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SIMULATION OF EFFECTS OF REACTIVE IMPURITIES ON PROPYLENE POLYMERIZATION IN LOOP REACTORS THROUGH GENERATION FUNCTION TECHNIQUE 被引量:1
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作者 罗正鸿 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2007年第4期365-377,共13页
The estimation of the amount of reactive impurities in a loop reactor is of strategic importance to the propylene polymerization industry. It is essential to investigate the level of impurities in order to develop rel... The estimation of the amount of reactive impurities in a loop reactor is of strategic importance to the propylene polymerization industry. It is essential to investigate the level of impurities in order to develop reliable monitoring and control strategies. This paper described one approach based on generation function technique with the following two steps. First, a new mechanism for propylene polymerization was proposed by considering the effects of the reactive impurities in the material on the propylene polymerization. Second, a series of equations of population balance for the propylene polymerization in loop reactors were established based on the proposed mechanism. Accordingly, the equations were transformed into the mathematic matrix through the generation function technique to investigate the effects of the reactive impurities on the propylene polymerization. Significant effects of the reactive impurities were analyzed through computational simulation. The results show that the concentration of active centre on catalysts and the polymerization conversion both decrease with the increase of the initial concentration of any reactive impurity; hydrogen concentration decreases with the increase of the initial concentration of ethylene or butylenes, whereas, it increases with the increase of the initial concentration of propadiene; the simulated weight average molecular weight and the molecular weight distribution index of polymer resins both increase with the increase of the initial concentration of ethylene or butylenes. They decrease with the increase of the initial concentration of propadiene. 展开更多
关键词 Propylene polymerization Reactive impurity Generation function technique Loop reactor
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Parameterization of the sea spray generation function with whitecap coverage
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作者 Jian Shi Wenjing Zhang +2 位作者 Xueyan Zhang Jingdong Liu Zhenyu Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2020年第8期24-33,共10页
Sea spray droplets are produced by waves breaking on the sea surface, and they vary the transfer of energy between the atmosphere and ocean. The sea spray generation function(SSGF) is generally considered as a functio... Sea spray droplets are produced by waves breaking on the sea surface, and they vary the transfer of energy between the atmosphere and ocean. The sea spray generation function(SSGF) is generally considered as a function of the initial radius of the spray droplets and the wind speed. However, ocean waves always exist at the air-sea interface, so it is not reasonable to consider only the effect of sea surface winds while ignoring the effects of ocean waves. Whitecap coverage is an important characteristic parameter of breaking waves, and researchers believe that this parameter is related to both wave state and wind speed. In this paper, the SSGF is parameterized by the whitecap coverage, and a new SSGF describing different droplet radii is organically integrated based on the whitecap coverage parameter. Then, with the relationship between the whitecap coverage and wave state, the influence of ocean waves on the SSGF for different wave states was analyzed by using observational data in the laboratory. The results show that the new SSGF that considers wave effects can reasonably describe the droplet generation process under different wave state conditions. 展开更多
关键词 sea spray generation function whitecap coverage wave state
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Optimization of Wind-Marine Hybrid Power System Configuration Based on Genetic Algorithm 被引量:1
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作者 SHI Hongda LI Linna ZHAO Chenyu 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第4期709-715,共7页
Multi-energy power systems can use energy generated from various sources to improve power generation reliability.This paper presents a cost-power generation model of a wind-tide-wave energy hybrid power system for use... Multi-energy power systems can use energy generated from various sources to improve power generation reliability.This paper presents a cost-power generation model of a wind-tide-wave energy hybrid power system for use on a remote island,where the configuration is optimized using a genetic algorithm.A mixed integer programming model is used and a novel object function,including cost and power generation,is proposed to solve the boundary problem caused by existence of two goals.Using this model,the final optimized result is found to have a good fit with local resources. 展开更多
关键词 genetic algorithm cost-power generation function multi-energy system marine energy
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Capacity and outage probability analysis of downlink MRT-SC in distributed antenna system
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作者 叶准 孙丽楠 张中兆 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2012年第3期43-48,共6页
This paper investigates the downlink capacity distribution and the outage probability of the interested area of maximum ratio transmission-selection combining(MRT-SC) scheme in the distributed antenna system(DAS).Comp... This paper investigates the downlink capacity distribution and the outage probability of the interested area of maximum ratio transmission-selection combining(MRT-SC) scheme in the distributed antenna system(DAS).Composite fading channels are assumed,which include path loss,lognormal shadowing and multi-path Rayleigh fading.Analytical approximations of the capacity's cumulative distribution function(CDF),the outage capacity,the mean capacity,and the outage probability of the interested area are derived by means of moment generation function(MGF) and Gauss-Hermite series expansion based approaches.The influence of antenna number,path loss exponent,and shadowing standard deviation on the capacity distribution are investigated.The simulation results agree with the analytical approximations well,and thus the analytical approximations are able to substitute the time-intensive Monte Carlo simulation for further investigation. 展开更多
关键词 distributed antenna system downlink capacity maximum ratio transmission selection combining moment generation function Gauss-Hermite series expansion
