This paper substantiates the idea that particular science reflects only a certain angle of a complex model of the world. Guidance as to ＂adding＂ particular science data in order to achieve a holistic picture of the ...This paper substantiates the idea that particular science reflects only a certain angle of a complex model of the world. Guidance as to ＂adding＂ particular science data in order to achieve a holistic picture of the world is a philosophical outlook. The meaning of each relatively closed system is revealed only in the context of a more capacious system. According to the author, as the material world itself, its epistemic models as well are built according to the principle of ＂matryoshka dolls.＂ The rational and irrational are discussed in the paper as equal moments of scientific knowledge. Contrary to the importance given to randomness in synergy, the author considers if it is possible to find out the causes of all events. In order to do this, other viewpoints and structure levels should be considered. There is a hidden order in every chaos, and that is revealed only in a certain situation. The main issue is taking into account the counter action of the system with the environment.展开更多
The principle for blood pressure measurement using pulse transit time is introduced in this paper.And the math model of synergetics theory is studied in detail.The synergetics theory is applied in the analysis of bloo...The principle for blood pressure measurement using pulse transit time is introduced in this paper.And the math model of synergetics theory is studied in detail.The synergetics theory is applied in the analysis of blood pressure measurement data.The simulation results show that the application of synergetics theory is helpful to judge the normal blood pressure,and the accuracy is up to 80%.展开更多
A ternary early-strengthening agent consisting of calcium formate+triethanolamine+lithium sulfate was compounded with quercetin to shorten the setting time of cementitious materials while ensuring their early strength...A ternary early-strengthening agent consisting of calcium formate+triethanolamine+lithium sulfate was compounded with quercetin to shorten the setting time of cementitious materials while ensuring their early strength.The optimum ratio of the three early-strengthening agents was determined as 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate by response surface methodology.The effects of the ternary early-strengthening agent composed of calcium formate+triethanolamine(TEA)+lithium sulfate on cementitious pore sealing materials under the synergistic effect of quercetin were studied by means of the performance tests of compressive strength,fluidity,and setting time,and the microstructural characterizations of X-ray powder diffractometer(XRD),thermogravimetry(TG-DSC)and scanning electron microscopy(SEM).The study shows that the synergistic effect of ternary early-strengthening agent and quercetin forms a multi-performance composite admixture for cementitious materials.The best performance was obtained with the compounding scheme of 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate ternary early-strengthening agent and 0.05%quercetin.The compressive strength of 1,3,7,and 28 d are 94.8%,39.8%,42%,and 28%higher than those of the blank group,respectively.The initial time and final setting time are 41 and 57 minutes,respectively.According to the microscopic analysis,the network and fibrous C-S-H gels generated by ternary early-strengthening agents are attached to the surface promoted by quercetin,which forms skeleton support while thickening and solidifying the cement slurry,which enhances the early compressive strength of the cement-based materials.展开更多
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
Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully...Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully synthesized via the sol–gel method and tested for their catalytic performance for simultaneous degradation of benzene and toluene.The CuMn_(2)O_(4)sample exhibited the best catalytic performance,the conversion of benzene reached 100%at 350℃,and toluene conversion reached 100%at 250℃.XRD,N_(2)adsorption-desorption,HRTEM-EDS,ED-XRF,Raman spectroscopy,H_(2)-TPR,NH_(3)-TPD,O_(2)-TPD and XPS were used to characterize the physical and chemical properties of MMn_(2)O_(4)catalysts.The excellent redox properties,high concentration of surface Mn4+,and adsorption of oxygen species over the CuMn_(2)O_(4)sample facilitated the simultaneous and efficient removal of benzene and toluene.Additionally,in situ DRIFTS illustrated the intermediate species and reaction mechanism for the synergetic catalytic oxidation of benzene and toluene.Notably,as an effective catalytic material,spinel oxide exhibited excellent synergistic degradation performance for benzene and toluene,providing some insight for the development of efficient multicomponent VOC catalysts.展开更多
In this study,injectable bone graft putty samples were developed using fine and coarse melt-quenched 45S5 bioactive glass(BG)incorporated into a carrier system composed of glycerol and polyethylene glycol(PEG)with dif...In this study,injectable bone graft putty samples were developed using fine and coarse melt-quenched 45S5 bioactive glass(BG)incorporated into a carrier system composed of glycerol and polyethylene glycol(PEG)with different average molecular weights.Selected putty samples were further incorporated with varying amounts of Denosumab(5wt%-10wt%)to investigate its influence on rhe-ological behavior and flow properties using mathematical modeling.All PEG/glycerol/45S5-based putty samples exhibited viscoelastic behavior(storage modulus>loss modulus)and pseudoplastic behavior(n<1),with viscosity values required for optimal flow remaining below 1000 Pa∙s.Both viscosity and thixotropic area increased proportionally with higher BG content and smaller-sized BG particles.All putty samples showed more than 98%injectability through a 12G cannula,suggesting potential clinical suitability.However,injectability decreased