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AbstractPolymeric composites with the hybrid filler network for high-performance electromagnetic interference (EMI) shielding brought increasing interest. Herein, UHMWPE/ground tire rubber (GTR)/conductive carbon black (CCB) (UGC) composites with a hybrid segregated structural CCB-GTR were constructed by solid-phase shear milling (S3M), mechanical blending, and compacted molding processes. The percolation behavior of electrical conductivity and EMI shielding effectiveness (SE) of composites was described using Sigmoidal/Growth models, and its EMI shielding mechanism was discussed. Results showed that the EMI SE of U30G70C20, U50G50C20, and U70G30C20composites were found to be 37.5, 41.7, and 43.8 dB, respectively, due to constructing a hybrid network. The attenuation rate of microwave radiation is above 99.99%, and the shielding mechanism is mainly electrical loss. Moreover, the relationship between electrical conductivity and EMI SE is consistent with Sigmoidal/Growth models, indicating that Sigmoidal/Growth models can successfully predict the percolation threshold of the EMI SE of UGC composites.

Hypereutectic Al-x(1.75Fe-1.25Ni) (x=1,2,4,6) alloys were designed and prepared by gravity casting in the present study. Both the microstructure and the thermophysical properties were investigated. The microstructure was significantly transformed from the eutectic phases to the coarse primary phases with the increase in alloying elements. The result of thermal analysis indicated that the solidification behaviors were modified by the increase in alloying elements, which was ascribed to the generation of different phases. The thermal conductivity and thermal expansion properties were also related to the alloy composition. From the variation in the ratio of thermal conductivity/electrical conductivity, it could be inferred the effective medium of heat conduction was changing, which decreased thermal conductivity due to the introduced defects that hindered the transport of electrons and low efficiency heat conducting medium of intermetallic. Meantime, the formation of bulk intermetallic with low thermal expansion coefficient and large volume fractions reduced effectively the thermal expansion of the alloy. The mathematical model was presented to quantify the influence of alloy content on thermophysical properties.

To address the practical application challenges of conductive polymer composites (CPCs) in portable electronics equipment, such as their low thermal conductivity (TC) and poor electromagnetic interference (EMI) shielding effectiveness (EMI SE), it is crucial to improve their TC, electrical conductivity(σ), and EMI SE of CPCs. In this work, we present a conducting composite made of ultrahigh molecular weight polyethylene (UHMWPE) and carbon nanostructures (CNS) with a unique segregated structure. This structure is achieved through a simple high-speed mechanical mixing and compression molding process. Microscopy characteristics demonstrated that both the matrix and segregated conductive network were in-situ oriented along the compress direction of UHMWPE granules under the static hot-pressing field. CNS are compacted together at the interface between UHMWPE granules to form an oriented and interconnected conductive pathways at low CNS loading levels. The resultant UHMWPE/CNS composites with 10 wt% CNS content exhibits excellent EMI shielding performance, with EMI SE of 60.7 dB (at X-band), high conductivity of 2.42 S/cm, and acceptable thermal conductivity of 0.7217 (W/m K). High EMI shielding performance and absorption dominant mechanism are beneficial from the unique segregated structure, and individual CNS coated UHMWPE granule are similar to an electromagnetic cage. Additionally, the ultimate tensile strength of the composite remains high at 37.6 MPa even at 10.0 wt% CNS loading, and it shows effective thermal stability. These properties are attributed to the strong interfacial bonding between CNS and UHMWPE. These materials have potential applications in efficient thermal management and EMI shielding for high-performance intelligent electrical devices.

The microstructure and thermal-physical properties of Al-xNi (x = 6–25 wt.%) alloys were investigated by experiments first. With the increase of Ni content, the volume fraction and size of the Al3Ni increase significantly, while the morphology has no change. The thermal expansion coefficient (CTE) and the thermal conductivity (TC) decrease at the same time. The CTE of Al-6 wt.%Ni alloy is 20.2 × 10−6/K at 100 °C, decreasing to 15.4 × 10−6/K for Al-25 wt.%Ni, which demonstrates favorable thermal expansion performance. The TC changes from 202.8 W/(m·K) to 103.9 W/(m·K). Besides, the structure and thermal properties of Al3Ni were studied by the first-principles calculation to provide relevant thermodynamic data. The expansion performance was analyzed at the same time, the linear CTE of Al3Ni is 13.82 × 10−6/K at 100 °C. Based on the experiments and first-principles calculations, the modified Turner and general Effective Medium Theory (GEMT) models were used to explain the relationships between microstructure and thermal expansion coefficient, thermal conductivity of Al-xNi alloys.

