Basic Research Research Articles

Two-dimensional valley photonic crystal resonant cavities

Introducing defects in photonic crystals is a common method for manipulating and controlling the propagation of electromagnetic waves. By introducing defects in photonic crystal waveguides, the periodicity of the waveguide structure can be disrupted, local modes can be formed, and resonant cavity functions can be achieved. In this study, we designed two groups of two-dimensional valley photonic crystal waveguides, each of which uses different methods to introduce defects and obtained different resonant cavity structures, and designed a resonant cavity sensor. We conducted a detailed theoretical analysis of the resonant cavity through simulation software. In addition, we fabricated the samples and conducted microwave experiments to demonstrate the accuracy of our theoretical research. Our research provides guidance for the application of photonic crystal devices.

Low temperature atomic layer deposition of PbO2 for electrochemical applications

A low temperature atomic layer deposition (ALD) process for PbO2was developed using bis(1-dimethylamino-2-methyl-2-propanolate)lead(II), Pb(DMAMP)2, and O3as the reactants, with a high growth rate of 2.6 Å/cycle. PbO2readily reduces under low oxygen partial pressures at moderate temperatures making it challenging to deposit ALD PbO2from Pb2+precursors. However, thin films deposited with this process showed small crystalline grains of α-PbO2and β-PbO2, without signs of reduced PbOxphases. The ALD PbO2thin films show the high electrical conductivity characteristic of bulk PbO2. In situ measurements of ALD PbO2film conductivity during growth suggest a reaction mechanism by which sub-surface oxygen mobility contributes to the growth of resistive PbO or PbOxduring the Pb(DMAMP)2surface reaction step, which is only fully oxidized from Pb2+to Pb4+during the O3reaction step. These films were electrochemically reduced to PbSO4in H2SO4and then reoxidized to PbO2, demonstrating their suitability for use as an electrode material for fundamental battery research and other electrochemical applications.

Exploring Mechanoluminescence of Zinc Alkaline Earth Metal Oxysulfides from Fundamentals to Advanced Applications

AbstractMechanoluminescent (ML) materials convert mechanical stimuli into light emission, enabling applications in stress distribution visualization, structural health monitoring, biomechanical imaging, and sono‐optogenetics. Achieving efficient and full‐spectrum ML materials represents a long‐standing challenge. Zinc alkaline earth metal oxysulfides, namely CaZnOS, SrZnOS, BaZnOS, and SrZn2S2O, have emerged as prominent contenders in this field due to their exceptional ML properties. These materials feature low‐stress thresholds for emission activation, high ML intensity without the need for irradiation charging, and tunable spectra ranging from visible to near‐infrared, thus advancing ML research and broadening application possibilities. Here, a comprehensive review of the significant advancements made in ML research on zinc alkaline earth metal oxysulfides over the past decade, encompassing synthesis, characterization, mechanisms, and promising applications is presented. Special attention is focused on addressing conflicting reports on ML generation conditions, recent progress in accurately characterizing ML performance, and understanding mechanical‐to‐optical conversion processes. Future directions in fundamental ML research and the challenges in translating these advancements into practical applications are also discussed.

Investigating the Antecedents of Corporate Governance Influencing the Investment Efficiency of Firms: A Synthesis of Literature and Future Research Agenda

This review study investigates the critical antecedents of corporate governance affecting firms’ investment efficiency. It proposes a comprehensive framework encompassing corporate governance’s multifaceted aspects for all stakeholders’ benefit. A thorough literature evaluation has been conducted using the SCOPUS database, encompassing all publications published between 2010 and June 2023. The existing body of literature has also been examined through the theoretical frameworks, journals, authors, articles and research construct questions. After synthesising 154 articles through bibliometric analysis, four key antecedents (financial reporting quality, auditing and accounting quality, environmental, social and governance (ESG), institutional ownership and board structure) of corporate governance were identified as primary influencers of investment efficiency. New corporate governance perspectives, such as ESG and carbon taxation in the context of investment efficiency, have been identified and can be explored in depth by future researchers. The review provides a holistic framework for corporate governance, which defines the association with investment efficiency. The study presents potential future research areas where scholars can extend the scope of corporate governance from the perspective of investment efficiency.

