Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we p...Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we propose a facile thermal-induced phase-segregation strategy to simultaneously master material operando strain and reconstruction effects for enhanced oxygen-evolving reaction(OER).Specifically,self-assembled and controllable layered LiCoO_(2)phase and Co_(3)O_(4)spinel can be generated from pristine Li2Co_(2)O_(4)spinel via Li and O volatilization under different temperatures,realizing controllable proportions of two phases by calcination temperature.Combined operando and ex-situ characterizations reveal that obvious tensile strain along(003)plane appears on layered LixCoO_(2)phase during OER,while low-valence Co_(3)O_(4)phase transforms into high-valence CoOOHx,realizing simultaneous operando strain and reconstruction effects.Further experimental and computational investigations demonstrate that both strained LixCoO_(2)phase and reconstructed CoOOHxcompound contribute to the beneficial adsorption of important OH-reactants,while respective roles in activity and stability are uncovered by exploring their latticeoxygen participation mechanism.This work not only reveals material operando strain effects during OER,but also inaugurates a new thermal-induced phase-segregation strategy to artificially master material operando strain and reconstruction effects,which will enlighten rational material design for many potential reactions and applications.展开更多
Perovskite-type mixed protonic-electronic conducting membranes have attracted attention because of their ability to separate and purify hydrogen from a mixture of gases generated by industrial-scale steam reforming ba...Perovskite-type mixed protonic-electronic conducting membranes have attracted attention because of their ability to separate and purify hydrogen from a mixture of gases generated by industrial-scale steam reforming based on an ion diffusion mechanism.Exploring cost-effective membrane materials that can achieve both high H_(2) permeability and strong CO_(2)-tolerant chemical stability has been a major challenge for industrial applications.Herein,we constructed a triple phase(ceramic-metal-ceramic)membrane composed of a perovskite ceramic phase BaZr_(0.1)Ce_(0.7)Y_(0.1)Yb_(0.1)O_(3-δ)(BZCYYb),Ni metal phase and a fluorite ceramic phase CeO_(2).Under H_(2) atmosphere,Ni metal in-situ exsolved from the oxide grains,and decorated the grain surface and boundary,thus the electronic conductivity and hydrogen separation performance can be promoted.The BZCYYbNi-CeO_(2)hybrid membrane achieved an exceptional hydrogen separation performance of 0.53 mL min^(-1)cm^(-2) at 800℃ under a 10 vol% H_(2) atmosphere,surpassing all other perovskite membranes reported to date.Furthermore,the CeO_(2) phase incorporated into the BZCYYb-Ni effectively improved the CO_(2)-tolerant chemical stability.The BZCYYbNi-CeO_(2) membrane exhibited outstanding long-term stability for at least 80 h at 700℃ under 10 vol%CO_(2)-10 vol%H_(2).The success of hybrid membrane construction creates a new direction for simultaneously improving their hydrogen separation performance and CO_(2) resistance stability.展开更多
Electrochemical carbon dioxide(CO_(2))reduction(ECR)is a promising technology to produce valuable fuels and feedstocks from CO_(2).Despite large efforts to develop ECR catalysts,the investigation of the catalytic perf...Electrochemical carbon dioxide(CO_(2))reduction(ECR)is a promising technology to produce valuable fuels and feedstocks from CO_(2).Despite large efforts to develop ECR catalysts,the investigation of the catalytic performance and electrochemical behavior of complex metal oxides,especially perovskite oxides,is rarely reported.Here,the inorganic perovskite oxide Ag-doped(La_(0.8)Sr_(0.2))_(0.95)Ag_(0.05)MnO_(3-δ)(LSA0.05M)is reported as an efficient electrocatalyst for ECR to CO for the first time,which exhibits a Faradaic efficiency(FE)of 84.3%,a remarkable mass activity of 75Ag^(-1)(normalized to the mass of Ag),and stability of 130 h at a moderate overpotential of 0.79 V.The LSA0.05M catalyst experiences structure reconstruction during ECR,creating the in operando-formed interface between the perovskite and the evolved Ag phase.The evolved Ag is uniformly distributed with a small particle size on the perovskite surface.Theoretical calculations indicate the reconstruction of LSA0.05M during ECR and reveal that the perovskite-Ag interface provides adsorption sites for CO_(2) and accelerates the desorption of the*CO intermediate to enhance ECR.This study presents a novel high-performance perovskite catalyst for ECR andmay inspire the future design of electrocatalysts via the in operando formation of metal-metal oxide interfaces.展开更多
The pantograph and its recess on the train roof are major aerodynamic noise sources on high-speed trains.Reducing this noise is particularly important because conventional noise barriers usually do not shield the pant...The pantograph and its recess on the train roof are major aerodynamic noise sources on high-speed trains.Reducing this noise is particularly important because conventional noise barriers usually do not shield the pantograph.However,less attention has been paid to the pantograph recess compared with the pantograph.In this paper,the flow features and noise contribution of two types of noise reduction treatments rounded and chamfered edges are studied for a simplified high-speed train pantograph recess,which is represented as a rectangular cavity and numerically investigated at 1/10 scale.Improved delayed detached-eddy simulations are performed for the near-field turbulent flow simulation,and the Ffowcs Williams and Hawkings aeroacoustic analogy is used for far-field noise prediction.The highly unsteady flow over the cavity is significantly reduced by the cavity edge modifications,and consequently,the noise radiated from the cavity is reduced.Furthermore,effects of the rounded cavity edges on the flow and noise of the pantographs(one raised and one folded)are investigated by comparing the flow features and noise contributions from the cases with and without rounding of the cavity edges.Different train running directions are also considered.Flow analysis shows that the highly unsteady flow within the cavity is reduced by rounding the cavity edges and a slightly lower flow speed occurs around the upper parts of the raised pantograph,whereas the flow velocity in the cavity is slightly increased by the rounding.Higher pressure fluctuations occur on the folded pantograph and the lower parts of the raised pantograph,whereas weaker fluctuations are found on the panhead of the raised pantograph.This study shows that by rounding the cavity edges,a reduction in radiated noise at the side and the top receiver positions can be achieved.Noise reductions in the other directions can also be found.展开更多
