Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practica...Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practical applications.Herein,we report an effective method for synthesizing mesocrystal zinc oxide nanorods(ZnONRs).The crystal,surface,and internal structures of the zinc oxide mesocrystals were fully characterized.Mesocrystal zinc oxide nanorods/reduced graphene oxide(ZnONRs/rGO)nanocomposite superstructure were synthesized also using the hydrothermal method.The crystal,surface,chemical,and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized.The optical absorption coefficient,bandgap energy,band structure,and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties.Finally,the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet(UV)photodetection applications.Finally,we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.展开更多
In the realm of the synthesis of heat-integrated distillation configurations,the conventional approach for exploring more heat integration possibilities typically entails the splitting of a single column into a twocol...In the realm of the synthesis of heat-integrated distillation configurations,the conventional approach for exploring more heat integration possibilities typically entails the splitting of a single column into a twocolumn configuration.However,this approach frequently necessitates tedious enumeration procedures,resulting in a considerable computational burden.To surmount this formidable challenge,the present study introduces an innovative remedy:The proposition of a superstructure that encompasses both single-column and multiple two-column configurations.Additionally,a simultaneous optimization algorithm is applied to optimize both the process parameters and heat integration structures of the twocolumn configurations.The effectiveness of this approach is demonstrated through a case study focusing on industrial organosilicon separation.The results underscore that the superstructure methodology not only substantially mitigates computational time compared to exhaustive enumeration but also furnishes solutions that exhibit comparable performance.展开更多
Controllable design of the catalytic electrodes with hierarchical superstructures is expected to improve their electrochemical performance.Herein,a self-supported integrated electrode(NiCo-ZLDH/NF)with a unique hierar...Controllable design of the catalytic electrodes with hierarchical superstructures is expected to improve their electrochemical performance.Herein,a self-supported integrated electrode(NiCo-ZLDH/NF)with a unique hierarchical quaternary superstructure was fabricated through a self-sacrificing template strategy from the metal–organic framework(Co-ZIF-67)nanoplate arrays,which features an intriguing well-defined hierarchy when taking the unit cells of the NiCo-based layered double hydroxide(NiCo-LDH)as the primary structure,the ultrathin LDH nanoneedles as the secondary structure,the mesoscale hollow plates of the LDH nanoneedle arrays as the tertiary structure,and the macroscale three-dimensional frames of the plate arrays as the quaternary structure.Notably,the distinctive structure of NiCo-ZLDH/NF can not only accelerate both mass and charge transfer,but also expose plentiful accessible active sites with high intrinsic activity,endowing it with an excellent electrochemical performance for urea oxidation reaction(UOR).Specially,it only required the low potentials of 1.335,1.368 and 1.388 V to deliver the current densities of 10,100 and 200 mA cm^(-2),respectively,much superior to those for typical NiCo-LDH.Employing NiCo-ZLDH/NF as the bifunctional electrode for both anodic UOR and cathodic HER,an energy-saving electrolysis system was further explored which can greatly reduce the needed voltage of 213 mV to deliver the current density of 100 mA cm^(-2),as compared to the conventional water electrolysis system composed of OER.This work manifests that it is prospective to explore the hierarchically nanostructured electrodes and the innovative electrolytic technologies for high-efficiency electrocatalysis.展开更多
In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spr...In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spreading.In this regard,an inclined base layer overlain by a very loose liquefiable layer was constructed in both models;while only in one model,a non-liquefiable crust layer was built.A lumped mass,being representative of a superstructure,was attached to the cap of one pile group in both models.The models were fully instrumented with various sensors,including acceleration,displacement,and pore water pressure transducers.Also,the piles were instrumented with pair strain gauges to measure pure bending moments induced by cyclic and monotonic loadings associated with ground shaking and lateral spreading,respectively.The results showed that the existence of the non-liquefiable crust layer increases both the maximum and residual soil displacements at the free field and also the maximum bending moments in the piles.The results of the experiments indicated that the crust layer induces a high kinematic lateral soil pressure and force on the piles which are not present in the crustless case.The crust layer increases the pile cap displacement before liquefaction,albeit decreases it after liquefaction,due to the elastic rebound of the piles in the liquefiable layer.The crust layer postpones both liquefaction triggering and dissipation of excess pore water pressure.The existence of the superstructure mass on the pile caps decreases the acceleration amplitude of the pile caps,while increases their maximum displacement.展开更多
