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面向合同生产的钢铁企业多阶段生产物流平衡模型 被引量:10
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作者 李苏剑 常志明 《北京科技大学学报》 EI CAS CSCD 北大核心 1999年第6期535-538,共4页
研究了典型钢铁产品生产工艺流程下的生产物流平衡问题,建立了面向合同交货期和交货量的多阶段生产物流平衡模型.采用启发式算法及粗平衡和细平衡通过调整用户合同的交货期予以解决.
关键词 钢铁企业 生产物流平衡 面向合同生产 粗平衡
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基于GCMR的中子输运方程模拟加速算法研究
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作者 李伟 喻宏 《计算机仿真》 北大核心 2021年第10期293-296,348,共5页
特征线方法(MOC)由于较强的复杂几何适应能力,广泛用于中子输运方程的求解。但是MOC方法存在收敛速度慢、计算耗时长的问题,因此目前普遍采粗网有限差分法(CMFD)对MOC求解过程进行加速。然而目前常用的CMFD方程不能保证偏中子流守恒,同... 特征线方法(MOC)由于较强的复杂几何适应能力,广泛用于中子输运方程的求解。但是MOC方法存在收敛速度慢、计算耗时长的问题,因此目前普遍采粗网有限差分法(CMFD)对MOC求解过程进行加速。然而目前常用的CMFD方程不能保证偏中子流守恒,同时在一些情况下存在发散的问题。为此考虑采用广义粗网再平衡方法(GCMR)对MOC求解过程进行加速。推导了基于GCMR方法的中子通量求解方程,并在DRAGON程序中加入了GCMR加速模块。最后结合C5G7-2D基准题对GCMR算法进行了验证,并与CMFD加速方法进行了对比。结果表明,GCMR具有与CMFD相同的加速效果,但是求解精度优于CMFD。 展开更多
关键词 广义网再平衡 网有限差分 中子输运方程 加速算法
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求解中子输运方程的粗网格再平衡方法
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作者 胡谨 袁达明 《数学的实践与认识》 北大核心 2019年第9期193-197,共5页
针对已知中子输运方程的标量通量P1近似值和网格边界通量模型情况下,我们提出了一种求解中子输运方程新的粗网格再平衡方法.方法将再平衡系统的稀疏矩阵变成对角占优矩阵,同时矩阵的逆是非负的.
关键词 输运方程 网格再平衡 源迭代法 保正算法
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Recovery of indium and lead from lead bullion 被引量:3
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作者 何静 王瑞祥 刘维 《Journal of Central South University of Technology》 EI 2008年第6期835-839,共5页
Lead and indium were recovered by electrolysis and nonequilibrium solvent extraction process from lead bullion. The effects of current density, electrolytic period and circle arpJ ant of electrolyte on the electrochem... Lead and indium were recovered by electrolysis and nonequilibrium solvent extraction process from lead bullion. The effects of current density, electrolytic period and circle arpJ ant of electrolyte on the electrochemical dissolution of lead and indium were investigated. The effects of extraction phase ratio and mixing time on solvent extraction of indium and striping phase ratio and stripping stage on the loaded organic phase stripping were also investigated. The experimental results indicate that under optimum conditions, the purity of lead deposited on cathode is 98.5% and the deposit rate of lead is 99.9%, the dissolution rate of indium is 94.28%, the extraction rate of indium is 98.69%, the stripping rate of indium is almost 100%, and the impurity elements, such as Zn, Fe and Sn can be removed. 展开更多
关键词 lead bullion INDIUM electrochemical dissolution nonequilibrium solvent extraction
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秸秆粉碎还田机刀轴的改进设计
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作者 牛吉朋 屈晓玮 +1 位作者 银广 王永亮 《南方农业》 2015年第6期166-167,共2页
介绍了1JH-180Q型刚性秸秆粉碎还田机的工作原理和结构特点,主要对刀轴优化结构设计,并对生产制造过程中出现的问题提出解决办法,与国内现有秸秆还田机相比具有机架刚性强、使用寿命长、粉碎效果好等特点。
关键词 秸秆粉碎还田机 刀轴 平衡
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Tool sharpness in precision micro cutting process
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作者 李晓舟 于化东 +1 位作者 赵平 许金凯 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2010年第1期123-126,共4页
As to probe the factors affecting the roughness and surface properties of work piece in mirco-cutting machining process, according to the principle of energy balance, using the method of experiments combining with the... As to probe the factors affecting the roughness and surface properties of work piece in mirco-cutting machining process, according to the principle of energy balance, using the method of experiments combining with theoretical analysis, this paper investigates the effect of cutting edge radius on the unit cutting force, the cutting component forces ratio Fy/Fz, as well as the roughness and surface properties of the work-piece. Experimental results show that the value of tool cutting edge arc ρ has a significant impact on elastic-plastic deformation of the cutting area, and its influence on the surface quality of processing and precision is greater than common cutting. The method of calculating the theoretical limits of the diamond tool cutting edge radius is feasible. The value of 0.0001 μm has some guiding significance for the developement of suitable cutting thickness to ensure the normal cutting. 展开更多
