Uneven Distribution Research Articles

Regulating the interaction between Bi metal and Bi24O31Br10 nanosheets for efficient photoreduction of CO2

Artificial photosynthesis converting CO2 into valuable compounds has garnered significant interest. However, the insufficient surface activity sites, weak adsorption capacity of CO2 and poor electron-hole separation capability hinder CO2 photoreduction used for practical implementation. Herein, Bi nanoparticles/Bi24O31Br10 composite photocatalyst (Bi/BOB) was designed constructed through in-situ reduction of bismuth metal on the surface of ultra-thin Bi24O31Br10 nanosheets. Bi/BOB exhibits an excellent ability to reduce CO2 to CO. The CO2 reduction rate of the optimized Bi/BOB composite catalyst is 43.07 μmol·g−1·h−1, which is significantly superior to other reported bismuth-based photocatalysts. Experimental characterization and Theoretical simulation calculation reveal that the in-situ reduction of bismuth metal causes significant local lattice distortion and uneven charge distribution, thereby producing a strong interaction between Bi nanoparticles and BOB support. So, it enhances the adsorption and activation of carbon dioxide molecules and reduces the Gibbs free energy barrier during the catalytic reaction. Moreover, the strong interaction helps to enhance the separation of photogenerated charge carriers and stability of catalysts. This study offers research suggestions for the interaction between metal and support to enhance CO2 reduction.

Synergistically flexible-robust effects mediate the dynamic reconfiguration of perylene diimide polymer to enhance piezo-photocatalytic nitrate reduction

Identifying the spatial dynamic reconstruction of π-conjugated polymers for efficient carrier transport and controlling the intermediate process of the reaction are urgent and formidable challenges. In this study, a fresh perspective has emerged proposing to synergistically enhance the adaptability and resilience of dynamic torsion patterns in π-conjugated polymers to mediate charge separation and molecular activation. Excitingly, the highest flexible-robust structure and polarity of naphthalene-linked perylene diimide polymer (N-PDA) demonstrates a highest nitrate reduction rate of 5.36 mmol g−1 h−1 under light irradiation and ultrasonic condition, which is 7.5 times that of H-PDA. Theoretical calculations and experimental observations indicate that the strongest flexible-robust structure of N-PDA enhances the inclination of the rigid plane and atomic bond length, resulting in an accelerated uneven distribution of charges, molecular polarity, and electronic coupling to facilitate charge separation dynamics. Moreover, it exposes active sites that promote the adsorption and activation of NO3- ions while simultaneously regulating intermediate hydrogenation processes. Our study offers innovative prospects for enhancing catalytic efficiency through the implementation of spatial steric configuration of π-conjugated polymers.

Online imbalance learning with unpredictable feature evolution and label scarcity

Recently, online learning with imbalanced data streams has aroused wide concern, which reflects an uneven distribution of different classes in data streams. Existing approaches have conventionally been conducted on stationary feature space and they assume that we can obtain the entire labels of data streams in the case of supervised learning. However, in many real scenarios, e.g., the environment monitoring task, new features flood in, and old features are partially lost during the changing environment as the different lifespans of different sensors. Besides, each instance needs to be labeled by experts, resulting in expensive costs and scarcity of labels. To address the above problems, this paper proposes a novel Online Imbalance learning with unpredictable Feature evolution and Label scarcity (OIFL) algorithm. First, we utilize margin-based online active learning to selectively label valuable instances. After obtaining the labels, we handle imbalanced class distribution by optimizing F-measure and transforming F-measure optimization into a weighted surrogate loss minimization. When data streams arrive with augmented features, we combine the online passive-aggressive algorithm and structural risk minimization to update the classifier in the divided feature space. When data streams arrive with incomplete features, we leverage variance to identify the most informative features following the empirical risk minimization principle and continue to update the existing classifier as before. Finally, we obtain a sparse but reliable learner by the strategy of projecting truncation. We derive theoretical analyses of OIFL. Also, experiments on the synthetic datasets and real-world data streams to validate the effectiveness of our method.

Knockout, Knockdown, and the Schrödinger Paradox: Genetic Immunity to Phenotypic Recapitulation in Zebrafish.

