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Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

Xinfeng WANG, Wenxing WANG, Likun XUE, Xiaomei GAO, Wei NIE, Yangchun YU, Yang ZHOU, Lingxiao YANG, Qingzhu ZHANG, Tao WANG

Frontiers of Environmental Science & Engineering 2013, Volume 7, Issue 6,   Pages 815-826 doi: 10.1007/s11783-013-0503-6

Abstract: were collected using a micro-orifice uniform deposit impactor (MOUDI) in spring 2009 at the summit of MountHeng (1269 m asl), followed by subsequent laboratory analyses of 13 inorganic and organic water-solubleCompared with Mount Tai in the North China Plain, the concentrations of both fine and coarse particleselevated concentrations of sulfates, nitrates, ammonium, potassium, and chloride in the fine particles at MountHeng.

Keywords： aerosol water-soluble ions     size distributions     secondary formation     dust storm     Mount Heng    

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Construction risks of Huaying mount tunnel and countermeasures

Haibo YAO, Feng GAO, Shigang YU, Wei DANG

Frontiers of Structural and Civil Engineering 2017, Volume 11, Issue 3,   Pages 279-285 doi: 10.1007/s11709-017-0414-x

Abstract: The Chongqing-Guang’an motorway is planned to cross Huaying mount at Jingguan town of Chongqing city.The whole mount is a colossal anticline whose core is consisted of coal measure strata (upper Permian

Keywords： tunnel?construction     gas?outburst     geology?prediction     automatic?monitoring?system    

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Special issue: Advances and prospect of engineering management

Lieyun DING, Heng LI

Frontiers of Engineering Management 2017, Volume 4, Issue 1,   Pages 1-3 doi: 10.15302/J-FEM-2017102

Abstract:
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Effect of calcium on porcine ICSI embryos expressing EGFP is related to activation of ooplasmic DNase I

Shuaishuai WU,Heng CHEN,Yingzheng WANG,Hui GAO,Shenming ZENG

Frontiers of Agricultural Science and Engineering 2015, Volume 2, Issue 1,   Pages 84-89 doi: 10.15302/J-FASE-2015046

Abstract: Several reliable methods to produce transgenic animals use the male genome. After penetration into oocytes, sperm DNA undergoes dramatic conformational changes that might represent an opportunity for exogenous DNA to integrate into the zygote genome. A nuclease, DNase I, with Ca /Mg dependent activity and Zn inhibition, is one of the enzymes responsible for sperm DNA remodeling. To date, the effect of different calcium concentrations in manipulation media on porcine intracytoplasmic sperm injection has not been fully investigated. The present study was conducted to examine the effect of calcium in the surrounding media, and we found that the number of embryos expressing green fluorescent protein (EGFP) was increased in media containing Ca . However, the number did not change over Ca concentrations from 2 to 8 mmol·L ( >0.05). Moreover, free Ca concentrations in the media were found to affect the efficiency which is ICSI embryos expressing EGFP protein, which was related to the activation of ooplasmic DNase I. These findings reveal a mechanism and pathway involving EGFP expression in ICSI embryos.

Keywords： ICSI     calcium     DNase I     GFP     porcine    

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Nanopositioning and Nonlinearity Compensation for Step Imprint Lithography Tool

LU Bing-heng, LIU Hong-zhong, DING Yu-cheng, WANG Li, QIU Zhi-hui

Frontiers of Mechanical Engineering 2006, Volume 1, Issue 1,   Pages 6-13 doi: 10.1007/s11465-005-0003-x

Abstract:

In this paper, the motion mode and nanopositioning accuracy in the step imprinting lithography process are presented, and the positioning errors different from the traditional errors, such as the gap error existing in the hinges of the stage structure and the random error produced during the process of the stage position adjustment, are analyzed. To avoid and eliminate these nonlinearity errors, radial basis function proportional integral derivative and position control algorithms are introduced into the macroand microdriving processes, respectively. The innovation of this driving method is that the motion locus is monotone, nonoscillatory, and a multistep approaching target, which eliminates the root of the random error by single direction driving mode and avoids the backlash error through preloading function. Driving experiments of different motion ranges prove that this nonlinearity compensation is very effective and the positioning accuracy during the step imprinting process can be improved up to 10 nm.

Keywords： different     nonoscillatory     nonlinearity     integral derivative     positioning    

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Heliosphere detection

Du Heng

Strategic Study of CAE 2008, Volume 10, Issue 6,   Pages 46-50

Abstract:

In this thesis, general situation of detection and significance of research to heliosphere are introduced. Important function of solar-terrestrial space process in space environment prediction is discussed. Ability insufficiency in heliosphere detection is also analyzed.

