Hepatocellular carcinoma(HCC)is a malignancy known for its unfavorable prognosis.The dysregulation of the tumor microenvironment(TME)can affect the sensitivity to immunotherapy or chemotherapy,leading to treatment fai...Hepatocellular carcinoma(HCC)is a malignancy known for its unfavorable prognosis.The dysregulation of the tumor microenvironment(TME)can affect the sensitivity to immunotherapy or chemotherapy,leading to treatment failure.The elucidation of PHLDA2’s involvement in HCC is imperative,and the clinical value of PHLDA2 is also underestimated.Here,bioinformatics analysis was performed in multiple cohorts to explore the phenotype and mechanism through which PHLDA2 may affect the progression of HCC.Then,the expression and function of PHLDA2 were examined via the qRT-PCR,Western Blot,and MTT assays.Our findings indicate a substantial upregulation of PHLDA2 in HCC,correlated with a poorer prognosis.The methylation levels of PHLDA2 were found to be lower in HCC tissues compared to normal liver tissues.Besides,noteworthy associations were observed between PHLDA2 expression and immune infiltration in HCC.In addition,PHLDA2 upregulation is closely associated with stemness features and immunotherapy or chemotherapy resistance in HCC.In vitro experiments showed that sorafenib or cisplatin significantly up-regulated PHLDA2 mRNA levels,and PHLDA2 knockdown markedly decreased the sensitivity of HCC cells to chemotherapy drugs.Meanwhile,we found that TGF-βinduced the expression of PHLDA2 in vitro.The GSEA and in vitro experiment indicated that PHLDA2 may promote the HCC progression via activating the AKT signaling pathway.Our study revealed the novel role of PHLDA2 as an independent prognostic factor,which plays an essential role in TME remodeling and treatment resistance in HCC.展开更多
Reconstruction during the catalytic process has been considered to play a key role for the performance.Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction(HER),which can benefit f...Reconstruction during the catalytic process has been considered to play a key role for the performance.Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction(HER),which can benefit from a long-term reconstruction during HER for 10 h to continuously increase the performance.The final catalyst(e-RuNiPO)shows a huge morphology change from bulk sphere to highly exposed layered structure in the electrocatalysis process,and exhibits an interesting electronic structure modification with the electron transfer from Ru to Ni for better interfacial interaction and quick charge transfer.Due to the favorable morphology with more exposed active sites and the optimized electronic structure,the final catalyst can achieve an outstanding performance with only an overpotential of 15 mV at 10 mA cm^(-2)(with a good stability more than 100 h),even outperforming the performance of benchmark 20 wt%Pt/C catalyst(18 mV at 10 mA cm^(-2))by using a much lower Ru content.展开更多
Photoelectrochemical hydrogen generation is a promising approach to address the environmental pollution and energy crisis.In this work,we present a hybridized mechanical and solar energy-driven selfpowered hydrogen pr...Photoelectrochemical hydrogen generation is a promising approach to address the environmental pollution and energy crisis.In this work,we present a hybridized mechanical and solar energy-driven selfpowered hydrogen production system.A rotatory disc-shaped triboelectric nanogenerator was employed to harvest mechanical energy from water and functions as a su cient external power source.WO3/BiVO4 heterojunction photoanode was synthesized in a PEC water-splitting cell to produce H2.After transformation and rectification,the peak current reaches 0.1 m A at the rotation speed of 60 rpm.In this case,the H2 evolution process only occurs with sunlight irradiation.When the rotation speed is over 130 rpm,the peak photocurrent and peak dark current have nearly equal value.Direct electrolysis of water is almost simultaneous with photoelectrocatalysis of water.It is worth noting that the hydrogen production rate increases to 5.45 and 7.27μL min-1 without or with light illumination at 160 rpm.The corresponding energy conversion e ciency is calculated to be 2.43%and 2.59%,respectively.All the results demonstrate such a self-powered system can successfully achieve the PEC hydrogen generation,exhibiting promising possibility of energy conversion.展开更多
Hematite is regarded as a promising photoanode for photoelectrochemical(PEC) water splitting.However,the charge recombination occurred at the interface of FTO/hematite strictly limits the PEC performance of hematite.H...Hematite is regarded as a promising photoanode for photoelectrochemical(PEC) water splitting.However,the charge recombination occurred at the interface of FTO/hematite strictly limits the PEC performance of hematite.Herein,we reported a Ti3C2 MXene underlayer modified hematite(Ti-Fe2O3) photoanode via a simple drop-casting followed by hydrothermal and annealing processes.Owing to the bifunctional role of Ti3C2 MXene underlayer in improving the interfacial properties of FTO/hematite and providing Ti source for the construction of Fe2 TiO5/Fe2O3 heterostructure in hematite nanostructure,the bulk and interfacial charge transfer dynamics of hematite are significantly enhanced,and consequently enhancing the PEC performance.Compared with the pristine hematite,the as-prepared Ti-Fe2O3 photoanode shows an increased photocurrent density from 0.80 mA/cm^(2) to 1.30 mA/cm^(2) at 1.23 V vs.RHE.Moreover,a further promoted PEC performance including a dramatically increased photocurrent density of 2.49 mA/cm^(2) at1.23 V vs.RHE and an obviously lowered onset potential is achieved for the Ti-Fe2O3 sample after the subsequent surface F-treatment and the loading of FeNiOOH cocatalyst.Such results suggest that the introduction of Ti3C2 MXene underlayer is a facile but effective approach to improve the PEC water splitting activity of hematite.展开更多
