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A novel approach to preparing ultra-lightweight ceramsite with a large amount of fly ash

Sen Liu, Congren Yang, Wei Liu, Longsheng Yi, Wenqing Qin

《环境科学与工程前沿（英文）》 2020年 第14卷 第4期 doi: 10.1007/s11783-020-1241-1

摘要： •Ultra-lightweight ceramsite is prepared with 80% fly ash. •SiO2, Al2O3, and flux contents significantly influence the performance of ceramsite. •The expansion of ceramsite is caused by the formation of a dense glaze and gas. •The bulk density of ultra-lightweight ceramsite is only 340 kg/m3. The disposal of fly ash has become a serious problem in China due to its rapid increase in volume in recent years. The most common method of fly ash disposal is solidification-stabilization-landfill, and the most common reuse is low-value-added building materials. A novel processing method for preparing ultra-lightweight ceramsite with fly ash was developed. The results show that the optimal parameters for preparation of ultra-lightweight ceramsite are as follows: mass ratio of fly ash:kaolin:diatomite= 80:15:5, preheating temperature of 800°C, preheating time of 5 min, sintering temperature of 1220°C, and sintering time of 10 min. The expansion agent is perlite, at 10 wt.% addition. Finally, a ceramsite with bulk density of 340 kg/m3, particle density of 0.68 g/cm3, and cylinder compressive strength of 1.02 MPa was obtained. Because of its low density and high porosity, ultra-lightweight ceramsite has excellent thermal insulation performance, and its strength is generally low, so it is usually used in the production of thermal insulation concrete and its products. The formation of a liquid-phase component on the surface, and generation of a gas phase inside ceramsite during the sintering process, make it possible to control the production of the suitable liquid phase and gas in this system, resulting in an optimization of the expansion behavior and microstructure of ceramsite. These characteristics show the feasibility of industrial applications of fly ash for the production of ultra-lightweight ceramsite, which could not only produce economic benefits, but also conserve land resources and protect the environment.

关键词： Fly ash     Ultra-lightweight ceramsite     Expansion mechanism     Sintering process    

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BORON：面向普适计算的超轻量低功耗加密设计 Article

Gaurav BANSOD,Narayan PISHAROTY,Abhijit PATIL

《信息与电子工程前沿（英文）》 2017年 第18卷 第3期   页码 317-331 doi: 10.1631/FITEE.1500415

摘要： 我们提出一种超轻量，紧凑且低功耗的分组密码：BORON。BORON是一种替换、互换网络，运行于64位纯文本上，支持128位或80位密钥长度。针对128位密钥和80位密钥，BORON的紧凑结构分别需要1939个和1626个等效门（gate equivalents, GE）。BORON包含移位、循环移位和异或操作。其的独特设计有助于在较少的回合内产生大量的活动S-box，从而挫败针对加密的线性或差分攻击。BORON在硬、软件平台上均具有较好的性能。与轻量加密LED相比，BORON具有更低的功耗水平；与现有SP网络加密相比，BORON具有更高的吞吐量。本文还展示了BORON的安全性分析及其作为超轻量紧凑型加密的性能。BORON可适用于将引脚面积和功率耗散作为关键参数的应用。

关键词： 轻量密码；SP网络；分组密码；物联网；加密；嵌入式安全    

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Flexural and longitudinal shear performance of precast lightweight steel–ultra-high performance concrete

《结构与土木工程前沿（英文）》 2023年 第17卷 第5期   页码 704-721 doi: 10.1007/s11709-023-0941-6

摘要： In this study, the flexural and longitudinal shear performances of two types of precast lightweight steel–ultra-high performance concrete (UHPC) composite beams are investigated, where a cluster UHPC slab (CUS) and a normal UHPC slab (NUS) are connected to a steel beam using headed studs through discontinuous shear pockets and full-length shear pockets, respectively. Results show that the longitudinal shear force of the CUS is greater than that of the NUS, whereas the interfacial slip of the former is smaller. Owing to its better integrity, the CUS exhibits greater flexural stiffness and a higher ultimate bearing capacity than the NUS. To further optimize the design parameters of the CUS, a parametric study is conducted to investigate their effects on the flexural and longitudinal shear performances. The square shear pocket is shown to be more applicable for the CUS, as the optimal spacing between two shear pockets is 650 mm. Moreover, a design method for transverse reinforcement is proposed; the transverse reinforcement is used to withstand the splitting force caused by studs in the shear pocket and prevent the UHPC slab from cracking. According to calculation results, the transverse reinforcement can be canceled when the compressive strength of UHPC is 150 MPa and the volume fraction of steel fiber exceeds 2.0%.

