The issues of fossil energy shortage and environmental pollution caused by the excessive consumption of conventional fossil fuels necessitates the exploration of renewable and clean energy sources such as hydrogen,whi...The issues of fossil energy shortage and environmental pollution caused by the excessive consumption of conventional fossil fuels necessitates the exploration of renewable and clean energy sources such as hydrogen,which is viable alternative to traditional energy sources in view of its high energy density and nonpolluting nature.In this regard,photocatalytic technology powered by inexhaustible solar energy is an ideal hydrogen production method.The recently developed copper-and zinc-based multinary metal sulfide(MMS)semiconductor photocatalysts exhibit the advantages of suitable bandgap,wide light-harvesting range,and flexible elemental composition,thus possessing great potential for achieving considerable photocatalytic hydrogen evolution(PHE)performance.Despite great progress has been achieved,the current photocatalysts still cannot meet the commercial application demands,which highlights the mechanisms understanding and optimization strategies for efficient PHE.Herein,the basic mechanisms of PHE,and effective optimization strategies are firstly introduced.Afterwards,the research process and the performance of copper-and zinc-based MMS photocatalysts,are thoroughly reviewed.Finally,the unresolved issues,and challenges hindering the achievement of overall water splitting have been discussed.展开更多
Lignin-derived hard carbon shows potential as an anode material for sodium-ion batteries(SIBs)due to its high carbon content and aromatic structure,but its limited reversible adsorption sites and low conductivity hind...Lignin-derived hard carbon shows potential as an anode material for sodium-ion batteries(SIBs)due to its high carbon content and aromatic structure,but its limited reversible adsorption sites and low conductivity hinder performance.This study introduces a self-activation strategy to optimize carbon layer stacking and surface functional groups in microporous carbon,significantly enhancing sodium storage capacity and rate performance.By utilizing oxygen-containing functional groups in organic solvent lignin,we induce micropore formation during pyrolysis,effectively regulating graphite domains and closed pores structures without disrupting carbon layer growth.Unstacked graphene layers serve as efficient electron transport channels and expose additional adsorption sites,simultaneously increasing sodium storage capacity and intrinsic conductivity.The resultant S-OLHC demonstrates a remarkable sodium storage capacity of 358 mA h/g at 0.05 A/g after 200 cycles and maintains 231 mA h/g after 1000 cycles at 2 A/g.This strategy eliminates the need for additional pore-forming agents,offering a simpler,more efficient,and environmentally friendly approach compared to traditional activation methods.This work advances the rational design of high-performance biomass-derived hard carbon for SIBs by leveraging inherent structural characteristics and provides a sustainable low-carbon strategy for lignin valorization in renewable energy storage.展开更多
The realization of high-efficiency photocatalysis is greatly meaningful to overcome the issues of current energy and environment,in which the core factor is the exploration of photocatalysts with promising semiconduct...The realization of high-efficiency photocatalysis is greatly meaningful to overcome the issues of current energy and environment,in which the core factor is the exploration of photocatalysts with promising semiconductor properties.The Cu-based metal sulfide photocatalysts of CuSbS_(2)and its derivative of bournonite CuPbSbS_(3)possess the features of earth-abundant elements,strong photostability,visiblelight range bandgap,and high absorption coefficient,possessing great potential for the realization of efficient photocatalytic applications.Although the photocatalysts of CuSbS_(2)and CuPbSbS_(3)have been investigated in photocatalysis application of hydrogen production and degradation,the exploration process is still in the early-development stage.In this review,the design concept and semiconductor properties of CuSbS_(2)and CuPbSbS_(3)are firstly introduced.Subsequently,the photocatalytic applications of CuSbS_(2)and CuPbSbS_(3)photocatalysts,mainly including hydrogen production and degradation,are systematically reviewed.Finally,the challenges and prospects for the further exploration of CuSbS_(2)and CuPbSbS_(3)photocatalysts are provided.展开更多
Semi-solid forging of iron-based alloys during solidification has unique characteristics distinct from those of the classical hot forging.With the aim of acquiring precise knowledge concerning the microstructural evol...Semi-solid forging of iron-based alloys during solidification has unique characteristics distinct from those of the classical hot forging.With the aim of acquiring precise knowledge concerning the microstructural evolution of bearing steel Cr4 Mo4 V in this process,a series of semi-solid forging experiments were carried out in which samples were wrapped in a designed pure iron sheath.The effects of forging temperature and forging reduction on the grain morphology and liquid flow behavior were investigated,respectively.By forging solidifying metal(FSM),bulky primary dendrites were broken and spheroidal grains with an average shape factor of 0.87 were obtained at 1360?C.With the decreasing forging temperature to 1340?C,the microstructural homogeneity can be improved.On the other hand,it shows that a higher forging reduction(50%)is essential for the spheroidization of grains and elimination of liquid segregation.Those microstructural characteristics are related to different motion mechanisms of solid and liquid phases at different forging temperatures.Additionally,the effect of semi-solid forging on the eutectic carbides was also investigated,and the results demonstrate that the higher diffusion capacity and less liquid segregation jointly lower the large eutectic carbides and consequently cause its uniform distribution during FSM.展开更多
