The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E ...The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E 1050-12.The Creality Ender-3,a 3D printer,was used for printing the honeycomb structures,and polylactic acid(PLA)material was employed for their construction.The organic,inorganic,and polymeric compounds within the composites were identified using fourier transformation infrared(FTIR)spectroscopy.The structure and homogeneity of the samples were examined using a field emission scanning electron microscope(FESEM).To determine the sound absorption coefficient of the 3D printed honeycomb structure,numerous samples were systematically developed using central composite design(CCD)and analysed using response surface methodology(RSM).The RSM mathematical model was established to predict the optimum values of each factor and noise reduction coefficient(NRC).The optimum values for an NRC of 0.377 were found to be 1.116 wt% carbon black,1.025 wt% aluminium powder,and 3.151 mm distance between parallel edges.Overall,the results demonstrate that a 3Dprinted honeycomb structure filled with nanofillers is an excellent material that can be utilized in various fields,including defence and aviation,where lightweight and acoustic properties are of great importance.展开更多
There is a perpetual pursuit for free-form glasses and ceramics featuring outstanding mechanical properties as well as chemical and thermal resistance.It is a promising idea to shape inorganic materials in three-dimen...There is a perpetual pursuit for free-form glasses and ceramics featuring outstanding mechanical properties as well as chemical and thermal resistance.It is a promising idea to shape inorganic materials in three-dimensional(3D)forms to reduce their weight while maintaining high mechanical properties.A popular strategy for the preparation of 3D inorganic materials is to mold the organic–inorganic hybrid photoresists into 3D micro-and nano-structures and remove the organic components by subsequent sintering.However,due to the discrete arrangement of inorganic components in the organic-inorganic hybrid photoresists,it remains a huge challenge to attain isotropic shrinkage during sintering.Herein,we demonstrate the isotropic sintering shrinkage by forming the consecutive–Si–O–Si–O–Zr–O–inorganic backbone in photoresists and fabricating 3D glass–ceramic nanolattices with enhanced mechanical properties.The femtosecond(fs)laser is used in two-photon polymerization(TPP)to fabricate 3D green body structures.After subsequent sintering at 1000℃,high-quality 3D glass–ceramic microstructures can be obtained with perfectly intact and smooth morphology.In-suit compression experiments and finite-element simulations reveal that octahedral-truss(oct-truss)lattices possess remarkable adeptness in bearing stress concentration and maintain the structural integrity to resist rod bending,indicating that this structure is a candidate for preparing lightweight and high stiffness glass–ceramic nanolattices.3D printing of such glasses and ceramics has significant implications in a number of industrial applications,including metamaterials,microelectromechanical systems,photonic crystals,and damage-tolerant lightweight materials.展开更多
A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their inter...A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their interpretability was analyzed by using Shapley additive explanations(SHAP).An F1-score changed from 0.8795 to 0.9310,accuracy from 0.8450 to 0.9070,precision from 0.8714 to 0.9000,recall from 0.8929 to 0.9643,and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features,demonstrating the high accuracy of our model and its high robustness.During the interpretability analysis of the model,it was found that the electronegativity,melting point,and sintering temperature of the dopant contribute highly to the formation of the core-shell structure,and based on these characteristics,specific ranges were delineated and twelve elements were finally obtained that met all the requirements,namely Si,Sc,Mn,Fe,Co,Ni,Pd,Er,Tm,Lu,Pa,and Cm.In the process of exploring the structure of the core-shell,the doping elements can be effectively localized to be selected by choosing the range of features.展开更多
A novel three-dimensional-fiber reinforced soft pneumatic actuator(3D-FRSPA)inspired by crab claw and human hand structure that can bend and deform independently in each segment is proposed.It has an omni-directional ...A novel three-dimensional-fiber reinforced soft pneumatic actuator(3D-FRSPA)inspired by crab claw and human hand structure that can bend and deform independently in each segment is proposed.It has an omni-directional bending configuration,and the fibers twined symmetrically on both sides to improve the bending performance of FRSPA.In this paper,the static and kinematic analysis of 3D-FRSPA are carried out in detail.The effects of fiber,pneumatic chamber and segment length,and circular air chamber radius of 3D-FRSPA on the mechanical performance of the actuator are discussed,respectively.The soft mobile robot composed of 3D-FRSPA has the ability to crawl.Finally,the crawling processes of the soft mobile robot on different road conditions are studied,respectively,and the motion mechanism of the mobile actuator is shown.The numerical results show that the soft mobile robots have a good comprehensive performance,which verifies the correctness of the proposedmodel.This work shows that the proposed structures have great potential in complex road conditions,unknown space detection and other operations.展开更多
