To enhance the operational capacity and space utilization of baffle-drop shafts,this study improved the traditional baffle-drop shaft by expanding the wet-side space,incorporating large rotation-angle baffles,and inst...To enhance the operational capacity and space utilization of baffle-drop shafts,this study improved the traditional baffle-drop shaft by expanding the wet-side space,incorporating large rotation-angle baffles,and installing overflow holes in the dividing wall.A three-dimensional turbulent model was developed using ANSYS Fluent to simulate the hydraulic characteristics of both traditional and new baffle-drop shafts across various flow rates.The simulation results demonstrated that the new shaft design allowed for discharge from both the wet and dry sides,significantly improving operational capacity,with the dry side capable of handling 40%of the inlet flow.Compared to the traditional shaft,the new design reduced shaft wall pressures and decreased the mean and standard deviation of pressure on typical baffles by 21%and 63%,respectively,therefore enhancing structural safety.Additionally,the new shaft achieved a 2%-12%higher energy dissipation rate than the traditional shaft across different flow rates.This study offers valuable insights for the design and optimization of drop shafts in deep tunnel drainage systems.展开更多
An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal an...An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal and NHC synergetic catalysis,which demonstrated a versatile three-component reaction pattern,thus enabling two C-C bonds forged regioselectively in the reaction.The important reaction intermediates were successfully captured and characterized by HRMS analysis,and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.展开更多
The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal M...The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal Mine as the engineering background,the deformation and failure law of the surrounding rock of the roadway in different fault protection pillar widths were obtained by numerical simulation method.On this basis,the mechanical model of the roadway under the action of hanging wall overburden migration and fault slip in normal faults was established,and the energy-driven mechanism of large deformation of the surrounding rock of the roadway was revealed.The ratio T of the energy applying on anchoring surrounding rock to the resistant energy of the anchored surrounding rock was defined as the criterion for the deformation of the roadway.Finally,it was calculated according to the actual working conditions on site,and the control method of“stress relief-support reinforcement”was used to support the roadway with the risk of large deformation.The on-site monitoring results show that the control effect of the surrounding rock of the roadway is obvious.展开更多
Oxidative carbonylation of ethanol to diethyl carbonate(DEC),an essential electrolyte for lithium-ion battery,has attracted broad interest from both academia and industry in recent years.But high selective formation o...Oxidative carbonylation of ethanol to diethyl carbonate(DEC),an essential electrolyte for lithium-ion battery,has attracted broad interest from both academia and industry in recent years.But high selective formation of DEC is a great challenge due to the difficultyin efficientactivation of CO at the same time as the site-specificactivation of O―H bond in ethanol.Herein,we propose a Pd-Cu_(x)O synergetic catalysis toward oxidative carbonylation of ethanol,where the synergy between Pd and Cu_(x)O promotes CO activation and carbonylation,thus increasing the selectivity to the site-specificactivation of O―H bond in ethanol.A nitrogen-doped carbon nanotubes supported Pd-Cu_(x)O(Pd-Cu_(x)O/NCNTs)has been designed via galvanic displacement of Pd on Cu_(x)O to form the strong interactions between Pd and Cu_(x)O,affording a selectivity of 94.7%to DEC and a space-time yield(STY)of up to 5966 mg·g^(-1)·h^(-1),which is an order of magnitude higher than that reported in the literatures.This work offers novel insights for the design of highly efficientcatalysts and advances the industrial development for the oxidative carbonylation of ethanol.展开更多
Hydrogen storage composite alloy Ti0.10Zr0.15V0.35Cr0.10Ni0.30–10% LaNi3 was prepared by two-step arc-melting to improve the electro-catalytic activity and the kinetic performance of Ti-V-based solid solution alloy. ...Hydrogen storage composite alloy Ti0.10Zr0.15V0.35Cr0.10Ni0.30–10% LaNi3 was prepared by two-step arc-melting to improve the electro-catalytic activity and the kinetic performance of Ti-V-based solid solution alloy. The electrochemical properties and synergetic effect of the composite alloy electrode were systematically investigated by using X-ray diffractometry, field emission scanning electron microscopy, energy-dispersive spectrometry, electrochemical impedance spectroscopy and galvanostatic charge/discharge test. It is found that the main phase of the composite alloy is composed of V-based solid solution phase with a BCC structure and C14 Laves phase with hexagonal structure, while the secondary phase is formed in the composite alloy. The comprehensive electrochemical properties of the composite alloy electrode are significantly improved. The activation cycle number, the maximum discharge capacity and the low temperature dischargeability of the composite alloy are 5 cycles, 362.5 mA-h/g and 65.84% at 233 K, respectively. It is suggested that distinct synergetic effect occurs in the activation process, composite process, cyclic process and discharge process at a low or high temperature under different current densities, in the charge–transfer resistance and exchange current density.展开更多