Although CoO is a promising electrode material for supercapacitors due to its high theoretical capacitance,the practical applications still suffering from inferior electrochemical activity owing to its low electrical ...Although CoO is a promising electrode material for supercapacitors due to its high theoretical capacitance,the practical applications still suffering from inferior electrochemical activity owing to its low electrical conductivity,poor structural stability and inefficient nanostructure.Herein,we report a novel Cu0/Cu+co-doped CoO composite with adjustable metallic Cu0 and ion Cu+via a facile strategy.Through interior(Cu+)and exterior(Cu0)decoration of CoO,the electrochemical performance of CoO electrode has been significantly improved due to both the beneficial flower-like nanostructure and the synergetic effect of Cu0/Cu+co-doping,which results in a significantly enhanced specific capacitance(695 F g^(-1) at 1 A g^(-1))and high cyclic stability(93.4%retention over 10,000 cycles)than pristine CoO.Furthermore,this co-doping strategy is also applicable to other transition metal oxide(NiO)with enhanced electrochemical performance.In addition,an asymmetric hybrid supercapacitor was assembled using the Cu0/Cu+co-doped CoO electrode and active carbon,which delivers a remarkable maximal energy density(35 Wh kg^(-1)),exceptional power density(16 kW kg^(-1))and ultralong cycle life(91.5%retention over 10,000 cycles).Theoretical calculations further verify that the co-doping of Cu^(0)/Cu^(+)can tune the electronic structure of CoO and improve the conductivity and electron transport.This study demonstrates a facile and favorable strategy to enhance the electrochemical performance of transition metal oxide electrode materials.展开更多
Detailed three-dimensional(3 D)microtomography characterizations of inclusions in electrode matrix,mushy zone(MZ)and liquid melt film(LMF)were performed to elucidate the motion and removal behavior of inclusions in el...Detailed three-dimensional(3 D)microtomography characterizations of inclusions in electrode matrix,mushy zone(MZ)and liquid melt film(LMF)were performed to elucidate the motion and removal behavior of inclusions in electrode tip during magnetically controlled electroslag remelting(MC-ESR)process.A transient 2 D numerical model was also built to verify the experimental results and proposed mechanisms.The number and size of inclusions exhibited an obvious increasing trend from edge to mid region in LMF,while remained almost the same in electrode matrix and MZ.The inclusions in LMF migrated from edge to mid region of LMF,accompanied with removal process.In addition,the kinetic conditions for inclusion migrating to LMF/slag interface(LSI)were enhanced during MC-ESR process,thereby improving the inclusion removal efficiency in LMF.This work highlights the 3 D characterization and motion/removal mechanisms of inclusions in electrode tip,as well as sheds new light on preparing high purity materials.展开更多
The effect of cerium(Ce)on the solidification microstructure of Cr_(4)Mo_(4)V bearing steel was investigated via a combined experimental and theoretical method.With a trace amount(0.056 wt%)of Ce addition,the coarse c...The effect of cerium(Ce)on the solidification microstructure of Cr_(4)Mo_(4)V bearing steel was investigated via a combined experimental and theoretical method.With a trace amount(0.056 wt%)of Ce addition,the coarse columnar grains in as-cast microstructure transform into equiaxed ones,and the average diameter is reduced from 56 to 27μm.The network-like and bulky primary MC and M2C carbides at the interdendritic regions become disconnected and refined,and their volume percentage decreases from4.15 vol%to 2.1 vol%.Ce-inclusions acting as heterogeneous nucleation agents of prior-austenite grains and Ce atoms segregating at grain boundaries,both contribute to the refinement of grains.Thermodynamic calculations reveal that primary carbides are precipitated afterγ-austenite forms near the end of the solidification process.The modification of primary carbides in size and amount is mainly attributed to the isolated remaining melt separated by refinedγ-austenite grains in which the nucleation of carbides is promoted,while the growth is restrained owing to the less segregation of alloying elements.展开更多
Time series forecasting and analysis are widely used in many fields and application scenarios.Time series historical data reflects the change pattern and trend,which can serve the application and decision in each appl...Time series forecasting and analysis are widely used in many fields and application scenarios.Time series historical data reflects the change pattern and trend,which can serve the application and decision in each application scenario to a certain extent.In this paper,we select the time series prediction problem in the atmospheric environment scenario to start the application research.In terms of data support,we obtain the data of nearly 3500 vehicles in some cities in China fromRunwoda Research Institute,focusing on the major pollutant emission data of non-road mobile machinery and high emission vehicles in Beijing and Bozhou,Anhui Province to build the dataset and conduct the time series prediction analysis experiments on them.This paper proposes a P-gLSTNet model,and uses Autoregressive Integrated Moving Average model(ARIMA),long and short-term memory(LSTM),and Prophet to predict and compare the emissions in the future period.The experiments are validated on four public data sets and one self-collected data set,and the mean absolute error(MAE),root mean square error(RMSE),and mean absolute percentage error(MAPE)are selected as the evaluationmetrics.The experimental results show that the proposed P-gLSTNet fusion model predicts less error,outperforms the backbone method,and is more suitable for the prediction of time-series data in this scenario.展开更多
In this study,we have modeled the sputtering process of energetic He;ions colliding with W nano-fuzz materials,based on the physical processes,such as the collision and diffusion of energetic particles,sputtering and ...In this study,we have modeled the sputtering process of energetic He;ions colliding with W nano-fuzz materials,based on the physical processes,such as the collision and diffusion of energetic particles,sputtering and redeposition.Our modeling shows that the fuzzy nanomaterials with a large surface-to-volume ratio exhibit very high resistance to sputtering under fusion-relevant He;irradiations,and their sputtering yields are mainly determined by the thickness of fuzzy nano0materials,the reflection coefficients and mean free paths of energetic particles,surface sputtering yields of a flat base material,and the geometry of nano-fuzz.Our measurements have confirmed that the surface sputtering yield of a W nano-fuzz layer with the columnar geometry of nano-fuzz in cross-section is about one magnitude of order lower than the one of smooth W substrates.This work provides a complete model for energetic particles colliding with the nano-fuzz layer and clarifies the fundamental sputtering process occurring in the nano-fuzz layer.展开更多