Internet of Vehicles (IoV) is a new system that enables individual vehicles to connect with nearby vehicles,people, transportation infrastructure, and networks, thereby realizing amore intelligent and efficient transp...Internet of Vehicles (IoV) is a new system that enables individual vehicles to connect with nearby vehicles,people, transportation infrastructure, and networks, thereby realizing amore intelligent and efficient transportationsystem. The movement of vehicles and the three-dimensional (3D) nature of the road network cause the topologicalstructure of IoV to have the high space and time complexity.Network modeling and structure recognition for 3Droads can benefit the description of topological changes for IoV. This paper proposes a 3Dgeneral roadmodel basedon discrete points of roads obtained from GIS. First, the constraints imposed by 3D roads on moving vehicles areanalyzed. Then the effects of road curvature radius (Ra), longitudinal slope (Slo), and length (Len) on speed andacceleration are studied. Finally, a general 3D road network model based on road section features is established.This paper also presents intersection and road section recognition methods based on the structural features ofthe 3D road network model and the road features. Real GIS data from a specific region of Beijing is adopted tocreate the simulation scenario, and the simulation results validate the general 3D road network model and therecognitionmethod. Therefore, thiswork makes contributions to the field of intelligent transportation by providinga comprehensive approach tomodeling the 3Droad network and its topological changes in achieving efficient trafficflowand improved road safety.展开更多
The structures,mechanical properties and electronic structures of M metals(M=Ti,V,Cr,Mn and Fe)dopedβ-Si_(3)N_(4) were investigated by First-principles calculations within CASTEP.The calculated lattice parameters of...The structures,mechanical properties and electronic structures of M metals(M=Ti,V,Cr,Mn and Fe)dopedβ-Si_(3)N_(4) were investigated by First-principles calculations within CASTEP.The calculated lattice parameters ofβ-Si_(3)N_(4) were consistent with previous date.The cohesive energy and formation enthalpy show that initialβ-Si_(3)N_(4) has the highest structural stability.The calculated elastic constant and the Voigt-Reuss-Hill approximation indicate that elastic moduli ofβ-Si_(3)N_(4) are slightly reduced by M doping.Based on Poisson’s and Pugh’s ratio,β-Si_(3)N_(4) is a ductile material and the toughness ofβ-Si_(3)N_(4) increases with M doping,and Fe doping exhibited the best toughness.The results of density of states,charge distributions and overlapping populations indicate thatβ-Si_(3)N_(4) has the strong covalent and ionic bond strength between N and Si.展开更多
The important supporting component in a gas turbine is the casing,which has the characteristics of large size,complex structure,and thin wall.In the context of existing 3DP sand casting processes,casting crack defects...The important supporting component in a gas turbine is the casing,which has the characteristics of large size,complex structure,and thin wall.In the context of existing 3DP sand casting processes,casting crack defects are prone to occur.This leads to an increase in the scrap rate of casings,causing significant resource wastage.Additionally,the presence of cracks poses a significant safety hazard after the casings are put into service.The generation of different types of crack defects in stainless steel casings is closely related to casting stress and the high-temperature concession of the sand mold.Therefore,the types and causes of cracks in stainless steel casing products,based on their structural characteristics,were systematically analyzed.Various sand molds with different internal topology designs were printed using the 3DP technology to investigate the impact of sand mold structures on high-temperature concession.The optimal sand mold structure was used to cast casings,and the crack suppression effect was verified by analyzing its eddy current testing results.The experimental results indicate that the skeleton structure has an excellent effect on suppressing cracks in the casing.This research holds important theoretical and engineering significance in improving the quality of casing castings and reducing production costs.展开更多
Aqueous zinc ion batteries(AZIBs) demonstrate tremendous competitiveness and application prospects because of their abundant resources,low cost, high safety, and environmental friendliness. Although the advanced elect...Aqueous zinc ion batteries(AZIBs) demonstrate tremendous competitiveness and application prospects because of their abundant resources,low cost, high safety, and environmental friendliness. Although the advanced electrochemical energy storage systems based on zinc ion batteries have been greatly developed, many severe problems associated with Zn anode impede its practical application, such as the dendrite formation,hydrogen evolution, corrosion and passivation phenomenon. To address these drawbacks, electrolytes, separators, zinc alloys, interfacial modification and structural design of Zn anode have been employed at present by scientists. Among them, the structural design for zinc anode is relatively mature, which is generally believed to enhance the electroactive surface area of zinc anode, reduce local current density, and promote the uniform distribution of zinc ions on the surface of anode. In order to explore new research directions, it is crucial to systematically summarize the structural design of anode materials. Herein, this review focuses on the challenges in Zn anode, modification strategies and the three-dimensional(3D) structure design of substrate materials for Zn anode including carbon substrate materials, metal substrate materials and other substrate materials. Finally, future directions and perspectives about the Zn anode are presented for developing high-performance AZIBs.展开更多
