Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellen...Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.展开更多
In modern industrial production,foreign object detection in complex environments is crucial to ensure product quality and production safety.Detection systems based on deep-learning image processing algorithms often fa...In modern industrial production,foreign object detection in complex environments is crucial to ensure product quality and production safety.Detection systems based on deep-learning image processing algorithms often face challenges with handling high-resolution images and achieving accurate detection against complex backgrounds.To address these issues,this study employs the PatchCore unsupervised anomaly detection algorithm combined with data augmentation techniques to enhance the system’s generalization capability across varying lighting conditions,viewing angles,and object scales.The proposed method is evaluated in a complex industrial detection scenario involving the bogie of an electric multiple unit(EMU).A dataset consisting of complex backgrounds,diverse lighting conditions,and multiple viewing angles is constructed to validate the performance of the detection system in real industrial environments.Experimental results show that the proposed model achieves an average area under the receiver operating characteristic curve(AUROC)of 0.92 and an average F1 score of 0.85.Combined with data augmentation,the proposed model exhibits improvements in AUROC by 0.06 and F1 score by 0.03,demonstrating enhanced accuracy and robustness for foreign object detection in complex industrial settings.In addition,the effects of key factors on detection performance are systematically analyzed,providing practical guidance for parameter selection in real industrial applications.展开更多
Biopolymeric nanocomposites have attracted considerable attention because of their biocompatibility,biodegradability,and unique physicochemical properties.It is essential to manufacture three-dimensional(3D)biocompati...Biopolymeric nanocomposites have attracted considerable attention because of their biocompatibility,biodegradability,and unique physicochemical properties.It is essential to manufacture three-dimensional(3D)biocompatible micro/nanostructures using biopolymeric nanocomposites.Herein,we demonstrate the high-fidelity fabrication of biocompatible 3D features with sub-50 nm resolution using femtosecond laser direct writing(FsLDW)of a biopolymeric nanocomposite composed of egg white and sulfonated graphene(S-graphene).The biopolymer nanocomposite acts as a negative photoresist suitable for water-based lithography.The introduction of S-graphene not only dramatically lowered the laser power threshold but also significantly modulated the morphology of the 3D features constructed by FsLDW.Microstructures with porous,rough,or smooth morphologies were obtained by optimizing the S-graphene concentration and laser scanning speed.The fabricated egg-white/S-graphene microstructures exhibited biocompatibility and environmental degradability.Egg white/S-graphene was also employed to fabricate diffractive gratings with superior optical quality.This study provides a promising method to manufacture biocompatible 3D features with controllable morphology,which has potential applications in biological and photonic fields.展开更多
Alkali metal thermochemical ablation is a promising anti-tumor therapy in which tumor tissue can be efficiently destroyed via both heat and hydroxyl ions released from the chemical reaction in tissue between an alkali...Alkali metal thermochemical ablation is a promising anti-tumor therapy in which tumor tissue can be efficiently destroyed via both heat and hydroxyl ions released from the chemical reaction in tissue between an alkali metal and water. Encouraging results have been reported from in vitro and in vivo trials in a previous study. However, the precise process of heat and mass transfer triggered by the above thermochemical reaction in tumor tissue has still remained confusing. Here, to better understand the temperature and p H responses of tumor tissue subject to alkali metal therapy, a theoretical model coupling temperature and concentration field is developed for characterizing the physicochemical reaction and the transport process occurring around the inserted sodium capsule during treatment. Preliminary experiments in tumor tissue are performed to validate the theoretical predictions of temperature, and the results indicate that the bioheat transfer model can predict the temperature responses in the tissues heated by the sodium capsule very well. Furthermore, comprehensive parametric studies are performed to evaluate the effects of either physiological or physicochemical parameters, including ablation time, time lags, and blood perfusion rate. Based on the numerical results, useful instructions are suggested for planning alkali metal tumor ablation treatment.展开更多
To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current(HVDC)links and multi-infeed DC systems in load-center regions,this paper proposes a hyb...To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current(HVDC)links and multi-infeed DC systems in load-center regions,this paper proposes a hybrid modular multilevel converter–capacitor-commutated line-commutated converter(MMC-CLCC)HVDC transmission system and its corresponding control strategy.First,the system topology is constructed,and a submodule configuration method for the MMC—combining full-bridge submodules(FBSMs)and half-bridge submodules(HBSMs)—is proposed to enable direct power flow reversal.Second,a hierarchical control strategy is introduced,includingMMCvoltage control,CLCC current control,and a coordinationmechanism,along with the derivation of the hybrid system’s power flow reversal characteristics.Third,leveraging the CLCC’s fast current regulation and theMMC’s negative voltage control capability,a coordinated power flow reversal control strategy is developed.Finally,an 800 kV MMC-CLCC hybrid HVDC system is modeled in PSCAD/EMTDC to validate the power flow reversal performance under a high proportion of full-bridge submodule configuration.Results demonstrate that the proposed control strategy enables rapid(1-s transition)and smooth switching of bidirectional power flow without modifying the structure of primary equipment:the transient fluctuation ofDC voltage from the rated value(UdcN)to themaximumreverse voltage(-kUdcN)is less than 5%;the DC current strictly follows the preset characteristic curve with a deviation of≤3%;the active power reverses continuously,and the system maintains stable operation throughout the reversal process.展开更多