According to the production experience,the author summarizes the cultivation techniques of Qiuyue pear from orchard construction,shaping and pruning,fruit management,underground management,coping with natural disaster...According to the production experience,the author summarizes the cultivation techniques of Qiuyue pear from orchard construction,shaping and pruning,fruit management,underground management,coping with natural disasters,and pest control,in order to provide a reference for producers.展开更多
A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing ...A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing molecular-scale grids(diameter~2.0 nm)allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process.A subsequent activation step produces activated porous carbons(APCs)with tailored pore structures,which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites.Coupled with large specific surface area and abundant heteroatoms,the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor.The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg,which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles.Moreover,this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.展开更多
Antimony selenide(Sb_(2)Se_(3))is an emerging solar cell material.Here,we demonstrate that an organic small molecule of 4,4',4''-tris(carbazol-9-yl)-triphenylamine(TCTA)can efficiently passivate the anode ...Antimony selenide(Sb_(2)Se_(3))is an emerging solar cell material.Here,we demonstrate that an organic small molecule of 4,4',4''-tris(carbazol-9-yl)-triphenylamine(TCTA)can efficiently passivate the anode interface of the Sb_(2)Se_(3)solar cell.We fabricated the device by the vacuum thermal evaporation,and took ITO/TCTA(3.0 nm)/Sb_(2)Se_(3)(50 nm)/C60(5.0 nm)/Alq3(3.0 nm)/Al as the device architecture,where Alq3 is the tris(8-hydroxyquinolinato)aluminum.By introducing a TCTA layer,the open-circuit voltage is raised from 0.36 to 0.42 V,and the power conversion efficiency is significantly improved from 3.2%to 4.3%.The TCTA layer not only inhibits the chemical reaction between the ITO and Sb_(2)Se_(3)during the annealing process but it also blocks the electron diffusion from Sb_(2)Se_(3)to ITO anode.The enhanced performance is mainly attributed to the suppression of the charge recombination at the anode interface.展开更多
Due to the advantages of cost-effectiveness and tunable band gap,hole transport layer(HTL)-free CsPbI_(X)Br_(3-X) carbon-based inorganic perovskite solar cells(C-IPSCs)are emerging candidates for both single junction ...Due to the advantages of cost-effectiveness and tunable band gap,hole transport layer(HTL)-free CsPbI_(X)Br_(3-X) carbon-based inorganic perovskite solar cells(C-IPSCs)are emerging candidates for both single junction and tandem solar cells.Because of the direct contact between the carbon electrode and the perovskite surface,energy barriers and defects at the interface limit the enhancement of power conversion efficiency(PCE).In this work,we first reported a preparation method of CsPbI_(2.75)Br_(0.25) HTL-free C-IPSCs and developed an effective surface sulfidation regulation(SSR)strategy to promote hole extraction and inhibit non-radiative recombination of inorganic perovskite by 2-(thiocyanomethylthio)benzothiazole(TCMTB)surface modification.The introduced S^(2-)anions form strong binding with uncoordinated Pb ions,inhibit the perovskite degradation reaction,and effectively passivate the surface defects.In addition,PbS formed by the SSR strategy constructed a gradient heterojunction,which promoted the arrangement energy levels and enhanced hole extraction.An additional back-surface field is induced at the interface of perovskite by energy band bending,which increases the opencircuit voltage(V_(OC)).As a result,the SSR-based CsPbI_(2.75)Br_(0.25) HTL-free C-IPSCs showed a PCE of 17.88%with a fill factor of 81.56%and V_(OC) of 1.19 V,which was among the highest reported values of CsPbI_(2.75)Br_(0.25) HTL-free C-IPSCs.展开更多
Wormholelike mesoporous carbons (WMCs) with three different pore diameters (D-P), namely WMC-F7 (D-p = 8.5 nm), WMC-F30 (D-p =4.4 nm), and WMC-F0 (D-p =3.1 nm) are prepared via a modified sol-gel process. Then PtRu na...Wormholelike mesoporous carbons (WMCs) with three different pore diameters (D-P), namely WMC-F7 (D-p = 8.5 nm), WMC-F30 (D-p =4.4 nm), and WMC-F0 (D-p =3.1 nm) are prepared via a modified sol-gel process. Then PtRu nanoparticles with the particle size (40 of 3.2 nm supported on WMCs are synthesized with a modified pulse microwave-assisted polyol method. It is found that the pore diameter of WMCs plays an important role in the electrochemical activity of PtRu toward alcohol electrooxidation reaction. PtRu/WMC-F7 with D-p > 2d(pt) exhibits the largest electrochemical surface area (ESA) and the highest activity toward methanol electrooxidation. With the decrease in Dp, PtRu/WMC-F30 and PtRu/WMC-F0 have much lower ESA and electrochemical activity, especially for the isopropanol electrooxidation with a larger molecular size. When D-p is more than twice d(pt), the mass transfer of reactants and electrolyte are easier, and thus more PtRu nanoparticles can be utilized and the catalysts activity can be enhanced. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
This consensus on multiple myeloma-related bone diseases(MBDs)underscores the importance of a multidisciplinary approach that encompasses hematology,radiology,orthopedics,and additional specialties to tackle its intri...This consensus on multiple myeloma-related bone diseases(MBDs)underscores the importance of a multidisciplinary approach that encompasses hematology,radiology,orthopedics,and additional specialties to tackle its intricate challenges.MBD,a prevalent and debilitating complication of multiple myeloma,leads to bone pain,fractures,and skeletal-related events(SREs),which profoundly impact patients’quality of life.The guidelines offer a thorough framework for diagnosis,treatment,and continual assessment,emphasizing early detection and consistent monitoring using imaging techniques such as positron emission tomography-computed tomography(PET-CT)and magnetic resonance imaging(MRI).Treatment strategies prioritize the careful application of antimyeloma agents,bisphosphonates,and denosumab to minimize bone loss and decrease SRE risk,complemented by surgical and radiotherapy interventions for structural or pain-related issues.Supportive care measures,including pain management,rehabilitation,nutritional support,and dental evaluations,play a crucial role in enhancing patient outcomes and preserving quality of life.This consensus advocates a standardized,evidencebased approach to managing MBD,ensuring comprehensive and coordinated care for patients.展开更多
