Visualization study of flow-excited acoustic resonance in closed tandem side branches using high time-resolved particle image velocimetry

Yanrong Li,Satoshi Someya,코지오카모토,Terumi Inagaki,Yasuyuki Nishi 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.3

Flow-induced acoustic resonance in a piping system containing closed tandem side branches was investigated experimentally. Velocityperturbation was induced at the mouth of a cavity by using two pumps and a block. An unusual acoustic mode change from a higher to alower mode was observed when the flow rate in the main pipe increased. This phenomenon was examined by high time-resolved particleimage velocimetry (PIV). It was found that fluid flows at different points in the cavity have some phase differences between them andthat they interact with each other. The relationship between the fluid flows was clarified and the phase difference between the acousticpressure fluctuations at different points in the cavity was obtained. Using these data, the phase delays of oscillations at different pointswere two-dimensionally mapped. This two-dimensional phase map was helpful in clarifying the feedback mechanism of self-inducedvibrations.

Constitutive Behavior of Binary Mixtures of Kaolin and Glass Beads in Direct Shear

Yanrong Li,Adnan Aydin,Qiang Xu,Jun Chen 대한토목학회 2012 KSCE Journal of Civil Engineering Vol.16 No.7

Composite soils having a wide range of particle size may be the most commonly encountered materials in geotechnical engineering practice. This study involves 21 direct shear tests to investigate the constitutive behavior of composite soils within the normal stress range from 50 to 200 kPa. The samples are mixtures of fine (kaolin) and coarse (glass beads) fractions at various proportions. The properties of the samples considered in the investigation are particle size distribution, water content of sheared specimens, structural features of shear surface and residual shear strength. It is shown that the particle size distribution influences the void ratio produced with the same compaction effort. Increasing fine fraction from zero to a threshold value (approximately 20-30%)causes a decrease in void ratio of the mixture. Beyond this threshold, a further increase of fine fraction causes an increase in void ratio. High proportion of fine fraction causes: (1) lower water content of shear zones relative to outer zones, (2) densification process within shear zone, (3) well slickensided shear surfaces, and (4) shearing in sliding mode and hence low residual shear strength.

Effects of Particle Shape on Shear Strength of Clay-gravel Mixture

Yanrong Li,Runqiu Huang,Lung S. Chan,Jun Chen 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.4

Soils containing gravel-sized particles attract much less attention from researchers than clay and sands, though they may be the most commonly encountered materials in geotechnical engineering practice, especially in mountainous area. Large direct shear tests are carried out in this study to investigate the shear behavior of such soil mixtures, with emphasis on influences of shape properties (symmetry and smoothness) of gravel particles. The tested samples are prepared by mixing kaolin and gravel-sized particles (2.0 mm < d < 15 mm) of different shapes at various volumetric proportions (40, 70 and 100%). Three types of gravel are used, i.e., glass beads, river cobbles and crushed granite fragments. The applied normal stresses is 150 kPa and the shearing rate is 0.006 mm/min. Results are presented in terms of shear dilatancy, and peak and constant volume friction angle. Based on the analysis of the test results, it is found: (1) increasing gravel content increases both peak and constant volume friction angle; (2) both particle symmetry (quantified by elongation) and surface smoothness (quantified by convexity) play an important role in peak and constant volume friction, though they work in different ways; (3) increasing convexity decreases constant volume friction angle, while increases peak friction angle; and (4) increasing elongation increases constant volume friction angle, but decreases peak friction angle.

Teaching and Practice Innovation of Embedded System Design Course Based on Proteus and Keil-electronic Stopwatch as an Example

Li Dan,He Erhu,Zhang Yanrong,Zhang Yu 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.4

This study aims at the status quo that theory is divorced from practice in embedded systems teaching process. A new theory teaching method is proposed that using Proteus as hardware simulation environment and Keil as software design environment. With this new method, in the teaching process, the hardware circuit can be simulated by the software environment. The joint use of Proteus and Keil in Embedded System Design Course teaching is clarified by an example of the design of electronic stopwatch which is using GPIO and timer in ARM7. This instance illustrates the flow and application methods about the joint application of Proteus and Keil in embedded system course teaching and practical application detailedly. By this method, it can stimulated students' interest in learning, and enhance the students' understanding of the principles and application of Embedded System Design. Thereby using this method can also improve the embedded system experiment teaching effect.

