Digital transformation and strategic risk taking dataset for China's public-listed companies.

This article presents a comprehensive dataset from the annual reports of China's public-listed companies, the China Stock Market and Accounting Research Database, and the Wind database, focusing on digital transformation and strategic risk taking. This dataset covers 14 years from 2008 to 2021 with 17,089 firm-year observations. Digital transformation is calculated using text mining techniques and keyword frequency analyses based on the firms' annual reports. Then, strategic risk taking is a composite strategic index that combines long-term debt, R&D expenditure, and capital expenditure. The dynamic capability is measured by a comprehensive index that includes three dimensions: absorptive capacity, adaptive capability, and innovation capability. This dataset can serve as a reference base for future studies on the effect of digital transformation on corporate strategic behavior. It can also be integrated into building core competencies to assist managers in identifying the role of dynamic capability.

Surface-bulk coupling in a Bi2Te3 nanoplate grown by van der Waals epitaxy.

We report an experimental study of the effect of coherent surface-bulk electron scattering on quantum transport in a three-dimensional topological insulator Bi2Te3 nanoplate. The nanoplate is grown via van der Waals epitaxy on a mica substrate and a top-gated Hall-bar device is fabricated from the nanoplate directly on the growth substrate. Top-gate voltage dependent measurements of the sheet resistance of the device reveal that the transport carriers in the nanoplate are of n-type and that, with decreasing top gate voltage, the carrier density in the nanoplate is decreased. However, the mobility is increased with decreasing top-gate voltage. This mobility increase with decreasing carrier density in the nanoplate is demonstrated to arise from a decrease in bulk-to-surface electron scattering rate. Low-field magnetotransport measurements are performed at low temperatures. The measured magnetoconductivity of the nanoplate shows typical weak anti-localization (WAL) characteristics. We analyze the measurements by taking surface-bulk inter-channel electron scattering into account and extract dephasing times τφ, diffusion coefficients D of electrons at the top surface and in the bulk, and the surface-bulk scattering times τSB as a function of top-gate voltage and temperature. It is found that the dephasing in the nanoplate arises dominantly from electron-electron scattering with small energy transfers. It is also found that the ratio of τφ/τSB (a measure of the surface-bulk electron coherent coupling) is decreased with decreasing gate voltage or increasing temperature. We demonstrate that taking the surface-bulk coherent electron scattering in our Bi2Te3 nanoplate into account is essential to understand quantum transport measurements at low temperatures.

How does strategic flexibility affect bricolage: The moderating role of environmental turbulence.

While most studies have viewed strategic flexibility as a capability to cope with the environmental turbulence and promote the product innovation, few of them investigate the mediating mechanism in the relationship between the strategic flexibility and product innovation. According to the resource-based view, we regard the bricolage as a concrete activity of recombining the different resources in the product development process and explore the underlying mechanism. Our results reveal that strategic flexibility has a positive and significant effect on bricolage. The effect of strategic flexibility on product innovation is partially mediated by bricolage. Furthermore, environmental turbulence moderates the relationship between strategic flexibility and bricolage positively. We contribute to the strategic flexibility research by exploring the effect of strategic flexibility on the bricolage and product innovation form a mediating perspective and offering a more nuanced and in-depth understanding of the impact of strategic flexibility. This research also provides new evidence on the effect of strategic flexibility on product innovation in transition economies such as China, where strategic flexibility is essential for firms to adapt to an uncertain environment.

A Single-Electron Transistor Made of a 3D Topological Insulator Nanoplate.

Quantum confined devices of 3D topological insulators are proposed to be promising and of great importance for studies of confined topological states and for applications in low-energy-dissipative spintronics and quantum information processing. The absence of energy gap on the topological insulator surface limits the experimental realization of a quantum confined system in 3D topological insulators. Here, the successful realization of single-electron transistor devices in Bi2 Te3 nanoplates using state-of-the-art nanofabrication techniques is reported. Each device consists of a confined central island, two narrow constrictions that connect the central island to the source and drain, and surrounding gates. Low-temperature transport measurements demonstrate that the two narrow constrictions function as tunneling junctions and the device shows well-defined Coulomb current oscillations and Coulomb-diamond-shaped charge-stability diagrams. This work provides a controllable and reproducible way to form quantum confined systems in 3D topological insulators, which should greatly stimulate research toward confined topological states, low-energy-dissipative devices, and quantum information processing.

Universal conductance fluctuations and phase-coherent transport in a semiconductor Bi2O2Se nanoplate with strong spin-orbit interaction.

We report on phase-coherent transport studies of a Bi2O2Se nanoplate and on observation of universal conductance fluctuations and spin-orbit interaction induced reduction in fluctuation amplitude in the nanoplate. Thin-layered Bi2O2Se nanoplates are grown by chemical vapor deposition (CVD) and transport measurements are made on a Hall-bar device fabricated from a CVD-grown nanoplate. The measurements show weak antilocalization at low magnetic fields at low temperatures, as a result of spin-orbit interaction, and a crossover toward weak localization with increasing temperature. Temperature dependences of characteristic transport lengths, such as spin relaxation length, phase coherence length, and mean free path, are extracted from the low-field measurement data. Universal conductance fluctuations are visible in the low-temperature magnetoconductance over a large range of magnetic fields and the phase coherence length extracted from the autocorrelation function is consistent with the result obtained from the weak localization analysis. More importantly, we find a strong reduction in amplitude of the universal conductance fluctuations and show that the results agree with the analysis assuming strong spin-orbit interaction in the Bi2O2Se nanoplate.