Constructing heterojunctions and hollow multi-shelled structures can render materials with fascinating physicochemical properties,and have been regarded as two promising strategies to overcome the severe shuttling and...Constructing heterojunctions and hollow multi-shelled structures can render materials with fascinating physicochemical properties,and have been regarded as two promising strategies to overcome the severe shuttling and sluggish kinetics of polysulfide in lithium-sulfur(Li-S)batteries.However,a single strategy can only take limited effect.Modulating catalytic hosts with synergistic effects are urgently desired.Herein,Mn_(3)O_(4)-MnS heterogeneous multi-shelled hollow spheres are meticulously designed by controlled sulfuration of Mn2O3 hollow spheres,and then applied as advanced encapsulation hosts for Li-S batteries.Benefiting from the separated spatial confinement by hollow multi-shelled structure,ample exposed active sites and built-in electric field by heterogeneous interface,and synergistic effects between Mn_(3)O_(4)(strong adsorption)and MnS(fast conversion)components,the assembled battery achieves prominent rate capability and decent cyclability(0.016%decay per cycle at 2 C,1000 cycles).More crucially,satisfactory areal capacity reaches up to 7.1 mAh cm^(-2)even with high sulfur loading(8.0 mg cm^(-2))and lean electrolyte(E/S=4.0 pL mg^(-1))conditions.This work will provide inspiration for the rational design of hollow multi-shelled heterostructure for various electrocatalysis applications.展开更多
Hollow structuring has been identified as an effective strategy to enhance the cycling stability of electrodes for rechargeable batteries due to the outstanding volume expansion buffering efficiency,which motivates ar...Hollow structuring has been identified as an effective strategy to enhance the cycling stability of electrodes for rechargeable batteries due to the outstanding volume expansion buffering efficiency,which motivates ardent pursuing on the synthetic approaches of hollow materials.Herein,an intriguing route,combining solid precursor transition and Ostwald ripening(SPTOR),is developed to craft nano single-crystal(SC)-constructed MnCO_(3) submicron hollow spindles homogeneously encapsulated in a reduced graphene oxide matrix(MnCO_(3) SMHSs/rGO).It is noteworthy that the H-bonding interaction between Mn_(3)O_(4) nanoparticles(NPs)and oxygen-containing groups on GO promotes uniform anchoring of Mn_(3)O_(4) NPs on GO,mild reductant ascorbic acid triggers the progressive solid-to-solid transition from Mn_(3)O_(4) NPs to MnCO_(3) submicron solid spindles(SMSSs)in situ on GO,and the Ostwald ripening process induces the gradual dissolution of interior polycrystals of MnCO_(3) SMSSs and subsequent recrystallization on surface SCs of MnCO_(3) SMHSs.Remarkably,MnCO_(3) SMHSs/rGO delivers a 500th lithium storage capacity of 2023 mAh g^(-1) at 1000 mAg^(-1),which is 10 times higher than that of MnCO_(3) microspheres/rGO fabricated from a conventional Mn^(2+)salt precursor(202 mAh g^(-1)).The ultrahigh capacity and ultralong lifespan of MnCO_(3) SMHSs/rGO can be primarily attributed to the superior reaction kinetics and reversibility combined with exceptional interfacial and capacitive lithium storage capability,enabled by the fast ion/electron transfer,large specific surface area,and robust electrode pulverization inhibition efficacy.Moreover,fascinating in-depth lithium storage reactions of MnCO_(3) are observed such as the oxidation of Mn^(2+)in MnCO_(3) to Mn^(3+)in charge process after long-term cycles and the further lithiation of Li_(2)CO_(3) in discharge process.As such,the Carbon Energy.SPTOR approach may represent a viable strategy for crafting various hollow functional materials with metastable nanomaterials as precursors.展开更多
In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and exper...In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and experimental data have shown that the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure has a stronger light absorption capacity and larger specific surface area than pure g-C_(3)N_(4) NCs and g-C_(3)N_(4) nanosheets(NSs),and the presence of the co-catalysts 1T'-MoS_(2) can effectively inhibit the photoinduced carrier recombination.As a result,the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure with an optimum 1T'-MoS_(2) loading of 9 wt%displays a hydrogen evolution rate of 1949 mmol h^(-1) g^(-1),162.4,1.2,1.5,1.6 and 1.2 times than pure g-C_(3)N_(4) NCs(12 mmol h^(-1) g^(-1)),Pt/g-C_(3)N_(4) NCs(1615 mmol h^(-1) g^(-1))and Pt/g-C_(3)N_(4) nanosheets(NSs,1297 mmol h^(-1) g^(-1)),1T'-MoS_(2)/g-C_(3)N_(4) nanosheets(1216 mmol h^(-1) g^(-1))and 2H-MoS_(2)/g-C_(3)N_(4) nanocages(1573 mmol h^(-1) g^(-1)),respectively,and exhibits excellent cycle stability.Therefore,1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure is a suitable photocatalyst for green H_(2) production.展开更多
Two compounds,3-oxo-N-o-tolylbenzo[d]isothiazole-2(3H)-carboxamide (1) and N-(2-methoxyphenyl)-3-oxobenzo[d]isothiazole-2(3H)-carboxamide (2),were synthesized from the initial compound benzo[d]isothiazol-3...Two compounds,3-oxo-N-o-tolylbenzo[d]isothiazole-2(3H)-carboxamide (1) and N-(2-methoxyphenyl)-3-oxobenzo[d]isothiazole-2(3H)-carboxamide (2),were synthesized from the initial compound benzo[d]isothiazol-3(2H)-one (BIT) and characterized by 1 H NMR,IR and elemental analysis,respectively.The single crystals of compounds 1 and 2 were obtained and determined by X-ray diffraction analysis.The preliminary results of biological activity experiment show that some of the title compounds exhibited a favorable antimicrobial activity.展开更多
A novel cobalt complex,[Co2(bptc)(bix)1.5](1,H4bptc=3,3',4,4'-biphenyltetra-carboxylic acid,bix = 1,4-bis(imidazol-1-ylmethyl)benzene),has been hydrothermally prepared and characterized by IR spectroscopy,el...A novel cobalt complex,[Co2(bptc)(bix)1.5](1,H4bptc=3,3',4,4'-biphenyltetra-carboxylic acid,bix = 1,4-bis(imidazol-1-ylmethyl)benzene),has been hydrothermally prepared and characterized by IR spectroscopy,elemental analysis and single-crystal X-ray diffraction.The crystal is of triclinic system,space group P1 with a=10.770(7),b=12.245(8),c=13.514(9),α=102.829(8),β=107.734(8),γ=98.833(9)°,C37H27N6O8Co2,Mr=801.51,V=1607.5(18)3,Dc=1.656g/cm3,F(000)=818,μ=1.100mm-1,Z=2,the final R = 0.0694 and wR = 0.1543 for 3034 observed reflections(I2σ(I)).In the title complex,the two Co(Ⅱ) ions are in different coordination environments with distorted octahedral and trigonal bipyramidal geometries,respectively.The Co atoms are linked together through hexadentate bptc ligands,giving rise to 2D layers which are bridged by the bix ligands into a 3-D supramolecular network.Magnetic susceptibilities of 1 reveal weak antiferromagnetic exchange interactions between the adjacent Co(Ⅱ) ions.展开更多