Robust ID based mutual authentication and key agreement scheme preserving user anonymity in mobile networks

( Yanrong Lu ),( Lixiang Li ),( Haipeng Peng ),( Yixian Yang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.3

With the swift growth of wireless technologies, an increasing number of users rely on the mobile services which can exchange information in mobile networks. Security is of key issue when a user tries to access those services in this network environment. Many authentication schemes have been presented with the purpose of authenticating entities and wishing to communicate securely. Recently, Chou et al. and Farash-Attari presented two ID authentication schemes. They both claimed that their scheme could withstand various attacks. However, we find that the two authentication schemes are vulnerable to trace attack while having a problem of clock synchronization. Additionally, we show that Farash-Attari`s scheme is still susceptible to key-compromise impersonation attack. Therefore, we present an enhanced scheme to remedy the security weaknesses which are troubled in these schemes. We also demonstrate the completeness of the enhanced scheme through the Burrow-Abadi-Needham (BAN) logic. Security analysis shows that our scheme prevents the drawbacks found in the two authentication schemes while supporting better secure attributes. In addition, our scheme owns low computation overheads compared with other related schemes. As a result, our enhanced scheme seems to be more practical and suitable for resource-constrained mobile devices in mobile networks.

Block-Based Projection Matrix Design for Compressed Sensing

Li Zhetao,Xie Jingxiong,Zhu Gengming,Peng Xin,Xie Yanrong,Choi Youngjune IET on behalf of the CIE 2016 Chinese journal of electronics Vol.25 No.3

<P>The objective of optimizing a projection matrix is to decrease the mutual coherence between a projection matrix and a basis matrix. In this paper, a novel block-based method is proposed to design a projection matrix in compressed sensing. Here, the projection matrix is divided into two blocks. The relationship between the two blocks was obtained by reasoning and proving. Theoretical analysis demonstrates that the mutual coherence between the whole projection matrix and the whole basis matrix keeps as good as the mutual coherence between the block matrix and blocked basis matrix. Experimental results show that the proposed method obtains better performance compared to existing methods.</P>

The antimicrobial activity of Cbf-K16 against MRSA was enhanced by β-lactamantibiotics through cell wall non-integrity

Bo Li,Wei Kang,Hanhan Liu,Yanrong Wang,Changzhong Yu,Xinyi Zhu,Jie Dou,Haibo Cai,Changlin Zhou 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.7

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as one of the most important pathogens both in health care and in community-onset infections. Cbf-K16, a cathelicidin-like antimicrobial peptide, presented broad antimicrobial activity during our previous studies. We evaluated the potential for synergy of Cbf-K16 with ceftazidime/ampicilin against MRSA, which was resistant to these two antibiotics with the minimum inhibitory concentration more than 64 μg/ml. The combinations showed a synergistic effect by a checkerboard assay with a fractional inhibitory concentration index ≤0.5. The killing curves of the combination treatment against MRSA showed that CFU counts decreased rapidly within 4 h by almost five logs, while single medication groups and the control group exhibited little inhibitory effect. In addition, in a mice bacteremia model, studies indicated that the combination treatment significantly prolonged the survival time of mice infected with MRSA, with a death protection rate of 80 %. Flow cytometry analysis and transmission electron microscopy indicated that combination- treated MRSA was completely ruptured with the cellular contents leaked out. The synergistic effect showed that Cbf-K16 selectively killed cells with non-integrity induced by cell wall inhibition antibiotics, suggesting that Cbf-K16 is a potential therapeutic agent and adjuvant for antimicrobial chemotherapy.

