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High-accuracy calibration for multi-laser powder bed fusion via in situ detection and parameter identification

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Advances in Manufacturing 2022年第4期10卷 556-570页

作者： Qi Zhong xiao-yong tian xiao-Kang Huang Zhi-Qiang Tong Yi Cao Di-Chen Li State Key Laboratory of Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an710049People’s Republic of China

Multi-laser powder bed fusion(ML-PBF)adopts multiple laser-scanner systems to increase the build envelope and build speed,but its calibration is an iterative and time-consuming *** particular,multiple large-scale scan fields have a complex distortion in the overlap area,challenging the calibration *** this study,owing to the enormous workload and alignment problems in the calibration of multiple scan fields,a novel calibration system is designed in this study to realize in situ auto-detection of numerous laser spots in the build chamber to ensure high efficiency and ***,because the detectable area could not cover the entire build area and the detection data still contained errors,a virtual laser-scanner system was established by identifying the assembly defects and galvo nonlinearities of the ML-PBF system from the detection data,which served as the system's controller to improve calibration *** multi-field alignment error was less than 0.012%,which could avoid the intersection and separation of scan paths in multi-laser scanning and therefore meet the requirements for high-precision ***,the reliability of the method was verified theoretically using principal component analysis.

关键词： Powder bed fusion Multi-laser technology Galvo calibration Assembly defects System identification

Real-time process control of powder bed fusion by monitoring dynamic temperature field

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Advances in Manufacturing 2020年第3期8卷 380-391页

作者： xiao-Kang Huang xiao-yong tian Qi Zhong Shun-Wen He Chun-Bao Huo Yi Cao Zhi-Qiang Tong Di-Chen Li State Key Laboratory of Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an710049People’s Republic of China

This study aims to optimize the uniformity of the temperature field during sintering to improve part performance.A temperature-field monitoring system is established based on an infrared thermal imager and the temperature field data obtained during the sintering of a part can be measured in real *** relationship among the sintering temperature field,sintering process parameters,and part performance is established ***,a temperature field monitoring and analysis system is constructed,and various sintering temperature-field control strategies are established for various part ***,a dynamic control strategy for controlling the temperature field during sintering is proposed,experimentally validated,and fully integrated into a developed powder bed fusion(PBF)*** eight-shaped standard parts,the range of sintering temperature field is optimized from 44.1℃to 19.7℃,whereas the tensile strength of the parts increased by 15.4%.For large-size H parts,localized over burning is eliminated and the final quality of the part is *** strategy is critical for the optimization of the PBF process for large-sized parts,in particular in the large-sized die manufacturing industry,which offers promise in the optimization of part performance.

关键词： Powder bed fusion(PBF) Sintering temperature field Monitoring system Infrared thermal imager

Calculation Method of Optimal Speed Profile for Hot Plate During Controlled Cooling Process

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Journal of Iron and Steel Research International 2011年第5期18卷 38-41页

作者： WANG Bing-xing CHEN xiao-lin tian yong WANG Zhao-dong WANG Jun ZHANG Dian-hua State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110004LiaoningChina

The healthy and rapid development of the controlled cooling technology was hampered by the uneven cooling phenomenon. During the process of hot plate production,the homogeneous cooling along the length direction of plate was constrained by lots of factors. And because the speed was a flexible control parameter,the calculation method of optimal speed profile was developed based on the measured start cooling temperature and its matrix equation was solved by the Cholesky decomposition method. The optimal speed profile was used in online control system. As a result,the temperature distribution along the plate length direction was relatively uniform,and 95% of measured final cooling temperature difference from the target temperature 700 ℃ was controlled within ±20 ℃.

