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Higher-order mode effects on the seismic performance of tall piers

Zhongguo GUAN, Jianzhong LI, Yan XU, Hao LU

《结构与土木工程前沿（英文）》 2011年 第5卷 第4期   页码 496-502 doi: 10.1007/s11709-011-0131-9

摘要： A comprehensive analysis was conducted to investigate the seismic performance of a typical tall bridge pier through incremental dynamical analysis (IDA). The effect of higher-order modes was studied specifically. The results showed that higher-order modes significantly contributed to the structural seismic response and should not be neglected. Including these modes resulted in an additional hinge midway up the pier. No plastic hinge would occur at this location for conventional bridge piers. Higher-order modes also led to an out-of-phase response between the hinge rotation at the pier bottom and the displacement at the top. This means that the displacement-based seismic design method cannot correctly predict the mechanical state of the critical hinge and therefore is not suitable for use in the seismic design of tall piers. Mistakenly using the displacement-based seismic design method for tall piers may result in a seriously unsafe condition.

关键词： tall bridges     higher-order mode effects     incremental dynamic analysis    

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表征不同DNA高阶结构的单分子分析方法 Review

刘泳麟, 边天元, 刘岩, 李治民, 裴羽丰, 宋杰

《工程（英文）》 2023年 第24卷 第5期   页码 277-292 doi: 10.1016/j.eng.2022.10.009

摘要：

DNA不仅是生命遗传信息的载体，而且是一种高度可编程和自组装的纳米材料。不同的DNA结构与其生物学和化学功能有关。因此，了解各种DNA结构的物理和化学性质在生物学和纳米化学中具有重要意义。然而，群体分子实验忽略了溶液中DNA结构的异质性。单分子分析方法是观察单个分子的行为和探测自由能态的高异质性的有力工具。本文介绍了单分子检测和操纵等单分子分析方法，并讨论了这些方法如何用于测量单/双链DNA（ss/dsDNA）、DNA高阶结构和DNA纳米结构的分子性质。最后，将DNA纳米技术和单分子分析方法进行结合以了解DNA和其他生物物质、软物质的生物物理特性。

关键词： 单分子分析方法     DNA结构     力学性能     构象转变    

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基于LiNbO3/SiO2/SiC异质结构实现44 GHz超高频声表面波谐振器 Article

周剑, 张定红, 刘炀辉, 卓凤玲, 钱莉荣, 李红浪, 傅永庆, 段辉高

《工程（英文）》 2023年 第20卷 第1期   页码 112-119 doi: 10.1016/j.eng.2022.05.003

摘要：

声表面波（SAW）技术广泛应用于无线通信、传感器、微流体、光子与量子信息通信等领域。然而，受限于制造技术的发展，SAW器件的频率通常在几个吉赫（GHz）以内，严重限制了SAW器件在5G通信、高精度传感、光子与量子控制中的应用。针对上述关键问题，本文提出将极端纳米制造技术与LiNbO3/SiO2/SiC异质结构衬底相结合的策略，成功制备出波长为160 nm的超高频SAW器件，其高阶模态谐振频率高达约44 GHz，获得的机电耦合系数高达15.7%。基于LiNbO3/SiO2/SiC 异质结构衬底的超高频SAW呈现出多种模态，理论仿真分析确定了高阶声波模态的波模态。进行了超高频SAW微质量传感应用研究，其最高质量灵敏度高达33151.9 MHz⋅mm2⋅μg−1，比频率为978 MHz的传统SAW器件质量灵敏度高4000 倍，是传统石英微天平（QCM）器件质量灵敏度的1011倍。

关键词： 超高频     声表面波     高阶声波模态     高灵敏度    

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Iterative HOEO fusion strategy: a promising tool for enhancing bearing fault feature

