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      • Risk Factors for Cervical Cancer in Rural Areas of Wuhan China: a Matched Case-control Study

        Zhang, Bin,Zhou, Ai-Fen,Zhu, Chang-Cai,Zhang, Ling,Xiang, Bing,Chen, Zhong,Hu, Rong-Hua,Zhang, Ya-Qi,Qiu, Lin,Zhang, Yi-Ming,Xiong, Chao-Du,Du, Yu-Kai,Shi, Yu-Qin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

        Cervical cancer is a serious public health problem in developing countries. We investigated possible risk factors for cervical cancer in rural areas of Wuhan China using a matched case-control study with 33 women diagnosed with cervical cancer and 132 healthy women selected from the same area as matched controls. A questionnaire, which included questions about general demography conditions, environmental and genetic factors, the first sexual intercourse, first marriage age, age at first pregnancy, pregnancy first child's age, female personal health history, social psychological factors, dietary habits, smoking and alcohol status and other living habits was presented to all participants. At the same time, HPV infection of every participant was examined in laboratory testing. Results showed HPV infection (P<0.000, OR=23.4) and pregnancy first child's age (P<0.000, OR=13.1) to be risk factors for cervical cancer. Menopause (P=0.003, OR=0.073) was a protective factor against cervical cancer. However, there was no indication of associations of environmental (drinking water, insecticide, disinfectant) genetic (cancer family history), or life-style factors (smoking status, alcohol status, physical training, sleep quality), including dietary habits (intake of fruit and vegetable, meat, fried food, bean products and pickled food) or social psychological factors with cervical cancer. The results suggest that the risk of cervical cancer in Chinese rural women may be associated with HPV infection, menopause and the pregnancy first child's age.

      • KCI등재

        Utilization of electron beam to modulate electron injection over Schottky barrier

        Qi Zhang,Junjie Qi,Yunhua Huang,Huifeng Li,Xin Li,Ruoshui Wang,Yue Zhang 한국물리학회 2011 Current Applied Physics Vol.11 No.3

        Modulation of electron injection over Schottky barrier was realized by employing electron beam irradiation on the metal/ZnO-nanowire contact. The structure revealed a good response to the illumination at a scanning frequency of 0.1 Hz, which can be enhanced by increasing bias and decreased with the increase of electron beam energy. These phenomena can be attributed to the Schottky barrier formed at the metal/ZnO-nanowire interface which limits the electron transport across the contact. The electron beam irradiation gives rise to high efficiency of electron injection over the barrier, while the interplay between charge discreteness, coherent scattering, and Coulomb interaction may reduce the conductivity.

      • KCI등재

        Time Series Prediction on Settlement of Metro Tunnels Adjacent to Deep Foundation Pit by Clustering Monitoring Data

        Qi Zhang,Yanning Ma,Bin Zhang,Longgang Tian,Guozhu Zhang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.5

        High requirements are put forward for the settlement control of metro tunnel to ensure the normal and safe operation of adjacent metro line during the process of deep foundation pit construction. Monitoring and predicting could constantly monitor the settlement of the tunnel and make safety early-warning, and massive data to be processed is collected by sensors in this process. In the study, an improved clustering method based on Gaussian mixture model (GMM) is proposed to deal with a large amount of monitoring data. Four initial eigenvalues are defined and the initial core points of clustering are selected by grouping monitoring sensors based on the characteristics of the project site and sensors. An improved method is utilized to the metro tunnel of Metro Line 9 near Xujiahui station. Compared with the traditionalclustering method, the improved method has more reliable results, and reduces the operation time by 57.9%. Representative monitoring sensors are selected from each cluster to predict based on Long Short-Term Memory (LSTM) neural network. The prediction results well agree with the measured value and the prediction accuracy is reaching to 99.3%. Compared with other sensor selection ways, the data of representative sensors exhibits good representativenessand effectiveness. Finally, the prediction result after data update is more consistent with the monitoring data than the prediction result without data update. Increasing the data update frequency improves the accuracy of the prediction results in practical engineering application.

      • KCI등재

        Which Indicator Among Lumbar Vertebral Hounsfield Unit, Vertebral Bone Quality, or Dual-Energy X-Ray Absorptiometry-Measured Bone Mineral Density Is More Efficacious in Predicting Thoracolumbar Fragility Fractures?

