The evolution of mechanical properties,localized corrosion resistance of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging(NIA)was investigated by hardness test,electrical conductivity test,tensile test,inte...The evolution of mechanical properties,localized corrosion resistance of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging(NIA)was investigated by hardness test,electrical conductivity test,tensile test,intergranular corrosion test,exfoliation corrosion test,slow strain rate tensile test and electrochemical test,and the mechanism has been discussed based on microstructure examination by optical microscopy,electron back scattered diffraction,scanning electron microscopy and scanning transmission electron microscopy.The NIA treatment includes a heating stage from 40℃to 180℃with a rate of 20℃/h and a cooling stage from 180℃to 40℃with a rate of 10℃/h.The results show that the hardness and strength increase rapidly during the heating stage of NIA since the increasing temperature favors the nucleation and the growth of strengthening precipitates and promotes the transformation of Guinier-Preston(GPI)zones toη'phase.During the cooling stage,the sizes ofη'phase increase with a little change in the number density,leading to a further slight increase of the hardness and strength.As NIA proceeds,the corroded morphology in the alloy changes from a layering feature to a wavy feature,the maximum corrosion depth decreases,and the reason has been analyzed based on the microstructural and microchemical feature of precipitates at grain boundaries and subgrain boundaries.展开更多
Revealing the localized corrosion process of Mg alloy is considered as one of the most significant ways for improving its corrosion resistance.The reliable monitor should be high distinguishability and real-time in li...Revealing the localized corrosion process of Mg alloy is considered as one of the most significant ways for improving its corrosion resistance.The reliable monitor should be high distinguishability and real-time in liquid environment.Herein,Mg-9Al-1Fe and Mg-9Al-1Fe-1Gd alloys were designed to highlight the impact of intermetallic on the corrosion behaviour.In-situ AFM with a special electrolyte circulation system and quasi-in-situ SEM observation were used to monitor the corrosion process of the designed alloys.SEM-EDS and TEM-SAED were applied to identify the intermetallic in the designed alloys,and their volta potentials were measured by SKPFM.According to the real-time and real-space in-situ AFM monitor,the corrosion process consisted of dissolution of anodicα-Mg phase,accumulation of corrosion products around cathodic phase and shedding of some fine cathodic phase.Then,the localized corrosion process of Mg alloy was revealed combined with the results of the monitor of corrosion process and Volta potential difference.展开更多
The commercialization of silicon-based anodes is affected by their low initial Coulombic efficiency(ICE)and capacity decay,which are attributed to the formation of an unstable solid electrolyte interface(SEI)layer.Her...The commercialization of silicon-based anodes is affected by their low initial Coulombic efficiency(ICE)and capacity decay,which are attributed to the formation of an unstable solid electrolyte interface(SEI)layer.Herein,a feasible and cost-effective prelithiation method under a localized highconcentration electrolyte system(LHCE)for the silicon-silica/graphite(Si-SiO_(2)/C@G)anode is designed for stabilizing the SEI layer and enhancing the ICE.The thin SiO_(2)/C layers with-NH_(2) groups covered on nano-Si surfaces are demonstrated to be beneficial to the prelithiation process by density functional theory calculations and electrochemical performance.The SEI formed under LHCE is proven to be rich in ionic conductivity,inorganic substances,and flexible organic products.Thus,faster Li+transportation across the SEI further enhances the prelithiation effect and the rate performance of Si-SiO_(2)/C@G anodes.LHCE also leads to uniform decomposition and high stability of the SEI with abundant organic components.As a result,the prepared anode shows a high reversible specific capacity of 937.5 mAh g^(-1)after 400 cycles at a current density of 1 C.NCM 811‖Li-SSGLHCE full cell achieves a high-capacity retention of 126.15 mAh g^(-1)at 1 C over 750 cycles with 84.82%ICE,indicating the great value of this strategy for Si-based anodes in large-scale applications.展开更多
We investigated the one-dimensional diamond ladder in the momentum lattice platform. By inducing multiple twoand four-photon Bragg scatterings among specific momentum states, we achieved a flat band system based on th...We investigated the one-dimensional diamond ladder in the momentum lattice platform. By inducing multiple twoand four-photon Bragg scatterings among specific momentum states, we achieved a flat band system based on the diamond model, precisely controlling the coupling strength and phase between individual lattice sites. Utilizing two lattice sites couplings, we generated a compact localized state associated with the flat band, which remained localized throughout the entire time evolution. We successfully realized the continuous shift of flat bands by adjusting the corresponding nearest neighbor hopping strength, enabling us to observe the complete localization process. This opens avenues for further exploration of more complex properties within flat-band systems, including investigating the robustness of flat-band localized states in disordered flat-band systems and exploring many-body localization in interacting flat-band systems.展开更多
Structural damage in heterogeneousmaterials typically originates frommicrostructures where stress concentration occurs.Therefore,evaluating the magnitude and location of localized stress distributions within microstru...Structural damage in heterogeneousmaterials typically originates frommicrostructures where stress concentration occurs.Therefore,evaluating the magnitude and location of localized stress distributions within microstructures under external loading is crucial.Repeating unit cells(RUCs)are commonly used to represent microstructural details and homogenize the effective response of composites.This work develops a machine learning-based micromechanics tool to accurately predict the stress distributions of extracted RUCs.The locally exact homogenization theory efficiently generates the microstructural stresses of RUCs with a wide range of parameters,including volume fraction,fiber/matrix property ratio,fiber shapes,and loading direction.Subsequently,the conditional generative adversarial network(cGAN)is employed and constructed as a surrogate model to establish the statistical correlation between these parameters and the corresponding localized stresses.The stresses predicted by cGAN are validated against the remaining true data not used for training,showing good agreement.This work demonstrates that the cGAN-based micromechanics tool effectively captures the local responses of composite RUCs.It can be used for predicting potential crack initiations starting from microstructures and evaluating the effective behavior of periodic composites.展开更多
