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API-based assessment on urban air environment bearing capability in China

Jinnan WANG,Jing ZHANG,Hongqiang JIANG,Yaling LU

《环境科学与工程前沿（英文）》 2015年第9卷第6期页码 1049-1055 doi: 10.1007/s11783-014-0662-0

摘要： Given the complexity and time-consuming of the conventional environmental capacity based assessment on air environment carrying capacity; a new method for assessing urban air environment carrying capacity based on air pollution index (API) is presented. By using this new method, the air environmental bearing capability of 333 cities at the prefecture level and above is assessed. The results show that of the 333 cities 9.6% is of high bearing capability, 34.5% relatively high bearing capability, 52.6% medium bearing capability, 2.7% low capability, and 0.6% is of weak bearing capability; in terms of regional distribution, the western region is of relatively high air environment bearing capability, followed by north-eastern and eastern regions, and the ambient air quality in the middle region is quite poor; among the 12 urban agglomerations in key regions, Pearl River delta, west side of Taiwan Strait and Chengdu-Chongqing agglomerations are of relatively high carrying capacity while other agglomerations are of medium bearing capability. The assessment results imply that the existing air quality standard (GB3095-1996) is quite unsound.

关键词： air pollution index (API) air environment bearing capability key city assessment method

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泰州大桥中塔沉井基础承载力模型试验研究

阮静,胡丰

《中国工程科学》 2012年第14卷第5期页码 57-61

摘要：

泰州大桥中塔位于江中心，基础覆盖层高达200 m。通过多方面比选，基础采用58 m×44 m四角倒圆的矩形沉井，高76 m。为确保泰州大桥中塔沉井基础的安全和稳定，开展了1∶100的模型试验，获取了泰州大桥沉井极限承载力以及沉井埋深、土体含水量、侧壁摩阻力对极限承载力的影响。

关键词：沉井承载力泰州大桥物理模型试验

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Electrorheological damper for the ultra-precision air bearing stage

ZHU Yu, JIA Songtao, CHEN Yaying, LI Guang

《机械工程前沿（英文）》 2008年第3卷第2期页码 158-163 doi: 10.1007/s11465-008-0031-4

摘要： This paper illustrates how the electrorheological damper substantially improves the performance of the ultra-precision air bearing stage. Smart materials such as electrorheological fluids have attracted many researchers’ attention because of their resistance changeable performance in different electric fields. Meanwhile, the ultra-precision air bearing stage driven by the linear-motor is characterized by zero mechanical damping and poor anti-disturbance. To solve this problem and consider the characteristics of electrorheological fluids, an electrorheological damper is proposed in this paper. The electrorheological damper’s characteristics in high electric fields are obtained based on the Eyring constitutive model, which smoothly transits from the pre-yield to post-yield region. To enhance the performance of the electrorheological damper, which takes effect only when the stage is going to decelerate or position, the on-off and sliding mode control methods design and optimize the controller. The results prove that by using the advanced sliding mode control method, the characteristics of the ultra-precision air bearing stage can be effectively improved through the introduction of the electrorheological damper.

关键词： post-yield linear-motor advanced sliding pre-yield position

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Air bearing center cross gap of neutron stress spectrometer sample table support system

Yang LI,Yunxin WU,Hai GONG,Xiaolei FENG

《机械工程前沿（英文）》 2016年第11卷第4期页码 403-411 doi: 10.1007/s11465-016-0405-y

摘要：

A support system is the main load-bearing component of sample table for neutron stress spectrometer, and air bearing is an important element of a support system. The neutron stress spectrometer sample table was introduced, and the scheme for air bearing combination was selected. To study the performance of air bearing center cross gap, finite element models (FEMs) were established based on air motion and Reynolds equations, effects of air supply pressure, and gap parameters on the overturning moment and bearing capacity of air bearing center cross gap were analyzed. Results indicate that the width, depth, and height differences of the marble floor gap played important roles in the performance of the air bearing. When gap width is lesser than 1 mm and gap depth is lower than 0.4 mm, bearing capacity and overturning moment would vary rapidly with the variation of the width and depth. A gap height difference results in the bearing capacity dropping rapidly. The FEM results agree well with experimental results. Further, findings of the study could guide the design of the support system and marble floor.

