Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil na...Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals.However,the effects of high concentrations of multiple heavy metals(HCMHMs)on plants and native soil microorganisms remain uncertain.Thus,further clarification of themechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required.Using the plant Sedum alfredii(S.alfredii)to restore HCMHM-contaminated soil,we further explored the mechanism of S.alfredii and native soil microorganisms in the remediation of HCMHM soils.The results showed that(i)S.alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil,which is conducive to the effect of plants on heavy metals.In addition,it can also enrich the absorbed heavy metals in its roots and leaves;(ii)native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes,such as trpE,trpG,bjaI,rpfF,ACSL,and yidC,and promote the expression of the pathway that converts serine to cysteine,then synthesize substances to chelate heavy metals.In addition,we speculated that genes such as K19703,K07891,K09711,K19703,K07891,and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals.The results provide scientific basis for S.alfredii to remediate heavy metals contaminated soils,and confirm the potential of phytoremediation of HCMHM contaminated soil.展开更多
The kitchen-oil wastewater is characterized by a high concentration of organicmatter,complex composition and refractory pollutants,which make wastewater treatment more difficult.Based on the study of using micro-elect...The kitchen-oil wastewater is characterized by a high concentration of organicmatter,complex composition and refractory pollutants,which make wastewater treatment more difficult.Based on the study of using micro-electric field characteristic catalyst HCLL-S8-M to enhance the electron transfer between microorganisms in kitchen-oil wastewater which further improved the COD removal rate,we focus on themicrobial community,intracellular metabolism and extracellular respiration,and make an in-depth analysis of the molecular biological mechanisms to microbial treatment in wastewater.It is found that electroactive microorganisms are enriched on the material surface,and the expression levels of cytochrome c and riboflavin genes related to electron transfer are up-regulated,confirming that the surface micro-electric field structure could enhance the electron transfer between microbial species and improve the efficiency ofwastewater degradation.This study provides a new idea for the treatment of refractory organic wastewater.展开更多
This study conducted shear resistance tests on steel-UHPC composite beams,focusing on structural stiffness changes during the test process,strain analysis of UHPC panels,internal reinforcement bars,steel structures,an...This study conducted shear resistance tests on steel-UHPC composite beams,focusing on structural stiffness changes during the test process,strain analysis of UHPC panels,internal reinforcement bars,steel structures,and shear connectors,as well as the failure processes and modes of UHPC panels and the structure.Through theoretical analysis,the contribution of UHPC panels to the overall vertical shear resistance capability was clarified.A shear load-bearing capacity calculation method was established,thereby considering the combined beam shear bearing capacity calculation formula of the UHPC panel and the steel beam web.展开更多
Selective laser melting(SLM)is an emerging additive manufacturing technology for fabricating aluminum alloys and aluminum matrix composites.Nevertheless,it remains unclear how to improve the properties of laser manufa...Selective laser melting(SLM)is an emerging additive manufacturing technology for fabricating aluminum alloys and aluminum matrix composites.Nevertheless,it remains unclear how to improve the properties of laser manufactured aluminum alloy by adding ceramic reinforcing particles.Here the effect of trace addition of TiB2 ceramic(1%weight fraction)on microstructural and mechanical properties of SLM-produced AlSi10Mg composite parts was investigated.The densification level increased with increasing laser power and decreasing scan speed.A near fully dense composite part(99.37%)with smooth surface morphology and elevated inter-layer bonding was successfully obtained.A decrease of lattice plane distance was identified by X-ray diffraction with the laser scan speed decreased,which implied that the crystal lattices were distorted due to the dissolution of Si and TiB2 particles.A homogeneous composite microstructure with the distribution of surface-smoothened TiB2 particles was present,and a small amount of Si particles precipitated at the interface between reinforcing particles and matrix.In contrast to the AlSi10Mg alloy,the composites showed a stabilized microhardness distribution.A higher ultimate tensile strength of 380.0 MPa,yield strength of 250.4 MPa and elongation of 3.43%were obtained even with a trace amount of ceramic addition.The improvement of tensile properties can be attributed to multiple mechanisms including solid solution strengthening,load-bearing strengthening and dispersion strengthening.This research provides a theoretical basis for ceramic reinforced aluminum matrix composites by additive manufacturing.展开更多
The intrusion of the Kuroshio into the East China Sea(ECS)aff ects the development of hypoxia off the Changjiang(Yangtze)River estuary;however,quantitative analysis of its impacts is lacking.In this study,the Regional...The intrusion of the Kuroshio into the East China Sea(ECS)aff ects the development of hypoxia off the Changjiang(Yangtze)River estuary;however,quantitative analysis of its impacts is lacking.In this study,the Regional Ocean Modeling Systems(ROMS)model coupled with the Carbon,Silicate and Nitrogen Ecosystem(CoSiNE)model was used to investigate the relative importance of dissolved oxygen(DO)and diff erent nutrients(silicate,nitrate,and phosphate)in the Kuroshio on hypoxia in the ECS.Results show that changes in DO concentrations in the Kuroshio modify the distribution and intensity of hypoxia through direct onshore transport by hydrodynamic processes.An increase in Kuroshio DO concentration by 25%or 50%would result in a decrease of the maximum hypoxia extent(MHE)in the ECS by 76%or 86%,respectively,while a 25%decrease in Kuroshio DO would increase the MHE by up to 219%.The contribution of DO in the Taiwan Strait is almost negligible.In contrast to Kuroshio DO,nutrients aff ect hypoxia in the ECS through onshore transport by hydrodynamic and biochemical processes.Changes in phosphate and nitrate concentrations by 25%in the Kuroshio would change the MHE by up to 30%and 18%,respectively,accompanied by apparent changes in surface chlorophyll-a concentrations.The eff ect of silicate on hypoxia is negligible because a 25%change in silicate concentrations in the Kuroshio would result in less than 1%change in the MHE.Our results reveal a hierarchical rank of importance for environmental variables in the Kuroshio(i.e.,DO>phosphate>nitrate>silicate)in modifying the development of hypoxia in the ECS.展开更多
