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In situ synthesis of FeS/Carbon fibers for the effective removal of Cr(VI) in aqueous solution

Rongrong Zhang, Daohao Li, Jin Sun, Yuqian Cui, Yuanyuan Sun

《环境科学与工程前沿（英文）》 2020年 第14卷 第4期 doi: 10.1007/s11783-020-1247-8

摘要： Abstract • FeS/carbon fibers were in situ synthesized with Fe-carrageenan hydrogel fiber. • The double helix structure of carrageenan is used to load and disperse Fe. • Pyrolyzing sulfate groups enriched carrageenan-Fe could easily generate FeS. • The adsorption mechanisms include reduction and complexation reaction. Iron sulfide (FeS) nanoparticles (termed FSNs) have attracted much attention for the removal of pollutants due to their high efficiency and low cost, and because they are environmentally friendly. However, issues of agglomeration, transformation, and the loss of active components limit their application. Therefore, this study investigates in situ synthesized FeS/carbon fibers with an Fe-carrageenan biomass as a precursor and nontoxic sulfur source to ascertain the removal efficiency of the fibers. The enrichment of sulfate groups as well as the double-helix structure in ι-carrageenan-Fe could effectively avoid the aggregation and loss of FSNs in practical applications. The obtained FeS/carbon fibers were used to control a Cr(VI) polluted solution, and exhibited a relatively high removal capacity (81.62 mg/g). The main mechanisms included the reduction of FeS, electrostatic adsorption of carbon fibers, and Cr(III)-Fe(III) complexation reaction. The pseudo-second-order kinetic model and Langmuir adsorption model both provided a good fit of the reaction process; hence, the removal process was mainly controlled by chemical adsorption, specifically monolayer adsorption on a uniform surface. Furthermore, co-existing anions, column, and regeneration experiments indicated that the FeS/carbon fibers are a promising remediation material for practical application.

关键词： Carrageenan     FeS     Double-helix structure     Hexavalent chromium    

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NiCo2O4@quinone-rich N–C core–shell nanowires as composite electrode for electric double layer capacitor

《化学科学与工程前沿（英文）》 2023年 第17卷 第4期   页码 373-386 doi: 10.1007/s11705-022-2223-6

摘要： The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability. Considering the close connection between their performance and the amount of carbon material loaded on the electrodes, in this work, NiCo2O4 nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction. Then, the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo2O4 nanowires, and the obtained composite was used as electrode for electric double layer capacitor. The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF∙cm–2 at the current density of 1 mA∙cm–2. The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW∙h∙cm–3 at a power density of 180 mW∙cm–3. The assembled symmetric capacitor exhibited a capacitance retention of 88.96% after 10000 charge/discharge cycles at the current density of 20 mA∙cm–2. These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.

关键词： carbon cloth     NiCo2O4 nanowires     core−shell structure     quinone-rich     electric double layer capacitor    

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Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

《机械工程前沿（英文）》 2006年 第1卷 第1期   页码 90-95 doi: 10.1007/s11465-005-0006-7

摘要：

To exactly describe the contact state and contact area of tooth surface of toroidal involute (TI) worm gearing, the authors introduced boundary condition into contact line analysis.With helix angle chosen as parameter, the criterion for the existence of meshing boundary line on the surface of TI worm gearing is derived. Results show that there can be four situations for meshing boundary line on the tooth surface of gear, namely, inexistence of meshing boundary line, a unique line, two lines, and two coincident lines. If the helix angle is equal to or slightly smaller than the bigger angle, which makes two meshing boundary lines superpose, a preferable meshing performance is obtained. Computer simulation proves the validity of the above conclusion.

关键词： preferable     inexistence     Results     validity     boundary condition    

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Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 711-725 doi: 10.1007/s11465-021-0647-1

摘要： The safety of human–robot interaction is an essential requirement for designing collaborative robotics. Thus, this paper aims to design a novel variable stiffness actuator (VSA) that can provide safer physical human–robot interaction for collaborative robotics. VSA follows the idea of modular design, mainly including a variable stiffness module and a drive module. The variable stiffness module transmits the motion from the drive module in a roundabout manner, making the modularization of VSA possible. As the key component of the variable stiffness module, a stiffness adjustment mechanism with a symmetrical structure is applied to change the positions of a pair of pivots in two levers linearly and simultaneously, which can eliminate the additional bending moment caused by the asymmetric structure. The design of the double-deck grooves in the lever allows the pivot to move freely in the groove, avoiding the geometric constraint between the parts. Consequently, the VSA stiffness can change from zero to infinity as the pivot moves from one end of the groove to the other. To facilitate building a manipulator in the future, an expandable electrical system with a distributed structure is also proposed. Stiffness calibration and control experiments are performed to evaluate the physical performance of the designed VSA. Experiment results show that the VSA stiffness is close to the theoretical design stiffness. Furthermore, the VSA with a proportional–derivative feedback plus feedforward controller exhibits a fast response for stiffness regulation and a good performance for position tracking.