Keywords： heliosphere     interplanetary space     detection    

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Transition metal-doped heteropoly catalysts for the selective oxidation of methacrolein to methacrylic acid

Yanxia Zheng,Heng Zhang,Lei Wang,Suojiang Zhang,Shaojun Wang

Frontiers of Chemical Science and Engineering 2016, Volume 10, Issue 1,   Pages 139-146 doi: 10.1007/s11705-015-1548-9

Abstract: Heteropoly compounds with the general formula Cs M H P Mo VO (M= Fe, Co, Ni, Cu or Zn) and Cs Cu H P Mo VO ( = 0.1, 0.3 or 0.7) were synthesized and then used as catalysts for the selective oxidation of methacrolein to methacrylic acid. The effects of the transition metals on the structure and activity of the catalysts were investigated. FTIR spectra showed that the transition metal-doped catalysts maintained the Keggin structure of the undoped catalysts. X-ray diffraction results indicated that before calcination, the catalysts doped with Fe and Cu had cubic secondary structures, while the catalysts doped with Co, Ni or Zn had both triclinic and cubic phases and the Co-doped catalyst had the highest content of the triclinic form. Thermal treatment can decrease the content of the triclinic phase. NH temperature-programmed desorption and H temperature-programmed reduction results showed that the transition metals changed the acid and redox properties of the catalysts. The addition of Fe or Cu had positive effects on the activities of the catalyst which is due to the improvement of the electron transfer between the Fe or Cu and the Mo. The effects of the copper content on structure and catalytic activity were also investigated. The Cs Cu H P Mo VO catalyst had the best performance for the selective oxidation of methacrolein to methacrylic acid.

Keywords： heteropoly compounds     transition metals     selective oxidation     methacrolein    

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A nano-scale alignment method for imprint lithography

WANG Li, LU Bing-heng, DING Yu-cheng, QIU Zhi-hui, LIU Hong-zhong

Frontiers of Mechanical Engineering 2006, Volume 1, Issue 2,   Pages 157-161 doi: 10.1007/s11465-006-0014-2

Abstract: A novel nano-scale alignment technique based on moiré signal for room-temperature imprint lithography in the submicron realm is proposed. The moiré signals generated by two pairs of quadruple gratings on mold and wafer are optically projected onto two photo-detector arrays, then the detected moiré signals are used to estimate the alignment errors in the x and y directions. The experiment results indicate that complex differential moiré signal is sensitive to relative displacement of the mold and wafer, and the alignment accuracy obtained in the x and γ directions and in θ are 20 nm , 25 nm and 1 μrad (3σ), respectively. They can meet the requirements of alignment accuracy for submicron imprint lithography.

Keywords： submicron     alignment accuracy     nano-scale alignment     quadruple     room-temperature    

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Research on the method of cavitations resistance in a piezoelectric pump with 3-dimensional mesh structure

ZHANG Jian-hui, Bai Heng-jun, XIA Qi-xiao, NING Hong-gang, ONUKI Akiyoshi

Frontiers of Mechanical Engineering 2006, Volume 1, Issue 4,   Pages 429-433 doi: 10.1007/s11465-006-0052-9

Abstract: The volume valve piezoelectric pump has received increasing attention from many areas because of its different characteristics such as the absence of chemical pollution and electromagnetic pollution. However, when the pump is working, it produces cavitations and the air bubbles that originate from these will flow out of the pump. Cavitations occurring in the pump will bring out noise and shorten the life of the pump. Furthermore, air bubbles flowing out of the pump will hinder its application in areas such as medical treatment and health care where blood transfusion and infusion are concerned. As a solution to this disadvantage, the CR3DMS (cavitations resistance with 3-dimensional mesh structure) method is developed, which is tested and verified to be effective on not only reducing the occurrence of cavitations and eliminating cavitations flowing out, but also restraining the emission of noise. In conclusion, the pump with CR3DMS, on the relationship between flow and driving frequency and the relationship between flow and the number of Resistant-Layers in both theory and test, are analyzed.

Keywords： different     3-dimensional     occurrence     effective     Resistant-Layers    

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Analysis of stability and nonlinear response of rotor system with elliptical sliding bearing supports

LU Yanjun, LIU Heng, YU Lie, LI Qi, JIANG Ming, ZHANG Zhiyu

Frontiers of Mechanical Engineering 2007, Volume 2, Issue 1,   Pages 37-45 doi: 10.1007/s11465-007-0006-x

