The main objective of this study is estimating environmental pollution of hybrid biomass and co-generation power plants. Efficiency of direct tapping of biomass is about 15%-20%. Consequently, about 80% of energy woul...The main objective of this study is estimating environmental pollution of hybrid biomass and co-generation power plants. Efficiency of direct tapping of biomass is about 15%-20%. Consequently, about 80% of energy would be waste in this method. While in co-generation power plant, this number could improve to more than 50%. Therefore, to achieve higher efficiency in utilizing biomass energy, co-generation power plants is proposed by using biogas as fuel instead of natural gas. Proposed system would be supplied thermal and electrical energy for non-urban areas of Iran. In this regard, process of fermentation and gas production from biomass in a vertical digester is studied and simulated using analytic methods. Various factors affecting the fermentation, such as temperature, humidity, PH and optimal conditions for the extraction of gas from waste agriculture and animal are also determined. Comparing between the pollution emission from fossil fuel power plants and power plants fed by biomass shows about 88% reduction in greenhouse emission which significant number.展开更多
This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃...This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃nian in conjunction with a scattering matrix method,the model effectively incorporates quantum confinement,strain effects,and interface states.This robust and numerically stable approach achieves exceptional agreement with experimental data,offering a reliable tool for analyzing and engineering the band structure of complex multi⁃layer systems.展开更多
2025 marks the 30th anniversary of nanoimprint lithography(NIL).Since its inception in 1995,and through global efforts over the past three decades,nanoimprint has emerged as the primary alternative to extreme ultravio...2025 marks the 30th anniversary of nanoimprint lithography(NIL).Since its inception in 1995,and through global efforts over the past three decades,nanoimprint has emerged as the primary alternative to extreme ultraviolet(EUV)lithography for deep-nanoscale silicon(Si)electronics.Numerous semiconductor companies have recognized NIL's manufacturing quality and are actively being evaluated for the production of the most advanced semiconductor devices.Nanoimprinting's potential extends beyond silicon chip fabrication and wafer-scale applica-tions.With its high throughput and 3D patterning capabilities,NIL is becoming a key technology for fabricating emerging devices,such as flat optics and augmented reality glasses.This review summarizes the key developments and applications of nanoimprint lithography,with a particular focus on the latest industry advancements in nano-Si device manufacturing and nanophotonics applications.展开更多
Background In recent years,the demand for interactive photorealistic three-dimensional(3D)environments has increased in various fields,including architecture,engineering,and entertainment.However,achieving a balance b...Background In recent years,the demand for interactive photorealistic three-dimensional(3D)environments has increased in various fields,including architecture,engineering,and entertainment.However,achieving a balance between the quality and efficiency of high-performance 3D applications and virtual reality(VR)remains challenging.Methods This study addresses this issue by revisiting and extending view interpolation for image-based rendering(IBR),which enables the exploration of spacious open environments in 3D and VR.Therefore,we introduce multimorphing,a novel rendering method based on the spatial data structure of 2D image patches,called the image graph.Using this approach,novel views can be rendered with up to six degrees of freedom using only a sparse set of views.The rendering process does not require 3D reconstruction of the geometry or per-pixel depth information,and all relevant data for the output are extracted from the local morphing cells of the image graph.The detection of parallax image regions during preprocessing reduces rendering artifacts by extrapolating image patches from adjacent cells in real-time.In addition,a GPU-based solution was presented to resolve exposure inconsistencies within a dataset,enabling seamless transitions of brightness when moving between areas with varying light intensities.Results Experiments on multiple real-world and synthetic scenes demonstrate that the presented method achieves high"VR-compatible"frame rates,even on mid-range and legacy hardware,respectively.While achieving adequate visual quality even for sparse datasets,it outperforms other IBR and current neural rendering approaches.Conclusions Using the correspondence-based decomposition of input images into morphing cells of 2D image patches,multidimensional image morphing provides high-performance novel view generation,supporting open 3D and VR environments.Nevertheless,the handling of morphing artifacts in the parallax image regions remains a topic for future research.展开更多
Detecting faces under occlusion remains a significant challenge in computer vision due to variations caused by masks,sunglasses,and other obstructions.Addressing this issue is crucial for applications such as surveill...Detecting faces under occlusion remains a significant challenge in computer vision due to variations caused by masks,sunglasses,and other obstructions.Addressing this issue is crucial for applications such as surveillance,biometric authentication,and human-computer interaction.This paper provides a comprehensive review of face detection techniques developed to handle occluded faces.Studies are categorized into four main approaches:feature-based,machine learning-based,deep learning-based,and hybrid methods.We analyzed state-of-the-art studies within each category,examining their methodologies,strengths,and limitations based on widely used benchmark datasets,highlighting their adaptability to partial and severe occlusions.The review also identifies key challenges,including dataset diversity,model generalization,and computational efficiency.Our findings reveal that deep learning methods dominate recent studies,benefiting from their ability to extract hierarchical features and handle complex occlusion patterns.More recently,researchers have increasingly explored Transformer-based architectures,such as Vision Transformer(ViT)and Swin Transformer,to further improve detection robustness under challenging occlusion scenarios.In addition,hybrid approaches,which aim to combine traditional andmodern techniques,are emerging as a promising direction for improving robustness.This review provides valuable insights for researchers aiming to develop more robust face detection systems and for practitioners seeking to deploy reliable solutions in real-world,occlusionprone environments.Further improvements and the proposal of broader datasets are required to developmore scalable,robust,and efficient models that can handle complex occlusions in real-world scenarios.展开更多
