The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxi...The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxide.However,the practical application of this method is significantly hindered by the inherent limitations of sodium methoxide,such as its high sensitivity to moisture and propensity for solid precipitation,which impede its effective use in continuous processes.This work proposed a continuous catalytic distillation(CD)process utilizing Amberlyst 15 cation exchange resin as the catalyst.A comprehensive series of reaction kinetic and CD experiments were conducted to evaluate the performance of the proposed process.The results demonstrate that under the optimal operating conditions,namely an ester-to-ether molar ratio of 6:1,a refluxratio of 5:1,a total feed rate of 0.92 g‧min^(-1),and an evaporation rate of 266.47 m^(3)‧m^(-2)‧h^(-1),the conversion rate of PM achieves 99.95%,and the PMA yield is 97.31%.Based on these findings,a process flowsheet for a continuous CD process tailored for the production of electronic-grade PMA is presented.This design incorporates light and heavy removal steps to ensure the production of PMA with a purity of 99.99%.Additionally,the process utilizes pressure swing distillation to recover MeOAc,thereby enhancing the overall efficiencyand sustainability of the production process.The proposed continuous CD process offers a highly efficient,cost-effective,and environmentally sustainable solution for the production of electronic-grade PMA.展开更多
8,2＇-Diprenylquercetin 3-methyl ether with significant anti-breast cancer activity is the main constituent of Tibetan medicine Sinopodophylli Fructus. In the present study, we developed and validated a rapid and sens...8,2＇-Diprenylquercetin 3-methyl ether with significant anti-breast cancer activity is the main constituent of Tibetan medicine Sinopodophylli Fructus. In the present study, we developed and validated a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） method for the determination of 8,2＇-diprenylquercetin 3-methyl ether in rat plasma. 8-Prenylkaempferol was used as the internal standard. The separation was carried out using Waters ACQUITY UPLC BEH C18 column （2.1 mm×100 ram, 1.7 μm） with a mobile phase consisting of acetonitrile and 0.1% formic acid in water on a gradient program at a flow rate of 0.4 mL＇min-1 and temperature of 30 ℃. Triple quadrupole mass spectrometric detection in negative ion mode was used for multiple-reaction monitoring of the transitions at m/z 451.30→177.25 and m/z 353.25→298.15 for 8,2＇-diprenylquercetin 3-methyl ether and 8-prenylkaempferol, respectively. The calibration curves were linear within the concentration range 0.1-2000 ng/mL （r = 0.9954）. The recoveries were 103%-115%, and the results were consistent across low, middle and high concentration levels. The intra- and inter-day precisions were within 15%, and the bias was between --6%-15%. This method was simple, rapid and sensitive, which could be applied to the determination of 8,2＇-diprenylquercetin 3-methyl ether in plasma and pharmacokinetic study in rats. Pharmacokinetic test indicated that the peak plasma concentration occurred in 2 h after the female rats were intragastrically administered with 8,2＇-diprenylquercetin 3-methyl ether at the dose of 100 mg/kg, and the biological half-life was 6.79 h. The blood drug concentration maintained equal amount for 20 h, which was conducive to the in vivo effects of drugs.展开更多
The intrinsic kinetics of dimethyl ether (DME) synthesis from syngas over amethanol synthesis catalyst mixed with methanol dehydration catalyst has been investigated in atubular integral reactor at 3-7 MPa and 220-260...The intrinsic kinetics of dimethyl ether (DME) synthesis from syngas over amethanol synthesis catalyst mixed with methanol dehydration catalyst has been investigated in atubular integral reactor at 3-7 MPa and 220-260℃. The three reactions including methanol synthesisfrom CO and H_2, CO_2 and H_2, and methanol dehydration were chosen as the independent reactions.The L-H kinetic model was presented for dimethyl ether synthesis and the parameters of the modelwere obtained by using simplex method combined with genetic algorithm. The model is reliableaccording to statistical analysis and residual error analysis. The synergy effect of the reactionsover the bifunctional catalyst was compared with the effect for methanol synthesis catalyst underthe same conditions based on the model. The effects of syngas containing Na on the reactions werealso simulated.展开更多
The chars in the natural environment can affect the migration of polybrominated diphenyl ethers(PBDEs). However, there is insufficient research relating to the adsorption behavior and mechanisms of PBDEs on biochars. ...The chars in the natural environment can affect the migration of polybrominated diphenyl ethers(PBDEs). However, there is insufficient research relating to the adsorption behavior and mechanisms of PBDEs on biochars. This study examined the adsorption kinetics of 2,2′,4,4′-tetrabromodiphenyl ether(BDE-47) on maize straw-derived biochars(MSBCs) pyrolyzed at four different temperatures via batch experiments. The biochar samples were characterized using Fourier transform infrared(FTIR) spectroscopy,Raman spectra, and elemental analysis. A two-compartment first-order model and pseudo-second-order model exhibited a better fit compared to a pseudo-first-order model in describing the BDE-47 adsorption on biochars, which was dominated by a slow adsorption compartment and chemisorption. The MSBC pyrolyzed at 600 °C had the highest BDE-47 adsorption capacity owing to its relatively large specific surface area and relatively high aromaticity compared with the other three MSBCs pyrolyzed at 300, 400, and 500 ℃.However, there was no significant difference in adsorption capacity among the other three biochars. The organic functional groups coupled with the graphene structures of biochars and the hydrophobic effect of the functional groups promoted the adsorption of BDE-47. Pore diffusion was not the sole rate-limiting step;film diffusion was also involved in the adsorption process of BDE-47 on biochars. The overall results demonstrate the transport and potential treatment of PBDEs using biochars.展开更多
Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks...Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.展开更多
The interconversion between the two distinct isomers of methyl vinyl ether （MVE）, the formation of the primary ozonides from O3-initated reactions of MVE, the transformation between the primary ozonides, and the sub...The interconversion between the two distinct isomers of methyl vinyl ether （MVE）, the formation of the primary ozonides from O3-initated reactions of MVE, the transformation between the primary ozonides, and the subsequent fragmentation were studied using quantum chemical methods at the BHandHLYP/6311＋＋G（d,p） level of theory for optimized geometries and frequency calculations and at the QCISD/631G（d,p） level for the single point energy calculations. The rate coefficients were calculated for the temperature range 280-440 K by using the canonical transition state theory （TST）. For ozone addition to MVE, there are two different possibilities discussed on the basis of two different possible orientations for ozone attack. The results of the theoretical study indicate that although the synperiplanar-MVE is 7.11 kJ/mol more stable than the antiperiplanar-MVE, the antiperiplanar-MVE plays a more important role in formation of the primary ozonides because the primary ozonides formed from the ozone addition antiperiplanar-MVE are more stable and the energy barriers corresponding to transition states are lower. The intereonversion between the primary ozonides formed from the ozone addition to antiperiplanar-MVE is the most accessible compared with the transformations between other primary ozonides. The cleavage of the primary ozonides mainly leads to the formation of the CH2OO, which is in agreement with the experimental estimates. The calculated overall rate constant for the ozone-initiated reactions is 4.8× 10^-17 cm^3/（molecule.s） at 298.15 K, which agrees with the experimental value for ethyl vinyl ether.展开更多
The paper presents the case that physics is already and effectively unified by the energetic tension field, ether. We identify this integrating power of ether first, by re-defining the action generating parameters of ...The paper presents the case that physics is already and effectively unified by the energetic tension field, ether. We identify this integrating power of ether first, by re-defining the action generating parameters of this energetic tension field as the electric-tension, <img src="Edit_1233fa02-9a1c-416a-8153-196733a12887.png" alt="" />, and the magnetic-resistance, <em>μ</em><sub>0</sub>, while re-deriving the Maxwell’s wave equation in analogy with the mechanically stretched string, where the <img src="Edit_07813a1b-d94f-4e68-a3ed-b3023cd3fb5f.png" alt="" />. Then, replacing <img src="Edit_7d06fa1e-760d-4b80-a503-db81378a3512.png" alt="" /> by <img src="Edit_58f15ef0-2e86-42ae-a899-d0b4741f12d0.png" alt="" /> and <em>m</em><sub>0</sub> by <img src="Edit_f8cb7020-1a27-404a-b146-5c1357e1c5b5.png" alt="" />, one can find that almost all working physics theories are being energized by<img src="Edit_f860fcdd-1dc1-40bf-aaf1-e07b0e4a7524.png" alt="" />and <em>μ</em><sub>0</sub>. To complete the unification, we can now postulate that the particles are also freely propagating EM waves, but they are spatially localized as in-phase, close-looped (IP-CL) vortex-like propagation modes of ether. Because of their IP-CL mode structure, they have space-finite spatial structures and remain spatially stationary in the absence of any spatially influencing potential gradients (forces) in their vicinity. Particles’ <em>harmonic phase</em> driven interactions between quantum particles give birth to the <em>appearance</em> of wave-particle duality. There is no need for the confusing and unnecessary de Broglie’s Pilot Wave. The inertia to spatial motion of IP-CL modes automatically accommodates Newton’s laws of motion. The cosmic universality of Maxwellian wave velocity, and particles as IP-CL modes, jointly accommodate the two key postulates of special relativity without the need for unphysical four-dimensionality. The observable universe is represented only by its diverse oscillatory excited states. The stable and stationary Cosmic Ether keeps holding 100% of its energy all the time. We have proposed a one-way light pulse propagation experiment to directly validate the existence of ether, rather than approaching Michelson’s way of measuring the ether drag. We have identified a good number of examples of working theoretical expressions in terms of <img src="Edit_fd739625-efbd-4edd-9e1e-ba4ab5b7c07f.png" alt="" />and<em> μ</em><sub>0</sub> and presented our critical views in physics thinking, belonging to Classical, Relativity, Quantum and Cosmology Physics.展开更多