Background A viral vector is a genetically modified vector produced by genetic engineering. As pathogenic genes in the virus are completely or largely eliminated, it is safe to be widely used in multidisciplinary rese...Background A viral vector is a genetically modified vector produced by genetic engineering. As pathogenic genes in the virus are completely or largely eliminated, it is safe to be widely used in multidisciplinary research fields for expressing genes, such as neuroscience, metabolism, oncology and so on. Neuroscience and psychiatry are the most closely related disciplines in either basic research or clinical research, but the application of viral vectors in neuropsychiatry has not received much attention or not been widely accepted.Aim This article will focus on the application of viral vectors in basic and clinical neuropsychiatric research.Methods By using viral vectors, scientists can perform neurological labelling, gene expression regulation and physiological manipulation for investigating phenomenon from molecular mechanisms to behaviours. At the same time, to treat mental or neurological disorders, viral vectors can be designed for gene therapy, which alter gene expression levels or repair mutated genes in the brains of patients.Perspective Viral vectors play an important role in basic research and clinical applications. To further understand brain function and prevent mental and neurological diseases, we hypothesize that viral vectors could be used along with various advanced technologies, such as sequencing and high-throughput expression analysis in the neuroscience research field.展开更多
We re-visit the anomalous sign reversal problem in the Hall effect of the sputtered Nb thin films. We find that the anomalous sign reversal in the Hall effect is extremely sensitive to a small tilting of the magnetic ...We re-visit the anomalous sign reversal problem in the Hall effect of the sputtered Nb thin films. We find that the anomalous sign reversal in the Hall effect is extremely sensitive to a small tilting of the magnetic field and to the magnitude of the applied current. Large anomalous variations are also observed in the symmetric part of the transverse resistance R_(xy).We suggest that the surface current loops on superconducting grains at the edges of the superconducting thin films may be responsible for the Hall sign reversal and the accompanying anomalous effects in the symmetric part of R_(xy).展开更多
Natural killer (NK) cells play an important role in innate immunity and in mediating antibody and Icon (an antibody-like factor VII/IgG1 Fc immunoconjugate, which, to our best knowledge, was the first therapeutic agen...Natural killer (NK) cells play an important role in innate immunity and in mediating antibody and Icon (an antibody-like factor VII/IgG1 Fc immunoconjugate, which, to our best knowledge, was the first therapeutic agent for dual targeting of both the tumor cells and tumor angiogenic endothelial cells) for cancer immunotherapy. However, a common yet often neglected observation and challenge in antibody immunotherapy is that NK cells are often impaired in cancer patients. Here we hypothesize that the impairment of NK cells significantly contributes to host resistance to antibody immunotherapy for cancer. In order for antibody and Icon to achieve their optimal therapeutic efficacy, we briefly reviewed the current strategies to enhance NK activity, including infusion of cytokines, vaccines or NK cells, and the use of dietary supplements. Moreover, from our point of view we identified some remaining challenges and propose to combine these NK-enhancing strategies with Icon or antibody to overcome NK impairment and ultimately to optimize the efficacy of Icon and antibody immunotherapy for cancer.展开更多
Photocatalytic water splitting has emerged as a new frontier for converting solar energy to green H_(2) and value-added chemicals.Nevertheless,great challenges still remain for developing efficient photocatalysts for ...Photocatalytic water splitting has emerged as a new frontier for converting solar energy to green H_(2) and value-added chemicals.Nevertheless,great challenges still remain for developing efficient photocatalysts for pure water splitting without sacrificial agents.In this work,we demonstrate that doping hexagonal ZnIn_(2)S_(4)(ZIS) with Pd single atoms(Pd_(0.03)/ZIS) can serve as a highly efficient photocatalyst for pure water splitting to simultaneously produce H_(2) and H_(2)O_(2) without any sacrificial agents.Results from aberration-corrected high-angle annular dark field scanning transmission electron microscopy,X-ray fine spectroscopy,insitu electron paramagnetic resonance and diffuse Fourier transform infrared spectroscopy reveal that doping ZIS with Pd single atoms facilitates the formation of S vacancies(S_(v)),where the photogenerated electrons can transfer to Pd single atoms,as a result of enhanced separation of electron-hole pairs and improved photocatalytic performance.Impressively,Pd_(0.03)/ZIS displays a stoichiometric ratio of H_(2) and H_(2)O_(2) with the productivity of 1,037.9 and 1,021.4μmol g^(-1)h^(-1),respectively,which has largely outperformed pure ZIS and other reported catalysts for pure water splitting.This work provides an efficient photocatalyst for water splitting to produce H_(2) and H_(2)O_(2),which may attract rapid interest in materials science,chemistry,and heterogeneous catalysis.展开更多
Developing electrocatalysts with fast kinetics and long-term stability for alkaline hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER)is of considerable importance for the industrial production of gr...Developing electrocatalysts with fast kinetics and long-term stability for alkaline hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER)is of considerable importance for the industrial production of green and sustainable energy.Here,an ultrathin Ir-Sb nanowires(Ir-Sb NWs)protected by antimony oxides(SbO_(x))was synthesized as an efficient bifunctional catalyst for both HOR and HER under alkaline media.Except from the much higher mass activities of Ir-Sb nanowires than those of Ir nanowires(Ir NWs)and commercial Pt/C,the SbO_(x) protective layer also contributes to the maintenance of morphology and anti-CO poisoning ability,leading to the long-term cycling performance in the presence of CO.Specifically,the Ir-Sb NW/SbO_(x) exhibits the highest catalytic activities,which are about 3.5 and 4.8 times to those of Ir NW/C and commercial Pt/C toward HOR,respectively.This work provides that the ultrathin morphology and H_(2)O-occupied Sb sites can exert the intrinsic high activity of Ir and effectively optimize the absorption of OH*both in alkaline HER/HOR electrolysis.展开更多
