The leaching efficiency(LE) of ion adsorption rare earth(IARE) by the sulfate and chloride of ammonium,magnesium and aluminum were comparatively determined using column leaching method. It is found that at equal equiv...The leaching efficiency(LE) of ion adsorption rare earth(IARE) by the sulfate and chloride of ammonium,magnesium and aluminum were comparatively determined using column leaching method. It is found that at equal equivalent concentration of cation, the LE of IARE by aluminum sulfate is the highest, and the zeta potential of clay mineral particles in the tailing is near to zero, which means a lower risk of landslide and pollutant emission. Furthermore, the optimum concentration of aluminum sulfate is determined to be0.02 mol/L, which is much lower than that of ammonium sulfate and magnesium sulfate. To reduce the production cost and environmental impact, we proposed a multi-stage leaching process, which was firstly leaching with ammonium sulfate and then with aluminum sulfate, following by water washing and lime neutralizing. With the ratio of ammonium sulfate to aluminum sulfate varying from 1:0 to 0.5:0.5, the residual ammonium in tailing decreases from 11.2% to 0.6%, however, the LE of RE shows an optimum value at 0.8:0.2. By neutralizing the pH of tailing with lime water to over 6, the ion concentration in water rinsing solution can meet the requirement for water discharge. At the same time, the zeta potential of clay particles is found to be around-5 mV, means a relatively lower risk of landslide. These facts indicate that the LE of IARE can be increased and the danger caused by tailings landslides and pollutant emissions can be reduced by replacing ammonium sulfate with aluminum sulfate as leaching reagent.展开更多
Two new copper complexes based on 2-naphthoxyacetic acid ligand, namely [Cu(L)2(CH3CN)]2(1) and [Cu(L)(1,10-phen)2](2), where L = 2-naphthoxyacetic acid and 1,10-phen = 1,10-phenanthroline, were obtained by hydrotherm...Two new copper complexes based on 2-naphthoxyacetic acid ligand, namely [Cu(L)2(CH3CN)]2(1) and [Cu(L)(1,10-phen)2](2), where L = 2-naphthoxyacetic acid and 1,10-phen = 1,10-phenanthroline, were obtained by hydrothermal reaction and characterized by single-crystal X-ray diffraction. The binuclear complex 1 and mononuclear complex 2 belong to space group C2/c and P■, respectively. The binding properties of the two compounds with ct-DNA were investigated by UV-Vis and fluorescence spectra. The two compounds could bind with ct-DNA through interactions. Compound 2 displays stronger binding ability in the reaction with ct-DNA.展开更多
Novel red phosphors,Li2Sr1-1.5xSiO4：xPr3＋（x=0.002,0.003,0.004,0.005,0.006 and 0.008）,were synthesized by conventional solid state reaction and the luminescent properties were investigated.The as-prepared phosphors...Novel red phosphors,Li2Sr1-1.5xSiO4：xPr3＋（x=0.002,0.003,0.004,0.005,0.006 and 0.008）,were synthesized by conventional solid state reaction and the luminescent properties were investigated.The as-prepared phosphors showed red emission at 610 nm under excitation of blue light at 452 nm,indicating that they were promising candidates for red phosphors in the fabrication of white LEDs via blue LED chips.Their excitation bands at 452,476 and 487 nm were attributed to transitions of 3H4→3P2,3H4→3P1＋1I6,3H4→3P0 of Pr3＋ ion.The red emissions at 606 and 610 nm were originated from the 3P0-3H6 and 1D2-3H4 transitions of Pr3＋.The optimum doping concentration of Pr3＋ in Li2Sr1-1.5xSiO4：xPr3＋ was determined to be x=0.004.With the concentration of Pr3＋ over x=0.004,the fluorescence intensity of Li2Sr1-1.5xSiO4：xPr3＋ decreased,indicating the concentration quenching occurred.展开更多
Green light-emitting Ba2SiO4：Eu^2＋ phosphors co-doped with La or Y were synthesized by conventional solid-state reaction technique in reductive atmosphere（a mixture of 5% H2 and 95% N2）.The results showed that the...Green light-emitting Ba2SiO4：Eu^2＋ phosphors co-doped with La or Y were synthesized by conventional solid-state reaction technique in reductive atmosphere（a mixture of 5% H2 and 95% N2）.The results showed that the co-doping of La and Y could greatly enhance the fluorescence intensity of Ba2SiO4：Eu2＋ phosphors.The optimum doping concentration expressed by the x value in（Ba0.985-1.5xREx）2SiO4：0.03Eu^2＋（RE=La or Y） was determined to be of 0.05.The excitation and emission peaks of all as-synthesized phosphors were wide bands.The excitation bands ranged from 250 to 400 nm, which matched well with the wavelength of near ultraviolet white light-emitting diodes（LED） chip and could be used as a potential candidate for the fabrication of white LED.The emission bands from 450 to 550 nm were typical 5d-4f transition emission of Eu^2＋ and displayed un-symmetry profiles because of the two substitution sites of Ba^2＋ with Eu^2＋.展开更多
