Low-temperature sintering of KNN with excess alkaline elements and the study of its ferroelectric domain structure

Yongjie Zhao,Rongxia Huang,Rongzheng Liu,Heping Zhou,Wei Zhao 한국물리학회 2013 Current Applied Physics Vol.13 No.9

In the present work, lead-free K0.48Na0.52NbO3 (KNN) ceramics were synthesized by conventional ceramicsprocesses. The excess 3.3 mol% Na2CO3 and 1.1 mol% K2CO3 were added to decrease the sinteringtemperature to 990 ℃ and effectively promote the densification of KNN ceramics. X-ray diffraction resultsindicated that the excess Na2CO3 and K2CO3 would induce the formation of the A-site riched secondaryphase with the sintering temperature. Compositional segregation phenomenon enhanced bydifferent sintering temperature, spurs the formation of secondary phase in KNN-AEe ceramics. Inaddition, the difference between ferroelectric domain structure of the poled and as-sintered KNN-AEesamples for 990 ℃ was investigated. Via XRD analysis and SEM observation, it was found that the domainorientation was urged during the poling process.

Ligustrazine attenuates inflammation and oxidative stress in a rat model of arthritis via the Sirt1/NF-jB and Nrf-2/HO-1 pathways

Yongji Li,Zaihua Zhu,Ting Zhang,Yan Zhou 대한약학회 2019 Archives of Pharmacal Research Vol.42 No.9

Inflammation responses and oxidative stress areclosely involved in the pathogenesis of arthritis. Ligustrazine(Lig), a natural four methyl which is isolated fromChinese herb ligusticum chuanxiong hort, has been provedsignificantly anti-inflammation and anti-oxidative stresseffects. The present study aimed to evaluate the effect ofLig on inflammation and oxidative stress in Freund’scomplete adjuvant (FCA)-induced arthritis in rats. Thetreatment of Lig significantly decreased the hind-pawvolume change and alleviated the histopathological changesin sections of rat paws induced by arthritis. Lig alsoreduced the serum levels of pro-inflammatory cytokines(interleukin [IL]-6, IL-1 beta, and tumor necrosis factoralpha),increased the activity of superoxide dismutase(SOD) and reduced the concentration of malondialdehyde(MDA). Besides that, the protein expressions of the sirtuin1 (Sirt1)/nuclear factor kappa B (NF-jB) and nuclearfactor (erythroid-derived 2)-like-2 factor (Nrf-2)/hemeoxygenase (HO)-1 pathways determined by western boltfurther confirmed that Lig effectively inhibited the Sirt1/NF-jB pathway and activated the Nrf-2/HO-1 pathway. Taken together, our results suggest Lig has therapeuticpotential for arthritis, which might be via the regulation ofSirt1/NF-jB and Nrf-2/HO-1 pathways.

Bayesian Networks Application to Reliability Evaluation of Distribution Systems Containing Micro-Grids or Looped Network

Gao Liai,Zhou Yongjie,Su Kun,Hou Chenwei,Huo Limin 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.10

It is one of the effective methods to improve the reliability of the distribution system by using looped network power supply. With the development of new energy technology, distributed generation has been more widely used. But a small power system named micro-grid which is assembled by the device such as distributed generation, energy storage device and controllable load in a certain operating rules catches the attention of people. It can operate in islanded mode with the power grid failure, which can greatly improve the reliability of the system. Traditional analytical method and Monte Carlo method are difficult to evaluate its reliability accurately. In this paper, a new artificial intelligence method based on Bayesian networks is used for the system reliability analysis and evaluation. The corresponding Bayesian networks are established for the reliability test bus 2 which containing looped network and the improve reliability test bus 6 which containing micro-grids separately. With the help of causal reasoning and diagnostic reasoning, the supply influence of different types of DG output intermittent, operation mode on loads are detected, the key factors which have an impact on important load power supply reliability are found out, which is the theoretical foundation for practical engineering decision, so as to improve system reliability, identify failures and make maintenance scheduling.