BACKGROUND An atrial septal defect is a common condition and accounts for 25%of adult congenital heart diseases.Transcatheter occlusion is a widely used technique for the treatment of secondary aperture-type atrial se...BACKGROUND An atrial septal defect is a common condition and accounts for 25%of adult congenital heart diseases.Transcatheter occlusion is a widely used technique for the treatment of secondary aperture-type atrial septal defects(ASDs).CASE SUMMARY A 30-year-old female patient was diagnosed with ASD by transthoracic echocardiography(TTE)1 year ago.The electrocardiogram showed a heart rate of 88 beats per minute,normal sinus rhythm,and no change in the ST-T wave.After admission,TTE showed an atrial septal defect with a left-to-right shunt,aortic root short-axis section with an ASD diameter of 8 mm,a parasternal four-chamber section with an ASD diameter of 9 mm,and subxiphoid biatrial section with a diameter of 13 mm.Percutaneous occlusion was proposed.The intraoperative TTE scan showed that the atrial septal defect was oval in shape,was located near the root of the aorta,and had a maximum diameter of 13 mm.A 10-F sheath was placed in the right femoral vein,and a 0.035°hard guidewire was used to establish the transport track between the left pulmonary vein and the inferior vena cava.A shape-memory alloy atrial septal occluder with a waist diameter of 20 mm was placed successfully and located correctly.TTE showed that the double disk unfolded well and that the clamping of the atrial septum was smooth.Immediately after the disc was revealed,electrocardiograph monitoring showed that the ST interval of the inferior leads was prolonged,the P waves and QRS waves were separated,a junctional escape rhythm maintained the heart rate,and the blood pressure began to decrease.After removing the occluder,the elevation in the ST segment returned to normal immediately,and the sinus rhythm returned to average approximately 10 min later.After consulting the patient’s family,we finally decided to withdraw from the operation.CONCLUSION Compression of the small coronary artery,which provides an alternative blood supply to the atrioventricular nodule during the operation,leads to the emergence of a complete atrioventricular block.展开更多
Efficient electrocatalysts for hydrogen evolution reaction(HER) in alkaline solution are highly required for water splitting.Here we design an ultra-small PtOx nanoparticle with hybrid Pt chemical states on carbon nan...Efficient electrocatalysts for hydrogen evolution reaction(HER) in alkaline solution are highly required for water splitting.Here we design an ultra-small PtOx nanoparticle with hybrid Pt chemical states on carbon nanotubes as highly efficient alkaline HER catalyst,which shows a low overpotential of 19.4 mV at 10 mA cm^(-2),a high mass activity of 5.56 A mg_(Pt)^(-1) at 0.1 V, and a stable durability for at least 20 h.The HER performance is better than that of the benchmark 20 wt% Pt/C while the Pt content in the catalyst is only about one tenth of that in Pt/C.It also represents one of the best catalysts ever reported for HER in alkaline solution.Synchrotron radiation X-ray absorption spectroscopy reveals that the efficient and stable alkaline HER performance can be attributed to the favorable design of hybrid chemical states of Pt with carbon nanotubes,which exhibits abundant surface Pt-O as active catalytic sites and forms stable Pt-C interfacial interaction to both anchor the NPs and improve the synergistic effect between catalyst and substrate.展开更多
Hematite is an excellent catalyst for photoelectrochemical (PEC) water splitting but its performance has been highly limited by poor conductivity and high charge recombination.Here by a Zr-based treatment to create bu...Hematite is an excellent catalyst for photoelectrochemical (PEC) water splitting but its performance has been highly limited by poor conductivity and high charge recombination.Here by a Zr-based treatment to create bulk Fe_(2)ZrO_(5) in hematite and a F-based treatment to form an ultrathin surface FeF_(x) layer,the charge transfer can be highly improved and the charge recombination can be significantly suppressed.As a result,the FeF_(x) /Zr-Fe_(2)O_(3) photoanode presents an enhanced PEC performance with a photocurrent density of 2.43 m A/cm^(2)at 1.23 V vs.RHE,which is around 3 times higher than that of the pristine Fe_(2)O_(3) .The FeF_(x) /Zr-Fe_(2)O_(3) photoanode also shows a low onset potential of 0.77 V vs.RHE (100 mV lower than the pristine hematite).The performance is much higher than that of the sample treated by Zr or F alone,suggesting the synergistic effect between bulk Fe_(2)ZrO_(5) and surface FeF_(x) .By coupling with the FeNiOOH co-catalyst,the final photoanode can achieve a high photocurrent density of 2.81 mA/cm^(2) at 1.23 V vs.RHE.The novel design of Zr and F co-modified hematite can be used as a promising way to prepare efficient catalysts for solar water splitting.展开更多
Traditional separation methods have limited ability to handle the speech separation problem in high reverberant and low signal-to-noise ratio(SNR)environments,and thus achieve unsatisfactory results.In this study,a co...Traditional separation methods have limited ability to handle the speech separation problem in high reverberant and low signal-to-noise ratio(SNR)environments,and thus achieve unsatisfactory results.In this study,a convolutional neural network with temporal convolution and residual network(TC-ResNet)is proposed to realize speech separation in a complex acoustic environment.A simplified steered-response power phase transform,denoted as GSRP-PHAT,is employed to reduce the computational cost.The extracted features are reshaped to a special tensor as the system inputs and implements temporal convolution,which not only enlarges the receptive field of the convolution layer but also significantly reduces the network computational cost.Residual blocks are used to combine multiresolution features and accelerate the training procedure.A modified ideal ratio mask is applied as the training target.Simulation results demonstrate that the proposed microphone array speech separation algorithm based on TC-ResNet achieves a better performance in terms of distortion ratio,source-to-interference ratio,and short-time objective intelligibility in low SNR and high reverberant environments,particularly in untrained situations.This indicates that the proposed method has generalization to untrained conditions.展开更多
Using the method in Biodiversity Risk and Opportunity Assessment Handbook of British American Tobacco Biodiversity Partnership,we assess biodiversity risks and opportunities in BAT and China's cooperative tobacco-...Using the method in Biodiversity Risk and Opportunity Assessment Handbook of British American Tobacco Biodiversity Partnership,we assess biodiversity risks and opportunities in BAT and China's cooperative tobacco-growing areas. The assessment results indicate that there are 8 risks and 1 opportunity. Action and monitoring plans have been made for medium and high risks as well as opportunity,to reduce impact on biodiversity.展开更多
