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Establishment and verification of a model for the movement of pulverized sweet sorghum stalks in a rotary drum bioreactor by discrete element method

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Particuology 2020年第4期18卷 53-63页

作者： Xiangwen Guan Zhixing Zhou jihong li Shizhong li Institute of New Energy Technology Tsinghua UniversityBeijing 100084China Beijing Engineering Research Center for Biofuels Institute of New Energy TechnologyTsinghua UniversityBeijing 100084China

The mixing of raw materials in a rotary drum bioreactor is important for advanced solid-state fermentation ***,the shape,size,and other properties of pulverized sweet sorghum stalk particles are more complicated than those of the spherical *** this study,a soft rod-shaped discrete particle model was established and verified to simulate the mixing behavior of sweet sorghum stalk particles in a rotary drum *** were inspired by the particle shape and established a rod-shaped particle model by investigating the influence of the shape(length-diameter ratio)and size(diameter)on the particle packing(stack height and bed porosity).We used orthogonal simulations and extremum difference analysis to determine the main factors,optimum level,and groups of other *** on calibrated parameters,twelve sets of simulations of radial mixing in the drum were performed,and the results were compared with experiments conducted under identical operating *** average relative error between the simulation and the experiment was 10.95%,which indicates that they agreed well and that the simulation could predict the mixing process well.

关键词： Sweet sorghum particles Radial mixing Discrete element method Rotary drum bioreactor Parameter determination

Unbiased Condition of the Dispersion Effects Estimator in Unreplicated Two-Level Factorial Experiments

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Journal of Systems Science & Complexity 2016年第6期29卷 1716-1736页

作者： YANG liu li jihong WANG Yu Department of Applied Mathematics Shanxi University of Finance and Economics Computer Center Shanxi University

This article presents a general form of the estimator for identifying dispersion effects from unreplicated two-level factorial experiments,and shows that the widely used estimators such as the BH,MH,and AMH estimators are all special cases of the proposed one,designated as the G *** unbiased condition of the G estimator is proved,and a lower bound of variance of the G estimator is provided.A simulation based on a realistic design illustrates the variation of the variance and MSE(mean square error) of the G estimator on different *** estimator may be more flexible and has better performance than other methods such as the BH and MH estimators by appropriately selecting the coefficients.

关键词： Dispersion effects location-dispersion model unreplicated factorial experiments.

Enhancing mixing of cohesive particles by baffles in a rotary drum

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Particuology 2016年第2期14卷 104-110页

作者： Zhixing Zhou jihong li Jingzhi Zhou Shizhong li Junxiao Feng Institute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 China Beijing Engineering Research Centre of Biofuels China MOST-USDA Joint Research Center for Biofuels Beijing 100084 China Department of Thermal Science an-d Energy Engineering School of Mechanical Engineering University of Science and Technology Beifing Beijing 100081 China

A soft-sphere discrete cohesive powder model was used to simulate the transverse mixing of particles in a rotary drum. Using this model, the effect of cohesion strength and baffle length was investigated. Mixing time （tR） and mixing entropy were used to characterize the mixing behavior. The results showed that increasing particle cohesiveness increases tR. Baffles enhanced transverse mixing, especially for high- cohesive particles. Moreover, the baffle length played a significant role on mixing. An optimized length of 0.50 （L/R） enhances transverse mixing for high-cohesive particles, Further increases in baffle length only decreases the mixing rate by impeding the surface flow layer. In contrast to high-cohesive particles, low-cohesive particles needed much shorter baffles.A soft-sphere discrete cohesive powder model was used to simulate the transverse mixing of particles in a rotary drum. Using this model, the effect of cohesion strength and baffle length was investigated. Mixing time （tR） and mixing entropy were used to characterize the mixing behavior. The results showed that increasing particle cohesiveness increases tR. Baffles enhanced transverse mixing, especially for high- cohesive particles. Moreover, the baffle length played a significant role on mixing. An optimized length of 0.50 （L/R） enhances transverse mixing for high-cohesive particles. Further increases in baffle length only decreases the mixing rate by impeding the surface flow layer. In contrast to high-cohesive particles, low-cohesive particles needed much shorter baffles.