The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution an...The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution and short wavelength.Efficient and compact 193 nm DUV laser source thus becomes a hot research area.Currently,193 nm Ar F excimer gas laser is widely employed in DUV lithography systems and serves as the enabling technology for 7 and 5 nm semiconductor fabrication.展开更多
The spatially-resolved laser-based high resolution angle resolved photoemission spectroscopy(ARPES)measurements have been performed on the optimally-doped HgBa_(2)Ca_(2)Cu_(3)O_(8+δ)(Hg1223)superconductor with a T_(c...The spatially-resolved laser-based high resolution angle resolved photoemission spectroscopy(ARPES)measurements have been performed on the optimally-doped HgBa_(2)Ca_(2)Cu_(3)O_(8+δ)(Hg1223)superconductor with a T_(c) of 133 K.Two distinct regions are identified on the cleaved surface:the single Fermi surface region where only one Fermi surface is observed,and the double Fermi surface region where two Fermi surface sheets are resolved coming from both the inner(IP)and outer(OP)CuO_(2) planes.The electronic structure and superconducting gap are measured on both of these two regions.In both cases,the observed electronic states are mainly concentrated near the nodal region.The momentum dependence of the superconducting gap deviates from the standard d-wave form.These results indicate that the surface electronic structure of Hg1223 behaves more like that of underdoped cuprates.展开更多
Photoelectrochemical CO_(2)reduction to multi-carbon products fuels remains challenged by inefficient C–C coupling and competing proton reduction reaction.Herein,we designed a cationic covalent organic framework(COF+...Photoelectrochemical CO_(2)reduction to multi-carbon products fuels remains challenged by inefficient C–C coupling and competing proton reduction reaction.Herein,we designed a cationic covalent organic framework(COF+)to create an electrostatic microenvironment that synergizes with CuPt alloy nanoparticles for selective ethylene/ethane production.By spatially decoupling CO_(2)enrichment from proton exclusion,the COF^(+)/CuPt interface simultaneously facilitates CO_(2)accessibility while impeding H+migration,suppressing the hydrogen evolution reaction(HER).This unique microenvironment stabilizes key anionic intermediates(*COO^(−),*OCCO^(−))and promotes*CO dimerization,steering electron transfer toward C–C coupling.The optimized system achieves a record-high Faradaic efficiency of 51.5%±5.3%for ethane and 10.6%±2.5%for ethylene with a total C2+yield exceeding 62%at−0.25 V vs.RHE and high stability(>300 min),representing the highest performance for photoelectrochemical CO_(2)reduction to ethane.The combined analyses of in situ spectroscopy and theoretical calculations reveal that electrostatic field effects lower the energy barrier for*OCCO formation while accelerating hydrogenation kinetics.Therefore,this work demonstrates that microenvironment modification of the active site by cationic covalent organic framework is a versatile strategy for solar-driven CO_(2)conversion into value-added hydrocarbons.展开更多
Online Public Opinion Reports consolidate news and social media for timely crisis management by governments and enterprises.While large language models(LLMs)enable automated report generation,this specific domain lack...Online Public Opinion Reports consolidate news and social media for timely crisis management by governments and enterprises.While large language models(LLMs)enable automated report generation,this specific domain lacks formal task definitions and corresponding benchmarks.To bridge this gap,we define the Automated Online Public Opinion Report Generation(OPOR-Gen)task and construct OPOR-Bench,an event-centric dataset with 463 crisis events across 108 countries(comprising 8.8 K news articles and 185 K tweets).To evaluate report quality,we propose OPOR-Eval,a novel agent-based framework that simulates human expert evaluation.Validation experiments show OPOR-Eval achieves a high Spearman’s correlation(ρ=0.70)with human judgments,though challenges in temporal reasoning persist.This work establishes an initial foundation for advancing automated public opinion reporting research.展开更多
Sixty students from both genders aged 19 - 22 years old at College of Technology undertaking halfterm exams of 2012-2013 are encountered in this study. Blood samples were collected twice, i.e. before the exam inside t...Sixty students from both genders aged 19 - 22 years old at College of Technology undertaking halfterm exams of 2012-2013 are encountered in this study. Blood samples were collected twice, i.e. before the exam inside the halls and during the rest time, to compare levels of some hormones, e.g. cortisol from all students, testosterone in male only and both estrogen and progesterone in female students. The female group was further subdivided into two subgroups, 15 each i.e. at the first half of the menstrual cycle (follicular phase) and second group at the second half of the menstrual cycle (luteal phase). The levels of cortisol had significantly (p ≤ 0.05) raised from 12.3 ± 3.6 to 32.3 ± 4.2 ng/mL and from 11.6 ± 1.8 to 31.6 ± 7.3 ng/mL in both male and female students, respectively during exams in comparison with rest times. However, the levels of testosterone had significantly dropped (p ≤ 0.05) from 6.63 ± 1.8 to 2.1 ± 0.4 ng/mL during the test-time. In female students, the levels of both estrogens and progesterone had significantly (p ≤ 0.05) increased, i.e. in follicular from 202 ± 38 to 365 ± 22 and from 64.6 ± 8.0 to 160 ± 37 ng/mL at luteal phases, respectively and from 0.74 ± 0.03 to 1.5 ± 0.04 in follicular and 14.4 ± 2.4 to 29 ± 4.2 ng/mL at luteal phase, respectively in progesterone during the exam in comparison with rest times. These results indicate that all students had sustained stress during the exam-time which might have disturbed the regulation of various hormones in both genders consequently leading to further health effects.展开更多