Previous research has highlighted significant phenotypic discrepancies between knockout and knockdown approaches in zebrafish, raising concerns about the reliability of these methods. However, our study suggests that these differences are not as pronounced as was once believed. By carefully examining the roles of maternal and zygotic gene contributions, we demonstrate that these factors significantly influence phenotypic outcomes, often accounting for the observed discrepancies. Our findings emphasize that morpholinos, despite their potential off-target effects, can be effective tools when used with rigorous controls. We introduce the concept of graded maternal contribution, which explains how the uneven distribution of maternal mRNA and proteins during gametogenesis impacts phenotypic variability. Our research categorizes genes into three types-susceptible, immune, and "Schrödinger" (conditional)-based on their phenotypic expression and interaction with genetic compensation mechanisms. This distinction provides new insights into the paradoxical outcomes observed in genetic studies. Ultimately, our work underscores the importance of considering both maternal and zygotic contributions, alongside rigorous experimental controls, to accurately interpret gene function and the mechanisms underlying disease. This study advocates for the continued use of morpholinos in conjunction with advanced genetic tools like CRISPR/Cas9, stressing the need for a meticulous experimental design to optimize the utility of zebrafish in genetic research and therapeutic development.

Unveiling nuances in data analysis to illuminate marine pilot strain.

Maritime studies, encompassing a range of disciplines, increasingly rely on advanced data analytics, particularly in the context of navigation. As technology advances, the statistical averaging of large datasets has become a critical component of these analyses. However, recent studies have highlighted discrepancies between statistical predictions and observable realities, especially in high-stress environments like port approach procedures conducted by marine pilots. This study analyzed physiological responses recorded during simulation exercises involving experienced marine pilots. The focus was not on the specific outcomes of the simulations but on the potential faults arising from conventional statistical signal processing, particularly mean-centered approaches. A large dataset of signals was generated, including one signal with a dominant characteristic intentionally designed to introduce imbalance, mimicking the uneven distribution of real-world data. Initial analysis suggested that the average physiological response of the pilots followed an S-shaped curve, indicative of a psycho-physiological reaction to stress. However, further post hoc analysis revealed that this pattern was primarily influenced by a single participant's data. This finding raises concerns about the generalizability of the S-curve as a typical stress response in maritime pilots. The results underscore the limitations of relying solely on conventional statistical methods, such as mean-centered approaches, in interpreting complex datasets. The study calls into question the validity of standardizing data interpretations based on dominant characteristic curves, particularly in environments as intricate as maritime navigation. The research highlights the need for a re-evaluation of these methods to ensure more reliable and nuanced conclusions in maritime studies. This study contributes to the ongoing discourse on data interpretation in maritime research, emphasizing the critical need to re-assess conventional statistical signal processing techniques. By recognizing the potential pitfalls in data generalization, the study advocates for more robust analytical approaches to better capture the complexities of real-world maritime challenges.

Assessing masseter muscle volume and activity in relation to craniofacial morphology: a 3D CBCT study.

Understanding the factors influencing craniofacial structure growth is crucial for addressing craniofacial deformities. This study evaluates masseter muscle volume, activity, and maximum bite force across different skeletal malocclusion groups and aims to evaluate the masseter muscle volume, activity, and maximum bite force (BF) according to different skeletal malocclusion groups. This study aimed to assess masseter muscle volume, activity, and maximum bite force (BF) across different skeletal malocclusion groups in 60 young adults (18-30 years) seeking treatment at Kirikkale University Faculty of Dentistry. Cone-Beam Computed Tomography (CBCT) imaging, radiological measurements, surface electromyography (sEMG), and force sensor measurements were employed. Results revealed significant differences in sEMG measurements based on sagittal classification. Vertical direction groups showed notable results in muscle volume and BF, though no significant differences were observed in sEMG values. A correlation was identified between BF and sEMG, but no correlation was found between muscle volume and other parameters. The findings obtained in this study suggest that the significant relationship between EMG and sagittal skeletal classification could be a valuable diagnostic tool. However, concerns about reliability were raised due to uneven distribution in muscle volume and BF among vertical direction groups. The lack of significant results in muscle volume, sEMG, and BF was attributed to CBCT limitations in soft tissue imaging and the small sample size, emphasizing caution in interpreting the findings.

