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Approaching the upper boundary of driver-response relationships: identifying factors using a novel framework

《环境科学与工程前沿（英文）》 2023年 第17卷 第6期 doi: 10.1007/s11783-023-1676-2

摘要：

● A novel framework integrating quantile regression with machine learning is proposed.

关键词： Driver-response     Upper boundary of relationship     Interpretable machine learning     Quantile regression     Total phosphorus     Chlorophyll a    

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Optimum design and preliminary experiments of a novel parallel end traction apparatus for upper-limb

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 726-746 doi: 10.1007/s11465-021-0651-5

摘要： Robot-assisted technology has been increasingly employed in the therapy of post stroke patients to deliver high-quality treatment and alleviate therapists’ burden. This paper introduces a novel parallel end traction apparatus (PETA) to supplement equipment selection. Considering the appearance and performance of the PETA, two types of special five-bar linkage mechanisms are selected as the potential configurations of the actuation execution unit because of their compact arrangement and parallel structure. Kinematic analysis of each mechanism, i.e., position solutions and Jacobian matrix, is carried out. Subsequently, a comparative study between the two mechanisms is conducted. In the established source of nondimensional parameter synthesis, the singularity, maximum continuous workspace, and performance variation trends are analyzed. Based on the evaluation results, the final scheme with determined configuration and corresponding near-optimized nondimensional parameters is obtained. Then, a prototype is constructed. By adding a lockable translational degree of freedom in the vertical direction, the PETA can provide 2D planar exercise and 3D spatial exercise. Finally, a control system is developed for passive exercise mode based on the derived inverse position solution, and preliminary experiments are performed to verify the applicability of the PETA.

关键词： parallel mechanism     upper-limb rehabilitation     singularity and workspace analyses     performance evaluation     optimum design    

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Regeneration of vernacular architecture: new rammed earth houses on the upper reaches of the Yangtze

Jiaping LIU, Rongrong HU, Liu YANG, Runshan WANG,

《能源前沿（英文）》 2010年 第4卷 第1期   页码 93-99 doi: 10.1007/s11708-010-0002-4

摘要： In rural areas of western China, most of the vernacular architectures are made of earth. In the process of urbanization, few residents like to build their houses with earth because the old traditional earth house cannot meet their requirement for higher standard of living. As a result, much more energy will be consumed if industrial building materials are used instead of earth. The regeneration of the traditional earth house, therefore, becomes a challenge in new village construction. This paper briefly describes a project about creating a new prototype of earth house for the migrants along the upper reaches of the Yangtze River to shed light on finding an appropriate approach for regenerating the traditional earth houses with the concept of low-energy housing. It includes an investigation of the traditional earth house and the environment condition of the new settlement, the new house design process, and the quantitative evaluation of the living quality of the new house.

关键词： earth house     low-energy housing     upper reaches of the Yangtze River     passive solar technique    

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Design and preliminary evaluation of an exoskeleton for upper limb resistance training

Tzong-Ming WU, Dar-Zen CHEN

《机械工程前沿（英文）》 2012年 第7卷 第2期   页码 188-198 doi: 10.1007/s11465-012-0327-2

摘要：

Resistance training is a popular form of exercise recommended by national health organizations, such as the American College of Sports Medicine (ACSM) and the American Heart Association (AHA). This form of training is available for most populations. A compact design of upper limb exoskeleton mechanism for home-based resistance training using a spring-loaded upper limb exoskeleton with a three degree-of-freedom shoulder joint and a one degree-of-freedom elbow joint allows a patient or a healthy individual to move the upper limb with multiple joints in different planes. It can continuously increase the resistance by adjusting the spring length to train additional muscle groups and reduce the number of potential injuries to upper limb joints caused by the mass moment of inertia of the training equipment. The aim of this research is to perform a preliminary evaluation of the designed function by adopting an appropriate motion analysis system and experimental design to verify our prototype of the exoskeleton and determine the optimal configuration of the spring-loaded upper limb exoskeleton.