Steel matrix composites(SMCs)reinforced with WC particles were fabricated via selective laser melting(SLM)by employing various laser scan strategies.A detailed relationship between the SLM strategies,defect formation,...Steel matrix composites(SMCs)reinforced with WC particles were fabricated via selective laser melting(SLM)by employing various laser scan strategies.A detailed relationship between the SLM strategies,defect formation,microstructural evolution,and mechanical properties of SMCs was established.The laser scan strategies can be manipulated to deliberately alter the thermal history of SMC during SLM processing.Particularly,the involved thermal cycling,which encompassed multiple layers,strongly affected the processing quality of SMCs.Sshaped scan sequence combined with interlayer offset and orthogonal stagger mode can effectively eliminate the metallurgical defects and retained austenite within the produced SMCs.However,due to large thermal stress,microcracks that were perpendicular to the building direction formed within the SMCs.By employing the checkerboard filling(CBF)hatching mode,the thermal stress arising during SLM can be significantly reduced,thus preventing the evolution of interlayer microcracks.The compressive properties of fabricated SMCs can be tailored at a high compressive strength(~3031.5 MPa)and fracture strain(~24.8%)by adopting the CBF hatching mode combined with the optimized scan sequence and stagger mode.This study demonstrates great feasibility in tuning the mechanical properties of SLM-fabricated SMCs without varying the set energy input,e.g.,laser power and scanning speed.展开更多
Injecting CO_(2)into the underground for oil displacement and shortage is an important technique for carbon capture,utilization and storage(CCUS).One of the main problems during the CO_(2)injection is the channeling p...Injecting CO_(2)into the underground for oil displacement and shortage is an important technique for carbon capture,utilization and storage(CCUS).One of the main problems during the CO_(2)injection is the channeling plugging.Finding an effective method for the gas channeling plugging is a critical issue in the CO_(2)EOR process.In this work,an acid-resistance microgel named dispersed particle gel(DPG)was characterized and its stability was tested in the CO_(2)environment.The microgel size selection strategies for the homogeneous and heterogeneous reservoirs were respectively investigated using the single core flooding and three parallel core flooding experiments.Moreover,the comparison of microgel alternate CO_(2)(MAC)injection and water alternate CO_(2)(WAC)injection in the dual core flooding experiments were presented for the investigation of the role of microgel on the conformance control in CO_(2)flooding process.The results have shown that the microgel featured with ANH and CAN groups can keep its morphology after aging 7 days in the CO_(2)environment.Where,the small microgel with unobstructed migration and large microgel with good plugging efficiency for the high permeability zone were respectively featured with the higher recovery factor in homogeneous and heterogeneous conditions,which indicate they are preferred used for the oil displacement and conformance control.Compared to WAC injection,MAC injection had a higher incremental recovery factor of 12.4%.It suggests the acid-resistance microgel would be a good candidate for the conformance control during CO_(2)flooding process.展开更多
In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’sh...In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’short life of use.The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer.The vial is grasped with the palm of the experimenter for several minutes without shaking.The proposed method is simple,rapid,green energy and cost-effective.By adjusting the concentration of trisodium citrate,not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved.As a SERS substrate,the silver colloid has high batch reproducibility and showed good SERS activity.The relative standard deviation between different manufacturers is 5.51%when the substrate of silver colloid is used for the detection of rhodamine 6 G.Using the substrate,the lowest detection concentrations of rhodamine 6 G,crystal violet,enrofloxacin,melamine and leucomalachite green are 1.0×10-8,6.1×10-8,1.4×10-6,7.1×10-5 and 5.1×10-8 mol/L,respectively.Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.展开更多
BACKGROUND Although transcatheter aortic valve implantation(TAVI)is a safe and effective treatment for aortic stenosis,it still carries some risks,such as valve leaks,stroke,and even death.The left ventricular global ...BACKGROUND Although transcatheter aortic valve implantation(TAVI)is a safe and effective treatment for aortic stenosis,it still carries some risks,such as valve leaks,stroke,and even death.The left ventricular global longitudinal strain(LVGLS)measurement may be useful for the prediction of adverse events during this operation.AIM To explore the change of LVGLS during TAVI procedure and the relationship between LVGLS and perioperative adverse events.METHODS In this study,61 patients who had undergone percutaneous transfemoral TAVI were evaluated by transthoracic echocardiography.Before surgery,data on left ventricular ejection fraction(LVEF)and LVGLS were collected separately following balloon expansion and stent implantation.Difference in values of LVGLS and LVEF during preoperative balloon expansion(pre-ex),preoperative stent implantation(pre-im)and balloon expansion-stent implantation(ex-im)were also examined.Adverse events were defined as perioperative death,cardiac rupture,heart arrest,moderate or severe perivalvular leakage,significant mitral regurgitation during TAVI,perioperative moderate or severe mitral regurgitation,perioperative left ventricular outflow tract obstruction,reoperation,and acute heart failure.RESULTS The occurrence of perioperative adverse events was associated with differences in pre-ex LVGLS,but not with difference in pre-ex LVEF.There were significant differences between pre-LVGLS and ex-LVGLS,and between pre-LVGLS and im-LVGLS(P=0.037 and P=0.020,respectively).However,differences in LVEF were not significant(P=0.358,P=0.254);however differences in pre-ex LVGLS were associated with pre-LVGLS(P=0.045).Compared to LVEF,LVGLS is more sensitive as a measure of left heart function during TAVI and the perioperative period.Moreover,the differences in LVGLS were associated with the occurrence of perioperative adverse events,and changes in LVGLS were apparent in patients with undesirable LVGLS before the surgery.Furthermore,LVGLS is useful to predict changes in cardiac function during TAVI.CONCLUSION Greater attention should be paid to the patients who plan to undergo TAVI with normal LVEF but poor LVGLS.展开更多
