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仿真器 1

各向异性 1

各向异性腐蚀 1

图像解析法 1

干燥应力 1

干缩异向性 1

弦向应变 1

微磁结构 1

树盘 1

热压－热变形 1

硅 1

稀土永磁体，磁各向异性，矫顽力，能积，磁性复合材料，增材制造 1

纳米晶Nd-Fe-B辐向环 1

角速度 1

非晶Sm-Co膜，面内单轴各向异性，磁控溅射 1

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Aspects of rock permeability

Lianyang ZHANG

《结构与土木工程前沿（英文）》 2013年第7卷第2期页码 102-116 doi: 10.1007/s11709-013-0201-2

摘要： Effective evaluation of rock permeability is required in different energy, engineering and environmental projects. Although much research has been conducted on rock permeability, it is still one of the most difficult tasks for practicing rock engineers to accurately determine rock permeability. Based on a comprehensive literature review, this paper outlines the key aspects of rock permeability by presenting the representative values of the permeability of different rocks, describing the empirical and semi-empirical correlations for estimating the permeability of rocks, and discussing the main factors affecting the permeability of rocks. The factors discussed include stress, depth, temperature, and discontinuity intensity and aperture. This paper also highlights the scale effect on rock permeability, interconnectivity of discontinuities, and anisotropy of rock permeability. This paper provides the fundamental and essential information required for effective evaluation of rock permeability.

关键词： rock permeability discontinuity stress temperature scale effect anisotropy

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树盘干缩异向性引起应变的测算及分析

付宗营,赵景尧,蔡英春

《中国工程科学》 2014年第16卷第4期页码 25-29

摘要：

研究探讨了干燥过程中树盘受抑制干缩应变、自由干缩应变、弹性应变、黏弹性蠕变应变以及机械吸附蠕变的图像解析测算法；运用该方法测算了白桦树盘常规缓慢干燥（含水率分布均匀）过程中干缩异向性引起的弦向各应变，分析了干燥过程中不同含水率阶段的应力状态及应力与各应变的关系。结果表明：应变的图像解析测算法可满足精度要求；树盘干燥至fiber saturation point( FSP)以下，弦向首先受拉伸应力作用，随着干燥的进行，拉伸应力转变为压缩应力；应力方向与各应变对应关系不同，与黏弹性蠕变应变无明显对应关系，与机械吸附蠕变基本对应。

关键词：图像解析法树盘干缩异向性干燥应力弦向应变

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Unified description of sand behavior

Feng ZHANG, Bin YE, Guanlin YE

《结构与土木工程前沿（英文）》 2011年第5卷第2期页码 121-150 doi: 10.1007/s11709-011-0104-z

摘要： In this paper, the mechanical behavior of sand, was systematically described and modeled with a elastoplastic model proposed by Zhang et al. [ ]. Without losing the generality of the sand, a specific sand called as Toyoura sand, a typical clean sand found in Japan, has been discussed in detail. In the model, the results of conventional triaxial tests of the sand under different loading and drainage conditions were simulated with a fixed set of material parameters. The model only employs eight parameters among which five parameters are the same as those used in Cam-clay model. Once the parameters are determined with the conventional drained triaxial compression tests and undrained triaxial cyclic loading tests, then they are fixed to uniquely describe the overall mechanical behaviors of the Toyoura sand, without changing the values of the eight parameters irrespective of what kind of the loadings or the drainage conditions may be. The capability of the model is discussed in a theoretical way.

