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Variable fuzzy assessment of water use efficiency and benefits in irrigation district

Water science and Engineering 2015年第3期8卷 205-210页

作者： Ming-hui Wang Guang-cheng Shao Jia-jia Meng Chang-ren Chen Dou-dou Huang Suqian Water Survey and Design Research Co. Ltd Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment in Southern China Ministry of Education College of Water Conservancy and Hydropower Engineering Hohai University Huai'an Water Resources Planning Office Water Resources Department of Jiangsu Province

In order to scientifically and reasonably evaluate water use efficiency and benefits in irrigation districts, a variable fuzzy assessment model was established. The model can reasonably determine the relative membership degree and relative membership function of the sample indices in each index’s standard interval, and obtain the evaluation level of the sample through the change of model parameters. According to the actual situation of the Beitun Irrigation District, which is located in Fuhai County, in Altay City, Xinjiang Uyghur Autonomous Region, five indices were selected as evaluation factors, including the canal water utilization coefficient, field water utilization coefficient, crop water productivity,effective irrigation rate in farmland, and water-saving irrigation area ratio. The water use efficiency and benefits in the Beitun Irrigation District in different years were evaluated with the model. The results showed that the comprehensive evaluation indices from 2006 to 2008 were all at the third level(medium efficiency), while the index in 2009 increased slightly, falling between the second level(relatively high efficiency) and third level, indicating an improvement in the water use efficiency and benefits in the Beitun Irrigation District, which in turn showed that the model was reliable and easy to use. This model can be used to assess the water use efficiency and benefits in similar irrigation districts.

关键词： Variable fuzzy assessment Water use efficiency and benefits Beitun Irrigation District

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Leaky Interface Wave Measurement at a Solid-Solid Interface with Laser Ultrasonics

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Chinese Physics Letters 2012年第10期29卷 93-96页

作者： WANG Hao HAN Qing-Bang QIAN Meng-Lu Institute of Acoustics Tongji UniversityShanghai 200092 Changzhou Key Laboratory of Sensor Networks and Environmental Sensing Hohai UniversityChangzhou 213022

The experimental investigation on transparent solid/solid(aluminum and plexiglas)interface leaky waves generated by a pulse laser and detected with a photoelastic effect technique is *** waves,i.e.,longitudinal head wave,leaky Rayleigh wave and leaky interface wave,are detected *** leaky waves propagating along the'weak bonding'interface are also *** is found that with the continuing epoxy solidification,the wave amplitude gradually decreases and the two leaky waves are more difficult to *** velocities of the detected interface wave are in good agreement with the theoretical calculation and the attenuation characteristics of the two leaky waves are also in accordance with the theoretical prediction.

关键词： solidification interface Solid

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Assessing the global averaged sea-level budget from 2003 to 2010

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Acta Oceanologica Sinica 2013年第10期32卷 16-23页

作者： LI Juan ZUO Juncheng CHEN Meixiang TAN Wei YANG Yiqiu Key Laboratory of Ministry of Education for Coastal Disaster and Defence Hohai University

A global mass balance （Greenland and Antarctica ice sheet mass loss, terrestrial water storage） and differ- ent sea-level components （observed sea-level from satellite altimetry, steric sea-level from Ishii data, and ocean mass from gravity recovery and climate experiment, GRACE） are estimated, in terms of seasonal and interannual variabilities from 2003 to 2010. The results show that a detailed analysis of the GRACE time series over the time period 2003-2010 unambiguously reveals an increase in mass loss from the Greenland ice sheet and Antarctica ice sheet. The mass loss of both ice sheets accelerated at a rate of （392.8±70.0） Gt/a during 2003-2010, which contributed （1.09±0.19） mm/a to the global mean sea-level during this time. The net terrestrial water storage （TWS） trend was negative over the 8 a time span, which gave a small positive contribution of （0.25±0.12） mm/a. The interannual variability of the global mean sea-level was at least part- ly caused by year-to-year variability of land water storage. Estimating GRACE-based ice sheet mass balance and terrestrial water storage by using published estimates for melting glaciers, the results further show that the ocean mass increase since 2003 has resulted half from an enhanced contribution of the polar ice sheets, and half from the combined ice sheet and terrestrial water storage loss. Taking also into account the melt- ing of mountain glaciers （0.41 mm/a） and the small GRACE-based contribution from continental waters （0.25 mm/a）, a total ocean mass contribution of （1.75±0.57） mm/a from 2003 to 2010 is found. Such a value represented 75% of the altimetry-based rate of sea-level rise over that period. The contributions to steric sea-level （i.e., ocean thermal expansion plus salinity effects） are estimated from：（1） the difference between altimetry-based sea-level and ocean mass change and （2） the latest Ishii data. The inferred steric sea-level rate from （1）（1.41 mm/a from 2003 to 2010） did not agree well with t