关键词： neutron stress spectrometer sample table support system air bearing center cross gap simulation experiment

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Air-bearing position optimization based on dynamic characteristics of ultra-precision linear stages

CHEN Xuedong, LI Zhixin

《机械工程前沿（英文）》 2008年第3卷第4期页码 400-407 doi: 10.1007/s11465-008-0060-z

摘要： Air-bearings are installed between the stator and the mover of ultra-precision linear stages to suppress vibration and mechanical contact. Spring-damping elements are used to emulate the complex interaction of the finite element model (FEM) developed in this paper and the system dynamic behaviors are analyzed. Through the experimental modal test, the validity and reliability of the model are proven. However, the dynamic characteristics including mode frequency, mode shape, and response amplitude are obviously changed with the position of air-bearings. The combined optimization method is used to optimize the air-bearings position. The best and worst positions are obtained using the dynamic characteristic analysis. The method can be generalized to the connection position of different components in manufacture elements and to implement the system dynamic characteristics optimization when the connection position can be changed.

关键词： manufacture different interaction air-bearings response amplitude

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知识互动共享视角——区域创新环境机理研究

饶扬德,王学军

《中国工程科学》 2006年第8卷第7期页码 72-77

摘要：

创新本质上是知识再创造的动态过程。知识既是创新不可缺少的投入要素，又是创新的最终目标和产出。在介绍隐性知识传播障碍的基础上，分析了区域创新优势，从知识互动共享视角阐释了区域创新环境机理。

关键词：知识互动和共享区域创新创新能力创新环境机理

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Same stimuli, different responses: a pilot study assessing air pollution visibility impacts on emotionalwell-being in a controlled environment

《环境科学与工程前沿（英文）》 2023年第17卷第2期 doi: 10.1007/s11783-023-1620-5

摘要：

● Emotional responses to visibility-reducing haze was assessed in a controlled lab.

关键词： Air pollution Emotional wellbeing Variability Visual exposure Emotional bias

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Model reduction techniques for dynamics analysis of ultra-precision linear stage

Xuedong CHEN, Zhixin LI

《机械工程前沿（英文）》 2009年第4卷第1期页码 64-70 doi: 10.1007/s11465-009-0009-x

摘要： Spring-damping elements are used to simplify the internal interaction in the proposed finite element (FE) model of an ultra-precision linear stage. The dynamics behavior is studied. The comparison between mode shapes from the eigenvalue analysis shows that the components, except the translator, can represent system dynamics characteristics. A reduction approach is used to simplify the system in a dynamic studied. There is little difference between the vibration mode and the response analysis. The experimental modal analysis proves the validity of the reduction approach, which can be generalized to the development and dynamics characteristic study of a complex system model to obviously save computational resource.

关键词： dynamics analysis air-bearing linear stage reduction

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Enhancing power transfer capability through flexible AC transmission system devices: a review

Fadi M. ALBATSH,Saad MEKHILEF,Shameem AHMAD,H. MOKHLIS,M. A. HASSAN

《信息与电子工程前沿（英文）》 2015年第16卷第8期页码 658-678 doi: 10.1631/FITEE.1500019

摘要： Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a transmission network should be enhanced. Researchers worldwide have addressed this issue by using flexible AC transmission system (FACTS) devices. We have conducted a comprehensive review of how FACTS controllers are used to enhance the available transfer capability (ATC) and power transfer capability (PTC) of power system networks. This review includes a discussion of the classification of different FACTS devices according to different factors. The popularity and applications of these devices are discussed together with relevant statistics. The operating principles of six major FACTS devices and their application in increasing ATC and PTC are also presented. Finally, we evaluate the performance of FACTS devices in ATC and PTC improvement with respect to different control algorithms.

关键词： FACTS devices Available transfer capability Power transfer capability Artificial intelligence

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Motion capability analysis of a quadruped robot as a parallel manipulator

Jingjun YU,Dengfeng LU,Zhongxiang ZHANG,Xu PEI

《机械工程前沿（英文）》 2014年第9卷第4期页码 295-307 doi: 10.1007/s11465-014-0317-7

摘要：

This paper presents the forward and inverse displacement analysis of a quadruped robot MANA as a parallel manipulator in quadruple stance phase, which is used to obtain the workspace and control the motion of the body. The robot MANA designed on the basis of the structure of quadruped mammal is able to not only walk and turn in the uneven terrain, but also accomplish various manipulating tasks as a parallel manipulator in quadruple stance phase. The latter will be the focus of this paper, however. For this purpose, the leg kinematics is primarily analyzed, which lays the foundation on the gait planning in terms of locomotion and body kinematics analysis as a parallel manipulator. When all four feet of the robot contact on the ground, by assuming there is no slipping at the feet, each contacting point is treated as a passive spherical joint and the kinematic model of parallel manipulator is established. The method for choosing six non-redundant actuated joints for the parallel manipulator from all twelve optional joints is elaborated. The inverse and forward displacement analysis of the parallel manipulator is carried out using the method of coordinate transformation. Finally, based on the inverse and forward kinematic model, two issues on obtaining the reachable workspace of parallel manipulator and planning the motion of the body are implemented and verified by ADAMS simulation.

