蒽醌法过氧化氢生产工艺中氢效分析偏差影响因素探讨

对蒽醌法过氧化氢生产工艺中氢效分析方法进行了详细研究,结果表明,气源、底液、溶剂体系、氧化时间等因素均会对氢效产生显著的影响。通过优化分析方法,确定氢效6~9g/L时的最佳分析条件:20mL四丁基脲和5mL纯水为底液,氧气为气源,氧化时间10~20min。

蒽醌法过氧化氢生产工艺中控自动化分析方法的研究

对蒽醌法过氧化氢生产工艺中控自动化分析方法进行了详细研究。结果表明,在一定条件下,射流萃取器和电位滴定仪联用的自动化分析方法,可代替传统的人工萃取滴定分析方法,在氢效、氧效和萃余3种中控分析项目中准确度高、精密度良好,具有良好工业应用前景。

光合细菌Chromatium vinosum可溶性氢酶的EPR研究

光合细菌 Chromatium vinosum可溶性氢酶经 5次柱层析 ( DE-2 3,TSK-DEAE( ) ,Ultragel Ac A-4 4 ,TSK-DEAE( ) ,Superdex TM75 )分离后被纯化 365倍 ,得率为 32 % ,其催化放氢的活性为 8.4μmol H2 /( min· mg prot) .氧化态可溶性氢酶在 4 5 K下 ,产生了 Ni( )的典型 EPR信号 ( gx,y,z=2 .37,2 .1 6,2 .0 1 6和 gx,y,z=2 .30 ,2 .2 3,2 .0 1 6) ;在 1 0 K下 ,没有出现膜结合态氢酶中存在的 [3Fe-4 S]簇特征 EPR信号 .可溶性氢酶被 H2 还原后 ,Ni( )的特征 EPR信号消失 ,同时出现一个 [4 Fe-4 S]簇的特征 EPR信号 ( gx,y,z=1 .88,1 .90 ,2 .0 4 5 ) .研究结果表明 ,C.vinosum可溶性氢酶在结构和功能上不同于膜结合态氢酶 ,是一种新的催化放氢的 Ni

蒽醌法生产H_2O_2工作液的改进

为了改进蒽醌法生产H2O2的由重芳烃(AR)和磷酸三辛酯(TOP)组成的工作液的氢效,考察了2-乙基蒽醌(2-EAQ)在添加邻甲基环己基醋酸酯(2-MCHA)或二异丁基甲醇(DIBC)的三组分工作液(AR+TOP+2-MCHA和AR+TOP+DIBC)中的溶解度,并分析了三组分工作液的密度、黏度、界面张力和H2O2的分配系数,从中选取了体积比为75∶20∶5的AR+TOP+2-MCHA和体积比为75∶5∶20的AR+TOP+DIBC 2种性能优异的工作液,采用微反装置评价了其氢效。结果表明,与两组分工作液相比,2-EAQ在三组分工作液中的溶解度得到了显著提高;与两组分工作液的氢效5.65g/L相比,三组分工作液的氢效得到显著提高,分别达到12.53和11.31g/L。

Effects of synthesis conditions on layered Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_2 positive-electrode via hydroxide co-precipitation method for lithium-ion batteries

Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.

自动电位滴定仪在双氧水装置在线分析中的应用

将自动电位滴定技术应用于双氧水装置氢效、氧效、萃余、前酸、后酸分析,该技术可以应用于在线检测,有利于实现双氧水装置自动化、智能化。减少人为操作对分析结果的影响,缩短了分析时间,提高了工作效率,避免了操作人员长期接触重芳烃对身体造成的损害。

Bioequivalent Evaluation of Two Brands of Losartan/Hydrochlorothiazide Compound Tablets in Healthy Chinese Male Volunteers

Aim To evaluate the bioequivalence of two brands of losartan/hydrochlorothiazide （50 mg/12.5 mg） compound tablets in healthy Chinese male volunteers. Methods An open, randomized, single-dose, two-period cross-over study with a wash-out period of 7 d was conducted. Twenty healthy male volunteers were given a single dose 50 mg losartan/12.5 mg hydrochlorothiazide of either test （T） or reference （R） compound tablets, respectively. Blood samples were collected up to 48 h after oral administration. The concentrations of losartan and hydrochlorothiazide in plasma were determined by a validated HPLC-ESI-MS method. Results In the case of losartan, the 90% confidence intervals of two one-side test for percent ratios with a significant level （α） of 0. 05 were 86% - 112% for AUC0-12 and 89% - 134% for Cmax, respectively, which were within the interval proposed in the Chinese Pharmacopoeia, 80% - 125% of AUC and 70% - 143% of Cmax, respectively. Similarly, the 90% confidence intervals for percent ratios were 85% - 100% and 75% - 102% for hydrochlorothiazide, both of which fell into the accepted interval. Conclusion Two immediate-release compound tablets of losartan/hydrochlorothiazide are bioequivalent from a statistical standpoint in the extent and rate of absorption from the single-dose study in healthy Chinese male volunteers.