关键词 cutting tools sharpness micro-cutting
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企业主生产计划的编制
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作者 何荣春 李苏剑 丁文英 《中国物流与采购》 北大核心 2003年第19期34-36,共3页
关键词 企业 主生产计划 编制方法 时间长度 单位 产品需求信息 资源平衡
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Effects of reducing dietary protein on the expression of nutrition sensing genes(amino acid transporters) in weaned piglets 被引量:3
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作者 Li WU Liu-qin HE +5 位作者 Zhi-jie CUI Gang LIU Kang YAO Fei WU Jun LI Tie-jun LI 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2015年第6期496-502,共7页
The effects of crude protein(CP) levels in the diet on the m RNA expression of amino acid(AA) transporters were studied in a 45-d trial. Eighteen piglets with an initial body weight(BW) of 9.57 kg were assigned ... The effects of crude protein(CP) levels in the diet on the m RNA expression of amino acid(AA) transporters were studied in a 45-d trial. Eighteen piglets with an initial body weight(BW) of 9.57 kg were assigned to three groups(14%, 17%, and 20% CP in the diet) in a completely randomized design(six replicates per treatment). Diets were supplemented with crystalline AA to achieve equal standardized ileal digestible contents of Lys, Met plus Cys, Thr, and Trp, and were provided ad libitum. After 45 d, all piglets were slaughtered to collect small intestine samples. Compared with the values in the 14% CP group, the expressions of ASCT2, 4F2 hc, and ATB0 m RNA in the jejunum were increased by 23.00%, 12.00%, 6.00% and 48.00%, 47.00%, 56.00% in the 17% and 20% CP groups, respectively. These results indicate that a 14% CP diet supplemented with crystalline AA may not transport enough AA into the body and maintain growth performance of piglets. However, a reduction of dietary 17% CP may reduce the excretion of nitrogen into the environment while supporting the development of piglets. Therefore, the 17% CP level is more suitable than 14% CP level. 展开更多
关键词 Crude protein Amino acid balance Amino acid transporters
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Construction of Coarse-Grained Models by Reproducing Equilibrium Probability Density Function
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作者 吕世靖 周昕 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第1期10-18,共9页
The present work proposes a novel methodology for constructing coarse-grained (CG) models, which aims at minimizing the difference between CG model and the corresponding original system. The difference is defined as... The present work proposes a novel methodology for constructing coarse-grained (CG) models, which aims at minimizing the difference between CG model and the corresponding original system. The difference is defined as a functional of their equilibrium conformationaJ probability densities, then is estimated from equilibrium averages of many independent physical quantities denoted as basis functions. An orthonormalization strategy is adopted to get the independent basis functions from su^ciently preselected interesting physical quantities of the system. Thus the current method is named as probability density matching coarse-graining (PMCG) scheme, which effectively takes into account the overall cha,~acteristics of the original systems to construct CG model, and it is a rtatural improvement of the usual CG scheme wherein some physical quantities are intuitively chosen without considering their correlations. We verify the general PMCG framework in constructing a one-site CG water model from TIP3P model. Both structure of liquids and pressure of the TIP3P water system are found to be well reproduced at the same time in the constructed CG model. 展开更多
关键词 coarse-graining models probability density functions molecular dynamics simulations
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