Based on the theory of continuum mechanics of multi-pbase media, a mathematical model and non-linear FEM equation of the coupling instability problem of solid-fluid biphase media for coal-methane outburst under finite...Based on the theory of continuum mechanics of multi-pbase media, a mathematical model and non-linear FEM equation of the coupling instability problem of solid-fluid biphase media for coal-methane outburst under finite deformation are established. The critical conditions of the surface instability are presented as the singularity of the total stiffness matrices of the coal body for coal-methaue outburst. That means the deformtion or the coal body emerges bifurcatiou phenomena. The numerical simulation of a typical outburst is made.展开更多
A novel phosphate ligand, tri-（methoxyl polyethylene glycol）-phosphate （TMPGPA）, has been synthesized and used in the Rhcatalyzed hydroformylation of cyclohexene in a thermoregulated PEG biphase system. Under the ...A novel phosphate ligand, tri-（methoxyl polyethylene glycol）-phosphate （TMPGPA）, has been synthesized and used in the Rhcatalyzed hydroformylation of cyclohexene in a thermoregulated PEG biphase system. Under the optimized conditions, pressure = 5 MPa （H2：CO = 1：1）, P/Rh = 10 （molar ratio）, reaction time = 4 h and temperature = 120 ℃, the conversion of cyclohexene and the yield of aldehyde are 99%. The catalyst retained in PEG phase can be easily separated from the organic phase containing product by simple phase separation and reused ten times without obvious loss in activity.展开更多
Polyethylene glycol （PEG）-stabilized palladium nanoparticles were prepared and applied to the selective hydrogenation of 1,5- cyclooctadiene （1,5-COD） in thermoregulated PEG biphase system, which allows a reaction...Polyethylene glycol （PEG）-stabilized palladium nanoparticles were prepared and applied to the selective hydrogenation of 1,5- cyclooctadiene （1,5-COD） in thermoregulated PEG biphase system, which allows a reaction in a single-phase at a higher temperature followed by a phase split at a lower temperature. Under the optimized reaction conditions, the conversion of 1,5-COD and the selectivity of cyclooctene （COE） were 100 and 98%, respectively. The catalyst could be easily separated from the product by phase separation and reused for 6 times without evident loss in activity and selectivity. 2007 Yan Hua Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Some apolar organic solvents is miscible with perfluorous nonene to form fluorous biphase systems.Perfluorous nonene could be used as a green solvent in equimolar esterification of carboxylic acids with alcohols witho...Some apolar organic solvents is miscible with perfluorous nonene to form fluorous biphase systems.Perfluorous nonene could be used as a green solvent in equimolar esterification of carboxylic acids with alcohols without removal of water or ester formed. Perfluorous nonene made the esterification equilibrium to move right and the yields of esterification to enhance in different degrees as compared with that in the absence of perfluorous nonene. After esterification perfluorous nonene is easy to be recovered and recycled.展开更多
Target detection is an important research content in the radar field.At present,efforts are being made to optimize the precision of detection information.In this paper,we use the high pulse repetition frequency(HPRF)t...Target detection is an important research content in the radar field.At present,efforts are being made to optimize the precision of detection information.In this paper,we use the high pulse repetition frequency(HPRF)transmission method and orthogonal biphase coded signals in each pulse to avoid velocity ambiguity and range ambiguity of radar detection.In addition,We also apply Walsh matrix and genetic algorithm(GA)to generate satisfying orthogonal biphase coded signals with low auto-correlation sidelobe peak and cross-correlation peak,which make the results more accurate.In a radar receiver,data rearrangement of echo signals is performed,and then pulse compression and moving target detection(MTD)are utilized to get the final velocity and range information of a target without velocity ambiguity and range ambiguity.Besides,a small transmitting pulse time width is adopted to reduce the working blind area,and two different high pulse repetition frequencies(HPRFs)are adopted to solve the problem of range eclipse.Simulation results finally prove the effectiveness and feasibility of the proposed method.展开更多
Magnesium ion batteries are emerging as promising alternatives to lithium ion batteries because of their advantages including high energydensity,dendrite-free features and low cost.Nevertheless,one of the major challe...Magnesium ion batteries are emerging as promising alternatives to lithium ion batteries because of their advantages including high energydensity,dendrite-free features and low cost.Nevertheless,one of the major challenges for magnesium ion batteries is the kinetically sluggishmagnesium insertion/extraction and diffusion in electrode materials.Aiming at this issue,biphase eutectic-like bismuth-tin film is designedherein to construct a self-supporting anode with interdigitated phase distribution and hierarchically porous structure,and further fabricated bya facile one-step magnetron cosputtering route.As benchmarked with single-phase bismuth or tin film,the biphase bismuth-tin film delivershigh specific capacity (538 mAh/g at 50 mA/g),excellent rate performance (417 mAh/g at 1,000 mA/g) and good cycling stability (233 mAh/gat the 200th cycle).The superior magnesium storage performance of the sputtered bismuth-tin film could be attributed to the synergetic effectof the interdigitated bismuth/tin phase distribution,hierarchically porous structure and biphase buffering matrices,which could increase ionictransport channels,shorten diffusion lengths and reduce total volume changes.展开更多
Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+d...Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.展开更多