Hierarchical layered structures,whether in a compact form like nacre or a porous manner like bone,are well known for their combined features of high stiffness,strength,and lightweight,inspiring many man-made materials...Hierarchical layered structures,whether in a compact form like nacre or a porous manner like bone,are well known for their combined features of high stiffness,strength,and lightweight,inspiring many man-made materials and structures for high performance applications.The use of nacre/bone like hierarchical structures in polymer nanocomposites can achieve excellent mechanical and functional properties with high filler volume fractions after carefully aligning functional nanofillers,although the fabrication and processing remain a great challenge.In this work,a bio-inspired lightweight nano-cellular epoxy/graphene-Fe_(3)O_(4) nanocomposite with high nanofiller loading of 75 wt.%was successfully fabricated by combining features from both nacre and bone structures,via a simple compression molding process together with an eco-friendly supercritical CO_(2) foaming process to achieve robust mechanical strength and excellent electromagnetic interference(EMI)shielding effectiveness(SE)simultaneously.Highly aligned graphene-Fe_(3)O_(4) nanoplatelets with well controlled nanoscale porous structures(52.6 nm)enabled both low density(1.26 g/cm^(3))and high specific EMI SE>5200 dB/cm^(2)/g,as well as preserved tensile strength of 67 MPa.This study provides a sustainable route to fabricate nature mimicked structures with high performance and high flexibility for a wide range of applications,from portable electronics to healthcare devices.展开更多
Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g....Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g.aerospace,automobiles,electronics,etc.Cuttlebone produced in the cuttlefish has evolved vertical walls with the optimal corrugation gradient,enabling stress homogenization,significant load bearing,and damage tolerance to protect the organism from high external pressures in the deep sea.This work illustrated that the complex hybrid wave shape in cuttlebone walls,becoming more tortuous from bottom to top,creates a lightweight,load-bearing structure with progressive failure.By mimicking the cuttlebone,a novel bionic hybrid structure(BHS)was proposed,and as a comparison,a regular corrugated structure and a straight wall structure were designed.Three types of designed structures have been successfully manufactured by laser powder bed fusion(LPBF)with NiTi powder.The LPBF-processed BHS exhibited a total porosity of 0.042% and a good dimensional accuracy with a peak deviation of 17.4μm.Microstructural analysis indicated that the LPBF-processed BHS had a strong(001)crystallographic orientation and an average size of 9.85μm.Mechanical analysis revealed the LPBF-processed BHS could withstand over 25000 times its weight without significant deformation and had the highest specific EA value(5.32 J·g^(−1))due to the absence of stress concentration and progressive wall failure during compression.Cyclic compression testing showed that LPBF-processed BHS possessed superior viscoelastic and elasticity energy dissipation capacity.Importantly,the uniform reversible phase transition from martensite to austenite in the walls enables the structure to largely recover its pre-deformation shape when heated(over 99% recovery rate).These design strategies can serve as valuable references for the development of intelligent components that possess high mechanical efficiency and shape memory capabilities.展开更多
In this study,an extreme rainfall event that occurred on 25 May 2018 over Shanghai and its nearby area was simulated using the Weather Research and Forecasting model,with a focus on the effects of planetary boundary l...In this study,an extreme rainfall event that occurred on 25 May 2018 over Shanghai and its nearby area was simulated using the Weather Research and Forecasting model,with a focus on the effects of planetary boundary layer(PBL)physics using double nesting with large grid ratios(15:1 and 9:1).The sensitivity of the precipitation forecast was examined through three PBL schemes:the Yonsei University Scheme,the Mellor−Yamada−Nakanishi Niino Level 2.5(MYNN)scheme,and the Mellor−Yamada−Janjic scheme.The PBL effects on boundary layer structures,convective thermodynamic and large-scale forcings were investigated to explain the model differences in extreme rainfall distributions and hourly variations.The results indicated that in single coarser grids(15 km and 9 km),the extreme rainfall amount was largely underestimated with all three PBL schemes.In the inner 1-km grid,the underestimated intensity was improved;however,using the MYNN scheme for the 1-km grid domain with explicitly resolved convection and nested within the 9-km grid using the Kain−Fritsch cumulus scheme,significant advantages over the other PBL schemes are revealed in predicting the extreme rainfall distribution and the time of primary peak rainfall.MYNN,with the weakest vertical mixing,produced the shallowest and most humid inversion layer with the lowest lifting condensation level,but stronger wind fields and upward motions from the top of the boundary layer to upper levels.These factors all facilitate the development of deep convection and moisture transport for intense precipitation,and result in its most realistic prediction of the primary rainfall peak.展开更多
The solid electrolyte interphase(SEI)with strong mechanical strength and high ion conductivity is highly desired for Li metal batteries,especially for harsh anode-free batteries.Herein,we report a pragmatic approach t...The solid electrolyte interphase(SEI)with strong mechanical strength and high ion conductivity is highly desired for Li metal batteries,especially for harsh anode-free batteries.Herein,we report a pragmatic approach to the in-situ construction of high-quality SEI by applying synergistic additives of Li NO_(3)and ethylene sulfite(ES)in the electrolyte.The obtained SEI exhibits a high average Young’s modulus(9.02GPa)and exchanging current density(4.59 mA cm^(-2)),which are 3.0 and 1.2 times as large as those using the sole additive of LiNO_(3),respectively.With this improved SEI,Li-dendrite growth and side reactions are effectively suppressed,leading to an ultra-high Coulombic efficiency(CE)of 99.7%for Li plating and stripping.When applying this improved electrolyte in full cells,it achieves a high capacity retention of 89.7%for over 150 cycles in a LiFePO_(4)||Li battery(~12 mg cm^(-2)cathode,50μm Li)and of 44.5%over 100 cycles in a LiFePO_(4)||Cu anode-free battery.展开更多