Vector of diagnostic signs(VDS)using torsional vibration(TV)signal on the main propulsion plant(MPP)is the vector of z maxima(or minima)values of the TV signal in accordance with the cylinder firing orders.The technic...Vector of diagnostic signs(VDS)using torsional vibration(TV)signal on the main propulsion plant(MPP)is the vector of z maxima(or minima)values of the TV signal in accordance with the cylinder firing orders.The technical states of the marine diesel engine(MDE)include R=z+1 classes and are presented in z-dimensional space coordinate of VDS.The presentation of Dk,k=1÷R using z diagnostic signs(Vi,i=1÷z)is nonfigurative and quite complicated.This paper aims to develop a new method for converting VDS from z-dimensional to 2-dimensional space(two-axes)based on the firing orders of the diesel cylinders,as an equivalent geometrical sign of the all diagnostic signs.The proposed model is useful for presenting a technical state Dk in two-dimensional space(x,y)for better visualization.The paper verifies the simulation of the classification illustration of the 7–state classes for the MDE 6S46-MCC,installed on the motor vessel(MV)34000DWT,using the new above mentioned method.The seven technical state classes(for 6-cylinder MDE,z=6)are drawn separately and visually in the Descartes.The received results are valuable to improve smart diagnostic system for analyzing normal/misfire states of cylinders in operation regimes.展开更多
In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypro...In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.展开更多
Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photod...Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photodynamic therapy(a PDT)holds significant potential for selective imaging and photo-inactivation of ICB while minimizing side effects on normal cells.Drawing inspiration from the elevated hypochlorous acid(HClO)levels in ICB infected phagocytes,herein we firstly designed and synthesized a series of HCl Oresponsive dinuclear Ru(Ⅱ)complexes(Ru1-Ru3)to achieve such a goal.Initially,the luminescence,^(1)O_(2)generation and a PDT activity of these Ru(Ⅱ)complexes were suppressed due to the quenching effect of the azo group,but were recovered after reaction with HCl O in solutions or within ICB infected phagocytes.The detailed results revealed that Ru1 and Ru3 could not only selectively visualize ICB,but also demonstrated remarkable a PDT activity against ICB,surpassing vancomycin both in vitro and in vivo.展开更多
Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityh...Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityhinders further applications.Conversely,all-inorganic perovskites possessexcellent thermal stability,but black-phase all-inorganic perovskite filmusually requires high-temperature annealing steps,which increases energy consumptionand is not conducive to the fabrication of flexible wearable devices.In this work,an unprecedented low-temperature fabrication of stable blackphaseCsPbI3perovskite films is demonstrated by the in situ hydrolysis reactionof diphenylphosphinic chloride additive.The released diphenyl phosphateand chloride ions during the hydrolysis reaction significantly lower the phasetransition temperature and effectively passivate the defects in the perovskitefilms,yielding high-performance photodetectors with a responsivity of 42.1 AW−1 and a detectivity of 1.3×10^(14)Jones.Furthermore,high-fidelity imageand photoplethysmography sensors are demonstrated based on the fabricated flexible wearable photodetectors.This work provides a newperspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.展开更多
In this work,iron-doped carbon dots(Fe-CDs)with strong peroxidase-mimicking activity were synthesized for tumor-specific therapy.Their intrinsic red fluorescence enabled high-contrast cellular imaging,revealing prefer...In this work,iron-doped carbon dots(Fe-CDs)with strong peroxidase-mimicking activity were synthesized for tumor-specific therapy.Their intrinsic red fluorescence enabled high-contrast cellular imaging,revealing preferen⁃tial mitochondrial accumulation.In the acidic and hydrogen peroxide(H_(2)O_(2))-rich tumor microenvironment,Fe-CDs catalyzed hydroxyl radical(·OH)generation,inducing oxidative stress and lipid peroxidation,ultimately triggering ferroptosis.In vitro and in vivo studies demonstrated potent tumor inhibition.Furthermore,Fe-CDs exhibited excel⁃lent biocompatibility with no significant systemic toxicity.By integrating fluorescence imaging and catalytic therapy,this study presents a promising nanoplatform for tumor treatment and ferroptosis research.展开更多
Against the backdrop of new quality productivity driving high-quality economic development,this paper examines how technological innovation,digital transformation,and green development reshape the competencies and tra...Against the backdrop of new quality productivity driving high-quality economic development,this paper examines how technological innovation,digital transformation,and green development reshape the competencies and training models of highly skilled talent.It analyzes multidimensional characteristics,including knowledge structure,innovation awareness,digital literacy,and cross-boundary collaboration,revealing a shift towards“innovative,composite,and intelligent”profiles.The study identifies misalignments in current vocational education,such as outdated curricula and insufficient industry-education integration.It proposes innovative training paths,including deep industry-education collaboration,digital-intelligent teaching,and lifelong learning ecosystems.Case studies validate the feasibility of aligning talent development with new quality productivity demands.展开更多