关键词： plate controlled cooling homogeneous cooling speed profile Cholesky decomposition method

Simulation Model for Photosynthetic Production in Oilseed Rape

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Pedosphere 2009年第6期19卷 700-710页

作者： TANG Liang, ZHU Yan 2 , LIU xiao-Jun, tian yong-Chao, YAO Xia and CAO Wei-Xing Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095 (China) [a]Jiangsu Key Laboratory for Information Agriculture Nanjing Agricultural University Nanjing 210095 (China)

Photosynthetic production is a major determinant of final yield in crop plants. A simulation model was developed for canopy photosynthesis and dry matter accumulation in oilseed rape (Brassica napus L.) based on the ecophysiological processes and using a three-layer radiation balance scheme for calculating the radiation interception and absorption by the layers of flowers, pods, and leaves within the canopy. Gaussian integration method was used to calculate photosynthesis of the pod and leaf layers, and the daily total canopy photosynthesis was determined by the sum of photosynthesis from the two layers of green organs. The effects of physiological age, temperature, nitrogen, and water deficit on maximum photosynthetic rate were quantified. Maintenance and growth respiration were estimated to determine net photosynthetic production. Partition index of the shoot in relation to physiological development time was used to calculate shoot dry matter from plant biomass and shoot biomass loss because of freezing was quantified by temperature effectiveness. Testing of the model for dynamic dry matter accumulation through field experiments of different genotypes, sowing dates, and nitrogen levels showed good fit between the observed and simulated data, with an average root mean square error of 10.9% for shoot dry matter. Thus, the present model appears to be reliable for the prediction of photosynthetic production in oilseed rape.

关键词： canopy CO2 assimilation dry matter accumulation N nutrition index radiation

社会资本影响农村生态环境治理的机制与对策分析

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理论探讨 2018年第1期 113-119页

作者：肖永添北京师范大学(珠海)特许经营学院广东珠海519085

在对社会资本影响农村生态环境治理的机制进行分析的基础上,探讨了政府治理机制与社会资本治理机制之间的关系,并提出相应的对策建议。研究发现我国农村地区的社会资本具有如下特性:关系网络的封闭性和同质性;规范的非正式性和道德声誉... 详细信息

在对社会资本影响农村生态环境治理的机制进行分析的基础上,探讨了政府治理机制与社会资本治理机制之间的关系,并提出相应的对策建议。研究发现我国农村地区的社会资本具有如下特性:关系网络的封闭性和同质性;规范的非正式性和道德声誉的重要性;信任的人际性和信任半径的有限性。这三个特征导致社会资本治理机制并不必然带来农村生态环境的治理和保护,但是其在小范围生态环境治理方面的效率要远远高于其在大范围生态环境治理方面的效率。同时,无论是目前主导的政府治理机制还是社会资本治理机制,都存在其自身的局限性,但是这两种治理机制之间并不是矛盾的。社会资本机制可以有效提高政府机制的治理能力,同时拓宽污染关系人的参与渠道;政府机制则可以解决大范围农村生态环境的治理问题,同时在一定程度上缓解社会资本机制所不能应对的新型生态环境治理问题。所以,社会资本机制和政府机制中的治理方式可以相互补充,共同发挥作用,促进农村生态环境的改善。

关键词：社会资本农村生态环境政府治理机制

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基于AMBA总线接口的以太网IP核

计算机工程 2007年第22期33卷 252-254,257页

作者：刘虎肖永田章军中国科学院计算技术研究所北京100083

介绍了一款32位SoC芯片中基于AMBA AHB总线接口的以太网IP核的设计。目前该IP核已通过RTL级测试与FPGA验证。通过性能测试,表明该以太网IP核能满足许多实际应用的需求。由于其具有标准的总线接口,因此完全可以作为一个可重用的IP核。

关键词：以太网控制器 SoC AMBA IP核

Characteristics of gut microbiota dysbiosis in patients with colorectal polyps

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World Journal of Gastrointestinal Oncology 2025年第1期17卷 13-21页

作者： Xian-Rong Wu xiao-Hong He yong-Fang Xie School of Life Health Information Science and Engineering Chongqing Post and Communications UniversityChongqing 400065China

