加味神术散雾化剂抗流感病毒的实验研究

目的探讨加味神术散雾化剂在体外对甲型H1N1流感病毒增殖的影响。方法以甲型H1N1流感病毒感染狗肾传代细胞(MDCK cell)为载体,观察加味神术散雾化剂不同药物浓度对流感病毒引起的细胞病变(CPE)的影响。采用Reed-Muench法计算流感病毒对MDCK细胞的半数细胞感染量(TCID 50)。采用四甲基偶氮唑盐微量酶反应比色法(MTT)测定光密度(OD)值,计算不同药物对MDCK细胞的破坏率,通过Probit回归计算不同药物对MDCK细胞的最大无毒浓度(TC 0)及半数中毒浓度(TC 50)。计算不同药物对流感病毒增殖的抑制率,通过Probit回归计算半数抑制浓度(IC 50)和治疗指数(TI)。结果甲型H1N1流感病毒对MDCK细胞的TCID 50为10-8/0.1 mL。加味神术散雾化剂对MDCK细胞的TC 50为366.63μg/mL,TC 0为31.25μg/mL;利巴韦林对MDCK细胞的TC 50为109.85μg/mL,TC 0为8.02μg/mL。加味神术散雾化剂对流感病毒直接抑制作用的IC 50=9.79μg/mL,TI=37.45;对预防流感病毒感染的IC 50=8.72μg/mL,TI=41.04;对治疗流感病毒感染的IC 50=17.40μg/mL,TI=21.07。利巴韦林对预防流感病毒感染的IC 50=84.30μg/mL,TI=1.30。结论加味神术散雾化剂可明显抑制甲型H1N1流感病毒在MDCK细胞中的增殖,具有抗甲型H1N1流感病毒作用。

石英砂在乳化炸药中的应用

为了提高乳化炸药的性能 ,采用化学发泡技术 ,对乳化炸药进行敏化 ,在保证生产安全的前提下 ,将微细粒末石英砂作为炸药的添加剂对乳化胶体进行敏化 ,提高了爆轰感度、缩短了保温发泡的时间 ,降低了散化剂的使用量 。

Development of Prolonged Release Microspheres of Metformin Hydrochloride Using Ion Exchange Resins

Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcellulose （EC） by the emulsion solvent diffusion technique. The release rate of mefformin from the microcapsules was highly dependent on the encapsulating formulation, thus being used as an index for formulation screening. Orthogonal experiments were performed to optimize the coating formulation. Results The final chosen formulation for coating of mefformin microcapsules were as follows： （ 1 ） the ratio of EC （20cps） to EC （45cps） was 50：50; （2） the ratio of plasticizer to coating materials was 20% ;and （3） the ratio of resin-mefformin complexes to coating materials was 5 ： 1. Conclusion The prolonged release microspheres of mefformin hydrochloride were successfully prepared.

Photochemical route for preparing atomically dispersed Pd_1/TiO_2 catalysts on(001)-exposed anatase nanocrystals and P25

Atomically dispersed catalysts have shown promising prospects in catalysis studies.Among all of the developed methods for synthesizing atomically dispersed catalysts,the photochemical approach has recently aroused much attention owing to its simple procedure and mild preparation conditions involved.In the present study,we demonstrate the application of the photochemical method to synthesize atomically dispersed Pd catalysts on(001)‐exposed anatase nanocrystals and commercial TiO2(P25).The as‐prepared catalysts exhibit both high activity and stability in the hydrogenation of styrene and catalytic oxidation of CO.

Metal cation crosslinking of Ti O_2-alginate hybrid gels

In order to improve the substrate diffusion properties and stability of an immobilized enzyme alginate microgels modified with TiO2 nanoparticles were employed as the enzyme immobilizing support.Ionotropic gelation was applied for the preparation of hybrid gels while Ca2＋ Ce3＋ Ni2＋Cu2＋and Fe3＋were employed as the crosslinkers.Papain was selected as the model enzyme. UV-Vis spectroscopy was employed to investigate the activity of papain to evaluate kinetics and stability.Analysis results show that the highest affinity the lowest Michaelis-Menten constant Km =11.0 mg/mL and the highest stability are obtained when using Cu2＋as the crosslinker.The effect of the mass ratio of TiO2 to papain on the stability and leakage of papain is also investigated and the results show that 10∶1 TiO2∶papain is optimal because the proper use of TiO2 can reduce enzyme leakage and ensure enzyme stability.Preparing Cu/alginate/TiO2 hybrid gels via ionotropic gelation can provide a satisfactory diffusion capability and enzyme stability.

