Room temperature NO_2 gas sensing of Au-loaded tungsten oxide nanowires/porous silicon hybrid structure

In this work, we report an enhanced nitrogen dioxide（NO_2） gas sensor based on tungsten oxide（WO_3）nanowires/porous silicon（PS） decorated with gold（Au） nanoparticles. Au-loaded WO_3 nanowires with diameters of 10 nm–25 nm and lengths of 300 nm–500 nm are fabricated by the sputtering method on a porous silicon substrate. The high-resolution transmission electron microscopy（HRTEM） micrographs show that Au nanoparticles are uniformly distributed on the surfaces of WO_3 nanowires. The effect of the Au nanoparticles on the NO_2-sensing performance of WO_3 nanowires/porous silicon is investigated over a low concentration range of 0.2 ppm–5 ppm of NO_2 at room temperature（25℃）. It is found that the 10-？ Au-loaded WO_3 nanowires/porous silicon-based sensor possesses the highest gas response characteristic. The underlying mechanism of the enhanced sensing properties of the Au-loaded WO_3 nanowires/porous silicon is also discussed.

Shake table testing of a multi-tower connected hybrid structure

Many single-tower reinforced concrete core wall-steel frame （RCC-SF） buildings have been built in China, but there are no buildings of different-height multi-tower hybrid system. A multi-tower RCC-SF tall building was thus studied because of its structural complexity and irregularity. First, a 1/15 scaled model structure was designed and tested on the shake table under minor, moderate, and major earthquake levels. Then, the dynamic responses of the model structure were interpreted to those of the prototype structure according to the similitude theory. Experimental results demonstrate that, despite the complexity of the structure, the lateral deformation bends as the ＂bending type＂ and the RC core walls contribute more than the steel frames to resist seismic loads. The maximum inter-story drift of the complex building under minor earthquakes is slightly beyond the elastic limitation specified in the Chinese code, and meets code requirements under major earthquakes. From the test results some suggestions are provided that could contribute favorable effect on the seismic behavior and the displacement of the building.

Synthesis and room-temperature NO_2 gas sensing properties of a WO_3 nanowires/porous silicon hybrid structure

We report on the fabrication and performance of a room-temperature NO2 gas sensor based on a WO3 nanowires/porous silicon hybrid structure. The W18O49 nanowires are synthesized directly from a sputtered tungsten film on a porous silicon （PS） layer under heating in an argon atmosphere. After a carefully controlled annealing treatment, WO3 nanowires are obtained on the PS layer without losing the morphology. The morphology, phase structure, and crystallinity of the nanowires are investigated by using field emission scanning electron microscopy （FESEM）, X-ray diffractometer （XRD）, and high-resolution transmission electron microscopy （HRTEM）. Comparative gas sensing results indicate that the sensor based on the WO3 nanowires exhibits a much higher sensitivity than that based on the PS and pure WO3 nanowires in detecting NO2 gas at room temperature. The mechanism of the WO3 nanowires/PS hybrid structure in the NO2 sensing is explained in detail.

Efficient removal of U(VI) from wastewater by a sponge-like 3D porous architecture with hybrid electrospun nanofibers

Removal of uranium(VI)from nuclear wastewater is urgent due to the global nuclear energy exploitation.This study synthesized novel sponge-like 3D porous materials for enhanced uranium adsorption by combining electrospinning and fibrous freeze-shaping techniques.The materials possessed an organic-inorganic hybrid architecture based on the electrospun fibers of polyacrylonitrile(PAN)and SiO_(2).As a sup-porting material,the surface of fibrous SiO_(2) could be further functionalized by cyano groups via(3-cyanopropyl)triethoxysilane.All the cyano groups were turned into amidoxime(AO)groups to obtain a amidoxime-functionalized sponge(PAO/SiO_(2)-AO)through the subsequent ami-doximation process.The proposed sponge exhibited enhanced uranium adsorption performance with a high removal capacity of 367.12 mg/g,a large adsorption coefficient of 4.0×10^(4)mL/g,and a high removal efficiency of 97.59%.The UO_(2)^(2+)adsorption kinetics perfectly conformed to the pseudo-second-order reaction.The sorbent also exhibited an excellent selectivity for UO_(2)^(2+) with other interfering metal ions.2023 Hohai University.Production and hosting by Elsevier B.V.

