Mg-based hydrogen storage materials have attracted much attention due to their high hydrogen content,abundant resources,and environmental friendliness.However,the high dehydrogenation temperature,slow kinetics and poo...Mg-based hydrogen storage materials have attracted much attention due to their high hydrogen content,abundant resources,and environmental friendliness.However,the high dehydrogenation temperature,slow kinetics and poor cycling stability are limiting its practical application.This work demonstrates the improved dehydrogenation kinetics and cycling stability of MgH_(2) modified by a hybrid of metallic Ni and layered MoS_(2)(denoted as“Ni-MoS_(2)”)introduced by ball milling,with Ni as the catalyst for MgH_(2) and MoS_(2) as the support for both Ni and MgH_(2).The onset dehydrogenation temperature of MgH_(2) is reduced to 198℃,and the rehydrogenation begins at a low temperature of 50℃.The MgH_(2)+10 wt%Ni-MoS_(2) composite has a fast dehydrogenation kinetics and can release 6.1 wt% hydrogen in 10 min at a constant temperature of 300℃,with the dehydrogenation activation energy significantly reduced from 151 to 85 kJ mol^(-1).During the cycling,the reversible capacity of the composite first exhibits a gradual increase for the initial 22 cycles and then maintains at 6.1 wt% from the 23th cycle to the 50th cycle.The Ni/MoS_(2) addition does not change the overall thermodynamic properties of MgH_(2) but can weaken the Mg-H bonds in the local regions as evident by theoretical calculation.Microstructure studies reveal that the metallic Ni will react with MgH_(2) to form Mg_(2)NiH_(0.3),which can act as a hydrogen pump,while the layered MoS_(2) serves as a support for the well dispersion of MgH_(2) and Ni.It is believed that the synergy of Mg_(2)NiH_(0.3) and layered MoS_(2) contributes to the significantly enhanced hydrogen storage of MgH_(2).This work provides a promising and simple strategy for enhancing the Mg-based hydrogen storage materials by combination of transition metals and layered materials introduced via simple ball milling.展开更多
As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather tha...As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).展开更多
CD5-positive(CD5+)diffuse large B-cell lymphoma(DLBCL)represents a special subgroup of DLBCL with a more aggressive disease course and is more likely to develop into relapsed/refractory(r/r)DLBCL in response to immuno...CD5-positive(CD5+)diffuse large B-cell lymphoma(DLBCL)represents a special subgroup of DLBCL with a more aggressive disease course and is more likely to develop into relapsed/refractory(r/r)DLBCL in response to immunochemotherapy.The incidence of CD5+DLBCL is 5%–10%among DLBCL patients1.展开更多
Objective:This study aimed to determine the correlation between the incidence of acute mountain sickness(AMS)and the body constitution of Tibetan medicine and other relevant factors to provide a reference for the pred...Objective:This study aimed to determine the correlation between the incidence of acute mountain sickness(AMS)and the body constitution of Tibetan medicine and other relevant factors to provide a reference for the prediction and prevention of AMS.Methods:A caseecontrol study was conducted to recruit participants who experienced or did not experience AMS after entering a plateau.The data was collected through online questionnaires for convenient sampling.Demographic characteristics,body constitution,and related states or behaviors were investigated before and after entering the plateau.The participants were divided into case and control groups based on the incidence of AMS.The distributions of relevant factors were compared.Binary logistic regression analysis was used to screen for risk and protective factors.Results:There were 167 participants who completed the questionnaire.A total of 54 cases were excluded,and 113 participants were included,including 52 in the case group and 61 in the control group.In the case group,37,13,and 2 patients had mild,moderate,and severe AMS,respectively.In terms of the Tibetan medicine constitution,the case group had the highest proportion of Bad-rlung(25.0%)and Rlung types(21.2%),whereas the control group had the highest proportion of Bad-rlung(29.5%)and Mkhrisbad types(24.6%).There was no significant difference in the distribution of the constitutional types between the two groups.Insomnia or insufficient sleep within the week prior to entering the plateau and fatigue after arrival were risk factors for AMS,with odds ratios(OR)and 95%confidence intervals(CI)of 5.012(1.871e13.426)and 3.387(1.393e8.236),respectively.A history of short-term plateau travel is a protective factor for AMS(OR:0.32,95%CI:0.129 to 0.792).Conclusion:Insomnia or lack of sleep before ascending to a plateau and fatigue after arrival are risk factors for AMS.The Rlung constitution might be related to the incidence of AMS;however,this still needs to be verified in large-sample observational studies.The risk factors identified in this study can provide a reference for the prevention practice and research of AMS.展开更多
Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compar...Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compared with conventional radiotherapy(CONV-RT)]in an extremely short time.This novel irradiation technique shows a protective effect on normal tissues,also known as the flash effect.At the same time,FLASH-RT is comparable to CONV-RT in terms of tumorkilling efficacy.As basic research dedicates to uncover the mechanisms by which FLASH-RT reduces radiation-induced normal tissue damage,clinical trials of FLASH-RT have been gradually conducted worldwide.This article systematically reviews the evidence of the feasibility and safety of FLASH-RT in clinical practice and offers insights into the future translation of this technology in clinic.展开更多
