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Microstructure and properties of ultrafine WC-Co-VC cemented carbides with different Co contents

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Rare Metals 2022年第6期41卷 1955-1960页

作者： kai-HuaShi Ke-Chao Zhou Zhi-You Li Xiu-Qi Zan kai-Lin dong Qing Jiang State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Precision Parts Department Zigong Cemented Carbide Corporation LimitedZigong 643011China

Ultrafine WC-Co-VC cemented carbides are used extensively in a variety of industrial environments due to their excellent mechanical properties and outstanding wear *** content affects the service performance of the cemented *** the present study,the influ-ences of Co content on microstructure,physical,and mechanical properties were investigated *** WC-Co-VC cemented carbides with Co content varying from 4 wt%and 7 wt%and assistance of VC(0.35 wt%)as inhibitor of WC grain growth were *** physical and mechanical properties were tested and the microstructure characteristics were observed by optical microscope(OM)and scanning electron microscopy(SEM).From the results,it is found that with Co content increasing,both the cobalt magnetism and bending strength increase,while the coercive force,Rockwell hardness,density,and abrasive wear resistance *** addition,the OM and SEM results show that the increase of Co content in WC-Co-VC cemented carbides tends to reduce the quantity and size of micro-pores,and make the fracture mode change from brittle fracture to ductile fracture.

关键词： Ultrafine Cemented carbide Co content Microstructure Properties

AocML： A Domain-Specific Language for Model-Driven Development of Activity-Oriented Context-Aware Applications

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Journal of Computer Science & Technology 2018年第5期33卷 900-917页

作者： Xuan-Song Li Xian-Ping Tao Wei Song kai dong School of Computer Science and Engineering Nanjing University of Science and Technology Nanfing 210093 China State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210023 China School of Computer Science and Engineering Southeast University Nanjing 211189 China

Activity-oriented context-aware （AOCA） applications are representative in pervasive computing. These appli- cations recognize daily-life human activities, perceive the environment status related to the activities, and react to ensure the smooth performance of the activities. Existing research proposed a specific light-weight, incremental method to support the development of such applications; however it is not easy to learn and use. This paper aims to facilitate the development of such applications and improve the productivity of developers. We propose AocML, a textual domain-specific language which provides a high-level abstraction of AOCA applications. Specifically, we first show the software model of AOCA applications and the abstract syntax of AocML. Then, we introduce the concrete syntax of AocML. We also implement the tools for AocML, including the development environment as well as the generation of Java code and ontology specification. Moreover, we use a case study and evaluation to demonstrate the advantages of AocML.

关键词： pervasive computing context-awareness model-driven development domain-specific language

CBSC: A Crowdsensing System for Automatic Calibrating of Barometers

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Journal of Computer Science & Technology 2019年第5期34卷 1007-1019页

作者： Hai-Bo Ye Xuan-Song Li Li Sheng kai dong College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Computer Science and Engineering Southeast UniversityNanjing 211189China

The mobile crowdsensing software systems can complete large-scale and complex sensing tasks with the help of the collective intelligence from large numbers of ordinary users. In this paper, we build a typical crowdsensing system, which can efficiently calibrate large numbers of smartphone barometer sensors. The barometer sensor now becomes a very common sensor on smartphones. It is very useful in many applications, such as positioning, environment sensing and activity detection. Unfortunately, most smartphone barometers today are not accurate enough, and it is rather challenging to efficiently calibrate a large number of smartphone barometers. Here, we try to achieve this goal by designing a crowdsensingbased smartphone calibration system, which is called CBSC. It makes use of low-power barometers on smartphones and needs few reference points and little human assistant. We propose a hidden Markov model for peer-to-peer calibration, and calibrate all the barometers by solving a minimum dominating set problem. The field studies show that CBSC can get an accuracy of within 0.1 hPa in 84% cases. Compared with the traditional solutions, CBSC is more practical and the accuracy is satisfying. The experience gained when building this system can also help the development of other crowdsensing-based systems.