Multi-scale design and optimization for solid-lattice hybrid structures and their application to aerospace vehicle components

By integrating topology optimization and lattice-based optimization,a novel multi-scale design method is proposed to create solid-lattice hybrid structures and thus to improve the mechanical performance as well as reduce the structural weight.To achieve this purpose,a two-step procedure is developed to design and optimize the innovative structures.Initially,the classical topology optimization is utilized to find the optimal material layout and primary load carrying paths.Afterwards,the solid-lattice hybrid structures are reconstructed using the finite element mesh based modeling method.And lattice-based optimization is performed to obtain the optimal crosssection area of the lattice structures.Finally,two typical aerospace structures are optimized to demonstrate the effectiveness of the proposed optimization framework.The numerical results are quite encouraging since the solid-lattice hybrid structures obtained by the presented approach show remarkably improved performance when compared with traditional designs.

Phosphorus-doped NiS_(2)electrocatalyst with a hybrid structure for hydrogen evolution

In this article,P-NiS_(2)/Ni_(x)P electrocatalysts were synthesized by dealloying the Ni-Al precursor followed by phosphosulfide treatment.We found that the hybrid structure of P-NiS_(2)/Ni_(x)P provides rich active sites for the surface hydrogen evolution reaction (HER),and the doping of P enhances the electronic conductivity of electrodes.In particular,the obtained electrode shows a low overpotential of 196 mV at 10 mA cm^(-2)and a small Tafel slope of only 110 mV dec^(-1)in the HER.Meanwhile,longterm constant current electrolysis test experiments indicate that P-NiS_(2)/Ni_(x)P has good service stability.This research will help to open a new window on the design and fabrication of HER electrocatalysts.

Numerical Investigation on Pool Boiling Mechanism of Hybrid Structures with Metal Foam and Square Column by LBM

In the present study, pool boiling heat transfer performance and bubble behaviors of hybrid structures with metal foam and square column are investigated by lattice Boltzmann method. By using the vapor-liquid phase change model of Gong-Cheng and Peng-Robinson equation of state, the effects of structural parameters, including metal foam thickness, porosity, column height and ratio of column width(W) to gap spacing(D) are investigated in details. The results show that hybrid structure performs better than pure columnar structure in pool boiling heat transfer. The hybrid structure accelerates bubble growth by fluid disturbance while metal skeletons prevent the bubble escaping. The optimum ratio of column width to gap spacing decreases with the increase of heat flux and HTC(heat transfer coefficient) can achieve an increase up to 25% when W/D change from 5/3 to 1/3. The increase of column height enhances heat transfer by expanding surface area and providing space for bubble motion. The metal foam thickness and porosity have a little influence on pool boiling heat transfer performance, but they have an important effect on bubble motion in the regime.

Magic hybrid structure as multifunctional electrocatalyst surpassing benchmark Pt/C enables practical hydrazine fuel cell integrated with energy-saving H_(2)production

A hybrid catalyst structure can provide abundant active sites and tailored electronic properties,but the major challenge lies in achieving delicate control over its composition and architecture to improve the catalytic activity toward different electrochemical reactions simultaneously.Herein,we present the rational design of a magic hybrid structure with low Pt loading(5.90 wt%),composed of CoPt_(3)and CoPt nanoparticles supported on N-doped carbon(CoPt_(3)/CoPt⊂PLNC).Importantly,it shows superior multifunctional catalytic activity in alkaline conditions,requiring a low overpotential of 341 and 20 mV to achieve 10 mA cm^(−2)for the hydrazine oxidation reaction(HzOR)/hydrogen evolution reaction(HER),respectively,and it delivers a half-wave potential of 0.847 V for the oxygen reduction reaction(ORR).Theoretical calculations reveal that the metal-carbon hybrid modulates kinetic behavior and induces electron redistribution,achieving the energetic requirements for multiple electrocatalysis.We demonstrate sustainable H_(2)production utilizing solely the CoPt_(3)/CoPt⊂PLNC catalyst,without external electric power input,suggesting its inspiring practical utility.