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Generation function for one-loop tensor reduction
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作者 Bo Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2023年第2期98-115,共18页
For loop integrals,reduction is the standard method.Having an efficient way to find reduction coefficients is an important topic in scattering amplitudes.In this paper,we present the generation functions of reduction ... For loop integrals,reduction is the standard method.Having an efficient way to find reduction coefficients is an important topic in scattering amplitudes.In this paper,we present the generation functions of reduction coefficients for general one-loop integrals with an arbitrary tensor rank in their numerator. 展开更多
关键词 generation function tensor reduction one-loop integral
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A New Shape Adjustment Method of S-λ Curve
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作者 CHEN Shu-ni ZHAO Chong ZENG Xiao-ming 《Computer Aided Drafting,Design and Manufacturing》 2014年第4期39-43,共5页
In this paper, we study a new method in shape adjustment ofS-λcurves. By examples of finite and infinite degree generation function, we get the conclusion thatS-λcurves can be adjusted by perturbation of generation ... In this paper, we study a new method in shape adjustment ofS-λcurves. By examples of finite and infinite degree generation function, we get the conclusion thatS-λcurves can be adjusted by perturbation of generation functionS(t)while the control points and parameters hold. 展开更多
关键词 S-λ curve PERTURBATION generation function
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Derivation of a wave-state-dependent sea spray generation function and its application in estimating sea spray heat flux 被引量:1
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作者 LIU Bin GUAN ChangLong +1 位作者 XIE LiAn ZHAO DongLiang 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第10期1862-1871,共10页
A sea spray generation function(SSGF)for bubble-derived droplets that takes into account the impact of wave state on whitecap coverage was presented in this study.By combining the new SSGF with a previous wave-state-d... A sea spray generation function(SSGF)for bubble-derived droplets that takes into account the impact of wave state on whitecap coverage was presented in this study.By combining the new SSGF with a previous wave-state-dependent SSGF for spume droplets,an SSGF applicable to both bubble-derived and spume droplets that includes the impacts of wave state was obtained.The produced SSGF varies with surface wind as well as with wave development.As sea surface wind increases,more sea spray droplets are produced,resulting in larger SSGFs and volume fluxes.Meanwhile,under the same wind conditions,the SSGF is mediated by wave state,with larger SSGFs corresponding to older waves and larger windsea Reynolds numbers.The impact of wave state on sea spray heat flux was then estimated by applying this SSGF while considering the thermodynamic feedback process.Under given atmospheric and oceanic conditions,the estimated sea spray heat flux increases with wind speed,wave age,and windsea Reynolds number. 展开更多
关键词 wave state sea spray sea spray generation function air-sea heat flux
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Donor-acceptor complex enables alkoxyl radical generation for metal-free inert bond functionalizations
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《Science Foundation in China》 CAS 2017年第4期6-,共1页
With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the dono... With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the donor-acceptor complex enables metal-free inert bond functionalizations,which was published in Angew Chem Int Ed(2017,56(41):12619-12623). 展开更多
关键词 Donor-acceptor complex enables alkoxyl radical generation for metal-free inert bond functionalizations
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NEW WAVE-DEPENDENT FORMULAE FOR SEA SPRAY FLUX AT AIR-SEA INTERFACE 被引量:4
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作者 SHI Jian ZHAO Dong-liang +1 位作者 LI Xun-qiang ZHONG Zhong 《Journal of Hydrodynamics》 SCIE EI CSCD 2009年第4期573-581,共9页
A bubble-derived Sea Spray Generation Function (SSGF) was deduced, which was integrated into the new wave-dependent SSGF. The effect of sea spray feedback was parameterized by the feedback coefficients A and B. The ... A bubble-derived Sea Spray Generation Function (SSGF) was deduced, which was integrated into the new wave-dependent SSGF. The effect of sea spray feedback was parameterized by the feedback coefficients A and B. The relationship of A(B) and the wind-sea Reynolds number was derived, which shows that the feedback effect of sea spray is decreasing with the wave developing. New sea spray flux formulae, including the new SSGF and new feedback coefficients, were proposed, which can reveal clearly the influence of wave state on sea spray fluxes. Spray fluxes in the Humidity Exchange Over the Sea (HEXOS) experiment were simulated again, and results show that spray momentum flux is small in this experiment, but spray heat flux is large. Comparisons of the sea spray fluxes calculated by two kinds of formulae in different wave states show that previous wave-independent spray flux formulae are the special cases of the presented new wave dependent formulae for sea spray flnx. 展开更多
关键词 sea sray flux HEXOS wave state Sea Spray Generation function (SSGF)
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Recurrence and decay a star-typed queueing properties of model with refusal
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作者 Junping LI Xiangxiang HUANG Juan WANG Lina ZHANG 《Frontiers of Mathematics in China》 SCIE CSCD 2015年第4期917-932,共16页
We consider a multiclass service system with refusal and bulk-arrival. The properties regarding recurrence, ergodicity, and decay properties of such model are discussed. The explicit criteria regarding recurrence and ... We consider a multiclass service system with refusal and bulk-arrival. The properties regarding recurrence, ergodicity, and decay properties of such model are discussed. The explicit criteria regarding recurrence and ergodicity are obtained. The stationary distribution is given in the ergodic case. Then, the exact value of the decay parameter, denoted by λE, is obtained in the transient case. The criteria for the λE-recurrence are also obtained. Finally, the corresponding λE-invariant vector/measure is considered. 展开更多
关键词 Generation function bulk-arrival queue RECURRENCE ergodicity decay parameter invariant measure
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