Picosecond Mid-Infrared 3.8 μm MgO:PPLN Optical Parametric Oscillator Laser with High Peak Power

Bing-Yan Chen,Yu-Heng Wang,Yong-Ji Yu,Guang-Yong Jin 한국광학회 2021 Current Optics and Photonics Vol.5 No.2

In this study, a compact, picosecond, mid-infrared 3.8 μm MgO:PPLN optical parametric oscillator(OPO) laser output with high peak power is realized using a master oscillator power amplifier (MOPA)1 μm solid-state laser seeded by a picosecond fiber laser as the pump source. The pump source was a 50MHz and 10 ps fiber seed source. After AOM pulse selection and two-stage solid-state amplification, a 1,064 nm laser output with a repetition frequency of 1–2 MHz, pulse width of 9.5 ps, and a maximum average power of 20 W was achieved. Furthermore, a compact short cavity with a unsynchronized pump is adopted through the design of an OPO cavity structure. When the injection pump power was 15 W and the repetition frequency was 1 MHz, the average output power of idler light was 1.19 W, and the corresponding peak power was 119 kW. The optical conversion efficiency was 7.93%. When the repetition frequency was increased to 2 MHz, the average output power of idler light was 1.63 W, the corresponding peak power was 81.5 kW, and the optical conversion efficiency was 10.87%. At the same time, the output wavelength was measured at 3,806 nm, and the beam quality was M X2 = 3.21 and M Y2 = 3.34.

SYNTHESIS AND PROPERTIES OF ONE-DIMENSIONAL ALUMINUM NITRIDE NANOSTRUCTURES

YONG-BING TANG,HONG-TAO CONG,HUI-MING CHENG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2007 NANO Vol.2 No.6

This article presents a brief review of the recent research progresses achieved in the field of one-dimensional (1D) aluminum nitride (AlN) nanostructures. It mainly covers three aspects: The first one is to introduce the synthetic strategies for several classic 1D AlN nanostructures (such as nanofibers, nanobelts, nanorods, nanowires, nanotips, etc.) including template-confined reaction, arc discharge, catalyst-assisted growth, and vapor transport and related growth methods. The second is to elaborate some special physical properties, such as field emission and photoluminescence, which associate with the uniqueness of 1D AlN nanostructures. It is revealed that aligned AlN 1D nanostructures have low turn-on and threshold voltages, high emission current and small current fluctuation, and that the photoluminescence of AlN nanobelts are different from those of conventional AlN material. The third is to briefly illustrate the potential application of these 1D AlN nanostructures in composite materials. It is found that AlN nanowire is a good reinforcement for improving the mechanical and thermal properties of metal matrix composites, which can be expected to be utilized as packaging material with high strength and low thermal expansion. Finally, we summarize the major challenges in this field. Among them, a thorough understanding of the growth mechanism of 1D AlN nanostructures is the most important issue, and more precisely controlled growth is required to obtain tailored AlN nanostructures according to device applications.

Asian Type 감마 3 정을 이용한 대퇴골 전자간 골절의 치료결과 분석

황병철 ( Bing Zhe Huang ),박용욱 ( Yong Wook Park ),박진수 ( Jin Su Park ),노규철 ( Kyu Cheol Noh ),김성연 ( Soung Yon Kim ),정국진 ( Kook Jin Chung ),김홍균 ( Hong Kyun Kim ),김형년 ( Hyong Nyun Kim ),윤용현 ( Yong Hyun Yoon ) 대한골절학회 2014 대한골절학회지 Vol.27 No.3

Purpose: This study was conducted in order to demonstrate the radiologic and clinical results of using the Asian type gamma 3 nail in treatment of trochanteric fractures. Materials and Methods: Patients underwent operations with gamma 3 nails between August 2010 and August 2012. For the radiologic evaluation, we analyzed bone quality, fracture pattern, reduction quality, union period, and position of lag screw (tip-apex distance, Cleveland index). For the clinical evaluation, we analyzed mobility score of Palmer and Parker and Jensen`s functional score. Results: The mean union was taken at 17.4 weeks (14-25 weeks). Two cases (4.3%) underwent reoperation due to cutting out of the hip screws. The clinical outcomes of Parker and Palmer`s average mobility score changed from 7.3 to 5.8 (79%), Jensen`s functional score was 1.3 to 1.8 (72%). Conclusion: We achieved excellent clinical and radiological outcomes; therefore, Asian type gamma 3 nail is effective in treatment of trochanteric fractures of the femur in Korea.