关键词： precast steel–UHPC composite beam     flexural performance     longitudinal shear performance     parametric study     transverse reinforcement ratio    

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Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable

Thomas ELLINGHAM, Hrishikesh KHARBAS, Mihai MANITIU, Guenter SCHOLZ, Lih-Sheng TURNG

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 96-106 doi: 10.1007/s11465-018-0498-6

摘要：

A three-stage molding process involving microcellular injection molding with core retraction and an “out-of-mold” expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm3 (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.

关键词： thermoplastic polyurethane     microcellular injection molding     cavity expansion     compressive strength     hysteresis loss ratio    

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A lightweight authentication scheme with user untraceability

Kuo-Hui YEH

《信息与电子工程前沿（英文）》 2015年 第16卷 第4期   页码 259-271 doi: 10.1631/FITEE.1400232

摘要： With the rapid growth of electronic commerce and associated demands on variants of Internet based applications, application systems providing network resources and business services are in high demand around the world. To guarantee robust security and computational efficiency for service retrieval, a variety of authentication schemes have been proposed. However, most of these schemes have been found to be lacking when subject to a formal security analysis. Recently, Chang (2014) introduced a formally provable secure authentication protocol with the property of user-untraceability. Unfortunately, based on our analysis, the proposed scheme fails to provide the property of user-untraceability as claimed, and is insecure against user impersonation attack, server counterfeit attack, and man-in-the-middle attack. In this paper, we demonstrate the details of these malicious attacks. A security enhanced authentication scheme is proposed to eliminate all identified weaknesses.

关键词： Authentication     Privacy     Security     Smart card     Untraceability    

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Influence of construction-induced damage on the degradation of freeze–thawed lightweight cellular concrete

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 781-792 doi: 10.1007/s11709-021-0733-9

摘要： During the construction of lightweight cellular concrete (LCC), material damage frequently occurs, causing the degradation and deterioration of the mechanical performance, durability, and subgrade quality of LCC. The construction-induced damage can be more significant than those from the service environment of LCC, such as freeze–thaw (F–T) action in cold regions. However, the effect of construction-induced damage on LCC during F–T cycles is often ignored and the deterioration mechanisms are not yet clarified. In this study, we investigated the factors causing damage during construction using a sample preparation method established to simulate the damage in the laboratory setting. We conducted F–T cycle tests and microstructural characterization to study the effect of microstructural damage on the overall strength of LCC with different water contents under F–T actions. We established the relationship between the pore-area ratio and F–T cycle times, pore-area ratio, and strength, as well as the F–T cycle times and strength under different damage forms. The damage evolution is provided with the rationality of the damage equation, verified by comparing the measured and predicted damage variables. This study would serve as a guide for the construction and performance of LCC in cold regions.

关键词： lightweight cellular concrete     construction-induced damage     freeze-thaw action     microstructure     degradation mechanism    

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Lightweight design of an electric bus body structure with analytical target cascading

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0718-y

摘要： Lightweight designs of new-energy vehicles can reduce energy consumption, thereby improving driving mileage. In this study, a lightweight design of a newly developed multi-material electric bus body structure is examined in combination with analytical target cascading (ATC). By proposing an ATC-based two-level optimization strategy, the original lightweight design problem is decomposed into the system level and three subsystem levels. The system-level optimization model is related to mass minimization with all the structural modal frequency constraints, while each subsystem-level optimization model is related to the sub-structural performance objective with sub-structure mass constraints. To enhance the interaction between two-level systems, each subsystem-level objective is reformulated as a penalty-based function coordinated with the system-level objective. To guarantee the accuracy of the model-based analysis, a finite element model is validated through experimental modal test. A sequential quadratic programming algorithm is used to address the defined optimization problem for effective convergence. Compared with the initial design, the total mass is reduced by 49 kg, and the torsional stiffness is increased by 17.5%. In addition, the obtained design is also validated through strength analysis.