Complex physical and chemical reactions during CO_(2)sequestration alter the microscopic pore structure of geological formations,impacting sequestration stability.To investigate CO_(2)sequestration dynamics,comprehens...Complex physical and chemical reactions during CO_(2)sequestration alter the microscopic pore structure of geological formations,impacting sequestration stability.To investigate CO_(2)sequestration dynamics,comprehensive physical simulation experiments were conducted under varied pressures,coupled with assessments of changes in mineral composition,ion concentrations,pore morphology,permeability,and sequestration capacity before and after experimentation.Simultaneously,a method using NMR T2spectra changes to measure pore volume shift and estimate CO_(2)sequestration is introduced.It quantifies CO_(2)needed for mineralization of soluble minerals.However,when CO_(2)dissolves in crude oil,the precipitation of asphaltene compounds impairs both seepage and storage capacities.Notably,the impact of dissolution and precipitation is closely associated with storage pressure,with a particularly pronounced influence on smaller pores.As pressure levels rise,the magnitude of pore alterations progressively increases.At a pressure threshold of 25 MPa,the rate of change in small pores due to dissolution reaches a maximum of 39.14%,while precipitation results in a change rate of-58.05%for small pores.The observed formation of dissolution pores and micro-cracks during dissolution,coupled with asphaltene precipitation,provides crucial insights for establishing CO_(2)sequestration parameters and optimizing strategies in low permeability reservoirs.展开更多
Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we deve...Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.展开更多
In the flotation of rare earth minerals(REMs), oxalic acid is reportedly acting both as a depressant and p H modifier. Although results of testing have established the significance of oxalic acid in the flotation proc...In the flotation of rare earth minerals(REMs), oxalic acid is reportedly acting both as a depressant and p H modifier. Although results of testing have established the significance of oxalic acid in the flotation process, its specific role in either the recovery or selectivity of REMs over their common gangue minerals is not well understood. Pulp p H reduction trials with alternative acids have not shown the same effect on the REMs recovery or the depression of gangue phases. This work studies the effect of oxalic acid on the surface of common REMs gangue minerals(quartz and carbonates(dolomite and calcite)) in a series of conditioning tests. Gangue surface analyses by time of flight secondary ion mass spectroscopy(TOFSIMS) indicate that oxalic acid inhibits the transfer of secondary ions generated during the conditioning process from one mineral to another. In this regard, the oxalate anion acts to fix ions in solution through chelation, limiting their participation in surface adsorption.展开更多
In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with ...In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.展开更多
Flotation is a complex multifaceted process that is widely used for the separation of finely ground minerals. The theory of froth flotation is complex and is not completely understood. This fact has been brought many ...Flotation is a complex multifaceted process that is widely used for the separation of finely ground minerals. The theory of froth flotation is complex and is not completely understood. This fact has been brought many monitoring challenges in a coal processing plant. To solve those challenges, it is important to understand the effect of different parameters on the fine particle separation, and control flotation performance for a particular system. This study is going to indicate the effect of various parameters （particle Characteristics and hydrodynamic conditions） on coal flotation responses （flotation rate constant and recovery） by different modeling techniques. A comprehensive coal flotation database was prepared for the statistical and soft computing methods. Statistical factors were used for variable selections. Results were in a good agreement with recent theoretical flotation investigations. Computational models accurately can estimate flotation rate constant and coal recovery （correlation coefficient 0.85, and 0.99, respectively）. According to the results, it can be concluded that the soft computing models can overcome the complexity of process and be used as an expert system to control, and optimize parameters of coal flotation process.展开更多
A second-order ordinary differential equation model is originally constructed for the phase q current system of a permanent magnet synchronous motor(PMSM).The phase q current model contains the effect of a counter ele...A second-order ordinary differential equation model is originally constructed for the phase q current system of a permanent magnet synchronous motor(PMSM).The phase q current model contains the effect of a counter electromotive force(CEMF),which introduces nonlinearity to the system.In order to compensate the nonlinearity and system uncertainties,a traditional sliding mode controller(SMC)combined with a low-pass filter(also known as a modified SMC)is designed on the phase q current model.The low-pass filter overcomes chattering effects in control efforts,and hence improves the performance of the controller.The phase q current control system is proved to be stable using Lyapunov approach.In addition,an alternative activedisturbance rejection controller(ADRC)with a reduced-order extended state observer(ESO)is applied to control the speed output of PMSM.Both SMC and ADRC are simulated on the PMSM system.The simulation results demonstrate the effectiveness of these two controllers in successfully driving the current and speed outputs to desired values despite load disturbances and system uncertainties.展开更多