Transcriptome analysis of the pheromone glands in Noorda blitealis reveals a novel AOX group of the superfamily Pyraloidea

Zhang Zu-Bing,Yin Ning-Na,Long Ji-Ming,Zhang Yong-Ke,Liu Nai-Yong,Zhu Jiaying 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

Noorda blitealis (Lepidoptera: Pyraloidea: Crambidae) is a major defoliating pest of Moringa trees. Focusing on its mating and reproduction, here we sequenced and analyzed the transcriptome of its pheromone glands (PGs) with a combination of Illumina sequencing, bioinformatics and phylogenetics approaches, coupled with a genomebased analysis. Transcriptome sequencing led to the yields of approximately 162 million clean reads, which were assembled into 60,578 unigenes and 121,692 transcripts, respectively. From the transcriptome, totally 117 genes encoding eight pheromone biosynthesis enzymes and one pheromone degradation enzyme were identified, 90 of which had complete open reading frames. A comparative analysis between PGs and bodies (removing PGs) revealed a large number of differentially expressed genes, including 79 pheromone biosynthesis and degradation related genes. Of the identified genes, NbliDES12 belonging to the △11 desaturase group was likely to a strong candidate for the desaturation of sex pheromones in N. blitealis, as implied by phylogenetic analyses and expression profiles. Finally and most notably, through genome and transcriptome analyses we discovered, for the first time, a novel aldehyde oxidase 6 (AOX6) group of the superfamily Pyraloidea that have been slightly expanded by gene duplications. Moreover, each orthologous AOX group shared highly conserved gene structure. Together, this current study has characterized the genes associated with sex pheromone biosynthesis and degradation from the PG transcriptome of N. blitealis, and more importantly, identifies a novel AOX group of the Pyraloidea.

The Blood Neutrophil-to-lymphocyte Ratio Predicts Survival in Patients with Advanced Hepatocellular Carcinoma Receiving Sorafenib

Zheng, You-Bing,Zhao, Wei,Liu, Bing,Lu, Li-Gong,He, Xu,Huang, Jian-Wen,Li, Yong,Hu, Bao-Shan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Background and Aim: Increasing evidence correlates the presence of systemic inflammation with poor survival in patients with hepatocellular carcinoma (HCC). The aim of this study was to investigate the prognostic significance of the blood neutrophil-to-lymphocyte ratio (NLR) in patients with advanced HCC who received sorafenib monotherapy. Methods: A total of sixty-five patients with advanced HCC, not eligible for locoregional therapy, treated with sorafenib were enrolled. Potential prognostic factors such as age, gender, tumoral characteristics, performance status and NLR were analyzed. Results: Median OS and TTP for the entire cohort were 10.0 months (95%CI, 7.6-12.3 months) and 4.5 months (95% CI, 4.0-4.9 months). The mean NLR at baseline was 2.89. The median OS of patients with a high NLR (>4) was 6.5 months (95%CI, 5.2-7.7 months) compared with 12.5 months (95%CI, 9.9-15.0) for patients with a normal NLR (${\leq}4$) (P=0.01). Age ${\leq}65$, NLR>4, extrahepatic metastases and vascular invasion were all predictors of poorer overall survival. Multivariate analysis showed that NLR > 4, vascular invasion and extrahepatic metastases were independent predictors of poorer overall survival. The median TTP of patients with a high NLR was 2.5 months (95%CI, 1.4-3.6 months) compared with 4.5 months (95%CI, 3.9-5.1 months) for patients with a normal NLR (P=0.012). Conclusions: High baseline NLR was associated with worse OS and TTP for patients with advanced HCC treated with sorafenib.

Baimantuoluosides D-G, Four New Withanolide Glucosides from the Flower of Datura metel L.

Bing-you Yang,Yong-gang Xia,Qiu-hong Wang,De-qiang Dou,Hai-xue Kuang 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.8

In our search for bioactive anti-psoriasis compounds from the flower of Datura metel L, we isolated four new withanolide glucosides, baimantuoluosides D, E, F and G (1-4). The structures of the new compounds are (5α,6α,7β,22R)-5,6,7,27-tetrahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (1), (5α,6β,7α,22R)-5,6,7,27-tetrahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (2), (5α,6β,7α,12β,22R)-5,6,7,12,27-pentahydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (3), and (5α,6β,22R)-5,6,27-trihydroxy-1-oxowitha-2,24-dien-27-O-β-D-glucopyranoside (4) on the basis of chemical and physicochemical evidence.

