The growth of high-quality germanium tin(Ge_(1–y)Sn_(y))binary alloys on a Si substrate using chemical vapor deposition(CVD)techniques holds immense potential for advancing electronics and optoelectronics application...The growth of high-quality germanium tin(Ge_(1–y)Sn_(y))binary alloys on a Si substrate using chemical vapor deposition(CVD)techniques holds immense potential for advancing electronics and optoelectronics applications,including the development of efficient and low-cost mid-infrared detectors and light sources.However,achieving precise control over the Sn concentration and strain relaxation of the Ge_(1–y)Sn_(y)epilayer,which directly influence its optical and electrical properties,remain a significant challenge.In this research,the effect of strain relaxation on the growth rate of Ge_(1–y)Sn_(y)epilayers,with Sn concentration>11at.%,is investigated.It is successfully demonstrated that the growth rate slows down by~55%due to strain relaxation after passing its critical thickness,which suggests a reduction in the incorporation of Ge into Ge_(1–y)Sn_(y)growing layers.Despite the increase in Sn concentration as a result of the decrease in the growth rate,it has been found that the Sn incorporation rate into Ge_(1–y)Sn_(y)growing layers has also decreased due to strain relaxation.Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge_(1–y)Sn_(y)epilayers with tuned Sn concentration and strain relaxation.展开更多
Microstructures determine mechanical properties of steels,but in actual steel product process it is difficult to accurately control the microstructure to meet the requirements.General microstructure characterization m...Microstructures determine mechanical properties of steels,but in actual steel product process it is difficult to accurately control the microstructure to meet the requirements.General microstructure characterization methods are time consuming and results are not rep-resentative for overall quality level as only a fraction of steel sample was selected to be examined.In this paper,a macro and micro coupled 3D model was developed for nondestructively characterization of steel microstructures.For electromagnetic signals analysis,the relative permeability value computed by the micro cellular model can be used in the macro electromagnetic sensor model.The effects of different microstructure components on the relative permeability of duplex stainless steel(grain size,phase fraction,and phase distribu-tion)were discussed.The output inductance of an electromagnetic sensor was determined by relative permeability values and can be val-idated experimentally.The findings indicate that the inductance value of an electromagnetic sensor at low frequency can distinguish dif-ferent microstructures.This method can be applied to real-time on-line characterize steel microstructures in process of steel rolling.展开更多
This study undertakes a thorough analysis of the sentiment within the r/Corona-virus subreddit community regarding COVID-19 vaccines on Reddit. We meticulously collected and processed 34,768 comments, spanning from No...This study undertakes a thorough analysis of the sentiment within the r/Corona-virus subreddit community regarding COVID-19 vaccines on Reddit. We meticulously collected and processed 34,768 comments, spanning from November 20, 2020, to January 17, 2021, using sentiment calculation methods such as TextBlob and Twitter-RoBERTa-Base-sentiment to categorize comments into positive, negative, or neutral sentiments. The methodology involved the use of Count Vectorizer as a vectorization technique and the implementation of advanced ensemble algorithms like XGBoost and Random Forest, achieving an accuracy of approximately 80%. Furthermore, through the Dirichlet latent allocation, we identified 23 distinct reasons for vaccine distrust among negative comments. These findings are crucial for understanding the community’s attitudes towards vaccination and can guide targeted public health messaging. Our study not only provides insights into public opinion during a critical health crisis, but also demonstrates the effectiveness of combining natural language processing tools and ensemble algorithms in sentiment analysis.展开更多
In the process of engineering construction such as tunnels and slopes,rock mass is frequently subjected to multiple levels of loading and unloading,while previous research ignores the impact of unloading rate on the s...In the process of engineering construction such as tunnels and slopes,rock mass is frequently subjected to multiple levels of loading and unloading,while previous research ignores the impact of unloading rate on the stability of rock mass.A number of uniaxial multi-level cyclic loading-unloading experiments were conducted to better understand the effect of unloading rate on the deformation behavior,energy evolution,and damage properties of rock-like material.The experimental results demonstrated that the unloading rate and relative cyclic number clearly influence the deformation behavior and energy evo-lution of rock-like samples.In particular,as the relative cyclic number rises,the total strain and reversible strain both increase linearly,while the total energy density,elastic energy density,and dissipated energy density all rise nonlinearly.In contrast,the irreversible strain first decreases quickly,then stabilizes,and finally rises slowly.As the unloading rate increases,the total strain and reversible strain both increase,while the irreversible strain decreases.The dissipated energy damage was examined in light of the aforementioned experimental findings.The accuracy of the proposed damage model,which takes into account the impact of the unloading rate and relative cyclic number,is then confirmed by examining the consistency between the model predicted and the experimental results.The proposed damage model will make it easier to foresee how the multi-level loading-unloading cycles will affect the rock-like materials.展开更多
Online parameter identification is essential for the accuracy of the battery equivalent circuit model(ECM).The traditional recursive least squares(RLS)method is easily biased with the noise disturbances from sensors,w...Online parameter identification is essential for the accuracy of the battery equivalent circuit model(ECM).The traditional recursive least squares(RLS)method is easily biased with the noise disturbances from sensors,which degrades the modeling accuracy in practice.Meanwhile,the recursive total least squares(RTLS)method can deal with the noise interferences,but the parameter slowly converges to the reference with initial value uncertainty.To alleviate the above issues,this paper proposes a co-estimation framework utilizing the advantages of RLS and RTLS for a higher parameter identification performance of the battery ECM.RLS converges quickly by updating the parameters along the gradient of the cost function.RTLS is applied to attenuate the noise effect once the parameters have converged.Both simulation and experimental results prove that the proposed method has good accuracy,a fast convergence rate,and also robustness against noise corruption.展开更多
