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Evaluation model for arc fluctuations of triple-electrode high speed fillet welding

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China Welding 2014年第2期23卷 17-21页

作者： Ma Xiaoli Hua xueming Wang Fei Wu Yixiong School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240

To improve the welding efficiency of conventional arc welding, triple-electrode fillet welding was proposed and developed. Stability of triple-electrode fillet welding process is the assurance for ideal joint. The evaluation model for arc fluctuations of triple-electrode fillet welding was established based on the characteristic parameters and their variation coefficients. This model indicated that variation coefficients could reflect arc voltage flnctuations of welding process, and its analysis result was consistent with the actual welding process.

关键词： process stability variation coefficient triple-electrode fillet welding

Evolutionary engineering of Phaffia rhodozyma for astaxanthin-overproducing strain

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Frontiers of Chemical Science and Engineering 2012年第2期6卷 174-178页

作者： Jixian GONG Nan duAN xueming ZHAO School of Textiles Tianjin Polytechnic UniversityTianjin 300160China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China

Evolutionary engineering is a novel whole- genome wide engineering strategy inspired by natural evolution for strain improvement. Astaxanthin has been widely used in cosmetics, pharmaceutical and health care food due to its capability of quenching active oxygen. Strain improvement ofPhaffia rhodozyma, one of the main sources for natural astaxanthin, is of commercial interest for astaxanthin production. In this study a selection procedure was developed for adaptive evolution of P. rhodozyma strains under endogenetic selective pressure induced by additive in environmental niches. Six agents, which can induce active oxygen in cells, were added to the culture medium respectively to produce selective pressure in process of evolution. The initial strain, P. rhodozyma AS2-1557, was mutagenized to acquire the initial strain population, which was then cultivated for 550 h at selective pressure and the culture was transferred every 48h. Finally, six evolved strains were selected after 150 generations of evolution. The evolved strains produced up to 48.2% more astaxanthin than the initial strain. Our procedure may provide a promising alternative for improvement of highproduction strain.

关键词： evolutionary engineering astaxanthin strain improvement

Urban Green Space, Uneven Development and Accessibility: A Case of Dalian′s Xigang District

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Chinese Geographical Science 2015年第5期25卷 644-656页

作者： YANG Jun LI Chuang LI Yuechen XI Jianhao GE Quansheng LI xueming Liaoning Key Laboratory of Physical Geography and Geomatics Liaoning Normal University Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

This study examines the socio-spatial context of uneven development and the residential accessibility of green space in Dalian of Liaoning Province, China. The social fairness was analyzed with a community scale as the basis. We combined social scientific methods with a GIS method using a behavior accessibility model from the perspectives of fairness of urban green space allocation based on social geography, geographic information science, management science and many other related discipline theories. The results show that: 1) Most of the urban green space distribution presents an unbalanced phenomenon, and it does not match with the population distribution; 2) We found some differences in the accessibility of the population with different attributes and opportunities to use and enjoy the urban green spaces, mainly due to: the dual social and spatial attributes of the residents and the serious stratum differentiation generated were the internal causes; the residential space differentiation and the pursuit of economic and real estate development were the direct causes; and unreasonable planning, in regard to the fact that government policies did not give consideration to efficiency and fairness, was also an important factor.

关键词： behavior accessibility fairness of green space behavior accessibility model Xigang District of Dalian GIS

Investigation of Amorphization of Nb-Si Alloys by Mechanical Alloying

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Chinese Physics Letters 1994年第11期11卷 681-684页

作者： LI Bing MA xueming LIU Lin QI Zhenzhong DONG Yuanda Institute of Solid State Physics Academia SinicaHefei 230031 Department of Metallurgy and Materials Shanghai University of TechnologyShanghai 200072