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0725-z

摘要： As parameter independent yet simple techniques, the energy operator (EO) and its variants have received considerable attention in the field of bearing fault feature detection. However, the performances of these improved EO techniques are subjected to the limited number of EOs, and they cannot reflect the non-linearity of the machinery dynamic systems and affect the noise reduction. As a result, the fault-related transients strengthened by these improved EO techniques are still subject to contamination of strong noises. To address these issues, this paper presents a novel EO fusion strategy for enhancing the bearing fault feature nonlinearly and effectively. Specifically, the proposed strategy is conducted through the following three steps. First, a multi-dimensional information matrix (MDIM) is constructed by performing the higher order energy operator (HOEO) on the analysis signal iteratively. MDIM is regarded as the fusion source of the proposed strategy with the properties of improving the signal-to-interference ratio and suppressing the noise in the low-frequency region. Second, an enhanced manifold learning algorithm is performed on the normalized MDIM to extract the intrinsic manifolds correlated with the fault-related impulses. Third, the intrinsic manifolds are weighted to recover the fault-related transients. Simulation studies and experimental verifications confirm that the proposed strategy is more effective for enhancing the bearing fault feature than the existing methods, including HOEOs, the weighting HOEO fusion, the fast Kurtogram, and the empirical mode decomposition.

关键词： higher order energy operator     fault diagnosis     manifold learning     rolling element bearing     information fusion    

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Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 429-455 doi: 10.1007/s11709-018-0483-5

摘要： In this study, average-interpolating radial basis functions (RBFs) are successfully integrated with central high-resolution schemes to achieve a higher-order central method. This proposed method is used for simulation of generalized coupled thermoelasticity problems including shock (singular) waves in their solutions. The thermoelasticity problems include the LS (systems with one relaxation parameter) and GN (systems without energy dissipation) theories with constant and variable coefficients. In the central high resolution formulation, RBFs lead to a reconstruction with the optimum recovery with minimized roughness on each cell: this is essential for oscillation-free reconstructions. To guarantee monotonic reconstructions at cell-edges, the nonlinear scaling limiters are used. Such reconstructions, finally, lead to the total variation bounded (TVB) feature. As RBFs work satisfactory on non-uniform cells/grids, the proposed central scheme can handle adapted cells/grids. To have cost effective and accurate simulations, the multiresolution–based grid adaptation approach is then integrated with the RBF-based central scheme. Effects of condition numbers of RBFs, computational complexity and cost of the proposed scheme are studied. Finally, different 1-D coupled thermoelasticity benchmarks are presented. There, performance of the adaptive RBF-based formulation is compared with that of the adaptive Kurganov-Tadmor (KT) second-order central high-resolution scheme with the total variation diminishing (TVD) property.

关键词： central high resolution schemes     RBFs     higher order accuracy     generalized thermoelasticity     multiresolution-based adaptation    

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Control mode selection for modal control of long-span arch bridge

Zhengying LI, Zhengliang LI,

《结构与土木工程前沿（英文）》 2009年 第3卷 第4期   页码 401-406 doi: 10.1007/s11709-009-0052-z

摘要： For seismic control of arch bridge, a model reduction of long-span arch bridge was implemented based on modal analysis. As for the critical mode selection, an approach based on the maximum modal displacement was presented. This approach takes into consideration the effect of external seismic excitation and is more reasonable than only considering dynamic bridge characteristics based on a modal contribution ratio. The time domain and frequency domain analysis method were used to verify the simplified model of the Nimu arch bridge in Tibet as an example. The numerical results show that the method of maximal modal displacement better analyze long-span arch bridge when multisupport seismic excitation must be considered. The reduced-order system also is more in line with the performance of the original model.

关键词： selection     reduced-order     excitation     long-span     simplified    

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基于改进级联观测器的永磁同步电机智能分数阶积分滑模控制 Research Articles

肖玲斐1,2,马磊明3,黄欣浩1

《信息与电子工程前沿（英文）》 2022年 第23卷 第2期   页码 328-338 doi: 10.1631/FITEE.2000317

摘要： 提出一种基于改进级联观测器的智能分数阶积分滑模控制（FOISMC）策略。首先，针对永磁同步电机设计了分数阶积分滑模控制器，该控制器有良好跟踪性能，具有强鲁棒性，且能有效削弱抖振。所提策略结合了积分能消除稳态跟踪误差和分数阶微积分灵活的优点。其次，提出一种改进的级联观测器，能获得较小的转子信息观测误差。所设计级联观测器结合了自适应滑模观测器和扩展高增益观测器。此外，利用改进的变速灰狼优化算法优化控制器参数。最后，在综合考虑模型不确定性和外部干扰的情况下，通过仿真和实验验证了所提策略的有效性。

