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Development of an Explicit Symplectic Scheme that Optimizes the Dispersion-Relation Equation of the Maxwell’s Equations

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Communications in Computational Physics 2013年第4期13卷 1107-1133页

作者： Tony W.H.sheu L.Y.Liang J.H.Li Department of Engineering Science and Ocean Engineering National TaiwanUniversityNo.1Sec.4Roosevelt RoadTaipeiTaiwan Taida Institute of Mathematical Science(TIMS) National Taiwan UniversityTaiwan Center for Quantum Science and Engineering(CQSE) National Taiwan UniversityTaiwan

In this paper an explicit finite-difference time-domain scheme for solving the Maxwell’s equations in non-staggered grids is *** proposed scheme for solving the Faraday’s and Amp`ere’s equations in a theoretical manner is aimed to preserve discrete zero-divergence for the electric and magnetic *** inherent local conservation laws in Maxwell’s equations are also preserved discretely all the time using the explicit second-order accurate symplectic partitioned Runge-Kutta *** remaining spatial derivative terms in the semi-discretized Faraday’s and Amp`ere’s equations are then discretized to provide an accurate mathematical dispersion relation equation that governs the numerical angular frequency and the wavenumbers in two space *** achieve the goal of getting the best dispersive characteristics,we propose a fourth-order accurate space centered scheme which minimizes the difference between the exact and numerical dispersion relation *** the computational exercises,the proposed dual-preserving solver is computationally demonstrated to be efficient for use to predict the long-term accurate Maxwell’s solutions.

关键词： Maxwell’s equations non-staggered grids zero-divergence fourth-order dualpreserving solver dispersion relation equations

GAS SORPTION AND TRANSPORT IN POLY (PHENYLENE OXIDE)(PPO)AND ARYL-BROMINATED PPO MEMBRANES

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Chinese Journal of Polymer Science 1989年第4期7卷 306-314页

作者：贾连达 F. R. sheu R.T.CHERN H.B.HOPFENBERG Changchun Institute of Applide Chemistry Academia SinicaChangchunPRC Department of Chemical Engineering North Carolina State UniversityRaleighNC 27695USA

The apparent solubility (S), concentration-average diffusivity (D), and permeability (P), for C0_2, CH_4 and N_2 through PPO and aryl-brominated PPO at 35℃ for pressure ranging from 1 to 26 atm are reported. It is found that P, D, and S of the membranes to all the three gases vary with the extent of bromination. S increases with the increase of the percent of bromine in each case, but D to CO_2 increases remarkably only at higher degree of brominafion, and therefore, P to CO_2 is increased by more than 100% over a wide range ofpressure in the case. The solubility data are well described by the dual mode sorption model. It is found that the gas molecules sorbed by the Langmuir mode are relatively more immobilized and the contribution of the nonequilibrinm character of the polymer to gas permeation increases obviously for CO_2 and is hardly changed for CH_4 with increasing bromine content. These observations are interpreted in terms of changes in specific free volume (SFV)and the cohesive energy density (CED) of the polymers.

关键词： Poly (Phenylene Oxide) (PPO) Bromination Membrane Permeability.

GIS-based Evaluation on the Fault Motion-Induced Coseismic Landslides

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Journal of Mountain Science 2012年第5期9卷 601-612页

作者： Ming-Wey HUANG Chien-Yuan CHEN Tzu-Hsiu WU Chi-Ling CHANG sheu-Yien LIU Ching-Yun KAO Taiwan Science & Technology Center for Disaster Reduction Sindian City Taipei County 231 Chinese Taipei Taiwan Chiayi University Department of Civil & Water Resources Engineering Chiayi City 60004 Chinese Taipei Chia Nan University of Pharmacy and Science Institute of Industrial Safety & Disaster Prevention Tainan City 71710 Chinese Taipei

