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A combined control strategy using tuned liquid dampers to reduce displacement demands of base-isolated structures: a probabilistic approach

Parham SHOAEI, Houtan Tahmasebi OROMI

《结构与土木工程前沿（英文）》 2019年第13卷第4期页码 890-903 doi: 10.1007/s11709-019-0524-8

摘要： This paper investigates a hybrid structural control system using tuned liquid dampers (TLDs) and lead-rubber bearing (LRB) systems for mitigating earthquake-induced vibrations. Furthermore, a new approach for taking into account the uncertainties associated with the steel shear buildings is proposed. In the proposed approach, the probabilistic distributions of the stiffness and yield properties of stories of a set of reference steel moment frame structures are derived through Monte-Carlo sampling. The approach is applied to steel shear buildings isolated with LRB systems. The base isolation systems are designed for different target base displacements by minimizing a relative performance index using Genetic Algorithm. Thereafter, the base-isolated structures are equipped with TLDs and a combination of the base and TLD properties is sought by which the maximum reduction occurs in the base displacement without compromising the performance of the system. In addition, the effects of TLD properties on the performance of the system are studied through a parametric study. Based on the analyses results, the base displacement can be reduced 23% by average, however, the maximum reduction can go beyond 30%.

关键词： tuned liquid damper lead-rubber bearing system probabilistic framework steel shear building relative performance index Monte-Carlo sampling

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我国天然橡胶业面临的挑战和发展战略

黄宗道

《中国工程科学》 2001年第3卷第2期页码 28-32

摘要：

自1949年中华人民共和国建立以来，中国的天然橡胶获得了迅速的发展。到1998年橡胶种植面积达到60×10⁴hm²，是1949前的215倍；产量达到45×10⁴t，是以前的2 250倍。致使中国成为世界天然橡胶的主要产胶国之一，植胶面积为世界第四位，产量为第五位。

我国加人世界贸易组织后，低价的天然橡胶将很快进入我国市场，冲击我国的天然橡胶业，我们必须清醒地了解我们现在所处的地位和情况及时采取对策。文中提出了我国天然橡胶今后的发展战略。

关键词：天然橡胶 WTO 割胶制度

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Vibratory behaviors of Jeffcott system on cylindrical roller bearings

Hao WU, Jianwen WANG, Qi AN

《机械工程前沿（英文）》 2009年第4卷第3期页码 305-309 doi: 10.1007/s11465-009-0036-7

摘要： A Jeffcott rotor system of cylindrical roller bearings is studied in detail. Its critical speed is calculated by a new calculation method with roller bearing stiffness and damping. The influences of bearing parameters, such as the roller length, rotor mass, distance between the bearings and the kinematics viscosity of oil on the system critical speed are numerically studied, and the influences of an oil film and damping on the critical speed are also studied. Regular curves of the relationship between the geometric parameters and the system critical speed are obtained. The results show that with increasing roller length and radial load, the critical speed increases; and with increasing rotor mass and the distance between the bearings and the kinematics viscosity, the critical speed decreases. This means that an oil film will decrease the critical rotational speed of the rotor system.

关键词： roller bearing bearing-rotor system design value critical rotational speed

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New analysis model for rotor-bearing systems based on plate theory

Zhinan ZHANG, Mingdong ZHOU, Weimin DING, Huifang MA

《机械工程前沿（英文）》 2019年第14卷第4期页码 461-473 doi: 10.1007/s11465-019-0525-2

摘要： The purpose of this work is to develop a new analysis model for angular-contact, ball-bearing systems on the basis of plate theory instead of commonly known approaches that utilize spring elements. Axial and radial stiffness on an annular plate are developed based on plate, Timoshenko beam, and plasticity theories. The model is developed using theoretical and inductive methods and validated through a numerical simulation with the finite element method. The new analysis model is suitable for static and modal analyses of rotor-bearing systems. Numerical examples are presented to reveal the effectiveness and applicability of the proposed approach.

关键词： rotor-bearing system rolling element bearing plate theory finite element analysis

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中国ADS 铅基反应堆设计与研发进展 Review

吴宜灿

《工程（英文）》 2016年第2卷第1期页码 124-131 doi: 10.1016/J.ENG.2016.01.023

摘要：

2011年，在中国科学院战略性先导专项“未来先进核裂变能——加速器驱动次临界嬗变系统”等项目的支持下，针对加速器驱动次临界系统和第四代铅冷快堆的技术发展目标和试验要求，完成了具有临界和加速器驱动次临界双模式运行能力的10 MW中国铅基研究堆CLEAR-I的概念设计，建成了KYLIN系列铅铋回路试验平台，并在此基础上开展了反应堆冷却剂技术、关键组件、结构材料与燃料、反应堆运行与控制技术等铅铋反应堆关键技术的研发。为验证及测试铅基堆关键组件和综合操作技术，正在开展铅合金冷却非核反应堆CLEAR-S、铅基零功率核反应堆CLEAR-0和铅基虚拟反应堆CLEAR-V的建设。

