First-principles calculations of the effect of Ge content on the electronic, mechanical and acoustic properties of Li17Si4-xGex

Xiaohong Li,Hong-Ling Cui,Rui-Zhou Zhang 한국물리학회 2019 Current Applied Physics Vol.19 No.6

The electronic, mechanical and acoustic properties of Li17Si4-xGex (x=0, 2.3, 3.08, 3.53, and 4) have been investigated by using first-principles calculations based on the density functional theory (DFT). The research shows that the bulk modulus B, Young's modulus E, shear modulus G, and hardness Hv gradually decrease with the increasing Ge content. Li17Si4-xGex have the brittle nature from the analysis of B/G ratio and Cauchy pressure. The maximum Young's moduli are all along [1 1 0] plane, and the sequence of degree of anisotropic property is Li17Ge4 > Li17Si0.48Ge3.52 > Li17Si0.92Ge3.08 > Li17Si1.7Ge2.3 > Li17Si4. The analysis of acoustic velocity shows that all the sound velocities decrease with the increasing Ge content for Li17Si4-xGex (x=0, 2.3, 3.08, 3.53, and 4), and the longitudinal wave along [111] direction is fastest for the studied compounds. Debye temperature ΘD, vt and vl decrease with the increasing Ge content. The minimum thermal conductivity decreases with the increasing Ge content, and Li17Si4-xGex have low thermal conductivities and are not potential thermal conductors. The analysis of electronic properties indicates that Li17Si4-xGex have the metal nature and anisotropic electrical conductivity. The electric conduction is improved with the increasing Ge content.

Ozone infusiblization and curing mechanism of polysilazane ceramic precursor fibers

Li Xiaohong,Luo Xiaoyu,Li Jing,Li Jinxia,Yang Jiahao,Ahmad Zahoor,Bao Zhihao,Zhang Xiao,Chen Jianjun 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.5

An appropriate infusible method plays a vital role as one of the key processes of the fabrication of polymer-derived ceramic fibers. In this work, ozone curing, a novel room temperature controllable curing strategy was used to prepare SiCN ceramic fibers. Some circular pores were observed on the surface of the obtained SiCN ceramic fibers. The tensile strength of the fibers was also investigated. To reveal the ozone-curing mechanisms of the PSZ fibers and the formation process of the circular pores, the FT-IR, SEM, OM, XRD and TG were characterized. The results showed that the Si–H bonds and Si-CH3 groups in the PSZ molecule were oxidized gradually to form oxygen-containing groups such as Si–OH, Si–O-Si and C = O in the ozone curing process, which contributed to the curing and weight gain of the PSZ fibers. Moreover, a hydrolysis reaction between Si-NH-Si and H2O might further accelerate the curing of the PSZ fibers. An unexpected result of the hydrolysis reaction is the formation of some circular pores on the surface layer of the PSZ fibers. This strategy provides a method to design, adjust and control the microstructure and composition of silicon-based ceramic fibers, and the obtained SiCN fibers may be used as catalyst support, bacterial culture and other fields.

Stability and optimal control of microorganisms in continuous culture

Xiaohong Li,Enmin Feng,Zhilong Xiu 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.22 No.1-2

The process of producing 1,3-preprandiol by microorganism continuous cultivation would attain its equilibrium state. How to get the highest concentration of 1,3-propanediol at that time is the aim for producers. Based on this fact, an optimization model is introduced in this paper, existence of optimal solution is proved. By infinite-dimensional optimal theory, the optimal condition of model is given and the equivalence between optimal condition and the zero of optimality function is proved.

A Unified Threat Model for Assessing Threat in Web Applications

Xiaohong Li,Ke He 보안공학연구지원센터 2008 International Journal of Security and Its Applicat Vol.2 No.3

This paper presents a unified threat model for assessing threat in web applications. We extend the threat tree model with more semantic and context information about threat to form the new model which is used to analyze and evaluate threat in the software design stage. We utilize historical statistical information contained in this model to design threat mitigation schemes. The threat assessing results and mitigation schemes can be used to direct secure coding and testing. This makes it possible to design threat-resistant web applications by means of detecting and mitigating threat in the early software design stage.

Enhancing the Robustness and Efficiency of Scale-free Network with Limited Link Addition

( Li Li ),( Qing-shan Jia ),( Xiaohong Guan ),( Hengtao Wang ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.5

The robustness of a network is usually measured by error tolerance and attack vulnerability. Significant research effort has been devoted to determining the network design with optimal robustness. However, little attention has been paid to the problem of how to improve the robustness of existing networks. In this paper, we investigate how to optimize attack tolerance and communication efficiency of an existing network under the limited link addition. A survival fitness metric is defined to measure both the attack tolerance and the communication efficiency of the network. We show that network topology reconfiguration optimization with limited link addition (NTRLA) problem is NP-hard. Two approximate solution methods are developed. First, we present a degree-fitness parameter to guide degree-based link addition method. Second, a preferential configuration node-protecting cycle (PCNC) method is developed to do trade-off between network robustness and efficiency. The performance of PCNC method is demonstrated by numerical experiments.