We present a class of preconditioners for the linear systems resulting from a finite element or discontinuous Galerkin discretizations of advection-dominated problems.These preconditioners are designed to treat the ca...We present a class of preconditioners for the linear systems resulting from a finite element or discontinuous Galerkin discretizations of advection-dominated problems.These preconditioners are designed to treat the case of geometrically localized stiffness,where the convergence rates of iterative methods are degraded in a localized subregion of the mesh.Slower convergence may be caused by a number of factors,including the mesh size,anisotropy,highly variable coefficients,and more challenging physics.The approach taken in this work is to correct well-known preconditioners such as the block Jacobi and the block incomplete LU(ILU)with an adaptive inner subregion iteration.The goal of these preconditioners is to reduce the number of costly global iterations by accelerating the convergence in the stiff region by iterating on the less expensive reduced problem.The tolerance for the inner iteration is adaptively chosen to minimize subregion-local work while guaranteeing global convergence rates.We present analysis showing that the convergence of these preconditioners,even when combined with an adaptively selected tolerance,is independent of discretization parameters(e.g.,the mesh size and diffusion coefficient)in the subregion.We demonstrate significant performance improvements over black-box preconditioners when applied to several model convection-diffusion problems.Finally,we present performance results of several variations of iterative subregion correction preconditioners applied to the Reynolds number 2.25×10^(6)fluid flow over the NACA 0012 airfoil,as well as massively separated flow at 30°angle of attack.展开更多
Background: Localized pancreatic cancer, including resectable (R), borderline resectable (BR) and locally advanced unresectable disease (LAU), is considered in clinical guidelines for diverse treatment options based o...Background: Localized pancreatic cancer, including resectable (R), borderline resectable (BR) and locally advanced unresectable disease (LAU), is considered in clinical guidelines for diverse treatment options based on clinical trials in selected populations. Hence, exploring with real world evidence (RWE) clinicians’ preferences for treatment options and their results seems pertinent. Methods: In a set of consecutive patients with localized pancreatic cancer assisted in a third level hospital from January 2013 to December 2022, medical records, symptoms, diagnostic process, distribution between subtypes, and treatment plans, with safety and efficacy results, were assessed. Results: A total of 152 patients with localized disease were included (43.4% R, 21.0% BR, 33.6% LAU). The population characteristics exemplified differences between daily practice and clinical trials. Tumor location and symptoms were as expected. Treatment plan was conditioned by PS or comorbidities in 23.0% of patients. In patients with R disease, surgery followed by different adjuvant chemotherapy (CT) regimes was the antineoplastic treatment of choice (64.8%) with efficacy results (OS 37.5 months;95% CI 18.4 - 56.7), in the range of contemporary standards. The common use of neoadjuvant CT for BR disease (94.4%), with surgery in 50% of them, and its results (OS 30.8 months;95% CI 10.5 - 51.2) reflected current controversies of treatment recommendations and evolution in this scenario. Paliative CT with or without radiotherapy was the standard specific treatment in LAU disease (95.1%) with survival results (PFS: 10.8 months;95% CI 8.8 - 12.7. OS: 20.3 months;95% CI 13.5 - 27.2) that justify the distinct character and the specific study of this entity. Conclusion: RWE for localized pancreatic cancer aroused from the analysis of this population confirms the distinct nature of patients assisted in daily practice, as well as mirrors the complexity of decision making in clinical assumptions in which achieving stronger evidence should be paramount.展开更多
Jakarta-Bandung HSR in Indonesia is the first“go global”project of China's high speed railway with a whole system,all elements and a whole industry chain,as well as the first overseas project adopting a complete...Jakarta-Bandung HSR in Indonesia is the first“go global”project of China's high speed railway with a whole system,all elements and a whole industry chain,as well as the first overseas project adopting a complete set of Chinese standards.This paper sorts out the differences between relevant standards in China and Indonesia,including those in concrete raw materials,rebar standards and other main material standards,and those in external interface standards,train operation direction requirements,project approval requirements,special acceptance requirements,etc.,and summarizes the realization methods and specific achievements of localized application of Chinese standards during the implementation of Jakarta-Bandung HSR Project,to provide reference for localized application of Chinese standards in overseas projects in the future.展开更多
A high speed LIGBT with localized lifetime control by using high dose and low en ergy helium implantation(LC-LIGBT) is proposed.Compared with conventional LIGB Ts,particle irradiation results show that trade-off relat...A high speed LIGBT with localized lifetime control by using high dose and low en ergy helium implantation(LC-LIGBT) is proposed.Compared with conventional LIGB Ts,particle irradiation results show that trade-off relationship between turn- off time and forward voltage drop is improved.At the same time,the forward volta ge drop and turn-off time of such device are researched,when localized lifetime control region place near the p+-n junction,even in p+ anode.The results s how for the first time,helium ions,which stop in the p+ anode,also contribute to the forward voltage drop increasing and turn-off time reducing.展开更多