Aneuploidy has profound effects on an organism,typically more so than polyploidy,and the basis of this contrast is not fully understood.A dosage series of the maize long arm of chromosome 1(1L)was used to compa re rel...Aneuploidy has profound effects on an organism,typically more so than polyploidy,and the basis of this contrast is not fully understood.A dosage series of the maize long arm of chromosome 1(1L)was used to compa re relative global gene expression in diffe rent types and degrees of aneuploidy to gain insights into how the magnitude of genomic imbalance as well as hypoploidy affects global gene expression.While previously available methods require a selective examination of specific genes,RNA sequencing provides a whole-genome view of gene expression in aneuploids.Most studies of global aneuploidy effects have concentrated on individual types of aneuploids because multiple dose aneuploidies of the same genomic region are difficult to produce in most model genetic organisms.The genetic toolkit of maize allows the examination of multiple ploidies and 1-4 doses of chromosome arms.Thus,a detailed examination of expression changes both on the varied chromosome arms and elsewhere in the genome is possible,in both hypoploids and hyperploids,compared with euploid controls.Previous studies observed the inverse trans effect,in which genes not varied in DNA dosage were expressed in a negative relationship to the varied chromosomal region.This response was also the major type of changes found globally in this study.Many genes varied in dosage showed proportional expression changes,though some were seen to be partly or fully dosage compensated.It was also found that the effects of aneuploidy were progressive,with more severe aneuploids producing effects of greater magnitude.展开更多
Coal and coal combustion byproducts can be considered as an alternative source of rare earth elements and yttrium （REY）. The study of relationships between REY and other main coal properties could have several advan...Coal and coal combustion byproducts can be considered as an alternative source of rare earth elements and yttrium （REY）. The study of relationships between REY and other main coal properties could have several advantages such as estimating REY content of coal particles and designing beneficial extraction method. In this investigation, inter-correlations between REY content with coal parameters （proximate and ash elements） for a wide range of eastern Kentucky coal samples （708 records） were explored. Results demonstrate that zircon and monazite are the main source of heavy and light rare earth elements （HREE and LREE）, respectively. Zr has the highest correlation with Y and Th has the strength relationship with Ce and La. In general, LREE have higher interaction with coal ash content in comparison with HREE. Results indicated that REY can be estimated quite satisfactorily by using their associated elements in coal ash.展开更多
The recent steady improvements in the performance of the nascent hybrid perovskite photovoltaic(PV)devices have led to power conversion efficiencies that rival the best-performing established PV technologies.However,t...The recent steady improvements in the performance of the nascent hybrid perovskite photovoltaic(PV)devices have led to power conversion efficiencies that rival the best-performing established PV technologies.However,to scale these laboratory demonstrations to PV module-scale production will require development of scalable deposition methods for perovskite thin films.Every record result for perovskite PVs so far was achieved via spin coating,a technique that is popular in research laboratories for thin-film coating over relatively small device areas,but not considered to be a method that could be used to scale up the manufacturing of perovskite PVs.Significantly larger thin-film areas are needed for future commercial PV products.Hence,some researchers have focused their efforts on perovskite deposition techniques that can be considered as scalable for mass production and have achieved notable results even on large areas.Here,we present an overview of the solution-based and vapor-based deposition processes;we explain their influence on the molecular crystal growth behavior of perovskite thin films and discuss the morphology as well as other material quality characteristics.By presenting a comprehensive comparison of the deposition techniques and the corresponding performance parameters for different device sizes,we intent to guide the growing research community through the methods that might enable mass production of perovskite solar products.展开更多
In this review article, we present more than a decade of our work on the development of brain–computer interface (BCI)systems for the restoration of walking following neurological injuries such as spinal cord injury ...In this review article, we present more than a decade of our work on the development of brain–computer interface (BCI)systems for the restoration of walking following neurological injuries such as spinal cord injury (SCI) or stroke. Most ofthis work has been in the domain of non-invasive electroencephalogram-based BCIs, including interfacing our system witha virtual reality environment and physical prostheses. Real-time online tests are presented to demonstrate the ability ofable-bodied subjects as well as those with SCI to purposefully operate our BCI system. Extensions of this work are alsopresented and include the development of a portable low-cost BCI suitable for at-home use, our ongoing eforts to develop afully implantable BCI for the restoration of walking and leg sensation after SCI, and our novel BCI-based therapy for strokerehabilitation.展开更多
Information-Centric Networking (ICN) is an innovative paradigm for the future internet architecture, which addresses IP network limitations in supporting content distribution and information access by decoupling conte...Information-Centric Networking (ICN) is an innovative paradigm for the future internet architecture, which addresses IP network limitations in supporting content distribution and information access by decoupling content from hosts and providing the ability to retrieve a content object by its name (identifier), rather than its storage location (IP address). Name resolution and routing is critical for content retrieval in ICN networks. In this research, we perform a comparative study of two widely used classes of ICN name resolution and routing schemes, namely flooding and Distributed Hash Table (DHT). We consider the flooding-based routing in Content-Centric Networks due to its wide acceptance. For the DHT scheme, we design a multi-level DHT that takes into account the underlying network topology and uses name aggregation to further reduce control overhead and improve network efficiency. Then, we compare the characteristics and performance of these two classes of name resolution and routing through extensive simulations. The evaluation results show that the performances of these two approaches are reliant on several factors, including network size, content location dynamics, and content popularity. Our study reveals insights into the design tradeoffs and offers guidelines for design strategies.展开更多