Large language models(LLMs)exhibit remarkable capabilities in various natural language processing tasks,such as machine translation.However,the large number of LLM parameters incurs significant costs during inference....Large language models(LLMs)exhibit remarkable capabilities in various natural language processing tasks,such as machine translation.However,the large number of LLM parameters incurs significant costs during inference.Previous studies have attempted to train translation-tailored LLMs with moderately sized models by fine-tuning them on the translation data.Nevertheless,when performing translations in zero-shot directions that are absent from the fine-tuning data,the problem of ignoring instructions and thus producing translations in the wrong language(i.e.,the off-target translation issue)remains unresolved.In this work,we design a twostage fine-tuning algorithm to improve the instruction-following ability of translation-tailored LLMs,particularly for maintaining accurate translation directions.We first fine-tune LLMs on the translation data to elicit basic translation capabilities.At the second stage,we construct instruction-conficting samples by randomly replacing the instructions with the incorrect ones.Then,we introduce an extra unlikelihood loss to reduce the probability assigned to those samples.Experiments on two benchmarks using the LLaMA 2 and LLaMA 3 models,spanning 16 zero-shot directions,demonstrate that,compared to the competitive baseline translation-finetuned LLaMA,our method could effectively reduce the off-target translation ratio(up to-62.4 percentage points),thus improving translation quality(up to+9.7 bilingual evaluation understudy).Analysis shows that our method can preserve the model's performance on other tasks,such as supervised translation and general tasks.Code is released at https://github.com/alphadl/LanguageAware_Tuning.展开更多
Gemcitabine(Gem)is the gold-standard chemotherapeutic drug for pancreatic cancer therapy in clinic.However,intratumoral bacteria can metabolize Gem into an inactive form,leading to Gem resistance.To address this chall...Gemcitabine(Gem)is the gold-standard chemotherapeutic drug for pancreatic cancer therapy in clinic.However,intratumoral bacteria can metabolize Gem into an inactive form,leading to Gem resistance.To address this challenge,Zn^(2+)-containing nanoparticles(ZGP NPs)are used to eliminate intracellular bacteria to enhance the therapeutic efficacy of Gem in pancreatic therapy.ZGP NPs are prepared via a facile one-pot method using Zn2+,epigallocatechin gallate(EGCG),and polyethylene glycol(PEG),which prevents metal ion chelation by proteins and ensures antibacterial activity.Leveraging the pH-responsive disassembly of metal-phenolic networks,ZGP NPs can be degraded in acidic lysosomes after cellular uptake,releasing Zn^(2+)to eliminate intracellular bacteria and thereby protecting Gem from bacteria-mediated inactivation.Moreover,the elimination of intratumoral bacteria enhances immunotherapy.The delivery of Zn^(2+)via ZGP NPs presents a promising strategy to eliminate intratumoral bacteria to overcome Gem resistance in pancreatic cancer therapy.展开更多
Few-shot classification models trained with clean samples poorly classify samples from the real world with various scales of noise.To enhance the model for recognizing noisy samples,researchers usually utilize data au...Few-shot classification models trained with clean samples poorly classify samples from the real world with various scales of noise.To enhance the model for recognizing noisy samples,researchers usually utilize data augmentation or use noisy samples generated by adversarial training for model training.However,existing methods still have problems:(i)The effects of data augmentation on the robustness of the model are limited.(ii)The noise generated by adversarial training usually causes overfitting and reduces the generalization ability of the model,which is very significant for few-shot classification.(iii)Most existing methods cannot adaptively generate appropriate noise.Given the above three points,this paper proposes a noise-robust few-shot classification algorithm,VADA—Variational Adversarial Data Augmentation.Unlike existing methods,VADA utilizes a variational noise generator to generate an adaptive noise distribution according to different samples based on adversarial learning,and optimizes the generator by minimizing the expectation of the empirical risk.Applying VADA during training can make few-shot classification more robust against noisy data,while retaining generalization ability.In this paper,we utilize FEAT and ProtoNet as baseline models,and accuracy is verified on several common few-shot classification datasets,including MiniImageNet,TieredImageNet,and CUB.After training with VADA,the classification accuracy of the models increases for samples with various scales of noise.展开更多
文摘The issues of fossil energy shortage and environmental pollution caused by the excessive consumption of conventional fossil fuels necessitates the exploration of renewable and clean energy sources such as hydrogen,which is viable alternative to traditional energy sources in view of its high energy density and nonpolluting nature.In this regard,photocatalytic technology powered by inexhaustible solar energy is an ideal hydrogen production method.The recently developed copper-and zinc-based multinary metal sulfide(MMS)semiconductor photocatalysts exhibit the advantages of suitable bandgap,wide light-harvesting range,and flexible elemental composition,thus possessing great potential for achieving considerable photocatalytic hydrogen evolution(PHE)performance.Despite great progress has been achieved,the current photocatalysts still cannot meet the commercial application demands,which highlights the mechanisms understanding and optimization strategies for efficient PHE.Herein,the basic mechanisms of PHE,and effective optimization strategies are firstly introduced.Afterwards,the research process and the performance of copper-and zinc-based MMS photocatalysts,are thoroughly reviewed.Finally,the unresolved issues,and challenges hindering the achievement of overall water splitting have been discussed.