with smaller cannulas,dropping to 34.7%-58.3%with a 19G cannula and further decreasing with a 23G cannula at higher BG contents.Incorporation of Denosumab preserved viscoelasticity and injectability but modified the flow behavior,shifting it from pseudo-plastic to more Newtonian with higher Denosumab content,while also reducing viscosity and thixotropic area values.Among all tested samples,putty containing a lower amount of Denosumab and smaller-sized BG exhibited the most suitable combination of injectability and rheological features.All putty samples were well described by both the Power law and Herschel-Bulkley rheological models(coeffi-cient of determination>0.95).This study highlights the influence of Denosumab on flowability and rheological relationships and sug-gests potential improvements in bioactivity through a dual synergistic effect of BG and Denosumab in minimally invasive bone graft sys-tems.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
In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of N...In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of NO.The phase transition process between Ce species and Ti species is limited by modulating the interaction between Ce4+and Ti4+,while a completely amorphous composite is generated with an appropriate molar ratio of Ti/Ce(1.5/1).The catalyst CeTi1.5Oxexhibits the best catalytic performance,where the values of T90and T50for deep degradation of toluene are 297 and 330℃respectively at high weight hours space velocity(WHSV=120000 mL/(g·h)).Compared with CeO_(2),T90and T50decrease by48 and 34℃respectively while declining by 67 and 70℃compared to TiO_(2).For the SCR reaction,CeTi1.5Oxreaches 100%NO conversion at 250℃with WHSV=60000 mL/(g·h),reduced by 50℃compared to pure CeO_(2).The amorphous nanostructure with highly dispersed Ce and Ti species was confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD)characterizations.The X-ray photoelectron spectroscopy(XPS)and Raman analyses show that a large number of active Ce-O-Ti species and surface oxygen vacancies are generated due to the strong interaction between Ti^(4+)and Ce^(4+)in CeTi_(1.5)O_(x).Additionally,H_(2)-TPR and O_(2)-TPD further confirm that the interaction promotes the low-temperature reducibility and mobility of surface-active oxygen species.Meanwhile,in-situ DRIFTS study reveals that CeTi1.5Oxwith amorphous nanostructure can dramatically enhance the dissociative and complete oxidation capacity for toluene.展开更多
Hydrogen production coupled with small molecule oxidation derived by renewable energy power has been widely studied as an effective method to reduce energy consumption and prepare added value production.Here,the coppe...Hydrogen production coupled with small molecule oxidation derived by renewable energy power has been widely studied as an effective method to reduce energy consumption and prepare added value production.Here,the copper-cobalt phosphide with a multilevel structure has been designed based on the hard and soft acids and bases theory.The nanocone composed of lamellas presented a sharp tip,which a positive effect on the mass transfer enhanced by a local electric field,and the nanolamellas contain CoP/Cu_(3)P interface provide the highly selective active site for the gluconic acid(GNA)synthesis and hydrogen evolution.The catalyst can drive hydrogen evolution at 5 A·cm^(-2)up to 437 h without active decay,and the electrocatalytic glucose oxidation at anode presents high efficiency due to Cu(I)introduction and the synergetic effect between interfaces.Density functional theory(DFT)calculation shows that water splitting more readily occurs at the CoP,which provides adsorbed H and-OH for hydrogen evolution and glucose oxidation,respectively,and glucose adsorption more readily occurs at the Cu_(3)P,which presents lower conversion energy for high value-added GNA.Efficient hydrogen evolution and glucose conversion indicate its high intrinsic activity and synergetic effect.This work provides a special interface construction strategy for the catalytic conversion of hydrogen and small molecules.展开更多
In the context of the global pursuit of sustainable energy,dual-atom catalysts(DACs)have attracted widespread attention due to their unique structural and excellent catalytic performance.Unlike the single-atom catalys...In the context of the global pursuit of sustainable energy,dual-atom catalysts(DACs)have attracted widespread attention due to their unique structural and excellent catalytic performance.Unlike the single-atom catalysts,DACs possess two active metal centers,exhibiting intriguing synergistic effects that significantly enhance their efficiency in various electrochemical reactions.This comprehensive review provides an overview of the recent advances in the field of dual-atom catalysts,focusing on their innovative preparation methods and strategies.It further delves into the intrinsic connections between structure and performance,discussing the applications of DACs in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,photocatalysis,carbon dioxide reduction reaction,and batteries.Lastly,a forward-looking perspective addresses the current challenges and outlines future directions.This review aims to deepen our understanding of DACs and stimulate further innovation in advanced catalysts for energy conversion systems.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