Advances in the mechanisms of vascular calcification in chronic kidney disease.

Vascular calcification (VC) is common in patients with advanced chronic kidney disease (CKD).A series of factors, such as calcium and phosphorus metabolism disorders, uremic toxin accumulation, inflammation and oxidative stress and cellular senescence, cause osteoblast-like differentiation of vascular smooth muscle cells, secretion of extracellular vesicles, and imbalance of calcium regulatory factors, which together promote the development of VC in CKD. Recent advances in epigenetics have provided better tools for the investigation of VC etiology and new approaches for finding more accurate biomarkers. These advances have not only deepened our understanding of the pathophysiological mechanisms of VC in CKD, but also provided valuable clues for the optimization of clinical predictors and the exploration of potential therapeutic targets. The aim of this article is to provide a comprehensive overview of the pathogenesis of CKD VC, especially the new advances made in recent years, including the various key factors mentioned above. Through the comprehensive analysis, we expect to provide a solid theoretical foundation and research direction for future studies targeting the specific mechanisms of CKD VC, the establishment of clinical predictive indicators and the development of potential therapeutic strategies.

The Acid-Stimulated Self-Assembled DNA Nanonetwork for Sensitive Detection and Living Cancer Cell Imaging of MicroRNA-221.

Herein, a novel functional DNA structure, acid-stimulated self-assembly DNA nanonetwork (ASDN), was proposed for miRNA-221 sensitive detection and high-resolution living cancer cell imaging. Significantly, the self-assembly of ASDN only occurred in the acidic extracellular environment of cancer cells, which could be endocytosed by cancer cells to eliminate the interference of noncancer cells and deliver the ASDN into cancer cells. Subsequently, endogenous miRNA-221 could trigger the catalytic hairpin assembly within ASDN, resulting in the separation of the fluorophore Cy5 and the quencher BHQ2 to recover the substantial Cy5 fluorescence signals, thus achieving signal amplification for sensitive detection of miRNA-221 with a detection limit of 5.5 pM, as well as facilitating high-resolution and low-background imaging of miRNA-221 in cancer cells. In consequence, this strategy provides an innovative DNA nanonetwork to distinguish cancer cells from other cells for sensitive detection of biomarkers, offering a meaningful reference for the application of DNA nanostructure self-assembly technology in relevant fundamental research and disease diagnosis.

Research and clearance analysis on of steam twin-screw expander employed in indutrial waste heat recovery

In actual factories, screw expanders frequently operate under partial loads.To address the lack of theoretical research and the risks of errors in engineering design associated with steam pressure differential power generation under these conditions,a simulation of the twin-screw expander's working process was developed. The rotor profile was designed, geometric variables such as rotor mesh clearance were calculated, and models for leakage and heat transfer were established. A suction pressure correction model was proposed for the suction process under partial loads, along with correction parameters to simplify simulations.Experimental results demonstrate that the twin-screw expander operates stably under highly fluctuating conditions, demonstrating excellent variable load performance.As the load decreases, the loss of suction pressure reduces the expander's pressure differential, leading to lower leakage and improved efficiency. When the load is reduced from 100 % to 65 %, the volumetric efficiency increases from 78.87 % to 84.76 %, and the isentropic efficiency rises from 66.81 % to 74.25 %.Compared to experimental data, the flow calculation error of the suction pressure correction model presented in this study is controlled within 3 %.This model addresses performance calculations under partial loads, ensuring that theoretical models better align with real-world applications and supporting accurate selection of twin-screw expanders.This model enables appropriate selection of expanders to reduce pressure losses and enhance economic efficiency.

