Photoelectrochemical(PEC)water splitting holds significant promise for sustainable energy harvesting that enables efficient conversion of solar energy into green hydrogen.Nevertheless,achievement of high performance i...Photoelectrochemical(PEC)water splitting holds significant promise for sustainable energy harvesting that enables efficient conversion of solar energy into green hydrogen.Nevertheless,achievement of high performance is often limited by charge carrier recombination,resulting in unsatisfactory saturation current densities.To address this challenge,we present a novel strategy for achieving ultrahigh current density by incorporating a bridge layer between the Si substrate and the NiOOH cocatalyst in this paper.The optimal photoanode(TCO/n-p-Si/TCO/Ni)shows a remarkably low onset potential of 0.92 V vs.a reversible hydrogen electrode and a high saturation current density of 39.6 mA·cm^(-2),which is about 92.7%of the theoretical maximum(42.7 mA·cm^(-2)).In addition,the photoanode demonstrates stable operation for 60 h.Our systematic characterizations and calculations demonstrate that the bridge layer facilitates charge transfer,enhances catalytic performance,and provides corrosion protection to the underlying substrate.Notably,the integration of this photoanode into a PEC device for overall water splitting leads to a reduction of the onset potential.These findings provide a viable pathway for fabricating highperformance industrial photoelectrodes by integrating a substrate and a cocatalyst via a transparent and conductive bridge layer.展开更多
This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycy...This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycyclic aromatic hydrocarbons(PAHs)from aqueous solutions.The Chitosan(CS)hydrogel beads were modified with single/twin-tailed anionic surfactants,sodium dodecyl sulfate(SDS)and sodium bis(2-ethylhexyl)sulfosuccinate(AOT),and cationic surfactants,dodecyltrimethylammonium bromide(DTAB)and didodecyldimethylammonium bromide(DDAB),to enhance their adsorption capacity of PAHs.The CS and SMCS beads were evaluated for their structural,mechanical,and adsorption properties using a range of techniques,including infrared spectroscopy(IR),energy-dispersive X-ray spectroscopy(EDX),rheometry,and field emission scanning electron microscopy(FESEM).Adsorption experiments of naphthalene(Nap),acenaphthene(Ace),and phenanthrene(Phe)on SMCS beads demonstrate that they have significantly higher adsorption capacities than CS beads,due to increase in hydrophobic interactions.Adsorption capacity followed the trend,Phen>Ace>Nap for all the beads revealing that twin-tailed SMCS bead possess much higher adsorption capacities(Qmax)compared to single-tailed SMCS beads.For twin tailed surfactants,the maximum adsorption capacities for Nap,Ace and Phe varied as CS-AOT(CS-DDAB):430.0(323.8)611.60(538.18)633.39(536.99)mg/g respectively,outperforming other reported hydrogel beads.The study highlights the simplicity,eco-friendliness,and enhanced performance of surfactant modification for developing high-efficiency adsorbents,paving the way for cost-effective solutions in water re-mediation.展开更多
In the context of the rapid development of artificial intelligence and robotics,their application scenarios are continuously expanding to a variety of complex environments,with increasing attention being paid to the u...In the context of the rapid development of artificial intelligence and robotics,their application scenarios are continuously expanding to a variety of complex environments,with increasing attention being paid to the use of flexible sensors in lowtemperature environments.In this study,an ionic hydrogel was synthesized using acrylamide(AM),hydroxyethyl cellulose(HEC),and lithium chloride(LiCl)as composites.This hydrogel exhibits high adhesion,excellent sensitivity(gauge factor(GF)=2.84),rapid response time(100 ms),exceptional stretch ability(>1776%),high toughness(2.5 MJ/m^(3)),and the ability to maintain detectability at low temperatures(-60℃).HEC imparts reliable mechanical properties to the sensor through hydrogen bonding interactions of its hydroxyl groups.LiCl ensures that the sensor has outstanding antifreezing properties,maintains good conductivity and mechanical performance.Used for robotic attitude detection,the sensor demonstrated accurate recognition of various joint movements at both 20 and -20℃.This technology was extended to industrial operations and maintenance,where a mechanical claw was used to grasp parts at both room temperature and low temperature.A convolutional neural network deep learning algorithm was employed to identify and classify eight types of parts,achieving an impressive recognition accuracy of 98.8%.The polyacrylamide(PAM)/HEC/LiCl hydrogel sensor demonstrates the capability for wide-temperature range detection in flexible robotics,holding significant potential for future applications in human-machine interaction,tactile perception,and related fields.展开更多
By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,t...By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.展开更多
Solar-driven interfacial desalination(SID)offers a sustainable route for freshwater production,yet its long-term performance is compromised by salt crystallization and microbial fouling under complex marine conditions...Solar-driven interfacial desalination(SID)offers a sustainable route for freshwater production,yet its long-term performance is compromised by salt crystallization and microbial fouling under complex marine conditions.Zwitterionic polymers offer promising nonfouling capabilities,but current zwitterionic hydrogel-based solar evaporators(HSEs)suffer from inadequate hydration and salt vulnerability.Inspired by the natural marine environmental adaptive characteristics of saltwater fish,we report a superhydrated zwitterionic poly(trimethylamine N-oxide,PTMAO)/polyacrylamide(PAAm)/polypyrrole(PPy)hydrogel(PTAP)with dedicated water channels for efficient,durable,and nonfouling SID.The directly linked N⁺and O⁻groups in PTMAO establish a robust hydration shell that facilitates rapid water transport while resisting salt and microbial adhesion.Integrated PAAm and PPy networks enhance mechanical strength and photothermal conversion.PTAP achieves a high evaporation rate of 2.35 kg m^(−2)h^(−1)under 1 kW m^(–2)in 10 wt%NaCl solution,maintaining stable operation over 100 h without salt accumulation.Furthermore,PTAP effectively resists various foulants including proteins,bacterial,and algal adhesion.Molecular dynamics simulations reveal that the exceptional hydration capacity supports its nonfouling properties.This work advances the development of nonfouling HSEs for sustainable solar desalination in real-world marine environments.展开更多
