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Infinitesimal dividing modeling method for dual suppliers inventory model with random lead times

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Journal of Systems Engineering and Electronics 2009年第3期20卷 527-536页

作者： ji Pengcheng song Shiji wu Cheng Dept. of Automation Tsinghua Univ. Beijing 100084 P. R. China

As one of the basic inventory cost models, the （Q, τ）inventory cost model of dual suppliers with random procurement lead time is mostly formulated by using the concepts of ＂effective lead time＂ and ＂lead time demand＂, which may lead to an imprecise inventory cost. Through the real-time statistic of the inventory quantities, this paper considers the precise （Q, τ） inventory cost model of dual supplier procurement by using an infinitesimal dividing method. The traditional modeling method of the inventory cost for dual supplier procurement includes complex procedures. To reduce the complexity effectively, the presented method investigates the statistics properties in real-time of the inventory quantities with the application of the infinitesimal dividing method. It is proved that the optimal holding and shortage costs of dual supplier procurement are less than those of single supplier procurement respectively. With the assumption that both suppliers have the same distribution of lead times, the convexity of the cost function per unit time is proved. So the optimal solution can be easily obtained by applying the classical convex optimization methods. The numerical examples are given to verify the main conclusions.

关键词： inventory precise model random lead times dual supplier infinitesimal dividing method optimiza- tion.

Numerical simulation of humping phenomenon in high speed gas metal arc welding

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Frontiers of Materials Science 2011年第2期5卷 90-97页

作者： ji CHEN Chuan-song wu State Key Lab of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China Institute of Materials Joining Shandong University Jinan 250061 China

It is of great significance to obtain a thorough understanding of the physical mechanisms responsible for humping bead phenomenon in high speed gas metal arc welding （GMAW） in order to raise welding efficiency. Experiments were conducted to observe the weld pool behaviors in high speed GMAW, and it was found that both the severely deformed weld pool surface and strong backward flowing play a dominant role in humping bead formation. In this study, a mathematical model is developed to quantitatively analyze the forming mechanism of humping beads for high speed GMAW through considering both the momentum and heat content distribution of the backward flowing molten metal inside the weld pool. The transient development of temperature profiles in the weld pool with severe deformation demonstrates the humping bead forming process under some welding conditions. The predicted and measured humping bead dimensions are in agreement.

关键词： numerical simulation humping weld bead high-speed GMAW

GCr15轴承钢超高速磨削表面粗糙度与烧伤试验分析

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组合机床与自动化加工技术 2016年第9期 32-34,39页

作者：刘晓初陈凡何铨鹏冯明松姬武勋广州大学机械与电气工程学院广州510006 广州大学金属材料强化研磨高性能加工重点实验室广州510006

为了探究超高速磨削条件下GCr15轴承钢表面粗糙度与烧伤的关系,进行了不同砂轮速度、工件速度下GCr15轴承钢超高速正交磨削试验,并测量了表面粗糙度,试验结果表明：GCr15轴承钢加工表面都出现了不同程度的烧伤,当砂轮速度为150~160m/s,... 详细信息

为了探究超高速磨削条件下GCr15轴承钢表面粗糙度与烧伤的关系,进行了不同砂轮速度、工件速度下GCr15轴承钢超高速正交磨削试验,并测量了表面粗糙度,试验结果表明：GCr15轴承钢加工表面都出现了不同程度的烧伤,当砂轮速度为150~160m/s,工件速度为3~5m/min时烧伤最为严重。且在一定范围内,砂轮速度增大、工件速度增大都会造成粗糙度增加。通过烧伤表面三维形貌分析,揭示了烧伤会增加工件表面粗糙度的原理,并分析出了合适的磨削加工参数,为超高速磨削GCr15轴承钢时避免发生磨削表面烧伤提供了参考依据。

关键词： GCr15轴承钢超高速磨削表面粗糙度磨削烧伤

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多通道冻土温度与含水率监测仪研制

传感器与微系统 2018年第10期37卷 117-119,122页

作者：董翰川宋继武庞丽丽中国地质调查局水文地质环境地质调查中心河北保定071051 国土资源部地质环境监测技术重点实验室河北保定071051

研制了一种多通道冻土温度含水率监测装置,用于冻土层区域土壤温度和含水率的监测。监测仪选用特制的电容式双参数传感器感知土层温度和含水率,以PIC32MX150F128单片机(MCU)作为核心,完成采集、存储和传输时序的控制,可同时采集8个通道... 详细信息