Organic cation and halide anion defects are omnipresent in the perovskite films,which will destroy perovskite electronic structure and downgrade the properties of devices.Defect passivation in halide perovskites is cr...Organic cation and halide anion defects are omnipresent in the perovskite films,which will destroy perovskite electronic structure and downgrade the properties of devices.Defect passivation in halide perovskites is crucial to the application of solar cells.Herein,tiny amounts of trivalent rhodium ion incorporation can help the nucleation of perovskite grain and passivate the defects in the grain boundaries,which can improve efficiency and stability of perovskite solar cells.Through first-principle calculations,rhodium ion incorporation into the perovskite structure can induce ordered arrangement and tune bandgap.In experiment,rhodium ion incorporation with perovskite can contribute to preparing larger crystalline and uniform film,reducing trap-state density and enlarging charge carrier lifetime.After optimizing the content of 1% rhodium,the devices achieved an efficiency up to 20.71% without obvious hysteresis,from 19.09% of that pristine perovskite.In addition,the unencapsulated solar cells maintain 92% of its initial efficiency after 500 h in dry air.This work highlights the advantages of trivalent rhodium ion incorporation in the characteristics of perovskite solar cells,which will promote the future industrial application.展开更多
Nanoporous Gd2O3 powders(NGPs) with different specific surface areas were prepared by a nonaqueous sol-gel method and utilized to tune the exothermal decomposition of ammonium perchlorate(AP) for enhanced propellant e...Nanoporous Gd2O3 powders(NGPs) with different specific surface areas were prepared by a nonaqueous sol-gel method and utilized to tune the exothermal decomposition of ammonium perchlorate(AP) for enhanced propellant efficiency and improved safety.It is found that with the increasing dosage of NGPs into AP,the two exothermal peaks of AP merge into one intense exothermal peak,indicating that an "energy stacking" has been achieved.Meanwhile,the unique delay of the first exothermal peak of AP is conducive to the safety of AP in application process.Furthermore,the dependence of decomposition heat of AP on dosage and calcination temperature is more evident than on the surface areas of NGPs,suggesting that the promotion effect of NGPs on the thermal decomposition of AP does not only rely on the surface interaction.Therefore,an electron transfer mechanism is proposed to illustrate the decomposition process of AP tuned by NGPs.展开更多
The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X...The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),wide-angle X-ray scattering,and microfocus SAXS(μSAXS)for a broad user community.To realize fast time-resolved USAXS experiments,the beamline adopted an in-vacuum undulator with a total length of 1.6 m as the photon source.An in-house cryogenic-cooled double multilayer monochromator was installed to deliver a photon flux of approximately 10^(13) photons/s at a photon energy of 10 keV.The three-year successful operation of this beamline demonstrated that the monochromator operated smoothly,as expected.BL10U1 has three end stations in succession:USAXS end station,μSAXS end station,and end station for industrial applications.The minimum scattering vector q~0.0042 nm^(-1) at 10 keV can be achieved at the USAXS end station equipped with a 28 m-long and 1.8 m-diameter vacuum flight tube.At theμSAXS end station,a beam spot of less than 10×8μm was achieved for micro-SAXS experiments.In contrast,in situ experimental instruments up to 5 m high and 8 m wide can be mounted at the industrial application end station,which offers industrial scientists the opportunity to use their large industrial equipment.BL10U1 opens up a new capability to investigate phenomena such as non-equilibrium and dynamic processes of materials with a wide length scale from angstroms to micrometers with millisecond time resolution.In this paper,we also report beamline design considerations and commissioning results.展开更多
Osteoarthritis(OA),a common disabling joint disease,is highly associated with microenvironmental changes in the cartilage and subchondral bone.Elevated reactive oxygen species(ROS)in the cartilage and subchondral bone...Osteoarthritis(OA),a common disabling joint disease,is highly associated with microenvironmental changes in the cartilage and subchondral bone.Elevated reactive oxygen species(ROS)in the cartilage and subchondral bone angiogenesis accelerate articular cartilage erosion.New cartilage-targeting drug deliv-ery systems that are aimed at preventing ROS production and angiogenesis may be of clinical significance for OA treatment.Herein,an ROS scavenger and an inflammatory-responsive nanocarrier are designed by immobilizing the natural polyphenol(curcumin)in chitosan-catechol nanoformulations(Cur-CS-C NPs)via boronate ester.The robust cartilage-targeting effects and ROS scavenging capacities of Cur-CS-C NPs were respectively determined in cartilage explants and chondrocytes.Intra-articular injection of Cur-CS-C NPs in OA rat models efficiently suppressed angiogenesis and cartilage degradation partially via the ROS-mediated NF-κB/PI3K-Akt signaling pathway.The developed curcumin-functionalized nanocarriers can significantly delay OA progression and provide a promising therapeutic strategy for other inflamma-tory diseases that are characterized by oxidative stress and angiogenesis.展开更多
The utilization of fiber reinforced thermoplastics(FRTP)is expected to fulfill lightweight demand in mass-produced aerospace products.Facing the unavoidable assembly of FRTP parts,fusion bonding methods such as resist...The utilization of fiber reinforced thermoplastics(FRTP)is expected to fulfill lightweight demand in mass-produced aerospace products.Facing the unavoidable assembly of FRTP parts,fusion bonding methods such as resistance welding are promising compared with mechanical joint and adhesive bonding.In this paper,a procedure has been brought out to understand the relationship between processing conditions and performance of the FRTP welding joints.The adherends were continuous glass fiber reinforced polypropylene(GF/PP)laminates fabricated by hotpressing method.The influences of time,current and pressure on the bending strength of the resistance welding joints were investigated.A processing window was drawn based on the optical observation of welded surfaces.The quantitative relationship between process parameters and mechanical property of GF/PP welding joint was established by Response Surface Method(RSM)with high accuracy.It was found that bending strength of GF/PP welding joint was improved by 31%compared with hot-pressing benchmark.展开更多