This study delves into both experimental and analytical examinations of heat exchange in a straight channel, where Al_(2)O_(3)-water nanofluids are utilized, spanning the Reynolds number spectrum from 100 to 1800. Div...This study delves into both experimental and analytical examinations of heat exchange in a straight channel, where Al_(2)O_(3)-water nanofluids are utilized, spanning the Reynolds number spectrum from 100 to 1800. Diverse volume fractions(1%, 2%, and 3%) of Al_(2)O_(3)-water nanofluids are meticulously prepared and analyzed. The essential physical properties of these nanofluids, critical for evaluating their thermal and flow characteristics, have been comprehensively assessed. From a quantitative perspective, numerical simulations are employed to predict the Nusselt number(Nu) and friction factor(f). The empirical findings reveal intriguing trends: the friction factor experiences an upward trend with diminishing velocity, attributed to heightened molecular cohesion. Conversely, the friction factor demonstrates a decline with diminishing volume fractions, a consequence of reduced particle size. Both the nanofluid's viscosity and heat transfer coefficient exhibit a rise in tandem with augmented volume flow rate and concentration gradient. Notably, the simulation results harmonize remarkably well with experimental data. Rigorous validation against prior studies underscores the robust consistency of these outcomes. In the pursuit of augmenting heat transfer, a volume fraction of 3% emerges as particularly influential, yielding an impressive 53.8% enhancement. Minor increments in the friction factor, while present, prove negligible and can be safely overlooked.展开更多
In a 5G mobile communication system,cell search is the initial step in establishing downlink synchronization between user equipment(UE)and base stations(BS).Primary synchronization signal(PSS)detection is a crucial pa...In a 5G mobile communication system,cell search is the initial step in establishing downlink synchronization between user equipment(UE)and base stations(BS).Primary synchronization signal(PSS)detection is a crucial part of this process,and enhancing PSS detection speed can reduce communication latency and improve overall quality.This paper proposes a fast PSS detection algorithm based on the correlation characteristics of PSS time-domain superposition signals.Conducting PSS signal correlation within a smaller range can reduce computational complexity and accelerates communication speed.Additionally,frequency offset can impact the accuracy of calculations during the PSS detection process.To address this issue,we propose applying convolutional neural networks(CNN)for frequency offset estimation of synchronization signals.By compensating for the frequency of related signals,the accuracy of PSS detection is improved.Finally,the analysis and simulation results demonstrate the effectiveness of the proposed approach.展开更多
Due to its unique properties,helium is critical in scientific research and industrial innovation,particularly in cryogenics;however,its scarcity necessitates efficient resource utilization.Through a review of the hist...Due to its unique properties,helium is critical in scientific research and industrial innovation,particularly in cryogenics;however,its scarcity necessitates efficient resource utilization.Through a review of the historical development of the helium industry,this study comprehensively evaluates the value,sources,production methods,supply dynamics,and sustainability challenges of helium.The processes and mechanisms of helium enrichment,along with effective exploration methods,are systematically analyzed here.We recommend focusing on the development of technologies for helium preservation,recovery,and extraction,particularly the extraction technology for helium-poor fields.Market analysis indicates that no imminent crisis in the global helium supply is expected before 2060.Thus,enhancing helium resource protection technologies is essential to improve its economic utilization and management while providing a timely reference for the scientific community.展开更多
文摘Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.
文摘In modern industrial production,foreign object detection in complex environments is crucial to ensure product quality and production safety.Detection systems based on deep-learning image processing algorithms often face challenges with handling high-resolution images and achieving accurate detection against complex backgrounds.To address these issues,this study employs the PatchCore unsupervised anomaly detection algorithm combined with data augmentation techniques to enhance the system’s generalization capability across varying lighting conditions,viewing angles,and object scales.The proposed method is evaluated in a complex industrial detection scenario involving the bogie of an electric multiple unit(EMU).A dataset consisting of complex backgrounds,diverse lighting conditions,and multiple viewing angles is constructed to validate the performance of the detection system in real industrial environments.Experimental results show that the proposed model achieves an average area under the receiver operating characteristic curve(AUROC)of 0.92 and an average F1 score of 0.85.Combined with data augmentation,the proposed model exhibits improvements in AUROC by 0.06 and F1 score by 0.03,demonstrating enhanced accuracy and robustness for foreign object detection in complex industrial settings.In addition,the effects of key factors on detection performance are systematically analyzed,providing practical guidance for parameter selection in real industrial applications.