A novel compound 5-(p-tolyl)-4-[2-(2,4-dichlorophenoxy)acetamido]-1,2,4-tria zole- 3-thione 2a has been synthesized by the reaction of 5-(p-tolyl)-4-amino-1,2,4-triazole-3-thione 1 with 2-(2,4-dich/orophenoxy)...A novel compound 5-(p-tolyl)-4-[2-(2,4-dichlorophenoxy)acetamido]-1,2,4-tria zole- 3-thione 2a has been synthesized by the reaction of 5-(p-tolyl)-4-amino-1,2,4-triazole-3-thione 1 with 2-(2,4-dich/orophenoxy)acetyl ch/oride. Interestingly, the title compound 2 was obtained when 2a crystallizes from a mixed solution of petroleum ether and ethyl acetate, and it has been characterized by elemental analysis, IR, ^1H NMR spectra and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 9.780(5), b = 10.876(6), c = 11.615(6) /A, a = 104.822(7), β= 94.105(6), ), = 94.305(6)°, V= 1185.7(11)/A3, Z = 2,μ = 0.397 mm^-1, Mr= 497.39, Dx= 1.393 g/cm^3, F(000) = 516, S = 1.097, the final R = 0.0730 and wR = 0.2133 for 4111 unique reflections (Rint = 0.0525) with 3212 observed ones. The dihedral angles made by the triazole ring with the methyl- and chloro-substituted benzene rings are 43.5(7) and 50.2(9)°, respectively. Some intra- and intermolecular hydrogen bonds together with C-H…π interactions existing in the lattice stabilize the crystal structure.展开更多
Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation ...Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multiphase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon(VN/C) membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g^(-1) at 0.5 A g^(-1) and an excellent rate capability with capacitance retention of 50.5% at 30 A g^(-1). For the asymmetric device fabricated using Ni(OH)_2//VN/C membranes, a high energy density of 43.0 Wh kg^(-1) at a power density of800 W kg^(-1) was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g^(-1) after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitridebased supercapacitor or other energy storage devices.展开更多
The title compound 2, 4-chloromethyl-3-anilino-2-(4-methyl-benzoylimido)thiazole, was prepared by the reaction of 1-p-methylbenzoyl-3-phenylaminothiourea 1 with 1,3-dichloro- acetone. The crystal is of monoclinic, s...The title compound 2, 4-chloromethyl-3-anilino-2-(4-methyl-benzoylimido)thiazole, was prepared by the reaction of 1-p-methylbenzoyl-3-phenylaminothiourea 1 with 1,3-dichloro- acetone. The crystal is of monoclinic, space group P21/c, with a = 8.1712(15), b = 10.998(2), c = 19.134(4)A, β= 94.610(5)°, C18H16ClN3OS, Mr = 357.85, Z = 4, V = 1714.0(6)A^3, De= 1.387 g/cm^3, μ(MoKa) = 0.354 mm^-1, F(000) = 744, the final R = 0.0518 and wR = 0.1167 for 3189 observed reflections (I〉 2σ(I). Its formation mechanism was proposed.展开更多
A novel organotin complex [(n-Bu)3Sn(OCOC5H4NO)]n has been synthesized and characterized by elemental analysis, IR and ^1H NMR. The crystal structure has been determined by X-ray single-crystal diffraction. The cr...A novel organotin complex [(n-Bu)3Sn(OCOC5H4NO)]n has been synthesized and characterized by elemental analysis, IR and ^1H NMR. The crystal structure has been determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P2 1/c with a = 8.982(2), b = 17.908(4), c = 13.219(3) A, β= 96.981(4)°, Z = 4, V= 2110.6(8) A^3, Dc = 1.347 g/cm^3, μ(MoKa) = 12.23 cm^-1, F(000) = 880, R = 0.0497 and wR = 0.1263. In the molecular structure of the title complex, the tin atoms are five-coordinated in a distorted trigonal bipyramidal geometry. A one-dimensional linear polymer is formed through an interaction between the O atoms of pyridine-3-carboxylic acid N-oxide and tin atoms of an adjacent molecule.展开更多
A novel benzisothiazolin-3-one derivative, 2-(benzo[d]isothiazol-3-yloxy)-N-(3- cyano-l-(4-fluorophenyl)-lH-pyrazol-5-yl) acetamide (8), was synthesized from the initial compound benzo[d]isothiazol-3(2H)-one...A novel benzisothiazolin-3-one derivative, 2-(benzo[d]isothiazol-3-yloxy)-N-(3- cyano-l-(4-fluorophenyl)-lH-pyrazol-5-yl) acetamide (8), was synthesized from the initial compound benzo[d]isothiazol-3(2H)-one (BIT) 1 and 4-fluoroaniline 3. The structure of the target compound 8 was determined by elemental analyses, IR and 1H NMR. The single crystals of intermediate compound 6 and the target compound 8 were obtained and determined by X-ray diffraction analysis. The preliminary biological activity was also evaluated and the results showed tile target compound exhibited a good anti-microbial activity.展开更多
文摘The novelty of this research lies in the successful fabrication of a 3D-printed honeycomb structure filled with nanofillers for acoustic properties,utilizing an impedance tube setup in accordance with ASTM standard E 1050-12.The Creality Ender-3,a 3D printer,was used for printing the honeycomb structures,and polylactic acid(PLA)material was employed for their construction.The organic,inorganic,and polymeric compounds within the composites were identified using fourier transformation infrared(FTIR)spectroscopy.The structure and homogeneity of the samples were examined using a field emission scanning electron microscope(FESEM).To determine the sound absorption coefficient of the 3D printed honeycomb structure,numerous samples were systematically developed using central composite design(CCD)and analysed using response surface methodology(RSM).The RSM mathematical model was established to predict the optimum values of each factor and noise reduction coefficient(NRC).The optimum values for an NRC of 0.377 were found to be 1.116 wt% carbon black,1.025 wt% aluminium powder,and 3.151 mm distance between parallel edges.Overall,the results demonstrate that a 3Dprinted honeycomb structure filled with nanofillers is an excellent material that can be utilized in various fields,including defence and aviation,where lightweight and acoustic properties are of great importance.