Kinetics of Hydrogenolysis of Glycerol to Propylene Glycol over Cu-ZnO-Al2O3 Catalysts

A series of Cu-ZnO-Al2O3 catalysts with various metal compositions of Cu/Zn/Al were prepared by the co-precipitation method,and screened for glycerol hydrogenolysis to propylene glycol.The catalyst with a Cu/Zn/Al molar ratio of 1:1:0.5 exhibited the best performance for glycerol hydrogenolysis,and thus selected for kinetic investigation.Under elimination of external and internal diffusion limitation,kinetic experiments were performed in an isothermal fixed-bed reactor at a hydrogen pressure range of 3.0-5.0 MPa and a temperature range of 493-513 K. Based on a dehydration-hydrogenation two-step hydrogenolysis mechanism,a two-site Langmuir-Hinshelwood kinetic model taking into account competitive adsorption of glycerol,acetol and propylene glycol was proposed and successfully fitted to the experimental data.The average relative errors between observed and predicted outlet concentrations of glycerol and propylene glycol were 6.3%and 7.6%,respectively.The kinetic and adsorption parameters were estimated by using the fourth-order Runge-Kutta method together with the Rosenbrock algorithm.The activation energies for dehydration and hydrogenation reactions were 86.56 and 57.80 kJ·mol-1,respectively.

高密度聚乙烯膜降解老化性能研究进展

近年来垃圾填埋场中越来越多的使用高密度聚乙烯(HDPE)膜与粘土组合作为复合防渗层,但是HDPE土工膜在填埋场中寿命如何以及它的降解规律国内研究甚少。针对这一问题,文章总结了国际上关于HDPE土工膜进行的室内老化降解试验研究并介绍Arrhenius模型预测抗氧化剂寿命,以期对国内的工程实践提供参考。HDPE膜的降解分三阶段,对其老化影响最大的是第一阶段即抗氧化剂耗散阶段。现有的室内试验主要通过将HDPE膜浸泡在空气,水及合成渗沥液中或通过模拟衬垫装置模拟进行升温老化,进而通过测量氧化诱导时间变化预测抗氧化剂寿命。然而室内试验均未能完全模拟实际条件,后续还需实地填埋场观察取样了解其降解情况。

A highly stable and active mesoporous ruthenium catalyst for ammonia synthesis prepared by a RuCl_3/SiO_2-templated approach

Molecular nitrogen is relatively inert and the activation of its triple bond is full of challenges and of significance.Hence,searching for an efficiently heterogeneous catalyst with high stability and dispersion is one of the important targets of chemical technology.Here,we report a Ba‐K/Ru‐MC catalyst with Ru particle size of 1.5–2.5 nm semi‐embedded in a mesoporous C matrix and with dual promoters of Ba and K that exhibits a higher activity than the supported Ba‐Ru‐K/MC catalyst,although both have similar metal particle sizes for ammonia synthesis.Further,the Ba‐K/Ru‐MC catalyst is more active than commercial fused Fe catalysts and supported Ru catalysts.Characterization techniques such as high‐resolution transmission electron microscopy,N2 physisorption,CO chemisorption,and temperature‐programmed reduction suggest that the Ru nanoparticles have strong interactions with the C matrix in Ba‐K/Ru‐MC,which may facilitate electron transport better than supported nanoparticles.

