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Asymmetric Oscillation and Acoustic Response from an Encapsulated Microbubble Bound within a Small Vessel

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Chinese Physics Letters 2010年第6期27卷 114-117页

作者： huang bei ZHENG Hai-Rong ZHANG Dong Institute of Acoustics Key Laboratory of Modern Acoustics (Ministry of Education) Nanjing University Nanjing 210093 Paul C. Lauterbur Research Center for Biomedical imaging IBHE Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055

Understanding the dynamics of ultrasonic excited microbubbles bound within microvessels is of significance for novel ultrasonic imaging, drug delivery and therapeutic biomedicad applications. A finite element model （FEM） considering acoustic nonlinearity is developed to describe the asymmetric oscillation and acoustic response from mn encapsulated microbubble bound within a small vessel. Numerical simulation is performed for a 2 μm encapsulated microbubble bound within 8-20μm vessels using 2 MHz ultrasound excitation. The oscillation of the bound microbubble becomes more asymmetric under larger ultrasound pressure or within the smaller vessel. The normalized difference between the major and minor axes of epllipse is estimated to be 2.16%for the 8 μm vessel at an acoustic pressure of 0.5 MPa. In addition, the fundamental component of the acoustic scattering from the bound microbubble is enhanced by 6 dB while the second harmonic component is decreased by approximately 29 dB compared with the free microbubble.

关键词： Ultrasonics Encapsulation Pressure

Discussion on the influence of truncation of ground motion residual distribution on probabilistic seismic hazard assessment

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Earthquake Engineering and Engineering Vibration 2011年第3期10卷 379-392页

作者： Wu Jian Gao Mengtan Chen Kun huang bei Institute of Geophysics China Earthquake Administration Beijing 100081 China Institute of Geology China Earthquake Administration Beijing 100029 China

Recent studies on assessment of a very low annual probability of exceeding （APE） ground motions, 10-4 or less, have highlighted the importance of the upper bound of ground motions when very low probability results are acquired. The truncation level adopted in probabilistic seismic hazard analysis （PSHA） should be determined by an aleatory uncertainty model （i.e., distribution model） of ground motions and the possible maximum and minimum ground motion values of a specific earthquake. However, at the present time, it is impossible to establish the upper bound model for ground motions based on the source characteristics and/or ground motion propagation. McGuire suggested a truncation level be fixed at a number of = 6, or the distribution of residuals be truncated in such a manner that site intensity cannot be greater than the epicenter intensity. This study aims to find a reasonable and feasible truncation level to be used in PSHA when the physical mechanism is not available to find the extreme ground motion. A mathematical analysis of the influence of the truncation level on PSHA, case studies of sites in different seismotectonic settings, and a distribution analysis of ground motion residuals are conducted in this study. It is concluded that = 4 is the minimum acceptable value for engineering applications for APEs within 0.002 to 10-4, and for low APEs, such as 10-5 and 10-6, the value of should be no less than 5 in most regions of China.

关键词： truncation of ground motions annual probability of exceeding PSHA distribution of ground motion residuals

A Finite Temperature Phase Diagram in Rotating Bosonic Optical Lattices

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Chinese Physics Letters 2011年第6期28卷 36-39页

作者： huang bei-Bing WAN Shao-Long Department of Experiment Teaching Yancheng Institute of TechnologyYancheng 224051 Institute for Theoretical Physics and Department of Modern Physics University of Science and Technology of ChinaHefei 230026

A finite temperature phase diagram of the rotating Bose–Hubbard model,including the crossover between Mott insulator and the normal state,is derived on the frame of the Gutzwiller mean-field *** addition,we calculate... 详细信息

关键词： transition theory phase

A continuing 30-year decline in water quality of Jiaojiang Estuary, China

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Water Science and Engineering 2015年第1期8卷 20-29页

作者： Chun-ye Wang Bin Zhou bei huang College of Marine Science Shanghai Ocean University College of Science Hangzhou Normal University Zhejiang Provincial Zhoushan Ocean Ecological Environment Monitoring Station