基金supported by the National Key Research and Development Program of China(2020YFA0715000)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0058)the Guangdong Basic and Applied Basic Research Foundation(2021B1515120041)。
文摘There is a perpetual pursuit for free-form glasses and ceramics featuring outstanding mechanical properties as well as chemical and thermal resistance.It is a promising idea to shape inorganic materials in three-dimensional(3D)forms to reduce their weight while maintaining high mechanical properties.A popular strategy for the preparation of 3D inorganic materials is to mold the organic–inorganic hybrid photoresists into 3D micro-and nano-structures and remove the organic components by subsequent sintering.However,due to the discrete arrangement of inorganic components in the organic-inorganic hybrid photoresists,it remains a huge challenge to attain isotropic shrinkage during sintering.Herein,we demonstrate the isotropic sintering shrinkage by forming the consecutive–Si–O–Si–O–Zr–O–inorganic backbone in photoresists and fabricating 3D glass–ceramic nanolattices with enhanced mechanical properties.The femtosecond(fs)laser is used in two-photon polymerization(TPP)to fabricate 3D green body structures.After subsequent sintering at 1000℃,high-quality 3D glass–ceramic microstructures can be obtained with perfectly intact and smooth morphology.In-suit compression experiments and finite-element simulations reveal that octahedral-truss(oct-truss)lattices possess remarkable adeptness in bearing stress concentration and maintain the structural integrity to resist rod bending,indicating that this structure is a candidate for preparing lightweight and high stiffness glass–ceramic nanolattices.3D printing of such glasses and ceramics has significant implications in a number of industrial applications,including metamaterials,microelectromechanical systems,photonic crystals,and damage-tolerant lightweight materials.
基金Funded by the National Key Research and Development Program of China(No.2023YFB3812200)。
文摘A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their interpretability was analyzed by using Shapley additive explanations(SHAP).An F1-score changed from 0.8795 to 0.9310,accuracy from 0.8450 to 0.9070,precision from 0.8714 to 0.9000,recall from 0.8929 to 0.9643,and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features,demonstrating the high accuracy of our model and its high robustness.During the interpretability analysis of the model,it was found that the electronegativity,melting point,and sintering temperature of the dopant contribute highly to the formation of the core-shell structure,and based on these characteristics,specific ranges were delineated and twelve elements were finally obtained that met all the requirements,namely Si,Sc,Mn,Fe,Co,Ni,Pd,Er,Tm,Lu,Pa,and Cm.In the process of exploring the structure of the core-shell,the doping elements can be effectively localized to be selected by choosing the range of features.
基金work is supported by the Fundamental Research Funds for the Central Universities(Grant No.B230205021)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(GrantNo.KYCX22_0592).The financial supports are gratefully acknowl-edged.
文摘A novel three-dimensional-fiber reinforced soft pneumatic actuator(3D-FRSPA)inspired by crab claw and human hand structure that can bend and deform independently in each segment is proposed.It has an omni-directional bending configuration,and the fibers twined symmetrically on both sides to improve the bending performance of FRSPA.In this paper,the static and kinematic analysis of 3D-FRSPA are carried out in detail.The effects of fiber,pneumatic chamber and segment length,and circular air chamber radius of 3D-FRSPA on the mechanical performance of the actuator are discussed,respectively.The soft mobile robot composed of 3D-FRSPA has the ability to crawl.Finally,the crawling processes of the soft mobile robot on different road conditions are studied,respectively,and the motion mechanism of the mobile actuator is shown.The numerical results show that the soft mobile robots have a good comprehensive performance,which verifies the correctness of the proposedmodel.This work shows that the proposed structures have great potential in complex road conditions,unknown space detection and other operations.
基金the National Natural Science Foundation of China(Nos.62272063,62072056 and 61902041)the Natural Science Foundation of Hunan Province(Nos.2022JJ30617 and 2020JJ2029)+4 种基金Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology,Nanjing University of Posts and Telecommunications(No.JZNY202102)the Traffic Science and Technology Project of Hunan Province,China(No.202042)Hunan Provincial Key Research and Development Program(No.2022GK2019)this work was funded by the Researchers Supporting Project Number(RSPD2023R681)King Saud University,Riyadh,Saudi Arabia.
