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Characterization and catalytic activity of soft-templated NiO-CeO

Luciano Atzori, Maria Giorgia Cutrufello, Daniela Meloni, Barbara Onida, Delia Gazzoli, Andrea Ardu, Roberto Monaci, Maria Franca Sini, Elisabetta Rombi

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 251-268 doi: 10.1007/s11705-020-1951-8

摘要： Nanosized NiO, CeO and NiO-CeO mixed oxides with different Ni/Ce molar ratios were prepared by the soft template method. All the samples were characterized by different techniques as to their chemical composition, structure, morphology and texture. On the catalysts submitted to the same reduction pretreatment adopted for the activity tests the surface basic properties and specific metal surface area were also determined. NiO and CeO nanocrystals of about 4 nm in size were obtained, regardless of the Ni/Ce molar ratio. The Raman and X-ray photoelectron spectroscopy results proved the formation of defective sites at the NiO-CeO interface, where Ni species are in strong interaction with the support. The microcalorimetric and Fourier transform infrared analyses of the reduced samples highlighted that, unlike metallic nickel, CeO is able to effectively adsorb CO , forming carbonates and hydrogen carbonates. After reduction in H at 400 °C for 1 h, the catalytic performance was studied in the CO and CO co-methanation reaction. Catalytic tests were performed at atmospheric pressure and 300 °C, using CO/CO /H molar compositions of 1/1/7 or 1/1/5, and space velocities equal to 72000 or 450000 cm ∙h ∙g . Whereas CO was almost completely hydrogenated in any investigated experimental conditions, CO conversion was strongly affected by both the CO/CO /H ratio and the space velocity. The faster and definitely preferred CO hydrogenation was explained in the light of the different mechanisms of CO and CO methanation. On a selected sample, the influence of the reaction temperature and of a higher number of space velocity values, as well as the stability, were also studied. Provided that the Ni content is optimized, the NiCe system investigated was very promising, being highly active for the CO co-methanation reaction in a wide range of operating conditions and stable (up to 50 h) also when submitted to thermal stress.

关键词： soft template method     NiO-CeO2 catalysts     CO and CO2 co-methanation     synthetic natural gas production    

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A simplified method for investigating the bending behavior of piles supporting embankments on soft ground

《结构与土木工程前沿（英文）》   页码 1021-1032 doi: 10.1007/s11709-023-0952-3

摘要： In recent years, concrete and reinforced concrete piles have been widely used to stabilize soft ground under embankments. Previous research has shown that bending failure, particularly during rapid filling on soft ground, is the critical failure mode for pile-supported embankments. Here, we propose an efficient two-stage method that combines a test-verified soil deformation mechanism and Poulos’ solution for pile–soil interaction to investigate the bending behavior of piles supporting embankments on soft ground. The results reveal that there are three possible bending failure scenarios for such piles: at the interface between the soft and firm ground layers, at mid-depths of the fan zone, and at the boundary of the soil deformation mechanism. The location of the bending failure depends on the position and relative stiffness of the given pile. Furthermore, the effect of embedding a pile into a firm ground layer on the bending behavior was investigated. When the embedded length of a pile exceeded a critical value, the bending moment at the interface between the soft and firm ground layers reached a limiting value. In addition, floating piles that are not embedded exhibit an overturning pattern of movement in the soft ground layer, and a potential failure is located in the upper part of these piles.

关键词： bending behavior     pile     embankment     soil−structure interaction     failure mode    

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Comparison of shallow tunneling method with pile and rib method for construction of subway station insoft ground

Sina AMIRI; Ali Naghi DEHGHAN

《结构与土木工程前沿（英文）》 2022年 第16卷 第6期   页码 704-717 doi: 10.1007/s11709-021-0746-4

摘要： In the present study, a comparison between the new shallow tunneling method (STM) and the traditional pile and rib method (PRM) was conducted to excavate and construct subway stations in the geological conditions of Tehran. First, by selecting Station Z6 located in the Tehran Subway Line 6 as a case study, the construction process was analyzed by PRM. The maximum ground settlement of 29.84 mm obtained from this method was related to the station axis, and it was within the allowable settlement limit of 30 mm. The acceptable agreement between the results of numerical modeling and instrumentation data indicated the confirmation and accuracy of the excavation and construction process of Station Z6 by PRM. In the next stage, based on the numerical model validated by instrumentation data, the value of the ground surface settlement was investigated during the station excavation and construction by STM. The results obtained from STM showed a significant reduction in the ground surface settlement compared to PRM. The maximum settlement obtained from STM was 6.09 mm as related to the front of the excavation face. Also, the sensitivity analysis results denoted that in addition to controlling the surface settlement by STM, it is possible to optimize some critical geometric parameters of the support system during the station excavation and construction.