The fabrication of well defined hierarchical structures of anatase TiO_(2) with a high percentage of reactive facets is of great importance and challenging.Hierarchically flower-like TiO_(2) superstructures(HFTS)self-...The fabrication of well defined hierarchical structures of anatase TiO_(2) with a high percentage of reactive facets is of great importance and challenging.Hierarchically flower-like TiO_(2) superstructures(HFTS)self-assembled from anatase TiO_(2) nanosheets with exposed{001}facets(up to 87%)were synthesized by a simple alcohothermal strategy in a HF-H_(2)O-C_(2)H_(5)OH mixed solution using titanate nanotubes as precursor.The samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and N2 adsorption-desorption isotherms.The photocatalytic activity was evaluated by the photocatalytic oxidation decomposition of acetone in air and methyl orange in aqueous solution under UV illumination.The photocatalytic activity of HFTS was much higher than that of commercial Degussa P25 and tabular-shaped anatase TiO_(2) obtained using pure water as the synthesis medium.The enhancement in photocatalytic activity was related to several factors,including the hierarchically porous structure,exposed{001}facets,and increased light harvesting ability.The HFTS was also of interest for use in solar cells,photocatalytic H_(2) production,optoelectronic devices,sensors,and catalysis.展开更多
A well-defined m-phenylenediimino-bridged ladder polymethylsiloxane(LP) was first synthesized through a welldefined ladder superstructure(LS) acting as synthetic template,which was self-assembled by concerted interact...A well-defined m-phenylenediimino-bridged ladder polymethylsiloxane(LP) was first synthesized through a welldefined ladder superstructure(LS) acting as synthetic template,which was self-assembled by concerted interaction of hydrogen bonding and aromaticπ-πstacking of the monomer(M),N,N'-bis(phenyldichlorosilyl)-m-phenylenediamine.Some key characterization data of LP and,in particular,the extremely vulnerable LS with very unstable Si-Cl and Si-N groups were given.The molecular weights(M_n) of LS and LP are 5...展开更多
Glioblastoma(GBM) remains a formidable challenge in oncology.Chemodynamic therapy(CDT) that triggers tumor cell death by reactive oxygen species(ROS) could open up a new door for GBM treatment.Herein,we report a novel...Glioblastoma(GBM) remains a formidable challenge in oncology.Chemodynamic therapy(CDT) that triggers tumor cell death by reactive oxygen species(ROS) could open up a new door for GBM treatment.Herein,we report a novel CDT nanoagent.Hemoglobin(Hb)and glucose oxidase(GOx) were employed as powerful CDT catalysts.Instead of encapsulating the proteins in drug delivery nanocarriers,we formulate multimeric superstructures as self-delivery entities by crosslinking techniques.Red blood cell(RBC) membranes are camouflaged on the protein superstructures to promote the delivery across blood-brain barrier.The as-prepared RBC@Hb@GOx nanoparticles(NPs) offer superior biocompatibility,simplified structure,and high accumulation at the tumor site.We successfully demonstrated that the NPs could efficiently produce toxic ROS to kill U87 MG cancer cells in vitro and inhibit the growth of GBM tumor in vivo,suggesting that the new CDT nanoagent holds great promise for treating GBM.展开更多
Urchin-like Ni O superstructures have been prepared via a thermal decomposition reaction of Ni C_2O_4 at 400 for 1h. The morphology and structure of the synthesized urchin-like superstructures have been characterized ...Urchin-like Ni O superstructures have been prepared via a thermal decomposition reaction of Ni C_2O_4 at 400 for 1h. The morphology and structure of the synthesized urchin-like superstructures have been characterized by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The results show that urchin-like Ni O superstructures were a polycrystal with cubic structure and typical diameters of 200 to 500 nm and the self-assembly nanoparticles average diameter is 14 nm. The as-prepared Ni O superstructures have a high Brunauer-Emmett-Teller surface area of about 60.32 m^2/g. The UV-vis spectrum of urchin-like Ni O consists of one peak at 357 nm(3.47 e V).展开更多
Integrating multiple systems into one has become an important trend in Process Systems Engineering research field since there is strong demand from the modern industries. In this study, a stage-wise superstructurebase...Integrating multiple systems into one has become an important trend in Process Systems Engineering research field since there is strong demand from the modern industries. In this study, a stage-wise superstructurebased method is proposed to synthesize a combined mass and heat exchange network(CM&HEN) which has two parts as the mass exchange network(MEN) and heat exchange network(HEN) involved. To express the possible heat exchange requirements resulted from mass exchange operations, a so called "indistinct HEN superstructure(IHS)", which can contain the all potential matches between streams, is constructed at first. Then, a non-linear programming(NLP) mathematical model is established for the simultaneous synthesis and optimization of networks. Therein, the interaction between mass exchange and heat exchange is modeling formulated.The NLP model has later been examined using an example from literature, and the effectiveness of the proposed method has been demonstrated with the results.展开更多
Previously, synthetic hexagonal bismuth sulfide iodide (polar space group P63, a = 15.629(3) ?, c = 4.018(1) ?, Z = 2) has been described by the rather unsatisfactory fractional formula Bi19/3IS9 [1] 08D0C9EA79F9BACE1...Previously, synthetic hexagonal bismuth sulfide iodide (polar space group P63, a = 15.629(3) ?, c = 4.018(1) ?, Z = 2) has been described by the rather unsatisfactory fractional formula Bi19/3IS9 [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370039000000 -[3] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370036000000 . A redetermination of the structure using old but reliable photographic intensity data indicated the presence of additional split positions and reduced atomic occupancies. From the observed pattern of this “averaged” structure a consistent model of a superstructure with lattice parameters of a' = √13·a = 56.35(1) ?, c' = c, and a formula Bi5-x(Bi2S3)39I12S emerged, with 2 formula units in a cell of likewise P63 space group. Structural modulation may be provoked by the space the lone electron pair of Bi requires. When Bi on the 0, 0, z position of the “averaged” cell is transferred to two general six-fold sites and one unoccupied twofold one of the super-cell, more structural stability is guaranteed due to compensation of its basal plane dipole momentum. Owing to the limited intensity data available, more details of the superstructure are not accessible yet. Some physical properties and solar cell application are discussed together with suggestions of ambient temperature synthesis routes of c-axis oriented nano-rod sheets.展开更多