The paper had studied localized design and construction of roof garden.Starting from the history of roof garden,it summarized development of roof garden.It was considered that roof garden could not only provide public...The paper had studied localized design and construction of roof garden.Starting from the history of roof garden,it summarized development of roof garden.It was considered that roof garden could not only provide public rest space,realize thermal insulation and noise reduction of architectures,help water-storage and urban drainage;but also beautify environment,ameliorate regional climate,enrich urban landscape,help to increase ground greening area and improve ecological quality.Finally,some designing principles for roof garden had been proposed,including ① enhancing security consciousness and highlighting roof load design;② emphasizing ecological use and stressing greening coverage;③ manifesting artistic feature;④ investing cautiously,saving construction cost and paying attention to later maintenance.展开更多
Recently, there was a hot controversy about the concept of localized orbitals, which was triggered by Grushow's work titled "Is it time to retire the hybrid atomic orbital?" [J. Chem. Educ. 88, 860 (2011)]. To c...Recently, there was a hot controversy about the concept of localized orbitals, which was triggered by Grushow's work titled "Is it time to retire the hybrid atomic orbital?" [J. Chem. Educ. 88, 860 (2011)]. To clarify the issue, we assess the delocalized and localized molecular orbitals from an experimental view using electron momentum spectroscopy. The delocalized and localized molecular orbitals based on various theoretical models for CH4, NH3, and H20 are compared with the experimental momentum distributions. Our results show that the delocalized molecular orbitals rather than the localized ones can give a direct interpretation of the experimental (e, 2e) results.展开更多
To clarify the corrosion mechanism associated with the precipitate of T1(Al2CuLi)in Al-Li alloys,the simulated bulk precipitate of T1 was fabricated through melting and casting.Its electrochemical behavior and couplin...To clarify the corrosion mechanism associated with the precipitate of T1(Al2CuLi)in Al-Li alloys,the simulated bulk precipitate of T1 was fabricated through melting and casting.Its electrochemical behavior and coupling behavior with α(Al)in 3.5% NaCl solution were investigated.Meanwhile,the simulated Al alloy containing T1 particle was prepared and its corrosion morphology was observed.The results show that there exists a dynamic conversion corrosion mechanism associated with the precipitate of T1.At the beginning,the precipitate of T1 is anodic to the alloy base and corrosion occurs on its surface.However,during its corrosion process,its potential moves to a positive direction with immersion time increasing,due to the preferential dissolution of Li and the enrichment of Cu.As a result,the corroded T1 becomes cathodic to the alloy base at a later stage,leading to the anodic dissolution and corrosion of the alloy base at its adjacent periphery.It is suggested that the localized corrosion associated with the precipitate of T1 in Al-Li alloys is caused by the alternate anodic dissolution of the T1 precipitate and the alloy base at its adjacent periphery.展开更多
By using a mapping approach and a linear variable separation approach, a new family of solitary wave solutions with arbitrary functions for the (2+1)-dimensional modified dispersive water-wave system (MDWW) is de...By using a mapping approach and a linear variable separation approach, a new family of solitary wave solutions with arbitrary functions for the (2+1)-dimensional modified dispersive water-wave system (MDWW) is derived. Based on the derived solutions and using some multi-valued functions, we obtain some novel folded localized excitations of the system.展开更多
The key to realize long-life high energy density lithium batteries is to exploit functional electrolytes capable of stabilizing both high voltage cathode and lithium anode.The emergence of localized high-concentration...The key to realize long-life high energy density lithium batteries is to exploit functional electrolytes capable of stabilizing both high voltage cathode and lithium anode.The emergence of localized high-concentration electrolytes(LHCEs)shows great promise for ameliorating the above-mentioned interfacial issues.In this work,a lithium difluoro(oxalate)borate(LiDFOB)based nonflammable dual-anion LHCE is designed and prepared.Dissolving in the mixture of trimethyl phosphate(TMP)/1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether(D_(2)),the continuously consumption of LiDFOB is suppressed by simply introducing lithium nitrate(LiNO_(3)).Meantime,as most of the TMP molecular are coordinated with Li^(+),the electrolyte does not show incompatibility issue between neither metal lithium nor graphite anode.Therefore,it demonstrates excellent capability in stabilizing the interface of Ni-rich cathode and regulating lithium deposition morphology.The Li||LiNi_(0.87)Co_(0.08)Mn_(0.05)O_(2)(NCM87)batteries exhibit high capacity retention of more than 90%after 200 cycles even under the high cutoff voltage of 4.5 V,1 C rate.This study offers a prospective method to develop safe electrolytes suitable for high voltage applications,thus providing higher energy densities.展开更多
The fabrication of pure copper microstructures with submicron resolution has found a host of applications,such as 5G communications and highly sensitive detection.The tiny and complex features of these structures can ...The fabrication of pure copper microstructures with submicron resolution has found a host of applications,such as 5G communications and highly sensitive detection.The tiny and complex features of these structures can enhance device performance during high-frequency operation.However,manufacturing pure copper microstructures remain challenging.In this paper,we present localized electrochemical deposition micro additive manufacturing(LECD-μAM).This method combines localized electrochemical deposition(LECD)and closed-loop control of atomic force servo technology,which can effectively print helical springs and hollow tubes.We further demonstrate an overall model based on pulsed microfluidics from a hollow cantilever LECD process and closed-loop control of an atomic force servo.The printing state of the micro-helical springs can be assessed by simultaneously detecting the Z-axis displacement and the deflection of the atomic force probe cantilever.The results showed that it took 361 s to print a helical spring with a wire length of 320.11μm at a deposition rate of 0.887μm s^(-1),which can be changed on the fly by simply tuning the extrusion pressure and the applied voltage.Moreover,the in situ nanoindenter was used to measure the compressive mechanical properties of the helical spring.The shear modulus of the helical spring material was about 60.8 GPa,much higher than that of bulk copper(~44.2 GPa).Additionally,the microscopic morphology and chemical composition of the spring were characterized.These results delineate a new way of fabricating terahertz transmitter components and micro-helical antennas with LECD-μAM technology.展开更多