Earthquake-induced potential landslides are commonly estimated using landslide susceptibility maps. Nevertheless, the fault location is not identified and the ground motion caused by it is unavailable in the map. Thus, potential coseismic landslides for a specific fault motion-induced earthquake could not be predicted using the map. It is meaningful to incorporate the fault location and ground motion characteristics into the landslide predication model. A new method for a specific fault motion-induced coseismic landslide prediction model using GIS (Geographic Information System) is proposed herein. Location of mountain ridges, slope gradients over 45 o , PVGA (Peak Vertical Ground Accelerations) exceeded 0.15 g, and PHGA (Peak Horizontal Ground Accelerations) exceeded 0.25 g of slope units were representing locations that initiated landslides during the 1999 Chi-Chi earthquake in Taiwan. These coseismic landslide characteristics were used to identify areas where landslides occurred during Meishan fault motion-induced strong ground motions in Chiayi County in Taiwan. The strong ground motion (over 8 Gal in the database, 1 Gal = 0.01 m/s 2 , and 1 g = 981 Gal) characteristics were evaluated by the fault length, site distance to the fault, and topography, and their attenuation relations are presented in GIS. The results of the analysis show that coseismic landslide areas could be identified promptly using GIS. The earthquake intensity and focus depth have visible effects on ground motion. The shallower the focus depth, the larger the magnitude increase of the landslides. The GIS-based landslide predication method is valuable combining the geomorphic characteristics and ground motion attenuation relationships for a potential region landslide hazard assessment and in disaster mitigation planning.

关键词：潜在滑坡断层错动 GIS 评价地震动衰减关系强地面运动地理信息系统故障位置

Sclerostin activity plays a key role in the negative effect of glucocorticoid signaling on osteoblast function in mice

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Bone Research 2017年第2期5卷 95-108页

作者： Eric E Beier Tzong-Jen sheu Emily A Resseguie Masahiko Takahata Hani A Awad Deborah A Cory-Slechta J Edward Puzas Department of Environmental Medicine University of Rochester School of Medicine and Dentistry Rochester NY USA Department of Environmental and Occupational Medicine Rutgers University Piscataway NJ USA and Center for Musculoskeletal Research University of Rochester School of Medicine and Dentistry Rochester NY USA

Stress during prenatal development is correlated with detrimental cognitive and behavioral outcomes in offspring. However, the long-term impact of prenatal stress(PS) and disrupted glucocorticoid signaling on bone mass and strength is not understood. In contrast, the detrimental effect of lead(Pb) on skeletal health is well documented. As stress and Pb act on common biological targets via glucocorticoid signaling pathways and co-occur in the environment, this study first sought to assess the combined effect of stress and Pb on bone quality in association with alterations in glucocorticoid signaling. Bone parameters were evaluated using microCT, histomorphometry, and strength determination in 8-month-old male mouse offspring subjected to PS on gestational days 16 and 17, lifetime Pb exposure(100 p.p.m. Pb in drinking water), or to both. Pb reduced trabecular bone mass and, when combined with PS, Pb unmasked an exaggerated decrement in bone mass and tensile strength. Next, to characterize a mechanism of glucocorticoid effect on bone, prednisolone was implanted subcutaneously(controlled-release pellet, 5 mg·kg^(-1) per day) in 5-month-old mice that decreased osteoblastic activity and increased sclerostin and leptin levels. Furthermore, the synthetic glucocorticoid dexamethasone alters the anabolic Wnt signaling pathway. The Wnt pathway inhibitor sclerostin has several glucocorticoid response elements, and dexamethasone administration to osteoblastic cells induces sclerostin expression. Dexamethasone treatment of isolated bone marrow cells decreased bone nodule formation, whereas removal of sclerostin protected against this decrement in ***, these findings suggest that bone loss associated with steroid-induced osteoporosis is a consequence of sclerostin-mediated restriction of Wnt signaling, which may mechanistically facilitate glucocorticoid toxicity in bone.

关键词： Sclerostin prenatal negative

Stimulatory effect of puerarin on bone formation through co-activation of nitric oxide and bone morphogenetic protein-2/ mitogen-activated protein kinases pathways in mice

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Chinese Medical Journal 2012年第20期125卷 3646-3653页

作者： sheu shiow-yunn TSAI Chia-chung SUN Jui-sheng CHEN Ming-hong LIU Man-hai SUN Man-ger School of Pharmacy College of PharmacyTaipei 11031TaiwanChina Graduate Institute of Clinical Medicine College of MedicineTaipei 11031TaiwanChina Taipei Medical University Taipei 11031TaiwanChina Department of Orthopedic'Surgery Hsin-Chu 30059TaiwanChina Department of Surgery Hsin-Chu 30059TaiwanChina National Taiwan University Hospital Hsin-Chu Branch Hsin-Chu 30059TaiwanChina Department of Food Science China University of Science and TechnologyTaipei 11581TaiwanChina Department of Biology Western Universityontario.N6A 5CICanada