The effect of coatings(Y_2O_3, Zr O_2 and Al_2O_3) on the interfacial reaction of Ti Al alloys was studied with molecular dynamics. The binding energy of coatings and the diffusion process of oxygen in the melt were s...The effect of coatings(Y_2O_3, Zr O_2 and Al_2O_3) on the interfacial reaction of Ti Al alloys was studied with molecular dynamics. The binding energy of coatings and the diffusion process of oxygen in the melt were simulated, and then the simulation results were compared with the experimental results. The simulation results indicate that for each of the three simulated coatings, inordinate interfacial reactions have occurred between the coating and the melt. The binding energy results show that Y_2O_3 has the best stability and is the most difficult to break down. Zr O_2 has the greatest decomposition energy and is the easiest to break down in the melt. Besides, the molecular dynamics indicate that the diffusion coefficient of the oxygen atom in Al_2O_3 is larger than that in the other two coatings, indicating that oxygen diffusion in Al_2O_3 is the fastest at a given temperature. The experimental results show that the oxygen concentration of the melt with Al_2O_3 coating is the highest, and the oxygen diffusion is of similar magnitude to the simulation values, from which the conclusion can be obtained that the oxygen concentration is significantly influenced by the coating materials.展开更多
To investigate the compression-shear behavior of a new circumferential joint based on the sleeve-straight bolt combination type connection of large-diameter shield tunnels,a series of full-scale joint experiments was ...To investigate the compression-shear behavior of a new circumferential joint based on the sleeve-straight bolt combination type connection of large-diameter shield tunnels,a series of full-scale joint experiments was carried out.In the process of the experiment,more attention was paid to the specimen displacement,bolt stress and joint damage mode.On the basis of these experiment phenomena,this study discussed the compression-shear bearing process of the new connector,analyzed the damage mode of the joint structure,and finally evaluated the performance of the new connector.It is found that the bearing process of the joint can be divided into four stages:the transitional stage for overcoming the friction of the concrete,the sleeve bearing stage for the sleeve bearing shear loads alone,the combined bearing stage for bearing shear loads by the connector system,and the structural damage stage for structural instability and damage.Generally speaking,affected by connector position and hand hole,the positive compression-shear stiffness of the joint is less than the negative compression-shear stiffness,and the positive shear strength of the joint is greater than the negative shear strength.The increase of longitudinal axial force will improve the compression-shear performance of the joint.The relationship between longitudinal axial force and joint stiffness is a logarithmic function.The use of new type of connector can effectively improve the compression-shear stiffness of joints under low shear loads,but the application of straight bolts will lose part of the strength performance.展开更多
Oxygen evolution reaction(OER)plays a crucial role in developing energy conversion and adjusting electronic structure of the electrocatalysts can effectively improve the catalytic activity and stability.However,it is ...Oxygen evolution reaction(OER)plays a crucial role in developing energy conversion and adjusting electronic structure of the electrocatalysts can effectively improve the catalytic activity and stability.However,it is a challenge to adjust the electronic structure on two-dimensional iridium dioxide nanosheets(IrO_(2)NS),which have the advantages of high atom utilization.Here,we regulate the surface properties of IrO_(2)NS through sulfonated carbon dots(SCDs)to promote the OER catalytic process.The catalyst IrO_(2)NS/SCDs-2 exhibited excellent catalytic activity with a lower overpotential of 180 mV than IrO_(2)NS(230 mV)at the current density of 10 mA·cm^(-2)in a 0.5 M H_(2)SO_(4) solution.And after 160 h of stability testing,the overpotential of IrO_(2)NS/SCDs-2 only decreased by 4 mV.Moreover,transient potential scanning test can visually demonstrate that the addition of SCDs improves the conductivity of the catalyst and increases the electron transfer rate.展开更多
Pancreatic cancer is one of the deadly malignancies with a significant mortality rate and there are currently few therapeutic options for it.The tumor microenvironment(TME)in pancreatic cancer,distinguished by fibrosi...Pancreatic cancer is one of the deadly malignancies with a significant mortality rate and there are currently few therapeutic options for it.The tumor microenvironment(TME)in pancreatic cancer,distinguished by fibrosis and the existence of cancer-associated fibroblasts(CAFs),exerts a pivotal influence on both tumor advancement and resistance to therapy.Recent advancements in the field of engineered extracellular vesicles(EVs)offer novel avenues for targeted therapy in pancreatic cancer.This study aimed to develop engineered EVs for the targeted reprogramming of CAFs and modulating the TME in pancreatic cancer.EVs obtained from bone marrow mesenchymal stem cells(BMSCs)were loaded with miR-138-5p and the anti-fibrotic agent pirfenidone(PFD)and subjected to surface modification with integrinα5-targeting peptides(named IEVs-PFD/138)to reprogram CAFs and suppress their pro-tumorigenic effects.Integrinα5-targeting peptide modification enhanced the CAF-targeting ability of EVs.miR-138-5p directly inhibited the formation of the FERMT2-TGFBR1 complex,inhibiting TGF-βsignaling pathway activation.In addition,miR-138-5p inhibited proline-mediated collagen synthesis by directly targeting the FERMT2-PYCR1 complex.The combination of miR-138-5p and PFD in EVs synergistically promoted CAF reprogramming and suppressed the pro-cancer effects of CAFs.Preclinical experiments using the orthotopic stroma-rich and patient-derived xenograft mouse models yielded promising results.In particular,IEVs-PFD/138 effectively reprogrammed CAFs and remodeled TME,which resulted in decreased tumor pressure,enhanced gemcitabine perfusion,tumor hypoxia amelioration,and greater sensitivity of cancer cells to chemotherapy.Thus,the strategy developed in this study can improve chemotherapy outcomes.Utilizing IEVs-PFD/138 as a targeted therapeutic agent to modulate CAFs and the TME represents a promising therapeutic approach for pancreatic cancer.展开更多
More than 90% of hepatocellular carcinoma(HCC)cases develop in the presence of fibrosis or cirrhosis,making the tumor microenvironment(TME)of HCC distinctive due to the intricate interplay between cancer-associated fi...More than 90% of hepatocellular carcinoma(HCC)cases develop in the presence of fibrosis or cirrhosis,making the tumor microenvironment(TME)of HCC distinctive due to the intricate interplay between cancer-associated fibroblasts(CAFs)and cancer stem cells(CSCs),which collectively regulate HCC progression.However,the mechanisms through which CSCs orchestrate the dynamics of the tumor stroma during HCC development remain elusive.Our study unveils a significant upregulation of Sema3C in fibrotic liver,HCC tissues,peripheral blood of HCC patients,as well as sorafenib-resistant tissues and cells,with its overexpression correlating with the acquisition of stemness properties in HCC.We further identify NRP1 and ITGB1 as pivotal functional receptors of Sema3C,activating downstream AKT/Gli1/c-Myc signaling pathways to bolster HCC self-renewal and tumor initiation.Additionally,HCCcells-derived Sema3Cfacilitated extracellular matrix(ECM)contraction and collagen deposition in vivo,while also promoting the proliferation and activation of hepatic stellate cells(HSCs).Mechanistically,Sema3C interacted with NRP1 and ITGB1 in HSCs,activating downstream NF-kB signaling,thereby stimulating the release of IL-6 and upregulating HMGCR expression,consequently enhancing cholesterol synthesis in HSCs.Furthermore,CAF-secreted TGF-β1 activates AP1 signaling to augment Sema3C expression in HCC cells,establishing a positive feedback loop that accelerates HCC progression.Notably,blockade of Sema3C effectively inhibits tumor growth and sensitizes HCC cells to sorafenib in vivo.In sum,our findings spotlight Sema3C as a novel biomarker facilitating the crosstalk between CsCs and stroma during hepatocarcinogenesis,thereby offering a promising avenue for enhancing treatment efficacy and overcoming drug resistance in HCC.展开更多
