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      • KCI등재

        Exogenous 5-aminolevulinic acid promotes plant growth and salinity tolerance of grape rootstocks in coastal areas

        Zheng Weiwei,Tian Yuting,Shi Haili,Chen Miaomiao,Hong Seungbeom,Xu Kai,Cheng Jianhui,Zang Yunxiang 한국원예학회 2023 Horticulture, Environment, and Biotechnology Vol.64 No.2

        Salinity stress is a key factor aff ecting grape production in coastal areas. Two grape rootstock cultivars, ‘Beta’ (sensitive to salt stress) and ‘3309 C’ (resistant to salt stress), were used to investigate the physiological role of 5-aminolevlinic acid (5-ALA) in salinity tolerance. Functional capacities in the rhizosphere, leaf phenotype, photosynthetic parameters, antioxidant enzymes activities and certain physiological indexes were determined after treatment with seawater or seawa- ter followed by 100 mg/L 5-ALA application. The results showed that the functional capacities of the rhizosphere were distinct between the two management regimes. Microbial biomass and soil enzyme activities were reduced by salinity but promoted by 5-ALA. Salinity also suppressed the overall plant growth, leaf chlorophyll content, photosynthetic rate, maxi- mal photochemical effi ciency (Fv/Fm), photochemical quenching (qP), electron transport rate (ETR), root activity, ATP content, ATPase activity, and activities of the antioxidant enzymes ascorbate peroxidase (APX), peroxidase (POD), cata- lase (CAT), and superoxide dismutase (SOD) in both cultivars. Although plant growth, chlorophyll content, and activities of antioxidant enzymes in Beta were decreased to a greater extent than those in 3309 C under salinity stress, exogenous application of 5-ALA signifi cantly improved plant growth along with enhancement of all the above photosynthetic param- eters and activities of the four antioxidant enzymes in both cultivars. Seawater treatment alone signifi cantly increased non- photochemical quenching (NPQ), relative electrical conductivity (REC), and malondialdehyde (MDA) contents in leaves, especially for Beta. However, 5-ALA treatment decreased the levels of NPQ, REC, and MDA, but increased ATP content and ATPase activity in roots and leaves of both cultivars. Thus, application of 5-ALA would be benefi cial to improve the salt tolerance of grape rootstocks grown in coastal areas.

      • KCI등재

        EHMM-CT: An Online Method for Failure Prediction in Cloud Computing Systems

        ( Weiwei Zheng ),( Zhili Wang ),( Haoqiu Huang ),( Luoming Meng ),( Xuesong Qiu ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.9

        The current cloud computing paradigm is still vulnerable to a significant number of system failures. The increasing demand for fault tolerance and resilience in a cost-effective and device-independent manner is a primary reason for creating an effective means to address system dependability and availability concerns. This paper focuses on online failure prediction for cloud computing systems using system runtime data, which is different from traditional tolerance techniques that require an in-depth knowledge of underlying mechanisms. A `failure prediction` approach, based on Cloud Theory (CT) and the Hidden Markov Model (HMM), is proposed that extends the HMM by training with CT. In the approach, the parameter ω is defined as the correlations between various indices and failures, taking into account multiple runtime indices in cloud computing systems. Furthermore, the approach uses multiple dimensions to describe failure prediction in detail by extending parameters of the HMM. The likelihood and membership degree computing algorithms in the CT are used, instead of traditional algorithms in HMM, to reduce computing overhead in the model training phase. Finally, the results from simulations show that the proposed approach provides very accurate results at low computational cost. It can obtain an optimal tradeoff between `failure prediction` performance and computing overhead.

      • KCI등재

        Influence of the silencing sex-peptide receptor on Bactrocera dorsalis adults and offspring by feeding with ds-spr

        Wenping Zheng,Yaru Liu,Weiwei Zheng,Yunli Xiao,Hongyu Zhang 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.3

        RNA interference (RNAi) has been shown to control insect pests using plant dsRNA expression. A key question in potentially applying RNAi is the possible effects on insects after being fed with dsRNA produced by a transgenic plant. Sex peptide receptor (spr) is the key gene that regulates the suppression of female receptivity and induction of oviposition. In this study, the expression level of the spr genewas significantly down-regulated to 52% by feeding Bactrocera dorsalis adults with ds-spr. The RNAi effects of continuous feeding ds-spr to adults led to a highly mortality rate, decreased their egg production capacity and profoundly impacted the eclosion rate of their offspring. Our results demonstrate that RNAi through uninterrupted dsRNA feeding can be used as a strategy to control insect pests. Moreover, the research presented here provides a potential RNAi target gene for controlling B. dorsalis and a theoretical basis for universally applying RNAi in insect pest management.

