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Atmospheric mercury over the marine boundary layer observed during the third China Arctic Research Expedition

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Journal of Environmental Sciences 2011年第9期23卷 1424-1430页

作者： Hui kang Zhouqing Xie Institute of Polar Environment University of Science and Technology of China Hefei 230026 China

TGM measurements on board ships have proved to provide valuable complementary information to measurements by a ground based monitoring *** the third China Arctic Research Expedition （from July 11 to September 24,2008）,TGM concentrations over the marine boundary layer along the cruise path were in-situ measured using an automatic mercury vapor *** we firstly reported the results in Japan Sea,North Western Pacific Ocean and Bering Sea,where there are rare *** value ranged between 0.30 and 6.02 ng/m 3 with an average of （1.52 ± 0.68） ng/m 3 ,being slightly lower than the background value of Northern Hemisphere （1.7 ng/m 3 ）.Notably TGM showed considerably spatial and temporal ***,the average value of TGM in Bering Sea was higher than those observed in Japan Sea and North Western Pacific *** the north of Japan Sea TGM levels were found to be lower than 0.5 ng/m 3 during forward cruise and displayed obviously diurnal cycle,indicating potential oxidation of gaseous mercury in the *** pronounced episode was recorded as *** levels of TGM were observed in the coastal regions of southern Japan Sea during backward cruise due primarily to air masses transported from the adjacent mainland reflecting the contribution from anthropogenic *** ship returned back and passed through Kamchatka Peninsula TGM increased by the potential contamination from volcano emissions.

关键词： total gaseous mercury atmosphere marine boundary layer Japan Sea North Western Pacific Ocean Bering Sea

Apparel Brand Overlap Based on Customer Perceived Value and Eye-Tracking Technology

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Tsinghua Science and Technology 2018年第1期23卷 47-64页

作者： Lei Jiang kang Zhang School of Computer Software Tianjin University Tianjin 300350 China Institute of Art and Fashion Tianjin Polytechnic University Tianjin 300387 China

Competition in the apparel market has developed from preliminary price competition, quality competition, and scale competition to the current state of brand competition. The phenomenon of brand overlap cannot be avoided by apparel enterprises during the process of building and manufacturing their brands. This paper has selected nine identification elements of three dimensions, which we used to construct an apparel brand overlap identification model. This model is based on the theories of customer perceived value and brand identity and was constructed by taking consumer perspectives as the starting point. Two apparel brands from the representative international E Company have been selected as our empirical research objects. An apparel brand overlap identification model has been constructed based on questionnaire analysis and a cognitive experiment involving eye-tracking technology. In addition, the overlap elements among apparel brands, as well as the cognitive situation of consumers with regard to brand overlap, have been analyzed.

关键词： eye-tracking technology customer perceived value brand overlap brand identity apparel brand

Task assignment for minimizing application completion time using honeybee mating optimization

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Frontiers of Computer Science 2013年第3期7卷 404-415页

作者： Qinma kang Hong HE School of Information Engineering Shandong University Weihai 264209 China State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing 100190 China

Effective task assignment is essential for achieving high performance in heterogeneous distributed computing systems. This paper proposes a new technique for minimizing the parallel application time cost of task assignment based on the honeybee mating optimization （HBMO） algorithm. The HBMO approach combines the power of simulated annealing, genetic algorithms, and an effective local search heuristic to find the best possible solution to the problem within an acceptable amount of computation time. The performance of the proposed HBMO algorithm is shown by comparing it with three existing task assignment techniques on a large number of randomly generated problem instances. Experimental results indicate that the proposed HBMO algorithm outperforms the competing algorithms.