Electroreduction of carbon dioxide into value-added fuels or chemicals using renewable energy helps to effectively reduce carbon dioxide emission and alleviate the greenhouse effect while storing intermittent energies...Electroreduction of carbon dioxide into value-added fuels or chemicals using renewable energy helps to effectively reduce carbon dioxide emission and alleviate the greenhouse effect while storing intermittent energies.Due to the existing infrastructure of global natural gas utilization and distribution,methane produced in such a green route attracts wide interests.However,limited success has been witnessed in the practical application of catalysts imparting satisfactory methane activity and selectivity.Herein,we report the fabrication of an atomically dispersed Co-Cu alloy through the reconstruction of trace-Co doped Cu metalorganic framework.This catalyst exhibits a methane Faradaic efficiency of 60%±1%with the corresponding partial current density of 303±5 mA·cm^(−2).Operando X-ray adsorption spectroscopy and attenuated-total-reflection surface enhanced infrared spectroscopy unravel that the introduction of atomically dispersed Co in Cu favors*CO protonation via enhancing surface water activation,and suppresses C−C coupling by reducing*CO coverage,thereby leading to high methane selectivity.展开更多
City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dis...City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dispersion,sandy cobble strata can be easily disturbed by shield tunneling.Based on the project of the Chengdu Metro Line 1,field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves,ground loss ratios and construction influence zones.The discrete element method(DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level.Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil.The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.展开更多
Super-resolution structured illumination microscopy(SR-SIM)is an outstanding method for visualizing the subcellular dynamics in living cells.To date,by using elaborately designed systems and algorithms,SR-SIM can achi...Super-resolution structured illumination microscopy(SR-SIM)is an outstanding method for visualizing the subcellular dynamics in living cells.To date,by using elaborately designed systems and algorithms,SR-SIM can achieve rapid,optically sectioned,SR observation with hundreds to thousands of time points.However,real-time observation is still out of reach for most SIM setups as conventional algorithms for image reconstruction involve a heavy computing burden.To address this limitation,an accelerated reconstruction algorithm was developed by implementing a simplified workflow for SR-SIM,termed joint space and frequency reconstruction.This algorithm results in an 80-fold improvement in reconstruction speed relative to the widely used Wiener-SIM.Critically,the increased processing speed does not come at the expense of spatial resolution or sectioning capability,as demonstrated by live imaging of microtubule dynamics and mitochondrial tubulation.展开更多
Lithium-sulfur batteries are promising candidates for next-generation energy storage but are confronted with several challenges. One of the possible solutions is to design proper cathode electrocatalysts to accelerate...Lithium-sulfur batteries are promising candidates for next-generation energy storage but are confronted with several challenges. One of the possible solutions is to design proper cathode electrocatalysts to accelerate the redox interconversion of solvated polysulfide intermediates. Herein, we report cobalt atoms dispersed on hierarchical carbon nitride support as an effective cathode electrocatalyst for lithium-polysulfide batteries. The electrocatalyst material is prepared from the simple reaction between melamine and cyanuric acid in the presence of Co^2+, followed by the Ar annealing. The product has a unique hierarchical structure consisting of many thin and porous C3 N4 nanosheets finely dispersed with Co atoms. The atomic dispersion of Co species is confirmed by X-ray absorption experiments.Electrochemical measurements reveal that it can promote the interconversion of polysulfides. As a result,batteries using this cathode electrocatalyst achieve large capacity($1400 mAh/g at 1.6 mA/cm^2), good rate performance($800 mAh/g at 12.8 mA/cm^2) and impressive cycling stability under different current densities and different sulfur loadings.展开更多
Bearings in a gas turbine engine are the key connecting components transmitting force and motion between rotors and thin-walled flexible casing.The bearing stiffness and damping of squeeze film damper(SFD)nearby beari...Bearings in a gas turbine engine are the key connecting components transmitting force and motion between rotors and thin-walled flexible casing.The bearing stiffness and damping of squeeze film damper(SFD)nearby bearings are easily affected by many factors,such as assembly process,load condition and temperature variation,resulting in uncertainties.The uncertainties may influence the response of the measuring point on the casing.Hence,it is difficult to carry out the fault diagnosis,whole machine balancing and other related works.In this paper,a double integral quantitative evaluation method is proposed to simultaneously analyze the influence of two uncertain dynamic coefficients on the response amplitude and phase of casing measuring points.Meanwhile,the coupling influence of stiffness and damping accompanied by dramatic changes with rotational speeds are essentially discussed.As an example,a typical engine bearing-casing system with complex dynamic characteristics is analyzed.The impact of uncertain dynamic coefficients on the unbalance response is quantitatively evaluated.展开更多
基金supported by the National Natural Science Foundation of China(Nos.81872255,62141109)the Leading-Edge Technology Programme of Jiangsu Natural Science Foundation:BK20212021.