A 63-year-old man was admitted to the hospital with a>1-year history of repeated acid reflux and belching and a 1-month history of an abdominal mass.On admission,the patient was in good condition,and his vital sign...A 63-year-old man was admitted to the hospital with a>1-year history of repeated acid reflux and belching and a 1-month history of an abdominal mass.On admission,the patient was in good condition,and his vital signs were stable.Laboratory examinations revealed no significant abnormalities.展开更多
The unique oxygen stacking sequence of O2-type structures restricts the irreversible transition metal movement into Li vacancies for the delithiated Li-rich layered oxides(LLOs)and maintains outstanding voltage stabil...The unique oxygen stacking sequence of O2-type structures restricts the irreversible transition metal movement into Li vacancies for the delithiated Li-rich layered oxides(LLOs)and maintains outstanding voltage stability.However,the ion-exchange synthesis promotes the Mn-ion valence reduction and aggravates the Jahn-Teller(J-T)distortion alongside disproportionation.Since the main oxidation state of the Mn ions is+4 in the traditional O3-type LLOs,synergistic effects of the O2-type and O3-type structures are expected in the O2/O3 diphasic Li-rich material.Herein,O2/O3 biphasic intergrowth LLOs were rationally designed,and the synergic optimization of the biphasic structure was planned to retard the J-T effect.The O2/O3 intergrowth nature was confirmed,and the percentages of the O2 and O3 phases were 56%and 44%,respectively.Density functional theory calculations demonstrated that the Mn^(2+)(EC)sheath had a remarkably lower energy barrier than the Li^(+)(EC)sheath.This finding suggests that Mn^(2+)ions that are dissolved into the electrolyte accelerate the electrolyte oxidization,so the deposition of the cathode electrolyte interface for pristine O2-LLOs causes a high electrochemical impedance.The designed O2/O3 biphasic LLOs boost the capacity stability and suppress the voltage drop upon repeated Li^(+)de-intercalation.The phase regulation strategy offers great potential for developing low-cost LLOs with enhanced structural stability for advanced Li-ion batteries.展开更多
An innovative strategy was proposed by integration of membrane contactor(MC)with biphasic solvent for efficient CO_(2) capture from flue gas.The accessible fly ash-based ceramic membrane(CM)underwent hydrophobic modif...An innovative strategy was proposed by integration of membrane contactor(MC)with biphasic solvent for efficient CO_(2) capture from flue gas.The accessible fly ash-based ceramic membrane(CM)underwent hydrophobic modification through silane grafting,followed by fluoroalkylsilane decoration,to prepare the superhydrophobic membrane(CSCM).The CSCM significantly improved resistance to wetting by the biphasic solvent,consisting of amine(DETA)and sulfolane(TMS).Morphological characterizations and chemical analysis revealed the notable enhancements in pore structure and hydrophobic chemical groups for the modified membrane.Predictions of wetting/bubbling behavior based on static wetting theory referred the liquid entry pressure(LEP)of CSCM increased by 20 kPa compared to pristine CM.Compared with traditional amine solvents,the biphasic solvent presented the expected phase separation.Performance experiments demonstrated that the CO_(2) capture efficiency of the biphasic solvent increased by 7%,and the electrical energy required for desorption decreased by 32%.The 60-h continuous testing and supplemental characterization of used membrane confirmed the excellent adaptability and durability of the CSCMs.This study provides a potential approach for accessing hydrophobic ceramic membranes and biphasic solvents for industrial CO_(2) capture.展开更多
The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the i...The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the issues,a novel pentamethyldiethylenetriamine(PMDETA)-2-amino-2-methyl-1-propanol(AMP)/diethylenetriamine(DETA)-sulfolane biphasic solvent was developed.The mechanism of AMP affecting CO_(2) recycling capacity was analyzed.By adjusting the ratio of AMP and DETA,the absorption and desorption performance were balanced,and the recycling capacity and renewable energy consumption of the absorbent were improved.For the P_(2.4)A_(0.8)D_(0.8)S_(2) biphasic solvent,the CO_(2) loading of the rich phase was 5.87 mol/L,and the proportion of the rich phase volume ratio was 35%,which surpasses most reported biphasic solvents.The viscosity of the absorbent significantly decreased from 527.00 mPa·s to 92.26 mPa·s,attributed to the beneficial effect of AMP.Thermodynamic analysis showed that the biphasic solvent produced a lower regeneration energy consumption of 1.70 GJ/t CO_(2),which was 57%lower than that of monoethanolamine(MEA).Overall,the PMDETA-AMP/DETA-sulfolane biphasic solvent exhibited cycle capacity,which provided new insights for the designing of biphasic solvent.展开更多
Phase change absorbents based on amine chemical absorption for CO_(2)capture exhibit energy-saving potential,but generally suffer from difficulties in CO_(2)regeneration.Alcohol,characterized as a protic reagent with ...Phase change absorbents based on amine chemical absorption for CO_(2)capture exhibit energy-saving potential,but generally suffer from difficulties in CO_(2)regeneration.Alcohol,characterized as a protic reagent with a low dielectric constant,can provide free protons to the rich phase of the absorbent,thereby facilitating CO_(2)regeneration.In this investigation,N-aminoethylpiperazine(AEP)/sulfolane/H_(2)O was employed as the liquid-liquid phase change absorbent,with alcohol serving as the regulator.First,appropriate ion pair models were constructed to simulate the solvent effect of the CO_(2)products in different alcohol solutions.The results demonstrated that these ion pair products reached the maximum solvation-free energy(△E_(solvation))in the rich phase containing ethanol(EtOH).Desorption experiment results validated that the inclusion of EtOH led to a maximum regeneration rate of 0.00763 mol/min,thus confirming EtOH’s suitability as the preferred regulator.Quantum chemical calculations and^(13)C NMR characterization were performed,revealing that the addition of EtOH resulted in the partial conversion of AEP-carbamate(AEPCOO−)into a new product known as ethyl carbonate(C_(2)H_(5)OCOO−),which enhanced the regeneration reactivity.In addition,the decomposition paths of different CO_(2)products were simulated visually,and every reaction’s activation energy(△E_(act))was calculated.Remarkably,the△E_(act)for the decomposition of C_(2)H_(5)OCOO−(9.465 kJ/mol)was lower than that of the AEPCOO−(26.163 kJ/mol),implying that CO_(2)was more likely to be released.Finally,the regeneration energy consumption of the alcohol-regulated absorbentwas estimated to be only 1.92 GJ/ton CO_(2),which had excellent energy-saving potential.展开更多
Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cath...Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cathode materials influence the cost and energy output of SIBs.Therefore,the development of advanced cathode materials is crucial for the practical application of SIBs.Among various cathode materials,layered transition metal oxides(LTMOs)have received widespread attention owing to their straightforward preparation,abundant availability,and cost-competitiveness.Notably,layered Fe-based oxide cathodes are deemed to be one of the most promising candidates for the lowest price and easy-to-improve performance.Nevertheless,the challenges such as severe phase transitions,sluggish diffusion kinetics and interfacial degradation pose significant hurdles in achieving high-performance cathodes for SIBs.This review first briefly outlines the classification of layered structures and the working principle of layered oxides.Then,recent advances in modification strategies employed to address current issues with layered iron-based oxide cathodes are systematically reviewed,including ion doping,biphasic engineering and surface modification.Furthermore,the review not only outlines the prospects and development directions for layered Fe-based oxide cathodes but also provides novel insights and directions for future research endeavors for SIBs.展开更多
Lithium-sulfur(Li-S)batteries promise high energy density but suffer from low conductivity,polysulfide shuttling,and sluggish conversion kinetics.The construction of heterointerfaces is an effective strategy for enhan...Lithium-sulfur(Li-S)batteries promise high energy density but suffer from low conductivity,polysulfide shuttling,and sluggish conversion kinetics.The construction of heterointerfaces is an effective strategy for enhancing both polysulfide adsorption and conversion;however,the poor lattice compatibility in the heterointerface formed by different materials hinders interfacial charge transfer.In response to these challenges,herein,a biphasic homojunction of TiO_(2)enriched with oxygen vacancies and decorated with nitrogen-doped carbon nanotubes(B-TiO_(2-x)@NCNT)was designed to simultaneously enhance adsorption ability and catalytic activity.This homojunction interface composed of rutile(110)and anatase(101)plane exhibits excellent compatibility,and density functional theory(DFT)calculations reveal that this biphasic interface possesses a much higher binding energy to polysulfides compared to single-phase TiO_(2).Additionally,NCNTs are in situ grown on both interior and exterior surfaces of the hollow TiO_(2)nanospheres,facilitating rapid electron transfer for the encapsulated sulfur.The homojunction interface synergistically leverages the oxygen vacancies and highly conductive NCNTs to enhance the bidirectional catalytic activity for polysulfide conversion.Therefore,in this multifunctional sulfur-host,polysulfides are first strongly adsorbed at the homojunction interfaces and subsequently undergo smooth conversion,nucleation,and decomposition,completing a rapid sulfur redox cycle.The assembled Li-S battery delivered a high specific capacity of 1234.3 mAh g^(-1)at 0.2 C,long cycling stability for over 1000 cycles at 5 C with a low decay rate of 0.035%,and exciting areal capacity at a high sulfur loading of 5.6 mg cm^(-2)for 200cycles.展开更多
With the development of chemical absorbers,biphasic absorbers have the potential for absorption performance and energy consumption.In this work,a new biphasic absorber composed of tetraethylene pentamine(TEPA)and Diet...With the development of chemical absorbers,biphasic absorbers have the potential for absorption performance and energy consumption.In this work,a new biphasic absorber composed of tetraethylene pentamine(TEPA)and Diethyl ethanolamine(DEEA)is formed to capture CO_(2).The appropriate stratification boundaries by experimentation are found for orthogonal experiment.The optimum capture CO_(2)conditions are obtained according to the orthogonal design.The ranking of factors affecting the ability and rate to absorb CO_(2)is C(waste flow rate)>A(mass ratio)>B(reaction temperature).The desorption efficiency of the new biphasic absorber reaches 96.66%at 140C.The new biphasic absorber has good recyclability and its energy consumption is 2.23 GJ·t^(-1)CO_(2).Through viscosity experiment,reaction products analyzed by 13C NMR date,functional groups and chemical bonds analyzed by FT-IR date analysis,the mechanisms of CO_(2)absorption and phase transition follow a zwitterionic mechanism.This is a biphasic amine that deserves in-depth study.展开更多
Constructing an in vitro vascularized liver tissue model that closely simulates the human liver is crucial for promoting cell proliferation,mimicking physiological heterogeneous structures,and recreating the cellular ...Constructing an in vitro vascularized liver tissue model that closely simulates the human liver is crucial for promoting cell proliferation,mimicking physiological heterogeneous structures,and recreating the cellular microenvironment.However,the layer-by-layer printing method is significantly constrained by the rheological properties of the bioink,making it challenging to form complex three-dimensional vascular structures in low-viscosity soft materials.To overcome this limitation,we developed a cross-linkable biphasic embedding medium by mixing low-viscosity biomaterials with gelatin microgel.This medium possesses yield stress and self-healing properties,facilitating efficient and continuous three-dimensional shaping of sacrificial ink within it.By adjusting the printing speed,we controlled the filament diameter,achieving a range from 250μm to 1000μm,and ensuring precise control over ink deposition locations and filament shapes.Using the in situ endothelialization method,we constructed complex vascular structures and ensured