-MS进行分析.使用Hamilton PRP X-100阴离子交换柱,以20 mmol/L柠檬酸水溶液为流动相(pH=7.0),流速1.2 mL/min,优化条件下实现了6种硒形态的分离.质谱采用He碰撞模式,硒代胱氨酸、亚硒酸根、甲基硒代半胱氨酸、硒酸根、硒脲、硒代蛋氨酸检出限分别为1.20、0.34、1.65、0.13、3.25和0.65 ng/mL.该方法操作简单、快速、灵敏度高,精密度好,加标回收率在86.1％～95.8％之间,适用于烟草中硒元素形态分析.

Objective] To research the transfer volume and law of heavy metal before and after cigarette smoking, and to provide references for reducing the damage of cigarette products.[ Method] Two pretreatment methods of microwave digestion and acid extraction were used to process the ash content, total particulate matter of mainstream smoke ( TPM) and cigarette filter rod.Detection results of heavy metal elements were compared by the two methods.[ Result] The microwave digestion method was better than acid solution extraction method on analysis of TPM, but not so good on analysis of ash and filter rod.Meanwhile, the migration amount and migration rate were studied, which showed that most heavy metal elements were escaped with lateral flow, which was between 66.89%-95.48%.and Hg was mostly escaped with lateral flow.Except Hg, other heavy metal elements were separately found in ash, TPM and filter rod.Cr, Ni, As and Se were mostly residual in ash, followed with TPM.And filter rod was the least, while Cd and Pb were just in the reverse order.Normally, 5% or less of the heavy metal elements were transferred to TPM, only a small part of which could reach 5% -10%.[ Conclusion] Most of the heavy metal elements are taken by lateral flow, ash and filter rod, while the migration amounts of mainstream smoke are extremely low.

采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术建立了烟草中铬元素形态分析方法.采用Hamilton PRP X-100阴离子交换柱,对盐溶液种类、流动相的浓度、pH值、EDTA浓度、络合温度等条件进行了考察.在0.100mol/L硝酸铵水溶液为流动相,pH=7.0,流速为1.0 mL/min条件下达到了Cr(Ⅲ)与Cr(Ⅵ)最佳分离效果,检出限分别为0.048ng/mL、0.054 ng/mL.在0.5～20 ng/mL线性范围内,Cr(Ⅲ)与Cr(Ⅵ)的R2分别为0.9998和0.9996.烟草样品采用20 mmol/LEDTA-2Na溶液在50℃条件下超声提取60 min,然后通过离心、过膜、进样分析.该方法前处理操作简单、灵敏度高、准确性和精密度好,适用于烟草中铬元素形态分析.

A biomorphic perovskite-type oxide, possessing a large surface area, was successfully fabricated using pinewood as a template. The porous structure prompted catalytic activity towards soot combustion under low temperature.

A novel algorithm, translation modification iteration (TMI), is proposed for resolving overlapping chromatographic peaks. By this method, a series of similar peaks are obtained from the initial construction of single component peaks and approach the profiles of real single component peaks by iteration. Both simulated and experimental data are investigated with TMI, consequently overlapping peaks can be resolved into reasonable single component peaks easily and efficiently. Quantitative analysis is also successfully achieved in both simulated and experimental data, and the quantitative results obtained from TMI are superior to those obtained from perpendicular drop (PD) and tangent skim (TS) methods. Without too much time devoted to the procedure, TMI is a simple and practicable method for resolution and quantification of overlapping chromatographic peaks.

Copper catalysts prepared using two kinds of supports (BaTiO3 and Fe2O3@BaTiO3) have been tested for soot combustion. Perovskite-type oxide BaTiO3 shows excellent properties as support but has small specific surface area. Fe2O3@BaTiO3 core/shell microspheres, as improved support of BaTiO3 support, were fabricated by a hydrothermal-annealing approach. Fe2O3@BaTiO3 support has large specific surface area, which optimizes the contact condition of the gas-soot-catalyst three-phase reaction. Due to the Cu-Fe2O3@BaTiO3 interaction, the redox properties of copper are improved. Soot combustion is tested under O-2 gas flow and NOx/O-2 gas flow, and Fe2O3@BaTiO3 supported copper catalyst (Cu/Fe2O3@BaTiO3) all shows higher catalytic activity and CO2 selectivity than BaTiO3 supported copper catalyst (Cu/BaTiO3).

Three-dimensionally ordered macroporous (3DOM) SiOC was successfully fabricated on a cordierite monolith, and LaCoO3 was coated onto the 3DOM SiOC/cordierite. The 3DOM structure produced a positive effect on soot combustion.

A novel, simple, and rapid method for the quantification of 27 commonly used pesticides in ginseng incorporating a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure was developed and validated. The pesticides were extracted with 1% acetic acid in acetonitrile and extracts purified by use of the mixed sorbents primary-secondary amine, C-18, and graphitized carbon black. Quantitative analysis of all pesticides was performed by ultra-performance LC/MS/MS in the positive ionization mode in a single run due to the fast polarity switching capability of the mass spectrometer. Two precursor-product ion transitions were monitored for each compound in the multiple reaction monitoring mode. Quantification was carried out using matrix-matched standards for calibration. Recoveries of the proposed method from the spiked samples were achieved in the range 62.8-108.5%, and RSD ranged from 1.5 to 11.8%.