Structurally diverse bispropargyl ethers using resorcinol,quinol,4,4￠-dihydroxy biphenyl,bisphenol-A,4,4￠-dihydroxy diphenyl ketone,4,4￠-dihydroxy diphenylsulphone,trimethyl indane bisphenol and tetramethyl spirobi...Structurally diverse bispropargyl ethers using resorcinol,quinol,4,4￠-dihydroxy biphenyl,bisphenol-A,4,4￠-dihydroxy diphenyl ketone,4,4￠-dihydroxy diphenylsulphone,trimethyl indane bisphenol and tetramethyl spirobiindane bisphenol were prepared by using phase transfer catalyst.Synthesized materials were separately blended with 4,4￠-bismaleimido diphenyl methane（BMIM）in mole ratios（0.5：0.5）.The materials were thermally cured and the structural characterisation and the thermal properties of these cross-linked materials are investigated using Fourier-transform infrared（FTIR）spectrophotometer and thermogravimetric analyzer（TGA）.Among the different materials investigated poly MRPE,poly MBPEBPA and poly MSPE show higher onset degradation temperature of 300°C indicating higher thermal stability.The degradation kinetics is investigated using Flynn-Wall-Ozawa（FWO）,Vyazovkin（VYZ）and Friedman（FRD）methods.Amongst the various cured materials investigated,the activation energy（Ea-D）values obtained for poly MRPE and poly MKPE were observed to increase continuously froma=0.2 to 0.8 and the values range from 199 kJ/mol to 245 k J/mol and 153 k J/mol to 295 k J/mol respectively.The crosslinked materials resulting from these bispropargyl monomers definitely need more energy for bond cleavage due to the presence of more aromatic units.The volatile products obtained during the thermal degradation of the polymers were analyzed using thermogravimetric-Fourier transform infrared analyses（TG-FTIR）.The phenols,substituted phenols,carbon monoxide,carbon dioxide and small amount of aniline were found to be the major products during thermal degradation of these cured blends.展开更多
Network crewn ether polymer with pendant sulfide side ohain in the networkstructure units has been synthesized via ring- opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl e...Network crewn ether polymer with pendant sulfide side ohain in the networkstructure units has been synthesized via ring- opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl ether. A kind of active catalyst suitable for this reaction was suggested. The title polymer was found tobe a good ligand for platinous chloride, and the platinous complex could catalyze thehydrosilylation of olefins with triethoxysilane efficiently.展开更多
Dimethyl ether (DME) is considered as a significant fuel alternative with a critical manufacturing process. Only a few authors have presented the kinetic analysis of attractive and alternative catalysts to Al<sub&g...Dimethyl ether (DME) is considered as a significant fuel alternative with a critical manufacturing process. Only a few authors have presented the kinetic analysis of attractive and alternative catalysts to Al<sub>2</sub>O<sub>3</sub> and/or zeolite in DME production, despite the fact that there is a large library of kinetic studies for these commercial catalysts. The purpose of this research was to contribute to this direction by conducting a catalytic test to determine kinetic parameters for methanol dehydration over sulfonic acid catalysts (resin). However, due to the relevance of the mathematical description of this process in the industry was also studied, a study of kinetics parameters and mathematical modeling of methanol dehydration in an atmospheric gas phase in a fixed bed reactor with a temperature range (90°C - 120°C) was examined. The Langmuir-Hinshelwood (L-H) model provides the best fit to experimental data, with an excellent R<sup>2</sup> = 0.9997, and the experimental results were compared to those predicted by these models with very small deviations. The kinetic parameters were found to be in good agreement with the Arrhenius equation, with acceptable straight-line graphs. The activation energy E was computed and found to be 27.66 kJ/mole, with an average variation of 0.32 percent between the predicted and calculated results. Simple mathematical continuum models (plug flow reactor PFR) showed an acceptable agreement with the experimental data.展开更多
The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether anddiethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that thisreaction could be catalyzed by sodium, bu...The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether anddiethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that thisreaction could be catalyzed by sodium, but not Lewis acid. The obtained polymer can coordinatewith platinum compound, and the platinum complex is a new kind of catalyst for thehydrosilylation of olefins with triethoxysilane.展开更多
Polyoxymethylene dimethyl ethers(CH_(3)-O-(CH_(2)O)_(n)-CH_(3),PODE_(n),n>1)can be added to diesel to reduce air pollution caused by incomplete combustion.Driven by this need,a cost-effective and efficient syntheti...Polyoxymethylene dimethyl ethers(CH_(3)-O-(CH_(2)O)_(n)-CH_(3),PODE_(n),n>1)can be added to diesel to reduce air pollution caused by incomplete combustion.Driven by this need,a cost-effective and efficient synthetic route is presented and investigated by this work for the production of PODE_(n),which are formed from methylal and trioxane with low water content(<10%(mass))over HZSM-5 catalyst in a batch slurry autoclave at the temperature from 353.15 K to 393.15 K.The reaction rate laws including the PODE_(n) and byproducts of polyoxymethylene hemiformals(HF_(n)),polyoxymethylene glycols(MG),methanol(MeOH)and methyl formate(MF)are developed.The rate constants of propagation step(k_(6))and depolymerization step(k_(-6))are assumed independent on polymerization degree of PODE_(n).The rate of reaction is proportional to the content of the catalyst(Wcat)for the catalytic reaction within the scope of the study.All kinetic parameters were estimated by combining genetic algorithm and least square regression to fit experimental data well.This work is valuable for process optimization and reactor design.展开更多