关键词：加速器驱动次临界系统中国铅基反应堆铅铋共晶技术研发进展

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Latest research progress for LBE coolant reactor of China initiative accelerator driven system project

《能源前沿（英文）》 2021年第15卷第4期页码 810-831 doi: 10.1007/s11708-021-0760-1

摘要： China’s accelerator driven subcritical system (ADS) development has made significant progress during the past decade. With the successful construction and operation of the international prototype of ADS superconducting proton linac, the lead-based critical/subcritical zero-power facility VENUS-II and the comprehensive thermal-hydraulic and material test facilities for LBE (lead bismuth eutectic) coolant, China is playing a pivotal role in advanced steady-state operations toward the next step, the ADS project. The China initiative Accelerator Driven System (CiADS) is the next facility for China’s ADS program, aimed to bridge the gaps between the ADS experiment and the LBE cooled subcritical reactor. The total power of the CiADS will reach 10 MW. The CiADS engineering design was approved by Chinese government in 2018. Since then, the CiADS project has been fully transferred to the construction application stage. The subcritical reactor is an important part of the whole CiADS project. Currently, a pool-type LBE cooled fast reactor is chosen as the subcritical reactor of the CiADS. Physical and thermal experiments and software development for LBE coolant were conducted simultaneously to support the design and construction of the CiADS LBE-cooled subcritical reactor. Therefore, it is necessary to introduce the efforts made in China in the LBE-cooled fast reactor to provide certain supporting data and reference solutions for further design and development for ADS. Thus, the roadmap of China’s ADS, the development process of the CiADS, the important design of the current CiADS subcritical reactor, and the efforts to build the LBE-cooled fast reactor are presented.

关键词： LBE (lead bismuth eutectic) coolant reactor China initiative Accelerator Driven System (CiADS) project research progress

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Evaluation of the compatibility between rubber and asphalt based on molecular dynamics simulation

Fucheng GUO, Jiupeng ZHANG, Jianzhong PEI, Weisi MA, Zhuang HU, Yongsheng GUAN

《结构与土木工程前沿（英文）》 2020年第14卷第2期页码 435-445 doi: 10.1007/s11709-019-0603-x

摘要： Using of rubber asphalt can both promote the recycling of waste tires and improve the performance of asphalt pavement. However, the segregation of rubber asphalt caused by the poor storage stability always appears during its application. Storage stability of asphalt and rubber is related to the compatibility and also influenced by rubber content. In this study, molecular models of different rubbers and chemical fractions of asphalt were built to perform the molecular dynamics simulation. The solubility parameter and binding energy between rubber and asphalt were obtained to evaluate the compatibility between rubber and asphalt as well as the influence of rubber content on compatibility. Results show that all three kinds of rubber are commendably compatible with asphalt, where the compatibility between asphalt and cis-polybutadiene rubber (BR) is the best, followed by styrene-butadiene rubber (SBR), and natural rubber (NR) is the worst. The optimum rubber contents for BR asphalt, SBR asphalt, and NR asphalt were determined as 15%, 15%, and 20%, respectively. In addition, the upper limits of rubber contents were found as between 25% and 30%, between 20% and 25%, and between 25% and 30%, respectively.

关键词： rubber asphalt compatibility rubber content molecular dynamics simulation

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ISA-YMG粗铅冶炼新工艺

王吉坤,周廷熙,冯桂林

《中国工程科学》 2004年第6卷第4期页码 61-66

摘要：

评述了铅提取技术的历史及现代铅提取技术的特点；针对我国目前粗铅冶炼现状，结合对高铅渣冶炼的多年研究，提出一种高效、节能、清洁的ISA-YMG粗铅冶炼新工艺，并提供了YMG还原熔炼工业试验结果。

关键词：铅ISA氧化熔炼高铅渣铅YMG还原熔炼粗铅冶炼新工艺

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Modeling limit force capacities of high force to volume lead extrusion dampers

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 609-622 doi: 10.1007/s11709-021-0724-x

