Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence archite...Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence architectures in terms of latency,energy efficiency,and computational power.To achieve this vision,it is of vital importance to scale up the PNNs while simultaneously reducing the high demand on the dimensions required by them.The underlying cause of this strategy is the enormous gap between the scales of photonic and electronic integrated circuits.Here,we demonstrate monolithically integrated optical convolutional processors on thin film lithium niobate(TFLN)that harness inherent parallelism in photonics to enable large-scale programmable convolution kernels and,in turn,greatly reduce the dimensions required by subsequent fully connected layers.Experimental validation achieves high classification accuracies of 96%(86%)on the MNIST(Fashion-MNIST)dataset and 84.6%on the AG News dataset while dramatically reducing the required subsequent fully connected layer dimensions to 196×10(from 784×10)and 175×4(from 800×4),respectively.Furthermore,our devices can be driven by commercial field-programmable gate array systems;a unique advantage in addition to their scalable channel number and kernel size.Our architecture provides a solution to build practical machine learning photonic devices.展开更多
Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sen...Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sensing mechanism of the human skin,we have developed a flexible monolithic 3D-integrated tactile sensing system based on a holey MXene paste,where each vertical one-body unit simultaneously functions as a microsupercapacitor and pressure sensor.The in-plane mesopores of MXene significantly improve ion accessibility,mitigate the self-stacking of nanosheets,and allow the holey MXene to multifunctionally act as a sensing material,an active electrode,and a conductive interconnect,thus drastically reducing the interface mismatch and enhancing the mechanical robustness.Furthermore,we fabricate a large-scale device using a blade-coating and stamping method,which demonstrates excellent mechanical flexibility,low-power consumption,rapid response,and stable long-term operation.As a proof-of-concept application,we integrate our sensing array into a smart access control system,leveraging deep learning to accurately identify users based on their unique pressing behaviors.This study provides a promising approach for designing highly integrated,intelligent,and flexible electronic systems for advanced human-computer interactions and personalized electronics.展开更多
Membrane-based vapor permeation(VP) is regarded as a highly efficient technology,featuring low energy consumption and free salt fouling.In this study,we have demonstrated upscaling chabazite(CHA) zeolite membranes on ...Membrane-based vapor permeation(VP) is regarded as a highly efficient technology,featuring low energy consumption and free salt fouling.In this study,we have demonstrated upscaling chabazite(CHA) zeolite membranes on the 19-channel α-Al_(2)O_(3) monolithic supports synthesized from high-silica gel(SiO_(2)/Al_(2)O_(3) ratio of 200) for the dehydration of acetic acid by VP.The monolithic membrane presents higher surface-to-volume ratio and a-tenfold greater mechanical strength compared to tubular ones.The micromorphology and crystallinity of the monolithic CHA zeolite membranes were characterized by scanning electron micrographs and X-ray diffraction analysis.The single-gas permeation test and the effects of temperature,feed water content and feed flow rate on the VP separation performance of monolithic CHA zeolite membrane for dehydration of acetic acid were investigated.Moreover,the stability test of monolithic CHA zeolite membranes was carried out.The 19-channel monolithic membrane achieved a comparable separation performance(water flux of 0.63 kg m^(-2)·h^(-1) and selectivity of 369 at 393 K) with the reported small-area zeolite membranes in water/acetic acid mixtures.It is demonstrated that the monolithic CHA zeolite membranes could be transformative candidates for industrial dehydration of acetic acid under harsh environments.展开更多
Carbon dioxide(CO_(2))can be efficiently converted and utilized through the CO_(2) methanation reaction,which has significant potential benefits for the environment and the economy.The contradiction between the thermo...Carbon dioxide(CO_(2))can be efficiently converted and utilized through the CO_(2) methanation reaction,which has significant potential benefits for the environment and the economy.The contradiction between the thermodynamics and kinetics of the CO_(2) methanation reaction process leads to low CO_(2) conversion at 200-350℃and low methane selectivity at 350-500℃.The utilization of catalysts can solve the contradiction between kinetics and thermodynamics,achieving high CO_(2) methanation efficiency at low temperatures.However,the poor thermal conductivity of powder catalysts leads to the rapid accumulation of heat,resulting in the formation of hot spots,which can cause the sintering or even deactivation of active species.To solve this problem,researchers have focused on monolithic catalysts with integrated reaction systems.This review categorizes the monolithic catalysts into two main groups based on their unique characteristics,namely structured catalysts and catalytic membrane reactors.The characteristics of these monolithic catalysts,commonly used support materials,preparation techniques,and their applications in the CO_(2) methanation reaction are discussed in depth.These studies provide theoretical basis and practical guidance for the design and optimization of structured catalysts and catalytic membrane reactors.Finally,challenges and prospects in the application of monolithic catalysts for the CO_(2) methanation reaction are proposed for the future development.展开更多