The application of high temperature liquid water（HTLW） to decomposition of lignin as efficient and green solution for phenolic compounds recovery was studied.Benzyl phenyl ether（BPE）,the lignin model compound,was ...The application of high temperature liquid water（HTLW） to decomposition of lignin as efficient and green solution for phenolic compounds recovery was studied.Benzyl phenyl ether（BPE）,the lignin model compound,was treated at temperatures ranging from 220 to 250℃.BPE undergo hydrolysis in HTLW,and main products were phenol and benzyl alcohol with the minimum selectivities of 75.7%and 82.8%,respectively.Lower temperature led to higher selectivity in 220-250℃temperature range.The kinetics on BPE hydrolysis was studied and the activation energy was determined as 150.3±12.5 kJ/mol with the first-order kinetic equations.Based on products distribution,the reaction mechanism for decomposition of benzyl phenyl ether was proposed.The investigated process provides insights into the design of a commercial method for utilization of lignin.展开更多
Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling sites.The association of PBDEs with soil colloids has been observed,indicating the potenti...Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling sites.The association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated transport.However,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely unknown.Herein,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous media.The colloids released froma soil sample collected at an e-waste recycling site in Tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).The colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater environments.Notably,under all the tested conditions(i.e.,varying flow velocity,pH,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids,even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions involved.Additionally,the mass of BDE-209 retained in the columns also correlates strongly with themass of retained colloids.Apparently,the PBDEs remain bound to soil colloids during transport in porous media.Findings in this study indicate that soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective carrier.This might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.展开更多
A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones w...A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.展开更多
The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques inc...The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques including XRD,XPS,N2O titration,and 27Al MAS-NMR.The results showed that when the crystal configurations of Al_(2)O_(3) were the same,increasing the specific surface area could effectively refine the size of copper nanoparticles(Cu NPs),and ultimately improve the conversion of DEO.Meanwhile,the smaller size ofγ-Al_(2)O_(3)(HSAl and SBAl)loaded Cu NPs promotes the reaction towards the deep hydrogenation to produce ethanol(EtOH)and ethylene glycol(EG).Besides,the larger size of Cu NPs on the surface of amorphous Al_(2)O_(3)(HTAl and SolAl)resulted in a lower conversion rate,where ethyl glycolate(Egly)is the main product.Despite there are differences in Al^(3+)ionic coordination in Al_(2)O_(3) with different crystal structures,the experimental data showed that the differences in Al^(3+)ionic coordination did not significantly affect the catalytic performance in the hydrogenation reaction.The formation of alcohol-ether ester chemicals is critically dependent on the interactions between Cu sites and acidic sites.Among them,EG and EtOH were dehydrated to form 2-ethoxyethanol via the SN2 mechanism,while Egly and EtOH were reacted to form ethyl ethoxyacetate(EEA)via the SN2 mechanism.This study provides a theoretical basis for the optimization of the coal-based glycol processes to achieve a diversified product portfolio.展开更多
Trehalase hydrolyzes trehalose to glucose to provide energy for insects or building blocks for chitin synthesis.Because trehalase is critical to insects but not to humans,it has long been considered a promising target...Trehalase hydrolyzes trehalose to glucose to provide energy for insects or building blocks for chitin synthesis.Because trehalase is critical to insects but not to humans,it has long been considered a promising target for green insecticides.However,the known trehalase inhibitors are mainly sugar derivatives with poor druggability.In this study,the trehalase from Ostrinia furnacalis(OfTreh)was expressed and characterized.By integrative computational strategies,diphenyl ether herbicides were discovered as the first non-carbohydrate inhibitors of insect trehalases.Bifenox and its more stable derivative,chlomethoxyfen,inhibited Of Treh with Ki values of 56 and 43μM,respectively.The oral administration of bifenox or chlomethoxyfen to locusts resulted in the inhibition of trehalose hydrolysis in vivo,leading to a mortality rate of 66%and server locomotion disorder in the survivors.This study not only established a platform for the development of insecticides targeting trehalase but also discovered a new mechanism for diphenyl ethers to kill insects as trehalase inhibitors.展开更多
基金supported by the National Natural Science Foundation of China(22378065,22278077 and 22278076)the Key Program of Natural Science Foundation of Fujian Province of China(2022J02019).