关键词： exoskeleton     free-weight exercise     upper limb     motion analysis    

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Chemically reactive solute transfer in a boundary layer slip flow along a stretching cylinder

Swati Mukhopadhyay

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 385-391 doi: 10.1007/s11705-011-1101-4

摘要： This paper presents the distribution of a solute undergoing a first order chemical reaction in an axisymmetric laminar boundary layer flow along a stretching cylinder. Velocity slip condition at the boundary is used instead of no-slip condition. Similarity transformations are used to convert the partial differential equations corresponding to momentum and concentration into highly nonlinear ordinary differential equations. Numerical solutions of these equations are obtained by the shooting method. The velocity decreases with increasing slip parameter. The skin friction as well as the mass transfer rate at the surface is larger for a cylinder than for a flat plate.

关键词： boundary layer     stretching cylinder     partial slip     mass transfer     similarity solution    

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Controlling nested wrinkle morphology through the boundary effect on narrow-band thin films

Hanyang XU, Tielin SHI, Guanglan LIAO, Qi XIA

《机械工程前沿（英文）》 2019年 第14卷 第2期   页码 235-240 doi: 10.1007/s11465-017-0458-6

摘要： We describe the formation of nested wrinkles created by the thermal mismatch between a narrow-band thin film and a compliant substrate. When a film is described as “narrow-band”, it literally means that the film band width is much shorter than its length; more precisely, it means that the width is comparable with the wavelength of the wrinkles. A silicon mask was used during film sputtering to create narrow-band films on poly (dimethylsiloxane) substrate, thus creating regular boundaries to steer local stresses and control wrinkle morphology. Disordered nano-scale wrinkles were found nested within highly ordered micro-scale sinusoidal wrinkles. The formation of nested wrinkles was explained through the amplitude and wavelength saturation of nano-scale wrinkles. The disordered morphology of nano-scale wrinkles and the highly ordered morphology of micro-scale wrinkles were explained by using the boundary effect.

关键词： nested and hierarchical wrinkles     morphology     amplitude saturation     boundary effect    

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EEG controlled neuromuscular electrical stimulation of the upper limb for stroke patients

Hock Guan TAN, Cheng Yap SHEE, Keng He KONG, Cuntai GUAN, Wei Tech ANG

《机械工程前沿（英文）》 2011年 第6卷 第1期   页码 71-81 doi: 10.1007/s11465-011-0207-1

摘要：

This paper describes the Brain Computer Interface (BCI) system and the experiments to allow post-acute (<3 months) stroke patients to use electroencephalogram (EEG) to trigger neuromuscular electrical stimulation (NMES)-assisted extension of the wrist/fingers, which are essential pre-requisites for useful hand function. EEG was recorded while subjects performed motor imagery of their paretic limb, and then analyzed to determine the optimal frequency range within the -rhythm, with the greatest attenuation. Aided by visual feedback, subjects then trained to regulate their -rhythm EEG to operate the BCI to trigger NMES of the wrist/finger. 6 post-acute stroke patients successfully completed the training, with 4 able to learn to control and use the BCI to initiate NMES. This result is consistent with the reported BCI literacy rate of healthy subjects. Thereafter, without the loss of generality, the controller of the NMES is developed and is based on a model of the upper limb muscle (biceps/triceps) groups to determine the intensity of NMES required to flex or extend the forearm by a specific angle. The muscle model is based on a phenomenological approach, with parameters that are easily measured and conveniently implemented.

关键词： brain computer interface     neuromuscular electrical stimulation     stroke     musculoskeletal modeling    

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CFD Simulation of thermal hydraulic characteristics in a typical upper plenum of RPV

Mingjun WANG, Lianfa WANG, Yingjie WANG, Wenxi TIAN, Jian DENG, Guanghui SU, Suizheng QIU