研制了一种多通道冻土温度含水率监测装置,用于冻土层区域土壤温度和含水率的监测。监测仪选用特制的电容式双参数传感器感知土层温度和含水率,以PIC32MX150F128单片机(MCU)作为核心,完成采集、存储和传输时序的控制,可同时采集8个通道数据。目前,监测仪已应用于张家口市崇礼县枯杨树村冻土层的监测。实际应用表明:研制的监测仪工作稳定可靠,能够监测冻土层的温度和含水率2种参数,为地质环境调查提供技术支撑。

关键词：冻土监测多通道 PIC32单片机温度和含水率

Layer-wise domain correction for unsupervised domain adaptation

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Frontiers of Information Technology & Electronic Engineering 2018年第1期19卷 91-103页

作者： Shuang LI Shi-ji song Cheng wu Automation Department Tsinghua University

Deep neural networks have been successfully applied to numerous machine learning tasks because of their impressive feature abstraction ***,conventional deep networks assume that the training and test data are sampled from the same distribution,and this assumption is often violated in real-world *** address the domain shift or data bias problems,we introduce layer-wise domain correction(LDC),a new unsupervised domain adaptation algorithm which adapts an existing deep network through additive correction layers spaced throughout the *** the additive layers,the representations of source and target domains can be perfectly *** corrections that are trained via maximum mean discrepancy,adapt to the target domain while increasing the representational capacity of the *** requires no target labels,achieves state-of-the-art performance across several adaptation benchmarks,and requires significantly less training time than existing adaptation methods.

关键词： Unsupervised domain adaptation Maximum mean discrepancy Residual network Deep learning

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不同齿科铸造合金电化学腐蚀的观测研究

口腔颌面修复学杂志 2007年第1期8卷 11-14页

作者：牟月照宋继武柳云霞山东大学山东省立医院口腔科副主任主任医师教授山东250021

目的:研究不同牙科铸造合金或合金的不同处理形式对合金耐腐蚀性能的影响,为临床烤瓷合金的选择提供依据。方法:(1)采用铸造方法分别制作普通镍铬合金、镍铬合金镀金及金合金试样各8个,在人工唾液中测定各试样的极化曲线。(2)对临床采... 详细信息

目的:研究不同牙科铸造合金或合金的不同处理形式对合金耐腐蚀性能的影响,为临床烤瓷合金的选择提供依据。方法:(1)采用铸造方法分别制作普通镍铬合金、镍铬合金镀金及金合金试样各8个,在人工唾液中测定各试样的极化曲线。(2)对临床采用上述3种合金烤瓷冠修复的735例病例,在修复1年后,分组对临床观察效果进行统计分析。结果:(1)镍铬合金试件和镀金试件,两次的阳极极化曲线皆有明显差异;贵金属试件,极化曲线的斜率和低腐蚀区宽度均无明显变化。(2)修复体戴用1年后,镍铬合金与镍铬合金镀金烤瓷的牙龈指数差异有显著性(P<0.05),而镀金与贵金属烤瓷修复体的牙龈指数差异无显著性(P<0.05);3组病例的菌斑指数在1年内差异均无显著性(P<0.05);镍铬合金烤瓷修复体牙龈退缩的比率明显高于其他2组(P<0.05),而镀金与贵金属烤瓷修复体牙龈退缩的比率无明显差别(P<0.05)。结论:应用极化曲线可以分析金属的表面状态,从而确定金属在何种情况下耐腐蚀性更好。就耐腐蚀性而言,贵金属合金最优,镀金次之,普通烤瓷合金最差。镀金试件镀层不全可造成合金更易受腐蚀,但随着时间的延长,其耐腐蚀能力增强。

关键词：牙科铸造合金电化学腐蚀极化曲线烤瓷熔附金属修复体

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三种不同烤瓷合金电化学腐蚀的试验研究

中华老年口腔医学杂志 2011年第2期9卷 80-82页

作者：宋继武柳云霞刘宗霞潍坊市人民医院牙科主治医师山东261041 潍坊医学院口腔学院助教山东261053

目的:研究不同烤瓷合金在人工唾液中的电化学行为,从而为临床应用提供依据。方法:采用铸造方法制作牙科合金试样,分别为:镍铬合金试件8个,镍铬合金镀金试件8个,金合金试件8个。在人工唾液中测定试件的自腐蚀电位,并测定其极化曲线。结果... 详细信息