文摘The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxide.However,the practical application of this method is significantly hindered by the inherent limitations of sodium methoxide,such as its high sensitivity to moisture and propensity for solid precipitation,which impede its effective use in continuous processes.This work proposed a continuous catalytic distillation(CD)process utilizing Amberlyst 15 cation exchange resin as the catalyst.A comprehensive series of reaction kinetic and CD experiments were conducted to evaluate the performance of the proposed process.The results demonstrate that under the optimal operating conditions,namely an ester-to-ether molar ratio of 6:1,a refluxratio of 5:1,a total feed rate of 0.92 g‧min^(-1),and an evaporation rate of 266.47 m^(3)‧m^(-2)‧h^(-1),the conversion rate of PM achieves 99.95%,and the PMA yield is 97.31%.Based on these findings,a process flowsheet for a continuous CD process tailored for the production of electronic-grade PMA is presented.This design incorporates light and heavy removal steps to ensure the production of PMA with a purity of 99.99%.Additionally,the process utilizes pressure swing distillation to recover MeOAc,thereby enhancing the overall efficiencyand sustainability of the production process.The proposed continuous CD process offers a highly efficient,cost-effective,and environmentally sustainable solution for the production of electronic-grade PMA.
基金National Natural Science Foundation of China(Grant No.81673590)National Key Technology R&D Program "New Drug Innovation" of China(Grant No.2013ZX09103002-006)
文摘8,2＇-Diprenylquercetin 3-methyl ether with significant anti-breast cancer activity is the main constituent of Tibetan medicine Sinopodophylli Fructus. In the present study, we developed and validated a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） method for the determination of 8,2＇-diprenylquercetin 3-methyl ether in rat plasma. 8-Prenylkaempferol was used as the internal standard. The separation was carried out using Waters ACQUITY UPLC BEH C18 column （2.1 mm×100 ram, 1.7 μm） with a mobile phase consisting of acetonitrile and 0.1% formic acid in water on a gradient program at a flow rate of 0.4 mL＇min-1 and temperature of 30 ℃. Triple quadrupole mass spectrometric detection in negative ion mode was used for multiple-reaction monitoring of the transitions at m/z 451.30→177.25 and m/z 353.25→298.15 for 8,2＇-diprenylquercetin 3-methyl ether and 8-prenylkaempferol, respectively. The calibration curves were linear within the concentration range 0.1-2000 ng/mL （r = 0.9954）. The recoveries were 103%-115%, and the results were consistent across low, middle and high concentration levels. The intra- and inter-day precisions were within 15%, and the bias was between --6%-15%. This method was simple, rapid and sensitive, which could be applied to the determination of 8,2＇-diprenylquercetin 3-methyl ether in plasma and pharmacokinetic study in rats. Pharmacokinetic test indicated that the peak plasma concentration occurred in 2 h after the female rats were intragastrically administered with 8,2＇-diprenylquercetin 3-methyl ether at the dose of 100 mg/kg, and the biological half-life was 6.79 h. The blood drug concentration maintained equal amount for 20 h, which was conducive to the in vivo effects of drugs.
基金Supported by Development Project of Shanghai Priority Academic Discipline
文摘The intrinsic kinetics of dimethyl ether (DME) synthesis from syngas over amethanol synthesis catalyst mixed with methanol dehydration catalyst has been investigated in atubular integral reactor at 3-7 MPa and 220-260℃. The three reactions including methanol synthesisfrom CO and H_2, CO_2 and H_2, and methanol dehydration were chosen as the independent reactions.The L-H kinetic model was presented for dimethyl ether synthesis and the parameters of the modelwere obtained by using simplex method combined with genetic algorithm. The model is reliableaccording to statistical analysis and residual error analysis. The synergy effect of the reactionsover the bifunctional catalyst was compared with the effect for methanol synthesis catalyst underthe same conditions based on the model. The effects of syngas containing Na on the reactions werealso simulated.