An Analytical Model for Electrochemical Tubular Flow Reactors

This paper introduces the first analytical model designed for tubular electrochemical flow reactor, enabling a detailed examination of how reactor geometry and material selection impact performance. The model revealed that certain conditions, such as high electrode resistance relative to charge transfer, electrolyte, and separator resistance, can lead to uneven current distributions and reduced electrode utilization. The model highlights a critical electrode radius, dependent on reactor geometry and material properties, that minimizes the Area Specific Resistance (ASR) while minimizing reactor size. Additionally, it was found that the ASR increases with reactor length, but this effect can be mitigated by using highly conductive electrodes, thus allowing for enhanced power output. These insights provide a foundation for future research and the development of more efficient tubular reactor designs.

Multibeam water column image super-resolution by combining morphological and intensity features

ABSTRACT Multibeam water column images (WCI) play a crucial role in the detection and recognition of underwater targets. However, WCI is not a complete image of underwater space due to the gaps between beams inherent in multibeam systems. In this study, we design the WCI super-resolution network (WCISRN) based on Swin-transformer to adapt to the uneven and sparse distribution of water column data. To enable WCISRN to learn morphological features effectively, we produced simulated datasets for pre-training. Subsequently, we conduct self-supervised training on the measured WCI dataset to fine-tune the network parameters, aiming to better adapt WCISRN to the backscattering intensity features of WCI. Finally, by performing network cross-fusion, the pre-trained network and self-supervised training network are combined to form a new network that achieves a balance between image morphology and intensity features. The proposed method is evaluated through visual analysis and quantitative comparison using simulated and real-world datasets. The experimental results demonstrate that our method exhibits stronger detail restoration ability and clearer image morphology. The average peak signal-to-noise ratio (PSNR) on the test set improved from 23.75–26.14, indicating a significant enhancement in the imaging quality of WCI.

The Spatiotemporal Surface Velocity Variations and Analysis of the Amery Ice Shelf from 2000 to 2022, East Antarctica

The surface velocity of the Amery Ice Shelf (AIS) is vital to assessing its stability and mass balance. Previous studies have shown that the AIS basin has a stable multi-year average surface velocity. However, spatiotemporal variations in the surface velocity of the AIS and the underlying physical mechanism remain poorly understood. This study combined offset tracking and DInSAR methods to extract the monthly surface velocity of the AIS and obtained the inter-annual surface velocity from the ITS_LIVE product. An uneven spatial distribution in inter-annual variation in the surface velocity was observed between 2000 and 2022, although the magnitude of variation was small at less than 20.5 m/yr. The increase and decrease in surface velocity on the eastern and western-central sides of the AIS, respectively, could be attributed to the change in the thickness of the AIS. There was clear seasonal variation in monthly average surface velocity at the eastern side of the AIS between 2017 and 2021, which could be attributed to variations in the area and thickness of fast-ice and also to variations in ocean temperature. This study suggested that changes in fast-ice and ocean temperature are the main factors driving spatiotemporal variation in the surface velocity of the AIS.

Asymmetric oxygen vacancies of self-supporting Co3O4/CuOx on Cu foam boosts propane total oxidation

As a low-cost and environmentally friendly transition metal oxides material, the Co3O4 has good catalytic activity for volatile organic compounds (VOCs) oxidation. However, the active components of powder cobalt-based catalysts may present uneven distribution and aggregation, thus affecting the catalytic efficiency. Herein, the Co/Cu-CF monolithic catalyst with asymmetric oxygen vacancies was developed through in-situ growth of Cu(OH)2 nanoarrays on Cu foam, which exhibits excellent performance for propane oxidation (T90 at 215 ℃). It is impressive that the catalyst shows satisfactory stability in terms of long-term, cyclic and water resistance. The results indicate that the existence of nanoarrays can provide a rich load surface and better disperse the active components, which effectively facilitates the interface interaction between cobalt and copper, inducing the generation of asymmetric oxygen vacancies. And, the activity of catalyst was significantly improved owing to the double activation effect of asymmetric oxygen vacancy on molecular oxygen and lattice oxygen. Therefore, this research offers a novel approach for designing efficient nanoarray monolithic catalysts for VOCs oxidation and other environmental applications.