关键词： constitutive model sand stress-induced anisotropy density structure

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Upper bound solution to seismic active earth pressure of submerged backfill subjected to partial drainage

《结构与土木工程前沿（英文）》 2021年第15卷第6期页码 1480-1493 doi: 10.1007/s11709-021-0776-y

摘要： In waterfront geotechnical engineering, seismic and drainage conditions must be considered in the design of retaining structures. This paper proposes a general analytical method to evaluate the seismic active earth pressure on a retaining wall with backfill subjected to partial steady seepage flow under seismic conditions. The method comprises the following steps: i) determination of the total head, ii) upper bound solution of seismic active earth thrust, and iii) deduction for the earth pressure distribution. The determination of total head h(x,z) relies on the Fourier series expansions, and the expressions of the seismic active earth thrust and pressure are derived by using the upper bound theorem. Parametric studies reveal that insufficient drainage and earthquakes are crucial factors that cause unfavorable earth pressure. The numerical results confirm the validity of the total head distribution. Comparisons indicate that the proposed method is consistent with other relevant existing methods in terms of predicting seismic active earth pressure. The method can be applied to the seismic design of waterfront retaining walls.

关键词： seismic active earth pressure partial seepage flow pore pressure anisotropy upper bound theorem

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Phosphorene: Current status, challenges and opportunities

Anandarup Goswami, Manoj B. Gawande

《化学科学与工程前沿（英文）》 2019年第13卷第2期页码 296-309 doi: 10.1007/s11705-018-1783-y

摘要： The field of 2-dimensional (2D) materials has witnessed a sharp growth since its inception and can majorly be attributed to the substantial technical and scientific developments, leading to significant improvements in their syntheses, characterization and applications. In the list of 2D materials, the relatively newer addition is phosphorene, which ideally consists of a single layer of black phosphorous. Keeping in mind the past, and ongoing research activities, this short account offers a brief overview of the present status and the associated challenges in the field of phosphorene-related research, with special emphasis on their syntheses, properties, applications and future opportunities.

关键词： phosphorene black phosphorous anisotropy single layer thermoelectric chemical vapor deposition catalysis battery supercapacitor

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Effect of anisotropic characteristics on the mechanical behavior of asphalt concrete overlay

Lingyun YOU, Zhanping YOU, Kezhen YAN

《结构与土木工程前沿（英文）》 2019年第13卷第1期页码 110-122 doi: 10.1007/s11709-018-0476-4

摘要： Asphalt concrete (AC) overlays placed over old asphalt pavement have become an alternative to repairing and reinforcing pavements. The strength contributed by the AC overlay is strongly influenced by the anisotropic properties of the pavement material. This study was conducted to analyze the influence of anisotropy, modulus gradient properties, and the condition of the AC overlay and old pavement contact plane on the mechanical behaviors of AC overlays, as well as to quantify the influence of the degree of anisotropy on the mechanical behaviors of AC overlay by a sensitivity analysis (SA). The mechanical behaviors of the AC overlay were numerically obtained using the three-dimensional finite element method with the aid of ABAQUS a commercial program. Variations in the AC overlay’s modulus as a function of temperature as well as the contact state between the AC overlay and AC layer were considered. The SA is based on standardized regression coefficients method. Comparing the mechanical behavior in terms of surface deflection, stress, and strain of the anisotropy model against those corresponding to the isotropic model under static loads show that the anisotropic properties had greater effects on the mechanical behavior of the AC overlay. In addition, the maximum shear stress in the AC overlay was the most significant output parameter affected by the degree of anisotropy. Therefore, future research concerning the reinforcement and repair of pavements should consider the anisotropic properties of the pavement materials.

关键词： asphalt concrete overlay anisotropy temperature gradients modulus gradients finite element simulation sensitivity analysis

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(011)取向单晶衬底上生长的非晶Sm-Co薄膜的面内各向异性调控 Article