Designing and fabricating efficient electromagnetic interference(EMI)shielding materials becomes a significant and urgent concern.Hence,a novel ultrathin,flexible,and oxidation-resistant MXene-based graphene(M-rGX)por...Designing and fabricating efficient electromagnetic interference(EMI)shielding materials becomes a significant and urgent concern.Hence,a novel ultrathin,flexible,and oxidation-resistant MXene-based graphene(M-rGX)porous film is successfully fabricated by electrostatic self-assembly between MXene and graphene oxide(GO)nanosheets,and subsequently thermal annealing under hydrogen-argon atmosphere.The rapid breakaway of functional groups on GO and MXene sheets induces formation of porous conductive network in film,thereby facilitating efficient shielding for incident electromagnetic waves.The optimal absolute shielding effectiveness(SSE/t)value of 76,422 dB·cm2·g−1 can be achieved at a thinner thickness of 15μm.More importantly,the effective removal of functional groups on MXene conspicuously improves the oxidation resistance of the film,endowing it with an excellent durability(12 months)in EMI shielding performance.展开更多
The separation of individual pigs from the pigpen scenes is crucial for precision farming,and the technology based on convolutional neural networks can provide a low-cost,non-contact,non-invasive method of pig image s...The separation of individual pigs from the pigpen scenes is crucial for precision farming,and the technology based on convolutional neural networks can provide a low-cost,non-contact,non-invasive method of pig image segmentation.However,two factors limit the development of this field.On the one hand,the individual pigs are easy to stick together,and the occlusion of debris such as pigpens can easily make the model misjudgment.On the other hand,manual labeling of group-raised pig data is time-consuming and labor-intensive and is prone to labeling errors.Therefore,it is urgent for an individual pig image segmentation model that can perform well in individual scenarios and can be easily migrated to a group-raised environment.In order to solve the above problems,taking individual pigs as research objects,an individual pig image segmentation dataset containing 2066 images was constructed,and a series of algorithms based on fully convolutional networks were proposed to solve the pig image segmentation problem.In order to capture the long-range dependencies and weaken the background information such as pigpens while enhancing the information of individual parts of pigs,the channel and spatial attention blocks were introduced into the best-performing decoders UNet and LinkNet.Experiments show that using ResNext50 as the encoder and Unet as the decoder as the basic model,adding two attention blocks at the same time achieves 98.30%and 96.71%on the F1 and IOU metrics,respectively.Compared with the model adding channel attention block alone,the two metrics are improved by 0.13%and 0.22%,respectively.The experiment of introducing channel and spatial attention alone shows that spatial attention is more effective than channel attention.Taking VGG16-LinkNet as an example,compared with channel attention,spatial attention improves the F1 and IOU metrics by 0.16%and 0.30%,respectively.Furthermore,the heatmap of the feature of different layers of the decoder after adding different attention information proves that with the increase of layers,the boundary of pig image segmentation is clearer.In order to verify the effectiveness of the individual pig image segmentation model in group-raised scenes,the transfer performance of the model is verified in three scenarios of high separation,deep adhesion,and pigpen occlusion.The experiments show that the segmentation results of adding attention information,especially the simultaneous fusion of channel and spatial attention blocks,are more refined and complete.The attention-based individual pig image segmentation model can be effectively transferred to the field of group-raised pigs and can provide a reference for its pre-segmentation.展开更多
The reviving of the“Holy Grail”lithium metal batteries(LMBs)is greatly hindered by severe parasitic reactions between Li anode and electrolytes.Herein,first,we comprehensively summarize the failure mechanisms and pr...The reviving of the“Holy Grail”lithium metal batteries(LMBs)is greatly hindered by severe parasitic reactions between Li anode and electrolytes.Herein,first,we comprehensively summarize the failure mechanisms and protection principles of the Li anode.Wherein,despite being in dispute,the formation of lithium hydride(LiH)is demonstrated to be one of the most critical factors for Li anode pulverization.Secondly,we trace the research history of LiH at electrodes of lithium batteries.In LMBs,LiH formation is suggested to be greatly associated with the generation of H_(2)from Li/electrolyte intrinsic parasitic reactions,and these intrinsic reactions are still not fully understood.Finally,density functional theory calculations reveal that H_(2)adsorption ability of representative Li anode protective species(such as LiF,Li_(3)N,BN,Li_(2)O,and graphene)is much higher than that of Li and LiH.Therefore,as an important supplement of well-known lithiophilicity theory/high interfacial energy theory and three key principles(mechanical stability,uniform ion transport,and chemical passivation),we propose that constructing an artificial solid electrolyte interphase layer enriched of components with much higher H_(2)adsorption ability than Li will serve as an effective principle for Li anode protection.In summary,suppressing formation of LiH and H_(2)will be very important for cycle life enhancement of practical LMBs.展开更多
At the very time of global paying the highest attention to the worst insults of smoking as well as haze on the airway, everybody knows both are exogenous and noticeable. However, people mostly, including many medical ...At the very time of global paying the highest attention to the worst insults of smoking as well as haze on the airway, everybody knows both are exogenous and noticeable. However, people mostly, including many medical personnel, do not know how badly the gastroesophageal reflux (GER) insults on our own airway. Symptoms of GER are commonly seen as heartburn and regurgitation, which can be mostly tolerated. However, when the up going gastric content reversely passes the esophagus and then the distal pharynx, where it appears a beak like stricture, serving as a nozzle, so as to produce numerous micro-particles and reach the oro-nasal cavity and also the airway causing allergic rhinitis and asthmatic attacks, even pulmonary parenchyma lesions. It will reduce life quality or even jeopardize life. The point that the endogenous insult appears in the respiratory system, but originates from the digestive tract is not well known and often undiagnosed and not correctly treated. The GER induced airway challenge is a treatable and preventive entity, as soon as a diagnosis is made, a good relief could be expected by means of life style adjustment, medicine, or fixation of the patulous cardia through radiofrequency or fundoplication. The author Dr. Zhonggao Wang had suffered it for long and symptoms disappeared for 8 years after anti-reflux surgery. Here is a presentation of Dr. Zhonggao Wang and his team's work and would call attention to the public so as to recognize this relatively unknown entity -- a treatable condition occurring from human itself, but not from outside surroundings as smoking or haze does.展开更多