Transition-metal phosphides(TMPs)-based hybrid structure have received considerable attention for efficient sodium storage owing to their high capacity and decent reversibility.However,the volume expansion&the poo...Transition-metal phosphides(TMPs)-based hybrid structure have received considerable attention for efficient sodium storage owing to their high capacity and decent reversibility.However,the volume expansion&the poor electronic conductivity of TMPs,the poor-rate capability,and fast capacity decay greatly hinder its practical application.To address these issues,a low-cost and facile strategy for the synthesis of Ni,N-codoped graphitized carbon(C)and cobalt phosphide(CoP)embedded in carbon fiber(Ni-CoP@CN⊂CF)as self-supporting anode material is demonstrated for the first time.The graphitized carbon and carbon fiber improve the electrical conductivity and inhibit the volume expansion issues.In addition to that,the microporous structure,and ultrasmall sized Ni-CoP offer a high surface area for electrolyte wettability,short Na-ion diffusion path and fast charge transport kinetics.As a result,outstanding electrochemical performance with an average capacity decay of 0.04%cycle^(−1)at 2000 mA g^(−1),an excellent rate capability of 270 mAh g^(−1)@2000 mA g^(−1)and a high energy density of~231.1 Wh kg^(−1)is achieved with binder-free self-supporting anode material.This work shows a potential for designing binder-free and high energy density sodium-ion batteries.展开更多
Considerable amounts of coal particles are accumulated in the tailing dams of washing plants which can make serious environmental problems. Recovery of these particles from tailings has economically and environmentall...Considerable amounts of coal particles are accumulated in the tailing dams of washing plants which can make serious environmental problems. Recovery of these particles from tailings has economically and environmentally several advantages. Maintaining natural resources and reducing discharges to the dams are the most important ones. This study was examined the possibility to recover coal particles from a tailing dam with 56.29% ash content by using series of processing techniques. For this purpose, gravity separation （jig, shaking table and spiral） and flotation tests were conducted to upgrade products. Based the optimum value of these processing methods, a flowsheet was designed to increase the rate of recovery for a wide range of coal particles. Results indicated that the designed circuit can recover over 90% of value coal particles and reduce ash content of product to less than 14%. These results can potentially be used for designing an industrial operation as a recycling plant and an appropriate instance for other areas to reduce the environmental issues of coal tailing dams.展开更多
Advancements in sensor technology have significantly enhanced atmospheric monitoring.Notably,metal oxide and carbon(MO_(x)/C)hybrids have gained attention for their exceptional sensitivity and room-temperature sensing...Advancements in sensor technology have significantly enhanced atmospheric monitoring.Notably,metal oxide and carbon(MO_(x)/C)hybrids have gained attention for their exceptional sensitivity and room-temperature sensing performance.However,previous methods of synthesizing MO_(x)/C composites suffer from problems,including inhomogeneity,aggregation,and challenges in micropatterning.Herein,we introduce a refined method that employs a metal–organic framework(MOF)as a precursor combined with direct laser writing.The inherent structure of MOFs ensures a uniform distribution of metal ions and organic linkers,yielding homogeneous MO_(x)/C structures.The laser processing facilitates precise micropatterning(<2μm,comparable to typical photolithography)of the MO_(x)/C crystals.The optimized MOF-derived MO_(x)/C sensor rapidly detected ethanol gas even at room temperature(105 and 18 s for response and recovery,respectively),with a broad range of sensing performance from 170 to 3,400 ppm and a high response value of up to 3,500%.Additionally,this sensor exhibited enhanced stability and thermal resilience compared to previous MOF-based counterparts.This research opens up promising avenues for practical applications in MOF-derived sensing devices.展开更多
Nowadays short texts can be widely found in various social data in relation to the 5G-enabled Internet of Things (IoT). Short text classification is a challenging task due to its sparsity and the lack of context. Prev...Nowadays short texts can be widely found in various social data in relation to the 5G-enabled Internet of Things (IoT). Short text classification is a challenging task due to its sparsity and the lack of context. Previous studies mainly tackle these problems by enhancing the semantic information or the statistical information individually. However, the improvement achieved by a single type of information is limited, while fusing various information may help to improve the classification accuracy more effectively. To fuse various information for short text classification, this article proposes a feature fusion method that integrates the statistical feature and the comprehensive semantic feature together by using the weighting mechanism and deep learning models. In the proposed method, we apply Bidirectional Encoder Representations from Transformers (BERT) to generate word vectors on the sentence level automatically, and then obtain the statistical feature, the local semantic feature and the overall semantic feature using Term Frequency-Inverse Document Frequency (TF-IDF) weighting approach, Convolutional Neural Network (CNN) and Bidirectional Gate Recurrent Unit (BiGRU). Then, the fusion feature is accordingly obtained for classification. Experiments are conducted on five popular short text classification datasets and a 5G-enabled IoT social dataset and the results show that our proposed method effectively improves the classification performance.展开更多
文摘The main objective of this study is estimating environmental pollution of hybrid biomass and co-generation power plants. Efficiency of direct tapping of biomass is about 15%-20%. Consequently, about 80% of energy would be waste in this method. While in co-generation power plant, this number could improve to more than 50%. Therefore, to achieve higher efficiency in utilizing biomass energy, co-generation power plants is proposed by using biogas as fuel instead of natural gas. Proposed system would be supplied thermal and electrical energy for non-urban areas of Iran. In this regard, process of fermentation and gas production from biomass in a vertical digester is studied and simulated using analytic methods. Various factors affecting the fermentation, such as temperature, humidity, PH and optimal conditions for the extraction of gas from waste agriculture and animal are also determined. Comparing between the pollution emission from fossil fuel power plants and power plants fed by biomass shows about 88% reduction in greenhouse emission which significant number.
