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考虑实时订单更新的拼车调度双层规划模型

计算机应用研究 2024年第6期41卷 1714-1721页

作者：李佶霖袁鹏程林徐勋胡凯上海理工大学管理学院上海200093 常州大学商学院江苏常州213164

针对订单实时更新的实际情况,为仍有待完成订单的司机持续分配任务,在保证司机收益增加的同时,提升拼车平台的派单效率。在考虑拼车系统服务质量与运行成本的基础上,基于平台角度构建了以司机总收益最大化为目标的双层规划模型,并给出... 详细信息

针对订单实时更新的实际情况,为仍有待完成订单的司机持续分配任务,在保证司机收益增加的同时,提升拼车平台的派单效率。在考虑拼车系统服务质量与运行成本的基础上,基于平台角度构建了以司机总收益最大化为目标的双层规划模型,并给出求解该模型的双层算法:底层模型对拼车路径进行规划,设计改进的遗传算法求解;上层模型决定订单分配的顺序,通过贪心算法调用底层模型,比较收益变化后得到最终的调度结果。通过具体算例对模型进行验证,结果表明模型能够较快求解出订单匹配结果及行驶路线,说明了模型的可行性及算法的有效性,且计算结果能够反映实际场景。对比实验结果表明,模型在满足提升司机收益的基础上,能有效减少延误时间及降低行驶距离,对于实时订单更新场景下拼车调度问题的相关研究具有积极的参考意义。

关键词：网约拼车匹配策略路径优化双层算法

Microstructure and properties of as-cast Cu-Cr-Zr alloys with lanthanum addition

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Journal of Rare Earths 2018年第4期36卷 424-429页

作者： jilin li lili Chang Shengli li Xinde Zhu Zhongxin An Department of Material Science and Engineering Shandong UniversityJinan 250061China Zhengzhou Yutong Bus Co.Ltd. Zhengzhou 450061China

Cu-0.45 Cr-0.2 Zr-xLa（x = 0-0.48） alloys were prepared by vacuum casting. The effects of La addition and orientation on the microstructure and properties of the as-cast alloy were investigated by an optical microscope, a scanning electron microscope with an energy dispersive X-ray spectrometer, a tensile testing machine and an electrical conductivity tester. The result shows that the addition of La significantly refines the columnar grainsize and decreases the secondary dendrite arm spacing. Trace addition of La improves the room temperature ultimate tensile strength,elongation and electrical conductivity mainly by purifying during melting and casting. The ultimate tensile strength, elongation and electrical conductivity significantly decrease with the increase of La content due to formation of coarse particles and oxides, which severely harm the performance of the Cu-0.45 Cr-0.2 Zr-xLa alloys. The Cu-0.45 Cr-0.2 Zr-0.13 La alloy possesses a good combination of room temperature ultimate tensile strength, elongation and electrical conductivity. In addition, room temperature ultimate tensile strength and electrical conductivity along transverse direction of the ingot are higher than that along longitudinal direction,which is mainly ascribed to different distribution of grain boundary and grain orientation.

关键词： La Cu-Cr-Zr alloy Orientation Ultimate tensile strength Electrical conductivity Rare earths

开挖宽度对异形基坑L形转角区支护结构变形影响研究

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建筑科学与工程学报 2024年第4期41卷 159-170页

作者：李吉林尹爱月魏焕卫郑晓李青原山东电力工程咨询院有限公司山东济南250013 山东建筑大学土木工程学院山东济南250101

为研究不同开挖宽度对基坑L形转角区支护结构变形规律的影响,基于滨州市某异形深基坑工程项目的现场实测数据,分析了基坑开挖过程中L形转角区阴阳角位置处支护结构变形规律的差异性;建立了不同基坑宽深比(B/H,B和H分别为基坑宽度和深度)... 详细信息

为研究不同开挖宽度对基坑L形转角区支护结构变形规律的影响,基于滨州市某异形深基坑工程项目的现场实测数据,分析了基坑开挖过程中L形转角区阴阳角位置处支护结构变形规律的差异性;建立了不同基坑宽深比(B/H,B和H分别为基坑宽度和深度)的L形转角基坑模型,研究了不同宽深比条件下转角位置处阴阳角相互作用条件下支护桩水平变形的空间分布规律,进一步明确基坑L形转角区支护桩不同深度处水平变形受影响范围。结果表明:当B/H1.0时,阳角侧支护桩浅部水平变形受转角效应影响的范围约为1.5H;坑内底部支护桩水平变形受基坑宽深比影响不明显,受转角效应影响的范围约为0.6H;当B/H1.0时其水平变形受影响范围约为0.6H+B;坑内开挖底面位置处阴角侧支护桩水平变形受影响范围约为0.6H+B,受宽深比变化影响不明显。