Although the rate-dependence of metals has been widely researched,the deformation mechanism under small-scale impact conditions lacked exploration and in-depth understanding.Using quasi-static nanoin-dentation(strain ...Although the rate-dependence of metals has been widely researched,the deformation mechanism under small-scale impact conditions lacked exploration and in-depth understanding.Using quasi-static nanoin-dentation(strain rate,SR,<1 s^(-1))and high strain-rate nano-impact(SR>10^(3)s^(-1))with a pyramidal Berkovich tip,this study investigates the influence of SR on the deformation response of an aluminium single crystal(110).The underlying microstructural variance was analyzed using on-axis TKD and TEM.The results show that the impact deformation involves great elastic recovery and different substructural characteristics.In contrast to the uniform sub-grain substructure with medium and high-angle grain boundaries formed during quasi-static indentation,the substructure formed under impact has a more heterogeneous nature including microbands near the surface and sub-grains underneath with dominant low-angle grain boundaries.The significant change in substructure for the impact deformation comes from suppressed thermally activated dislocation motion,leading to the conversion of dislocation glide from wave-like(quasi-static)to planar regime(impacting),and the insufficient rearrangement of geomet-rically necessary dislocations(GNDs).The heterogeneous microstructure develops due to the competition between high strain-rate-induced planar-slip and strain gradient-induced GND rearrangement,as well as the uneven distribution of SR and strain gradient.Moreover,the underlying incipient mechanism of the microband is proposed,in which successive primary dislocations are nucleated at the surface and glide perpendicular to flanks to pile up.Finally,the influence of SR on indentation size effects is discussed.展开更多
Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable dep...Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable deposition of uniform defect-free perovskite films over large areas,which is an unsettled but urgent issue.In this work,a long-chain gemini surfactant is introduced into perovskite precursor ink to enforce self-assembly into a network structure,considerably enhancing the coverage and smoothness of the perovskite films.The long gemini surfactant plays a distinctively synergistic role in perovskite film construction,crystallization kinetics modulation and defect passivation,leading to a certified record power conversion efficiency of 15.46%with Voc of 1.13 V and Jsc of 22.92 mA cm^(-2)for this type of modules.Importantly,all of the functional layers of the module are printed through a simple and high-speed(300 cm min^(-1))blade coating strategy in ambient atmosphere.These results mark a significant step toward the commercialization of all-printable carbon-based perovskite solar modules.展开更多
A novel repetitive contact technique, micro-impact testing, has been developed forcoating evaluation. Impact test results have proved a more consistent measure of coating per-formance under impact/fatigue conditions t...A novel repetitive contact technique, micro-impact testing, has been developed forcoating evaluation. Impact test results have proved a more consistent measure of coating per-formance under impact/fatigue conditions than traditional tribological methods such as scratch orpin-on-disk testing. The operating principles of the technique are described with some illustrativeresults on hard and soft coatings. The technique can provide information on impact wear resis-tance, susceptibility to brittle fracture, and strength of interfacial adhesion to substrate.展开更多
Organic-inorganic hybrid perovskites with 3D perovskite structure have gained much attention as light harvesting materials in thinfilm photovoltaics.This is because of their outstanding light-absorption characteristic...Organic-inorganic hybrid perovskites with 3D perovskite structure have gained much attention as light harvesting materials in thinfilm photovoltaics.This is because of their outstanding light-absorption characteristics,charge-transport dynamics and their simple processability using lab-scale solution and vapor phase deposition techniques.However,the inherent instability and lead toxicity of lead-based PSCs are the major problems at present.Recent studies have shown that the(CH_(3)NH_(3)T_(3)Bi_(2)I_(9)(MBI)0D bismuth-based compound can be used as an optical absorption layer in solar cells.In this paper,the(CH_(3)NH_(3)T_(3)Bi_(2)I_(9)was doped with Cland a series of(CH_(3)NH_(3)T_(3)Bi_(2)I_(9-x)Cl_(x)films were prepared.The effects of different doping amounts on the microstructure,photovoltaic properties and ferroelectric properties were systematically investigated.Scanning electron microscope(SEM)and Atomic force microscope(AFM)analysis showed that with the increase of doping content,the density of the films increased and the roughness decreased.The photoelectric conversion efficiency of(CH_(3)NH_(3)T_(3)Bi_(2)I_(9-x)Cl_(x)raises with the increase of doping content.For example,the photoelectric conversion efficiency of(C_(H)3NH_(3)T_(3)Bi_(2)I_(3)Cl_(6)is 0.473%.We find that the leakage current descends into the increase in doping content,which may be due to the increase in the film density and the decrease of porosity.These research results have a positive effect on the development of Bi-based lead-free perovskite.展开更多
