Controlled synthesis and luminescence properties of doped NaLa(WO4)2 microstructures

Yunhua Han,Yan Wang,Shaohua Huang,Fan-Long Jin,Shili Gai,Na Niu,Liuzhen Wang,Piaoping Yang 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.34 No.-

In this work, well-defined NaLa(WO4)2microstructures were prepared by a facile hydrothermal processin the presence of oleylamine and oleic acid as a mixed surfactant. The phase, morphology, size andluminescence properties were well characterized by means of X-ray diffraction (XRD), scanning electronmicroscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra, and decaytime, respectively. The results reveal that the morphology and size of the as-synthesized samples can betuned by altering the reaction time and the amounts of oleic acid. A possible formation mechanism oftetragonal NaLa(WO4)2 is proposed on the basis of oleic acid amount-dependent experiments. Uponultraviolet (UV) excitation, NaLa(WO4)2:Eu3+ and NaLa(WO4)2:Tb3+ exhibit the characteristic downconversionemissions of Eu3+ and Tb3+. Yb3+/Er3+ and Yb3+/Tm3+ co-doped NaLa(WO4)2 samples showstrong green (Er3+, 4S3/2, 2H11/2!4I15/2) and blue (Tm3+, 1G4!3H6) up-conversion emission under980 nm laser diode excitation. Upconversion emission mechanisms of NaLa(WO4)2:Ln (Ln = Yb/Er, Yb/Tm) are also presented based on the emission spectra and the plot of luminescence intensity to pumppower. It should be noted that the intensity of the upconversion emissions can be dramatically enhancedcompared with sodium free tungstates, which can be attributed to the charge compensation and meansthe introduction of Na+ ions in WO42 causes less distortion in the crystal structure.

자외선 (UVB) 노출 증가에 대한 피부암 위해도 예측 모델의 적용

신동천,이종태,정용,강나경,양지연 한국환경독성학회 1996 환경독성보건학회지 Vol.11 No.1

A decrease in stratospheric ozone probably caused by chloroflurocarbons (CFCs) emissions, has been observed large parts of the globe. It is generally accepted that if ozone levels in the stratosphere are depleted, greater amounts of shortwave ultraviolet radiation-B (UVB) will reach the earth's surface, resulting in increased incidence of nonmelanoma skin cancer. In this study, we evaluated several mathematical models, such as a power and an exponential model, and a geometric model considering the surface area of a human body part and ages for the prediction of skin cancer incidence caused by exposure to the UVB radiation. These models basically estimated the risk of skin cancer based on those measurements of the local ozone in stratosphere and UVB. Both were measured at a part of Seoul with a Dobson ozone spectrometer and Robertson-Berger UV Biometer for 1995. As a result, we calculated the point estimation applying a biological amplification factor (BAF), UVB radiation and other factors. We used a Monte-Carlo simulation technique with assumption on the distribution of each considered factor. The sensitivity analysis of model by there components conducted using Gaussian sensitivity method. The annual integral of UVB radiation was 2275 MED (minimal erythema dose)/yr. Also, an estimate of the annual amount of UVB reaching the earth's surface at a korea's latitude and altitude was 3328 MED/yr. The values of the radiation amplification factor (RAF) were ranged from 0.9 to 1.5 in Seoul. To give the effective factors required to model the prediction of skin cancer incidence caused by exposure to the UVB radiation in Korea, we studied the pros and cons of above mentioned models with the application of those parameters measured in Seoul, Korea.

Output Feedback Stabilization for an ODE Coupled with a Wave Equation with Variable Coefficients

Yan Xing Zhao,Jun Jun Liu,Yan Na Jia 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.2

In this paper, we are concerned with the output feedback problem for coupled ODE-wave systems subject to spatially-varying coefficients. An original transformation is designed to turn the wave equation into an equation of the same type with constant coefficient and low order term. Taking advantage of the backstepping method, a state observer is constructed by non-collocated boundary displacement and velocity measurement. Output feedback on the based of the observer output feedback is then constructed, which makes use of the backstepping method to make the system exponentially stable. Finally, we demonstrate the well-posed and the exponential stability of the closed-loop system.