关键词：异形基坑变形规律数值模拟转角效应

Characterization and Prediction of Microporosity Defect in Sand Cast WE54 Alloy Castings

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Journal of Materials Science & Technology 2014年第10期30卷 991-997页

作者： jilin li Rongshi Chen Yuequn Ma Wei Ke State Key Laboratory for Corrosion and Protection Institute of Metal ResearchChinese Academy of Sciences

In order to study the effect of Zr modification and riser size on microporosity defect distributions in WE54 alloy sand castings, the microporosity volume percentage in Zr-free and Zr-containing WE54 alloy plate castings was determined by density measurement based on Archimedes＇ principle, and the microstructure of the microporosity defects was observed by optical microscopy and scanning electron microscopy. Then by using Procast software, the Niyama criterion was calculated in order to investigate the validity of Niyama criterion on prediction of microporosity defects in WE54 alloy sand castings. It is found from the density measurement results that Zr addition does not affect the microporosity distributions in WE54 alloy castings. While the distribution area of microporosity defect in the plate castings decreases significantly as the riser size increases. Based on the experimental results, a riser selection principle for production of compact WE54 alloy castings is proposed that the solidification modulus of the riser should be greater than that of the casting by 30%, simply mr ≥ 1.3mc. By comparing the experimental and simulating results, it is found that the predicted microporosity regions by Niyama criterion agrees well with experimental results, and a critical Niyama value of 0.4 ℃0.5 s0.5 mm-1 is suggested for prediction of microporosity formation in WE54 alloy sand castings.

关键词： Microporosity defect WE54 alloy Sand cast Niyama criterion

Hot Tearing of Sand Cast Mg-5 wt.% Y-4 wt.% RE (WE54) Alloy

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Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 728-734页

作者： jilin li Rongshi CHEN Yuequn MA Wei KE State Key Laboratory for Corrosion and Protection Institute of Metal ResearchChinese Academy of Sciences

Hot tearing is a common and severe defect occurring during solidification of castings. The rational understand- ing of hot tearing formation mechanism is beneficial to the foundry process design. In the present research, a new developed instrumented ＂CRC＂ equipment was applied in characterization of hot tearing in sand cast Mg-5 wt.% Y-4 wt.% RE （WE54） alloy with and without Zr addition. Microstructure observation and thermal analysis were carried out to help analyzing the results. The results showed that hot tearing onset occurs at a relatively low solid fraction （fs） in WE54 alloy sand castings, which indicates the participation of remaining liquid during hot tearing formation. Microstructure observation of the hot tearing surface also proves the liquid film existence between solidifying dendrites. The contraction strain caused by casting solidification induces the flowing of remaining liquid between solidifying dendrites and results in formation of interdendritic liquid films. These liquid films are separated by sufficient contraction stress and form hot cracks. The addition of Zr in WE54 alloy significantly refines the alloy microstructure and increases the solid fraction at hot tearing onset, both of which result in increasing of the fracture stress of interdendritic liquid film. Thus the hot tearing susceptibility of WE54 alloy is weakened by Zr addition.

关键词： Mg-5 wt.% Y-4 wt.% RE (WE54) magnesium alloy Sand cast Hot tearingdefect Instrumented "CRC"

神经外科住院患者医院感染病原菌与耐药性分析

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沈阳医学院学报 2024年第5期26卷 485-489页

作者：李季林陈华张权刘祥璐复旦大学附属中山医院青浦分院神经外科上海201700

目的:回顾性分析神经外科住院患者常见病原菌的分布变迁及对抗菌药的耐药情况,为合理使用抗菌药物、控制耐药率提供依据。方法:收集我院神经外科2020年7月1日至2023年7月1日送检的7 636份标本检验结果,分析感染病原菌的分布及耐药率。结... 详细信息

目的:回顾性分析神经外科住院患者常见病原菌的分布变迁及对抗菌药的耐药情况,为合理使用抗菌药物、控制耐药率提供依据。方法:收集我院神经外科2020年7月1日至2023年7月1日送检的7 636份标本检验结果,分析感染病原菌的分布及耐药率。结果:7 636份送检标本,分离出3 205株病原菌;标本以痰液为主,共2 790株,占87.05%;菌种以革兰阴性菌为主,共2 586株,占80.69%;革兰阴性菌和革兰阳性菌耐药率呈上升趋势,真菌耐药率呈下降趋势;革兰阳性菌对万古霉素和利奈唑胺保持较高的敏感。结论:我院神经外科住院患者送检标本培养的病原菌中以革兰阴性菌多见,病原菌的耐药率整体呈逐年升高趋势。