Ice shelves are important passageways for ice sheets flowing into the ocean.Through iceberg calving and basal melting,ice shelves exert considerable influence on the mass balance of the Antarctic Ice Sheet and glacier...Ice shelves are important passageways for ice sheets flowing into the ocean.Through iceberg calving and basal melting,ice shelves exert considerable influence on the mass balance of the Antarctic Ice Sheet and glacier stability.The Ross Ice Shelf(RIS),the largest body of floating ice on Earth,plays an essential role in any changes in the mass balance of the Antarctic Ice Sheet.The long-term elevation change trend of RIS has been calculated with multiple satellite altimetry in previous studies.However,the seasonal variations were less revealed.Based on crossover analysis and indirect observation adjustments,this study proposed a new method for constructing seasonal records for surface elevation changes in the RIS using ICESat laser altimetry data from 2003 to 2009.The results showed that surface elevation changes exhibited seasonal variations with fluctuations over 20 cm,and the seasonal change characteristics were closely related to the temperature.Interannual variations in RIS surface elevation decreased from 2003 to2009 at a rate of 2 cm/yr.From March 2003 to April 2007,the surface elevation decreased at 3.7 cm/yr;however,after April 2007,the surface elevation increased at 5.5 cm/yr.The more recent stages of surface elevation growth have been influenced by reductions in the summer basal melt,which is related to the decreases in ocean heat content.展开更多
Rail surface damage is a critical component of high-speed railway infrastructure,directly affecting train operational stability and safety.Existing methods face limitations in accuracy and speed for small-sample,multi...Rail surface damage is a critical component of high-speed railway infrastructure,directly affecting train operational stability and safety.Existing methods face limitations in accuracy and speed for small-sample,multi-category,and multi-scale target segmentation tasks.To address these challenges,this paper proposes Pyramid-MixNet,an intelligent segmentation model for high-speed rail surface damage,leveraging dataset construction and expansion alongside a feature pyramid-based encoder-decoder network with multi-attention mechanisms.The encoding net-work integrates Spatial Reduction Masked Multi-Head Attention(SRMMHA)to enhance global feature extraction while reducing trainable parameters.The decoding network incorporates Mix-Attention(MA),enabling multi-scale structural understanding and cross-scale token group correlation learning.Experimental results demonstrate that the proposed method achieves 62.17%average segmentation accuracy,80.28%Damage Dice Coefficient,and 56.83 FPS,meeting real-time detection requirements.The model’s high accuracy and scene adaptability significantly improve the detection of small-scale and complex multi-scale rail damage,offering practical value for real-time monitoring in high-speed railway maintenance systems.展开更多
The Māori people are indigenous to Aotearoa New Zealand,and their language and culture are considered vital components of the nation’s cultural heritage.However,Te Reo Māori is regarded as a lowresource language ou...The Māori people are indigenous to Aotearoa New Zealand,and their language and culture are considered vital components of the nation’s cultural heritage.However,Te Reo Māori is regarded as a lowresource language outside of New Zealand,and its literary works usually rely on English as a pivot language for translation and communication.Therefore,in the process of promoting Māori literature as part of world literature by translating it into non-English languages,the accurate translation of cultural keywords is crucial to prevent dilemmas such as information loss and cultural misappropriation.In this article,we aim to explore effective translation strategies to enhance the international visibility and readership of Māori literature by analysing the rendition of Māori cultural keywords in the Chinese translation of“The Whale Rider”.展开更多
Many existing aircraft engine fault detection methods are highly dependent on performance deviation data that are provided by the original equipment manufacturer. To improve the independent engine fault detection abil...Many existing aircraft engine fault detection methods are highly dependent on performance deviation data that are provided by the original equipment manufacturer. To improve the independent engine fault detection ability, Aircraft Communications Addressing and Reporting System(ACARS) data can be used. However, owing to the characteristics of high dimension, complex correlations between parameters, and large noise content, it is difficult for existing methods to detect faults effectively by using ACARS data. To solve this problem, a novel engine fault detection method based on original ACARS data is proposed. First, inspired by computer vision methods, all variables were divided into separated groups according to their correlations. Then, an improved convolutional denoising autoencoder was used to extract the features of each group. Finally, all of the extracted features were fused to form feature vectors. Thereby, fault samples could be identified based on these feature vectors. Experiments were conducted to validate the effectiveness and efficiency of our method and other competing methods by considering real ACARS data as the data source. The results reveal the good performance of our method with regard to comprehensive fault detection and robustness. Additionally, the computational and time costs of our method are shown to be relatively low.展开更多
