Zhejing University

Hangzhou, China

Zhejing University

Hangzhou, China
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Zhang S.,Ocean University of China | Guo Y.,University of Bradford | Wang Z.,Zhejing University
Journal of Hydrology | Year: 2015

Urban flooding is a combined product of the climate and watershed geomorphology. River system is one of the vital components of watershed geomorphology. The geomorphic characteristics of rivers have important effect on the formation of flooding. However, there have been few attempts so far to investigate the relationship between flooding frequency, the probability of flooding, and the geomorphological complexity of river system. Such relationship is essential in order to predict likely responses of flooding frequency to the large-scale changes in the complexity of the rivers network induced by accelerating urbanization around rivers. In this study we investigate the correlation between geomorphological characteristics of river system and the probability of flooding. Hangzhou city in China, which has suffered severe flooding, is chosen as a case study to evaluate this correlation and to investigate the impact of changes of drainage networks morphology on the local flooding. The fractal dimension, which is used to quantitatively assess geomorphological complexity of rivers network, is calculated by using box-counting method based on fractal geometry for eight sub rivers network in Hangzhou. A model based on the correlation of flooding frequency and fractal dimension is established. The model is applied to investigate the effect of the rapid urbanization induced changes of river geomorphology on the local flood frequency in two typical regions in Hangzhou. The results show that the flood frequency/event increases with the decrease of fractal dimension of the rivers network, indicating that the geomorphologic complexity of rivers network has an important effect on flooding. This research has great referential value for future flood quantitative investigations and provides new method for urban flood control and river system protection. © 2015.

Liu Q.,Renmin University of China | Zhuang K.,Zhejing University | Shenglong Q.,Renmin University of China | Fang J.,Renmin University of China | And 4 more authors.
AIDS and Behavior | Year: 2014

Prior research on female sex workers (FSW) in China, and their risk for HIV and STI, neglects the nuanced experiences of ethnic minority FSW. We conducted participant observations and in-depth interviews with 33 FSW and six venue bosses to describe the experiences of FSW and management structures in low and high-priced sex work venues in Liuzhou, China. In low-priced venues, FSW had more autonomy and stronger relationships with their ethnic minority peers. Mid- and high-priced venues had more formal management structures. Ethnic minority FSW working in higher priced venues experienced less support and kinship with their peers. HIV/STI prevention outreach activities occurred in all of the venues, but they were not tailored for different venue types or for ethnic minority FSW. Our findings provide guidance for tailoring public health programs that meet the needs of ethnic minority women working in different types of sex work venues. © Springer Science+Business Media New York 2013.

Xie X.,Zhejiang University | Liao M.,Zhejing University | Liao M.,Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition | Yang J.,Zhejing University | Yang J.,Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011

Polycyclic aromatic hydrocarbons (PAHs) is one kind of persistent organic pollutants in environment, some previous researches have indicated plant could facilitate the dissipation of PAHs in contaminated soil. Phytoremediation is an important measure to remove organic pollutants from contaminated soil, and the root secretion of plant is considered to be closely related to the mechanisms of phytoremediation to organic pollutants. It is in favor of revealing the mechanisms of remediation by studying the characteristics of root exudates of plant with phytoremediation potential under the stress of pollutant. In the present research, pyrene and ryegrass (Lolium perenne L.) which has been testified to be tolerant to PAHs dtress were selected as studied objects. A solution culture experiment with series of pyrene concentration was conducted to investigate the effects of pyrene on low molecule weight organic compounds in the root exudates of ryegrass (Lolium perenne L.). The series concentration of pyrene in culture solution were designed as 0 mg/L, 3 mg/L, 6 mg/L and 9 mg/L. The results showed that, ryegrass had stronger tolerance to pyrene stress and grew well in culture solution spiked with 9 mg/L pyrene. Despite the biomass raised appreciably at relative low pyrene concentrations treatment (<3 mg/L) and reduced at relative high pyrene concentrations treatments (>3 mg/L), no significant changes of ryegrass biomass were found in all pyrene stress treatment (P<0.05). At the pyrene spiked levels of 3 mg/L, 6 mg/L and 9 mg/L pyrene stress, the organic acids, including oxlic acid, lactic acid and malic acid, were found in the root exudates of ryegrass, such component of organic acid in root exudates of ryegrass was stabilization in all pyrene stress treatment, but oxlic acid was the main composition of organic acid in root exudates of ryegrass, with a percentage greater than 97 %, and its content increased significantly with the increase of pyrene spiked level (P<0.05). Compared with control treatment (0 mg/L), oxlic acid content in root exudates of ryegrass increased from 24. 6 mg/kg to 53. 7 mg/kg in 9 mg/L pyrene treatment. The content of carbohydrate in root exudates of ryegrass raised appreciably at relative low pyrene spiked level (<3 mg/L) and reduced at relative high pyrene spiked level (> 3 mg/L), the highest carbohydrate content in root exudates took on 3 mg/L pyrene treatment, but the differences of carbohydrate content in root exudates were insignificant in all pyrene treatments (P <0. 05). Total amount of amino acids secreted increased significantly with the pyrene concentration increase, which were 1. 37, 2. 02 and 2. 65 times than that of control treatment (0 mg/L) under 3 mg/L, 6 mg/L and 9 mg/L pyrene treatment, respectively. Data also indicated that 19 types of familiar amino acids were found in root exudates of ryegrass and the component of amino acids in root exudates of ryegrass was stabilization under all pyrene stress treatments, but the each content of 19 types of amino acids examined was different in those root exudates under the stress of different pyrene concentration. The contents of all amino acid in those root exudates was increased with the pyrene concentration increase, especially, the contents secreted of threonine, serine, proline, glycine, alanine, histidine and ornithine increased significantly among 19 types of amino acids and the differences were significantly among different treatments with different pyrene concentration (P<0.05).

