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A Remark on Extension of Into Isometries

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Acta Mathematica Sinica,English Series 2010年第1期26卷 203-208页

作者： rui dong WANG School of Mathematics Nankai University Tianjin 300071 P. R. China Department of Mathematics Tianjin University of Technology Tianjin 300191 P. R. China

In this paper, we prove that an into isometry form S（l（n）^∞） to S（E）, which under some conditions, can be extended to be a linear isometry defined on the whole space. Therefore we improve the results of [Ding, G. G.： The isometric extension of an into mapping from the unit sphere S（l（2）^∞） to S（Lμ^1）. Acta Mathematica Sinica, English Series, 22（6）, 1721-1724 （2006）].

关键词： isometric extension Tingley's problem l(n)^∞-space

POD analysis on vortical structures in MVG wake by Liutex core line identification

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Journal of Hydrodynamics 2020年第3期32卷 497-509页

作者： Xiang-rui dong Xiao-shu Cai Yinlin dong Chaoqun Liu School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Multiphase Flow and Heat Transfer in Shanghai Power Engineering Shanghai 200093China Department of Mathematics University of Central ArkansasConway 72035USA Department of Mathematics University of Texas at ArlingtonArlington 76019USA

The Liutex core line method, first combined with the snapshot proper orthogonal decomposition (POD), is utilized in a supersonic micro-vortex generator (MVG) wake flow at Ma = 2.5 and Reθ = 5 760 to reveal the physical significance of each POD mode of the flow field. Compared with other scalar-based vortex identification methods, the Liutex core line identification is verified to be the most appropriate approach that is threshold-free and provides full information of a fluid rotation motion. Meanwhile, the Liutex integration is employed to quantitatively track the evolution of the vortices in MVG wake and is applied to the determination of the effective control section of the MVG wake for the optimization study of MVG design. The physical mechanism of each POD mode for multi-scale and multi-frequency vortical structures is investigated by using Liutex core line identification to give some revelations. For the mean mode (mode 0) indicating the time-averaged velocity flowfield of the MVG wake flow, a pair of primary counter-rotating streamwise vortices and another pair of secondary vortices is uniquely identified by two pairs of Liutex core lines with Liutex magnitude. In contrast, mode 1 is featured by a fluctuated roll-up motion of streamwise vortex, and the streamwise component of the MVG wake is demonstrated to be dominant in terms of the total kinetic energy contribution. Meanwhile, a dominant shedding frequency of St = 0.072 is detected from the temporal behavior of mode 2, which has the organized arc-shaped vortex structures shedding from MVG induced by the K-H instability. Additionally, mode 4 subjects to low-frequency oscillations of the wall vortices and thus takes a relatively lower frequency of St = 0.044.

关键词： Proper orthogonal decomposition(POD) vortex identification Liutex vortex core lines micro-vortex generator(MVG)

Gastrointestinal symptoms in patients undergoing peritoneal dialysis: Multivariate analysis of correlated factors

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World Journal of Gastroenterology 2010年第22期16卷 2812-2817页

作者： dong, rui Guo, Zhi-Yong Second Mil Med Univ Changhai Hosp Dept Nephrol Shanghai 200433 Peoples R China

AIM: To investigate gastrointestinal (GI) symptoms in peritoneal dialysis (PD) patients and to explore related factors contributing to GI symptoms. METHODS: One hundred and twelve patients undergoing PD participated in the study. The gastrointestinal symptom rating scale was used for measuring GI symptoms. Information on age, height, weight, body mass index, disease leading to chronic renal failure, history of corticosteroid therapy, presence of predialytic GI symptoms, daily dosage of pills, and duration, type and daily dialysate volume of PD was obtained by interviewing patients and/or reviewing the medical records. Hemoglobin, albumin and Kt/V data were obtained from follow-up database. We used multiple regression analysis with stepwise backward variable selection to test for factors predicting GSRS scores with significance level of selection entry at 0.05 and selection of stay at 0.10. RESULTS: The prevalence of eating dysfunction, reflux and indigestion in the PD patients was 44.2%, 32.7%,32.7%, respectively. A history of corticosteroid therapy (b = 8.93, P 0.05. CONCLUSION: Eating dysfunction, reflux and indigestion were common in PD patients. Daily dosage of pills and corticosteroid history predicted GI symptoms, while residual renal function prevented them.