OBJECTIVE:To evaluate the effectiveness and safety of Chinese herbal medicine(CHM) in the treatmentofsubacutethyroiditis.METHODS: Randomized controlled trials found in PubMed, Cochrane Library, and three Chinese datab...OBJECTIVE:To evaluate the effectiveness and safety of Chinese herbal medicine(CHM) in the treatmentofsubacutethyroiditis.METHODS: Randomized controlled trials found in PubMed, Cochrane Library, and three Chinese databases were selected. RevMan 5.2 software was used to analyze the data with relative risk or mean difference, expressed with 95% of confidence interval. The quality of trials was assessed and gradedthe quality of evidence with GRADE profiler software.RESULTS: Twenty one studies were included. CHM was superior to Western Medicine(include prednisone and NSAIDs) in abating fever, relieving thyroid pain, recovering blood sedimentation, improving thyroid function, and preventing hypothyroidism(P<0.05), while no statistical differences were found in eliminating goiter and reducing relapse rate.CHM plusWestern Medicine were superior toWestern Medicine in abating fever, relieving thyroid pain, eliminating goiter, and reducing relapse rate,while no statistical differences(P>0.05) were found in recovering blood sedimentation and improving thyroid function. The incidence of adverse reactions in treatment group was lower than that in control group(relative risk was 0.12 and 95% confidence interval was 0.03-0.51). The methodological quality of trials is generally poor with a high risk of bias.CONCLUSION: CHM(particularly CHM combined withWestern Medicine) used to treat subacute thyroiditis may improve clinical symptoms and signs,reduce relapse rate, and alleviate the side effects of hormones. Due to poor methodological quality of included trials, further more high-quality studies are warranted to confirm the effectiveness and safety of CHM.展开更多
Magnesium hydride(MgH_(2))is a potential material for solid-state hydrogen storage.However,the thermodynamic and kinetic properties are far from practical application in the current stage.In this work,two-dimensional ...Magnesium hydride(MgH_(2))is a potential material for solid-state hydrogen storage.However,the thermodynamic and kinetic properties are far from practical application in the current stage.In this work,two-dimensional vanadium carbide(V_(2)C)MXene with layer thickness of 50−100 nm was fist synthesized by selectively HF-etching the Al layers from V_(2)AlC MAX phase and then introduced into MgH_(2) to improve the hydrogen sorption performances of MgH_(2).The onset hydrogen desorption temperature of MgH_(2) with V_(2)C addition is significantly reduced from 318℃ for pure MgH_(2) to 190℃,with a 128℃ reduction of the onset temperature.The MgH_(2)+10 wt%V_(2)C composite can release 6.4 wt%of H_(2) within 10 min at 300℃ and does not loss any capacity for up to 10 cycles.The activation energy for the hydrogen desorption reaction of MgH_(2) with V_(2)C addition was calculated to be 112 kJ mol^(−1) H_(2) by Arrhenius’s equation and 87.6 kJ mol^(−1) H_(2) by Kissinger’s equation.The hydrogen desorption reaction enthalpy of MgH_(2)+10 wt%V_(2)C was estimated by van’t Hoff equation to be 73.6 kJ mol^(−1) H_(2),which is slightly lower than that of the pure MgH_(2)(77.9 kJ mol^(−1) H_(2)).Microstructure studies by XPS,TEM,and SEM showed that V_(2)C acts as an efficient catalyst for the hydrogen desorption reaction of MgH_(2).The first-principles density functional theory(DFT)calculations demonstrated that the bond length of Mg−H can be reduced from 1.71A for pure MgH_(2) to 2.14A for MgH_(2) with V_(2)C addition,which contributes to the destabilization of MgH_(2).This work provides a method to significantly and simultaneously tailor the hydrogen sorption thermodynamics and kinetics of MgH_(2) by two-dimensional MXene materials.展开更多
Many MXenes are efficient catalysts for MgH_(2)hydrogen storage material.Nevertheless,the synthesis of MXenes should consume a large amount of corrosive HF to etch out the Al layers from the transition metal aluminum ...Many MXenes are efficient catalysts for MgH_(2)hydrogen storage material.Nevertheless,the synthesis of MXenes should consume a large amount of corrosive HF to etch out the Al layers from the transition metal aluminum carbides or nitrides(MAX) phases,which is environmentally unfriendly.In this work,Ti_(3)AlCN MAX without HFetching was employed directly to observably enhance the kinetics and the cycling stability of MgH_(2).With addition of10 wt% Ti_(3)AlCN,the onset dehydrogenation temperature of MgH2 was dropped from 320 to 205℃,and the rehydrogenation of MgH2 under 6 MPa H2 began at as low as50℃.Furthermore,at 300℃,it could provide 6.2 wt% of hydrogen in 10 min.Upon cycling,the composite underwent an activation process during the initial 40 cycles,with the reversible capacity increased from 4.7 wt% to 6.5 wt%.After that,the capacity showed almost no attenuation for up to 100 cycles.The enhancing effect of Ti_(3)AICN on MgH_(2) was comparable to many MXenes.It was demonstrated that Ti_(3)AICN did not destabilize MgH_(2) but acted as an efficient catalyst for MgH_(2).Ti_(3)AICN was observed to be the active sites for the nucleation and growth of MgH_(2)and might also help in dissociation and recombination of hydrogen molecules.Such two factors are believed to contribute to the improvement of MgH_(2).This study not only provides a promising strategy for improving the hydrogen storage performances of MgH_(2) by using noncorrosive MAX materials,but also adds evidence of nucleation and growth of MgH_(2) on a catalyst.展开更多