Roles of Immunohistochemical Staining in Diagnosing Pulmonary Squamous Cell Carcinoma

Yan, Yue,Zhang, Ya-Xiong,Fang, Wen-Feng,Kang, Shi-Yang,Zhan, Jian-Hua,Chen, Nan,Hong, Shao-Dong,Liang, Wen-Hua,Tang, Yan-Na,He, Da-Cheng,Wu, Xuan,Zhang, Li Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: Differentiating morphologic features based on hematoxylin-eosin (HE) staining is the most common method to classify pathological subtypes of non-small-cell lung cancer (NSCLC). However, its accuracy and inter-observer reproducibility in pathological diagnosis of poorly differentiated NSCLC remained to be improved. Materials and Methods: We attempted to explore the role of immunohistochemistry (IHC) staining in diagnosing pulmonary squamous cell carcinoma (SQCC) with poorly differentiated features by HE staining or with elevated serum adenocarcinoma-specific tumor markers (AD-TMs). We also compared the difference of epidermal growth factor receptor (EGFR) mutation rate between patients with confirmed SQCC and those with revised pathological subtype. Logistic regression analyses were used to test the association between different factors and diagnostic accuracy. Results: A total of 132 patients who met the eligible criteria and had adequate specimens for IHC confirmation were included. Pathological revised cases in poor differentiated subgroup, biopsy samples and high-level AD-TMs cases were more than those with high/moderate differentiation, surgical specimens and normal-level AD-TMs. Moreover, biopsy sample was a significant factor decreasing diagnostic accuracy of pathological subtype (OR, 4.037; 95% CI 1.446-11.267, p=0.008). Additionally, EGFR mutation rate was higher in patients with pathological diagnostic changes than those with confirmed SQCC (16.7% vs 4.4%, p=0.157). Conclusions: Diagnosis based on HE staining only might cause pathological misinterpretation in NSCLC patients with poor differentiation or high-level AD-TMs, especially those with biopsy samples. HE staining and IHC should be combined as pathological diagnostic standard. The occurrence of EGFR mutations in pulmonary SQCC might be overestimated.

Analysis of the Sideband Effect on the Stability of the Voltage-Mode-Controlled Boost Converter

Na Yan,Xinbo Ruan,Yazhou Wang,Xinze Huang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Although the small-signal model of the loop gain, which quantitatively include the sideband effect, have been proposed in the resent research, all results are for buck converters. When applying these results for the Voltage-Mode-Controlled(VMC) boost converter, the instability phenomenon, in some cases the converter with the leadingedge modulation is stable while with the trailing-edge modulation it becomes unstable, still couldn’t be explained as the case that using average model. In order to indicate why these results aren’t suitable for boost converter, it is firstly pointed out that the high-frequency characteristic of the duty ratio-to-output transfer function Gvd(s), which the average model fails to describe, could affect the low-frequency performance of the loop gain and the modulator. Then, we give the theoretical prediction of Gvd(s) by using the describe function method, which has excellent agreement with the measured results especially in the high-frequency region. By using the corresponding obtained loop gain, the aforementioned phenomenon would be explained. The work demonstrates significant importance of the research into the sideband effect on the stability for the DC/DC converter and the DC system.

Study on the Morphological Parameters and Evolution of Caragana microphylla Lam, Nebkhas in Inner Mongolia, China

Na Yan,Eerdun Hasi,Ki Hyung Park,Xian Dong Xia,Kun Woo Chun 한국임학회 2009 한국산림과학회지 Vol.98 No.2

Designing Co7Fe3@TiO2 Core–Shell Nanospheres for Electromagnetic Wave Absorption in S and C Bands

Na Chen,Jian‑Tang Jiang,Zhen‑Jie Guan,Shao‑Jiu Yan,Liang Zhen,Cheng‑Yan Xu 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.5

Ferromagnetic-dielectric nanocomposites have attracted extensive interests for its high electromagnetic wave absorption(EMA) performance due to the synergetic effects between different components. Herein, we report the design of core–shellstructured Co7Fe3@TiO2 composite particles, which are subsequently annealed in H2/Ar atmosphere to further improve itsEMA performance. The introducing of TiO2dielectric shell together with hydrogen annealing contributes greatly to theelectromagnetic properties due to the increased conductivity and enhanced ferromagnetic resonance. Excellent EMA performanceis achieved in S (2–4 GHz) and C (4–8 GHz) bands in coatings using Co7Fe3@TiO2 as absorbents. Apart from thehigh EMA efficiency, the location of EMA band can be tailored in a wide range through regulating the coating thickness. Specifically, an effective absorption band of 2.0 GHz in C band at a thickness of 2.62 mm, and an effective absorption bandof 1.7 GHz are achieved in S band at thicknesses of 4.0–5.0 mm. The excellent electromagnetic properties are ascribed tothe effective complementary between dielectric loss and ferromagnetic loss.