The corrosion behaviors of Fe-Cr alloy under three different pH values solutions with C1- and SO42- were investigated by localized electrochemical impedance spectroscopy (LEIS) measurements and the corrosion product...The corrosion behaviors of Fe-Cr alloy under three different pH values solutions with C1- and SO42- were investigated by localized electrochemical impedance spectroscopy (LEIS) measurements and the corrosion products were analyzed by laser Raman spectrometry. The results show that the high corrosion resistance of Fe-Cr Alloy is attributed to a passive film which is formed more easily when the alloy contains a large quantity of Cr element. However, its corrosion resistance varies in the solutions with different pH values, especially in the initial corrosion. The average impedance values in neutral and alkaline solution are much higher than that in acidic solution because the passive film is more likely to dissolve in the acidic condition. Moreover, the destructive effect of C1- and SO42 ions on the passive film is also demonstrated in corrosion process through the change of the impedance value with the steeping time.展开更多
The subwavelength confinement feature of localized surface plasmon resonance(LSPR) allows plasmonic nanostructures to be functionalized as powerful platforms for detecting various molecular analytes as well as weak ...The subwavelength confinement feature of localized surface plasmon resonance(LSPR) allows plasmonic nanostructures to be functionalized as powerful platforms for detecting various molecular analytes as well as weak processes with nanoscale spatial resolution. One of the main goals of this field of research is to lower the absolute limit-of-detection(LOD)of LSPR-based sensors. This involves the improvement of(i) the figure-of-merit associated with structural parameters such as the size, shape and interparticle arrangement and,(ii) the spectral resolution. The latter involves advanced target identification and noise reduction techniques. By highlighting the strategies for improving the LOD, this review introduces the fundamental principles and recent progress of LSPR sensing based on different schemes including 1) refractometric sensing realized by observing target-induced refractive index changes, 2) plasmon rulers based on target-induced relative displacement of coupled plasmonic structures, 3) other relevant LSPR-based sensing schemes including chiral plasmonics,nanoparticle growth, and optomechanics. The ultimate LOD and the future trends of these LSPR-based sensing are also discussed.展开更多
This paper presents an all-parametric model of radar target in optic region, in which the localized scattering center's frequency and aspect angle dependent scattering level, distance and azimuth locations are mod...This paper presents an all-parametric model of radar target in optic region, in which the localized scattering center's frequency and aspect angle dependent scattering level, distance and azimuth locations are modeled as the feature vectors. And the traditional TLS-Prony algorithm is modified to extract these feature vectors. The analysis of Cramer-Rao bound shows that the modified algorithm not only improves the restriction of high signal-to-noise ratio(SNR)threshold of traditional TLS-Prony algorithm, but also is suitable to the extraction of big damped coefficients and high-resolution estimation of near separation poles. Finally, an illustrative example is presented to verify its practicability in the applications. The experimental results show that the method developed can not only recognize two airplane-like targets with similar shape at low SNR, but also compress the original radar data with high fidelity.展开更多
Radical prostatectomy (RP) continues to be an effective surgical therapy for prostate carcinoma, particularly for organ-confined prostate cancer (PCa). Recently, RP has also been used in the treatment of locally a...Radical prostatectomy (RP) continues to be an effective surgical therapy for prostate carcinoma, particularly for organ-confined prostate cancer (PCa). Recently, RP has also been used in the treatment of locally advanced prostate cancer. However, little research has been performed to elucidate the perioperative complications associated with RP in patients with clinically localized or locally advanced PCa. We sought to analyse the incidence of complications in these two groups after radical retropubic prostatectomy (RRP). From June 2002 to July 2010, we reviewed 379 PCa patients who underwent RRP in our hospital. Among these cases, 196 had clinically localized PCa (Tla-T2c group 1), and 183 had locally advanced PCa ( ≥ T3,: group 2). The overall complication incidence was 21.9%, which was lower than other studies have reported. Perioperative complications in patients with locally advanced PCa mirror those in patients with clinically localized PCa (26.2% vs. 17.8%, P=0.91). Our results showed that perioperative complications could not be regarded as a factor to consider in regarding RP in patients with cT3 or greater.展开更多
BACKGROUND Liver cancer is a malignant tumor with a high incidence.At present,the most effective treatment is laparoscopic hepatectomy(LH).Indocyanine green fluorescence imaging(ICG-FI)has become an important tool in ...BACKGROUND Liver cancer is a malignant tumor with a high incidence.At present,the most effective treatment is laparoscopic hepatectomy(LH).Indocyanine green fluorescence imaging(ICG-FI)has become an important tool in LH,and the most common fluorescent types of tumors are total fluorescence,partial fluorescence,and rim fluorescence.CASE SUMMARY We presented four cases of LH guided by ICG-FI in which we also observed the fourth special fluorescent type.When the tumor or intrahepatic stone compresses the adjacent bile duct to cause local cholestasis,the liver segment or subsegment with obstructed bile drainage will show strong fluorescence.Complete removal of the lesion together with the fluorescent liver parenchyma may help reduce the risk of tumor or stone recurrence.CONCLUSION This type of partial fluorescence can indicate local biliary compression,and the resection method is related to bile drainage,which may be called functional anatomical hepatectomy and ensures radical resection of the lesion.展开更多