In Synergetics, when a complex system evolves from one sate to another, the order parameter plays a dominant role. We can analyze the complex system state by studying the dynamic of order parameter. We developed a syn...In Synergetics, when a complex system evolves from one sate to another, the order parameter plays a dominant role. We can analyze the complex system state by studying the dynamic of order parameter. We developed a synergetic model of electricity market operation system, and studied the dynamic process of the system with empirical example, which revealed the internal mechanism of the system evolution. In order to verify the accuracy of the synergetic model, fourth-order Runge-Kutta algorithm and grey relevance method were used. Finally, we found that the reserve rate of generation was the order parameter of the system. Then we can use the principle of Synergetics to evaluate the efficiency of electricity market operation.展开更多
The frequent occurrence of rockburst and the difficulty in predicting were considered in deep engineering and underground engineering.In this work,laboratory experiments on rockburst under true triaxial conditions wer...The frequent occurrence of rockburst and the difficulty in predicting were considered in deep engineering and underground engineering.In this work,laboratory experiments on rockburst under true triaxial conditions were carried out with granite samples.Combined with the deformation characteristics of granite,acoustic emission(AE)technology was well applied in revealing the evolution law of micro-cracks in the process of rockburst.Based on the comprehensive analysis of acoustic emission parameters such as impact,ringing and energy,the phased characteristics of crack propagation and damage evolution in granite were obtained,which were consistent with the stages of rock deformation and failure.Subsequently,based on the critical point theory,the accelerated release characteristics of acoustic emission energy during rockburst were analyzed.Based on the damage theory,the damage evolution model of rock under different loading conditions was proposed,and the prediction interval of rock failure time was ascertained concurrently.Finally,regarding damage as an intermediate variable,the synergetic prediction model of rock failure time was constructed.The feasibility and validity of model were verified.展开更多
The effect and mechanism of ultrasound and CaF_(2) on vanadium leaching from vanadium-bearing shale were investigated systematically.In consideration of the enhancement for vanadium recovery,the combination of ultraso...The effect and mechanism of ultrasound and CaF_(2) on vanadium leaching from vanadium-bearing shale were investigated systematically.In consideration of the enhancement for vanadium recovery,the combination of ultrasound and CaF_(2)(66.28%) exerts more evident effects than ultrasound(26.97%) and CaF_(2)(60.35%) alone,demonstrating the synergetic effect of ultrasound and CaF_(2).Kinetic analysis manifests that the product layer diffusion controls vanadium leaching in ultrasound system without CaF_(2),however product layer diffusion and interfacial reaction is the rate-controlling step for vanadium leaching in other three leaching systems.The combination of ultrasound and CaF_(2) notably decreases the activation energy(E_(a)) from 62.03 to 27.61 kJ/mol,nevertheless individual CaF_(2) only reduces the E_(a) to 50.70 kj/mol.X-ray diffraction and fourier transform infrared spectrometer analyses show that the decomposition degree of the vanadium-bearing mica structure is the most significant in ultrasound and CaF_(2) system,proving the highest release degree of vanadium.Specific surface area and pore distribution combined with scanning electron microscope analyses reveal that the action of ultrasound and CaF_(2) would provide higher specific surface area,more abundant pores structure and cracks for the particles,which further prompts the rapid diffusion of H^(+),F^(-)and HF,and achieves the conspicuous improvement of vanadium leaching recovery.展开更多
The BiOCl/Bi12O17Cl2@MoS2(BOC-MS)composites were successfully synthesized by a facile method at room temperature.The physicochemical properties of the as-obtained samples were characterized by X-ray diffractometer(XRD...The BiOCl/Bi12O17Cl2@MoS2(BOC-MS)composites were successfully synthesized by a facile method at room temperature.The physicochemical properties of the as-obtained samples were characterized by X-ray diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),ultraviolet–visible diffuse reflection spectra(UV–Vis DRS),photoluminescence(PL),Brunauer–Emmett–Teller–Barrett–Joyner–Halenda(BET–BJH),and electron spin resonance(ESR)in detail.Moreover,the in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)was applied to elucidate the adsorption and photocatalytic reaction mechanism.The optimized BOC-MS-1.0 composites exhibited excellent visible light photocatalytic capability(51.1%)and photochemical stability for removal of NO.Based on the DMPOESR spin trapping,the·O2-radicals andáOH radicals were identified as the main active species generated from BOCMS-1.0 under visible light irradiation.The enhanced photocatalytic performance can be ascribed to the positive synergetic effect of the MoS2 and the effective carrier separation ability.展开更多
In this study, a hybrid process using non‐thermal plasma (NTP) and photocatalytic oxidation (PCO) was adopted for the degradation of gas‐phase toluene using TiO2 as the photocatalyst. To discover the synergetic effe...In this study, a hybrid process using non‐thermal plasma (NTP) and photocatalytic oxidation (PCO) was adopted for the degradation of gas‐phase toluene using TiO2 as the photocatalyst. To discover the synergetic effect between NTP and PCO, the performances of both sole (O3, UV, NTP, and PCO) and combined (O3 + TiO2, O3 + UV, NTP + UV, O3 + PCO, and NTP + PCO) processes were investigated from different perspectives, such as the toluene removal efficiency, selectivity of COx, mineralization rate, ozone utilization, and the generation of by‐products. The toluene removal efficiency of the combined NTP + PCO process was 80.2%, which was much higher than that of a sole degradation process such as NTP (18.8%) and PCO (13.4%). The selectivity of CO2 and the ozone utilization efficiency also significantly improved. The amount of by‐products in the gas phase and the carbon‐ based intermediates adsorbed on the catalyst surface dramatically reduced. The improvement in the overall performances of the combined NTP + PCO process was mainly ascribed to the efficient utilization of ozone in the photocatalytic oxidation, and the ozone further acting as an electron acceptor and scavenger, generating more hydroxyl radicals and reducing the recombination of electron‐ hole pairs.展开更多