文摘Hepatocellular carcinoma(HCC)is a malignancy known for its unfavorable prognosis.The dysregulation of the tumor microenvironment(TME)can affect the sensitivity to immunotherapy or chemotherapy,leading to treatment failure.The elucidation of PHLDA2’s involvement in HCC is imperative,and the clinical value of PHLDA2 is also underestimated.Here,bioinformatics analysis was performed in multiple cohorts to explore the phenotype and mechanism through which PHLDA2 may affect the progression of HCC.Then,the expression and function of PHLDA2 were examined via the qRT-PCR,Western Blot,and MTT assays.Our findings indicate a substantial upregulation of PHLDA2 in HCC,correlated with a poorer prognosis.The methylation levels of PHLDA2 were found to be lower in HCC tissues compared to normal liver tissues.Besides,noteworthy associations were observed between PHLDA2 expression and immune infiltration in HCC.In addition,PHLDA2 upregulation is closely associated with stemness features and immunotherapy or chemotherapy resistance in HCC.In vitro experiments showed that sorafenib or cisplatin significantly up-regulated PHLDA2 mRNA levels,and PHLDA2 knockdown markedly decreased the sensitivity of HCC cells to chemotherapy drugs.Meanwhile,we found that TGF-βinduced the expression of PHLDA2 in vitro.The GSEA and in vitro experiment indicated that PHLDA2 may promote the HCC progression via activating the AKT signaling pathway.Our study revealed the novel role of PHLDA2 as an independent prognostic factor,which plays an essential role in TME remodeling and treatment resistance in HCC.
基金supported by the National Key R&D Program of China(2020YFA0406103)the National Natural Science Foundation of China(U1932211,12205213)+2 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds(7121453621)the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Project。
文摘Reconstruction during the catalytic process has been considered to play a key role for the performance.Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction(HER),which can benefit from a long-term reconstruction during HER for 10 h to continuously increase the performance.The final catalyst(e-RuNiPO)shows a huge morphology change from bulk sphere to highly exposed layered structure in the electrocatalysis process,and exhibits an interesting electronic structure modification with the electron transfer from Ru to Ni for better interfacial interaction and quick charge transfer.Due to the favorable morphology with more exposed active sites and the optimized electronic structure,the final catalyst can achieve an outstanding performance with only an overpotential of 15 mV at 10 mA cm^(-2)(with a good stability more than 100 h),even outperforming the performance of benchmark 20 wt%Pt/C catalyst(18 mV at 10 mA cm^(-2))by using a much lower Ru content.
基金supported by National Natural Science Foundation of China(NSFC)(Nos.61804103,U1932124)the National Science and Technology Major Project from Minister of Science and Technology of China(Grant No.2018AAA0103104)+8 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.18KJA535001)Natural Science Foundation of Jiangsu Province of China(Nos.BK20170343,BK20180242)Jiangsu Key Laboratory for Carbon Based Functional Materials and Devices,Soochow University(KJS1803)the XJTLU Key Programme Special Fund(KSF-A-18)Jiangsu Province Engineering Laboratory of High Efficient Energy Storage Technology and Equipments,China University of Mining and Technology(CUMT)supported by Collaborative Innovation Center of Suzhou Nano Science and Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices.
文摘Photoelectrochemical hydrogen generation is a promising approach to address the environmental pollution and energy crisis.In this work,we present a hybridized mechanical and solar energy-driven selfpowered hydrogen production system.A rotatory disc-shaped triboelectric nanogenerator was employed to harvest mechanical energy from water and functions as a su cient external power source.WO3/BiVO4 heterojunction photoanode was synthesized in a PEC water-splitting cell to produce H2.After transformation and rectification,the peak current reaches 0.1 m A at the rotation speed of 60 rpm.In this case,the H2 evolution process only occurs with sunlight irradiation.When the rotation speed is over 130 rpm,the peak photocurrent and peak dark current have nearly equal value.Direct electrolysis of water is almost simultaneous with photoelectrocatalysis of water.It is worth noting that the hydrogen production rate increases to 5.45 and 7.27μL min-1 without or with light illumination at 160 rpm.The corresponding energy conversion e ciency is calculated to be 2.43%and 2.59%,respectively.All the results demonstrate such a self-powered system can successfully achieve the PEC hydrogen generation,exhibiting promising possibility of energy conversion.
基金the support from the high-performance computing platform of Jiangsu UniversityThe Jiangsu University Foundation (18JDG019)+3 种基金the Postdoctoral Foundation of Jiangsu Province (2018K072C)Six Talent Peak Project of Jiangsu Province (XLC-158)the China Postdoctoral Science Foundation (2019M651727, 2019M651719)the National Natural Science Foundation of China (21808090, 51902139, U1932211) financially supported this work。
文摘Hematite is regarded as a promising photoanode for photoelectrochemical(PEC) water splitting.However,the charge recombination occurred at the interface of FTO/hematite strictly limits the PEC performance of hematite.Herein,we reported a Ti3C2 MXene underlayer modified hematite(Ti-Fe2O3) photoanode via a simple drop-casting followed by hydrothermal and annealing processes.Owing to the bifunctional role of Ti3C2 MXene underlayer in improving the interfacial properties of FTO/hematite and providing Ti source for the construction of Fe2 TiO5/Fe2O3 heterostructure in hematite nanostructure,the bulk and interfacial charge transfer dynamics of hematite are significantly enhanced,and consequently enhancing the PEC performance.Compared with the pristine hematite,the as-prepared Ti-Fe2O3 photoanode shows an increased photocurrent density from 0.80 mA/cm^(2) to 1.30 mA/cm^(2) at 1.23 V vs.RHE.Moreover,a further promoted PEC performance including a dramatically increased photocurrent density of 2.49 mA/cm^(2) at1.23 V vs.RHE and an obviously lowered onset potential is achieved for the Ti-Fe2O3 sample after the subsequent surface F-treatment and the loading of FeNiOOH cocatalyst.Such results suggest that the introduction of Ti3C2 MXene underlayer is a facile but effective approach to improve the PEC water splitting activity of hematite.