文摘Internet of Vehicles (IoV) is a new system that enables individual vehicles to connect with nearby vehicles,people, transportation infrastructure, and networks, thereby realizing amore intelligent and efficient transportationsystem. The movement of vehicles and the three-dimensional (3D) nature of the road network cause the topologicalstructure of IoV to have the high space and time complexity.Network modeling and structure recognition for 3Droads can benefit the description of topological changes for IoV. This paper proposes a 3Dgeneral roadmodel basedon discrete points of roads obtained from GIS. First, the constraints imposed by 3D roads on moving vehicles areanalyzed. Then the effects of road curvature radius (Ra), longitudinal slope (Slo), and length (Len) on speed andacceleration are studied. Finally, a general 3D road network model based on road section features is established.This paper also presents intersection and road section recognition methods based on the structural features ofthe 3D road network model and the road features. Real GIS data from a specific region of Beijing is adopted tocreate the simulation scenario, and the simulation results validate the general 3D road network model and therecognitionmethod. Therefore, thiswork makes contributions to the field of intelligent transportation by providinga comprehensive approach tomodeling the 3Droad network and its topological changes in achieving efficient trafficflowand improved road safety.
文摘The structures,mechanical properties and electronic structures of M metals(M=Ti,V,Cr,Mn and Fe)dopedβ-Si_(3)N_(4) were investigated by First-principles calculations within CASTEP.The calculated lattice parameters ofβ-Si_(3)N_(4) were consistent with previous date.The cohesive energy and formation enthalpy show that initialβ-Si_(3)N_(4) has the highest structural stability.The calculated elastic constant and the Voigt-Reuss-Hill approximation indicate that elastic moduli ofβ-Si_(3)N_(4) are slightly reduced by M doping.Based on Poisson’s and Pugh’s ratio,β-Si_(3)N_(4) is a ductile material and the toughness ofβ-Si_(3)N_(4) increases with M doping,and Fe doping exhibited the best toughness.The results of density of states,charge distributions and overlapping populations indicate thatβ-Si_(3)N_(4) has the strong covalent and ionic bond strength between N and Si.
基金financially supported by the National Natural Science Foundation of China(No.52175352)the Xing Liao Ying Cai Project of Liaoning Province(No.XLYC2008036)the Shenyang Youth Innovation Talent Support Program(No.RC220429)。
文摘The important supporting component in a gas turbine is the casing,which has the characteristics of large size,complex structure,and thin wall.In the context of existing 3DP sand casting processes,casting crack defects are prone to occur.This leads to an increase in the scrap rate of casings,causing significant resource wastage.Additionally,the presence of cracks poses a significant safety hazard after the casings are put into service.The generation of different types of crack defects in stainless steel casings is closely related to casting stress and the high-temperature concession of the sand mold.Therefore,the types and causes of cracks in stainless steel casing products,based on their structural characteristics,were systematically analyzed.Various sand molds with different internal topology designs were printed using the 3DP technology to investigate the impact of sand mold structures on high-temperature concession.The optimal sand mold structure was used to cast casings,and the crack suppression effect was verified by analyzing its eddy current testing results.The experimental results indicate that the skeleton structure has an excellent effect on suppressing cracks in the casing.This research holds important theoretical and engineering significance in improving the quality of casing castings and reducing production costs.
基金financially supported by the National Natural Science Foundation of China (Grants Nos. 52064013, 52064014, 52072323 and 52122211)the “Double-First Class” Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University。
文摘Aqueous zinc ion batteries(AZIBs) demonstrate tremendous competitiveness and application prospects because of their abundant resources,low cost, high safety, and environmental friendliness. Although the advanced electrochemical energy storage systems based on zinc ion batteries have been greatly developed, many severe problems associated with Zn anode impede its practical application, such as the dendrite formation,hydrogen evolution, corrosion and passivation phenomenon. To address these drawbacks, electrolytes, separators, zinc alloys, interfacial modification and structural design of Zn anode have been employed at present by scientists. Among them, the structural design for zinc anode is relatively mature, which is generally believed to enhance the electroactive surface area of zinc anode, reduce local current density, and promote the uniform distribution of zinc ions on the surface of anode. In order to explore new research directions, it is crucial to systematically summarize the structural design of anode materials. Herein, this review focuses on the challenges in Zn anode, modification strategies and the three-dimensional(3D) structure design of substrate materials for Zn anode including carbon substrate materials, metal substrate materials and other substrate materials. Finally, future directions and perspectives about the Zn anode are presented for developing high-performance AZIBs.
基金The support from the National Natural Science Foundation of China(No.51971083)the Natural Science Foundation of Heilongjiang Province,China(YQ 2020E007)is gratefully acknowledgedfinancially sponsored by Heilongjiang Touyan Team Program.
文摘Constructing heterojunctions and hollow multi-shelled structures can render materials with fascinating physicochemical properties,and have been regarded as two promising strategies to overcome the severe shuttling and sluggish kinetics of polysulfide in lithium-sulfur(Li-S)batteries.However,a single strategy can only take limited effect.Modulating catalytic hosts with synergistic effects are urgently desired.Herein,Mn_(3)O_(4)-MnS heterogeneous multi-shelled hollow spheres are meticulously designed by controlled sulfuration of Mn2O3 hollow spheres,and then applied as advanced encapsulation hosts for Li-S batteries.Benefiting from the separated spatial confinement by hollow multi-shelled structure,ample exposed active sites and built-in electric field by heterogeneous interface,and synergistic effects between Mn_(3)O_(4)(strong adsorption)and MnS(fast conversion)components,the assembled battery achieves prominent rate capability and decent cyclability(0.016%decay per cycle at 2 C,1000 cycles).More crucially,satisfactory areal capacity reaches up to 7.1 mAh cm^(-2)even with high sulfur loading(8.0 mg cm^(-2))and lean electrolyte(E/S=4.0 pL mg^(-1))conditions.This work will provide inspiration for the rational design of hollow multi-shelled heterostructure for various electrocatalysis applications.