The development of nanomedicines provides new opportunities for the treatment of atherosclerosis(AS)due to their great advantages such as the improved drug solubility,enhanced bioavailability and reduced side effects....The development of nanomedicines provides new opportunities for the treatment of atherosclerosis(AS)due to their great advantages such as the improved drug solubility,enhanced bioavailability and reduced side effects.Despite these advantages,nanomedicines are still facing some challenges.The problems remain in the short circulation life,lack of specific targeting and poor drug release controllability.In order to overcome the shortages of conventional nanomedicines,the combination of biomimetic strategy with smart nanoagents has been proposed.In light with the high reactive oxygen species(ROS)level in AS microenvironment and the fact that macrophages play a critical role in the pathogenesis of AS,we fabricated ROS-responsive biomimetic nanoparticles(NPs),which camouflaged macrophage membrane(MM)on ROS-responsive NPs loaded with rapamycin(RNPs)for potential application in AS therapy.The resulting ROSresponsive biomimetic NPs(MM/RNPs)exhibited favorable hydrodynamic size with negative surface charge,retained the functional proteins from MM,and showed ROS-responsive drug release.Because of the biomimetic camouflaging on surface,MM/RNPs could effectively escape from macrophages uptake and target to inflammatory endothelial cells.Meanwhile,MM/RNPs could inhibit the proliferation of macrophages and smooth muscle cells in vitro.Furthermore,the MM-coated NPs were found to be nontoxic in both cytotoxicity assay and in vivo toxicity evaluation.Consequently,these results demonstrated that MM/RNPs could be a potential candidate of drug delivery system for safe and effective anti-AS applications.展开更多
The transport and metabolism of lipids in cerebrovascular endothelial cells(ECs)have been hypothesized to regulate blood-brain barrier(BBB)maturation and homeostasis.Long-chain polyunsaturated fatty acids(LCPUFAs)as t...The transport and metabolism of lipids in cerebrovascular endothelial cells(ECs)have been hypothesized to regulate blood-brain barrier(BBB)maturation and homeostasis.Long-chain polyunsaturated fatty acids(LCPUFAs)as the important lipids components of cell membranes are essential for the development and function of BBB,but the direct links of lipid metabolism and ECs barrier function remain to be established.Here,we comprehensively characterize the transcriptomic phenotype of developmental cerebrovascular ECs in single-cell resolution and firstly find that trans-2-enoyl-CoA reductase(Tecr),a verylong-chain fatty acid synthesis,is highly expressed during barriergenesis and decreased after BBB maturation.EC-specific knockout of Tecr compromises angiogenesis due to delayed vascular sprouting.Importantly,EC-specific deletion of Tecr loss restrictive quality of vascular permeability from neonatal stages to adulthood,with high levels of transcytosis,but maintains the vascular tight junctions.Moreover,lipidomic analysis shows that the expression of Tecr in ECs is associated with the containing of omega-3 fatty acids,which directly suppresses caveolae vesicles formation.These results reveal a protective role for Tecr in BBB integrity and suggest that Tecr as a novel therapeutic target in the central nervous system(CNS)diseases associated with BBB dysfunction.展开更多
基金supported by the National Natural Science Foundation of China(51864033,21161014,51274123)the National Key Basic Research Development Program of China(2012CBA01204)
文摘The leaching efficiency(LE) of ion adsorption rare earth(IARE) by the sulfate and chloride of ammonium,magnesium and aluminum were comparatively determined using column leaching method. It is found that at equal equivalent concentration of cation, the LE of IARE by aluminum sulfate is the highest, and the zeta potential of clay mineral particles in the tailing is near to zero, which means a lower risk of landslide and pollutant emission. Furthermore, the optimum concentration of aluminum sulfate is determined to be0.02 mol/L, which is much lower than that of ammonium sulfate and magnesium sulfate. To reduce the production cost and environmental impact, we proposed a multi-stage leaching process, which was firstly leaching with ammonium sulfate and then with aluminum sulfate, following by water washing and lime neutralizing. With the ratio of ammonium sulfate to aluminum sulfate varying from 1:0 to 0.5:0.5, the residual ammonium in tailing decreases from 11.2% to 0.6%, however, the LE of RE shows an optimum value at 0.8:0.2. By neutralizing the pH of tailing with lime water to over 6, the ion concentration in water rinsing solution can meet the requirement for water discharge. At the same time, the zeta potential of clay particles is found to be around-5 mV, means a relatively lower risk of landslide. These facts indicate that the LE of IARE can be increased and the danger caused by tailings landslides and pollutant emissions can be reduced by replacing ammonium sulfate with aluminum sulfate as leaching reagent.