Mitochondria, usually ovoid structures no larger than 0.5 microns can fuse into structures that are 5 microns and larger such as nebenkern, spheroidal or cup-shaped mitochondria, and even mega-mitochondria. In studyin...Mitochondria, usually ovoid structures no larger than 0.5 microns can fuse into structures that are 5 microns and larger such as nebenkern, spheroidal or cup-shaped mitochondria, and even mega-mitochondria. In studying differentiation of human endometrial epithelial cells, it became clear that formation of mitochondrial superstructures was an essential part of the process. In this paper, the origins, function, and demise of these superstructures called mitonucleons are described. In the course of reading papers about mitochondrial superstructures, it became obvious that there are important similarities, particularly with regard to function, between the mitonucleon and the nebenkern, a superstructure essential for dramatic tail elongation during spermatogenesis in grasshoppers, drosophila, and other insects. Close inspection of photomicrographs of differentiating mitonucleons during the first 12 hours suggests that gases build up in vacuoles within the mitochondrial superstructure creating pressure that elevates syncytial membranes and compresses nuclear aggregates contained within the mitonucleon.展开更多
It was revealed that an average energy of special boundaries is proportional to APB energy in the alloys with the L12 superstructure. This fact proves the appearance of the GAPBs in the planes of location of special b...It was revealed that an average energy of special boundaries is proportional to APB energy in the alloys with the L12 superstructure. This fact proves the appearance of the GAPBs in the planes of location of special boundaries in coincidence sites of ordered alloys. It was determined that the more energy of special boundaries in ordered alloys, the more energy of complex stacking fault. There is a correlation between the distribution of special boundaries as a function its relative energy and ordering energy: the more ordering energy, the more degree of washed away of distribution. The correlation between average relative energy of special boundaries and ordering energy was detected: the more ordering energy, the more average energy of special boundaries. The reverse dependence between ordering energy and average number of special boundaries in grains limited by boundaries of general type was discovered.展开更多
Using finite analysis element software, the transient displacement field of automatic submerged arc welding is established. It was also considered that the thermal physical properties changes were depended on the temp...Using finite analysis element software, the transient displacement field of automatic submerged arc welding is established. It was also considered that the thermal physical properties changes were depended on the temperatureand the heat loss on the surface. At the same time, it analyzed the influence of the deformation and stress, whichgenerated in the plate butt-welding process, to the superstructure steel welding deformation. The result showedthat the deformation and stress generated in the steel plate butt-welding process are considered to be the mainfactors to influence the welding deformation of superstructure steel. It found the effective ways to reduce the weldingdeformation of the hull superstructure steel is to relieve the butt-welding deformation and release butt-welding stressbefore welding the hull superstructure steel.展开更多
Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work.A stream that expands through expanders can produce work and cold load,while expansion th...Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work.A stream that expands through expanders can produce work and cold load,while expansion through valves barely affects heat integration.In addition,expansion through expanders at higher temperature produces more work,but consumes more hot utility.Therefore,there is a need to weigh work production and heat consumption.To this end,an enhanced stage-wise superstructure is proposed that involves synchronous optimization of expander/valve placement and heat integration for each pressure-change sub-stream in stages.A mixed-integer nonlinear programming(MINLP)model is established for synthesizing sub and aboveambient heat exchanger networks with multi-stream expansion,which explicitly considers the optimized selection of end-heaters and end-coolers to adjust temperature requirement.Our proposed method can commendably achieve the optimal selection of expanders and valves in a bid for minimizing exergy consumption and total annual cost.Four example studies are conducted with two distinct objective function(minimization of exergy consumption and total annual cost,respectively)to illustrate the feasibility and efficacy of the proposed method.展开更多