基金General Research Project of Zhejiang Provincial Department of Education,Grant/Award Number:Y202250766National Natural Science Foundation of China,Grant/Award Numbers:21905208,22250410263Natural Science Foundation of Zhejiang Province,Grant/Award Numbers:LY23B030001,LZ18E030001。
文摘Hollow structuring has been identified as an effective strategy to enhance the cycling stability of electrodes for rechargeable batteries due to the outstanding volume expansion buffering efficiency,which motivates ardent pursuing on the synthetic approaches of hollow materials.Herein,an intriguing route,combining solid precursor transition and Ostwald ripening(SPTOR),is developed to craft nano single-crystal(SC)-constructed MnCO_(3) submicron hollow spindles homogeneously encapsulated in a reduced graphene oxide matrix(MnCO_(3) SMHSs/rGO).It is noteworthy that the H-bonding interaction between Mn_(3)O_(4) nanoparticles(NPs)and oxygen-containing groups on GO promotes uniform anchoring of Mn_(3)O_(4) NPs on GO,mild reductant ascorbic acid triggers the progressive solid-to-solid transition from Mn_(3)O_(4) NPs to MnCO_(3) submicron solid spindles(SMSSs)in situ on GO,and the Ostwald ripening process induces the gradual dissolution of interior polycrystals of MnCO_(3) SMSSs and subsequent recrystallization on surface SCs of MnCO_(3) SMHSs.Remarkably,MnCO_(3) SMHSs/rGO delivers a 500th lithium storage capacity of 2023 mAh g^(-1) at 1000 mAg^(-1),which is 10 times higher than that of MnCO_(3) microspheres/rGO fabricated from a conventional Mn^(2+)salt precursor(202 mAh g^(-1)).The ultrahigh capacity and ultralong lifespan of MnCO_(3) SMHSs/rGO can be primarily attributed to the superior reaction kinetics and reversibility combined with exceptional interfacial and capacitive lithium storage capability,enabled by the fast ion/electron transfer,large specific surface area,and robust electrode pulverization inhibition efficacy.Moreover,fascinating in-depth lithium storage reactions of MnCO_(3) are observed such as the oxidation of Mn^(2+)in MnCO_(3) to Mn^(3+)in charge process after long-term cycles and the further lithiation of Li_(2)CO_(3) in discharge process.As such,the Carbon Energy.SPTOR approach may represent a viable strategy for crafting various hollow functional materials with metastable nanomaterials as precursors.
基金funding from the National Natural Science Foundation of China (No.51872173)Taishan Scholar Foundation of Shandong Province (No.tsqn201812068)+2 种基金Youth Innovation Technology Project of Higher School in Shandong Province (No.2019KJA013)Science and Technology Special Project of Qingdao City (No.20-3-4-3-nsh)the Opening Fund of State Key Laboratory of Heavy Oil Processing (No.SKLOP202002006)。
文摘In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and experimental data have shown that the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure has a stronger light absorption capacity and larger specific surface area than pure g-C_(3)N_(4) NCs and g-C_(3)N_(4) nanosheets(NSs),and the presence of the co-catalysts 1T'-MoS_(2) can effectively inhibit the photoinduced carrier recombination.As a result,the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure with an optimum 1T'-MoS_(2) loading of 9 wt%displays a hydrogen evolution rate of 1949 mmol h^(-1) g^(-1),162.4,1.2,1.5,1.6 and 1.2 times than pure g-C_(3)N_(4) NCs(12 mmol h^(-1) g^(-1)),Pt/g-C_(3)N_(4) NCs(1615 mmol h^(-1) g^(-1))and Pt/g-C_(3)N_(4) nanosheets(NSs,1297 mmol h^(-1) g^(-1)),1T'-MoS_(2)/g-C_(3)N_(4) nanosheets(1216 mmol h^(-1) g^(-1))and 2H-MoS_(2)/g-C_(3)N_(4) nanocages(1573 mmol h^(-1) g^(-1)),respectively,and exhibits excellent cycle stability.Therefore,1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure is a suitable photocatalyst for green H_(2) production.
基金Supported by the National Natural Science Foundation of China (No. 20962007)the Creative Talents Plan of Hainan University 211 Project
文摘Two compounds,3-oxo-N-o-tolylbenzo[d]isothiazole-2(3H)-carboxamide (1) and N-(2-methoxyphenyl)-3-oxobenzo[d]isothiazole-2(3H)-carboxamide (2),were synthesized from the initial compound benzo[d]isothiazol-3(2H)-one (BIT) and characterized by 1 H NMR,IR and elemental analysis,respectively.The single crystals of compounds 1 and 2 were obtained and determined by X-ray diffraction analysis.The preliminary results of biological activity experiment show that some of the title compounds exhibited a favorable antimicrobial activity.
基金supported by the National Natural Science Foundation of China (No 20971004)the Outstanding Youth Foundation of Education Commission of Anhui Province (No 2010SQRL108ZD)
文摘A novel cobalt complex,[Co2(bptc)(bix)1.5](1,H4bptc=3,3',4,4'-biphenyltetra-carboxylic acid,bix = 1,4-bis(imidazol-1-ylmethyl)benzene),has been hydrothermally prepared and characterized by IR spectroscopy,elemental analysis and single-crystal X-ray diffraction.The crystal is of triclinic system,space group P1 with a=10.770(7),b=12.245(8),c=13.514(9),α=102.829(8),β=107.734(8),γ=98.833(9)°,C37H27N6O8Co2,Mr=801.51,V=1607.5(18)3,Dc=1.656g/cm3,F(000)=818,μ=1.100mm-1,Z=2,the final R = 0.0694 and wR = 0.1543 for 3034 observed reflections(I2σ(I)).In the title complex,the two Co(Ⅱ) ions are in different coordination environments with distorted octahedral and trigonal bipyramidal geometries,respectively.The Co atoms are linked together through hexadentate bptc ligands,giving rise to 2D layers which are bridged by the bix ligands into a 3-D supramolecular network.Magnetic susceptibilities of 1 reveal weak antiferromagnetic exchange interactions between the adjacent Co(Ⅱ) ions.