A quantitative description of a long-term series of aquatic environmental factors and their spatial distributions was generated using measured data from the Jiaojiang Estuary from 1982 to 2011. The aquatic environmental factors included suspended matter, salinity, and nutrients. Based on these factors, the aquatic ecosystem health in the Jiaojiang Estuary over the last 30 years was analyzed. The results indicated that the suspended matter concentration in the estuary was mainly affected by the amounts of suspended sediment and solid waste, with the value fluctuating over a long period, and the range of high concentration expanded continually; the salinity was mainly affected by precipitation and surface water resources, showing an overall decreasing trend, and the region with low salinity moved seaward and toward the reclamation areas; and the nutritional status, mainly affected by discharge of industrial wastewater and domestic sewage, was satisfactory in the 1980s and 1990s, but the status became severe in recent years. Reclamation had a great influence on these three factors： high reclamation strength led to a significant increase in the suspended matter concentration and a deterioration of the nutritional status, and the reclamation rate was negatively related with the salinity in the estuary. There was a significant positive correlation between the health status of the aquatic ecosystem and salinity, with a correlation coefficient of 0.93. The correlation coefficient between the health status and nutritional status was -0.71, while the correlation between the suspended matter concentration and health status was not as significant as that of the other two factors. The dynamics of the aquatic environment could be divided into four stages： sustainable health from the 1980s to the 1990s, continued deterioration from 2000 to 2003, improvement from 2004 to 2005, and secondary deterioration from 2006 to 2011. The Jiaojiang Estuary is faced with imminent environmental

关键词： Water quality decline Aquatic ecosystem health Aquatic environmental factor Suspended matter concentration Salinity Nutritional status Jiaojiang Estuary

Nodal Topological Phases in s-wave Superfluid of Ultracold Fermionic Gases

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Communications in Theoretical Physics 2018年第2期69卷 137-142页

作者： bei-Bing huang Xiao-Sen Yang Department of Physics Yancheng Institute of Technology Yancheng 224051 China Department of Physics Jiangsu University Zhenjiang 212013 China

The gapless Weyl superfluid has been widely studied in the three-dimensional ultracold fermionic superfluid. In contrast to Weyl superfluid, there exists another kind of gapless superfluid with topologically protected nodal lines, which can be regarded as the superttuid counterpart of nodal line semimetal in the condensed matter physics, just as Weyl superfluid with Weyl semimetal. In this paper we study the ground states of the cold fermionic gases in cubic optical lattices with one-dimensional spin-orbit coupling and transverse Zeeman field and map out the topological phase diagram of the system. We demonstrate that in addition to a fully gapped topologically trivial phase, some different nodal line superfluid phases appear when the Zeeman field is adjusted. The presence of topologically stable nodal lines implies the dispersionless zero-energy fiat band in a finite region of the surface Brillouin zone. Experimentally these nodal line superfluid states can be detected via the momentum-resolved radio-frequency spectroscopy. The nodal line topological superfluid provide fertile grounds for exploring exotic quantum matters in the context of ultraeold atoms.

关键词： gapless topological superfluid nodal line surface flat band

Permeabilities of rebamipide via rat intestinal membranes and its colon specific delivery using chitosan capsule as a carrier

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World Journal of Gastroenterology 2008年第31期14卷 4928-4937页

作者： bei-bei huang Guo-Feng Li Jing-Hui Luo Lian Duan Kishimoto Nobuaki Yamamoto Akira Department of pharmacy Nanfang Hospital Southern Medical University Guangzhou 510515 Guangdong Province China Department of Biopharmaceutics Kyoto Pharmaceutical University Misasagi Yamashinaku Kyoto 6078414 Japan

AIM: To investigate the permeability characteristics of rebamipide across intestinal mucosa, and examine the effects of some absorption enhancers on the permeability across the colonic tissue. Another purpose is to demonstrate the colon-specific delivery of rebamipide with or without absorption enhancers using chitosan capsule as a carrier. METHODS: The permeability of rebamipide was evaluated using an in vitro diffusion chamber system, and the effects of some absorption enhancers on the permeability via colon were further investigated. The release of rebamipide from chitosan or gelatin capsule was studied by Japan Pharmacopoeia rotating basket method. The colonic and plasma concentrations were analyzed by high performance liquid chromatography (HPLC) to evaluate colon-targeting action after oral administration of various dosage forms, and rebamipide with absorption enhancers in chitosan dosage forms. RESULTS: The permeability of rebamipide across the jejunal or ileal membranes was higher than the colonic membranes. Both sodium laurate (C12) and labrasol signifi cantly increased permeability across the colon membranes. On the other hand, the release of rebamipide from chitosan capsule was less than 10%totally within 6 h. The area under concentration-time profile of drug in the colon mucosa using chitosan capsules (AUCLI, 1 6011.2 ng·h/g) was 2.5 times and 4.4 times greater than using gelatin capsules and CMC suspension, respectively. Meanwhile, the area under concentration-time profile of drug in the plasma (AUCPL) was 1016.0 ng·h/mL for chitosan capsule, 1887.9 ng·h/mL for CMC suspension p and 2163.5 ng·h/mL for gelatin capsule. Overall, both AUCLI and AUCPL were increased when C12 was co-administrated, but the increase of AUCLI was much greater; the drug delivery index (DDI) was more than 1 compared with simple chitosan capsule group. CONCLUSION: There was a regional difference in the permeability of Rabamipide across the jejunum, ileum and the colon, and passive