关键词： 永磁同步电机；分数阶积分滑模；优化算法；无传感器控制；观测器    

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Aerobic granular sludge formation based on substrate availability: Effects of flow pattern and fermentation

Quan Yuan, Hui Gong, Hao Xi, Kaijun Wang

《环境科学与工程前沿（英文）》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1226-0

摘要： Penetration depth and substrate characters affect AGS formation and performance. The relationship between substrate gradient and particle size affects AGS stability. The fermentation process is proposed as a pretreatment to improve AGS stability. The influences of flow patterns (mixed-flow and plug-flow) and fermentation pretreatment on aerobic granular sludge (AGS) formation with various substrate availability levels were investigated by running four identical laboratory-scale sequencing batch reactors (R1–R4), comparing two anaerobic feeding strategies and three kinds of substrates. R1 achieved faster granulation with a fast influent fill step followed by a modified anaerobic mixed-flow phase, but the AGS showed poorer stability with a cracked structure and a high suspended solids concentration in the effluent. The anaerobic plug-flow feeding mode (with influent fed slowly from the bottom) in R2 provided deeper penetration depth for the substance to reach the core of AGS and accordingly strengthen AGS stability. An acidogenic up-flow sludge bed reactor was introduced as a pretreatment to improve the AGS performance by enhancing glucose pre-fermentation (R4). AGS fed with mixed volatile fatty acids (VFA) after glucose fermentation showed similar performance compared with the reactor fed with acetate in the aspects of stability, structure, size distribution and nitrogen removal efficiency, and 74% similarity in the microbial community. For actual wastewater with low VFA concentrations, fermentation treatment was suggested as a promising pretreatment for stable AGS granulation and operation.

关键词： Anaerobic plug-flow feeding mode     Anaerobic mixed-flow mode     Fermentation pretreatment     Substrate gradient     Penetration depth    

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Surficial stability analysis of soil slope under seepage based on a novel failure mode

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 712-726 doi: 10.1007/s11709-021-0729-5

摘要： Normally, the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes. In this study, the limit stress state and discrimination equation of an infinite slope under saturated seepage flow were analyzed based on the Mohr-Coulomb strength criterion. Therefore, a novel failure mode involving three sliding zones (upper tension zone, middle shear sliding zone, and lower compression zone) was proposed. Accordingly, based on the limit equilibrium analysis, a semi-analytical framework considering the edge effect for the surficial stability of a soil slope under downslope seepage was established. Subsequently, the new failure mode was verified via a numerical finite element analysis based on the reduced strength theory with ABAQUS and some simplified methods using SLIDE software. The results obtained by the new failure mode agree well with those obtained by the numerical analysis and traditional simplified methods, and can be efficiently used to assess the surficial stability of soil slopes under rainwater seepage. Finally, an evaluation of the infinite slope method was performed using the semi-analytical method proposed in this study. The results show that the infinite slope tends to be conservative because the edge effect is neglected, particularly when the ratio of surficial slope length to depth is relatively small.

关键词： soil slope     seepage     surficial failure mode     stress state     edge effects    

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FUNCTIONAL GAIN OF FRUIT NETTED-CRACKING IN AN INTROGRESSION LINE OF TOMATO WITH HIGHER EXPRESSION OF

《农业科学与工程前沿（英文）》 2021年 第8卷 第2期

摘要：

Fruit cracking is a major disorder that affects the integrity of fruit and reduces the commercial value of tomato and other fleshy fruit. Here, we have found a novel fruit ‘netted-cracking’ (FNC) phenotype in tomato introgression line IL4-4 which is present in neither the donor parent (LA0716) nor the receptor parent (M82). An F2 population was generated by crossing IL4-4 with M82 to genetically characterize the FNC gene and this showed that a single dominant gene determined fruit netted-cracking. Further map-based cloning narrowed down the FNC locus to a 230 kb region on chromosome 4. Sequencing and annotation analysis show that FNC(Solyc04 g082540) was the most likely candidate gene. Functional characterization of FNC by overexpressing FNCAC and FNCIL4-4resulted in the fruit netted-cracking phenotype, suggesting that the FNC transcript level results in the functional gain of fruit netted-cracking. These findings were further confirmed by FNC ortholog in netted-cracking pepper and melon, indicating a common regulatory mechanism in different plant species. Furthermore, cytoplasm and nucleus-localized FNC indicates increased expression of genes involved in suberin, lignin, lipid transport and cell wall metabolism. These findings provide novel genetic insights into fruit netted-cracking and offer a way to promote molecular improvement toward cracking resistant cultivars.