STABILITY AND OPTIMAL CONTROL OF MICROORGANISMS IN CONTINUOUS CULTURE

Li, Xiaohong,Feng, Enmin,Xiu, Zhilong 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.22 No.1

The process of producing 1,3-preprandiol by microorganism continuous cultivation would attain its equilibrium state. How to get the highest concentration of 1,3-propanediol at that time is the aim for producers. Based on this fact, an optimization model is introduced in this paper, existence of optimal solution is proved. By infinite-dimensional optimal theory, the optimal condition of model is given and the equivalence between optimal condition and the zero of optimality function is proved.

Effects of Annealing Pressures on the Ordering and Microstructures of FePt

Xiaohong Li,Zhaodi Feng,Yang Li,Wenpeng Song,Qian Zhang,Baoting Liu 한국자기학회 2013 Journal of Magnetics Vol.18 No.4

FePt:Ag (100 nm) nanocomposite thin films were prepared on naturally-oxidized Si substrates by dc magnetron sputtering at room temperature. X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to investigate the effects of annealing pressures on the ordering processes and microstructures of these films. The average sizes for the L10 ordered domains and the FePt grains are reduced to d = 9 nm and D = 13 nm from d = 19 nm and D = 34 nm, respectively, when the annealing pressure is enhanced to 0.6 GPa from room pressure at 873 K. Furthermore, the size distribution is improved into a narrow range. With increasing pressure, the coercivity of L10-FePt:Ag thin films decreases from 15.1 to 7.6 kOe. In the present study, the effects of high pressure on the L10 ordering processes and microstructures of FePt:Ag nanocomposite films were discussed.

Emericella spp . in Soils of North China

( Li Dongmei,Wang Duanli,Li Ryoyu,Wang Xiaohong ) 한국균학회 1997 97 KOREA CHINA JOINT SYMPOSIUM Vol.- No.-