基金financially supported by the National Key Research and Development Program of China(Nos.2024YFB4607402 and 2016YFC1100502)the National Natural Science Foundation of China(Nos.51673208 and 61975213)。
文摘Biopolymeric nanocomposites have attracted considerable attention because of their biocompatibility,biodegradability,and unique physicochemical properties.It is essential to manufacture three-dimensional(3D)biocompatible micro/nanostructures using biopolymeric nanocomposites.Herein,we demonstrate the high-fidelity fabrication of biocompatible 3D features with sub-50 nm resolution using femtosecond laser direct writing(FsLDW)of a biopolymeric nanocomposite composed of egg white and sulfonated graphene(S-graphene).The biopolymer nanocomposite acts as a negative photoresist suitable for water-based lithography.The introduction of S-graphene not only dramatically lowered the laser power threshold but also significantly modulated the morphology of the 3D features constructed by FsLDW.Microstructures with porous,rough,or smooth morphologies were obtained by optimizing the S-graphene concentration and laser scanning speed.The fabricated egg-white/S-graphene microstructures exhibited biocompatibility and environmental degradability.Egg white/S-graphene was also employed to fabricate diffractive gratings with superior optical quality.This study provides a promising method to manufacture biocompatible 3D features with controllable morphology,which has potential applications in biological and photonic fields.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDB1030000)the Beijing United Fund (Grant No.L252063)。
文摘Alkali metal thermochemical ablation is a promising anti-tumor therapy in which tumor tissue can be efficiently destroyed via both heat and hydroxyl ions released from the chemical reaction in tissue between an alkali metal and water. Encouraging results have been reported from in vitro and in vivo trials in a previous study. However, the precise process of heat and mass transfer triggered by the above thermochemical reaction in tumor tissue has still remained confusing. Here, to better understand the temperature and p H responses of tumor tissue subject to alkali metal therapy, a theoretical model coupling temperature and concentration field is developed for characterizing the physicochemical reaction and the transport process occurring around the inserted sodium capsule during treatment. Preliminary experiments in tumor tissue are performed to validate the theoretical predictions of temperature, and the results indicate that the bioheat transfer model can predict the temperature responses in the tissues heated by the sodium capsule very well. Furthermore, comprehensive parametric studies are performed to evaluate the effects of either physiological or physicochemical parameters, including ablation time, time lags, and blood perfusion rate. Based on the numerical results, useful instructions are suggested for planning alkali metal tumor ablation treatment.
基金supported by Science and Technology Project of the headquarters of the State Grid Corporation of China(No.5500-202324492A-3-2-ZN).
文摘To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current(HVDC)links and multi-infeed DC systems in load-center regions,this paper proposes a hybrid modular multilevel converter–capacitor-commutated line-commutated converter(MMC-CLCC)HVDC transmission system and its corresponding control strategy.First,the system topology is constructed,and a submodule configuration method for the MMC—combining full-bridge submodules(FBSMs)and half-bridge submodules(HBSMs)—is proposed to enable direct power flow reversal.Second,a hierarchical control strategy is introduced,includingMMCvoltage control,CLCC current control,and a coordinationmechanism,along with the derivation of the hybrid system’s power flow reversal characteristics.Third,leveraging the CLCC’s fast current regulation and theMMC’s negative voltage control capability,a coordinated power flow reversal control strategy is developed.Finally,an 800 kV MMC-CLCC hybrid HVDC system is modeled in PSCAD/EMTDC to validate the power flow reversal performance under a high proportion of full-bridge submodule configuration.Results demonstrate that the proposed control strategy enables rapid(1-s transition)and smooth switching of bidirectional power flow without modifying the structure of primary equipment:the transient fluctuation ofDC voltage from the rated value(UdcN)to themaximumreverse voltage(-kUdcN)is less than 5%;the DC current strictly follows the preset characteristic curve with a deviation of≤3%;the active power reverses continuously,and the system maintains stable operation throughout the reversal process.
基金supported by the National Natural Science Foundation of China(Grant Nos.62450006,62304217,62274157,62127807,62234011,62034008,62074142,62074140)Tianshan Innovation Team Program(Grant No.2022TSYCTD0005)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0880000)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant Nos.2023124,Y2023032)。
文摘The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution and short wavelength.Efficient and compact 193 nm DUV laser source thus becomes a hot research area.Currently,193 nm Ar F excimer gas laser is widely employed in DUV lithography systems and serves as the enabling technology for 7 and 5 nm semiconductor fabrication.
基金supported by the National Key Research and Development Program of China(Grant Nos.2021YFA1401800,2022YFA1604200,2022YFA1403900,2023YFA1406002,2024YFA1408301 and 2024YFA1408100)the National Natural Science Foun-dation of China(Grant Nos.12488201,12374066,12374154,12494593)+2 种基金Quantum Science and Technology-National Science and Technology Major Project(Grant No.2021ZD0301800)CAS Superconducting Research Project(Grant No.SCZX-0101)the Synergetic Extreme Condition User Facility(SECUF).