Disposing of coal gangue and fly-ash on the surface is a risky method with tremendous potential catastrophic consequences for the environment.Backfill mining is a promising practice for turning those hazardous wastes ...Disposing of coal gangue and fly-ash on the surface is a risky method with tremendous potential catastrophic consequences for the environment.Backfill mining is a promising practice for turning those hazardous wastes into functional backfill materi-als.Unfortunately,how to efficiently deliver the slurry to the desired places remains under-researched.To address this issue,the computational fluid dynamics software Fluent was used in the current study in addition to a laboratory rheological test to simulate the impact of various parameters on the evolution of pressure at a particular section of the pipeline.Furthermore,the response surface method was employed to investigate how the various components and their corresponding influencing weights interact to affect the pressure drop.This study demonstrates that the pressure drop of the slurry is highly influenced by slurry concentration,speed,and pipe diameter.While conveying speed is the main component in the bend section,pipe diameter takes over in the horizontal and vertical pipe sections.展开更多
Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many appli...Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many applications,including oil repellency,liquid/droplet manipulation,anti-icing,heat transfer,water collection,and oil–water separation.In this review,we focus on recent developments in the theory,design,fabrication,and application of bio-inspired MAAMs-SW.We first review the history of the basic theory of special wettability and discuss representative structures and corresponding functions of some biological surfaces,thus setting the stage for the design and fabrication of bio-inspired MAAMs-SW.We then summarize the fabrication methods of special wetting MAAs in terms of three categories:additive manufacturing,subtractive manufacturing,and formative manufacturing,as well as their diverse functional applications,providing insights into the development of these MAAMs-SW.Finally,the challenges and directions of future research on bio-inspired MAAMs-SW are briefy addressed.Worldwide efforts,progress,and breakthroughs from surface engineering to functional applications elaborated herein will promote the practical application of bio-inspired MAAMs-SW.展开更多
铁铬氧化还原液流电池(ICRFB)是一种具有成本效益的可规模化储能系统,其利用资源丰富、低成本的铬和铁作为电解液的活性物质。然而,ICRFB存在Cr^(3+)/Cr^(2+)电化学活性低、负极易产生严重的析氢反应(HER)等问题。本文报道了一种简单的...铁铬氧化还原液流电池(ICRFB)是一种具有成本效益的可规模化储能系统,其利用资源丰富、低成本的铬和铁作为电解液的活性物质。然而,ICRFB存在Cr^(3+)/Cr^(2+)电化学活性低、负极易产生严重的析氢反应(HER)等问题。本文报道了一种简单的合成策略,即通过自聚合和湿化学还原方法结合煅烧处理,在氮掺杂石墨毡(GF)表面沉积了非晶态铋(Bi)纳米颗粒(NPs),其作为ICRFB的负极材料时可展示出高效的电化学性能。生成的BiNPs与H+形成中间体,极大地抑制了HER副反应。此外,Bi的引入和GF表面的N掺杂通过协同作用显著提高了Fe^(2+)/Fe^(3+)和Cr^(3+)/Cr^(2+)的电化学活性,降低了电荷传递电阻,提高了反应传质速率。在不同的电流密度下,经25次循环,库仑效率仍高达97.7%。在60.0 mA cm^(-2)电流密度下,能量效率达到85.8%,超过了许多其他报道的材料。循环100次后容量达到862.7 mAh/L,约为GF的5.3倍。展开更多
Subject identification via the subject’s gait is challenging due to variations in the subject’s carrying and dressing conditions in real-life scenes.This paper proposes a novel targeted 3-dimensional(3D)gait model(3...Subject identification via the subject’s gait is challenging due to variations in the subject’s carrying and dressing conditions in real-life scenes.This paper proposes a novel targeted 3-dimensional(3D)gait model(3DGait)represented by a set of interpretable 3DGait descriptors based on a 3D parametric body model.The 3DGait descriptors are utilised as invariant gait features in the 3DGait recognition method to address object carrying and dressing.The 3DGait recognitionmethod involves 2-dimensional(2D)to 3DGaitdata learningbasedon3Dvirtual samples,a semantic gait parameter estimation Long Short Time Memory(LSTM)network(3D-SGPE-LSTM),a feature fusion deep model based on a multi-set canonical correlation analysis,and SoftMax recognition network.First,a sensory experiment based on 3D body shape and pose deformation with 3D virtual dressing is used to fit 3DGait onto the given 2D gait images.3Dinterpretable semantic parameters control the 3D morphing and dressing involved.Similarity degree measurement determines the semantic descriptors of 2D gait images of subjects with various shapes,poses and styles.Second,using the 2D gait images as input and the subjects’corresponding 3D semantic descriptors as output,an end-to-end 3D-SGPE-LSTM is constructed and trained.Third,body shape,pose and external gait factors(3D-eFactors)are estimated using the 3D-SGPE-LSTM model to create a set of interpretable gait descriptors to represent the 3DGait Model,i.e.,3D intrinsic semantic shape descriptor(3DShape);3D skeleton-based gait pose descriptor(3D-Pose)and 3D dressing with other 3D-eFators.Finally,the 3D-Shape and 3D-Pose descriptors are coupled to a unified pattern space by learning prior knowledge from the 3D-eFators.Practical research on CASIA B,CMU MoBo,TUM GAID and GPJATK databases shows that 3DGait is robust against object carrying and dressing variations,especially under multi-cross variations.展开更多
Dual ion storage hybrid supercapacitors(HsCs)are considered as a promising device to overcome the limited energy density of existing supercapacitors while preserving high power and long cyclability.However,the develop...Dual ion storage hybrid supercapacitors(HsCs)are considered as a promising device to overcome the limited energy density of existing supercapacitors while preserving high power and long cyclability.However,the development of high-capacity anion-storing materials,which can be paired with fast charg-ing capacitive electrodes,lags behind cation-storing counterparts.Herein,we demonstrate the surface faradaic OH-storage mechanism of anion storing perovskite oxide composites and their application in high-performance dual ion HsCs.The oxygen vacancy and nanoparticle size of the reduced LaMnO_(3)(r-LaMnO_(3))were controlled,while r-LaMnO_(3) was chemically coupled with ozonated carbon nanotubes(oCNTs)for the improved anion storing capacity and cycle performance.As taken by in-situ and ex-situ spectroscopic and computational analyses,OH-ions are inserted into the oxygen vacancies coordi-nating with octahedral Mn with the increase in the oxidation state of Mn during the charging process or vice versa.Configuring OH-storing r-LaMnO_(3)/oCNT composite with Na*storing MXene,the as-fabricated aqueous dual ion HSCs achieved the cycle performance of 73.3%over 10,000 cycles,delivering the max-imum energy and power densities of 47.5 w h kg^(-1) and 8 kw kg^(-1),respectively,far exceeding those of previously reported aqueous anion and dual ion storage cells.This research establishes a foundation for the unique anion storage mechanism of the defect engineered perovskite oxides and the advancement of dual ion hybrid energy storage devices with high energy and power densities.展开更多
An online ride-hailing driver(ORHD)refers to a driver who takes orders and provides rental car services to passengers via an online service platform.1 ORHD plays a significant role in the urban transport system worldw...An online ride-hailing driver(ORHD)refers to a driver who takes orders and provides rental car services to passengers via an online service platform.1 ORHD plays a significant role in the urban transport system worldwide,operating through many platforms.According to official data from the Chinese Ministry of Transport,a total of 1.6 million vehicle transport permits were issued by the end of March 2022.展开更多