文摘BACKGROUND An atrial septal defect is a common condition and accounts for 25%of adult congenital heart diseases.Transcatheter occlusion is a widely used technique for the treatment of secondary aperture-type atrial septal defects(ASDs).CASE SUMMARY A 30-year-old female patient was diagnosed with ASD by transthoracic echocardiography(TTE)1 year ago.The electrocardiogram showed a heart rate of 88 beats per minute,normal sinus rhythm,and no change in the ST-T wave.After admission,TTE showed an atrial septal defect with a left-to-right shunt,aortic root short-axis section with an ASD diameter of 8 mm,a parasternal four-chamber section with an ASD diameter of 9 mm,and subxiphoid biatrial section with a diameter of 13 mm.Percutaneous occlusion was proposed.The intraoperative TTE scan showed that the atrial septal defect was oval in shape,was located near the root of the aorta,and had a maximum diameter of 13 mm.A 10-F sheath was placed in the right femoral vein,and a 0.035°hard guidewire was used to establish the transport track between the left pulmonary vein and the inferior vena cava.A shape-memory alloy atrial septal occluder with a waist diameter of 20 mm was placed successfully and located correctly.TTE showed that the double disk unfolded well and that the clamping of the atrial septum was smooth.Immediately after the disc was revealed,electrocardiograph monitoring showed that the ST interval of the inferior leads was prolonged,the P waves and QRS waves were separated,a junctional escape rhythm maintained the heart rate,and the blood pressure began to decrease.After removing the occluder,the elevation in the ST segment returned to normal immediately,and the sinus rhythm returned to average approximately 10 min later.After consulting the patient’s family,we finally decided to withdraw from the operation.CONCLUSION Compression of the small coronary artery,which provides an alternative blood supply to the atrioventricular nodule during the operation,leads to the emergence of a complete atrioventricular block.
基金supported by the National Natural Science Foundation of China(U1932211,U1732110)the Collaborative Innovation Center of Suzhou Nano Science&Technology+3 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Projectthe support from Users with Excellence Program of Hefei Science Center CAS(2019HSC-UE002)Post graduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX19_1921)。
文摘Efficient electrocatalysts for hydrogen evolution reaction(HER) in alkaline solution are highly required for water splitting.Here we design an ultra-small PtOx nanoparticle with hybrid Pt chemical states on carbon nanotubes as highly efficient alkaline HER catalyst,which shows a low overpotential of 19.4 mV at 10 mA cm^(-2),a high mass activity of 5.56 A mg_(Pt)^(-1) at 0.1 V, and a stable durability for at least 20 h.The HER performance is better than that of the benchmark 20 wt% Pt/C while the Pt content in the catalyst is only about one tenth of that in Pt/C.It also represents one of the best catalysts ever reported for HER in alkaline solution.Synchrotron radiation X-ray absorption spectroscopy reveals that the efficient and stable alkaline HER performance can be attributed to the favorable design of hybrid chemical states of Pt with carbon nanotubes,which exhibits abundant surface Pt-O as active catalytic sites and forms stable Pt-C interfacial interaction to both anchor the NPs and improve the synergistic effect between catalyst and substrate.
基金supported by the National Key R&D Program of China (2020YFA0406103)the National Natural Science Foundation of China (U1932211)+1 种基金the Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the 111 Project。
文摘Hematite is an excellent catalyst for photoelectrochemical (PEC) water splitting but its performance has been highly limited by poor conductivity and high charge recombination.Here by a Zr-based treatment to create bulk Fe_(2)ZrO_(5) in hematite and a F-based treatment to form an ultrathin surface FeF_(x) layer,the charge transfer can be highly improved and the charge recombination can be significantly suppressed.As a result,the FeF_(x) /Zr-Fe_(2)O_(3) photoanode presents an enhanced PEC performance with a photocurrent density of 2.43 m A/cm^(2)at 1.23 V vs.RHE,which is around 3 times higher than that of the pristine Fe_(2)O_(3) .The FeF_(x) /Zr-Fe_(2)O_(3) photoanode also shows a low onset potential of 0.77 V vs.RHE (100 mV lower than the pristine hematite).The performance is much higher than that of the sample treated by Zr or F alone,suggesting the synergistic effect between bulk Fe_(2)ZrO_(5) and surface FeF_(x) .By coupling with the FeNiOOH co-catalyst,the final photoanode can achieve a high photocurrent density of 2.81 mA/cm^(2) at 1.23 V vs.RHE.The novel design of Zr and F co-modified hematite can be used as a promising way to prepare efficient catalysts for solar water splitting.
基金This work is supported by the National Key Research and Development Program of China under Grant 2020YFC2004003 and Grant 2020YFC2004002the National Nature Science Foundation of China(NSFC)under Grant No.61571106.
文摘Traditional separation methods have limited ability to handle the speech separation problem in high reverberant and low signal-to-noise ratio(SNR)environments,and thus achieve unsatisfactory results.In this study,a convolutional neural network with temporal convolution and residual network(TC-ResNet)is proposed to realize speech separation in a complex acoustic environment.A simplified steered-response power phase transform,denoted as GSRP-PHAT,is employed to reduce the computational cost.The extracted features are reshaped to a special tensor as the system inputs and implements temporal convolution,which not only enlarges the receptive field of the convolution layer but also significantly reduces the network computational cost.Residual blocks are used to combine multiresolution features and accelerate the training procedure.A modified ideal ratio mask is applied as the training target.Simulation results demonstrate that the proposed microphone array speech separation algorithm based on TC-ResNet achieves a better performance in terms of distortion ratio,source-to-interference ratio,and short-time objective intelligibility in low SNR and high reverberant environments,particularly in untrained situations.This indicates that the proposed method has generalization to untrained conditions.
基金Supported by Technology Project of Yunnan Tobacco Monopoly Bureau(201-5YN25)
文摘Using the method in Biodiversity Risk and Opportunity Assessment Handbook of British American Tobacco Biodiversity Partnership,we assess biodiversity risks and opportunities in BAT and China's cooperative tobacco-growing areas. The assessment results indicate that there are 8 risks and 1 opportunity. Action and monitoring plans have been made for medium and high risks as well as opportunity,to reduce impact on biodiversity.
基金financially supported by the National Natural Science Foundation of China(No.51304198)the Natural Science Foundation of Jiangsu Province,China(Nos.2013106,20141134 and 2014028-08)
文摘The effect of coatings(Y_2O_3, Zr O_2 and Al_2O_3) on the interfacial reaction of Ti Al alloys was studied with molecular dynamics. The binding energy of coatings and the diffusion process of oxygen in the melt were simulated, and then the simulation results were compared with the experimental results. The simulation results indicate that for each of the three simulated coatings, inordinate interfacial reactions have occurred between the coating and the melt. The binding energy results show that Y_2O_3 has the best stability and is the most difficult to break down. Zr O_2 has the greatest decomposition energy and is the easiest to break down in the melt. Besides, the molecular dynamics indicate that the diffusion coefficient of the oxygen atom in Al_2O_3 is larger than that in the other two coatings, indicating that oxygen diffusion in Al_2O_3 is the fastest at a given temperature. The experimental results show that the oxygen concentration of the melt with Al_2O_3 coating is the highest, and the oxygen diffusion is of similar magnitude to the simulation values, from which the conclusion can be obtained that the oxygen concentration is significantly influenced by the coating materials.