文摘The spatially-resolved laser-based high resolution angle resolved photoemission spectroscopy(ARPES)measurements have been performed on the optimally-doped HgBa_(2)Ca_(2)Cu_(3)O_(8+δ)(Hg1223)superconductor with a T_(c) of 133 K.Two distinct regions are identified on the cleaved surface:the single Fermi surface region where only one Fermi surface is observed,and the double Fermi surface region where two Fermi surface sheets are resolved coming from both the inner(IP)and outer(OP)CuO_(2) planes.The electronic structure and superconducting gap are measured on both of these two regions.In both cases,the observed electronic states are mainly concentrated near the nodal region.The momentum dependence of the superconducting gap deviates from the standard d-wave form.These results indicate that the surface electronic structure of Hg1223 behaves more like that of underdoped cuprates.
基金financial support from the National Natural Science Foundation of China(No.52273187)the Guangdong Basic and Applied Basic Research Foundation(2022A1515110372,2023A1515011306,2023A1515240077)+1 种基金the National Key Research and Development Program of China(2022YFA1502900)the Guangdong-Hong Kong Joint Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province(2023B1212120011).
文摘Photoelectrochemical CO_(2)reduction to multi-carbon products fuels remains challenged by inefficient C–C coupling and competing proton reduction reaction.Herein,we designed a cationic covalent organic framework(COF+)to create an electrostatic microenvironment that synergizes with CuPt alloy nanoparticles for selective ethylene/ethane production.By spatially decoupling CO_(2)enrichment from proton exclusion,the COF^(+)/CuPt interface simultaneously facilitates CO_(2)accessibility while impeding H+migration,suppressing the hydrogen evolution reaction(HER).This unique microenvironment stabilizes key anionic intermediates(*COO^(−),*OCCO^(−))and promotes*CO dimerization,steering electron transfer toward C–C coupling.The optimized system achieves a record-high Faradaic efficiency of 51.5%±5.3%for ethane and 10.6%±2.5%for ethylene with a total C2+yield exceeding 62%at−0.25 V vs.RHE and high stability(>300 min),representing the highest performance for photoelectrochemical CO_(2)reduction to ethane.The combined analyses of in situ spectroscopy and theoretical calculations reveal that electrostatic field effects lower the energy barrier for*OCCO formation while accelerating hydrogenation kinetics.Therefore,this work demonstrates that microenvironment modification of the active site by cationic covalent organic framework is a versatile strategy for solar-driven CO_(2)conversion into value-added hydrocarbons.
基金supported by the Fundamental Research Funds for the Central Universities(No.CUC25SG013)the Foundation of Key Laboratory of Education Informatization for Nationalities(Yunnan Normal University),Ministry of Education(No.EIN2024C006).
文摘Online Public Opinion Reports consolidate news and social media for timely crisis management by governments and enterprises.While large language models(LLMs)enable automated report generation,this specific domain lacks formal task definitions and corresponding benchmarks.To bridge this gap,we define the Automated Online Public Opinion Report Generation(OPOR-Gen)task and construct OPOR-Bench,an event-centric dataset with 463 crisis events across 108 countries(comprising 8.8 K news articles and 185 K tweets).To evaluate report quality,we propose OPOR-Eval,a novel agent-based framework that simulates human expert evaluation.Validation experiments show OPOR-Eval achieves a high Spearman’s correlation(ρ=0.70)with human judgments,though challenges in temporal reasoning persist.This work establishes an initial foundation for advancing automated public opinion reporting research.
基金supported by the National Natural Science Foundation of China(U24A2079,22272003,22301013)the Program of Beijing Municipal Education Commission(KZ20231000506)+1 种基金the National Key Research and Development Program of China(2023YFB3810800)the China Postdoctoral Science Foundation(2025M770117,GZC20250088)。
文摘Carbon dots(CDs),as emerging zero-dimensional carbon-based nanomaterials,demonstrate immense potential across optical displays,bioimaging,chemical sensing,information anti-counterfeiting,and optoelectronic devices.This promise stems from their exceptional tunable photoluminescence,low toxicity,biocompatibility,and abundant raw material sources.Since their discovery,research has centered on resolving controversies regarding classification,formation mechanism,microstructure,and luminescence principles while achieving controllable optoelectronic properties.Applications have evolved from basic fluorescent labeling to advanced domains including multimodal theranostics,high-sensitivity(bio/chemical)sensing,stable optoelectronic devices,intelligent anticounterfeiting systems,and environmental/energy catalysis.Future challenges demand breakthroughs in structural homogeneity/scalable eco-fabrication,universal structure-opto/electronic-property models,stability/efficiency in complex environments,and multifunctional synergy(e.g.,photo-electro-catalysis).This comprehensive review systematically examines milestone advances in CDs research over the past decade—spanning synthesis methodologies,photo/electronic property modulation mechanisms,and innovative applications—while dissecting key challenges and envisioning future pathways as versatile intelligent nanoplatforms.