This study aimed to investigate the outcome of treatment with Stretta radiofrequency (SRF) or laparoscopic Nissen fundoplication (LNF). A total of 137 gastroesophageal reflux disease (GERD) patients with severe ...This study aimed to investigate the outcome of treatment with Stretta radiofrequency (SRF) or laparoscopic Nissen fundoplication (LNF). A total of 137 gastroesophageal reflux disease (GERD) patients with severe asthmatic symptoms who responded inadequately to medical treatment for asthma were investigated. The patients were followed up 1 year and 5 years after SRF (n = 82) or LNF (n = 55) treatment. A questionnaire covering 29 related symptoms and medication use was employed. Digestive, respiratory, and ear-nose-throat (ENT) symptom scores significantly decreased after antireflux treatment. Symptom scores respectively changed from 17.2 ± 10.1, 31.9 ± 6.6, and 21.1± 11.8 to 5.0 ±6.2, 11.5 ±10.2, and 6.3± 6.8 at 1 year and to 5.6 ± 6.5, 13.1± 10.1, and 7.8 ± 7.2 at 5 years (P 〈 0.001). The outcome of LNF was significantly better than that of SRF in terms of digestive (P 〈 0.001, P = 0.001), respiratory (P = 0.006, P = 0.001), and ENT symptoms (P = 0.006, P = 0.003) at both 1 year and 5 years. SRF and LNF were both effective against the digestive symptoms of GERD as well as GERD-related severe asthmatic and ENT symptoms, with better outcomes exhibited by the LNF group. Severe asthmatic symptoms and GERD were closely associated, and this finding warrants further study.展开更多
This study aims to determine whether successful laparoscopic fundoplication for gastroesophageal reflux disease (GERD) can improve the control of hypertension. We conducted an observational study of GERD patients wi...This study aims to determine whether successful laparoscopic fundoplication for gastroesophageal reflux disease (GERD) can improve the control of hypertension. We conducted an observational study of GERD patients with hypertension. The esophageal and gastroesophageal symptoms of these patients were successfully treated with laparoscopic fundoplication, as measured by the reduced GERD symptoms and proton pump inhibitor consumption. A hypertension control scale was used to classify the use of antihypertensive medications and the quality of blood pressure control before and after anti-reflux surgery. Wilcoxon signed-ranks test was used for the statistical analyses. Seventy GERD patients were included in the analysis and followed up for a mean period of 3.5± 1.4 years. Prior to surgery, all participating patients were taking at least one class of antihypertensive medication, and 56 patients (80%) had intermittently high blood pressure. After surgery, the mean number of antihypertensive medication classes per patient was significantly reduced from 1.61 ± 0.77 pre-procedure to 1.27 ± 0.88 post-procedure (P 〈 0.001). The blood pressure of 48 of the 56 cases (86±) with preoperative intermittent high blood pressure returned to normal post procedure. A total of 50 patients (71%) recorded improvements on the hypertension control scale, with the overall mean score decreasing from 3.1 ± 1.0 pre- procedure to 1.4 ± 1.0 post-procedure (P 〈 0.001). Therefore, successful laparoscopic fundoplication may result in better blood pressure control in some hypertensive GERD patients. This result suggests a possible connection between gastroesophageal reflux and hypertension.展开更多
Although high-efficiency production of hydrogen peroxide(H_(2)O_(2))can be realized separately by means of direct,electrochemical,and photocatalytic synthesis,developing versatile catalysts is particularly challenging...Although high-efficiency production of hydrogen peroxide(H_(2)O_(2))can be realized separately by means of direct,electrochemical,and photocatalytic synthesis,developing versatile catalysts is particularly challenging yet desirable.Herein,for the first time we reported that palladium-sulphur nanocrystals(Pd-S NCs)can be adopted as robust and universal catalysts,which can realize the efficient O_(2) conversion by three methods.As a result,Pd-S NCs exhibit an excellent selectivity(89.5%)to H_(2)O_(2)with high productivity(133.6 mol·kgcat^(−1)·h^(−1))in the direct synthesis,along with the significantly enhanced H_(2)O_(2)production activity and stability via electrocatalytic and photocatalytic syntheses.It is demonstrated that the isolated Pd sites can enhance the adsorption of O_(2) and inhibit its O–O bond dissociation,improving H_(2)O_(2)selectivity and reducing H_(2)O_(2)degradation.Further study confirms that the difference in surface atom composition and arrangement is the key factor for different ORR mechanisms on Pd NCs and Pd-S NCs.展开更多
基金funded by the Australian Research Council Discovery Projects(DP160104835,Z.Shao)the Guangdong Basic and Applied Basic Research Foundation(2023A1515012878,D.Guan)+1 种基金the PolyU Distinguished Postdoctoral Fellowship Scheme(1-YWBU,D.Guan)the support from the Max Planck-POSTECH-Hsinchu Center for Complex Phase Materials。
文摘Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we propose a facile thermal-induced phase-segregation strategy to simultaneously master material operando strain and reconstruction effects for enhanced oxygen-evolving reaction(OER).Specifically,self-assembled and controllable layered LiCoO_(2)phase and Co_(3)O_(4)spinel can be generated from pristine Li2Co_(2)O_(4)spinel via Li and O volatilization under different temperatures,realizing controllable proportions of two phases by calcination temperature.Combined operando and ex-situ characterizations reveal that obvious tensile strain along(003)plane appears on layered LixCoO_(2)phase during OER,while low-valence Co_(3)O_(4)phase transforms into high-valence CoOOHx,realizing simultaneous operando strain and reconstruction effects.Further experimental and computational investigations demonstrate that both strained LixCoO_(2)phase and reconstructed CoOOHxcompound contribute to the beneficial adsorption of important OH-reactants,while respective roles in activity and stability are uncovered by exploring their latticeoxygen participation mechanism.This work not only reveals material operando strain effects during OER,but also inaugurates a new thermal-induced phase-segregation strategy to artificially master material operando strain and reconstruction effects,which will enlighten rational material design for many potential reactions and applications.