close adhesion between hepatocytes and endothelial cells.In vitro experiments demonstrated that the vascularized liver tissue model exhibited enhanced protein synthesis and metabolic function compared to mixed liver tissue.We also investigated the impact of varying vascular densities on liver tissue function.Transcriptome sequencing revealed that liver tissues with higher vascular density exhibited upregulated gene expression in metabolic and angiogenesis-related pathways.In summary,this method is adaptable to various materials,allowing the rheological properties of the supporting bath and the tissue's porosity to be modified using microgels,thus enabling precise regulation of the liver tissue microenvironment.Additionally,it facilitates the rapid construction of three-dimensional vascular structures within liver tissue.The resulting vascularized liver tissue model exhibits enhanced biological functionality,opening new opportunities for biomedical applications.展开更多
The conversion process of chitin,one of the abundant biomass resources on the earth,not only follows the principles of green chemistry,but also has significant value in industrial applications.However,it is a great ch...The conversion process of chitin,one of the abundant biomass resources on the earth,not only follows the principles of green chemistry,but also has significant value in industrial applications.However,it is a great challenge to directly convert insoluble and rigid structured chitin to 5-hydroxymethylfurfural(HMF).To address this issue,we developed a green conversion process combining pretreatment and catalytic system.Chitin was first pretreated by hexafluoro isopropanol(HFIP),which somewhat disrupted the hydrogen bonding network within the chitin structure.Subsequently,formic acid(FA)and silicotungstic acid(STA)synergistically catalyzed the conversion to HMF in a biphasic system of 2-methyltetrahydrofuran(2-Me-THF)/H2O,and high yields(40.2%)HMF was obtained under the optimism conditions.The product distribution was analyzed by HPLC-MS and the co-catalysis of FA with STA was evidenced.A dual-function catalytic system with both Lewis and Br?nsted acids was created,the catalytic system that significantly improved the efficiency of complex tandem catalytic reactions with chitin.Based on the experimental results,a possible pathway for chitin conversion was deduced,providing a new catalytic idea for the efficient conversion of chitin to HMF.展开更多
5-Hydroxymethylfurfural(5-HMF)is one of the important bio-based platform compounds,and the catalytic conversion of glucose to 5-HMF is a highly desirable approach that is receiving increasing attention.Herein,we repor...5-Hydroxymethylfurfural(5-HMF)is one of the important bio-based platform compounds,and the catalytic conversion of glucose to 5-HMF is a highly desirable approach that is receiving increasing attention.Herein,we reported the synthesis of lignin-derived carbon supported tin oxides(SnOx/LC)catalyst via a two-step hydrothermal-pyrolytic method using wheat straw alkali lignin as a cost-effective carbon source with high carbon content.The key preparation conditions of the catalyst and its catalytic conditions for the conversion of glucose to 5-HMF were investigated,respectively.Results show that under the preparation conditions of tin tetrachloride dosage of 3.0 mmol and pyrolysis temperature of 500 ℃,the optimized catalyst(3.0-SnOx/LC-500)with a high yield of 63.4%exhibits good catalytic performance of 5-HMF yield of 50.1%and reaction selectivity of 86.0%under the optimum conditions of reaction temperature and time of 190 ℃ and 3 h,initial glucose concentration of 10%(mass),3.0-SnOx/LC-500 dosage of 100 mg in a biphasic solvent system of volume ratio of water to tetrahydrofuran of 1:4.In addition,3.0-SnOx/LC-500 exerts an excellent reusability in a five-cycle experiment.Furthermore,SnOx/LC was characterized in detail using X-ray diffraction patterns(XRD),X-ray photoelectron spectroscopy(XPS),Brunauer-Emmett-Teller(BET),ammonia temperature-programmed-desorption(NH3-TPD),pyridine adsorption infrared spectroscopy(Py-FTIR),scanning electron microscope(SEM)and thermal gravimetric analysis(TGA).Results indicate that Brønsted acid sites and Lewis acid sites coexist on 3.0-SnOx/LC-500,and more Sn^(4+),as well as a proper ratio of weak acidity to medium acidity,are conductive to its catalytic performance in glucose-to-5-HMF reaction.展开更多
The recent advances in accelerated polymerization of N-carboxyanhydrides (NCAs) offer an effective strategy to simplify the preparation of polypeptide materials. However, the fine-tuning of polymerization kinetics, wh...The recent advances in accelerated polymerization of N-carboxyanhydrides (NCAs) offer an effective strategy to simplify the preparation of polypeptide materials. However, the fine-tuning of polymerization kinetics, which is critical to differentiate the main polymerization and the side reactions, remains largely unexplored. Herein we report the modulation of polymerization rate of NCA in a water/oil biphasic system. By altering the aqueous pH, the initial location of the initiators, and the pK_(a) of initiating amines, we observed the change in polymerization time from several minutes to a few hours. Due to the high interfacial activity and low pKa value, controlled polymerization was observed from multi-amine initiators even if they were initially located in the aqueous phase. This work not only improves our understanding on the biphasic polymerization mechanism, but also facilitates preparation of versatile polypeptide materials.展开更多
文摘Based on the theory of continuum mechanics of multi-pbase media, a mathematical model and non-linear FEM equation of the coupling instability problem of solid-fluid biphase media for coal-methane outburst under finite deformation are established. The critical conditions of the surface instability are presented as the singularity of the total stiffness matrices of the coal body for coal-methaue outburst. That means the deformtion or the coal body emerges bifurcatiou phenomena. The numerical simulation of a typical outburst is made.
基金Financial support from Fok Ying Tung Education Foundation(No.91071)the National Natural Science Foundation of China(No.20376013)are gratefully acknowledged.