基金supports of the National Key R&D Program of China(Grant No.2021YFB2600900)National Natural Science Foundation of China(Grant No.52078430)Yunnan Provincial Science and Technology Department of China(Grant No.202002AF080003).
文摘To investigate the compression-shear behavior of a new circumferential joint based on the sleeve-straight bolt combination type connection of large-diameter shield tunnels,a series of full-scale joint experiments was carried out.In the process of the experiment,more attention was paid to the specimen displacement,bolt stress and joint damage mode.On the basis of these experiment phenomena,this study discussed the compression-shear bearing process of the new connector,analyzed the damage mode of the joint structure,and finally evaluated the performance of the new connector.It is found that the bearing process of the joint can be divided into four stages:the transitional stage for overcoming the friction of the concrete,the sleeve bearing stage for the sleeve bearing shear loads alone,the combined bearing stage for bearing shear loads by the connector system,and the structural damage stage for structural instability and damage.Generally speaking,affected by connector position and hand hole,the positive compression-shear stiffness of the joint is less than the negative compression-shear stiffness,and the positive shear strength of the joint is greater than the negative shear strength.The increase of longitudinal axial force will improve the compression-shear performance of the joint.The relationship between longitudinal axial force and joint stiffness is a logarithmic function.The use of new type of connector can effectively improve the compression-shear stiffness of joints under low shear loads,but the application of straight bolts will lose part of the strength performance.
基金supported by Natural Science Foundation of Jiangsu Province(No.BK20220028)the National Key R&D Program of China(Nos.2020YFA0406104 and 2020YFA0406101)+2 种基金the National Natural Science Foundation of China(Nos.52271223,52272043,52202107,52201269,22273063 and 52302296)the Science and Technology Development Fund,Macao SAR(No.0009/2022/ITP)Collaborative Innovation Center of Suzhou Nano Science and Technology,the 111 Project and Suzhou Key Laboratory of Functional Nano and Soft Materials.
文摘Oxygen evolution reaction(OER)plays a crucial role in developing energy conversion and adjusting electronic structure of the electrocatalysts can effectively improve the catalytic activity and stability.However,it is a challenge to adjust the electronic structure on two-dimensional iridium dioxide nanosheets(IrO_(2)NS),which have the advantages of high atom utilization.Here,we regulate the surface properties of IrO_(2)NS through sulfonated carbon dots(SCDs)to promote the OER catalytic process.The catalyst IrO_(2)NS/SCDs-2 exhibited excellent catalytic activity with a lower overpotential of 180 mV than IrO_(2)NS(230 mV)at the current density of 10 mA·cm^(-2)in a 0.5 M H_(2)SO_(4) solution.And after 160 h of stability testing,the overpotential of IrO_(2)NS/SCDs-2 only decreased by 4 mV.Moreover,transient potential scanning test can visually demonstrate that the addition of SCDs improves the conductivity of the catalyst and increases the electron transfer rate.
基金supported by National Major Scientific Research Instrument Development Project:62227803the Key Program of the National Natural Science Foundation of China:62331016+2 种基金National Natural Science Foundation of China:62141109the Leading-edge Technology Programme of Jiangsu Natural Science Foundation:BK20212012Key Research and Development Plan Project of Jiangsu Province:BE2022812.
文摘Pancreatic cancer is one of the deadly malignancies with a significant mortality rate and there are currently few therapeutic options for it.The tumor microenvironment(TME)in pancreatic cancer,distinguished by fibrosis and the existence of cancer-associated fibroblasts(CAFs),exerts a pivotal influence on both tumor advancement and resistance to therapy.Recent advancements in the field of engineered extracellular vesicles(EVs)offer novel avenues for targeted therapy in pancreatic cancer.This study aimed to develop engineered EVs for the targeted reprogramming of CAFs and modulating the TME in pancreatic cancer.EVs obtained from bone marrow mesenchymal stem cells(BMSCs)were loaded with miR-138-5p and the anti-fibrotic agent pirfenidone(PFD)and subjected to surface modification with integrinα5-targeting peptides(named IEVs-PFD/138)to reprogram CAFs and suppress their pro-tumorigenic effects.Integrinα5-targeting peptide modification enhanced the CAF-targeting ability of EVs.miR-138-5p directly inhibited the formation of the FERMT2-TGFBR1 complex,inhibiting TGF-βsignaling pathway activation.In addition,miR-138-5p inhibited proline-mediated collagen synthesis by directly targeting the FERMT2-PYCR1 complex.The combination of miR-138-5p and PFD in EVs synergistically promoted CAF reprogramming and suppressed the pro-cancer effects of CAFs.Preclinical experiments using the orthotopic stroma-rich and patient-derived xenograft mouse models yielded promising results.In particular,IEVs-PFD/138 effectively reprogrammed CAFs and remodeled TME,which resulted in decreased tumor pressure,enhanced gemcitabine perfusion,tumor hypoxia amelioration,and greater sensitivity of cancer cells to chemotherapy.Thus,the strategy developed in this study can improve chemotherapy outcomes.Utilizing IEVs-PFD/138 as a targeted therapeutic agent to modulate CAFs and the TME represents a promising therapeutic approach for pancreatic cancer.
