Search

This paper examines why individuals invested in the nascent and underregulated Chinese P2P lending market based on the categorization theory in marketing studies. Using a unique account-level database of investors from a large P2P platform, we find that investors from regions with better-developed FinTech products that involve financial intermediaries invested more and took more risks in P2P lending. The effect is stronger among investors with a lower level of generalized trust or less investment experience in P2P lending. Our results suggest that category-based evaluation may occur when individuals decide whether to invest in a new risky financial market. [ABSTRACT FROM AUTHOR]

We construct a measure of public gambling sentiment using the Baidu index and empirically examine the influence of temporal fluctuations in gambling sentiment on the performance of lottery‐type stocks. The empirical findings reveal that heightened gambling sentiment correlates with increased selling volume, short‐term order imbalances and liquidity in the lottery‐type stock market, while diminishing abnormal returns, including the initial returns of IPOs. We attribute this to investors' gambling mentality stemming from the accumulation of wealth rather than the pursuit of excitement, as they view lotteries and lottery‐related stocks as interchangeable investment options. [ABSTRACT FROM AUTHOR]

In this study, a series of mesoporous TiO2 nanotablets implanted with uniformly distributed MoO3 were formed by the heat treatment of a titanium-based metal–organic framework (MIL-125) in the presence of Mo ions, and their hydrogen sensing properties were investigated for the first time. The TiO2 and MoO3/TiO2 composites present a typical tablet-like morphology. Compared with the bare TiO2, the MoO3/TiO2 (Mo6+/Ti4+ = 1:10) composite has a richer porous structure (3 times larger than pure TiO2) which can provide a larger surface area (2.1 times larger than pure TiO2). The sensing performance reveals that the MoO3/TiO2 composite (Mo6+: Ti4+ = 1:10) not only exhibits the highest response of 47.57 (5 times higher than pure TiO2) to 1000 ppm of H2 at room temperature but also shows good reproducibility, long-term stability, and selectivity, which is mainly due to the richer porous structures, the n–n heterojunction, and the catalytic effect between MoO3 and hydrogen. It is noteworthy that the response of the optimal MoO3/TiO2 composite has shown an exponential increase at higher hydrogen concentrations and reaches 1178 at 4000 ppm of hydrogen. [ABSTRACT FROM AUTHOR]

In order to investigate the impact of design parameters (depth, width, and location) of the single-circumferential groove (SCG) on tip leakage flow (TLF) reduction in a transonic turbine stage, a systematic investigation was conducted by high-precision numerical simulation method. The numerical results show that the introduction of SCG could improve the stage efficiency (η) of turbine significantly. The optimal design parameters of depth coefficient (ζ), width (W), and location (L) were ζ = 3, W = W3, and L = 20%Cax (where Cax denotes the axial chord of the blade), which could reduce tip clearance leakage rate (m*) by 28.9% and improve the η by 0.56%. The implementation of flow field display methods reveals that the introduction of SCG influences the formation and development of the vortex system at the rotor tip region. The circumferential groove vortex (CGV), induced by SCG, divided the tip leakage vortex (TLV) into two segments TLV_1 and TLV_2 due to its blocking effect. TLV_1 interacted with the passage vortex (PV) and depress the strength of PV. Meantime, TLV_2 would regenerate from the trailing edge of SCG, due to its limited development range and insufficient growth, the strength and scale of TLV_2 were weakened. Given that the TLF passing through SCG flows in an opposite direction to the original TLF, the SCG at appropriate location could lead to a fact that the net flow rate of the leakage flow reached the minimum value, thereby considerably reducing the m* and flow loss caused by TLF. [ABSTRACT FROM AUTHOR]

Spark discharge is essential for extracting energy from triboelectric nanogenerators (TENGs). However, the lack of universal technical standards for most discharge switches limits their widespread application. Herein, a buck circuit utilizing gas discharge tube (GDT) as discharge switches is presented. The GDT switch significantly enhances the instantaneous power to 30 mW, 15 times higher than the direct method. When VGDT (the breakdown voltage of GDT) ≤1000 V, it can be integrated with an LC converter, forming the GDTx‐Buck circuit with a maximum energy conversion efficiency of 92.2%. When VGDT >1000 V, GDT can combine with a transformer, forming the GDT‐nT circuit, which enables higher voltage power management. The results demonstrate GDT's universal applicability, reducing circuit complexity during design. In practical applications, the circuit can illuminate 1250 LEDs at an ultra‐low operating frequency of 0.6 Hz, generating electromagnetic waves during GDT breakover, which proves valuable for self‐powered wireless applications. Additionally, the circuit drives parallel calculators and thermometers at 2 Hz in micro‐nano energy applications and provides continuous power to high‐power fire sensors. Its high integration and simple design render it highly promising for large‐scale energy management applications based on TENGs. [ABSTRACT FROM AUTHOR]

Mixed oxide β-ZrWMoO8-containing composites with monoclinic zirconia (m-ZrO2) were prepared in search for zero thermal expansion ceramics over a wide temperature range. Thermomechanical analyzer (TMA) results indicate that the thermal expansion coefficients of the β-ZrWMoO8-containing composites decrease with increasing amount of β-ZrWMoO8 and that the composite with 50 wt. % β-ZrWMoO8 and 50 wt. % m-ZrO2 exhibits near-zero thermal expansion from 30 to about 600oC. However, its relative density is low. The addition of a small amount of Al(NO3)3.9H2O as a sintering aid increases the density (possibly because the Al3+ ion promotes sintering and densification) while affecting the structure and thermal expansion only insignificantly.