关键词： heterogeneous distributed computing task assignment task interaction graph honeybee mating optimization meta-heuristics

Dynamic data packing towards the optimization of QoC and QoS in networked control systems

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Science China(Technological Sciences) 2016年第1期59卷 72-80页

作者： kang Yu ZHAO YunBo Department of Automation and State Key Laboratory of Fire Science University of Science and Technology of China Key Laboratory of Technology in Geo-Spatial Information Processing and Application System Chinese Academy of Sciences Department of Automation Zhejiang University of Technology

A class of networked control systems is investigated whose communication network is shared with other applications. The design objective for such a system setting is not only the optimization of the control performance but also the efficient utilization of the communication resources. We observe that at a large time scale the data packet delay in the communication network is roughly varying piecewise constant, which is typically true for data networks like the Internet. Based on this observation, a dynamic data packing scheme is proposed within the recently developed packet-based control framework for networked control systems. As expected this proposed approach achieves a fine balance between the control performance and the communication utilization: the similar control performance can be obtained at dramatically reduced cost of the communication resources. Simulations illustrate the effectiveness of the proposed approach.

关键词： networked control systems packet delay variation dynamic data packing quality of control quality of service

STABILITY ANALYSIS OF COUPLED SYSTEM OF MAGNETIC HEAD AND ULTRA-THIN GAS FILM

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Journal of Hydrodynamics 2005年第2期17卷 134-140页

作者： CHENHai-xia WUJian-kang DepartmentofMechanics HuazhongUniversityofScienceandTechnologyWuhan430074China

This paper presents a pressure perturbation equation for the ultra-thin gas film lubrication of magnetic head-disk based on a generalized gas lubrication equation applicable to arbitrary Knudsen number. The gas film pressure of Air Bearing Slider (ABS) was obtained by using the operator-splitting and finite element method. The pressure perturbation equation was solved by the finite element method with unstructured triangle grids to calculate the stiffness and damping coefficients of the gas film. Modal analysis of coupled system of magnetic head and gas film was carried out to obtain natural frequencies, damping rates and mode shapes of the magnetic head vibrations. Vibration stability of Ω-type magnetic head was predicted in this work. Numerical results indicate that the natural frequencies of the coupled system increases as the gas film thickness decreases, and the natural frequencies and damping rate of the coupled vibration modes of heave and pitch motions are much lower than those of uncoupled modes. And it is concluded that the stability of magnetic head is slightly worsened when the disk rotation speed increases.

关键词： Air Bearing Slider (ABS) magnetic head gas film lubrication stability analysis

Characteristics of carbonaceous aerosols analyzed using a multiwavelength thermal/optical carbon analyzer: A case study in Lanzhou City

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Science China Earth Sciences 2019年第2期62卷 389-402页

作者： Yulan ZHANG Shichang kang State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environmental Resources Chinese Academy of Sciences Geoscience Innovation and Innovation Center of the Tibetan Plateau Chinese Academy of Sciences University of Chinese Academy of Sciences

Characteristics of atmospheric carbonaceous aerosols in Lanzhou City from December 2014 to November 2015 are analyzed using a multiwavelength thermal/optical carbon analyzer. Results reveal that average concentrations of black carbon (BC) and organic carbon in atmospheric aerosols at Lanzhou are 6.7 and 25.4 μg m^(-3), respectively, showing obvious seasonality (higher in winter and lower in summer). This is consistent with findings in cities of northern China. Primary organic aerosols and secondary organic aerosols respectively account for approximately 60% and 17% of carbonaceous aerosols. No significant seasonality is found for secondary organic carbon, indicating that its potential sources do not vary significantly throughout the study period. The mass absorption cross-section (MAC_(632nm)) of BC is 7.1 m^2g^(-1), slightly higher than that of immediately emitted BC. MAC values of BC at different wavelengths vary drastically; they are higher for ultraviolet and visible light (8.5–10.2 m^2g^(-1)) than for near-infrared light (4.9–5.7 m^2g^(-1)). The aerosol absorption optical depth generally declines from the near-infrared to the near-ultraviolet region. The values are higher in winter than in summer, thus showing there are different contributions of BC deposition in different seasons. Brown carbon (BrC) has an ?ngstr?m absorption exponent (AAE) value of approximately 2.75, which is similar to the AAE value of BrC generated by diesel combustion (2.3). The contribution of BrC to light absorption is as much as 34% at a wavelength of 635 nm. This study demonstrates that the multiwavelength thermal/optical carbon analyzer can quantify absorption properties of BrC in atmospheric aerosols. This can enhance understanding of carbonaceous aerosols and provide key parameters for simulations of climate models.