 

关键词： fine mapping / fruit netted-cracking / introgression line / transcript level    

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High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 406-416 doi: 10.1007/s11709-018-0475-5

摘要： We approximate the fracture surface energy functional based on phase-field method with smooth local maximum entropy (LME) and second-order maximum entropy (SME) approximants. The higher-order continuity of the meshfree methods such as LME and SME approximants allows to directly solve the fourth-order phase-field equations without splitting the fourth-order differential equation into two second-order differential equations. We will first show that the crack surface functional can be captured more accurately in the fourth-order model with smooth approximants such as LME, SME and B-spline. Furthermore, smaller length scale parameter is needed for the fourth-order model to approximate the energy functional. We also study SME approximants and drive the formulations. The proposed meshfree fourth-order phase-field formulation show more stable results for SME compared to LME meshfree methods.

关键词： second-order maximum entropy     local maximum entropy     second- and fourth-order phase-field models     B-spline    

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An assemble-to-order production planning with the integration of order scheduling and mixed-model sequencing

Baoxi WANG, Zailin GUAN, Yarong CHEN, Xinyu SHAO, Ming JIN, Chaoyong ZHANG

《机械工程前沿（英文）》 2013年 第8卷 第2期   页码 137-145 doi: 10.1007/s11465-013-0251-0

摘要：

For assemble-to-order enterprises, both order scheduling and mixed-model sequencing need to be taken into consideration in the formulation of order-oriented assembly plan. First, determining production priority for the received orders, and then conducting assembly sequence to the mixed-model products in each order. Order scheduling is aimed to ensure order delivery with the optimization goal of minimal total overdue time, while product sequencing is aimed to minimize the makespan so as to meet the requirement on completion time of the order. In the end, the paper establishes a mixed integer programming model based on an industrial case, and makes programming calculation with Xpress-MP to accomplish an order-oriented assembly plan conforming to actual production.

关键词： mixed-model assembly line     assemble-to-order     order scheduling     sequencing    

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Split-order consolidation optimization for online supermarkets: Process analysis and optimization models

《工程管理前沿（英文）》   页码 499-516 doi: 10.1007/s42524-022-0221-5

摘要： The large-scale online supermarket is a newly emerging online retailing mode which brings great convenience to people. Online supermarkets are characterized by having large amounts of daily orders with potentially multiple items, diverse delivery times, and a high order-split rate. Multiple shipments for one order caused by order splitting result in high cost and disturbance and a large number of discarded consumable packages at online retailers and customers, causing severe damage to the environment. Accordingly, research on split-order consolidation fulfilment is critical for the advancement of the practice and theory in the context of highly complex online retailing. This paper first analyzes the characteristics and the challenges associated with the split-order consolidation problem that online supermarket is confronting and summarizes the new operational process of split-order consolidation fulfilment. Then, a time–space network optimization model is built, and its corresponding solution algorithm is presented to solve the questions of where and when to consolidate the split orders. Finally, the computation results of the numerical experiments are provided to verify the effectiveness of the algorithm, and a sensitivity analysis of the relevant parameters is performed. This work highlights the effect of order consolidation processes and fulfilment methods on the order fulfilment decision-making for online supermarkets. The purpose of this article is to help pave the way for more effective online supermarket management and order implementation.