Sohn H.,University of California at Los Angeles | Chen Z.,University of California at Los Angeles | Jung Y.S.,Ulsan National Institute of Science and Technology | Xiao Q.,General Motors | And 3 more authors.
Journal of Materials Chemistry A | Year: 2013

Robust composite particles containing Fe3O4 cores and porous conductive carbon-silicate layers were synthesized using an aerosol-assisted process followed by vapor coating using organosilanol as the precursor. Such unique synthesis enables the composites with high capacity and good cycle performance, and can be extended towards other oxide composites for energy storage. This journal is © The Royal Society of Chemistry.

Chiu C.F.,Hohai University | Chiu C.F.,Zhejing University | Ni X.W.,Hohai University | Zhang L.S.,Hohai University
Engineering Geology | Year: 2014

A vadose zone may exist within man-made or natural slopes under the condition of a deep water table. During repeated cyclic infiltration (wetting) and evaporation (drying), the suction and degree of saturation may change within this regime. Thus, it is crucial to have a thorough understanding of the effects of a cycle of wetting and drying on the shear strength of unsaturated soils to assess the long term stability of these slopes. Three series of laboratory tests are presented in this paper, from which the water retention and shear behaviors of an unsaturated clay are studied. A three-dimensional main wetting surface is proposed and a unique failure envelope expressed in terms of Bishop's stress can be used to characterize the shear strength of unsaturated soil subjected to different hydraulic histories. The measured shear strengths are compared with those predicted by the proposed main wetting surface and the drying curve under no confining stress. It is found that a better prediction is obtained by using the main wetting surface for unsaturated specimens subjected to different hydraulic histories. © 2014 Elsevier B.V.

Li G.,Ocean University of China | Chen S.,Zhejing University | Wang Y.,Ocean University of China | Xue Y.,Ocean University of China | And 4 more authors.
International Journal of Biological Macromolecules | Year: 2011

A novel glycosaminoglycan-like sulfated polysaccharide (AAP) from the pleopods of Haliotis discus hannai Ino was purified by DEAE ion exchange chromatography followed with S-300 HR geltrion chromatography. Chemical composition analysis indicated that AAP was composed of galactosamine, glucuronic acid, fucose, galactose with a ratio of 2.14:2.37:2.94:1, the content of sulfate was 15.5%. The average molecular weight (M w) was 56.2kDa in a TSK G4000 column. Further IR, 1D, 2D NMR spectroscopic analysis of the correlation signals of different sugar units gave a proposal repeating structure, as follows:In vitro anticoagulant assay indicated AAP prolonged both the activated partial thromboplastin time (APTT) and thrombin time (TT), with a 22.5. U/mg and 72.0. U/mg compared with standard heparin, respectively. The anticoagulant property of AAP was mainly attributed to powerful potentiation thrombin by anti-thrombin III. © 2011 Elsevier B.V.

