Energy trapping of thickness-extensional modes in thin film bulk acoustic wave resonators

Zinan Zhao,Zhenghua Qian,Bin Wang,Jiashi Yang 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.7

We perform a theoretical analysis on a rectangular trapped-energy piezoelectric resonator operating with thickness-extensional modesof a thin zinc oxide film on a silicon layer. The driving electrode covers the central part of the resonator only. The two-dimensional scalardifferential equation for such a structure derived by Tiersten and Stevens is employed which can describe in-plane mode variations. Avariational formulation is developed which provides the theoretical foundation for the Ritz method used in our analysis. Free vibrationfrequencies and modes are obtained and examined. Modes with vibrations trapped under the driving electrode are found. An approximationused to obtain the classical result of the resonator by Tiersten and Stevens, i.e., the neglect of the four corner regions of the resonator,is removed in our variational analysis. It is shown that their approximation causes a frequency difference on the order of dozens of partsper million for the fundamental thickness-extensional operating mode, quite significant in resonator design and operation.

Traffic Driven Epidemic Spreading in Weighted Homogeneous Networks

Zinan Chang,Fei Shao 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.1

To investigate the impact of weights on the traffic driven epidemic spreading in weighted homogeneous networks, an epidemic model in pseudo-random network with adjustable weights is presented. In the scenario that epidemic pathway is defined and driven by traffic flows, the epidemic spreading velocity of SI model in weighted homogeneous networks is obviously accelerated when the edge weight is different. And in traffic driven SIS model, the epidemic threshold is found to be proportional to the inverse of the average node betweenness. It is better to control the epidemic spreading when the edges have the same weight. Simulation results have confirmed the theoretical predictions.

Research on vibration of ceramic motorized spindle influenced by interference and thermal displacement

Zinan Wang,Ke Zhang,Zhan Wang,Xiaotian Bai,Qingyuan Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

The vibration of ceramic motorized spindle determines the machining quality of CNC machine tools. The dynamic characteristics of a motorized spindle were explored under the influence of interference fit and thermal displacement. Using heat transfer theory and bearing Harris theory, the temperature field model of motorized spindle was established, which aims to find the relationship of thermal displacement and interference. In addition, the dynamic and thermal factors were coupled to the dynamic model of the ceramic motorized spindle rotor system, of which the variation rules of bearing stiffness and rotor vibration characteristics were calculated and analyzed. The accuracy of the motorized spindle rotor system dynamic model was verified by experiments. The results show that the interference fit of shaft and bearing decreases with the rotating speed increase under the combined influence of centrifugal force, load and thermal displacement. The vibration was calculated by the dynamic model of motorized spindle rotor system considering dynamic and thermal factors. The maximum error was 3.9 %, which is well consistent with the experimental results. The dynamic characteristics of ceramic motorized spindle can be improved by appropriately increasing the degree of interference tightness at high speed.

Poetic Convention and Hierarchy at the Imperial Court-Analysing the Structure of Qing Examination Poems

Zinan Yan 한국중어중문학회 2012 中語中文學 Vol.52 No.-

This paper scrutinises examination poems written by three candidates, Hang Shijun 杭世駿 (1695-1773), Yu Zhen 于振 (fl.I723-1741), and Liu Lun 劉綸 (1711-1773), at the Boxue hongci 博學鴻詞(erudite learning and great literacy) examination held in 1736. A further study on a relevant poem composed by Emperor Qianlong is also presented, and comparison will be made between the works by the emperor and the three candidates. The focus of the analysis is on the structural resemblance and difference between the poems, in which a review of the poetic convention of court poetry as well as a discussion on the relationship between literature and social hierarchy are also involved.

Tumor-induced osteomalacia

Zinan Yin,Juan Du,Fan Yu,Weibo Xia 대한골다공증학회 2018 Osteoporosis and Sarcopenia Vol.4 No.4

Tumor-induced osteomalacia (TIO), also known as oncogenic osteomalacia, is a rare paraneoplastic syndrome characterized by hypophosphatemia resulting from decreased tubular phosphate reabsorption, with a low or inappropriately normal level of active vitamin D. The culprit tumors of TIO could produce fibroblast growth factor 23 which plays a role in regulating renal Pi handling and 25hydroxyvitamin D 1a-hydroxylase activity. Chronic hypophosphatemia could eventually lead to inadequate bone mineralization, presenting as osteomalacia. The diagnosis should be considered when patients manifest as hypophosphatemia and osteomalacia, or rickets and needs to be differentiated from other disorders of phosphate metabolism, such as the inhereditary diseases like X-linked hypophosphataemic rickets, autosomal dominant hypophosphataemic rickets, autosomal recessive hypophosphataemic rickets and acquired diseases like vitamin D deficiency. Localization of responsible tumors could be rather difficult since the vast majority are very small and could be everywhere in the body. A combination of thorough physical examination, laboratory tests and imaging techniques should be applied and sometimes a venous sampling may come into handy. The technology of somatostatinreceptor functional scintigraphy markedly facilitates the localization of TIO tumor. Patients undergoing complete removal of the causative neoplasm generally have favorable prognoses while a few have been reported to suffer from recurrence and metastasis. For those undetectable or unresectable cases, phosphate supplements and active vitamin D should be administrated and curative intended radiotherapy or ablation is optional.