Modified Model Free Adaptive Control for a Class of Nonlinear Systems with Multi-threshold Quantized Observations

Xiangquan Li,Zhengguang Xu,Yanrong Lu,Jiarui Cui,Lixin Zhang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.10

This paper addresses a pattern-moving-based modified model free adaptive control (PMFAC) scheme and illustrates the convergence of its tracking error for a class of nonlinear systems with unknown model and multi-threshold quantized observations. The basic idea is to consider the system’s quantization error as an external disturbance and an improved performance index function of control law is proposed from the perspective of twoplayer zero-sum game (TP-ZSG) based on the existed MFAC algorithms. The PMFAC scheme is established which mainly includes an improved tracking control law and a pseudo-partial derivative (PPD) estimation algorithm. Under certain conditions, the bounded convergence of system tracking error and the stability of PMFAC system with quantization errors can be guaranteed. The theoretical results are demonstrated by two numerical examples.

Genetic diversity analysis based on sequence-related amplified polymorphism (SRAP) reveals the genetic background of Xinan tree peony group cultivars from different geographical provenances

Zongyan Li,Kunmei Yang,Yanrong Zhao,Ping Lin 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.4

The Xinan tree peony cultivar group, one of four Chinese peony cultivar groups, is distributed sparsely throughout Southwest China. This study aimed to characterize its genetic diversity and its genetic relationships with other peony groups. A total of 96 specimens from seven groups of different geographical provenances were collected and their genetic similarity was analyzed based on sequence-related amplified polymorphism molecular markers. Twenty primer pairs were selected to detect DNA polymorphisms. A total of 868 bands were generated with an average of 43.4 bands per primer pair and 98.39% polymorphic ratio. The genetic similarity coefficient varied from 0.5081 to 0.9173. The closest phylogenetic relationship was found between hybrids 2 and 3 of Paeonia rockii, while the farthest genetic relationship was between P. lutea and P. suffruticosa ‘Bangningzi’. Among the 20 Xinan samples the genetic similarity coefficient ranged from 0.6351 to 0.8710, revealing slight genetic variation. The 96 cultivars clustered into five branches at the genetic similarity coefficient of 0.6419. The results revealed that the Xinan group has a closer relationship with Japanese, French and American groups. Additionally, these results show that the phylogenetic relationships of different tree peony germplasms correspond to their origins and are primarily related with flower color.

“新中国正在诞生”: 美军观察组眼中的延安精神

李方木(Fangmu Li),殷严茸(Yanrong Yin) YIXIN 출판사 2024 Journal of China Studies Vol.2 No.3

抗战期间,中国共产党在延安接访美军观察组,由此开创了外交事业的序幕。这个团组在华期间积极融入军民生产生活、收集抗战情报、深入考察革命根据地,客观上促成了我国革命文化尤其是延安精神的海外传播。通过解读观察组包瑞德、戴维斯、高林和彼得金等部分成员的回忆录,再现抗战军民以坚定共产主义信念、解放思想实事求是、自力更生艰苦奋斗、全心全意为人民服务为核心的延安精神,发掘美军观察组在抗战末期以及冷战期间对世界反法西斯战线的巩固与中美建交的双重推动作用。 这些回忆录是宝贵的海外红色文献,塑造了中国共产党高大正直的国际形象,理应得到更好的保护与宣传。 Abstract: During the Anti-Japanese War, the Communist Party of China (CPC) got visited by the Dixie Mission at Yan’an, which marked the start of the Party’s foreign affairs. The Mission were actively involved in common people’s life while in China, worked to collect intelligence concerning the War and investigated revolutionary bases carefully, such efforts promoting the overseas spread of the revolution culture, the Yan’an Spirit in particular, of China. By interpreting the memoirs of some Mission members, such as David D. Barrett, John Paton Davies, Jr., John G. Colling and Wilbur J. Peterkin, this essayreproduces the Yan’an spirit of the Anti-Japanese War soldiers and civilians who centered on firm communist beliefs, emancipating the mind and seeking truth from facts, selfreliance, hard work, and wholehearted service to the people, and explores the dual role of the US military observation group in consolidating the world's anti-fascist front and establishing diplomatic relations between China and the United States at the end of the Anti-Japanese War and during the Cold War. The memoirs by these mission members prove to be valuable in the sense of overseas revolution reference, and fashion a great image of CPC on an international basis. They deserve better protection and publicity.