Transcription factor Sp1 is necessary and functional in regulating expression of oncogene ZNF703

Xiaolin Liao,Yongjie Lu,Junbao Yang,Tao Kuang,Lilin Jiang,Yanjun Wang,Huiqun Kang,Bo Jiang,Xiaoli Zhou,Sheng He 한국유전학회 2017 Genes & Genomics Vol.39 No.10

Zinc finger protein 703 (ZNF703) is a putative oncogene in patients with the luminal B molecular subtype of breast cancer. Although the exact function of ZNF703 protein remains largely unknown, its expression and regulation have been implicated in several physiological and pathological processes. In the current study, for the first time, we identified and characterized the human ZNF703 gene promoter region. As a means of characterizing the transcription elements required for expression of ZNF703 protein at different stages, we cloned the promoter region of ZNF703 then created chimeric reporter plasmids for use in luciferase assays. A progressive deletion analysis of the ZNF703 gene’s 5′ and 3′ -flanking regions revealed that the core promoter is located in a 256-bp region ranging from nt-539 to nt-283. Next, we examined the effects of sitespecific mutations and treatment with mithramycin A to identify the functional Sp1 binding site, which was found to be located in a 447 bp region that ranged from nt-509 to nt-76, displayed the characteristics of a CpG island, and overlapped with the promoter region. In conclusion, our data suggest that ZNF703 transcription is regulated by transcription factor Sp1. This finding should facilitate future studies of the mechanism which regulates expression of this important gene.

Effects of sintering temperature and alkaline elements excess on the structure and electrical properties of (K_0.462Na_0.48Li_0.058)_(1+x)NbO_3 lead-free piezoelectric ceramics

Rongxia Huang,Yuzhen Zhao,Yongjie Zhao,Rongzheng Liu,Heping Zhou 한국물리학회 2011 Current Applied Physics Vol.11 No.5

Lead-free (K_0.462Na_0.48Li_0.058)_(1+x)NbO_3(0 ≤ x ≤ 0.03) ceramics with excessive alkaline elements were synthesized by conventional ceramics processes as functions of sintering temperatures and quantities of excess alkaline elements. X-ray diffraction results reveal a transformation from tetragonal phase to orthorhombic phase with increasing the contents of excessive alkaline elements. The grain size and the piezoelectric properties were enhanced when a certain amount of excessive alkaline elements were added. Further elevation in the amount of alkaline elements added resulted in excessive liquid phase in the ceramics and deteriorated the piezoelectric properties. With x = 0.01, the ceramics sintered at 1050 ℃ show better properties of planar electromechanical coupling factor k_p = 43.4%, piezoelectric constant d_33 = 204 pC/N, dielectric constant ε^T_33/ε_0 = 704.4, and loss tangent tan δ = 2.8%.

Spatial Regeneration for Preservation of Historic Urban Features and Improvement of Living Conditions in High-density Historic Districts: Urban Renewal Design Strategies for Shanghai's Old Town

Huang, Na,Cai, Yongjie,Zhuang, Mingyu,Zhou, Yi,Zhou, Jun Council on Tall Building and Urban Habitat Korea 2021 International journal of high-rise buildings Vol.10 No.1

Being the origin of Shanghai City, the Old Town presents a high-density spatial texture, a characteristic of local living conditions in the Shanghai context. However, the Old Town is faced with competing interests: the preservation of historic urban features and the improvement of contemporary living conditions. In view of its high density and poor living conditions, this paper focuses on two types of blocks for urban design research, and proposes two spatial regeneration strategies, as "overlapping lilong" and "texture continuity". It is expected to inherit the regional characteristics of urban space, improve the plot ratio and supplement the mix of functions, through the translation of the traditional lilong typology and the reproduction of historical streets and alleys, so as to provide operable spatial strategies and design methods for the organic renewal of Old Town and other historic districts.

Type synthesis of 3T2R decoupled hybrid mechanisms with large bearing capacity

Sen Wang,Shihua Li,Haoran Li,Yajie Zhou,Yongjie Wang,Xinyu Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4

This paper proposes a new synthesis method of three translational and two rotational (3T2R) decoupled hybrid mechanism with large bearing capacity, based on the screw theory and the atlas method. According to the degree of freedom and decoupled characteristics of the 3T and 2R mechanisms, the decoupled conditions for the 3T and 2R parallel mechanisms are proposed. The optimal conditions for the motion/force transmission performance of the 3T decoupled parallel mechanisms with redundant actuation is presented. A redundant actuated limb construction method is proposed to improve the load capacity of the hybrid mechanism. Following the design steps of the fully decoupled hybrid mechanism, 3T2R hybrid mechanisms with large load capacity are obtained. Kinematics and statics analysis verify the correctness of the proposed synthesis method. The mechanism synthesized by this method has a good application prospect in large load occasion.