关键词： shallow tunneling method     pile and rib method     ground surface settlement     subway station construction     numerical modeling    

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Numerical investigation of the ultimate lateral resistance of piles in soft clay

Konstantinos P. TZIVAKOS,Michael J. KAVVADAS

《结构与土木工程前沿（英文）》 2014年 第8卷 第2期   页码 194-200 doi: 10.1007/s11709-014-0251-0

摘要： The paper presents a numerical study on the undrained lateral response of a single, free-head, reinforced concrete pile in soft clays. Soil conditions simulating normally consolidated clays are examined—undrained shear strength increasing with depth—and the pile-soil interaction under static lateral loading is analyzed. The nonlinear ? curves proposed in literature for soft clays are imported into a beam-on-nonlinear-Winkler-foundation simulation in order to predict the pile head lateral load—displacement curve and the distribution of the horizontal displacement and bending moment along the pile. The striking differences among these methods require further investigation via 3D finite element analyses. The determination of the ultimate soil resistance from the results of the finite element analyses aims at providing the estimation of a range of values for the ultimate soil resistance coefficient with depth and the comparison of the derived values to the corresponding ones proposed by existing methodologies.

关键词： laterally loaded     pile     soft clay     p?y curves     finite element method (FEM)    

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A mini review: Functional nanostructuring with perfectly-ordered anodic aluminum oxide template for energy

Huaping Zhao, Long Liu, Yong Lei

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 481-493 doi: 10.1007/s11705-018-1707-x

摘要：

Nanostructures have drawn great attentions for functional device applications. Among the various techniques developed for fabricating arrayed nanostructures of functional materials, nanostructuring technique with porous anodic aluminum oxide (AAO) membrane as templates becomes more attractive owing to the superior geometrical characteristics and low-cost preparation process. In this mini review, we summarize our recent progress about functional nanostructuring based on perfectly-ordered AAO membrane to prepare perfectly-ordered nanostructure arrays of functional materials toward constructing high-performance energy conversion and storage devices. By employing the perfectly-ordered AAO membrane as templates, arrayed nanostructures in the form of nanodot, nanorod, nanotube and nanopore have been synthesized over a large area. These as-obtained nanostructure arrays have large specific surface area, high regularity, large-scale implementation, and tunable nanoscale features. All these advanced features enable them to be of great advantage for the performance improvement of energy conversion and storage devices, including photoelectrochemical water splitting cells, supercapacitors, and batteries, etc.

关键词： nanostructuring     perfectly-ordered AAO template     photoelectrochemical water splitting     sodium-ion batteries     supercapacitors    

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Fabrication of magnetic multi-template molecularly imprinted polymer composite for the selective and

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-021-1395-5

摘要：

• Magnetic multi-template molecularly imprinted polymer composite was synthesized.

关键词： Tetracyclines     Removal     Adsorption     Molecularly imprinted polymer     Magnetic graphene oxide    

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Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy

Farouq TWAIQ,M.S. NASSER,Sagheer A. ONAIZI

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 488-497 doi: 10.1007/s11705-014-1459-1

摘要： The key aim of this study is to evaluate the adsorption of heavy oil from aqueous solutions with different oil contents over mesoporous silicate materials having different surfactant template contents. The mesoporous silicate materials have been synthesized from tetraethylorthosilicate as a silica precursor and cetyltrimethylammonium bromide as a template using the sol-gel technique. Four samples were prepared by (1) totally removing the template using the calcination process, (2) partially removing the template via ethanol extraction, (3) partially removing the template via water extraction, and (4) keeping the template as synthesized, respectively. These four samples have been characterized using X-ray diffraction, nitrogen adsorption, thermal gravimetric analysis and Fourier transformed infrared. The effect of the degree of template removal of these mesoporous materials for the oil removal has been investigated. The oil removal is inversely proportional to the surfactant content in the mesoporous material, being highest for the calcined sample but lowest for the as-synthesized sample. The kinetic of oil adsorption over the calcined material has been also studied and the data obtained fit well a second-order model.