Hierarchy in the Politics of Migration: Revisiting Race, Ethnicity, and Power in the Migration State

Migrants and refugees face hostile publics and organized political interests, and contend with new and evolving forms of surveillance, deportability, and political violence. Researchers show that these political dynamics are fundamentally shaped by the politics of race and ethnicity. Yet, even as this work is increasingly abundant, it has not always been taken up by mainstream accounts of migration. In this article, we revisit scholarship on the politics of international migration, bringing together a collection of — sometimes disparate — research to explore how scholars can forge new lines of inquiry regarding the relationship between migration, race, ethnicity, and power. To do so, we evaluate three types of relationships at the core of migration politics: the relationship between migration and the state, the migration-related demands of domestic publics on the state, and how migrants interact and contend with the state. Across these relationships, we examine how ethnoracial hierarchies draw on, legitimize, and reinforce uneven distributions of political power, disparate deployments of state action and violence, and projects of nation- and state-building. Combining the intellectual prowess of distinct fields and approaches, we draw on productive convergences and tensions between existing and emerging frameworks and analytic starting points across disciplines to map future research trajectories in the multidisciplinary study of immigration, citizenship, asylum, and racial and ethnic politics. We conclude with a note on the politics of knowledge production–whereby some accounts of migration have been privileged over others–and point to important epistemological and methodological interventions for advancing research on the politics of migration.

Influence of Reed Fiber Length and Dosage on the Properties of Reed-Fiber-Modified Bitumen and Bituminous Mortar

In order to explore the feasibility and efficacy of reed-fiber-modified bitumen (RFMB), three lengths and three dosages of reed fibers were selected to modify bitumen and bituminous mortar, while the physicochemical properties of RFMB and RFMB mortar were analyzed. In this work, FTIR spectroscopy was employed to characterize the chemical impact of fiber on bitumen. The viscidity and rheology of RFMB and the tensile strength of RFMB mortar were evaluated using a Brookfield viscometer, dynamic shear rheometer, and monotonic tensile test. The results showed that adding fibers primarily affects the physical structure rather than the chemical composition of bitumen, confirmed by FTIR spectroscopy. RFMB viscosity increased with higher fiber dosage and fiber length. Rheological evaluations showed an enhanced complex shear modulus for RFMB, suggesting improved performance at higher temperatures but increased stiffness at lower temperatures, with the latter indicating reduced flexibility. RFMB also demonstrated superior fatigue and rutting resistance, albeit with compromised stress sensitivity. Tensile tests on RFMB mortar highlighted significant improvements, especially with longer fibers, while shorter 0.4 mm fibers showed modest reinforcement effects, possibly due to uneven distribution during sample preparation.

Synthesis and characterization of Fe3O4@SiO2 core-shell nanoparticles for mirror and efficient magnetic compound fluid polishing of TC4 titanium alloy

To fully investigate the polishing performance of the Fe3O4@SiO2 core–shell abrasive for TC4 titanium alloy plate and solve the problem of uneven distribution of abrasive particles in magnetic compound fluid polishing (MCFP) and obtain ultra-smooth titanium alloy surface. In this paper, the functional Fe3O4@SiO2 core–shell abrasives were prepared and characterized by XRD, FTIR, VSM and TEM to demonstrate the successful encapsulation of SiO2 in Fe3O4 first. Second, a new polishing device was built to perform polishing experiments. Four different fractions of Magnetic compound fluid (MCF) were configured and utilized in polishing experiments for MCFP of TC4 titanium alloy to verify the polishing properties. Finally, the contact model between abrasive particles and workpiece is established and the material removal mechanism is discussed. The results show that SiO2 was successfully coated on Fe3O4. The polishing results show that the MCF containing the core–shell structure had the best polishing effect. The surface roughness Ra decreased from 0.201 μm to 0.025 μm after 20 min of polishing. The surface roughness of TC4 titanium alloy with an initial roughness Sa of 0.248 μm is reduced to 0.023 μm after polishing by Fe3O4@SiO2 core–shell abrasive. It is shown that the application of core–shell abrasive to process titanium alloys can obtain smooth and defect-free surfaces with good polishing performance. The surface quality of titanium alloy can be improved effectively by using core–shell abrasive, and a new idea for polishing titanium alloy is proposed. This study plays an important role in solving the problem of uneven particle distribution in MCFP. These results pave the way for further research into the application of core–shell abrasives in precision machining and expand the application scope of particles with core–shell structure.