Estimation Method of State-of-Charge For Lithium-ion Battery Used in Hybrid Electric Vehicles Based on Variable Structure Extended Kalman Filter

Since the main power source of hybrid electric vehicle（HEV） is supplied by the power battery,the predicted performance of power battery,especially the state-of-charge（SOC） estimation has attracted great attention in the area of HEV.However,the value of SOC estimation could not be greatly precise so that the running performance of HEV is greatly affected.A variable structure extended kalman filter（VSEKF）-based estimation method,which could be used to analyze the SOC of lithium-ion battery in the fixed driving condition,is presented.First,the general lower-order battery equivalent circuit model（GLM）,which includes column accumulation model,open circuit voltage model and the SOC output model,is established,and the off-line and online model parameters are calculated with hybrid pulse power characteristics（HPPC） test data.Next,a VSEKF estimation method of SOC,which integrates the ampere-hour（Ah） integration method and the extended Kalman filter（EKF） method,is executed with different adaptive weighting coefficients,which are determined according to the different values of open-circuit voltage obtained in the corresponding charging or discharging processes.According to the experimental analysis,the faster convergence speed and more accurate simulating results could be obtained using the VSEKF method in the running performance of HEV.The error rate of SOC estimation with the VSEKF method is focused in the range of 5% to 10% comparing with the range of 20% to 30% using the EKF method and the Ah integration method.In Summary,the accuracy of the SOC estimation in the lithium-ion battery cell and the pack of lithium-ion battery system,which is obtained utilizing the VSEKF method has been significantly improved comparing with the Ah integration method and the EKF method.The VSEKF method utilizing in the SOC estimation in the lithium-ion pack of HEV can be widely used in practical driving conditions.

Au Microdisk-Size Dependence of Quantum Dot Emission from the Hybrid Metal-Distributed Bragg Reflector Structures Employed for Single Photon Sources

We investigate metallic microdisk-size dependence of quantum dot （QD） spontaneous emission rate and micro- antenna directional emission effect for the hybrid metM-distributed Bragg reflector structures based on a particular single QD emission. It is found that the measured photolumineseence （PL） intensity is very sensitive to the size of metMlic disk, showing an enhancement factor of 11 when the optimal disk diameter is 2μm and the numerical aperture of microscope objective NA=0.5. It is found that for large metal disks, the Purcell effect is dominant for enhanced PL intensity, whereas for small size disks the main contribution comes from plasmon scattering at the disk edge within the light cone collected by the microscope objective.

Symbiosis between fungi and the hybrid Cymbidium and its mycorrhizal microstructures

Tissue culture seedlings of the hybrid Cymbidium were inoculated with six different fungal strains, isolated from the roots of different wild terrestrial orchids. About three months later, the average increment of fresh weight of seedlings inoculated with strains CF1, CF3 and CF12 were respectively 130.26%, 345.65% and 153.34% while that of the control was only 88.40%. The differences between the three treatments and the control were statistically significant （α = 0.05）, highlighting the treatment with strain CF3 （α = 0.01）. In addition, the three strains were obtained by re-isolating. Pelotons, regarded as typical structures of orchid mycorrhiza, were also found in the inoculating roots under a microscope. It seems that the strains of CF1, CF3, and CF12 are associated with the hybrid Cymbidium and supplied the orchid with nutrition. It can be confirmed that the three strains are beneficial for the seedlings of this hybrid.

Investigation on Effects of Mooring Line Fractures and Connector Failures for A Hybrid Modular Floating Structure System

The present work reports a Hybrid Modular Floating Structure(HMFS)system with typical malfunction conditions.The effects of both fractured mooring lines and failed connectors on main hydrodynamic responses(mooring line tensions,module motions,connector loads and wave power production)of the HMFS system under typical sea con-ditions are comparatively investigated.The results indicate that the mooring tension distribution,certain module motions(surge,sway and yaw)and connector loads(Mz)are significantly influenced by mooring line fractures.The adjacent mooring line of the fractured line on the upstream side suffers the largest tension among the remaining mooring lines,and the case with two fractured mooring lines in the same group on the upstream side is the most dangerous among all cases of two-line failures in view of mooring line tensions,module motions and connector loads.There-fore,one emergency strategy with appropriate relaxation of a proper mooring line has been proposed and proved effective to reduce the risk of more progressive mooring line fractures.In addition,connector failures substantially affect certain module motions(heave and pitch),certain connector loads(Fz and My)and wave power production.The present work can be helpful and instructive for studies on malfunction conditions of modular floating structure(MFS)systems.