Yonggang L.,Jiaxing University | Yonggang L.,Polytechnic University of Mozambique | Haiming Y.,Jiaxing University | Haiming Y.,Zhejing University
International Review on Computers and Software | Year: 2013

A specific erotic image detection method (SEIDM) is presented for some special kinds of erotic images which are difficult to be identified by conventional algorithm in this paper. According to the features of these specific erotic images, an improved skin-color model is presented and a new image text detection method using integral image is designed. Text information and skin-color information detected are fed to a trained Support Vector Machine (SVM) which gives the final result. The experimental results indicate that SEIDM can detect special erotic image with high recall and precision. © 2013 Praise Worthy Prize S.r.l. - All rights reserved.

Bai Z.,Zhejing University | Ruan X.,Huazhong University of Science and Technology | Xu L.,Huazhong University of Science and Technology
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2011

Grid-connected inverter system with LCL filter is a third-ordersystem, which has a gain peak at its resonant frequency, and hence lower stability margin and involved complicated design of current regulators. In order to solve these problems, this paper proposes a novel control strategy with the combination of the grid (or inverter side) current feedback and another state variable feedforward, which can degrade the system order from the third to the first. Therefore, not only the stability margin is enlarged, but also the gain peak is eliminated and the current regulator design is greatly simplified. Besides, additional controls are also developed to attenuate the effects of grid voltage distortion or local load disturbance on the grid current, and the grid current waveforms can be further improved. Theoretical analysis, simulation and experimental results verified the proposition.

Liu W.B.,Zhejing University
Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences | Year: 2011

To investigate the variability of event-related potentials P(300) and the relationship with memory function/psychopathology in patients with first-episode paranoid schizophrenia. Thirty patients with first-episode paranoid schizophrenia (patient group) and twenty health subjects (control group) were enrolled in the study. The auditory event-related potentials P 300 at the scalp electrodes Cz, Pz and Wechsler Memory Scale (WMS) were examined in both groups, Positive And Negative Syndrome Scale (PANSS) was evaluated in patient group. In comparison with control group, patients had longer latency of P 300 [(390.6 ± 47.6)ms at Cz and (393.3 ± 50.1)ms at Pz] (P<0.01), lower amplitude of P 300 [(7.7 ± 3.4) μV at Cz and (8.5 ± 3.9)μV at Pz] (P<0.05-0.01). The memory quotient (88.1 ± 10.0) scores and short-term memory, immediate memory in patient group were damaged significantly (P<0.05-0.01). In patient group, the latency of P300 was correlated positively with PANSS scores and negatively with WMS scores (P<0.05-0.01). First-episode paranoid schizophrenia has memory deficit, which can be evaluated comprehensively by P 300 and WMS. The longer latency of P 300 might be associated with the increased severity of first-episode paranoid schizophrenia.

Xie X.-M.,Zhejiang University | Liao M.,Zhejing University | Liao M.,Zhejiang Province Key Laboratory of Subtropic Soil and Plant Nutrition | Yang J.,Zhejing University | Yang J.,Zhejiang Province Key Laboratory of Subtropic Soil and Plant Nutrition
Chinese Journal of Applied Ecology | Year: 2011

By simulating a gradually decreasing concentration of root exudates with the distance away from root surface in rhizosphere, this paper studied the effects of ryegrass(Lolium perenne) root exudates dose on the pyrene degradation and microbial ecological characteristics in a pyrenecontaminated soil. It was observed that with the increasing dose of ryegrass root exudates, the residual amount of soil pyrene changed nonlinearly, i. e., increased after an initial decrease. When the root exudates dose was 32.75 mg·kg-1 of total organic carbon, the residual pyrene was the minimum, indicating that the root exudates at this dose stimulated pyrene degradation significantly. In the meantime, soil microbial biomass carbon and microbial quotient had an opposite trend, suggesting the close relationship between pyrene degradation and soil microbes. In the test soil, microbial community was dominated by bacteria, and the bacteria had the same variation trend as the pyrene degradation, which indicated that the pyrene was degraded mainly by bacteria, and the effects of root exudates on pyrene degradation were mainly carried out through the effects on bacterial population. There was a similar variation trend between the activity of soil dehydrogenase, a microbial endoenzyme catalyzing the dehydrogenation of organic matter, and the soil microbes, which further demonstrated that the variations of soil microbes and their biochemical characteristics were the ecological mechanisms affecting the pyrene degradation in the pyrene-contaminated soil when the ryegrass root exudates dose increased.

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