梁文会, 周厚博, 熊杰夫, 胡凤霞, 李佳, 张健, 王晶, 孙继荣, 沈保根

《工程（英文）》 2020年第6卷第2期页码 158-163 doi: 10.1016/j.eng.2019.11.010

摘要：

具有单轴面内各向异性的非晶Sm-Co薄膜在信息存储和自旋电子学领域中都具有广阔的应用前景。产生单轴面内各向异性的最有效方法是在薄膜沉积过程中施加面内磁场。然而，这种方法通常需要复杂的设备。本文中，我们报道了一种产生单轴面内各向异性的新方法，只需要将非晶Sm-Co薄膜生长在(011)取向的单晶衬底上，薄膜生长过程中不需要施加任何外部磁场。薄膜的各向异性常数k_A随衬底晶格常数的变化而变化。生长在LaAlO₃ (011)衬底上的非晶Sm-Co薄膜的各向异性常数k_A高达3.3×10⁴ J·m⁻³。详细分析表明，衬底各向异性应变引起的铁磁畴的择优生长，以及薄膜中Sm-Co、Co-Co取向对的有序化，在非晶Sm-Co薄膜单轴面内各向异性的产生上起到了重要作用。这项工作为在非晶Sm-Co薄膜中获得单轴面内各向异性提供了一种新方法。

关键词：非晶Sm-Co膜，面内单轴各向异性，磁控溅射

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Anisotropy of multi-layered structure with sliding and bonded interlayer conditions

Lingyun YOU, Kezhen YAN, Jianhong MAN, Nengyuan LIU

《结构与土木工程前沿（英文）》 2020年第14卷第3期页码 632-645 doi: 10.1007/s11709-020-0617-4

摘要： A better understanding of the mechanical behavior of the multi-layered structure under external loading is the most important item for the structural design and the risk assessment. The objective of this study are to propose and develop an analytical solution for the mechanical behaviors of multi-layered structure generated by axisymmetric loading, and to investigate the impact of anisotropic layers and interlayer conditions on the multi-layered structure. To reach these objectives, first, according to the governing equations, the analytical solution for a single layer was formulated by adopting the spatial Hankel transform. Then the global matrix technique is applied to achieve the analytical solution of multi-layered structure in Hankel domain. The sliding and bonded interlayer conditions were considered in this process. Finally, the numerical inversion of integral transform was used to solve the components of displacement and stress in real domain. Gauss-Legendre quadrature is a key scheme in the numerical inversion process. Moreover, following by the verification of the proposed analytical solution, one typical three-layered flexible pavement was applied as the computing carrier of numerical analysis for the multi-layered structure. The results have shown that the anisotropic layers and the interlayer conditions significantly affect the mechanical behaviors of the proposed structure.

关键词： multi-layered structure Hankel transformation anisotropic transversely isotropic interlayer condition Gauss-Legendre quadrature

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Thermal buckling behavior of laminated composite plates: a finite-element study

Houdayfa OUNIS,Abdelouahab TATI,Adel BENCHABANE

《机械工程前沿（英文）》 2014年第9卷第1期页码 41-49 doi: 10.1007/s11465-014-0284-z

摘要：

In this paper, the thermal buckling behavior of composite laminated plates under a uniform temperature distribution is studied. A finite element of four nodes and 32 degrees of freedom (DOF), previously developed for the bending and mechanical buckling of laminated composite plates, is extended to investigate the thermal buckling behavior of laminated composite plates. Based upon the classical plate theory, the present finite element is a combination of a linear isoparametric membrane element and a high precision rectangular Hermitian element. The numerical implementation of the present finite element allowed the comparison of the numerical obtained results with results obtained from the literature: 1) with element of the same order, 2) the first order shear deformation theory, 3) the high order shear deformation theory and 4) the three-dimensional solution. It was found that the obtained results were very close to the reference results and the proposed element offers a good convergence speed. Furthermore, a parametrical study was also conducted to investigate the effect of the anisotropy of composite materials on the critical buckling temperature of laminated plates. The study showed that: 1) the critical buckling temperature generally decreases with the increasing of the modulus ratio E_L/E_T and thermal expansion ratio α_T/α_L, and 2) the boundary conditions and the orientation angles significantly affect the critical buckling temperature of laminated plates.