      • SCISCIESCOPUS

        Covalent bonding of ZnO nanostructures with dispersible carbon nanotubes for self-assembly photocatalytic heterostructures

        Tie, Weiwei,Jin, Jiaming,Bhattacharyya, Surjya Sarathi,Yue, Hongwei,Lei, Yan,Zheng, Zhi,He, Weiwei,Lee, Seung Hee Elsevier BV * North-Holland 2019 Applied Surface Science Vol.492 No.-

        <P><B>Abstract</B></P> <P>This work demonstrates the fabrication of zinc oxide‑carbon nanotube (ZnO/CNT) heterostructures with tunable photocatalytic activity via microstructure modulation. The ZnO/CNT heterostructures are constructed in one-step hydrothermal procedure consisting of in situ anchoring of ZnO nanostructures with dispersible CNTs in an aqueous alkali solution containing bile salts as a dispersant. Observation via scanning (SEM) and transmission (TEM) electron microscopy reveals self-assembled heterostructures of monodispersible CNTs tightly surrounding ZnO nanostructures with multimorphology. The XRD, FT-IR, Raman and XPS analysis confirm that the CNTs were successfully incorporated into the ZnO nanostructures with strong interfacial contact of covalent bonding rather than simple mixing. A series of ZnO/CNT heterostructures, which varies according to their degree of doping with dispersible CNTs, exhibit distinct sunlight-induced photocatalytic activity onto the degradation of Rhodamine B (RhB). The superior photocatalytic performance of ZnO/CNT heterostructures originates from synergistic effects of sufficient interfacial bonding, self-assembly microstructures, and continuous conducting pathways between ZnO nanostructures and CNTs, which acquires better sunlight utilization and more efficient separation of electron-hole pair, confirmed by UV–Visible diffuse reflectance spectra as well as photocurrent and photovoltage analysis. This study also proposes a photocatalytic degradation mechanism of RhB dyes through detection of active species confirmed by electron-spin-resonance analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ZnO nanostructures covalently linking with dispersible carbon nanotubes for self-assembly heterostructures are synthesized. </LI> <LI> This sunlight-driven self-assembly heterostructures possess tunable photocatalytic activity via microstructure modulation. </LI> <LI> The charge separation and transfer process are monitored by transient photovoltaic and photocurrent measurement. </LI> </UL> </P>

      • KCI등재

        Electrospun Fibrous Silk Fibroin/Poly(L-Lactic Acid) Scaffold for Cartilage Tissue Engineering

        Weiwei Liu,Zhengqiang Li,Lu Zheng,Xiaoyan Zhang,Peng Liu,Ting Yang,Bing Han 한국조직공학과 재생의학회 2016 조직공학과 재생의학 Vol.13 No.5

        For successful tissue engineering of articular cartilage, a scaffold with mechanical properties that match those of natural cartilage as closely as possible is needed. In the present study, we prepared a fibrous silk fibroin (SF)/poly(L-lactic acid) (PLLA) scaffold via electrospinning and investigated the morphological, mechanical, and degradation properties of the scaffolds fabricated using different electrospinning conditions, including collection distance, working voltage, and the SF:PLLA mass ratio. In addition, in vitro cell-scaffold interactions were evaluated in terms of chondrocyte adhesion to the scaffolds as well as the cytotoxicity and cytocompatibility of the scaffolds. The optimum electrospinning conditions for generating a fibrous SF/PLLA scaffold with the best surface morphology (ordered alignment and suitable diameter) and tensile strength (~1.5 MPa) were a collection distance of 20 cm, a working voltage of 15 kV, and a SF:PLLA mass ratio of S50P50. The degradation rate of the SF/PLLA scaffolds was found to be determined by the SF:PLLA mass ratio, and it could be increased by reducing the PLLA proportion. Furthermore, chondrocytes spread well on the fibrous SF/PLLA scaffolds and secreted extracellular matrix, indicating good adhesion to the scaffold. The cytotoxicity of SF/PLLA scaffold extract to chondrocytes over 24 and 48 h in culture was low, indicating that the SF/PLLA scaffolds are biocompatible. Chondrocytes grew well on the SF/PLLA scaffold after 1, 3, 5, and 7 days of direct contact, indicating the good cytocompatibility of the scaffold. These results demonstrate that the fibrous SF/PLLA scaffold represents a promising composite material for use in cartilage tissue engineering.

