A novel process was proposed for treating nickeliferous laterite ores with molten sodium hydroxide.The effect on silicon extraction caused by the factors,such as stirring speed,reaction temperature,particle size and N...A novel process was proposed for treating nickeliferous laterite ores with molten sodium hydroxide.The effect on silicon extraction caused by the factors,such as stirring speed,reaction temperature,particle size and NaOH-to-ore mass ratio,was investigated.The results show that increasing stirring speed,reaction temperature and NaOH-to-ore mass ratio while decreasing particle size increases silicon extraction rate.The desiliconization kinetics of nickeliferous laterite ores in molten sodium hydroxide system was described successfully by chemical reaction control model.The activation energy of the desiliconization process was found to be 44.01 kJ/mol,and the reaction rate based on a chemical reaction-controlled process can be expressed as:1-(1-α) 1/3 = 27.67exp[-44 010/(RT)]t.展开更多
HL-2A is a new middle-sized tokamak device with two closed divertors. In 2004 campaign siliconization as a wall condition has been first done on HL-2A since the starting operation of the device. By using sil-iconizati...HL-2A is a new middle-sized tokamak device with two closed divertors. In 2004 campaign siliconization as a wall condition has been first done on HL-2A since the starting operation of the device. By using sil-iconization we observed that impurity has been obviously decreased. The character of the siliconization and the effect of wall condition on plasma have been investigated as well as on the wall recycling.展开更多
The sputtering of impurities is caused by the interactions between plasma and the first wall, and the recycling of the gas affects the particle and energy transport of plasmas with a complicated mechanism in plasma op...The sputtering of impurities is caused by the interactions between plasma and the first wall, and the recycling of the gas affects the particle and energy transport of plasmas with a complicated mechanism in plasma operation. It is important for present tokarnaks to achieve a good confinement and high performance plasmas by means of controls of the vacuum condition, usage of low Z materials, control of the recycling of neutral particles and suppressions of the appearances and yield of impurities. For higher plasma parameters, some of the first wall of HL-2A is covered with graphite materials and carbon fiber tiles. Hence the studies on the in-situ coating application and development, and the interactions between the coating film and plasma are needed to effectively control the impurity, improve plasma confinement and achieve high performance plasma.展开更多
Intense chemical weathering in tropical regions produces soils characterized by silicon(Si)depletion and iron and aluminum oxide accumulation,leading to soil degradation.Consequently,Si cycling is of paramount importa...Intense chemical weathering in tropical regions produces soils characterized by silicon(Si)depletion and iron and aluminum oxide accumulation,leading to soil degradation.Consequently,Si cycling is of paramount importance in tropical regions.This review summarizes the key processes of the terrestrial Si biogeochemical cycle in tropical areas and underscores its biogeochemical significance in ecosystems.Runoff outputs constitute the dominant mechanism of Si depletion in tropical soils.However,the combined effects of dissolved Si(DSi)retention by highly weathered soil and Si uptake by vegetation attenuate desilication rates in these ecosystems.Tropical soils exhibit limited quantities of weatherable minerals,resulting in soil solution with low concentrations of DSi.Consequently,the primary sources of available Si are atmospheric dust inputs from distant sources and biogenic silica originating from plants.Irrigation,application of Si fertilizers,crop harvesting,and corresponding Si exports significantly impact soil Si cycling within agroecosystems.Therefore,soil Si cycling in tropical regions is different from that in other climatic zones.However,there are still many knowledge gaps within contemporary research.We propose to delve into several perspectives,including the exploration of the processes,fluxes,rates,related factors,and mechanisms associated with Si cycling in tropical regions.Comprehensive research from these perspectives would significantly enhance the understanding of pedogenesis and soil evolution and provide valuable insights for guiding the sustainable management of tropical soils.展开更多
AIM:To investigate the effects of shortening the duration of silicone oil tamponade on retinal structure and function in patients undergoing silicone oil removal(SOR)after surgery for primary rhegmatogenous retinal de...AIM:To investigate the effects of shortening the duration of silicone oil tamponade on retinal structure and function in patients undergoing silicone oil removal(SOR)after surgery for primary rhegmatogenous retinal detachment(RRD).METHODS:A total of 58 eligible patients were enrolled and randomly assigned to two groups based on tamponade duration:the short-term group(30-45d)and the conventional group(≥90d).Comprehensive evaluations were performed before and after SOR,including slitlamp examination,best-corrected visual acuity(BCVA)measurement,intraocular pressure(IOP)testing,optical coherence tomography(OCT),optical coherence tomography angiography(OCTA),microperimetry,electroretinography(ERG),and visual evoked potential(VEP)assessment.RESULTS:A total of 33 patients(23 males and 10 females;33 eyes)were enrolled in the short-term SO tamponade group with mean age of 52.45±9.35y,and 25 patients(15 males and 10 females;25 eyes)were enrolled in the conventional SO tamponade group with mean age of 50.80±12.06y.Compared with the conventional group,the short-term silicone oil tamponade group had a significantly lower incidence of silicone oil emulsification and cataract progression,with no significant difference in retinal reattachment success rate.Structurally,short-term tamponade was associated with increased thickness of the retinal ganglion cell layer(RGCL)in the nasal and superior macular regions and improved recovery of superficial retinal vascular density in these areas.Functionally,the shortterm group showed better BCVA and retinal sensitivity both before and 1mo after SOR;additionally,the P100 amplitude in VEP tests was significantly increased in this group.CONCLUSION:Shortening the duration of silicone oil tamponade effectively reduces damage to retinal structure and function without compromising the success rate of retinal reattachment in patients with primary RRD.展开更多
