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中国铁路“走出去” 5

“走出去” 4

渤海海峡 3

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Performance enhancement of partially shaded solar PV array using novel shade dispersion technique

Namani RAKESH,T. Venkata MADHAVARAM

《能源前沿(英文)》 2016年 第10卷 第2期   页码 227-239 doi: 10.1007/s11708-016-0405-y

摘要: Solar photo voltaic array (SPVA) generates a smaller amount of power than the standard rating of the panel due to the partial shading effect. Since the modules of the arrays receive different solar irradiations, the P-V characteristics of photovoltaic (PV) arrays contain multiple peaks or local peaks. This paper presents an innovative method (magic square) in order to increase the generated power by configuring the modules of a shaded photovoltaic array. In this approach, the physical location of the modules in the total cross tied (TCT) connected in the solar PV array is rearranged based on the magic square arrangement pattern. This connection is done without altering any electrical configurations of the modules in the PV array. This method can distribute the shading effect over the entire PV array, without concentrating on any row of modules and can achieve global peaks. For different types of shading patterns, the output power of the solar PV array with the proposed magic square configuration is compared with the traditional configurations and the performance is calculated. This paper presents a new reconfiguration technique for solar PV arrays, which increases the PV power under different shading conditions. The proposed technique facilitates the distribution of the effect of shading over the entire array, thereby, reducing the mismatch losses caused by partial shading. The theoretical calculations are tested through simulations in Matlab/Simulink to validate the results. A comparison of power loss for different types of topologies under different types of shading patterns for a 4 × 4 array is also explained.

关键词: photovoltaic cells     mismatch loss     shading patterns     partial shading     magic square     power enhancement     global peaks and total cross tied (TCT)    

Characteristics of plankton Hg bioaccumulations based on a global data set and the implications for aquatic

《环境科学与工程前沿(英文)》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1471-x

摘要:

• Hg bioaccumulation by phytoplankton varies among aquatic ecosystems.

关键词: Plankton     Hg bioaccumulation     Physiological characteristics     A cross-system analysis     Nutrient compositions     Global data set    

Design and stability analysis of continuous skew tied-arch bridge over Bin Jiang River

YU Jiancheng, TONG Hao, HUANG Wei

《结构与土木工程前沿(英文)》 2008年 第2卷 第1期   页码 37-42 doi: 10.1007/s11709-008-0004-z

摘要: A tied arch bridge without wind bracing was built over the Bin Jiang River, with oblique angle of 20°. Its main design details are described and mechanical performances are analyzed. The stability analytical types are also introduced and the first elastic stability theory is used. A space finite element model has been built to analyze the stability performances in both construction and operation stages for single span or continuous, orthogonal or oblique bridge. The influence of stiffness of the end crossbeam is also analyzed. The result shows that out-plane buckling occur for a rigid tie and similar no matter whether it is single span or continuous and orthogonal or oblique. When there are more and stronger inner crossbeams, the influence of the end crossbeams on arch stability becomes unremarkable.

关键词: out-plane buckling     unremarkable     crossbeam     stability analytical     orthogonal    

中国铁路运营“走出去”发展策略研究

高峰,刘东,李文杰,郑乃明,马思远

《中国工程科学》 2017年 第19卷 第5期   页码 44-48 doi: 10.15302/J-SSCAE-2017.05.008

摘要:

本文深入分析了中国铁路运营“走出去”存在的问题,如中国铁路建设与运营脱节、运营企业缺乏“走出去”的主动性、跨文化管理经验不足等问题,提出了转化现有理念和机制,融合国内外标准、规章、维修、安全、能力、绩效评价等管理体系,实现运营角色由提供服务向提供咨询的转变,加强跨文化管理人才储备,完善人才培养与储备机制等发展策略。

关键词: 中国铁路     运营     管理体系     跨文化    

Simultaneous removal of total oxidizable carbon, phosphate and various metallic ions from HO solution

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 470-482 doi: 10.1007/s11705-022-2231-6