基金financially supported by the National Key R&D Program of China(2021YFA1502400)the"Transformational Technologies for Clean Energy and Demonstration"+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA2100000)the National Natural Science Foundation of China(52172005,21905295,22179141)the DNL Cooperation Fund,CAS(DNL202008)the Photon Science Center for Carbon Neutrality and the Major Scientific and Technological Innovation Project of Shandong Province(2020CXGC010402)。
文摘Perovskite-type mixed protonic-electronic conducting membranes have attracted attention because of their ability to separate and purify hydrogen from a mixture of gases generated by industrial-scale steam reforming based on an ion diffusion mechanism.Exploring cost-effective membrane materials that can achieve both high H_(2) permeability and strong CO_(2)-tolerant chemical stability has been a major challenge for industrial applications.Herein,we constructed a triple phase(ceramic-metal-ceramic)membrane composed of a perovskite ceramic phase BaZr_(0.1)Ce_(0.7)Y_(0.1)Yb_(0.1)O_(3-δ)(BZCYYb),Ni metal phase and a fluorite ceramic phase CeO_(2).Under H_(2) atmosphere,Ni metal in-situ exsolved from the oxide grains,and decorated the grain surface and boundary,thus the electronic conductivity and hydrogen separation performance can be promoted.The BZCYYbNi-CeO_(2)hybrid membrane achieved an exceptional hydrogen separation performance of 0.53 mL min^(-1)cm^(-2) at 800℃ under a 10 vol% H_(2) atmosphere,surpassing all other perovskite membranes reported to date.Furthermore,the CeO_(2) phase incorporated into the BZCYYb-Ni effectively improved the CO_(2)-tolerant chemical stability.The BZCYYbNi-CeO_(2) membrane exhibited outstanding long-term stability for at least 80 h at 700℃ under 10 vol%CO_(2)-10 vol%H_(2).The success of hybrid membrane construction creates a new direction for simultaneously improving their hydrogen separation performance and CO_(2) resistance stability.
基金Australian Centre for Neutron ScatteringAustralian Nuclear Science and Technology Organisation,Grant/Award Number:MI8046+1 种基金Max Planck-POSTECH-Hsinchu Center for Complex Phase MaterialsHigh-Performance Computing Center of Nanjing Tech University。
文摘Electrochemical carbon dioxide(CO_(2))reduction(ECR)is a promising technology to produce valuable fuels and feedstocks from CO_(2).Despite large efforts to develop ECR catalysts,the investigation of the catalytic performance and electrochemical behavior of complex metal oxides,especially perovskite oxides,is rarely reported.Here,the inorganic perovskite oxide Ag-doped(La_(0.8)Sr_(0.2))_(0.95)Ag_(0.05)MnO_(3-δ)(LSA0.05M)is reported as an efficient electrocatalyst for ECR to CO for the first time,which exhibits a Faradaic efficiency(FE)of 84.3%,a remarkable mass activity of 75Ag^(-1)(normalized to the mass of Ag),and stability of 130 h at a moderate overpotential of 0.79 V.The LSA0.05M catalyst experiences structure reconstruction during ECR,creating the in operando-formed interface between the perovskite and the evolved Ag phase.The evolved Ag is uniformly distributed with a small particle size on the perovskite surface.Theoretical calculations indicate the reconstruction of LSA0.05M during ECR and reveal that the perovskite-Ag interface provides adsorption sites for CO_(2) and accelerates the desorption of the*CO intermediate to enhance ECR.This study presents a novel high-performance perovskite catalyst for ECR andmay inspire the future design of electrocatalysts via the in operando formation of metal-metal oxide interfaces.
基金supported by the “Transformational Technologies for clean Energy and Demonstration”,Strategic Priority Research Program of the Chinese Academy of Sciences(XDA2100000)the Youth Innovation Promotion Association,Chinese Academy of Sciences(2014237)+1 种基金the National Natural Science Foundation of China(21876183)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(YJKYYQ20180066)~~
基金This research project has been supported by the Iridis 4 and Lyceum High Performance Computing Facility at the University of Southampton.
文摘The pantograph and its recess on the train roof are major aerodynamic noise sources on high-speed trains.Reducing this noise is particularly important because conventional noise barriers usually do not shield the pantograph.However,less attention has been paid to the pantograph recess compared with the pantograph.In this paper,the flow features and noise contribution of two types of noise reduction treatments rounded and chamfered edges are studied for a simplified high-speed train pantograph recess,which is represented as a rectangular cavity and numerically investigated at 1/10 scale.Improved delayed detached-eddy simulations are performed for the near-field turbulent flow simulation,and the Ffowcs Williams and Hawkings aeroacoustic analogy is used for far-field noise prediction.The highly unsteady flow over the cavity is significantly reduced by the cavity edge modifications,and consequently,the noise radiated from the cavity is reduced.Furthermore,effects of the rounded cavity edges on the flow and noise of the pantographs(one raised and one folded)are investigated by comparing the flow features and noise contributions from the cases with and without rounding of the cavity edges.Different train running directions are also considered.Flow analysis shows that the highly unsteady flow within the cavity is reduced by rounding the cavity edges and a slightly lower flow speed occurs around the upper parts of the raised pantograph,whereas the flow velocity in the cavity is slightly increased by the rounding.Higher pressure fluctuations occur on the folded pantograph and the lower parts of the raised pantograph,whereas weaker fluctuations are found on the panhead of the raised pantograph.This study shows that by rounding the cavity edges,a reduction in radiated noise at the side and the top receiver positions can be achieved.Noise reductions in the other directions can also be found.