文摘This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃nian in conjunction with a scattering matrix method,the model effectively incorporates quantum confinement,strain effects,and interface states.This robust and numerically stable approach achieves exceptional agreement with experimental data,offering a reliable tool for analyzing and engineering the band structure of complex multi⁃layer systems.
基金the National Science Foundation for the partial support(NSF-2213684),and LJG acknowledges an Emmett Leith Collegiate Professorship for this writing.
文摘2025 marks the 30th anniversary of nanoimprint lithography(NIL).Since its inception in 1995,and through global efforts over the past three decades,nanoimprint has emerged as the primary alternative to extreme ultraviolet(EUV)lithography for deep-nanoscale silicon(Si)electronics.Numerous semiconductor companies have recognized NIL's manufacturing quality and are actively being evaluated for the production of the most advanced semiconductor devices.Nanoimprinting's potential extends beyond silicon chip fabrication and wafer-scale applica-tions.With its high throughput and 3D patterning capabilities,NIL is becoming a key technology for fabricating emerging devices,such as flat optics and augmented reality glasses.This review summarizes the key developments and applications of nanoimprint lithography,with a particular focus on the latest industry advancements in nano-Si device manufacturing and nanophotonics applications.
基金Supported by the Bavarian Academic Forum(BayWISS),as a part of the joint academic partnership digitalization program.
文摘Background In recent years,the demand for interactive photorealistic three-dimensional(3D)environments has increased in various fields,including architecture,engineering,and entertainment.However,achieving a balance between the quality and efficiency of high-performance 3D applications and virtual reality(VR)remains challenging.Methods This study addresses this issue by revisiting and extending view interpolation for image-based rendering(IBR),which enables the exploration of spacious open environments in 3D and VR.Therefore,we introduce multimorphing,a novel rendering method based on the spatial data structure of 2D image patches,called the image graph.Using this approach,novel views can be rendered with up to six degrees of freedom using only a sparse set of views.The rendering process does not require 3D reconstruction of the geometry or per-pixel depth information,and all relevant data for the output are extracted from the local morphing cells of the image graph.The detection of parallax image regions during preprocessing reduces rendering artifacts by extrapolating image patches from adjacent cells in real-time.In addition,a GPU-based solution was presented to resolve exposure inconsistencies within a dataset,enabling seamless transitions of brightness when moving between areas with varying light intensities.Results Experiments on multiple real-world and synthetic scenes demonstrate that the presented method achieves high"VR-compatible"frame rates,even on mid-range and legacy hardware,respectively.While achieving adequate visual quality even for sparse datasets,it outperforms other IBR and current neural rendering approaches.Conclusions Using the correspondence-based decomposition of input images into morphing cells of 2D image patches,multidimensional image morphing provides high-performance novel view generation,supporting open 3D and VR environments.Nevertheless,the handling of morphing artifacts in the parallax image regions remains a topic for future research.
基金funded by A’Sharqiyah University,Sultanate of Oman,under Research Project grant number(BFP/RGP/ICT/22/490).
文摘Detecting faces under occlusion remains a significant challenge in computer vision due to variations caused by masks,sunglasses,and other obstructions.Addressing this issue is crucial for applications such as surveillance,biometric authentication,and human-computer interaction.This paper provides a comprehensive review of face detection techniques developed to handle occluded faces.Studies are categorized into four main approaches:feature-based,machine learning-based,deep learning-based,and hybrid methods.We analyzed state-of-the-art studies within each category,examining their methodologies,strengths,and limitations based on widely used benchmark datasets,highlighting their adaptability to partial and severe occlusions.The review also identifies key challenges,including dataset diversity,model generalization,and computational efficiency.Our findings reveal that deep learning methods dominate recent studies,benefiting from their ability to extract hierarchical features and handle complex occlusion patterns.More recently,researchers have increasingly explored Transformer-based architectures,such as Vision Transformer(ViT)and Swin Transformer,to further improve detection robustness under challenging occlusion scenarios.In addition,hybrid approaches,which aim to combine traditional andmodern techniques,are emerging as a promising direction for improving robustness.This review provides valuable insights for researchers aiming to develop more robust face detection systems and for practitioners seeking to deploy reliable solutions in real-world,occlusionprone environments.Further improvements and the proposal of broader datasets are required to developmore scalable,robust,and efficient models that can handle complex occlusions in real-world scenarios.
