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Probability distributions of arsenic in soil from brownfield sites in Beijing (China): statistical characterization of the background populations and implications for site assessment studies

Marina ACCORNERO,Lin JIANG,Eugenio NAPOLI,Marco CREMONINI,Giovanni FERRO,Federica BELLORO,Maosheng ZHONG

《环境科学与工程前沿（英文）》 2015年 第9卷 第3期   页码 465-474 doi: 10.1007/s11783-014-0678-5

摘要： A probabilistic analysis was performed on soil arsenic concentration data from 4 brownfield sites at Beijing (Chaoyang and Haidian Districts), involved in environmental assessment studies. The available data sets were processed to provide a statistical characterization of the background populations and differentiate “anomalous data” from the natural range of variation of arsenic concentrations in soil. The site-specific background distributions and the existing wide-scale background values defined for the Beijing area were compared, discussing related implications for the definition of metal contamination soil screening levels (SSLs) in site assessment studies. The statistical analysis of As data sets discriminated site-specific background populations, encompassing 88% to 94% of the sample data, from outliers values, associated with either subsoil natural enrichments or possible anthropogenic releases. Upper Baseline Concentration ( ) limits (+ 2 level), including most of the site-specific metal background variability, were derived based on the statistical characterization of the background populations. Sites in the Chaoyang South District area had values in the range 10.4–12.6 mg·kg . These ranges provide meaningful SSL values to be adopted for As in local site assessment studies. Using the wide-scale background value for the Beijing area would have erroneously classified most of the areas in the subject sites as potentially contaminated.

关键词： upper baseline concentration     site assessment     arsenic     probability plot    

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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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Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1354-1371 doi: 10.1007/s11705-022-2286-4

摘要： With the increasing development of digital devices and electric vehicles, high energy-density rechargeable batteries are strongly required. As one of the most promising anode materials with an ultrahigh specific capacity and extremely low electrode potential, lithium metal is greatly considered an ideal candidate for next-generation battery systems. Nevertheless, limited Coulombic efficiency and potential safety risks severely hinder the practical applications of lithium metal batteries due to the inevitable growth of lithium dendrites and poor interface stability. Tremendous efforts have been explored to address these challenges, mainly focusing on the design of novel electrolytes. Here, we provide an overview of the recent developments of localized high-concentration electrolytes in lithium metal batteries. Firstly, the solvation structures and physicochemical properties of localized high-concentration electrolytes are analyzed. Then, the developments of localized high-concentration electrolytes to suppress the formation of dendritic lithium, broaden the voltage window of electrolytes, enhance safety, and render low-temperature operation for robust lithium metal batteries are discussed. Lastly, the remaining challenges and further possible research directions for localized high-concentration electrolytes are outlined, which can promisingly render the practical applications of lithium metal batteries.

关键词： high-concentration electrolyte     localized high-concentration electrolyte     lithium metal battery     solid electrolyte interphase     dendrite    

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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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PM concentration declining saves health expenditure in China

《环境科学与工程前沿（英文）》 2023年 第17卷 第7期 doi: 10.1007/s11783-023-1690-4

摘要：

● Monthly hospitalization expenses are sensitive to increases in PM2.5 exposure.

关键词： Air pollution     Health expenditure     PM2.5 concentration     Economic impact     Heterogeneous effect    

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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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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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Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 595-608 doi: 10.1007/s11709-021-0720-1

摘要： The effective notch stress approach for evaluating the fatigue strength of rib–deck welds requires notch stress concentration factors obtained from complex finite element analysis. To improve the efficiency of the approach, the notch stress concentration factors for three typical fatigue-cracking modes (i.e., root–toe, root–deck, and toe–deck cracking modes) were thoroughly investigated in this study. First, we developed a model for investigating the effective notch stress in rib–deck welds. Then, we performed a parametric analysis to investigate the effects of multiple geometric parameters of a rib–deck weld on the notch stress concentration factors. On this basis, the multiple linear stepwise regression analysis was performed to obtain the optimal regression functions for predicting the notch stress concentration factors. Finally, we employed the proposed formulas in a case study. The notch stress concentration factors estimated from the developed formulas show agree well with the finite element analysis results. The results of the case study demonstrate the feasibility and reliability of the proposed formulas. It also shows that the fatigue design curve of FAT225 seems to be conservative for evaluating the fatigue strength of rib–deck welds.