Background Estrogen deficiency results in loss of bone mass compounds with estrogen-like activity that bind to estrogen receptors effect of the phytoestrogen puerarin on adult mouse osteoblasts. Methods Osteoblast cells were harvested from 8-month old female Phytoestrogens are plant-derived non-steroidal The main aim of this study was to investigate the mprinting control region （ICR） mice. The effects of puerarin stimulation on the proliferation, differentiation and maturation of osteoblasts were examined. The production of nitric oxide （NO） and the expression of bone morphogenetic protein-2 （BMP-2）, SMAD4, mitogen-activated protein kinases （MAPK）, core binding factor all runt-related transcription factor 2 （Cbfal/Runx2）, osteoprotegerin （OPG）, and receptor activator of NF-KB ligand （RANKL） genes were analyzed. The activation of signal pathways was further confirmed by specific pathway inhibitors. Results The osteoblast viability reached its maximum at 10-8 mol/L puerarin. At this concentration, puerarin increases the proliferation and matrix mineralization of osteoblasts and promotes NO synthesis. With 108 mol/L puerarin treatment, BMP-2, SMAD4, Cbfal/Runx2, and OPG gene expression were up-regulated, while the RANKL gene expression is down-regulated. Concurrent treatment involving the （bone morphogenetic protein） BMP antagonist Noggin or the NOS inhibitor L-NAME diminishes puerarin induced cell proliferation, Alkaline phosphatase （ALP） activity, NO production, as well as the BMP-2, SMAD4, Cbfal/Runx2, OPG, and RANKL gene expression. Conclusions In this in vitro study, we demonstrate that puerarin is a bone anabolic agent that exerts its osteogenic effects through the induction of BMP-2 and NO synthesis, subsequently regulating Cbfal/Runx2, OPG, and RANKL gene expression. This effect may contribute to its induction of osteoblast proliferation and differentiation, resulting in bone formation.

关键词： puerarin nitric oxide bone morphogenetic protein mitogen-activated protein kinases osteoblasts

Brain-targeting,acid-responsive antioxidant nanoparticles for stroke treatment and drug delivery

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Bioactive Materials 2022年第10期7卷 57-65页

作者： shenqi Zhang Bin Peng Zeming Chen Jiang Yu Gang Deng Youmei Bao Chao Ma Fengyi Du Wendy C.sheu W.Taylor Kimberly J.Marc Simard Daniel Coman Qianxue Chen Fahmeed Hyder Jiangbing Zhou Kevin N.sheth Department of Neurosurgery USA Department of Biomedical Engineering USA Department of Radiology and Biomedical Imaging USA Department of Neurology Yale UniversityNew HavenCT06510USA Department of Neurosurgery Renmin Hospital of Wuhan UniversityWuhanHubei430060China Department of Neurology Division of Neurocritical CareMassachusetts General HospitalBostonMAUSA Department of Neurosurgery University of Maryland School of MedicineBaltimoreMD21201USA

Stroke is the leading cause of death and ***,there is no effective pharmacological treatment for this disease,which can be partially attributed to the inability to efficiently deliver therapeutics to the *** we report the development of natural compound-derived nanoparticles(NPs),which function both as a potent therapeutic agent for stroke treatment and as an efficient carrier for drug delivery to the ischemic ***,we screened a collection of natural nanomaterials and identified betulinic acid(BA)as one of the most potent antioxidants for stroke ***,we engineered BA NPs for preferential drug release in acidic ischemic tissue through chemically converting BA to betulinic amine(BAM)and for targeted drug delivery through surface conjugation of AMD3100,a CXCR4 *** resulting AMD3100-conjugated BAM NPs,or A-BAM NPs,were then assessed as a therapeutic agent for stroke treatment and as a carrier for delivery of NA1,a neuroprotective *** show that intravenous administration of A-BAM NPs effectively improved recovery from stroke and its efficacy was further enhanced when NA1 was *** to their multifunctionality and significant efficacy,we anticipate that A-BAM NPs have the potential to be translated both as a therapeutic agent and as a drug carrier to improve the treatment of stroke.