文摘A novel phosphate ligand, tri-（methoxyl polyethylene glycol）-phosphate （TMPGPA）, has been synthesized and used in the Rhcatalyzed hydroformylation of cyclohexene in a thermoregulated PEG biphase system. Under the optimized conditions, pressure = 5 MPa （H2：CO = 1：1）, P/Rh = 10 （molar ratio）, reaction time = 4 h and temperature = 120 ℃, the conversion of cyclohexene and the yield of aldehyde are 99%. The catalyst retained in PEG phase can be easily separated from the organic phase containing product by simple phase separation and reused ten times without obvious loss in activity.
基金Financial support from the National Natural Science Foundation of China （No. 20573015） is gratefully acknowledged.
文摘Polyethylene glycol （PEG）-stabilized palladium nanoparticles were prepared and applied to the selective hydrogenation of 1,5- cyclooctadiene （1,5-COD） in thermoregulated PEG biphase system, which allows a reaction in a single-phase at a higher temperature followed by a phase split at a lower temperature. Under the optimized reaction conditions, the conversion of 1,5-COD and the selectivity of cyclooctene （COE） were 100 and 98%, respectively. The catalyst could be easily separated from the product by phase separation and reused for 6 times without evident loss in activity and selectivity. 2007 Yan Hua Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Supported by the Natural Science Foundation of Zhejiang Province （Y 405396）.
文摘Some apolar organic solvents is miscible with perfluorous nonene to form fluorous biphase systems.Perfluorous nonene could be used as a green solvent in equimolar esterification of carboxylic acids with alcohols without removal of water or ester formed. Perfluorous nonene made the esterification equilibrium to move right and the yields of esterification to enhance in different degrees as compared with that in the absence of perfluorous nonene. After esterification perfluorous nonene is easy to be recovered and recycled.
基金supported by the Special Science Foundation of Quzhou(2020D007,2021D009).
文摘Target detection is an important research content in the radar field.At present,efforts are being made to optimize the precision of detection information.In this paper,we use the high pulse repetition frequency(HPRF)transmission method and orthogonal biphase coded signals in each pulse to avoid velocity ambiguity and range ambiguity of radar detection.In addition,We also apply Walsh matrix and genetic algorithm(GA)to generate satisfying orthogonal biphase coded signals with low auto-correlation sidelobe peak and cross-correlation peak,which make the results more accurate.In a radar receiver,data rearrangement of echo signals is performed,and then pulse compression and moving target detection(MTD)are utilized to get the final velocity and range information of a target without velocity ambiguity and range ambiguity.Besides,a small transmitting pulse time width is adopted to reduce the working blind area,and two different high pulse repetition frequencies(HPRFs)are adopted to solve the problem of range eclipse.Simulation results finally prove the effectiveness and feasibility of the proposed method.
基金National Natural Science Foundation of China (Nos. 51671115 and 51871133)Department of Science and Technology of Shandong Province for Young Tip-top Talent Support ProjectYoung Tip-top Talent Support Project (the Organization Department of the Central Committee of the CPC).
文摘Magnesium ion batteries are emerging as promising alternatives to lithium ion batteries because of their advantages including high energydensity,dendrite-free features and low cost.Nevertheless,one of the major challenges for magnesium ion batteries is the kinetically sluggishmagnesium insertion/extraction and diffusion in electrode materials.Aiming at this issue,biphase eutectic-like bismuth-tin film is designedherein to construct a self-supporting anode with interdigitated phase distribution and hierarchically porous structure,and further fabricated bya facile one-step magnetron cosputtering route.As benchmarked with single-phase bismuth or tin film,the biphase bismuth-tin film delivershigh specific capacity (538 mAh/g at 50 mA/g),excellent rate performance (417 mAh/g at 1,000 mA/g) and good cycling stability (233 mAh/gat the 200th cycle).The superior magnesium storage performance of the sputtered bismuth-tin film could be attributed to the synergetic effectof the interdigitated bismuth/tin phase distribution,hierarchically porous structure and biphase buffering matrices,which could increase ionictransport channels,shorten diffusion lengths and reduce total volume changes.
基金supported by the National Natural Science Foundation of China(No.21805018)by Sichuan Science and Technology Program(Nos.2022ZHCG0018,2023NSFSC0117 and 2023ZHCG0060)Yibin Science and Technology Program(No.2022JB005)and China Postdoctoral Science Foundation(No.2022M722704).
文摘Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.
基金supported by the National Natural Science Foundation of China(Project No.82160348)the Yunnan Province Major Special Plan(No.202302AA310018-D-8)+1 种基金the Youth Talent Project of Yunnan Province's“Xingdian Talent Support Program”(No.XDYC-QNRC-2022-0608)the 2024 Senior Health Technology and Medical Discipline Leader of Yunnan Provincial Health Commission(No.D-2024056).
文摘A 63-year-old man was admitted to the hospital with a>1-year history of repeated acid reflux and belching and a 1-month history of an abdominal mass.On admission,the patient was in good condition,and his vital signs were stable.Laboratory examinations revealed no significant abnormalities.
基金supported by the National Natural Science Foundation of China(Nos.22379052,22479062 and 52102252)Taishan Scholars of Shandong Province(No.tsqnz20221143)Independent Cultivation Program of Innovation Team of Ji’nan City(No.202333042).