基金supported by the National Natural Science Foundation of China(21101090 and 21561021)
文摘Two new copper complexes based on 2-naphthoxyacetic acid ligand, namely [Cu(L)2(CH3CN)]2(1) and [Cu(L)(1,10-phen)2](2), where L = 2-naphthoxyacetic acid and 1,10-phen = 1,10-phenanthroline, were obtained by hydrothermal reaction and characterized by single-crystal X-ray diffraction. The binuclear complex 1 and mononuclear complex 2 belong to space group C2/c and P■, respectively. The binding properties of the two compounds with ct-DNA were investigated by UV-Vis and fluorescence spectra. The two compounds could bind with ct-DNA through interactions. Compound 2 displays stronger binding ability in the reaction with ct-DNA.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University(IRT0730)the Key Project of De-partment of Science and Technology of Jiangxi Province
文摘Novel red phosphors,Li2Sr1-1.5xSiO4：xPr3＋（x=0.002,0.003,0.004,0.005,0.006 and 0.008）,were synthesized by conventional solid state reaction and the luminescent properties were investigated.The as-prepared phosphors showed red emission at 610 nm under excitation of blue light at 452 nm,indicating that they were promising candidates for red phosphors in the fabrication of white LEDs via blue LED chips.Their excitation bands at 452,476 and 487 nm were attributed to transitions of 3H4→3P2,3H4→3P1＋1I6,3H4→3P0 of Pr3＋ ion.The red emissions at 606 and 610 nm were originated from the 3P0-3H6 and 1D2-3H4 transitions of Pr3＋.The optimum doping concentration of Pr3＋ in Li2Sr1-1.5xSiO4：xPr3＋ was determined to be x=0.004.With the concentration of Pr3＋ over x=0.004,the fluorescence intensity of Li2Sr1-1.5xSiO4：xPr3＋ decreased,indicating the concentration quenching occurred.
基金Program for Changjiang Scholars and Innovative Research Team in University (IRT0730)the Key Project of Department of Science and Technology of Jiangxi ProvinceProject of Education Department of Jiangxi
文摘Green light-emitting Ba2SiO4：Eu^2＋ phosphors co-doped with La or Y were synthesized by conventional solid-state reaction technique in reductive atmosphere（a mixture of 5% H2 and 95% N2）.The results showed that the co-doping of La and Y could greatly enhance the fluorescence intensity of Ba2SiO4：Eu2＋ phosphors.The optimum doping concentration expressed by the x value in（Ba0.985-1.5xREx）2SiO4：0.03Eu^2＋（RE=La or Y） was determined to be of 0.05.The excitation and emission peaks of all as-synthesized phosphors were wide bands.The excitation bands ranged from 250 to 400 nm, which matched well with the wavelength of near ultraviolet white light-emitting diodes（LED） chip and could be used as a potential candidate for the fabrication of white LED.The emission bands from 450 to 550 nm were typical 5d-4f transition emission of Eu^2＋ and displayed un-symmetry profiles because of the two substitution sites of Ba^2＋ with Eu^2＋.