Potential Use of Soil in Lightweight Foamed Concrete

Yong Yang,Bing Chen 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.6

This research investigates the application of soil in foamed concrete as a sand replacement. Foamed concrete with dry densities ranging between 800 and 1500 kg/m3 and cube strength from 5 to 25 MPa tested. The potential improvement of soil-based foamed concrete regarding thermal insulation compared with sand-based foamed concrete was also investigated. Silica fume was also used to improve the properties of soil-based foamed concrete. Dry density, 28-day compressive strength, and thermal conductivity and pore structure tests, were conducted to investigate the effects of silica fume on the properties of foamed concrete. Results show that the replacement of sand with soil can significantly decrease the dry density of foamed concrete. Also, the compressive strength and thermal insulation improved by the addition of silica fume. In the end, a soil-based foamed concrete with a density of 800 kg/m3, compressive strength of 7.5 MPa and thermal conductivity of 0.16 W/mK was produced.

Effect of Argon Gas Pressure on Residual Stress, Microstructure Evolution and Electrical Resistivity of Beryllium Films

Bing-Chi Luo,Kai Li,Ji-Qiang Zhang,Jiang-Shan Luo,Wei-Dong Wu,Yong-Jian Tang 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.4

The residual stress in beryllium films fabricated on K9 substrates by using magnetron sputtering deposition is measured by using a curvature method and is theoretically estimated by using the Nix and Clemens (NC) model. The experimental results indicate that the 1.3-μm-thick film is always in a tensile state for pressure variations in the range from 0.4 to 1.2 Pa. When the sputtering gas pressure is increased, the average stress increases at first, after which it decreases by a remarkable amount. The observed descending trend of the tensile stress when the sputtering gas pressure is beyond 0.6 Pa is mainly attributed to the grain size in the film being larger than that in the film when the pressure is below 0.6 Pa. The maximal residual stress of 552 MPa at a sputtering gas pressure of 0.6 Pa is close to the tensile strength (550 MPa) of the corresponding beryllium bulk material and is about 8 times smaller than that calculated by using the N-C model. In addition, the surface morphologies of the as-fabricated films reveal fibrous grains while the cross-sectional morphologies are characterized by a coarsening of columnar grains. The measured electric resistivity of each film strongly depends on its porosity and the sizes of its grains.

TiO 2 SUB-MICROSPHERES AS A BI-FUNCTIONAL SCATTERING LAYER FOR HIGH- PERFORMANCE DYE-SENSITIZED SOLAR CELLS

YONG DING,SONGYUAN DAI,Litao Jia,YANMEI MA,ZHAOQIAN LI,CHANGNENG ZHANG,JIANXI YAO,LIE MO,LINHUA HU,BING ZHANG,LING JIANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.5

The sub-microspheres play multiple roles in enhancing dye adsorption and light-scattering toimprove the performance of dye-sensitized solar cells (DSSCs). In this work, the well-de¯ned TiO 2sub-microspheres with anatase granular-like nanocrystals are prepared in high yield by com-bining hydrolytic process with solvothermal treatment. Scanning electron microscopy (SEM) andtransmission electron microscopy (TEM) results indicated that plenty of rhombic nanoparticleswith ? 18 nm diameter having mutual contacts to neighboring nanoparticles were densely self-assembled into sub-microspheres, and abundant mesopores existed in the whole sub-microsphereswith superior light scattering ability. The appropriate pore diameter and relatively high speci¯csurface area of the as-obtained sub-microsphere result in a higher dye adsorption. As expected, byusing the sub-microspheres as a scattering layer, a higher photovoltaic conversion e±ciency of10.15% is obtained for DSSCs.

Study on stiffness deterioration in steel-concrete composite beams under fatigue loading

Bing Wang,Qiao Huang,Xiaoling Liu,Yong Ding 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.4

The purpose of this paper is to investigate the degradation law of stiffness of steel-concrete composite beams after certain fatigue loads. First, six test beams with stud connectors were designed and fabricated for static and fatigue tests. The resultant failure modes under different fatigue loading cycles were compared. And an analysis was performed for the variations in the load-deflection curves, residual deflections and relative slips of the composite beams during fatigue loading. Then, the correlations among the stiffness degradation of each test beam, the residual deflection and relative slip growth during the fatigue test were investigated, in order to clarify the primary reasons for the stiffness degradation of the composite beams. Finally, based on the stiffness degradation function under fatigue loading, a calculation model for the residual stiffness of composite beams in response to fatigue loading cycles was established by parameter fitting. The results show that the stiffness of composite beams undergoes irreversible degradation under fatigue loading. And stiffness degradation is associated with the macrobehavior of material fatigue damage and shear connection degradation. In addition, the stiffness degradation of the composite beams exhibit S-shaped monotonic decreasing trends with fatigue cycles. The general agreement between the calculation model and experiment shows good applicability of the proposed model for specific beam size and fatigue load parameters. Moreover, the research results provide a method for establishing a stiffness degradation model for composite beams after fatigue loading.