Hierarchical Data Gathering Scheme for Energy Efficient Wireless Sensor Network

Jinping Chen,Zinan Chang 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.3

Compressive Data Gathering (CDG) has recently emerged to provide energy efficient data aggregation in wireless sensor networks (WSNs). Existing CDG is done by forming a span-tree from all sensors to the data sink, which leads to a lot of energy consumption in maintain this tree. In this paper, we present a clustering based CDG scheme for large-scale WSNs. This scheme reduces traditional network communication cost by introducing in-network compression and recovers sensory data accurately by using compress sensing theory. With extensive simulation, we demonstrate that our scheme prolongs nearly 45% network’s lifetime compared with the Hybrid compressive data gathering schemes.

Enhancing Transmission Capacity of Weighted Networks

Fei Shao,Zinan Chang 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.1

How to control the traffic congestion and improve the transmission capacity of weighted network is of great importance in real world networks. In some weighted networks, the weight is the geographic distance between nodes. The transmission capacity of weighted network is investigated according to different node delivery capability schemes. In the schemes that delivery capability of each node is proportional to its degree and proportional to its strength, the transmission capacity can be enhanced greatly after deleting some edges while the network integrity is still maintained. Simulations show that deleting edges according to their original weight is proved to be more effective. It is of great practical importance in designing the network topological structure.

Metabolic Engineering of Vitamin C Production in Arabidops

Ling Xiao,Ying Xiao,Zinan Wang,Hexin Tan,Kexuan Tang,Lei Zhang 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.4

Vitamin C (L-ascorbic acid, AsA) is a compound which provides major nutritional value, both for plants and humans. In this study, three distinct metabolic engineering strategies, including overexpression of biosynthesis enzyme, suppression of catabolism enzyme and switching the sub-cellular localization of compartment enzyme, were employed to enhance the production of AsA in Arabidopsis thaliana. The results showed that (1) overexpression of L-Galactose-1-P Phosphatase (GalPPase) enhanced AsA content to 3.96 μmol/g FW, which was 1.6-fold more than that in their wild-type (WT) counterparts; (2) RNAi suppression of ascorbate oxidase (AO) resulted in a significant increase of AsA accumulation (0.86 μmol/g FW) in apoplast; (3) both mitochondrion-target and none-target overexpression of L-Galactose dehydrogenase (GalDH) did not significantly promote AsA production compared with WT (1.96 μmol/g), however a dramatic enhancement was observed following infiltration with L-galactono-1, 4-lactone (L-GalL), both in transgenic and WT plants. The best line produced AsA with the content of 3.90 μmol/g FW, which was about 2-fold of that in the untreated control (1.99 μmol/g FW). This study provides new strategies including GalPPase overexpression, AO suppression as well as L-GalL feeding for modern breeding aimed at stimulating the AsA content in plants.

A Brief Analysis of The Aesthetic Thinking and Cultural Reflection of Chen Kaige's Films - Take “The Legend of the Demon Cat” As An Example

Yin Jun,Huang Zinan 한중경제문화학회 2021 한중경제문화연구 Vol.16 No.-

Dynamic changes of bacterial communities and nitrite character during northeastern Chinese sauerkraut fermentation

Qi Zhou,Shizhu Zang,Zinan Zhao,Xinli Li 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.1

Northeastern Chinese sauerkraut is a wellknown traditional fermented vegetable in China. Incomplete identification of the microorganisms’ (bacteria in spontaneous fermentation) diversity and accumulation of nitrite make it difficult to normalize the fermentation process and product qualities of northeastern Chinese sauerkraut. Conventional culturing and polymerase chain reaction-denaturing gradient gel electrophoresis methods were combined to describe microbial structure and diversity. Lactobacillus, Leuconostoc, Enterobacter, Accumulibacter, Thermotoga, Pseudomonas, Clostridium, Rahnella and Citrobacter were predominant microorganisms in different fermentation periods. The pH value and nitrite concentration presented a certain relevance to the amount of lactic acid bacteria. Lactobacillus and Leuconostoc had the ability to decrease nitrite by inhibiting nitrate-reducing bacteria such as Enterobacter. Therefore, Northeastern Chinese sauerkraut should not be eaten until 4 weeks of fermentation for the safety and quality of fermented foods. Northeastern Chinese sauerkraut is rich in lactic acid bacteria, which demonstrate its ability as an excellent probiotic for applications in functional foods.