Dirac semimetal-enabled multi-bit coding metasurface for dynamic manipulation of terahertz beams

Zhang Yonggang,Yin Kehao,Liang Lanju,Yao Haiyun,Yan Xin,Hu Xiaofei,Huang Chengcheng,Qiu Fu,Zhang Rui,Li Yuanping,Wang Yaru,Li Zhenhua,Wang Ziqun 한국물리학회 2024 Current Applied Physics Vol.58 No.-

In this study, a switchable multi-bit coding metasurface that is applied under a terahertz (THz) frequency by adjusting the Fermi level (EF) of Dirac semimetals (DSMs) is proposed. At a EF of 0.2 eV, a 1-bit coding metasurface can be applied in the 2.58–2.62 THz. At 0.3 eV, a 3-bit coding metasurface is realized at 1.88 THz, and at 0.05 eV, the phase of the coding units coincides in the 1.5–3 THz. So, different functions of the metasurface can be realized. The proposed coding metasurfaces has promising applications in terahertz communication.

Optimization for Scenedesmus obliquus Cultivation: the Effects of Temperature, Light Intensity and pH on Growth and Biochemical Composition

Zhang, Yonggang,Ren, Li,Chu, Huaqiang,Zhou, Xuefei,Yao, Tianming,Zhang, Yalei The Korean Society for Microbiology and Biotechnol 2019 한국미생물·생명공학회지 Vol.47 No.4

Microalgae have been explored as potential host species for biofuel production. Environmental factors affect algal growth and cellular composition. The effects of several key environmental factors, such as temperature, light, and pH of the medium on the growth and biochemical composition of Scenedesmus obliquus were investigated in this study. The highest growth rate of microalgae was observed at an optimal temperature of 25℃, 150 μmol/(m²·s) light intensity, and pH 10.0. The biochemical composition analysis revealed that the carbohydrate content decreased at lower (20℃) or higher temperature (35℃), whereas the protein and lipid contents increase at these temperatures. The fluctuation of light intensity significantly affected the contents of protein, carbohydrate, and lipid. The protein levels varied greatly when the pH of the medium was below 7.0. The carbohydrate and lipid contents significantly increased at pH above 7.0.

Optimization for Scenedesmus obliquus Cultivation: the Effects of Temperature, Light Intensity and pH on Growth and Biochemical Composition

Yonggang Zhang,Li Ren,Hua-qiang Chu,Xue-fei Zhou,Tianming Yao,Ya-lei Zhang 한국미생물·생명공학회 2019 한국미생물·생명공학회지 Vol.47 No.4

Microalgae have been explored as potential host species for biofuel production. Environmental factors affect algal growth and cellular composition. The effects of several key environmental factors, such as temperature, light, and pH of the medium on the growth and biochemical composition of Scenedesmus obliquus were investigated in this study. The highest growth rate of microalgae was observed at an optimal temperature of 25℃, 150 μmol/(m2·s) light intensity, and pH 10.0. The biochemical composition analysis revealed that the carbohydrate content decreased at lower (20℃) or higher temperature (35℃), whereas the protein and lipid contents increase at these temperatures. The fluctuation of light intensity significantly affected the contents of protein, carbohydrate, and lipid. The protein levels varied greatly when the pH of the medium was below 7.0. The carbohydrate and lipid contents significantly increased at pH above 7.0.

Numerical investigation on the multiphase flow field at various muzzle velocities

Jinghui Zhang,Yonggang Yu,Xinwei Zhang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

To predict the multiphase flow field during the underwater launch, a twodimensional (2D) transient model and a visual experiment platform were employed. The simulated graphs were compared to the experimental photos, and the results indicate the reasonableness of the model. Furthermore, the effects of muzzle velocity on the flow field were investigated. The results demonstrate that a partially formed bottle-shaped shock wave is generated when t = 0.4 ms for various velocities, and a greater muzzle velocity can accelerate its expansion process. Additionally, the maximum displacement of the Mach disk fulfills the binomial law with the muzzle velocity. The maximum peak pressure of oscillations increases with the greater muzzle velocity, but the duration of pressure oscillations decreases.

Synthesis and Characterization of Curcumin-Incorporated Glycopolymers with Enhanced Water Solubility and Reduced Cytotoxicity

Haisong Zhang,Tianci Ren,Meng Yu,Hailei Zhang,Libin Bai,Yonggang Wu,Sujuan Wang,Xinwu Ba 한국고분자학회 2016 Macromolecular Research Vol.24 No.8

Curcumin is the physiologically and pharmacologically active component of turmeric (Curcuma longa L.) with attractive fluorescent property. However, the applications in live cell imaging field are restricted mainly due to the water-insolubility and cytotoxicity. To overcome this problem, curcumin-incorporated glycopolymers are synthesized by free radical copolymerization in this study. The glycopolymers are well-characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), UV-Vis absorption spectroscopy and photoluminescence spectroscopy. Furthermore, obtained glycopolymers are assayed by MTT assay and cell imaging for supporting the potential bio application. The MTT result indicates that the introduction of carbohydrate units can reduce the cytotoxicity of curcumin unit. The live cell imaging investigations reveal that the curcuminincorporated glycopolymers are good candidates for cell imaging and may find broad applications in biological areas such as biological diagnosis, imaging, and detection.