关键词： thermal buckling laminated composite plates anisotropy critical buckling temperature finite-element method high precision rectangular Hermitian element

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Experimental study on compaction-induced anisotropic mechanical property of rockfill material

Xiangtao ZHANG, Yizhao GAO, Yuan WANG, Yu-zhen YU, Xun SUN

《结构与土木工程前沿（英文）》 2021年第15卷第1期页码 109-123 doi: 10.1007/s11709-021-0693-0

摘要： The anisotropy of rockfill materials has a significant influence on the performance of engineering structures. However, relevant research data are very limited, because of the difficulty with preparing specimens with different inclination angles using traditional methods. Furthermore, the anisotropy test of rockfill materials is complex and complicated, especially for triaxial tests, in which the major principal stress plane intersects with the compaction plane at different angles. In this study, the geometric characteristics of a typical particle fraction consisting of a specific rockfill material were statistically investigated, and the distribution characteristics of particle orientation in specimens prepared via different compaction methods were examined. For high-density rockfill materials, a set of specimen preparation devices for inclined compaction planes was developed, and a series of conventional triaxial compression tests with different principal stress direction angles were conducted. The results reveal that the principal stress direction angle has a significant effect on the modulus, shear strength, and dilatancy of the compacted rockfill materials. Analysis of the relationship between the principal stress direction angles, change in the stress state, and change in the corresponding dominant shear plane shows that the angle between the compacted surface and dominant shear plane is closely related to interlocking resistance associated with the particle orientation. In addition, different principal stress direction angles can change the extent of the particle interlocking effect, causing the specimen to exhibit different degrees of anisotropy.

关键词： rockfill inclination of specimen preparation anisotropy mechanical property mechanism

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Analysis of cement-treated clay behavior by micromechanical approach

Dong-Mei ZHANG, Zhen-Yu YIN, Pierre-Yves HICHER, Hong-Wei HUANG

《结构与土木工程前沿（英文）》 2013年第7卷第2期页码 137-153 doi: 10.1007/s11709-013-0204-z

摘要： Experimental results show the significant influence of cement content on the mechanical properties of cement-treated clays. Cementation is produced by mixing a certain amount of cement with the saturated clay. The purpose of this paper is to model the cementation effect on the mechanical behavior of cement-treated clay. A micromechanical stress-strain model is developed considering explicitly the cementation at inter-cluster contacts. The inter-cluster bonding and debonding during mechanical loading are introduced in two ways: an additional cohesion in the shear sliding and a higher yield stress in normal compression. The model is used to simulate isotropic compression and undrained triaxial tests under various confining stresses on cement-treated Ariake clay and Singapore clay with various cement contents. The applicability of the present model is evaluated through comparisons between numerical and experimental results. The evolution of local stresses and local strains in inter-cluster planes are discussed in order to explain the induced anisotropy due to debonding at contact level under the applied loads. The numerical simulations demonstrate that the proposed micromechanical approach is well adapted for taking into account the main physical properties of cement-treated clay, including damage and induced anisotropy under mechanical loading.

关键词： microstructure cementation clay micromechanics anisotropy debonding

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旋转体自身驱动的硅微机械陀螺

张福学,毛旭,张伟

《中国工程科学》 2006年第8卷第8期页码 23-27

摘要：

报道了一种利用旋转体自身角速度作为驱动力，通过各向异性刻蚀硅片制作的硅微机械陀螺。介绍了该陀螺敏感结构（硅摆）的设计、制作与封装工艺，用仿真器测试了旋转体的角速率。模拟试验和性能测试表明，该陀螺结构原理正确，可用于敏感旋转体的偏航或俯仰角速度，以及旋转体自身的角速度。