Constructing new photocatalysts for the photocatalytic reduction of CO_(2)and efficient degradation of Lev-ofloxacin is of great importance to renewable energy.Here,S-scheme Bi_(2)MoO_(6-x)/MoS_(2)heterojunction nanos...Constructing new photocatalysts for the photocatalytic reduction of CO_(2)and efficient degradation of Lev-ofloxacin is of great importance to renewable energy.Here,S-scheme Bi_(2)MoO_(6-x)/MoS_(2)heterojunction nanospheres containing abundant surface defects(oxygen vacancies)were designed and successfully syn-thesized to enhance CO_(2)photoreduction activity in the absence of other sacrificial agents,co-catalysts or photosensitisers.At the same time,it can efficiently degrade organic pollutants(Levofloxacin).This heterogeneous structure with surface defects provides an abundance of reactive sites,accelerates charge separation and improves oxidation capacity.The improved Bi_(2)MoO_(6-x)/MoS_(2)heterogeneous nanospheres show excellent performance under simulated solar light,with the selectivity and yield of 92.45%and 29.01μmol h^(−1),respectively,for the generation of CO.Under visible light,the degradation efficiency of levofloxacin hydrochloride(LVX)reached 96.3%within 25 min and remained as high as 95%after three cycles.This work provides a new idea for the design of new S-scheme photocatalysts and an important reference for the preparation of photocatalysts for the efficient photocatalytic reduction of CO_(2)and the efficient degradation of organic pollutants at the same time.展开更多
The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions....The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.展开更多
This paper reports accurate use of silanized support based substrate for surface-enhanced Raman spectroscopy（SERS） determination of illegal additives chrysoidin and malachite green. Detection of these illegal additi...This paper reports accurate use of silanized support based substrate for surface-enhanced Raman spectroscopy（SERS） determination of illegal additives chrysoidin and malachite green. Detection of these illegal additives is very meaningful and the developed method meets this objective in a simple, rapid and cost effective way. Detection limits for chrysoidin and malachite green in aqueous solutions reached0.001 mg/L and 0.0001 mg/L respectively. Linear relationship between the Raman intensities and chrysoidin concentrations in range of 0.001-0.05 mg/L was found with regression coefficient（R） of 0.994.To investigate the practical application performance of the method, the substrate was applied to detect chrysoidin in Sprite at 0.01 mg/L and malachite green in fish pond water at 0.0001 mg/L. The SERS method could be an alternative approach for monitoring illegal additives and toxic harmful substances.展开更多
A facile and rapid approach for detecting low concentration of iron ion(Fe3+) with improved sensitivity was developed on the basis of plasmon enhanced fluorescence and subsequently amplified fluorescence quenching.Au1...A facile and rapid approach for detecting low concentration of iron ion(Fe3+) with improved sensitivity was developed on the basis of plasmon enhanced fluorescence and subsequently amplified fluorescence quenching.Au1Ag4@Si O2 nanoparticles were synthesized and dispersed into fluorescein isothiocyanate(FITC) solution. The fluorescence of the FITC solution was improved due to plasmon enhanced fluorescence. However, efficient fluorescence quenching of the FITC/Au1Ag4@Si O2 solution was subsequently achieved when Fe3+, with a concentration ranging from17 n M to 3.4 l M, was added into the FITC/Au1Ag4@Si O2 solution, whereas almost no fluorescence quenching was observed for pure FITC solution under the same condition. FITC/Au1Ag4@Si O2 solution shows a better sensitivity for detecting low concentration of Fe3+compared to pure FITC solution. The quantized limit of detection toward Fe3+was improved from 4.6 l M for pure FITC solution to 20 n M for FITC/Au1Ag4@Si O2 solution.展开更多
Buried interfacial voids have always been a notorious phenomenon observed in the fabrication of lead perovskite films. The existence of interfacial voids at the buried interface will capture the carrier, suppress carr...Buried interfacial voids have always been a notorious phenomenon observed in the fabrication of lead perovskite films. The existence of interfacial voids at the buried interface will capture the carrier, suppress carrier transport efficiencies, and affect the stability of photovoltaic devices. However, the impact of these buried interfacial voids on tin perovskites, a promising avenue for advancing lead-free photovoltaics, has been largely overlooked. Here, we utilize an innovative weakly polar solvent pretreatment strategy(WPSPS) to mitigate buried interfacial voids of tin perovskites. Our investigation reveals the presence of numerous voids in tin perovskites during annealing, attributed to trapped dimethyl sulfoxide(DMSO) used in film formation. The WPSPS method facilitates accelerated DMSO evaporation, effectively reducing residual DMSO. Interestingly, the WPSPS shifts the energy level of PEDOT:PSS downward, making it more aligned with the perovskite. This alignment enhances the efficiency of charge carrier transport. As the result, tin perovskite film quality is significantly improved,achieving a maximum power conversion efficiency approaching 12% with only an 8.3% efficiency loss after 1700 h of stability tests, which compares well with the state-of-the-art stability of tin-based perovskite solar cells.展开更多
基金supported by the Fundamental Research Funds for Central PublicWelfare Scientific Research Institutes of China(No.2021-JY-37)the Yellow River Basin Ecological Protection and High-quality Development Joint Study(Phase I)(No.2022-YRUC-01-0202).
文摘Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals.However,the effects of high concentrations of multiple heavy metals(HCMHMs)on plants and native soil microorganisms remain uncertain.Thus,further clarification of themechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required.Using the plant Sedum alfredii(S.alfredii)to restore HCMHM-contaminated soil,we further explored the mechanism of S.alfredii and native soil microorganisms in the remediation of HCMHM soils.The results showed that(i)S.alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil,which is conducive to the effect of plants on heavy metals.In addition,it can also enrich the absorbed heavy metals in its roots and leaves;(ii)native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes,such as trpE,trpG,bjaI,rpfF,ACSL,and yidC,and promote the expression of the pathway that converts serine to cysteine,then synthesize substances to chelate heavy metals.In addition,we speculated that genes such as K19703,K07891,K09711,K19703,K07891,and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals.The results provide scientific basis for S.alfredii to remediate heavy metals contaminated soils,and confirm the potential of phytoremediation of HCMHM contaminated soil.