关键词： heavy oil     mesoporous silicate material     kinetics     template removal     adsorption    

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Development of soft kernel durum wheat

Craig F. MORRIS

《农业科学与工程前沿（英文）》 2019年 第6卷 第3期   页码 273-278 doi: 10.15302/J-FASE-2019259

摘要：

Kernel texture (grain hardness) is a fundamental and determining factor related to wheat ( spp.) milling, baking and flour utilization. There are three kernel texture classes in wheat: soft and hard hexaploid ( ), and very hard durum ( subsp. ). The genetic basis for these three classes lies with the Puroindoline genes. Phenotypically, the easiest means of quantifying kernel texture is with the Single Kernel Characterization System (SKCS), although other means are valid and can provide fundamental material properties. Typical SKCS values for soft wheat would be around 25 and for durum wheat≥80. Soft kernel durum wheat was created via homeologous recombination using the mutation, which facilitated the transfer of ca. 28 Mbp of 5DS that replaced ca. 21 Mbp of 5BS. The 5DS translocation contained a complete and intact locus and both puroindoline genes. Expression of the puroindoline genes in durum grain resulted in kernel texture and flour milling characteristics nearly identical to that of soft wheat, with high yields of break and straight-grade flours, which had small particle size and low starch damage. Dough water absorption was markedly reduced compared to durum flour and semolina. Dough was essentially unchanged and reflected the inherent gluten properties of the durum background. Pasta quality was essentially equal-to-or-better than pasta made from semolina. Agronomically, soft durum germplasm showed good potential with moderate grain yield and resistance to a number of fungal pathogens and insects. Future breeding efforts will no doubt further improve the quality and competitiveness of soft durum cultivars.

关键词： soft durum wheat     grain hardness     puroindolines     milling     baking     pasta     noodles    

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Solution properties and self-association of multi-blocks like copolymer P(AM/AA) prepared by template

ZHANG Yuxi, WU Feipeng, LI Miaozhen, WANG Erjian

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 68-71 doi: 10.1007/s11705-007-0014-8

摘要： The association and properties of multi-block like copolymers (TP) of acrylamide (AM) and acrylic acid (AA) prepared by template copolymerization in aqueous solution were studied. The results showed that the copolymers of this type exhibited a significant structure effect compared with that of similar random copolymers (CP) obtained by copolymerization in the absence of template. Decreasing the value of pH or adding Ca ion to the copolymer solution will make phase separation occur. The TEM images demonstrated that the phase separation caused by Ca ion was due to the formation of extensively intermolecular cross-linking. With the increase of the pH value of copolymer solution, the changes of the solution viscosity was similar with that of homopolyacrylic acid, which originally increased and then decreased. But the increase range of template copolymer was higher than that of homopolyacrylic acid. TEM images indicated that at the maximal viscosity the copolymer obtained in the presence of template formed coiled aggregates.

关键词： aqueous solution     homopolyacrylic     copolymer solution     significant structure     presence    

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Performance of soft-hard-soft (SHS) cement based composite subjected to blast loading with consideration

Jun WU,Xuemei LIU

《结构与土木工程前沿（英文）》 2015年 第9卷 第3期   页码 323-340 doi: 10.1007/s11709-015-0301-2

摘要： This paper presents a combined experimental and numerical study on the damage and performance of a soft-hard-soft (SHS) multi-layer cement based composite subjected to blast loading which can be used for protective structures and infrastructures to resist extreme loadings, and the composite consists of three layers of construction materials including asphalt concrete (AC) on the top, high strength concrete (HSC) in the middle, and engineered cementitious composites (ECC) at the bottom. To better characterize the material properties under dynamic loading, interface properties of the composite were investigated through direct shear test and also used to validate the interface model. Strain rate effects of the asphalt concrete were also studied and both compressive and tensile dynamic increase factor (DIF) curves were improved based on split Hopkinson pressure bar (SHPB) test. A full-scale field blast test investigated the blast behavior of the composite materials. The numerical model was established by taking into account the strain rate effect of all concrete materials. Furthermore, the interface properties were also considered into the model. The numerical simulation using nonlinear finite element software LS-DYNA agrees closely with the experimental data. Both the numerical and field blast test indicated that the SHS composite exhibited high resistance against blast loading.