基金supported by the Ministry of Education of China(IRT1148)the National Natural Science Foundation of China(U1732126,11804166,51602161,51372119)+3 种基金China Postdoctoral Science Foundation(2018M630587)the Priority Academic Program Development of Jiangsu Higher Education Institutions(YX03001)Guangdong Science and Technology Program(2017B030314002)Graduate Research Innovation Fund of Jiangsu Province(KYCX18_0863,KYCX18_0847,KYCX18_0869)。
文摘Organic cation and halide anion defects are omnipresent in the perovskite films,which will destroy perovskite electronic structure and downgrade the properties of devices.Defect passivation in halide perovskites is crucial to the application of solar cells.Herein,tiny amounts of trivalent rhodium ion incorporation can help the nucleation of perovskite grain and passivate the defects in the grain boundaries,which can improve efficiency and stability of perovskite solar cells.Through first-principle calculations,rhodium ion incorporation into the perovskite structure can induce ordered arrangement and tune bandgap.In experiment,rhodium ion incorporation with perovskite can contribute to preparing larger crystalline and uniform film,reducing trap-state density and enlarging charge carrier lifetime.After optimizing the content of 1% rhodium,the devices achieved an efficiency up to 20.71% without obvious hysteresis,from 19.09% of that pristine perovskite.In addition,the unencapsulated solar cells maintain 92% of its initial efficiency after 500 h in dry air.This work highlights the advantages of trivalent rhodium ion incorporation in the characteristics of perovskite solar cells,which will promote the future industrial application.
基金Project supported by the National Natural Science Foundation of China(51864033,51274123,21761020)the National Key Basic Research Program of China(973 Program,2012CBA01204)Jiangxi Provincial Scientific&Technological Support Project of China(20132BBE500041)
文摘Nanoporous Gd2O3 powders(NGPs) with different specific surface areas were prepared by a nonaqueous sol-gel method and utilized to tune the exothermal decomposition of ammonium perchlorate(AP) for enhanced propellant efficiency and improved safety.It is found that with the increasing dosage of NGPs into AP,the two exothermal peaks of AP merge into one intense exothermal peak,indicating that an "energy stacking" has been achieved.Meanwhile,the unique delay of the first exothermal peak of AP is conducive to the safety of AP in application process.Furthermore,the dependence of decomposition heat of AP on dosage and calcination temperature is more evident than on the surface areas of NGPs,suggesting that the promotion effect of NGPs on the thermal decomposition of AP does not only rely on the surface interaction.Therefore,an electron transfer mechanism is proposed to illustrate the decomposition process of AP tuned by NGPs.
基金This work was supported by the National Key R&D Program of China(No.2020YFA0405802)the Shanghai Large Scientific Facilities Center.
文摘The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),wide-angle X-ray scattering,and microfocus SAXS(μSAXS)for a broad user community.To realize fast time-resolved USAXS experiments,the beamline adopted an in-vacuum undulator with a total length of 1.6 m as the photon source.An in-house cryogenic-cooled double multilayer monochromator was installed to deliver a photon flux of approximately 10^(13) photons/s at a photon energy of 10 keV.The three-year successful operation of this beamline demonstrated that the monochromator operated smoothly,as expected.BL10U1 has three end stations in succession:USAXS end station,μSAXS end station,and end station for industrial applications.The minimum scattering vector q~0.0042 nm^(-1) at 10 keV can be achieved at the USAXS end station equipped with a 28 m-long and 1.8 m-diameter vacuum flight tube.At theμSAXS end station,a beam spot of less than 10×8μm was achieved for micro-SAXS experiments.In contrast,in situ experimental instruments up to 5 m high and 8 m wide can be mounted at the industrial application end station,which offers industrial scientists the opportunity to use their large industrial equipment.BL10U1 opens up a new capability to investigate phenomena such as non-equilibrium and dynamic processes of materials with a wide length scale from angstroms to micrometers with millisecond time resolution.In this paper,we also report beamline design considerations and commissioning results.
基金financially supported by the National Natural Science Foundation of China (Nos.11532004 and 11832008)the Innovation and Attracting Talents Program for College and Univer-sity (“111”Project) (No.B06023).
文摘Osteoarthritis(OA),a common disabling joint disease,is highly associated with microenvironmental changes in the cartilage and subchondral bone.Elevated reactive oxygen species(ROS)in the cartilage and subchondral bone angiogenesis accelerate articular cartilage erosion.New cartilage-targeting drug deliv-ery systems that are aimed at preventing ROS production and angiogenesis may be of clinical significance for OA treatment.Herein,an ROS scavenger and an inflammatory-responsive nanocarrier are designed by immobilizing the natural polyphenol(curcumin)in chitosan-catechol nanoformulations(Cur-CS-C NPs)via boronate ester.The robust cartilage-targeting effects and ROS scavenging capacities of Cur-CS-C NPs were respectively determined in cartilage explants and chondrocytes.Intra-articular injection of Cur-CS-C NPs in OA rat models efficiently suppressed angiogenesis and cartilage degradation partially via the ROS-mediated NF-κB/PI3K-Akt signaling pathway.The developed curcumin-functionalized nanocarriers can significantly delay OA progression and provide a promising therapeutic strategy for other inflamma-tory diseases that are characterized by oxidative stress and angiogenesis.
