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Journal of Hydrodynamics 2022年第6期34卷 1156-1161页

作者： Bo Wu ya-an hu Shu Xue State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing210029China Key Laboratory of Transport Technology in Navigation Building Construction Nanjing Hydraulic Research InstituteNanjing210029China

The hydro-floating ship lift originally invented in China is a major innovation in the field of navigation *** shaft water levels synchronization of its unique hydraulic-driven system plays a crucial role in reducing the torque of the synchronous shafts and ensuring the safety and stability operation of the ship *** study aims to investigate the muti-shaft water level synchronization and the flow velocity uniformity of the combined type hydraulic-driven *** on the theory of residual energy,a new index m2 proposed in this study is more suitable for evaluating the flow velocity uniformity of the combined hydraulic-driven ***,the critical value of m2=75 is calculated via the results of the scaled physical mode test as the threshold of water flow uniformity,and it provides a basis for determining the reasonable height of the pressure stabilizing chamber.

关键词： Hydro-floating ship lift water levels synchronism residual energy velocity distribution uniformity coefficient

A PRECONDITIONER FOR COUPLING SYSTEM OF NATURAL BOUNDARY ELEMENT AND COMPOSITE GRID FINITE ELEMENT

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Journal of Computational Mathematics 2002年第2期20卷 165-174页

作者： Qi-ya hu De-hao Yu Chinese Acad Sci Acad Math & Syst Sci ICMSEC LSEC Beijing 100080 Peoples R China

Discusses a coupling boundary element methods with finite element method for the Dirichlet exterior problems. Information on the natural boundary reduction; Discussion on the composite grid discretization; Details on ... 详细信息

关键词： natural boundary reduction composite grid error estimate preconditioner condition number

Experimental study of anti-cavitation mechanism of valve lintel natural aeration of high head lock

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Journal of Hydrodynamics 2020年第2期32卷 337-344页

作者： Xin Wang ya-an hu Jian-min Zhang Hydraulic Engineering Department Nanjing Hydraulic Research InstituteNanjing210029China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing210029China

To study the serious valve top gap cavitation of Datengxia high head single-lift ship lock,the 1:1 scale slice experiment is carried out,to truly reveal the gap flow characteristics,as well as the valve top gap cavitation characteristics and the anti-cavitation mechanism of natural *** kinds of cavitation,namely,the throat cavitation,the mainstream inner cavitation,and the valve plate cavitation,are determined and they are found to occur step-by-step in the gap section in the development of the *** to the anti-cavitation mechanism of the natural aeration,the pressure of the gap flow through the ventilation is increased,to avoid the mainstream inner cavitation and the valve plate cavitation,and to weaken the throat *** negative pressure zone in the gap section gradually extends with the development of the cavitation until the gap section is filled with a stable−10 m water *** the natural aeration measure is employed,the pressure in the gap section approximately reaches the−2 m water head,and the cavitation *** systematic tests reveal the quadratic polynomial relationship between the pressure in the gap and the ventilation per meter *** pressure,which corresponds to the maximum value of the ventilation at the beginning of the gap,approximately reaches the−2 m water head,and the pressure and the ventilation reach the equilibrium state *** the pressure in the gap increases when the valve is opened,the ventilation gradually decreases until the natural aeration *** gap section length for the high head valves has a great effect on the natural aeration and should be long enough to maintain the stable negative pressure in the gap,whereas the throat width has a minimal *** can be used for the anti-cavitation design of the high head lock valve.

关键词： High head lock valve top gap cavitation natural aeration slice experiment

Objective Reduction Solutions to Higher-Order Boussinesq System in (2+1)-Dimensions

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Communications in Theoretical Physics 2009年第1期51卷 47-52页

作者： hu ya-Hong ZHENG Chun-Long College of Mathematics and Physics Lishui University Lishui Zhejiang 323000 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

With the help of an objective reduction approach （ORA）, abundant exact solutions of （2＋1）-dimensional higher-order Boussinesq system （including some hyperboloid function solutions, trigonometric function solutions, and a rational function solution） are obtained. It is shown that some novel soliton structures, like single linearity soliton structure, breath soliton structure, single linearity y-periodic solitary wave structure, libration dromion structure, and kink-like multisoliton structure with actual physical meaning exist in the （2＋1）-dimensional higher-order Boussinesq system.

