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燃气轮机透平盘腔流动换热及轮盘热固耦合特性数值研究

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中国电机工程学报 2024年第4期44卷 1460-1467,I0017页

作者：王培宇张鑫磊张荻苏鹏飞谢永慧孔祥林西安交通大学能源与动力工程学院陕西省西安市710049 东方电气集团东方汽轮机有限公司四川省德阳市618000

针对燃气轮机安全运行问题,为保证盘腔良好冷却效果以及轮盘强度可靠性,该文对盘腔流动换热以及轮盘热固耦合特性进行数值研究。建立三级轮盘盘腔分析模型,对比转速及流量对盘腔流动换热特性的影响。基于流动换热结果分析轮盘应力及变... 详细信息

针对燃气轮机安全运行问题,为保证盘腔良好冷却效果以及轮盘强度可靠性,该文对盘腔流动换热以及轮盘热固耦合特性进行数值研究。建立三级轮盘盘腔分析模型,对比转速及流量对盘腔流动换热特性的影响。基于流动换热结果分析轮盘应力及变形特性。结果表明:当转速增大时,各腔室内压力损失降低,换热面努塞尔数(Nu)呈现下降趋势,最多降低约66.1%;而当流量增大时,各腔室内压力损失升高,部分换热面Nu呈现上升趋势,最多升高约198%。在多种载荷综合作用下,轮盘最大等效应力为996.06 MPa,最大径向变形为2.62 mm。结果可为保证燃气轮机轮盘安全性提供一定技术支撑及数据参考。

关键词：燃气轮机轮盘盘腔流动换热热固耦合

基于改进凸内逼近法的主动配电网有功-无功协调优化

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中国电机工程学报 2024年第14期44卷 5528-5537,I0007页

作者：黄永红王玉祥孔维健曹程苏家宇王克威江苏大学电气信息工程学院江苏省镇江市212013 亨通光电股份有限公司江苏省苏州市215200

以风电、光伏为代表的分布式电源接入配电网后容易导致系统电压波动变大以及局部电压越限。以二阶锥优化为代表的松弛技术在优化时为了保证松弛后解的精确,约束条件极为严苛并且在功率的极端注入下容易导致对偶间隙增大。针对上述问题,... 详细信息

以风电、光伏为代表的分布式电源接入配电网后容易导致系统电压波动变大以及局部电压越限。以二阶锥优化为代表的松弛技术在优化时为了保证松弛后解的精确,约束条件极为严苛并且在功率的极端注入下容易导致对偶间隙增大。针对上述问题,该文提出基于改进凸内逼近法的主动配电网有功-无功优化方法。首先,基于支路潮流方程定义与支路电流、节点电压和视在功率流相关的非线性项的凸包,并与剩余线性元素结合形成凸内部近似,建立完善的数学模型;进一步提出网络容许性判据以及引入KKT条件收缩最优解的对偶间隙。最后,基于IEEE 33系统及PG&E69节点系统,利用Yalmip等平台求得电网中各有功、无功决策变量的出力区间,验证所提方法的稳定、精确与高效性。

关键词：分布式电源凸内逼近电压调度区域

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蓖麻波形圆盘割刀刃口曲线拟合与优化

农业工程学报 2024年第10期40卷 66-75页

作者：孔凡婷吴腾张彬赵华洋孙勇飞陈长林谢庆农业农村部南京农业机械化研究所南京210014 内蒙古民族大学工学院通辽028000 蒙东高寒经济特色作物智能农机装备内蒙古自治区工程研究中心通辽028000

为减少蓖麻收获的切割功耗,该研究对前期设计的蓖麻波形圆盘割刀进行刃口曲线拟合与优化。基于国内种植的低矮蓖麻物理力学特性,采用B样条算法和基于三点圆曲率分析并带几何约束的最小二乘拟合方法对蓖麻波形圆盘割刀刃口曲线进行参数... 详细信息