基金supported by the National Natural Science Foundation of China(Nos.52150056 and 51838005)the Basic and Applied Basic Research Foundation of Guangdong Province(No.2023A1515111061).
文摘The kitchen-oil wastewater is characterized by a high concentration of organicmatter,complex composition and refractory pollutants,which make wastewater treatment more difficult.Based on the study of using micro-electric field characteristic catalyst HCLL-S8-M to enhance the electron transfer between microorganisms in kitchen-oil wastewater which further improved the COD removal rate,we focus on themicrobial community,intracellular metabolism and extracellular respiration,and make an in-depth analysis of the molecular biological mechanisms to microbial treatment in wastewater.It is found that electroactive microorganisms are enriched on the material surface,and the expression levels of cytochrome c and riboflavin genes related to electron transfer are up-regulated,confirming that the surface micro-electric field structure could enhance the electron transfer between microbial species and improve the efficiency ofwastewater degradation.This study provides a new idea for the treatment of refractory organic wastewater.
文摘This study conducted shear resistance tests on steel-UHPC composite beams,focusing on structural stiffness changes during the test process,strain analysis of UHPC panels,internal reinforcement bars,steel structures,and shear connectors,as well as the failure processes and modes of UHPC panels and the structure.Through theoretical analysis,the contribution of UHPC panels to the overall vertical shear resistance capability was clarified.A shear load-bearing capacity calculation method was established,thereby considering the combined beam shear bearing capacity calculation formula of the UHPC panel and the steel beam web.
基金Supported by National Key Research and Development Program“Additive Manufacturing and Laser Manufacturing”of China(Grant Nos.2016YFB1100101,2018YFB1106302)National Natural Science Foundation of China(Grant No.51735005)+4 种基金Jiangsu Provincial Natural Science Foundation for Youth(Grant No.BK20180439)National Natural Science Foundation of China for Creative Research Groups(Grant No.51921003)The 15th Batch of“Six Talents Peaks”Innovative Talents Team Program(Grant No.TD-GDZB-001)2017 Excellent Scientific and Technological Innovation Teams of Universities in Jiangsu ProvinceNanjing University of Aeronautics and Astronautics Graduate Innovation Base(Laboratory)Open Fund Project(Grant No.kfjj20190606).
文摘Selective laser melting(SLM)is an emerging additive manufacturing technology for fabricating aluminum alloys and aluminum matrix composites.Nevertheless,it remains unclear how to improve the properties of laser manufactured aluminum alloy by adding ceramic reinforcing particles.Here the effect of trace addition of TiB2 ceramic(1%weight fraction)on microstructural and mechanical properties of SLM-produced AlSi10Mg composite parts was investigated.The densification level increased with increasing laser power and decreasing scan speed.A near fully dense composite part(99.37%)with smooth surface morphology and elevated inter-layer bonding was successfully obtained.A decrease of lattice plane distance was identified by X-ray diffraction with the laser scan speed decreased,which implied that the crystal lattices were distorted due to the dissolution of Si and TiB2 particles.A homogeneous composite microstructure with the distribution of surface-smoothened TiB2 particles was present,and a small amount of Si particles precipitated at the interface between reinforcing particles and matrix.In contrast to the AlSi10Mg alloy,the composites showed a stabilized microhardness distribution.A higher ultimate tensile strength of 380.0 MPa,yield strength of 250.4 MPa and elongation of 3.43%were obtained even with a trace amount of ceramic addition.The improvement of tensile properties can be attributed to multiple mechanisms including solid solution strengthening,load-bearing strengthening and dispersion strengthening.This research provides a theoretical basis for ceramic reinforced aluminum matrix composites by additive manufacturing.
基金Supported by the National Key Research and Development Project of China(No.2016YFC1401603)the Scientifi c Research Fund of the Second Institute of Oceanography,MNR(No.JG2008)+7 种基金the National Program on Global Change and Air-Sea Interaction(No.GASI-04-WLHY-01)the National Natural Science Foundation of China(Nos.41705048,41876026)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(No.SL2020MS032)the State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.LTO2007)the CEES Visiting Fellowship Program(No.CEESRS202001)the Zhejiang Provincial Natural Science Foundation(No.LR16D060001)the Zhejiang Provincial Key Research and Development Project(No.2021C03186)the Sino-German Mobility Program:CHESS-Chinese and European Coastal Shelf Seas Ecosystem Dynamics-A Comparative Assessment(No.M-0053)。
文摘The intrusion of the Kuroshio into the East China Sea(ECS)aff ects the development of hypoxia off the Changjiang(Yangtze)River estuary;however,quantitative analysis of its impacts is lacking.In this study,the Regional Ocean Modeling Systems(ROMS)model coupled with the Carbon,Silicate and Nitrogen Ecosystem(CoSiNE)model was used to investigate the relative importance of dissolved oxygen(DO)and diff erent nutrients(silicate,nitrate,and phosphate)in the Kuroshio on hypoxia in the ECS.Results show that changes in DO concentrations in the Kuroshio modify the distribution and intensity of hypoxia through direct onshore transport by hydrodynamic processes.An increase in Kuroshio DO concentration by 25%or 50%would result in a decrease of the maximum hypoxia extent(MHE)in the ECS by 76%or 86%,respectively,while a 25%decrease in Kuroshio DO would increase the MHE by up to 219%.The contribution of DO in the Taiwan Strait is almost negligible.In contrast to Kuroshio DO,nutrients aff ect hypoxia in the ECS through onshore transport by hydrodynamic and biochemical processes.Changes in phosphate and nitrate concentrations by 25%in the Kuroshio would change the MHE by up to 30%and 18%,respectively,accompanied by apparent changes in surface chlorophyll-a concentrations.The eff ect of silicate on hypoxia is negligible because a 25%change in silicate concentrations in the Kuroshio would result in less than 1%change in the MHE.Our results reveal a hierarchical rank of importance for environmental variables in the Kuroshio(i.e.,DO>phosphate>nitrate>silicate)in modifying the development of hypoxia in the ECS.