Since there may exist dark matter particles ν and δ with mass - 10^-1 e V in the universe, the superstructures with a scale of 10^19 solar masses (large number A - 10^19) appeared during the era near and before th...Since there may exist dark matter particles ν and δ with mass - 10^-1 e V in the universe, the superstructures with a scale of 10^19 solar masses (large number A - 10^19) appeared during the era near and before the hydrogen recombination. Since there are superstructures in the universe, there may be no necessity for the existence of dark energy. For checking the superstructure in the universe by CMB anisotropy, we need to measure CMB angular power spectrum especially around ten degrees across the sky- in more details, While neutrino u is related to electroweak unification, the fourth stable elementary particle 6 may be related to strong-gravity unification, which suggests p + p^- → n + δ^- and that some new baryons appeared in the TeV region.展开更多
High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized ...High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized by transmission electron microscope(TEM) and measured by high resolution laser-based angle-resolved photoemission spectroscopy(ARPES) with different photon energies.A systematic evolution of the electronic structure and superstructure with Pb substitution has been revealed for the first time.The superstructure shows a significant change with Pb substitution and the incommensurate modulation vector(Q) decreases with increasing Pb substitution.In the meantime, the superstructure intensity from ARPES measurements also decreases dramatically with increasing Pb concentration.The superstructure in Bi2212 can be effectively suppressed by Pb substitution and it nearly disappears with a Pb substitution of x = 0.8.We also find that the superstructure bands in ARPES measurements depend sensitively on the photon energy of lasers used;they can become even stronger than the main band when using a laser photon energy of 10.897 eV.These results provide important information on the origin of the incommensurate superstructure and its control and suppression in bismuth-based high temperature superconductors.展开更多
La3+ and V5+ co-doped BiFeO3 ceramics are synthesized by rapid liquid sintering technique. The modulated structure in Bi0.85La0.15Fe0.97V0.03O3 is investigated by using transmission electron microscopy (TEM). Two ...La3+ and V5+ co-doped BiFeO3 ceramics are synthesized by rapid liquid sintering technique. The modulated structure in Bi0.85La0.15Fe0.97V0.03O3 is investigated by using transmission electron microscopy (TEM). Two kinds of superstructures are observed in the samples. One is the component modulated superstructure and twin-domain, which is generated by La3+ ordered substitution for Bi3+ and frequently appears. The chemical composition of the superstructure is explored by x-ray energy dispersive spectroscopy (EDS). The model of the ordered structure is proposed. Simulation based on the model is conducted. The second is the fluorite-type δ-Bi2O3 related superstructure. The relation between the ferroelectric property and the microstructure of the sample is also discussed.展开更多
The ultrathinβ-Sn(001)films have attracted tremendous attention owing to its topological superconductivity(TSC),which hosts Majorana bound state(MBSs)for quantum computation.Recently,β-Sn(001)thin films have been su...The ultrathinβ-Sn(001)films have attracted tremendous attention owing to its topological superconductivity(TSC),which hosts Majorana bound state(MBSs)for quantum computation.Recently,β-Sn(001)thin films have been successfully fabricated via phase transition engineering.However,the understanding of structural phase transition ofβ-Sn(001)thin films is still elusive.Here,we report the direct growth of ultrathinβ-Sn(001)films epitaxially on the highly oriented pyrolytic graphite(HOPG)substrate and the characterization of intricate structural-transition-induced superstructures.The morphology was obtained by using atomic force microscopy(AFM)and low-temperature scanning tunneling microscopy(STM),indicating a structure-related bilayer-by-bilayer growth mode.The ultrathinβ-Sn film was made of multiple domains with various superstructures.Both high-symmetric and distorted superstructures were observed in the atomic-resolution STM images of these domains.The formation mechanism of these superstructures was further discussed based on the structural phase transition ofβtoα-Sn at the atomic-scale thickness.Our work not only brings a deep understanding of the structural phase transition of Sn film at the two-dimensional limit,but also paves a way to investigate their structure-sensitive topological properties.展开更多
Using scanning tunneling microscopy we observe a stripe phase smoothly interfacing with a triangular 2 ×2 super- structure on the surface of 2H-NbSe2 single crystM. Proximity-induced superconductivity is demonstr...Using scanning tunneling microscopy we observe a stripe phase smoothly interfacing with a triangular 2 ×2 super- structure on the surface of 2H-NbSe2 single crystM. Proximity-induced superconductivity is demonstrated in these new ordered structures by measurements of low-temperature tunneling spectra. The modulation of superconduc- tivity by the reconstruction provides an opportunity to understand the interplay between superconductivity and charge orders.展开更多
文摘Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practical applications.Herein,we report an effective method for synthesizing mesocrystal zinc oxide nanorods(ZnONRs).The crystal,surface,and internal structures of the zinc oxide mesocrystals were fully characterized.Mesocrystal zinc oxide nanorods/reduced graphene oxide(ZnONRs/rGO)nanocomposite superstructure were synthesized also using the hydrothermal method.The crystal,surface,chemical,and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized.The optical absorption coefficient,bandgap energy,band structure,and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties.Finally,the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet(UV)photodetection applications.Finally,we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.