《能源前沿（英文）》 2021年 第15卷 第4期   页码 930-945 doi: 10.1007/s11708-021-0728-1

摘要： A comparative computational fluid dynamics (CFD) study was conducted on the three different types of pressurized water reactor (PWR) upper plenum, named TYPE 1 (support columns (SCs) and control rod guide tubes (CRGTs) with two large windows), TYPE 2 (SCs and CRGTs without windows), and TYPE 3 (two parallel perforated barrel shells and CRGTs). First, three types of upper plenum geometry information were collected, simplified, and adopted into the BORA facility, which is a 1/5 scale system of the four-loop PWR reactor. Then, the geometry, including the upper half core, upper plenum region, and hot legs, was built using the platform. After that, an unsteady calculation to simulate the reactor balance operation at hot full power scenario was performed. Finally, the differences of flowrate distribution at the core outlet and temperature distribution and transverse velocity inside the hot legs with different upper plenum internals were compared. The results suggest that TYPE 1 upper plenum internals cause the largest flowrate difference at the core outlet while TYPE 3 leads to the most even distributed flowrate. The distribution and evolution pattern of the tangential velocity inside hot legs is highly dependent on the upper plenum internals. Two counter-rotating swirls exist inside the TYPE 1 hot leg and only one swirl revolving around the hog leg axis exist inside the TYPE 2 hot leg. For TYPE 3, two swirls like that of TYPE 1 rotating around the hot leg axis significantly increase the temperature homogenization speed. This research provides meaningful guidelines for the future optimization and design of advanced PWR upper plenum internal structures.

关键词： pressurized water reactor (PWR)     upper plenum     internal structures     temperature distribution     computational fluid dynamics (CFD)    

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Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

《结构与土木工程前沿（英文）》 2021年 第15卷 第6期   页码 1480-1493 doi: 10.1007/s11709-021-0776-y

摘要： In waterfront geotechnical engineering, seismic and drainage conditions must be considered in the design of retaining structures. This paper proposes a general analytical method to evaluate the seismic active earth pressure on a retaining wall with backfill subjected to partial steady seepage flow under seismic conditions. The method comprises the following steps: i) determination of the total head, ii) upper bound solution of seismic active earth thrust, and iii) deduction for the earth pressure distribution. The determination of total head h(x,z) relies on the Fourier series expansions, and the expressions of the seismic active earth thrust and pressure are derived by using the upper bound theorem. Parametric studies reveal that insufficient drainage and earthquakes are crucial factors that cause unfavorable earth pressure. The numerical results confirm the validity of the total head distribution. Comparisons indicate that the proposed method is consistent with other relevant existing methods in terms of predicting seismic active earth pressure. The method can be applied to the seismic design of waterfront retaining walls.

关键词： seismic active earth pressure     partial seepage flow     pore pressure     anisotropy     upper bound theorem    

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Comparison of indirect boundary element and finite element methods A case study: Shiraz-Esfahan railway

Amin MANOUCHEHRIAN, Mohammad Fatehi MARJI, Mohsen MOHEBBI

《结构与土木工程前沿（英文）》 2012年 第6卷 第4期   页码 385-392 doi: 10.1007/s11709-012-0173-7

摘要： Because of the high importance of transportation tunnels, most precise analyses of stress concentration and displacement around them are essential to provide safety of them as much as possible. Recently, various numerical methods such as finite element method (FEM), discrete element method (DEM), finite difference method (FDM) and boundary element method (BEM) have been used extremely in geosciences problems, but among these numerical methods, BEM has been used less than others because the computational algorithm is not so straightforward. This paper suggests the implementation of the indirect boundary element method (IBEM) as a formulation of BEM to analyze displacement around Shiraz-Esfahan railway tunnel in Zagros Mountains southwest of Iran. For this purpose, this tunnel has been modeled numerically using two-dimensional fictitious stress method (TWOFS) algorithm. To validate the results, they were compared with FEM results as a commonly used numerical method. Results of current theoretical study have shown that the presented approach using IBEM is reasonably accurate and can be used for analysis of displacement in geosciences problems. In rock mechanics, for problems with a low ratio of boundary surface to volume, FEM is not very well suited and may be cumbersome, but use of such a proposed IBEM approach can be particularly attractive.