As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells(PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide(GO)-modified PEDO...As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells(PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide(GO)-modified PEDOT:PSS hole transport layer was fabricated by spin-coating a GO solution onto the PEDOT:PSS surface. PSCs fabricated on a GO-modified PEDOT:PSS layer exhibited a power conversion efficiency(PCE) of 15.34%, which is higher than 11.90% of PSCs with the PEDOT:PSS layer.Furthermore, the stability of the PSCs was significantly improved, with the PCE remaining at 83.5% of the initial PCE values after aging for 39 days in air. The hygroscopic PSS material at the PEDOT:PSS surface was partlyremoved during spin-coating with the GO solution, which improves the moisture resistance and decreases the contact barrier between the hole transport layer and perovskite layer. The scattered distribution of the GO at the PEDOT:PSS surface exhibits superior wettability, which helps to form a high-quality perovskite layer with better crystallinity and fewer pin holes. Furthermore, the hole extraction selectivity of the GO further inhibits the carrier recombination at the interface between the perovskite and PEDOT:PSS layers. Therefore, the cooperative interactions of these factors greatly improve the light absorption of the perovskite layer, the carrier transport and collection abilities of the PSCs, and especially the stability of the cells.展开更多
Aluminum hydride(AlH3) is a binary metal hydride that contains more than 10.1 wt% of hydrogen and possesses a high volumetric hydrogen density of 148 kg H2 m^(-3).Pristine AlH3 can readily release hydrogen at a modera...Aluminum hydride(AlH3) is a binary metal hydride that contains more than 10.1 wt% of hydrogen and possesses a high volumetric hydrogen density of 148 kg H2 m^(-3).Pristine AlH3 can readily release hydrogen at a moderate temperature below 200℃.Such high hydrogen density and low desorption temperature make AlH3 one of most promising hydrogen storage media for mobile application.This review covers the research activity on the structures,synthesis,decomposition thermodynamics and kinetics,regeneration and application validation of AlH3 over the past decades.Finally,the future research directions of AlH3 as a hydrogen storage material will be revealed.展开更多
Platinum was supported on c-AlOand ultrastable Y zeolite(USY) by an incipient wetness impregnation method. The catalysts were characterized by nitrogen physisorption, transmission electron microscopy(TEM),CO/CHisother...Platinum was supported on c-AlOand ultrastable Y zeolite(USY) by an incipient wetness impregnation method. The catalysts were characterized by nitrogen physisorption, transmission electron microscopy(TEM),CO/CHisothermal oxidations, NHtemperature-programmed desorption(NH–TPD) and infrared(IR) spectroscopy of adsorbed probe molecules(CO, CHand CH+ O). Compared with Pt/AlO, Pt USY catalyst shows obviously higher activity for the combustion of propane. After estimating the size effect of Pt particles and propane adsorption capacity of USY, the excellent activity of Pt USY is also attributed to the strong interactions between the precious metal and the acidic zeolite. It inhibits the oxidation of Pt in an oxygen-rich atmosphere at high temperatures, which facilitate the initial oxidation step involving the C–H bond activation on metallic Pt as reflected by in situ diffuse reflectance infrared Fouriertransformed(DRIFT) spectra.展开更多
SnO2-reduced graphene oxide （SnO2-rGO） composites were prepared via a hydro-thermal reaction of graphene oxide （GO） and SnCI2·2H2O in the mixed solvent of ethylene glycol and water. During the redox reaction,...SnO2-reduced graphene oxide （SnO2-rGO） composites were prepared via a hydro-thermal reaction of graphene oxide （GO） and SnCI2·2H2O in the mixed solvent of ethylene glycol and water. During the redox reaction, GO was reduced to rGO while Sn2＋ was oxidized to Sn02, uniformly depositing on the surface of rGO sheets. The composites were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, thermogravimetric analysis （TGA）, infrared spectra analysis （IR） and transmission electron microscopy （TEM）, respectively, and their gas sensing properties were further investigated. Compared with pure SnO2 nanoparticles, the as-prepared SnO2-rGO gas sensor and response-recovery time to ethanol and H2S at responding and low cost SnO2-rGO gas sensor could showed much better gas sensing behavior in sensitivity ow concentrations. Overall, the highly sensitive, quick- be potentially applied in environmental monitoring area.展开更多
Hydrogen can serve as a carrier to store renewable energy in large scale.However,hydrogen storage still remains a challenge in the current stage.It is difficult to meet the technical requirements applying the conventi...Hydrogen can serve as a carrier to store renewable energy in large scale.However,hydrogen storage still remains a challenge in the current stage.It is difficult to meet the technical requirements applying the conventional storage of compressed gaseous hydrogen in high-pressure tanks or the solid-state storage of hydrogen in suitable materials.In the present work,a gaseous and solid-state(G-S)hybrid hydrogen storage system with a low working pressure below 5 MPa for a 10 kW hydrogen energy storage experiment platform is developed and validated.A Ti-Mn type hydrogen storage alloy with an effective hydrogen capacity of 1.7 wt%was prepared for the G-S hybrid hydrogen storage system.The G-S hybrid hydrogen storage tank has a high volumetric hydrogen storage density of 40.07 kg H_(2)m^(-3) and stores hydrogen under pressure below5 MPa.It can readily release enough hydrogen at a temperature as low as-15C when the FC system is not fully activated and hot water is not available.The energy storage efficiency of this G-S hybrid hydrogen storage system is calculated to be 86.4%-95.9%when it is combined with an FC system.This work provides a method on how to design a G-S hydrogen storage system based on practical demands and demonstrates that the G-S hybrid hydrogen storage is a promising method for stationary hydrogen storage application.展开更多
基金supported by the Science and Technology Department of Guangxi Zhuang Autonomous[grant numbers 2025GXNSFFA069003]the National Natural Science Foundation of China[grant numbers 22379030]+1 种基金Bagui Young Scholars Program of Guangxi Zhuang Autonomous Regionthe high-performance computing platform of Guangxi University.