Amorphous Nb_(62.5)Si_(37.5) and Nb_(75)Si_(25) alloys were produced from mixtures of elemental Nb and Si powders by mechanical alloying(MA).The structural changes of mechanically alloyed powders were monitored by x-ray *** was found that NbSi_(2),intermetallic compound was formed in the initial stage of MA of or Nb_(62.5)Si_(37.5) or Nb_(75)Si_(25) *** continued milling,the mixtures of intermetallic NbSi_(2) and elemental Nb transformed into amorphous Nb-Si alloys(Nb_(62.5)Si_(37.5) or Nb_(75)Si_(25)).The slow interdiffusion of Nb and Si and the slower diffusion of silicon atoms to niobium matrix than that of niobium atoms to silicon matrix were suggested to be responsible for the formation of intermetallic NbSi_(2).The amorphization of 3NbSi_(2)+7Nb mixtures(or NbSi_(2)+5Nb mixtures)is believed to be controlled by material transfer,which moves composition of line intermetallic NbSi2 off stoichiometry,and causes the matrix of elemental Nb deformed.

关键词： intermetallic alloys alloying

The design of a low-noise preamplifier for MRI

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Science China(Technological Sciences) 2011年第7期54卷 1766-1770页

作者： CAO xueming ZU DongLin ZHAO XuNa FAN Yang GAO JiaHong Beijing Key Laboratory of Medical Physics and Engineering IHIP of Physics School Peking University Beijing 100871 China

In this paper, a low-noise preamplifier for MRI is designed and studied. A noise matching network consisting of three elements is presented. To the single-stage AsGa-FET preamplifier working at 128 MHz, the measured gain through network analyzer (HP8712C) and noise figure through noise figure analyzer (8970B) are 25 and 0.43 dB, respectively.

关键词： MRI noise figure preamplifier noise matching network gain source impedance

A high-efficient triboelectric-electromagnetic hybrid nanogenerator for vibration energy harvesting and wireless monitoring

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Science China(Information Sciences) 2022年第4期65卷 229-237页

作者： Jian HE xueming FAN Dongyang ZHAO Min CUI Bing HAN Xiaojuan HOU Xiujian CHOU Science and Technology on Electronic Test and Measurement Laboratory North University of China College of Mechatronic Engineering North University of China Beijing Institute of Computer Application China North Industries Group Corporation Limited

Scavenging mechanical vibration energy by combining triboelectric nanogenerators(TENGs) and electromagnetic generators(EMGs) is a renewable and low-carbon way to generate electric power. In this paper, we fabricate a cylindrical structure hybrid nanogenerator based on spring structure to effectively scavenge vibration energy. The introduction of spring structure not only enhances the space utilization, but also supports the moving magnet. Owing to its innovative structure, the instantaneous output power of TENG and EMG are 0.88 mW at a load of 10 MΩ and 216.7 mW at a load of 60 Ω, respectively. With the aids of a power management circuit, the hybrid nanogenerator can provide continuous power for two hygrothermographs connected in series. In addition, a self-powered wireless acceleration sensing monitoring system(SWAM) is developed to measure the acceleration signals of vibration sources. This study provides a novel guideline for harvesting mechanical vibration energy.

关键词： mechanical vibration energy spring structure triboelectric electromagnetic wireless monitoring system

IFT140^(+)/K14^(+) cells function as stem/progenitor cells in salivary glands

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International Journal of Oral Science 2022年第4期14卷 561-571页

作者： xueming Zhang Ji Zhou Xinyu Wang Jiangyu Geng Yubei Chen Yao Sun Department of Oral and Maxillofacial Surgery Stomatological Hospital and Dental School of Tongji UniversityShanghai Engineering Research Center of Tooth Restoration and RegenerationNo.399YanChang Middle RoadShanghaiChina Department of Implantology Stomatological Hospital and Dental School of Tongji UniversityShanghai Engineering Research Center of Tooth Restoration and RegenerationNo.399YanChang Middle RoadShanghaiChina