基金supported by the National Natural Science Foundation of China(22278155,U23A6005)。
文摘Lignin-derived hard carbon shows potential as an anode material for sodium-ion batteries(SIBs)due to its high carbon content and aromatic structure,but its limited reversible adsorption sites and low conductivity hinder performance.This study introduces a self-activation strategy to optimize carbon layer stacking and surface functional groups in microporous carbon,significantly enhancing sodium storage capacity and rate performance.By utilizing oxygen-containing functional groups in organic solvent lignin,we induce micropore formation during pyrolysis,effectively regulating graphite domains and closed pores structures without disrupting carbon layer growth.Unstacked graphene layers serve as efficient electron transport channels and expose additional adsorption sites,simultaneously increasing sodium storage capacity and intrinsic conductivity.The resultant S-OLHC demonstrates a remarkable sodium storage capacity of 358 mA h/g at 0.05 A/g after 200 cycles and maintains 231 mA h/g after 1000 cycles at 2 A/g.This strategy eliminates the need for additional pore-forming agents,offering a simpler,more efficient,and environmentally friendly approach compared to traditional activation methods.This work advances the rational design of high-performance biomass-derived hard carbon for SIBs by leveraging inherent structural characteristics and provides a sustainable low-carbon strategy for lignin valorization in renewable energy storage.
基金supported by the National Natural Science Foundation of China(Nos.22109034,22109035,52164028,62105083,22202053,52304326,22309037,22305055,52362010)the Startup Research Foundation of Hainan University(Nos.KYQD(ZR)20008,20082,20083,20084,21065,21124,21125)+3 种基金the Innovative Research Projects for Graduate Students of Hainan Province(No.Qhyb2023-20)the Collaborative Innovation Center of Marine Science and Technology of Hainan University(No.XTCX2022HYC21)the first batch of“Nanhai New Star”Industrial Innovation Talent Platform Project(No.NHXXRCXM202309006)the specific research fund of The Innovation Platform for Academicians of Hainan Province。
文摘The realization of high-efficiency photocatalysis is greatly meaningful to overcome the issues of current energy and environment,in which the core factor is the exploration of photocatalysts with promising semiconductor properties.The Cu-based metal sulfide photocatalysts of CuSbS_(2)and its derivative of bournonite CuPbSbS_(3)possess the features of earth-abundant elements,strong photostability,visiblelight range bandgap,and high absorption coefficient,possessing great potential for the realization of efficient photocatalytic applications.Although the photocatalysts of CuSbS_(2)and CuPbSbS_(3)have been investigated in photocatalysis application of hydrogen production and degradation,the exploration process is still in the early-development stage.In this review,the design concept and semiconductor properties of CuSbS_(2)and CuPbSbS_(3)are firstly introduced.Subsequently,the photocatalytic applications of CuSbS_(2)and CuPbSbS_(3)photocatalysts,mainly including hydrogen production and degradation,are systematically reviewed.Finally,the challenges and prospects for the further exploration of CuSbS_(2)and CuPbSbS_(3)photocatalysts are provided.
基金supported financially by the National Key Research and Development Program(No.2018YFA0702900)the National Natural Science Foundation of China(Nos.U1508215,51774265 and 51701225)+3 种基金the National Science and Technology Major Project of China(No.2019ZX06004010)the Key Program of the Chinese Academy of Sciences(No.ZDRW-CN-2017-1)the Program of CAS Interdisciplinary Innovation TeamGleeble engineer Jiajun He for her technical support in superhot experiments.
文摘Semi-solid forging of iron-based alloys during solidification has unique characteristics distinct from those of the classical hot forging.With the aim of acquiring precise knowledge concerning the microstructural evolution of bearing steel Cr4 Mo4 V in this process,a series of semi-solid forging experiments were carried out in which samples were wrapped in a designed pure iron sheath.The effects of forging temperature and forging reduction on the grain morphology and liquid flow behavior were investigated,respectively.By forging solidifying metal(FSM),bulky primary dendrites were broken and spheroidal grains with an average shape factor of 0.87 were obtained at 1360?C.With the decreasing forging temperature to 1340?C,the microstructural homogeneity can be improved.On the other hand,it shows that a higher forging reduction(50%)is essential for the spheroidization of grains and elimination of liquid segregation.Those microstructural characteristics are related to different motion mechanisms of solid and liquid phases at different forging temperatures.Additionally,the effect of semi-solid forging on the eutectic carbides was also investigated,and the results demonstrate that the higher diffusion capacity and less liquid segregation jointly lower the large eutectic carbides and consequently cause its uniform distribution during FSM.