Interatomic diffusion in Pd-Pt core-shell nanoparticles

Pt monolayer-based core-shell catalysts have garnered significant interest for the application of low temperature fuel cell technology as their use may enable a decreased loading of Pt while still providing sufficient current density to meet volumetric requirements. One promising candidate in this class of materials is a Pd@Pt core-shell catalyst, which shows enhanced activity toward oxygen reduction reaction(ORR). One concern with the use of Pd@Pt, however, is the durability of the core-shell structure as Pd atoms are thermodynamically favored to migrate to the surface. The pathway of the migration has not been systematically studied. The current study explores the stability of this structure to thermal annealing and probes the effect of this heat treatment on the catalyst surface structure and its oxygen reduction activity. It was found that surface alloying between Pd and Pt occurs at temperatures as low as 200 °C, and significantly alters the structure and ORR catalytic activity in the range of 200–300 °C. Our results shed lights on the thermal induced interatomic diffusion in all core-shell and thin film structures.

Ru/FeO_x catalyst performance design: Highly dispersed Ru species for selective carbon dioxide hydrogenation

A series of Ru/FeOx catalysts were synthesized for the selective hydrogenation of CO2to CO.Detailed characterizations of the catalysts through X‐ray diffraction,X‐ray photoelectron spectroscopy,transmission electron microscopy,and temperature‐programmed techniques were performed to directly monitor the surface chemical properties and the catalytic performance to elucidate the reaction mechanism.Highly dispersed Ru species were observed on the surface of FeOx regardless of the initial Ru loading.Varying the Ru loading resulted in changes to the Ru coverage over the FeOx surface,which had a significant impact on the interaction between Ru and adsorbed H,and concomitantly,the H2activation capacity via the ability for H2dissociation.FeOx having0.01%of Ru loading exhibited100%selectivity toward CO resulting from the very strong interaction between Ru and adsorbed H,which limits the desorption of the activated H species and hinders over‐reduction of CO to CH4.Further increasing the Ru loading of the catalysts to above0.01%resulted in the adsorbed H to be easily dissociated,as a result of a weaker interaction with Ru,which allowed excessive CO reduction to produce CH4.Understanding how to selectively design the catalyst by tuning the initial loading of the active phase has broader implications on the design of supported metal catalysts toward preparing liquid fuels from CO2.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences toward preparing liquid fuels from CO2.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Supercritical synthesis of platinum-modified titanium dioxide for solar fuel production from carbon dioxide

This paper investigates the properties of TiO2‐based photocatalysts synthesised under supercriticalconditions.Specifically,the characteristics of Pt dispersed on TiO2catalysts obtained in supercriticalCO2are discussed and compared with those of commercial TiO2.The photocatalytic activity of thesynthesised catalysts in the CO2photoreduction reaction to produce solar fuel is tested.The mainconclusion of the study is that photocatalysts with better or similar features,including high surfacearea,crystallisation degree,hydroxyl surface concentration,pore volume,absorbance in the visiblerange and methane production rate,to those of commercial TiO2may be produced for the reductionof CO2to fuel by synthesis in supercritical media.

Preparation of Monodispersed O/W Emulsion by Ceramic External Membrane Emulsification System——Preliminary Study on Integrated Ceramic Membrane Emulsification Reactor

A new reactor with integrated conventional slurry stirred reactor and ceramic external membrane emulsification system, was introduced in this paper. Toluene and toluene containing surfactant was separately used as dispersed phase for preparation of emulsions. Two kinds of emulsions were prepared and compared. The volume average sizes of prepared emulsions were 3.53μm and 3.6μm respectively. The results showed that the droplet sizes of two kinds of emulsions were similar, but the monodispersed emulsion was only obtained with addition of surfactant into the dispersed phase.

