In this study,low-rank coal-water slurry(LCWS)was prepared using polyoxyethylene dodecylphenol ether(PDPE)and polyoxyethylene lauryl ether(PLE),respectively.A combination of experiments and simulations was used to inv...In this study,low-rank coal-water slurry(LCWS)was prepared using polyoxyethylene dodecylphenol ether(PDPE)and polyoxyethylene lauryl ether(PLE),respectively.A combination of experiments and simulations was used to investigate the pulping properties and microscopic mechanism of the LCWS samples prepared using the two agents,so as to explore the influence of benzene ring on the performance of dispersant.The results of the LCWS preparation experiments revealed that the pulp-forming performance of PDPE exceeded that of PLE.When LCWS concentration is 62%,64%,and 66%,the apparent viscosity corresponding to PDPE is 247.80,504.17,and 653.10 mPa·s,and the apparent viscosity corresponding to PLE is 548.10,1470.61,and 1549.98 mPa·s,respectively.The C_(1000)(When the apparent viscosity is 1000 mPa·s,the corresponding concentration of LCWS is defined as C_(1000))values of PDPE and PLE are 67.60%and 62.95%,respectively.In addition to the van der Waals forces and hydrogen bonds between the PDPE and/or PLE molecules and coal,the benzene rings of PDPE presentπ-πstacking effect with the aromatic rings of coal.That could facilitate and strengthen the adsorption of PDPE on coal,which would be conducive to further improving the dispersion of coal particles.The two dispersants have no significant difference in effect on the pyrolysis of LCWS.The simulation results indicated that the times for PDPE and PLE molecules to reach flat adsorption state on coal are approximately 290 and 565 ps,respectively.The self-diffusion coefficient(D)of the PDPE and PLE on coal is 3.16 x 10^(-6)and6.57×10^(-6)m~2/s,respectively,and their interaction energies with coal are 785.71 and 648.60 kcal/mol,respectively.The results of the simulation calculations demonstrated that PDPE adsorbed on coal easier than PLE,and its binding is more stable than that of PLE owing to theπ-πstacking effect,which is conducive to uniform dispersion of coal in solution.The simulation results confirmed the experimental results.展开更多
The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropr...The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration.Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface,andΔG_(ads)^(0) was negative,proving that the reaction was spontaneous.Zeta potential measurements showed that SL increased the negative charge on coal.FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption,and it was found that the content of oxygen functional groups on coal increased after adsorption.Simulation results show that when a large number of SL molecules exist in the solution,some SL molecules will bind to hydrophobic hydrocarbon groups on coal.The rest of the SL molecule s,their hydrophobic alkyl tails,come into contact with each other and aggregate in solution.The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction,which is conducive to the even dispersion of coal particles.The results of mean square displacement(MSD)and self-diffusion coefficient(D)show that the addition of SL reduces the diffusion rate of water molecules.Simulation results correspond to experimental results,indicating that MD simulation is accurate and feasible.展开更多
A myriad of abiotic stress responses in plants are controlled by abscisic acid(ABA)signaling.ABA receptors can be degraded by both the 26S proteasome pathway and vacuolar degradation pathway after processing via the e...A myriad of abiotic stress responses in plants are controlled by abscisic acid(ABA)signaling.ABA receptors can be degraded by both the 26S proteasome pathway and vacuolar degradation pathway after processing via the endosomal sorting complex required for transport(ESCRT)proteins.Despite being essential for ABA signaling,the upstream regulators of ESCRTs remain unknown.Here,we report that the ESCRT-I component VPS23A is an unstable protein that is degraded via the ubiquitin-proteasome system(UPS).The UEV domain of VPS23A physically interacts with the two PSAP motifs of XBAT35,an E3 ubiquitin ligase,and this interaction results in the deposition of K48 polyubiquitin chains on VPS23A,marking it for degradation by 26S proteasomes.We showed that XBAT35 in plants is a positive regulator of ABA responses that acts via the VPS23A/PYL4 complex,specifically by accelerating VPS23A turnover and thereby increasing accumulation of the ABA receptor PYL4.This work deciphers how an ESCRT component is regulated in plants and deepens our understanding of plant stress responses by illustrating a mechanism whereby crosstalk between the UPS and endosome-vacuole-mediated degradation pathways controls ABA signaling.展开更多
基金supported by National Natural Science Foundation of China(Nos.51904174 and 52074175)Postdoctoral Science Foundation of China(No.2019M662403)+3 种基金Young Science and Technology Innovation Program of Shandong Province(No.2020KJD001)Key Research and Development Project of Shandong(No.2019GGX103035)SDUST Research Fund(No.2018TDJH101)Project of Shandong Province Higher Educational Young Innovative Talent Introduction and Cultivation Team。