基金co-supported by National Natural Science Foundation of China(81571326,81501153)
文摘Background A viral vector is a genetically modified vector produced by genetic engineering. As pathogenic genes in the virus are completely or largely eliminated, it is safe to be widely used in multidisciplinary research fields for expressing genes, such as neuroscience, metabolism, oncology and so on. Neuroscience and psychiatry are the most closely related disciplines in either basic research or clinical research, but the application of viral vectors in neuropsychiatry has not received much attention or not been widely accepted.Aim This article will focus on the application of viral vectors in basic and clinical neuropsychiatric research.Methods By using viral vectors, scientists can perform neurological labelling, gene expression regulation and physiological manipulation for investigating phenomenon from molecular mechanisms to behaviours. At the same time, to treat mental or neurological disorders, viral vectors can be designed for gene therapy, which alter gene expression levels or repair mutated genes in the brains of patients.Perspective Viral vectors play an important role in basic research and clinical applications. To further understand brain function and prevent mental and neurological diseases, we hypothesize that viral vectors could be used along with various advanced technologies, such as sequencing and high-throughput expression analysis in the neuroscience research field.
基金partially supported by the National Natural Science Foundation of China (Grant No. 51772200) (PI: R. J. Tang)。
文摘We re-visit the anomalous sign reversal problem in the Hall effect of the sputtered Nb thin films. We find that the anomalous sign reversal in the Hall effect is extremely sensitive to a small tilting of the magnetic field and to the magnitude of the applied current. Large anomalous variations are also observed in the symmetric part of the transverse resistance R_(xy).We suggest that the surface current loops on superconducting grains at the edges of the superconducting thin films may be responsible for the Hall sign reversal and the accompanying anomalous effects in the symmetric part of R_(xy).
文摘Natural killer (NK) cells play an important role in innate immunity and in mediating antibody and Icon (an antibody-like factor VII/IgG1 Fc immunoconjugate, which, to our best knowledge, was the first therapeutic agent for dual targeting of both the tumor cells and tumor angiogenic endothelial cells) for cancer immunotherapy. However, a common yet often neglected observation and challenge in antibody immunotherapy is that NK cells are often impaired in cancer patients. Here we hypothesize that the impairment of NK cells significantly contributes to host resistance to antibody immunotherapy for cancer. In order for antibody and Icon to achieve their optimal therapeutic efficacy, we briefly reviewed the current strategies to enhance NK activity, including infusion of cytokines, vaccines or NK cells, and the use of dietary supplements. Moreover, from our point of view we identified some remaining challenges and propose to combine these NK-enhancing strategies with Icon or antibody to overcome NK impairment and ultimately to optimize the efficacy of Icon and antibody immunotherapy for cancer.
基金financially supported by the National Key R&D Program of China(2020YFB1505802)the Ministry of Science and Technology of China(2017YFA0208200)+2 种基金the National Natural Science Foundation of China(22025108,U21A20327,22121001)Guangdong Provincial Natural Science Fund for Distinguished Young Scholars(2021B1515020081)the start-up support from Xiamen University。
文摘Photocatalytic water splitting has emerged as a new frontier for converting solar energy to green H_(2) and value-added chemicals.Nevertheless,great challenges still remain for developing efficient photocatalysts for pure water splitting without sacrificial agents.In this work,we demonstrate that doping hexagonal ZnIn_(2)S_(4)(ZIS) with Pd single atoms(Pd_(0.03)/ZIS) can serve as a highly efficient photocatalyst for pure water splitting to simultaneously produce H_(2) and H_(2)O_(2) without any sacrificial agents.Results from aberration-corrected high-angle annular dark field scanning transmission electron microscopy,X-ray fine spectroscopy,insitu electron paramagnetic resonance and diffuse Fourier transform infrared spectroscopy reveal that doping ZIS with Pd single atoms facilitates the formation of S vacancies(S_(v)),where the photogenerated electrons can transfer to Pd single atoms,as a result of enhanced separation of electron-hole pairs and improved photocatalytic performance.Impressively,Pd_(0.03)/ZIS displays a stoichiometric ratio of H_(2) and H_(2)O_(2) with the productivity of 1,037.9 and 1,021.4μmol g^(-1)h^(-1),respectively,which has largely outperformed pure ZIS and other reported catalysts for pure water splitting.This work provides an efficient photocatalyst for water splitting to produce H_(2) and H_(2)O_(2),which may attract rapid interest in materials science,chemistry,and heterogeneous catalysis.
基金supports by the National Key R&D Program of China(No.2020YFB1505802)Ministry of Science and Technology of China(No.2017YFA0208200)+1 种基金the National Natural Science Foundation of China(Nos.22025108,U21A20327,22121001 and 22275152)start-up support from Xiamen University.We thank beamline TLS01C1(“National Synchrotron Radiation Research Center”)for providing the beam time.We acknowledge support from the Max Planck-POSTECHHsinchu Center for Complex Phase Materials.