Microstructures and electrochemical corrosion properties of Mg-Al-Pb and Mg-Al-Pb-Ce anode materials

Mg-Al-Pb alloy is a good candidate for the anode material of magnesium seawater battery. For improving the low current utilization efficiency of Mg-Al-Pb alloy, the influence of Ce on the microstructures and electrochemical corrosion properties in a 3.5% NaCl solution was investigated using scanning electron microscope and electrochemical measurements. The results indicate that Ce refines the grain structure of Mg-Al-Pb alloy. The formation of strip Al11Ce3 second phase promotes the uniform distribution of Mg17Al12 phase in Mg-Al-Pb-Ce alloy. The addition of cerium accelerates the discharge activity of Mg-Al-Pb alloy. Due to a large number of cathodic Al11Ce3 and MglyAla2 phases, Ce promotes the micro-galvanic corrosion and leads to larger corrosion current density and hydrogen evolution rate in Mg-Al-Pb-Ce alloy than those in Mg-Al-Pb alloy. However, Mg-Al-Pb alloy expresses smaller utilization efficiency than Mg-Al-Pb-Ce alloy because of grain detachment.

Determination of Phytoene Content in Tomato Ketchup by HPLC

[Objective] The aim was to establish an HPLC method for determination of phytoene content in tomato ketchup. [Method] The chromatographic conditions were as follows： column, Agilent AT C18 （250 mm×4.6 mm, 5 μm）; mobile phase, methanol-THF （75：25）; detection wavelength, 287 nm; flow rate, 1.0 ml/min; column temperature, 30 ℃; sample size, 50 μl. [Result] There was a good linear relation- ship in the phytoene content range of 0.186-1.116μg. The average recovery rate was 103.8% with RSD of 1.47%. The phytoene content in the tomato ketchup sample was determined as 10.7 rag/100 g simple, accurate, rapid and reliable, and phytoene content in tomato ketchup. [Conclusion] The established method is it can be used for the determination of

Hydrogenation and Ammoniation of SrTiO3 for an Enhanced Visible-light Photocatalysis

Hydrogenation and ammoniation of SrTiOa （STO）, a normal ultraviolet photocatalyst, were performed by annealing STO（100） in Hz：N2=5%：95% and NH3, respectively, at various temperatures T. It was found that hydrogenation at T≥900℃ remarkably enhanced the UV photocatalytic ability of STO, but the visible-light photocatalysis was still unavailable, while ammoniation at T≥800℃ introduced the N doping, resulting in visible-light photocat- alytie activity. Furthermore, when a hydrogenated STO was subjected to ammoniation, the visible-light photocatalytie ability was nearly the same as that of the ammoniated one; but the hydrogenation of an ammoniated one significantly enhanced visible-light photoeatalysis, indicating a synergetic effect of hydrogenation and ammoniation. Discussions and identifications have been made to analyze these results.

Urchin-like CoCu Bimetallic Nanocomposites for Catalytic Hydrogenolysis of Glycerol to Propanediols

Bimetallic CoCu nanocomposites were synthesized in polyol by using Ru as heterogeneous nucleation agent and stearic acid as surfactant, and their catalytic properties were investi- gated by hydrogenolysis of glycerol to propanediols. It was found that the surfactant could induce Co nanocrystals to form nanowires as structure-directing agent, while it＇s ineffective for Cu because only spherical Cu particles were produced under the same condition. When Co2＋ and Cu2＋ coexist in polyol, Cu2＋ is firstly reduced and forms the spherical particles, and then the Cu particles afford surface for the subsequential reduction of Co2＋ and growth of Co nanocrystals to form the nanorods, obtaining the urchin-like CoCu nanocomposites. The catalytic performance in selective hydrogenolysis of glycerol to propanediols proposed that the CoCu urchin-like nanocomposites was superior to the Co nanowires possibly due to that the synergistic effect between Co and Cu component promoted conversion of glyc- erol and obtained the higher propanediol yields based on the specific surface areas of the catalysts.