With the development of electronic components towards high frequency,high efficiency,and miniaturization,the demand for non-oriented silicon steel ultra-thin ribbons is increasing,which were usually prepared by multi-...With the development of electronic components towards high frequency,high efficiency,and miniaturization,the demand for non-oriented silicon steel ultra-thin ribbons is increasing,which were usually prepared by multi-pass rolling with complex processes and high cost.The ultra-thin non-oriented silicon steel ribbons with silicon content of 2–4.5 wt.%Si were prepared with the planar flow casting technology,and the microstructure and properties of ribbons were investigated.The results showed that as the silicon content increased,the grain size of the as-cast ribbons gradually decreased,and the dislocation density and internal stress were higher.The proportion of{100}oriented grains gradually increased from 29.3 to 37.3%,and the ratio of{110}and{111}oriented grains decreased.Meanwhile,the magnetic induction B50 showed a decline trend from 1.62 to 1.45 T with the increase in silicon content,while the iron loss P_(1.0/400) increased from 20.61 to 66.65 W/kg.This may be related to the silicon content affecting the wettability of melt and the wheel,thereby affecting the cooling capacity.The grains grew significantly after annealing,the internal stress was released and dislocations were eliminated.All this greatly improved the magnetic properties and decreased the hardness.B_(50) of ribbons with 2 wt.%Si reached 1.66 T and P_(1.0/400) of ribbons with 4.5 wt.%Si was reduced to 13.40 W/kg.The percentage of{110}fiber grains increased obviously while{100}fiber grains decreased slightly after heat treatment.展开更多
The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study intro...The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study introduces a molten salt electrochemical strategy for converting photovoltaic wSi into NiSi_(2)-silicon nanorods(NiSi_(2)-SiNRs)as high-performance anode materials for lithium-ion batteries.A stable oxidized passivation layer is formed on the wSi surface via controlled oxidation,and further in situ generated highly active NiSi_(2) droplets.The molten salt electric field modulates the surface energy of silicon,while particle integration drives localized directional growth,enabling the self-assembly of NiSi_(2)-SiNRs composites.These NiSi_(2)-SiNRs anodes exhibit rapid ion transport and effective strain buffering.The high aspect ratio of SiNRs and the presence of retained NiSi_(2) facilitate both longitudinal and transverse Li^(+) diffusion.Owing to their robust structural design,the NiSi_(2)-SiNRs anode achieves an excellent initial Coulombic efficiency of 91.61%and retains 72.99%of its capacity after 800 cycles at 2 A·g^(−1).This study establishes a model system for investigating silicide/silicon interfaces in molten salt electrochemical synthesis and provides an effective strategy for upcycling photovoltaic wSi into high-performance lithium-ion battery anodes.展开更多
Silicon possesses a high theoretical capacity,making it a potential contender for lithium-ion battery(LIB)anodes.Nonetheless,its practical usage is challenged by low electrical conductivity and significant volume expa...Silicon possesses a high theoretical capacity,making it a potential contender for lithium-ion battery(LIB)anodes.Nonetheless,its practical usage is challenged by low electrical conductivity and significant volume expansion during cycling.Here,we synthesized a novel silicon/carbon(Si/C)anode doped with ZnO via a template-derived method and high-temperature carbonization.The carbon structure,originated from metal-organic frameworks(MOFs)and ZnO doping,substantially enhanced the electrochemical properties of the composite material.It exhibited an initial capacity of 2100.3 mA h g^(-1)at a current density of 0.2 A g^(-1)and demonstrated excellent capacity retention over successive cycles.Moreover,the composite material displayed superior rate performance at higher current densities of 2 A g^(-1)and 3 A g^(-1).To address the low initial Coulombic efficiency(ICE)of siliconbased materials,we adopted a direct contact prelithiation approach and optimized the lithiation process by controlling the prelithiation time.After 30 min of prelithiation,the ICE reached 97.9%,thereby reducing the initial irreversible capacity loss(ICL)and realizing stable discharge-charge in subsequent cycles.This rational design provides valuable insights for achieving high-performance silicon anode.展开更多
Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wave...Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wavelength division multiplexing silicon photonics receiver chip composed of an arrayed waveguide grating and Ge-on-Si photodetectors. Integrated inductors are introduced to enhance the high-speed performance of photodetectors, enabling data rates up to 112 Gbps with high responsivity and low dark current. The operating wavelength range of the arrayed wavelength grating is adjusted according to the response of the Ge-on-Si photodetector. The optical insertion loss, cross talk and central wavelength of the array waveguide grating are 2.1 to 3.7 d B,-12 to-15 d B, and 1538 nm, respectively. The proposed receiver chip offers a solution to meet the challenges of modern data transmission requirements.展开更多
The differences in the competitive reactions of hydrogarnet and quicklime when reacting with titaniumcontaining and silicon-containing minerals during the Bayer digestion process were investigated.Thermodynamic analys...The differences in the competitive reactions of hydrogarnet and quicklime when reacting with titaniumcontaining and silicon-containing minerals during the Bayer digestion process were investigated.Thermodynamic analysis,artificial mineral experiments,and an evaluation of the digestion effect of natural diasporic bauxite were conducted.The results indicate that hydrogarnet shows a preferential reaction with anatase,and this preference becomes more pronounced as the silicon saturation coefficient increases.In contrast,quicklime participates in non-selective reactions with both anatase and desilication products(DSP).The preference of hydrogarnet for anatase significantly enhances the utilization efficiency of CaO in the high-temperature Bayer digestion process.展开更多