关键词： Drug delivery Acid-triggered release Antioxidant nanoparticles NA1 Ischemic stroke

High-Order Spectral Stochastic Finite Element Analysis of Stochastic Elliptical Partial Differential Equations

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Applied Mathematics 2013年第5期4卷 18-28页

作者： Guang Yih sheu Department of Accounting and Information System Chang-Jung Christian University Gueiren Tainan Taiwan

This study presents an experiment of improving the performance of spectral stochastic finite element method using high-order elements. This experiment is implemented through a two-dimensional spectral stochastic finite element formulation of an elliptic partial differential equation having stochastic coefficients. Deriving this spectral stochastic finite element formulation couples a two-dimensional deterministic finite element formulation of an elliptic partial differential equation with generalized polynomial chaos expansions of stochastic coefficients. Further inspection of the performance of resulting spectral stochastic finite element formulation with adopting linear and quadratic (9-node or 8-node) quadrilateral elements finds that more accurate standard deviations of unknowns are surprisingly predicted using quadratic quadrilateral elements, especially under high autocorrelation function values of stochastic coefficients. In addition, creating spectral stochastic finite element results using quadratic quadrilateral elements is not unacceptably time-consuming. Therefore, this study concludes that adopting high-order elements can be a lower-cost method to improve the performance of spectral stochastic finite element method.

关键词： Spectral Stochastic Finite Element Method Generalized Polynomial Chaos Expansion High-Order Elements

Structural Reliability Assessment by a Modified Spectral Stochastic Meshless Local Petrov-Galerkin Method

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World Journal of Mechanics 2013年第2期3卷 101-111页

作者： Guang Yih sheu Department of Accounting and Information System Chang-Jung Christian University Tainan Chinese Taipei Department of Civil Engineering Feng-Chia University Taichung Chinese Taipei

This study presents a new tool for solving stochastic boundary-value problems. This tool is created by modify the previous spectral stochastic meshless local Petrov-Galerkin method using the MLPG5 scheme. This modified spectral stochastic meshless local Petrov-Galerkin method is selectively applied to predict the structural failure probability with the uncertainty in the spatial variability of mechanical properties. Except for the MLPG5 scheme, deriving the proposed spectral stochastic meshless local Petrov-Galerkin formulation adopts generalized polynomial chaos expansions of random mechanical properties. Predicting the structural failure probability is based on the first-order reliability method. Further comparing the spectral stochastic finite element-based and meshless local Petrov-Galerkin-based predicted structural failure probabilities indicates that the proposed spectral stochastic meshless local Petrov-Galerkin method predicts the more accurate structural failure probability than the spectral stochastic finite element method does. In addition, generating spectral stochastic meshless local Petrov-Galerkin results are considerably time-saving than generating Monte-Carlo simulation results does. In conclusion, the spectral stochastic meshless local Petrov-Galerkin method serves as a time-saving tool for solving stochastic boundary-value problems sufficiently accurately.

关键词： Spectral Stochastic Meshless Local Petrov-Galerkin Method Generalized Polynomial Chaos Expansion First-Order Reliability Method Structural Failure Probability Reliability Index

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热力学遗传算法计算效率的改进

软件学报 2008年第7期19卷 1613-1622页

作者：应伟勤李元香 sheu Phillip C-Y 武汉大学软件工程国家重点实验室湖北武汉430072 Department of Electrical Engineering and Computer Science University of CaliforniaIrvineCA 92697USA

热力学遗传算法(thermodynamical genetic algorithms,简称TDGA)借鉴固体退火过程中能量与熵的竞争模式来协调GA中"选择压力"和"种群多样性"之间的冲突.然而TDGA目前极高的计算代价限制了其应用.为了提高TDGA的计算效率,首先定义一种等... 详细信息

热力学遗传算法(thermodynamical genetic algorithms,简称TDGA)借鉴固体退火过程中能量与熵的竞争模式来协调GA中"选择压力"和"种群多样性"之间的冲突.然而TDGA目前极高的计算代价限制了其应用.为了提高TDGA的计算效率,首先定义一种等级熵(rating-based entropy,简称RE)度量方法,它能以较小的计算成本度量种群中个体适应值的分散程度.然后引入分量热力学替换规则(component thermodynamical replacement,简称CTR),有效地降低了替换规则的复杂度.同时也证明了CTR规则具有驱动种群自由能近似最速下降的能力.在0-1背包问题上的实验结果表明,RE方法和CTR规则在保持TDGA良好的性能与稳定性的同时,极大地提高了其计算效率.

关键词：遗传算法热力学计算效率多样性度量潜换规则