An AZ41 magnesium alloy in the hot-rolled condition without further thermomechanical processing to modify its microstructure was investigated to establish its suitability for use within a superplastic forming process ...An AZ41 magnesium alloy in the hot-rolled condition without further thermomechanical processing to modify its microstructure was investigated to establish its suitability for use within a superplastic forming process and to establish optimum forming parameters.Formability was assessed using elevated temperature tensile testing and hot gas bulging,across a range of strain rates(1×10^(−1)−1×10^(−3)s^(−1))and temperatures(350−450℃).Circle grid analysis with GOM Aramis cameras was used to understand peak strains and material thinning in relation to industrial forming processes.Post forming EBSD and STEM analysis was conducted to understand the mechanisms responsible for the materials formability,with dynamic recrystallization being clearly evident.Peak elongation of 520%was achieved at 450℃ and 1×10^(−3)s^(−1);industrially relevant elongation was achieved at 1×10^(−2) s^(−1) at both 450℃(195%)and 400℃(170%).展开更多
The compliance modeling is one of the most significant issues in the stage of preliminary design for parallel kinematic machine(PKM). The gravity ignored in traditional compliance analysis has a significant effect o...The compliance modeling is one of the most significant issues in the stage of preliminary design for parallel kinematic machine(PKM). The gravity ignored in traditional compliance analysis has a significant effect on pose accuracy of tool center point(TCP) when a PKM is horizontally placed. By taking gravity into account, this paper presents a semi-analytical approach for compliance analysis of a 3-DOF spindle head named the A3 head. The architecture behind the A3 head is a 3-RPS parallel mechanism having one translational and two rotational movement capabilities, which can be employed to form the main body of a 5-DOF hybrid kinematic machine especially designed for high-speed machining of large aircraft components. The force analysis is carried out by considering both the externally applied wrench imposed upon the platform as well as gravity of all moving components. Then, the deflection analysis is investigated to establish the relationship between the deflection twist and compliances of all joints and links using semi-analytical method. The merits of this approach lie in that platform deflection twist throughout the entire task workspace can be evaluated in a very efficient manner. The effectiveness of the proposed approach is verified by the FEA and experiment at different configurations and the results show that the discrepancy of the compliances is less than 0.04 μm/N^-1 and that of the deformations is less than 10μm. The computational and experimental results show that the deflection twist induced by gravity forces of the moving components has significant bearings on pose accuracy of the platform, providing an informative guidance for the improvement of the current design. The proposed approach can be easily applied to the compliance analysis of PKM by considering gravitational effects and to evaluate the deformation caused by gravity throughout the entire workspace.展开更多
Unifying the models for topology design and kinematic analysis has long been a desire for the research of parallel kinematic machines(PKMs). This requires that analytical description, formulation and operation for bot...Unifying the models for topology design and kinematic analysis has long been a desire for the research of parallel kinematic machines(PKMs). This requires that analytical description, formulation and operation for both finite and instantaneous motions are performed by the same mathematical tool. Based upon finite and instantaneous screw theory, a unified and systematic approach for topology design and kinematic analysis of PKMs is proposed in this paper. Using the derivative mapping between finite and instantaneous screws built in the authors’ previous work, the finite and instantaneous motions of PKMs are analytically described by the simple and non?redundant screws in quasi?vector and vector forms. And topological and parametric models of PKMs are algebraically formulated and related. These related topological and parametric models are ready to do type synthesis and kinematic analysis of PKMs under the unified framework of screw theory. In order to show the validity of the proposed approach, a kind of two?translational and three?rotational(2T3R)5?axis PKMs is taken as example. Numerous new structures of the 2T3R PKMs are synthe?sized as the results of topology design, and their Jacobian matrix is obtained easily for parameter optimization and performance evaluation. Some of the synthesized PKMs have outstanding capabilities in terms of large workspaces and flexible orientations, and have great potential for industrial applications of machining and manufacture. Among them, METROM PKM is a typical example which has attracted a lot of attention from global companies and already been developed as commercial products. The approach is a general and unified approach that can be used in the innovative design of different kinds of PKMs.展开更多
Bile acids(BAs) are essential for the absorption of lipids. BA synthesis is inhibited through intestinal farnesoid X receptor(FXR) activity. BA sequestration is known to influence BA metabolism and control serum lipid...Bile acids(BAs) are essential for the absorption of lipids. BA synthesis is inhibited through intestinal farnesoid X receptor(FXR) activity. BA sequestration is known to influence BA metabolism and control serum lipid concentrations. Animal data has demonstrated a regulatory role for the FXR in triglyceride metabolism. FXR inhibits hepatic lipogenesis by inhibiting the expression of sterol regulatory element binding protein 1c via small heterodimer primer activity. Conversely, FXR promotes free fatty acids oxidation by inducing the expression of peroxisome proliferator-activated receptor α. FXR can reduce the expression of microsomal triglyceride transfer protein, which regulates the assembly of very low-density lipoproteins(VLDL). FXR activation in turn promotes the clearance of circulating triglycerides by inducing apolipoprotein C-Ⅱ, very low-density lipoproteins receptor(VLDL-R) and the expression of Syndecan-1 together with the repression of apolipoprotein C-Ⅲ, which increases lipoprotein lipase activity. There is currently minimal clinical data on triglyceride metabolism in patients with bile acid diarrhoea(BAD). Emerging data suggests that a third of patients with BAD have hypertriglyceridemia. Further research is required to establish the risk of hypertriglyceridaemia in patients with BAD and elicit the mechanisms behind this, allowing for targeted treatment.展开更多
To establish a rapid quantification method for heparinase I during its production in recombinant Escherichia coli, a translational fusion vector was constructed by fusing the N terminus of heparinase I to the C termin...To establish a rapid quantification method for heparinase I during its production in recombinant Escherichia coli, a translational fusion vector was constructed by fusing the N terminus of heparinase I to the C terminus of a green fluorescent protein mutant (GFPmutl). As a result, not only was the functional recombinant expression of heparinase I in E. coli accomplished, but also a linear correlation was obtained between the GFP fluorescence intensity and heparinase I activity, allowing enzyme activity to be quantified rapidly during the fermentation.展开更多