Electrochemical water splitting has attracted tremendous interest as a promising approach for generating sustainable hydrogen for transportation and other industrial applications.However,the oxygen evolution reaction(...Electrochemical water splitting has attracted tremendous interest as a promising approach for generating sustainable hydrogen for transportation and other industrial applications.However,the oxygen evolution reaction(OER)significantly limits the efficiency of electrochemical water splitting because of the sluggish reaction kinetics derived from the intrinsic four-electron-transfer process.In addition,the stability of OER electrocatalysts encounters significant challenges during long-term operation under harsh conditions.To overcome these challenges,we demonstrate that monolithic electrodes composed of medium-entropy alloys(MEAs)containing Fe,Co,Cr,and Ni can be used as efficient and stable OER catalysts in alkaline solutions.The monolithic FeCoCrNi alloy electrode exhibited a remarkably low overpotential of 237 mV at a current density of 10 mA/cm^(2) in a 1 mol/L KOH solution.Significantly,the monolithic alloy electrode can operate stably for more than 2000 h at a practical current density of 1 A/cm^(2).The enhanced activity and stability of the alloy electrode are ascribed to surface reconstruction.This work presents a novel and effective approach for fabricating high-performance electrodes with excellent stability for the oxygen evolution reaction.展开更多
In the background of carbon neutrality,monolithic ceramic catalysts are universally used in energy conversion and chemical catalysis due to the high heat and mass transfer efficiencies,low bed pressures,and scalabilit...In the background of carbon neutrality,monolithic ceramic catalysts are universally used in energy conversion and chemical catalysis due to the high heat and mass transfer efficiencies,low bed pressures,and scalability through modular design.However,traditional manufacturing processes are limited by mold dependence,organic solvent toxicity,and insufficient molding capability for complex structures,resulting in difficulty achieving precise regulation of cross-scale pores.Additive manufacturing(AM)technology employs a digital layered molding strategy to achieve the cross-scale structural regulation of catalysts from macroscopic flow channels to mesopores and micropores.This paper summarizes recent advances in the structural design of monolithic catalysts enabled by AM technologies and highlights their emerging applications in catalytic processes.Structurally,AM-fabricated monoliths have been effectively employed in key chemical reactions such as fuel reforming,CO_(2)conversion,biofuel synthesis.Strategies such as geometrical topology optimization,multi-scale pore synergy,biomimetic structural design,and functional gradient integration have been utilized to enhance heat and mass transport,reduce pressure drops,and improve overall catalytic performance.By overcoming the limitations of traditional catalysts,AM technologies create a new paradigm for addressing the longstanding challenge of coupling mass transfer with reaction kinetics.This approach provides a feasible pathway for driving both theoretical innovation and practical implementation of high-efficiency catalytic systems.展开更多
Monolithic aerogels are promising candidates for use in atmospheric environmental purification due to their structural advantages,such as fine building block size together with high specific surface area,abundant pore...Monolithic aerogels are promising candidates for use in atmospheric environmental purification due to their structural advantages,such as fine building block size together with high specific surface area,abundant pore structure,etc.Additionally,monolithic aerogels possess a unique monolithic macrostructure that sets them apart from aerogel powders and nanoparticles in practical environmental clean-up applications.This review delves into the available synthesis strategies and atmospheric environmental applications of monolithic aerogels,covering types of monolithic aerogels including SiO_(2),graphene,metal oxides and their combinations,along with their preparation methods.In particular,recent developments for VOC adsorption,CO_(2)capture,catalytic oxidation of VOCs and catalytic reduction of CO_(2)are highlighted.Finally,challenges and future opportunities for monolithic aerogels in the atmospheric environmental purification field are proposed.This reviewprovides valuable insights for designing and utilizing monolithic aerogel-based functional materials.展开更多
Monolithic catalysts have been widely investigated for CO_(2) methanation due to their fast mass and heat transfer rate,but the effect of the interaction between the catalyst layer and the monolithic support has been ...Monolithic catalysts have been widely investigated for CO_(2) methanation due to their fast mass and heat transfer rate,but the effect of the interaction between the catalyst layer and the monolithic support has been little studied.In this work,Ni/Al_(2)O_(3)/SiC monolithic catalysts,Ni/Al_(2)O_(3) powder catalysts and Ni/Al_(2)O_(3)/SiC-M catalysts were prepared to explore the effect of Si-Al interaction between the catalyst layer and SiC ceramic for CO_(2) methanation performance.Ni/Al_(2)O_(3)/SiC exhibited a CO_(2) conversion of 53% and a CH_(4) specific reaction rate of 0.05 m mol·g^(-1)·s^(-1) under conditions of 0.1 M Pa,4 00℃,and a WHSV of 60000 ml·g^(-1)·h^(-1).The CO_(2) conversion raised by 0.15-fold and the CH_(4) specific reaction rate raised by 0.25-fold compared to Ni/Al_(2)O_(3) with the same catalyst content.SEM,XRD,Raman,and other characterization results revealed that the formation of Si-Al interaction between the catalyst layer and SiC ceramic could weaken the interaction between Ni and Al_(2)O_(3),thereby improving the catalytic activity of Ni/Al_(2)O_(3)/SiC catalyst.However,the Si-Al interaction was further strengthened during the hightemperature reaction process,which significantly weakened the interaction between Ni and Al_(2)O_(3),thereby leading to a decline in the catalytic performance of Ni/Al_(2)O_(3)/SiC catalyst during an 80-h stability test.This study provides valuable insights for future research and development of monolithic catalysts.展开更多