基金Supports from the National Natural Science Foundation of China(Nos.11972096 and 11572059)CAST Young Elite Scientists Sponsorship Program(2017QNRC001)+3 种基金Chinese-Foreign Excellent Youth Exchange Program(2017CASTQNJL042)Fundamental Research Funds for the Central Universities(2018CDQYHK0029)Chongqing Key R&D Program(cstc2017zdcy-zdyfX0005)Chongqing Natural Science Foundation(cstc2018jcyjAX0089)。
文摘The utilization of fiber reinforced thermoplastics(FRTP)is expected to fulfill lightweight demand in mass-produced aerospace products.Facing the unavoidable assembly of FRTP parts,fusion bonding methods such as resistance welding are promising compared with mechanical joint and adhesive bonding.In this paper,a procedure has been brought out to understand the relationship between processing conditions and performance of the FRTP welding joints.The adherends were continuous glass fiber reinforced polypropylene(GF/PP)laminates fabricated by hotpressing method.The influences of time,current and pressure on the bending strength of the resistance welding joints were investigated.A processing window was drawn based on the optical observation of welded surfaces.The quantitative relationship between process parameters and mechanical property of GF/PP welding joint was established by Response Surface Method(RSM)with high accuracy.It was found that bending strength of GF/PP welding joint was improved by 31%compared with hot-pressing benchmark.
基金This work was supported by the National Natural Science Foun-dation of China(No.52371058)the Ministry of Science and Tech-nology of the People’s Republic of China(No.2019YFE0191500)the State Key Laboratory for Mechanical Behavior of Materials(No.20222406).
文摘Although the rate-dependence of metals has been widely researched,the deformation mechanism under small-scale impact conditions lacked exploration and in-depth understanding.Using quasi-static nanoin-dentation(strain rate,SR,<1 s^(-1))and high strain-rate nano-impact(SR>10^(3)s^(-1))with a pyramidal Berkovich tip,this study investigates the influence of SR on the deformation response of an aluminium single crystal(110).The underlying microstructural variance was analyzed using on-axis TKD and TEM.The results show that the impact deformation involves great elastic recovery and different substructural characteristics.In contrast to the uniform sub-grain substructure with medium and high-angle grain boundaries formed during quasi-static indentation,the substructure formed under impact has a more heterogeneous nature including microbands near the surface and sub-grains underneath with dominant low-angle grain boundaries.The significant change in substructure for the impact deformation comes from suppressed thermally activated dislocation motion,leading to the conversion of dislocation glide from wave-like(quasi-static)to planar regime(impacting),and the insufficient rearrangement of geomet-rically necessary dislocations(GNDs).The heterogeneous microstructure develops due to the competition between high strain-rate-induced planar-slip and strain gradient-induced GND rearrangement,as well as the uneven distribution of SR and strain gradient.Moreover,the underlying incipient mechanism of the microband is proposed,in which successive primary dislocations are nucleated at the surface and glide perpendicular to flanks to pile up.Finally,the influence of SR on indentation size effects is discussed.
基金supported by the National Natural Science Foundation of China(U2001217,22261160370 and 21972006)Guangdong-Hong Kong-Macao Joint Innovation Foundation(2021A0505110003)+1 种基金Shenzhen Basic Research(JCYJ20220818101018038 and JCYJ20200109110628172)Guangdong Province Regional Joint Innovation Foundation(2020B1515120039)。
文摘Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable deposition of uniform defect-free perovskite films over large areas,which is an unsettled but urgent issue.In this work,a long-chain gemini surfactant is introduced into perovskite precursor ink to enforce self-assembly into a network structure,considerably enhancing the coverage and smoothness of the perovskite films.The long gemini surfactant plays a distinctively synergistic role in perovskite film construction,crystallization kinetics modulation and defect passivation,leading to a certified record power conversion efficiency of 15.46%with Voc of 1.13 V and Jsc of 22.92 mA cm^(-2)for this type of modules.Importantly,all of the functional layers of the module are printed through a simple and high-speed(300 cm min^(-1))blade coating strategy in ambient atmosphere.These results mark a significant step toward the commercialization of all-printable carbon-based perovskite solar modules.
文摘A novel repetitive contact technique, micro-impact testing, has been developed forcoating evaluation. Impact test results have proved a more consistent measure of coating per-formance under impact/fatigue conditions than traditional tribological methods such as scratch orpin-on-disk testing. The operating principles of the technique are described with some illustrativeresults on hard and soft coatings. The technique can provide information on impact wear resis-tance, susceptibility to brittle fracture, and strength of interfacial adhesion to substrate.
基金The program for innovation teams in University of Chongqing,China(Grant No.CXTDX201601032)Chongqing Science and Technology College Graduate Technology Innovation Project(YKJCX1720209)the program for Technical and Scientific Innovation led by Academician of Chongqing,China.