关键词： indirect boundary element method     finite element method     displacement     tunnel     case study    

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Seepage analysis of Upper Gotvand Dam concerning gypsum karstification (2D and 3D approaches)

Jamshid SADREKARIMI, Majid KIYANI, Behnam FAKHRI, Mohammad Javad VAHDATIRAD, Amin BARARI

《结构与土木工程前沿（英文）》 2011年 第5卷 第1期   页码 71-78 doi: 10.1007/s11709-010-0083-5

摘要： Upper Gotvand Dam is constructed on the Karun River at the south west of Iran. In this paper, 2D and 3D models of the dam together with the foundation and abutments were established, and several seepage analyses were carried out. Then, the gypsum veins that are scattered throughout the foundation ground were included in the models, and the seepage pattern, considering the dissolution law of gypsum, was analyzed. It was disclosed that the discharge fluxes obtained from 2D and 3D analyses are not similar, and the discharge flux in 3D model is about four times that of the 2D model. Also, the 3D model locates the phreatic surface somewhat higher than the 2D model. This means that the 2D model estimates lower pore water pressure pattern in comparison with the 3D model. These may be attributed to the fact that with 2D model the lateral components of vectors of seepage velocity are ignored. In the current case, the rate of increase of discharge flux due to dissolution of gypsum veins was obtained to be a third-order function of the aperture width. In spite of the fact that the grout curtain is designed to be about 170 m deep, however, complete dissolve of gypsum will severely increase the discharge flux through the foundation ground.

关键词： Upper Gotvand Dam     seepage analysis     gypsum veins     3D model     discharge flux    

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Expression status of GATA3 and mismatch repair proteins in upper tract urothelial carcinoma

Yue Wang, Jinxia Zhang, Yunfan Wang, Shufang Wang, Yu Zhang, Qi Miao, Fei Gao, Huiying He

《医学前沿（英文）》 2019年 第13卷 第6期   页码 730-740 doi: 10.1007/s11684-019-0687-7

摘要： GATA binding protein 3 (GATA3) and mismatch repair (MMR) deficiency contribute to the development of urothelial carcinoma. However, the combined expression of GATA3 and microsatellite instability (MSI) in upper tract urothelial carcinoma (UTUC) and its prognostic value have not been investigated. Here, we immunohistochemically stained GATA3 and MMR proteins in 108 UTUC samples. GATA3 was positive in 74 cases, and its expression was significantly lower than in adjacent benign urothelium ( <0.001). Loss of GATA3 expression was statistically associated with adverse clinicopathologic parameters, such as advanced stage, lymphovascular invasion, neural invasion, lymph node metastasis, and extensive necrosis. Cancer-specific survival (CSS, =0.028) and disease-free survival (DFS, =0.024) were significantly shorter in patients with GATA3 negative tumors than in patients with GATA3 positive tumors. The absence of MMR proteins was observed in 8.3% of the cases, and focal staining was identified in 13.0%. When using “lax criteria” which resulted in counting cases as negative where MMR staining was in fact focally positive (<5%), we found that GATA3 was inversely associated with MSI ( =0.005). Moreover, GATA3 /microsatellite stability (MS) tumors were correlated with advanced pT stage ( <0.001) and poor outcome ( =0.019 for CSS, =0.016 for DFS) compared with GATA3 /MSI ones. The GATA3 /MSI cases had unfavorable clinical outcomes compared with GATA3 /MSI cases ( =0.008 for CSS, =0.023 for DFS). This finding raises a question as to whether GATA3 interacts with MSI through the TGF- signaling pathway and regulates UTUC progression.

关键词： upper tract urothelial carcinoma     GATA binding protein 3     mismatch repair     microsatellite instability     prognosis    

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Influence of freeze–thaw damage gradient on stress–strain relationship of stressed concrete

《结构与土木工程前沿（英文）》   页码 1326-1340 doi: 10.1007/s11709-023-0014-x

摘要： Influence of freeze–thaw damage gradient on stress–strain relationship of stressed concrete

关键词： strain relationship concrete    

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Engineering the grain boundary: a promising strategy to configure NiCoPO/NiCoP nanowire arrays for ultra-stable

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1259-1267 doi: 10.1007/s11705-021-2132-0

摘要： NiCoP4O12/NiCoP nanorod-like arrays with tunable grain boundary density and pores were synthesized by the processes composed of hydrothermal and pyrolysis, in which, the electron structure of Ni and Co atoms characterized by X-ray photoelectron spectroscopy was contemporaneous inverse manipulated. The optimized NiCoP4O12/NiCoP arrays have a high specific capacitance of 507.8 μAh∙cm–2 at 1 mA∙cm–2, and good rate ability of 64.7% retention at 30-folds increased current density. Importantly, an ultra-stable ability, 88.5% of retention after 10000 cycles, was achieved in an asymmetric cell assembled of the NiCoP4O12/NiCoP arrays with activated carbon. In addition, the energy and power densities of an asymmetric cell were higher than those of other work, demonstrating as-prepared NiCoP4O12/NiCoP arrays are promising electrodes for supercapacitors.

