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      • SCIESCOPUSKCI등재
      • SCIESCOPUSKCI등재

        Heavy concrete shielding properties for carbon therapy

        Jin-Long Wang,Jiade J Lu,Da-Jun Ding,Wen-Hua Jiang,Ya-Dong Li,Rui Qiu,Hui Zhang,Xiao-Zhong Wang,Huo-Sheng Ruan,Yan-Bing Teng,Xiao-Guang Wu,Yun Zheng,Zi-Hao Zhao,Kai-Zhong Liao,Huan-Cheng Mai,Xiao-Dong Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

        As medical facilities are usually built at urban areas, special concrete aggregates and evaluation methods are needed to optimize the design of concrete walls by balancing density, thickness, material composition, cost, and other factors. Carbon treatment rooms require a high radiation shielding requirement, as the neutron yield from carbon therapy is much higher than the neutron yield of protons. In this case study, the maximum carbon energy is 430 MeV/u and the maximum current is 0.27 nA from a hybrid particle therapy system. Hospital or facility construction should consider this requirement to design a special heavy concrete. In this work, magnetite is adopted as the major aggregate. Density is determined mainly by the major aggregate content of magnetite, and a heavy concrete test block was constructed for structural tests. The compressive strength is 35.7 MPa. The density ranges from 3.65 g/cm<sup>3</sup> to 4.14 g/cm<sup>3</sup>, and the iron mass content ranges from 53.78% to 60.38% from the 12 cored sample measurements. It was found that there is a linear relationship between density and iron content, and mixing impurities should be the major reason leading to the nonuniform element and density distribution. The effect of this nonuniformity on radiation shielding properties for a carbon treatment room is investigated by three groups of Monte Carlo simulations. Higher density dominates to reduce shielding thickness. However, a higher content of high-Z elements will weaken the shielding strength, especially at a lower dose rate threshold and vice versa. The weakened side effect of a high iron content on the shielding property is obvious at 2.5 µSv=h. Therefore, we should not blindly pursue high Z content in engineering. If the thickness is constrained to 2 m, then the density can be reduced to 3.3 g/cm<sup>3</sup>, which will save cost by reducing the magnetite composition with 50.44% iron content. If a higher density of 3.9 g/cm<sup>3</sup> with 57.65% iron content is selected for construction, then the thickness of the wall can be reduced to 174.2 cm, which will save space for equipment installation.

      • SCOPUSKCI등재

        Identification of Quantitative Trait Loci (QTLs) for Flowering Time Using SSR Marker in Maize under Water Stress

        Xiao, Yan-Nong,Li, Xin-Hai,Zhang, Shi-Huang,Wang, Xiang-Dong,Li, Ming-Shun,Zheng, Yong-Lian 한국유전학회 2004 Genes & Genomics Vol.26 No.4

        The selection of reduction of anthesis-silking interval (ASI) in maize breeding is an efficient way to develop maize varieties more tolerant to dry growing conditions. Characterization of the quantitative trait loci (QTL) that controlled the flowering time will be helpful for selection in maize breeding. In this study, flowering time of individuals in a 234 F_(2:3) family, derived from the cross between inbred lines X178 and B73, was evaluated under well-watered and water-stressed conditions at the same location. SSR (microsatellite) was used to identify flowering time QTL. The results showed that the broad-sense heritability for male flowering time (MFT), female flowering time (FFT) and ASI were 0.72, 0.72 - 0.74 and 0.40 - 0.42, respectively, and ASI was significantly correlated to FFT. Under water-stressed condition, 9, 6 and 6 QTLs were identified for MFT, FFT and ASI, respectively, and individual QTL accounted for approximately 2.88% - 31.65% of the phenotypic variation. Some QTLs for MFT were mapped overlapping with those for FIT and ASI. One QTL on chromosome 9 (near nc134) had the strongest effect on MFT, FTT and ASI. It was suggested that the epistasis contributed to the phenotypic variation of flowering time.