关键词： electric vehicle     body in white (BIW)     lightweight     analytical target cascading (ATC)    

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Landing control method of a lightweight four-legged landing and walking robot

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0707-1

摘要： The prober with an immovable lander and a movable rover is commonly used to explore the Moon’s surface. The rover can complete the detection on relatively flat terrain of the lunar surface well, but its detection efficiency on deep craters and mountains is relatively low due to the difficulties of reaching such places. A lightweight four-legged landing and walking robot called “FLLWR” is designed in this study. It can take off and land repeatedly between any two sites wherever on deep craters, mountains or other challenging landforms that are difficult to reach by direct ground movement. The robot integrates the functions of a lander and a rover, including folding, deploying, repetitive landing, and walking. A landing control method via compliance control is proposed to solve the critical problem of impact energy dissipation to realize buffer landing. Repetitive landing experiments on a five-degree-of-freedom lunar gravity testing platform are performed. Under the landing conditions with a vertical velocity of 2.1 m/s and a loading weight of 140 kg, the torque safety margin is 10.3% and 16.7%, and the height safety margin is 36.4% and 50.1% for the cases with or without an additional horizontal disturbance velocity of 0.4 m/s, respectively. The study provides a novel insight into the next-generation lunar exploration equipment.

关键词： landing and walking robot     lunar exploration     buffer landing     compliance control    

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Review on the progress of ultra-precision machining technologies

Julong YUAN, Binghai LYU, Wei HANG, Qianfa DENG

《机械工程前沿（英文）》 2017年 第12卷 第2期   页码 158-180 doi: 10.1007/s11465-017-0455-9

摘要：

Ultra-precision machining technologies are the essential methods, to obtain the highest form accuracy and surface quality. As more research findings are published, such technologies now involve complicated systems engineering and been widely used in the production of components in various aerospace, national defense, optics, mechanics, electronics, and other high-tech applications. The conception, applications and history of ultra-precision machining are introduced in this article, and the developments of ultra-precision machining technologies, especially ultra-precision grinding, ultra-precision cutting and polishing are also reviewed. The current state and problems of this field in China are analyzed. Finally, the development trends of this field and the coping strategies employed in China to keep up with the trends are discussed.

关键词： ultra-precision grinding     ultra-precision cutting     ultra-precision polishing     research status in China     development tendency    

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Quality evaluation of lightweight cellular concrete by an ultrasound-based method

Xin LIU; Dongning SUN; Jinhe LIAO; Zhiwei SHAO; Yunqiang SHI; Siqing ZHANG; Yunlong YAO; Baoning HONG

《结构与土木工程前沿（英文）》 2022年 第16卷 第9期   页码 1170-1182 doi: 10.1007/s11709-022-0874-5

摘要： The accuracy of subgrade quality evaluation is important for road safety assessment. Since there is little research work devoted to testing lightweight cellular concrete (LCC) by an ultrasound-based method, the quantitative relation between ultrasonic testing results and the quality of LCC subgrade is not well understood. In this paper, the quality of LCC subgrade was evaluated with respect to compressive strength and crack discrimination. The relation between ultrasonic testing results and LCC quality was explored through indoor tests. Based on the quantitative relation between ultrasonic pulse velocity and compressive strength of LCC, a fitting formula was established. Moreover, after the LCC became cracked, the ultrasonic pulse velocity and ultrasonic pulse amplitude decreased. After determining the lower limiting values of the ultrasonic pulse velocity and ultrasonic pulse amplitude through the statistical data, it could be calculated whether there were cracks in LCC subgrade. The ultrasonic testing results showed that the compressive strength of the LCC subgrade was suitable for purpose and there was no crack in the subgrade. Then core samples were taken from the subgrade. Comparisons between ultrasonic testing results of subgrade and test results of core samples demonstrated a good agreement.