Spatial‐Temporal Distribution Characteristics of Linear Heritage Hiking Tourism Based on GPS Data Analysis: A Case Study of the Great Wall in Beijing, China

ABSTRACTHiking plays a significant role in experiencing linear heritage, and gaining insights into the spatiotemporal distribution of hikers' behavior is imperative for effectively utilizing heritage resources. This study employed GPS trajectory data to examine the spatiotemporal patterns of hiking behavior on the Great Wall in Beijing and investigate the utilization patterns of heritage resources in hiking tourism. The results revealed that: there were notable variations in trajectory quantity among different months with extended activity durations, early finishing times, and an absence of nighttime activities. Spatially, the trajectories exhibited dispersion and uneven distribution, leading to the underutilization of numerous heritage resources. The distribution of starting and ending points of trajectories demonstrated a substantial correlation with neighboring natural villages. Consequently, this study offers valuable insights for informing decision‐making processes related to the development, construction, and optimization of the scenic area along the Great Wall and the planning and design of tourist routes.

Microstructural and electrical properties of La0.9B0.1AlO3 (B=Pr, Nd, Sm) ceramics obtained by rare-earth ion doping

This study used the solid-phase method to prepare thermosensitive perovskite ceramics, La0.9B0.1AlO3 (B = Pr, Nd, Sm). The XRD and EDS results indicated that all components presented a single phase and all elements were uniformly distributed, formed a good solid solution. The SEM results clearly illustrated that the doped elements had enhanced the surface morphology, resulting in more uniform grain formation. The TEM results showed that linear defects were present, which led to an uneven stress distribution; consequently, this enhanced the carrier transport. The alternating current (AC) impedance showed that the grain boundary resistance determined the overall complex impedance and exhibited a different conductive mechanism with increasing temperature, from polariton to ion conduction. With the introduction of Nd3+, the conductivity of La0.9Nd0.1AlO3 increased and its temperature range increased from 600 – 1400 °C to 100–1500 °C. In La0.9Sm0.1AlO3, the presence of Sm2+ enhances the aging stability by elevating the oxygen vacancy concentration and the aging drift rate (ΔR/R0) was found to be lower than 2 %. In addition, DFT-based calculations were performed to investigate the property changes in the crystal structure and energy band structure of pure and doped LaAlO3. This study demonstrated an effective way to improve the performance of high-temperature thermistor materials using different doping strategies.

Enhancing Chinese Pension Funds Development through ESG Investment Perspectives

In current China, where the pension funds system is facing enormous pressure, this article will explore the positive impact of incorporating ESG investments into the Chinese pension funds system on its future development. Through research on the current situation of China's pension system, it is found that there are problems such as uneven regional distribution, unbalanced development of the three pillars, high population pressure and funding gap, high investment return requirements, and limited investment channels. By studying the feasible experiences of top ESG investment companies and leading countries in development, it is concluded that ESG investment contributes to improving the return on investment and stability of pension funds, and can alleviate the existing problems in China's pension funds. Finally, it is summarized that the feasible experience of combining ESG investment with China's pension funds is to take the lead in policies first, combined with strict supervision, and pay attention to talent cultivation.

FSI investigation on the discharge valve lift in a R32 rotary compressor and its verification

R32 rotary compressor is commonly applied in the household air conditioner. The valve motion is significant to the performance and reliability of rotary compressor. Valve lift is an important factor which directly affects the valve motion. A suitable valve lift can both reduce power consumption and fracture risk of valve plate. Based on a compressor prototype, this paper developed a FSI model to simulate the working process of discharge valve. The simulation results show that a large valve lift means a large discharge effective flow area and a low indicated power. But both the velocity of valve plate impacting the retainer and the impact stress of valve plate are relatively large, which will lead to the fracture in the valve plate. The simulated initial impact location on the head of valve plate is near the oblique incision due to the uneven pressure distribution in the discharge port and the torsional movement of valve plate. The maximum impact stress distribution areas on the valve plate obtained from simulation results are matched with the fracture areas of two valve plate samples, which proves that the simulation results are accurate enough to guide the optimization design of discharge valve in the rotary compressor.