关键词： online supermarkets     split-order consolidation     time–space network     genetic algorithm    

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Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption

Junxiong LIN , Lan WANG ,

《环境科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 320-324 doi: 10.1007/s11783-009-0030-7

摘要： The best-fit equations of linear and non-linear forms of the two widely used kinetic models, namely pseudo-first-order and pseudo-second-order equations, were compared in this study. The experimental kinetics of methylene blue adsorption on activated carbon was used for this research. Both the correlation coefficient () and the normalized standard deviation Δ(%) were employed as error analysis methods to determine the best-fitting equations. The results show that the non-linear forms of pseudo-first-order and pseudo-second-order models were more suitable than the linear forms for fitting the experimental data. The experimental kinetics may have been distorted by linearization of the linear kinetic equations, and thus, the non-linear forms of kinetic equations should be primarily used to obtain the adsorption parameters. In addition, the Δ(%) method for error analysis may be better to determine the best-fitting model in this case.

关键词： adsorption     pseudo-first order     pseudo-second order     kinetic model     linear method     non-linear method    

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Effects of delamination in drilling glass/polyester composite

Mehdi GANJIANI, Majid SAFARABADI, Nabi MEHRI-KHANSARI, Hossein ORUJI

《结构与土木工程前沿（英文）》 2021年 第15卷 第2期   页码 552-567 doi: 10.1007/s11709-021-0699-7

摘要： Considering failures during machinery processes such as drilling, a precautionary analysis involving delamination and the corresponding dissipated energy is required, especially for composite structures. In this context, because of the complexity of both the analysis procedure and experimental test setup, most studies prefer to represent mode I and III interlaminar crack propagation instead of that involving mode II. Therefore, in this study, the effect of mode delamination and corresponding interlaminar crack propagation was considered during the drilling process of multilayered glass/polyester composites using both numerical and experimental approaches. In the experimental procedure, the mechanical properties of the glass/polyester specimens were obtained according to ASTM D3039. In addition, the interlaminar mixed-mode (I/II) loadings were determined using an ARCAN test fixture so that the fracture toughness of glass/polyester could then be identified. The mode II critical strain energy release rate (CSERR) was then obtained using an experimental test performed using an ARCAN fixture and the virtual crack closure technique (VCCT). It was determined that the numerical approach was in accordance with the experiments, and more than 95% of crack propagation could be attributed to mode II compared to the two other modes.

关键词： delamination     VCCT     ARCAN specimen     drilling     mode II    

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标题 作者 时间 类型 操作

Higher-order mode effects on the seismic performance of tall piers

Zhongguo GUAN, Jianzhong LI, Yan XU, Hao LU

期刊论文

表征不同DNA高阶结构的单分子分析方法

刘泳麟, 边天元, 刘岩, 李治民, 裴羽丰, 宋杰

期刊论文

基于LiNbO3/SiO2/SiC异质结构实现44 GHz超高频声表面波谐振器

周剑, 张定红, 刘炀辉, 卓凤玲, 钱莉荣, 李红浪, 傅永庆, 段辉高

期刊论文

Iterative HOEO fusion strategy: a promising tool for enhancing bearing fault feature

期刊论文

Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI

期刊论文

Control mode selection for modal control of long-span arch bridge

Zhengying LI, Zhengliang LI,

期刊论文

基于改进级联观测器的永磁同步电机智能分数阶积分滑模控制

肖玲斐1,2,马磊明3,黄欣浩1

期刊论文

Aerobic granular sludge formation based on substrate availability: Effects of flow pattern and fermentation

Quan Yuan, Hui Gong, Hao Xi, Kaijun Wang

期刊论文

Surficial stability analysis of soil slope under seepage based on a novel failure mode

期刊论文

FUNCTIONAL GAIN OF FRUIT NETTED-CRACKING IN AN INTROGRESSION LINE OF TOMATO WITH HIGHER EXPRESSION OF

期刊论文

High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

期刊论文

An assemble-to-order production planning with the integration of order scheduling and mixed-model sequencing

Baoxi WANG, Zailin GUAN, Yarong CHEN, Xinyu SHAO, Ming JIN, Chaoyong ZHANG

期刊论文

Split-order consolidation optimization for online supermarkets: Process analysis and optimization models

期刊论文

Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption

Junxiong LIN , Lan WANG ,

期刊论文

Effects of delamination in drilling glass/polyester composite

Mehdi GANJIANI, Majid SAFARABADI, Nabi MEHRI-KHANSARI, Hossein ORUJI

期刊论文