基金support of the National Natural Science Foundation of China(Grant Nos.52174030,52474042 and 52374041)the Postgraduate Innovation Fund Project of Xi'an Shiyou University(No.YCX2411001)the Natural Science Basic Research Program of Shaanxi(Program Nos.2024JCYBMS-256 and 2022JQ-528)。
文摘Complex physical and chemical reactions during CO_(2)sequestration alter the microscopic pore structure of geological formations,impacting sequestration stability.To investigate CO_(2)sequestration dynamics,comprehensive physical simulation experiments were conducted under varied pressures,coupled with assessments of changes in mineral composition,ion concentrations,pore morphology,permeability,and sequestration capacity before and after experimentation.Simultaneously,a method using NMR T2spectra changes to measure pore volume shift and estimate CO_(2)sequestration is introduced.It quantifies CO_(2)needed for mineralization of soluble minerals.However,when CO_(2)dissolves in crude oil,the precipitation of asphaltene compounds impairs both seepage and storage capacities.Notably,the impact of dissolution and precipitation is closely associated with storage pressure,with a particularly pronounced influence on smaller pores.As pressure levels rise,the magnitude of pore alterations progressively increases.At a pressure threshold of 25 MPa,the rate of change in small pores due to dissolution reaches a maximum of 39.14%,while precipitation results in a change rate of-58.05%for small pores.The observed formation of dissolution pores and micro-cracks during dissolution,coupled with asphaltene precipitation,provides crucial insights for establishing CO_(2)sequestration parameters and optimizing strategies in low permeability reservoirs.
基金supported in part by the National Nature Science Fundation(61174009,61203323)Youth Foundation of Hebei Province(F2016202327)+3 种基金the Colleges and Universities in Hebei Province Science and Technology Research Project(ZC2016020)supported in part by Key Project of NSFC(61533009)111 Project(B08015)Research Project(JCYJ20150403161923519)
文摘Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.
文摘In the flotation of rare earth minerals(REMs), oxalic acid is reportedly acting both as a depressant and p H modifier. Although results of testing have established the significance of oxalic acid in the flotation process, its specific role in either the recovery or selectivity of REMs over their common gangue minerals is not well understood. Pulp p H reduction trials with alternative acids have not shown the same effect on the REMs recovery or the depression of gangue phases. This work studies the effect of oxalic acid on the surface of common REMs gangue minerals(quartz and carbonates(dolomite and calcite)) in a series of conditioning tests. Gangue surface analyses by time of flight secondary ion mass spectroscopy(TOFSIMS) indicate that oxalic acid inhibits the transfer of secondary ions generated during the conditioning process from one mineral to another. In this regard, the oxalate anion acts to fix ions in solution through chelation, limiting their participation in surface adsorption.
基金the council of Iran National Science Foundation and University of Kashan for supporting this work by Grant No (159271/999)
文摘In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.
文摘Flotation is a complex multifaceted process that is widely used for the separation of finely ground minerals. The theory of froth flotation is complex and is not completely understood. This fact has been brought many monitoring challenges in a coal processing plant. To solve those challenges, it is important to understand the effect of different parameters on the fine particle separation, and control flotation performance for a particular system. This study is going to indicate the effect of various parameters （particle Characteristics and hydrodynamic conditions） on coal flotation responses （flotation rate constant and recovery） by different modeling techniques. A comprehensive coal flotation database was prepared for the statistical and soft computing methods. Statistical factors were used for variable selections. Results were in a good agreement with recent theoretical flotation investigations. Computational models accurately can estimate flotation rate constant and coal recovery （correlation coefficient 0.85, and 0.99, respectively）. According to the results, it can be concluded that the soft computing models can overcome the complexity of process and be used as an expert system to control, and optimize parameters of coal flotation process.
文摘A second-order ordinary differential equation model is originally constructed for the phase q current system of a permanent magnet synchronous motor(PMSM).The phase q current model contains the effect of a counter electromotive force(CEMF),which introduces nonlinearity to the system.In order to compensate the nonlinearity and system uncertainties,a traditional sliding mode controller(SMC)combined with a low-pass filter(also known as a modified SMC)is designed on the phase q current model.The low-pass filter overcomes chattering effects in control efforts,and hence improves the performance of the controller.The phase q current control system is proved to be stable using Lyapunov approach.In addition,an alternative activedisturbance rejection controller(ADRC)with a reduced-order extended state observer(ESO)is applied to control the speed output of PMSM.Both SMC and ADRC are simulated on the PMSM system.The simulation results demonstrate the effectiveness of these two controllers in successfully driving the current and speed outputs to desired values despite load disturbances and system uncertainties.