基金This study was supported by the National Natural Science Foundation of China(Nos.62331016,62227803,U22A2023,62325112)the Leading-edge Technology Programme of Jiangsu Natural Science Foundation:BE2022812,BK20212021。
文摘More than 90% of hepatocellular carcinoma(HCC)cases develop in the presence of fibrosis or cirrhosis,making the tumor microenvironment(TME)of HCC distinctive due to the intricate interplay between cancer-associated fibroblasts(CAFs)and cancer stem cells(CSCs),which collectively regulate HCC progression.However,the mechanisms through which CSCs orchestrate the dynamics of the tumor stroma during HCC development remain elusive.Our study unveils a significant upregulation of Sema3C in fibrotic liver,HCC tissues,peripheral blood of HCC patients,as well as sorafenib-resistant tissues and cells,with its overexpression correlating with the acquisition of stemness properties in HCC.We further identify NRP1 and ITGB1 as pivotal functional receptors of Sema3C,activating downstream AKT/Gli1/c-Myc signaling pathways to bolster HCC self-renewal and tumor initiation.Additionally,HCCcells-derived Sema3Cfacilitated extracellular matrix(ECM)contraction and collagen deposition in vivo,while also promoting the proliferation and activation of hepatic stellate cells(HSCs).Mechanistically,Sema3C interacted with NRP1 and ITGB1 in HSCs,activating downstream NF-kB signaling,thereby stimulating the release of IL-6 and upregulating HMGCR expression,consequently enhancing cholesterol synthesis in HSCs.Furthermore,CAF-secreted TGF-β1 activates AP1 signaling to augment Sema3C expression in HCC cells,establishing a positive feedback loop that accelerates HCC progression.Notably,blockade of Sema3C effectively inhibits tumor growth and sensitizes HCC cells to sorafenib in vivo.In sum,our findings spotlight Sema3C as a novel biomarker facilitating the crosstalk between CsCs and stroma during hepatocarcinogenesis,thereby offering a promising avenue for enhancing treatment efficacy and overcoming drug resistance in HCC.
基金supported by the National Natural Science Foundation of China(Nos.22072101 and 22075193)the Natural Science Foundation of Jiangsu Province(No.BK20211306)+1 种基金Six Talent Peaks Project in Jiangsu Province(No.TD-XCL-006)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Electroreduction of carbon dioxide into value-added fuels or chemicals using renewable energy helps to effectively reduce carbon dioxide emission and alleviate the greenhouse effect while storing intermittent energies.Due to the existing infrastructure of global natural gas utilization and distribution,methane produced in such a green route attracts wide interests.However,limited success has been witnessed in the practical application of catalysts imparting satisfactory methane activity and selectivity.Herein,we report the fabrication of an atomically dispersed Co-Cu alloy through the reconstruction of trace-Co doped Cu metalorganic framework.This catalyst exhibits a methane Faradaic efficiency of 60%±1%with the corresponding partial current density of 303±5 mA·cm^(−2).Operando X-ray adsorption spectroscopy and attenuated-total-reflection surface enhanced infrared spectroscopy unravel that the introduction of atomically dispersed Co in Cu favors*CO protonation via enhancing surface water activation,and suppresses C−C coupling by reducing*CO coverage,thereby leading to high methane selectivity.
基金Project supported by the National Basic Research (973) Program of China (No. 2010CB732105)the National Natural Science Foundation of China (Nos. 50908193,50925830,and 51208432)
文摘City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dispersion,sandy cobble strata can be easily disturbed by shield tunneling.Based on the project of the Chengdu Metro Line 1,field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves,ground loss ratios and construction influence zones.The discrete element method(DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level.Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil.The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.
基金supported by the National Natural Science Foundation of China (NSFC) (Nos. 62005208, 62135003, and 61905189)Innovation Capability Support Program of Shaanxi (No. 2021TD-57)+1 种基金China Postdoctoral Science Foundation (Nos. 2020M673365 and 2019M663656)National Institutes of Health Grant GM100156 to PRB
文摘Super-resolution structured illumination microscopy(SR-SIM)is an outstanding method for visualizing the subcellular dynamics in living cells.To date,by using elaborately designed systems and algorithms,SR-SIM can achieve rapid,optically sectioned,SR observation with hundreds to thousands of time points.However,real-time observation is still out of reach for most SIM setups as conventional algorithms for image reconstruction involve a heavy computing burden.To address this limitation,an accelerated reconstruction algorithm was developed by implementing a simplified workflow for SR-SIM,termed joint space and frequency reconstruction.This algorithm results in an 80-fold improvement in reconstruction speed relative to the widely used Wiener-SIM.Critically,the increased processing speed does not come at the expense of spatial resolution or sectioning capability,as demonstrated by live imaging of microtubule dynamics and mitochondrial tubulation.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education InstitutionsCollaborative Innovation Center of Suzhou Nano Science and Technology
文摘Lithium-sulfur batteries are promising candidates for next-generation energy storage but are confronted with several challenges. One of the possible solutions is to design proper cathode electrocatalysts to accelerate the redox interconversion of solvated polysulfide intermediates. Herein, we report cobalt atoms dispersed on hierarchical carbon nitride support as an effective cathode electrocatalyst for lithium-polysulfide batteries. The electrocatalyst material is prepared from the simple reaction between melamine and cyanuric acid in the presence of Co^2+, followed by the Ar annealing. The product has a unique hierarchical structure consisting of many thin and porous C3 N4 nanosheets finely dispersed with Co atoms. The atomic dispersion of Co species is confirmed by X-ray absorption experiments.Electrochemical measurements reveal that it can promote the interconversion of polysulfides. As a result,batteries using this cathode electrocatalyst achieve large capacity($1400 mAh/g at 1.6 mA/cm^2), good rate performance($800 mAh/g at 12.8 mA/cm^2) and impressive cycling stability under different current densities and different sulfur loadings.
基金co-supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.51905025)the Joint Funds of the National Natural Science Foundation of China(No.U1708257)the Fundamental Research Funds for the Central Universities(No.JD1911)。
文摘Bearings in a gas turbine engine are the key connecting components transmitting force and motion between rotors and thin-walled flexible casing.The bearing stiffness and damping of squeeze film damper(SFD)nearby bearings are easily affected by many factors,such as assembly process,load condition and temperature variation,resulting in uncertainties.The uncertainties may influence the response of the measuring point on the casing.Hence,it is difficult to carry out the fault diagnosis,whole machine balancing and other related works.In this paper,a double integral quantitative evaluation method is proposed to simultaneously analyze the influence of two uncertain dynamic coefficients on the response amplitude and phase of casing measuring points.Meanwhile,the coupling influence of stiffness and damping accompanied by dramatic changes with rotational speeds are essentially discussed.As an example,a typical engine bearing-casing system with complex dynamic characteristics is analyzed.The impact of uncertain dynamic coefficients on the unbalance response is quantitatively evaluated.