Effects of La, N, and P doping on the structural, electronic and optical properties of TiO_2 synthesized from TiCl_4 hydrolysis via a microwave-hydrothermal process were investigated by X-ray diffraction, transmission...Effects of La, N, and P doping on the structural, electronic and optical properties of TiO_2 synthesized from TiCl_4 hydrolysis via a microwave-hydrothermal process were investigated by X-ray diffraction, transmission electron microscopy, N_2 adsorption-desorption isotherm, X-ray photoelectron spectroscopy, electron paramagnetic resonance, UV-vis absorbance spectroscopy, photoelectrochemical measurements, and photoluminescence spectroscopy. The results showed that the presence of La in the tri-doped TiO_2 played a predominant role in inhibiting the recombination of the photogenerated electrons and holes. The existence of the substitutional N, interstitial N, and oxygen vacancies in TiO_2 lattices led to the band gap narrowing. It was P-doping rather than La or N doping that played a key role in inhibiting both anatase-to-rutile phase transformation and crystal growth, in stabilizing the mesoporous textural properties, and in increasing the content of surface bridging hydroxyl. Moreover, the tri-doping significantly enhanced the surface Ti^（4＋）-O^（2-）-Ti^（4＋）-O^（-·） species. All above-mentioned factors cooperated to result in the enhanced photoactivity of the tri-doped TiO_2. As a result, it exhibited the highest photoactivity towards the degradation of 4-chlorophenol（4-CP） under visible-light irradiation among all samples, which was much superior to commercial P25 TiO_2.展开更多
Designing highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)plays a paramount importance for proton exchange membrane fuel cells.Pt-based binary alloys Pt-M(M=3d-transition metals)posses...Designing highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)plays a paramount importance for proton exchange membrane fuel cells.Pt-based binary alloys Pt-M(M=3d-transition metals)possessing excellent electronic and geometric properties have received increasing interests as highly active electrocatalysts.Herein,we report a series of Pt_(x)Co/C(x=1,2,3)catalysts by a facile one-pot soft-chemistry method.In the acidic conditions,the mass activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 0.526,0.462 and 0.441 A·mgPt^(-1),which are 2.60,2.31 and 2.22 times higher than that of Pt/C(0.200 A·mgPt^(-1)),respectively.The specific activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 706.59,679.41 and 801.83μA·cm^(-2),which are accordingly 2.89,2.76 and 3.28 times higher than that of Pt/C(244.75μA·cm^(-2)).Notably,Pt_(3)Co/C shows a remarkable durability.After 5000 cycles of the accelerated durability testing,the mass activity and specific activity of Pt_(3)Co/C catalyst are 2.47 and 3.80 times higher than that of the commercial Pt/C,respectively.The improved ORR activity and durability can be ascribed to the synergistic interaction between Pt and Co.展开更多
4-Chlorophenol (4-CP) solution was treated by dual-frequency ultrasound inconjunction with Fenton reagent, and obvious improvement in the 4-CP degradation rate was observedin this advanced oxidation process. Experimen...4-Chlorophenol (4-CP) solution was treated by dual-frequency ultrasound inconjunction with Fenton reagent, and obvious improvement in the 4-CP degradation rate was observedin this advanced oxidation process. Experimental results showed that ultrasonic intensity,saturating gas and pH value affected greatly the 4-CP removal rate. Among four different saturatinggases (Ar, O_2, air and N_2), 4-CP degradation with Ar-saturated solution was the best. However, inthe view of practical wastewater treatment, using oxygen as the saturating gas would be moreeconomical. The addition of Fenton reagent followed the first-order kinetics and increased the 4-CPdegradation rate. The 4-CP removal rate increased by around 126% within 15 min treatment. Thesynergetic effect of dual-frequency ultrasound with Fenton reagent on 4-CP degradation was obviouslyobserved.展开更多
Au-Ag bimetallic nanoparticle‐supported microporous titanium silicalite‐1catalysts were prepared via a hydrothermal‐immersion method,and their structures were examined.These materials serve as efficient catalysts f...Au-Ag bimetallic nanoparticle‐supported microporous titanium silicalite‐1catalysts were prepared via a hydrothermal‐immersion method,and their structures were examined.These materials serve as efficient catalysts for the photosynthesis of propylene oxide via the epoxidation of propene.The Au/Ag mass ratio and reaction temperature were demonstrated to have significant effects on the catalytic activity and selectivity of propylene oxide.The optimal formation rate(68.3μmol/g·h)and selectivity(52.3%)toward propylene oxide were achieved with an Au:Ag mass ratio of4:1.Notably,the strong synergistic effect between Au and Ag resulted in superior photocatalysis of the bimetallic systems compared with those of the individual systems.A probable reaction mechanism was proposed based on the theoretical and experimental results.展开更多