关键词： NiCo     array electrode     grain boundary     stability     supercapacitor    

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Slender reinforced concrete shear walls with high-strength concrete boundary elements

《结构与土木工程前沿（英文）》 2023年 第17卷 第1期   页码 138-151 doi: 10.1007/s11709-022-0897-y

摘要： Reinforced concrete structural walls are commonly used for resisting lateral forces in buildings. Owing to the advancements in the field of concrete materials over the past few decades, concrete mixes of high compressive strength, commonly referred to as high-strength concrete (HSC), have been developed. In this study, the effects of strategic placement of HSC on the performance of slender walls were examined. The finite-element model of a conventional normal-strength concrete (NSC) prototype wall was validated using test data available in extant studies. HSC was incorporated in the boundary elements of the wall to compare its performance with that of the conventional wall at different axial loads. Potential reductions in the reinforcement area and size of the boundary elements were investigated. The HSC wall exhibited improved strength and stiffness, and thereby, allowed reduction in the longitudinal reinforcement area and size of the boundary elements for the same strength of the conventional wall. Cold joints resulting from dissimilar concrete pours in the web and boundary elements of the HSC wall were modeled and their impact on behavior of the wall was examined.

关键词： slender walls     high-strength concrete     rectangular and barbell-shaped walls     cold joints    

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标题 作者 时间 类型 操作

Approaching the upper boundary of driver-response relationships: identifying factors using a novel framework

期刊论文

Optimum design and preliminary experiments of a novel parallel end traction apparatus for upper-limb

期刊论文

Regeneration of vernacular architecture: new rammed earth houses on the upper reaches of the Yangtze

Jiaping LIU, Rongrong HU, Liu YANG, Runshan WANG,

期刊论文

Design and preliminary evaluation of an exoskeleton for upper limb resistance training

Tzong-Ming WU, Dar-Zen CHEN

期刊论文

Chemically reactive solute transfer in a boundary layer slip flow along a stretching cylinder

Swati Mukhopadhyay

期刊论文

Controlling nested wrinkle morphology through the boundary effect on narrow-band thin films

Hanyang XU, Tielin SHI, Guanglan LIAO, Qi XIA

期刊论文

EEG controlled neuromuscular electrical stimulation of the upper limb for stroke patients

Hock Guan TAN, Cheng Yap SHEE, Keng He KONG, Cuntai GUAN, Wei Tech ANG

期刊论文

CFD Simulation of thermal hydraulic characteristics in a typical upper plenum of RPV

Mingjun WANG, Lianfa WANG, Yingjie WANG, Wenxi TIAN, Jian DENG, Guanghui SU, Suizheng QIU

期刊论文

Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

期刊论文

Comparison of indirect boundary element and finite element methods A case study: Shiraz-Esfahan railway

Amin MANOUCHEHRIAN, Mohammad Fatehi MARJI, Mohsen MOHEBBI

期刊论文

Seepage analysis of Upper Gotvand Dam concerning gypsum karstification (2D and 3D approaches)

Jamshid SADREKARIMI, Majid KIYANI, Behnam FAKHRI, Mohammad Javad VAHDATIRAD, Amin BARARI

期刊论文

Expression status of GATA3 and mismatch repair proteins in upper tract urothelial carcinoma

Yue Wang, Jinxia Zhang, Yunfan Wang, Shufang Wang, Yu Zhang, Qi Miao, Fei Gao, Huiying He

期刊论文

Influence of freeze–thaw damage gradient on stress–strain relationship of stressed concrete

期刊论文

Engineering the grain boundary: a promising strategy to configure NiCoPO/NiCoP nanowire arrays for ultra-stable

期刊论文

Slender reinforced concrete shear walls with high-strength concrete boundary elements

期刊论文