关键词： crowdsensing system smartphone sensing barometer calibration

Modeling of an Impinging Oxygen Jet on Molten Bath Surface in 150t EAF

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Journal of Iron and Steel Research International 2011年第9期18卷 13-20页

作者： HE Chun-lai ZHU Rong dong kai QIU Yong-quan SUN kai-ming Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China Tianjin Pipe (Group) Corporation Tianjin 300301 China

A transient three-dimensional mathematical model has been developed to analyze the three-phase flow in a 150 t EAF （electric arc furnace） using oxygen. VOF （multiphase volume of fluid） method is used to simulate the behaviors of molten steel and slag. Numerical simulation was conducted to clarify the transient phenomena of oxygen impingement on molten bath. When oxygen jet impinges on the surface of molten bath, the slag layer is broken and the penetrated cavity in molten steel is created. Simultaneously, the wave is formed at the surface of uncovered steel on which the slag layer is pushed away by jet. The result of numerical simulations shows that the area and velocity of uncovered steel created by impingement, jet penetration depth change from 0. 10 m2 , 0. 012 5 m/s, 3.58 cm to 0.72 m2 , 0. 1445 m/s, 11.21 cm, when the flow rate of an oxygen lance varies from 500 to 2000 m3/h. The results have been validated against water model experiments. More specially, the relation between the penetration depth and oxygen flow rate predicted by numerical simulation has been found to agree well with that concluded by water model.

关键词： electric arc furnace three-phase flow numerical simulation

铑催化7-辛烯醛氢甲酰化反应合成1,9-壬二醛

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分子催化（中英文） 2024年第2期38卷 160-170,I0005页

作者：刘传卓李志坚汤易天李永刚董开武上海中化科技有限公司上海201315 华东师范大学化学与分子工程学院上海200062

脂肪族二醛是一类重要的工业化学品中间体,可以经过氧化、还原、还原酯化、还原胺化等反应获得二酸、二醇、二酯、二胺等各种重要的化学品.我们报道了一种以丁二烯下游中间体—7-辛烯醛为原料的铑催化氢甲酰化反应合成1,9-壬二醛的方法... 详细信息

脂肪族二醛是一类重要的工业化学品中间体,可以经过氧化、还原、还原酯化、还原胺化等反应获得二酸、二醇、二酯、二胺等各种重要的化学品.我们报道了一种以丁二烯下游中间体—7-辛烯醛为原料的铑催化氢甲酰化反应合成1,9-壬二醛的方法,考察了不同膦配体对催化剂性能的影响,对反应工艺条件进行了研究和优化.使用Rh(I)/Xantphos催化剂,较优工艺条件下, 7-辛烯醛转化率>99%,直链壬二醛收率86%,醛产物正异比27, TON可达49 500.最后,对7-辛烯醛的氢甲酰化主反应和副反应机理进行了探讨.

关键词： 1 9-壬二醛 7-辛烯醛氢甲酰化 Xantphos 铑

考虑碳排放流与需求响应的电力系统两阶段优化调度

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电力工程技术 2024年第5期43卷 81-90页

作者：蔡新雷董锴崔艳林林旭夏雨星余洋广东电网有限责任公司电力调度控制中心广东广州510600 新能源电力系统全国重点实验室(华北电力大学(保定)) 河北保定071003 河北省分布式储能与微网重点实验室(华北电力大学(保定)) 河北保定071003

风电接入从发电侧降低了电力系统碳排放,而引入需求响应消纳弃风为负荷侧降碳提供了新思路。文中综合考虑风电和需求响应,基于电力系统碳排放流理论提出日前、日内两阶段电网低碳优化调度方法。首先,分析电力系统碳排放流理论,建立负荷... 详细信息

风电接入从发电侧降低了电力系统碳排放,而引入需求响应消纳弃风为负荷侧降碳提供了新思路。文中综合考虑风电和需求响应,基于电力系统碳排放流理论提出日前、日内两阶段电网低碳优化调度方法。首先,分析电力系统碳排放流理论,建立负荷侧的节点碳势模型;其次,将柔性负荷分为可转移负荷和可削减负荷,基于负荷节点碳势模型设计调用这两类负荷降碳的响应机制;然后,建立考虑低碳性和经济性的源荷协调日前优化调度模型,基于模型预测控制求解日前优化调度模型,并通过反馈校正调整日内调度结果。最后,分别通过改进PJM-5节点和IEEE 300系统进行仿真验证,证明了文中所提优化调度方法能有效促进柔性负荷消纳风电,减少弃风,同时实现负荷侧降碳。

关键词：碳排放流风电需求响应优化调度柔性负荷模型预测控制

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肌肉减少症对脊柱手术影响的研究现状

中国矫形外科杂志 2024年第13期32卷 1199-1203页

作者：张俊裕吕秋男董凯旋李宏键云南省第一人民医院骨科云南昆明650100

肌肉减少症是老年患者常见的一种与年龄密切相关的代谢性疾病,目前关于肌肉减少症的研究还不够透彻,但它对脊柱手术带来的不良预后已被证实。可能因为肌肉减少症的存在,会对脊柱手术患者的相关治疗方案、术前规划及围手术期管理产生一... 详细信息