Desulfurization of CaO–Al_(2)O_(3) particles in molten steel was observed in situ using high-temperature confocal scanning laser microscopy.The effects of the aluminum and silicon contents of molten steel on desulfur...Desulfurization of CaO–Al_(2)O_(3) particles in molten steel was observed in situ using high-temperature confocal scanning laser microscopy.The effects of the aluminum and silicon contents of molten steel on desulfurization were analyzed.When the total aluminum content in the steel increased from 6 to 1100 ppm,the CaS content in CaO–Al_(2)O_(3) particles increased from 2.1wt%to 84.84wt%after the reaction for 90 s.Furthermore,when the silicon content in the steel increased from 0.01wt%to 2.20wt%,the CaS content in CaO–Al_(2)O_(3) particles increased from 1.53wt%to 79.01wt%after the reaction for 90 s.This indicates that the increase in the aluminum and silicon contents of the steel promoted the desulfurization of CaO–Al_(2)O_(3) particles.A kinetic model was established to predict the CaO–Al_(2)O_(3) particles composition,and the diffusion coefficient of sulfur in CaO–Al_(2)O_(3) particles was 9.375×10^(−10)m^(2)·s^(−1) at 1600℃,which provided a new method for the calculation of diffusion coefficient.展开更多
Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,...Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,conventional carbon coatings are limited by their volume expansion and structural degradation,which lead to capacity fading and reduced durability.This study introduces a scalable and practical one-step carbon-coating strategy for directly coating silicon suboxide(SiO_(x))-based materials using aqueous quasi-defect-free reduced graphene oxide(QrGO)without post-treatment,unlike conventional graphene oxide(GO)-based coating methods.This simple process enables uniform encapsulation with QrGO for a highly adhesive and conductive coating.The QrGO-based composite anode material has several advantages,including reduced cracking due to volume expansion and enhanced charge carrier transport,as well as an increased Si content of 20 wt.%compared to the 5 wt.%in typical commercial Si-based active materials.In particular,the capacity retention of the QrGO-coated Si electrodes dramatically increases at high C-rate.The full cell exhibited long-term stability and capacity that were twice that of commercial SiO_(x)-based cells.Therefore,the QrGO-based one-step coating process represents a scalable,transformative,and commercially viable strategy for developing high-performance LIBs.展开更多
The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbi...The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.展开更多
Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LE...Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LEDs are predominantly thermally cured,which is energy-and time-consuming and can adversely affect electronic components.In this study,a novel UV-curable silicone resin containing phenyl,disulfide,and acryloyl groups(SPASR)is developed from commercially available siloxanes.The resin exhibits a refractive index(n_(d))higher than 1.5,and it can be cured within 30 s under UV irradiation.After curing,it exhibits an optical transparency exceeding 92%,a lap adhesion strength of up to1.84 MPa,and good thermostability(T_(5%)>265℃).Notably,the volume shrinkage is less than 4.83%,attributed to the release of photopolymerization stress via UV-induced disulfide metathesis during UV curing.Mini-LEDs encapsulated with this resin show luminescence properties comparable to those of conventional thermally-cured sealants,and show excellent sealability wihtout visible penetration after being immersed in red ink for 12 h.Consequently,these excellent properties make the SPASR resin an ideal candidate for microelectronic encapsulation,offering a more reliable and efficient solution for the electronics industry.展开更多
The widespread application of aluminum silicon coatings in hot-stamping steel can be attributed to their exceptional heat resistance and oxidation resilience.However,alterations in the diffusion behavior of aluminum s...The widespread application of aluminum silicon coatings in hot-stamping steel can be attributed to their exceptional heat resistance and oxidation resilience.However,alterations in the diffusion behavior of aluminum silicon coatings during the heating process,such as coating corrosion and welding,considerably affect the ultimate performance of components post hot stamping.This study scrutinized the distinctive behaviors exhibited by two typical coatings,namely 30/30 and 75/75 coatings,throughout the heat treatment process and their consequential effects on welding and other inherent properties of typical components.Our investigation unveiled the heightened susceptibility of the 30/30 coating to the development of pinhole leakage defects on the surface compared with the 75/75 coating.Moreover,the diffusion rate of the 30/30 coating surpassed that of the 75/75 coating.This discrepancy holds significance as it influences welding processes,coating corrosion resistance,and attainable heat treatment windows.展开更多
Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic condu...Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.展开更多
Silicon steel is characterized by a high melting point,poor fluidity,and limited wettability,and the process window for the preparation of non-oriented silicon steel ribbons by planar flow casting(PFC)is limited.Durin...Silicon steel is characterized by a high melting point,poor fluidity,and limited wettability,and the process window for the preparation of non-oriented silicon steel ribbons by planar flow casting(PFC)is limited.During the production process,the melt puddle(MP)behavior is a key factor in determining the final quality of ribbons,and the influence mechanism of the airflow boundary layer on the MP behavior and the surface quality of ribbons is still unclear.The effects of wheel speed on the quality of PFC Fe–3.0%Si non-oriented silicon steel ultra-thin ribbons were systematically investigated.Combined with experiments and numerical simulations,the mechanism of different wheel speeds on the behavior of MP and the surface quality of ribbons was analyzed in depth.It is found that when the MP reaches a steady state,the upstream meniscus shows a C-shape,while the downstream meniscus exhibits a sloped shape.During the formation of the MP,the vortex phenomena occur both around and within the MP.With the increase in wheel speed,the thickness of the ribbons gradually decreases from 67 to 31μm.Furthermore,the air vortex on the upstream and downstream meniscus becomes more and more intense,which significantly increases the possibility of air entrapment in the MP and leads to a significant increase in the percentage of air pockets.When the wheel speed is 10–15 m/s,the surface of the ribbon is smooth,the thickness uniformity is better,and there are fewer defects.However,when the wheel speed is more than 15 m/s,the MP’s stability deteriorates,and the ribbons have obvious veining,wrinkles,and uneven thickness.展开更多