关键词： objective reduction approach higher-order Boussinesq exact solution localized excitation

Direct synthesis of diaryl sulfides by copper-catalyzed coupling of aryl halides with aminothiourea

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Chinese Chemical Letters 2012年第4期23卷 391-394页

作者： Xiang Mei Wu Wei ya hu Department of Chemistry College of ScienceLishui UniversityLishui 323000China

An efficient and simple protocol of copper-catalyzed C-S bond formation between aryl halides and inexpensive and commercially available aminothiourea is reported.A variety of symmetrical diaryl sulfides can be synthes... 详细信息

关键词： Copper Diaryl sulfide Aryl halide Aminothiourea

Experimental and CFD investigations of choked cavitation characteristics of the gap flow in the valve lintel of navigation locks

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Journal of Hydrodynamics 2020年第5期32卷 997-1008页

作者： Bo Wu ya-an hu Xin Wang Xiu-jun yan Key Laboratory of Transport Technology in Navigation Building Construction Nanjing Hydraulic Research InstituteNanjing 210029China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing 210029China School of Water Resources and Hydropower Engineering Wuhan UniversityWuhan 430072China

The cavitation is ubiquitous in the water delivery system of high hydraulic head navigation *** paper studies the choked cavitation characteristics of the gap flows in the valve lintel of the navigation locks and analyzes the critical self-aeration *** cavitation gap flow in the valve lintel is experimentally and numerically investigated.A visualized 1:1 full-scale slicing model is designed,with a high-speed camera,the details of the cavitation flow is captured without the reduced scale ***,the numerical simulations are conducted to reveal the flow structures in the *** experimental results show that the flow pattern of the gap flow in the valve lintel could be separated into four models,namely,the incipient(1)the developing,(2),the intensive,(3),and the choked(4)cavitation *** numerical simulation results are consistent with the experimental *** choked cavitation conditions are crucial to the gap flow in the valve *** the choked cavitation occurs,the gap is entirely occupied by two cavitation cloud *** gap pressure then decreases sharply to the saturated water vapor pressure at the operating *** water vapor pressure is the ultimate negative pressure in the gap that remains unchanged with the continuous decrease of the downstream *** volumetric flow rate reaches a peak,then remains constant,with the further decrease of the pressure ratio or the cavitation *** the choking point,the volumetric flow rate is proportional to the root mean square of the difference between the upstream pressure(absolute pressure)and the saturated pressure of the ***,the pressure ratio is linearly correlated with the downstream cavitation number with a slope of(1+ζc).

关键词： Cavitation cavitation control by aeration self-aerated flows critical self-aerated conditions choked cavitation

On the gauge dependence of scalar induced secondary gravitational waves during radiation and matter domination eras

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Science China(Physics,Mechanics & Astronomy) 2023年第9期66卷 23-41页

作者： Arshad Ali ya-Peng hu Mudassar Sabir Taotao Sui College of Physics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Aerospace Information Materials and Physics(NUAA) MIITNanjing 211106China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China School of Geophysics and Geomatics China University of GeosciencesWuhan 430074China

We revisit the vital issue of gauge dependence in the scalar-induced secondary gravitational waves(SIGWs), focusing on the radiation domination(RD) and matter domination(MD) eras. The energy density spectrum is the main physical observable in such induced gravitational waves. For various gauge choices, there has been a divergence in the energy density, ?GW, of *** calculate SIGWs in diferent gauges to quantify this divergence to address the gauge-dependent problem. In our previous studies, we had found that the energy density diverges in the polynomial power of conformal time(e.g., η^(6) in uniform density gauge). We try to fix this discrepancy by adding a counter-term that removes the fictitious terms in secondary tensor perturbations. We graphically compare the calculations in various gauges and also comment on the physical origin of the observed gauge dependence.