Marine Geo-environmental Disaster: Field Survey and In-situ Long-term Observation

( Yonggang Jia ),( Cong Hu ),( Zhiwen Sun ),( Hong Zhang ),( Hongxian Shan ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Ocean exploitation has entered full ocean depth era. However, frequent marine geological disasters seriously restrict its development. Due to the complex marine engineering geology environment, in-situ observation has become an important means of submarine engineering survey. Based on the common types of marine geological disasters in marine engineering activities, this paper introduces the marine engineering geological survey and in-situ monitoring technology and its application from the perspective of marine engineering geological environment and dynamic action, so as to provide new ideas for the study of marine geological disasters in China.

A Combination of Baicalin and Berberine Hydrochloride Ameliorates Dextran Sulfate Sodium-Induced Colitis by Modulating Colon Gut Microbiota

Yonggang Yan,Luhan Li,Kenan Wu,Gang Zhang,Liang Peng,Yanni Liang,Zheng Wang 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.8

Baicalin and berberine hydrochloride are the main chemical compositions of Scutellariae Radix and Coptidis Rhizoma, respectively. S. Radix and C. Rhizoma are two traditional Chinese herbs that are commonly used together in compounded formulations to treat colitis. Therefore, the combination of Baicalin and berberine hydrochloride (BBH) to treat colitis was studied. The results of pharmacological evaluations demonstrated the excellent protective effects of BBH on colitis induced by dextran sulfate sodium (DSS). BBH could improve the morphological condition of colitis in mice and maintain the balance of proinflammation cytokines (IL-6, IL-8, IL-1β, and TNF-α) and anti-inflammation cytokines (IL-4 and IL-10). The 16s rDNA sequencing revealed that BBH was able to modulate the composition of intestinal microflora, especially the abundances of Eubacterium_brachy_group, Holdemania, Erysipelotrichaceae_UCG_003, Christensenellaceae_R-7_group, and Sellimonas. The results of PICRUSt indicated that the therapeutic effects of BBH were tightly connected with DNA synthesis, replication and repair of gut microbiota. In summary, it was concluded that BBH could protect mice against DSS-induced colitis, and the protective effects were tightly correlated with gut microbiota.

Source Camera Identification with Imbalanced Training Dataset

Yonggang Huang,Jun Zhang,Xinkai Lan 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.2

In this paper, we address the problem of unbalanced training dataset for source camera identification, namely, there are fewer training examples for some camera models compared to other camera models. A new source camera identification approach is proposed to alleviate the influence of imbalanced training dataset. In the proposed approach, firstly, we treat source camera identification as a multi-class classification problem, and decompose it into binary classification problems. After decomposing, the problem of imbalanced training dataset for multiclass classification is transformed to the problem of imbalanced training dataset for binary classification. Then, we incorporate SMOTE and AdaBoost algorithms to construct SVM ensemble to address the issue of imbalanced training dataset for binary classification. A number of experiments show the proposed approach can deal with the imbalanced training dataset effectively.

A second order analytical solution of focused wave group interacting with a vertical wall

Yonggang Sun,Xiantao Zhang 대한조선학회 2017 International Journal of Naval Architecture and Oc Vol.9 No.2

The interaction of focused wave groups with a vertical wall is investigated based on the second order potential theory. The NewWave theory, which represents the most probable surface elevation under a large crest, is adopted. The analytical solutions of the surface elevation, velocity potential and wave force exerted on the vertical wall are derived, up to the second order. Then, a parametric study is made on the interaction between nonlinear focused wave groups and a vertical wall by considering the effects of angles of incidence, wave steepness, focal positions, water depth, frequency bandwidth and the peak lifting factor. Results show that the wave force on the vertical wall for obliquely-incident wave groups is larger than that for normally-incident waves. The normalized peak crest of wave forces reduces with the increase of wave steepness. With the increase of the distance of focal positions from the vertical wall, the peak crest of surface elevation, although fluctuates, decreases gradually. Both the normalized peak crest and adjacent crest and trough of wave forces become larger for shallower water depth. For focused wave groups reflected by a vertical wall, the frequency bandwidth has little effects on the peak crest of wave elevation or forces, but the adjacent crest and trough become smaller for larger frequency bandwidth. There is no significant change of the peak crest and adjacent trough of surface elevation and wave forces for variation of the peak lifting factor. However, the adjacent crest increases with the increase of the peak lifting factor.

A study of hydroelastic behavior of hinged VLFS

Yonggang Sun,Da Lu,Jin Xu,Xiantao Zhang 대한조선학회 2018 International Journal of Naval Architecture and Oc Vol.10 No.2

This paper introduces a new method to study the hydroelastic behavior of hinged Very Large Floating Structures (VLFSs). A hinged twomodule structure is used to confirm the present approach. For each module, the hydroelasticity theory proposed by Lu et al. (2016) is adopted to consider the coupled effects of wave dynamics and structural deformation. The continuous condition at the connection position between two adjacent modules is also satisfied. Then the hydroelastic motion equation can be established and numerically solved to obtain the vertical displacement, force and bending moment of the hinged structure. The results calculated by the present new method are compared with those obtained using three-dimensional hydroelasticity theory (Fu et al., 2007), which shows rather good agreement.