Ab initio Study of Hyperconjugative Effect on Electronic Wavefunctions of 2-chloroethanol

The electronic structure of five conformers of 2-chloroethanol was studied by ab initio calculations at B3LYP and MP2 levels of theory with aug-cc-pVTZ basis set. The existing hydrogen bond and hyperconjugation effects on the stability of 2-chloroethanol conformers were discussed on the base of natural bond orbital analyses. The result exhibits that hyperconjugation is the main factor to determine the stability of conformers. Such effects on the electron wavefunctions of the highest-occupied molecular orbital （HOMO） of different conformers are demonstrated with electron momentum spectroscopy, exhibiting the obviously different symmetries of the HOMO wavefunctions in momentum space.

Carbon supported IrM(M= Fe,Ni,Co) alloy nanoparticles for the catalysis of hydrogen oxidation in acidic and alkaline medium

We studied the alloying effect in lr-based alloys on the catalysis of the hydrogen oxidation reaction （HOP,） in both acidic and alkaline medium. IrFe, lrNi and IrCo alloy catalysts with nanoparticle size of 〈S nm were obtained by our solvent-vaporization plus hydrogen reduction method. The second metal played an important role in tuning the crystal structure and surface electronic structure of the Ir-based alloy catalyst. Among the lrFe, IrCo and lrNi alloy catalysts, Ni induced a mid-sized contrac- tion of the lr lattice, and gave the best HOR activity in both acidic and alkaline medium. In acidic medium, the weakening of the Ir-Had interaction caused by the electronic effect of M （M = Fe, Ni, Co） alloying is responsible for the enhancement of HOR activity. The oxophilic effect of the catalytic metal surface, which affects OHad adsorption and desorption and surface Had coverage, has a large impact on the HOR activity in the case of alkaline medium,

Determination of Dehydroepiandrosterone Sulfate with High Performance Liquid Chromatography

本文报道了用高效液相色谱-示差检测法(HPLC-RI)测定去氢表雄酮硫酸酯钠盐(DHA-S)及其制剂含量的方法。采用反相 ODS C_(18)色谱柱,乙腈-水(含0.8%磷酸和10μmol/L 四丁基氢氧化铵)作流动相,研究了色谱条件、回收率、检测限量及线性范围。

Construction of LSPR-enhanced 0D/2D CdS/MoO3‒x S-scheme heterojunctions for visible-light-driven photocatalytic H2 evolution

Plasmonic nonmetal semiconductors with localized surface plasmon resonance(LSPR)effects possess extended light-response ranges and can act as highly efficient H2 generation photocatalysts.Herein,an LSPR-enhanced 0D/2D CdS/MoO3‒x heterojunction has been synthesized by the growth of 0D CdS nanoparticles on 2D plasmonic MoO3‒x elliptical nanosheets via a simple coprecipitation method.Taking advantage of the LSPR effect of the MoO3‒x elliptical nanosheets,the light absorption of the CdS/MoO3‒x heterojunction was extended from 600 nm to the near-infrared region(1400 nm).Furthermore,the introduction of 2D plasmonic MoO3‒x elliptical nanosheets not only provided a platform for the growth of CdS nanoparticles,but also contributed to the construction of an LSPR-enhanced S-scheme structure due to the interface between the MoO3‒x and CdS,accelerating the separation of light-induced electrons and holes.Therefore,the CdS/MoO3‒x heterojunction exhibited higher photocatalytic H2 generation activity than pristine CdS under visible light irradiation,including under 420,450,550,and 650 nm monochromic light,as well as improved photo-corrosion performance.

A Straightforward Method of Calculating Finely the Soft X-Ray Spectra of Hydrogenlike Highly Ionized-States

A new method of calculating finely the soft X ray spectra of hydrogenlike highly ionized states is presented. It is based on the relation of the ionicity and the ionization energies of hydrogenlike atoms and the new model of potential function of hydrogenlike atoms. The relativistic revision and the spin orbit couping of excitation energy levels are taken into account. The calculated results are in good agreement with the experiments.

Kinetic Implication from Temperature Effect on Hydrogen Evolution Reaction at Ag Electrode

Hydrogen evolution reaction （HER） at polycrystalline silver electrode in 0.1 mol/L HClO4 solution is investigated by cyclic voltammetry in the temperature range of 278-333 K. We found that at electrode potential φa,app decreases with φ, while pre-exponential factor A remains nearly unchanged,which conforms well the prediction from Butler-Volmer equation. In contrast, with φ nega-tive shifts from the onset potential for HER to the potential of zero charge （PZC≈-0.4 V）, both Ea,app and A for HER increase （e.g., Ea,app increases from 24 kJ/mol to 32 kJ/mol）. The increase in Ea,app and A with negative shift in φ from -0.25 V to PZC is explained by the increases of both internal energy change and entropy change from reactants to the transition states, which is correlated with the change in the hydrogen bond network during HER. The positive entropy effects overcompensate the adverse effect from the increase in the activation energy, which leads to a net increase in HER current with the activation energy negative shift from the onset potential of HER to PZC. It is pointed out that entropy change may contribute greatly to the kinetics for electrode reaction which involves the transfer of electron and proton, such as HER.