基金the National Key Research and Development Program“Additive Manufacturing and Laser Manufacturing”(No.2016YFB1100101)the National Natural Science Foundation of China(No.51735005)+3 种基金the Basic Strengthening Program of Science and Technology(No.2019-JCJQ-JJ-331)the 5th Jiangsu Province 333 High Level Talents Training Project,China(No.BRA2019048)the 15th Batch of“Six Talents Peaks”Innovative Talents Team Program“Laser Precise Additive Manufacturing of Structure-Performance Integrated Lightweight Alloy Components”(No.TD-GDZB-001)and the 2017 Excellent Scientific and Technological Innovation Teams of Universities in Jiangsu“Laser Additive Manufacturing Technologies for Metallic Components”funded by Jiangsu Provincial Department of Education of China(No.51921003).Konrad Kosiba acknowledges the support from DFG under Grant No.KO 5771/1-1.
文摘Steel matrix composites(SMCs)reinforced with WC particles were fabricated via selective laser melting(SLM)by employing various laser scan strategies.A detailed relationship between the SLM strategies,defect formation,microstructural evolution,and mechanical properties of SMCs was established.The laser scan strategies can be manipulated to deliberately alter the thermal history of SMC during SLM processing.Particularly,the involved thermal cycling,which encompassed multiple layers,strongly affected the processing quality of SMCs.Sshaped scan sequence combined with interlayer offset and orthogonal stagger mode can effectively eliminate the metallurgical defects and retained austenite within the produced SMCs.However,due to large thermal stress,microcracks that were perpendicular to the building direction formed within the SMCs.By employing the checkerboard filling(CBF)hatching mode,the thermal stress arising during SLM can be significantly reduced,thus preventing the evolution of interlayer microcracks.The compressive properties of fabricated SMCs can be tailored at a high compressive strength(~3031.5 MPa)and fracture strain(~24.8%)by adopting the CBF hatching mode combined with the optimized scan sequence and stagger mode.This study demonstrates great feasibility in tuning the mechanical properties of SLM-fabricated SMCs without varying the set energy input,e.g.,laser power and scanning speed.
基金supported by the National Natural Science Foundation of China(52004305)the Postdoctoral Research Foundation of China(2021M693497)the Science Foundation of China University of Petroleum,Beijing(2462020XKBH006)。
文摘Injecting CO_(2)into the underground for oil displacement and shortage is an important technique for carbon capture,utilization and storage(CCUS).One of the main problems during the CO_(2)injection is the channeling plugging.Finding an effective method for the gas channeling plugging is a critical issue in the CO_(2)EOR process.In this work,an acid-resistance microgel named dispersed particle gel(DPG)was characterized and its stability was tested in the CO_(2)environment.The microgel size selection strategies for the homogeneous and heterogeneous reservoirs were respectively investigated using the single core flooding and three parallel core flooding experiments.Moreover,the comparison of microgel alternate CO_(2)(MAC)injection and water alternate CO_(2)(WAC)injection in the dual core flooding experiments were presented for the investigation of the role of microgel on the conformance control in CO_(2)flooding process.The results have shown that the microgel featured with ANH and CAN groups can keep its morphology after aging 7 days in the CO_(2)environment.Where,the small microgel with unobstructed migration and large microgel with good plugging efficiency for the high permeability zone were respectively featured with the higher recovery factor in homogeneous and heterogeneous conditions,which indicate they are preferred used for the oil displacement and conformance control.Compared to WAC injection,MAC injection had a higher incremental recovery factor of 12.4%.It suggests the acid-resistance microgel would be a good candidate for the conformance control during CO_(2)flooding process.
文摘In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’short life of use.The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer.The vial is grasped with the palm of the experimenter for several minutes without shaking.The proposed method is simple,rapid,green energy and cost-effective.By adjusting the concentration of trisodium citrate,not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved.As a SERS substrate,the silver colloid has high batch reproducibility and showed good SERS activity.The relative standard deviation between different manufacturers is 5.51%when the substrate of silver colloid is used for the detection of rhodamine 6 G.Using the substrate,the lowest detection concentrations of rhodamine 6 G,crystal violet,enrofloxacin,melamine and leucomalachite green are 1.0×10-8,6.1×10-8,1.4×10-6,7.1×10-5 and 5.1×10-8 mol/L,respectively.Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.
文摘BACKGROUND Although transcatheter aortic valve implantation(TAVI)is a safe and effective treatment for aortic stenosis,it still carries some risks,such as valve leaks,stroke,and even death.The left ventricular global longitudinal strain(LVGLS)measurement may be useful for the prediction of adverse events during this operation.AIM To explore the change of LVGLS during TAVI procedure and the relationship between LVGLS and perioperative adverse events.METHODS In this study,61 patients who had undergone percutaneous transfemoral TAVI were evaluated by transthoracic echocardiography.Before surgery,data on left ventricular ejection fraction(LVEF)and LVGLS were collected separately following balloon expansion and stent implantation.Difference in values of LVGLS and LVEF during preoperative balloon expansion(pre-ex),preoperative stent implantation(pre-im)and balloon expansion-stent implantation(ex-im)were also examined.Adverse events were defined as perioperative death,cardiac rupture,heart arrest,moderate or severe perivalvular leakage,significant mitral regurgitation during TAVI,perioperative moderate or severe mitral regurgitation,perioperative left ventricular outflow tract obstruction,reoperation,and acute heart failure.RESULTS The occurrence of perioperative adverse events was associated with differences in pre-ex LVGLS,but not with difference in pre-ex LVEF.There were significant differences between pre-LVGLS and ex-LVGLS,and between pre-LVGLS and im-LVGLS(P=0.037 and P=0.020,respectively).However,differences in LVEF were not significant(P=0.358,P=0.254);however differences in pre-ex LVGLS were associated with pre-LVGLS(P=0.045).Compared to LVEF,LVGLS is more sensitive as a measure of left heart function during TAVI and the perioperative period.Moreover,the differences in LVGLS were associated with the occurrence of perioperative adverse events,and changes in LVGLS were apparent in patients with undesirable LVGLS before the surgery.Furthermore,LVGLS is useful to predict changes in cardiac function during TAVI.CONCLUSION Greater attention should be paid to the patients who plan to undergo TAVI with normal LVEF but poor LVGLS.