Hyperbilirubinemia Reduces the Streptozotocin-Induced Pancreatic Damage through Attenuating the Oxidative Stress in the Gunn Rat

Fu, Yan Yan,Kang, Kyung Ja,Ahn, Jung Myung,Kim, Hae-Ryoung,Na, Ki Young,Chae, Dong-Wan,Kim, Suhnggwon,Chin, Ho Jun Tohoku University Medical Press 2010 The Tohoku journal of experimental medicine Vol.222 No.4

<P>Oxidative stress is an important pathogenic factor in diabetes. Bilirubin may serve a cytoprotective function as an anti-oxidant. The Gunn rat lacks the enzyme uridine-diphosphate glucuronosyltransferase that is responsible for conjugation of bilirubin, exhibiting elevation of plasma bilirubin. We examined the effect of hyperbilirubinemia on the pancreatic damage caused by streptozotocin (STZ) in the Gunn rat. Male Wistar rats and male Gunn rats were treated with STZ (WS and GS groups, respectively) or vehicle (WC and GC groups, respectively). All 5 rats in the WS group developed diabetes, defined as fasting blood glucose 300 mg/dL or more, at 3 days, whereas only 2 of the 5 GS rats became diabetic at 7 days after STZ injection. Without insulin supplement at 7 days after STZ injection, the WS group displayed higher levels of fasting blood glucose (510.3 ± 50.3 vs. 236.4 ± 42.5 mg/dL, <I>p</I> = 0.003) and HbA1c (5.0 ± 0.1 vs. 3.9 ± 0.1, <I>p</I> = 0.001), compared to those of GS group. In Wistar rats, STZ induced apoptosis of the pancreatic islet cells, accompanied with activation of NADPH oxidase and increased production of reactive oxygen species and nitric oxide, but not in Gunn rats. Moreover, in a rat insulinoma cell line (RIN-m5F), pre-treatment with bilirubin (0.1 mg/dL) decreased cell death and apoptosis caused by STZ, and also reduced H<SUB>2</SUB>O<SUB>2</SUB> production. Considering the protective effect of hyperbilirubinemia against STZ-induced injury, we postulate that bilirubin could be a potential therapeutic modality for oxidative stress of pancreas islets.</P>

Slender RC columns strengthened with combined CFRP and steel jacket under axial load

Yi-Yan Lu,Shan Li,Na Li,Tian-yan Ou 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.5

This paper presents an experimental study on the effectiveness of simultaneous application of carbon fiber-reinforced polymer (CFRP) and steel jacket in strengthening slender reinforced concrete (RC) column. The columns were 200 mm square cross section with lengths ranging from 1600 to 3000 mm. Ten columns were tested under axial load. The effects of the strengthening technique, slenderness ratio, cross-section area of steel angle and CFRP layer number were examined in terms of axial load-axial strain curve, CFRP strain, steel strip strain and steel angle strain. The experiments indicate that strengthening RC columns with combined CFRP and steel jacket is effective in enhancing the load capacity, ductility and energy dissipation capacity of RC column. Based on the existing models for RC columns strengthened with CFRP and with steel jacket, a design formula considering a slenderness reduction factor is proposed to predict the load capacity of the RC columns strengthened with combined CFRP and steel jacket. The predictions agree well with the experimental results.

The TO901317, an agonist of LXRα, Increased Mesangial Matrix and Renal Collagen 4 with the Enhancement of SREBP1 in Diabetic Animals

푸얀얀 ( Yan Yan Fu ),이은성 ( En Sung Lee ),이윤미 ( Yun Mi Lee ),유선진 ( Sun Jin You ),송영림 ( Young Rim Song ),진호준 ( Ho Jun Chin ),나기영 ( Ki Young Na ),김성권 ( Suhng Gwon Kim ),채동완 ( Dong Wan Chae ) 대한신장학회 2008 춘계학술대회 초록집 Vol.28 No.1