Synthesis and Structure of a Novel Chain-like Inorganic-organic Hybrid Constructed from Isopolyanion and Oxalato-bridged Dinuclear Copper Complex

A novel inorganic-organic hybrid based on isopolyanion,{[Cu2（phen）2（μ-ox）][H2Mo8O26]}·4EtOH·Et2O（1） （phen=phenanthroline,ox=oxalate）,was synthesized under open-air mild reaction conditions,and characterized by elemental analysis,IR,ICP,TG and single crystal X-ray diffraction analysis.The crystal structure belongs to triclinic system with space group Pī and cell parameters：a=1.1075（5） nm,b=1.1608（5） nm,c=1.3333（5） nm,α=91.683（5）o,β=113.996（5）o,γ=112.170（5）o,V=1.4159（10） nm3,Mr=2017.44,Z=1,Dc=2.366 g/cm3 and F（000）=980.0.The structure of hybrid 1 is a 1D chain constructed of alternating octamolybdate isopolyanions [β-（Mo8O26）4-] and oxalato-bridged dinuclear copper complex cations [Cu2（phen）2（μ-ox）]2＋.Ultimately,a 3D supramolecular network was formed by hydrogen bond interactions among the adjacent chains.The result shows that hybrid 1 is the first example of inorganic-organic hybrid constructed from isopolyanion and oxalato-bridged dinuclear copper complex fragment （CCDC No.665101）.

Formation of Hybrid Ring Structure of Cyanurate/Isocyanurate in the Reaction be-tween 2,4,6-Tris(4-Phenyl-Phenoxy)-1, 3,5-Triazine and Phenyl Glycidyl Ether

Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.

Modeling and petrophysical properties of digital rock models with various pore structure types: An improved workflow

Pore structure is a crucial factor affecting the physical properties of porous materials,and understanding the mechanisms and laws of these effects is of great significance in the fields of geosciences and petroleum engineering.However,it remains a challenge to accurately understand and quantify the relationship between pore structures and effective properties.This paper improves a workflow to focus on investigating the effect of pore structure on physical properties.First,a hybrid modeling approach combining process-based and morphology-based methods is proposed to reconstruct 3D models with diverse pore structure types.Then,the characteristics and differences in pore structure in these models are compared.Finally,the varia-tion laws and pore-scale mechanisms of the influence of pore structure on physical properties(permeability and elasticity)are discussed based on the reconstructed models.The relationship models between pore structure parameters and perme-ability/elastic parameters in the grain packing model are established.The effect of pore structure evolution on permeability/elasticity and the microscopic mechanism in three types of morphology-based reconstruction models are explored.The influence degree of pore structure on elastic parameters(bulk modulus,shear modulus,P-wave velocity,and S-wave veloc-ity)is quantified,reaching 29.54%,51.40%,18.94%,and 23.18%,respectively.This work forms a workflow for exploring the relationship between pore structures and petrophysical properties at the microscopic scale,providing more ideas and references for understanding the complex physical properties in porous media.

Bifunctional ZnCo_(2)S_(4)/CoZn_(13) hybrid electrocatalysts for high efficient overall water splitting

To develop highly active and low-cost electrocatalyst is very important to improve the efficiency of water splitting.However,the current catalysts still present serious challenges due to the poor intrinsic activity and high overpotential.Herein,we report several amino induced Co-based composite catalysts.As a structure-mediating agent,ethylenediamine (EDA) can not only regulate the crystal structure and but also provide many surface amino groups.The obtained ZnCo_(2)S_(4)/CoZn_(13) catalysts show an excellent oxygen evolution reaction (OER) performance (274 mV@50 mA cm^(-2)) and the overpotential of 160 mV at-10 mA cm^(-2) for hydrogen evolution reaction (HER).For electrolysis of water,the electrocatalysts deliver a cell voltage of 1.61 V at 50 m A cm^(-2).This study provides a facile synthetic strategy to construct advanced electrocatalysts for future applications.