基金the National Natural Science Foundation of China(Grant No.51773170)the Shaanxi Coal Joint Fund(Grant 2019JLM-24)+3 种基金funded by the International Science&Technology Cooperation Plan of Shaanxi Province(2021KW-52)Fund of Natural Science Foundation of Shaanxi Provincial(2021JQ-111)Fund of Basic and Applied Fundamental Research of Guangdong Provincial(2020A1515110861)sponsored by Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX202051)。
文摘Hierarchical layered structures,whether in a compact form like nacre or a porous manner like bone,are well known for their combined features of high stiffness,strength,and lightweight,inspiring many man-made materials and structures for high performance applications.The use of nacre/bone like hierarchical structures in polymer nanocomposites can achieve excellent mechanical and functional properties with high filler volume fractions after carefully aligning functional nanofillers,although the fabrication and processing remain a great challenge.In this work,a bio-inspired lightweight nano-cellular epoxy/graphene-Fe_(3)O_(4) nanocomposite with high nanofiller loading of 75 wt.%was successfully fabricated by combining features from both nacre and bone structures,via a simple compression molding process together with an eco-friendly supercritical CO_(2) foaming process to achieve robust mechanical strength and excellent electromagnetic interference(EMI)shielding effectiveness(SE)simultaneously.Highly aligned graphene-Fe_(3)O_(4) nanoplatelets with well controlled nanoscale porous structures(52.6 nm)enabled both low density(1.26 g/cm^(3))and high specific EMI SE>5200 dB/cm^(2)/g,as well as preserved tensile strength of 67 MPa.This study provides a sustainable route to fabricate nature mimicked structures with high performance and high flexibility for a wide range of applications,from portable electronics to healthcare devices.
基金supported by the National Natural Science Foundation of China(Grant No.52225503)National Key Research and Development Program of China(Grant No.2022YFB3805701)+1 种基金Development Program of Jiangsu Province(Grant Nos.BE2022069 and BE2022069-1)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX21-0207).
文摘Lightweight porous materials with high load-bearing,damage tolerance and energy absorption(EA)as well as intelligence of shape recovery after material deformation are beneficial and critical for many applications,e.g.aerospace,automobiles,electronics,etc.Cuttlebone produced in the cuttlefish has evolved vertical walls with the optimal corrugation gradient,enabling stress homogenization,significant load bearing,and damage tolerance to protect the organism from high external pressures in the deep sea.This work illustrated that the complex hybrid wave shape in cuttlebone walls,becoming more tortuous from bottom to top,creates a lightweight,load-bearing structure with progressive failure.By mimicking the cuttlebone,a novel bionic hybrid structure(BHS)was proposed,and as a comparison,a regular corrugated structure and a straight wall structure were designed.Three types of designed structures have been successfully manufactured by laser powder bed fusion(LPBF)with NiTi powder.The LPBF-processed BHS exhibited a total porosity of 0.042% and a good dimensional accuracy with a peak deviation of 17.4μm.Microstructural analysis indicated that the LPBF-processed BHS had a strong(001)crystallographic orientation and an average size of 9.85μm.Mechanical analysis revealed the LPBF-processed BHS could withstand over 25000 times its weight without significant deformation and had the highest specific EA value(5.32 J·g^(−1))due to the absence of stress concentration and progressive wall failure during compression.Cyclic compression testing showed that LPBF-processed BHS possessed superior viscoelastic and elasticity energy dissipation capacity.Importantly,the uniform reversible phase transition from martensite to austenite in the walls enables the structure to largely recover its pre-deformation shape when heated(over 99% recovery rate).These design strategies can serve as valuable references for the development of intelligent components that possess high mechanical efficiency and shape memory capabilities.
基金This research was supported by the National Natural Science Foundation of China(Grant No.41730646)National Natural Science Foundation for Young Scientists of China(Grant No.41605079)the National Key R&D Program of China(Grant No.2018YFC1507702)。
文摘In this study,an extreme rainfall event that occurred on 25 May 2018 over Shanghai and its nearby area was simulated using the Weather Research and Forecasting model,with a focus on the effects of planetary boundary layer(PBL)physics using double nesting with large grid ratios(15:1 and 9:1).The sensitivity of the precipitation forecast was examined through three PBL schemes:the Yonsei University Scheme,the Mellor−Yamada−Nakanishi Niino Level 2.5(MYNN)scheme,and the Mellor−Yamada−Janjic scheme.The PBL effects on boundary layer structures,convective thermodynamic and large-scale forcings were investigated to explain the model differences in extreme rainfall distributions and hourly variations.The results indicated that in single coarser grids(15 km and 9 km),the extreme rainfall amount was largely underestimated with all three PBL schemes.In the inner 1-km grid,the underestimated intensity was improved;however,using the MYNN scheme for the 1-km grid domain with explicitly resolved convection and nested within the 9-km grid using the Kain−Fritsch cumulus scheme,significant advantages over the other PBL schemes are revealed in predicting the extreme rainfall distribution and the time of primary peak rainfall.MYNN,with the weakest vertical mixing,produced the shallowest and most humid inversion layer with the lowest lifting condensation level,but stronger wind fields and upward motions from the top of the boundary layer to upper levels.These factors all facilitate the development of deep convection and moisture transport for intense precipitation,and result in its most realistic prediction of the primary rainfall peak.
