Response properties of axion insulators and Weyl semimetals driven by screw dislocations and dynamical axion strings

You, Yizhi,Cho, Gil Young,Hughes, Taylor L. American Physical Society 2016 Physical review. B Vol.94 No.8

<P>In this paper, we investigate the theory of dynamical axion strings emerging from chiral symmetry breaking in three-dimensional Weyl semimetals. The chiral symmetry is spontaneously broken by a charge density wave (CDW) order which opens an energy gap and converts the Weyl semimetal into an axion insulator. Indeed, the phase fluctuations of the CDW order parameter act as a dynamical axion field theta((x) over right arrow ,t) and couple to electromagnetic field via L-theta = theta((x) over right arrow ,t)/32 pi(2) epsilon(sigma tau nu mu) F-sigma tau F-nu mu. Additionally, when the axion insulator is coupled to deformations of the background geometry/strain fields via torsional defects, e.g., screw dislocations, there is interesting interplay between the crystal dislocations and dynamical axion strings. For example, the screw dislocation traps axial charge, and there is a Berry phase accumulation when an axion string (which carries axial flux) is braided with a screw dislocation. In addition, a cubic coupling between the axial current and the geometry fields is nonvanishing and indicates a Berry phase accumulation during a particular three-loop braiding procedure where a dislocation loop is braided with another dislocation and they are both threaded by an axion string. We also observe a chiral magnetic effect induced by a screw dislocation density in the absence of a nodal energy imbalance between Weyl points and describe an additional chiral geometric effect and a geometric Witten effect.</P>

Production of Dimethylsulfide and Dimethyisulfoniopropionate by Phytoplankton in the Water of Jiaozhou Bay

Huizhen, Zhang,Zhen, Cui,Yizhi, Chen,Wei, Cui,Ping, Sheng,Manping, Zhang 목포해양대학교해사산업기술연구소 1997 심포지움강연논집 Vol.1997 No.11

The concentration of dimethylsulfide (DMS) and its metabolic precursor, dimethylsulfonio propionate (DMSP) in water and particulate samples obtained along transects through Jiaozhou Bay, China was determined. Here we report the distribution, diurnal change and seasonal variation of DMS and DMSP in water of Jiaozhous Bay and the adjacent area, including some of the biogeochemical factors controlling the distribution, change and variation. Eight individual clones of phytoplankton representing four classes were examined in exponential growth for DMS and KMSP by laboratory batch cultures. There is a strong correlation between the taxonomic position of the phytoplankton and the production of DKSP(DMS). The DMS and DMSP variation in growth and with variations in nutrient and salinity were reported.

Collaborative Learning Group Formation with Density Clustering

Mengxiong Zhou,Yanming Ye,Yizhi Ren,Yueshen Xu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.6

The formation of the collaborative learning group is a challenging problem, especially the principle construction and multi-objective optimization. In this paper, we propose an improved density clustering algorithm, and further implement the group formation based on the proposed algorithm. The proposed algorithm first constructs the distance matrix for learners, and clusters learners into different groups. After the random selection of the initial cluster centers, our algorithm achieves superior clustering result by iteratively adjusting the clustering centers. We conduct sufficient experiments and the experimental results demonstrate that the proposed algorithm well satisfies our aim, that is, inter-group heterogeneity maximization and intra-group homogeneity maximization.

Quantum Chaotic Image Encryption with One Time Running Key

Cao Guanghui,Zhou Jun,Zhang Yizhi,Jiang Yueling,Zhang Xing 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.4

Effects of early commercial milk supplement on the mucosal morphology, bacterial community and bacterial metabolites in jejunum of the pre- and post-weaning piglets

Hu, Ping,Niu, Qingyan,Zhu, Yizhi,Shi, Chao,Wang, Jing,Zhu, Weiyun Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.3

Objective: Sow milk (SM) may not be able to meet the piglet's nutritional needs in late lactation. Hence, this study was conducted to investigate the effects of early commercial milk (CM) supplement on the mucosal morphology, bacterial community and bacterial metabolites in jejunum of piglets. Methods: Ten litters of newborn piglets ([Yorkshire×Landrace]×Duroc) were randomly divided into 2 groups of 5 litters. The piglets in the control group were suckled by the sow (SM), while the piglets in the treatment group (CM supplement) were supplemented with a CM supplement along with suckling from d 4 to d 28 of age. Results: No significant differences were observed about jejunal mucosal morphology on d 28 and d 35 between two groups. On d 28, the activity of lactase in the jejunum was significantly decreased in the CM group, while the activity of sucrase and the ratio of maltase to lactase were significantly increased (p<0.05). On d 35, the activity of maltase in the jejunum was significantly increased in the CM group (p<0.05), and maltase to lactase ratio tended to increase in the CM group (p = 0.065). In addition, piglets in the CM group had a higher abundance of Clostridium XI, Tuicibater, and Moraxella in the jejunum on d 28, while the abundance of Lactobacillus was significantly increased on d 35 (p<0.05). Conclusion: The early CM supplement improved the maturation of the jejunum to some extent by enhancing the maltase and sucrase activities. Moreover, the early CM supplement could help maintain the homeostasis of internal environment in jejunum by increasing the microbial-derived metabolites.