      • KCI등재

        Robust video watermarking algorithm for H.264/AVC based on JND model

        ( Weiwei Zhang ),( Xin Li ),( Yuzhao Zhang ),( Ru Zhang ),( Lixin Zheng ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.5

        With the purpose of copyright protection for digital video, a novel H.264/AVC watermarking algorithm based on JND model is proposed. Firstly, according to the characteristics of human visual system, a new and more accurate JND model is proposed to determine watermark embedding strength by considering the luminance masking, contrast masking and spatial frequency sensitivity function. Secondly, a new embedding strategy for H.264/AVC watermarking is proposed based on an analysis on the drift error of energy distribution. We argue that more robustness can be achieved if watermarks are embedded in middle and high components of 4×4 integer DCT since these components are more stable than dc and low components when drift error occurs. Finally, according to different characteristics of middle and high components, the watermarks are embedded using different algorithms, respectively. Experimental results demonstrate that the proposed watermarking algorithm not only meets the imperceptibility and robustness requirements, but also has a high embedding capacity.

      • KCI등재

        A Comparative Study on the Insulation Ageing of 10 kV XLPE Cable via Accelerated Electrical Test and Accelerated Water Tree Test

        Li Weiwei,Zheng Wenyue,Ren Lulu,Li Huan,Zhao Xuetong,Wang Can,Li Jianying 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.1

        Medium and high voltage XLPE cables were widely used in urban distribution network. The electric-thermal eff ect of the cable conductor and water in the running environment are two important factors that cause ageing of cable insulating material. In this work, accelerated electrical test (AET) and accelerated water tree test (AWTT) on 10 kV XLPE cable were carried out for 1440 h, 2880 h and 4320 h, respectively. The physicochemical and dielectric properties of both aged and unaged XLPE samples were tested. Physicochemical investigation of Fourier Transform Infrared (FTIR) spectroscopy and X-Ray Diff raction (XRD) show that higher carbonyl groups index, and lower crystallinity of the XLPE insulating materials were generated in AWTT process than that in AET process. The thermal decomposition process of the AWTT XLPE are complicated, presenting a multi-peak phenomenon in the diff erential thermogravimetry (DTG) curve. The insulating strength of the samples after AWTT is monotonically decreased from 23.03 kV to 21.74 kV with ageing time. The dielectric properties show that the permittivity and dielectric loss of AWTT samples increased more severely than that of AET samples, with a new dielectric relaxation peak appearing at around 100 Hz. The combination of physicochemical and dielectric results reveals that AWTT process leads to more serious degradation for XLPE insulating materials. A schematic illustration is given to elucidate the development of micro defects in XLPE during the AET and AWTT processes.

      • KCI등재

        Efficacy of combination of endo-xylanase and xylan-debranching enzymes in improving cereal bran utilization in piglet diet

        Wang Weiwei,Zheng Dawen,Zhang Zhenzhen,Ye Hui,Cao Qingyun,Zhang Changming,Dong Zemin,Feng Dingyuan,Zuo Jianjun 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.11

        Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet. Methods: In vitro experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. In vivo experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme. Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed brancontaining diet. Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet. Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet.Methods: <i>In vitro</i> experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. <i>In vivo</i> experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme.Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed bran-containing diet.Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet.

      • KCI등재

        Shear behavior and analytical model of perfobond connectors

        Shuangjie Zheng,Yuqing Liu,Teruhiko Yoda,Weiwei Lin 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.1

        In steel and concrete composite girders, the load transfer between the steel beam and the concrete slab is commonly ensured by installing shear connectors. In this paper, to investigate the nonlinear behavior of perfobond connectors, a total of 60 push-out specimens were fabricated and tested with the variables for the hole diameter, the concrete strength, the thickness of concrete slab, the diameter, strength and existence of perforating rebar, the thickness, height and distance of perfobond ribs. The failure mode and the load-slip behavior of perfobond connectors were obtained. A theoretical model was put forward to express the load-slip relationship. Analytical formulas of shear capacity and peak slip were also proposed considering the interaction between the concrete dowel and the perforating rebar. The calculation results of the proposals agreed well with the experimental values.

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