关键词： Carbonaceous aerosol Black carbon Organic carbon Brown carbon Multiwavelength thermal/optical carbon analyzer

Influence of baffle position on liquid sloshing during braking and turning of a tank truck

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第5期11卷 317-324页

作者： Ning kang Kui LIU School of Transportation Science and Engineering University of A eronautics and Asttvnautics Beijing 100191 China

The influence of baffle position on liquid sloshing during the braking and turning of a tank truck was studied using a volume of fluid (VOF) model. The forces,their positions and weight distribution during braking and the forces and rolling moment during turning were calculated. The reliability of the calculation method was validated by comparisons with experimental results. The results showed that during braking,liquid splashes in the tank and the maximum forces and G (the ratio of weight acting on the front axle to the rear axle) are large when A (the ratio of the arch area above the baffle to the area of cross section)≤0.1. When A≥0.2,as the position of the baffle is lowered,the maximum of Fx (the force in direction x) first decreases then increases,and the maximum of Fy (the force in direction y) and G increase. During turning,liquid splashes in the tank and the maximum forces and M (the rolling moment) are large when D (the ratio of the arch area above the baffle to the area of cross section)≤0.2. When D≥0.3,as the position of the baffle is lowered,the maximums of Fy,Fz (the force in direction z) and M increase.

关键词： Tank truck Volume of fluid (VOF) method Liquid sloshing Two phase flow Baffle

Synthesis of Cobalt Containing Block Copolymers Via Ring Opening Metathesis Polymerizastion (ROMP)

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Journal of Rare Earths 2004年第Z2期22卷 145-152页

作者： Bongjin Moon Minhyuk kang Departmen of Chemistry Sogang UniversityShinsoo-Dong 1-1Mapo-GuSeoul121-742Korea Departmen of ChemistrySogang UniversityShinsoo-Dong 1-1Mapo-GuSeoul121-742Korea

In order to realize a metal containing nano-structure, a block-copolymer containing alkynyl groups in one block was designed and synthesized by living ring opening metathesis polymerization (ROMP) technique. The newly developed bis-3-bromopyridine complex of Grubbs catalyst was employed in the series of polymerization and it yielded the desired polymers with great molecular weight control and narrow polydispersities. The characteristics of the block copolymers were investigated by gel permeation chromatography, H- and 13H- NMR spectroscopy. Complexation of the alkynyl group containing block copolymers by treatment with dicobalt octacarbonyl occurred smoothly in 5 min at room temperature. GPC analysis before and after cobalt complexation indicated a significant increase of the hydrodynamic volume. AFM images of the films before and after the complexation also showed a noticeable change in its morphology where grain sizes become smaller and more regular upon complexation.

关键词： ring opening metathesis polymerization (ROMP) metal containing block copolymer polynorbornene derivative

Facile synthesis of gold nanoplates by thermally reducing AuCl_4^- with aniline

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Chinese Chemical Letters 2009年第2期20卷 241-244页

作者： kang Xu State Key Laboratory of Bioelectronics Southeast University Nanjing 210096 China Jiangsu Laboratory for Biomaterials and Devices Southeast University Nanjing 210096 China School of Chemistry and Chemical engineering Southeast University Nanjing 210096 China

We herein report a one-step, wet-chemical approach to synthesizing gold nanoplates in large quantities via the AuCl4^- thermal reduction process by aniline, without introducing additional capping agent or surfactant. It is found that the reduction kinetics of AuCl4^- is greatly altered by varying the initial molar ratio of aniline to AuCl4^-. Moreover, further investigation reveals that the insitu formed polyaniline could serve effectively as a capping agent to preferably adsorb the { 1 1 1 } facets of gold crystals during a slow reduction process, directing the formation of gold nanoplates.

关键词： Gold nanoplates Aniline Shape control