文摘The unique oxygen stacking sequence of O2-type structures restricts the irreversible transition metal movement into Li vacancies for the delithiated Li-rich layered oxides(LLOs)and maintains outstanding voltage stability.However,the ion-exchange synthesis promotes the Mn-ion valence reduction and aggravates the Jahn-Teller(J-T)distortion alongside disproportionation.Since the main oxidation state of the Mn ions is+4 in the traditional O3-type LLOs,synergistic effects of the O2-type and O3-type structures are expected in the O2/O3 diphasic Li-rich material.Herein,O2/O3 biphasic intergrowth LLOs were rationally designed,and the synergic optimization of the biphasic structure was planned to retard the J-T effect.The O2/O3 intergrowth nature was confirmed,and the percentages of the O2 and O3 phases were 56%and 44%,respectively.Density functional theory calculations demonstrated that the Mn^(2+)(EC)sheath had a remarkably lower energy barrier than the Li^(+)(EC)sheath.This finding suggests that Mn^(2+)ions that are dissolved into the electrolyte accelerate the electrolyte oxidization,so the deposition of the cathode electrolyte interface for pristine O2-LLOs causes a high electrochemical impedance.The designed O2/O3 biphasic LLOs boost the capacity stability and suppress the voltage drop upon repeated Li^(+)de-intercalation.The phase regulation strategy offers great potential for developing low-cost LLOs with enhanced structural stability for advanced Li-ion batteries.
基金supported by the National Key R&D Program of China(2023YFF0614301,2023YFC3707004,and 2018YFB0604302)Fundamental Research Funds for the Central Universities(No.2022MS041)+1 种基金National Natural Science Foundation of China(No.22106084)Tsinghua University Initiative Scientific Research Program(2023Z02JMP001).
文摘An innovative strategy was proposed by integration of membrane contactor(MC)with biphasic solvent for efficient CO_(2) capture from flue gas.The accessible fly ash-based ceramic membrane(CM)underwent hydrophobic modification through silane grafting,followed by fluoroalkylsilane decoration,to prepare the superhydrophobic membrane(CSCM).The CSCM significantly improved resistance to wetting by the biphasic solvent,consisting of amine(DETA)and sulfolane(TMS).Morphological characterizations and chemical analysis revealed the notable enhancements in pore structure and hydrophobic chemical groups for the modified membrane.Predictions of wetting/bubbling behavior based on static wetting theory referred the liquid entry pressure(LEP)of CSCM increased by 20 kPa compared to pristine CM.Compared with traditional amine solvents,the biphasic solvent presented the expected phase separation.Performance experiments demonstrated that the CO_(2) capture efficiency of the biphasic solvent increased by 7%,and the electrical energy required for desorption decreased by 32%.The 60-h continuous testing and supplemental characterization of used membrane confirmed the excellent adaptability and durability of the CSCMs.This study provides a potential approach for accessing hydrophobic ceramic membranes and biphasic solvents for industrial CO_(2) capture.
基金supported by the Key R&D Program of Yunnan Province(No.202303AC100008)the National Natural Science Foundation of China(No.52100133)the Major Science and Technology-Special Plan“Unveiling and Leading”Project of Shanxi Province(No.202201050201011).
文摘The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the issues,a novel pentamethyldiethylenetriamine(PMDETA)-2-amino-2-methyl-1-propanol(AMP)/diethylenetriamine(DETA)-sulfolane biphasic solvent was developed.The mechanism of AMP affecting CO_(2) recycling capacity was analyzed.By adjusting the ratio of AMP and DETA,the absorption and desorption performance were balanced,and the recycling capacity and renewable energy consumption of the absorbent were improved.For the P_(2.4)A_(0.8)D_(0.8)S_(2) biphasic solvent,the CO_(2) loading of the rich phase was 5.87 mol/L,and the proportion of the rich phase volume ratio was 35%,which surpasses most reported biphasic solvents.The viscosity of the absorbent significantly decreased from 527.00 mPa·s to 92.26 mPa·s,attributed to the beneficial effect of AMP.Thermodynamic analysis showed that the biphasic solvent produced a lower regeneration energy consumption of 1.70 GJ/t CO_(2),which was 57%lower than that of monoethanolamine(MEA).Overall,the PMDETA-AMP/DETA-sulfolane biphasic solvent exhibited cycle capacity,which provided new insights for the designing of biphasic solvent.
基金supported by the National Natural Science Foundation of China(Nos.22278168 and 22276064)the MOE Key Laboratory of Resources and Environmental System Optimization(No.KLRE-KF202205)the Science and Technology Project of Fujian province(No.2022Y3007).
文摘Phase change absorbents based on amine chemical absorption for CO_(2)capture exhibit energy-saving potential,but generally suffer from difficulties in CO_(2)regeneration.Alcohol,characterized as a protic reagent with a low dielectric constant,can provide free protons to the rich phase of the absorbent,thereby facilitating CO_(2)regeneration.In this investigation,N-aminoethylpiperazine(AEP)/sulfolane/H_(2)O was employed as the liquid-liquid phase change absorbent,with alcohol serving as the regulator.First,appropriate ion pair models were constructed to simulate the solvent effect of the CO_(2)products in different alcohol solutions.The results demonstrated that these ion pair products reached the maximum solvation-free energy(△E_(solvation))in the rich phase containing ethanol(EtOH).Desorption experiment results validated that the inclusion of EtOH led to a maximum regeneration rate of 0.00763 mol/min,thus confirming EtOH’s suitability as the preferred regulator.Quantum chemical calculations and^(13)C NMR characterization were performed,revealing that the addition of EtOH resulted in the partial conversion of AEP-carbamate(AEPCOO−)into a new product known as ethyl carbonate(C_(2)H_(5)OCOO−),which enhanced the regeneration reactivity.In addition,the decomposition paths of different CO_(2)products were simulated visually,and every reaction’s activation energy(△E_(act))was calculated.Remarkably,the△E_(act)for the decomposition of C_(2)H_(5)OCOO−(9.465 kJ/mol)was lower than that of the AEPCOO−(26.163 kJ/mol),implying that CO_(2)was more likely to be released.Finally,the regeneration energy consumption of the alcohol-regulated absorbentwas estimated to be only 1.92 GJ/ton CO_(2),which had excellent energy-saving potential.