Impact of typical environments in China's western mountainous areas on the durability of railway concrete: a review

PurposeThis study aims to analyze the impact mechanism of typical environments in China's western mountainous areas on the durability of railway concrete and propose measures to improve durability.Design/methodology/approachWith the continuous promotion of infrastructure construction, the focus of China's railway construction has gradually shifted to the western region. The four typical environments of large temperature differences, strong winds and dryness, high cold and low air pressure unique to the western mountainous areas of China have adverse effects on the durability of typical railway structure concrete (bridges, ballastless tracks and tunnels). This study identified the characteristics of four typical environments in the western mountainous areas of China through on-site research. The impact mechanism of the four typical environments on the durability of concrete in different structural parts of railways has been explored through theoretical analysis and experimental research; Finally, a strategy for improving the durability of railway concrete suitable for the western mountainous areas of China was proposed.FindingsThe daily temperature difference in the western mountainous areas of China is more than twice that of the plain region, which will lead to significant temperature deformation and stress in the multi-layered structure of railway ballastless tracks. It will result in cracking. The wind speed in the western plateau region is about 2.5 to 3 times that of the plain region, and the average annual rainfall is only 1/5 of that in the plain region. The drying effect on the surface of casting concrete will significantly accelerate its cracking process, leading to serious durability problems. The environmental temperature in the western mountainous areas of China is generally low, and there are more freeze-thaw cycles, which will increase the risk of freeze-thaw damage to railway concrete. The environmental air pressure in the western plateau region is only 60% of that in the plain region. The moisture inside the concrete is more likely to diffuse into the surrounding environment under the pressure difference, resulting in greater water loss and shrinkage deformation of the concrete in the plateau region. The above four issues will collectively lead to the rapid deterioration of concrete durability in the western plateau region. The corresponding durability improvement suggestions from theoretical research, new technology development and standard system was proposed in this paper.Originality/valueThe research can provide the mechanism of durability degradation of railway concrete in the western mountainous areas of China and corresponding improvement strategies.

Savings and Sustainable Economic Growth Nexus: A South African Perspective

The savings behavior of individuals has been a topic of both macroeconomic and policy importance throughout history. Theoretical and empirical research shows that savings result from several demographic and economic factors working together to produce long-term, sustainable economic growth. This study therefore examined the nexus between domestic savings and sustainable economic growth in a South African perspective between 1990–2023, emphasizing the critical role that savings play in fostering long-term economic stability and environmental resilience. The ARDL framework was used to analyze data from the World Bank and the South African Reserve Bank. The results of the study demonstrate that corporate savings have a major effect on sustainable economic growth, especially over the long term. When corporate savings rise by 1%, the economy expands by 3.12%, which highlights the significant multiplier effect of investment. The extent of this impact depends on factors such as the efficiency of capital allocation, technological capacity, financial market development, government policies, and macroeconomic stability. These factors collectively determine how effectively corporate savings are transformed into productive investments that drive sustainable economic growth. Conversely, savings made by the government and the public, especially in the long run, have no appreciable impact on sustainable economic growth. Given that domestic savings mobilization is the most suitable channel for financing capital accumulation to support economic growth and development, the study suggests reviewing current policies to encourage domestic savings mobilization. This paper contributes to the broader discourse on sustainable economic policies in emerging markets, offering actionable insights for policymakers, financial institutions, and stakeholders promoting a more sustainable economic future for South Africa.

Cognitive Aspects of Translation: The Latest Research in Psycholinguistics and Cognitive Science

The study of the cognitive aspect of translation opens up new possibilities for understanding and analysing the translation process through the prism of cognitive science. By analysing the cognitive processes that take place in the translator's brain while performing translation, it is possible to reveal various aspects of this complex and multifaceted process. The purpose of this article is to conduct a literature review of cognition-oriented translation studies in order to contribute to the development of the science of translation studies. The method included the analysis of related literature from the scientific databases Scopus and Google Scholar. As a result of this study, advanced theoretical models were put forward and developed to reveal the so-called “black box” of the translator, which is considered a key aspect in understanding the cognitive processes of translation. These theoretical approaches aimed to uncover the internal mechanism and strategies used by the translator when performing translation in order to reveal and analyse how these processes occur in the translator's brain. Conclusions – the research focused on translation processes has great potential, as it uses the latest theoretical models and research methods from related cognitive disciplines such as cognitive psychology, cognitive linguistics, neurophysiology and computational linguistics. The paper attempts to identify challenges in cognitive translation research in order to contribute to a broader understanding of the cognitive aspects of translation and to help address key challenges in this area.