关键词： variable stiffness actuator     variable stiffness module     drive module     symmetrical structure     double-deck grooves     expandable electrical system    

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Experimental measurement of double-K fracture parameters of concrete with small-size aggregates

ZHANG Xiufang, XU Shilang, ZHENG Shuang

《结构与土木工程前沿（英文）》 2007年 第1卷 第4期   页码 448-457 doi: 10.1007/s11709-007-0061-8

摘要： The double- fracture model can well describe the development of cracks undergoing during the entire fracture process in concrete. Therefore, it has been selected as the theoretical basis of the Norm for fracture test of

关键词： development     concrete     theoretical     double- fracture    

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波浪与外壁透空双筒柱的互相作用

滕斌,李玉成,孙路

《中国工程科学》 2001年 第3卷 第10期   页码 41-47

摘要：

对于波浪与透空外壁同轴双筒柱的相互作用问题，利用速度势的特征函数展开式和透空壁内流体速度与两壁间压力差成正比的线性模型，建立了一个线性解析解。应用这一模型开展了数值实验，用以检验孔隙系数和透空部分大小以及内外柱径之比对双筒柱上波浪力和波面高度的影响。计算结果表明，外壁孔隙系数和透空部分大小对波面升高和波浪荷载有很大影响，通过调整各个系数，应用双筒透空柱可以减小周围的波面高度及其上的波浪荷载。

关键词： 波浪绕射     波浪力     波面升高     有孔建筑     圆柱    

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Numerical study of thermal characteristics of double skin facade system with middle shade

Shaoning LIU, Xiangfei KONG, Hua YANG, Minchao FAN, Xin ZHAN

《能源前沿（英文）》 2021年 第15卷 第1期   页码 222-234 doi: 10.1007/s11708-017-0480-8

摘要： Architectural shade is an effective method for improving building energy efficiency. A new shade combined with the double skin façade (DSF) system, called middle shade (MS), was introduced and developed for buildings. In this paper, a 3D dynamic simulation was conducted to analyze the influence of MS combined with DSF on the indoor thermal characteristics. The research on MS for DSF involves the temperature, the ventilation rate, the velocity distribution of the air flow duct, and the indoor temperature. The results show that the angle and position of the shade in the three seasons are different, and different conditions effectively enhance the indoor thermal characteristics. In summer, the appearance of MS in DSF makes the indoor temperature significantly lower. The indoor temperature is obviously lower than that of the air flow duct, and the temperature of the air flow duct is less affected by MS. The influence of the position of blinds on indoor temperature and ventilation rate is greater than the influence of the angle of blinds. According to the climate characteristics of winter and transition season, in winter, early spring, and late autumn, the indoor temperature decreases with the increase of the position of blinds at daytime, but the opposite is true at night. The results found in this paper can provide reference for the design and use of MS combined with DSF in hot summer and cold winter zone.

关键词： middle shade     position     thermal characteristics     double skin facade    

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Moment-curvature relationship of FRP-concrete-steel double-skin tubular members

Mingxue LIU, Jiaru QIAN

《结构与土木工程前沿（英文）》 2009年 第3卷 第1期   页码 25-31 doi: 10.1007/s11709-009-0012-7

摘要： Tests were conducted on 3 specimens to study the flexural behavior of fiber reinforced polymer (FRP)-concrete-steel double-skin tubular members (DSTMs). The strip method was used to calculate the section moment-curvature curves of the 3 specimens and 12 models. A theoretical formula is presented for the flexural strength of DSTMs. The test results show that the tension zone of the specimen FRP tubes was in hoop compression while the compression zone was in hoop tension. The load-carrying capacity did not decrease even when the mid-span deflection reached about 1/24 of the span length. The tests, simulation and theoretical analysis resulted in a simplified formula for the flexural strength of DSTMs and a tri-linear moment-curvature model was expressed as a function of the section bending stiffness for DSTMs.