Semi-volatile organic compounds(SVOCs)from the China Ⅱ non-load diesel engine were sampled and analyzed. The results indicate that the SVOCs emissions in gas phase are higher than those in particulate matters(PMs). Meanwhile,the SVOCs emissions increase with the growing of load in both phases. Alkanes are the main compounds detected in SVOCs,followed by PAHs such as 2,3-dihydro indene,tetrahydro naphthalene,biphenyl,naphthalene,fluorine and homologous series. The results also indicate that the PAHs emission proportion in gas phase is much higher than that in PMs. In gas phase,Nap,Acpy,Acp,Flu,PA and Ant are the main compounds,which account for more than 95% of all the PAHs emissions,while in PMs,Pyr,FL,CHR,BaA and Bap are the main compounds. BaA and CHR account for more than 80% of total PAHs in PMs. Most PAHs in gas phase have 2 or 3 benzene rings. However,in particulate matter 4 benzene ring compounds are the main ingredient,followed by 3 rings.

Based on the enlightenment from the crystallization behavior of polymer, a novel retention equation constructed with only three pairs of isothermal retention data was proposed to predict retention times in temperature programmed gas chromatography (TPGC). The new retention equation worked beautifully in both the single- and the multiple-ramp temperature-programmed modes, yielding the average absolute relative errors of 0.65% for single-ramp TPGC across all the 18 analytes in 3 temperature programmed experiments and 0.30% for multiple-ramp TPGC across all the 8 analytes in 6 temperature programmed experiments tested in this work. Moreover, to compare with the new retention equation systematically and thoroughly, another 13 retention equations determined by two or three parameters were derived from a universal formula In k = a(0) + a(1)/T + a(2)/T-2 + a(3) In T + a(4)T + a(5)T(2) as a combination of the relationships between Ink and T with reference to four widely used retention equations in publications. Calculated by these 14 retention equations with the same experimental data, the absolute relative errors of prediction retention times for single-ramp TPGC mode were compared by means of statistical analysis. At a very high significance level of 1%, statistical evidences of paired t-test strictly implied that the new retention equation yielded the best prediction results among all of the 14 retention equations. In addition, remarkably, among the 13 retention equations, three seldom used in publications retention equations also worked nicely, yielding satisfactory average absolute relative errors of 0.78%, 0.81% and 0.84% for single-ramp TPGC. (C) 2013 Elsevier B.V. All rights reserved.

A serials of La1−x Ce x MnO3 (x = 0, 0.2, 0.4, 0.6 and 0.8) catalysts have been prepared via a sol-gel process using citric acid as a chelating agent. The phase composition and morphology of the catalysts are characterized by XRD, SEM and TEM. La1−x Ce x MnO3/γ-Al2O3/cordierite catalyst has also been prepared by immersion process using cordierite honeycomb ceramic as carrier and γ-Al2O3 as support agents. The effect of Ce-doping on the structure of perovskite and catalytic property of methane combustion is explored. The results show that with the increase of Ce substitution, the crystal structure of perovskite changes from the tetragonal system to the orthorhombic system and when the x is equal to 0.2, the catalytic property in methane combustion is the best.

Barium-ferrite-containing glass ceramic fibers were successfully prepared by the combination of a sol–gel process and electrospinning technique using basic iron formate, barium acetate and boric acid as the starting materials. After leaching of barium borate matrix, pure phase BaFe12O19 fibers were obtained. The relationship of aged time and viscosity of the precursor solution was studied and the results showed that the viscosity corresponding to the spinnable state was 1–4 Pa s. The morphology, structure and magnetic properties of the obtained fibers were characterized with scanning electron microscopy, transmission electron microscopy, fourier transform infrared spectroscopy, thermo gravimetric analysis–differential scanning calorimetry, vibrating sample magnetometer. The X-ray diffraction results indicate that only the M-type Ba-ferrite and Ba-borate exist. The fibers had rough surface and hollow structure with the diameter no more than 1 μm. The fibers were composed of 40 nm BaFe12O19 nanoparticles embedded in the borate matrix. The coercivity and saturation magnetization of the synthesized fibers were 4,106.9 Oe and 17.8 emu/g, respectively.

Silicon oxycarbide (SiOC) fibers were produced through the electrospinning of the solution containing vinyltrimethoxysilane and tetraethoxysilane in the course of sol–gel reaction with pyrolysis to ceramic. The effect of the amount of spinning agent Polyvinylpyrrolidone (PVP) on the dope spinnability was investigated. At a mass ratio of PVP/alkoxides=0.05, the spinning sol exhibited an optimal spinnable time of 50min and generated a large quantity of fibers. Electrospun fibers were characterized by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis–differential scanning calorimetry (TGA–DSC), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The SEM results revealed that the SiOC fibers had a smooth surface and dense cross-section, free of residue pores and cracks. The XPS results gave high content of SiC (13.99%) in SiOC fibers. The SiOC fibers prepared at 1000°C had a high tensile strength of 967MPa and Young's modulus of 58GPa.

A series of complex oxide Cu1-xKxFe2O4 fibers have been prepared via a sol-gel process related electron-spinning procedure, in which x is among 0, 0.05, 0.1 and 0.2 corresponding to the quantity of Cu2+ partial substitution by K+. The average diameter of the fiber was 500 nm. The catalytic activity of the catalysts in removal of NOx and carbon black from diesel exhaust gases were examined in detail using temperature-programmed reaction technique. The results show that after partial substitution of Cu2+ with K+, the catalytic activities have been improved. Cu0.95K0.05Fe2O4 as an optimal catalyst can significantly decrease the ignition temperature (Tig) of the PM, and has high catalytic activity on the removal of NOx.