Acidic-and alkalic-hydrolyses are selective in breaking functional bonds and falling off pharmacological moieties of antibiotics in production wastewater in comparison with advanced oxidation processes.Elevating tempe...Acidic-and alkalic-hydrolyses are selective in breaking functional bonds and falling off pharmacological moieties of antibiotics in production wastewater in comparison with advanced oxidation processes.Elevating temperature can accelerate hydrolytic kinetics and improve efficiency.In this work,magnetic sulfonated polypropylene resin(Fe_(3)O_(4)@PS-S)composites were reported for acidic-thermal hydrolysis of tylosin by employing the acidic feature of sulfonic group,the dielectric effect of resin,and the magnetic-loss effect of magnetite under microwave irradiation.As observed,a rapid and complete mitigation 100 mg/L of tylosin was achieved within 15 min by the catalysts.Acidic cleavage of tylosin was fulfilled by sulfonic groups in the composites,and microwave thermal accelerated the hydrolysis reactions due to the dielectric and magnetic-loss effects.Differentiating the dielectric and magnetic-loss effects through electromagnetic analyses indicated that the latter contributed more in converting microwave energy to heat.The interactions under multiple operational conditions were quantitatively fitted using the Behnajady model and visually demonstrated,which indicated that a synergic effect of microwave thermal-and acidichydrolyses contributed to the efficient mitigation of tylosin.The transformation products were identified and the pathways were supposed.Cleaving deoxyaminosugars groups and destructing lactone structures led to reduced antibacterial potential and toxicity reduction.The acute toxicity of tylosin and transformation products to fish,daphnia,and green algae were all classified as non-toxic.This work suggested that this synergistic acid-thermal hydrolytic method is attractive and promising in pretreating tylosin production wastewater in field.展开更多
As a novel material,high-entropy compounds have attracted extensive attention in the field of lithium–sulfur battery host materials due to their diverse elemental composition with a wide range of properties.The abili...As a novel material,high-entropy compounds have attracted extensive attention in the field of lithium–sulfur battery host materials due to their diverse elemental composition with a wide range of properties.The ability to effectively mitigate the shuttle effect of lithium polysulfides and catalyze the bidirectional conversion of Li_(2)S_(2)/Li_(2)S is crucial to enhance the overall performance of the battery.In this study,a unique sulfur host nanosized highentropy material comprising selenium-doped HEO(AlCrFeCoNi)_(3)O_(4-x)-Se_(x)is fabricated using an in situ thermal reduction and selenylation method.In the high-entropy compounds,the introduction of Se causes that the generation of oxygen vacancies during the lattice distortion serves as ion transfer pathway and the formation of M-Se bonds provides a high adsorption capability for LiPSs.Moreover,the polymetallic cooperative high-entropy nanoparticles also provide numerous active sites favoring redox kinetics of the sulfur electrode.The resulting selenium-doped HEO(AlCrFeCoNi)_(3)O_(4-x)-Se_(x)not only enhances discharge capacity but also maintains excellent capacity cycling stability.As a result,the HEO-Se/S composite exhibits a specific capacity of 1233.9 mAh g^(-1)at 0.1C and experiences minimal capacity fading at a rate of 0.038%per cycle over 500 cycles at 0.2C,while host materials with sulfur loading of 4.33 mg cm^(-2)and E/S ratio of 5.88μL mg^(-1)exhibit excellent capacity retention after 100 cycles at 0.2C.This work offers new insights into synthesizing high-entropy nanomaterials for improving the electrochemical performance of Li–S batteries.展开更多
Birefringence and second harmonic generation(SHG)are important optical properties of functional crystals.However,it is relatively rare for a compound to exhibit both enhanced properties simultaneously.In this study,we...Birefringence and second harmonic generation(SHG)are important optical properties of functional crystals.However,it is relatively rare for a compound to exhibit both enhanced properties simultaneously.In this study,we used DFT calculations to discover an ideal functional gene:protonated 3,5-dipicolinic acid(C_(7)H_(4)NO_(4),HDPA).By combining HPDA with the traditional IO_(3)-anion,we obtained a non-centrosymmetric and polar semiorganic iodate,namely HDPA(IO_(3)).The organic cations and iodate anions in HDPA(IO_(3))are bridged via the N-H···O and O-H···O hydrogen bonds,forming the wave-shaped layers.The synergistic effect between the expandedπ-conjugation of the organic cation and the stereochemically active lone pair electrons in the inorganic iodate anion results that HDPA(IO_(3))exhibiting a strong SHG effect,3.6 times that of KH_(2)PO_(4),and an unusually large birefringence of 0.35 at 546 nm,larger than most of SHG-active iodates.Additionally,HDPA(IO_(3))has a wide bandgap of 4.12 e V with a corresponding cutoff edge at 269 nm,indicating its potential as a promising short-wave ultraviolet(UV)optical crystal.展开更多
Photodynamic therapy(PDT),as a non-invasive treatment,is expected to be widely used in clinical cancer treatment.In this paper,a near-infrared(NIR)light responsive Lu_(2)O_(3):Yb/Er/Li-Ce6@MIL-101/GOx-PDA(LCMGP)nanodi...Photodynamic therapy(PDT),as a non-invasive treatment,is expected to be widely used in clinical cancer treatment.In this paper,a near-infrared(NIR)light responsive Lu_(2)O_(3):Yb/Er/Li-Ce6@MIL-101/GOx-PDA(LCMGP)nanodiagnostic platform was prepared for CT/PA imaging-guided multimodality synergistic therapy.Under 808 nm laser irradiation,Lu_(2)O_(3):Yb/Er/Li-Ce6(LC)NPs in the nano-diagnostic platform are activated and sensitized by NIR light,resulting in the generation of more single-linear oxygen(^(1)O_(2))for efficient PDT.Glucose oxidase(GOx)and MIL-101(Fe)nanozymes can utilize their excellent enzyme cascade catalytic properties and peroxidase-like catalytic properties to undergo glycolysis reactions and catalyze the decomposition of endogenous hydrogen peroxide(H_(2)O_(2)),producing a large amount of hydroxyl radicals(·OH),achieving efficient chemodynamic therapy(CDT).The functionalized modification of polydopamine(PDA)endows the LCMGP nanoparticles with higher photothermal conversion efficiency,which can prompt high local temperature at the tumor site under the irradiation of NIR light to achieve efficient photothermal therapy(PTT).In addition,hyperthermia accelerates the catalytic efficiency of the nanozymatic cascade of LCMGP nanoparticles to enhance ROS production while increasing cellular uptake,resulting in PTT-induced PDT/CDT synergistic effect(96%).Based on the excellent photothermal conversion effect of PDA and the high X-ray atte nuation effect of Lu/Fe,the LCMGP nanotherapeutic system demonstrates good CT/PA imaging function,providing new insights and ideas for imaging-mediated multimodal synergistic therapy.展开更多
Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains...Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains a great challenge to avoid the inhomogeneous distribution and aggregation of metal single-atomic active centers in the construction of bifunctional electrocatalysts with atomically dispersed multimetallic sites because of the common calcination method.Herein,we report a novel catalyst with phthalocyanine-assembled Fe-Co-Ni single-atomic triple sites dispersed on sulfur-doped graphene using a simple ultrasonic procedure without calcination,and X-ray absorption fine structure(XAFS),aberration-corrected scanning transmission electron microscopy(AC-STEM),and other detailed characterizations are performed to demonstrate the successful synthesis.The novel catalyst shows extraordinary bifunctional ORR/OER activities with a fairly low potential difference(ΔE=0.621 V)between the OER overpotential(Ej10=315 mV at 10 m A cm^(-2))and the ORR half-wave potential(Ehalf-wave=0.924 V).Moreover,the above catalyst shows excellent ZAB performance,with an outstanding specific capacity(786 mAh g^(-1)),noteworthy maximum power density(139 mW cm^(-2)),and extraordinary rechargeability(discharged and charged at 5 mA cm^(-2) for more than 1000 h).Theoretical calculations reveal the vital importance of the preferable synergetic coupling effect between adjacent active sites in the Fe-Co-Ni trimetallic single-atomic sites during the ORR/OER processes.This study provides a new avenue for the investigation of bifunctional electrocatalysts with atomically dispersed trimetallic sites,which is intended for enhancing the ORR/OER performance in ZABs.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
Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared t...Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared through atom-trapping strategy and relevant vacancy defect inductive effect was proposed.The 0.6Pt/VO-Co_(3)O_(4)catalyst presented a reaction rate value of 32.2×10^(-5)mol·g_(cat)^(-1)·s^(-1)at 160℃for catalytic propane total oxidation,which was nearly 5 times the reaction rate of Co_(3)O_(4)(6.7×10^(-5)mol·g_(cat)^(-1)·s^(-1)).Also,it exhibited excellent water-resistance and catalytic stability.The Pt atoms were stabilized on the Co_(3)O_(4)surface by vacancy defects to improve dispersion.Meanwhile,the vacancy defect inductive effect induced stronger electron interaction between Pt and Co_(3)O_(4)on the surface,thus promote the redox ability at low-temperature.The mobility and oxygen-activating ability of surface lattice oxygen were also strengthened by the vacancy defect inductive effect.This facilitated the generation of more surface-active oxygen species for the cleavage of C-H bond and the deep oxidation of intermediate species.Overall,this study proposed a novel concept the fabrication of highly efficient catalysts for the purpose of catalytic oxidation.展开更多
This work aimed to demonstrate possibilities for both active and passive control of the vortex-induced vibration and fatigue life of steel catenary risers via an analysis of the self-organization and evolution of the ...This work aimed to demonstrate possibilities for both active and passive control of the vortex-induced vibration and fatigue life of steel catenary risers via an analysis of the self-organization and evolution of the structural vibration based on synergetic theory. An analysis of the complex interrelated and synergistic relationship between the order parameter and the fast variable was performed, and the master equation of the nodal displacements was established as the order parameter for the evolution of the riser's structural vibration. Passive control methods include modifying the structure's elastic modulus, the internal fluid velocity, the top tension and the structural damping ratio, while an active control involves adjusting the external flow rate. Optimized parameters were obtained by analyzing the non-steady state solution of the master equation. The results show that the fatigue life greatly increases as the riser's elastic modulus decreases. In contrast, the fatigue life decreases with an increase of the internal fluid velocity. With an increase of the top tension, the vibration amplitudes and the number of modes may decrease, resulting in fewer bending stress cycles and a longer fatigue life. Furthermore, the structural damping ratio should be as large as possible. Finally, an active and passive control of the riser structure's response to vortex-induced vibration and its fatigue life can be achieved by carefully modifying the parameters mentioned above. The results may provide a theoretical framework for engineering practice concerning the design and control of steel catenary riser structures which are affected by vortex-induced vibration.展开更多
文摘This paper substantiates the idea that particular science reflects only a certain angle of a complex model of the world. Guidance as to ＂adding＂ particular science data in order to achieve a holistic picture of the world is a philosophical outlook. The meaning of each relatively closed system is revealed only in the context of a more capacious system. According to the author, as the material world itself, its epistemic models as well are built according to the principle of ＂matryoshka dolls.＂ The rational and irrational are discussed in the paper as equal moments of scientific knowledge. Contrary to the importance given to randomness in synergy, the author considers if it is possible to find out the causes of all events. In order to do this, other viewpoints and structure levels should be considered. There is a hidden order in every chaos, and that is revealed only in a certain situation. The main issue is taking into account the counter action of the system with the environment.