基金financially supported by the Outstanding Youth Fund of the Natural Science Foundation of Jiangsu, China (No. BK20150050)the National Key Research and Development Program, China (No. 2016YFD0800204)+2 种基金the National Natural Science Foundation of China (No. 21677149)the Institute of Soil Science, Chinese Academy of Sciences (No. ISSASIP1616)the Key Program of Frontier Sciences, Chinese Academy of Sciences (No. QYZDJSSW-DQC035)
文摘The chars in the natural environment can affect the migration of polybrominated diphenyl ethers(PBDEs). However, there is insufficient research relating to the adsorption behavior and mechanisms of PBDEs on biochars. This study examined the adsorption kinetics of 2,2′,4,4′-tetrabromodiphenyl ether(BDE-47) on maize straw-derived biochars(MSBCs) pyrolyzed at four different temperatures via batch experiments. The biochar samples were characterized using Fourier transform infrared(FTIR) spectroscopy,Raman spectra, and elemental analysis. A two-compartment first-order model and pseudo-second-order model exhibited a better fit compared to a pseudo-first-order model in describing the BDE-47 adsorption on biochars, which was dominated by a slow adsorption compartment and chemisorption. The MSBC pyrolyzed at 600 °C had the highest BDE-47 adsorption capacity owing to its relatively large specific surface area and relatively high aromaticity compared with the other three MSBCs pyrolyzed at 300, 400, and 500 ℃.However, there was no significant difference in adsorption capacity among the other three biochars. The organic functional groups coupled with the graphene structures of biochars and the hydrophobic effect of the functional groups promoted the adsorption of BDE-47. Pore diffusion was not the sole rate-limiting step;film diffusion was also involved in the adsorption process of BDE-47 on biochars. The overall results demonstrate the transport and potential treatment of PBDEs using biochars.
基金support of the National Natural Science Foundation of China(Nos. 21603197, 21703212,21233006 and 21473164)Natural Science Foundation of Hubei Province of China(No.2016CFB181)+1 种基金Fundamental Research Funds for the Central University, China University of Geosciences (Wuhan)(No. CUGL180403)China University of Geosciences (Wuhan) for the program of Center for Advanced Energy Research and Technologies
文摘Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.
文摘The interconversion between the two distinct isomers of methyl vinyl ether （MVE）, the formation of the primary ozonides from O3-initated reactions of MVE, the transformation between the primary ozonides, and the subsequent fragmentation were studied using quantum chemical methods at the BHandHLYP/6311＋＋G（d,p） level of theory for optimized geometries and frequency calculations and at the QCISD/631G（d,p） level for the single point energy calculations. The rate coefficients were calculated for the temperature range 280-440 K by using the canonical transition state theory （TST）. For ozone addition to MVE, there are two different possibilities discussed on the basis of two different possible orientations for ozone attack. The results of the theoretical study indicate that although the synperiplanar-MVE is 7.11 kJ/mol more stable than the antiperiplanar-MVE, the antiperiplanar-MVE plays a more important role in formation of the primary ozonides because the primary ozonides formed from the ozone addition antiperiplanar-MVE are more stable and the energy barriers corresponding to transition states are lower. The intereonversion between the primary ozonides formed from the ozone addition to antiperiplanar-MVE is the most accessible compared with the transformations between other primary ozonides. The cleavage of the primary ozonides mainly leads to the formation of the CH2OO, which is in agreement with the experimental estimates. The calculated overall rate constant for the ozone-initiated reactions is 4.8× 10^-17 cm^3/（molecule.s） at 298.15 K, which agrees with the experimental value for ethyl vinyl ether.
文摘The paper presents the case that physics is already and effectively unified by the energetic tension field, ether. We identify this integrating power of ether first, by re-defining the action generating parameters of this energetic tension field as the electric-tension, <img src="Edit_1233fa02-9a1c-416a-8153-196733a12887.png" alt="" />, and the magnetic-resistance, <em>μ</em><sub>0</sub>, while re-deriving the Maxwell’s wave equation in analogy with the mechanically stretched string, where the <img src="Edit_07813a1b-d94f-4e68-a3ed-b3023cd3fb5f.png" alt="" />. Then, replacing <img src="Edit_7d06fa1e-760d-4b80-a503-db81378a3512.png" alt="" /> by <img src="Edit_58f15ef0-2e86-42ae-a899-d0b4741f12d0.png" alt="" /> and <em>m</em><sub>0</sub> by <img src="Edit_f8cb7020-1a27-404a-b146-5c1357e1c5b5.png" alt="" />, one can find that almost all working physics theories are being energized by<img src="Edit_f860fcdd-1dc1-40bf-aaf1-e07b0e4a7524.png" alt="" />and <em>μ</em><sub>0</sub>. To complete the unification, we can now postulate that the particles are also freely propagating EM waves, but they are spatially localized as in-phase, close-looped (IP-CL) vortex-like propagation modes of ether. Because of their IP-CL mode structure, they have space-finite spatial structures and remain spatially stationary in the absence of any spatially influencing potential gradients (forces) in their vicinity. Particles’ <em>harmonic phase</em> driven interactions between quantum particles give birth to the <em>appearance</em> of wave-particle duality. There is no need for the confusing and unnecessary de Broglie’s Pilot Wave. The inertia to spatial motion of IP-CL modes automatically accommodates Newton’s laws of motion. The cosmic universality of Maxwellian wave velocity, and particles as IP-CL modes, jointly accommodate the two key postulates of special relativity without the need for unphysical four-dimensionality. The observable universe is represented only by its diverse oscillatory excited states. The stable and stationary Cosmic Ether keeps holding 100% of its energy all the time. We have proposed a one-way light pulse propagation experiment to directly validate the existence of ether, rather than approaching Michelson’s way of measuring the ether drag. We have identified a good number of examples of working theoretical expressions in terms of <img src="Edit_fd739625-efbd-4edd-9e1e-ba4ab5b7c07f.png" alt="" />and<em> μ</em><sub>0</sub> and presented our critical views in physics thinking, belonging to Classical, Relativity, Quantum and Cosmology Physics.