基金financially supported by the National Science Foundation of China(Grant No.11804106)。
文摘Although CoO is a promising electrode material for supercapacitors due to its high theoretical capacitance,the practical applications still suffering from inferior electrochemical activity owing to its low electrical conductivity,poor structural stability and inefficient nanostructure.Herein,we report a novel Cu0/Cu+co-doped CoO composite with adjustable metallic Cu0 and ion Cu+via a facile strategy.Through interior(Cu+)and exterior(Cu0)decoration of CoO,the electrochemical performance of CoO electrode has been significantly improved due to both the beneficial flower-like nanostructure and the synergetic effect of Cu0/Cu+co-doping,which results in a significantly enhanced specific capacitance(695 F g^(-1) at 1 A g^(-1))and high cyclic stability(93.4%retention over 10,000 cycles)than pristine CoO.Furthermore,this co-doping strategy is also applicable to other transition metal oxide(NiO)with enhanced electrochemical performance.In addition,an asymmetric hybrid supercapacitor was assembled using the Cu0/Cu+co-doped CoO electrode and active carbon,which delivers a remarkable maximal energy density(35 Wh kg^(-1)),exceptional power density(16 kW kg^(-1))and ultralong cycle life(91.5%retention over 10,000 cycles).Theoretical calculations further verify that the co-doping of Cu^(0)/Cu^(+)can tune the electronic structure of CoO and improve the conductivity and electron transport.This study demonstrates a facile and favorable strategy to enhance the electrochemical performance of transition metal oxide electrode materials.
基金the financial support of the National Key Research and Development Program of China(Nos.2016YFB0300401,2018YFF0109404 and 2016YFB0301401)the National Natural Science Foundation of China(Nos.U1860202,U1732276,50134010,51704193,51904184 and 52004156)+1 种基金the Science and Technology Commission of Shanghai Municipality(Nos.13JC14025000 and 15520711000)the China Postdoctoral Science Foundation(No.2020M671072)。
文摘Detailed three-dimensional(3 D)microtomography characterizations of inclusions in electrode matrix,mushy zone(MZ)and liquid melt film(LMF)were performed to elucidate the motion and removal behavior of inclusions in electrode tip during magnetically controlled electroslag remelting(MC-ESR)process.A transient 2 D numerical model was also built to verify the experimental results and proposed mechanisms.The number and size of inclusions exhibited an obvious increasing trend from edge to mid region in LMF,while remained almost the same in electrode matrix and MZ.The inclusions in LMF migrated from edge to mid region of LMF,accompanied with removal process.In addition,the kinetic conditions for inclusion migrating to LMF/slag interface(LSI)were enhanced during MC-ESR process,thereby improving the inclusion removal efficiency in LMF.This work highlights the 3 D characterization and motion/removal mechanisms of inclusions in electrode tip,as well as sheds new light on preparing high purity materials.
基金Project supported by the National Natural Science Foundation of China(52031013,52173305,52233017)the National Key Research and Development Program(2018YFA0702900)。
文摘The effect of cerium(Ce)on the solidification microstructure of Cr_(4)Mo_(4)V bearing steel was investigated via a combined experimental and theoretical method.With a trace amount(0.056 wt%)of Ce addition,the coarse columnar grains in as-cast microstructure transform into equiaxed ones,and the average diameter is reduced from 56 to 27μm.The network-like and bulky primary MC and M2C carbides at the interdendritic regions become disconnected and refined,and their volume percentage decreases from4.15 vol%to 2.1 vol%.Ce-inclusions acting as heterogeneous nucleation agents of prior-austenite grains and Ce atoms segregating at grain boundaries,both contribute to the refinement of grains.Thermodynamic calculations reveal that primary carbides are precipitated afterγ-austenite forms near the end of the solidification process.The modification of primary carbides in size and amount is mainly attributed to the isolated remaining melt separated by refinedγ-austenite grains in which the nucleation of carbides is promoted,while the growth is restrained owing to the less segregation of alloying elements.
基金the Beijing Chaoyang District Collaborative Innovation Project(No.CYXT2013)the subject support of Beijing Municipal Science and Technology Key R&D Program-Capital Blue Sky Action Cultivation Project(Z19110900910000)+1 种基金“Research and Demonstration ofHigh Emission Vehicle Monitoring Equipment System Based on Sensor Integration Technology”(Z19110000911003)This work was supported by the Academic Research Projects of Beijing Union University(No.ZK80202103).
文摘Time series forecasting and analysis are widely used in many fields and application scenarios.Time series historical data reflects the change pattern and trend,which can serve the application and decision in each application scenario to a certain extent.In this paper,we select the time series prediction problem in the atmospheric environment scenario to start the application research.In terms of data support,we obtain the data of nearly 3500 vehicles in some cities in China fromRunwoda Research Institute,focusing on the major pollutant emission data of non-road mobile machinery and high emission vehicles in Beijing and Bozhou,Anhui Province to build the dataset and conduct the time series prediction analysis experiments on them.This paper proposes a P-gLSTNet model,and uses Autoregressive Integrated Moving Average model(ARIMA),long and short-term memory(LSTM),and Prophet to predict and compare the emissions in the future period.The experiments are validated on four public data sets and one self-collected data set,and the mean absolute error(MAE),root mean square error(RMSE),and mean absolute percentage error(MAPE)are selected as the evaluationmetrics.The experimental results show that the proposed P-gLSTNet fusion model predicts less error,outperforms the backbone method,and is more suitable for the prediction of time-series data in this scenario.