基金supported by the National Natural Science Foundation of China(no.52374301)the Open Project of Guangxi Key Laboratory of Electrochemical Energy Materials(no.GXUEEM2024001)+2 种基金the Hebei Provincial Natural Science Foundation(no.E2024501010)the Shijiazhuang Basic Research Project(no.241790667A)the Performance subsidy fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(no.22567627H)。
文摘Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cathode materials influence the cost and energy output of SIBs.Therefore,the development of advanced cathode materials is crucial for the practical application of SIBs.Among various cathode materials,layered transition metal oxides(LTMOs)have received widespread attention owing to their straightforward preparation,abundant availability,and cost-competitiveness.Notably,layered Fe-based oxide cathodes are deemed to be one of the most promising candidates for the lowest price and easy-to-improve performance.Nevertheless,the challenges such as severe phase transitions,sluggish diffusion kinetics and interfacial degradation pose significant hurdles in achieving high-performance cathodes for SIBs.This review first briefly outlines the classification of layered structures and the working principle of layered oxides.Then,recent advances in modification strategies employed to address current issues with layered iron-based oxide cathodes are systematically reviewed,including ion doping,biphasic engineering and surface modification.Furthermore,the review not only outlines the prospects and development directions for layered Fe-based oxide cathodes but also provides novel insights and directions for future research endeavors for SIBs.
基金supported by the National Natural Science Foundation of China(Grant No.52372281)the Fundamental Research Funds for the Central Universities(2232020G-07)+3 种基金the foundation of Shanghai Institute of Technology(grant no.YJ2022-37)the Graduate Student Innovation Fund of Donghua University(CUSF-DH-D-2022007)the State Key Laboratory of Advanced Fiber Materials(KF2517)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Lithium-sulfur(Li-S)batteries promise high energy density but suffer from low conductivity,polysulfide shuttling,and sluggish conversion kinetics.The construction of heterointerfaces is an effective strategy for enhancing both polysulfide adsorption and conversion;however,the poor lattice compatibility in the heterointerface formed by different materials hinders interfacial charge transfer.In response to these challenges,herein,a biphasic homojunction of TiO_(2)enriched with oxygen vacancies and decorated with nitrogen-doped carbon nanotubes(B-TiO_(2-x)@NCNT)was designed to simultaneously enhance adsorption ability and catalytic activity.This homojunction interface composed of rutile(110)and anatase(101)plane exhibits excellent compatibility,and density functional theory(DFT)calculations reveal that this biphasic interface possesses a much higher binding energy to polysulfides compared to single-phase TiO_(2).Additionally,NCNTs are in situ grown on both interior and exterior surfaces of the hollow TiO_(2)nanospheres,facilitating rapid electron transfer for the encapsulated sulfur.The homojunction interface synergistically leverages the oxygen vacancies and highly conductive NCNTs to enhance the bidirectional catalytic activity for polysulfide conversion.Therefore,in this multifunctional sulfur-host,polysulfides are first strongly adsorbed at the homojunction interfaces and subsequently undergo smooth conversion,nucleation,and decomposition,completing a rapid sulfur redox cycle.The assembled Li-S battery delivered a high specific capacity of 1234.3 mAh g^(-1)at 0.2 C,long cycling stability for over 1000 cycles at 5 C with a low decay rate of 0.035%,and exciting areal capacity at a high sulfur loading of 5.6 mg cm^(-2)for 200cycles.
基金The authors would appreciate the financial support provided by Special Fund Project for Central Guidance of Local Scientific and Technological Development through the Grant ZYYD2022C16Major Science and Technology Projects of Xinjiang Uygur Autonomous Region through the Grant 2023A01005-2Natural Science Foundation of Xinjiang Uygur Autonomous Region through the Grant 2022D01C87.
文摘With the development of chemical absorbers,biphasic absorbers have the potential for absorption performance and energy consumption.In this work,a new biphasic absorber composed of tetraethylene pentamine(TEPA)and Diethyl ethanolamine(DEEA)is formed to capture CO_(2).The appropriate stratification boundaries by experimentation are found for orthogonal experiment.The optimum capture CO_(2)conditions are obtained according to the orthogonal design.The ranking of factors affecting the ability and rate to absorb CO_(2)is C(waste flow rate)>A(mass ratio)>B(reaction temperature).The desorption efficiency of the new biphasic absorber reaches 96.66%at 140C.The new biphasic absorber has good recyclability and its energy consumption is 2.23 GJ·t^(-1)CO_(2).Through viscosity experiment,reaction products analyzed by 13C NMR date,functional groups and chemical bonds analyzed by FT-IR date analysis,the mechanisms of CO_(2)absorption and phase transition follow a zwitterionic mechanism.This is a biphasic amine that deserves in-depth study.
基金the funding from the National Natural Science Foundation of China No.52275294the National Key Research and Development Program of China(No.2018YFA0703000)。
文摘Constructing an in vitro vascularized liver tissue model that closely simulates the human liver is crucial for promoting cell proliferation,mimicking physiological heterogeneous structures,and recreating the cellular microenvironment.However,the layer-by-layer printing method is significantly constrained by the rheological properties of the bioink,making it challenging to form complex three-dimensional vascular structures in low-viscosity soft materials.To overcome this limitation,we developed a cross-linkable biphasic embedding medium by mixing low-viscosity biomaterials with gelatin microgel.This medium possesses yield stress and self-healing properties,facilitating efficient and continuous three-dimensional shaping of sacrificial ink within it.By adjusting the printing speed,we controlled the filament diameter,achieving a range from 250μm to 1000μm,and ensuring precise control over ink deposition locations and filament shapes.Using the in situ endothelialization method,we constructed complex vascular structures and ensured close adhesion between hepatocytes and endothelial cells.In vitro experiments demonstrated that the vascularized liver tissue model exhibited enhanced protein synthesis and metabolic function compared to mixed liver tissue.We also investigated the impact of varying vascular densities on liver tissue function.Transcriptome sequencing revealed that liver tissues with higher vascular density exhibited upregulated gene expression in metabolic and angiogenesis-related pathways.In summary,this method is adaptable to various materials,allowing the rheological properties of the supporting bath and the tissue's porosity to be modified using microgels,thus enabling precise regulation of the liver tissue microenvironment.Additionally,it facilitates the rapid construction of three-dimensional vascular structures within liver tissue.The resulting vascularized liver tissue model exhibits enhanced biological functionality,opening new opportunities for biomedical applications.