We propose a suite of strategies for the parallel solution of fully implicit monolithic fluid-structure interaction(FSI).The solver is based on a modeling approach that uses the velocity and pressure as the primitive ...We propose a suite of strategies for the parallel solution of fully implicit monolithic fluid-structure interaction(FSI).The solver is based on a modeling approach that uses the velocity and pressure as the primitive variables,which offers a bridge between computational fluid dynamics(CFD)and computational structural dynamics.The spatiotemporal discretization leverages the variational multiscale formulation and the generalized-αmethod as a means of providing a robust discrete scheme.In particular,the time integration scheme does not suffer from the overshoot phenomenon and optimally dissipates high-frequency spurious modes in both subproblems of FSI.Based on the chosen fully implicit scheme,we systematically develop a combined suite of nonlinear and linear solver strategies.Invoking a block factorization of the Jacobian matrix,the Newton-Raphson procedure is reduced to solving two smaller linear systems in the multi-corrector stage.The first is of the elliptic type,indicating that the algebraic multigrid method serves as a well-suited option.The second exhibits a two-by-two block structure that is analogous to the system arising in CFD.Inspired by prior studies,the additive Schwarz domain decomposition method and the block-factorization-based preconditioners are invoked to address the linear problem.Since the number of unknowns matches in both subdomains,it is straightforward to balance loads when parallelizing the algorithm for distributed-memory architectures.We use two representative FSI benchmarks to demonstrate the robustness,efficiency,and scalability of the overall FSI solver framework.In particular,it is found that the developed FSI solver is comparable to the CFD solver in several aspects,including fixed-size and isogranular scalability as well as robustness.展开更多
Lappaconitine is a water-insoluble drug, which was used as model drug in this study. Currently, two osmotically controlled delivery systems that are widely used for water-insoluble drug are monolithic osmotic tablet ...Lappaconitine is a water-insoluble drug, which was used as model drug in this study. Currently, two osmotically controlled delivery systems that are widely used for water-insoluble drug are monolithic osmotic tablet （MOT） and push-pull osmotic pump （PPOP）. In the present study, lappaconitine solid dispersion monolithic osmotic tablet （lappaconitine-SD-MOT） and lappaconitine-PPOP were developed. The prepared lappaconitine-PPOP was able to delivery drug at the rate of approximate zero-order （r = 0.9931）, and the cumulative release was above 95.0%. The lappaconitine-SD-MOT showed a comparatively poor linearity when the data were plotted according to the zero-order equation （r = 0.9798）, and the cumulative release was 84.69%. Lappaconitine-PPOP exhibited better controlled drug release （higher regression value） compared with lappaconitine-SD-MOT. The similarity index （f2） between lappaconitine-PPOP and lappaconitine-SD-MOT was 49.1 （〈50）. A clear difference of drug release characteristics between the lappaconitine-SD-MOT and lappaconitine-PPOP was revealed. It indicated that the drug release performance of lappaconitine-PPOP could gain favorable zero-order kinetics and higher cumulative release compared with lappaconitine-SD-MOT. Therefore, these results suggested that PPOP was still a very effective device for the delivery of poorly water-soluble drug with zero-order pattern.展开更多
The objective of this study was to prepare monolithic osmotic tablet of quercetin for controlled drug release. Quercetin-PVP solid dispersion was prepared to enhance its solubility and dissolution rate. Solid dispersi...The objective of this study was to prepare monolithic osmotic tablet of quercetin for controlled drug release. Quercetin-PVP solid dispersion was prepared to enhance its solubility and dissolution rate. Solid dispersion, suspending agents, osmotic agents and other conventional excipients were used as tablet core composition and cellulose acetate （CA） with plasticizer as release controlling membrane. Different formulation variables, the amounts of PEO （polyethylene oxide）, NaC1, plasticizer, and coating weight gain were optimized to gain the optimum formulation. The mechanism of drug release from monolithic osmotic tablet was also discussed. The optimal monolithic osmotic pump tablet could deliver quercetin at the rate of approximate zero-order up to 12 h, and the cumulative release was 90.74%. The developed monolithic osmotic system for quercetin loaded by solid dispersion was found to be a promising approach for controlled release of poorly-water soluble drug candidates.展开更多
The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate （MHP） and operating...The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate （MHP） and operating under constant bias voltage conditions was designed. A new monolithic integrating mode was proposed,in which the dielectric and passiva- tion layers in standard CMOS processes were used as sensor structure layers,gate polysilicon as the sacrificial layer,and the second polysilicon layer as the sensor heating resistor. Then, the fabricating processes were designed and the monolithic thermal vacuum sensor was fabricated with a 0. 6μm mixed signal CMOS process followed by sacrificial layer etching technology. The measurement results show that the fabricated monolithic vacuum sensor can measure the pressure range of 2- 10^5 Pa and the output voltage is adjustable.展开更多