Nature is an information sourcebook of behaviour, function, colour and shape which can inspire visual design and invention. Studying the form and functional characteristics of a natural object can provide inspiration ...Nature is an information sourcebook of behaviour, function, colour and shape which can inspire visual design and invention. Studying the form and functional characteristics of a natural object can provide inspiration for product design and help to improve the marketability of manufactured products. The inspiration can be triggered either by direct observation or captured by three-dimensional (3D) digitising techniques to obtain superficial information (geometry and colour). An art designer often creates a concept in the form of a two-dimensional (2D) sketch while engineering methods lead to a point cloud in 3D. Each has its limitations in that the art designer commonly lacks the knowledge to build a final product from a 2D sketch and the engi- neering designer's 3D point clouds may not be very beautiful. We propose a method for Product Design from Nature (PDN), coupling aesthetic intent and geometrical characteristics, exploring the interactions between designers and nature's systems in PDN. We believe that this approach would considerably reduce the lead time and cost of product design from nature.展开更多
Colorectal cancer(CRC) is a multifactorial disease characterized by several genetic and epigenetic alterations occurring in epithelial cells. It is increasingly recognized that tumour progression is also regulated by ...Colorectal cancer(CRC) is a multifactorial disease characterized by several genetic and epigenetic alterations occurring in epithelial cells. It is increasingly recognized that tumour progression is also regulated by tumour microenvironment(TME). The bidirectional cross-talk between tumour resident adipocytes and cancer cells within TME has been proposed as active contributor to carcinogenesis. Tumour resident adipocytes exhibit an activated phenotype characterized by increased secretion of pro-tumorigenic factors(angiogenic/inflammatory/immune) which contribute to cancer cell proliferation, invasion, neoangiogenesis, evasion of immune surveillance and therapy resistance. Furthermore, adipocytes represent a fuel rich source for increasing energy demand of rapidly proliferating tumour cells. Interestingly, a relationship between obesity and molecular variants in CRC has recently been identified. Whether adipose tissue promotes cancer progression in subsets of molecular phenotypes or whether local tissue adipocytes are involved in inactivation of tumour suppressor genes and/or activation of oncogenes still needs to be explored. This editorial highlights the major findings related to crosstalk between adipocytes and colon cancer cells and how local paracrine interactions may promote cancer progression. Furthermore, we provide future strategies in studying colonic TME which could provide insights in bidirectional cross-talk mechanisms between adipocytes and colonic epithelial cells. This could enable to decipher critical signalling pathways of both early colonic carcinogenesis and cancer progression.展开更多
3D printing of functional energy storage devices is receiving escalating attention over the years due to the customizable manufacturing flexibility and imparted high areal and gravimetric energy density of three-dimen...3D printing of functional energy storage devices is receiving escalating attention over the years due to the customizable manufacturing flexibility and imparted high areal and gravimetric energy density of three-dimensional structured devices, which contribute to the creation of numerous new opportunities for futuristic electronics. Graphene-based inks are ideal elements for the realization of 3D printed energy storage devices if the attractive intrinsic physiochemical properties of graphene could be preserved. However, it is still a great challenge to prepare uniformly dispersed graphene-based materials with desired rheological properties for 3D printing. Here we report a facile strategy for 3D printing of supercapacitors from a highly concentrated graphene oxide (GO) ink. The GO is properly dispersed and the ink fulfills the stringent rheological specifications for 3D printing. The printed GO electrode is functionalized with enhanced structural stability for proper reduction to graphene. The printed supercapacitors deliver the potential to linearly scale up in areal capacitance without jeopardizing the gravimetric capacitance when increasing printed layers. The results hold great promise for the construction of 3D structured energy storage devices that cater to the challenges from next-generation electronics.展开更多
With the rising global prevalence in diabetes, healthcare systems are facing a growing challenge to provide efficient and effective diabetes care management in the face of spiralling treatment costs. Diabetes is a maj...With the rising global prevalence in diabetes, healthcare systems are facing a growing challenge to provide efficient and effective diabetes care management in the face of spiralling treatment costs. Diabetes is a major cause of premature mortality and associated with devastating complications especially if managed poorly. Although diabetes care is improving in England and Wales, recent audit data suggests care remains imperfect with wide geographical variations in quality. Diabetes care is expensive with a sizeable amount of available expenditure used for treating the complications of diabetes. A target driven, long-term, multifactorial intervention in patients with type 2 diabetes has been shown to reduce mortality and morbidity. The alphabet strategy is a novel approach to effective diabetes care provision, aiming to address patient education and empowerment, provide consistent comprehensive care delivered in a timely fashion, and allowing multidisciplinary team work.展开更多
文摘The growth of high-quality germanium tin(Ge_(1–y)Sn_(y))binary alloys on a Si substrate using chemical vapor deposition(CVD)techniques holds immense potential for advancing electronics and optoelectronics applications,including the development of efficient and low-cost mid-infrared detectors and light sources.However,achieving precise control over the Sn concentration and strain relaxation of the Ge_(1–y)Sn_(y)epilayer,which directly influence its optical and electrical properties,remain a significant challenge.In this research,the effect of strain relaxation on the growth rate of Ge_(1–y)Sn_(y)epilayers,with Sn concentration>11at.%,is investigated.It is successfully demonstrated that the growth rate slows down by~55%due to strain relaxation after passing its critical thickness,which suggests a reduction in the incorporation of Ge into Ge_(1–y)Sn_(y)growing layers.Despite the increase in Sn concentration as a result of the decrease in the growth rate,it has been found that the Sn incorporation rate into Ge_(1–y)Sn_(y)growing layers has also decreased due to strain relaxation.Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge_(1–y)Sn_(y)epilayers with tuned Sn concentration and strain relaxation.
