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Synthesis of Novel Scolopendra-type Polydodecyloxybenzoyl[1,5]-diazocine as New Material for Optical Sensor

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Chinese Journal of Polymer Science 2018年第6期36卷 736-741页

作者： Ya-Nan Liu jian-zhong Li Xiao-Bo Wan College of Chemistry and Pharmaceutical Sciences Qingdao Agricultural UniversityQingdao 266109China Qingdao institute of Bioprocess Technology Chinese Academy of ScienceQingdao 266101China

A new scolopendra-type polymer of polydodecyloxybenzoyl[1,5]-diazocine（PDBD） was designed and prepared using 2,5-bis（4-（dodecyloxy）-benzoyl）terephthaloyl azide with trifluoroacetic acid（TFA） via one-pot reaction in good yields. The structure of polymer was characterized using ~1 H-NMR, ^（13） C-NMR and MALDI-TOF spectra. The polymer PDBD exhibits good thermal stability as measured by TGA and DSC, and can be dissolved well in common organic solvents such as chloroform and tetrahydrofuran. In addition, UV-Vis spectral studies indicate that the polymer PDBD shows unique optical property changes（protonation/deprotonation） in the different trifluoroacetic acid environments. The new polymer is expected to be utilized as an optical functional material for fabricating optical sensors in environmental and biological fields.

关键词： Diazocine Scolopendra-type polymer Trifluoroacetic acid UV-Vis

RESEARCH ON THE FLOW PROPERTY IN THREE DIMENSIONAL CAVITY OF MICRO-CHANNEL

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Journal of Hydrodynamics 2006年第1期18卷 20-25页

作者： BAO Fu-bing LIN jian-zhong LIU Yan-hua Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China China Jiliang University Hangzhou 310018 China

The vortical property in a three dimensional cavity of micro-channel flow, which is very important, was investigated numerically. The results show that the rotation direction of vortex in the cavity depends on the dimension and shape of the cavity as well as the viscosity of the fluid. With the dimension and shape of the cavity fixed, there exists a critical inlet velocity. When the inlet velocity is less than the critical value, the rotation direction of vortex in the cavity will change. The critical velocity is directly proportional to the vis- cosity of the fluid, and inversely proportional to square of the thickness, length and depth of cavity. For the ratio of length and depth of cavity equals to one, there is a critical dimensionless parameter Recr , when Recr＇ is less than Recr＇ , the rotation direction of vortex will change too. Recr＇ is equal to 11.8 approximately.

关键词： micro channel cavity flow vortex numerical simulation

Influences of Temperature and Coal Particle Size on the Flash Pyrolysis of Coal in a Fast-entrained Bed

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Chemical Research in Chinese Universities 2006年第1期22卷 103-110页

作者： CUI Li-jie LIN Wei-gang YAO jian-zhong Multi-phase Reaction Laboratory Institute of Process Engineering Chinese Academy of Sciences Bering 100080 P. R. China Graduate School Chinese Academy of Sciences Beijing 100080 P. R. China

The experiments on the flash pyrolysis of a lignite were carried out in a fast-entrained bed reactor as a basic study on a so-called ＇ coal topping process＇. The investigation focused on the effects of pyrolysis temperature and coal particle size on the product distribution and composition. The experimental results show that an increase in the pyrolysis temperature results in a higher yield of gaseous products while a larger particle size leads to a decrease of the liquid yield. An optimum temperature for the liquid yield was found to be 650℃. A certain amount of phenol groups was found in the liquid products, which may be used to produce high-valued fine chemicals. The FTIR analyses of the coal and chars show that aliphatic structures in the chars are gradually replaced by aromatic structures with the increasing of pyrolysis temperature and coal particle size. The results of this study provide fundamental data and optimal conditions to maximize light oils yields for the coal topping process.