摘要： Lead extrusion dampers are supplemental energy-dissipation devices that are used to mitigate seismic structural damage. Small volumetric sizes and high force capacities define high-force-to-volume (HF2V) devices, which can absorb significant response energy without sacrificial damage. However, the design of such devices for specific force capacities has proven difficult based on the complexities of their internal reaction mechanisms, leading to the adoption of empirical approaches. This study developed upper- and lower-bound force capacity estimates from analytical mechanics based on direct and indirect metal extrusion for guiding design. The derived equations are strictly functions of HF2V device geometric parameters, lead material properties, and extrusion mechanics. The upper-bound estimates from direct and indirect extrusion are denoted as (F_UB,1, F_UB,2) and (F_UB,3, F_UB,4), respectively, and the lower-bound estimates are denoted as (F_LB, F_LB,1) based on the combination of extrusion and friction forces. The proposed models were validated by comparing the predicted bounds to experimental force capacity data from 15 experimental HF2V device tests. The experimental device forces all lie above the lower-bound estimates (F_LB, F_LB,1) and below the upper-bound estimates (F_UB,1, F_UB,2, F_UB,4). Overall, the (F_LB, F_UB,2) pair provides wider bounds and the (F_LB,1, F_UB,4/F_UB,1) pair provides narrower bounds. The (F_LB,1, F_UB,1) pair has a mean lower-bound gap of 36%, meaning the lower bound was 74% of the actual device force on average. The mean upper-bound gap was 33%. The bulge area and cylinder diameter of HF2V devices are key parameters affecting device forces. These relatively tight bounds provide useful mechanics-based predictive design guides for ensuring that device forces are within the targeted design range after manufacturing.

关键词： extrusion lead dampers upper and lower bound analytical modelling limit force

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Removal of lead from aqueous solution by hydroxyapatite/manganese dioxide composite

Lijing DONG,Zhiliang ZHU,Yanling QIU,Jianfu ZHAO

《环境科学与工程前沿（英文）》 2016年第10卷第1期页码 28-36 doi: 10.1007/s11783-014-0722-5

摘要： A novel composite adsorbent, hydroxyapatite/manganese dioxide (HAp/MnO ), has been developed for the purpose of removing lead ions from aqueous solutions. The combination of HAp with MnO is meant to increase its adsorption capacity. Various factors that may affect the adsorption efficiency, including solution pH, coexistent substances such as humic acid and competing cations (Ca , Mg ), initial solute concentration, and the duration of the reaction, have been investigated. Using this composite adsorbent, solution pH and coexistent calcium or magnesium cations were found to have no significant influence on the removal of lead ions under the experimental conditions. The adsorption equilibrium was described well by the Langmuir isotherm model, and the calculated maximum adsorption capacity was 769 mg·g . The sorption processes obeyed the pseudo-second-order kinetics model. The experimental results indicate that HAp/MnO composite may be an effective adsorbent for the removal of lead ions from aqueous solutions.

关键词： lead composite materials manganese dioxide hydroxyapatite adsorption

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Analysis of stability and nonlinear response of rotor system with elliptical sliding bearing supports

LU Yanjun, LIU Heng, YU Lie, LI Qi, JIANG Ming, ZHANG Zhiyu

《机械工程前沿（英文）》 2007年第2卷第1期页码 37-45 doi: 10.1007/s11465-007-0006-x

摘要： Based on the variational constraint approach, the variational form of Reynolds equation in hydrodynamic lubrication is revised continuously to satisfy certain constraints in the cavitation zone of oil film field. According to the physical characteristic of oil film, an eight-node isoparametric finite element method is used to convert the revised variational form of Reynolds equation to a discrete form of finite dimensional algebraic variational equation. By this approach, a perturbance equation can be obtained directly on the finite element equation. Consequently, nonlinear oil film forces and their Jacobian matrices are calculated simultaneously, and compatible accuracy is obtained without increasing the computational costs. A method, which is a combination of predictor corrector mechanism and Newton Raphson method, is presented to calculate equilibrium position and critical speed corresponding to Hopf bifurcation point of bearing-rotor system, as by-product dynamic coefficients of bearing are obtained. The timescale, i.e., the unknown whirling period of Hopf bifurcation solution of bearing-rotor system is drawn into the iterative process using Poincar?Newton Floquet method. The stability of the Hopf bifurcation solution can be detected when estimating Hopf bifurcation solution and its periods. The nonlinear unbalanced periodic responses of the system are obtained by using PNF method and path-following technique. The local stability and bifurcation behaviors of periodic motions are analyzed by Floquet theory. Chaotic motions are analyzed by Lyapunov exponents. The numerical results revealed the rich and complex nonlinear behavior of the system, such as periodic, quasiperiodic, jumped solution, chaos, and coexistence of multisolution, and so on.