Octopuses,due to their flexible arms,marvelous adaptability,and powerful suckers,are able to effortlessly grasp and disengage various objects in the marine surrounding without causing devastation.However,manipulating ...Octopuses,due to their flexible arms,marvelous adaptability,and powerful suckers,are able to effortlessly grasp and disengage various objects in the marine surrounding without causing devastation.However,manipulating delicate objects such as soft and fragile foods underwater require gentle contact and stable adhesion,which poses a serious challenge to now available soft grippers.Inspired by the sucker infundibulum structure and flexible tentacles of octopus,herein we developed a hydraulically actuated hydrogel soft gripper with adaptive maneuverability by coupling multiple hydrogen bond-mediated supramolecular hydrogels and vat polymerization three-dimensional printing,in which hydrogel bionic sucker is composed of a tunable curvature membrane,a negative pressure cavity,and a pneumatic chamber.The design of the sucker structure with the alterable curvature membrane is conducive to realize the reliable and gentle switchable adhesion of the hydrogel soft gripper.As a proof-of-concept,the adaptive hydrogel soft gripper is capable of implement diversified underwater tasks,including gingerly grasping fragile foods like egg yolks and tofu,as well as underwater robots and vehicles that station-keeping and crawling based on switchable adhesion.This study therefore provides a transformative strategy for the design of novel soft grippers that will render promising utilities for underwater exploration soft robotics.展开更多
Diabetic wound healing remains a major clinical challenge,primarily due to excessive inflammation,bacterial infection,and impaired angiogenesis.Although various biomaterial-based strategies have been explored,coordina...Diabetic wound healing remains a major clinical challenge,primarily due to excessive inflammation,bacterial infection,and impaired angiogenesis.Although various biomaterial-based strategies have been explored,coordinating the complex diabetic wound microenvironment remains difficult to achieve.This study proposes a novel multifunctional hydrogel dressing designed to synergistically address multiple issues.Its key innovation lies in dynamically crosslinking deer antler decellularized matrix(dECM)with oxidized dextran via imine bonds,creating a self-healing hydrogel(dECMH).The deer antler dECM,rich in pro-regenerative components,provides a biomimetic scaffold,while Schiff base crosslinking confers mechanical self-healing and injectability.To further address the complexity of diabetic wounds,magnesium gallate metalorganic frameworks(Mg-EGCG)were embedded within the dECMH network,forming Mg-EGCG@dECMH.This innovative combination enables sustained co-delivery of epigallocatechin gallate(EGCG)—possessing antibacterial,anti-inflammatory,and antioxidant properties—alongside magnesium ions that actively promote cell proliferation and vascular regeneration.In vitro analyses confirmed the hydrogel's capacity to enhance endothelial cell proliferation,boost angiogenesis,and mitigate oxidative stress.In vivo evaluations demonstrated accelerated wound healing,manifested by rapid inflammation resolution,ordered collagen deposition,and stimulated neovascularization.Additionally,the material exhibited excellent biocompatibility,hemostatic effects,and antimicrobial activity.This multifunctional dressing synergistically integrates the inherent bioactivity of unique antler decellularized matrix with the multimodal therapeutic effects of metal-organic nanocomposites,offering an innovative and effective strategy for diabetic wound management.展开更多
Bone regeneration for non-load-bearing defects remains a significant clinical challenge requiring advanced biomaterials and cellular strategies.Adiposederived mesenchymal stem cells(AD-MSCs)have garnered significant i...Bone regeneration for non-load-bearing defects remains a significant clinical challenge requiring advanced biomaterials and cellular strategies.Adiposederived mesenchymal stem cells(AD-MSCs)have garnered significant interest in bone tissue engineering(BTE)because of their abundant availability,minimally invasive harvesting procedures,and robust differentiation potential into osteogenic lineages.Unlike bone marrow-derived mesenchymal stem cells,AD-MSCs can be easily obtained in large quantities,making them appealing alternatives for therapeutic applications.This review explores hydrogels containing polymers,such as chitosan,collagen,gelatin,and hyaluronic acid,and their composites,tailored for BTE,and emphasizes the importance of these hydrogels as scaffolds for the delivery of AD-MSCs.Various hydrogel fabrication techniques and biocompatibility assessments are discussed,along with innovative modifications to enhance osteogenesis.This review also briefly outlines AD-MSC isolation methods and advanced embedding techniques for precise cell placement,such as direct encapsulation and three-dimensional bioprinting.We discuss the mechanisms of bone regeneration in the AD-MSC-laden hydrogels,including osteoinduction,vascularization,and extracellular matrix remodeling.We also review the preclinical and clinical applications of AD-MSC-hydrogel systems,emphasizing their success and limitations.In this review,we provide a comprehensive overview of AD-MSC-based hydrogel systems to guide the development of effective therapies for bone regeneration.展开更多
Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological prop...Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.展开更多