It is a hot issue in communication research field to select the best network for Heterogeneous Wireless Networks(HWNs),and it is also a difficult problem to reduce the handoff number of vertical handoff.In order to so...It is a hot issue in communication research field to select the best network for Heterogeneous Wireless Networks(HWNs),and it is also a difficult problem to reduce the handoff number of vertical handoff.In order to solve this problem,the paper proposes a multiple attribute network selection algorithm based on Analytic Hierarchy Process(AHP)and synergetic theory.The algorithm applies synergetics to network selection,considering the candidate network as a compound system composed of multiple attribute subsystems,and combines the subsystem order degree with AHP weight to obtain entropy of the compound system,which is opposite the synergy degree of a network system.The greater the synergy degree,the better the network performance.The algorithm takes not only the coordination of objective attributes but also Quality of Service(QoS)requirements into consideration,ensuring that users select the network with overall good performance.The simulation results show that the proposed algorithm can effectively reduce the handoff number and provide uses with satisfactory QoS according to different services.展开更多
At present,frequent outbreaks of bacteria and viruses have seriously affected people's normal lives.Therefore,the study of broad-spectrum antibacterial nanocomposites is very promising.However,most antibacterial m...At present,frequent outbreaks of bacteria and viruses have seriously affected people's normal lives.Therefore,the study of broad-spectrum antibacterial nanocomposites is very promising.However,most antibacterial materials have some disadvantages,such as single bactericidal mechanisms and unrepeatable use.Based on the current situation,a kind of nanocomposite with three structures of graphene oxide(GO),quaternary ammonium salt(QAs)and N-halamine was prepared,which showed synergistic effect to improve antibacterial activity and combined with a variety of sterilization mechanisms.Meanwhile,GO can provide richer ways of sterilization and high specific surface area,which is conducive to the grafting of quaternarized N-halamine.The advantages of physical sterilization of GO,charge adsorption of QAs,reuse of N-halamine and efficient sterilization are fully utilized.The results showed that the quaternarized N-halamine-grafted GO was obtained successfully.GO grafted with quaternarized N-halamine polymer showed strong speedy bactericidal activity against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)(99%).It had good storage and regeneration properties.展开更多
Pt-TiO2/Ce-MnOx catalysts were obtained by depositing TiO2 and platinum, respectively, on the Ce-Mn oxides prepared by co-precipitation method. The phases of CeO2 and anatase TiO2 were observed in the catalysts from X...Pt-TiO2/Ce-MnOx catalysts were obtained by depositing TiO2 and platinum, respectively, on the Ce-Mn oxides prepared by co-precipitation method. The phases of CeO2 and anatase TiO2 were observed in the catalysts from X-ray diffraction （XRD） patterns. X-ray photoelectron spectroscopy （XPS） revealed that lattice oxygen and surface active oxygen were found to be the major components of O 1 s. The experiment results showed that the kinetic constant of thermo-photocatalysis was 7.6 times of the kinetic constant of single photocatalysis, and was 2.29 times of the kinetic constant sum of photocatalytic and thermal catalytic reaction.展开更多
An evidence for the synergetic effect between the stacked bed of Mo/γ-Al2O3 and Ni/γ-Al2O3 in the hydrodenitrogenation （HDN） reaction of quinoline has been provided in this paper. The synergism factor decreases wh...An evidence for the synergetic effect between the stacked bed of Mo/γ-Al2O3 and Ni/γ-Al2O3 in the hydrodenitrogenation （HDN） reaction of quinoline has been provided in this paper. The synergism factor decreases when the reaction temperature increases （280？340 ？C）. The synergetic effect leads to improve the hydrogenation activity for the stacked bed compared with the single Mo/γ-Al2O3 bed, which may be attributed to the generation of hydrogen spillover on the Ni/γ-Al2O3 catalyst.展开更多
Synergetic effects for p-nitrophenol degradation were observed in the combination of two-advanced oxidation processes, UV/Fe3+ and electrocatalysis. The enhancement of removal rate for p-nitrophenol and COD was aroun...Synergetic effects for p-nitrophenol degradation were observed in the combination of two-advanced oxidation processes, UV/Fe3+ and electrocatalysis. The enhancement of removal rate for p-nitrophenol and COD was around 123% and 278%, respectively. The possible contributions for the synergetic effects were the electrochemically regeneration of ferric ion and the role of the oxygen that formed on the anode.展开更多
The present work investigated the synergetic effect of pyrolysis-derived char,tar and gas(py-gas)on NO reduction,which may occur in circulating fluidized-bed decoupling combustion(CFBDC)system treating N-rich fuel.Exp...The present work investigated the synergetic effect of pyrolysis-derived char,tar and gas(py-gas)on NO reduction,which may occur in circulating fluidized-bed decoupling combustion(CFBDC)system treating N-rich fuel.Experiments were carried out in a lab-scale drop-tube reactor for NO reduction by some binary mixtures of reagents including char/py-gas,tar/py-gas and tar/char.At a specified total mass rate of0.15 g·min^-1 for NO-reduction reagent,the char/py-gas(binary reagent)enabled the best synergetic NO reduction in comparison with the others.There existed effective interactions between char and some species in py-gas(i.e.,H2,CxHy)during NO reduction by pyrolysis products,meanwhile the tar/py-gas or tar/char mixture only caused a positive effect when tar proportion was necessarily lowered to about 26%.On the other hand,the synergetic effects were not improved for all tested binary reagents by increasing the reaction temperature and residence time.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2021YFD1700802).