The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicat...The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.展开更多
A new type strongly gain coupled (GC) DFB laser and a new type self alignment spot size converter (SA SSC) are proposed and successfully fabricated.The strongly GC DFB laser is monolithically integrated with the ...A new type strongly gain coupled (GC) DFB laser and a new type self alignment spot size converter (SA SSC) are proposed and successfully fabricated.The strongly GC DFB laser is monolithically integrated with the SA SSC with three step epitaxies.A high single mode yield and large side mode suppression ratio is obtained from the strongly GC DFB laser.A near circle far field pattern is obtained by using the SA SSC.展开更多
Based on the principle of chemical engineering in the multisubject field—drug delivery, the release kinetics of the slab monolithic matrix with an initially linear concentration distribution is studied in this paper....Based on the principle of chemical engineering in the multisubject field—drug delivery, the release kinetics of the slab monolithic matrix with an initially linear concentration distribution is studied in this paper. It can be used to describe the later stage when drug loading is above its solubility limit. A comprehensive model is proposed and the generalized solutions are acquired by Laplace transformation, from which a special case, i.e. a perfect sink has been deduced. According to the derived equations, the concentration profiles in the matrix has been computed and illustrated and the effect of volume of extraction medium on release has been investigated.展开更多
2.5 Gbit/s monolithic integrated circuits （ICs） for optical fiber transmitter and receiver in 0.35 μm CMOS （complementary metal-oxide-semiconductor transistor） process are presented. The transmitter, which includ...2.5 Gbit/s monolithic integrated circuits （ICs） for optical fiber transmitter and receiver in 0.35 μm CMOS （complementary metal-oxide-semiconductor transistor） process are presented. The transmitter, which includes a 4： 1 multiplexer and a laser diode driver （LDD）, has four 622 Mbit/s random signals as its inputs and gets a 2.5 Gbit/s driving signal as its output; the receiver detects a 2.5 Gbit/s random signal and gets four 622 Mbit/s signals at the output. The main circuits include a trans-impedance amplifier （TIA）, a limiting amplifier, a clock and data recovery （CDR） unit, and a 1： 4 demultiplexer （DEMUX）. Test results prove the logic functions of the transmitter to be right, and the 10% to 90% rise and fall times of transmitter＇s output data eye diagram are 211.1 ps and 200 ps, respectively. The sensitivity of the receiver is measured to be better than 20 mV. The root mean square jitter of the DEMUX＇s output data is 15.6 ps and that of the clock after 1： 4 frequency dividing is 1.9 ps. Two chips are both applicable to 2.5 Gbit/s optical fiber communication systems.展开更多
A behavioral model of the photodiode is presented.The model describes the relationship between photocurrent and incident optical power,and it also illustrates the impact of the reverse bias to the variation of the jun...A behavioral model of the photodiode is presented.The model describes the relationship between photocurrent and incident optical power,and it also illustrates the impact of the reverse bias to the variation of the junction capacitance.According to this model,the photodiode and a CMOS receiver circuit are simulated and designed simultaneously under a universal circuit simulation environment.展开更多
A monolithically integrated optoelectronic receiver is presented. A silicon-based photo-diode and receiver circuits are integrated on identical substrates in order to eliminate the parasitics induced by hybrid packagi...A monolithically integrated optoelectronic receiver is presented. A silicon-based photo-diode and receiver circuits are integrated on identical substrates in order to eliminate the parasitics induced by hybrid packaging. Implemented in the present deep sub-micron MS/RF （mixed signal, radio frequency） CMOS,this monolithically OEIC takes advantage of several new features to improve the performance of the photo-diode and eventually the whole OEIC.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12192251,12334014,62335019,12134001,1230441812474378)+1 种基金the Quantum Science and Technology National Science and Technology Major Project(Grant No.2021ZD0301403)the Shanghai Municipal Science and Technology Major Project (Grant No.2019SHZDZX01)。
文摘Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence architectures in terms of latency,energy efficiency,and computational power.To achieve this vision,it is of vital importance to scale up the PNNs while simultaneously reducing the high demand on the dimensions required by them.The underlying cause of this strategy is the enormous gap between the scales of photonic and electronic integrated circuits.Here,we demonstrate monolithically integrated optical convolutional processors on thin film lithium niobate(TFLN)that harness inherent parallelism in photonics to enable large-scale programmable convolution kernels and,in turn,greatly reduce the dimensions required by subsequent fully connected layers.Experimental validation achieves high classification accuracies of 96%(86%)on the MNIST(Fashion-MNIST)dataset and 84.6%on the AG News dataset while dramatically reducing the required subsequent fully connected layer dimensions to 196×10(from 784×10)and 175×4(from 800×4),respectively.Furthermore,our devices can be driven by commercial field-programmable gate array systems;a unique advantage in addition to their scalable channel number and kernel size.Our architecture provides a solution to build practical machine learning photonic devices.