关键词： fiber reinforced polymer (FRP)     concrete     steel     double-skin tubular members (DSTMs)     moment-curvature curve     flexural strength    

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Enhancement of distillate output of double basin solar still with vacuum tubes

Hitesh N PANCHAL, P K SHAH

《能源前沿（英文）》 2014年 第8卷 第1期   页码 101-109 doi: 10.1007/s11708-014-0299-5

摘要： The latent heat of condensation is lost to the atmosphere; hence it is not utilized to increase distillate output of single basin solar stills. This difficulty was overcome by attaching an additional basin to the main basin. The performance of the double basin solar still was also increased by attaching vacuum tubes to the lower basin; hence the lower basin possessed a higher temperature throughout the day. The latent heat of condensation of the bottom basin was also utilized to increase distillate. But the distillate output of the top basin was even lower compared with that of the bottom basin. This paper proposed a novel approach to increase the distillate output of the double basin solar still attached with vacuum tubes by introducing different sensible energy storage materials like pebbles, black granite gravel and calcium stones to increase the basin area. Experiments were conducted in climate conditions of Mehsana (23.6000° N, 72.4000° E) Gujarat from April to September 2013 with a constant water depth of 2 cm in the top basin with and without the use of basin materials. The results showed that the distillate output of basin material with calcium stones is greater (74%) compared with that of black granite gravel and pebbles. The integration of vacuum tubes with solar still greatly increases the distillate output of the solar still by providing hot water at the lower basin.

关键词： double basin solar still     calcium stones     pebbles     granite gravel     distillate output    

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Latest development of double perovskite electrode materials for solid oxide fuel cells: a review

Shammya AFROZE, AfizulHakem KARIM, Quentin CHEOK, Sten ERIKSSON, Abul K. AZAD

《能源前沿（英文）》 2019年 第13卷 第4期   页码 770-797 doi: 10.1007/s11708-019-0651-x

摘要： Recently, the development and fabrication of electrode component of the solid oxide fuel cell (SOFC) have gained a significant importance, especially after the advent of electrode supported SOFCs. The function of the electrode involves the facilitation of fuel gas diffusion, oxidation of the fuel, transport of electrons, and transport of the byproduct of the electrochemical reaction. Impressive progress has been made in the development of alternative electrode materials with mixed conducting properties and a few of the other composite cermets. During the operation of a SOFC, it is necessary to avoid carburization and sulfidation problems. The present review focuses on the various aspects pertaining to a potential electrode material, the double perovskite, as an anode and cathode in the SOFC. More than 150 SOFCs electrode compositions which had been investigated in the literature have been analyzed. An evaluation has been performed in terms of phase, structure, diffraction pattern, electrical conductivity, and power density. Various methods adopted to determine the quality of electrode component have been provided in detail. This review comprises the literature values to suggest possible direction for future research.

关键词： double perovskites     electrode materials     hydrocarbon fuel     solid oxide fuel cells    

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Nanosilver anchored alginate/poly(acrylic acid/acrylamide) double-network hydrogel composites for efficient

《化学科学与工程前沿（英文）》 2023年 第17卷 第7期   页码 893-905 doi: 10.1007/s11705-022-2290-8

摘要： A novel alginate/poly(acrylic acid/acrylamide) double-network hydrogel composite with silver nanoparticles was successfully fabricated using the sol–gel method. The presence of carboxyl and amide groups in the network structure provided abundant active sites for complexing silver ions, facilitating the in situ reduction and confinement of silver nanoparticles. In batch experiments, the optimal silver loading was 20%, and 5 mmol·L–1 of p-nitrophenol was completely degraded in 113 s with a rate constant value of 4.057 × 10−2 s–1. In the tap water system and simulated seawater system, the degradation time of p-nitrophenol at the same concentration was 261 and 276 s, respectively, with a conversion rate above 99%. In the fixed-bed experiment, the conversion rate remained above 74% after 3 h at a flowing rate of 7 mL·min–1. After 8 cycling tests, the conversion rate remained at 98.7%. Moreover, the catalyst exhibited outstanding performance in the degradation experiment of four typical organic dyes.

关键词： double-network hydrogel     dye degradation     silver nanoparticles     alginate    

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KDD中双库协同机制的研究（Ⅰ）

杨炳儒,王建新

《中国工程科学》 2002年 第4卷 第4期   页码 41-51

摘要：

针对KDD（基于数据库的知识发现）主流发展中存在的典型问题提出了用知识库去 制约与驱动数据库, 并通过数据库改善知识库结构的知识发现的新思想，形成了具有双库协同机制的KDD的开放系统KDD*，从而提高了知识发现的速度、精度和认知自主性，并使知识库在结构上具备了实时维护与自我进化的能力，同时阐述了作为双库协同基础的数据库和知识库在本质上的对应关系。

关键词： 知识结点     本原知识库     本原数据库     数据子类结构     双库协同机制    

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Synergistic effect of V and Fe in Ni/Fe/V ternary layered double hydroxides for efficient and durable