文摘To enhance the operational capacity and space utilization of baffle-drop shafts,this study improved the traditional baffle-drop shaft by expanding the wet-side space,incorporating large rotation-angle baffles,and installing overflow holes in the dividing wall.A three-dimensional turbulent model was developed using ANSYS Fluent to simulate the hydraulic characteristics of both traditional and new baffle-drop shafts across various flow rates.The simulation results demonstrated that the new shaft design allowed for discharge from both the wet and dry sides,significantly improving operational capacity,with the dry side capable of handling 40%of the inlet flow.Compared to the traditional shaft,the new design reduced shaft wall pressures and decreased the mean and standard deviation of pressure on typical baffles by 21%and 63%,respectively,therefore enhancing structural safety.Additionally,the new shaft achieved a 2%-12%higher energy dissipation rate than the traditional shaft across different flow rates.This study offers valuable insights for the design and optimization of drop shafts in deep tunnel drainage systems.
基金the National Natural Science Foundation of China(Nos.21831008,22025109,22101286)CAS Project for Young Scientists in Basic Research(No.YSBR-050)+1 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-201901)the State Key Laboratory of Fine Chemicals,Dalian University of Technology(No.KF2102)are gratefully acknowledged.
文摘An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal and NHC synergetic catalysis,which demonstrated a versatile three-component reaction pattern,thus enabling two C-C bonds forged regioselectively in the reaction.The important reaction intermediates were successfully captured and characterized by HRMS analysis,and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.
基金Projects(52374094,52374218,52174122)supported by the National Natural Science Foundation of ChinaProject(ZR2022YQ49)supported by the Excellent Youth Fund of Shandong Natural Science Foundation,ChinaProjects(tspd20210313,tsqn202211150)supported by the Taishan Scholar Project in Shandong Province,China。
文摘The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal Mine as the engineering background,the deformation and failure law of the surrounding rock of the roadway in different fault protection pillar widths were obtained by numerical simulation method.On this basis,the mechanical model of the roadway under the action of hanging wall overburden migration and fault slip in normal faults was established,and the energy-driven mechanism of large deformation of the surrounding rock of the roadway was revealed.The ratio T of the energy applying on anchoring surrounding rock to the resistant energy of the anchored surrounding rock was defined as the criterion for the deformation of the roadway.Finally,it was calculated according to the actual working conditions on site,and the control method of“stress relief-support reinforcement”was used to support the roadway with the risk of large deformation.The on-site monitoring results show that the control effect of the surrounding rock of the roadway is obvious.
基金Financial support from the National Natural Science Foundation of China(22138001 and 22288102)。
文摘Oxidative carbonylation of ethanol to diethyl carbonate(DEC),an essential electrolyte for lithium-ion battery,has attracted broad interest from both academia and industry in recent years.But high selective formation of DEC is a great challenge due to the difficultyin efficientactivation of CO at the same time as the site-specificactivation of O―H bond in ethanol.Herein,we propose a Pd-Cu_(x)O synergetic catalysis toward oxidative carbonylation of ethanol,where the synergy between Pd and Cu_(x)O promotes CO activation and carbonylation,thus increasing the selectivity to the site-specificactivation of O―H bond in ethanol.A nitrogen-doped carbon nanotubes supported Pd-Cu_(x)O(Pd-Cu_(x)O/NCNTs)has been designed via galvanic displacement of Pd on Cu_(x)O to form the strong interactions between Pd and Cu_(x)O,affording a selectivity of 94.7%to DEC and a space-time yield(STY)of up to 5966 mg·g^(-1)·h^(-1),which is an order of magnitude higher than that reported in the literatures.This work offers novel insights for the design of highly efficientcatalysts and advances the industrial development for the oxidative carbonylation of ethanol.
基金Project (B2011203074) supported by the Natural Science Foundation of Hebei Province, ChinaProject (201101A129) supported by the Technology Research and Development Program of Qinhuangdao, Hebei Province, China
文摘Hydrogen storage composite alloy Ti0.10Zr0.15V0.35Cr0.10Ni0.30–10% LaNi3 was prepared by two-step arc-melting to improve the electro-catalytic activity and the kinetic performance of Ti-V-based solid solution alloy. The electrochemical properties and synergetic effect of the composite alloy electrode were systematically investigated by using X-ray diffractometry, field emission scanning electron microscopy, energy-dispersive spectrometry, electrochemical impedance spectroscopy and galvanostatic charge/discharge test. It is found that the main phase of the composite alloy is composed of V-based solid solution phase with a BCC structure and C14 Laves phase with hexagonal structure, while the secondary phase is formed in the composite alloy. The comprehensive electrochemical properties of the composite alloy electrode are significantly improved. The activation cycle number, the maximum discharge capacity and the low temperature dischargeability of the composite alloy are 5 cycles, 362.5 mA-h/g and 65.84% at 233 K, respectively. It is suggested that distinct synergetic effect occurs in the activation process, composite process, cyclic process and discharge process at a low or high temperature under different current densities, in the charge–transfer resistance and exchange current density.