基金supported by the National Natural Science Foundation of China(52272177,12204010)the Foundation for the Introduction of High-Level Talents of Anhui University(S020118002/097)+1 种基金the University Synergy Innovation Program of Anhui Province(GXXT-2023-066)the Scientific Research Project of Anhui Provincial Higher Education Institution(2023AH040008)。
文摘Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sensing mechanism of the human skin,we have developed a flexible monolithic 3D-integrated tactile sensing system based on a holey MXene paste,where each vertical one-body unit simultaneously functions as a microsupercapacitor and pressure sensor.The in-plane mesopores of MXene significantly improve ion accessibility,mitigate the self-stacking of nanosheets,and allow the holey MXene to multifunctionally act as a sensing material,an active electrode,and a conductive interconnect,thus drastically reducing the interface mismatch and enhancing the mechanical robustness.Furthermore,we fabricate a large-scale device using a blade-coating and stamping method,which demonstrates excellent mechanical flexibility,low-power consumption,rapid response,and stable long-term operation.As a proof-of-concept application,we integrate our sensing array into a smart access control system,leveraging deep learning to accurately identify users based on their unique pressing behaviors.This study provides a promising approach for designing highly integrated,intelligent,and flexible electronic systems for advanced human-computer interactions and personalized electronics.
基金financially supported by the National Key Research and Development Program of China (2023YFB3810700)the National Natural Science Foundation of China (22378189,U22A20414 and 22378188)+1 种基金the Natural Science Foundation of Jiangsu Provincial Department of Science and Technology(BK20232010 and BG2024018)National State Key Laboratory of Material-oriented Chemical Engineering (SKL-MCE-22A02 and SKL-MCE23B14)。
文摘Membrane-based vapor permeation(VP) is regarded as a highly efficient technology,featuring low energy consumption and free salt fouling.In this study,we have demonstrated upscaling chabazite(CHA) zeolite membranes on the 19-channel α-Al_(2)O_(3) monolithic supports synthesized from high-silica gel(SiO_(2)/Al_(2)O_(3) ratio of 200) for the dehydration of acetic acid by VP.The monolithic membrane presents higher surface-to-volume ratio and a-tenfold greater mechanical strength compared to tubular ones.The micromorphology and crystallinity of the monolithic CHA zeolite membranes were characterized by scanning electron micrographs and X-ray diffraction analysis.The single-gas permeation test and the effects of temperature,feed water content and feed flow rate on the VP separation performance of monolithic CHA zeolite membrane for dehydration of acetic acid were investigated.Moreover,the stability test of monolithic CHA zeolite membranes was carried out.The 19-channel monolithic membrane achieved a comparable separation performance(water flux of 0.63 kg m^(-2)·h^(-1) and selectivity of 369 at 393 K) with the reported small-area zeolite membranes in water/acetic acid mixtures.It is demonstrated that the monolithic CHA zeolite membranes could be transformative candidates for industrial dehydration of acetic acid under harsh environments.