摘要: Amino-functionalized zirconia was synthesized by the co-condensation method using zirconium butanol and 3-aminopropyltriethoxy silane for the simultaneous removal of various impurities from aqueous 30% H2O2 solution. The results of Fourier transform infrared (FTIR) and Zeta potential showed that the content of N in amino-functionalized zirconia increased with the added amount of 3-aminopropyltriethoxy silane. Accordingly, the removal efficiency of total oxidizable carbon, phosphate and metallic ions from the H2O2 solution increased. The adsorbent with an N content of 1.62% exhibited superior adsorption performance. The removal efficiency of 82.7% for total oxidizable carbon, 34.2% for phosphate, 87.1% for Fe3+, 83.2% for Al3+, 55.1% for Ca2+ and 66.6% for Mg2+, with a total adsorption capacity of 119.6 mg·g–1, could be achieved. The studies conducted using simulated solutions showed that the adsorption process of phosphate on amino-functionalized zirconia is endothermic and spontaneous, and the behaviors could be well described by the pseudo-second-order model and Langmuir model with a maximum adsorption capacity of 186.7 mg·g–1. The characterizations of the spent adsorbents by Zeta potential, FTIR and X-ray photoelectron spectroscopy revealed that the adsorption mechanism of phosphate is predominantly electrostatic attraction by the protonated functional groups and complementary ligand exchange with zirconium hydroxyl groups.

关键词: adsorption     zirconia     total oxidizable carbon     phosphate     metallic ions     hydrogen peroxide    

Implementation of total Lagrangian formulation for the elasto-plastic analysis of plane steel frames

Bing XIA, Yuching WU, Zhanfei HUANG

《结构与土木工程前沿(英文)》 2012年 第6卷 第3期   页码 257-266 doi: 10.1007/s11709-012-0163-9

摘要: In this paper, the co-rotational total Lagrangian forms of finite element formulations are derived to perform elasto-plastic analysis for plane steel frames that either experience increasing external loading at ambient temperature or constant external loading at elevated temperatures. Geometric nonlinearities and thermal-expansion effects are considered. A series of programs were developed based on these formulations. To verify the accuracy and efficiency of the nonlinear finite element programs, numerical benchmark tests were performed, and the results from these tests are in a good agreement with the literature. The effects of the nonlinear terms of the stiffness matrices on the computational results were investigated in detail. It was also demonstrated that the influence of geometric nonlinearities on the incremental steps of the finite element analysis for plane steel frames in the presence of fire is limited.

关键词: co-rotational     total Lagrangian     geometrical nonlinearity     fire     elasto-plastic    

Exergy and exergoeconomic analyses for integration of aromatics separation with aromatics upgrading

《化学科学与工程前沿(英文)》 2023年 第17卷 第2期   页码 183-193 doi: 10.1007/s11705-022-2192-9

摘要: Methanol to aromatics produces multiple products, resulting in a limited selectivity of xylene. Aromatics upgrading is an effective way to produce more valuable xylene product, and different feed ratios generate discrepant product distributions. This work integrates the aromatics separation with toluene disproportionation, transalkylation of toluene and trimethylbenzene, and isomerization of xylene and trimethylbenzene. Exergy and exergoeconomic analyses are conducted to give insights in the splitting ratios of benzene, toluene and heavy aromatics for aromatics upgrading. First, a detailed simulation model is developed in Aspen HYSYS. Then, 300 splitting ratio sets of benzene and toluene for conversion are studied to investigate the process performances. The results indicate that there are different preferences for the splitting ratios of benzene and toluene in terms of exergy and exergoeconomic performances. The process generates lower total exergy destruction when the splitting ratio of toluene varies between 0.07 and 0.18, and that of benzene fluctuates between 0.55 and 0.6. Nevertheless, the process presents lower total product unit cost with the splitting ratio of toluene less than 0.18 and that of benzene fluctuating between 0.44 and 0.89. Besides, it is found that distillation is the biggest contributor to the total exergy destruction, accounting for 94.97%.

关键词: aromatics separation and upgrading     variant splitting ratios     total exergy destruction     total product unit cost    

Critical flow-storm approach to total maximum daily load (TMDL) development: an analytical conceptual

Zhang Harry, Yu Shaw

《环境科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 267-273 doi: 10.1007/s11783-008-0058-0

摘要: One of the key challenges in the total maximum daily load (TMDL) development process is how to define the critical condition for a receiving waterbody. The main concern in using a continuous simulation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scarcity of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continuous and event-based approaches in defining critical condition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the critical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having certain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.

关键词: representative hydrologic     occurrence     simulation approach     scarcity     alternative    

钢复合结构压力容器技术

朱国辉,朱立,郑津洋,郑传祥,陈志平,吴红梅

《中国工程科学》 2001年 第3卷 第7期   页码 79-84

摘要:

对压力容器设计提出了一种技术先进的多功能壳和长远发展根本要求的新理念,并介绍了钢复合结构压力容器技术的四项新的专利技术发展体系。钢复合结构压力容器技术是一种国际创新的,涵盖各种高、中、低压,应用范围广阔的压力容器新技术。其主要特点是具抑爆抗爆、简化制造、分散缺陷和可实现经济可靠的在线安全状态自动监控等多功能壳特性,可降低制造成本30%~50%。