        Bo Zhang,Lu-Ping Zhou,Xian-Liang Zhang,Dui Li,Jia-Qi Wang,Chong-Yu Jia,Hua-Qing Zhang,Liang Kang,Ren-Jie Zhang,Cai-Liang Shen 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

        Objective: Hounsfield units (HU), vertebral bone quality (VBQ), and bone mineral density (BMD) can all serve as predictive indicators for thoracolumbar fragility fractures. This study aims to explore which indicator provides better risk prediction for thoracolumbar fragility fractures. Methods: Patients who have received medical attention from The First Affiliated Hospital of Anhui Medical University for thoracolumbar fragility fractures were selected. A total of 78 patients with thoracolumbar fragility fractures were included in the study. To establish a control group, 78 patients with degenerative spinal diseases were matched to the fracture group on the basis of gender, age, and body mass index. The lumbar vertebral HU, the VBQ, and the BMD were obtained for all the 156 patients through computed tomography, magnetic resonance imaging, and dual-energy x-ray absorptiometry (DEXA). The correlations among these parameters were analyzed. The area under curve (AUC) analysis was employed to assess the predictive efficacy and thresholds of lumbar vertebral HU, VBQ, and BMD in relation to the risk of thoracolumbar fragility fractures. Results: Among the cohort of 156 patients, lumbar vertebral HU exhibited a positive correlation with BMD (p < 0.01). Conversely, VBQ showed a negative correlation with HU, BMD (p < 0.05). HU and BMD displayed a favorable predictive efficacy for thoracolumbar fragility fractures (p < 0.01), with HU (AUC = 0.863) showcasing the highest predictive efficacy, followed by the DEXA-measured BMD (AUC = 0.813). VBQ (AUC = 0.602) ranked lowest among the 3 indicators. The thresholds for predicting thoracolumbar fragility fractures were as follows: HU (88),VBQ (3.37), and BMD (0.81). Conclusion: All 3 of these indicators, HU, VBQ, and BMD, can predict thoracolumbar fragility fractures. Notably, lumbar vertebral HU exhibits the highest predictive efficacy, followed by the BMD obtained through DEXA scanning, with VBQ demonstrating the lowest predictive efficacy.

      • KCI등재
      • SCIESCOPUSKCI등재

        Experiment and molecular simulation for liquid phase adsorption of triethylenetetramine on activated carbon: equilibrium, kinetics, thermodynamics and molecular behavior

        Qi Zhang,Xiang C. Ma,Chang He,Qing L. Chen,Bing J. Zhang 한국탄소학회 2023 Carbon Letters Vol.33 No.7

        Modification of the surface of raw activated carbon using chemical solvents can significantly improve the adsorption performance of activated carbon. Triethylenetetramine is one of the most important chemical solvents used to modify raw activated carbon for formaldehyde removal indoor. We conducted the liquid impregnation experiments at different initial concentrations, temperatures, adsorbent dosage and time ranges to fully investigate the adsorption of triethylenetetramine on the surface of raw activated carbon for modification. We found that the Langmuir isotherm model and pseudo-first-order kinetic model fit quite well with the experimental data and the R2 are 0.9883 and 0.9954, respectively. The theoretical maximum adsorption capacity is 166.67 mg/g. The change in Gibbs free energy (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were also calculated to study the direction and driving force of the liquid adsorption process. In order to understand the adsorption process at the molecular level, a new activated carbon model based on the actual physical and chemical properties of activated carbon was carefully established in the Materials Studio to simulate the liquid-phase adsorption. The pore structure, elemental composition, functional group content, density, pore volume, and porosity of the activated carbon model converge close to the actual activated carbon and the adsorption isotherms obtained from the simulation agree well with the experimental results. The results show that the adsorption of triethylenetetramine on activated carbon is a spontaneous, endothermic and monolayer physical adsorption process.

      • KCI등재

        Hexadecyltrimethylammonium Bromide-Modified Sericite Mica-Based Polyimide Composites: A Comparison Between In situ Polymerization and Solution Intercalation Processes

        Qi Zhang,Duxin Li,Dengwang Lai,Baoli Ou 한국고분자학회 2015 Macromolecular Research Vol.23 No.9

        In order to increase the spacing between clay layers and study the effects of processing on the morphology and properties of PI/organoclay composites, polyimide (PI) composites containing multi-step procedure-modified sericite mica were prepared via in situ polymerization and solution intercalation. The structure-property relationships of the composites were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS). The results of XRD patterns revealed d002-spacing of clay was expanded from 0.99 to 2.77 nm. TEM photographs indicated majority of the organoclay exhibited an exfoliated morphology in composites prepared by in situ polymerization. TGA summarized the composites prepared by solution intercalation and in situ polymerization had a 9 and 29 oC increment in T5 compared with pristine PI respectively. XPS indicated the interaction of organoclay and polymer matrix in composites prepared by in situ polymerization was stronger than other types of composites. The glass transition temperature (Tg) and storage modulus of the composites prepared via in situ polymerization was much higher. Especially the Tg of this composites revealed a 33 oC increase compared with pure PI.