文摘Developing electrocatalysts with fast kinetics and long-term stability for alkaline hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER)is of considerable importance for the industrial production of green and sustainable energy.Here,an ultrathin Ir-Sb nanowires(Ir-Sb NWs)protected by antimony oxides(SbO_(x))was synthesized as an efficient bifunctional catalyst for both HOR and HER under alkaline media.Except from the much higher mass activities of Ir-Sb nanowires than those of Ir nanowires(Ir NWs)and commercial Pt/C,the SbO_(x) protective layer also contributes to the maintenance of morphology and anti-CO poisoning ability,leading to the long-term cycling performance in the presence of CO.Specifically,the Ir-Sb NW/SbO_(x) exhibits the highest catalytic activities,which are about 3.5 and 4.8 times to those of Ir NW/C and commercial Pt/C toward HOR,respectively.This work provides that the ultrathin morphology and H_(2)O-occupied Sb sites can exert the intrinsic high activity of Ir and effectively optimize the absorption of OH*both in alkaline HER/HOR electrolysis.
基金We are gratefully for the financial support from the National Natural Science Foundation of China(Nos.52003106,21674019,and 52161135302)the Fundamental Research Funds for the Central Universities(Nos.JUSRP12032 and 2232019A3-03)+4 种基金the Research Foundation Flanders(No.G0F2322N)China Postdoctoral Science Foundation(No.2021M691265)Ministry of Education of the People’s Republic of China(No.6141A0202202)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Nos.KYCX22_2319 and SJCX22_1110)Innovation Program of Shanghai Municipal Education Commission(No.2021-01-07-00-03-E00108).
文摘Designing and fabricating efficient electromagnetic interference(EMI)shielding materials becomes a significant and urgent concern.Hence,a novel ultrathin,flexible,and oxidation-resistant MXene-based graphene(M-rGX)porous film is successfully fabricated by electrostatic self-assembly between MXene and graphene oxide(GO)nanosheets,and subsequently thermal annealing under hydrogen-argon atmosphere.The rapid breakaway of functional groups on GO and MXene sheets induces formation of porous conductive network in film,thereby facilitating efficient shielding for incident electromagnetic waves.The optimal absolute shielding effectiveness(SSE/t)value of 76,422 dB·cm2·g−1 can be achieved at a thinner thickness of 15μm.More importantly,the effective removal of functional groups on MXene conspicuously improves the oxidation resistance of the film,endowing it with an excellent durability(12 months)in EMI shielding performance.
基金supported by the National Natural Science Foundation of China(Grant No.31671571)the Shanxi Province Basic Research Program Project(Free Exploration)(No.20210302124523,20210302123408,202103021224149,and 202103021223141)the Youth Agricultural Science and Technology Innovation Fund of Shanxi Agricultural University(Grant No.2019027)。
文摘The separation of individual pigs from the pigpen scenes is crucial for precision farming,and the technology based on convolutional neural networks can provide a low-cost,non-contact,non-invasive method of pig image segmentation.However,two factors limit the development of this field.On the one hand,the individual pigs are easy to stick together,and the occlusion of debris such as pigpens can easily make the model misjudgment.On the other hand,manual labeling of group-raised pig data is time-consuming and labor-intensive and is prone to labeling errors.Therefore,it is urgent for an individual pig image segmentation model that can perform well in individual scenarios and can be easily migrated to a group-raised environment.In order to solve the above problems,taking individual pigs as research objects,an individual pig image segmentation dataset containing 2066 images was constructed,and a series of algorithms based on fully convolutional networks were proposed to solve the pig image segmentation problem.In order to capture the long-range dependencies and weaken the background information such as pigpens while enhancing the information of individual parts of pigs,the channel and spatial attention blocks were introduced into the best-performing decoders UNet and LinkNet.Experiments show that using ResNext50 as the encoder and Unet as the decoder as the basic model,adding two attention blocks at the same time achieves 98.30%and 96.71%on the F1 and IOU metrics,respectively.Compared with the model adding channel attention block alone,the two metrics are improved by 0.13%and 0.22%,respectively.The experiment of introducing channel and spatial attention alone shows that spatial attention is more effective than channel attention.Taking VGG16-LinkNet as an example,compared with channel attention,spatial attention improves the F1 and IOU metrics by 0.16%and 0.30%,respectively.Furthermore,the heatmap of the feature of different layers of the decoder after adding different attention information proves that with the increase of layers,the boundary of pig image segmentation is clearer.In order to verify the effectiveness of the individual pig image segmentation model in group-raised scenes,the transfer performance of the model is verified in three scenarios of high separation,deep adhesion,and pigpen occlusion.The experiments show that the segmentation results of adding attention information,especially the simultaneous fusion of channel and spatial attention blocks,are more refined and complete.The attention-based individual pig image segmentation model can be effectively transferred to the field of group-raised pigs and can provide a reference for its pre-segmentation.
基金supported by the National Key R&D Program of China(2020YFB1505802)Ministry of Science and Technology of China(2017YFA0208200)+2 种基金the National Natural Science Foundation of China(22025108,U21A20327,and 22121001)Guangdong Provincial Natural Science Fund for Distinguished Yong Scholars(2021B1515020081)start-up support from Xiamen University。
基金Taishan Scholars of Shandong Province,Grant/Award Number:ts201511063National Natural Science Foundation of China,Grant/Award Numbers:22102206,U22A20440+2 种基金Strategic Priority Research Program of Chinese Academy of Sciences,Grant/Award Number:XDA22010600Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2021QB030Key-Area Research and Development Program of Guangdong Province,Grant/Award Number:2020B090919005。
文摘The reviving of the“Holy Grail”lithium metal batteries(LMBs)is greatly hindered by severe parasitic reactions between Li anode and electrolytes.Herein,first,we comprehensively summarize the failure mechanisms and protection principles of the Li anode.Wherein,despite being in dispute,the formation of lithium hydride(LiH)is demonstrated to be one of the most critical factors for Li anode pulverization.Secondly,we trace the research history of LiH at electrodes of lithium batteries.In LMBs,LiH formation is suggested to be greatly associated with the generation of H_(2)from Li/electrolyte intrinsic parasitic reactions,and these intrinsic reactions are still not fully understood.Finally,density functional theory calculations reveal that H_(2)adsorption ability of representative Li anode protective species(such as LiF,Li_(3)N,BN,Li_(2)O,and graphene)is much higher than that of Li and LiH.Therefore,as an important supplement of well-known lithiophilicity theory/high interfacial energy theory and three key principles(mechanical stability,uniform ion transport,and chemical passivation),we propose that constructing an artificial solid electrolyte interphase layer enriched of components with much higher H_(2)adsorption ability than Li will serve as an effective principle for Li anode protection.In summary,suppressing formation of LiH and H_(2)will be very important for cycle life enhancement of practical LMBs.