A Review of Common Acceleration Models in Accelerated Life Testing

The core of accelerated life testing (ALT) is the development of acceleration models. These models can be classified into three types based on their underlying methodologies: physics-based, empirical inductive, and statistical inference models. This paper primarily examines the acceleration models that are commonly applied in engineering practice and presents the relevant computational formulas to highlight the fundamental research methodologies of ALT. Additionally, the paper underscores that ALT is increasingly recognized as a vital and emerging trend, driven by its role in shortening design cycles, enhancing product reliability, and managing costs.

Cognition, horizon and practice: formation of the nonsynchronism in theoretical research of information science

Purpose The nonsynchronism in theoretical research of information science (IS) is an interesting phenomenon that has not been sufficiently examined. This study is to reveal the mechanism of its formation from a microscopic perspective.Design/methodology/approach A qualitative research approach was adopted and 22 professors from different IS fields were interviewed. The data were analyzed with a six-step thematic analysis method.Findings The nonsynchronism in IS theoretical research is reflected in three dimensions. Theory cognition and theory practice shape each other under the constraint of theory horizon. Researchers with similar theory cognition and practice form a theoretical generation. The inter-generational gap may exist among IS researchers in different research areas, at different ages, or located in different countries or regions.Research limitations/implications This study reveals the formation mechanism of the nonsynchronism in IS theoretical research from a microscopic perspective of individual researcher’s theory using practice and offers new insights into the dynamics of the structural evolution of IS theoretical knowledge.Practical implicationsThe results of this study can help to promote internal or external communication in IS and enhance theoretical education for doctoral students.Originality/valueThis study identifies and theoretically defines a few core themes, theory horizon, theory cognition, theory practice and theoretical generation, and reveals their relationships. On this basis, a conceptual model of nonsynchronism in theoretical research is developed.

B-Doped Graphdiynes and Several of Their Corresponding Oxides: A Theoretical Study by X-ray Spectra.

Boron doping can significantly improve the electronic structure and physical and chemical properties of graphdiyne (GDY), which also expands its application prospects in photoelectricity, catalysis, and biology. The accurate configurations characterization of B-doped graphdiyne (B-GDY) has not been achieved due to insufficient experimental and theoretical research. The current work involves the simulation of the geometries of 11 typical B-GDY and B-doped graphdiyne oxides [B(O)-GDY] as well as a pristine GDY, along with their X-ray photoelectron (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra at the density functional theory (DFT) level. The boron and carbon spectra for various bonding types were theoretically imitated to assess the spectral contributions. Calculated outcomes indicate that there is a noticeable dependence of the NEXAFS spectra on the local structure. The simulated XPS spectra provide precise assignments and an extra supplement to the spectra peaks, in addition to the position and general peak forms of simulated spectral peaks matching the experimental spectra fairly well. The combination of XPS and NEXAFS spectra can give useful information for identifying typical B-GDY and B(O)-GDY molecules. This paper offers a comprehensive structure-spectrum relationship of B-GDY and its oxides as well as a further theoretical prediction and guidance for experimental synthesis, which is helpful to solve the challenging issue of identification of B-doped carbon-based materials.

Designing C9N10 Anchored Single Mo Atom as an Efficient Electrocatalyst for Nitrogen Fixation.

Electrochemical nitrogen reduction reaction (NRR) is a promising route for realizing green and sustainable ammonia synthesis under ambient conditions. However, one of the major challenges of currently available Single-atom catalysts (SACs) is poor catalytic activity and low catalytic selectivity, which is far away from the requirements of industrial applications. Herein, first-principle calculations within the density functional theory were performed to evaluate the feasibility of a single Mo atom anchored on a g-C9N10 monolayer (Mo@g-C9N10) as NRR electrocatalysts. The results demonstrated that the gas phase N2 molecule can be sufficiently activated on Mo@g-C9N10, and N2 reduction dominantly occurs on the active Mo atom via the preferred enzymatic mechanism, with a low limiting potential of -0.48 V. In addition, Mo@g-C9N10 possesses a good prohibition ability for the competitive hydrogen evolution reaction. More impressively, good electronic conductivity and high electron transport efficiency endow Mo SACs with excellent activity for electrocatalytic N2 reduction. This theoretical research not only accelerates the development of NRR electrocatalysts but also increases our insights into optimizing the catalytic performance of SACs.