基金financially supported by the Management and Principal of Kamaraj College of Engineering and Technology,S.P.G.C.Nagar,K.Vellakulam Post-625701,India for providing all of the facilities to do the work
文摘Structurally diverse bispropargyl ethers using resorcinol,quinol,4,4￠-dihydroxy biphenyl,bisphenol-A,4,4￠-dihydroxy diphenyl ketone,4,4￠-dihydroxy diphenylsulphone,trimethyl indane bisphenol and tetramethyl spirobiindane bisphenol were prepared by using phase transfer catalyst.Synthesized materials were separately blended with 4,4￠-bismaleimido diphenyl methane（BMIM）in mole ratios（0.5：0.5）.The materials were thermally cured and the structural characterisation and the thermal properties of these cross-linked materials are investigated using Fourier-transform infrared（FTIR）spectrophotometer and thermogravimetric analyzer（TGA）.Among the different materials investigated poly MRPE,poly MBPEBPA and poly MSPE show higher onset degradation temperature of 300°C indicating higher thermal stability.The degradation kinetics is investigated using Flynn-Wall-Ozawa（FWO）,Vyazovkin（VYZ）and Friedman（FRD）methods.Amongst the various cured materials investigated,the activation energy（Ea-D）values obtained for poly MRPE and poly MKPE were observed to increase continuously froma=0.2 to 0.8 and the values range from 199 kJ/mol to 245 k J/mol and 153 k J/mol to 295 k J/mol respectively.The crosslinked materials resulting from these bispropargyl monomers definitely need more energy for bond cleavage due to the presence of more aromatic units.The volatile products obtained during the thermal degradation of the polymers were analyzed using thermogravimetric-Fourier transform infrared analyses（TG-FTIR）.The phenols,substituted phenols,carbon monoxide,carbon dioxide and small amount of aniline were found to be the major products during thermal degradation of these cured blends.
文摘Network crewn ether polymer with pendant sulfide side ohain in the networkstructure units has been synthesized via ring- opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl ether. A kind of active catalyst suitable for this reaction was suggested. The title polymer was found tobe a good ligand for platinous chloride, and the platinous complex could catalyze thehydrosilylation of olefins with triethoxysilane efficiently.
文摘Dimethyl ether (DME) is considered as a significant fuel alternative with a critical manufacturing process. Only a few authors have presented the kinetic analysis of attractive and alternative catalysts to Al<sub>2</sub>O<sub>3</sub> and/or zeolite in DME production, despite the fact that there is a large library of kinetic studies for these commercial catalysts. The purpose of this research was to contribute to this direction by conducting a catalytic test to determine kinetic parameters for methanol dehydration over sulfonic acid catalysts (resin). However, due to the relevance of the mathematical description of this process in the industry was also studied, a study of kinetics parameters and mathematical modeling of methanol dehydration in an atmospheric gas phase in a fixed bed reactor with a temperature range (90°C - 120°C) was examined. The Langmuir-Hinshelwood (L-H) model provides the best fit to experimental data, with an excellent R<sup>2</sup> = 0.9997, and the experimental results were compared to those predicted by these models with very small deviations. The kinetic parameters were found to be in good agreement with the Arrhenius equation, with acceptable straight-line graphs. The activation energy E was computed and found to be 27.66 kJ/mole, with an average variation of 0.32 percent between the predicted and calculated results. Simple mathematical continuum models (plug flow reactor PFR) showed an acceptable agreement with the experimental data.
基金This work was supported by the National Natural Science Foundation of China
文摘The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether anddiethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that thisreaction could be catalyzed by sodium, but not Lewis acid. The obtained polymer can coordinatewith platinum compound, and the platinum complex is a new kind of catalyst for thehydrosilylation of olefins with triethoxysilane.
基金This research was supported by the National Key R&D Program of China(2018YFB0604900).
文摘Polyoxymethylene dimethyl ethers(CH_(3)-O-(CH_(2)O)_(n)-CH_(3),PODE_(n),n>1)can be added to diesel to reduce air pollution caused by incomplete combustion.Driven by this need,a cost-effective and efficient synthetic route is presented and investigated by this work for the production of PODE_(n),which are formed from methylal and trioxane with low water content(<10%(mass))over HZSM-5 catalyst in a batch slurry autoclave at the temperature from 353.15 K to 393.15 K.The reaction rate laws including the PODE_(n) and byproducts of polyoxymethylene hemiformals(HF_(n)),polyoxymethylene glycols(MG),methanol(MeOH)and methyl formate(MF)are developed.The rate constants of propagation step(k_(6))and depolymerization step(k_(-6))are assumed independent on polymerization degree of PODE_(n).The rate of reaction is proportional to the content of the catalyst(Wcat)for the catalytic reaction within the scope of the study.All kinetic parameters were estimated by combining genetic algorithm and least square regression to fit experimental data well.This work is valuable for process optimization and reactor design.