为减少蓖麻收获的切割功耗,该研究对前期设计的蓖麻波形圆盘割刀进行刃口曲线拟合与优化。基于国内种植的低矮蓖麻物理力学特性,采用B样条算法和基于三点圆曲率分析并带几何约束的最小二乘拟合方法对蓖麻波形圆盘割刀刃口曲线进行参数拟合。并采用SPH-FEM(smoothed particle hydrodynamics-finite element modeling)耦合仿真方法模拟蓖麻茎秆切割过程,以刀盘厚度、底圆曲率半径和刃口角为试验因素,以最大切割力、切割功耗为评价指标进行正交旋转组合试验,对割刀结构参数进行优化,并对优化参数组合进行试验验证。最优割刀参数组合为:刀盘厚度3 mm、底圆曲率半径7 mm、刃口角19°,此时最大切割力为109.763 N、切割功耗为1.43 j.台架试验验证表明,SPH-FEM耦合仿真方法与台架试验获得的最大切割力(112.5 N)和切割功耗(1.45 j.基本吻合,误差在5%以内,所提方法能很好地研究模拟蓖麻割刀的切割过程,可为蓖麻收获装备研制提供支撑。

关键词：农业机械优化圆盘割刀蓖麻耦合方法

基于三电平的超声波电机驱动电路调速性能研究

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微特电机 2024年第1期52卷 51-57页

作者：傅平孔晨蔡康伟闽江学院物理学与电子信息工程学院福州350121 闽江学院福建省教育厅先进运动控制重点实验室福州350121 温州大学电气与电子工程学院温州325000

从超声波电机驱动电路拓扑结构出发,使用三相全桥电路构建三电平波形发生电路,得到基于三电平的超声波电机驱动电路,通过改变相关PWM驱动参数可以实现电机驱动波形的调频、调压和调相功能,进而实现电机调速。通过分析得到驱动电压、驱... 详细信息

从超声波电机驱动电路拓扑结构出发,使用三相全桥电路构建三电平波形发生电路,得到基于三电平的超声波电机驱动电路,通过改变相关PWM驱动参数可以实现电机驱动波形的调频、调压和调相功能,进而实现电机调速。通过分析得到驱动电压、驱动频率与行波幅值之间的关系,使用半实物仿真平台对基于三电平的超声波电机驱动电路进行测试,验证空载、带载时超声波电机在调压、调频、调相的情况下转速的变化情况,从而实现基于三电平的超声波电机的调速性能测试,为电机调速打下基础。

关键词：超声波电机驱动电路三电平半实物仿真

Advance in Studies of Dissolved Organic Carbon Flux in Wetland Ecosystem

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湿地科学 2013年第3期11卷 326-333页

作者： kong Fanting LI Yue XI Min kong Fanlong CHEN Wan College of Chemical and Environmental Engineering Qingdao University

Wetland ecosystem is an important part of the terrestrial ecosystem,and it plays a significant role in the global carbon *** wetlands are also maj.r sources of dissolved organic carbon(DOC).The studies on DOC flux in wetlands have focused on its relation with carbon cycle *** was reported that there have been significant spatial and temporal variations of DOC in the wetlands associated with sloughs,streams and rivers in boreal and sub-boreal *** in DOC concentration and flux are considered to be related to a variety of factors affected by global climate change and human *** estimation of DOC concentration and flux from the terrestrial biosphere has been of great attention because of its importance for the status of carbon storage in the wetlands and the potential impact on global biogeochemical *** this paper,it is discussed the sources,compositions and characteristics of DOC,furthermore reviewed the research methods and the influential factors as well as some estimated models of DOC *** a conclusion,some suggestions and prospects for the direction of the future study have been addressed.

关键词：生态学环境地理学 DOC 二氧化碳

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X Chen M M Chen Y Liu D W Cao G j.Chen Department of Microelectronics Jiangsu UniversityZhenjiang 212013China Department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong kong–Macao j.int Laboratory for Intelligent Micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CMOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

应力波作用下水平倾向液体充填岩石节理动态响应规律试验

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煤炭学报 2024年第4期49卷 1873-1881页

作者：朱建波孔骥黄震天孙家鑫吕岸霖张凯王加英深圳大学广东省深地科学与地热能开发利用重点实验室广东深圳518060 深圳大学土木与交通工程学院广东深圳518060 广西交建工程建设集团有限公司广西南宁530003 临沂市水利工程保障中心山东临沂276037

地下岩体工程中,液体充填岩石节理不可避免会受到地震、爆破等动力扰动。由于液体具有流动性,不同倾向节理中的液体呈现不同空间分布状态,受应力波扰动后液体的运动状态也相异。为阐明应力波作用下水平倾向液体充填岩石节理动态响应规律... 详细信息