基金Project(202302AB080024)supported by the Department of Science and Technology of Yunnan Province,China。
文摘The evolution of mechanical properties,localized corrosion resistance of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging(NIA)was investigated by hardness test,electrical conductivity test,tensile test,intergranular corrosion test,exfoliation corrosion test,slow strain rate tensile test and electrochemical test,and the mechanism has been discussed based on microstructure examination by optical microscopy,electron back scattered diffraction,scanning electron microscopy and scanning transmission electron microscopy.The NIA treatment includes a heating stage from 40℃to 180℃with a rate of 20℃/h and a cooling stage from 180℃to 40℃with a rate of 10℃/h.The results show that the hardness and strength increase rapidly during the heating stage of NIA since the increasing temperature favors the nucleation and the growth of strengthening precipitates and promotes the transformation of Guinier-Preston(GPI)zones toη'phase.During the cooling stage,the sizes ofη'phase increase with a little change in the number density,leading to a further slight increase of the hardness and strength.As NIA proceeds,the corroded morphology in the alloy changes from a layering feature to a wavy feature,the maximum corrosion depth decreases,and the reason has been analyzed based on the microstructural and microchemical feature of precipitates at grain boundaries and subgrain boundaries.
基金support by the National Natural Science Foundation of China(51961026)the Interdisciplinary Innovation Fund of Nanchang University(Project No.2019-9166-27060003).
文摘Revealing the localized corrosion process of Mg alloy is considered as one of the most significant ways for improving its corrosion resistance.The reliable monitor should be high distinguishability and real-time in liquid environment.Herein,Mg-9Al-1Fe and Mg-9Al-1Fe-1Gd alloys were designed to highlight the impact of intermetallic on the corrosion behaviour.In-situ AFM with a special electrolyte circulation system and quasi-in-situ SEM observation were used to monitor the corrosion process of the designed alloys.SEM-EDS and TEM-SAED were applied to identify the intermetallic in the designed alloys,and their volta potentials were measured by SKPFM.According to the real-time and real-space in-situ AFM monitor,the corrosion process consisted of dissolution of anodicα-Mg phase,accumulation of corrosion products around cathodic phase and shedding of some fine cathodic phase.Then,the localized corrosion process of Mg alloy was revealed combined with the results of the monitor of corrosion process and Volta potential difference.
基金National Natural Science Foundation of China,Grant/Award Number:22179006Natural Science Foundation of Zhejiang Province,Grant/Award Number:LQ23E020002+4 种基金National Natural Science Foundation of China,Grant/Award Numbers:52202284,52072036Cooperation between Industry and Education Project of Ministry of Education,Grant/Award Number:220601318235513WenZhou Natural Science Foundation,Grant/Award Numbers:G20220019,G20220021State Key Laboratory of Electrical Insulation and Power Equipment,Xi'an Jiaotong University,Grant/Award Number:EIPE22208Key Research and Development Program of Henan province,China,Grant/Award Number:231111242500。
文摘The commercialization of silicon-based anodes is affected by their low initial Coulombic efficiency(ICE)and capacity decay,which are attributed to the formation of an unstable solid electrolyte interface(SEI)layer.Herein,a feasible and cost-effective prelithiation method under a localized highconcentration electrolyte system(LHCE)for the silicon-silica/graphite(Si-SiO_(2)/C@G)anode is designed for stabilizing the SEI layer and enhancing the ICE.The thin SiO_(2)/C layers with-NH_(2) groups covered on nano-Si surfaces are demonstrated to be beneficial to the prelithiation process by density functional theory calculations and electrochemical performance.The SEI formed under LHCE is proven to be rich in ionic conductivity,inorganic substances,and flexible organic products.Thus,faster Li+transportation across the SEI further enhances the prelithiation effect and the rate performance of Si-SiO_(2)/C@G anodes.LHCE also leads to uniform decomposition and high stability of the SEI with abundant organic components.As a result,the prepared anode shows a high reversible specific capacity of 937.5 mAh g^(-1)after 400 cycles at a current density of 1 C.NCM 811‖Li-SSGLHCE full cell achieves a high-capacity retention of 126.15 mAh g^(-1)at 1 C over 750 cycles with 84.82%ICE,indicating the great value of this strategy for Si-based anodes in large-scale applications.
基金Project supported by the National Natural Science Foundation of China (Grant No.12074367)Anhui Initiative in Quantum Information Technologies,the National Key Research and Development Program of China (Grant No.2020YFA0309804)+3 种基金Shanghai Municipal Science and Technology Major Project (Grant No.2019SHZDZX01)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No.XDB35020200)Innovation Program for Quantum Science and Technology (Grant No.2021ZD0302002)New Cornerstone Science Foundation。
文摘We investigated the one-dimensional diamond ladder in the momentum lattice platform. By inducing multiple twoand four-photon Bragg scatterings among specific momentum states, we achieved a flat band system based on the diamond model, precisely controlling the coupling strength and phase between individual lattice sites. Utilizing two lattice sites couplings, we generated a compact localized state associated with the flat band, which remained localized throughout the entire time evolution. We successfully realized the continuous shift of flat bands by adjusting the corresponding nearest neighbor hopping strength, enabling us to observe the complete localization process. This opens avenues for further exploration of more complex properties within flat-band systems, including investigating the robustness of flat-band localized states in disordered flat-band systems and exploring many-body localization in interacting flat-band systems.