关键词： computational corrector mechanism predictor corrector multisolution quasiperiodic

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Parametric study on seismic performance of self-centering reinforced concrete column with bottom-placed rubber

《结构与土木工程前沿（英文）》页码 1145-1162 doi: 10.1007/s11709-023-0945-2

摘要： To realize seismic-resilient reinforced concrete (RC) moment-resisting frame structures, a novel self-centering RC column with a rubber layer placed at the bottom (SRRC column) is proposed herein. For the column, the longitudinal reinforcement dissipates seismic energy, the rubber layer allows the rocking of the column, and the unbonded prestressed tendon enables self-centering capacity. A refined finite element model of the SRRC column is developed, the effectiveness of which is validated based on experimental results. Results show that the SRRC column exhibits stable energy dissipation capacity and no strength degradation; additionally, it can significantly reduce permanent residual deformation and mitigate damage to concrete. Extensive parametric studies pertaining to SRRC columns have been conducted to investigate the critical factors affecting their seismic performance.

关键词： seismic resilience self-centering rubber layer flag-shaped hysteresis loop parametric study

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Performance investigation on ultrasonic levitation axial bearing for flywheel storage system

Taijiang PENG, Zhigang YANG, Junwu KAN, Fengjun TIAN, Xiaohong CHE,

《机械工程前沿（英文）》 2009年第4卷第4期页码 415-419 doi: 10.1007/s11465-009-0051-8

摘要： The bearing is an important basic mechanical part for supporting a shaft. A flywheel storage system needs a type of noncontact support bearing to enhance the speed of the axis. A magnetic suspension bearing is one type of noncontact bearing but has electromagnetic interference to other electric equipment. Based on the performance research of ultrasonic levitation technology, a novel noncontact bearing called ultrasonic bearing is presented, which consists of a special piezoelectric vibrator supporting the load. Experiments are carried out to study the relationships among the amplitude of the vibrator and levitation clearance, the highest speed of the axis, and the frictional moment of the axis. Results show that the levitation clearance becomes smaller gradually with increasing load; the rotation speed is up to 8946 r/min, and the friction moment is only 2.095×10 N·m when the levitation clearance is 8.53 μm. The ultrasonic bearing is highlighted because of its simple structure, strong levitation ability, and low friction moment.

关键词： ultrasonic bearing flywheel storage system piezoelectric ceramic piezoelectric vibrator

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Using thermodynamic parameters to study self-healing and interface properties of crumb rubber modified

Dongliang HU, Jianzhong PEI, Rui LI, Jiupeng ZHANG, Yanshun JIA, Zepeng FAN

《结构与土木工程前沿（英文）》 2020年第14卷第1期页码 109-122 doi: 10.1007/s11709-019-0579-6

摘要： The thermodynamic property of asphalt binder is changed by the addition of crumb rubber, which in turn influences the self-healing property as well as the cohesion and adhesion within the asphalt-aggregate system. This study investigated the self-healing and interface properties of crumb rubber modified asphalt (CRMA) using thermodynamic parameters based on the molecular simulation approach. The molecular models of CRMA were built with representative structures of the virgin asphalt and the crumb rubber. The aggregate was represented by SiO and Al O crystals. The self-healing capability was evaluated with the thermodynamic parameter wetting time, work of cohesion and diffusivity. The interface properties were evaluated by characterizing the adhesion capability, the debonding potential and the moisture susceptibility of the asphalt-aggregate interface. The self-healing capability of CRMA is found to decrease as the rubber content increases. The asphalt-Al O interface with higher rubber content has stronger adhesion and moisture stability. But the influence of crumb rubber on the interfacial properties of asphalt-SiO interface has no statistical significance. Comparing with the interfacial properties of the asphalt-SiO interface, the asphalt-Al O interface is found to have a stronger adhesion but a worse moisture susceptibility for its enormous thermodynamic potential for water to displace the asphalt binder.

关键词： crumb rubber modified asphalt surface free energy self-healing interface properties molecular dynamics simulation

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溶液聚合合成橡胶节能技术和节能型橡胶的开发

曹湘洪,张爱民

《中国工程科学》 2001年第3卷第7期页码 59-63

摘要：

总结了燕山石化溶液聚合合成橡胶节能技术和节能型橡胶的开发情况。通过改进催化体系，提高反应速度，提高反应器的生产能力，并在聚合反应器中采用带刮刀的搅拌器，同时改进聚合、凝聚、溶剂回收的部分工艺及设备，燕山石化顺丁橡胶的能耗不断下降，达到世界先进水平。溶液聚合合成橡胶凝聚过程热泵技术的工业化，使生产每吨胶可节约1MPa的低压蒸汽0.72t。橡胶溶液直接脱挥，聚丁二烯橡胶气相聚合工艺技术开发,溶聚丁苯橡胶（SSBR）、中乙烯基聚丁二烯橡胶、苯乙烯-异戊二烯-丁二烯橡胶（SIBR）、苯乙烯-丁二烯热塑性弹性体（SBS）等新型节能型合成橡胶的技术开发也在进行中，其中SSBR、SBS技术已经工业化。

关键词：溶液聚合合成橡胶节能节能型橡胶