文摘In Synergetics, when a complex system evolves from one sate to another, the order parameter plays a dominant role. We can analyze the complex system state by studying the dynamic of order parameter. We developed a synergetic model of electricity market operation system, and studied the dynamic process of the system with empirical example, which revealed the internal mechanism of the system evolution. In order to verify the accuracy of the synergetic model, fourth-order Runge-Kutta algorithm and grey relevance method were used. Finally, we found that the reserve rate of generation was the order parameter of the system. Then we can use the principle of Synergetics to evaluate the efficiency of electricity market operation.
基金Projects(52074294,51574246,51674008)supported by the National Natural Science Foundation of ChinaProjects(2017YFC0804201,2017YFC0603000)supported by the National Key Research and Development Program of ChinaProject(2011QZ01)supported by the Fundamental Research Funds for the Central Universities,China。
文摘The frequent occurrence of rockburst and the difficulty in predicting were considered in deep engineering and underground engineering.In this work,laboratory experiments on rockburst under true triaxial conditions were carried out with granite samples.Combined with the deformation characteristics of granite,acoustic emission(AE)technology was well applied in revealing the evolution law of micro-cracks in the process of rockburst.Based on the comprehensive analysis of acoustic emission parameters such as impact,ringing and energy,the phased characteristics of crack propagation and damage evolution in granite were obtained,which were consistent with the stages of rock deformation and failure.Subsequently,based on the critical point theory,the accelerated release characteristics of acoustic emission energy during rockburst were analyzed.Based on the damage theory,the damage evolution model of rock under different loading conditions was proposed,and the prediction interval of rock failure time was ascertained concurrently.Finally,regarding damage as an intermediate variable,the synergetic prediction model of rock failure time was constructed.The feasibility and validity of model were verified.
基金supported by the National Natural Science Foundation of China (51874222 and 52074204)the Fundamental Research Funds for the Central Universities (No. 2020-YB029)。
文摘The effect and mechanism of ultrasound and CaF_(2) on vanadium leaching from vanadium-bearing shale were investigated systematically.In consideration of the enhancement for vanadium recovery,the combination of ultrasound and CaF_(2)(66.28%) exerts more evident effects than ultrasound(26.97%) and CaF_(2)(60.35%) alone,demonstrating the synergetic effect of ultrasound and CaF_(2).Kinetic analysis manifests that the product layer diffusion controls vanadium leaching in ultrasound system without CaF_(2),however product layer diffusion and interfacial reaction is the rate-controlling step for vanadium leaching in other three leaching systems.The combination of ultrasound and CaF_(2) notably decreases the activation energy(E_(a)) from 62.03 to 27.61 kJ/mol,nevertheless individual CaF_(2) only reduces the E_(a) to 50.70 kj/mol.X-ray diffraction and fourier transform infrared spectrometer analyses show that the decomposition degree of the vanadium-bearing mica structure is the most significant in ultrasound and CaF_(2) system,proving the highest release degree of vanadium.Specific surface area and pore distribution combined with scanning electron microscope analyses reveal that the action of ultrasound and CaF_(2) would provide higher specific surface area,more abundant pores structure and cracks for the particles,which further prompts the rapid diffusion of H^(+),F^(-)and HF,and achieves the conspicuous improvement of vanadium leaching recovery.
基金financially supported by the National Natural Science Foundation of China (Nos. 51708078 and 41801063)the Natural Science Foundation of Chongqing (No. 2018jcyjA1040)
文摘The BiOCl/Bi12O17Cl2@MoS2(BOC-MS)composites were successfully synthesized by a facile method at room temperature.The physicochemical properties of the as-obtained samples were characterized by X-ray diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),ultraviolet–visible diffuse reflection spectra(UV–Vis DRS),photoluminescence(PL),Brunauer–Emmett–Teller–Barrett–Joyner–Halenda(BET–BJH),and electron spin resonance(ESR)in detail.Moreover,the in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)was applied to elucidate the adsorption and photocatalytic reaction mechanism.The optimized BOC-MS-1.0 composites exhibited excellent visible light photocatalytic capability(51.1%)and photochemical stability for removal of NO.Based on the DMPOESR spin trapping,the·O2-radicals andáOH radicals were identified as the main active species generated from BOCMS-1.0 under visible light irradiation.The enhanced photocatalytic performance can be ascribed to the positive synergetic effect of the MoS2 and the effective carrier separation ability.