关键词: 压力容器技术     钢复合结构     多功能壳     钢带错绕     全双层     抑爆抗爆    

中国开创的抗爆钢复合材料压力容器技术

朱国辉

《中国工程科学》 2000年 第2卷 第6期   页码 8-11

摘要:

压力容器是一种应用广泛的重要工程装置。大型压力贮罐、氨合成塔、尿素合成塔、石油加氢反应器、导弹壳体和液氢、液氧燃料压力容器,以及核堆压力壳等是国际上公认的高科技重大承压装备。纤维复合材料和普通钢制是当今世界压力容器技术的两大种类。作者开创了一种新的具有优良综合特性,已含国家发明奖励和18项中美专利成果的抗爆钢复合材料压力容器技术,使压力容 器的使用安全性和制造经济性发生了极大的变革;其典型代表钢带缠绕式压力容器,已被美国机械工程师学会正式列入ASME标准,居国际领先水平,将为21世纪国际压力容器的设计、制造和安全保障技术的发展开创出新的局面。

关键词: 压力容器技术     纤维复合材料     钢复合材料     复合薄内筒     交错缠绕     全双层结构     抑爆抗爆    

From total quality management to Quality 4.0: A systematic literature review and future research agenda

《工程管理前沿(英文)》 2023年 第10卷 第2期   页码 191-205 doi: 10.1007/s42524-022-0243-z

摘要: Quality 4.0 is an emerging concept that has been increasingly appreciated because of the intensification of competition, continually changing customer requirements and technological evolution. It deals with aligning quality management practices with the emergent capabilities of Industry 4.0 to improve cost, time, and efficiency and increase product quality. This article aims to comprehensively review extant studies related to Quality 4.0 to uncover current research trends, distil key research topics, and identify areas for future research. Thus, 46 journal articles extracted from the Scopus database from 2017 to 2022 were collected and reviewed. A descriptive analysis was first performed according to the year-wise publication, sources of publication, and research methods. Then, the selected articles were analyzed and classified according to four research themes: Quality 4.0 concept, Quality 4.0 implementation, quality management in Quality 4.0, and Quality 4.0 model and application. By extracting the literature review findings, we identify the Quality 4.0 definitions and features, develop the quality curve theory, and highlight future research opportunities. This study supports practitioners, managers, and academicians in effectively recognizing and applying Quality 4.0 to enhance customer satisfaction, achieve innovation enterprise efficiency, and increase organizational competitiveness in the era of Industry 4.0.

关键词: quality management     Quality 4.0     Industry 4.0     literature review     predictive quality    

Methods and applications of DEA cross-efficiency: Review and future perspectives

Jie WU, Jiasen SUN, Liang LIANG

《工程管理前沿(英文)》 2021年 第8卷 第2期   页码 199-211 doi: 10.1007/s42524-020-0133-1

摘要: The field of engineering management usually involves evaluation issues, such as program selection, team performance evaluation, technology selection, and supplier evaluation. The traditional self-evaluation data envelopment analysis (DEA) method usually exaggerates the effects of several inputs or outputs of the evaluated decision-making unit (DMU), resulting in unrealistic results. To address this problem, scholars have proposed the cross-efficiency evaluation (CREE) method. Compared with the DEA method, CREE can rank DMUs more completely by using reasonable weights. With the extensive application of this technique, several problems, such as non-unique weights and non-Pareto optimal results, have arisen in CREE methods. Therefore, the improvement of CREE has attracted the attention of many scholars. This paper reviews the theory and applications of CREE, including the non-uniqueness problem, the aggregation of cross-efficiency data, and applications in engineering management. It also discusses the directions for future research on CREE.

关键词: cross-efficiency evaluation     efficiency     secondary goal model     aggregation     review    

Total stress rapid drawdown analysis of the Pilarcitos Dam failure using the finite element method

Daniel R. VANDENBERGE

《结构与土木工程前沿(英文)》 2014年 第8卷 第2期   页码 115-123 doi: 10.1007/s11709-014-0249-7

摘要: Rapid drawdown is a critical design condition for the upstream or riverside slope of earth dams and levees. A new total stress rapid drawdown method based on finite element analysis is used to analyze the rapid drawdown failure that occurred at Pilarcitos Dam in 1969. Effective consolidation stresses in the slope prior to drawdown are determined using linear elastic finite element analysis. Undrained strengths from isotropically consolidated undrained (ICU) triaxial compression tests are related directly to the calculated consolidation stresses and assigned to the elements in the model by interpolation. Two different interpretations of the undrained strength envelope are examined. Strength reduction finite element analyses are used to evaluate stability of the dam. Back analysis suggests that undrained strengths from ICU tests must be reduced by 30% for use with this rapid drawdown method. The failure mechanism predicted for Pilarcitos Dam is sensitive to the relationship between undrained strength and consolidation stress.