关键词： Fluidized Bed Coal Flash pyrolysis Particle Size Temperature

Numerical computations of the flow in a finite diverging channel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第1期11卷 50-60页

作者： Zhao-sheng YU Xue-ming SHAO jian-zhong LIN State Key Laboratory of Fluid Power Transmission and Control Department of Mechanics Zhejiang University Hangzhou 31002 7 China

The flow in a finite diverging channel opening into a large space and resembling the experimental prototype of Putkaradze and Vorobieff (2006) was numerically investigated. The effects of the Reynolds number,initial condition,intersection angle,length of the wedge edges,and the outer boundary condition were examined. The numerical results showed that the flow in the wedge undergoes a change from symmetrical flow to unsymmetrical flow with a weak backflow,then a vortical (circulation) flow and finally an unsteady jet flow as the Reynolds number is increased for an intersection angle of 32° and a wedge edge of length 30 times the width of the inlet slit. For the unsteady flow,the jet attached to one side of the wedge constantly loses stability and rolls up into a mushroom-shaped vortex-pair near the outlet of the wedge. As the intersection angle is increased to 50°,a stable jet flow is observed as a new regime between the vortex and unsteady regimes. Both the intersection angle and the wedge length have negative effects on the stability of the flow,although the effect of the wedge length on the critical Reynolds number for the symmetry-breaking instability is not pronounced. The outer boundary condition was found not to affect the flow patterns inside the wedge significantly. At a certain Re regime above the onset of symmetry-breaking instability,the flows evolve into steady state very slowly except for the initial stage in the case of decreasing flow flux. Two different solutions can be observed within the normal observation time for the experiment,providing a possible explanation for the hysteresis phenomenon in the experiment.

关键词： Diverging channel Flow structures Bifurcation Fictitious domain

On the hydrodynamic stability of a particle-laden flow in growing flat plate boundary layer

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第2期8卷 275-284页

作者： XIE Ming-liang LIN jian-zhong XING Fu-tang Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China College of Metrology Technology and Engineering China Jiliang University Hangzhou 310018 China Department of Environment Engineering Wuhan University of Science and Technology Wuhan 430081 China

The parabolized stability equation (PSE) was derived to study the linear stability of particle-laden flow in growing Blasius boundary layer. The stability characteristics for various Stokes numbers and particle concentrations were analyzed after solving the equation numerically using the perturbation method and finite difference. The inclusion of the nonparallel terms produces a reduction in the values of the critical Reynolds number compared with the parallel flow. There is a critical value for the effect of Stokes number, and the critical Stokes number being about unit, and the most efficient instability suppression takes place when Stokes number is of order 10. But the presence of the nonparallel terms does not affect the role of the particles in gas. That is, the addition of fine particles (Stokes number is much smaller than 1) reduces the critical Reynolds number while the addition of coarse particles (Stokes number is much larger than 1) enhances it. Qualitatively the effect of nonparallel mean flow is the same as that for the case of plane parallel flows.

关键词： Hydrodynamic stability Blasius boundary layer Particle-laden nonparallel flow Numerical simulation

Westward Migration of Tropical Cyclone Activity in the Western North Pacific during 1982–2020:Features and Possible Causes

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Journal of Meteorological Research 2024年第1期38卷 1-9页

作者： jian zhong Huadong DU Yuqin WU Yuehua PENG China Satellite Maritime Tracking and Control Department Jiangyin 2144312 College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 4100733 Dalian Naval Academy Dalian 1160184 Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029

The westward migration of tropical cyclone(TC)activity has been identified in the western North Pacific(WNP),but the related features and causes remain ***,based on the best track data from China,Japan,and the US,and the NCEP–NCAR reanalysis data in 1982–2020,we investigate characteristics of the westward migration of the WNP TC activity with various metrics,and reveal possible causes for the migration of TC tracks through analyzing its seasonality and dependence on environmental *** results show that the WNP TCs show significant westward migrations in a number of metrics,including location of tracks,genesis,the first track point at which TC reaches its lifetime-maximum intensity,and the last track point in the TC *** is found that TC tracks exhibit more significant westward migrations in the easterly steering flow than in the westerly steering ***,the TC longitude shift shows notable seasonal variations,for which the TCs in the easterlies move further west than those in the westerlies during July–September,vice versa during October–*** dependence of the westward migration of TC tracks on background steering flow is associated with the different environmental *** westward shift in the westerly steering is mainly due to the reduced vertical wind shear(VWS),while the weakened zonal easterly steering and reduced VWS are both closely related to the westward migration in the easterly *** results have important implications for understanding current and future variations in TC longitude shift.