文摘In this study,low-rank coal-water slurry(LCWS)was prepared using polyoxyethylene dodecylphenol ether(PDPE)and polyoxyethylene lauryl ether(PLE),respectively.A combination of experiments and simulations was used to investigate the pulping properties and microscopic mechanism of the LCWS samples prepared using the two agents,so as to explore the influence of benzene ring on the performance of dispersant.The results of the LCWS preparation experiments revealed that the pulp-forming performance of PDPE exceeded that of PLE.When LCWS concentration is 62%,64%,and 66%,the apparent viscosity corresponding to PDPE is 247.80,504.17,and 653.10 mPa·s,and the apparent viscosity corresponding to PLE is 548.10,1470.61,and 1549.98 mPa·s,respectively.The C_(1000)(When the apparent viscosity is 1000 mPa·s,the corresponding concentration of LCWS is defined as C_(1000))values of PDPE and PLE are 67.60%and 62.95%,respectively.In addition to the van der Waals forces and hydrogen bonds between the PDPE and/or PLE molecules and coal,the benzene rings of PDPE presentπ-πstacking effect with the aromatic rings of coal.That could facilitate and strengthen the adsorption of PDPE on coal,which would be conducive to further improving the dispersion of coal particles.The two dispersants have no significant difference in effect on the pyrolysis of LCWS.The simulation results indicated that the times for PDPE and PLE molecules to reach flat adsorption state on coal are approximately 290 and 565 ps,respectively.The self-diffusion coefficient(D)of the PDPE and PLE on coal is 3.16 x 10^(-6)and6.57×10^(-6)m~2/s,respectively,and their interaction energies with coal are 785.71 and 648.60 kcal/mol,respectively.The results of the simulation calculations demonstrated that PDPE adsorbed on coal easier than PLE,and its binding is more stable than that of PLE owing to theπ-πstacking effect,which is conducive to uniform dispersion of coal in solution.The simulation results confirmed the experimental results.
基金supported by SDUST Research Fund(Grant No.2018TDJH101)Key Research and Development Project of Shandong(Grant No.2019GGX103035)+2 种基金National Natural Science Foundation of China(Grant Nos.51904174,52074175)Young Science and Technology Innovation Program of Shandong Province(Grant No.2020KJD001)Project of Shandong Province Higher Educational Young Innovative Talent Introduction and Cultivation Team。
文摘The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration.Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface,andΔG_(ads)^(0) was negative,proving that the reaction was spontaneous.Zeta potential measurements showed that SL increased the negative charge on coal.FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption,and it was found that the content of oxygen functional groups on coal increased after adsorption.Simulation results show that when a large number of SL molecules exist in the solution,some SL molecules will bind to hydrophobic hydrocarbon groups on coal.The rest of the SL molecule s,their hydrophobic alkyl tails,come into contact with each other and aggregate in solution.The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction,which is conducive to the even dispersion of coal particles.The results of mean square displacement(MSD)and self-diffusion coefficient(D)show that the addition of SL reduces the diffusion rate of water molecules.Simulation results correspond to experimental results,indicating that MD simulation is accurate and feasible.
基金grant 2016YFA0500500 from the National Key R&D Program of Chinagrant 31800228 from the National Natural Science Foundation of China.
文摘A myriad of abiotic stress responses in plants are controlled by abscisic acid(ABA)signaling.ABA receptors can be degraded by both the 26S proteasome pathway and vacuolar degradation pathway after processing via the endosomal sorting complex required for transport(ESCRT)proteins.Despite being essential for ABA signaling,the upstream regulators of ESCRTs remain unknown.Here,we report that the ESCRT-I component VPS23A is an unstable protein that is degraded via the ubiquitin-proteasome system(UPS).The UEV domain of VPS23A physically interacts with the two PSAP motifs of XBAT35,an E3 ubiquitin ligase,and this interaction results in the deposition of K48 polyubiquitin chains on VPS23A,marking it for degradation by 26S proteasomes.We showed that XBAT35 in plants is a positive regulator of ABA responses that acts via the VPS23A/PYL4 complex,specifically by accelerating VPS23A turnover and thereby increasing accumulation of the ABA receptor PYL4.This work deciphers how an ESCRT component is regulated in plants and deepens our understanding of plant stress responses by illustrating a mechanism whereby crosstalk between the UPS and endosome-vacuole-mediated degradation pathways controls ABA signaling.