关键词： Rebamipide Diffusion chamber Permeability Sodium laurate Chitosan capsule Colon-specific delivery

Some notes on numerical simulation of the turbulent cavitating flow with a dynamic cubic nonlinear sub-grid scale model in OpenFOAM

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Journal of Hydrodynamics 2020年第4期32卷 790-794页

作者： Zi-yang Wang Xian-bei huang Huai-yu Cheng Bin Ji State Key Laboratory of Water Resources and Hydropower Engineering Science School of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China College of Electrical Energy and Power EngineeringYangzhou UniversityYangzhou 225127China

The accuracy of large eddy simulation(LES)is highly dependent on the performance of sub-grid scale(SGS)*** the present paper,a dynamic cubic nonlinear sub-grid scale model(DCNM)proposed by huang et *** implemented for the simulation of unsteady cavitating flow around a 3-D Clark-Y hydrofoil in *** performance in predicting the evolution of cloud cavitation is discussed in *** simulation with a linear model,the dynamic Smagorinsky model(DSM),is also conducted as a *** results with DCNM show a better agreement with the available experimental *** comparison between DCNM and DSM further suggests that the DCNM is able to predict the backscatter more precisely,which is an important feature in *** characteristics of DCNM is analyzed to account for its advantages in the prediction of unsteady cloud cavitation as *** results reveal that it is the nonlinear terms of DCNM that makes DCNM capture sub-grid scale vortices better and more suitable for studying the transient behaviors of cloud cavitation than DSM.

关键词： Cavitation large eddy simulation(LES) nonlinear sub-grid scale model OpenFOAM

Study of the internal characteristics of the stall in a centrifugal pump with a cubic non-linear SGS model

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Journal of Hydrodynamics 2019年第4期31卷 788-799页

作者： Xian-bei huang Zhu-qing Liu Yao-jun Li Wei Yang Qiang Guo School of Hydraulic Energy and Power Engineering Yangzhou University Yangzhou 225127 China College of Water Resources and Civil Engineering China Agricultural University Beijing 100083 China

The stall in a centrifugal pump impeller under a quarter-load condition is investigated by using a third-order SGS model named the DCNM, for a better understanding of the rotation effect on the stall phenomenon. The study of the distributions of the Reynolds stresses, the production tei*m and the rotation term reveals that the production and the rotation jointly result in the non-uniform Reynolds stress distribution. Further study of the two components of the production and the rotation shows that they jointly transport a certain energy from the Reynolds component R、to Ruu.

关键词： Centrifligal pump large-eddy simulation non-linear model OpenFOAM stall

Analysis of trace mercury in water by solid phase extraction using dithizone modified nanometer titanium dioxide and cold vapor atomic absorption spectrometry

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Rare Metals 2007年第6期26卷 541-546页

作者： MA Xiaoguo huang bei CHENG Meiqing Faculty of Environmental Science and Engineering Guangdong University of Technology Guangzhou 510090 China Department of Chemical Engineering Maoming University Maoming 525000 China

A new method for analysis of trace mercury in water samples was developed, based on the combination of preconcentration/separation using dithizone-modified nanometer titanium dioxide （TiO2） as a solid phase extractant and determination by cold vapor atomic adsorption spectrometry （CVAAS）. Dithizone was dissolved with alcohol and loaded on the surface of nano-sized TiO2 powders by stirring. The static adsorption behavior of Hg^2＋on the dithizone-modified nanoparficles was investigated in detail. It was found that excellent adsorption ratio for Hg^2＋ could be obtained in the pH range of 7-8 with an oscillation time of 15 rain, and a 5 mL of 3.5 mol·L^-1 HCI solution could quantitatively elute Hg^2＋ from nanometer TiO2 powder. Common coexisting ions caused no obvious influence on the determination of mercury. The mechanisms for the adsorption and desorption were discussed. The detection limit （30） for Hg^2＋ was calculated to be 5 ng·L^-1. The proposed method was applied to the determination of Hg^2＋ in a mineral water sample and a Zhujiang River water sample. By the standard addition method, the average recoveries were found to be 94.4%-108.3% with RSD （n = 5） of 2.9%-3.5%.

关键词： analytical chemistry mercury solid-phase extraction TiO2 nanoparticle cold vapor atomic adsorption spectrometry (CVAAS)