文摘The principle for blood pressure measurement using pulse transit time is introduced in this paper.And the math model of synergetics theory is studied in detail.The synergetics theory is applied in the analysis of blood pressure measurement data.The simulation results show that the application of synergetics theory is helpful to judge the normal blood pressure,and the accuracy is up to 80%.
基金Funded by the Key Technologies Research and Development Program(No.2021YFC28000900)the National Natural Science Foundation of China(No.52374178)the Collaborative Innovation Project of Colleges and Universities of Anhui Province(No.GXXT-2020-057)。
文摘A ternary early-strengthening agent consisting of calcium formate+triethanolamine+lithium sulfate was compounded with quercetin to shorten the setting time of cementitious materials while ensuring their early strength.The optimum ratio of the three early-strengthening agents was determined as 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate by response surface methodology.The effects of the ternary early-strengthening agent composed of calcium formate+triethanolamine(TEA)+lithium sulfate on cementitious pore sealing materials under the synergistic effect of quercetin were studied by means of the performance tests of compressive strength,fluidity,and setting time,and the microstructural characterizations of X-ray powder diffractometer(XRD),thermogravimetry(TG-DSC)and scanning electron microscopy(SEM).The study shows that the synergistic effect of ternary early-strengthening agent and quercetin forms a multi-performance composite admixture for cementitious materials.The best performance was obtained with the compounding scheme of 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate ternary early-strengthening agent and 0.05%quercetin.The compressive strength of 1,3,7,and 28 d are 94.8%,39.8%,42%,and 28%higher than those of the blank group,respectively.The initial time and final setting time are 41 and 57 minutes,respectively.According to the microscopic analysis,the network and fibrous C-S-H gels generated by ternary early-strengthening agents are attached to the surface promoted by quercetin,which forms skeleton support while thickening and solidifying the cement slurry,which enhances the early compressive strength of the cement-based materials.
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supported by the National Natural Science Foundation of China(Nos.22206146,22006079,and U21A20524)the Fundamental Research Funds for the Central Universities,the Youth Innovation Promotion Association of Chinese Academy of Sciences,the Fundamental Research Program of Shanxi Province(No.202103021223280)+1 种基金the Special Fund for Science and Technology Innovation Teams of Shanxi Province(No.202204051002026)the Natural Science Foundation of Shandong Province(No.ZR2021QB133).
文摘Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully synthesized via the sol–gel method and tested for their catalytic performance for simultaneous degradation of benzene and toluene.The CuMn_(2)O_(4)sample exhibited the best catalytic performance,the conversion of benzene reached 100%at 350℃,and toluene conversion reached 100%at 250℃.XRD,N_(2)adsorption-desorption,HRTEM-EDS,ED-XRF,Raman spectroscopy,H_(2)-TPR,NH_(3)-TPD,O_(2)-TPD and XPS were used to characterize the physical and chemical properties of MMn_(2)O_(4)catalysts.The excellent redox properties,high concentration of surface Mn4+,and adsorption of oxygen species over the CuMn_(2)O_(4)sample facilitated the simultaneous and efficient removal of benzene and toluene.Additionally,in situ DRIFTS illustrated the intermediate species and reaction mechanism for the synergetic catalytic oxidation of benzene and toluene.Notably,as an effective catalytic material,spinel oxide exhibited excellent synergistic degradation performance for benzene and toluene,providing some insight for the development of efficient multicomponent VOC catalysts.
基金supported by Yildiz Technical University Scientific Research Projects Coordination Unit under project number FBA-2023-5377support from the Scientific and Technological Research Council of Turkey(TUBITAK)under the BIDEB/2211-A National PhD Scholarship Program and 2250-Performance-Based Scholarships Program for PhD.
文摘In this study,injectable bone graft putty samples were developed using fine and coarse melt-quenched 45S5 bioactive glass(BG)incorporated into a carrier system composed of glycerol and polyethylene glycol(PEG)with different average molecular weights.Selected putty samples were further incorporated with varying amounts of Denosumab(5wt%-10wt%)to investigate its influence on rhe-ological behavior and flow properties using mathematical modeling.All PEG/glycerol/45S5-based putty samples exhibited viscoelastic behavior(storage modulus>loss modulus)and pseudoplastic behavior(n<1),with viscosity values required for optimal flow remaining below 1000 Pa∙s.Both viscosity and thixotropic area increased proportionally with higher BG content and smaller-sized BG particles.All putty samples showed more than 98%injectability through a 12G cannula,suggesting potential clinical suitability.However,injectability decreased with smaller cannulas,dropping to 34.7%-58.3%with a 19G cannula and further decreasing with a 23G cannula at higher BG contents.Incorporation of Denosumab preserved viscoelasticity and injectability but modified the flow behavior,shifting it from pseudo-plastic to more Newtonian with higher Denosumab content,while also reducing viscosity and thixotropic area values.Among all tested samples,putty containing a lower amount of Denosumab and smaller-sized BG exhibited the most suitable combination of injectability and rheological features.All putty samples were well described by both the Power law and Herschel-Bulkley rheological models(coeffi-cient of determination>0.95).This study highlights the influence of Denosumab on flowability and rheological relationships and sug-gests potential improvements in bioactivity through a dual synergistic effect of BG and Denosumab in minimally invasive bone graft sys-tems.