基金the National Natural Science Foundation of China(22325804 and 22308148)the Natural Science Foundation of Jiangsu Province(BK20230344)+1 种基金the Natural Science Research Project of Jiangsu University(22KJB610001)the Jiangsu Funding Program for Excellent Postdoctoral Talent(2023ZB505)。
文摘Carbon dioxide(CO_(2))can be efficiently converted and utilized through the CO_(2) methanation reaction,which has significant potential benefits for the environment and the economy.The contradiction between the thermodynamics and kinetics of the CO_(2) methanation reaction process leads to low CO_(2) conversion at 200-350℃and low methane selectivity at 350-500℃.The utilization of catalysts can solve the contradiction between kinetics and thermodynamics,achieving high CO_(2) methanation efficiency at low temperatures.However,the poor thermal conductivity of powder catalysts leads to the rapid accumulation of heat,resulting in the formation of hot spots,which can cause the sintering or even deactivation of active species.To solve this problem,researchers have focused on monolithic catalysts with integrated reaction systems.This review categorizes the monolithic catalysts into two main groups based on their unique characteristics,namely structured catalysts and catalytic membrane reactors.The characteristics of these monolithic catalysts,commonly used support materials,preparation techniques,and their applications in the CO_(2) methanation reaction are discussed in depth.These studies provide theoretical basis and practical guidance for the design and optimization of structured catalysts and catalytic membrane reactors.Finally,challenges and prospects in the application of monolithic catalysts for the CO_(2) methanation reaction are proposed for the future development.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0450302)the National Natural Science Foundation of China(Nos.52072358,51902304,22209162,U21A2082)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.YD2060002043,WK2060000048)the Hefei Municipal Natural Science Foundation(No.BJ2060000042)the financial support from the R&D Department of Petro China。
文摘Electrochemical water splitting has attracted tremendous interest as a promising approach for generating sustainable hydrogen for transportation and other industrial applications.However,the oxygen evolution reaction(OER)significantly limits the efficiency of electrochemical water splitting because of the sluggish reaction kinetics derived from the intrinsic four-electron-transfer process.In addition,the stability of OER electrocatalysts encounters significant challenges during long-term operation under harsh conditions.To overcome these challenges,we demonstrate that monolithic electrodes composed of medium-entropy alloys(MEAs)containing Fe,Co,Cr,and Ni can be used as efficient and stable OER catalysts in alkaline solutions.The monolithic FeCoCrNi alloy electrode exhibited a remarkably low overpotential of 237 mV at a current density of 10 mA/cm^(2) in a 1 mol/L KOH solution.Significantly,the monolithic alloy electrode can operate stably for more than 2000 h at a practical current density of 1 A/cm^(2).The enhanced activity and stability of the alloy electrode are ascribed to surface reconstruction.This work presents a novel and effective approach for fabricating high-performance electrodes with excellent stability for the oxygen evolution reaction.
基金supported by the National Natural Science Foundation of China(Grant No.52405414)the China Postdoctoral Science Foundation(Grant No.2024M762580)+1 种基金Young Talent Fund of Xi'an Association for Science and Technology(Grant No.0959202513033)the Youth Innovation Team of Shaanxi Universities,and the Fundamental Research Funds for Central Universities.The authors gratefully acknowledge the support by the Instrumental Analysis Center of Xi’an Jiaotong University for sample characterization.
文摘In the background of carbon neutrality,monolithic ceramic catalysts are universally used in energy conversion and chemical catalysis due to the high heat and mass transfer efficiencies,low bed pressures,and scalability through modular design.However,traditional manufacturing processes are limited by mold dependence,organic solvent toxicity,and insufficient molding capability for complex structures,resulting in difficulty achieving precise regulation of cross-scale pores.Additive manufacturing(AM)technology employs a digital layered molding strategy to achieve the cross-scale structural regulation of catalysts from macroscopic flow channels to mesopores and micropores.This paper summarizes recent advances in the structural design of monolithic catalysts enabled by AM technologies and highlights their emerging applications in catalytic processes.Structurally,AM-fabricated monoliths have been effectively employed in key chemical reactions such as fuel reforming,CO_(2)conversion,biofuel synthesis.Strategies such as geometrical topology optimization,multi-scale pore synergy,biomimetic structural design,and functional gradient integration have been utilized to enhance heat and mass transport,reduce pressure drops,and improve overall catalytic performance.By overcoming the limitations of traditional catalysts,AM technologies create a new paradigm for addressing the longstanding challenge of coupling mass transfer with reaction kinetics.This approach provides a feasible pathway for driving both theoretical innovation and practical implementation of high-efficiency catalytic systems.
基金supported by the National Key R&D Program of China(No.2022YFC3702800).
文摘Monolithic aerogels are promising candidates for use in atmospheric environmental purification due to their structural advantages,such as fine building block size together with high specific surface area,abundant pore structure,etc.Additionally,monolithic aerogels possess a unique monolithic macrostructure that sets them apart from aerogel powders and nanoparticles in practical environmental clean-up applications.This review delves into the available synthesis strategies and atmospheric environmental applications of monolithic aerogels,covering types of monolithic aerogels including SiO_(2),graphene,metal oxides and their combinations,along with their preparation methods.In particular,recent developments for VOC adsorption,CO_(2)capture,catalytic oxidation of VOCs and catalytic reduction of CO_(2)are highlighted.Finally,challenges and future opportunities for monolithic aerogels in the atmospheric environmental purification field are proposed.This reviewprovides valuable insights for designing and utilizing monolithic aerogel-based functional materials.