Stem/progenitor cells are important for salivary gland development, homeostasis maintenance, and regeneration following ***-14^(+)(K14^(+)) cells have been recognized as bona fide salivary gland stem/progenitor cells. However, K14 is also expressed in terminally differentiated myoepithelial cells;therefore, more accurate molecular markers for identifying salivary stem/progenitor cells are required. The intraflagellar transport(IFT) protein IFT140 is a core component of the IFT system that functions in signaling transduction through the primary cilia. It is reportedly expressed in mesenchymal stem cells and plays a role in bone formation. In this study, we demonstrated that IFT140 was intensively expressed in K14^(+)stem/progenitor cells during the developmental period and early regeneration stage following ligation-induced injuries in murine submandibular glands. In addition, we demonstrated that IFT140^(+)/K14^(+)could self-renew and differentiate into granular duct cells at the developmental stage in vivo. The conditional deletion of Ift140 from K14^(+)cells caused abnormal epithelial structure and function during salivary gland development and inhibited regeneration. IFT140 partly coordinated the function of K14^(+)stem/progenitor cells by modulating ciliary membrane trafficking. Our investigation identified a combined marker, IFT140^(+)/K14^(+), for salivary gland stem/progenitor cells and elucidated the essential role of IFT140 and cilia in regulating salivary stem/progenitor cell differentiation and gland regeneration.

关键词： salivary progenitor injuries

Temporo-spatial Characteristics of Swarm Distribution before Two Ms6.0 Earthquakes in the Tianshan Area,China and Their Application to Earthquake Prediction

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Earthquake Research in China 2017年第3期31卷 395-402页

作者： Zhang Linlin Ao xueming Earthquake Administration of Xinjiang Uygur Autonomous Region Urumqi 830011China

The Nilka-Gongliu earthquake with M_S6.0 and Xinyuan-Hejing earthquake with M_S6. 6 successively occurred in Xinjiang on November 1,2011 and June 30,2012. Massive swarm activity was observed in a large area around the main shock epicenters before the two strong earthquakes. Main features are as follows:(1) The swarm activities not only increased significantly in number of earthquakes,but also presented a distinct swarm gap in spatial distribution,and the epicenters of the following strong earthquakes were all located in the swarm gap.(2) The duration of the swarm gap lasted longer,for 2-3 years.(3) The time-history characteristics of the swarms cumulative frequency indicates that swarm activity was quieter a few months before the main shocks. Finally,we discuss the results as well as the issues of their application in earthquake prediction.

关键词： Earthquake Temporal-spatial swarm activity Earthquake prediction

Effect of high-molecular weight dextran-enriched sourdough fermented using Leuconostoc mesenteroides ATCC 8293 on bread quality and gluten

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FOOD BIOSCIENCE 2023年第3期53卷 2663-2670页

作者： Bi, Qing Hong, Tingting Mei, Xing Xu, xueming Xu, Dan Jiangnan Univ State Key Lab Food Sci & Resources 1800 Lihu Rd Wuxi 214122 Peoples R China Jiangnan Univ Sch Food Sci & Technol 1800 Lihu Rd Wuxi 214122 Peoples R China Jiangnan Univ Collaborat Innovat Ctr Food Safety & Qual Control 1800 Lihu Rd Wuxi 214122 Peoples R China Licheng Detect & Certificat Grp Co Ltd Zhongshan 528436 Peoples R China

This study aimed to prepare high-molecular-weight (HMw) dextran-enriched sourdough (HMw-DT-SD) using Leuconostoc mesenteroides ATCC 8293 and to evaluate its effect on the quality of bread. The results demonstrated that HMw-DT-SD improved the bread quality by increasing the bread volume from 3.86 cm3/g to 5.04 cm3/g;the bread staling rate decreased by 49.02% compared with that in control. The relationship between bread quality and dough gluten was further investigated. The acidity during bread making greatly influenced the effect of dextran on gluten. The HMw-DT-SD hindered the gluten depolymerization under acidic conditions (pH = 3.6) and had a low free thiol content. In addition, the lower content of antiparallel & beta;-sheets in the bread dough might contribute to the depolymerization of macromolecular gluten (pH > 4.4), thus improving the bread volume and texture. The HMw-DT-SD increased the content of & beta;-turn structures in bread, suggesting gluten of lower resis-tance to extension.

关键词： Bread Gluten High-molecular-weight dextran Leuconostoc mesenteroides Sourdough