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Adaptive Finite Element Modeling Techniques for the Poisson-Boltzmann Equation

Communications in Computational Physics 2012年第1期11卷 179-214页

作者： M.Holst J.A.McCammon Z.yu y.C.Zhou y.zhu Department of Mathematics University of California at San DiegoLa JollaCA 92093USA Department of Physics University of California at San DiegoLa JollaCA 92093USA Department of Chemistry&Biochemistry University of California at San DiegoLa JollaCA 92093USA Center for Theoretical Biological Physics(CTBP) University of California at San DiegoLa JollaCA 92093USA National Biomedical Computation Resource(NBCR) University of California at San DiegoLa JollaCA 92093USA Howard Hughes Medical Institute University of California at San DiegoLa JollaCA 92093USA

We consider the design of an effective and reliable adaptive finite element method(AFEM)for the nonlinear Poisson-Boltzmann equation(PBE).We first examine the two-term regularization technique for the continuous problem recently proposed by Chen,Holst and Xu based on the removal of the singular electrostatic potential inside biomolecules;this technique made possible the development of the first complete solution and approximation theory for the Poisson-Boltzmann equation,the first provably convergent discretization and also allowed for the development of a provably convergent ***,in practical implementation,this two-term regularization exhibits numerical ***,we examine a variation of this regularization technique which can be shown to be less susceptible to such *** establish a priori estimates and other basic results for the continuous regularized problem,as well as for Galerkin finite element *** show that the new approach produces regularized continuous and discrete problemswith the samemathematical advantages of the original *** then design an AFEM scheme for the new regularized problem and show that the resulting AFEM scheme is accurate and reliable,by proving a contraction result for the *** result,which is one of the first results of this type for nonlinear elliptic problems,is based on using continuous and discrete a priori L¥*** provide a high-quality geometric model as input to the AFEM algorithm,we also describe a class of feature-preserving adaptive mesh generation algorithms designed specifically for constructing meshes of biomolecular structures,based on the intrinsic local structure tensor of the molecular *** of the algorithms described in the article are implemented in the Finite Element Toolkit(FETK),developed and maintained at *** stability advantages of the new regularization scheme are demonstrated with FETK through comparisons with the original regula

关键词： Poisson-Boltzmann equation semi-linear partial differential equations supercritical nonlinearity singularity a priori L¥estimates existence uniqueness well-posedness Galerkin methods discrete a priori L¥estimates quasi-optimal a priori error estimates adaptive finite methods contraction convergence optimality surface and volume mesh generation mesh improvement and decimation.

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Achieving high hetero-deformation induced(HDI)strengthening and hardening in brass by dual heterostructures

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Journal of Materials Science & Technology 2022年第3期98卷 244-247页

作者： X.T.Fang Z.K.Li y.F.Wang M.Ruiz X.L.Ma H.y.Wang y.zhu R.Schoell C.Zheng D.Kaoumi y.T.zhu Department of Materials Science and Engineering North Carolina State UniversityRaleighNC 27695USA Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education Northeastern UniversityShenyang 110819China School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China Department of Materials Science and Engineering Texas A and M UniversityCollege StationTX 77840USA Department of Mechanical and Aerospace Engineering North Carolina State UniversityRaleighNC 27695USA Department of Nuclear Engineering North Carolina State UniversityRaleighNC 27695USA Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China

Heterostructured materials,defined as materials that contain multiple zones with dramatically different flow stresses,have the potential to push the envelope of the strength-ductility of metals and alloys beyond what can be obtained conventionally[1–3].A prominent example is the heterogeneous lamella Ti that is as strong as its ultrafine-grained Ti,while as ductile as the coarsegrained Ti[4].

关键词： grain strengthening deformation

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Influence of Ice on Soil Elemental Characterization via Portable X-Ray Fluorescence Spectrometry

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Pedosphere 2014年第1期24卷 1-12页

作者： D.C.WEINDORF N.BAKR y.zhu A.MCWHIRT C.L.PING G.MICHAELSON C.NELSON K.SHOOK S.NUSS Texas Tech University Department of Plant and Soil Sciences Louisiana State University Agricultural Center University of Alaska Fairbanks Palmer Research Center