Ultralow thermal conductivity and excellent thermoelectric performance in Janus Bi2X2Y (X=Se, Te; Y=S, Se, Te) monolayers induced by suppressed membrane effect

We use density functional theory (DFT) implemented in the Vienna Ab initio Simulation Package (VASP) combined with Boltzmann transport equations to investigate the relationships between the structure, phonon hybridization, transport and thermoelectric properties of two-dimensional (2D) Janus Bi2X2Y (X=Se, Te; Y=S, Se, Te) monolayers. Among them, Janus Bi2Te2S monolayer shows a unique ultralow lattice thermal conductivity (1.09 W·m−1·K−1 at 300 K) and excellent thermoelectric performance. We find that, by suppressing the membrane effect of 2D materials to enable the negative-positive conversion of the Grüneisen parameter of the out-of-plane acoustic (ZA) phonon modes, the three-phonon scattering of the material can be effectively enhanced thereby reducing their lattice thermal conductivity. Besides, we also find the suppression of the membrane effect is highly correlated to the non-orthogonal bond angles. Our results indicate a new path to reduce the lattice thermal conductivity of 2D materials and are meaningful for further theoretical and experimental research on the development of high-performance thermoelectric materials.

Discovering technology opportunities of latecomers based on RGNN and patent data: The example of Huawei in self-driving vehicle industry

Emerging technologies provide competitive opportunities for latecomers to catch up with leading giants. As most of the extant literature indicated, types of single-dimensional relations from patent data have been revealed in technology opportunity discovery (TOD) research. Still, few have been aware of the more complex characteristics extracted from higher-dimensional patent information such as the patentee-technology relation. To derive this valuable relation for more robust results, this article introduces a novel TOD method, utilizing a recursive graph neural network (RGNN) to transform this high-dimensional information into measures of heterogeneity as internal capability, and combining it with external challenges evaluated by the competitiveness index, to identify technological opportunities. Taking the self-driving vehicle (SDV) industry with 33,347 patent families from 2010 to 2021 as the initial dataset, it shows significant performance promotions compared to previous analogous TOD models. Meanwhile, tested by recent filing patent data, the predicted opportunities are consistent with Huawei and other enterprises. Upon illuminating the intense technological competition situation among the preeminent SDV firms worldwide as a case exploration, this research contributes theoretical and practical views to the TOD research and network analysis.

Influence of Reaction Conditions on the Yield of Supercritical Multicomponent Thermal Fluids

Supercritical multicomponent thermal fluid (scMCTF) is a novel medium with great potential for heavy oil thermal recovery. The production rate of scMCTF will affect the injection efficiency of thermal fluid, and then affect the development effect of thermal recovery. However, at present, there are few reports on the production rate of each component of scMCTF, and their understanding is not clear. According to the existing production rate data of supercritical water (scH2O) gasification products, based on the generation mechanism of scMCTF, the production rate of thermal fluid generation products under different generation conditions was calculated, and its influencing factors were identified. The results show the following: (1) The factors affecting the production rate of scMCTF generation products can be divided into three categories: reaction raw material factors, reaction condition factors, and catalytic factors. (2) The hydrocarbon number of raw material, reaction temperature, reaction time, and catalyst concentration were positively correlated with the production rate of the product. (3) The concentration of the reaction raw material is negatively correlated with the production rate of the product. The higher the concentration of the raw material is, the lower the concentration of H2O is, and the steam reforming reaction is inhibited, which leads to the decrease in the production rate. (4) The effect of reaction pressure and catalyst load on the product is not significant. (5) The reaction product production rate increased first and then decreased with the ratio of H2O to oil in the raw material emulsion and the ratio of preheated H2O to raw material discharge. (6) The effect of metal salt catalysts is relatively stable, and the catalytic effect of simple metal catalysts is significantly different under the action of different types of accelerators, so it is necessary to study the degree of synergization of different accelerators on the catalytic effect. The results can lay a foundation for the subsequent experimental and theoretical research design.