      • KCI등재

        Icariside II Promotes the Differentiation of Adipose Tissue-Derived Stem Cells to Schwann Cells to Preserve Erectile Function after Cavernous Nerve Injury

        Zheng, Tao,Zhang, Tian-biao,Wang, Chao-liang,Zhang, Wei-xing,Jia, Dong-hui,Yang, Fan,Sun, Yang-yang,Ding, Xiao-ju,Wang, Rui Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.6

        Icariside II (ICA II) is used in erectile dysfunction treatment. Adipose tissue-derived stem cells (ADSCs) are efficient at improving erectile function. This study aimed to explore the action mechanism of ADSCs in improving erectile function. ADSCs were isolated from the adipose tissues of rats. Cell proliferation was determined using the Cell Counting Kit-8 (CCK-8) assay. The expressions of mRNA and protein were determined separately through qRT-PCR and western blot. The endogenous expressions of related genes were regulated using recombinant plasmids and cell transfection. A Dual-Luciferase Reporter Assay was performed to determine the interaction between miR-34a and STAT3. Rat models with bilateral cavernous nerve injuries (BCNIs) were used to assess erectile function through the detection of mean arterial pressure (MAP) and intracavernosal pressure (ICP). ICA II promoted ADSCs' proliferation and differentiation to Schwann cells (SCs) through the inhibition of miR-34a. Suppressed miR-34a promoted the differentiation of ADSCs to SCs by upregulating STAT3. ICA II promoted the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway. The combination of ICA II and ADSCs preserved the erectile function of the BCNI model rats. ADSCs treated with ICA II markedly preserved the erectile function of the BCNI model rats, which was reversed through miR-34a overexpression. ICA II promotes the differentiation of ADSCs to SCs through the miR34a/STAT3 pathway, contributing to erectile function preservation after the occurrence of a cavernous nerve injury.

      • SCIESCOPUSKCI등재

        An Improved Wavelet PWM Technique with Output Voltage Amplitude Control for Single-phase Inverters

        Zheng, Chun-Fang,Zhang, Bo,Qiu, Dong-Yuan,Zhang, Xiao-Hui,Li, Rui The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

        Unlike existing pulse-width modulation (PWM) techniques, such as sinusoidal PWM and random PWM, the wavelet PWM (WPWM) technique based on a Harr wavelet function can achieve a high fundamental component for the output voltage, low total harmonic distortion, and simple digital implementation. However, the original WPWM method lacks output voltage control. Thus, the practical application of the WPWM technique is limited. This study proposes an improved WPWM technique that can regulate output voltage amplitude with the addition of a parameter. The relationship between the additional parameter and the output voltage amplitude is analyzed in detail. Experimental results verify that the improved WPWM exhibits output voltage control in addition to all the merits of the WPWM technique.

      • KCI등재

        Dynamic temperature gradient and unfalsified control approach for machine tool thermal error compensation

        Xiao-dong Yao,Zheng-Chun Du,Guang-yan Ge,Jian-Guo Yang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

        In this work, a novel machine tool thermal error modeling method based on dynamic temperature gradient is proposed, and a thermal error compensation method based on unfalsified control is developed. The dynamic temperature gradient is used to optimize the locations of temperature measuring points on the machine tool. Real-time compensation for the thermal error can be achieved using the developed compensation method by establishing the correlations between dynamic temperature gradient and thermal error in the machine tool. Different from traditional model-based methods, the developed compensation approach does not rely on an accurate model of the thermal error but instead uses online input/output data to adaptively select the best controller at any moment, thereby improving thermal error prediction accuracy and robustness. The effectiveness of the developed thermal error compensation method is demonstrated on a turning center, where the spindle thermal error is compensated during the manufacturing of 120 inner bore parts and 120 shaft parts. After compensation using the proposed approach, thermal errors are reduced from 27 µm to 9 µm for the inner bore parts and from 31 µm to 11 µm for the shaft parts, respectively.

      • KCI등재

        Revelation of the early responses of salt tolerance in maize via SSH libraries

        Dong Ding,Zhixia Xiao,Hailin Xiao,Tao Xia,YongLian Zheng,Fazhan Qiu 한국유전학회 2012 Genes & Genomics Vol.34 No.3

        Maize (Zea mays L.), one of the most important cereal crops in the world, is salt-sensitive. It is critical to study the genes associated with salt tolerance, the differential gene expression pattern between salt-tolerant and salt-sensitive lines, and the mechanism of salt tolerance in maize. Two maize inbred lines with different salt sensitivity, NC286 and Huangzao4, were used to reveal early responsive genes under high salinity condition. Suppression subtractive hybridization (SSH) assay was conducted to identify potential genes involved in the early stage of maize seedlings in responses to 200mM NaCl. A custom μparafloTM microfluidic array (LC science USA) containing Release version 10.1 plant miRNA probes (http://microrna. sanger.ac.uk/) was used to discover salt stress responsive miRNAs using the differences in miRNAs expression between these two maize lines. Cis-elemnet analysis was performed in the promoter regions of these two kinds of salt stress responsive transcriptions. The expression of a total of 141unique genes was significantly changed under 200mM NaCl salt shock within 24 hours. These genes were involved in a broad spectrum of biochemical, cellular, and physiological processes. They were assigned to 14 categories based on their biological functions. Some of them were previously reported to be associated with biotic and abiotic stresses, and several novel genes detected. A gene model was proposed which showed how these genes could sense and response to the high salinity environment. The promoter regions of these 141 salt responsive genes were analyzed, and salt responsive key cis-elements uncovered. The cis-elements usage bias of the salt responsive mRNAs and non-coding RNAs were of the same. The different expression profiles of the genes, especially the ones involved in salt signal cascades and phytohormones responding,could explain the different salt stress response in the two maize inbred lines. The similar cis-elements usage bias of two kinds of salt responsive transcriptions suggests they may be regulated by the same trans-factors.