基金supported by the National Key R&D Program of China(No.2017YFE0300106)National Natural Science Foundation of China(No.11320101005)+1 种基金Liaoning Provincial Natural Science Foundation(Nos.20180510006,2019-ZD0186)Natural Science Basis Research Program of Shanxi Province(No.2020GY-268)。
文摘In this study,we have modeled the sputtering process of energetic He;ions colliding with W nano-fuzz materials,based on the physical processes,such as the collision and diffusion of energetic particles,sputtering and redeposition.Our modeling shows that the fuzzy nanomaterials with a large surface-to-volume ratio exhibit very high resistance to sputtering under fusion-relevant He;irradiations,and their sputtering yields are mainly determined by the thickness of fuzzy nano0materials,the reflection coefficients and mean free paths of energetic particles,surface sputtering yields of a flat base material,and the geometry of nano-fuzz.Our measurements have confirmed that the surface sputtering yield of a W nano-fuzz layer with the columnar geometry of nano-fuzz in cross-section is about one magnitude of order lower than the one of smooth W substrates.This work provides a complete model for energetic particles colliding with the nano-fuzz layer and clarifies the fundamental sputtering process occurring in the nano-fuzz layer.
文摘According to the production experience,the author summarizes the cultivation techniques of Qiuyue pear from orchard construction,shaping and pruning,fruit management,underground management,coping with natural disasters,and pest control,in order to provide a reference for producers.
基金financial support from National Natural Science Foundation of China(Nos.51902222,51603142,U1610255)Key Laboratory of Yarn Materials Forming and Composite Processing Technology,Zhejiang Province(No.MTC2019-03)+2 种基金Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(Nos.2019L0164 and 2019L0255)the Shanxi Provincial Key Innovative Research Team in Science and Technology(Nos.2015013002-10 and 201605D131045-10)Key R&D Program of Shanxi Province(International Cooperation,No.201903D421077)。
文摘A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing molecular-scale grids(diameter~2.0 nm)allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process.A subsequent activation step produces activated porous carbons(APCs)with tailored pore structures,which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites.Coupled with large specific surface area and abundant heteroatoms,the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor.The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg,which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles.Moreover,this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.
基金This work was supported by the High Level Talents Project Fund of Hainan Basic and Applied Research Program(NATURAL SCIENCE)(Grant No.2019RC118).
文摘Antimony selenide(Sb_(2)Se_(3))is an emerging solar cell material.Here,we demonstrate that an organic small molecule of 4,4',4''-tris(carbazol-9-yl)-triphenylamine(TCTA)can efficiently passivate the anode interface of the Sb_(2)Se_(3)solar cell.We fabricated the device by the vacuum thermal evaporation,and took ITO/TCTA(3.0 nm)/Sb_(2)Se_(3)(50 nm)/C60(5.0 nm)/Alq3(3.0 nm)/Al as the device architecture,where Alq3 is the tris(8-hydroxyquinolinato)aluminum.By introducing a TCTA layer,the open-circuit voltage is raised from 0.36 to 0.42 V,and the power conversion efficiency is significantly improved from 3.2%to 4.3%.The TCTA layer not only inhibits the chemical reaction between the ITO and Sb_(2)Se_(3)during the annealing process but it also blocks the electron diffusion from Sb_(2)Se_(3)to ITO anode.The enhanced performance is mainly attributed to the suppression of the charge recombination at the anode interface.
基金National Natural Science Foundation of China,Grant/Award Number:22005013。
文摘Due to the advantages of cost-effectiveness and tunable band gap,hole transport layer(HTL)-free CsPbI_(X)Br_(3-X) carbon-based inorganic perovskite solar cells(C-IPSCs)are emerging candidates for both single junction and tandem solar cells.Because of the direct contact between the carbon electrode and the perovskite surface,energy barriers and defects at the interface limit the enhancement of power conversion efficiency(PCE).In this work,we first reported a preparation method of CsPbI_(2.75)Br_(0.25) HTL-free C-IPSCs and developed an effective surface sulfidation regulation(SSR)strategy to promote hole extraction and inhibit non-radiative recombination of inorganic perovskite by 2-(thiocyanomethylthio)benzothiazole(TCMTB)surface modification.The introduced S^(2-)anions form strong binding with uncoordinated Pb ions,inhibit the perovskite degradation reaction,and effectively passivate the surface defects.In addition,PbS formed by the SSR strategy constructed a gradient heterojunction,which promoted the arrangement energy levels and enhanced hole extraction.An additional back-surface field is induced at the interface of perovskite by energy band bending,which increases the opencircuit voltage(V_(OC)).As a result,the SSR-based CsPbI_(2.75)Br_(0.25) HTL-free C-IPSCs showed a PCE of 17.88%with a fill factor of 81.56%and V_(OC) of 1.19 V,which was among the highest reported values of CsPbI_(2.75)Br_(0.25) HTL-free C-IPSCs.
