Design of High Brightness Cubic-GaN LEDs Grown on GaAs Substrate

Yuanping Sun,D. G. Zhao,Hui Yang,S. M. Zhang,X. M. Shen,Y. Fu,Z. H. Zhang,Z. H. Feng 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.III

The Principle of optical thin film was used to calculate the feasibility of improving the light extraction efficiency of GaN/GaAs optical devices by wafer-bonding technique. The calculated results show that the light extraction efficiency of bonded samples can be improved by 2.66 times than the as-grown GaN/GaAs samples when a thin Ni layer was used as adhesive layer and Ag layer as reflective layer. Full reflectance spectrum comparison shows that reflectivity for the incident light of 459.2 nm of the bonded samples was improved by 2.4 times than the as-grown samples, which is consistent with the calculated results.

Effects of GaN Capping on the Structural and the Optical Properties of InN Nanostructures Grown by Using MOCVD

Yuanping Sun,Yuanping Sun,조용훈,Hui Wang,Lili Wang,Shuming Zhang,Hui Yang 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.1

InN nanostructures with and without GaN capping layers were grown by using metal-organic chemical vapor deposition. Morphological, structural, and optical properties were systematically studied by using atomic force microscopy, X-ray diffraction (XRD) and temperature-dependent photoluminescence (PL). XRD results show that an InGaN structure is formed for the sample with a GaN capping layer, which will reduce the quality and the IR PL emission of the InN. The lower emission peak at 0.7 eV was theoretically fitted and assigned as the band edge emission of InN. Temperature-dependent PL shows a good quantum efficiency for the sample without a GaN capping layers; this corresponds to a lower density of dislocations and a small activation energy.

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.

A Hydrogel-based First-Aid Tissue Adhesive with Effective Hemostasis and Anti-bacteria for Trauma Emergency Management

Dongjie Zhang,Li Mei,Yuanping Hao,Bingcheng Yi,Jilin Hu,Danyang Wang,Yaodong Zhao,Zhe Wang,Hailin Huang,Yongzhi Xu,Xuyang Deng,Cong Li,Xuewei Li,Qihui Zhou,Yun Lu 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Clinical tissue adhesives remain some critical drawbacks for managing emergency injuries, such as inadequate adhesive strength and insufficient anti-infection ability. Herein, a novel, self-healing, and antibacterial carboxymethyl chitosan/polyaldehyde dextran (CMCS/PD) hydrogel is designed as the first-aid tissue adhesive for effective trauma emergency management. Methods We examined the gel-forming time, porosity, self-healing, antibacterial properties, cytotoxicity, adhesive strength, and hemocompatibility. Liver hemorrhage, tail severance, and skin wound infection models of rats are constructed in vivo, respectively. Results Results demonstrate that the CMCS/PD hydrogel has the rapid gel-forming (~ 5 s), good self-healing, and effective antibacterial abilities, and could adhere to tissue firmly (adhesive strength of ~ 10 kPa and burst pressure of 327.5 mmHg) with excellent hemocompatibility and cytocompatibility. This suggests the great prospect of CMCS/ PD hydrogel in acting as a first-aid tissue adhesive for trauma emergency management. The CMCS/PD hydrogel is observed to not only achieve rapid hemostasis for curing liver hemorrhage and tail severance in comparison to commercial hemostatic gel (Surgiflo ®) but also exhibit superior anti-infection for treating acute skin trauma compared with clinical disinfectant gel (Prontosan ®). Conclusions Overall, the CMCS/PD hydrogel offers a promising candidate for first-aid tissue adhesives to manage the trauma emergency. Because of the rapid gel-forming time, it could also be applied as a liquid first-aid bandage for mini-invasive surgical treatment.

Optical properties of InN rods on sapphire grown by metal–organic chemical vapor deposition

Sun, Yuanping,Cho, Yong-Hoon,Dai, Zhenhong,Wang, Weitian,Wang, Hui,Wang, Lili,Zhang, Shuming,Yang, Hui Elsevier 2010 Physica E, Low-dimensional systems & nanostructure Vol.43 No.1

<P><B>Abstract</B></P><P>The InN rods were grown by metal–organic chemical vapor deposition with a density of 1.4×10<SUP>9</SUP>cm<SUP>−2</SUP>. Optical properties of InN rods have been systematically investigated by means of temperature dependent photoluminescence (PL) and power dependent PL. Four peaks appear in the PL spectra and the origination was analyzed. The lowest energy peak P1 (0.665eV) is attributed to transitions of conduction band electrons to the photo-holes captured by deep acceptor; P2 (0.717eV) is the direct band-to-band transition peak of InN; main peak P3 (0.759eV) results from the recombination of degenerate electrons with photo-holes near the top of the valence band (Burstein–Moss effects); the high energy shoulder P4 (0.787eV) was by the co-effect of quantum confinement and the Burstein–Moss effects due to the small size distribution of InN wetting layers.</P>

Monitoring and Evaluation of Artificial Ground Freezing in Metro Tunnel Construction-A Case Study

Qixiang Yan,Wang Wu,Chuan Zhang,Shuqi Ma,Yuanping Li 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.5