基金supported by the NN S F of China (No. 20672073)Shanghai Leading Academic Discipline (No. T0402)
文摘A novel compound 5-(p-tolyl)-4-[2-(2,4-dichlorophenoxy)acetamido]-1,2,4-tria zole- 3-thione 2a has been synthesized by the reaction of 5-(p-tolyl)-4-amino-1,2,4-triazole-3-thione 1 with 2-(2,4-dich/orophenoxy)acetyl ch/oride. Interestingly, the title compound 2 was obtained when 2a crystallizes from a mixed solution of petroleum ether and ethyl acetate, and it has been characterized by elemental analysis, IR, ^1H NMR spectra and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 9.780(5), b = 10.876(6), c = 11.615(6) /A, a = 104.822(7), β= 94.105(6), ), = 94.305(6)°, V= 1185.7(11)/A3, Z = 2,μ = 0.397 mm^-1, Mr= 497.39, Dx= 1.393 g/cm^3, F(000) = 516, S = 1.097, the final R = 0.0730 and wR = 0.2133 for 4111 unique reflections (Rint = 0.0525) with 3212 observed ones. The dihedral angles made by the triazole ring with the methyl- and chloro-substituted benzene rings are 43.5(7) and 50.2(9)°, respectively. Some intra- and intermolecular hydrogen bonds together with C-H…π interactions existing in the lattice stabilize the crystal structure.
基金supported by the National Natural Science Foundation of China (51203071,51363014,51463012,and 51763014)China Postdoctoral Science Foundation (2014M552509 and 2015T81064)+2 种基金Natural Science Funds of the Gansu Province (1506RJZA098)the Program for Hongliu Distinguished Young Scholars in Lanzhou University of Technology (J201402)Joint fund between Shenyang National Laboratory for Materials Science and State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals (18LHPY002)
文摘Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multiphase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon(VN/C) membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g^(-1) at 0.5 A g^(-1) and an excellent rate capability with capacitance retention of 50.5% at 30 A g^(-1). For the asymmetric device fabricated using Ni(OH)_2//VN/C membranes, a high energy density of 43.0 Wh kg^(-1) at a power density of800 W kg^(-1) was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g^(-1) after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitridebased supercapacitor or other energy storage devices.
基金the Natural Science Foundation of University,Anhui Province(No.2006KJ156B)
文摘The title compound 2, 4-chloromethyl-3-anilino-2-(4-methyl-benzoylimido)thiazole, was prepared by the reaction of 1-p-methylbenzoyl-3-phenylaminothiourea 1 with 1,3-dichloro- acetone. The crystal is of monoclinic, space group P21/c, with a = 8.1712(15), b = 10.998(2), c = 19.134(4)A, β= 94.610(5)°, C18H16ClN3OS, Mr = 357.85, Z = 4, V = 1714.0(6)A^3, De= 1.387 g/cm^3, μ(MoKa) = 0.354 mm^-1, F(000) = 744, the final R = 0.0518 and wR = 0.1167 for 3189 observed reflections (I〉 2σ(I). Its formation mechanism was proposed.
基金The project was supported by the National Natural Science Foundation of China (No. 20271025), the Natural Science Foundation of Shandong Province (No. Z2001B02) and the State Key Laboratory of Crystal Material
文摘A novel organotin complex [(n-Bu)3Sn(OCOC5H4NO)]n has been synthesized and characterized by elemental analysis, IR and ^1H NMR. The crystal structure has been determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P2 1/c with a = 8.982(2), b = 17.908(4), c = 13.219(3) A, β= 96.981(4)°, Z = 4, V= 2110.6(8) A^3, Dc = 1.347 g/cm^3, μ(MoKa) = 12.23 cm^-1, F(000) = 880, R = 0.0497 and wR = 0.1263. In the molecular structure of the title complex, the tin atoms are five-coordinated in a distorted trigonal bipyramidal geometry. A one-dimensional linear polymer is formed through an interaction between the O atoms of pyridine-3-carboxylic acid N-oxide and tin atoms of an adjacent molecule.
基金financial support of this work from 2011 Key projects of Natural Science of Jiangsu province-owned colleges(No.11KJA610001)Innovation project designated for graduate students of Jiangsu province(No.CXZZ13_0452)the Postdoctoral research funding plan of Jiangsu province(No.1202106C)
文摘A novel benzisothiazolin-3-one derivative, 2-(benzo[d]isothiazol-3-yloxy)-N-(3- cyano-l-(4-fluorophenyl)-lH-pyrazol-5-yl) acetamide (8), was synthesized from the initial compound benzo[d]isothiazol-3(2H)-one (BIT) 1 and 4-fluoroaniline 3. The structure of the target compound 8 was determined by elemental analyses, IR and 1H NMR. The single crystals of intermediate compound 6 and the target compound 8 were obtained and determined by X-ray diffraction analysis. The preliminary biological activity was also evaluated and the results showed tile target compound exhibited a good anti-microbial activity.