PbS films grown on quartz substrates by the chemical bath deposition method were annealed in an O2 atmosphere to investigate the role of oxygen in the sensitization process at different annealing temperatures. The average grain size of the PbS films gradually increased as the annealing temperature increased from 400 °C to 700 °C. At an annealing temperature of 650 °C, the photoresponsivity and detectivity reached 1.67 A W−1 and 1.22 × 1010 cm Hz1/2 W−1, respectively. The role of oxides in the sensitization process was analyzed in combination with X-ray diffraction and scanning electron microscopy results, and a three-dimensional network model of the sensitization mechanism of PbS films was proposed. During the annealing process, O functioned as a p-type impurity, forming p+-type PbS layers with high hole concentrations on the surface and between the PbS grains. As annealing proceeds, the p+-type PbS layers at the grain boundaries interconnect to form a three-dimensional network structure of hole transport channels, while the unoxidized p-type PbS layers act as electron transport channels. Under bias, photogenerated electron–hole pairs were efficiently separated by the formed p+-p charge separation junction, thereby reducing electron–hole recombination and facilitating a higher infrared response. [ABSTRACT FROM AUTHOR]

Blockchain technology, as a revolutionary technology that has emerged in recent years, holds significant potential for application in supply chain operations. This paper provides a systematic review of blockchain-based supply chain case studies. The existing literature primarily focuses on the food, agriculture, and pharmaceutical sectors, highlighting the advantages of blockchain technology in terms of traceability and transparency. However, there is a limited number of studies addressing the improvement of collaboration efficiency in supply chains, particularly within the realm of information technology enterprises. By conducting semi-structured interviews, we present a case study of Lenovo, a leading enterprise utilizing blockchain technology, to elucidate the advantages of using blockchain technology. Subsequently, it proposes a conceptual model for a blockchain-based information collaboration system and discusses the potential applications of blockchain technology in supply chain collaboration. Our study contributes to the existing work on blockchain applications to enhance supply chain collaboration. [ABSTRACT FROM AUTHOR]

Abstract ZnO nanowires with both good crystallinity and oxygen vacancies defects were synthesized by thermal oxidation of Zn substrate pretreated in concentrated sulfuric acid under the air atmosphere, Ar- and air-mixed gas stream. The photoluminescence spectra reveal that only near-band-edge (NBE) emission peak was observed for the sample grown in the air atmosphere; the broad blue–green and the red-shifted NBE emission peaks were observed for the sample grown in the mixed gas stream, indicating that the sample grown in the mixed gas stream has a defective structure and its optical properties can be modulated by controlling its structure. The high-resolution transmission electron microscope and the corresponding structural simulation confirm that the oxygen vacancies exist in the crystal of the nanowires grown in the mixed gas stream. The ZnO nanowires with oxygen vacancies defects exhibit better photocatalytic activity than the nanowires with good crystallinity. The photocatalytic process obeys the rules of first-order kinetic reaction, and the rate constants were calculated.

Abstract Single crystalline indium nanowires were prepared on Zn substrate which had been treated in concentrated sulphuric acid by galvanic displacement in the 0.002 mol L−1In2(SO4)3-0.002 mol L−1SeO2-0.02 mol L−1SDS-0.01 mol L−1citric acid aqueous solution. The typical diameter of indium nanowires is 30 nm and most of the nanowires are over 30 μm in length. XRD, HRTEM, SAED and structural simulation clearly demonstrate that indium nanowires are single-crystalline with the tetragonal structure, the growth direction of the nanowires is along [100] facet. The UV-Vis absorption spectra showed that indium nanowires display typical transverse resonance of SPR properties. The surfactant (SDS) and the pretreatment of Zn substrate play an important role in the growth process. The mechanism of indium nanowires growth is the synergic effect of treated Zn substrate (hard template) and SDS (soft template).