The two distinct types of composite materials(5%to 10%)were developed using recycled polyvinyl alcohol fiber(RPA),silicon nitride fiber(SN),and reduced carbon nanoparticles(RCN).Enhanced microstructural properties and...The two distinct types of composite materials(5%to 10%)were developed using recycled polyvinyl alcohol fiber(RPA),silicon nitride fiber(SN),and reduced carbon nanoparticles(RCN).Enhanced microstructural properties and mechanical strength were attained through the application of the 3-glycidoxypropyltrimethoxysilane coupling method.The combination of the resin-like properties of RPA-SN fiber resulted in the formation of robust outer strength and a high bonding structure.RPA-RCN composite materials with a weight percentage of 10%exhibited a tensile strength of 42 MPa.In contrast,RPA-SN-RCN composite materials containing 5%to 10%demonstrated enhanced tensile,bending,and hardness properties.Pyramid structures,solid structures,and crystal phases were formed using RCN particles.The resin and silane properties on hardness were gradually 14%increasing the outside region,whereas RPA-SN-RCN(10 wt%)on average hardness were attained at 86(Shore-D).The microstructures on RPA-RCN(5%to 10%)samples were observed solid structure,twin boundary’s structure and lattice structure.The tensile strength of RPA-SN-RCN(10%)was 67.3MPa,whereas the impact strength of RPA-RCN(10 wt%)was 53 J/mm2.The scanning electron microscopies(SEM)were used to investigate the microstructure of the RPA-SN-RCN(5%)and RPA-SN-RCN(10%)composite materials,respectively.展开更多
Li metal anodes,with high theoretical capacity(3860 mAh g^(-1))and low redox potential,are promising for high-capacity rechargeable batteries.Especially,ultra-thin Li metal anodes can improve energy density and minimi...Li metal anodes,with high theoretical capacity(3860 mAh g^(-1))and low redox potential,are promising for high-capacity rechargeable batteries.Especially,ultra-thin Li metal anodes can improve energy density and minimize lithium excess.However,their poor processability leads to non-uniform Li layers and unstable plating/stripping behavior.In this study,we present a current collector interphase(CCI)-based strategy using a Cu foil coated with a lithiophilic Si3N4 layer,followed by molten Li dip-coating to form around 20 lm Li layer.Furthermore,the scalable dip-coating method,compatibility with large-area current collectors(up to 100 cm^(2)),and stable cycling in pouch cells demonstrate the practical viability of the proposed SNLMA design for commercial lithium metal batteries.During the process,an in-situ Li–Si–N alloy gradient interphase forms at the interface,enhancing wettability and mechanical integrity.This unique gradient CCI provides synergistic lithiophilicity and structural stability,enabling high-performance Li metal batteries.The resulting LixSiy and LixNy phases reduce nucleation barriers and enable uniform Li deposition.As a result,the Si3N4–Li anode paired with a high-loading LCO cathode(22 mg cm^(-2))achieved 83%capacity retention after 100 cycles.This work offers a scalable and practical CCI design for next-generation Li metal batteries.展开更多
Quality control plays a critical role in modern manufacturing.With the rapid development of electric vehicles,5G communications,and the semiconductor industry,high-speed and high-precision detection of surface defects...Quality control plays a critical role in modern manufacturing.With the rapid development of electric vehicles,5G communications,and the semiconductor industry,high-speed and high-precision detection of surface defects on silicon carbide(SiC)wafers has become essential.This study developed an automated inspection framework for identifying surface defects on SiC wafers during the coarse grinding stage.Thecomplex machining textures on wafer surfaces hinder conventional machine vision models,often leading to misjudgment.To address this,deep learning algorithms were applied for defect classification.Because defects are rare and imbalanced across categories,data augmentation was performed using aWasserstein generative adversarial network with gradient penalty(WGAN-GP),along with conventionalmethods.An improved YOLOv8-seg instance segmentationmodel was then trained and tested on datasets with different augmentation strategies.Experimental results showed that,when trained withWGAN-GP–generated data,YOLOv8-seg achieved mean average precision values of 87.0%(bounding box)and 86.6%(segmentation mask).Compared with the traditional WGAN-GP,the proposed model reduced Frechet inception distance by 32.2%and multiscale structural similarity index by 29.8%,generating more realistic and diverse defect images.The proposed framework effectively improves defect detection accuracy under limited data conditions and shows strong potential for industrial applications.展开更多
基金Project(2007CB613603)supported by the National Basic Research Program of China
文摘A novel process was proposed for treating nickeliferous laterite ores with molten sodium hydroxide.The effect on silicon extraction caused by the factors,such as stirring speed,reaction temperature,particle size and NaOH-to-ore mass ratio,was investigated.The results show that increasing stirring speed,reaction temperature and NaOH-to-ore mass ratio while decreasing particle size increases silicon extraction rate.The desiliconization kinetics of nickeliferous laterite ores in molten sodium hydroxide system was described successfully by chemical reaction control model.The activation energy of the desiliconization process was found to be 44.01 kJ/mol,and the reaction rate based on a chemical reaction-controlled process can be expressed as:1-(1-α) 1/3 = 27.67exp[-44 010/(RT)]t.