目的:研究不同烤瓷合金在人工唾液中的电化学行为,从而为临床应用提供依据。方法:采用铸造方法制作牙科合金试样,分别为:镍铬合金试件8个,镍铬合金镀金试件8个,金合金试件8个。在人工唾液中测定试件的自腐蚀电位,并测定其极化曲线。结果:自腐蚀电位以金合金试件最高,镍铬合金试件次之,镍铬合金镀金试件最低。极化曲线结果表明镍铬合金镀金试件和金合金试件具有较大的钝化区域,而镍铬合金试件的钝化区间则较小。结论:从电化学表现看,镍铬合金镀金耐腐蚀性不优于镍铬合金,二者均不如金合金。

关键词：镍铬合金镀金电化学腐蚀

可摘局部义齿修复后龈沟液中白介素-1变化的实验研究

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临床口腔医学杂志 2010年第11期26卷 661-663页

作者：柳云霞宋继武牟月照潍坊医学院口腔医学院山东潍坊261051

目的:探讨可摘局部义齿对龈沟液中白介素-1(IL-1)表达水平的影响,为临床可摘局部义齿设计和制作提供依据。方法:对牙列缺损患者进行铸造支架式可摘局部义齿修复,修复后6个月,分别采取近缺隙侧基牙区和非基牙区龈沟液,用酶联免疫吸附法... 详细信息

目的:探讨可摘局部义齿对龈沟液中白介素-1(IL-1)表达水平的影响,为临床可摘局部义齿设计和制作提供依据。方法:对牙列缺损患者进行铸造支架式可摘局部义齿修复,修复后6个月,分别采取近缺隙侧基牙区和非基牙区龈沟液,用酶联免疫吸附法测定分析龈沟液中IL-1的表达水平。结果:可摘局部义齿修复后,近缺隙侧基牙区龈沟液中IL-1的表达水平升高,非基牙区无明显改变。结论:对于可摘局部义齿修复者,近缺隙侧基牙龈沟液中IL-1的表达水平升高,且明显高于非基牙区龈沟液IL-1水平。

关键词：可摘局部义齿龈沟液白细胞介素-1(IL-1)

Tectonic modes of mantle convection and their implications for Earth's tectonic evolution based on three-dimensional numerical simulations

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Science China Earth Sciences 2025年第1期 270-296页

作者： song XIANG jinshui HUANG Bingcheng wu School of Earth and Space Sciences University of Science and Technology of China CAS Center of Excellence in Comparative Planetary Studies

Five tectonic modes of mantle convection are obtained and analyzed with three-dimensional numerical models in a spherical shell domain. The five tectonic convective modes are non-plate mobile-lid, plate-like mobile-lid, episodic plate-like mobile-lid, episodic stagnant-lid, and stagnant-lid convective modes, respectively. The typical characteristics of these five tectonic modes and their numerical classification criteria based on plateness, mobility, and their standard deviations are presented and discussed. The results show that the yield stress of the lithosphere has profound effects on the tectonic convective *** the gradual increase of yield stress, the tectonic mode of mantle convection changes from one to another sequentially through the aforementioned five modes. Additionally, as the Rayleigh number increases, the range of yield stress for the platelike mobile-lid convective mode decreases, and the dimensionless transition stress between different tectonic modes ***, the dimensional transition stress between the non-plate mobile-lid convective mode and plate-like mobile-lid convective mode increases with the increase of Rayleigh number, but decreases between other tectonic modes. Furthermore, we find that the transition stress between different tectonic modes is inversely proportional to the internal heating rate, with the transition stress decreasing as the internal heating rate increases. The fitting analysis of the transition stress between tectonic modes shows that Earth's current plate tectonics correspond to a lithospheric yield stress of 150–250 MPa, which aligns with the strength of serpentinized mantle rock determined by experimental petrography. If the Archean mantle was 300°C warmer than it is today, then the Earth was in an episodic stagnant-lid convective mode. The tectonic evolution of the Earth's surface is closely related to the lithospheric strength and the process of thermal evolution. If the lithospheric strength w

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