基金supported by the National Key Research and Development Plan of China (2016YFC0204700)National Natural Science Foundation of China (NSFC-51578488)+3 种基金Zhejiang Provincial "151" Talents Program (2013)Key Project of Zhejiang Provincial Science and Technology Programthe Program for Zhejiang Leading Team of S&T Innovation (2013TD07)the Changjiang Scholar Incentive Program (2009)~~
文摘In this study, a hybrid process using non‐thermal plasma (NTP) and photocatalytic oxidation (PCO) was adopted for the degradation of gas‐phase toluene using TiO2 as the photocatalyst. To discover the synergetic effect between NTP and PCO, the performances of both sole (O3, UV, NTP, and PCO) and combined (O3 + TiO2, O3 + UV, NTP + UV, O3 + PCO, and NTP + PCO) processes were investigated from different perspectives, such as the toluene removal efficiency, selectivity of COx, mineralization rate, ozone utilization, and the generation of by‐products. The toluene removal efficiency of the combined NTP + PCO process was 80.2%, which was much higher than that of a sole degradation process such as NTP (18.8%) and PCO (13.4%). The selectivity of CO2 and the ozone utilization efficiency also significantly improved. The amount of by‐products in the gas phase and the carbon‐ based intermediates adsorbed on the catalyst surface dramatically reduced. The improvement in the overall performances of the combined NTP + PCO process was mainly ascribed to the efficient utilization of ozone in the photocatalytic oxidation, and the ozone further acting as an electron acceptor and scavenger, generating more hydroxyl radicals and reducing the recombination of electron‐ hole pairs.
基金Project supported by the Natural Science Foundation of Heilongjiang Province(E201323)the Science and Technology Research Program of Education Bureau of Heilongjiang Province(12531213)
文摘Effects of La, N, and P doping on the structural, electronic and optical properties of TiO_2 synthesized from TiCl_4 hydrolysis via a microwave-hydrothermal process were investigated by X-ray diffraction, transmission electron microscopy, N_2 adsorption-desorption isotherm, X-ray photoelectron spectroscopy, electron paramagnetic resonance, UV-vis absorbance spectroscopy, photoelectrochemical measurements, and photoluminescence spectroscopy. The results showed that the presence of La in the tri-doped TiO_2 played a predominant role in inhibiting the recombination of the photogenerated electrons and holes. The existence of the substitutional N, interstitial N, and oxygen vacancies in TiO_2 lattices led to the band gap narrowing. It was P-doping rather than La or N doping that played a key role in inhibiting both anatase-to-rutile phase transformation and crystal growth, in stabilizing the mesoporous textural properties, and in increasing the content of surface bridging hydroxyl. Moreover, the tri-doping significantly enhanced the surface Ti^（4＋）-O^（2-）-Ti^（4＋）-O^（-·） species. All above-mentioned factors cooperated to result in the enhanced photoactivity of the tri-doped TiO_2. As a result, it exhibited the highest photoactivity towards the degradation of 4-chlorophenol（4-CP） under visible-light irradiation among all samples, which was much superior to commercial P25 TiO_2.
基金financially supported by the Project of National Natural Science Foundation of China(No.5202780089)。
文摘Designing highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)plays a paramount importance for proton exchange membrane fuel cells.Pt-based binary alloys Pt-M(M=3d-transition metals)possessing excellent electronic and geometric properties have received increasing interests as highly active electrocatalysts.Herein,we report a series of Pt_(x)Co/C(x=1,2,3)catalysts by a facile one-pot soft-chemistry method.In the acidic conditions,the mass activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 0.526,0.462 and 0.441 A·mgPt^(-1),which are 2.60,2.31 and 2.22 times higher than that of Pt/C(0.200 A·mgPt^(-1)),respectively.The specific activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 706.59,679.41 and 801.83μA·cm^(-2),which are accordingly 2.89,2.76 and 3.28 times higher than that of Pt/C(244.75μA·cm^(-2)).Notably,Pt_(3)Co/C shows a remarkable durability.After 5000 cycles of the accelerated durability testing,the mass activity and specific activity of Pt_(3)Co/C catalyst are 2.47 and 3.80 times higher than that of the commercial Pt/C,respectively.The improved ORR activity and durability can be ascribed to the synergistic interaction between Pt and Co.
基金Partly supported by the National Natural Science Foundation of China (No. 20176053)Academic Foundation of Zhejiang University of Technology (No. 20040004).
文摘4-Chlorophenol (4-CP) solution was treated by dual-frequency ultrasound inconjunction with Fenton reagent, and obvious improvement in the 4-CP degradation rate was observedin this advanced oxidation process. Experimental results showed that ultrasonic intensity,saturating gas and pH value affected greatly the 4-CP removal rate. Among four different saturatinggases (Ar, O_2, air and N_2), 4-CP degradation with Ar-saturated solution was the best. However, inthe view of practical wastewater treatment, using oxygen as the saturating gas would be moreeconomical. The addition of Fenton reagent followed the first-order kinetics and increased the 4-CPdegradation rate. The 4-CP removal rate increased by around 126% within 15 min treatment. Thesynergetic effect of dual-frequency ultrasound with Fenton reagent on 4-CP degradation was obviouslyobserved.
基金supported by the National Natural Science Foundation of China(21576050)the Natural Science Foundation of Jiangsu Province(BK20150604)~~
文摘Au-Ag bimetallic nanoparticle‐supported microporous titanium silicalite‐1catalysts were prepared via a hydrothermal‐immersion method,and their structures were examined.These materials serve as efficient catalysts for the photosynthesis of propylene oxide via the epoxidation of propene.The Au/Ag mass ratio and reaction temperature were demonstrated to have significant effects on the catalytic activity and selectivity of propylene oxide.The optimal formation rate(68.3μmol/g·h)and selectivity(52.3%)toward propylene oxide were achieved with an Au:Ag mass ratio of4:1.Notably,the strong synergistic effect between Au and Ag resulted in superior photocatalysis of the bimetallic systems compared with those of the individual systems.A probable reaction mechanism was proposed based on the theoretical and experimental results.