肌肉减少症是老年患者常见的一种与年龄密切相关的代谢性疾病,目前关于肌肉减少症的研究还不够透彻,但它对脊柱手术带来的不良预后已被证实。可能因为肌肉减少症的存在,会对脊柱手术患者的相关治疗方案、术前规划及围手术期管理产生一定程度的影响。肌肉减少症近期正处于研究热点,有大量关于肌肉减少症的发展、肌肉减少症对脊柱手术预后的研究以及肌肉减少症的药物、营养和运动治疗干预措施的报道。本文重点总结肌肉减少症与脊柱手术之间联系的研究进展,为肌肉减少症在脊柱手术方面的研究及临床诊疗提供思路,并为后期相关临床研究做准备。

关键词：肌肉减少症脊柱手术老年

18味中草药制剂对PRRSV感染猪场母猪繁殖性能和仔猪生长性能的影响

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饲料研究 2024年第10期47卷 32-36页

作者：陈秋鹏孙开冬邵三勤李俊朋平顶山市农业科学院河南平顶山467000

试验旨在研究饲粮中添加复方中草药制剂对猪繁殖与呼吸综合征病毒(PRRSV)感染妊娠母猪繁殖性能和仔猪生长性能的影响。试验将60头PRRSV核酸和抗体均呈阳性的妊娠母猪随机分为3组(对照组、试验组Ⅰ和试验组Ⅱ),每组4个重复,每个重复5头... 详细信息

试验旨在研究饲粮中添加复方中草药制剂对猪繁殖与呼吸综合征病毒(PRRSV)感染妊娠母猪繁殖性能和仔猪生长性能的影响。试验将60头PRRSV核酸和抗体均呈阳性的妊娠母猪随机分为3组(对照组、试验组Ⅰ和试验组Ⅱ),每组4个重复,每个重复5头妊娠母猪。对照组饲喂基础饲粮,试验组Ⅰ母猪妊娠第70 d开始在饲粮中添加0.2%复方中草药制剂,连续饲喂21 d;试验组Ⅱ母猪妊娠第90 d开始饲喂酒石酸泰万菌素0.8 g/(头·d),连续饲喂7 d。试验期为母猪妊娠第70 d至分娩后第30 d。结果显示,与对照组相比,试验组Ⅰ和试验组Ⅱ妊娠母猪的采食性能无显著差异(P>0.05),初生仔猪的健仔数显著升高(P<0.05),弱仔数显著下降(P<0.05),试验组Ⅰ死胎和木乃伊胎数显著下降(P<0.05)。与对照组相比,试验组Ⅰ断奶仔猪的平均日增重和成活率显著升高(P<0.05),试验组Ⅰ和试验组Ⅱ哺乳仔猪发病率均显著下降(P<0.05)。试验组Ⅰ和Ⅱ妊娠母猪给药后的血清PRRSV载量显著低于给药前(P<0.05),对照组显著高于给药前(P<0.05)。研究表明,饲粮中添加复方中草药制剂具有防治猪繁殖与呼吸综合征的作用,同时能够改善妊娠母猪繁殖性能和仔猪生长性能。

关键词：猪繁殖与呼吸综合征病毒中草药制剂妊娠母猪繁殖性能仔猪生长性能

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Influences of Cooling Rate After Solution Treatment on Microstructural Evolution and Mechanical Properties of Superalloy Rene 80

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Acta Metallurgica Sinica(English Letters) 2017年第3期30卷 261-271页

作者： Shuang Gao Jie-Shan Hou kai-Xin dong Lan-Zhang Zhou Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China

Influences of the cooling rate after solution treatment on microstructural evolution and mechanical properties of Rene 80 nickel-based superalloy were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy and mechanical test. Results showed that the high cooling rate decreased the size of secondary γ＇particles in the supersaturated matrix, but led to a high coarsening rate of γ＇ particles during subsequent aging treatment. Despite various coarsening rates, the size and morphology of γ＇ particles in the final microstructures of all samples were close due to the long enough holding time to an equilibrium state. During the aging of 870 ℃/2 h, primary MC started to decompose with the carbide reaction： MC ＋ γ＇ --＊ MrC or M23C6 -t- γ＇. And a number of observations showed that the coarsening of γ＇ particles on grain boundaries resulted in the depletion of γ＇ during aging treatment. The test results indicated that high cooling rate resulted in the presence of quench crack, and the air cooling method following solution treatment was an optimum heat treatment method for Rene 80.

关键词： Ni-based superalloy Cooling rate Precipitates Ripening theory Heat treatment Microstructural evolution