基金This work was supported by the National Science Foundation grants IOS-1545780,NSF 1615789,and NSF 1853556。
文摘Aneuploidy has profound effects on an organism,typically more so than polyploidy,and the basis of this contrast is not fully understood.A dosage series of the maize long arm of chromosome 1(1L)was used to compa re relative global gene expression in diffe rent types and degrees of aneuploidy to gain insights into how the magnitude of genomic imbalance as well as hypoploidy affects global gene expression.While previously available methods require a selective examination of specific genes,RNA sequencing provides a whole-genome view of gene expression in aneuploids.Most studies of global aneuploidy effects have concentrated on individual types of aneuploids because multiple dose aneuploidies of the same genomic region are difficult to produce in most model genetic organisms.The genetic toolkit of maize allows the examination of multiple ploidies and 1-4 doses of chromosome arms.Thus,a detailed examination of expression changes both on the varied chromosome arms and elsewhere in the genome is possible,in both hypoploids and hyperploids,compared with euploid controls.Previous studies observed the inverse trans effect,in which genes not varied in DNA dosage were expressed in a negative relationship to the varied chromosomal region.This response was also the major type of changes found globally in this study.Many genes varied in dosage showed proportional expression changes,though some were seen to be partly or fully dosage compensated.It was also found that the effects of aneuploidy were progressive,with more severe aneuploids producing effects of greater magnitude.
文摘Coal and coal combustion byproducts can be considered as an alternative source of rare earth elements and yttrium （REY）. The study of relationships between REY and other main coal properties could have several advantages such as estimating REY content of coal particles and designing beneficial extraction method. In this investigation, inter-correlations between REY content with coal parameters （proximate and ash elements） for a wide range of eastern Kentucky coal samples （708 records） were explored. Results demonstrate that zircon and monazite are the main source of heavy and light rare earth elements （HREE and LREE）, respectively. Zr has the highest correlation with Y and Th has the strength relationship with Ce and La. In general, LREE have higher interaction with coal ash content in comparison with HREE. Results indicated that REY can be estimated quite satisfactorily by using their associated elements in coal ash.
基金funded by the MIT-Tata Grid Edge Solar research program
文摘The recent steady improvements in the performance of the nascent hybrid perovskite photovoltaic(PV)devices have led to power conversion efficiencies that rival the best-performing established PV technologies.However,to scale these laboratory demonstrations to PV module-scale production will require development of scalable deposition methods for perovskite thin films.Every record result for perovskite PVs so far was achieved via spin coating,a technique that is popular in research laboratories for thin-film coating over relatively small device areas,but not considered to be a method that could be used to scale up the manufacturing of perovskite PVs.Significantly larger thin-film areas are needed for future commercial PV products.Hence,some researchers have focused their efforts on perovskite deposition techniques that can be considered as scalable for mass production and have achieved notable results even on large areas.Here,we present an overview of the solution-based and vapor-based deposition processes;we explain their influence on the molecular crystal growth behavior of perovskite thin films and discuss the morphology as well as other material quality characteristics.By presenting a comprehensive comparison of the deposition techniques and the corresponding performance parameters for different device sizes,we intent to guide the growing research community through the methods that might enable mass production of perovskite solar products.
基金This work was partially supported by the National Science Foundation(award#1646275)the National Institute of Health(project#R01HD095457).
文摘In this review article, we present more than a decade of our work on the development of brain–computer interface (BCI)systems for the restoration of walking following neurological injuries such as spinal cord injury (SCI) or stroke. Most ofthis work has been in the domain of non-invasive electroencephalogram-based BCIs, including interfacing our system witha virtual reality environment and physical prostheses. Real-time online tests are presented to demonstrate the ability ofable-bodied subjects as well as those with SCI to purposefully operate our BCI system. Extensions of this work are alsopresented and include the development of a portable low-cost BCI suitable for at-home use, our ongoing eforts to develop afully implantable BCI for the restoration of walking and leg sensation after SCI, and our novel BCI-based therapy for strokerehabilitation.
文摘Information-Centric Networking (ICN) is an innovative paradigm for the future internet architecture, which addresses IP network limitations in supporting content distribution and information access by decoupling content from hosts and providing the ability to retrieve a content object by its name (identifier), rather than its storage location (IP address). Name resolution and routing is critical for content retrieval in ICN networks. In this research, we perform a comparative study of two widely used classes of ICN name resolution and routing schemes, namely flooding and Distributed Hash Table (DHT). We consider the flooding-based routing in Content-Centric Networks due to its wide acceptance. For the DHT scheme, we design a multi-level DHT that takes into account the underlying network topology and uses name aggregation to further reduce control overhead and improve network efficiency. Then, we compare the characteristics and performance of these two classes of name resolution and routing through extensive simulations. The evaluation results show that the performances of these two approaches are reliant on several factors, including network size, content location dynamics, and content popularity. Our study reveals insights into the design tradeoffs and offers guidelines for design strategies.