关键词： quadruped robot actuated joints selection kinematics analysis motion planning parallel manipulator

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Selective pseudosolubilization capability of

Fei HUA, Hongqi WANG

《环境科学与工程前沿（英文）》 2013年第7卷第4期页码 539-551 doi: 10.1007/s11783-013-0498-z

摘要： Pseudosolubilized ability of sp. DG17 on -alkanes, role of biosurfactants in -octadecane uptake and trans-membrane transport mechanism of -octadecane were studied by analyzing amount of pseudosolubilized oil components in water phase, and the fraction of radiolabeled C -octadecane in the broth and cell pellet. GC-MS results showed that pseudosolubilized oil components were mainly C to C of -alkanes. In -octadecane broth, pseudosolubilized -octadecane could be accumulated as long as pseudosolubilized rate was faster than mineralization rate of substrate, and the maximum concentration of pseudosolubilized -octadecane achieved to 45.37 mg·L . All of these results showed that sp. DG17 mainly utilized alkanes by directly contacting with pseudosolubilized small oil droplets in the water phase. Analysis of C amount in cell pellet revealed that an energy-dependent system mainly controlled the trans-membrane transport of -octadecane.

关键词： Pseudomonas alkane uptake pseudosolubilization trans-membrane transport

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Evaluation of stray current corrosion resistance of concrete in metro construction

YANG Shucai, YANG Xu

《结构与土木工程前沿（英文）》 2008年第2卷第3期页码 246-252 doi: 10.1007/s11709-008-0036-4

摘要： By simulation tests of concrete specimens in saturated Ca(OH) solution and seawater, and based on micro mechanism analysis, this paper evaluates the stray current corrosion resistance of concrete specimens of different mixture ratios, and reaches a conclusion that the capability to resist stray current corrosion of optimally designed concrete mixed with good-quality fly ash and powdered slag is increased by over 5 times more than the reference concrete with the same water to binder ratio, and the service life of such kind of concrete meets the basic requirement of a metro project.

关键词： project different requirement simulation capability

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Insights into simultaneous anammox and denitrification system with short-term pyridine exposure: Process capability

《环境科学与工程前沿（英文）》 2021年第15卷第6期 doi: 10.1007/s11783-021-1433-3

摘要：

• Short-term effect of the pyridine exposure on the SAD process was investigated.

关键词： Anammox Inhibition Metabolic pathway Microbial community Pyridine SAD

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埋地热油管道运行参数的准周期变化

崔慧

《中国工程科学》 2006年第8卷第1期页码 51-53

摘要：

从理论上分析了在大气温度变化的影响下埋地热油管道的运行参数以及周围土壤环境均随季节变化而呈现准周期变化规律，在分析大量实际运行数据的基础上，进一步验证了该规律的合理性，建议在有关管道的节能降耗、优化运行以及经济清蜡等问题的研究中，应该考虑运行参数的滞后影响。

关键词：热油管道大气温度土壤环境准周期

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Iterative HOEO fusion strategy: a promising tool for enhancing bearing fault feature

《机械工程前沿（英文）》 2023年第18卷第1期 doi: 10.1007/s11465-022-0725-z

摘要： As parameter independent yet simple techniques, the energy operator (EO) and its variants have received considerable attention in the field of bearing fault feature detection. However, the performances of these improved EO techniques are subjected to the limited number of EOs, and they cannot reflect the non-linearity of the machinery dynamic systems and affect the noise reduction. As a result, the fault-related transients strengthened by these improved EO techniques are still subject to contamination of strong noises. To address these issues, this paper presents a novel EO fusion strategy for enhancing the bearing fault feature nonlinearly and effectively. Specifically, the proposed strategy is conducted through the following three steps. First, a multi-dimensional information matrix (MDIM) is constructed by performing the higher order energy operator (HOEO) on the analysis signal iteratively. MDIM is regarded as the fusion source of the proposed strategy with the properties of improving the signal-to-interference ratio and suppressing the noise in the low-frequency region. Second, an enhanced manifold learning algorithm is performed on the normalized MDIM to extract the intrinsic manifolds correlated with the fault-related impulses. Third, the intrinsic manifolds are weighted to recover the fault-related transients. Simulation studies and experimental verifications confirm that the proposed strategy is more effective for enhancing the bearing fault feature than the existing methods, including HOEOs, the weighting HOEO fusion, the fast Kurtogram, and the empirical mode decomposition.

关键词： higher order energy operator fault diagnosis manifold learning rolling element bearing information fusion