21世紀中國散文作家的精神守望

李曉虹(Li Xiaohong) 대한중국학회 2008 중국학 Vol.30 No.-

  21세기 중국산문은 소설과 시의 스타일을 가져와 더욱 다양한 독자층의 주목을 받았다. 그 주요 원인은 이렇게 창작된 산문이 풍부한 정신과 깊은 인상을 바탕으로 창작되었기 때문이며 이러한 특성은 몇 가지 방면에서 두드러지게 표현되고 있다.<BR>  이 중에서도 哲理散文이 비교적 크게 주목받았다. 점점 세속화되고 심미적인 이상을 추구하는 현실 속에서 산문을 통해 정신적 수준을 그대로 유지하며 ‘생과 사’, ‘사랑과 고독’, ‘행복과 고통’, ‘삶과 의미’, ‘시간과 영원’ 등의 질문에 더욱 직접적으로 빠져들 수 있었다. 곧 산문의 방식을 통해 생명의식을 표현하고 예술의 힘을 이끌어 낸 것이다.<BR>  역사문화 산문도 새로운 발전을 맞이했다. 1990년대 등장한 역사문화 산문은 일찍이 붐을 일으켰으나 그 길이가 너무 길고, 역사사료와 작가의 개인적 정감이 유리되는 등, 비판을 크게 받기도 했다. 21세기 들어서 쏟아진 다량의 글들은 적극적인 변화를 시도했는데, 역사를 회고하면서 현대적 의식과 인성의 깊이를 실현해냈으며 이로써 독자들의 호응을 얻었다.<BR>  끊임없이 변화하는 현실생활을 표현하면서 산문의 제재도 다양성을 추구하게 되었다. 21세기 이후의 중국사회의 거대한 변화가 곧 산문에 재현되었다. 하층민들이나 보통 서민들의 삶과 그들의 인생을 표현하게 된 것이다. 그리고 도시민의 바쁜 삶의 속도와 인간관계의 변화는 물론휴대폰 문자, 온라인 채팅 등이 가져온 새로운 삶의 형태와 같은 과학 기술의 발전이 사람들의 삶에 끼친 영향까지, 이 모든 것들이 산문 속에 반영되어 나타났다.<BR>  산문은 인간의 감정을 표현하고 영원한 사랑과 고통도 표현한다. 인간의 감정에 대한 집착은 문학작품의 영원한 주제이며, 특히 삶의 속도가 갈수록 빨라질 때, 그리고 외부적 스트레스가 늘어만 가는 현대를 살아가는 사람들에게 있어서는 더더욱 그러한데, 이는 마음 속으로부터 친밀한 정서를 바라게 된 것과도 통한다. 21세기 이래로 친정과 우정, 애정의 정서를 다룬 작품들은 비교적 많으며 이들이 역시 독자들에게 많이 읽혔다.<BR>  일반인들의 소소한 일상도 산문가들의 시선에 들어오게 되었다. 맛있는 음식 먹기, 차 마시기, 음주, 낚시, 사냥, 화초 가꾸기, 동물 기르기, 옷 등에서부터 언어, 전고, 음악, 민속, 독서, 향락, 그림감상 등등까지 많은 글들이 다양한 잡지에 실렸다.<BR>  이와 같은 21세기 산문의 발전 과정에도 문제는 있다. 사회의 부조, 물질이익의 과도한 추구로 인해 작품들이 세속화되는 경향을 보이게 된다는 점이다. 어떤 글들은 너무나 많은 흥미위주의 방법을 사용하여 허풍과 유머만 늘어나 내용은 부실해지고 정신은 결핍되게 되기도 했다. 그리하여 결국 산문의 본질적 특성을 상실하고 심미적 요소도 간과하게되어 진실을 멀리하고 위기를 맞게 되기도 했던 것이다.   Chinese prose writings of 21<SUP>st</SUP> century attracted public attention. The principle reason why they got a wide range of notice is that these writings are written based on abundant of mentality and deep impression so that they were expressed in some dimensions.<BR>  Most of all, philosophical writings have attracted a lot of readers. These works brought out the fundamental notion like ‘life and death’, ‘love and solitude’, ‘happiness and pain’, ‘life and its meaning’ and ‘time and infinity’ under the world of just chasing ultimate object and secularization.<BR>  Historical writings also faced new waves and changes. At the first time, these pieces of works were so long to be read and separated from original emotions, so they could not help criticizing in the 1990. After 21<SUP>st</SUP> century, a lot of works tried affirmative changes and they reminisce the past, at the same time, they tried to embody modern consciousness and the deepness to get notice from readers.<BR>  The total changes in contemporary Chinese society has represented into modern Chinese prose writings as well. Soon these writings got subjects from the lower status people as well as the city life.<BR>  The performance of 21 relatives and friends, love of prose works a lot.<BR>  In addition, Daily life and ordinary people of the state also entered the large number of prose.<BR>  Finally, some essays the question is: vulgar. false and game attitude.

Novel splice isoforms of pig myoneurin and their diverse mRNA expression patterns

Guo, Xiaohong,Li, Meng,Gao, Pengfei,Cao, Guoqing,Cheng, Zhimin,Zhang, Wanfeng,Liu, Jianfeng,Liu, Xiaojun,Li, Bugao Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.10

Objective: The aim of this study was to clone alternative splicing isoforms of pig myoneurin (MYNN), predict the structure and function of coding protein, and study temporal and spatial expression characteristics of each transcript. Methods: Alternative splice isoforms of MYNN were identified using RNA sequencing (RNA-seq) and cloning techniques. Quantitative real-time polymerase chain reaction (qPCR) was employed to detect expression patterns in 11 tissues of Large White (LW) and Mashen (MS) pigs, and to study developmental expression patterns in cerebellum (CE), stomach (ST), and longissimus dorsi (LD). Results: The results showed that MYNN had two alternatively spliced isoforms, MYNN-1 (GenBank accession number: KY470829) and MYNN-2 (GenBank accession number: KY670835). MYNN-1 coding sequence (CDS) is composed of 1,830 bp encoding 609 AA, whereas MYNN-2 CDS is composed of 1,746 bp encoding 581 AA. MYNN-2 was 84 bp less than MYNN-1 and lacked the sixth exon. MYNN-2 was found to have one $C_2H_2$ type zinc finger protein domain less than MYNN-1. Two variants were ubiquitously expressed in all pig tissues, and there were significant differences in expression of different tissues (p<0.05; p<0.01). The expression of MYNN-1 was significantly higher than that of MYNN-2 in almost tissues (p<0.05; p<0.01), which testified that MYNN-1 is the main variant. The expression of two isoforms decreased gradually with increase of age in ST and CE of MS pig, whereas increased gradually in LW pig. In LD, the expression of two isoforms increased first and then decreased with increase of age in MS pig, and decreased gradually in LW pig. Conclusion: Two transcripts of pig MYNN were successfully cloned and MYNN-1 was main variant. MYNN was highly expressed in ST, CE, and LD, and their expression was regular. We speculated that MYNN plays important roles in digestion/absorption and skeletal muscle growth, whereas the specific mechanisms require further elucidation.