基金supported by the National Natural Science Foundation of China(No.52204340)the Natural Science Foundation of Guangxi,China(No.2022GXNSFBA035621)The authors wish to thank the Advanced Manufacturing and Materials Centre from Warwick Manufacturing Group(WMG),University of Warwick for the provision of facilities and equipment.
文摘Microstructures determine mechanical properties of steels,but in actual steel product process it is difficult to accurately control the microstructure to meet the requirements.General microstructure characterization methods are time consuming and results are not rep-resentative for overall quality level as only a fraction of steel sample was selected to be examined.In this paper,a macro and micro coupled 3D model was developed for nondestructively characterization of steel microstructures.For electromagnetic signals analysis,the relative permeability value computed by the micro cellular model can be used in the macro electromagnetic sensor model.The effects of different microstructure components on the relative permeability of duplex stainless steel(grain size,phase fraction,and phase distribu-tion)were discussed.The output inductance of an electromagnetic sensor was determined by relative permeability values and can be val-idated experimentally.The findings indicate that the inductance value of an electromagnetic sensor at low frequency can distinguish dif-ferent microstructures.This method can be applied to real-time on-line characterize steel microstructures in process of steel rolling.
文摘This study undertakes a thorough analysis of the sentiment within the r/Corona-virus subreddit community regarding COVID-19 vaccines on Reddit. We meticulously collected and processed 34,768 comments, spanning from November 20, 2020, to January 17, 2021, using sentiment calculation methods such as TextBlob and Twitter-RoBERTa-Base-sentiment to categorize comments into positive, negative, or neutral sentiments. The methodology involved the use of Count Vectorizer as a vectorization technique and the implementation of advanced ensemble algorithms like XGBoost and Random Forest, achieving an accuracy of approximately 80%. Furthermore, through the Dirichlet latent allocation, we identified 23 distinct reasons for vaccine distrust among negative comments. These findings are crucial for understanding the community’s attitudes towards vaccination and can guide targeted public health messaging. Our study not only provides insights into public opinion during a critical health crisis, but also demonstrates the effectiveness of combining natural language processing tools and ensemble algorithms in sentiment analysis.
基金the Water Conservancy Science and Technology Major Project of Hunan Province,China(Project XSKJ2019081-10)the China Scholarship Council(Grant No.202006370344)the First-class Project Special Funding of Yellow River Laboratory,China(Grant No.YRL22YL07).
文摘In the process of engineering construction such as tunnels and slopes,rock mass is frequently subjected to multiple levels of loading and unloading,while previous research ignores the impact of unloading rate on the stability of rock mass.A number of uniaxial multi-level cyclic loading-unloading experiments were conducted to better understand the effect of unloading rate on the deformation behavior,energy evolution,and damage properties of rock-like material.The experimental results demonstrated that the unloading rate and relative cyclic number clearly influence the deformation behavior and energy evo-lution of rock-like samples.In particular,as the relative cyclic number rises,the total strain and reversible strain both increase linearly,while the total energy density,elastic energy density,and dissipated energy density all rise nonlinearly.In contrast,the irreversible strain first decreases quickly,then stabilizes,and finally rises slowly.As the unloading rate increases,the total strain and reversible strain both increase,while the irreversible strain decreases.The dissipated energy damage was examined in light of the aforementioned experimental findings.The accuracy of the proposed damage model,which takes into account the impact of the unloading rate and relative cyclic number,is then confirmed by examining the consistency between the model predicted and the experimental results.The proposed damage model will make it easier to foresee how the multi-level loading-unloading cycles will affect the rock-like materials.
基金National Natural Science Foundation of China(Grant No.52107229)the Fund of Robot Technology Used for Special Environment Key Laboratory of Sichuan Province(Grant No.20KFKT02)。
文摘Online parameter identification is essential for the accuracy of the battery equivalent circuit model(ECM).The traditional recursive least squares(RLS)method is easily biased with the noise disturbances from sensors,which degrades the modeling accuracy in practice.Meanwhile,the recursive total least squares(RTLS)method can deal with the noise interferences,but the parameter slowly converges to the reference with initial value uncertainty.To alleviate the above issues,this paper proposes a co-estimation framework utilizing the advantages of RLS and RTLS for a higher parameter identification performance of the battery ECM.RLS converges quickly by updating the parameters along the gradient of the cost function.RTLS is applied to attenuate the noise effect once the parameters have converged.Both simulation and experimental results prove that the proposed method has good accuracy,a fast convergence rate,and also robustness against noise corruption.