文摘At the very time of global paying the highest attention to the worst insults of smoking as well as haze on the airway, everybody knows both are exogenous and noticeable. However, people mostly, including many medical personnel, do not know how badly the gastroesophageal reflux (GER) insults on our own airway. Symptoms of GER are commonly seen as heartburn and regurgitation, which can be mostly tolerated. However, when the up going gastric content reversely passes the esophagus and then the distal pharynx, where it appears a beak like stricture, serving as a nozzle, so as to produce numerous micro-particles and reach the oro-nasal cavity and also the airway causing allergic rhinitis and asthmatic attacks, even pulmonary parenchyma lesions. It will reduce life quality or even jeopardize life. The point that the endogenous insult appears in the respiratory system, but originates from the digestive tract is not well known and often undiagnosed and not correctly treated. The GER induced airway challenge is a treatable and preventive entity, as soon as a diagnosis is made, a good relief could be expected by means of life style adjustment, medicine, or fixation of the patulous cardia through radiofrequency or fundoplication. The author Dr. Zhonggao Wang had suffered it for long and symptoms disappeared for 8 years after anti-reflux surgery. Here is a presentation of Dr. Zhonggao Wang and his team's work and would call attention to the public so as to recognize this relatively unknown entity -- a treatable condition occurring from human itself, but not from outside surroundings as smoking or haze does.
文摘This study aimed to investigate the outcome of treatment with Stretta radiofrequency (SRF) or laparoscopic Nissen fundoplication (LNF). A total of 137 gastroesophageal reflux disease (GERD) patients with severe asthmatic symptoms who responded inadequately to medical treatment for asthma were investigated. The patients were followed up 1 year and 5 years after SRF (n = 82) or LNF (n = 55) treatment. A questionnaire covering 29 related symptoms and medication use was employed. Digestive, respiratory, and ear-nose-throat (ENT) symptom scores significantly decreased after antireflux treatment. Symptom scores respectively changed from 17.2 ± 10.1, 31.9 ± 6.6, and 21.1± 11.8 to 5.0 ±6.2, 11.5 ±10.2, and 6.3± 6.8 at 1 year and to 5.6 ± 6.5, 13.1± 10.1, and 7.8 ± 7.2 at 5 years (P 〈 0.001). The outcome of LNF was significantly better than that of SRF in terms of digestive (P 〈 0.001, P = 0.001), respiratory (P = 0.006, P = 0.001), and ENT symptoms (P = 0.006, P = 0.003) at both 1 year and 5 years. SRF and LNF were both effective against the digestive symptoms of GERD as well as GERD-related severe asthmatic and ENT symptoms, with better outcomes exhibited by the LNF group. Severe asthmatic symptoms and GERD were closely associated, and this finding warrants further study.
文摘This study aims to determine whether successful laparoscopic fundoplication for gastroesophageal reflux disease (GERD) can improve the control of hypertension. We conducted an observational study of GERD patients with hypertension. The esophageal and gastroesophageal symptoms of these patients were successfully treated with laparoscopic fundoplication, as measured by the reduced GERD symptoms and proton pump inhibitor consumption. A hypertension control scale was used to classify the use of antihypertensive medications and the quality of blood pressure control before and after anti-reflux surgery. Wilcoxon signed-ranks test was used for the statistical analyses. Seventy GERD patients were included in the analysis and followed up for a mean period of 3.5± 1.4 years. Prior to surgery, all participating patients were taking at least one class of antihypertensive medication, and 56 patients (80%) had intermittently high blood pressure. After surgery, the mean number of antihypertensive medication classes per patient was significantly reduced from 1.61 ± 0.77 pre-procedure to 1.27 ± 0.88 post-procedure (P 〈 0.001). The blood pressure of 48 of the 56 cases (86±) with preoperative intermittent high blood pressure returned to normal post procedure. A total of 50 patients (71%) recorded improvements on the hypertension control scale, with the overall mean score decreasing from 3.1 ± 1.0 pre- procedure to 1.4 ± 1.0 post-procedure (P 〈 0.001). Therefore, successful laparoscopic fundoplication may result in better blood pressure control in some hypertensive GERD patients. This result suggests a possible connection between gastroesophageal reflux and hypertension.
基金the National Key R&D Program of China(Nos.2017YFA0208200 and 2016YFA0204100)the National Natural Science Foundation of China(No.22025108)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the start-up supports from Xiamen University.
文摘Although high-efficiency production of hydrogen peroxide(H_(2)O_(2))can be realized separately by means of direct,electrochemical,and photocatalytic synthesis,developing versatile catalysts is particularly challenging yet desirable.Herein,for the first time we reported that palladium-sulphur nanocrystals(Pd-S NCs)can be adopted as robust and universal catalysts,which can realize the efficient O_(2) conversion by three methods.As a result,Pd-S NCs exhibit an excellent selectivity(89.5%)to H_(2)O_(2)with high productivity(133.6 mol·kgcat^(−1)·h^(−1))in the direct synthesis,along with the significantly enhanced H_(2)O_(2)production activity and stability via electrocatalytic and photocatalytic syntheses.It is demonstrated that the isolated Pd sites can enhance the adsorption of O_(2) and inhibit its O–O bond dissociation,improving H_(2)O_(2)selectivity and reducing H_(2)O_(2)degradation.Further study confirms that the difference in surface atom composition and arrangement is the key factor for different ORR mechanisms on Pd NCs and Pd-S NCs.