关键词： sea-level ice sheet melt terrestrial water steric sea-level

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All-optical modulator based on a ferrofluid core metal cladding waveguide chip

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Chinese Physics B 2013年第9期22卷 470-473页

作者：韩庆邦殷澄李建汤一彬单鸣雷曹庄琪 Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Hohai University Department of Physics State Key Lab of Advanced Optical Communication Systems and NetworksShanghai Jiao Tong University

We propose a novel optical intensity modulator based on the combination of a symmetrical metal cladding optical waveguide （SMCW） and ferrofluid, where the ferrofluid is sealed in the waveguide to act as a guiding layer. The light matter interaction in the ferrofluid film leads to the formation of a regular nanoparticle pattern, which changes the phase match condition of the ultrahigh order modes in return. When two lasers are incident on the same spot of the waveguide chip, experiments illustrate all-optical modulation of one laser beam by adjusting the intensity of the other laser. A possible theoretical explanation may be due to the optical trapping and Soret effect since the phenomenon is considerable only when the control laser is effectively coupled into the waveguide.

关键词： symmetrical metal cladding waveguide chip ultrahigh order modes ferrofluids all-optical devices

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Can the Fullerene Cso Encage the Tetrahedral Td-N4？ A Density Functional Study

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Chinese Physics Letters 2009年第9期26卷 193-195页

作者：唐春梅朱卫华邓开明 College of science Hohai University Nanjing 210098 Department of Applied Physics Nanjing University of Science and Technology Nanjing 210094

The generalized gradient approximation based on density functional theory is used to study the structural, electronic and magnetic properties of the endohedral complex of Cso with tetrahedral Td N4. The most unstable Ih Cso can most effectively stabilize the N4 molecule, similar to the ease of Ih N4 C60 [Structural Chemistry 16 （2005）567]. It is worth noting that the cage becomes nonmagnetic due to the encaging of N4.

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A SELFISH ROUTING BASED NETWORK IMPROVEMENT PROBLEM

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Journal of Systems science & Complexity 2011年第1期24卷 68-78页

作者： Binwu ZHANG Shu-Cherng FANG Department of Mathematics and Physics Hohai University Changzhou Campus Changzhou 213022 China Department of Industrial and Systems Engineering North Carolina State University Raleigh NC 27695-7906 USA Mathematical sciences and Industrial Engineering Tsinghua University Beijing 100084 China

This paper considers a selfish routing based network improvement problem, in which the authors would like to find a modified latency function that results in a new Nash equilibrium flow satisfying all traffic demands subject to the target capacity, while the total modification cost on edge latency is minimized. By using the reduction from the 3-Satisfiability （3-SAT） problem to our problem, the authors show that this problem is strongly NP-hard, even for the single commodity network.

关键词： Nash equilibrium NP-hard selfish routing price of anarchy.

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Transmission time in the reflectionless complex potential

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Chinese Physics B 2014年第10期23卷 7-11页

作者：殷澄王贤平单鸣雷韩庆邦朱昌平 Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Hohai University School of Physics and Communication Electronics Jiangxi Normal University

A phase time definition directly obtained from the Schr6dinger equation is used to investigate the time delay of a particle scattered by complex reflectionless potential. The artifacts introduced by truncating in the numerical simulation are clarified. The time delay of the transmitted wave packet is found to be equal to the reflection time of the truncated potential. Both time delays are the same as the traversal time in the free space, but shorter than the time taken by a classical particle to pass the same potential.