文摘HL-2A is a new middle-sized tokamak device with two closed divertors. In 2004 campaign siliconization as a wall condition has been first done on HL-2A since the starting operation of the device. By using sil-iconization we observed that impurity has been obviously decreased. The character of the siliconization and the effect of wall condition on plasma have been investigated as well as on the wall recycling.
文摘The sputtering of impurities is caused by the interactions between plasma and the first wall, and the recycling of the gas affects the particle and energy transport of plasmas with a complicated mechanism in plasma operation. It is important for present tokarnaks to achieve a good confinement and high performance plasmas by means of controls of the vacuum condition, usage of low Z materials, control of the recycling of neutral particles and suppressions of the appearances and yield of impurities. For higher plasma parameters, some of the first wall of HL-2A is covered with graphite materials and carbon fiber tiles. Hence the studies on the in-situ coating application and development, and the interactions between the coating film and plasma are needed to effectively control the impurity, improve plasma confinement and achieve high performance plasma.
基金financially supported by the National Natural Science Foundation of China(Nos.42277312 and 41877010)。
文摘Intense chemical weathering in tropical regions produces soils characterized by silicon(Si)depletion and iron and aluminum oxide accumulation,leading to soil degradation.Consequently,Si cycling is of paramount importance in tropical regions.This review summarizes the key processes of the terrestrial Si biogeochemical cycle in tropical areas and underscores its biogeochemical significance in ecosystems.Runoff outputs constitute the dominant mechanism of Si depletion in tropical soils.However,the combined effects of dissolved Si(DSi)retention by highly weathered soil and Si uptake by vegetation attenuate desilication rates in these ecosystems.Tropical soils exhibit limited quantities of weatherable minerals,resulting in soil solution with low concentrations of DSi.Consequently,the primary sources of available Si are atmospheric dust inputs from distant sources and biogenic silica originating from plants.Irrigation,application of Si fertilizers,crop harvesting,and corresponding Si exports significantly impact soil Si cycling within agroecosystems.Therefore,soil Si cycling in tropical regions is different from that in other climatic zones.However,there are still many knowledge gaps within contemporary research.We propose to delve into several perspectives,including the exploration of the processes,fluxes,rates,related factors,and mechanisms associated with Si cycling in tropical regions.Comprehensive research from these perspectives would significantly enhance the understanding of pedogenesis and soil evolution and provide valuable insights for guiding the sustainable management of tropical soils.
基金Supported by the Key Science&Technology Project of Guangzhou(No.202103000045)the National Natural Science Foundation of China(No.82070972,No.82271093).
文摘AIM:To investigate the effects of shortening the duration of silicone oil tamponade on retinal structure and function in patients undergoing silicone oil removal(SOR)after surgery for primary rhegmatogenous retinal detachment(RRD).METHODS:A total of 58 eligible patients were enrolled and randomly assigned to two groups based on tamponade duration:the short-term group(30-45d)and the conventional group(≥90d).Comprehensive evaluations were performed before and after SOR,including slitlamp examination,best-corrected visual acuity(BCVA)measurement,intraocular pressure(IOP)testing,optical coherence tomography(OCT),optical coherence tomography angiography(OCTA),microperimetry,electroretinography(ERG),and visual evoked potential(VEP)assessment.RESULTS:A total of 33 patients(23 males and 10 females;33 eyes)were enrolled in the short-term SO tamponade group with mean age of 52.45±9.35y,and 25 patients(15 males and 10 females;25 eyes)were enrolled in the conventional SO tamponade group with mean age of 50.80±12.06y.Compared with the conventional group,the short-term silicone oil tamponade group had a significantly lower incidence of silicone oil emulsification and cataract progression,with no significant difference in retinal reattachment success rate.Structurally,short-term tamponade was associated with increased thickness of the retinal ganglion cell layer(RGCL)in the nasal and superior macular regions and improved recovery of superficial retinal vascular density in these areas.Functionally,the shortterm group showed better BCVA and retinal sensitivity both before and 1mo after SOR;additionally,the P100 amplitude in VEP tests was significantly increased in this group.CONCLUSION:Shortening the duration of silicone oil tamponade effectively reduces damage to retinal structure and function without compromising the success rate of retinal reattachment in patients with primary RRD.
基金supported by the financial support from National Key Research and Development Program of China(No.2021YFB3800501)。
文摘With the development of electronic components towards high frequency,high efficiency,and miniaturization,the demand for non-oriented silicon steel ultra-thin ribbons is increasing,which were usually prepared by multi-pass rolling with complex processes and high cost.The ultra-thin non-oriented silicon steel ribbons with silicon content of 2–4.5 wt.%Si were prepared with the planar flow casting technology,and the microstructure and properties of ribbons were investigated.The results showed that as the silicon content increased,the grain size of the as-cast ribbons gradually decreased,and the dislocation density and internal stress were higher.The proportion of{100}oriented grains gradually increased from 29.3 to 37.3%,and the ratio of{110}and{111}oriented grains decreased.Meanwhile,the magnetic induction B50 showed a decline trend from 1.62 to 1.45 T with the increase in silicon content,while the iron loss P_(1.0/400) increased from 20.61 to 66.65 W/kg.This may be related to the silicon content affecting the wettability of melt and the wheel,thereby affecting the cooling capacity.The grains grew significantly after annealing,the internal stress was released and dislocations were eliminated.All this greatly improved the magnetic properties and decreased the hardness.B_(50) of ribbons with 2 wt.%Si reached 1.66 T and P_(1.0/400) of ribbons with 4.5 wt.%Si was reduced to 13.40 W/kg.The percentage of{110}fiber grains increased obviously while{100}fiber grains decreased slightly after heat treatment.