基金supported by the National Natural Science Foundation of China(No.20976160)Zhejiang Provincial Natural Science Foundation of China(No.R4080110)
文摘The application of high temperature liquid water（HTLW） to decomposition of lignin as efficient and green solution for phenolic compounds recovery was studied.Benzyl phenyl ether（BPE）,the lignin model compound,was treated at temperatures ranging from 220 to 250℃.BPE undergo hydrolysis in HTLW,and main products were phenol and benzyl alcohol with the minimum selectivities of 75.7%and 82.8%,respectively.Lower temperature led to higher selectivity in 220-250℃temperature range.The kinetics on BPE hydrolysis was studied and the activation energy was determined as 150.3±12.5 kJ/mol with the first-order kinetic equations.Based on products distribution,the reaction mechanism for decomposition of benzyl phenyl ether was proposed.The investigated process provides insights into the design of a commercial method for utilization of lignin.
基金supported by the National Key Research and Development Program of China(No.2019YFC1804202)the National Natural Science Foundation of China(No.22020102004)+1 种基金the Tianjin Municipal Science and Technology Bureau(No.21JCZDJC00280)the Fundamental Research Funds for the Central Universities by the Ministry of Education of China(No.T2017002).
文摘Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling sites.The association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated transport.However,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely unknown.Herein,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous media.The colloids released froma soil sample collected at an e-waste recycling site in Tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).The colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater environments.Notably,under all the tested conditions(i.e.,varying flow velocity,pH,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids,even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions involved.Additionally,the mass of BDE-209 retained in the columns also correlates strongly with themass of retained colloids.Apparently,the PBDEs remain bound to soil colloids during transport in porous media.Findings in this study indicate that soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective carrier.This might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.
文摘A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.
文摘The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques including XRD,XPS,N2O titration,and 27Al MAS-NMR.The results showed that when the crystal configurations of Al_(2)O_(3) were the same,increasing the specific surface area could effectively refine the size of copper nanoparticles(Cu NPs),and ultimately improve the conversion of DEO.Meanwhile,the smaller size ofγ-Al_(2)O_(3)(HSAl and SBAl)loaded Cu NPs promotes the reaction towards the deep hydrogenation to produce ethanol(EtOH)and ethylene glycol(EG).Besides,the larger size of Cu NPs on the surface of amorphous Al_(2)O_(3)(HTAl and SolAl)resulted in a lower conversion rate,where ethyl glycolate(Egly)is the main product.Despite there are differences in Al^(3+)ionic coordination in Al_(2)O_(3) with different crystal structures,the experimental data showed that the differences in Al^(3+)ionic coordination did not significantly affect the catalytic performance in the hydrogenation reaction.The formation of alcohol-ether ester chemicals is critically dependent on the interactions between Cu sites and acidic sites.Among them,EG and EtOH were dehydrated to form 2-ethoxyethanol via the SN2 mechanism,while Egly and EtOH were reacted to form ethyl ethoxyacetate(EEA)via the SN2 mechanism.This study provides a theoretical basis for the optimization of the coal-based glycol processes to achieve a diversified product portfolio.
基金the staff of the BL18U/BL19U1 Beamline of the National Facility for Protein Science,Shanghai,at the Shanghai Synchrotron Radiation Facility for assistance during data collectionthe National Key Research and Development Program of China(Grant No.2023YFD1700500,2022YFD1700200)the Project of Natural Science Foundation of Liaoning Province(2022-KF-15-02).
文摘Trehalase hydrolyzes trehalose to glucose to provide energy for insects or building blocks for chitin synthesis.Because trehalase is critical to insects but not to humans,it has long been considered a promising target for green insecticides.However,the known trehalase inhibitors are mainly sugar derivatives with poor druggability.In this study,the trehalase from Ostrinia furnacalis(OfTreh)was expressed and characterized.By integrative computational strategies,diphenyl ether herbicides were discovered as the first non-carbohydrate inhibitors of insect trehalases.Bifenox and its more stable derivative,chlomethoxyfen,inhibited Of Treh with Ki values of 56 and 43μM,respectively.The oral administration of bifenox or chlomethoxyfen to locusts resulted in the inhibition of trehalose hydrolysis in vivo,leading to a mortality rate of 66%and server locomotion disorder in the survivors.This study not only established a platform for the development of insecticides targeting trehalase but also discovered a new mechanism for diphenyl ethers to kill insects as trehalase inhibitors.