文摘In the realm of the synthesis of heat-integrated distillation configurations,the conventional approach for exploring more heat integration possibilities typically entails the splitting of a single column into a twocolumn configuration.However,this approach frequently necessitates tedious enumeration procedures,resulting in a considerable computational burden.To surmount this formidable challenge,the present study introduces an innovative remedy:The proposition of a superstructure that encompasses both single-column and multiple two-column configurations.Additionally,a simultaneous optimization algorithm is applied to optimize both the process parameters and heat integration structures of the twocolumn configurations.The effectiveness of this approach is demonstrated through a case study focusing on industrial organosilicon separation.The results underscore that the superstructure methodology not only substantially mitigates computational time compared to exhaustive enumeration but also furnishes solutions that exhibit comparable performance.
基金support of the National Natural Science Foundation of China(21901246,22105203 and 22175174)the Natural Science Foundation of Fujian Province(2020J01116 and 2021J06033)the China Postdoctoral Science Foundation(2021TQ0332 and 2021M703215).
文摘Controllable design of the catalytic electrodes with hierarchical superstructures is expected to improve their electrochemical performance.Herein,a self-supported integrated electrode(NiCo-ZLDH/NF)with a unique hierarchical quaternary superstructure was fabricated through a self-sacrificing template strategy from the metal–organic framework(Co-ZIF-67)nanoplate arrays,which features an intriguing well-defined hierarchy when taking the unit cells of the NiCo-based layered double hydroxide(NiCo-LDH)as the primary structure,the ultrathin LDH nanoneedles as the secondary structure,the mesoscale hollow plates of the LDH nanoneedle arrays as the tertiary structure,and the macroscale three-dimensional frames of the plate arrays as the quaternary structure.Notably,the distinctive structure of NiCo-ZLDH/NF can not only accelerate both mass and charge transfer,but also expose plentiful accessible active sites with high intrinsic activity,endowing it with an excellent electrochemical performance for urea oxidation reaction(UOR).Specially,it only required the low potentials of 1.335,1.368 and 1.388 V to deliver the current densities of 10,100 and 200 mA cm^(-2),respectively,much superior to those for typical NiCo-LDH.Employing NiCo-ZLDH/NF as the bifunctional electrode for both anodic UOR and cathodic HER,an energy-saving electrolysis system was further explored which can greatly reduce the needed voltage of 213 mV to deliver the current density of 100 mA cm^(-2),as compared to the conventional water electrolysis system composed of OER.This work manifests that it is prospective to explore the hierarchically nanostructured electrodes and the innovative electrolytic technologies for high-efficiency electrocatalysis.
基金support by the Construction and Development of Transportation Infrastructures Company affiliated with the Ministry of Roads and Urban Development of Iran and partial financial support granted by the Research Deputy of the Sharif University of Technology are acknowledged.
文摘In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spreading.In this regard,an inclined base layer overlain by a very loose liquefiable layer was constructed in both models;while only in one model,a non-liquefiable crust layer was built.A lumped mass,being representative of a superstructure,was attached to the cap of one pile group in both models.The models were fully instrumented with various sensors,including acceleration,displacement,and pore water pressure transducers.Also,the piles were instrumented with pair strain gauges to measure pure bending moments induced by cyclic and monotonic loadings associated with ground shaking and lateral spreading,respectively.The results showed that the existence of the non-liquefiable crust layer increases both the maximum and residual soil displacements at the free field and also the maximum bending moments in the piles.The results of the experiments indicated that the crust layer induces a high kinematic lateral soil pressure and force on the piles which are not present in the crustless case.The crust layer increases the pile cap displacement before liquefaction,albeit decreases it after liquefaction,due to the elastic rebound of the piles in the liquefiable layer.The crust layer postpones both liquefaction triggering and dissipation of excess pore water pressure.The existence of the superstructure mass on the pile caps decreases the acceleration amplitude of the pile caps,while increases their maximum displacement.