基金the National Natural Science Foundation of China (22325804 and 22308148)the Natural Science Foundation of Jiangsu Province (BK20230344)the Natural Science Research Project of Jiangsu University (22KJB610001)。
文摘Monolithic catalysts have been widely investigated for CO_(2) methanation due to their fast mass and heat transfer rate,but the effect of the interaction between the catalyst layer and the monolithic support has been little studied.In this work,Ni/Al_(2)O_(3)/SiC monolithic catalysts,Ni/Al_(2)O_(3) powder catalysts and Ni/Al_(2)O_(3)/SiC-M catalysts were prepared to explore the effect of Si-Al interaction between the catalyst layer and SiC ceramic for CO_(2) methanation performance.Ni/Al_(2)O_(3)/SiC exhibited a CO_(2) conversion of 53% and a CH_(4) specific reaction rate of 0.05 m mol·g^(-1)·s^(-1) under conditions of 0.1 M Pa,4 00℃,and a WHSV of 60000 ml·g^(-1)·h^(-1).The CO_(2) conversion raised by 0.15-fold and the CH_(4) specific reaction rate raised by 0.25-fold compared to Ni/Al_(2)O_(3) with the same catalyst content.SEM,XRD,Raman,and other characterization results revealed that the formation of Si-Al interaction between the catalyst layer and SiC ceramic could weaken the interaction between Ni and Al_(2)O_(3),thereby improving the catalytic activity of Ni/Al_(2)O_(3)/SiC catalyst.However,the Si-Al interaction was further strengthened during the hightemperature reaction process,which significantly weakened the interaction between Ni and Al_(2)O_(3),thereby leading to a decline in the catalytic performance of Ni/Al_(2)O_(3)/SiC catalyst during an 80-h stability test.This study provides valuable insights for future research and development of monolithic catalysts.
基金This work was supported by the National Natural Science Foundation of China(Grant No.12172160)Shenzhen Science and Technology Program(Grant No.JCYJ20220818100600002)+1 种基金South-ern University of Science and Technology(Grant No.Y01326127)the Department of Science and Technology of Guangdong Province(Grant Nos.2020B1212030001 and 2021QN020642).
文摘We propose a suite of strategies for the parallel solution of fully implicit monolithic fluid-structure interaction(FSI).The solver is based on a modeling approach that uses the velocity and pressure as the primitive variables,which offers a bridge between computational fluid dynamics(CFD)and computational structural dynamics.The spatiotemporal discretization leverages the variational multiscale formulation and the generalized-αmethod as a means of providing a robust discrete scheme.In particular,the time integration scheme does not suffer from the overshoot phenomenon and optimally dissipates high-frequency spurious modes in both subproblems of FSI.Based on the chosen fully implicit scheme,we systematically develop a combined suite of nonlinear and linear solver strategies.Invoking a block factorization of the Jacobian matrix,the Newton-Raphson procedure is reduced to solving two smaller linear systems in the multi-corrector stage.The first is of the elliptic type,indicating that the algebraic multigrid method serves as a well-suited option.The second exhibits a two-by-two block structure that is analogous to the system arising in CFD.Inspired by prior studies,the additive Schwarz domain decomposition method and the block-factorization-based preconditioners are invoked to address the linear problem.Since the number of unknowns matches in both subdomains,it is straightforward to balance loads when parallelizing the algorithm for distributed-memory architectures.We use two representative FSI benchmarks to demonstrate the robustness,efficiency,and scalability of the overall FSI solver framework.In particular,it is found that the developed FSI solver is comparable to the CFD solver in several aspects,including fixed-size and isogranular scalability as well as robustness.
基金Science and Technology Department of Henan Pro vince Fund Project(Grant No.144300510019)
文摘Lappaconitine is a water-insoluble drug, which was used as model drug in this study. Currently, two osmotically controlled delivery systems that are widely used for water-insoluble drug are monolithic osmotic tablet （MOT） and push-pull osmotic pump （PPOP）. In the present study, lappaconitine solid dispersion monolithic osmotic tablet （lappaconitine-SD-MOT） and lappaconitine-PPOP were developed. The prepared lappaconitine-PPOP was able to delivery drug at the rate of approximate zero-order （r = 0.9931）, and the cumulative release was above 95.0%. The lappaconitine-SD-MOT showed a comparatively poor linearity when the data were plotted according to the zero-order equation （r = 0.9798）, and the cumulative release was 84.69%. Lappaconitine-PPOP exhibited better controlled drug release （higher regression value） compared with lappaconitine-SD-MOT. The similarity index （f2） between lappaconitine-PPOP and lappaconitine-SD-MOT was 49.1 （〈50）. A clear difference of drug release characteristics between the lappaconitine-SD-MOT and lappaconitine-PPOP was revealed. It indicated that the drug release performance of lappaconitine-PPOP could gain favorable zero-order kinetics and higher cumulative release compared with lappaconitine-SD-MOT. Therefore, these results suggested that PPOP was still a very effective device for the delivery of poorly water-soluble drug with zero-order pattern.