文摘Disposing of coal gangue and fly-ash on the surface is a risky method with tremendous potential catastrophic consequences for the environment.Backfill mining is a promising practice for turning those hazardous wastes into functional backfill materi-als.Unfortunately,how to efficiently deliver the slurry to the desired places remains under-researched.To address this issue,the computational fluid dynamics software Fluent was used in the current study in addition to a laboratory rheological test to simulate the impact of various parameters on the evolution of pressure at a particular section of the pipeline.Furthermore,the response surface method was employed to investigate how the various components and their corresponding influencing weights interact to affect the pressure drop.This study demonstrates that the pressure drop of the slurry is highly influenced by slurry concentration,speed,and pipe diameter.While conveying speed is the main component in the bend section,pipe diameter takes over in the horizontal and vertical pipe sections.
基金supported by the National Defense Basic Scientific Research Project(No.JCKY2020210B001)the National Natural Science Foundation of China(No.U19A20103),the China Postdoctoral Science Foundation(No.2019M661184)+2 种基金the Jilin Province Scientific and Technological Development Program(No.YDZJ202101ZYTS025)the Jilin Province Young Science and Technology Talent Lift Project(No.QT202030)the Science and Technology Innovation Fund of CUST(No.XJJLG-2019-05)。
文摘Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many applications,including oil repellency,liquid/droplet manipulation,anti-icing,heat transfer,water collection,and oil–water separation.In this review,we focus on recent developments in the theory,design,fabrication,and application of bio-inspired MAAMs-SW.We first review the history of the basic theory of special wettability and discuss representative structures and corresponding functions of some biological surfaces,thus setting the stage for the design and fabrication of bio-inspired MAAMs-SW.We then summarize the fabrication methods of special wetting MAAs in terms of three categories:additive manufacturing,subtractive manufacturing,and formative manufacturing,as well as their diverse functional applications,providing insights into the development of these MAAMs-SW.Finally,the challenges and directions of future research on bio-inspired MAAMs-SW are briefy addressed.Worldwide efforts,progress,and breakthroughs from surface engineering to functional applications elaborated herein will promote the practical application of bio-inspired MAAMs-SW.
文摘铁铬氧化还原液流电池(ICRFB)是一种具有成本效益的可规模化储能系统,其利用资源丰富、低成本的铬和铁作为电解液的活性物质。然而,ICRFB存在Cr^(3+)/Cr^(2+)电化学活性低、负极易产生严重的析氢反应(HER)等问题。本文报道了一种简单的合成策略,即通过自聚合和湿化学还原方法结合煅烧处理,在氮掺杂石墨毡(GF)表面沉积了非晶态铋(Bi)纳米颗粒(NPs),其作为ICRFB的负极材料时可展示出高效的电化学性能。生成的BiNPs与H+形成中间体,极大地抑制了HER副反应。此外,Bi的引入和GF表面的N掺杂通过协同作用显著提高了Fe^(2+)/Fe^(3+)和Cr^(3+)/Cr^(2+)的电化学活性,降低了电荷传递电阻,提高了反应传质速率。在不同的电流密度下,经25次循环,库仑效率仍高达97.7%。在60.0 mA cm^(-2)电流密度下,能量效率达到85.8%,超过了许多其他报道的材料。循环100次后容量达到862.7 mAh/L,约为GF的5.3倍。
基金funded by the Research Foundation of Education Bureau of Hunan Province,China,under Grant Number 21B0060the National Natural Science Foundation of China,under Grant Number 61701179.
文摘Subject identification via the subject’s gait is challenging due to variations in the subject’s carrying and dressing conditions in real-life scenes.This paper proposes a novel targeted 3-dimensional(3D)gait model(3DGait)represented by a set of interpretable 3DGait descriptors based on a 3D parametric body model.The 3DGait descriptors are utilised as invariant gait features in the 3DGait recognition method to address object carrying and dressing.The 3DGait recognitionmethod involves 2-dimensional(2D)to 3DGaitdata learningbasedon3Dvirtual samples,a semantic gait parameter estimation Long Short Time Memory(LSTM)network(3D-SGPE-LSTM),a feature fusion deep model based on a multi-set canonical correlation analysis,and SoftMax recognition network.First,a sensory experiment based on 3D body shape and pose deformation with 3D virtual dressing is used to fit 3DGait onto the given 2D gait images.3Dinterpretable semantic parameters control the 3D morphing and dressing involved.Similarity degree measurement determines the semantic descriptors of 2D gait images of subjects with various shapes,poses and styles.Second,using the 2D gait images as input and the subjects’corresponding 3D semantic descriptors as output,an end-to-end 3D-SGPE-LSTM is constructed and trained.Third,body shape,pose and external gait factors(3D-eFactors)are estimated using the 3D-SGPE-LSTM model to create a set of interpretable gait descriptors to represent the 3DGait Model,i.e.,3D intrinsic semantic shape descriptor(3DShape);3D skeleton-based gait pose descriptor(3D-Pose)and 3D dressing with other 3D-eFators.Finally,the 3D-Shape and 3D-Pose descriptors are coupled to a unified pattern space by learning prior knowledge from the 3D-eFators.Practical research on CASIA B,CMU MoBo,TUM GAID and GPJATK databases shows that 3DGait is robust against object carrying and dressing variations,especially under multi-cross variations.
基金supported by the National Research Foundation of Korea grant funded by the Korea government(MSIT)(NRF-2020R1A3B2079803)the computational time provided by KISTI(KSC-2023-CRE-0166).