关键词： lightweight cellular concrete     subgrade     ultrasound testing     quality evaluation     crack discrimination    

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Gas marbles: ultra-long-lasting and ultra-robust bubbles formed by particle stabilization

《化学科学与工程前沿（英文）》   页码 1681-1687 doi: 10.1007/s11705-022-2180-0

摘要： Bubbles and foams are ubiquitous in daily life and industrial processes. Studying their dynamic behaviors is of key importance for foam manufacturing processes in food packaging, cosmetics and pharmaceuticals. Bare bubbles are inherently fragile and transient; enhancing their robustness and shelf lives is an ongoing challenge. Their rupture can be attributed to liquid evaporation, thin film drainage and the nuclei of environmental dust. Inspired by particle-stabilized interfaces in Pickering emulsions, armored bubbles and liquid marble, bubbles are protected by an enclosed particle-entrapping liquid thin film, and the resultant soft object is termed gas marble. The gas marble exhibits mechanical strength orders of magnitude higher than that of soap bubbles when subjected to overpressure and underpressure, owing to the compact particle monolayer straddling the surface liquid film. By using a water-absorbent glycerol solution, the resulting gas marble can persist for 465 d in normal atmospheric settings. This particle-stabilizing approach not only has practical implications for foam manufacturing processes but also can inspire the new design and fabrication of functional biomaterials and biomedicines.

关键词： bubble     particles     interfaces     armored bubble     liquid marble     gas marble     Pickering emulsion    

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Properties of cement grout modified with ultra-fine slag

Sowmini GOPINATHAN, K B ANAND

《结构与土木工程前沿（英文）》 2018年 第12卷 第1期   页码 58-66 doi: 10.1007/s11709-017-0383-0

摘要： The purpose of the study is to obtain a cement grout with improved performance. The grout mixes of the present study contain cement, ultra-fine slag (UFS), super plasticizer and water. Properties like flowability, bleeding, compressive strength and shrinkage of cement grouts have been studied. Rheological parameters were also studied in order to explain the grout workability. The results show that, cement replacement with slag in grouts could reduce bleeding substantially without affecting the workability of the mixes. Introduction of slag enhanced the compressive strength and reduced shrinkage reasonably. Ultra-fine slag can be used as a supplementary cementitious material in cementitious grouts in order to improve the grout behavior.

关键词： cement grout     ultra-fine slag     flowability     bleeding     viscosity    

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Acoustic analysis of lightweight auto-body based on finite element method and boundary element method

LIANG Xinhua, ZHU Ping, LIN Zhongqin, ZHANG Yan

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 99-103 doi: 10.1007/s11465-007-0017-7

摘要： A lightweight automotive prototype using alternative materials and gauge thickness is studied by a numerical method. The noise, vibration, and harshness (NVH) performance is the main target of this study. In the range of 1 150 Hz, the frequency response function (FRF) of the body structure is calculated by a finite element method (FEM) to get the dynamic behavior of the auto-body structure. The pressure response of the interior acoustic domain is solved by a boundary element method (BEM). To find the most contributing panel to the inner sound pressure, the panel acoustic contribution analysis (PACA) is performed. Finally, the most contributing panel is located and the resulting structural optimization is found to be more efficient.

关键词： harshness     automotive prototype     structural optimization     vibration     efficient    

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Properties and effect of forming sewage sludge into lightweight ceramics

Min YUE, Qinyan YUE, Yuanfeng QI, Baoyu GAO, Hui YU

《环境科学与工程前沿（英文）》 2012年 第6卷 第1期   页码 117-124 doi: 10.1007/s11783-010-0220-3

摘要： In this work we investigated the chemical, thermal and toxic properties of dried sewage sludge (DSS), the preparation and properties of lightweight sludge ceramic (LSC) and the mechanisms of action of the organic and inorganic foaming agents (OFAs and IFAs). The chemical components and thermal properties of the raw materials were studied by Energy Dispersive X-ray Detection (EDX) and Thermogravimetric Analysis and Differential Scanning Calorimetry (DSC/TGA). The mineral phases of the raw materials and the formed ceramics were determined by X-ray Diffraction (XRD). The leaching characteristics of heavy metals were investigated with Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Different ratios of DSS and clay were mixed and pressed into raw pellets. After drying and preheating treatment, the raw pellets were sintered at 1150°C for 10 min. The physical properties of LSC (50 wt% DSS added) were tested. The results showed that when the addition of DSS was above 50 wt%, LSC began to shrink, and a maximum density occurred. The environmental safety of LSC was satisfactory. XRD showed that some new mineral phases formed in the LSC. Observation of the microstructure by Scanning Electron Microscope (SEM) indicated that the body of LSC was porous.