High-throughput identification of G protein-coupled receptor modulators through affinity mass spectrometry screening.

G protein-coupled receptors (GPCRs) represent the largest class of cell surface proteins and thus constitute an important family of therapeutic targets. Therefore, significant effort has been put towards the identification of novel ligands that can modulate the activity of a GPCR target with high efficacy and selectivity. However, due to limitations inherent to the most common techniques for GPCR ligand discovery, there is a pressing need for more efficient and effective ligand screening methods especially for the identification of potential allosteric modulators. Here we present a high-throughput, label-free and unbiased screening approach for the identification of small molecule ligands towards GPCR targets based on affinity mass spectrometry. This new approach features the usage of target-expressing cell membranes rather than purified proteins for ligand screening and allows the detection of both orthosteric and allosteric ligands targeting specific GPCRs. Screening a small compound library with this approach led to the rapid discovery of an antagonist for the 5-HT receptor and four positive allosteric modulators for GLP-1 receptor that were not previously reported.

Strong spin-orbit interaction and magnetotransport in semiconductor Bi2O2Se nanoplates.

Semiconductor Bi2O2Se nanolayers of high crystal quality have been realized via epitaxial growth. These two-dimensional (2D) materials possess excellent electron transport properties with potential application in nanoelectronics. It is also strongly expected that the 2D Bi2O2Se nanolayers can be an excellent material platform for developing spintronic and topological quantum devices if the presence of strong spin-orbit interaction in the 2D materials can be experimentally demonstrated. Herein, we report the experimental determination of the strength of spin-orbit interactions in Bi2O2Se nanoplates through magnetotransport measurements. The nanoplates are epitaxially grown by chemical vapor deposition, and the magnetotransport measurements are performed at low temperatures. The measured magnetoconductance exhibits a crossover behavior from weak antilocalization to weak localization at low magnetic fields with increasing temperature or decreasing back gate voltage. We have analyzed this transition behavior of magnetoconductance based on an interference theory, which describes quantum correction to the magnetoconductance of a 2D system in the presence of spin-orbit interaction. Dephasing length and spin relaxation length are extracted from the magnetoconductance measurements. Compared to the case of other semiconductor nanostructures, the extracted relatively short spin relaxation length of ∼150 nm indicates the existence of a strong spin-orbit interaction in Bi2O2Se nanolayers.

High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se.

High-mobility semiconducting ultrathin films form the basis of modern electronics, and may lead to the scalable fabrication of highly performing devices. Because the ultrathin limit cannot be reached for traditional semiconductors, identifying new two-dimensional materials with both high carrier mobility and a large electronic bandgap is a pivotal goal of fundamental research. However, air-stable ultrathin semiconducting materials with superior performances remain elusive at present. Here, we report ultrathin films of non-encapsulated layered Bi2O2Se, grown by chemical vapour deposition, which demonstrate excellent air stability and high-mobility semiconducting behaviour. We observe bandgap values of ∼0.8 eV, which are strongly dependent on the film thickness due to quantum-confinement effects. An ultrahigh Hall mobility value of >20,000 cm2 V-1 s-1 is measured in as-grown Bi2O2Se nanoflakes at low temperatures. This value is comparable to what is observed in graphene grown by chemical vapour deposition and at the LaAlO3-SrTiO3 interface, making the detection of Shubnikov-de Haas quantum oscillations possible. Top-gated field-effect transistors based on Bi2O2Se crystals down to the bilayer limit exhibit high Hall mobility values (up to 450 cm2 V-1 s-1), large current on/off ratios (>106) and near-ideal subthreshold swing values (∼65 mV dec-1) at room temperature. Our results make Bi2O2Se a promising candidate for future high-speed and low-power electronic applications.

Epitaxial Growth of Ternary Topological Insulator Bi2 Te2 Se 2D Crystals on Mica.

Nanostructures of ternary topological insulator (TI) Bi2 Te2 Se are, in principle, advantageous to the manifestation of topologically nontrivial surface states, due to significantly enhanced surface-to-volume ratio compared with its bulk crystals counterparts. Herein, the synthesis of 2D Bi2 Te2 Se crystals on mica via the van der Waals epitaxy method is explored and systematically the growth behaviors during the synthesis process are investigated. Accordingly, 2D Bi2 Te2 Se crystals with domain size up to 50 µm large and thickness down to 2 nm are obtained. A pronounced weak antilocalization effect is clearly observed in the 2D Bi2 Te2 Se crystals at 2 K. The method for epitaxial growth of 2D ternary Bi2 Te2 Se crystals may inspire materials engineering toward enhanced manifestation of the subtle surface states of TIs and thereby facilitate their potential applications in next-generation spintronics.

Synthesis of Bi2Te3 Nanotubes Using Te Nanotubes as a Template.

Bi2Te3 nanotubes are synthesized by a facile two-step hydrothermal method. Te nanotubes are prepared firstly and then used as a template to produce Bi2Te3 nanotubes. The structure and morphology of the synthesized nanotubes are characterized by X-ray diffraction, field emission scanning electron microscope, and transmission electron microscope. The synthesized Bi2Te3 nanotubes are several microns in length and about 400 nm in diameter. The growth process is investigated in detail under different experimental conditions. The formation mechanism of Bi2Te3 nanotubes from the Te nanotube template is proposed and discussed. Electrical property of single Bi2Te3 nanotube is investigated. The synthesis of smooth Bi2Te3 nanotubes opens up the opportunities of investigating novel physical phenomena of topological insulators with two independent surfaces.