Muslin Deweaving through Combined Mechanical, Thermal and Chemical Methods

Hang Zhang Cao,Jamie DeCoster,Jamie DeCoster,Kelvin Linskens,Kareem Mehdi,Yizhi Meng,Gary Halada,Hye-Jung Jung,Theanne Schiros,Asta Skocir,Taejin Kim 한국섬유공학회 2022 Fibers and polymers Vol.23 No.11

Fabric waste has become an escalating problem that stems from the ever-shortening clothing lifecycle. Previouscotton recycling processes used mechanical methods to break the cotton down into fiber; this comes at the cost ofcompromised strength. Sodium hydroxide has long been used in the textile industry to increase dye absorption and lusterthrough mercerization. In this paper, the deweaving of cotton muslin fabric was attempted using the chemical interactions ofNaOH in combination with heat and mechanical forces through agitation. Different NaOH concentrations were tested todetermine the optimum condition for fabric decomposition on a laboratory scale. Overall, the muslin fabric treatment with0.5 M NaOH yielded the most promising results for fiber quality retention and chemical usage. The NaOH solution wasshown to be feasible in effectively deweaving multiple muslin fabrics consecutively. While the deweaving process reducesthe mechanical strength of the fabric, overall, the recycling method was successful in minimizing chemical waste anddeweaving time.

여름철 기온상승에 대한 주관감과 의복선택변화 실태조사 ╶ 한국 거주중인 한인ㆍ중국인 성인여성을 대상으로╶

김정연(Jeong Yeon Kim),최서영(Seo Young Choi),왕이지(yizhi Wang),장몽(meng Zhang),김재영(Jae Young Kim) 경희대학교 산학협력단 예술디자인연구원 2017 예술· 디자인학연구 Vol.20 No.2

이 연구에서는 기온상승 시 의복선택이 어떻게 변화하는지 파일럿 설문조사를 실시하였다. 설문대상은 한국에 거주하는 성인여성 114명이었다. 설문내용은 여름철 기온상승 및 여름철 의복선택변화정도에 대한 주관감(7점 척도), 의복ㆍ헤어스타일ㆍ신의 구체적 선택변화에 대한 yes/no 문항으로 이루어졌다. (A)여름철 기온상승에 대한 정적 주관감은 86.8%였고, (B)여름철의복선택변화 정도에 대한 정적 주관감은 86.0%였다. (A)와 (B) 사이의 상관계수는 0.579(p=.001)였다. 여름철 의복선택변화에 대한 yes/no 설문에서 50%의이상의 yes 응답을 얻은 문항들은 다음과 같았다: ‘민소매/어깨오픈 소매를 선호하게 됨’, ‘바지보다 스커트를 선호하게 됨’, ‘바지/스커트를 더 짧게 착용하게 됨’, ‘스타킹 착용을 하지 않게 됨’, ‘시원한 소재의 의복을 선택하게 됨’, ‘한 겹 의류 착용을 선호하게 됨’, ‘시원해 보이는 칼라의 의복을 선호하게 됨’, ‘포니테일을 선호하게 됨’, ‘샌들 착용을 선호하게 됨’, ‘풋케어에 더욱 관심을 가지게 됨’. 여름철 기온증가현상이 매년 지속될 경우 의복의 형태변화가 예견되기 때문에기후변화에 대한 주관감과 의복행동과의 관련성에 대한 분석과 의복선택변화에 대한 적절한 예측은 의류산업발전과 인체환경적응연구에 기여할 것이다. In this study, pilot surveys were conducted to investigate the change of clothing selection during the temperature rise. The subjects of this study were 114 adult women living in Korea. The questionnaire consisted of subjective sensation about summer temperature rise and about change of clothing selection in summer(7 point method), yes/no question about change of clothes/ hair-style/ shoes. (A)Positive sensation of summer temperature rise was 86.8%. (B)Positive sensation of degree of change of clothing selection in summer was 86.0%. The correlation coefficient between (A) and (B) was 0.579(p=.001). In the yes/no questionnaire for change of clothing choice in the summer, the questions with more than 50% yes response were as follows: 'prefer sleeveless or shoulder open sleeves', 'prefer skirts to pants', 'wear pants or skirts shorter', 'dislike stockings', 'prefer cooler clothing', 'prefer to wear one layer of clothing', ‘prefer the clothes of color that looked cool’, ‘prefer ponytail', ’increased wear of sandals', and 'interest in foot care‘. If summer temperature increases every year, the change in clothing choice is predicted. The appropriate prediction of clothing selection change will contribute to the development of apparel industry and adaptation to the thermal environment.