The major aim of stroke therapy is to stimulate brain repair and improve behavioral recovery after cerebral ischemia.One option is to stimulate endogenous neurogenesis in the subventricular zone and direct the newly f...The major aim of stroke therapy is to stimulate brain repair and improve behavioral recovery after cerebral ischemia.One option is to stimulate endogenous neurogenesis in the subventricular zone and direct the newly formed neurons to the damaged area.However,only a small percentage of these neurons survive,and many do not reach the damaged area,possibly because the corpus callosum impedes the migration of subventricular zone-derived stem cells into the lesioned cortex.A second major obstacle to stem cell therapy is the strong inflammatory reaction induced by cerebral ischemia,whereby the associated phagocytic activity of brain macrophages removes both therapeutic cells and/or cell-based drug carriers.To address these issues,neurogenesis was electrically stimulated in the subventricular zone,followed by isolation of proliferating cells,including newly formed neurons,which were subsequently mixed with a nutritional hydrogel.This mixture was then transferred to the stroke cavity of day 14 post-stroke mice.We found that the performance of the treated animals improved in behavioral tests,including novel object,open field,hole board,grooming,and“time-to-feel”adhesive tape tests.Furthermore,immunostaining revealed that the stem cell marker nestin,the neuroepithelial marker Mash1,and the immature neuronal marker doublecortin-positive cells survived in the transplanted area for 2 weeks,possibly due to reduced phagocytic activity and supportive angiogenesis.These results clearly indicate that the transplantation of committed subventricular zone stem cells combined with a protective nutritional gel directly into the infarct cavity after the peak of stroke-induced neuroinflammation represents a feasible approach to improve neurorestoration after cerebral ischemia.展开更多
The solvation structure of Li^(+) in chemical prelithiation reagent plays a key role in improving the low initial Coulombic efficiency(ICE) and poor cycle performance of silicon-based materials. Never theless, the che...The solvation structure of Li^(+) in chemical prelithiation reagent plays a key role in improving the low initial Coulombic efficiency(ICE) and poor cycle performance of silicon-based materials. Never theless, the chemical prelithiation agent is difficult to dope active Li^(+) in silicon-based anodes because of their low working voltage and sluggish Li^(+) diffusion rate. By selecting the lithium–arene complex reagent with 4-methylbiphenyl as an anion ligand and 2-methyltetrahydrofuran as a solvent, the as-prepared micro-sized Si O/C anode can achieve an ICE of nearly 100%. Interestingly, the best prelithium efficiency does not correspond to the lowest redox half-potential(E_(1/2)), and the prelithiation efficiency is determined by the specific influencing factors(E_(1/2), Li^(+) concentration, desolvation energy, and ion diffusion path). In addition, molecular dynamics simulations demonstrate that the ideal prelithiation efficiency can be achieved by choosing appropriate anion ligand and solvent to regulate the solvation structure of Li^(+). Furthermore, the positive effect of prelithiation on cycle performance has been verified by using an in-situ electrochemical dilatometry and solid electrolyte interphase film characterizations.展开更多
An ultra-wideband mixing component cascaded by a mixing multi-function chip and a frequency multiplier multi-function chip was demonstrated and implemented using 3D heterogeneous integration based on the silicon adapt...An ultra-wideband mixing component cascaded by a mixing multi-function chip and a frequency multiplier multi-function chip was demonstrated and implemented using 3D heterogeneous integration based on the silicon adapter board technology.Four layers of high-resistance silicon substrate stack packaging are implemented based on the wafer-level gold-gold bonding process.Each layer adopts though silicon via(TSV)technology to realize signal interconnection.A core monolithic integrated microwave chip(MMIC)is embedded in the silicon cavity,and the silicon-based filter is integrated with the high-resistance silicon substrate.The interconnect line,cavity and filter of the silicon-based adapter board are designed with AutoCAD,and HFSS is adopted for 3D electromagnetic field simulation.According to the measured results,the radio frequency(RF)of the mixing multi-function chip is 40-44 GHz and its intermediate frequency(IF)can cover the Ku band with a chip size of 10 mm×11 mm×1 mm.The multiplier multi-function chip operates at 16-20 GHz.The fundamental suppression is greater than 50 dB and the second harmonic suppression is better than 40 dB with a chip size of 8 mm×8 mm×1 mm.The cascaded fully assembled mixing component achieves a spur of better than-50 dBc and a gain of better than 15 dB.展开更多
The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which ...The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip,but also improves the system performance through advanced heterogeneous integrated packaging.This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection.The research status,development trend and application of ultra-low loss optical waveguides,high-speed detectors,high-speed modulators,lasers and 2D,2.5D,3D and monolithic integration are focused on.展开更多
A three-terminal silicon-based light emitting device is proposed and fabricated in standard 0.35 μm complementary metal-oxide-semiconductor technology. This device is capable of versatile working modes： it can emit ...A three-terminal silicon-based light emitting device is proposed and fabricated in standard 0.35 μm complementary metal-oxide-semiconductor technology. This device is capable of versatile working modes： it can emit visible to near infra-red （NIR） light （the spectrum ranges from 500 nm to 1000 nm） in reverse bias avalanche breakdown mode with working voltage between 8.35 V-12 V and emit NIR light （the spectrum ranges from 900 nm to 1300 nm） in the forward injection mode with working voltage below 2 V. An apparent modulation effect on the light intensity from the polysilicon gate is observed in the forward injection mode. Furthermore, when the gate oxide is broken down, NIR light is emitted from the polysilicon/oxide/silicon structure. Optoelectronic characteristics of the device working in different modes are measured and compared. The mechanisms behind these different emissions are explored.展开更多
The micro-mechanism of the silicon-based waveguide surface smoothing is investigated systematically to explore the effects of silicon-hydrogen bonds on high-temperature hydrogen annealing waveguides. The effect of sil...The micro-mechanism of the silicon-based waveguide surface smoothing is investigated systematically to explore the effects of silicon-hydrogen bonds on high-temperature hydrogen annealing waveguides. The effect of silicon- hydrogen bonds on the surface migration movement of silicon atoms and the waveguide surface topography are revealed. The micro-migration from an upper state to a lower state of silicon atoms is driven by silicon- hydrogen bonding, which is the key to ameliorate the rough surface morphology of the silicon-based waveguide. The process of hydrogen annealing is experimentally validated based on the simulated parameters. The surface roughness declines from 1.523nm to 0.461 nm.展开更多
Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical capacity.However,the significant volume expansion of silicon seriously hinders its utiliz...Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical capacity.However,the significant volume expansion of silicon seriously hinders its utilization as a lithium-ion anode.Herein,a functionalized high-toughness polyimide(PDMI) is synthesized by copolymerizing the 4,4'-Oxydiphthalic anhydride(ODPA) with 4,4'-oxydianiline(ODA),2,3-diaminobenzoic acid(DABA),and 1,3-bis(3-aminopropyl)-tetramethyl disiloxane(DMS).The combination of rigid benzene rings and flexible oxygen groups(-O-) in the PDMI molecular chain via a rigidness/softness coupling mechanism contributes to high toughness.The plentiful polar carboxyl(-COOH) groups establish robust bonding strength.Rapid ionic transport is achieved by incorporating the flexible siloxane segment(Si-O-Si),which imparts high molecular chain motility and augments free volume holes to facilitate lithium-ion transport(9.8 × 10^(-10) cm^(2) s^(-1) vs.16 × 10^(-10) cm^(2) s~(-1)).As expected,the SiO_x@PDMI-1.5 electrode delivers brilliant long-term cycle performance with a remarkable capacity retention of 85% over 500 cycles at 1.3 A g^(-1).The well-designed functionalized polyimide also significantly enhances the electrochemical properties of Si nanoparticles electrode.Meanwhile,the assembled SiO_x@PDMI-1.5/NCM811 full cell delivers a high retention of 80% after 100 cycles.The perspective of the binder design strategy based on polyimide modification delivers a novel path toward high-capacity electrodes for high-energy-density batteries.展开更多
A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative ...A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.展开更多
In view of the existing design challenges for Terahertz(THz)power amplifiers(PAs),the common design methods and the efforts of the State Key Laboratory of Millimeter Wave,Southeast University,China in the development ...In view of the existing design challenges for Terahertz(THz)power amplifiers(PAs),the common design methods and the efforts of the State Key Laboratory of Millimeter Wave,Southeast University,China in the development of silicon-based THz PAs,mainly including silicon-based PAs with operating frequencies covering 100–300 GHz,are summarized in this paper.Particularly,we design an LC-balun-based two-stage differential cascode PA with a center frequency of 150 GHz and an output power of 14 dBm.Based on a Marchand balun,we report a 220 GHz three-stage differential cascode PA with a saturated output power of 9.5 dBm.To further increase the output power of THz PA,based on a four-way differential power combining technique,we report a 211–263 GHz dual-LC-tank-based broadband PA with a recorded 14.7 dBm Psat and 16.4 dB peak gain.All the above circuits are designed in a standard 130 nm silicon germanium(SiGe)BiCMOS process.展开更多
This paper presents a brief overview of several promising design technologies for high efficiency silicon-based radio frequency （RF） power amplifiers （PAs） as well as the use of these technologies in mobile broadb...This paper presents a brief overview of several promising design technologies for high efficiency silicon-based radio frequency （RF） power amplifiers （PAs） as well as the use of these technologies in mobile broadband wireless communications. Four important aspects of PA design are addressed in this paper. First, we look at class-E PA design equations and provide an example of a class-E PA that achieves efficiency of 65-70% at 2.4 GHz. Then, we discuss state-of-the-art envelope tracking （ET） design for monolithic wideband RF mobile transmitter applications. A brief overview of Doherty PA design for the next-generation wireless handset applications is then given. Towards the end of the paper, we discuss an inherently broadband and highly efficient class-J PA design targeting future multi-band multi-standard wireless communication protocols.展开更多
The extinction ratio and insertion loss of spatial light modulator are subject to the material problem, thus limiting its applications. One reflection-type silicon-based spatial light modulator with high reflective ma...The extinction ratio and insertion loss of spatial light modulator are subject to the material problem, thus limiting its applications. One reflection-type silicon-based spatial light modulator with high reflective materials outside the Fabry-Perot cavity is demonstrated in this paper. The reflectivity values of the outside-cavity materials with different film layer numbers are simulated. The reflectivity values of 6-pair Ta2O5/SiO2 films at 1550 nm are experimentally verified to be as high as 99.9%. The surfaces of 6-pair Ta2O5/SiO2 films are smooth: their root-mean-square roughness values are as small as 0.53 nm. The insertion loss of the device at 1550 nm is only 1.2 dB. The high extinction ratio of the device at 1550 nm and 11 V is achieved to be 29.7 dB. The spatial light modulator has a high extinction ratio and low insertion loss for applications.展开更多
基金supported by Multi-Year Research Grants from the University of Macao(MYRG-GRG2023-00010-IAPME,MYRG-GRG2024-00038-IAPME,MYRG2022-00026-IAPME)the Science and Technology Development Fund(FDCT)from Macao SAR(0023/2023/AFJ,0050/2023/RIB2,006/2022/ALC,0087/2024/AFJ,0111/2022/A2).
文摘Photoelectrochemical(PEC)water splitting holds significant promise for sustainable energy harvesting that enables efficient conversion of solar energy into green hydrogen.Nevertheless,achievement of high performance is often limited by charge carrier recombination,resulting in unsatisfactory saturation current densities.To address this challenge,we present a novel strategy for achieving ultrahigh current density by incorporating a bridge layer between the Si substrate and the NiOOH cocatalyst in this paper.The optimal photoanode(TCO/n-p-Si/TCO/Ni)shows a remarkably low onset potential of 0.92 V vs.a reversible hydrogen electrode and a high saturation current density of 39.6 mA·cm^(-2),which is about 92.7%of the theoretical maximum(42.7 mA·cm^(-2)).In addition,the photoanode demonstrates stable operation for 60 h.Our systematic characterizations and calculations demonstrate that the bridge layer facilitates charge transfer,enhances catalytic performance,and provides corrosion protection to the underlying substrate.Notably,the integration of this photoanode into a PEC device for overall water splitting leads to a reduction of the onset potential.These findings provide a viable pathway for fabricating highperformance industrial photoelectrodes by integrating a substrate and a cocatalyst via a transparent and conductive bridge layer.