Design strategies and structure‐performance relationships of heterogeneous catalysts for selective hydrogenation of 1,3‐butadiene

Selective hydrogenation of 1,3‐butadiene is an essential process in the upgrading of the crude C4 cut from the petroleum chemical sector.Catalyst design is crucial to achieve a virtually alkadiene‐free product while avoiding over‐hydrogenating valuable olefins.In addition to the great industrial relevance,this demanding selectivity pattern renders 1,3‐butadiene hydrogenation a widely used model reaction to discriminate selective hydrogenation catalysts in academia.Nonetheless,critical reviews on the catalyst development are extremely lacking in literature.In this review,we aim to provide the reader an in‐depth overview of different catalyst families,particularly the precious metal‐based monometallic catalysts(Pd,Pt,and Au),developed in the last half century.The emphasis is placed on the development of new strategies to design high‐performance architectures,the establishment of structure‐performance relationships,and the reaction and deactivation mechanisms.Thrilling directions for future optimization of catalyst formulations and engineering aspect are also provided.

Hydrodeoxygenation of Phenolic Model Compounds over MoS2 Catalysts with Different Structures

Several MoS2 catalysts of different structure, prepared by in situ decomposition of ammonium heptamolybdate （AHM） and molybdenum naphthenate （MoNaph）, and by MoS2 exfoliation （TDM）, were characterized by BET, X-ray diffraction （XRD）, Energy Dispersive X-ray （EDX） and transmission electron microscopy （TEM）. The analysis showed that MoS2 structure was dependant upon the preparation procedure. The activity of the catalysts was determined by measuring the hydrodeoxygenation （HDO） of phenol, 4-methylphenol and 4-methoxyphenol using a batch autoclave reactor operated at 2.8 MPa of hydrogen and temperatures ranging from 320-370℃. By comparing the conversion, the reactivity order of the catalysts was： AHM〉TDM-D〉MoNaph〉thermal〉MoS2 powder〉 TDM-W. Also, the effect of reaction temperature on the HDO conversion was explained in terms of equilibrium of reversible reaction kinetics. The main products of the HDO for phenolic compounds were identified by gas chromatography/mass spectrometry （GC/MS）. The results showed that the product distribution and the HDO selectivity were correlated with the reaction temperature. Two parallel reaction routes, direct hydrogenolysis and combined hydrogenation-hydrogenolysis, were confirmed by the analysis of the product distribution. High temperature favored hydrogenolysis over hydrogenation for HDO of phenol and 4-methoxyphenol, whereas for 4-methylphenol the reverse was true.

Basic and clinical study of increased effect of partial anti-tumor agents by infusing sodium bicarbonate through target artery

Objective： To observe the influence of pH value on the proliferation of LAK cells and on the killing effect of rlL-2, IFN-α2b, TNF-α, LAK cells and doxorubicin on malignant tumor cells, and investigate the possibility of increasing the efficacy of rlL-2 or IFN-α2b and doxorubicin by infusing sodium bicarbonate （NaHCO3） through target arteries. Methods： Separating single nucleus cells from peripheral blood of healthy men, and observing the influence of pH on the activation of single nucleus cells by rlL-2. MTT assay was used to measure the killing effect of rlL-2, IFN-α2b and TNF-α on 7404 cells and the increased effect of doxorubicin on rlL-2 and IFN-α2b, the cytotoxity of LAK cells in different pH. Forty-two patients with advanced primary liver cancer were obtained by stratified random, NaHCO3, rIL-2/IFN-α2b and doxorubicin were infused through target arteries. The efficacy was estimated after two cycles. Results： The conditions of pH 7.3 and pH 7.6 in vitro helped the proliferation of LAK cells and the killing effect of rIL-2, IFN-α2b and LAK cells on 7404 cells. In the condition of pH 6.8 there was almost no killing effect for LAK cells. In the condition of pH 7.0, 7.2, 7.4 and 7.6, the killing rate of TNF-α to 7404 cells increased by degrees, and in pH 7.4 the killing effect was the optimum. After two cycles treatments in the 42 patients with advanced primary liver cancer, the response rate （CR＋PR） was 88% （37/42）. The median overall response and median overall survival were increased, and no complication associated with infusing sodium bicarbonate was observed. Conclusion： The killing effect of rIL-2, IFN-α2b, TNF-α and doxorubicin on malignant tumor cells was enhanced by increasing the pH value.