基金supported by the Yunnan Province Basic Research General Program,China(No.202201BE070001-002)the Major Science and Technology Projects in Yunnan Province,China(No.202402AF 080005).
文摘The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study introduces a molten salt electrochemical strategy for converting photovoltaic wSi into NiSi_(2)-silicon nanorods(NiSi_(2)-SiNRs)as high-performance anode materials for lithium-ion batteries.A stable oxidized passivation layer is formed on the wSi surface via controlled oxidation,and further in situ generated highly active NiSi_(2) droplets.The molten salt electric field modulates the surface energy of silicon,while particle integration drives localized directional growth,enabling the self-assembly of NiSi_(2)-SiNRs composites.These NiSi_(2)-SiNRs anodes exhibit rapid ion transport and effective strain buffering.The high aspect ratio of SiNRs and the presence of retained NiSi_(2) facilitate both longitudinal and transverse Li^(+) diffusion.Owing to their robust structural design,the NiSi_(2)-SiNRs anode achieves an excellent initial Coulombic efficiency of 91.61%and retains 72.99%of its capacity after 800 cycles at 2 A·g^(−1).This study establishes a model system for investigating silicide/silicon interfaces in molten salt electrochemical synthesis and provides an effective strategy for upcycling photovoltaic wSi into high-performance lithium-ion battery anodes.
基金supported by the National Key R&D Program of China(No.2022YFA1504100)the Anhui Provincial Major Science and Technology Project(No.202203a05020017)+4 种基金the National Natural Science Foundation of China(Nos.52222210,51925207,U1910210,52161145101,51972067,51902062,and 52002083)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA21000000)the National Synchrotron Radiation Laboratory(No.KY2060000173)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(No.YLU-DNL Fund 2021002)the Fundamental Research Funds for the Central Universities(No.WK2060140026)。
文摘Silicon possesses a high theoretical capacity,making it a potential contender for lithium-ion battery(LIB)anodes.Nonetheless,its practical usage is challenged by low electrical conductivity and significant volume expansion during cycling.Here,we synthesized a novel silicon/carbon(Si/C)anode doped with ZnO via a template-derived method and high-temperature carbonization.The carbon structure,originated from metal-organic frameworks(MOFs)and ZnO doping,substantially enhanced the electrochemical properties of the composite material.It exhibited an initial capacity of 2100.3 mA h g^(-1)at a current density of 0.2 A g^(-1)and demonstrated excellent capacity retention over successive cycles.Moreover,the composite material displayed superior rate performance at higher current densities of 2 A g^(-1)and 3 A g^(-1).To address the low initial Coulombic efficiency(ICE)of siliconbased materials,we adopted a direct contact prelithiation approach and optimized the lithiation process by controlling the prelithiation time.After 30 min of prelithiation,the ICE reached 97.9%,thereby reducing the initial irreversible capacity loss(ICL)and realizing stable discharge-charge in subsequent cycles.This rational design provides valuable insights for achieving high-performance silicon anode.
基金National Key Research and Development Program of China (2022YFB2802400)National Natural Science Foundation of China (62250010, 62090054, 62274160)Youth Innovation Promotion Association of the Chinese Academy of Sciences (2021111)。
文摘Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wavelength division multiplexing silicon photonics receiver chip composed of an arrayed waveguide grating and Ge-on-Si photodetectors. Integrated inductors are introduced to enhance the high-speed performance of photodetectors, enabling data rates up to 112 Gbps with high responsivity and low dark current. The operating wavelength range of the arrayed wavelength grating is adjusted according to the response of the Ge-on-Si photodetector. The optical insertion loss, cross talk and central wavelength of the array waveguide grating are 2.1 to 3.7 d B,-12 to-15 d B, and 1538 nm, respectively. The proposed receiver chip offers a solution to meet the challenges of modern data transmission requirements.
基金the financial support from the Natural Science Foundation of Hunan Province,China(No.2022JJ40616)。
文摘The differences in the competitive reactions of hydrogarnet and quicklime when reacting with titaniumcontaining and silicon-containing minerals during the Bayer digestion process were investigated.Thermodynamic analysis,artificial mineral experiments,and an evaluation of the digestion effect of natural diasporic bauxite were conducted.The results indicate that hydrogarnet shows a preferential reaction with anatase,and this preference becomes more pronounced as the silicon saturation coefficient increases.In contrast,quicklime participates in non-selective reactions with both anatase and desilication products(DSP).The preference of hydrogarnet for anatase significantly enhances the utilization efficiency of CaO in the high-temperature Bayer digestion process.
基金supported by the National Key R&D Program of China(No.2023YFB3709900)the National Nature Science Foundation of China(No.U22A20171)+1 种基金the China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202315)the High Steel Center(HSC)at North China University of Technology and University of Science and Technology Beijing,China.