基金the Department of Science and Technology(DST),Govt.of India for providing funds under the FIST program and PURSE grant vide No.SR/PURSE/2020/31 to the department of Chemistry,University of Kashmir.
文摘This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycyclic aromatic hydrocarbons(PAHs)from aqueous solutions.The Chitosan(CS)hydrogel beads were modified with single/twin-tailed anionic surfactants,sodium dodecyl sulfate(SDS)and sodium bis(2-ethylhexyl)sulfosuccinate(AOT),and cationic surfactants,dodecyltrimethylammonium bromide(DTAB)and didodecyldimethylammonium bromide(DDAB),to enhance their adsorption capacity of PAHs.The CS and SMCS beads were evaluated for their structural,mechanical,and adsorption properties using a range of techniques,including infrared spectroscopy(IR),energy-dispersive X-ray spectroscopy(EDX),rheometry,and field emission scanning electron microscopy(FESEM).Adsorption experiments of naphthalene(Nap),acenaphthene(Ace),and phenanthrene(Phe)on SMCS beads demonstrate that they have significantly higher adsorption capacities than CS beads,due to increase in hydrophobic interactions.Adsorption capacity followed the trend,Phen>Ace>Nap for all the beads revealing that twin-tailed SMCS bead possess much higher adsorption capacities(Qmax)compared to single-tailed SMCS beads.For twin tailed surfactants,the maximum adsorption capacities for Nap,Ace and Phe varied as CS-AOT(CS-DDAB):430.0(323.8)611.60(538.18)633.39(536.99)mg/g respectively,outperforming other reported hydrogel beads.The study highlights the simplicity,eco-friendliness,and enhanced performance of surfactant modification for developing high-efficiency adsorbents,paving the way for cost-effective solutions in water re-mediation.
基金supported by the National Natural Science Foundation of China(No.52475580)the Special Foundation of the Taishan Scholar Project(No.tsqn202211077)+3 种基金the Shandong Provincial Natural Science Foundation(No.ZR2023ME118)the Open Project of State Key Laboratory of Chemical Safety(No.SKLCS-2024020)the Fundamental Research Funds for the Central Universities(No.24CX02014A)the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China).
文摘In the context of the rapid development of artificial intelligence and robotics,their application scenarios are continuously expanding to a variety of complex environments,with increasing attention being paid to the use of flexible sensors in lowtemperature environments.In this study,an ionic hydrogel was synthesized using acrylamide(AM),hydroxyethyl cellulose(HEC),and lithium chloride(LiCl)as composites.This hydrogel exhibits high adhesion,excellent sensitivity(gauge factor(GF)=2.84),rapid response time(100 ms),exceptional stretch ability(>1776%),high toughness(2.5 MJ/m^(3)),and the ability to maintain detectability at low temperatures(-60℃).HEC imparts reliable mechanical properties to the sensor through hydrogen bonding interactions of its hydroxyl groups.LiCl ensures that the sensor has outstanding antifreezing properties,maintains good conductivity and mechanical performance.Used for robotic attitude detection,the sensor demonstrated accurate recognition of various joint movements at both 20 and -20℃.This technology was extended to industrial operations and maintenance,where a mechanical claw was used to grasp parts at both room temperature and low temperature.A convolutional neural network deep learning algorithm was employed to identify and classify eight types of parts,achieving an impressive recognition accuracy of 98.8%.The polyacrylamide(PAM)/HEC/LiCl hydrogel sensor demonstrates the capability for wide-temperature range detection in flexible robotics,holding significant potential for future applications in human-machine interaction,tactile perception,and related fields.
基金financially supported by the Science and Technology Innovation Program of Hunan Province(2024RC3003)the Central South University Innovation-Driven Research Programme(2023CXQD012)the Initiative for Sustainable Energy for its financial support。
文摘By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.
基金supported by National Natural Science Foundation of China(22209036,U23A20119)Hebei Provincial Natural Science Foundation,Excellent Youth Project(E2023202069)+1 种基金National Key R&D Program of China(2024YFF0506000,2024YFB4609100)Fundamental Research Foundation from Hebei University of Technology(424132016,282021485).
文摘Solar-driven interfacial desalination(SID)offers a sustainable route for freshwater production,yet its long-term performance is compromised by salt crystallization and microbial fouling under complex marine conditions.Zwitterionic polymers offer promising nonfouling capabilities,but current zwitterionic hydrogel-based solar evaporators(HSEs)suffer from inadequate hydration and salt vulnerability.Inspired by the natural marine environmental adaptive characteristics of saltwater fish,we report a superhydrated zwitterionic poly(trimethylamine N-oxide,PTMAO)/polyacrylamide(PAAm)/polypyrrole(PPy)hydrogel(PTAP)with dedicated water channels for efficient,durable,and nonfouling SID.The directly linked N⁺and O⁻groups in PTMAO establish a robust hydration shell that facilitates rapid water transport while resisting salt and microbial adhesion.Integrated PAAm and PPy networks enhance mechanical strength and photothermal conversion.PTAP achieves a high evaporation rate of 2.35 kg m^(−2)h^(−1)under 1 kW m^(–2)in 10 wt%NaCl solution,maintaining stable operation over 100 h without salt accumulation.Furthermore,PTAP effectively resists various foulants including proteins,bacterial,and algal adhesion.Molecular dynamics simulations reveal that the exceptional hydration capacity supports its nonfouling properties.This work advances the development of nonfouling HSEs for sustainable solar desalination in real-world marine environments.