文摘Mg-based hydrogen storage materials have attracted much attention due to their high hydrogen content,abundant resources,and environmental friendliness.However,the high dehydrogenation temperature,slow kinetics and poor cycling stability are limiting its practical application.This work demonstrates the improved dehydrogenation kinetics and cycling stability of MgH_(2) modified by a hybrid of metallic Ni and layered MoS_(2)(denoted as“Ni-MoS_(2)”)introduced by ball milling,with Ni as the catalyst for MgH_(2) and MoS_(2) as the support for both Ni and MgH_(2).The onset dehydrogenation temperature of MgH_(2) is reduced to 198℃,and the rehydrogenation begins at a low temperature of 50℃.The MgH_(2)+10 wt%Ni-MoS_(2) composite has a fast dehydrogenation kinetics and can release 6.1 wt% hydrogen in 10 min at a constant temperature of 300℃,with the dehydrogenation activation energy significantly reduced from 151 to 85 kJ mol^(-1).During the cycling,the reversible capacity of the composite first exhibits a gradual increase for the initial 22 cycles and then maintains at 6.1 wt% from the 23th cycle to the 50th cycle.The Ni/MoS_(2) addition does not change the overall thermodynamic properties of MgH_(2) but can weaken the Mg-H bonds in the local regions as evident by theoretical calculation.Microstructure studies reveal that the metallic Ni will react with MgH_(2) to form Mg_(2)NiH_(0.3),which can act as a hydrogen pump,while the layered MoS_(2) serves as a support for the well dispersion of MgH_(2) and Ni.It is believed that the synergy of Mg_(2)NiH_(0.3) and layered MoS_(2) contributes to the significantly enhanced hydrogen storage of MgH_(2).This work provides a promising and simple strategy for enhancing the Mg-based hydrogen storage materials by combination of transition metals and layered materials introduced via simple ball milling.
基金financially supported by the National Natural Science Foundation of China(Nos.22379030,52001079,52261038)the Science and Technology Department of Guangxi Zhuang Autonomous(Nos.2024JJG160001,GuiKeAD21238022)the Innovation Project of Guangxi Graduate Education(No.YCBZ2023011)
文摘As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).
基金supported by funding from the National Natural Science Foundation of China(Grant No.82170167 to Xiaoxi Zhou and Grant No.82300226 to Hui Luo)。
文摘CD5-positive(CD5+)diffuse large B-cell lymphoma(DLBCL)represents a special subgroup of DLBCL with a more aggressive disease course and is more likely to develop into relapsed/refractory(r/r)DLBCL in response to immunochemotherapy.The incidence of CD5+DLBCL is 5%–10%among DLBCL patients1.
基金funded by the institutional program of China Tibetology Research Center(CTRC20236JS08).
文摘Objective:This study aimed to determine the correlation between the incidence of acute mountain sickness(AMS)and the body constitution of Tibetan medicine and other relevant factors to provide a reference for the prediction and prevention of AMS.Methods:A caseecontrol study was conducted to recruit participants who experienced or did not experience AMS after entering a plateau.The data was collected through online questionnaires for convenient sampling.Demographic characteristics,body constitution,and related states or behaviors were investigated before and after entering the plateau.The participants were divided into case and control groups based on the incidence of AMS.The distributions of relevant factors were compared.Binary logistic regression analysis was used to screen for risk and protective factors.Results:There were 167 participants who completed the questionnaire.A total of 54 cases were excluded,and 113 participants were included,including 52 in the case group and 61 in the control group.In the case group,37,13,and 2 patients had mild,moderate,and severe AMS,respectively.In terms of the Tibetan medicine constitution,the case group had the highest proportion of Bad-rlung(25.0%)and Rlung types(21.2%),whereas the control group had the highest proportion of Bad-rlung(29.5%)and Mkhrisbad types(24.6%).There was no significant difference in the distribution of the constitutional types between the two groups.Insomnia or insufficient sleep within the week prior to entering the plateau and fatigue after arrival were risk factors for AMS,with odds ratios(OR)and 95%confidence intervals(CI)of 5.012(1.871e13.426)and 3.387(1.393e8.236),respectively.A history of short-term plateau travel is a protective factor for AMS(OR:0.32,95%CI:0.129 to 0.792).Conclusion:Insomnia or lack of sleep before ascending to a plateau and fatigue after arrival are risk factors for AMS.The Rlung constitution might be related to the incidence of AMS;however,this still needs to be verified in large-sample observational studies.The risk factors identified in this study can provide a reference for the prevention practice and research of AMS.
文摘Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compared with conventional radiotherapy(CONV-RT)]in an extremely short time.This novel irradiation technique shows a protective effect on normal tissues,also known as the flash effect.At the same time,FLASH-RT is comparable to CONV-RT in terms of tumorkilling efficacy.As basic research dedicates to uncover the mechanisms by which FLASH-RT reduces radiation-induced normal tissue damage,clinical trials of FLASH-RT have been gradually conducted worldwide.This article systematically reviews the evidence of the feasibility and safety of FLASH-RT in clinical practice and offers insights into the future translation of this technology in clinic.