关键词：神经外科住院患者医院感染病原菌耐药性

Breeding of *** translocation lines with *** cytoplasm and characterization by GISH

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Chinese Science Bulletin 2000年第15期45卷 1404-1408,1443页

作者： MU Jinye li jilin WANG Xianping JING Jiankang ZHANG Xiangqi Institute of Genetics Chinese Academy of SciencesBeijing 100101China Department of Biology Harbin Normal UniversityHarbin 150080China

A male-sterile T. aestivum-Ag. intermedium partial amphiploid with cytoplasm of T. timopheevii as a female parent was crossed to common wheat. The hybrid was backcrossed to the male parent several times continually and self-crossed at last. Two stable lines with common wheat phenotype, H96269-2 and H96278, have been obtained. The chromosome numbers of the two lines are all 2n = 42 in somatic cells. By inoculation test, the two lines show a high level of resistance to yellow rust. Through genomic in situ hybridization (GISH) with Ag. intermedium total genomic DNA as a probe, it is demonstrated that the two stable lines are all small segmental translocation lines, and the translocated chromosome segments from Ag. intermedium are located on the short arm terminals of wheat chromosomes. Genetics analysis suggests that the yellow rust resistance gene(s) are probably located on the translocated chromosome segments of Ag. intermedium.

关键词： T. aestivum-Ag. intermedium translocation line ailoplasmic line genomic in situ hybridization yellow rust.

Effect of Zr modification on solidification behavior and mechanical properties of Mg–Y–RE (WE54) alloy

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Journal of Magnesium and Alloys 2013年第4期1卷 346-351页

作者： jilin li Rongshi Chen Yuequn Ma Wei Ke State Key Laboratory for Corrosion and Protection Institute of Metal ResearchChinese Academy of Sciences62 Wencui RoadShenyang 110016China

Magnesium alloys containing rare earth elements (RE) have received considerable attention in recent years due to their high mechanical strength and good heat-resisting performance. Among them, Mg–5%Y–4%RE (WE54) magnesium alloy is a high strength sand casting magnesium alloy for use at temperatures up to 300 ℃, which is of great interest to engineers in the aerospace industry. In the present work, the solidification behavior of Zr-containing WE54 alloy and Zr-free alloy was investigated by computer-aided cooling curve analysis (CA-CCA) technique. And the solidification microstructure and mechanical properties of them were also investigated comparatively. It is found from the cooling curves and as-cast microstructure of WE54 alloy that the nucleation temperature of α-Mg in WE54 alloy increases after Zr addition, and the as-cast microstructure of the alloy is significantly refined by Zr. While the phase constitution of WE54 alloy is not changed after Zr addition. These phenomena indicate that Zr acts as heterogeneous nuclei during the solidification of WE54 alloy. Due to refined microstructure, the mechanical properties of Zr-containing WE54 alloy is much higher than Zr-free WE54 alloy.

关键词： WE54 alloy Zr modification Solidification behavior Mechanical properties

Preparation of α-High Strength Gypsum from Flue Gas Desulfurization Gypsum Pretreated by Hydrothermal-aging Method

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 75-81页

作者：苏一鑫 GAO lili 陈学青 li Zhishui 李雲 CAO jilin Engineering Research Center of Seawater Utilization Technology of Ministry of Education School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China Heze Center for Disease Control and Prevention Heze 274010China Tianjin Bohua Yongli Chemical Industry Co. Ltd.Tianjin 300452China

The synthesis of α-calcium sulfate hemihydrate (α-CSH) from flue gas desulfurization (FGD)gypsum is a good way to realize the comprehensive utilization of FGD gypsum. To obtainα-CSH with the satisfactory performances, a facile hydrothermal-aging pretreatment process for FGD gypsum raw materials was proposed, where FGD gypsum was firstly hydrothermally converted to α-CSH whiskers, and α-CSH whiskers were further hydrated to synthesize CaSO4·2H2O (CSD) by aging under the regulation of N,N'-methylenebisacrylamide (MBA). The effects of aging time, MBA addition, aging temperature, and pH on the morphology of the synthesized CSD were investigated. The synthesized CSD crystals exhibit highly uniform prismatic morphology with the length of ca 100μm and the whiteness of 91.56%. The regulation mechanism of MBA was also illustrated. The synthesized CSD crystals with prismatic morphology were further used as raw materials to synthesize the short columnar α-CSH. The absolute dry compressive strength of paste prepared from the short columnar α-CSH is 40.85 MPa, which reaches α40 strength grade.

关键词： flue gas desulphurization gypsum α-calcium sulfate hemihydrate hydrothermal-aging method N,N'-methylenebisacrylamide prismatic CSD