文摘Dual ion storage hybrid supercapacitors(HsCs)are considered as a promising device to overcome the limited energy density of existing supercapacitors while preserving high power and long cyclability.However,the development of high-capacity anion-storing materials,which can be paired with fast charg-ing capacitive electrodes,lags behind cation-storing counterparts.Herein,we demonstrate the surface faradaic OH-storage mechanism of anion storing perovskite oxide composites and their application in high-performance dual ion HsCs.The oxygen vacancy and nanoparticle size of the reduced LaMnO_(3)(r-LaMnO_(3))were controlled,while r-LaMnO_(3) was chemically coupled with ozonated carbon nanotubes(oCNTs)for the improved anion storing capacity and cycle performance.As taken by in-situ and ex-situ spectroscopic and computational analyses,OH-ions are inserted into the oxygen vacancies coordi-nating with octahedral Mn with the increase in the oxidation state of Mn during the charging process or vice versa.Configuring OH-storing r-LaMnO_(3)/oCNT composite with Na*storing MXene,the as-fabricated aqueous dual ion HSCs achieved the cycle performance of 73.3%over 10,000 cycles,delivering the max-imum energy and power densities of 47.5 w h kg^(-1) and 8 kw kg^(-1),respectively,far exceeding those of previously reported aqueous anion and dual ion storage cells.This research establishes a foundation for the unique anion storage mechanism of the defect engineered perovskite oxides and the advancement of dual ion hybrid energy storage devices with high energy and power densities.
基金This research received funds from National Social Science Fund of China(22&ZD142).
文摘An online ride-hailing driver(ORHD)refers to a driver who takes orders and provides rental car services to passengers via an online service platform.1 ORHD plays a significant role in the urban transport system worldwide,operating through many platforms.According to official data from the Chinese Ministry of Transport,a total of 1.6 million vehicle transport permits were issued by the end of March 2022.
基金The authors would like to thank the WMG High Value Manufacturing Catapult Centre for funding this work.In addition,the characterisation facility is supported from the Higher Education Funding Council for England(HEFCE).
文摘An AZ41 magnesium alloy in the hot-rolled condition without further thermomechanical processing to modify its microstructure was investigated to establish its suitability for use within a superplastic forming process and to establish optimum forming parameters.Formability was assessed using elevated temperature tensile testing and hot gas bulging,across a range of strain rates(1×10^(−1)−1×10^(−3)s^(−1))and temperatures(350−450℃).Circle grid analysis with GOM Aramis cameras was used to understand peak strains and material thinning in relation to industrial forming processes.Post forming EBSD and STEM analysis was conducted to understand the mechanisms responsible for the materials formability,with dynamic recrystallization being clearly evident.Peak elongation of 520%was achieved at 450℃ and 1×10^(−3)s^(−1);industrially relevant elongation was achieved at 1×10^(−2) s^(−1) at both 450℃(195%)and 400℃(170%).
基金Supported by National Natural Science Foundation of China(Grant No.51135008)PhD Programs Foundation of Ministry of Education of China(Grant No.20110032130006)
文摘The compliance modeling is one of the most significant issues in the stage of preliminary design for parallel kinematic machine(PKM). The gravity ignored in traditional compliance analysis has a significant effect on pose accuracy of tool center point(TCP) when a PKM is horizontally placed. By taking gravity into account, this paper presents a semi-analytical approach for compliance analysis of a 3-DOF spindle head named the A3 head. The architecture behind the A3 head is a 3-RPS parallel mechanism having one translational and two rotational movement capabilities, which can be employed to form the main body of a 5-DOF hybrid kinematic machine especially designed for high-speed machining of large aircraft components. The force analysis is carried out by considering both the externally applied wrench imposed upon the platform as well as gravity of all moving components. Then, the deflection analysis is investigated to establish the relationship between the deflection twist and compliances of all joints and links using semi-analytical method. The merits of this approach lie in that platform deflection twist throughout the entire task workspace can be evaluated in a very efficient manner. The effectiveness of the proposed approach is verified by the FEA and experiment at different configurations and the results show that the discrepancy of the compliances is less than 0.04 μm/N^-1 and that of the deformations is less than 10μm. The computational and experimental results show that the deflection twist induced by gravity forces of the moving components has significant bearings on pose accuracy of the platform, providing an informative guidance for the improvement of the current design. The proposed approach can be easily applied to the compliance analysis of PKM by considering gravitational effects and to evaluate the deformation caused by gravity throughout the entire workspace.
基金Supported by National Natural Science Foundation of China(Grant No.51675366)Tianjin Research Program of Application Foundation and Advanced Technology(Grant Nos.16JCYBJC19300,15JCZDJC38900)
文摘Unifying the models for topology design and kinematic analysis has long been a desire for the research of parallel kinematic machines(PKMs). This requires that analytical description, formulation and operation for both finite and instantaneous motions are performed by the same mathematical tool. Based upon finite and instantaneous screw theory, a unified and systematic approach for topology design and kinematic analysis of PKMs is proposed in this paper. Using the derivative mapping between finite and instantaneous screws built in the authors’ previous work, the finite and instantaneous motions of PKMs are analytically described by the simple and non?redundant screws in quasi?vector and vector forms. And topological and parametric models of PKMs are algebraically formulated and related. These related topological and parametric models are ready to do type synthesis and kinematic analysis of PKMs under the unified framework of screw theory. In order to show the validity of the proposed approach, a kind of two?translational and three?rotational(2T3R)5?axis PKMs is taken as example. Numerous new structures of the 2T3R PKMs are synthe?sized as the results of topology design, and their Jacobian matrix is obtained easily for parameter optimization and performance evaluation. Some of the synthesized PKMs have outstanding capabilities in terms of large workspaces and flexible orientations, and have great potential for industrial applications of machining and manufacture. Among them, METROM PKM is a typical example which has attracted a lot of attention from global companies and already been developed as commercial products. The approach is a general and unified approach that can be used in the innovative design of different kinds of PKMs.