文摘Desulfurization of CaO–Al_(2)O_(3) particles in molten steel was observed in situ using high-temperature confocal scanning laser microscopy.The effects of the aluminum and silicon contents of molten steel on desulfurization were analyzed.When the total aluminum content in the steel increased from 6 to 1100 ppm,the CaS content in CaO–Al_(2)O_(3) particles increased from 2.1wt%to 84.84wt%after the reaction for 90 s.Furthermore,when the silicon content in the steel increased from 0.01wt%to 2.20wt%,the CaS content in CaO–Al_(2)O_(3) particles increased from 1.53wt%to 79.01wt%after the reaction for 90 s.This indicates that the increase in the aluminum and silicon contents of the steel promoted the desulfurization of CaO–Al_(2)O_(3) particles.A kinetic model was established to predict the CaO–Al_(2)O_(3) particles composition,and the diffusion coefficient of sulfur in CaO–Al_(2)O_(3) particles was 9.375×10^(−10)m^(2)·s^(−1) at 1600℃,which provided a new method for the calculation of diffusion coefficient.
基金supported by Korea Electrotechnology Research Institute(KERI)Primary research program through the National Research Council of Science&Technology(NST)funded by the Ministry of Science and ICT(MSIT)(No.25A01015)by the Technology Innovation Program(20019091)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)by the National Research Council of Science&Technology(NST)grant from the Korea government(MSIT)(No.GTL24012-000).
文摘Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,conventional carbon coatings are limited by their volume expansion and structural degradation,which lead to capacity fading and reduced durability.This study introduces a scalable and practical one-step carbon-coating strategy for directly coating silicon suboxide(SiO_(x))-based materials using aqueous quasi-defect-free reduced graphene oxide(QrGO)without post-treatment,unlike conventional graphene oxide(GO)-based coating methods.This simple process enables uniform encapsulation with QrGO for a highly adhesive and conductive coating.The QrGO-based composite anode material has several advantages,including reduced cracking due to volume expansion and enhanced charge carrier transport,as well as an increased Si content of 20 wt.%compared to the 5 wt.%in typical commercial Si-based active materials.In particular,the capacity retention of the QrGO-coated Si electrodes dramatically increases at high C-rate.The full cell exhibited long-term stability and capacity that were twice that of commercial SiO_(x)-based cells.Therefore,the QrGO-based one-step coating process represents a scalable,transformative,and commercially viable strategy for developing high-performance LIBs.
基金supported by the National Natural Science Foundation of China(No.52436008)the Inner Mongolia Science and Technology Projects,China(Nos.JMRHZX20210003 and 2023YFCY0009)+3 种基金the Huaneng Group Co Ltd.,China(No.HNKJ23-H50)the National Natural Science Foundation of China(No.22408044)the China Postdoctoral Science Foundation(No.2024M761877)the National Key R&D Program of China(No.SQ2024YFD2200039)。
文摘The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.
基金financially supported by the National Natural Science Foundation of China(No.52273104)。
文摘Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LEDs are predominantly thermally cured,which is energy-and time-consuming and can adversely affect electronic components.In this study,a novel UV-curable silicone resin containing phenyl,disulfide,and acryloyl groups(SPASR)is developed from commercially available siloxanes.The resin exhibits a refractive index(n_(d))higher than 1.5,and it can be cured within 30 s under UV irradiation.After curing,it exhibits an optical transparency exceeding 92%,a lap adhesion strength of up to1.84 MPa,and good thermostability(T_(5%)>265℃).Notably,the volume shrinkage is less than 4.83%,attributed to the release of photopolymerization stress via UV-induced disulfide metathesis during UV curing.Mini-LEDs encapsulated with this resin show luminescence properties comparable to those of conventional thermally-cured sealants,and show excellent sealability wihtout visible penetration after being immersed in red ink for 12 h.Consequently,these excellent properties make the SPASR resin an ideal candidate for microelectronic encapsulation,offering a more reliable and efficient solution for the electronics industry.
基金supported by Research Institute(R&D Center)of Baosteel.The flat model test received support from Shanghai University and Baosteel High-tech Parts Company.
文摘The widespread application of aluminum silicon coatings in hot-stamping steel can be attributed to their exceptional heat resistance and oxidation resilience.However,alterations in the diffusion behavior of aluminum silicon coatings during the heating process,such as coating corrosion and welding,considerably affect the ultimate performance of components post hot stamping.This study scrutinized the distinctive behaviors exhibited by two typical coatings,namely 30/30 and 75/75 coatings,throughout the heat treatment process and their consequential effects on welding and other inherent properties of typical components.Our investigation unveiled the heightened susceptibility of the 30/30 coating to the development of pinhole leakage defects on the surface compared with the 75/75 coating.Moreover,the diffusion rate of the 30/30 coating surpassed that of the 75/75 coating.This discrepancy holds significance as it influences welding processes,coating corrosion resistance,and attainable heat treatment windows.
基金financially supported by the National Key Research and Development Program(2022YFE0127400)the National Natural Science Foundation of China(52172040,52202041,and U23B2077)+1 种基金Taishan Scholar Project of Shandong Province(tsqn202211086,ts202208832,tsqnz20221118)the Fundamental Research Funds for the Central Universities(23CX06055A).
文摘Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.
基金supported by the National Key Research and Development Program of China(No.2021YFB3800501)Numerical calculation in this research is supported by the High-Performance Computing Center of Wuhan University of Science and Technology.