基金the support from the National Key R&D Program of China underGrant(Grant No.2020YFA0711700)the National Natural Science Foundation of China(Grant Nos.52122801,11925206,51978609,U22A20254,and U23A20659)G.W.is supported by the National Natural Science Foundation of China(Nos.12002303,12192210 and 12192214).
文摘Structural damage in heterogeneousmaterials typically originates frommicrostructures where stress concentration occurs.Therefore,evaluating the magnitude and location of localized stress distributions within microstructures under external loading is crucial.Repeating unit cells(RUCs)are commonly used to represent microstructural details and homogenize the effective response of composites.This work develops a machine learning-based micromechanics tool to accurately predict the stress distributions of extracted RUCs.The locally exact homogenization theory efficiently generates the microstructural stresses of RUCs with a wide range of parameters,including volume fraction,fiber/matrix property ratio,fiber shapes,and loading direction.Subsequently,the conditional generative adversarial network(cGAN)is employed and constructed as a surrogate model to establish the statistical correlation between these parameters and the corresponding localized stresses.The stresses predicted by cGAN are validated against the remaining true data not used for training,showing good agreement.This work demonstrates that the cGAN-based micromechanics tool effectively captures the local responses of composite RUCs.It can be used for predicting potential crack initiations starting from microstructures and evaluating the effective behavior of periodic composites.
文摘We present a class of preconditioners for the linear systems resulting from a finite element or discontinuous Galerkin discretizations of advection-dominated problems.These preconditioners are designed to treat the case of geometrically localized stiffness,where the convergence rates of iterative methods are degraded in a localized subregion of the mesh.Slower convergence may be caused by a number of factors,including the mesh size,anisotropy,highly variable coefficients,and more challenging physics.The approach taken in this work is to correct well-known preconditioners such as the block Jacobi and the block incomplete LU(ILU)with an adaptive inner subregion iteration.The goal of these preconditioners is to reduce the number of costly global iterations by accelerating the convergence in the stiff region by iterating on the less expensive reduced problem.The tolerance for the inner iteration is adaptively chosen to minimize subregion-local work while guaranteeing global convergence rates.We present analysis showing that the convergence of these preconditioners,even when combined with an adaptively selected tolerance,is independent of discretization parameters(e.g.,the mesh size and diffusion coefficient)in the subregion.We demonstrate significant performance improvements over black-box preconditioners when applied to several model convection-diffusion problems.Finally,we present performance results of several variations of iterative subregion correction preconditioners applied to the Reynolds number 2.25×10^(6)fluid flow over the NACA 0012 airfoil,as well as massively separated flow at 30°angle of attack.
文摘Background: Localized pancreatic cancer, including resectable (R), borderline resectable (BR) and locally advanced unresectable disease (LAU), is considered in clinical guidelines for diverse treatment options based on clinical trials in selected populations. Hence, exploring with real world evidence (RWE) clinicians’ preferences for treatment options and their results seems pertinent. Methods: In a set of consecutive patients with localized pancreatic cancer assisted in a third level hospital from January 2013 to December 2022, medical records, symptoms, diagnostic process, distribution between subtypes, and treatment plans, with safety and efficacy results, were assessed. Results: A total of 152 patients with localized disease were included (43.4% R, 21.0% BR, 33.6% LAU). The population characteristics exemplified differences between daily practice and clinical trials. Tumor location and symptoms were as expected. Treatment plan was conditioned by PS or comorbidities in 23.0% of patients. In patients with R disease, surgery followed by different adjuvant chemotherapy (CT) regimes was the antineoplastic treatment of choice (64.8%) with efficacy results (OS 37.5 months;95% CI 18.4 - 56.7), in the range of contemporary standards. The common use of neoadjuvant CT for BR disease (94.4%), with surgery in 50% of them, and its results (OS 30.8 months;95% CI 10.5 - 51.2) reflected current controversies of treatment recommendations and evolution in this scenario. Paliative CT with or without radiotherapy was the standard specific treatment in LAU disease (95.1%) with survival results (PFS: 10.8 months;95% CI 8.8 - 12.7. OS: 20.3 months;95% CI 13.5 - 27.2) that justify the distinct character and the specific study of this entity. Conclusion: RWE for localized pancreatic cancer aroused from the analysis of this population confirms the distinct nature of patients assisted in daily practice, as well as mirrors the complexity of decision making in clinical assumptions in which achieving stronger evidence should be paramount.
文摘Jakarta-Bandung HSR in Indonesia is the first“go global”project of China's high speed railway with a whole system,all elements and a whole industry chain,as well as the first overseas project adopting a complete set of Chinese standards.This paper sorts out the differences between relevant standards in China and Indonesia,including those in concrete raw materials,rebar standards and other main material standards,and those in external interface standards,train operation direction requirements,project approval requirements,special acceptance requirements,etc.,and summarizes the realization methods and specific achievements of localized application of Chinese standards during the implementation of Jakarta-Bandung HSR Project,to provide reference for localized application of Chinese standards in overseas projects in the future.