关键词： notch stress concentration factor     rib–deck weld     parametric analysis     regression analysis     parametric equation    

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Energy efficiency and carbon dioxide emissions reduction opportunities in district heating source in Tianjin

Gaofeng CHEN, Xuejing ZHENG, Lin CONG

《能源前沿（英文）》 2012年 第6卷 第3期   页码 285-295 doi: 10.1007/s11708-012-0197-7

摘要： Building a trading market can promote energy conservation provided that the trading method is determined. Energy consumption for heat supply is huge. Tianjin Municipal Government is planning to establish an energy efficiency trading platform for district heating taking into consideration the experience in carbon trading market and specific situation in Tianjin. This paper presented an in-depth analysis of the district heating industry in Tianjin municipality, and identified the potentials of energy saving and carbon dioxide emissions reduction. Since energy efficiency was closely related to different heating source technologies, baselines were determined for boiler plants and thermal power plants respectively. Three scenarios were discussed for baseline determination. 472 boiler plants were surveyed and operational data relating to energy consumption were collected. Through data analysis, 27 boiler plants which have reasonable recorded energy consumption values were chosen as samples. By analyzing the dataset and referring to the related standards, method of determining the baseline for district heating carbon market was established. Finxally, the baseline for boiler plant was determined to be 52.0 kgce/GJ, and that for thermal power plant was 43.0 kgce/GJ in 2011. Carbon abatement against the baselines above was calculated and considerable carbon dioxide emissions reduction could be achieved.

关键词： district heating     energy efficiency     baseline     carbon abatement    

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Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1065-1071 doi: 10.1007/s11705-019-1909-x

摘要： Micro-arc oxidation (MAO) is an efficient approach to improve the hardness, wear resistance, and other properties of aluminum alloys. In order to investigate the effect of the electrolyte concentration on the properties of MAO coatings for LY12 alloy, the voltage variation during the MAO process was recorded. The surface morphologies and phase compositions of the coatings produced with different electrolytes were investigated using scanning electron microscopy and X-ray diffraction, respectively. The roughness and thickness of the coatings were measured using a pocket roughness meter and an eddy-current thickness meter, respectively. The tribological performances of the coatings were investigated against GCr15 bearing steel on a ball-on-disc wear tester in open air. The results showed that with an increase in the Na SiO content, the working voltage of the MAO process decreased, the roughness and thickness of the coatings increased significantly, and the relative content of the -Al O phase decreased. With an increase in the KOH content, the working voltage decreased slightly, the roughness and thickness of the coatings increased slightly, and the α- and -Al O phase contents remained unchanged. The friction coefficient and wear rate of the coatings increased with an increase in the Na SiO and KOH concentrations. A decrease in the porosity and roughness and an increase in the α-Al O content of the coatings reduced their wear mass loss.

关键词： aluminum alloy     micro-arc oxidation     coating     electrolyte concentration     tribological performance    

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标题 作者 时间 类型 操作

Probability distributions of arsenic in soil from brownfield sites in Beijing (China): statistical characterization of the background populations and implications for site assessment studies

Marina ACCORNERO,Lin JIANG,Eugenio NAPOLI,Marco CREMONINI,Giovanni FERRO,Federica BELLORO,Maosheng ZHONG

期刊论文

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

Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

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

PM concentration declining saves health expenditure in China

期刊论文

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

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

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

期刊论文

Energy efficiency and carbon dioxide emissions reduction opportunities in district heating source in Tianjin

Gaofeng CHEN, Xuejing ZHENG, Lin CONG

期刊论文

Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

期刊论文