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.

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.

A Into-Plane Rotating Micromirror Actuated by a Hybrid Electrostatic Driving Structure

A novel into-plane rotating rnicromirror actuated by a hybrid electrostatic driving structure is presented. The hybrid driving structure is made up of a planar plate drive and a vertical comb drive. The device is fabricated in SOI substrate by using a bulk-and-surface mixed silicon micromachining process. As demonstrated by experiment, the novel driving structure can actuate the mirror to achieve large-range continuous rotation as well as spontaneous 90°rotation induced by the pull-in effect. The continuous rotating range of the micromirror is increased to about 46° at an increased yielding voltage. The measured yielding voltages of the mirrors with torsional springs of 1 and 0.5μm in thickness are 390 - 410V and 140 - 160V, respectively. The optical insertion loss has also been measured to be --1.98dB when the mirror serves as an optical switch.

High Performance Ultraviolet Photodetector Fabricated with ZnO Nanoparticles-graphene Hybrid Structures

Ultraviolet （UV） photodetector constructed by ZnO material has attracted intense research and commercial interest. However, its photoresistivity and photoresonse are still unsatisfied. Herein, we report a novel method to assemble ZnO nanoparticles （NPs） onto the reduced graphite oxide （RGO） sheet by simple hydrothermal process without any surfactant. It is found that the high-quality crystallized ZnO NPs with the average diameter of 5 nm are well dispersed on the RGO surface, and the density of ZnO NPs can be readily controlled by the concentration of the precursor. The photodetector fabricated with this ZnO NPs- RGO hybrid structure demonstrates an excellent photoresponse for the UV irradiation. The results make this hybrid especially suitable as a novel material for the design and fabrication of high performance UV photodector.

The Design of Water-reusing Network with a Hybrid Structure Through Mathematical Programming

A new design method for a water-reusing network, with a hybrid structure, to reduce the complexity of the network and to minimize freshwater consumption, is proposed. The unique feature of the methodology proposed .in this article is to control the complexity of the water network by regulation of the control number in a water-reusing system. It combines the advantages of a conventional water-reusing network and a water-reusing net work with internal water mains. To illustrate the proposed method, a single contaminant system and a multiple contaminant system serve as examples of the problems.

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.

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.

Sound Absorption Enhancement by Thin Multi-Slit Hybrid Structures

We report an extraordinary sound absorption enhancement in low and intermediate frequencies achieved by a thin multi-slit hybrid structure formed by incorporating micrometer scale micro-slits into a sub-millimeter scale meso-slit matrix. Theoretical and numerical results reveal that this exotic phenomenon is attributed to the noticeable velocity and temperature gradients induced at the junctures of the micro- and meso-slits, which cause significant loss of sound energy as a result of viscous and thermal effects. It is demonstrated that the proposed thin multi-slit hybrid structure with micro-scale configuration is capable of controling low frequency noise with large wavelength, which is attractive for applications where the size and weight of a sound absorber are restricted.

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.

Giant magnetoresistance in Fe/SiO_2/p-Si hybrid structure under non-equilibrium conditions

The giant magnetoresistive（MR） effect was investigated in a simple Fe/Si O2/p-Si-hybrid-structure-based device from two back-to-back Schottky diodes. The effect was revealed only under the non-equilibrium conditions caused by optical radiation. It is demonstrated that the magnetoresistance ratio attains 100 or more. The main peculiarity of the MR behavior is its strong dependence on the magnitude and the sign of the bias current across the device and, most surprisingly, upon polarity of the magnetic field. It is important that the magnetoresistive effect is implemented exclusively in the subsystem of minority charge carriers transferred to the non-equilibrium states. The development of magneto-sensitive devices of this type can give grounds for a novel direction of semiconductor spintronics.

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.

Static and Dynamic Analyses of Long-Span Spatial Steel-Cable-Membrane Hybrid Structures

With the increment of the complexity of structural systems and the span of spatial structures, the interactions between parts of the structures, especially between some flexible substructures, become too complex to be analyzed clearly. In this paper, taking an actual gymnasium of a long-span spatial steel-cable-membrane hybrid structure as the calculation model, the static and dynamic analyses of the hybrid structures are performed by employing the global analysis of the whole hybrid structure and the substructural analysis of the truss arch substructure, the cable-membrane substructure, etc. In addition, the comparison of stresses and displacements of structural members in the global and substructural analyses is made. The numerical results show that serious errors exist in the substructural analysis of the hybrid structure, and the global analysis is necessary for the hybrid structure under the excitation of static loads and seismic loads.

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.

The Effect of Blending Ratio on the Structure and Properties of the PPR/PS In situ Fiber Reinforced System Prepared by Multi-Flow Vibration Injection Molding

To enhance the mechanical properties of polypropylene random copolymer(PPR),polystyrene(PS)with four different contents were added to the PPR matrix through melt blending.Subsequently,using the Multi-Flow Vibration Injection Molding(MFVIM)technology,PPR/PS in situ microfiber composites(MFC)with different blending ratios were prepared.The results indicated that blending ratio had a great impact on the phase morphology and crystal structure of MFVIM samples,which was different from those of conventional injection molding(CIM)samples.PS ultrafine fibers could be formed under the shear field and could absorb the PPR molecular chains to form hybrid shish-kebab structures.Meanwhile,the PPR matrix could also form shish-kebab structures under the effect of strong shear.When the PS content reached 20%,under the combined action of PS in situ microfibers and highly oriented crystal structure,the tensile strength and Young’s modulus of the sample were obviously improved and the impact strength remained at a relatively high level.So a strong and tough balanced PPR based material was obtained.These results provide valuable insights for expanding the industrial and daily-life applications of PPR and show promising development prospects.

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.