Abstract: Based on the variational constraint approach, the variational form of Reynolds equation in hydrodynamic lubrication is revised continuously to satisfy certain constraints in the cavitation zone of oil film field. According to the physical characteristic of oil film, an eight-node isoparametric finite element method is used to convert the revised variational form of Reynolds equation to a discrete form of finite dimensional algebraic variational equation. By this approach, a perturbance equation can be obtained directly on the finite element equation. Consequently, nonlinear oil film forces and their Jacobian matrices are calculated simultaneously, and compatible accuracy is obtained without increasing the computational costs. A method, which is a combination of predictor corrector mechanism and Newton Raphson method, is presented to calculate equilibrium position and critical speed corresponding to Hopf bifurcation point of bearing-rotor system, as by-product dynamic coefficients of bearing are obtained. The timescale, i.e., the unknown whirling period of Hopf bifurcation solution of bearing-rotor system is drawn into the iterative process using Poincar?Newton Floquet method. The stability of the Hopf bifurcation solution can be detected when estimating Hopf bifurcation solution and its periods. The nonlinear unbalanced periodic responses of the system are obtained by using PNF method and path-following technique. The local stability and bifurcation behaviors of periodic motions are analyzed by Floquet theory. Chaotic motions are analyzed by Lyapunov exponents. The numerical results revealed the rich and complex nonlinear behavior of the system, such as periodic, quasiperiodic, jumped solution, chaos, and coexistence of multisolution, and so on.

Keywords： computational     corrector mechanism     predictor corrector     multisolution     quasiperiodic    

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Motion-based analysis for construction workers using biomechanical methods

Xincong YANG, Yantao YU, Heng LI, Xiaochun LUO, Fenglai WANG

Frontiers of Engineering Management 2017, Volume 4, Issue 1,   Pages 84-91 doi: 10.15302/J-FEM-2017004

Abstract: Sustaining awkward postures and overexertion are common factors in construction industry that result in work-related injuries of workers. To address there safety and health issues, conventional observational methods on the external causes are tedious and subjective, while the direct measurement on the internal causes is intrusive leading to productivity reduction. Therefore, it is essential to construct an effective approach that maps the external and internal causes to realize the non-intrusive identification of safety and health risks. This research proposes a theoretical method to analyze the postures tracked by videos with biomechanical models. Through the biomechanical skeleton representation of human body, the workload and joint torques are rapidly and accurately evaluated based on the rotation angles of joints. The method is then demonstrated by two case studies about (1) plastering and (2) carrying. The experiment results illustrate the changing intramuscular torques across the construction activities in essence, validating the proposed approach to be effective in theory.

Keywords： biomechanical method     motion-based analysis     construction worker     muscular torques     workload    

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Impacts of building information modeling (BIM) implementation on design and construction performance: a resource dependence theory perspective

Dongping CAO, Heng LI, Guangbin WANG

Frontiers of Engineering Management 2017, Volume 4, Issue 1,   Pages 20-34 doi: 10.15302/J-FEM-2017010

Abstract: Drawing on resource dependence theory, this paper develops and empirically tests a model for understanding how the implementation of building information modeling (BIM) in construction projects impacts the performance of different project participating organizations through improving their interorganizational collaboration capabilities. Based on two sets of survey data collected from designers and general contractors in BIM-based construction projects in China, the results from partial least squares analysis and bootstrapping mediation test provide clear evidence that BIM-enabled capabilities of information sharing and collaborative decision-making as a whole play a significant role in determining BIM-enabled efficiency and effectiveness benefits for both designers and general contractors. The results further reveal that designers and general contractors benefit from project BIM implementation activities significantly non-equivalently, and that this non-equivalence closely relates to the different roles played by designers and general contractors in BIM-enabled interorganizational resource exchange processes. The findings validate the resource dependence theory perspective of BIM as a boundary spanning tool to manage interorganizational resource dependence in construction projects, and contribute to deepened understandings of how and why project participating organizations benefit differently from the implementation of interorganizational information technologies like BIM.

Keywords： building information modeling     interorganizational collaboration     construction project performance     resource dependence theory     partial least squares modeling    

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A low power consumption control scheme: application to a piezostack-based active mount

T. LOUKIL, O. BAREILLE, M. N. ICHCHOU, M. HADDAR

Frontiers of Mechanical Engineering 2013, Volume 8, Issue 4,   Pages 383-389 doi: 10.1007/s11465-013-0274-6

Abstract: semi-active control strategy presented by Ichchou et al. [ ] for a control system consisting of an active mount

Keywords： hybrid mount     energy     control     piezoelectric     harvesting    

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Stability and coupling dynamic behavior of nonlinear journal active electromagnetic bearing rotor system

LU Yanjun, HEI Di, WANG Yuan, DAI Rong, LU Yanjun, LIU Heng, YU Lie

Frontiers of Mechanical Engineering 2008, Volume 3, Issue 2,   Pages 193-199 doi: 10.1007/s11465-008-0023-4

Abstract: The stability and coupling dynamic behavior of a journal active electromagnetic bearing rotor system are analyzed. The gyroscopic effect is considered in the rotor model. The system equations are formulated by combining equations for rotor motion and decentralized proportional integral differential (PID) controllers. A method combining the predictor-corrector mechanism and the Netwon-Raphson method is presented to calculate the critical speed at the corresponding Hopf bifurcation point of the system. For periodic motions, a continuation method combining the predictor-corrector mechanism and shooting method is presented. Nonlinear unbalanced periodic motions and their stability margins are obtained using the shooting method and established continuation method for periodic motions. With the change of control parameters, the system local stability and bifurcation behaviors are obtained using the Floquet theory. The numerical examples show that the schemes not only significantly save computing cost, but also have high precision.