文摘Sixty students from both genders aged 19 - 22 years old at College of Technology undertaking halfterm exams of 2012-2013 are encountered in this study. Blood samples were collected twice, i.e. before the exam inside the halls and during the rest time, to compare levels of some hormones, e.g. cortisol from all students, testosterone in male only and both estrogen and progesterone in female students. The female group was further subdivided into two subgroups, 15 each i.e. at the first half of the menstrual cycle (follicular phase) and second group at the second half of the menstrual cycle (luteal phase). The levels of cortisol had significantly (p ≤ 0.05) raised from 12.3 ± 3.6 to 32.3 ± 4.2 ng/mL and from 11.6 ± 1.8 to 31.6 ± 7.3 ng/mL in both male and female students, respectively during exams in comparison with rest times. However, the levels of testosterone had significantly dropped (p ≤ 0.05) from 6.63 ± 1.8 to 2.1 ± 0.4 ng/mL during the test-time. In female students, the levels of both estrogens and progesterone had significantly (p ≤ 0.05) increased, i.e. in follicular from 202 ± 38 to 365 ± 22 and from 64.6 ± 8.0 to 160 ± 37 ng/mL at luteal phases, respectively and from 0.74 ± 0.03 to 1.5 ± 0.04 in follicular and 14.4 ± 2.4 to 29 ± 4.2 ng/mL at luteal phase, respectively in progesterone during the exam in comparison with rest times. These results indicate that all students had sustained stress during the exam-time which might have disturbed the regulation of various hormones in both genders consequently leading to further health effects.
文摘Vector of diagnostic signs(VDS)using torsional vibration(TV)signal on the main propulsion plant(MPP)is the vector of z maxima(or minima)values of the TV signal in accordance with the cylinder firing orders.The technical states of the marine diesel engine(MDE)include R=z+1 classes and are presented in z-dimensional space coordinate of VDS.The presentation of Dk,k=1÷R using z diagnostic signs(Vi,i=1÷z)is nonfigurative and quite complicated.This paper aims to develop a new method for converting VDS from z-dimensional to 2-dimensional space(two-axes)based on the firing orders of the diesel cylinders,as an equivalent geometrical sign of the all diagnostic signs.The proposed model is useful for presenting a technical state Dk in two-dimensional space(x,y)for better visualization.The paper verifies the simulation of the classification illustration of the 7–state classes for the MDE 6S46-MCC,installed on the motor vessel(MV)34000DWT,using the new above mentioned method.The seven technical state classes(for 6-cylinder MDE,z=6)are drawn separately and visually in the Descartes.The received results are valuable to improve smart diagnostic system for analyzing normal/misfire states of cylinders in operation regimes.
文摘In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.
基金supported by National Natural Science Foundation of China(No.22371289)。
文摘Intracellular bacteria(ICB),cloaked by the protective barriers of host cells,pose a formidable challenge to selective and efficient eradication.The employment of activatable photosensitizers based antibacterial photodynamic therapy(a PDT)holds significant potential for selective imaging and photo-inactivation of ICB while minimizing side effects on normal cells.Drawing inspiration from the elevated hypochlorous acid(HClO)levels in ICB infected phagocytes,herein we firstly designed and synthesized a series of HCl Oresponsive dinuclear Ru(Ⅱ)complexes(Ru1-Ru3)to achieve such a goal.Initially,the luminescence,^(1)O_(2)generation and a PDT activity of these Ru(Ⅱ)complexes were suppressed due to the quenching effect of the azo group,but were recovered after reaction with HCl O in solutions or within ICB infected phagocytes.The detailed results revealed that Ru1 and Ru3 could not only selectively visualize ICB,but also demonstrated remarkable a PDT activity against ICB,surpassing vancomycin both in vitro and in vivo.
基金supported by the National Natural Science Foundation of China(52303257,52321006,T2394480,and T2394484)the National Key R&D Program of China(Grant No.2023YFE0111500)+3 种基金Key Research&Development and Promotion of Special Project(Scientific Problem Tackling)of Henan Province(242102211090)the China Postdoctoral Science Foundation(2023TQ0300,and 2023M743171)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(GZB20230666)College Student Innovation and Entrepreneurship Training Program of Zhengzhou University(202410459200)。
文摘Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityhinders further applications.Conversely,all-inorganic perovskites possessexcellent thermal stability,but black-phase all-inorganic perovskite filmusually requires high-temperature annealing steps,which increases energy consumptionand is not conducive to the fabrication of flexible wearable devices.In this work,an unprecedented low-temperature fabrication of stable blackphaseCsPbI3perovskite films is demonstrated by the in situ hydrolysis reactionof diphenylphosphinic chloride additive.The released diphenyl phosphateand chloride ions during the hydrolysis reaction significantly lower the phasetransition temperature and effectively passivate the defects in the perovskitefilms,yielding high-performance photodetectors with a responsivity of 42.1 AW−1 and a detectivity of 1.3×10^(14)Jones.Furthermore,high-fidelity imageand photoplethysmography sensors are demonstrated based on the fabricated flexible wearable photodetectors.This work provides a newperspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.