Triboelectric nanogenerators (TENGs) are efficient low-frequency and high-entropy mechanical energy harvesting devices that can provide sustainable power supply for Internet of Things applications. However, TENGs have low versatility and practicability because they need to be optimized for every application scenario. Inspired by LEGO blocks, we developed small-size, high-energy-density multifunctional triboelectric nanogenerators (LI-TENGs). Similar to a power cell, LI-TENGs are compact, can be rapidly assembled and connected, do not require additional wires for connecting devices, have high space utilization, and exhibit considerable capability for various low-frequency vibration mechanical energy harvesting applications. With an arched spring-steel sheet laminating structure, a tiny LI-TENG can transfer charge up to 760 nC and reach an open-circuit voltage of 210 V, an output charge volume density of up to 7 mC m−3 under mechanical vibrations at low frequencies (<5 Hz), and a volume power density of 48.47 W m−3 at a load resistance of 2.72 MΩ. LI-TENG units can be assembled into a parallel or perpendicular configuration for harvesting multi-directional vibration energies. Moreover, the LI-TENG has been successfully applied to various practical scenarios, such as vehicle night warning and blue energy harvesting. Thus, LI-TENGs provide a novel design approach for obtaining versatile TENGs and their arrays. [ABSTRACT FROM AUTHOR]

The movement of electrostatically actuated microbridges is measured by sensing the field of a permanent magnet, deposited and patterned on top of the microbridge, with a spin valve magnetic sensor fabricated beside the bridge at the level of the substrate. The spin valve sensor is sensitive to the position of the magnet and thus to the position of the bridge. The thin-film microbridges are fabricated using thin-film technology and surface micromachining at low temperatures ([less than or equal] 100[degrees]C) on glass substrates. The bridges are electrostatically actuated by applying a voltage between the bridges and a gate counter electrode placed beneath them. The deflection of the bridge is at the same time characterized optically by focusing a laser on the structure and monitoring the position of the reflected beam with a photodetector. A comparison of the bridge position sensing using the optical and magnetic methods is made. The absolute movement of the structures is measured with a precision close to 0.1 [Angstrom] using the integrated magnetic sensor. The deflection of the electrostatically actuated structures is studied as a function of the applied gate voltage and length of the bridges. The experimental results show qualitative agreement with an electromechanical model. [868] Index Terms--Integrated magnetic detection, low temperature processing, microelectromechanical structures, thin films.

In this paper, we propose a novel polarization conversion mechanism based on bianisotropic response of split ring resonator (SRR) metamaterial. It is found that under oblique incidence condition with the incident terahertz electric field parallel to the SRR gap, the magnetic field component of the incident wave can excite the fundamental LC resonance of SRR and form an electric dipole perpendicular to the SRR gap, which radiates orthogonal electric field thus resulting in polarization conversion. Numerical simulations and experiments are performed to verify this idea and the results are in excellent agreement. This study contributes to our understanding of the bianisotropic electromagnetic response of SRR and opens new opportunities for creating high-efficiency and low-loss polarization conversion devices in THz or other frequencies using bianisotropic metamaterials. [ABSTRACT FROM AUTHOR]

We demonstrate a dielectric metamolecule composed of ceramic and ferrite, which can be regarded as an equivalent LC circuit. When temperature varies, inductance is adjusted via the active ambient effective permeability of the metamolecule, thus counteracting the frequency drift caused by the temperature coefficient of the ceramic. The introduction of the ferrite meta-atom permits magnetic tunability, widening the working band of the filter. Additionally, the metamolecule inherits the high Q-value of the ceramic resonator. This work opens up an opportunity for realizing miniaturized, thermostable, tunable microwave filters with high-Q values in the fields of communication. [ABSTRACT FROM AUTHOR]

Actively controllable material properties are desirable for applications in materials science and microwave engineering. We design and fabricate a magnetically-coupled metamolecule with ferrite for X-band microwave frequencies that shows tunable responses to external magnetic fields. When compared with the metamolecule's magnetic Mie resonance, superior field sensitivity is observed in the vicinity of the Fano resonance through analysis of the transmission spectra. The mechanism is investigated by emulating the field distributions, and the phenomenon is attributed to specially coupled magnetic dipoles. The simulation results are verified experimentally. This work substantiates the metamaterial's enhanced electromagnetic properties for potential application to tunable microwave devices. [ABSTRACT FROM AUTHOR]

The Mie resonance of two dielectric meta-atoms causes a destructive coupling effect between them and results in hybridization induced transparency in the metamolecule. By actively adjusting the temperature, permittivities of the dielectric with opposite temperature coefficients vary in contrary trends, appearing as the field redistribution in each meta-atom. At the same time, two collective modes of the metamolecule behave as addition and subtraction of magnetic fields in meta-atoms. Combining both the intrinsic properties of materials and the collective properties of the coupling "dimer" system together, varying degrees of asymmetry of the metamolecule are obtained as the temperature changes. Since the intensity of the excited magnetic field can reflect the resonance amplitudes of the metamolecule onto the incident wave, the ratio of the transmission amplitudes of the two collective modes changes in a manner similar to the average magnetic field intensity of the metamolecule in two hybridized modes. Based on this behavior, we propose a method to estimate the degree of asymmetry of the metamolecule according to the field distribution intensity. [ABSTRACT FROM AUTHOR]