关键词： Eating dysfunction Gastroesophageal reflux Dyspepsia Peritoneal dialysis Residual renal function

On Extension of Isometries Between the Unit Spheres of Normed Space E and l^p(p>1)

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Acta Mathematica Sinica,English Series 2009年第7期25卷 1139-1144页

作者： Ji Jin YI rui dong WANG School of Mathematics Liaocheng University Liaocheng 252059 P. R. China School of Mathematics Nankai University Tianjing 300071 P. R. China Department of Mathematics Tianjin University of Technology Tianjin 300191 P. R. China

In this paper, we study the extension of isometries between the unit spheres of normed space E and lP（p 〉 1）. We arrive at a conclusion that any surjective isometry between the unit sphere of normed space lP（p 〉 ... 详细信息

关键词： isometric mapping isometric extension strictly convex

Isometries and Additive Mapping on the Unit Spheres of Normed Spaces

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Acta Mathematica Sinica,English Series 2017年第10期33卷 1431-1442页

作者： rui dong WANG Xu Jian HUANG Science of College Tianjin University of Technology Tianjin 300384 P. R. China

In this paper, we investigate isometric extension problem in general normed space. We prove that an isometry between spheres can be extended to a linear isometry between the spaces if and only if the natural positive homogeneous extension is additive on spheres. Moreover, this conclusion still holds provided that the additivity holds on a restricted domain of spheres.

关键词： Isometric extension additive mapping unit sphere angle

Analytical Solution for the Transient Response of A Sloping Seabed Induced by A P-Wave Line Source

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China Ocean Engineering 2023年第6期37卷 1044-1054页

作者： MA Rong SHAN Zhen-dong XIE Zhi-nan dong rui JING Li-ping Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

Many offshore marine structures are built on the seabed that are slightly or considerably *** study the sloping seabed transient response during marine earthquakes,an analytical solution induced by a P-wave line source embedded in the solid is *** the derivation,the wave fields in the fluid layer and the semi-infinite solid are firstly constructed by using the generalized ray method and the fluid-solid interface reflection and transmission ***,the analytical solution in the transformed domain is obtained by superposing these wave fields,and the analytical solution in the time domain by applying the analytical inverse Laplace transform *** the head wave generation conditions and arrival times at the fluid-solid interface are derived through this *** the use of numerical examples,the analytical solution is proved right and the impacts of the sloping angle on the hydrodynamic pressure in the sea,the seismic wave propagation in the seabed,the head wave,and the Scholte wave at the seawater-seabed interface are also addressed.

关键词： marine earthquake seismic wave head wave Scholte wave sloping seabed

Dynamic simulation of tropical coral reef ecosystem being disturbed by multiple situations

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Acta Oceanologica Sinica 2021年第9期40卷 105-116页

作者： Geng Wang rui dong Huimin Xu Dewen Ding School of Geography Liaoning Normal UniversityDalian 116029China Ocean College Beibu Gulf UniversityQinzhou 535011China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266071China South China Sea Institute of Oceanology Chinese Academy of SciencesGuangzhou 510301China