This editorial,inspired by a recent study published in the World Journal of Gastrointestinal Oncology,covers the research findings on microbiota changes in various *** recurrent colorectal polyps,the abundances of Klebsiella,Parvimonas,and Clostridium increase,while those of Bifidobacterium and Lactoba-cillus *** dysbiosis may promote the formation and recurrence of *** microbial changes have also been observed in colorectal cancer,inflammatory bowel disease,autism spectrum disorder,and metabolic syndrome,indicating the role of increased pathogens and decreased probiotics in these *** the gut microbiota,particularly by increasing probiotic levels,may help prevent polyp recurrence and promote gut *** microbial intervention strategy holds promise as an adjunctive treatment for patients with colorectal polyps.

关键词： Recurrent colorectal polyps Gut microbiota dysbiosis Klebsiella Probiotics Intestinal inflammation Microbial intervention strategy

川西獐牙菜牻牛儿基焦磷酸合成酶基因的克隆及表达分析

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中草药 2017年第5期48卷 962-970页

作者：向蓓蓓李晓雪王勇田晓轩杨琳马琳天津中医药大学中药学院天津300193 南开大学生命科学学院天津300071 天津中医药大学中医药研究院天津300193 天津师范大学生命科学学院天津300387

目的从川西獐牙菜Swertia mussotii中克隆牻牛儿基焦磷酸合成酶(Sm GPPS)编码基因,并进行生物信息分析及该基因的表达研究。方法根据川西獐牙菜转录组Sm GPPS基因序列,设计特异性引物,通过RT-PCR扩增得到c DNA序列,通过生物信息对该序... 详细信息

目的从川西獐牙菜Swertia mussotii中克隆牻牛儿基焦磷酸合成酶(Sm GPPS)编码基因,并进行生物信息分析及该基因的表达研究。方法根据川西獐牙菜转录组Sm GPPS基因序列,设计特异性引物,通过RT-PCR扩增得到c DNA序列,通过生物信息对该序列进行分析;构建原核表达载体p ET-28a-Sm GPPS,转入大肠杆菌BL-21(DE3)中,在37℃、1 mmol/L IPTG诱导下进行表达。采用半定量RT-PCR方法检测Sm GPPS基因在川西獐牙菜不同组织中的表达强度。结果 Sm GPPS c DNA全长1 119bp,编码372个氨基酸。并对其蛋白二级、三级结构进行了分析和预测。Sm GPPS蛋白与其他植物中GPPS蛋白具有高度的相似性。SDS-PAGE结果表明所表达蛋白与预期蛋白大小一致。半定量RT-PCR结果表明Sm GPPS在叶中表达量最高。结论为进一步研究该基因的功能和利用基因工程手段提高川西獐牙菜中环烯醚萜类化合物产量提供了基础。

关键词：川西獐牙菜牻牛儿基焦磷酸合成酶基因克隆生物信息学分析原核表达半定量RT-PCR

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一种通过互联网实现异地仿真的解决方案

系统仿真学报 2004年第12期16卷 2661-2663页

作者：张振山余小勇柴天佑东北大学自动化研究中心沈阳110004

为实现用IE调用远程的仿真资源并进行实验和研究,提出了采用客户层、应用服务层和数据层三层结构的解决方案,并为数据实时传输开发了基于SOCKET的通讯接口。与采用大型分布式网上仿真平台实现仿真资源异地使用相比,此架构简单实用,无需... 详细信息

为实现用IE调用远程的仿真资源并进行实验和研究,提出了采用客户层、应用服务层和数据层三层结构的解决方案,并为数据实时传输开发了基于SOCKET的通讯接口。与采用大型分布式网上仿真平台实现仿真资源异地使用相比,此架构简单实用,无需在本地搭建专业级的硬件和软件仿真环境,也无需将仿真模型源代码下载到本地,从而方便了技术交流与合作,使得仿真资源的使用更加便捷。所提方案在某钢厂连退张力仿真系统项目中得到实现。最后还对所提架构存在的问题进行了说明,提出了改进方案。

关键词：异地仿真远程仿真 Linux socket