Structural Synthesis of a Class of 2R2T Hybrid Mechanisms

Conventional overconstrained parallel manipulators have been widely studied both in industry and academia,however the structural synthesis of hybrid mechanisms with additional constraints is seldom studied,especially for the four degrees of freedom（DOF） hybrid mechanisms.In order to develop a manipulator with additional constraints,a class of important spatial mechanisms with coupling chains（CCs） whose motion type is two rotations and two translations（2R2T） is presented.Based on screw theory,the combination of different types of limbs which are used to construct parallel mechanisms and coupling chains is proposed.The basic types of the general parallel mechanisms and geometric conditions of the kinematic chains are given using constraint synthesis method.Moreover,the 2R2T motion pattern hybrid mechanisms which are derived by adding coupling chains between different serial kinematic chains（SKCs） of the corresponding parallel mechanisms are presented.According to the constraint analysis of the mechanisms,the movement relationship of the moving platform and the kinematic chains is derived by disassembling the coupling chains.At last,fourteen novel hybrid mechanisms with two or three serial kinematic chains are presented.The proposed novel hybrid mechanisms and construction method enrich the family of the spatial mechanisms and provide an instruction to design more complex hybrid mechanisms.

A Novel Inorganic-organic Hybrid Borate with Unique One-dimensional Infinite Aluminium-oxygen Chains

A novel inorganic-organic hybrid borate,[Al2（fum）（H3BO3）（OH） 4]n·n（H3BO3） （1,H2fum = fumaric acid） ,has been synthesized and characterized by single-crystal X-ray diffraction,FTIR and elemental analysis. Crystal data for compound 1： orthorhombic,space group Pnma,a = 14.108（3） ,b = 6.9412（14） ,c = 14.995（3）A,V = 1468.3（5）A^3,Z = 4,Mr = 359.72,Dc = 1.627 g/cm^3,μ = 0.254 mm^-1,F（000） = 736,the final R = 0.0492 and wR = 0.1650 with I 〉 2σ（I） . In compound 1,each Al^Ⅲ ion is coordinated by six oxygen atoms to adopt a distorted octahedral geometry. Both fumarate anion and the coordinated boric acid act as bidentate bridging ligands to link two neighboring Al^Ⅲ centers simultaneously. Each Al^Ⅲ ion is bridged by two μ2-hydroxyl ligands to construct an infinite wave-like [Al2（fum）（H3BO3）（OH） 4]n chain. These one-dimensional chains form hydrogen bonds with free boric acid molecules giving rise to a three-dimensional supramolecular network.

High-order discontinuous Galerkin solver on hybrid anisotropic meshes for laminar and turbulent simulations

Efficient and robust solution strategies are developed for discontinuous Galerkin （DG） discretization of the Navier-Stokes （NS） and Reynolds-averaged NS （RANS） equations on structured/unstructured hybrid meshes. A novel line-implicit scheme is devised and implemented to reduce the memory gain and improve the computational eificiency for highly anisotropic meshes. A simple and effective technique to use the mod- ified Baldwin-Lomax （BL） model on the unstructured meshes for the DC methods is proposed. The compact Hermite weighted essentially non-oscillatory （HWENO） limiters are also investigated for the hybrid meshes to treat solution discontinuities. A variety of compressible viscous flows are performed to examine the capability of the present high- order DG solver. Numerical results indicate that the designed line-implicit algorithms exhibit weak dependence on the cell aspect-ratio as well as the discretization order. The accuracy and robustness of the proposed approaches are demonstrated by capturing com- plex flow structures and giving reliable predictions of benchmark turbulent problems.

The First Hybrid Wells-Dawson-type Polytungstate Monosupported by Cd-coordination Complex via Di-bridging O-atom

Polyoxometalates（POMs） with Cd-coordination complexes acting as supporting units are rarely reported. The linkage of the supporting units with inorganic building block（polyanion） is generally established on terminal O-atoms, but scarcely via bridging O-atoms. By introducing liquid small organic molecule（pyridine, C5NH5） as assistant ＂structure-directing agent＂, we obtained a novel organic-inorganic hybrid polytungstate,（Hpy）4[Cd（phen）2（P2W18O62）]·nH2O（1, n ≈ 3, py = pyridine, phen = 1,10-phenanthroline）, under hydrothermal conditions. The single-crystal X-ray diffraction analysis shows that 1 is the first compound containing an asymmetric heteropolyanion, [Cd（phen）2（P2W18O62）]4–, a Wells-Dawson-type polyanion monosupported by Cd-coordination complex via di-bridging O-atoms.