Keywords： proportional integral     bifurcation     corresponding     integral differential     predictor-corrector mechanism    

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An automated arc spray tooling system for rapid die-making of large-sized automobile body panels

HE Zhong-yun, LU Bing-heng, WANG Yi-qing, HONG Jun, TANG Yi-ping

Frontiers of Mechanical Engineering 2006, Volume 1, Issue 2,   Pages 209-214 doi: 10.1007/s11465-006-0012-4

Abstract: A creative robot wrist consisting of link mechanisms and a novel robot motion control method based on the cross-sectional vector contours of an STL-formatted model was proposed. By using the wrist and the control method, an industrial robot with five degrees of freedom for rapid tooling using metal arc spraying and electric brush plating techniques was developed. The wrist of the robot including a specially designed link mechanism can maintain the position of the spraying point on the surface of the master pattern whatever the orientation of the gun. Therefore, the kinematic nonlinear coupling between the position mechanism and orientation mechanism in a traditional robot can be avoided. The only input of the control system is the STL-formatted 3D CAD model of the pattern. Without the need of any manual programming, the metal arc spraying and brush plating (if necessary) processes can be performed automatically and efficiently after receiving the 3D CAD data of the pattern. Using this robot system in new car development and trial production, the cost and lead-time can be reduced substantially as compared with the conventional tool making method.

Keywords： industrial     position mechanism     orientation     surface     cross-sectional    

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Title Author Date Type Operation

Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

Xinfeng WANG, Wenxing WANG, Likun XUE, Xiaomei GAO, Wei NIE, Yangchun YU, Yang ZHOU, Lingxiao YANG, Qingzhu ZHANG, Tao WANG

Journal Article

Construction risks of Huaying mount tunnel and countermeasures

Haibo YAO, Feng GAO, Shigang YU, Wei DANG

Journal Article

Special issue: Advances and prospect of engineering management

Lieyun DING, Heng LI

Journal Article

Effect of calcium on porcine ICSI embryos expressing EGFP is related to activation of ooplasmic DNase I

Shuaishuai WU,Heng CHEN,Yingzheng WANG,Hui GAO,Shenming ZENG

Journal Article

Nanopositioning and Nonlinearity Compensation for Step Imprint Lithography Tool

LU Bing-heng, LIU Hong-zhong, DING Yu-cheng, WANG Li, QIU Zhi-hui

Journal Article

Heliosphere detection

Du Heng

Journal Article

Transition metal-doped heteropoly catalysts for the selective oxidation of methacrolein to methacrylic acid

Yanxia Zheng,Heng Zhang,Lei Wang,Suojiang Zhang,Shaojun Wang

Journal Article

A nano-scale alignment method for imprint lithography

WANG Li, LU Bing-heng, DING Yu-cheng, QIU Zhi-hui, LIU Hong-zhong

Journal Article

Research on the method of cavitations resistance in a piezoelectric pump with 3-dimensional mesh structure

ZHANG Jian-hui, Bai Heng-jun, XIA Qi-xiao, NING Hong-gang, ONUKI Akiyoshi

Journal Article

Analysis of stability and nonlinear response of rotor system with elliptical sliding bearing supports

LU Yanjun, LIU Heng, YU Lie, LI Qi, JIANG Ming, ZHANG Zhiyu

Journal Article

Motion-based analysis for construction workers using biomechanical methods

Xincong YANG, Yantao YU, Heng LI, Xiaochun LUO, Fenglai WANG

Journal Article

Impacts of building information modeling (BIM) implementation on design and construction performance: a resource dependence theory perspective

Dongping CAO, Heng LI, Guangbin WANG

Journal Article

A low power consumption control scheme: application to a piezostack-based active mount

T. LOUKIL, O. BAREILLE, M. N. ICHCHOU, M. HADDAR

Journal Article

Stability and coupling dynamic behavior of nonlinear journal active electromagnetic bearing rotor system

LU Yanjun, HEI Di, WANG Yuan, DAI Rong, LU Yanjun, LIU Heng, YU Lie

Journal Article

An automated arc spray tooling system for rapid die-making of large-sized automobile body panels

HE Zhong-yun, LU Bing-heng, WANG Yi-qing, HONG Jun, TANG Yi-ping

Journal Article