The characteristic of medical personnel resources in the state health care system of the Region

The indicator of provision with medical personnel under primary health care support significantly varies in Subjects of the Russian Federation. This indicator is affected by such territorial characteristics as long distance of territory, poor transport accessibility, low population density, migration processes. The purpose of the study is to analyze indicators of medical personnel resources in state health care system of the Transbaikal Krai. The sources of information were data from forms of Federal statistical monitoring № 30 "Information on the medical organization" of the Krai medical organizations in 2018-2022. The span diagram was made for levels of provision with physicians over 5 year period in regions of the Krai. The cluster analysis was applied to classify municipalities according to level and dynamics of indicators of provision with physicians. It is established that indicators of provision of district therapists and district pediatricians in the Transbaikal Krai remain below similar ones in the Far Eastern Federal Okrug and the Russian Federation. The making of span diagram demonstrated significant difference in indicators of provision with mentioned specialists in municipalities of the Krai over 5 year period that testifies instability of medical personnel situation in districts of the Krai. The maximal indicators of provision in certain regions are conditioned by higher wages and location of medical organizations in the Krai center. The shortage in medical personnel of primary health care is marked in the Krai. In order to implement tasks of overcoming medical personnel shortage, disproportions in structure of medical personnel, uneven territorial distribution of medical specialists in the Krai it is necessary to improve mechanisms of human resources planning.

Variability and Challenges in Pulmonary Rehabilitation Practices across India: Insights from a Nationwide Survey.

Pulmonary rehabilitation (PR) is vital for managing chronic respiratory diseases. This study aimed to assess PR practices in India, focusing on quality standards, provider affiliations, service offerings, and structural components. A survey was conducted among Indian cardiopulmonary physiotherapists via WhatsApp, Facebook, and Gmail, covering demographics, structural, process, and outcome quality indicators, and PR delivery challenges. Of 50 respondents, 54% were affiliated with educational institutions, and 46% with private establishments. Significant variability in PR practices was observed, primarily in urban areas. Key challenges included limited awareness, accessibility issues, inadequate interdisciplinary teamwork, and lack of standardization. Structural elements varied, with inconsistent team compositions and uneven resource distribution. Only 36% of centers conducted regular audit meetings, and many lacked essential emergency equipment. The survey highlights the need for standardized protocols and national guidelines to improve PR service consistency and quality in India. Emphasizing multidisciplinary teams, regular audits, and comprehensive data collection can enhance PR delivery and outcomes. Further research is needed to develop robust, evidence-based PR programs across diverse settings in India.

Temperature- and alkali-resistant induced domestication of Bacillus pasteurii in drilling fluid and its borehole wall enhancement properties

The microbial induced calcium carbonate precipitation (MICP) technology provides a new approach to solve borehole destabilization in broken formations; however, the high-temperature and alkaline environments inhibit the growth of microorganisms, which in turn affects the performance of their wall enhancement performance. In this study, a pH and temperature-coupled induced domestication method was applied to Bacillus pasteurii, and its wall enhancement performance was evaluated. Post domestication, Bacillus pasteurii exhibited high growth activity at pH 10.3 and temperature 45 °C. In a sodium carboxymethyl cellulose (CMC) drilling fluid environment, bacterial concentration reached 1.373 with urease activity at 1.98 after 24 h, and in a xanthan gum (XG) environment, the figures were 0.931 and 1.76, respectively—significantly higher than those before domestication. The Bacillus pasteurii-CMC system exhibited enhanced performance with the unconfined compressive strength of the specimen up to 1.232 MPa, permeability coefficient as low as 0.024, and calcium carbonate production up to 24.685 g. The crushed specimen portions remained lumpy with even calcium carbonate distribution. In contrast, the Bacillus pasteurii-XG system exhibited the highest unconfined compressive strength of 0.561 MPa, lowest permeability coefficient of 0.081, and the greatest calcium carbonate production of 16.03 g, with an externally cemented shell but internally loose structure and uneven calcium carbonate distribution, resulting in weaker mechanical properties. The Bacillus pasteurii induced predominantly vaterite calcium carbonate crystals in the CMC drilling fluid. In the XG drilling fluid, the crystals were mainly calcite. Both types effectively cemented the broken particles, improving formation strength and reducing permeability. However, under the same conditions, the Bacillus pasteurii-CMC system demonstrated a more pronounced enhancement effect.