Field portable X-ray fluorescence （PXRF） spectrometry has become an increasingly popular technique for in-situ elemental characterization of soils. The technique is fast, portable, and accurate, requiring minimal sample preparation and no consumables. However, soil moisture 〉 20% has been known to cause fluorescence denudation and error in elemental reporting and few studies have evaluated the presence of soil moisture in solid form as ice. Gelisols （USDA Soil Taxonomy）, permafrost-affected soils, cover a large amount of the land surface in the northern and southern hemispheres. Thus, the applicability of PXRF in those areas requires further investigation. PXRF was used to scan the elemental composition （Ba, Ca, Cr, Fe, K, Mn, Pb, Rb, Sr, Ti, Zn, and Zr） of 13 pedons in central and northern Alaska, USA. Four types of scans were completed： 1） in-situ frozen soil, 2） re-frozen soil in the laboratory, 3） melted soil/water mixture in the laboratory, and 4） moisture-corrected soil. All were then compared to oven dry soil scans. Results showed that the majority of PXRF readings from in-situ, re-frozen, and melted samples were significantly underestimated, compared to the readings on oven dry samples, owing to the interference expected by moisture. However, when the moisture contents were divided into 〉 40% and 〈 40〈 groups, the PXRF readings under different scanning conditions performed better in the group with 〈 40% moisture contents. Most elements of the scans on the melted samples with 〈 40% moisture contents acceptably compared to those of the dry samples, with R2 values ranging from 0.446 （Mn） to 0.930 （St）. However, underestimation of the melted samples was still quite apparent. Moisture-corrected sample PXRF readings provided the best correlation to those of the dry, ground samples as indicated by higher R2 values, lower root mean square errors （RMSEs）, and slopes closer to 1 in linear regression equations. However, the in-situ （frozen） sample scans did not differ

关键词： Gelisols moisture permafrost proximal sensing regression

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脊髓空洞症10例患者皮肤感觉阈值的测定

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中华神经科杂志 2003年第6期36卷 447-449页

作者：崔丽英 Patrick y.zhu 管宇宙中国医学科学院中国协和医科大学北京协和医院神经科 100730 Department of Physical Medicine and Rehabilitation State University of New York

目的　研究选择性神经诊断刺激器在 10例脊髓空洞症患者中的特点和临床意义。方法　对 10例 (男 6例 ,女 4例 )经病史、临床表现和脊髓MRI检查证实的脊髓空洞症患者在双侧的拇指 (C6皮节 )和小指 (C8皮节 )进行了不同频率 (5、2 5 0和 2... 详细信息

目的　研究选择性神经诊断刺激器在 10例脊髓空洞症患者中的特点和临床意义。方法　对 10例 (男 6例 ,女 4例 )经病史、临床表现和脊髓MRI检查证实的脊髓空洞症患者在双侧的拇指 (C6皮节 )和小指 (C8皮节 )进行了不同频率 (5、2 5 0和 2 0 0 0Hz)皮肤感觉阈值 (CPT)的测定 ,并与年龄匹配的健康人对照。结果　患者组C6和C8皮节对 5和 2 5 0Hz刺激感觉阈值与健康对照组比较 ,差异有非常显著意义 (P <0 .0 1) ,而 2 0 0 0Hz刺激两组之间差异无显著意义。其中 2例临床上有明显的触觉和音叉震动觉减低 ,MRI显示空洞影响脊髓前角和后角 ,2 0 0 0Hz刺激CPT阈值也有明显的增高 (C6和C8刺激CPT阈值分别为 5 32和 718)。不同频率刺激CPT的异常率是不同的 ,5Hz刺激CPT的异常率最高 (C6和C8刺激分别为 5 5 .0 %和 70 .0 % ) ,2 0 0 0Hz刺激的阳性率最低 (C6和C8刺激分别为 15 .0 %和 2 3.5 % )。结论　通过对 10例不同程度脊髓空洞症的研究 ,进一步证明了不同刺激频率CPT的测定可评价不同感觉神经的功能 ,较客观地对不同直径的感觉纤维进行定量测定。

关键词：脊髓空洞症皮肤感觉阈值选择性神经诊断刺激器 MRI 临床特点

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Spatial Variability of Soil Properties at Capulin Volcano,New Mexico,USA:Implications for Sampling Strategy

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Pedosphere 2010年第2期20卷 185-197页

作者： D.C.WEINDORF School of Soil Plant and Environmental SciencesLouisiana State University