文摘Organic-inorganic hybrid perovskites with 3D perovskite structure have gained much attention as light harvesting materials in thinfilm photovoltaics.This is because of their outstanding light-absorption characteristics,charge-transport dynamics and their simple processability using lab-scale solution and vapor phase deposition techniques.However,the inherent instability and lead toxicity of lead-based PSCs are the major problems at present.Recent studies have shown that the(CH_(3)NH_(3)T_(3)Bi_(2)I_(9)(MBI)0D bismuth-based compound can be used as an optical absorption layer in solar cells.In this paper,the(CH_(3)NH_(3)T_(3)Bi_(2)I_(9)was doped with Cland a series of(CH_(3)NH_(3)T_(3)Bi_(2)I_(9-x)Cl_(x)films were prepared.The effects of different doping amounts on the microstructure,photovoltaic properties and ferroelectric properties were systematically investigated.Scanning electron microscope(SEM)and Atomic force microscope(AFM)analysis showed that with the increase of doping content,the density of the films increased and the roughness decreased.The photoelectric conversion efficiency of(CH_(3)NH_(3)T_(3)Bi_(2)I_(9-x)Cl_(x)raises with the increase of doping content.For example,the photoelectric conversion efficiency of(C_(H)3NH_(3)T_(3)Bi_(2)I_(3)Cl_(6)is 0.473%.We find that the leakage current descends into the increase in doping content,which may be due to the increase in the film density and the decrease of porosity.These research results have a positive effect on the development of Bi-based lead-free perovskite.
基金This work was supported by the National Natural Science Foundation of China(31971301,31971242,12032007)the China Postdoctoral Science Foundation(2020M673143)+1 种基金the Natural Science Foundation of Chongqing(cstc2020jcyj-bsh0025,cstc2019jcyj-zdxmX0028,cstc2017jcyjAX0186)Fundamental Research Funds for Central Universities(2020CDJQY-A061,2020CDJYGSX006,2019CDYGZD008,2018CDHB1B08)as well as the National‘111 Project’Base(B0625)are gratefully acknowledged.
文摘The development of nanomedicines provides new opportunities for the treatment of atherosclerosis(AS)due to their great advantages such as the improved drug solubility,enhanced bioavailability and reduced side effects.Despite these advantages,nanomedicines are still facing some challenges.The problems remain in the short circulation life,lack of specific targeting and poor drug release controllability.In order to overcome the shortages of conventional nanomedicines,the combination of biomimetic strategy with smart nanoagents has been proposed.In light with the high reactive oxygen species(ROS)level in AS microenvironment and the fact that macrophages play a critical role in the pathogenesis of AS,we fabricated ROS-responsive biomimetic nanoparticles(NPs),which camouflaged macrophage membrane(MM)on ROS-responsive NPs loaded with rapamycin(RNPs)for potential application in AS therapy.The resulting ROSresponsive biomimetic NPs(MM/RNPs)exhibited favorable hydrodynamic size with negative surface charge,retained the functional proteins from MM,and showed ROS-responsive drug release.Because of the biomimetic camouflaging on surface,MM/RNPs could effectively escape from macrophages uptake and target to inflammatory endothelial cells.Meanwhile,MM/RNPs could inhibit the proliferation of macrophages and smooth muscle cells in vitro.Furthermore,the MM-coated NPs were found to be nontoxic in both cytotoxicity assay and in vivo toxicity evaluation.Consequently,these results demonstrated that MM/RNPs could be a potential candidate of drug delivery system for safe and effective anti-AS applications.
基金the National Natural Science Foundation of China(12032007,31971242)to Guixue Wangthe Chongqing Science and Technology Bureau(cstc2019jcyj-zdxmX0028)to Guixue WangChongqing Municipal Education Commission,China(KYYJ202001)to Guixue Wang。
文摘The transport and metabolism of lipids in cerebrovascular endothelial cells(ECs)have been hypothesized to regulate blood-brain barrier(BBB)maturation and homeostasis.Long-chain polyunsaturated fatty acids(LCPUFAs)as the important lipids components of cell membranes are essential for the development and function of BBB,but the direct links of lipid metabolism and ECs barrier function remain to be established.Here,we comprehensively characterize the transcriptomic phenotype of developmental cerebrovascular ECs in single-cell resolution and firstly find that trans-2-enoyl-CoA reductase(Tecr),a verylong-chain fatty acid synthesis,is highly expressed during barriergenesis and decreased after BBB maturation.EC-specific knockout of Tecr compromises angiogenesis due to delayed vascular sprouting.Importantly,EC-specific deletion of Tecr loss restrictive quality of vascular permeability from neonatal stages to adulthood,with high levels of transcytosis,but maintains the vascular tight junctions.Moreover,lipidomic analysis shows that the expression of Tecr in ECs is associated with the containing of omega-3 fatty acids,which directly suppresses caveolae vesicles formation.These results reveal a protective role for Tecr in BBB integrity and suggest that Tecr as a novel therapeutic target in the central nervous system(CNS)diseases associated with BBB dysfunction.