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Project supported by the National Natural Science Foundation of China(22072096,22108184)。
文摘In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of NO.The phase transition process between Ce species and Ti species is limited by modulating the interaction between Ce4+and Ti4+,while a completely amorphous composite is generated with an appropriate molar ratio of Ti/Ce(1.5/1).The catalyst CeTi1.5Oxexhibits the best catalytic performance,where the values of T90and T50for deep degradation of toluene are 297 and 330℃respectively at high weight hours space velocity(WHSV=120000 mL/(g·h)).Compared with CeO_(2),T90and T50decrease by48 and 34℃respectively while declining by 67 and 70℃compared to TiO_(2).For the SCR reaction,CeTi1.5Oxreaches 100%NO conversion at 250℃with WHSV=60000 mL/(g·h),reduced by 50℃compared to pure CeO_(2).The amorphous nanostructure with highly dispersed Ce and Ti species was confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD)characterizations.The X-ray photoelectron spectroscopy(XPS)and Raman analyses show that a large number of active Ce-O-Ti species and surface oxygen vacancies are generated due to the strong interaction between Ti^(4+)and Ce^(4+)in CeTi_(1.5)O_(x).Additionally,H_(2)-TPR and O_(2)-TPD further confirm that the interaction promotes the low-temperature reducibility and mobility of surface-active oxygen species.Meanwhile,in-situ DRIFTS study reveals that CeTi1.5Oxwith amorphous nanostructure can dramatically enhance the dissociative and complete oxidation capacity for toluene.
基金supported by the National Nature Science Foundation of China(No.22269021)Tianshan Talent Project of Xinjiang Uygur Autonomous Region(No.2023TSYCQNTJ0039)the Open project of Key Laboratory in Xinjiang Uygur Autonomous Region of China(No.2023D04027).
文摘Hydrogen production coupled with small molecule oxidation derived by renewable energy power has been widely studied as an effective method to reduce energy consumption and prepare added value production.Here,the copper-cobalt phosphide with a multilevel structure has been designed based on the hard and soft acids and bases theory.The nanocone composed of lamellas presented a sharp tip,which a positive effect on the mass transfer enhanced by a local electric field,and the nanolamellas contain CoP/Cu_(3)P interface provide the highly selective active site for the gluconic acid(GNA)synthesis and hydrogen evolution.The catalyst can drive hydrogen evolution at 5 A·cm^(-2)up to 437 h without active decay,and the electrocatalytic glucose oxidation at anode presents high efficiency due to Cu(I)introduction and the synergetic effect between interfaces.Density functional theory(DFT)calculation shows that water splitting more readily occurs at the CoP,which provides adsorbed H and-OH for hydrogen evolution and glucose oxidation,respectively,and glucose adsorption more readily occurs at the Cu_(3)P,which presents lower conversion energy for high value-added GNA.Efficient hydrogen evolution and glucose conversion indicate its high intrinsic activity and synergetic effect.This work provides a special interface construction strategy for the catalytic conversion of hydrogen and small molecules.
基金supported by the China Postdoctoral Science Foundation(Nos.2021M700981,2022M711787,2021M691759 and 2021TQ0169)Shuimu Tsinghua Scholar program(No.2021SM071)Beijing Natural Science Foundation(No.2224103).
文摘In the context of the global pursuit of sustainable energy,dual-atom catalysts(DACs)have attracted widespread attention due to their unique structural and excellent catalytic performance.Unlike the single-atom catalysts,DACs possess two active metal centers,exhibiting intriguing synergistic effects that significantly enhance their efficiency in various electrochemical reactions.This comprehensive review provides an overview of the recent advances in the field of dual-atom catalysts,focusing on their innovative preparation methods and strategies.It further delves into the intrinsic connections between structure and performance,discussing the applications of DACs in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,photocatalysis,carbon dioxide reduction reaction,and batteries.Lastly,a forward-looking perspective addresses the current challenges and outlines future directions.This review aims to deepen our understanding of DACs and stimulate further innovation in advanced catalysts for energy conversion systems.
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supported by the National Natural Science Foundation of China(Nos.51978052 and 22306012)the National Key Research and Development Program of China(No.2023YFC3711300)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110578).
文摘Acidic-and alkalic-hydrolyses are selective in breaking functional bonds and falling off pharmacological moieties of antibiotics in production wastewater in comparison with advanced oxidation processes.Elevating temperature can accelerate hydrolytic kinetics and improve efficiency.In this work,magnetic sulfonated polypropylene resin(Fe_(3)O_(4)@PS-S)composites were reported for acidic-thermal hydrolysis of tylosin by employing the acidic feature of sulfonic group,the dielectric effect of resin,and the magnetic-loss effect of magnetite under microwave irradiation.As observed,a rapid and complete mitigation 100 mg/L of tylosin was achieved within 15 min by the catalysts.Acidic cleavage of tylosin was fulfilled by sulfonic groups in the composites,and microwave thermal accelerated the hydrolysis reactions due to the dielectric and magnetic-loss effects.Differentiating the dielectric and magnetic-loss effects through electromagnetic analyses indicated that the latter contributed more in converting microwave energy to heat.The interactions under multiple operational conditions were quantitatively fitted using the Behnajady model and visually demonstrated,which indicated that a synergic effect of microwave thermal-and acidichydrolyses contributed to the efficient mitigation of tylosin.The transformation products were identified and the pathways were supposed.Cleaving deoxyaminosugars groups and destructing lactone structures led to reduced antibacterial potential and toxicity reduction.The acute toxicity of tylosin and transformation products to fish,daphnia,and green algae were all classified as non-toxic.This work suggested that this synergistic acid-thermal hydrolytic method is attractive and promising in pretreating tylosin production wastewater in field.