基金Supported by the National Natural Science Foundation of China(No.42076126)the Shandong Key R&D Plan+2 种基金Major Scientific and Technological Innovation Project(No.2022CXGC020413)the Natural Science Foundation of Shandong Province(Nos.ZR2020MD072,ZR2021QD014)the Liaoning Provincial Natural Science Foundation:Joint Open Fund of the State Key Laboratory for the Creation and Development of New Pesticides(No.2022-KF-25-03)。
文摘The conversion process of chitin,one of the abundant biomass resources on the earth,not only follows the principles of green chemistry,but also has significant value in industrial applications.However,it is a great challenge to directly convert insoluble and rigid structured chitin to 5-hydroxymethylfurfural(HMF).To address this issue,we developed a green conversion process combining pretreatment and catalytic system.Chitin was first pretreated by hexafluoro isopropanol(HFIP),which somewhat disrupted the hydrogen bonding network within the chitin structure.Subsequently,formic acid(FA)and silicotungstic acid(STA)synergistically catalyzed the conversion to HMF in a biphasic system of 2-methyltetrahydrofuran(2-Me-THF)/H2O,and high yields(40.2%)HMF was obtained under the optimism conditions.The product distribution was analyzed by HPLC-MS and the co-catalysis of FA with STA was evidenced.A dual-function catalytic system with both Lewis and Br?nsted acids was created,the catalytic system that significantly improved the efficiency of complex tandem catalytic reactions with chitin.Based on the experimental results,a possible pathway for chitin conversion was deduced,providing a new catalytic idea for the efficient conversion of chitin to HMF.
基金supported by the independent research major project of Key Laboratory of Biomass Energy and Materials of Jiangsu Province, China (JSBEM-S-202202)the key project of Science and Technology Plan of Nanping, China (N2022B002)the Open Research Fund of Academy of Advanced Carbon Conversion Technology, Huaqiao University, China
文摘5-Hydroxymethylfurfural(5-HMF)is one of the important bio-based platform compounds,and the catalytic conversion of glucose to 5-HMF is a highly desirable approach that is receiving increasing attention.Herein,we reported the synthesis of lignin-derived carbon supported tin oxides(SnOx/LC)catalyst via a two-step hydrothermal-pyrolytic method using wheat straw alkali lignin as a cost-effective carbon source with high carbon content.The key preparation conditions of the catalyst and its catalytic conditions for the conversion of glucose to 5-HMF were investigated,respectively.Results show that under the preparation conditions of tin tetrachloride dosage of 3.0 mmol and pyrolysis temperature of 500 ℃,the optimized catalyst(3.0-SnOx/LC-500)with a high yield of 63.4%exhibits good catalytic performance of 5-HMF yield of 50.1%and reaction selectivity of 86.0%under the optimum conditions of reaction temperature and time of 190 ℃ and 3 h,initial glucose concentration of 10%(mass),3.0-SnOx/LC-500 dosage of 100 mg in a biphasic solvent system of volume ratio of water to tetrahydrofuran of 1:4.In addition,3.0-SnOx/LC-500 exerts an excellent reusability in a five-cycle experiment.Furthermore,SnOx/LC was characterized in detail using X-ray diffraction patterns(XRD),X-ray photoelectron spectroscopy(XPS),Brunauer-Emmett-Teller(BET),ammonia temperature-programmed-desorption(NH3-TPD),pyridine adsorption infrared spectroscopy(Py-FTIR),scanning electron microscope(SEM)and thermal gravimetric analysis(TGA).Results indicate that Brønsted acid sites and Lewis acid sites coexist on 3.0-SnOx/LC-500,and more Sn^(4+),as well as a proper ratio of weak acidity to medium acidity,are conductive to its catalytic performance in glucose-to-5-HMF reaction.
基金the National Natural Science Foundation of China(No.22101194 for Z.Song and No.52233015 for J.Cheng)Natural Science Foundation of Jiangsu Province(No.BK20210733 for Z.Song)+1 种基金Suzhou Municipal Science and Technology Bureau(No.ZXL2021447 for Z.Song)Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project.,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,and Suzhou Key Laboratory of Nanotechnology and Biomedicine.
文摘The recent advances in accelerated polymerization of N-carboxyanhydrides (NCAs) offer an effective strategy to simplify the preparation of polypeptide materials. However, the fine-tuning of polymerization kinetics, which is critical to differentiate the main polymerization and the side reactions, remains largely unexplored. Herein we report the modulation of polymerization rate of NCA in a water/oil biphasic system. By altering the aqueous pH, the initial location of the initiators, and the pK_(a) of initiating amines, we observed the change in polymerization time from several minutes to a few hours. Due to the high interfacial activity and low pKa value, controlled polymerization was observed from multi-amine initiators even if they were initially located in the aqueous phase. This work not only improves our understanding on the biphasic polymerization mechanism, but also facilitates preparation of versatile polypeptide materials.