The turn-back tunnel of Guangzhou Metro Line 3 Tianhe Station with a large span was excavated in sandy clay which may easily break and disintegrate. The artificial ground freezing (AGF) technique was used to stabilize the soil and to prevent its collapse during excavations. Most of the existing theoretical analysis and numerical simulation on the AGF technique are purely based on a couple of assumptions, which are not able to produce accurate predictions. It would be more accurate for the AGF analysis to include the field monitoring. In this study, the coupled method of the field monitoring, the analytical formula, and the numerical method is used to evaluate the thickness and average temperature of the frozen zone. Field monitoring was conducted to measure the temperature of the brine and the ground. Analytical formula was used to compute the thickness and the average temperature of the frozen zone. Numerical simulation is also carried out to predict the thickness and the temperature field of the frozen zone. According to the analytical and numerical analysis, the computed thickness and average temperature of the frozen zone meet the designed requirements of the project, which are further confirmed by the successful excavation of the tunnel. This indicates that the coupled method used in this paper is reliable and would be helpful for the AGF application in practical engineering.

Effects of Sulfur Introduction on the UV and the Visible Emission Properties of ZnO

Hongying Guo,Feihong Jiang,Run Yuan,Jun Zhang,Yuanping Sun,Yifan Liu,Yongxin Qiu,Taofei Zhou,Xionghui Zeng,Baoshun Zhang,Ke Xu,Hui Yang 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.4

Hexagonal ZnO particles have been synthesized by using the hydrothermal method with differentsulfur concentrations in the reaction solutions. Structural and optical characterizations have beenconducted to study the effects of the sulfur in the reaction solutions on the properties of thesynthesized ZnO in the ultraviolet (UV) and the visible (VIS) bands. The existance of sulfur inthe solutions can help to introduce compression strain along the a axis and an opposite trend forthe parameter c with strain inside the formed ZnO particles, which means the total strain in thesamples is presented along the c axis. The average size of the ZnO particles, as calculated fromSEM images, shows the same trend as the strain in the samples. The increasing incorporation ofsulfur causes an increase in the VIS luminescence band, which can be attributed to an increase inthe number of sulfur-induced defects.

The growth improvement of DvGS2-transgenic Arabidopsis thaliana arises from the higher efficiency of nitrogen and carbon assimilation

Chenguang Zhu,Shilin Chen,Guimin Zhang,Wei Wang,Yuanping Tang,Bing Mei,Rentao Song 한국식물생명공학회 2015 Plant biotechnology reports Vol.9 No.4

The overexpression of algal glutamine synthetase (GS) gene DvGS2 in Arabidopsis thaliana resulted in higher plant biomass and better growth phenotype. The purpose of this study was to understand the biological mechanism for the improvement of growth phenotype of DvGS2-transgenic Arabidopsis. A series of molecular and biochemical investigation related to nitrogen and carbon metabolism in DvGS2-transgenic line was, respectively, conducted. Analysis of nitrogen use efficiency (NUE)-related gene expression and enzymatic activity revealed that the transcriptional level and enzymatic activity of genes encoding glutamate synthase, glutamate dehydrogenase and alanine aminotransferase were significantly up-regulated especially under low nitrate condition. The DvGS2- transgenic line showed higher total nitrogen content and lower carbon: nitrogen ratio than the wild type. Significant reduced concentration of leaf free ammonium, higher concentrations of total amino acids, individual amino acid (glutamine, methionine, alanine, asparagine) together with increased concentrations of glucose, fructose and starch, confirmed the higher efficiency of nitrogen and carbon assimilation. These improved metabolisms of nitrogen and carbon conferred the DvGS2-transgenic Arabidopsis more biomass, better growth phenotype and higher NUE compared with the wild type plant.

PRDX6 regulates the H2O2 and blue light-induced APRE-19 cell apoptosis via down-regulating and interacting with RARA

Xu Zha,Guojiu Wu,Hong Zhang,Yanni Yang,Yuanping Zhang,Linkun Ma 한국통합생물학회 2019 Animal cells and systems Vol.23 No.4

Hereditary retinal disease (HRD) is the primary retinal degeneration that leads to severe visual impairments and refractory blindness, and the therapy of HRD was most important in ophthalmology. The apoptosis of retinal cells plays important roles in HRD progression. Therefore, in this study, we explore the mechanism of H2O2 and blue light-induced apoptosis of ARPE-19 cells. Co-immunoprecipitation (Co-IP) is employed to test the interactions between proteins, and western blotting is used to detect the protein levels. Apoptosis is analyzed by Flow cytometry. Our results found that PRDX6 could interact with RARA in ARPE-19 cells, and H2O2 and blue light could significantly reduce the RARA protein expression, and also could inhibit the interaction between PRDX6 and RARA. Using a rescue experiment, we further elucidated that H2O2 and blue light reduced the RARA expression via down-regulating PRDX6. And H2O2 and blue light induced the ARPE-19 cell apoptosis via decreasing the expression of PRDX6. Our results suggested that the interaction between PRDX6 and RARA played important roles in the apoptosis of ARPE-19 cells.