基金supported by Jilin Province Science and Technology Development Project(Nos.20250102158JC,20240302035GX)
文摘As a novel material,high-entropy compounds have attracted extensive attention in the field of lithium–sulfur battery host materials due to their diverse elemental composition with a wide range of properties.The ability to effectively mitigate the shuttle effect of lithium polysulfides and catalyze the bidirectional conversion of Li_(2)S_(2)/Li_(2)S is crucial to enhance the overall performance of the battery.In this study,a unique sulfur host nanosized highentropy material comprising selenium-doped HEO(AlCrFeCoNi)_(3)O_(4-x)-Se_(x)is fabricated using an in situ thermal reduction and selenylation method.In the high-entropy compounds,the introduction of Se causes that the generation of oxygen vacancies during the lattice distortion serves as ion transfer pathway and the formation of M-Se bonds provides a high adsorption capability for LiPSs.Moreover,the polymetallic cooperative high-entropy nanoparticles also provide numerous active sites favoring redox kinetics of the sulfur electrode.The resulting selenium-doped HEO(AlCrFeCoNi)_(3)O_(4-x)-Se_(x)not only enhances discharge capacity but also maintains excellent capacity cycling stability.As a result,the HEO-Se/S composite exhibits a specific capacity of 1233.9 mAh g^(-1)at 0.1C and experiences minimal capacity fading at a rate of 0.038%per cycle over 500 cycles at 0.2C,while host materials with sulfur loading of 4.33 mg cm^(-2)and E/S ratio of 5.88μL mg^(-1)exhibit excellent capacity retention after 100 cycles at 0.2C.This work offers new insights into synthesizing high-entropy nanomaterials for improving the electrochemical performance of Li–S batteries.
基金supported by the National Natural Science Foundation of China(Nos.22205037 and 22373014)the Natural Science Foundation of Fujian Province(No.2023J01498)。
文摘Birefringence and second harmonic generation(SHG)are important optical properties of functional crystals.However,it is relatively rare for a compound to exhibit both enhanced properties simultaneously.In this study,we used DFT calculations to discover an ideal functional gene:protonated 3,5-dipicolinic acid(C_(7)H_(4)NO_(4),HDPA).By combining HPDA with the traditional IO_(3)-anion,we obtained a non-centrosymmetric and polar semiorganic iodate,namely HDPA(IO_(3)).The organic cations and iodate anions in HDPA(IO_(3))are bridged via the N-H···O and O-H···O hydrogen bonds,forming the wave-shaped layers.The synergistic effect between the expandedπ-conjugation of the organic cation and the stereochemically active lone pair electrons in the inorganic iodate anion results that HDPA(IO_(3))exhibiting a strong SHG effect,3.6 times that of KH_(2)PO_(4),and an unusually large birefringence of 0.35 at 546 nm,larger than most of SHG-active iodates.Additionally,HDPA(IO_(3))has a wide bandgap of 4.12 e V with a corresponding cutoff edge at 269 nm,indicating its potential as a promising short-wave ultraviolet(UV)optical crystal.