基金the BRET (Bardhan Research Education Trust) charity, which has supported funding for materials and equipment costs
文摘Bile acids(BAs) are essential for the absorption of lipids. BA synthesis is inhibited through intestinal farnesoid X receptor(FXR) activity. BA sequestration is known to influence BA metabolism and control serum lipid concentrations. Animal data has demonstrated a regulatory role for the FXR in triglyceride metabolism. FXR inhibits hepatic lipogenesis by inhibiting the expression of sterol regulatory element binding protein 1c via small heterodimer primer activity. Conversely, FXR promotes free fatty acids oxidation by inducing the expression of peroxisome proliferator-activated receptor α. FXR can reduce the expression of microsomal triglyceride transfer protein, which regulates the assembly of very low-density lipoproteins(VLDL). FXR activation in turn promotes the clearance of circulating triglycerides by inducing apolipoprotein C-Ⅱ, very low-density lipoproteins receptor(VLDL-R) and the expression of Syndecan-1 together with the repression of apolipoprotein C-Ⅲ, which increases lipoprotein lipase activity. There is currently minimal clinical data on triglyceride metabolism in patients with bile acid diarrhoea(BAD). Emerging data suggests that a third of patients with BAD have hypertriglyceridemia. Further research is required to establish the risk of hypertriglyceridaemia in patients with BAD and elicit the mechanisms behind this, allowing for targeted treatment.
基金Supported by the National Natural Science Foundation of China (No.20336010 and No.20176025).
文摘To establish a rapid quantification method for heparinase I during its production in recombinant Escherichia coli, a translational fusion vector was constructed by fusing the N terminus of heparinase I to the C terminus of a green fluorescent protein mutant (GFPmutl). As a result, not only was the functional recombinant expression of heparinase I in E. coli accomplished, but also a linear correlation was obtained between the GFP fluorescence intensity and heparinase I activity, allowing enzyme activity to be quantified rapidly during the fermentation.
文摘Nature is an information sourcebook of behaviour, function, colour and shape which can inspire visual design and invention. Studying the form and functional characteristics of a natural object can provide inspiration for product design and help to improve the marketability of manufactured products. The inspiration can be triggered either by direct observation or captured by three-dimensional (3D) digitising techniques to obtain superficial information (geometry and colour). An art designer often creates a concept in the form of a two-dimensional (2D) sketch while engineering methods lead to a point cloud in 3D. Each has its limitations in that the art designer commonly lacks the knowledge to build a final product from a 2D sketch and the engi- neering designer's 3D point clouds may not be very beautiful. We propose a method for Product Design from Nature (PDN), coupling aesthetic intent and geometrical characteristics, exploring the interactions between designers and nature's systems in PDN. We believe that this approach would considerably reduce the lead time and cost of product design from nature.
文摘Colorectal cancer(CRC) is a multifactorial disease characterized by several genetic and epigenetic alterations occurring in epithelial cells. It is increasingly recognized that tumour progression is also regulated by tumour microenvironment(TME). The bidirectional cross-talk between tumour resident adipocytes and cancer cells within TME has been proposed as active contributor to carcinogenesis. Tumour resident adipocytes exhibit an activated phenotype characterized by increased secretion of pro-tumorigenic factors(angiogenic/inflammatory/immune) which contribute to cancer cell proliferation, invasion, neoangiogenesis, evasion of immune surveillance and therapy resistance. Furthermore, adipocytes represent a fuel rich source for increasing energy demand of rapidly proliferating tumour cells. Interestingly, a relationship between obesity and molecular variants in CRC has recently been identified. Whether adipose tissue promotes cancer progression in subsets of molecular phenotypes or whether local tissue adipocytes are involved in inactivation of tumour suppressor genes and/or activation of oncogenes still needs to be explored. This editorial highlights the major findings related to crosstalk between adipocytes and colon cancer cells and how local paracrine interactions may promote cancer progression. Furthermore, we provide future strategies in studying colonic TME which could provide insights in bidirectional cross-talk mechanisms between adipocytes and colonic epithelial cells. This could enable to decipher critical signalling pathways of both early colonic carcinogenesis and cancer progression.
基金financially supported by the National Key R&D Program of China (no. 2017YFE0111500)the National Natural Science Foundation of China (nos. 51673123 and 51222305 and 51803141)Sichuan Province Science and Technology Project (no. 2016JQ0049)
文摘3D printing of functional energy storage devices is receiving escalating attention over the years due to the customizable manufacturing flexibility and imparted high areal and gravimetric energy density of three-dimensional structured devices, which contribute to the creation of numerous new opportunities for futuristic electronics. Graphene-based inks are ideal elements for the realization of 3D printed energy storage devices if the attractive intrinsic physiochemical properties of graphene could be preserved. However, it is still a great challenge to prepare uniformly dispersed graphene-based materials with desired rheological properties for 3D printing. Here we report a facile strategy for 3D printing of supercapacitors from a highly concentrated graphene oxide (GO) ink. The GO is properly dispersed and the ink fulfills the stringent rheological specifications for 3D printing. The printed GO electrode is functionalized with enhanced structural stability for proper reduction to graphene. The printed supercapacitors deliver the potential to linearly scale up in areal capacitance without jeopardizing the gravimetric capacitance when increasing printed layers. The results hold great promise for the construction of 3D structured energy storage devices that cater to the challenges from next-generation electronics.
文摘With the rising global prevalence in diabetes, healthcare systems are facing a growing challenge to provide efficient and effective diabetes care management in the face of spiralling treatment costs. Diabetes is a major cause of premature mortality and associated with devastating complications especially if managed poorly. Although diabetes care is improving in England and Wales, recent audit data suggests care remains imperfect with wide geographical variations in quality. Diabetes care is expensive with a sizeable amount of available expenditure used for treating the complications of diabetes. A target driven, long-term, multifactorial intervention in patients with type 2 diabetes has been shown to reduce mortality and morbidity. The alphabet strategy is a novel approach to effective diabetes care provision, aiming to address patient education and empowerment, provide consistent comprehensive care delivered in a timely fashion, and allowing multidisciplinary team work.