基金the financial support from the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB0470303)the National Key Research and Development Program of China (2022YFB4600101)+5 种基金the National Natural Science Foundation of China (52175201)the Research Program of Science and Technology Department of Gansu Province (24JRRA059, 24JRRA044, and 24YFFA014)the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai (AMGM2024F12)the Major Program (ZYFZFX-2) of the Lanzhou Institute of Chemical Physics, CASthe Special Research Assistant Project of the Chinese Academy of Sciencesthe Oasis Scholar of Shihezi University
文摘Octopuses,due to their flexible arms,marvelous adaptability,and powerful suckers,are able to effortlessly grasp and disengage various objects in the marine surrounding without causing devastation.However,manipulating delicate objects such as soft and fragile foods underwater require gentle contact and stable adhesion,which poses a serious challenge to now available soft grippers.Inspired by the sucker infundibulum structure and flexible tentacles of octopus,herein we developed a hydraulically actuated hydrogel soft gripper with adaptive maneuverability by coupling multiple hydrogen bond-mediated supramolecular hydrogels and vat polymerization three-dimensional printing,in which hydrogel bionic sucker is composed of a tunable curvature membrane,a negative pressure cavity,and a pneumatic chamber.The design of the sucker structure with the alterable curvature membrane is conducive to realize the reliable and gentle switchable adhesion of the hydrogel soft gripper.As a proof-of-concept,the adaptive hydrogel soft gripper is capable of implement diversified underwater tasks,including gingerly grasping fragile foods like egg yolks and tofu,as well as underwater robots and vehicles that station-keeping and crawling based on switchable adhesion.This study therefore provides a transformative strategy for the design of novel soft grippers that will render promising utilities for underwater exploration soft robotics.
基金supported by the National Natural Science Foundation of China(Nos.32300413 and 32371563)the Natural Science Basic Research Program of Shaanxi Province(No.2023-JCQN-0206)+1 种基金the Shaanxi Fundamental Science Research Project for Chemistry&Biology(No.22JHQ037)the National Key R&D Program of China(No.2024YFF1307302).
文摘Diabetic wound healing remains a major clinical challenge,primarily due to excessive inflammation,bacterial infection,and impaired angiogenesis.Although various biomaterial-based strategies have been explored,coordinating the complex diabetic wound microenvironment remains difficult to achieve.This study proposes a novel multifunctional hydrogel dressing designed to synergistically address multiple issues.Its key innovation lies in dynamically crosslinking deer antler decellularized matrix(dECM)with oxidized dextran via imine bonds,creating a self-healing hydrogel(dECMH).The deer antler dECM,rich in pro-regenerative components,provides a biomimetic scaffold,while Schiff base crosslinking confers mechanical self-healing and injectability.To further address the complexity of diabetic wounds,magnesium gallate metalorganic frameworks(Mg-EGCG)were embedded within the dECMH network,forming Mg-EGCG@dECMH.This innovative combination enables sustained co-delivery of epigallocatechin gallate(EGCG)—possessing antibacterial,anti-inflammatory,and antioxidant properties—alongside magnesium ions that actively promote cell proliferation and vascular regeneration.In vitro analyses confirmed the hydrogel's capacity to enhance endothelial cell proliferation,boost angiogenesis,and mitigate oxidative stress.In vivo evaluations demonstrated accelerated wound healing,manifested by rapid inflammation resolution,ordered collagen deposition,and stimulated neovascularization.Additionally,the material exhibited excellent biocompatibility,hemostatic effects,and antimicrobial activity.This multifunctional dressing synergistically integrates the inherent bioactivity of unique antler decellularized matrix with the multimodal therapeutic effects of metal-organic nanocomposites,offering an innovative and effective strategy for diabetic wound management.
文摘Bone regeneration for non-load-bearing defects remains a significant clinical challenge requiring advanced biomaterials and cellular strategies.Adiposederived mesenchymal stem cells(AD-MSCs)have garnered significant interest in bone tissue engineering(BTE)because of their abundant availability,minimally invasive harvesting procedures,and robust differentiation potential into osteogenic lineages.Unlike bone marrow-derived mesenchymal stem cells,AD-MSCs can be easily obtained in large quantities,making them appealing alternatives for therapeutic applications.This review explores hydrogels containing polymers,such as chitosan,collagen,gelatin,and hyaluronic acid,and their composites,tailored for BTE,and emphasizes the importance of these hydrogels as scaffolds for the delivery of AD-MSCs.Various hydrogel fabrication techniques and biocompatibility assessments are discussed,along with innovative modifications to enhance osteogenesis.This review also briefly outlines AD-MSC isolation methods and advanced embedding techniques for precise cell placement,such as direct encapsulation and three-dimensional bioprinting.We discuss the mechanisms of bone regeneration in the AD-MSC-laden hydrogels,including osteoinduction,vascularization,and extracellular matrix remodeling.We also review the preclinical and clinical applications of AD-MSC-hydrogel systems,emphasizing their success and limitations.In this review,we provide a comprehensive overview of AD-MSC-based hydrogel systems to guide the development of effective therapies for bone regeneration.
基金supported by the Shenzhen Hong Kong Joint Funding Project,No.SGDX20230116093645007(to LY)the Shenzhen Science and Technology Innovation Committee International Cooperation Project,No.GJHZ20200731095608025(to LY)+7 种基金Shenzhen Development and Reform Commission’s Intelligent Diagnosis,Treatment and Prevention of Adolescent Spinal Health Public Service Platform,No.S2002Q84500835(to LY)Shenzhen Medical Research Fund,No.B2303005(to LY)Team-based Medical Science Research Program,No.2024YZZ02(to LY)Zhejiang Provincial Natural Science Foundation of China,No.LWQ20H170001(to RL)Basic Research Project of Shenzhen Science and Technology from Shenzhen Science and Technology Innovation Commission,No.JCYJ20210324103010029(to BY)Shenzhen Second People’s Hospital Clinical Research Fund of Guangdong Province High-level Hospital Construction Project,Nos.2023yjlcyj029(to BY),2023yjlcyj021(to LL)Guangdong Basic and Applied Basic Research Foundation,No.2022A1515110679(to LL)China Postdoctoral Science Foundation,No.2022M722203(to GL).