基金Project supported by the Natural Science Foundation of Shandong Province(ZR2020ME045,ZR2020ME046)the Taishan Scholar Project of Shandong Province(tsqn201812130)+2 种基金the National Natural Science Foundation of China(82272833)"New Universities 20"Foundation of Jinan(2021GXRC099,T202204)China Postdoctoral Science Foundation(2022M711438)。
文摘Photodynamic therapy(PDT),as a non-invasive treatment,is expected to be widely used in clinical cancer treatment.In this paper,a near-infrared(NIR)light responsive Lu_(2)O_(3):Yb/Er/Li-Ce6@MIL-101/GOx-PDA(LCMGP)nanodiagnostic platform was prepared for CT/PA imaging-guided multimodality synergistic therapy.Under 808 nm laser irradiation,Lu_(2)O_(3):Yb/Er/Li-Ce6(LC)NPs in the nano-diagnostic platform are activated and sensitized by NIR light,resulting in the generation of more single-linear oxygen(^(1)O_(2))for efficient PDT.Glucose oxidase(GOx)and MIL-101(Fe)nanozymes can utilize their excellent enzyme cascade catalytic properties and peroxidase-like catalytic properties to undergo glycolysis reactions and catalyze the decomposition of endogenous hydrogen peroxide(H_(2)O_(2)),producing a large amount of hydroxyl radicals(·OH),achieving efficient chemodynamic therapy(CDT).The functionalized modification of polydopamine(PDA)endows the LCMGP nanoparticles with higher photothermal conversion efficiency,which can prompt high local temperature at the tumor site under the irradiation of NIR light to achieve efficient photothermal therapy(PTT).In addition,hyperthermia accelerates the catalytic efficiency of the nanozymatic cascade of LCMGP nanoparticles to enhance ROS production while increasing cellular uptake,resulting in PTT-induced PDT/CDT synergistic effect(96%).Based on the excellent photothermal conversion effect of PDA and the high X-ray atte nuation effect of Lu/Fe,the LCMGP nanotherapeutic system demonstrates good CT/PA imaging function,providing new insights and ideas for imaging-mediated multimodal synergistic therapy.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.22305071,52472200,52271176,and52072114)the 111 Project(Grant No.D17007)+3 种基金Henan Center for Outstanding Overseas Scientists(Grant No.GZS2022017)the China Postdoctoral Science Foundation(Grant No.2022M721049)the Henan Province Key Research and Development Project(Grant No.231111520500)the Natural Science Foundation of Henan Province(Grant No.252300421556)。
文摘Development of high-efficiency bifunctional oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)electrocatalysts is vital for the widespread application of zinc-air batteries(ZABs).However,it still remains a great challenge to avoid the inhomogeneous distribution and aggregation of metal single-atomic active centers in the construction of bifunctional electrocatalysts with atomically dispersed multimetallic sites because of the common calcination method.Herein,we report a novel catalyst with phthalocyanine-assembled Fe-Co-Ni single-atomic triple sites dispersed on sulfur-doped graphene using a simple ultrasonic procedure without calcination,and X-ray absorption fine structure(XAFS),aberration-corrected scanning transmission electron microscopy(AC-STEM),and other detailed characterizations are performed to demonstrate the successful synthesis.The novel catalyst shows extraordinary bifunctional ORR/OER activities with a fairly low potential difference(ΔE=0.621 V)between the OER overpotential(Ej10=315 mV at 10 m A cm^(-2))and the ORR half-wave potential(Ehalf-wave=0.924 V).Moreover,the above catalyst shows excellent ZAB performance,with an outstanding specific capacity(786 mAh g^(-1)),noteworthy maximum power density(139 mW cm^(-2)),and extraordinary rechargeability(discharged and charged at 5 mA cm^(-2) for more than 1000 h).Theoretical calculations reveal the vital importance of the preferable synergetic coupling effect between adjacent active sites in the Fe-Co-Ni trimetallic single-atomic sites during the ORR/OER processes.This study provides a new avenue for the investigation of bifunctional electrocatalysts with atomically dispersed trimetallic sites,which is intended for enhancing the ORR/OER performance in ZABs.
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.
文摘Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared through atom-trapping strategy and relevant vacancy defect inductive effect was proposed.The 0.6Pt/VO-Co_(3)O_(4)catalyst presented a reaction rate value of 32.2×10^(-5)mol·g_(cat)^(-1)·s^(-1)at 160℃for catalytic propane total oxidation,which was nearly 5 times the reaction rate of Co_(3)O_(4)(6.7×10^(-5)mol·g_(cat)^(-1)·s^(-1)).Also,it exhibited excellent water-resistance and catalytic stability.The Pt atoms were stabilized on the Co_(3)O_(4)surface by vacancy defects to improve dispersion.Meanwhile,the vacancy defect inductive effect induced stronger electron interaction between Pt and Co_(3)O_(4)on the surface,thus promote the redox ability at low-temperature.The mobility and oxygen-activating ability of surface lattice oxygen were also strengthened by the vacancy defect inductive effect.This facilitated the generation of more surface-active oxygen species for the cleavage of C-H bond and the deep oxidation of intermediate species.Overall,this study proposed a novel concept the fabrication of highly efficient catalysts for the purpose of catalytic oxidation.
基金Financial support from the China Postdoctoral Science Foundation Fund (Grant No.2013M531563)the Qingdao Agricultural University High-Level Talents Research Fund (Grant No. 631424)is gratefully acknowledged
文摘This work aimed to demonstrate possibilities for both active and passive control of the vortex-induced vibration and fatigue life of steel catenary risers via an analysis of the self-organization and evolution of the structural vibration based on synergetic theory. An analysis of the complex interrelated and synergistic relationship between the order parameter and the fast variable was performed, and the master equation of the nodal displacements was established as the order parameter for the evolution of the riser's structural vibration. Passive control methods include modifying the structure's elastic modulus, the internal fluid velocity, the top tension and the structural damping ratio, while an active control involves adjusting the external flow rate. Optimized parameters were obtained by analyzing the non-steady state solution of the master equation. The results show that the fatigue life greatly increases as the riser's elastic modulus decreases. In contrast, the fatigue life decreases with an increase of the internal fluid velocity. With an increase of the top tension, the vibration amplitudes and the number of modes may decrease, resulting in fewer bending stress cycles and a longer fatigue life. Furthermore, the structural damping ratio should be as large as possible. Finally, an active and passive control of the riser structure's response to vortex-induced vibration and its fatigue life can be achieved by carefully modifying the parameters mentioned above. The results may provide a theoretical framework for engineering practice concerning the design and control of steel catenary riser structures which are affected by vortex-induced vibration.