地下岩体工程中,液体充填岩石节理不可避免会受到地震、爆破等动力扰动。由于液体具有流动性,不同倾向节理中的液体呈现不同空间分布状态,受应力波扰动后液体的运动状态也相异。为阐明应力波作用下水平倾向液体充填岩石节理动态响应规律,利用辉长岩切槽试样、有机玻璃管与丙三醇制备了液体充填岩石节理试样,采用类霍普金森杆试验测试系统,开展了液体充填岩石节理试样的竖向冲击加载试验,考虑了节理匹配系数(j.(MC))、液体体积分数与黏度3个影响因素,并从应力波透射能量与液体运动2个方面分析了液体充填岩石节理动态响应规律。试验结果表明:液体充填岩石节理j.(MC)增大,应力波透射能量增大;随着液体体积分数增大,高幅低频应力波的透射能量单调增大,低幅高频应力波的透射能量先不变后增大;当液体体积分数为50%时,应力波透射能量随着液体黏度增大而减小,而当液体体积分数为100%时,应力波透射能量随着液体黏度增大呈现先减小后增大的趋势;节理边界处,液体运动方向垂直于水平节理面向上,节理排液能力和液体运动剧烈程度随液体黏度增大而减弱。

关键词：应力波液体充填岩石节理动态响应透射能量液体运动

Roles of bile acids in enteric virus replication

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Animal Diseases 2021年第1期1卷 39-47页

作者： Fanzhi kong Linda j.Saif Qiuhong Wang Center for Food Animal Health Department of Animal SciencesCollege of FoodAgricultural and Environmental SciencesThe Ohio State UniversityWoosterOHUSA. College of Animal Science and Veterinary Medicine Heilongjiang Bayi Agricultural UniversityNo.5 Xinfeng RoadSartu DistrictDaqingChina Department of Veterinary Preventive Medicine College of Veterinary MedicineThe Ohio State UniversityColumbusOHUSA.

Bile acids(BAs)are evolutionally conserved molecules synthesized in the liver from cholesterol to facilitating the absorption of fat-soluble *** the intestines,where enteric viruses replicate,BAs also act as signaling molecules that modulate various biological functions via activation of specific receptors and cell signaling *** date,BAs present either pro-viral or anti-viral effects for the replication of enteric viruses in vivo and in *** this review,we summarized current information on biosynthesis,transportation and metabolism of BAs and the role of BAs in replication of enteric caliciviruses,rotaviruses,and *** also discussed the application of BAs for cell culture adaptation of fastidious enteric caliciviruses and control of virus infection,which may provide novel insights into the development of antivirals and/or disinfectants for enteric viruses.

关键词： Bile acids Coronavirus Calicivirus Rotavirus Norovirus Sapovirus

Acid tolerance of lactate-utilizing bacteria of the order Bacteroidales contributes to prevention of ruminal acidosis in goats adapted to a high-concentrate diet

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Animal Nutrition 2023年第3期14卷 130-140页

作者： Zhongyan Lu Lingmeng kong Shenhao Ren j.rg RAschenbach Hong Shen Key Lab of Animal Physiology and Biochemistry College of Veterinary MedicineNanjing Agricultural UniversityNanjingJiangsuChina College of Life Science Nanjing Agricultural UniversityNanjingJiangsuChina Institute of Veterinary Physiology Freie Universitat BerlinBerlinGermany Bioinformatics Center Academy for Advanced Interdisciplinary StudiesNanjing Agricultural UniversityNanjingJiangsuChina

The rapid accumulation of organic acids,particularly lactate,has been suggested as the main cause of ruminal acidosis(RA)for ruminants fed high-concentrate *** research has shown that a gradual shift from low-to high-concentrate diets within 4 to 5 weeks effectively reduces the risk for ***,the mechanisms remain *** this study,20 goats were randomly allocated into four groups(n=5)and fed with a diet containing a weekly increasing concentrate portion of 20%,40%,60%,and 80%over 28 *** d 7,14,21,and 28,one group(named C20,C40,C60,and C80 according to the last concentrate level that they received)was killed and the ruminal microbiome was *** acidosis was not detected in any of the goats during the ***,ruminal pH dropped sharply from 6.2 to 5.7(Pj.r types of sugar transporter for lactate-producing bacteria(LPB)and lactate-utilizing bacteria(LUB),***,more adenosine triphosphate was required for the phosphorylation of sugars to initiate their catabolic pathways in LPB compared to ***,the low dependence of sugar transport systems and

关键词： Ruminal microbiome Ruminal acidosis Acid tolerance Lactate metabolism