A novel ethylene-responsive factor IbERF4 from sweetpotato negatively regulates abiotic stress

Yu Yang,김호수,Ma Peiyong,Jia Zhaodong,Guo Xiaoding,Xie Yizhi,곽상수,Zhang Peng,Bian Xiaofeng 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.4

The ERF (ethylene-responsive element-binding factor) transcription factor family plays important roles in abiotic and biotic stress responses in plants. An EAR motif-containing ERF gene, IbERF4, was isolated from sweetpotato [Ipomoea batatas (L.) Lam]. IbERF4 was highly expressed in the early stage of storage roots and can be induced by various stresses. By overexpressing IbERF4 in Arabidopsis, the transgenic Arabidopsis showed greater sensitivity to drought and salt stress by down-regulating stress-related genes, such as rd22, rd29, AtCBF1 and AtCBF2. Overexpressing IbERF4 in sweetpotato made the transgenic sweetpotato more sensitive to salt stress and made propagating new seedlings more difficult. Consistently, the transcriptomic profiling results showed that genes involved in oxidative stress were significantly down-regulated in sweetpotato overexpression lines. These results indicated that IbERF4 plays as key regulators in sweetpotato abiotic stress.

Self-adjusting strategy based on rotating injection for sensorless control of high-power PMSM drives

Xiaofan Wang,Xiaochun Fang,Zhi Wang,Zhihong Zhong,Yizhi Wang,Fei Lin,Zhongping Yang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

As a sensorless control method suitable for permanent magnet synchronous motor (PMSM) at lowspeed, rotating high-frequency injection method will face some special problems in high power applications. On the one hand, the low switching frequency limits the injected signal frequency, which is very close to the fundamental frequency. On the other hand, under heavy load conditions, the fundamental current amplitude is several hundred times of the negative sequence current. This will result in difficulty in signal extraction. In this paper, current spectrum is analyzed quantitatively based on the parameters of PMSM drive for rail vehicles, which illustrates the limitations of conventional bandpass filters. A method based on self-adjusting filter is proposed. The negative sequence current is successfully extracted, and the precise rotor position is obtained under the condition of variable speed and variable load. Based on a fullscale test platform the effectiveness of the proposed method is proved.

Reactive Oxygen Species Scavenging Hydrogel Regulates Stem Cell Behavior and Promotes Bone Healing in Osteoporosis

Ye Yuanjian,Zhong Haobo,Huang Shoubin,Lai Weiqiang,Huang Yizhi,Sun Chunhan,Zhang Yanling,Zheng Shaowei 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.6

BACKGROUND: Implantation of bone marrow mesenchymal stem cells (BMSCs) is a potential alternative for promoting bone defects healing or osseointegration in osteoporosis. However, the reactive oxygen species (ROS) accumulated and excessive inflammation in the osteoporotic microenvironment could weaken the self-replication and multi-directional differentiation of transplanted BMSCs. METHODS: In this study, to improve the hostile microenvironment in osteoporosis, Poloxamer 407 and hyaluronic acid (HA) was crosslinked to synthetize a thermos-responsive and injectable hydrogel to load MnO2 nanoparticles as a protective carrier (MnO2@Pol/HA hydrogel) for delivering BMSCs. RESULTS: The resulting MnO2@Pol/HA hydrogel processed excellent biocompatibility and durable retention time, and can eliminate accumulated ROS effectively, thereby protecting BMSCs from ROS-mediated inhibition of cell viability, including survival, proliferation, and osteogenic differentiation. In osteoporotic bone defects, implanting of this BMSCs incorporated MnO2@Pol/HA hydrogel significantly eliminated ROS level in bone marrow and bone tissue, induced macrophages polarization from M1 to M2 phenotype, decreased the expression of pro-inflammatory cytokines (e.g., TNFa, IL-1b, and IL-6) and osteogenic related factors (e.g., TGF-b and PDGF). CONCLUSION: This hydrogel-based BMSCs protected delivery strategy indicated better bone repair effect than BMSCs delivering or MnO2@Pol/HA hydrogel implantation singly, which providing a potential alternative strategy for enhancing osteoporotic bone defects healing.