基金supported by the National Natural Science Foundation of China (no. 91434106)
文摘Wormholelike mesoporous carbons (WMCs) with three different pore diameters (D-P), namely WMC-F7 (D-p = 8.5 nm), WMC-F30 (D-p =4.4 nm), and WMC-F0 (D-p =3.1 nm) are prepared via a modified sol-gel process. Then PtRu nanoparticles with the particle size (40 of 3.2 nm supported on WMCs are synthesized with a modified pulse microwave-assisted polyol method. It is found that the pore diameter of WMCs plays an important role in the electrochemical activity of PtRu toward alcohol electrooxidation reaction. PtRu/WMC-F7 with D-p > 2d(pt) exhibits the largest electrochemical surface area (ESA) and the highest activity toward methanol electrooxidation. With the decrease in Dp, PtRu/WMC-F30 and PtRu/WMC-F0 have much lower ESA and electrochemical activity, especially for the isopropanol electrooxidation with a larger molecular size. When D-p is more than twice d(pt), the mass transfer of reactants and electrolyte are easier, and thus more PtRu nanoparticles can be utilized and the catalysts activity can be enhanced. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
文摘This consensus on multiple myeloma-related bone diseases(MBDs)underscores the importance of a multidisciplinary approach that encompasses hematology,radiology,orthopedics,and additional specialties to tackle its intricate challenges.MBD,a prevalent and debilitating complication of multiple myeloma,leads to bone pain,fractures,and skeletal-related events(SREs),which profoundly impact patients’quality of life.The guidelines offer a thorough framework for diagnosis,treatment,and continual assessment,emphasizing early detection and consistent monitoring using imaging techniques such as positron emission tomography-computed tomography(PET-CT)and magnetic resonance imaging(MRI).Treatment strategies prioritize the careful application of antimyeloma agents,bisphosphonates,and denosumab to minimize bone loss and decrease SRE risk,complemented by surgical and radiotherapy interventions for structural or pain-related issues.Supportive care measures,including pain management,rehabilitation,nutritional support,and dental evaluations,play a crucial role in enhancing patient outcomes and preserving quality of life.This consensus advocates a standardized,evidencebased approach to managing MBD,ensuring comprehensive and coordinated care for patients.
基金Project supported by the National Natural Science Foundation of China(No.62372468)the Shandong Natural Science Foundation(No.ZR2023MF008)+1 种基金the Major Basic Research Projects in Shandong Province(No.ZR2023ZD32)the Qingdao Natural Science Foundation(No.23-2-1-161-zyyd-jch)。
文摘Large language models(LLMs)exhibit remarkable capabilities in various natural language processing tasks,such as machine translation.However,the large number of LLM parameters incurs significant costs during inference.Previous studies have attempted to train translation-tailored LLMs with moderately sized models by fine-tuning them on the translation data.Nevertheless,when performing translations in zero-shot directions that are absent from the fine-tuning data,the problem of ignoring instructions and thus producing translations in the wrong language(i.e.,the off-target translation issue)remains unresolved.In this work,we design a twostage fine-tuning algorithm to improve the instruction-following ability of translation-tailored LLMs,particularly for maintaining accurate translation directions.We first fine-tune LLMs on the translation data to elicit basic translation capabilities.At the second stage,we construct instruction-conficting samples by randomly replacing the instructions with the incorrect ones.Then,we introduce an extra unlikelihood loss to reduce the probability assigned to those samples.Experiments on two benchmarks using the LLaMA 2 and LLaMA 3 models,spanning 16 zero-shot directions,demonstrate that,compared to the competitive baseline translation-finetuned LLaMA,our method could effectively reduce the off-target translation ratio(up to-62.4 percentage points),thus improving translation quality(up to+9.7 bilingual evaluation understudy).Analysis shows that our method can preserve the model's performance on other tasks,such as supervised translation and general tasks.Code is released at https://github.com/alphadl/LanguageAware_Tuning.
基金the National Natural Science Foundation of China(Nos.52473152,and 52273154)the Key Project of Natural Science Foundation of Zhejiang Province(No.LZ23B040002)is gratefully acknowledged.
文摘Gemcitabine(Gem)is the gold-standard chemotherapeutic drug for pancreatic cancer therapy in clinic.However,intratumoral bacteria can metabolize Gem into an inactive form,leading to Gem resistance.To address this challenge,Zn^(2+)-containing nanoparticles(ZGP NPs)are used to eliminate intracellular bacteria to enhance the therapeutic efficacy of Gem in pancreatic therapy.ZGP NPs are prepared via a facile one-pot method using Zn2+,epigallocatechin gallate(EGCG),and polyethylene glycol(PEG),which prevents metal ion chelation by proteins and ensures antibacterial activity.Leveraging the pH-responsive disassembly of metal-phenolic networks,ZGP NPs can be degraded in acidic lysosomes after cellular uptake,releasing Zn^(2+)to eliminate intracellular bacteria and thereby protecting Gem from bacteria-mediated inactivation.Moreover,the elimination of intratumoral bacteria enhances immunotherapy.The delivery of Zn^(2+)via ZGP NPs presents a promising strategy to eliminate intratumoral bacteria to overcome Gem resistance in pancreatic cancer therapy.
基金supported by Yunnan Provincial Major Science and Technology Special Plan Projects(202202AD080003)the Natural Science Foundation of Shandong Province(ZR2022MD090).
文摘Few-shot classification models trained with clean samples poorly classify samples from the real world with various scales of noise.To enhance the model for recognizing noisy samples,researchers usually utilize data augmentation or use noisy samples generated by adversarial training for model training.However,existing methods still have problems:(i)The effects of data augmentation on the robustness of the model are limited.(ii)The noise generated by adversarial training usually causes overfitting and reduces the generalization ability of the model,which is very significant for few-shot classification.(iii)Most existing methods cannot adaptively generate appropriate noise.Given the above three points,this paper proposes a noise-robust few-shot classification algorithm,VADA—Variational Adversarial Data Augmentation.Unlike existing methods,VADA utilizes a variational noise generator to generate an adaptive noise distribution according to different samples based on adversarial learning,and optimizes the generator by minimizing the expectation of the empirical risk.Applying VADA during training can make few-shot classification more robust against noisy data,while retaining generalization ability.In this paper,we utilize FEAT and ProtoNet as baseline models,and accuracy is verified on several common few-shot classification datasets,including MiniImageNet,TieredImageNet,and CUB.After training with VADA,the classification accuracy of the models increases for samples with various scales of noise.