基金supported by the National Key Research and Development Program of China under grant numbers 2023YFC2809103 and 2024YFC2813505the National Natural Science Foundation of China under the grant number 41706216+2 种基金the Fundamental Research Funds for the Central Universities under grant numbers 2042022kf1204,2042022kf1069,2042023gf0012,2042022dx0001the Hubei Provincial Natural Science Foundation of China under grant number 2022CFB081the State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology under grant number SKLGED2023-2-6。
文摘Ice shelves are important passageways for ice sheets flowing into the ocean.Through iceberg calving and basal melting,ice shelves exert considerable influence on the mass balance of the Antarctic Ice Sheet and glacier stability.The Ross Ice Shelf(RIS),the largest body of floating ice on Earth,plays an essential role in any changes in the mass balance of the Antarctic Ice Sheet.The long-term elevation change trend of RIS has been calculated with multiple satellite altimetry in previous studies.However,the seasonal variations were less revealed.Based on crossover analysis and indirect observation adjustments,this study proposed a new method for constructing seasonal records for surface elevation changes in the RIS using ICESat laser altimetry data from 2003 to 2009.The results showed that surface elevation changes exhibited seasonal variations with fluctuations over 20 cm,and the seasonal change characteristics were closely related to the temperature.Interannual variations in RIS surface elevation decreased from 2003 to2009 at a rate of 2 cm/yr.From March 2003 to April 2007,the surface elevation decreased at 3.7 cm/yr;however,after April 2007,the surface elevation increased at 5.5 cm/yr.The more recent stages of surface elevation growth have been influenced by reductions in the summer basal melt,which is related to the decreases in ocean heat content.
基金supported in part by the National Natural Science Foundation of China under Grant 6226070954Jiangxi Provincial Key R&D Programme under Grant 20244BBG73002.
文摘Rail surface damage is a critical component of high-speed railway infrastructure,directly affecting train operational stability and safety.Existing methods face limitations in accuracy and speed for small-sample,multi-category,and multi-scale target segmentation tasks.To address these challenges,this paper proposes Pyramid-MixNet,an intelligent segmentation model for high-speed rail surface damage,leveraging dataset construction and expansion alongside a feature pyramid-based encoder-decoder network with multi-attention mechanisms.The encoding net-work integrates Spatial Reduction Masked Multi-Head Attention(SRMMHA)to enhance global feature extraction while reducing trainable parameters.The decoding network incorporates Mix-Attention(MA),enabling multi-scale structural understanding and cross-scale token group correlation learning.Experimental results demonstrate that the proposed method achieves 62.17%average segmentation accuracy,80.28%Damage Dice Coefficient,and 56.83 FPS,meeting real-time detection requirements.The model’s high accuracy and scene adaptability significantly improve the detection of small-scale and complex multi-scale rail damage,offering practical value for real-time monitoring in high-speed railway maintenance systems.
基金supported by Victoria University of Wellington 2024 PhD Faculty Grant HSSE(Grant No.:FG-HSSE-12486).
文摘The Māori people are indigenous to Aotearoa New Zealand,and their language and culture are considered vital components of the nation’s cultural heritage.However,Te Reo Māori is regarded as a lowresource language outside of New Zealand,and its literary works usually rely on English as a pivot language for translation and communication.Therefore,in the process of promoting Māori literature as part of world literature by translating it into non-English languages,the accurate translation of cultural keywords is crucial to prevent dilemmas such as information loss and cultural misappropriation.In this article,we aim to explore effective translation strategies to enhance the international visibility and readership of Māori literature by analysing the rendition of Māori cultural keywords in the Chinese translation of“The Whale Rider”.
基金co-supported by the Key Program of National Natural Science Foundation of China (No. U1533202)the Civil Aviation Administration of China (No. MHRD20150104)Shandong Independent Innovation and Achievements Transformation Fund (No. 2014CGZH1101)
文摘Many existing aircraft engine fault detection methods are highly dependent on performance deviation data that are provided by the original equipment manufacturer. To improve the independent engine fault detection ability, Aircraft Communications Addressing and Reporting System(ACARS) data can be used. However, owing to the characteristics of high dimension, complex correlations between parameters, and large noise content, it is difficult for existing methods to detect faults effectively by using ACARS data. To solve this problem, a novel engine fault detection method based on original ACARS data is proposed. First, inspired by computer vision methods, all variables were divided into separated groups according to their correlations. Then, an improved convolutional denoising autoencoder was used to extract the features of each group. Finally, all of the extracted features were fused to form feature vectors. Thereby, fault samples could be identified based on these feature vectors. Experiments were conducted to validate the effectiveness and efficiency of our method and other competing methods by considering real ACARS data as the data source. The results reveal the good performance of our method with regard to comprehensive fault detection and robustness. Additionally, the computational and time costs of our method are shown to be relatively low.
基金Supported by Effectiveness of External Therapy of Traditional Chinese Medicine for Subacute Thyroiditis:a Evaluation Research(sci-tech project,No.WZF2012-12)Research on Professor Wu Ruimin's Academic Thought on Treating Subacute Thyroiditis(research project,No.JJ2010-65)from Beijing Municipality of Traditional Chinese Medicine
文摘OBJECTIVE:To evaluate the effectiveness and safety of Chinese herbal medicine(CHM) in the treatmentofsubacutethyroiditis.METHODS: Randomized controlled trials found in PubMed, Cochrane Library, and three Chinese databases were selected. RevMan 5.2 software was used to analyze the data with relative risk or mean difference, expressed with 95% of confidence interval. The quality of trials was assessed and gradedthe quality of evidence with GRADE profiler software.RESULTS: Twenty one studies were included. CHM was superior to Western Medicine(include prednisone and NSAIDs) in abating fever, relieving thyroid pain, recovering blood sedimentation, improving thyroid function, and preventing hypothyroidism(P<0.05), while no statistical differences were found in eliminating goiter and reducing relapse rate.CHM plusWestern Medicine were superior toWestern Medicine in abating fever, relieving thyroid pain, eliminating goiter, and reducing relapse rate,while no statistical differences(P>0.05) were found in recovering blood sedimentation and improving thyroid function. The incidence of adverse reactions in treatment group was lower than that in control group(relative risk was 0.12 and 95% confidence interval was 0.03-0.51). The methodological quality of trials is generally poor with a high risk of bias.CONCLUSION: CHM(particularly CHM combined withWestern Medicine) used to treat subacute thyroiditis may improve clinical symptoms and signs,reduce relapse rate, and alleviate the side effects of hormones. Due to poor methodological quality of included trials, further more high-quality studies are warranted to confirm the effectiveness and safety of CHM.