关键词： scalar induced gravitational waves gauge transformation cosmology

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AS/RS based yard and yard planning

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第8期9卷 1083-1089页

作者： ya-hong hu Zheng-dong Zhu Wen-jing HSU College of Information Engineering Zhejiang University of Technology Hangzhou 310032 China Department of Computer Science Xi ＂an Jiaotong University Xi ＇an 710049 China School of Computer Engineering Nanyang Technological University Singapore 639798 Singapore

In this paper, we apply the split-platform automated storage/retrieval systems (SP-AS/RSs) (hu et al., 2005) to store containers in the yard to improve the yard performance and to increase the utilization of the yard space. The layout of an SP-AS/RS based yard is described in detail. To achieve an efficient operation, we present a novel yard space allocation policy called the ‘second-carrier-based allocation policy’, which can help to alleviate the out-of-sequence problem of containers and the congestion of vehicles at the AS/RS racks. Different allocation policies are compared by an integrated container terminal simulation system. The simulation results show that the second-carrier-based policy is very efficient and has the potential to offer high terminal performance.

关键词： Container terminal Automated storage/retrieval system (AS/RS) yard planning Transportation system

Spatial Pattern of Long-term Residence in the Urban Floating Population of China and its Influencing Factors

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Chinese Geographical Science 2021年第2期31卷 342-358页

作者： CHEN Le XI Meijun JIN Wanfu hu ya School of Tourism&Research Institute of human Geography Xi’an International Studies UniversityXi’an 710128China School of Economics Xi’an University of Finance and EconomicsXi’an 710100China School of Geography and Tourism Guangdong University of Finance and EconomicsGuangzhou 510320China

Exploring long-term residence among the urban floating population is crucial to understanding urban growth in China,particularly since the 2008 financial *** using China Migrants Dynamic Survey data for 2012–2014,China Labor-force Dynamics Survey data for 2014–2016,and macroscale urban matched data,we analyzed the spatial pattern of long-term residential behavior in China’s urban floating population in 2012–2016 and developed an urban spatial utility equilibrium model containing‘macro’urban factors and‘micro’individual and household factors to explain the *** results first revealed that long-term residence is defined as≥6 yr for the urban floating population in ***,members of this population are more likely to be long-term residents of the megacities in the three urban agglomerations in eastern China as well as of small and medium-sized cities in western and northeastern China,whereas short-term residence is more likely in cities in central China and near the three urban ***,urban population density and housing prices,both have a significant U-shaped effect,are main factors affecting the spatial pattern of long-term residence.

关键词： long-term residence urban floating population spatial pattern spatial utility equilibrium model China

CSLabel： An Approach for Labelling Mobile App Reviews

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Journal of Computer Science & Technology 2017年第6期32卷 1076-1089页

作者： Li Zhang Xin-Yue huang Jing Jiang ya-Kun hu State Key Laboratory of Software Development Environment Beihang University Beijing 100191 China

Mobile apps （applications） have become a popular form of software, and the app reviews by users have become an important feedback resource. Users may raise some issues in their reviews when they use apps, such as a functional bug, a network lag, or a request for a feature. Understanding these issues can help developers to focus on users＇ concerns, and help users to evaluate similar apps for download or purchase. However, we do not know which types of issues are raised in a review. Moreover, the amount of user reviews is huge and the nature of the reviews＇ text is unstructured and informal. In this paper, we analyze 3 902 user reviews from 11 mobile apps in a Chinese app store -- 360 Mobile Assistant, and uncover 17 issue types. Then, we propose an approach CSLabel that can label user reviews based on the raised issue types. CSLabel uses a cost-sensitive learning method to mitigate the effects of the imbalanced data, and optimizes the setting of the support vector machine （SVM） classifier＇s kernel function. Results show that CSLabel can correctly label reviews with the precision of 66.5%, the recall of 69.8%, and the F1 measure of 69.8%. In comparison with the state-of-the-art approach, CSLabel improves the precision by 14%, the recall by 30%, the F1 measure by 22%. Finally, we apply our approach to two real scenarios： 1） we provide an overview of 1 076 786 user reviews from 1 100 apps in the 360 Mobile Assistant and 2） we find that some issue types have a negative correlation with users＇ evaluation of apps.

关键词： mobile app user review classification