关键词: rapid drawdown     finite element     total stress     slope stability    

Prevalence and determinations of physical inactivity among public hospital employees in Shanghai, China: a cross-sectional

null

《医学前沿(英文)》 2015年 第9卷 第1期   页码 100-107 doi: 10.1007/s11684-014-0372-9

摘要:

This study aims to explore the prevalence and determinations of physical inactivity among hospital employees in Shanghai, China. A cross-sectional study of 4612 employees aged 19 to 68 years was conducted through stratified cluster sampling from different classes of Shanghai hospitals in 2011. The total physical activity was evaluated using the metabolic equivalent according to the Global Physical Activity Questionnaire. Among the participants, 38.5%, 32.3%, and 64.6% of the employees are inactive at work, commuting, and taking leisure time, respectively. Up to 41.8% of the men and 37.8% of the women (P = 0.012) are physically inactive. When the age and educational level are adjusted, male doctors and medical technicians show a higher percentage of physical inactivity than male workers in logistics (P = 0.001). Among females, employees who are working in second- and third-class hospitals show a higher proportion of physical inactivity than those who are working in community health care centers. Logistic regression analyses show that the odds ratios (ORs) of leisure-time physical inactivity associated with the intensity of physical activity at work are 2.259, 2.897, and 4.266 for men (P<0.001) and 2.456, 3.259, and 3.587 for women (P<0.001), respectively. The time during commuting activities is significantly associated with leisure-time physical inactivity in either sex (OR= 2.116 for men and 2.173 for women, P<0.001). Hospital employees, particularly doctors and medical technicians, show a higher proportion of physical inactivity than other inhabitants in Shanghai. The time and intensity of activity at work and commuting are associated with leisure-time activities.

关键词: prevalence     determination     employee     public hospital     cross-sectional study     physical inactivity    

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

《机械工程前沿(英文)》 2012年 第7卷 第2期   页码 219-230 doi: 10.1007/s11465-012-0320-9

摘要:

This article focuses on the dynamic index and performance of a radial symmetric six-legged robot. At first the structure of the robot is described in brief and its inverse kinematics is presented. Then the dynamic model is formulated as based on the Lagrange equations. A novel index of total torque is proposed by considering the posture of the supporting legs. The new index can be used to optimize the leg’s structure and operation for consuming minimum power and avoiding unstable postures of the robot. A characterization of the proposed six-legged robot is obtained by a parametric analysis of robot performance through simulation using the presented dynamic model. Main influences are outlined as well as the usefulness of the proposed performance index.

关键词: six-legged robots     dynamic modeling     performance index    

标题 作者 时间 类型 操作

Performance enhancement of partially shaded solar PV array using novel shade dispersion technique

Namani RAKESH,T. Venkata MADHAVARAM

期刊论文

Characteristics of plankton Hg bioaccumulations based on a global data set and the implications for aquatic

期刊论文

Design and stability analysis of continuous skew tied-arch bridge over Bin Jiang River

YU Jiancheng, TONG Hao, HUANG Wei

期刊论文

中国铁路运营“走出去”发展策略研究

高峰,刘东,李文杰,郑乃明,马思远

期刊论文

Simultaneous removal of total oxidizable carbon, phosphate and various metallic ions from HO solution

期刊论文

Implementation of total Lagrangian formulation for the elasto-plastic analysis of plane steel frames

Bing XIA, Yuching WU, Zhanfei HUANG

期刊论文

Exergy and exergoeconomic analyses for integration of aromatics separation with aromatics upgrading

期刊论文

Critical flow-storm approach to total maximum daily load (TMDL) development: an analytical conceptual

Zhang Harry, Yu Shaw

期刊论文

钢复合结构压力容器技术

朱国辉,朱立,郑津洋,郑传祥,陈志平,吴红梅

期刊论文

中国开创的抗爆钢复合材料压力容器技术

朱国辉

期刊论文

From total quality management to Quality 4.0: A systematic literature review and future research agenda

期刊论文

Methods and applications of DEA cross-efficiency: Review and future perspectives

Jie WU, Jiasen SUN, Liang LIANG

期刊论文

Total stress rapid drawdown analysis of the Pilarcitos Dam failure using the finite element method

Daniel R. VANDENBERGE

期刊论文

Prevalence and determinations of physical inactivity among public hospital employees in Shanghai, China: a cross-sectional

null

期刊论文

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

期刊论文