基金National Science & Technology Pillar Program during the 12~(th) Five-year Plan Period(Grant No.2012BAI29B08)
文摘The objective of this study was to prepare monolithic osmotic tablet of quercetin for controlled drug release. Quercetin-PVP solid dispersion was prepared to enhance its solubility and dissolution rate. Solid dispersion, suspending agents, osmotic agents and other conventional excipients were used as tablet core composition and cellulose acetate （CA） with plasticizer as release controlling membrane. Different formulation variables, the amounts of PEO （polyethylene oxide）, NaC1, plasticizer, and coating weight gain were optimized to gain the optimum formulation. The mechanism of drug release from monolithic osmotic tablet was also discussed. The optimal monolithic osmotic pump tablet could deliver quercetin at the rate of approximate zero-order up to 12 h, and the cumulative release was 90.74%. The developed monolithic osmotic system for quercetin loaded by solid dispersion was found to be a promising approach for controlled release of poorly-water soluble drug candidates.
文摘The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate （MHP） and operating under constant bias voltage conditions was designed. A new monolithic integrating mode was proposed,in which the dielectric and passiva- tion layers in standard CMOS processes were used as sensor structure layers,gate polysilicon as the sacrificial layer,and the second polysilicon layer as the sensor heating resistor. Then, the fabricating processes were designed and the monolithic thermal vacuum sensor was fabricated with a 0. 6μm mixed signal CMOS process followed by sacrificial layer etching technology. The measurement results show that the fabricated monolithic vacuum sensor can measure the pressure range of 2- 10^5 Pa and the output voltage is adjustable.
文摘The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.
文摘A new type strongly gain coupled (GC) DFB laser and a new type self alignment spot size converter (SA SSC) are proposed and successfully fabricated.The strongly GC DFB laser is monolithically integrated with the SA SSC with three step epitaxies.A high single mode yield and large side mode suppression ratio is obtained from the strongly GC DFB laser.A near circle far field pattern is obtained by using the SA SSC.
文摘Based on the principle of chemical engineering in the multisubject field—drug delivery, the release kinetics of the slab monolithic matrix with an initially linear concentration distribution is studied in this paper. It can be used to describe the later stage when drug loading is above its solubility limit. A comprehensive model is proposed and the generalized solutions are acquired by Laplace transformation, from which a special case, i.e. a perfect sink has been deduced. According to the derived equations, the concentration profiles in the matrix has been computed and illustrated and the effect of volume of extraction medium on release has been investigated.
基金The National High Technology Research and Develop-ment Program of China (863 Program) (No.2001AA312010).
文摘2.5 Gbit/s monolithic integrated circuits （ICs） for optical fiber transmitter and receiver in 0.35 μm CMOS （complementary metal-oxide-semiconductor transistor） process are presented. The transmitter, which includes a 4： 1 multiplexer and a laser diode driver （LDD）, has four 622 Mbit/s random signals as its inputs and gets a 2.5 Gbit/s driving signal as its output; the receiver detects a 2.5 Gbit/s random signal and gets four 622 Mbit/s signals at the output. The main circuits include a trans-impedance amplifier （TIA）, a limiting amplifier, a clock and data recovery （CDR） unit, and a 1： 4 demultiplexer （DEMUX）. Test results prove the logic functions of the transmitter to be right, and the 10% to 90% rise and fall times of transmitter＇s output data eye diagram are 211.1 ps and 200 ps, respectively. The sensitivity of the receiver is measured to be better than 20 mV. The root mean square jitter of the DEMUX＇s output data is 15.6 ps and that of the clock after 1： 4 frequency dividing is 1.9 ps. Two chips are both applicable to 2.5 Gbit/s optical fiber communication systems.
文摘A behavioral model of the photodiode is presented.The model describes the relationship between photocurrent and incident optical power,and it also illustrates the impact of the reverse bias to the variation of the junction capacitance.According to this model,the photodiode and a CMOS receiver circuit are simulated and designed simultaneously under a universal circuit simulation environment.
文摘A monolithically integrated optoelectronic receiver is presented. A silicon-based photo-diode and receiver circuits are integrated on identical substrates in order to eliminate the parasitics induced by hybrid packaging. Implemented in the present deep sub-micron MS/RF （mixed signal, radio frequency） CMOS,this monolithically OEIC takes advantage of several new features to improve the performance of the photo-diode and eventually the whole OEIC.