基金supported by National Natural Science Foundation of China(Grant No.U1710256,U1810115 and 52072256)ShanXi Science and Technology Major Project(Grant No.20181102018,20181102019 and 20201101016)
文摘Transition-metal phosphides(TMPs)-based hybrid structure have received considerable attention for efficient sodium storage owing to their high capacity and decent reversibility.However,the volume expansion&the poor electronic conductivity of TMPs,the poor-rate capability,and fast capacity decay greatly hinder its practical application.To address these issues,a low-cost and facile strategy for the synthesis of Ni,N-codoped graphitized carbon(C)and cobalt phosphide(CoP)embedded in carbon fiber(Ni-CoP@CN⊂CF)as self-supporting anode material is demonstrated for the first time.The graphitized carbon and carbon fiber improve the electrical conductivity and inhibit the volume expansion issues.In addition to that,the microporous structure,and ultrasmall sized Ni-CoP offer a high surface area for electrolyte wettability,short Na-ion diffusion path and fast charge transport kinetics.As a result,outstanding electrochemical performance with an average capacity decay of 0.04%cycle^(−1)at 2000 mA g^(−1),an excellent rate capability of 270 mAh g^(−1)@2000 mA g^(−1)and a high energy density of~231.1 Wh kg^(−1)is achieved with binder-free self-supporting anode material.This work shows a potential for designing binder-free and high energy density sodium-ion batteries.
文摘Considerable amounts of coal particles are accumulated in the tailing dams of washing plants which can make serious environmental problems. Recovery of these particles from tailings has economically and environmentally several advantages. Maintaining natural resources and reducing discharges to the dams are the most important ones. This study was examined the possibility to recover coal particles from a tailing dam with 56.29% ash content by using series of processing techniques. For this purpose, gravity separation （jig, shaking table and spiral） and flotation tests were conducted to upgrade products. Based the optimum value of these processing methods, a flowsheet was designed to increase the rate of recovery for a wide range of coal particles. Results indicated that the designed circuit can recover over 90% of value coal particles and reduce ash content of product to less than 14%. These results can potentially be used for designing an industrial operation as a recycling plant and an appropriate instance for other areas to reduce the environmental issues of coal tailing dams.
基金supported by the National Research Foundation of Korea(NRF)grants funded by the Ministry of Science and ICT(MSIT)(RS-2023-00251283,and 2022M3D1A2083618)by the Ministry of Education(2020R1A6A1A03040516).
文摘Advancements in sensor technology have significantly enhanced atmospheric monitoring.Notably,metal oxide and carbon(MO_(x)/C)hybrids have gained attention for their exceptional sensitivity and room-temperature sensing performance.However,previous methods of synthesizing MO_(x)/C composites suffer from problems,including inhomogeneity,aggregation,and challenges in micropatterning.Herein,we introduce a refined method that employs a metal–organic framework(MOF)as a precursor combined with direct laser writing.The inherent structure of MOFs ensures a uniform distribution of metal ions and organic linkers,yielding homogeneous MO_(x)/C structures.The laser processing facilitates precise micropatterning(<2μm,comparable to typical photolithography)of the MO_(x)/C crystals.The optimized MOF-derived MO_(x)/C sensor rapidly detected ethanol gas even at room temperature(105 and 18 s for response and recovery,respectively),with a broad range of sensing performance from 170 to 3,400 ppm and a high response value of up to 3,500%.Additionally,this sensor exhibited enhanced stability and thermal resilience compared to previous MOF-based counterparts.This research opens up promising avenues for practical applications in MOF-derived sensing devices.
基金supported in part by the Beijing Natural Science Foundation under grants M21032 and 19L2029in part by the National Natural Science Foundation of China under grants U1836106 and 81961138010in part by the Scientific and Technological Innovation Foundation of Foshan under grants BK21BF001 and BK20BF010.
文摘Nowadays short texts can be widely found in various social data in relation to the 5G-enabled Internet of Things (IoT). Short text classification is a challenging task due to its sparsity and the lack of context. Previous studies mainly tackle these problems by enhancing the semantic information or the statistical information individually. However, the improvement achieved by a single type of information is limited, while fusing various information may help to improve the classification accuracy more effectively. To fuse various information for short text classification, this article proposes a feature fusion method that integrates the statistical feature and the comprehensive semantic feature together by using the weighting mechanism and deep learning models. In the proposed method, we apply Bidirectional Encoder Representations from Transformers (BERT) to generate word vectors on the sentence level automatically, and then obtain the statistical feature, the local semantic feature and the overall semantic feature using Term Frequency-Inverse Document Frequency (TF-IDF) weighting approach, Convolutional Neural Network (CNN) and Bidirectional Gate Recurrent Unit (BiGRU). Then, the fusion feature is accordingly obtained for classification. Experiments are conducted on five popular short text classification datasets and a 5G-enabled IoT social dataset and the results show that our proposed method effectively improves the classification performance.