Al-22Si-xNi (x = 0, 5, 10, 15, 20) alloys were prepared by sub-rapid solidification in the present study. Their microstructures were observed and thermophysical properties were tested. Solidification reactions of the alloys changed with the increase of Ni content. Al3Ni compounds with different morphologies were formed in different solidification stages. The eutectic Al3Ni and primary Al3Ni phase assumed fiber-like and fishbone-like, respectively. Al3Ni–Si binary eutectic structure appeared when Ni content reached 15wt.%. After annealing, the eutectic phase was spheroidized and coarsened. The thermal conductivity decreased with the increasing Ni content. Annealing could enhance the thermal conductivity of the alloys. With the increase of Ni content, the thermal expansion coefficient of the alloys decreased linearly. The as-annealed Al–22Si–15Ni alloy had good comprehensive performance in thermal properties, i.e., the thermal conductivity at 25 °C was 107.09W/(m·K) and coefficient of thermal expansion at 100 °C was 13.04 × 10−6/K. The predicted linear coefficient of thermal expansion values by Turner model agreed well with the experimental values.

Developmental nicotine exposure has been implicated in the association between maternal smoking and adverse outcomes in offspring. The 3rd trimester of human pregnancy is equivalent to the 1 st postnatal week in rodents; both are periods of active brain growth during which nicotinic acetylcholine receptors are transiently upregulated. Chronic neonatal nicotine (CNN; 6 mg/kg/day) from postnatal Days 1 to 7 was given orally to rat pups to evaluate long-term behavioral effects. Males and females were tested as adolescents or as young adults. CNN significantly decreased center time, ambulatory behavior, and rearing in the open-field test and decreased the number of entrances and time spent in the open arm of the elevated plus-maze in both sexes and ages. CNN did not change performance in the T maze or in the water maze in adult males or females. Motor coordination was not altered. In summary, CNN had long-term effects on anxiety-like behavior but did not affect spatial learning and memory functions. This finding is particularly important when evaluating the benefits of nicotine-replacement therapies during human pregnancies, which may improve smoking cessation rates but could result in long-term behavioral consequences. Keywords: nicotinic, learning and memory, anxiety, motor coordination

Researchers are still faced, with the challenge of creating a readily fabricated ion-imprinted electrode that can quickly and precisely detect trace metal ions. In this paper, a novel surface ion-imprinted polymer (sur-IIP) based on Au nanoparticle with high conductivity was synthesized and modified on the glassy carbon electrode (GCE). From structural characterization, the functional monomer, thiolated chitosan, was self-assembled on the surface of Au nanoparticle by the ‘Au-S’ bond and formed an imprinted layer in 15 nm thick. During the electrochemical measurement, different detection parameters such as supporting electrolyte, pH, deposition potential, deposition time were optimized under the optimal conditions, the modified electrode exhibited a extensive linear range from (0.05–30 μmol L-1) and lowest limit of detection was 0.0487 μmol L-1. The developed sensor was applied for the detection of traces of Cu (II) ions from tap water as well as from drinking water successfully. Compared with other surface ion-imprinted polymers, the sur-IIP in this paper were more conductive and could be modified tightly on the electrode by dip-dropping. The overall strategy of preparing the ion-imprinted polymer on the surface of Au nanoparticles were accessible and efficient.

Poly( p -phenylenevinylene) thin film was prepared by spin-casting onto optically transparent ITO conduction glass substrate, and its photoelectric properties were studied with surface photovoltage spectra. A localized subgap electronic transition is found, which causes the photovoltaic response with polarity opposite to that from band-to-band electronic transition ( π-π *). With the help of the photovoltaic properties under the external electric field, this localized transition is assigned to a electronic transition from the valence band to a local state below the bottom of the conduction band.

This paper studies the notion of hierarchical (chained) structure of stochastic tracking of marked feature points while a person is moving in the field of view of a RGB and depth sensor. The objective is to explore how the information between the two sensing modalities (namely, RGB sensing and depth sensing) can be cascaded in order to distribute and share the implicit knowledge associated with the tracking environment. In the first layer, the prior estimate of the state of the object is distributed based on the novel expected motion constraints approach associated with the movements. For the second layer, the segmented output resulting from the RGB image is used for tracking marked feature points of interest in the depth image of the person. Here we proposed two approaches for associating a measure (weight) for the distribution of the estimates (particles) of the tracking feature points using depth data. The first measure is based on the notion of spin-image and the second is based on the geodesic distance. The paper presents the overall implementation of the proposed method combined with some case study results.

Abstract: Two types of soliton deflexion of (1+3)D Kadomtsev–Petviashvili (K–P) equation are considered. Using the Hirota bilinear form and the new technique of “homoclinic test”, a type of exact periodic soliton solution of the K–P equation with positive transverse dispersion effects is obtained. Another type of periodic soliton solution is found by means of the periodic soliton solution of the K–P equation with negative transverse dispersion effects and a temporal and spatial transformation. It is also investigated that the equilibrium solution is an unique deflexion point, periodic soliton of traveling in different spatial directions will be interchanged with the solution varying from one side of to the other side. [Copyright &y& Elsevier]