文摘A high speed LIGBT with localized lifetime control by using high dose and low en ergy helium implantation(LC-LIGBT) is proposed.Compared with conventional LIGB Ts,particle irradiation results show that trade-off relationship between turn- off time and forward voltage drop is improved.At the same time,the forward volta ge drop and turn-off time of such device are researched,when localized lifetime control region place near the p+-n junction,even in p+ anode.The results s how for the first time,helium ions,which stop in the p+ anode,also contribute to the forward voltage drop increasing and turn-off time reducing.
文摘The paper had studied localized design and construction of roof garden.Starting from the history of roof garden,it summarized development of roof garden.It was considered that roof garden could not only provide public rest space,realize thermal insulation and noise reduction of architectures,help water-storage and urban drainage;but also beautify environment,ameliorate regional climate,enrich urban landscape,help to increase ground greening area and improve ecological quality.Finally,some designing principles for roof garden had been proposed,including ① enhancing security consciousness and highlighting roof load design;② emphasizing ecological use and stressing greening coverage;③ manifesting artistic feature;④ investing cautiously,saving construction cost and paying attention to later maintenance.
基金supported by the National Natural Science Foundation of China(Grant No.11174175)the Tsinghua University Initiative Scientific Research Program,China
文摘Recently, there was a hot controversy about the concept of localized orbitals, which was triggered by Grushow's work titled "Is it time to retire the hybrid atomic orbital?" [J. Chem. Educ. 88, 860 (2011)]. To clarify the issue, we assess the delocalized and localized molecular orbitals from an experimental view using electron momentum spectroscopy. The delocalized and localized molecular orbitals based on various theoretical models for CH4, NH3, and H20 are compared with the experimental momentum distributions. Our results show that the delocalized molecular orbitals rather than the localized ones can give a direct interpretation of the experimental (e, 2e) results.
基金Project(50401012) supported by the National Natural Science Foundation of China
文摘To clarify the corrosion mechanism associated with the precipitate of T1(Al2CuLi)in Al-Li alloys,the simulated bulk precipitate of T1 was fabricated through melting and casting.Its electrochemical behavior and coupling behavior with α(Al)in 3.5% NaCl solution were investigated.Meanwhile,the simulated Al alloy containing T1 particle was prepared and its corrosion morphology was observed.The results show that there exists a dynamic conversion corrosion mechanism associated with the precipitate of T1.At the beginning,the precipitate of T1 is anodic to the alloy base and corrosion occurs on its surface.However,during its corrosion process,its potential moves to a positive direction with immersion time increasing,due to the preferential dissolution of Li and the enrichment of Cu.As a result,the corroded T1 becomes cathodic to the alloy base at a later stage,leading to the anodic dissolution and corrosion of the alloy base at its adjacent periphery.It is suggested that the localized corrosion associated with the precipitate of T1 in Al-Li alloys is caused by the alternate anodic dissolution of the T1 precipitate and the alloy base at its adjacent periphery.
基金Project supported by the Natural Science Foundation of Zhejiang Province, China (Grant Nos. Y6100257 and Y6110140)
文摘By using a mapping approach and a linear variable separation approach, a new family of solitary wave solutions with arbitrary functions for the (2+1)-dimensional modified dispersive water-wave system (MDWW) is derived. Based on the derived solutions and using some multi-valued functions, we obtain some novel folded localized excitations of the system.
基金financially supported by National Key Research and Development Program of China(No.2019YFA0705603)National Natural Science Foundation of China(No.22078341,No.21808228 and No.21776290)+1 种基金Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.21921005)S&T Program of Hebei(No.B2020103028).
文摘The key to realize long-life high energy density lithium batteries is to exploit functional electrolytes capable of stabilizing both high voltage cathode and lithium anode.The emergence of localized high-concentration electrolytes(LHCEs)shows great promise for ameliorating the above-mentioned interfacial issues.In this work,a lithium difluoro(oxalate)borate(LiDFOB)based nonflammable dual-anion LHCE is designed and prepared.Dissolving in the mixture of trimethyl phosphate(TMP)/1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether(D_(2)),the continuously consumption of LiDFOB is suppressed by simply introducing lithium nitrate(LiNO_(3)).Meantime,as most of the TMP molecular are coordinated with Li^(+),the electrolyte does not show incompatibility issue between neither metal lithium nor graphite anode.Therefore,it demonstrates excellent capability in stabilizing the interface of Ni-rich cathode and regulating lithium deposition morphology.The Li||LiNi_(0.87)Co_(0.08)Mn_(0.05)O_(2)(NCM87)batteries exhibit high capacity retention of more than 90%after 200 cycles even under the high cutoff voltage of 4.5 V,1 C rate.This study offers a prospective method to develop safe electrolytes suitable for high voltage applications,thus providing higher energy densities.