基金supported by the National Natural Science Foundation of China(50625208,20773097,and 20877061)the National Basic Research Program of China(973Program,2007CB613302and2009CB939704)Fundamental Research Funds for the Central Universities(2010-YB-01)
文摘The fabrication of well defined hierarchical structures of anatase TiO_(2) with a high percentage of reactive facets is of great importance and challenging.Hierarchically flower-like TiO_(2) superstructures(HFTS)self-assembled from anatase TiO_(2) nanosheets with exposed{001}facets(up to 87%)were synthesized by a simple alcohothermal strategy in a HF-H_(2)O-C_(2)H_(5)OH mixed solution using titanate nanotubes as precursor.The samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and N2 adsorption-desorption isotherms.The photocatalytic activity was evaluated by the photocatalytic oxidation decomposition of acetone in air and methyl orange in aqueous solution under UV illumination.The photocatalytic activity of HFTS was much higher than that of commercial Degussa P25 and tabular-shaped anatase TiO_(2) obtained using pure water as the synthesis medium.The enhancement in photocatalytic activity was related to several factors,including the hierarchically porous structure,exposed{001}facets,and increased light harvesting ability.The HFTS was also of interest for use in solar cells,photocatalytic H_(2) production,optoelectronic devices,sensors,and catalysis.
文摘A well-defined m-phenylenediimino-bridged ladder polymethylsiloxane(LP) was first synthesized through a welldefined ladder superstructure(LS) acting as synthetic template,which was self-assembled by concerted interaction of hydrogen bonding and aromaticπ-πstacking of the monomer(M),N,N'-bis(phenyldichlorosilyl)-m-phenylenediamine.Some key characterization data of LP and,in particular,the extremely vulnerable LS with very unstable Si-Cl and Si-N groups were given.The molecular weights(M_n) of LS and LP are 5...
基金supported by the Villum Fonden, Denmark, Project No. 13153the China Scholarship Council (CSC) for its generous support。
文摘Glioblastoma(GBM) remains a formidable challenge in oncology.Chemodynamic therapy(CDT) that triggers tumor cell death by reactive oxygen species(ROS) could open up a new door for GBM treatment.Herein,we report a novel CDT nanoagent.Hemoglobin(Hb)and glucose oxidase(GOx) were employed as powerful CDT catalysts.Instead of encapsulating the proteins in drug delivery nanocarriers,we formulate multimeric superstructures as self-delivery entities by crosslinking techniques.Red blood cell(RBC) membranes are camouflaged on the protein superstructures to promote the delivery across blood-brain barrier.The as-prepared RBC@Hb@GOx nanoparticles(NPs) offer superior biocompatibility,simplified structure,and high accumulation at the tumor site.We successfully demonstrated that the NPs could efficiently produce toxic ROS to kill U87 MG cancer cells in vitro and inhibit the growth of GBM tumor in vivo,suggesting that the new CDT nanoagent holds great promise for treating GBM.
基金supported by Fund of Weinan Teachers University(10YKF014)
文摘Urchin-like Ni O superstructures have been prepared via a thermal decomposition reaction of Ni C_2O_4 at 400 for 1h. The morphology and structure of the synthesized urchin-like superstructures have been characterized by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The results show that urchin-like Ni O superstructures were a polycrystal with cubic structure and typical diameters of 200 to 500 nm and the self-assembly nanoparticles average diameter is 14 nm. The as-prepared Ni O superstructures have a high Brunauer-Emmett-Teller surface area of about 60.32 m^2/g. The UV-vis spectrum of urchin-like Ni O consists of one peak at 357 nm(3.47 e V).
基金Supported by the Fundamental Research Funds for the Central Universities of China(DUT14RC(3)046)China Postdoctoral Science Foundation(2014M551091)the National Natural Science Foundation of China(21406026)
文摘Integrating multiple systems into one has become an important trend in Process Systems Engineering research field since there is strong demand from the modern industries. In this study, a stage-wise superstructurebased method is proposed to synthesize a combined mass and heat exchange network(CM&HEN) which has two parts as the mass exchange network(MEN) and heat exchange network(HEN) involved. To express the possible heat exchange requirements resulted from mass exchange operations, a so called "indistinct HEN superstructure(IHS)", which can contain the all potential matches between streams, is constructed at first. Then, a non-linear programming(NLP) mathematical model is established for the simultaneous synthesis and optimization of networks. Therein, the interaction between mass exchange and heat exchange is modeling formulated.The NLP model has later been examined using an example from literature, and the effectiveness of the proposed method has been demonstrated with the results.