Study on the Optimization of Culture Parameters of Oxygen-Consuming Bacterium for Preventing CSC and Its Effect on the Coal Oxidation Characteristic

ABSTRACT Microorganisms can work together to prevent coal spontaneous combustion (CSC) by consuming oxygen and changing coal oxidation characteristics. In order to explore the influence of oxygen-consuming microorganisms on coal spontaneous combustion characteristics, a highly oxygen-consuming bacterium was isolated and identified from the soil near mine drainage, named ZQ-1. The oxygen consumption characteristics of microorganisms were investigated and optimized by single-factor and response surface experiments. Further, the effect of microorganisms on CSC was analyzed from both macroscopic and microscopic perspectives by using programmed warming, simultaneous thermal analysis, and Fourier-transform infrared spectroscopy (FTIR). The results revealed that the isolated bacterium was Pseudomonas aeruginosa. Its optimal culture conditions were pH = 6.98, temperature 28.15°C, and carbon nitrogen ratio (C/N) = 12.94 when the oxygen consumption rate was maximum. After bacterial action, coal showed a decrease in the release of the indicator gas CO during the combustion process, a delay in the cross point temperature (CPT) by 18.63°C, and an increase in the residual mass at the end of combustion. In addition, the average activation energy of the coal samples in the oxidative combustion stage was increased by 2.05721 kJ/mol. Finally, the FTIR results showed that microorganisms were able to destroy the reactive groups in the coal samples, especially hydroxyl, aliphatic hydrocarbon, and oxygen-containing functional groups, which resulted in the inhibition of CSC. This paper has important theoretical research value and practical significance for CSC prevention and control.

Exploration of the Technologies Application Experience of Landscape-Scale Green Infrastructure by the Conservation Fund

As the earliest discussed concept of Green Infrastructure (GI), Landscape-scale GI, in the form of an ecological network capable of balancing development and conservation, has received widespread attention. Its multifunctionality is one of the important features. However, the lack of information and funding, weakness of management authority and technical support make the practice of Landscape-scale GI challenging. Compared to GI adapted in stormwater management, which has comprehensive guidance from theory to practical technologies by officials during its introduction and promotion in other countries, Landscape-scale GI, despite a rich theoretical research foundation, is often overlooked due to insufficient summary research on practical techniques. To address this gap, this study uses mixed methods research to comprehensively analyze 27 Landscape-scale GI practical projects led by the Conservation Fund over the past 20 years to explore patterns in their technical applications. Through qualitative analysis, we standardized and classified descriptive information for these 27 projects and, combined with statistical analysis, clarified the practice development trends committed to balancing development and conservation. The quantitative analysis concentrated on the corresponding relationships between technical applications and project objectives, and GI functions. Based on this, the study categorized the technologies used, summarizing core technologies applicable to most Landscape-scale GI practices, providing some support for the promotion of Landscape-scale GI.

Magnetic Nanoparticles and Radio Frequency Induction: From Specific Heating to Magnetically Induced Catalysis

AbstractThis comprehensive review explores the potential of radio frequency (RF) induction heating in chemical reactions, explicitly focusing on magnetically induced catalysis using magnetic nanoparticles (NPs). We trace the recent historical progress of induction heating and highlight the advancements in liquid and gas‐phase reactions, particularly in its integration with heterogeneous catalysis. The review finds that induction heating profoundly impacts reaction kinetics, and selectivity, and can even reduce overpotentials in electrocatalytic processes. A final outlook unveils the challenges and opportunities associated with aspects such as fundamental research and reactor design, with a particular focus on expanding its use to higher pressures and necessary optimizations to improve energy efficiency. Moreover, it highlights the pressing need for standardized reporting in induction‐heated catalysis. The study underscores the significance of this brand‐new field in developing efficient and sustainable catalytic processes, which are essential for meeting the growing demand for clean energy and sustainable chemical production.