基金supported by the National Natural Science Foundation of China(21975207,52202303)the Westlake Education Foundation,and the Zhejiang Provincial Natural Science Foundation of China(LQ21B030006)。
文摘The solid electrolyte interphase(SEI)with strong mechanical strength and high ion conductivity is highly desired for Li metal batteries,especially for harsh anode-free batteries.Herein,we report a pragmatic approach to the in-situ construction of high-quality SEI by applying synergistic additives of Li NO_(3)and ethylene sulfite(ES)in the electrolyte.The obtained SEI exhibits a high average Young’s modulus(9.02GPa)and exchanging current density(4.59 mA cm^(-2)),which are 3.0 and 1.2 times as large as those using the sole additive of LiNO_(3),respectively.With this improved SEI,Li-dendrite growth and side reactions are effectively suppressed,leading to an ultra-high Coulombic efficiency(CE)of 99.7%for Li plating and stripping.When applying this improved electrolyte in full cells,it achieves a high capacity retention of 89.7%for over 150 cycles in a LiFePO_(4)||Li battery(~12 mg cm^(-2)cathode,50μm Li)and of 44.5%over 100 cycles in a LiFePO_(4)||Cu anode-free battery.
基金supported by the Anhui Provincial Natural Science Foundation of China(No.1508085SME219).
文摘Constructing new photocatalysts for the photocatalytic reduction of CO_(2)and efficient degradation of Lev-ofloxacin is of great importance to renewable energy.Here,S-scheme Bi_(2)MoO_(6-x)/MoS_(2)heterojunction nanospheres containing abundant surface defects(oxygen vacancies)were designed and successfully syn-thesized to enhance CO_(2)photoreduction activity in the absence of other sacrificial agents,co-catalysts or photosensitisers.At the same time,it can efficiently degrade organic pollutants(Levofloxacin).This heterogeneous structure with surface defects provides an abundance of reactive sites,accelerates charge separation and improves oxidation capacity.The improved Bi_(2)MoO_(6-x)/MoS_(2)heterogeneous nanospheres show excellent performance under simulated solar light,with the selectivity and yield of 92.45%and 29.01μmol h^(−1),respectively,for the generation of CO.Under visible light,the degradation efficiency of levofloxacin hydrochloride(LVX)reached 96.3%within 25 min and remained as high as 95%after three cycles.This work provides a new idea for the design of new S-scheme photocatalysts and an important reference for the preparation of photocatalysts for the efficient photocatalytic reduction of CO_(2)and the efficient degradation of organic pollutants at the same time.
基金the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM026).
文摘The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.
基金supported by Science and Technology Commission of Shanghai Municipality (No.17142202600)
文摘This paper reports accurate use of silanized support based substrate for surface-enhanced Raman spectroscopy（SERS） determination of illegal additives chrysoidin and malachite green. Detection of these illegal additives is very meaningful and the developed method meets this objective in a simple, rapid and cost effective way. Detection limits for chrysoidin and malachite green in aqueous solutions reached0.001 mg/L and 0.0001 mg/L respectively. Linear relationship between the Raman intensities and chrysoidin concentrations in range of 0.001-0.05 mg/L was found with regression coefficient（R） of 0.994.To investigate the practical application performance of the method, the substrate was applied to detect chrysoidin in Sprite at 0.01 mg/L and malachite green in fish pond water at 0.0001 mg/L. The SERS method could be an alternative approach for monitoring illegal additives and toxic harmful substances.
基金supported by the National Natural Science Foundation of China (51003069)Natural Science Foundation of Jiangsu Higher Education Institutions of China (10KJB430014)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A facile and rapid approach for detecting low concentration of iron ion(Fe3+) with improved sensitivity was developed on the basis of plasmon enhanced fluorescence and subsequently amplified fluorescence quenching.Au1Ag4@Si O2 nanoparticles were synthesized and dispersed into fluorescein isothiocyanate(FITC) solution. The fluorescence of the FITC solution was improved due to plasmon enhanced fluorescence. However, efficient fluorescence quenching of the FITC/Au1Ag4@Si O2 solution was subsequently achieved when Fe3+, with a concentration ranging from17 n M to 3.4 l M, was added into the FITC/Au1Ag4@Si O2 solution, whereas almost no fluorescence quenching was observed for pure FITC solution under the same condition. FITC/Au1Ag4@Si O2 solution shows a better sensitivity for detecting low concentration of Fe3+compared to pure FITC solution. The quantized limit of detection toward Fe3+was improved from 4.6 l M for pure FITC solution to 20 n M for FITC/Au1Ag4@Si O2 solution.
基金National Natural Science Foundation of China (62274094, 62175117)Natural Science Foundation of Jiangsu Higher Education Institutions (22KJB510011)+1 种基金Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University (KJS2260)Huali Talents Program of Nanjing University of Posts and Telecommunications。
文摘Buried interfacial voids have always been a notorious phenomenon observed in the fabrication of lead perovskite films. The existence of interfacial voids at the buried interface will capture the carrier, suppress carrier transport efficiencies, and affect the stability of photovoltaic devices. However, the impact of these buried interfacial voids on tin perovskites, a promising avenue for advancing lead-free photovoltaics, has been largely overlooked. Here, we utilize an innovative weakly polar solvent pretreatment strategy(WPSPS) to mitigate buried interfacial voids of tin perovskites. Our investigation reveals the presence of numerous voids in tin perovskites during annealing, attributed to trapped dimethyl sulfoxide(DMSO) used in film formation. The WPSPS method facilitates accelerated DMSO evaporation, effectively reducing residual DMSO. Interestingly, the WPSPS shifts the energy level of PEDOT:PSS downward, making it more aligned with the perovskite. This alignment enhances the efficiency of charge carrier transport. As the result, tin perovskite film quality is significantly improved,achieving a maximum power conversion efficiency approaching 12% with only an 8.3% efficiency loss after 1700 h of stability tests, which compares well with the state-of-the-art stability of tin-based perovskite solar cells.