文摘In this work,iron-doped carbon dots(Fe-CDs)with strong peroxidase-mimicking activity were synthesized for tumor-specific therapy.Their intrinsic red fluorescence enabled high-contrast cellular imaging,revealing preferen⁃tial mitochondrial accumulation.In the acidic and hydrogen peroxide(H_(2)O_(2))-rich tumor microenvironment,Fe-CDs catalyzed hydroxyl radical(·OH)generation,inducing oxidative stress and lipid peroxidation,ultimately triggering ferroptosis.In vitro and in vivo studies demonstrated potent tumor inhibition.Furthermore,Fe-CDs exhibited excel⁃lent biocompatibility with no significant systemic toxicity.By integrating fluorescence imaging and catalytic therapy,this study presents a promising nanoplatform for tumor treatment and ferroptosis research.
基金Research Project of Humanities and Social Sciences by the Ministry of Education:Exploration on the Reshaping of High-Quality Technical and Skilled Talent Cultivation System for the Development of Emerging Productive Forces(24YJA880042)2024 Vocational Education Theory and Practice Research Support Project Funded by the National Center for Vocational Education Development,Ministry of Education:Research on the Multidimensional Portrayal and Innovative Training Paths of Highly Skilled Talents from the Perspective of New Quality Productivity(JZYY25010)+1 种基金Shanghai Education Scientific Research Project“Special Project of Philosophy and Social Sciences in Universities and Colleges”:Exploration on the Cultivation Path of Integrating the“Scientist Spirit”into the“Three-Dimensional Education”System in Higher Vocational Colleges(2024ZSD023)Research Startup Funding Projects for High-Level and Scarce Talents in Shanghai Electronic and Information Vocational College of Technology(GCC2024016 and GCC2023013)。
文摘Against the backdrop of new quality productivity driving high-quality economic development,this paper examines how technological innovation,digital transformation,and green development reshape the competencies and training models of highly skilled talent.It analyzes multidimensional characteristics,including knowledge structure,innovation awareness,digital literacy,and cross-boundary collaboration,revealing a shift towards“innovative,composite,and intelligent”profiles.The study identifies misalignments in current vocational education,such as outdated curricula and insufficient industry-education integration.It proposes innovative training paths,including deep industry-education collaboration,digital-intelligent teaching,and lifelong learning ecosystems.Case studies validate the feasibility of aligning talent development with new quality productivity demands.
文摘This study delves into both experimental and analytical examinations of heat exchange in a straight channel, where Al_(2)O_(3)-water nanofluids are utilized, spanning the Reynolds number spectrum from 100 to 1800. Diverse volume fractions(1%, 2%, and 3%) of Al_(2)O_(3)-water nanofluids are meticulously prepared and analyzed. The essential physical properties of these nanofluids, critical for evaluating their thermal and flow characteristics, have been comprehensively assessed. From a quantitative perspective, numerical simulations are employed to predict the Nusselt number(Nu) and friction factor(f). The empirical findings reveal intriguing trends: the friction factor experiences an upward trend with diminishing velocity, attributed to heightened molecular cohesion. Conversely, the friction factor demonstrates a decline with diminishing volume fractions, a consequence of reduced particle size. Both the nanofluid's viscosity and heat transfer coefficient exhibit a rise in tandem with augmented volume flow rate and concentration gradient. Notably, the simulation results harmonize remarkably well with experimental data. Rigorous validation against prior studies underscores the robust consistency of these outcomes. In the pursuit of augmenting heat transfer, a volume fraction of 3% emerges as particularly influential, yielding an impressive 53.8% enhancement. Minor increments in the friction factor, while present, prove negligible and can be safely overlooked.
文摘In a 5G mobile communication system,cell search is the initial step in establishing downlink synchronization between user equipment(UE)and base stations(BS).Primary synchronization signal(PSS)detection is a crucial part of this process,and enhancing PSS detection speed can reduce communication latency and improve overall quality.This paper proposes a fast PSS detection algorithm based on the correlation characteristics of PSS time-domain superposition signals.Conducting PSS signal correlation within a smaller range can reduce computational complexity and accelerates communication speed.Additionally,frequency offset can impact the accuracy of calculations during the PSS detection process.To address this issue,we propose applying convolutional neural networks(CNN)for frequency offset estimation of synchronization signals.By compensating for the frequency of related signals,the accuracy of PSS detection is improved.Finally,the analysis and simulation results demonstrate the effectiveness of the proposed approach.
基金the Strategic Pilot Science and Technology Projects of Chinese Academy of Sciences,China(No.XDC10040000).
文摘Due to its unique properties,helium is critical in scientific research and industrial innovation,particularly in cryogenics;however,its scarcity necessitates efficient resource utilization.Through a review of the historical development of the helium industry,this study comprehensively evaluates the value,sources,production methods,supply dynamics,and sustainability challenges of helium.The processes and mechanisms of helium enrichment,along with effective exploration methods,are systematically analyzed here.We recommend focusing on the development of technologies for helium preservation,recovery,and extraction,particularly the extraction technology for helium-poor fields.Market analysis indicates that no imminent crisis in the global helium supply is expected before 2060.Thus,enhancing helium resource protection technologies is essential to improve its economic utilization and management while providing a timely reference for the scientific community.