关键词： Cohesive particles Mixing Baffles Rotary drum

Risk-based security-constrained economic dispatch in power systems

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Journal of Modern Power Systems and Clean Energy 2013年第2期1卷 142-149页

作者： Qin WANG Aimin YANG Fushuan WEN jihong li Iowa State University AmesIA 50011-2151USA A.YANGSouth China University of TechnologyGuangzhou 510640China Zhejiang University Hangzhou 310027China Zhejiang Electric Power Corporation Hangzhou 310007China

Based on a new perspective in coordinating with the traditional"N-1"criteria and system risk,a real-time electricity market model is presented,in which the system risk is employed to model the system’s overall security *** new model is called the risk-based security-constrained economic dispatch(RB-SCED).Relative to the securityconstrained economic dispatch(SCED)used in the power industry today,the RB-SCED finds more secure and economic operating *** does this by obtaining solutions that achieve a better balance between post-contingency flows on individual branches and the overall system *** method exploits the fact that,in a SCED solution,some postcontingency branch flows which exceed their limits impose little risk while other post-contingency branch flows which are within their limits impose significant *** RB-SCED softens constraints for the former and hardens constraints for the latter,thus achieving simultaneous improvement in both security and *** this work,the basic concept and the mathematical formulation of the RB-SCED model are systematically *** results on a 9-bus system and the ISO New England actual system have demonstrated the advantages of RB-SCED over SCED.

关键词： Economic dispatch Security-constrained economic dispatch(SCED) Risk-based securityconstrained economic dispatch(RB-SCED) Contingency Power system

Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production

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Journal of Environmental Sciences 2011年第7期23卷 1122-1128页

作者： Xiaoxia Niu Xili li jihong Zhao Yigang Ren Yanqin Yang Henan Provincial Key Laboratory of Surface and Interface Science School of Materials and Chemical Engineering Zhengzhou University of Light Industry Zhengzhou 450002 China

The aim of the present work was to produce a polyaluminium ferric silicate chloride （PAFSiC） coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride （PAC）. The PAFSiC coagulant was prepared by co-polymerization. The effects of （Al＋Fe）/Si molar ratio, OH/（Al＋Fe） molar ratio （i.e., γ value）, coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand （COD）, and total phosphate （TP）. The PAFSiC with a γ value of 2.0 and （Al＋Fe）/Si ratio of 5 （PAFSiC 2.0/5） showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0–9.0, slightly wider than that of PAC （6.0–8.0）. The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant.

关键词： polyaluminium ferric silicate chloride industrial minerals recycling coagulant wastewater

√2 Rule for Controlling the Tree Pattern in Forest Cut

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Frontiers in Biology 2006年第1期1卷 71-75页

作者： Luo Chuanwen li jihong College of Forestry Northeast Forestry UniversityHarbin 150040China Forest Management Department College of ForestryNortheast Forestry UniversityHarbin 150040China

A forest’s productivity can be optimized by the application of rules derived from monopolized circles.A monopolized circle is defined as a circle whose center is a tree and whose radius is half of the distance between the tree itself and its nearest *** characteristics of monopolized circle are proved.(1)Monopolized circles do not overlay each other,the nearest relationship being tangent.(2)“Full uniform pattern”means that the grid of trees(a×b=N)covers the whole plot,so that the distance between each tree in a row is the same as the row *** total monopolized circle area with a full uniform pattern is independent on the number of trees and4 times the plot area.(3)If a tree is removed,the area of some trees’monopolized circle will increase without decreasing the monopolized circles of the other *** to the above three characteristics,“uniform index”is defined as the total area of monopolized circles in a plot divided by the total area of the monopolized circles,arranged in a uniform pattern in the same shaped *** to the definition of monopolized circle,the distribution of uniform index(L)=x^(2)(2n)/2πn for a random pattern and E(L)=1/n;the variance of L is D(L)=1/nπ^(2).It is evident that E(L)is independent on N and the plot area;hence,L is a relative index.L can be used to compare the uniformity among plots with different areas and the numbers of *** a random pattern,where L is equivalent to the tree density of the plot in which the number of trees is 1 and the area isπ,the influence of tree number and plot area to L is *** n→∞,D(L)→0 and L→1/π=0.318;it indicates that the greater the number of tree is in the plots,the smaller the difference between the uniform indices will *** are three types of patterns for describing tree distribution(aggregated,random,and uniform patterns).Since the distribution of L in the random pattern is accurately derived,L can be used to test the pattern *** research on M