文摘Previously, synthetic hexagonal bismuth sulfide iodide (polar space group P63, a = 15.629(3) ?, c = 4.018(1) ?, Z = 2) has been described by the rather unsatisfactory fractional formula Bi19/3IS9 [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370039000000 -[3] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370036000000 . A redetermination of the structure using old but reliable photographic intensity data indicated the presence of additional split positions and reduced atomic occupancies. From the observed pattern of this “averaged” structure a consistent model of a superstructure with lattice parameters of a' = √13·a = 56.35(1) ?, c' = c, and a formula Bi5-x(Bi2S3)39I12S emerged, with 2 formula units in a cell of likewise P63 space group. Structural modulation may be provoked by the space the lone electron pair of Bi requires. When Bi on the 0, 0, z position of the “averaged” cell is transferred to two general six-fold sites and one unoccupied twofold one of the super-cell, more structural stability is guaranteed due to compensation of its basal plane dipole momentum. Owing to the limited intensity data available, more details of the superstructure are not accessible yet. Some physical properties and solar cell application are discussed together with suggestions of ambient temperature synthesis routes of c-axis oriented nano-rod sheets.
文摘Mitochondria, usually ovoid structures no larger than 0.5 microns can fuse into structures that are 5 microns and larger such as nebenkern, spheroidal or cup-shaped mitochondria, and even mega-mitochondria. In studying differentiation of human endometrial epithelial cells, it became clear that formation of mitochondrial superstructures was an essential part of the process. In this paper, the origins, function, and demise of these superstructures called mitonucleons are described. In the course of reading papers about mitochondrial superstructures, it became obvious that there are important similarities, particularly with regard to function, between the mitonucleon and the nebenkern, a superstructure essential for dramatic tail elongation during spermatogenesis in grasshoppers, drosophila, and other insects. Close inspection of photomicrographs of differentiating mitonucleons during the first 12 hours suggests that gases build up in vacuoles within the mitochondrial superstructure creating pressure that elevates syncytial membranes and compresses nuclear aggregates contained within the mitonucleon.
基金B.V.Konovalova., N.A. Koneva and E.V.Kozlov acknowledge the INTAS for the partial support of this research under INTAS97-319
文摘It was revealed that an average energy of special boundaries is proportional to APB energy in the alloys with the L12 superstructure. This fact proves the appearance of the GAPBs in the planes of location of special boundaries in coincidence sites of ordered alloys. It was determined that the more energy of special boundaries in ordered alloys, the more energy of complex stacking fault. There is a correlation between the distribution of special boundaries as a function its relative energy and ordering energy: the more ordering energy, the more degree of washed away of distribution. The correlation between average relative energy of special boundaries and ordering energy was detected: the more ordering energy, the more average energy of special boundaries. The reverse dependence between ordering energy and average number of special boundaries in grains limited by boundaries of general type was discovered.
文摘Using finite analysis element software, the transient displacement field of automatic submerged arc welding is established. It was also considered that the thermal physical properties changes were depended on the temperatureand the heat loss on the surface. At the same time, it analyzed the influence of the deformation and stress, whichgenerated in the plate butt-welding process, to the superstructure steel welding deformation. The result showedthat the deformation and stress generated in the steel plate butt-welding process are considered to be the mainfactors to influence the welding deformation of superstructure steel. It found the effective ways to reduce the weldingdeformation of the hull superstructure steel is to relieve the butt-welding deformation and release butt-welding stressbefore welding the hull superstructure steel.
基金the financial support provided by the National Natural Science Foundation of China(No.21776035)China Postdoctoral Science Foundation(No.2019TQ0045)。
文摘Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work.A stream that expands through expanders can produce work and cold load,while expansion through valves barely affects heat integration.In addition,expansion through expanders at higher temperature produces more work,but consumes more hot utility.Therefore,there is a need to weigh work production and heat consumption.To this end,an enhanced stage-wise superstructure is proposed that involves synchronous optimization of expander/valve placement and heat integration for each pressure-change sub-stream in stages.A mixed-integer nonlinear programming(MINLP)model is established for synthesizing sub and aboveambient heat exchanger networks with multi-stream expansion,which explicitly considers the optimized selection of end-heaters and end-coolers to adjust temperature requirement.Our proposed method can commendably achieve the optimal selection of expanders and valves in a bid for minimizing exergy consumption and total annual cost.Four example studies are conducted with two distinct objective function(minimization of exergy consumption and total annual cost,respectively)to illustrate the feasibility and efficacy of the proposed method.