基金supported by the National Natural Science Foundation of China under Grant U19A20103the Fund for Jilin Province Scientific and Technological Development Program under No.Z20190101005JH。
文摘The fabrication of pure copper microstructures with submicron resolution has found a host of applications,such as 5G communications and highly sensitive detection.The tiny and complex features of these structures can enhance device performance during high-frequency operation.However,manufacturing pure copper microstructures remain challenging.In this paper,we present localized electrochemical deposition micro additive manufacturing(LECD-μAM).This method combines localized electrochemical deposition(LECD)and closed-loop control of atomic force servo technology,which can effectively print helical springs and hollow tubes.We further demonstrate an overall model based on pulsed microfluidics from a hollow cantilever LECD process and closed-loop control of an atomic force servo.The printing state of the micro-helical springs can be assessed by simultaneously detecting the Z-axis displacement and the deflection of the atomic force probe cantilever.The results showed that it took 361 s to print a helical spring with a wire length of 320.11μm at a deposition rate of 0.887μm s^(-1),which can be changed on the fly by simply tuning the extrusion pressure and the applied voltage.Moreover,the in situ nanoindenter was used to measure the compressive mechanical properties of the helical spring.The shear modulus of the helical spring material was about 60.8 GPa,much higher than that of bulk copper(~44.2 GPa).Additionally,the microscopic morphology and chemical composition of the spring were characterized.These results delineate a new way of fabricating terahertz transmitter components and micro-helical antennas with LECD-μAM technology.
基金National Natural Science Foundation of China (No. 50871021)
文摘The corrosion behaviors of Fe-Cr alloy under three different pH values solutions with C1- and SO42- were investigated by localized electrochemical impedance spectroscopy (LEIS) measurements and the corrosion products were analyzed by laser Raman spectrometry. The results show that the high corrosion resistance of Fe-Cr Alloy is attributed to a passive film which is formed more easily when the alloy contains a large quantity of Cr element. However, its corrosion resistance varies in the solutions with different pH values, especially in the initial corrosion. The average impedance values in neutral and alkaline solution are much higher than that in acidic solution because the passive film is more likely to dissolve in the acidic condition. Moreover, the destructive effect of C1- and SO42 ions on the passive film is also demonstrated in corrosion process through the change of the impedance value with the steeping time.
基金Project supported by the National Key Basic Research Program(Grant No.2015CB932400)the National Key Research and Development Program of China(Grant Nos.2017YFA0205800 and 2017YFA0303504)the National Natural Science Foundation of China(Grant Nos.11674255 and 11674256)
文摘The subwavelength confinement feature of localized surface plasmon resonance(LSPR) allows plasmonic nanostructures to be functionalized as powerful platforms for detecting various molecular analytes as well as weak processes with nanoscale spatial resolution. One of the main goals of this field of research is to lower the absolute limit-of-detection(LOD)of LSPR-based sensors. This involves the improvement of(i) the figure-of-merit associated with structural parameters such as the size, shape and interparticle arrangement and,(ii) the spectral resolution. The latter involves advanced target identification and noise reduction techniques. By highlighting the strategies for improving the LOD, this review introduces the fundamental principles and recent progress of LSPR sensing based on different schemes including 1) refractometric sensing realized by observing target-induced refractive index changes, 2) plasmon rulers based on target-induced relative displacement of coupled plasmonic structures, 3) other relevant LSPR-based sensing schemes including chiral plasmonics,nanoparticle growth, and optomechanics. The ultimate LOD and the future trends of these LSPR-based sensing are also discussed.
文摘This paper presents an all-parametric model of radar target in optic region, in which the localized scattering center's frequency and aspect angle dependent scattering level, distance and azimuth locations are modeled as the feature vectors. And the traditional TLS-Prony algorithm is modified to extract these feature vectors. The analysis of Cramer-Rao bound shows that the modified algorithm not only improves the restriction of high signal-to-noise ratio(SNR)threshold of traditional TLS-Prony algorithm, but also is suitable to the extraction of big damped coefficients and high-resolution estimation of near separation poles. Finally, an illustrative example is presented to verify its practicability in the applications. The experimental results show that the method developed can not only recognize two airplane-like targets with similar shape at low SNR, but also compress the original radar data with high fidelity.
文摘Radical prostatectomy (RP) continues to be an effective surgical therapy for prostate carcinoma, particularly for organ-confined prostate cancer (PCa). Recently, RP has also been used in the treatment of locally advanced prostate cancer. However, little research has been performed to elucidate the perioperative complications associated with RP in patients with clinically localized or locally advanced PCa. We sought to analyse the incidence of complications in these two groups after radical retropubic prostatectomy (RRP). From June 2002 to July 2010, we reviewed 379 PCa patients who underwent RRP in our hospital. Among these cases, 196 had clinically localized PCa (Tla-T2c group 1), and 183 had locally advanced PCa ( ≥ T3,: group 2). The overall complication incidence was 21.9%, which was lower than other studies have reported. Perioperative complications in patients with locally advanced PCa mirror those in patients with clinically localized PCa (26.2% vs. 17.8%, P=0.91). Our results showed that perioperative complications could not be regarded as a factor to consider in regarding RP in patients with cT3 or greater.
基金Supported by National Natural Science Foundation of China,No.81972792.
文摘BACKGROUND Liver cancer is a malignant tumor with a high incidence.At present,the most effective treatment is laparoscopic hepatectomy(LH).Indocyanine green fluorescence imaging(ICG-FI)has become an important tool in LH,and the most common fluorescent types of tumors are total fluorescence,partial fluorescence,and rim fluorescence.CASE SUMMARY We presented four cases of LH guided by ICG-FI in which we also observed the fourth special fluorescent type.When the tumor or intrahepatic stone compresses the adjacent bile duct to cause local cholestasis,the liver segment or subsegment with obstructed bile drainage will show strong fluorescence.Complete removal of the lesion together with the fluorescent liver parenchyma may help reduce the risk of tumor or stone recurrence.CONCLUSION This type of partial fluorescence can indicate local biliary compression,and the resection method is related to bile drainage,which may be called functional anatomical hepatectomy and ensures radical resection of the lesion.