《化学科学与工程前沿（英文）》 2023年 第17卷 第1期   页码 102-115 doi: 10.1007/s11705-022-2179-6

摘要： High-performance and stable electrocatalysts are vital for the oxygen evolution reaction (OER). Herein, via a one-pot hydrothermal method, Ni/Fe/V ternary layered double hydroxides (NiFeV-LDH) derived from Ni foam are fabricated to work as highly active and durable electrocatalysts for OER. By changing the feeding ratio of Fe and V salts, the prepared ternary hydroxides were optimized. At an Fe:V ratio of 0.5:0.5, NiFeV-LDH exhibits outstanding OER activity superior to that of the binary hydroxides, requiring overpotentials of 269 and 274 mV at 50 mA·cm–2 in the linear sweep voltammetry and sampled current voltammetry measurements, respectively. Importantly, NiFeV-LDH shows extraordinary long-term stability (≥ 75 h) at an extremely high current density of 200 mA·cm–2. In contrast, the binary hydroxides present quick decay at 200 mA·cm–2 or even reduced current densities (150 and 100 mA·cm–2). The outstanding OER performance of NiFeV-LDH benefits from the synergistic effect of V and Fe while doping the third metal into bimetallic hydroxide layers: (a) Fe plays a crucial role as the active site; (b) electron-withdrawing V stabilizes the high valence state of Fe, thus accelerating the OER process; (c) V further offers great stabilization for the formed intermediate of FeOOH, thus achieving superior durability.

关键词： oxygen evolution reaction     electrocatalysts     ternary layered double hydroxides     long-term stability    

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Prediction and cause investigation of ozone based on a double-stage attention mechanism recurrent neural

《环境科学与工程前沿（英文）》 2023年 第17卷 第2期 doi: 10.1007/s11783-023-1621-4

摘要：

● Used a double-stage attention mechanism model to predict ozone.

关键词： Ozone prediction     Deep learning     Time series     Attention     Volatile organic compounds    

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中国开创的抗爆钢复合材料压力容器技术

朱国辉

《中国工程科学》 2000年 第2卷 第6期   页码 8-11

摘要：

压力容器是一种应用广泛的重要工程装置。大型压力贮罐、氨合成塔、尿素合成塔、石油加氢反应器、导弹壳体和液氢、液氧燃料压力容器，以及核堆压力壳等是国际上公认的高科技重大承压装备。纤维复合材料和普通钢制是当今世界压力容器技术的两大种类。作者开创了一种新的具有优良综合特性，已含国家发明奖励和18项中美专利成果的抗爆钢复合材料压力容器技术，使压力容 器的使用安全性和制造经济性发生了极大的变革；其典型代表钢带缠绕式压力容器，已被美国机械工程师学会正式列入ASME标准，居国际领先水平，将为21世纪国际压力容器的设计、制造和安全保障技术的发展开创出新的局面。

关键词： 压力容器技术     纤维复合材料     钢复合材料     复合薄内筒     交错缠绕     全双层结构     抑爆抗爆    

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标题 作者 时间 类型 操作

In situ synthesis of FeS/Carbon fibers for the effective removal of Cr(VI) in aqueous solution

Rongrong Zhang, Daohao Li, Jin Sun, Yuqian Cui, Yuanyuan Sun

期刊论文

NiCo2O4@quinone-rich N–C core–shell nanowires as composite electrode for electric double layer capacitor

期刊论文

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

期刊论文

Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

期刊论文

Experimental measurement of double-K fracture parameters of concrete with small-size aggregates

ZHANG Xiufang, XU Shilang, ZHENG Shuang

期刊论文

波浪与外壁透空双筒柱的互相作用

滕斌,李玉成,孙路

期刊论文

Numerical study of thermal characteristics of double skin facade system with middle shade

Shaoning LIU, Xiangfei KONG, Hua YANG, Minchao FAN, Xin ZHAN

期刊论文

Moment-curvature relationship of FRP-concrete-steel double-skin tubular members

Mingxue LIU, Jiaru QIAN

期刊论文

Enhancement of distillate output of double basin solar still with vacuum tubes

Hitesh N PANCHAL, P K SHAH

期刊论文

Latest development of double perovskite electrode materials for solid oxide fuel cells: a review

Shammya AFROZE, AfizulHakem KARIM, Quentin CHEOK, Sten ERIKSSON, Abul K. AZAD

期刊论文

Nanosilver anchored alginate/poly(acrylic acid/acrylamide) double-network hydrogel composites for efficient

期刊论文

KDD中双库协同机制的研究（Ⅰ）

杨炳儒,王建新

期刊论文

Synergistic effect of V and Fe in Ni/Fe/V ternary layered double hydroxides for efficient and durable

期刊论文

Prediction and cause investigation of ozone based on a double-stage attention mechanism recurrent neural

期刊论文

中国开创的抗爆钢复合材料压力容器技术

朱国辉

期刊论文