Non-agricultural lands are surveyed sparsely in ***,soils in these areas usually exhibit strong spatial variability which requires more samples for producing acceptable *** Volcano National Monument,as a typical sparsely-surveyed area,was chosen to assess spatial variability of a variety of soil properties,and furthermore,to investigate its implications for sampling *** hundred and forty one composited soil samples were collected across the Monument and the surrounding *** properties including pH,organic matter content,extractable elements such as calcium (Ca),magnesium (Mg),potassium (K),sodium (Na),phosphorus (P),sulfur (S),zinc (Zn),and copper (Cu),as well as sand,silt,and clay percentages were analyzed for each *** of all properties were constructed,standardized,and compared to estimate the spatial variability of the soil properties in the *** on the similarity among standardized semivariograms,we found that the semivariograms could be generalized for physical and chemical properties,*** generalized semivariogram for physical properties had a much greater sill value (2.635) and effective range (7 500 m) than that for chemical *** sampling density (OSD),which is derived from the generalized semivariogram and defines the relationship between sampling density and expected error percentage,was proposed to represent,interpret,and compare soil spatial variability and to provide guidance for sample scheme *** showed that chemical properties exhibit a stronger local spatial variability than soil texture parameters,implying more samples or analysis are required to achieve a similar level of precision.

关键词： generalized semivariogram GIS optimal sampling density sampling design

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基于定量分析的深度学习在临床0-Ⅰ期肺腺癌中的预后影响

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国际医学放射学杂志 2024年第1期 128-128页

作者： y.zhu L.Chen y.Luo L.Zhang H.Ma H.yang 武鑫宏

摘要目的评估基于肺腺癌（LUAD）的大小、质量和体积测量的深度学习（DL）算法在预测LUAD预后中的效能，并与手动测量进行比较。方法共纳入542例临床0-Ⅰ期周围

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基于血凝块的时间密度曲线作为急性缺血性卒中机械取栓功能性结局的新型影像学预测因子

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国际医学放射学杂志 2024年第3期 376-376页

作者： J.Wei J.Jiang y.zhu X.Wei Z.Sun J.Sun 吴小佳

摘要目的从CT灌注成像（CTP）中获得的血栓通透性的新评价指标可否更准确地预测急性缺血性脑卒中（AIS）中机械血栓切除术（MT）的临床反应。方法研究纳入2018年4

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Generation of wavelength-independent subwavelength Bessel beams using metasurfaces

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Light(Science & Applications) 2016年第1期5卷 39-44页

作者： Wei Ting Chen Mohammadreza Khorasaninejad Alexander y.zhu Jaewon Oh Robert C.Devlin Aun Zaidi Federico Capasso Harvard John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138USA University of Waterloo WaterlooON N2L 3G1Canada

Bessel beams are of great interest due to their unique non-diffractive *** a conical prism or an objective paired with an annular aperture are two typical approaches for generating zeroth-order Bessel ***,the former approach has a limited numerical aperture(NA),and the latter suffers from low efficiency,as most of the incident light is blocked by the ***,an additional phase-modulating element is needed to generate higher-order Bessel beams,which in turn adds complexity and bulkiness to the *** overcome these problems using dielectric metasurfaces to realize meta-axicons with additional functionalities not achievable with conventional *** demonstrate meta-axicons with high NA up to 0.9 capable of generating Bessel beams with full width at half maximum about as small as~λ/3(λ=405 nm).Importantly,these Bessel beams have transverse intensity profiles independent of wavelength across the visible *** meta-axicons can enable advanced research and applications related to Bessel beams,such as laser fabrication,imaging and optical manipulation.

关键词： Bessel beam high numerical aperture light angular momentum metasurface

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Research of abnormity membrane electrode assembly

Research of abnormity membrane electrode assembly

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第九届全国氢能学术会议

作者： X.X.Wang,H.J.Ni,y.zhu,M.y.Huang Nantong University,China

＜正＞In order to to reduce the costs,to improve the performances and to promote the industry process,basing on calculus and finite element thinking,conceptual design of abnormity membrane electrode assembly（A-MEA） was proposed and prototype making was researched, which was derived from the need of structural optimization for direct methanol fuel cells

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Research of 1# direct methanol fuel cells

Research of 1# direct methanol fuel cells

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第九届全国氢能学术会议

作者： H.J.Ni,X.X.Wang,M.y.Huang,y.zhu Nantong University,China

In order to to reduce the costs,to improve the performances and to promote the industry process,basing on calculus and finite element thinking,conceptual design was proposed and prototype making was researched for a new type direct methanol fuel cells(DMFCs),which was derived from common 1 battery in modem society and was named"1 DMFCs".Every basic parameter was gained from experiment and *** size and shape were

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