基金supported by National Natural Science Foundation of China(No.52001079)Education Department of Guangxi Zhuang Autonomous Region(No.2019KY0021)the Natural Science Foundation of Guangxi Province(2019GXNSFBA185004,2018GXNSFAA281308,2019GXNSFAA245050)。
文摘Magnesium hydride(MgH_(2))is a potential material for solid-state hydrogen storage.However,the thermodynamic and kinetic properties are far from practical application in the current stage.In this work,two-dimensional vanadium carbide(V_(2)C)MXene with layer thickness of 50−100 nm was fist synthesized by selectively HF-etching the Al layers from V_(2)AlC MAX phase and then introduced into MgH_(2) to improve the hydrogen sorption performances of MgH_(2).The onset hydrogen desorption temperature of MgH_(2) with V_(2)C addition is significantly reduced from 318℃ for pure MgH_(2) to 190℃,with a 128℃ reduction of the onset temperature.The MgH_(2)+10 wt%V_(2)C composite can release 6.4 wt%of H_(2) within 10 min at 300℃ and does not loss any capacity for up to 10 cycles.The activation energy for the hydrogen desorption reaction of MgH_(2) with V_(2)C addition was calculated to be 112 kJ mol^(−1) H_(2) by Arrhenius’s equation and 87.6 kJ mol^(−1) H_(2) by Kissinger’s equation.The hydrogen desorption reaction enthalpy of MgH_(2)+10 wt%V_(2)C was estimated by van’t Hoff equation to be 73.6 kJ mol^(−1) H_(2),which is slightly lower than that of the pure MgH_(2)(77.9 kJ mol^(−1) H_(2)).Microstructure studies by XPS,TEM,and SEM showed that V_(2)C acts as an efficient catalyst for the hydrogen desorption reaction of MgH_(2).The first-principles density functional theory(DFT)calculations demonstrated that the bond length of Mg−H can be reduced from 1.71A for pure MgH_(2) to 2.14A for MgH_(2) with V_(2)C addition,which contributes to the destabilization of MgH_(2).This work provides a method to significantly and simultaneously tailor the hydrogen sorption thermodynamics and kinetics of MgH_(2) by two-dimensional MXene materials.
基金financially supported by the Science and Technology Department of Guangxi Zhuang Autonomous (No.GuiKeAD21238022)the Natural Science Foundation of Guangxi Province (No.2019GXNSFBA185004)National Natural Science Foundation of China (Nos.52001079,51961005 and 52261038)。
文摘Many MXenes are efficient catalysts for MgH_(2)hydrogen storage material.Nevertheless,the synthesis of MXenes should consume a large amount of corrosive HF to etch out the Al layers from the transition metal aluminum carbides or nitrides(MAX) phases,which is environmentally unfriendly.In this work,Ti_(3)AlCN MAX without HFetching was employed directly to observably enhance the kinetics and the cycling stability of MgH_(2).With addition of10 wt% Ti_(3)AlCN,the onset dehydrogenation temperature of MgH2 was dropped from 320 to 205℃,and the rehydrogenation of MgH2 under 6 MPa H2 began at as low as50℃.Furthermore,at 300℃,it could provide 6.2 wt% of hydrogen in 10 min.Upon cycling,the composite underwent an activation process during the initial 40 cycles,with the reversible capacity increased from 4.7 wt% to 6.5 wt%.After that,the capacity showed almost no attenuation for up to 100 cycles.The enhancing effect of Ti_(3)AICN on MgH_(2) was comparable to many MXenes.It was demonstrated that Ti_(3)AICN did not destabilize MgH_(2) but acted as an efficient catalyst for MgH_(2).Ti_(3)AICN was observed to be the active sites for the nucleation and growth of MgH_(2)and might also help in dissociation and recombination of hydrogen molecules.Such two factors are believed to contribute to the improvement of MgH_(2).This study not only provides a promising strategy for improving the hydrogen storage performances of MgH_(2) by using noncorrosive MAX materials,but also adds evidence of nucleation and growth of MgH_(2) on a catalyst.