In consideration of the rapid degradation of coral reef ecosystems, the establishment of models is helpful to comprehend the degradation mechanism of coral reef ecosystems and predict the development process of coral reef communities. According to the characteristics of complex ecosystem of tropical coral reefs in China, the coral reef functional group is the core level variable;combined with the multiple feedback effects of coral reef functional groups and environmental changes, the study presents a coral reef ecosystem dynamics model with hermatypic corals as the core. Based on the simulation of the assumed initial value and the internal feedback of the system, the results show that in the basic simulation(relative health conditions), the coverage area of live corals and coral reefs generally decreased first and then increased, and increased by 4.67% and 6.38% between2010 and 2050, respectively. Based on the calibration model and the current situation of the studied area, the multi-factor disturbance effects of coral reef communities were simulated and explored by setting up three scenarios involving fishing policy, terrestrial deposition, and inorganic nitrogen emissions. Among them, in the single factor disturbance, the fishing policy exerts the most direct impact on the community decline;and the succession phenomenon is obvious;the terrestrial sedimentation has a faster and more integrated effect on the community decline;the effect of inorganic nitrogen emission on the community decline is relatively slow. In the double/multi-factor disturbance, the superimposed disturbance will aggravate the multi-source feedback effect of the coral reef communities development, accelerate the community decay rate, and make its development trajectory more complicated and diverse. This method provides a scientific and feasible method for simulating the damage of long-term coral reef community and exploring the development law and adaptive management of coral reef ecosystems. In

关键词： coral reef ecosystem system dynamics situational disturbance simulation

Hydraulics and swimming behavior of schizothorax prenanti in vertical slot fishways

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Journal of Hydrodynamics 2019年第1期31卷 169-176页

作者： rui-dong An Jia Li Wen-min Yi Xi Mao State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYaan 625014China

This paper presents a novel experiment for the correlation between the hydraulics and the swimming behavior of Schizothorax prenanti,a rare species of fish in southwest China,in passing a vertical slot *** an acoustic Doppler velocimeter,the velocities of a physical model in the equidimension fishway in the Shaping II power station are *** hydraulic parameters include the hydraulic head drop,the velocity patterns and the flow rate,and the swimming behavior includes the burst-coast,the sustained swimming and the migratory path,and they are analyzed under the test *** sustained swimming velocity is in the range from 0.65m/s to 1.09m/*** estimated hydraulic head drop of each pool is calculated and is in the range from 0.08-0.11 m,which means that 2.6% slope is *** the same slope,the maximum velocity is further reduced from 1.24 m/s to 1.14 m/s by using an L shape baffle *** above findings are used as the basis to evaluate the hydraulic performance of the fishways,where the L shape baffle structure is expected to be effective tor creating a preterencial flow for the *** the main stream of the pool,an "Ω" shape flow pattern is more fish-friendly,which can effectively extend the energy dissipation distance and avoid the bursting through a high velocity *** paper provides a useful complementary tool for practical designs.

关键词： Hydraulics swimming behavior vertical slot fishways burst-coast energy dissipation

Numerical simulation of gas-liquid two-phase flow impacting fixed structure by CLSVOF/IB method based on OpenFOAM

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Journal of Hydrodynamics 2021年第6期33卷 1176-1189页

作者： Wen-kang Meng Ching-hao Yu Jia Li rui-dong An State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China

In this paper,a coupled level set and volume of fluid,immersed boundary(CLSVOF/IB)method is proposed and implemented into the interFoam solver of the OpenFOAM to simulate the gas-liquid two-phase flows,involving the gas-liquid and fluid-structure *** the volume of fluid(VOF)method,the multidimensional universal limiter with explicit solution(MULES)approach is used to restrain the volume *** approach for calculating the grid characteristic size for the level set(LS)initial function and the re-initialization equation is proposed in order to make it more applicable to non-uniform grids in the finite volume *** the proposed CLSVOF method,the continuous LS function is used to calculate the gas-liquid interface curvature so that the surface tension term can be calculated *** the immersed boundary(IB)method proposed in this paper,a virtual forcing term is introduced in the momentum equation to deal with the fluid-structure interface by defining a solid volume fraction,which is convenient for the three-dimensional numerical *** the present flow field solver,an improved scheme of the velocity predictor loop of the PIMPLE framework is also *** benchmark cases:the Zalesak’s notched disk and a circular bubble at equilibrium,are simulated first to examine the accuracy of the present CLSVOF ***,the effects of several gas-liquid two-phase flows on different fixed structures are *** simulation results are in good agreement with the published numerical and experimental results.

关键词： Volume of fluid(VOF)method level set(LS)method immersed boundary method gas-liquid interface fluid-structure interface