关键词： complex reflectionless potentials transmission time supersymmetric quantum mechanics

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Pressure fluctuation signal analysis of pump based on ensemble empirical mode decomposition method

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Water science and Engineering 2014年第2期7卷 227-235页

作者： Hong PAN Min-sheng BU College of Energy and Electrical Engineering Hohai University College of Mechanical and Electrical Engineering Hohai University

Pressure fluctuations, which are inevitable in the operation of pumps, have a strong non-stationary characteristic and contain a great deal of important information representing the operation conditions. With an axial-flow pump as an example, a new method for time-frequency analysis based on the ensemble empirical mode decomposition （EEMD） method is proposed for research on the characteristics of pressure fluctuations. First, the pressure fluctuation signals are preprocessed with the empirical mode decomposition （EMD） method, and intrinsic mode functions （IMFs） are extracted. Second, the EEMD method is used to extract more precise decomposition results, and the number of iterations is determined according to the number of IMFs produced by the EMD method. Third, correlation coefficients between IMFs produced by the EMD and EEMD methods and the original signal are calculated, and the most sensitive IMFs are chosen to analyze the frequency spectrum. Finally, the operation conditions of the pump are identified with the frequency features. The results show that, compared with the EMD method, the EEMD method can improve the time-frequency resolution and extract main vibration components from pressure fluctuation signals.

关键词： pressure fluctuation ensemble empirical mode decomposition intrinsic modefunction correlation coefficient

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In situ synthesis of Fe-based alloy clad coatings containing TiB_2–TiN –(h-BN)

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International Journal of Minerals,Metallurgy and Materials 2015年第6期22卷 613-619页

作者： Shao-qun Jiang Gang Wang Qing-wen Ren Chuan-duo Yang Ze-hua Wang and Ze-hua Zhou College of Mechanics and Materials Hohai University Changzhou hohai Institute of science and Technology Limited Liability Company

Fe-based alloy coatings containing TiB2–TiN –（h-BN） were synthesized in situ on Q235 steel substrates by a plasma cladding process using the powders of Fe901 alloy, Ti, and h-BN as raw materials. The effects of Ti/h-BN mass ratio on interfacial bonds between the coating and substrate along with the microstructures and microhardnesses of the coatings were investigated. The results show that the Ti/h-BN mass ratio is a vital factor in the formation of the coatings. Free h-BN can be introduced into the coatings by adding an excess amount of h-BN into the precursor. Decreases in the Ti/h-BN mass ratio improve the microstructural uniformity and compactness and enhance the interfacial bonds of the coatings. At a Ti/h-BN mass ratio of 10/20, the coating is free of cracks and micropores, and mainly consists of Fe-Cr, Fe3B, TiB2, TiN, Ti2N, TiB, FeN, FeB, Fe2B, and h-BN phases. Its average microhardness in the zone between 0.1–2.8 mm from the coating surface is about Hv0.2 551.5.

关键词： iron-based materials coatings plasma cladding in situ synthesis microhardness

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Multi-approach analysis of maximum riverbed scour depth above subway tunnel

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Water science and Engineering 2010年第4期3卷 431-442页

作者： Jun CHEN Hong-wu TANG Zui-sen LI Wen-hong DAI State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 P. R. China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 P. R. China

When subway tunnels are routed underneath rivers, riverbed scour may expose the structure, with potentially severe consequences. Thus, it is important to identify the maximum scour depth to ensure that the designed buried depth is adequate. There are a range of methods that may be applied to this problem, including the fluvial process analysis method, geological structure analysis method, scour formula method, scour model experiment method, and numerical simulation method. However, the application ranges and forecasting precision of these methods vary considerably. In order to quantitatively analyze the characteristics of the different methods, a subway tunnel passing underneath a river was selected, and the aforementioned five methods were used to forecast the maximum scour depth. The fluvial process analysis method was used to characterize the river regime and evolution trend, which were the baseline for examination of the scour depth of the riverbed. The results obtained from the scour model experiment and the numerical simulation methods are reliable; these two methods are suitable for application to tunnel projects passing underneath rivers. The scour formula method was less accurate than the scour model experiment method; it is suitable for application to lower risk projects such as pipelines. The results of the geological structure analysis had low precision; the method is suitable for use as a secondary method to assist other research methods. To forecast the maximum scour depth of the riverbed above the subway tunnel, a combination of methods is suggested, and the appropriate analysis method should be chosen with respect to the local conditions.

关键词： high flow subway tunnel, scour depth scour model, numerical simulation

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