Acid‐promoted Ir‐La‐S/AC‐catalyzed methanol carbonylation on single atomic active sites

Highly active Ir‐La‐S/AC catalyst was successfully prepared by co‐impregnation of an activated carbon（AC） carrier with a sulfuric acid solution of Ir and La species and compared with a tradition‐ally prepared Ir‐La/AC catalyst. High angle annular dark‐field‐scanning transmission electron mi‐croscopy（HAADF‐STEM） measurement results show that most of the Ir species on Ir‐La‐S/AC exist as single atomic sites, while those on Ir‐La/AC exist as nanoparticles with an average diameter of 1.5 nm. Evaluation of Ir‐La‐S/AC as a catalyst for heterogeneous carbonylation of methanol to acetyl gave a maximum TOF （turn‐over‐frequency） of 2760 h^–1, which was distinctly higher than that achieved by the Ir‐La/AC catalyst（approximately 1000 h^-1）. Temperature‐programmed desorption of ammonia（NH3‐TPD） result shows that the addition of sulfuric acid during the preparation pro‐cedure results in significantly more acidic sites on Ir‐La‐S/AC than those on Ir‐La/AC, which plays a key role in the enhancement of CO insertion as the rate‐determining step. Tempera‐ture‐programmed reduction（TPR） and in situ X‐ray photoelectron spectroscopy reveal that Ir spe‐cies are more reducible, and that more Ir^＋ might be formed by activation of Ir‐La‐S/AC than those on the Ir‐La/AC catalyst, which is thought to be beneficial for reductive elimination of AcI from Ir^3＋ species as an essential step for CH3I regeneration and acetyl formation.

Synthesis of Silica-Dispersed NiMo Hydrodesulfurization Catalysts

Silica-dispersed NiMo hydrodesulfurization catalysts were synthesized by the deposition-precipitation method. For comparative purposes, bulk NiMo catalysts were obtained by co-precipitation. The silica-dispersed NiMo catalyst had highly active metals content. Silica was employed to disperse active metals for full utilization of active components. The BET analysis showed that the silica-dispersed NiMo catalysts had a high surface area （147.0 m2/g） and pore volume （0.27 mL/g）, whereas the bulk NiMo catalysts exhibited a very low surface area （87.5 m2/g）. Transmission electron microscopy results proved that the active components were dispersed on the SiO2 substrate. X-ray diffraction patterns of the silicadispersed NiMo catalyst and the bulk NiMo catalyst were indexed to NiMoO4. The hydrodesulfurization activity of silicadispersed NiMo catalysts was much higher than that of reference catalysts and could be up to twice greater than those of commercial NiMo alumina-supported systems per gram of catalyst. The activity testing results also demonstrated that the silica-dispersed NiMo catalyst was an effective hydrodesulflarization catalyst.

Gas Diffusion in Bi-disperse Porous Catalyst Pellets

A flux equation of diffusion for bi-disperse porous catalyst pellets was proposed by modifying the previously developed model equation over fractal trajectories. The proposed fractal model equation considered the same tortuous degree for both micro-and macro-pores. The experimental data of diffusion over a bi-disperse Ni/gamma-alumina pellet were obtained with a standard Wicke-Kallenbach diffusion cell for both carbon monoxide- ethylene and carbon dioxide-ethylene binary mixtures. The fitting between experimental results and the fractal model equation leads to a fractal dimension of 1.11. The prediction of diffusion flux over the bi-disperse Ni/gamma- alumina pellet by the proposed fractal model equation is much better than the traditional tortuosity-based model equation by comparison with the measured flux through the pellet.

Catalytic performance of highly dispersed WO_3 loaded on CeO_2 in the selective catalytic reduction of NO by NH_3

The influence of tungsten trioxide(WO3)loading on the selective catalytic reduction(SCR)of nitric oxide(NO)by ammonia(NH3)over WO3/cerium dioxide(CeO2)was investigated.The NO conversion first rose and then declined with increasing WO3loading.It was found that the crystalline WO3in the1.6WO3/CeO2sample could be removed in25wt%ammonium hydroxide at70°C,which improved the catalytic activity of the sample.The obtained samples were characterized by X‐ray diffraction,Raman spectroscopy,X‐ray photoelectron spectroscopy,hydrogen(H2)temperature programmed reduction,NH3temperature programmed desorption,and in situ diffuse reflectance infrared Fourier transform spectroscopy.The results revealed that the dispersed WO3promoted the catalytic activity of WO3/CeO2while the crystalline WO3inhibited catalytic activity.The oxygen activation of CeO2was inhibited by the coverage of WO3,which weakened NO oxidation and adsorption of nitrate species over WO3/CeO2.In addition,the NH3adsorption performance on CeO2was improved by modification with WO3.NH3was the most stable adsorbed species under NH3SCR reaction conditions.In situ DRIFT spectra suggested that the NH3SCR reaction proceeded via the Eley‐Rideal mechanism over WO3/CeO2.Thus,when the loading of WO3was close to the dispersion capacity,the effects of NH3adsorption and activation were maximized to promote the reaction via the Eley‐Rideal route.