关键词： forest ecology monopolized circle pattern Poisson distribution pattern control uniform index

Electrospun naringin-loaded microsphere/sucrose acetate isobutyrate system promotes macrophage polarization toward M2 and facilitates osteoporotic bone defect repair

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Regenerative Biomaterials 2023年第1期10卷 470-485页

作者： jihong li Jinlin Song Di Meng Yin Yi Ting Zhang Yu Shu Xiaohong Wu Stomatological Hospital of Chongqing Medical University No.426 Songshibei RoadYubei DistrictChongqing 401147China Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences Chongqing 401147China Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing 401147China

Repairing osteoporotic bone defects is still a major clinical *** studies have revealed that immune response is also essential in *** intrinsic inflammatory response of the host,especially the M1/M2 polarization status and inflammatory secretory function of macrophages,can directly affect osteogenic ***,in this study,an electrospun naringin-loaded microspheres/sucrose acetate isobutyrate(Ng-m-SAIB)system was constructed to investigate its effect on the polarization of macrophage and osteoporotic bone *** results of both in vitro and in vivo experiments showed that Ng-m-SAIB had good biocompatibility and could promote the polarization of macrophage toward M2,thereby forming a favorable microenvironment for *** animal experiments also showed that Ng-m-SAIB could promote the osteogenesis of critical size defects in the skull of the osteoporotic model mouse(the senescence-accelerated mouse-strain P6).Together,these results collectively suggested that Ng-m-SAIB might be a promising biomaterial to treat osteoporotic bone defects with favorable osteo-immunomodulatory effects.

关键词： electrospun microspheres macrophage polarization Ng-m-SAIB osteoporotic bone defects

Outline of Metallogenic Regularity of Bauxite Deposits in China

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Acta Geologica Sinica(English Edition) 2015年第6期89卷 2072-2084页

作者： GAO Lan li jihong WANG Denghong XIONG Xiaoyun YI Chengwei HAN Meizhi MRL Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological Science Hubei Land Resources Vocational College China University of Mining & Technology China University of Geosciences

Among the abundant aluminum ore resources in China, bauxite is dominated, which is mainly distributed in 19 provinces and regions, including Shanxi, Henan, Guizhou and Guangxi. The major deposit type of bauxite is paleo-weathering crust sedimentary type, and the other one is the accumulation type. The main metallogenic period is the late Paleozoic Era followed by the Cenozoic Era. The metallogenic tectonic background is characterized by a cratonic environment. This paper summarizes the bauxite metallogenic regularity based on the characteristics of bauxite resources, bauxite deposit type, bauxite metallogenic belt and metallogenic series in China, and 15 bauxite metallogenic belts, 8 bauxite metallogenic series and 7 bauxite ore concentrated areas were identified in the study. This paper also provides a theoretical basis for the evaluation of the potential of bauxite resources.

关键词： bauxite deposit type bauxite metallogenic belt metallogenic series metallogenicregularity

Do root modules still exist after they die?

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Forest Ecosystems 2021年第2期8卷 303-310页

作者： jihong li Chengming You li Zhang Han li Bo Tan Yang liu lixia Wang Sining liu Zhenfeng Xu Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province&National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River&Rainy Area of West China Plantation Ecosystem Permanent Scientific Research Base Institute of Ecology&ForestrySichuan Agricultural UniversityChengdu 611130China

Background:The terminal branch orders of plant root systems are increasingly known as an ephemeral *** concept is crucial to recognize belowground ***,it is unknown if root modules still exist after they die?Methods:The decomposition patterns of the first five root orders were observed for 3 years using a branch-order classification,a litter-bag method and sequential sampling in a common subalpine tree species(Picea asperata)of southwestern ***:Two root modules were observed during the 3-year *** the first five branch orders,the first three order roots exhibited temporal patterns of mass loss,nutrients and stoichiometry distinct from their woody mother roots throughout the experimental *** study,for the first time,reported the decomposition pattern of each individual root order and found a similar decomposition dynamic among ephemeral root branches in a forest tree ***:Results from this study suggest that root modules may also exist after death,while more data are needed for *** findings may further advance our understanding of architecture-associated functional heterogeneity in the fine-root system and also improve our ability to predict belowground processes.

关键词： Root branch order Fine roots Picea asperata Nitrogen Phosphorus Stoichiometry Root decomposition