      • KCI등재

        An Effective Method for Extraction of Glutaryl-7-aminocephalosporanic Acid Acylase from Recombinant E. coli Cells

        Xiao-qiang Ma,Er-zheng Su,Sen-wen Deng,Dong-zhi Wei 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.4

        In this study, several chemical treatment techniques commonly used for protein extraction were investigated for recovering glutaryl-7-aminocephalosporanic acid acylase (GLA) from recombinant E. coli cells. The best results were obtained by the combined use of cetyltrimethylammonium bromide (CTAB) and KCl. Subsequently, various extraction conditions, such as cation salt, concentrations of CTAB and KCl, extraction temperature, extraction time, and biomass, were optimized to further enhance the release yield and specific activity of GLA. Our results showed that 110% of GLA was released after treatment with 0.5% CTAB (w/v, %) and 0.3 M KCl at 10°C for 12 h, and its specific activity in this extracting solution was approximately 1.5 times higher as compared to that obtained by sonication. This extraction method could avoid the inactivation of GLA caused by drastic mechanical methods, and also enhance its specific activity for industrial extraction.

      • KCI등재

        Oxidation behavior of C/C composites with B4C-SiCZrC-ZrB2 coating prepared by infiltration and pyrolysis

        Xiao-Hua Zuo,Zhi-Jun Dong,Guan-Ming Yuan,Zheng-Wei Cui,Xuan-Ke Li 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.1

        Polycarbosilane, B-Si and B-Si-Zr modification coal tar pitch were used as impregnate agent for infiltration and pyrolysis formation of carbon/carbon (abbreviated as C/C) composites with B4C-SiC-ZrC-ZrB2 coating. The density of the composites was examined to be 1.0 g·cm-3, 1.4 g·cm-3 and 1.8 g·cm-3, respectively. The phase compositions, surface morphologies and element distributions of the coating were analyzed by X-ray diffraction (XRD) scanning electron microscopy (SEM) and energy dispervive spectroscopy (EDS), respectively. The result showed that the two composites with a density of 1.4 g·cm-3 and 1.8 g·cm-3 displayed compact microstructures. The oxidation behavior of the composites was studied by oxidation in air at temperatures from 800 to 1,550 ℃ for 1 h. The composites with a density of 1.8 g·cm-3 exhibited a lower weight loss of 1.8 % after oxidation. B4C-SiC-ZrC-ZrB2 coating was found to provide the best protection by the precipitated B2O3, SiO2 and ZrO2 on the surface of the composites during the oxidation process, which were characterized by self-healing and antioxidation. The C/C composites with B4C-SiC-ZrC-ZrB2 coating performed well at high temperatures with the formation of complex oxides glass film that prevented oxygen from further spreading into the matrix.

      • KCI등재

        Preparation and Photocatalytic Hydrogen Production Properties of Mesoporous CdS/TiO2 Composites

        Xiao-Li Wang,Ren-Rong Zheng,Hui Yu,Xiangting Dong 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

        The mesoporous CdS/TiO2 composites were synthesized by a sol–gel method combined with solvothermal method. The material showed the gel block-like structures which were composed of heterogeneous spherical gel particles, the average size of the particles was about 14nm, with specific surface area as 300.254 m2 g -1. The mesoporous CdS/TiO2 composites exhibited a wide absorption band to simulated sunlight whose adsorb wavelength reached to 550 nm, its absorption intensity and catalytic performance of photocatalytic water-producing hydrogenation were also increased with the increase of CdS contents. When the molar ratio of TiO2:CdS was 1:1, the photocatalytic activity reached the highest, and the average hydrogen production rate reached 2167.32 μmol g -1 h -1.

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