Nanoscale graphene oxide sheets as highly efficient carbocatalysts in green oxidation of benzylic alcohols and aromatic aldehydes

Nanoscale graphene oxide(NGO)sheets were synthesized and used as carbocatalysts for effectiveoxidation of benzylic alcohols and aromatic aldehydes.For oxidation of alcohols in the presence ofH2O2at80°C,the NGOs(20%mass fraction)as carbocatalysts showed selectivity toward aldehyde.The rate and yield of this reaction strongly depended on the nature of substituents on the alcohol.For4‐nitrobenzyl alcohol,<10%of it was converted into the corresponding carboxylic acid after24h.By contrast,4‐methoxybenzyl alcohol and diphenylmethanol were completely converted into thecorresponding carboxylic acid and ketone after only9and3h,respectively.The conversion ratesfor oxidation of aromatic aldehydes by NGO carbocatalysts were higher than those for alcohol oxidation.For all the aldehydes,complete conversion to the corresponding carboxylic acids wasachieved using7%(mass fraction)of NGO at70°C within2–3h.Possible mechanisms for NGOcarbocatalyst structure‐dependent oxidation of benzyl alcohols and structure‐independent oxidationof aromatic aldehydes are discussed.

Preparation and Evaluation of Microcapsule Containing Volatile Oil of Herba Schizonepetae by Emulsion Solvent Diffusion Method

Microcapsules of volatile oil containing Herba Schizonepetae(VOHS) were prepared by emulsion solvent diffusion method to improve the drug loading and reduce the amount of pharmaceutical excipients.Orthogonal assay was applied to optimize the preparation condition of microcapsulation,and the results illustrated that the ratio of ethyl cellulose(EC) to VOHS influenced the property of VOHS microcapsule significantly.GC-MS analysis indicated that some volatile components with low concentration in VOHS were lost after microencapsulation.The microcapsules prepared with optimum condition had good fluidity,and the holes on the surface of the microcapsules contributed to the release of VOHS.The particles of the microcapsule conformed to a normal distribution with the diameter of 45—220 μm.In the simulated intestinal fluid containing 0.2% sodium dodecyl sulfate,pulegone in VOHS microcapsule showed a certain degree of slow release.Compared with β-cyclodextrin method,the microencapsulation used in the present work could reduce the amount of excipients and increase the drug loading.It was beneficial to reduce the dose of Chinese medicines containing volatile oils.

破碎顶板加固技术在常村矿的应用

破碎顶板条件下,"三软"煤层断面综放巷道采用传统金属网、工字钢棚支护,进尺慢、支护效果差,限制了工作面的高产高效。常村矿针对这种条件采用一种新型煤体加固技术,取得了理想效果。

Solvation structure and dynamics of Li and LiO_(2)and their transformation in non-aqueous organic electrolyte solvents from first-principles simulations

Density functional theory calculations together with ab initio molecular dynamics(AIMD)simulations have been used to study the solvation,diffusion and transformation of Li^(+)and LiO_(2)upon O_(2)reduction in three organic electrolytes.These processes are critical for the performance of Li-air batteries.Apart from studying the structure of the solvation shells in detail,AIMD simulations have been used to derive the diffusivity and together with the Blue Moon ensemble approach to explore LiO_(2)formation from Li^(+)and O_(2)−and the subsequent disproportionation of 2LiO_(2)into Li_(2)O_(2)+O_(2).By comparing the results of the simulations to gas phase calculations,the impact of electrolytes on these reactions is assessed which turns out to be more pronounced for the ionic species involved in these reactions.