      • KCI등재

        Effect of compressible membrane’s nonlinear stress-strain behavior on spiral case structure

        Qi-Ling Zhang,He-Gao Wu 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.1

        With an active structural involvement in spiral case structure (SCS) that is always the design and research focus of hydroelectric power plant (HPP), the compressible membrane sandwiched between steel spiral case and surrounding reinforced concrete was often assumed to be linear elastic material in conventional design analysis of SCS. Unfortunately considerable previous studies have proved that the foam material serving as membrane exhibits essentially nonlinear mechanical behavior. In order to clarify the effect of membrane (foam) material’s nonlinear stress-strain behavior on SCS, this work performed a case study on SCS with a compressible membrane using the ABAQUS code after a sound calibration of the employed constitutive model describing foam material. In view of the successful capture of fitted stress-strain curve of test by the FEM program, we recommend an application and dissemination of the simulation technique employed in this work for membrane material description to structural designers of SCS. Even more important, the case study argues that taking into account the nonlinear stress-strain response of membrane material in loading process is definitely essential. However, we hold it unnecessary to consider the membrane material’s hysteresis and additionally, employment of nonlinear elastic model for membrane material description is adequate to the structural design of SCS. Understanding and accepting these concepts will help to analyze and predict the structural performance of SCS more accurately in design effort.

      • KCI등재

        Producing magnetite concentrate via self-magnetization roasting in N2 atmosphere: Phase and structure transformation, and extraction kinetics

        Qi Zhang,Yongsheng Sun,Yuexin Han,Yanjun Li,Peng Gao 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

        In this work, a green self-magnetization roasting technology for producing magnetite was proposed withoutadding additional. The regulatory mechanisms of the main factors (siderite dosage, roasting temperature,and roasting time) on the self-magnetization roasting process were investigated. In-situ kinetic ofthe self-magnetization roasting process was analyzed by the infrared gas analyzer, and the phase transformationwas investigated by in-situ X-ray diffraction and Mössbauer. Under the optimal roasting conditionsof 30% siderite dosage, 730 C, and 7.5 min, the iron concentrate with Fe grade 68.82% and Ferecovery 99.48% was obtained. The kinetic and phase transformation results indicated that the selfmagnetizationroasting process was divided into two stages: siderite pyrolysis in the prophase stage,and hematite reduced to magnetite by reductant (FeO and CO) from siderite pyrolysis in the anaphasestage. The SEM analyses showed that the newborn magnetite crystals were mainly coarse-grained andneedles, which fitted the kinetics characteristics for the Nucleation model. Using self-magnetizationroasting technology, siderite and hematite would promote mutual reduction to improve product magnetismand roasting efficiency without adding reductant. Also, self-magnetization roasting will enhancethe utilization rate of siderite, and it contributes to energy conservation and CO2 emission reduction.

      • Study on Signal De-Noising for Multi-Channel Automatic Ultrasonic Testing System

        Qi Zhang,Li Hou 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.8

        To ensure the quality of thick-walled seamless steel pipe, the defects in thick-walled seamless steel pipe should be detect. This paper has developed PC-based microcomputer water immersion, digital multi-channel automatic ultrasonic testing system based on the principle of ultrasonic flaw detection of thick-walled seamless steel pipe. The hardware and software of this detection system were designed. To improve detection efficiency and accuracy, all sorts of effective anti-interference measures were proposed. They could effectively remove interference signals in ultrasonic echo signal by analyzing interference source and dissemination way of automatic ultrasonic flaw detection system for small-diameter steel pipe with thick wall. An improved wavelet threshold was proposed to remove mixed noise in the echo signal to improve the echo signal-to-noise ratio at the same time. Experimental results show that the ultrasonic flaw detection system can achieve defect detection of the Small-Diameter Steel Pipe with Thick Wall, the wavelet threshold de-noising method can effectively remove mixed noise in the ultrasonic echo signal and the echo signal-to-noise ratio was improved greatly.

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