文摘Silicon steel is characterized by a high melting point,poor fluidity,and limited wettability,and the process window for the preparation of non-oriented silicon steel ribbons by planar flow casting(PFC)is limited.During the production process,the melt puddle(MP)behavior is a key factor in determining the final quality of ribbons,and the influence mechanism of the airflow boundary layer on the MP behavior and the surface quality of ribbons is still unclear.The effects of wheel speed on the quality of PFC Fe–3.0%Si non-oriented silicon steel ultra-thin ribbons were systematically investigated.Combined with experiments and numerical simulations,the mechanism of different wheel speeds on the behavior of MP and the surface quality of ribbons was analyzed in depth.It is found that when the MP reaches a steady state,the upstream meniscus shows a C-shape,while the downstream meniscus exhibits a sloped shape.During the formation of the MP,the vortex phenomena occur both around and within the MP.With the increase in wheel speed,the thickness of the ribbons gradually decreases from 67 to 31μm.Furthermore,the air vortex on the upstream and downstream meniscus becomes more and more intense,which significantly increases the possibility of air entrapment in the MP and leads to a significant increase in the percentage of air pockets.When the wheel speed is 10–15 m/s,the surface of the ribbon is smooth,the thickness uniformity is better,and there are fewer defects.However,when the wheel speed is more than 15 m/s,the MP’s stability deteriorates,and the ribbons have obvious veining,wrinkles,and uneven thickness.
基金the support provided by the Department of Mechanical Engineering,AAA college of Engineering and Technology,Sivakasi,Tamilnadu,India for facilitating the experimental and characterization facilities required to carry out this research work.
文摘The two distinct types of composite materials(5%to 10%)were developed using recycled polyvinyl alcohol fiber(RPA),silicon nitride fiber(SN),and reduced carbon nanoparticles(RCN).Enhanced microstructural properties and mechanical strength were attained through the application of the 3-glycidoxypropyltrimethoxysilane coupling method.The combination of the resin-like properties of RPA-SN fiber resulted in the formation of robust outer strength and a high bonding structure.RPA-RCN composite materials with a weight percentage of 10%exhibited a tensile strength of 42 MPa.In contrast,RPA-SN-RCN composite materials containing 5%to 10%demonstrated enhanced tensile,bending,and hardness properties.Pyramid structures,solid structures,and crystal phases were formed using RCN particles.The resin and silane properties on hardness were gradually 14%increasing the outside region,whereas RPA-SN-RCN(10 wt%)on average hardness were attained at 86(Shore-D).The microstructures on RPA-RCN(5%to 10%)samples were observed solid structure,twin boundary’s structure and lattice structure.The tensile strength of RPA-SN-RCN(10%)was 67.3MPa,whereas the impact strength of RPA-RCN(10 wt%)was 53 J/mm2.The scanning electron microscopies(SEM)were used to investigate the microstructure of the RPA-SN-RCN(5%)and RPA-SN-RCN(10%)composite materials,respectively.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(RS-2024-00405905)This research was supported by BrainLink program funded by the Ministry of Science and ICT through the National Research Foundation of Korea(RS-2023-00236798)Following are results of a study on the“Busan Regional Innovation System&Education(RISE)”Project,supported by the Ministry of Education and Busan Metropolitan City。
文摘Li metal anodes,with high theoretical capacity(3860 mAh g^(-1))and low redox potential,are promising for high-capacity rechargeable batteries.Especially,ultra-thin Li metal anodes can improve energy density and minimize lithium excess.However,their poor processability leads to non-uniform Li layers and unstable plating/stripping behavior.In this study,we present a current collector interphase(CCI)-based strategy using a Cu foil coated with a lithiophilic Si3N4 layer,followed by molten Li dip-coating to form around 20 lm Li layer.Furthermore,the scalable dip-coating method,compatibility with large-area current collectors(up to 100 cm^(2)),and stable cycling in pouch cells demonstrate the practical viability of the proposed SNLMA design for commercial lithium metal batteries.During the process,an in-situ Li–Si–N alloy gradient interphase forms at the interface,enhancing wettability and mechanical integrity.This unique gradient CCI provides synergistic lithiophilicity and structural stability,enabling high-performance Li metal batteries.The resulting LixSiy and LixNy phases reduce nucleation barriers and enable uniform Li deposition.As a result,the Si3N4–Li anode paired with a high-loading LCO cathode(22 mg cm^(-2))achieved 83%capacity retention after 100 cycles.This work offers a scalable and practical CCI design for next-generation Li metal batteries.
基金funded by the National Science and Technology Council(NSTC),Taiwan,grant number NSTC 114-2218-E-167-001.
文摘Quality control plays a critical role in modern manufacturing.With the rapid development of electric vehicles,5G communications,and the semiconductor industry,high-speed and high-precision detection of surface defects on silicon carbide(SiC)wafers has become essential.This study developed an automated inspection framework for identifying surface defects on SiC wafers during the coarse grinding stage.Thecomplex machining textures on wafer surfaces hinder conventional machine vision models,often leading to misjudgment.To address this,deep learning algorithms were applied for defect classification.Because defects are rare and imbalanced across categories,data augmentation was performed using aWasserstein generative adversarial network with gradient penalty(WGAN-GP),along with conventionalmethods.An improved YOLOv8-seg instance segmentationmodel was then trained and tested on datasets with different augmentation strategies.Experimental results showed that,when trained withWGAN-GP–generated data,YOLOv8-seg achieved mean average precision values of 87.0%(bounding box)and 86.6%(segmentation mask).Compared with the traditional WGAN-GP,the proposed model reduced Frechet inception distance by 32.2%and multiscale structural similarity index by 29.8%,generating more realistic and diverse defect images.The proposed framework effectively improves defect detection accuracy under limited data conditions and shows strong potential for industrial applications.