关键词： sludge     foaming agents     ceramics     preheating process    

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一种具有大工作空间的轻量级力反馈手套 Article

郑宇铠, 王党校, 王子琦, 张昱, 张玉茹, 徐卫良

《工程（英文）》 2018年 第4卷 第6期   页码 869-880 doi: 10.1016/j.eng.2018.10.003

摘要：

在虚拟现实场景中，佩戴力反馈手套是一种有效的增强穿戴者与虚拟物体交互沉浸感的方法。这种手套的设计难点在于需要提供足够大的手指运动工作空间，在模拟自由空间和约束空间交互时提供所需的力反馈感觉，以及确保一个轻量级的结构。本文提出了一种将气动驱动器安装在使用者手背侧的力反馈手套。该手套采用了一种凸轮连杆组合机构，利用带有弯曲滑槽和三个运动副的连杆将阻力从气缸活塞杆传递到指尖。为了得到穿戴者指尖反馈力的一个较大的法向分量，通过分析带有三个运动副的连杆上的力平衡，计算出了滑槽的轮廓。本文研制了质量为245 g 的五指力反馈手套样机，建立了可穿戴的力测量系统，对自由空间和约束空间的力反馈性能进行了定量评价。实验结果表明，该手套在自由空间模拟中平均阻力小于0.1 N，在约束空间模拟中指尖力最大为4 N。实验进一步证实，这种手套能够保证手指的自由移动以及模拟典型的抓取操作手势。

关键词： 力反馈手套     轻量级     大工作空间     气压驱动     虚拟现实    

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标题 作者 时间 类型 操作

A novel approach to preparing ultra-lightweight ceramsite with a large amount of fly ash

Sen Liu, Congren Yang, Wei Liu, Longsheng Yi, Wenqing Qin

期刊论文

BORON：面向普适计算的超轻量低功耗加密设计

Gaurav BANSOD,Narayan PISHAROTY,Abhijit PATIL

期刊论文

Flexural and longitudinal shear performance of precast lightweight steel–ultra-high performance concrete

期刊论文

Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable

Thomas ELLINGHAM, Hrishikesh KHARBAS, Mihai MANITIU, Guenter SCHOLZ, Lih-Sheng TURNG

期刊论文

A lightweight authentication scheme with user untraceability

Kuo-Hui YEH

期刊论文

Influence of construction-induced damage on the degradation of freeze–thawed lightweight cellular concrete

期刊论文

Lightweight design of an electric bus body structure with analytical target cascading

期刊论文

Landing control method of a lightweight four-legged landing and walking robot

期刊论文

Review on the progress of ultra-precision machining technologies

Julong YUAN, Binghai LYU, Wei HANG, Qianfa DENG

期刊论文

Quality evaluation of lightweight cellular concrete by an ultrasound-based method

Xin LIU; Dongning SUN; Jinhe LIAO; Zhiwei SHAO; Yunqiang SHI; Siqing ZHANG; Yunlong YAO; Baoning HONG

期刊论文

Gas marbles: ultra-long-lasting and ultra-robust bubbles formed by particle stabilization

期刊论文

Properties of cement grout modified with ultra-fine slag

Sowmini GOPINATHAN, K B ANAND

期刊论文

Acoustic analysis of lightweight auto-body based on finite element method and boundary element method

LIANG Xinhua, ZHU Ping, LIN Zhongqin, ZHANG Yan

期刊论文

Properties and effect of forming sewage sludge into lightweight ceramics

Min YUE, Qinyan YUE, Yuanfeng QI, Baoyu GAO, Hui YU

期刊论文

一种具有大工作空间的轻量级力反馈手套

郑宇铠, 王党校, 王子琦, 张昱, 张玉茹, 徐卫良

期刊论文