关键词： high strength concrete (SHS)     engineered cementitious composite     interface     blast test     strain rate effect    

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Design and modeling of a novel soft parallel robot driven by endoskeleton pneumatic artificial muscles

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0678-2

摘要： Owing to their inherent great flexibility, good compliance, excellent adaptability, and safe interactivity, soft robots have shown great application potential. The advantages of light weight, high efficiency, non-polluting characteristic, and environmental adaptability provide pneumatic soft robots an important position in the field of soft robots. In this paper, a soft robot with 10 soft modules, comprising three uniformly distributed endoskeleton pneumatic artificial muscles, was developed. The robot can achieve flexible motion in 3D space. A novel kinematic modeling method for variable-curvature soft robots based on the minimum energy method was investigated, which can accurately and efficiently analyze forward and inverse kinematics. Experiments show that the robot can be controlled to move to the desired position based on the proposed model. The prototype and modeling method can provide a new perspective for soft robot design, modeling, and control.

关键词： pneumatic artificial muscles     soft robot     modeling approach     principle of virtual work     external load    

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一种基于特征模板和CNN-BiLSTM-CRF的网络安全实体识别方法 Research Papers

Ya QIN, Guo-wei SHEN, Wen-bo ZHAO, Yan-ping CHEN, Miao YU, Xin JIN

《信息与电子工程前沿（英文）》 2019年 第20卷 第6期   页码 872-884 doi: 10.1631/FITEE.1800520

摘要： 利用海量网络安全威胁情报数据，构建网络安全知识图谱实施深度关联分析和挖掘，可帮助识别安全威胁并提出相应防御措施。这已成为网络安全领域研究热点。本文针对网络安全文本数据，研究实体识别算法，为构建网络安全知识图谱奠定基础。传统方法难以识别网络安全领域的新实体、中英文混合安全实体等，且提取的特征不够充分。本文在神经网络模型基础上，提出基于特征模板的CNN-BiLSTM-CRF网络安全实体识别算法。首先构建人工特征模板，提取局部上下文特征。再利用CNN提取字符特征，与局部上下文特征结合，传入BiLSTM模型提取语义特征。最后利用CRF对安全实体进行标注。结果表明，在大规模网络安全数据集上，该方法优于其它算法，F值达到86%。

关键词： 网络安全知识图谱；网络安全实体；特征模板；实体识别；神经网络    

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Analysis of load and adaptability of disc cutters during shield tunneling in soft–hard varied strata

《结构与土木工程前沿（英文）》 2023年 第17卷 第4期   页码 533-545 doi: 10.1007/s11709-023-0946-1

摘要： The disc cutters of shield machines exhibit unsatisfactory adaptability and performance during the soft–hard varied strata tunneling process. To analyze the rotation state, cutting performance, and adaptability of disc cutters during shield tunneling in soft–hard varied strata, the Holmquist Johnson Cook and Federal Highway Administration constitutive models are introduced to numerically simulate the failure process of materials on the excavation face and to calculate the load of disc cutters. Additionally, the parameters of the models are modified based on laboratory disc cutter excavation test results. The results of numerical calculation can reflect the load level and the behavior of the disc cutters during operation. The tangential loads of the disc cutters during the cutting of four typical soft-strata excavation face models are numerically calculated, thus providing reference values for the starting torque of the disc cutters. A greater penetration is suggested for soft-strata tunneling to allow the disc cutters to rotate smoothly and continuously as well as to guarantee a better cutting effect. The disc cutters in the center of the cutterhead should be specified with a lower starting torque to prevent uneven wear, rotation stagnation, cutterhead clogging, and other adverse phenomena.