文摘Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.
基金supported by European Union Funding Programme,PNRR,No. 760058(to DMH)the UEFISCDI Project,No. PN-III-P4-IDPCE-2020-059(to APW)
文摘The major aim of stroke therapy is to stimulate brain repair and improve behavioral recovery after cerebral ischemia.One option is to stimulate endogenous neurogenesis in the subventricular zone and direct the newly formed neurons to the damaged area.However,only a small percentage of these neurons survive,and many do not reach the damaged area,possibly because the corpus callosum impedes the migration of subventricular zone-derived stem cells into the lesioned cortex.A second major obstacle to stem cell therapy is the strong inflammatory reaction induced by cerebral ischemia,whereby the associated phagocytic activity of brain macrophages removes both therapeutic cells and/or cell-based drug carriers.To address these issues,neurogenesis was electrically stimulated in the subventricular zone,followed by isolation of proliferating cells,including newly formed neurons,which were subsequently mixed with a nutritional hydrogel.This mixture was then transferred to the stroke cavity of day 14 post-stroke mice.We found that the performance of the treated animals improved in behavioral tests,including novel object,open field,hole board,grooming,and“time-to-feel”adhesive tape tests.Furthermore,immunostaining revealed that the stem cell marker nestin,the neuroepithelial marker Mash1,and the immature neuronal marker doublecortin-positive cells survived in the transplanted area for 2 weeks,possibly due to reduced phagocytic activity and supportive angiogenesis.These results clearly indicate that the transplantation of committed subventricular zone stem cells combined with a protective nutritional gel directly into the infarct cavity after the peak of stroke-induced neuroinflammation represents a feasible approach to improve neurorestoration after cerebral ischemia.
基金supported by the National Natural Science Foundation of China (21875107, U1802256, and 22209204)Leading Edge Technology of Jiangsu Province (BK20220009), the Natural Science Foundation of Jiangsu Province (BK20221140)+2 种基金the China Postdoctoral Science Foundation (2022M713364)Jiangsu Specially Appointed Professors ProgramPriority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘The solvation structure of Li^(+) in chemical prelithiation reagent plays a key role in improving the low initial Coulombic efficiency(ICE) and poor cycle performance of silicon-based materials. Never theless, the chemical prelithiation agent is difficult to dope active Li^(+) in silicon-based anodes because of their low working voltage and sluggish Li^(+) diffusion rate. By selecting the lithium–arene complex reagent with 4-methylbiphenyl as an anion ligand and 2-methyltetrahydrofuran as a solvent, the as-prepared micro-sized Si O/C anode can achieve an ICE of nearly 100%. Interestingly, the best prelithium efficiency does not correspond to the lowest redox half-potential(E_(1/2)), and the prelithiation efficiency is determined by the specific influencing factors(E_(1/2), Li^(+) concentration, desolvation energy, and ion diffusion path). In addition, molecular dynamics simulations demonstrate that the ideal prelithiation efficiency can be achieved by choosing appropriate anion ligand and solvent to regulate the solvation structure of Li^(+). Furthermore, the positive effect of prelithiation on cycle performance has been verified by using an in-situ electrochemical dilatometry and solid electrolyte interphase film characterizations.
文摘An ultra-wideband mixing component cascaded by a mixing multi-function chip and a frequency multiplier multi-function chip was demonstrated and implemented using 3D heterogeneous integration based on the silicon adapter board technology.Four layers of high-resistance silicon substrate stack packaging are implemented based on the wafer-level gold-gold bonding process.Each layer adopts though silicon via(TSV)technology to realize signal interconnection.A core monolithic integrated microwave chip(MMIC)is embedded in the silicon cavity,and the silicon-based filter is integrated with the high-resistance silicon substrate.The interconnect line,cavity and filter of the silicon-based adapter board are designed with AutoCAD,and HFSS is adopted for 3D electromagnetic field simulation.According to the measured results,the radio frequency(RF)of the mixing multi-function chip is 40-44 GHz and its intermediate frequency(IF)can cover the Ku band with a chip size of 10 mm×11 mm×1 mm.The multiplier multi-function chip operates at 16-20 GHz.The fundamental suppression is greater than 50 dB and the second harmonic suppression is better than 40 dB with a chip size of 8 mm×8 mm×1 mm.The cascaded fully assembled mixing component achieves a spur of better than-50 dBc and a gain of better than 15 dB.
基金Project supported in part by the National Key Research and Development Program of China(Grant No.2021YFB2206504)the National Natural Science Foundation of China(Grant No.62235017)the China Postdoctoral Science Foundation(Grant No.2021M703125).