关键词： tropical cyclone westward migration steering flow vertical wind shear

Effect of land-use and land-cover change on nutrients in soil in Bashang area,China

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Journal of Environmental Sciences 2003年第4期15卷 548-553页

作者： SHENG Xue-bin SUN jian-zhong LIU Yun-xia Research Center for Eco Environmental Sciences Chinese Academy of SciencesBeijing 100085China.

The Bashang area is a water source area and ecological barrier zone for Beijing and Tianjin. The area is located at 200 km from Beijing and Tianjin and is a typical agriculture pasture interlacing zone, in which the eco environment is vulnerable and hence it is sensitive to environmental change. The area is relatively lagged in social and economic development, where the traditional cultivation mode is predominated in agriculture and animal husbandry, but the disturbance by human activity is relatively small. Therefore, in order to reveal the interrelation between eco environmental change in the area and environmental change in Beijing and Tianjin area, it is fairly necessary to study the effect of land use and land cover change on nutrients in soil in this area. According to the actual situation of changed land use for the limited time period, five series of changed land plots were selected and 4 samples were collected from each series for the study. The samples were collected from different soil forming levels at the same site in different time. Analysis of the collected samples indicates that in the process of change of land use and land cover, the nutrients in soil, such as organic matter, total N, total P, total K, and available N, P, K, and B, Mo, Mn, Zn, Cu, and Fe, have regularly changed. When the land had changed from grassland and non irrigated farmland into woodland, and from non irrigated farmland into irrigated field, the nutrients in soil totally increased. But there exists some exception, i.e. quick acting N, P, K, and some microelements have appeared to be inconsistent with the mentioned above regularity in some cases.

关键词： Bashang area land use change variation of nutrients

Cascaded plasmonic nanorod antenna for large broadband local electric field enhancement

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Chinese Physics B 2019年第10期28卷 535-540页

作者： Dou Zhang zhong-jian Yang Jun He Hunan Key Laboratory of Super Microstructure and Ultrafast Process School of Physics and ElectronicsCentral South University

We propose a cascaded plasmonic nanorod antenna for large broadband electric near-field enhancement. The structure has one big gold nanorod on each side of a small two-wire antenna which consists of two small gold nanorods. For each small nanorod, the enhanced and broadened optical response can be obtained due to the efficient energy transfer from its adjacent big nanorod through strong plasmonic near-field coupling. Thus, the electric field intensity of the cascaded antenna is significantly larger and broader than that of the individual small two-wire antenna. The resonant position, field intensity enhancement, and spectral width of the cascaded antenna are highly tunable by varying the geometry of the system. The quantum efficiency of the cascaded antenna is also greatly enhanced compared with that of the small antenna. Our results are important for the applications in field-enhanced spectroscopy.

关键词： surface plasmon optical antenna electric field enhancement broadband cascaded

Bayesian networks modeling for thermal error of numerical control machine tools

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第11期9卷 1524-1530页

作者： Xin-hua YAO jian-zhong FU Zi-chen CHEN College of Mechanical and Energy Engineering Zhejiang University Hangzhou 310027 China Zhejiang Provincial Key Lab of Advanced Manufacturing Technology Hangzhou 310027 China

The interaction between the heat source location, its intensity, thermal expansion coefficient, the machine system configuration and the running environment creates complex thermal behavior of a machine tool, and also makes thermal error prediction difficult. To address this issue, a novel prediction method for machine tool thermal error based on Bayesian networks (BNs) was presented. The method described causal relationships of factors inducing thermal deformation by graph theory and estimated the thermal error by Bayesian statistical techniques. Due to the effective combination of domain knowledge and sampled data, the BN method could adapt to the change of running state of machine, and obtain satisfactory prediction accuracy. Ex- periments on spindle thermal deformation were conducted to evaluate the modeling performance. Experimental results indicate that the BN method performs far better than the least squares (LS) analysis in terms of modeling estimation accuracy.

关键词： Bayesian networks (BNs) Thermal error model Numerical control (NC) machine tool