基金supported by National Natural Science Foundation of China(Grant Nos.61275038 and 11274119)
文摘As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells(PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide(GO)-modified PEDOT:PSS hole transport layer was fabricated by spin-coating a GO solution onto the PEDOT:PSS surface. PSCs fabricated on a GO-modified PEDOT:PSS layer exhibited a power conversion efficiency(PCE) of 15.34%, which is higher than 11.90% of PSCs with the PEDOT:PSS layer.Furthermore, the stability of the PSCs was significantly improved, with the PCE remaining at 83.5% of the initial PCE values after aging for 39 days in air. The hygroscopic PSS material at the PEDOT:PSS surface was partlyremoved during spin-coating with the GO solution, which improves the moisture resistance and decreases the contact barrier between the hole transport layer and perovskite layer. The scattered distribution of the GO at the PEDOT:PSS surface exhibits superior wettability, which helps to form a high-quality perovskite layer with better crystallinity and fewer pin holes. Furthermore, the hole extraction selectivity of the GO further inhibits the carrier recombination at the interface between the perovskite and PEDOT:PSS layers. Therefore, the cooperative interactions of these factors greatly improve the light absorption of the perovskite layer, the carrier transport and collection abilities of the PSCs, and especially the stability of the cells.
基金financially supported by the National Natural Science Foundation of China (No. 51771171, and 51971199)Education Department of Guangxi Zhuang Autonomous Region (No. 2019KY0021)the Natural Science Foundation of Guangxi Province (2019GXNSFBA185004, and 2018GXNSFAA281308)。
文摘Aluminum hydride(AlH3) is a binary metal hydride that contains more than 10.1 wt% of hydrogen and possesses a high volumetric hydrogen density of 148 kg H2 m^(-3).Pristine AlH3 can readily release hydrogen at a moderate temperature below 200℃.Such high hydrogen density and low desorption temperature make AlH3 one of most promising hydrogen storage media for mobile application.This review covers the research activity on the structures,synthesis,decomposition thermodynamics and kinetics,regeneration and application validation of AlH3 over the past decades.Finally,the future research directions of AlH3 as a hydrogen storage material will be revealed.
基金financially supported by the Ministry of Science and Technology of China (No. 2013AA061902)the Ministry of Education of China (No. 113007A)financial support from the State Key Laboratory of New Ceramics and Fine Processing
文摘Platinum was supported on c-AlOand ultrastable Y zeolite(USY) by an incipient wetness impregnation method. The catalysts were characterized by nitrogen physisorption, transmission electron microscopy(TEM),CO/CHisothermal oxidations, NHtemperature-programmed desorption(NH–TPD) and infrared(IR) spectroscopy of adsorbed probe molecules(CO, CHand CH+ O). Compared with Pt/AlO, Pt USY catalyst shows obviously higher activity for the combustion of propane. After estimating the size effect of Pt particles and propane adsorption capacity of USY, the excellent activity of Pt USY is also attributed to the strong interactions between the precious metal and the acidic zeolite. It inhibits the oxidation of Pt in an oxygen-rich atmosphere at high temperatures, which facilitate the initial oxidation step involving the C–H bond activation on metallic Pt as reflected by in situ diffuse reflectance infrared Fouriertransformed(DRIFT) spectra.
基金supported by the University of Science and Technology BeijingNational Center for Nanoscience and Technology Beijingthe National Basic Research Program of China (No.2007CB714304)
文摘SnO2-reduced graphene oxide （SnO2-rGO） composites were prepared via a hydro-thermal reaction of graphene oxide （GO） and SnCI2·2H2O in the mixed solvent of ethylene glycol and water. During the redox reaction, GO was reduced to rGO while Sn2＋ was oxidized to Sn02, uniformly depositing on the surface of rGO sheets. The composites were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, thermogravimetric analysis （TGA）, infrared spectra analysis （IR） and transmission electron microscopy （TEM）, respectively, and their gas sensing properties were further investigated. Compared with pure SnO2 nanoparticles, the as-prepared SnO2-rGO gas sensor and response-recovery time to ethanol and H2S at responding and low cost SnO2-rGO gas sensor could showed much better gas sensing behavior in sensitivity ow concentrations. Overall, the highly sensitive, quick- be potentially applied in environmental monitoring area.
基金supported by State Grid Corporation of China(No.SGRIDGKJ[2016]123)Education Department of Guangxi Zhuang Autonomous Region(No.2019KY0021)the Natural Science Foundation of Guangxi Province(2019GXNSFBA185004,2018GXNSFAA281308,2019GXNSFAA245050)。
文摘Hydrogen can serve as a carrier to store renewable energy in large scale.However,hydrogen storage still remains a challenge in the current stage.It is difficult to meet the technical requirements applying the conventional storage of compressed gaseous hydrogen in high-pressure tanks or the solid-state storage of hydrogen in suitable materials.In the present work,a gaseous and solid-state(G-S)hybrid hydrogen storage system with a low working pressure below 5 MPa for a 10 kW hydrogen energy storage experiment platform is developed and validated.A Ti-Mn type hydrogen storage alloy with an effective hydrogen capacity of 1.7 wt%was prepared for the G-S hybrid hydrogen storage system.The G-S hybrid hydrogen storage tank has a high volumetric hydrogen storage density of 40.07 kg H_(2)m^(-3) and stores hydrogen under pressure below5 MPa.It can readily release enough hydrogen at a temperature as low as-15C when the FC system is not fully activated and hot water is not available.The energy storage efficiency of this G-S hybrid hydrogen storage system is calculated to be 86.4%-95.9%when it is combined with an FC system.This work provides a method on how to design a G-S hydrogen storage system based on practical demands and demonstrates that the G-S hybrid hydrogen storage is a promising method for stationary hydrogen storage application.