文摘The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip,but also improves the system performance through advanced heterogeneous integrated packaging.This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection.The research status,development trend and application of ultra-low loss optical waveguides,high-speed detectors,high-speed modulators,lasers and 2D,2.5D,3D and monolithic integration are focused on.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.60536030,61036002,60776024,60877035 and 61036009)National High Technology Research and Development Program of China(Grant Nos.2007AA04Z329 and 2007AA04Z254)
文摘A three-terminal silicon-based light emitting device is proposed and fabricated in standard 0.35 μm complementary metal-oxide-semiconductor technology. This device is capable of versatile working modes： it can emit visible to near infra-red （NIR） light （the spectrum ranges from 500 nm to 1000 nm） in reverse bias avalanche breakdown mode with working voltage between 8.35 V-12 V and emit NIR light （the spectrum ranges from 900 nm to 1300 nm） in the forward injection mode with working voltage below 2 V. An apparent modulation effect on the light intensity from the polysilicon gate is observed in the forward injection mode. Furthermore, when the gate oxide is broken down, NIR light is emitted from the polysilicon/oxide/silicon structure. Optoelectronic characteristics of the device working in different modes are measured and compared. The mechanisms behind these different emissions are explored.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51505324,91123036,61471255 and 61474079the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No 20131402110013the Foundation for Young Scholars of Shanxi Province under Grant No 2014021023-3
文摘The micro-mechanism of the silicon-based waveguide surface smoothing is investigated systematically to explore the effects of silicon-hydrogen bonds on high-temperature hydrogen annealing waveguides. The effect of silicon- hydrogen bonds on the surface migration movement of silicon atoms and the waveguide surface topography are revealed. The micro-migration from an upper state to a lower state of silicon atoms is driven by silicon- hydrogen bonding, which is the key to ameliorate the rough surface morphology of the silicon-based waveguide. The process of hydrogen annealing is experimentally validated based on the simulated parameters. The surface roughness declines from 1.523nm to 0.461 nm.
基金supported by the National Natural Science Foundation of China (51673017)the National Natural Science Foundation of China (21404005)+1 种基金the Fundamental Research Funds for the Central Universities (XK1802-2)the Natural Science Foundation of Jiangsu Province (BK20150273)。
文摘Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical capacity.However,the significant volume expansion of silicon seriously hinders its utilization as a lithium-ion anode.Herein,a functionalized high-toughness polyimide(PDMI) is synthesized by copolymerizing the 4,4'-Oxydiphthalic anhydride(ODPA) with 4,4'-oxydianiline(ODA),2,3-diaminobenzoic acid(DABA),and 1,3-bis(3-aminopropyl)-tetramethyl disiloxane(DMS).The combination of rigid benzene rings and flexible oxygen groups(-O-) in the PDMI molecular chain via a rigidness/softness coupling mechanism contributes to high toughness.The plentiful polar carboxyl(-COOH) groups establish robust bonding strength.Rapid ionic transport is achieved by incorporating the flexible siloxane segment(Si-O-Si),which imparts high molecular chain motility and augments free volume holes to facilitate lithium-ion transport(9.8 × 10^(-10) cm^(2) s^(-1) vs.16 × 10^(-10) cm^(2) s~(-1)).As expected,the SiO_x@PDMI-1.5 electrode delivers brilliant long-term cycle performance with a remarkable capacity retention of 85% over 500 cycles at 1.3 A g^(-1).The well-designed functionalized polyimide also significantly enhances the electrochemical properties of Si nanoparticles electrode.Meanwhile,the assembled SiO_x@PDMI-1.5/NCM811 full cell delivers a high retention of 80% after 100 cycles.The perspective of the binder design strategy based on polyimide modification delivers a novel path toward high-capacity electrodes for high-energy-density batteries.
基金Supported by the National Natural Science Foundation of China(21306088)National Key Technologies R&D Program of China(2015BAD15B07)+1 种基金State Key Laboratory of Chemical Engineering(SKL-Ch E-13A01,Tsinghua University,China)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,China)
文摘A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.62101117 and 62188102in part by ZTE Industry-University-Institute Cooperation Fundsin part by the Project funded by China Postdoctoral Science Foundation under Grant Nos.2021M700763 and 2022T150113.
文摘In view of the existing design challenges for Terahertz(THz)power amplifiers(PAs),the common design methods and the efforts of the State Key Laboratory of Millimeter Wave,Southeast University,China in the development of silicon-based THz PAs,mainly including silicon-based PAs with operating frequencies covering 100–300 GHz,are summarized in this paper.Particularly,we design an LC-balun-based two-stage differential cascode PA with a center frequency of 150 GHz and an output power of 14 dBm.Based on a Marchand balun,we report a 220 GHz three-stage differential cascode PA with a saturated output power of 9.5 dBm.To further increase the output power of THz PA,based on a four-way differential power combining technique,we report a 211–263 GHz dual-LC-tank-based broadband PA with a recorded 14.7 dBm Psat and 16.4 dB peak gain.All the above circuits are designed in a standard 130 nm silicon germanium(SiGe)BiCMOS process.
文摘This paper presents a brief overview of several promising design technologies for high efficiency silicon-based radio frequency （RF） power amplifiers （PAs） as well as the use of these technologies in mobile broadband wireless communications. Four important aspects of PA design are addressed in this paper. First, we look at class-E PA design equations and provide an example of a class-E PA that achieves efficiency of 65-70% at 2.4 GHz. Then, we discuss state-of-the-art envelope tracking （ET） design for monolithic wideband RF mobile transmitter applications. A brief overview of Doherty PA design for the next-generation wireless handset applications is then given. Towards the end of the paper, we discuss an inherently broadband and highly efficient class-J PA design targeting future multi-band multi-standard wireless communication protocols.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61575076 and 61804148)the National Key Research and Development Plan of China(Grant No.2016YFB0402502)
文摘The extinction ratio and insertion loss of spatial light modulator are subject to the material problem, thus limiting its applications. One reflection-type silicon-based spatial light modulator with high reflective materials outside the Fabry-Perot cavity is demonstrated in this paper. The reflectivity values of the outside-cavity materials with different film layer numbers are simulated. The reflectivity values of 6-pair Ta2O5/SiO2 films at 1550 nm are experimentally verified to be as high as 99.9%. The surfaces of 6-pair Ta2O5/SiO2 films are smooth: their root-mean-square roughness values are as small as 0.53 nm. The insertion loss of the device at 1550 nm is only 1.2 dB. The high extinction ratio of the device at 1550 nm and 11 V is achieved to be 29.7 dB. The spatial light modulator has a high extinction ratio and low insertion loss for applications.