关键词：硅各向异性腐蚀角速度仿真器

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稀土永磁体的前景与展望 Review

J.M.D. Coey

《工程（英文）》 2020年第6卷第2期页码 118-130 doi: 10.1016/j.eng.2018.11.034

摘要：

稀土永磁是一项成熟的技术，但2011年稀土危机的冲击导致人们重新考量20世纪80年代和90年代的许多关于几乎不含稀土（或重稀土）的新型硬磁材料的想法。Nd-Fe-B永磁通过精心巧妙的优化，适用于需要以合理成本获得高性能的广泛应用领域。当需要高温稳定性时，Sm-Co是首选材料，而某些应用也逐渐开始使用Sm-Fe-N磁体。对这些基本材料的元素替代改进的范围已经进行了相当深入的探讨，同时制备技术对微观结构和磁滞现象的影响也已深入了解。上一代的一个很宏大的想法，即制备交换耦合硬/软纳米复合的各向异性磁体，来显著提高创纪录的磁能积。然而，事实证明这很难实现。尽管如此，该领域已取得发展，而其他领域的创新也在不断蓬勃发展。例如，电动私人交通已经从电动自行车发展到电驱动的汽车和卡车成为主流，并且由此可见，电动运输很有可能结束内燃机的主导地位。随着越来越清晰地了解特定永磁体的局限性，人们开始围绕它进行具有独创性和想象力的设计，并最有效地利用了可用的稀土资源混合物。此外，机器人技术正在吸引着巨大的新市场，而且人们才刚刚开始探索增材制造所提供的机会。提高磁体高温稳定性的新方法也正在开发中，并且具有其他有用特性的硬磁体的集成多功能性也正在设想中。这些研究课题将在本文中通过各种示例进行详细说明。

关键词：稀土永磁体，磁各向异性，矫顽力，能积，磁性复合材料，增材制造

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各向异性热压稀土永磁体的热变形机制及微磁结构研究

李卫,朱明刚

《中国工程科学》 2011年第13卷第10期页码 4-12

摘要：

重点研究制备工艺对各向异性热压稀土永磁体性能的影响，探讨了热压永磁体的热变形机理和数学描述模型，并尝试从微磁结构的角度研究各向异性纳米晶Nd-Fe-B磁体，揭示纳米晶粒之间的静磁和交换耦合相互作用、磁化和反磁化、热退磁等微观机制。获得了最佳磁性能为：Hcj=1 157 kA/m，Br=1.465 T，(BH)max=426 kJ/m³纳米晶Nd-Fe-B磁体。

关键词：纳米晶Nd-Fe-B辐向环热压－热变形各向异性微磁结构

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Altered white matter microarchitecture in Parkinson’s disease: a voxel-based meta-analysis of diffusion tensor imaging studies

Xueling Suo, Du Lei, Wenbin Li, Lei Li, Jing Dai, Song Wang, Nannan Li, Lan Cheng, Rong Peng, Graham J Kemp, Qiyong Gong

《医学前沿（英文）》 2021年第15卷第1期页码 125-138 doi: 10.1007/s11684-019-0725-5

摘要： This study aimed to define the most consistent white matter microarchitecture pattern in Parkinson’s disease (PD) reflected by fractional anisotropy (FA), addressing clinical profiles and methodology-related heterogeneity. Web-based publication databases were searched to conduct a meta-analysis of whole-brain diffusion tensor imaging studies comparing PD with healthy controls (HC) using the anisotropic effect size–signed differential mapping. A total of 808 patients with PD and 760 HC coming from 27 databases were finally included. Subgroup analyses were conducted considering heterogeneity with respect to medication status, disease stage, analysis methods, and the number of diffusion directions in acquisition. Compared with HC, patients with PD had decreased FA in the left middle cerebellar peduncle, corpus callosum (CC), left inferior fronto-occipital fasciculus, and right inferior longitudinal fasciculus. Most of the main results remained unchanged in subgroup meta-analyses of medicated patients, early stage patients, voxel-based analysis, and acquisition with ＜30 diffusion directions. The subgroup meta-analysis of medication-free patients showed FA decrease in the right olfactory cortex. The cerebellum and CC, associated with typical motor impairment, showed the most consistent FA decreases in PD. Medication status, analysis approaches, and the number of diffusion directions have an important impact on the findings, needing careful evaluation in future meta-analyses.

关键词： Parkinson’s disease diffusion tensor imaging fractional anisotropy meta-analysis anisotropic effect size–signed differential mapping