文摘Since there may exist dark matter particles ν and δ with mass - 10^-1 e V in the universe, the superstructures with a scale of 10^19 solar masses (large number A - 10^19) appeared during the era near and before the hydrogen recombination. Since there are superstructures in the universe, there may be no necessity for the existence of dark energy. For checking the superstructure in the universe by CMB anisotropy, we need to measure CMB angular power spectrum especially around ten degrees across the sky- in more details, While neutrino u is related to electroweak unification, the fourth stable elementary particle 6 may be related to strong-gravity unification, which suggests p + p^- → n + δ^- and that some new baryons appeared in the TeV region.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0300300 and 2017YFA0302900)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant Nos.XDB07020300 and XDB25000000)+1 种基金the National Natural Science Foundation of China(Grant Nos.11334010 and 11534007)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2017013)
文摘High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized by transmission electron microscope(TEM) and measured by high resolution laser-based angle-resolved photoemission spectroscopy(ARPES) with different photon energies.A systematic evolution of the electronic structure and superstructure with Pb substitution has been revealed for the first time.The superstructure shows a significant change with Pb substitution and the incommensurate modulation vector(Q) decreases with increasing Pb substitution.In the meantime, the superstructure intensity from ARPES measurements also decreases dramatically with increasing Pb concentration.The superstructure in Bi2212 can be effectively suppressed by Pb substitution and it nearly disappears with a Pb substitution of x = 0.8.We also find that the superstructure bands in ARPES measurements depend sensitively on the photon energy of lasers used;they can become even stronger than the main band when using a laser photon energy of 10.897 eV.These results provide important information on the origin of the incommensurate superstructure and its control and suppression in bismuth-based high temperature superconductors.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51372174,11074193,and 51132001)the Fundamental Research Funds for the Central Universities
文摘La3+ and V5+ co-doped BiFeO3 ceramics are synthesized by rapid liquid sintering technique. The modulated structure in Bi0.85La0.15Fe0.97V0.03O3 is investigated by using transmission electron microscopy (TEM). Two kinds of superstructures are observed in the samples. One is the component modulated superstructure and twin-domain, which is generated by La3+ ordered substitution for Bi3+ and frequently appears. The chemical composition of the superstructure is explored by x-ray energy dispersive spectroscopy (EDS). The model of the ordered structure is proposed. Simulation based on the model is conducted. The second is the fluorite-type δ-Bi2O3 related superstructure. The relation between the ferroelectric property and the microstructure of the sample is also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61674045,61911540074,and 21622304)the Fund from the Ministry of Science and Technology of China(Grant No.2016YFA0200700)+1 种基金the Strategic Priority Research Program and Key Research Program of Frontier Sciences(Chinese Academy of Sciences)(Grant Nos.XDB30000000 and QYZDB-SSW-SYS031)Zhihai Cheng was supported by the Fundamental Research Funds for the Central Universities and the Research Funds of Renmin University of China(Grant No.21XNLG27).
文摘The ultrathinβ-Sn(001)films have attracted tremendous attention owing to its topological superconductivity(TSC),which hosts Majorana bound state(MBSs)for quantum computation.Recently,β-Sn(001)thin films have been successfully fabricated via phase transition engineering.However,the understanding of structural phase transition ofβ-Sn(001)thin films is still elusive.Here,we report the direct growth of ultrathinβ-Sn(001)films epitaxially on the highly oriented pyrolytic graphite(HOPG)substrate and the characterization of intricate structural-transition-induced superstructures.The morphology was obtained by using atomic force microscopy(AFM)and low-temperature scanning tunneling microscopy(STM),indicating a structure-related bilayer-by-bilayer growth mode.The ultrathinβ-Sn film was made of multiple domains with various superstructures.Both high-symmetric and distorted superstructures were observed in the atomic-resolution STM images of these domains.The formation mechanism of these superstructures was further discussed based on the structural phase transition ofβtoα-Sn at the atomic-scale thickness.Our work not only brings a deep understanding of the structural phase transition of Sn film at the two-dimensional limit,but also paves a way to investigate their structure-sensitive topological properties.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11574372 and 11322432the 'Strategic Priority Research Program(B)' of the Chinese Academy of Sciences under Grant No XDB07020300
文摘Using scanning tunneling microscopy we observe a stripe phase smoothly interfacing with a triangular 2 ×2 super- structure on the surface of 2H-NbSe2 single crystM. Proximity-induced superconductivity is demonstrated in these new ordered structures by measurements of low-temperature tunneling spectra. The modulation of superconduc- tivity by the reconstruction provides an opportunity to understand the interplay between superconductivity and charge orders.