基金Supported by the Major State Basic Research Development Program of China(973 Program)(No.2013CB329005)the National Natural Science Foundation of China(No.61171094)+1 种基金the National Science & Technology Key Project(No.2011ZX03001-006-02.No.2011ZX03005004-03)the Key Project of Jiangsu Provincial Natural Science Foundation(No.BK2011027)
文摘It is a hot issue in communication research field to select the best network for Heterogeneous Wireless Networks(HWNs),and it is also a difficult problem to reduce the handoff number of vertical handoff.In order to solve this problem,the paper proposes a multiple attribute network selection algorithm based on Analytic Hierarchy Process(AHP)and synergetic theory.The algorithm applies synergetics to network selection,considering the candidate network as a compound system composed of multiple attribute subsystems,and combines the subsystem order degree with AHP weight to obtain entropy of the compound system,which is opposite the synergy degree of a network system.The greater the synergy degree,the better the network performance.The algorithm takes not only the coordination of objective attributes but also Quality of Service(QoS)requirements into consideration,ensuring that users select the network with overall good performance.The simulation results show that the proposed algorithm can effectively reduce the handoff number and provide uses with satisfactory QoS according to different services.
基金supported by the National Natural Science Foundation of China(No.51603020)the Jilin Province Science and Technology Natural Science Foundation Project of China(No.20180101193JC).
文摘At present,frequent outbreaks of bacteria and viruses have seriously affected people's normal lives.Therefore,the study of broad-spectrum antibacterial nanocomposites is very promising.However,most antibacterial materials have some disadvantages,such as single bactericidal mechanisms and unrepeatable use.Based on the current situation,a kind of nanocomposite with three structures of graphene oxide(GO),quaternary ammonium salt(QAs)and N-halamine was prepared,which showed synergistic effect to improve antibacterial activity and combined with a variety of sterilization mechanisms.Meanwhile,GO can provide richer ways of sterilization and high specific surface area,which is conducive to the grafting of quaternarized N-halamine.The advantages of physical sterilization of GO,charge adsorption of QAs,reuse of N-halamine and efficient sterilization are fully utilized.The results showed that the quaternarized N-halamine-grafted GO was obtained successfully.GO grafted with quaternarized N-halamine polymer showed strong speedy bactericidal activity against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)(99%).It had good storage and regeneration properties.
文摘Pt-TiO2/Ce-MnOx catalysts were obtained by depositing TiO2 and platinum, respectively, on the Ce-Mn oxides prepared by co-precipitation method. The phases of CeO2 and anatase TiO2 were observed in the catalysts from X-ray diffraction （XRD） patterns. X-ray photoelectron spectroscopy （XPS） revealed that lattice oxygen and surface active oxygen were found to be the major components of O 1 s. The experiment results showed that the kinetic constant of thermo-photocatalysis was 7.6 times of the kinetic constant of single photocatalysis, and was 2.29 times of the kinetic constant sum of photocatalytic and thermal catalytic reaction.
基金supported by the State Key Development Program for Basic Research of China (No. 2010CB226905)supported by the Basic Research Program " Green Chemistry and Engineering of Heavy Oil Conversionwith High Efficiency "
文摘An evidence for the synergetic effect between the stacked bed of Mo/γ-Al2O3 and Ni/γ-Al2O3 in the hydrodenitrogenation （HDN） reaction of quinoline has been provided in this paper. The synergism factor decreases when the reaction temperature increases （280？340 ？C）. The synergetic effect leads to improve the hydrogenation activity for the stacked bed compared with the single Mo/γ-Al2O3 bed, which may be attributed to the generation of hydrogen spillover on the Ni/γ-Al2O3 catalyst.
文摘Synergetic effects for p-nitrophenol degradation were observed in the combination of two-advanced oxidation processes, UV/Fe3+ and electrocatalysis. The enhancement of removal rate for p-nitrophenol and COD was around 123% and 278%, respectively. The possible contributions for the synergetic effects were the electrochemically regeneration of ferric ion and the role of the oxygen that formed on the anode.
基金Supported by the National Basic Research Program of China(2014BAC26B04,2014CB744303)the National Natural Science Foundation of China(U1302273)
文摘The present work investigated the synergetic effect of pyrolysis-derived char,tar and gas(py-gas)on NO reduction,which may occur in circulating fluidized-bed decoupling combustion(CFBDC)system treating N-rich fuel.Experiments were carried out in a lab-scale drop-tube reactor for NO reduction by some binary mixtures of reagents including char/py-gas,tar/py-gas and tar/char.At a specified total mass rate of0.15 g·min^-1 for NO-reduction reagent,the char/py-gas(binary reagent)enabled the best synergetic NO reduction in comparison with the others.There existed effective interactions between char and some species in py-gas(i.e.,H2,CxHy)during NO reduction by pyrolysis products,meanwhile the tar/py-gas or tar/char mixture only caused a positive effect when tar proportion was necessarily lowered to about 26%.On the other hand,the synergetic effects were not improved for all tested binary reagents by increasing the reaction temperature and residence time.