关键词： shield tunneling     disc cutter load     laboratory excavation test     numerical calculation     soft–hard varied strata    

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Risk stratification system for skin and soft tissue infections after allogeneic hematopoietic stem cell

《医学前沿（英文）》 2022年 第16卷 第6期   页码 957-968 doi: 10.1007/s11684-021-0910-1

摘要： Skin and soft tissue infections (SSTIs) refer to infections involving the skin, subcutaneous tissue, fascia, and muscle. In transplant populations with hematological malignancies, an immunocompromised status and the routine use of immunosuppressants increase the risk of SSTIs greatly. However, to date, the profiles and clinical outcomes of SSTIs in hematopoietic stem cell transplantation (HSCT) patients remain unclear. This study included 228 patients (3.67%) who developed SSTIs within 180 days after allogeneic HSCT from January 2004 to December 2019 in Peking University People’s Hospital. The overall annual survival rate was 71.5%. We compared the differences between survivors and non-survivors a year after transplant and found that primary platelet graft failure (PPGF), comorbidities of acute kidney injury (AKI), and hospital-acquired pneumonia (HAP) were independent risk factors for death in the study population. A PPGF–AKI–HAP risk stratification system was established with a mortality risk score of 1×PPGF+1×AKI+1×HAP. The areas under the curves of internal and external validation were 0.833 (95% CI 0.760–0.906) and 0.826 (95% CI 0.715–0.937), respectively. The calibration plot revealed the high consistency of the estimated risks, and decision curve analysis showed considerable net benefits for patients.

关键词： skin and soft tissue infections     hematopoietic stem cell transplantation     risk stratification system     mortality    

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Design and experiment of a novel pneumatic soft arm based on a deployable origami exoskeleton

《机械工程前沿（英文）》 2023年 第18卷 第4期 doi: 10.1007/s11465-023-0770-2

摘要： Soft arms have shown great application potential because of their flexibility and compliance in unstructured environments. However, soft arms made from soft materials exhibit limited cargo-loading capacity, which restricts their ability to manipulate objects. In this research, a novel soft arm was developed by coupling a rigid origami exoskeleton with soft airbags. The joint module of the soft arm was composed of a deployable origami exoskeleton and three soft airbags. The motion and load performance of the soft arm of the eight-joint module was tested. The developed soft arm withstood at least 5 kg of load during extension, contraction, and bending motions; exhibited bistable characteristics in both fully contracted and fully extended states; and achieved a bending angle of more than 240° and a contraction ratio of more than 300%. In addition, the high extension, contraction, bending, and torsional stiffnesses of the soft arm were experimentally demonstrated. A kinematic-based trajectory planning of the soft arm was performed to evaluate its error in repetitive motion. This work will provide new design ideas and methods for flexible manipulation applications of soft arms.

关键词： pneumatic soft arm     soft airbag     deployable origami exoskeleton     bistable characteristics     cargo-loading capacity    

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标题 作者 时间 类型 操作

Characterization and catalytic activity of soft-templated NiO-CeO

Luciano Atzori, Maria Giorgia Cutrufello, Daniela Meloni, Barbara Onida, Delia Gazzoli, Andrea Ardu, Roberto Monaci, Maria Franca Sini, Elisabetta Rombi

期刊论文

A simplified method for investigating the bending behavior of piles supporting embankments on soft ground

期刊论文

Comparison of shallow tunneling method with pile and rib method for construction of subway station insoft ground

Sina AMIRI; Ali Naghi DEHGHAN

期刊论文

Numerical investigation of the ultimate lateral resistance of piles in soft clay

Konstantinos P. TZIVAKOS,Michael J. KAVVADAS

期刊论文

A mini review: Functional nanostructuring with perfectly-ordered anodic aluminum oxide template for energy

Huaping Zhao, Long Liu, Yong Lei

期刊论文

Fabrication of magnetic multi-template molecularly imprinted polymer composite for the selective and

期刊论文

Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy

Farouq TWAIQ,M.S. NASSER,Sagheer A. ONAIZI

期刊论文

Development of soft kernel durum wheat

Craig F. MORRIS

期刊论文

Solution properties and self-association of multi-blocks like copolymer P(AM/AA) prepared by template

ZHANG Yuxi, WU Feipeng, LI Miaozhen, WANG Erjian

期刊论文

Performance of soft-hard-soft (SHS) cement based composite subjected to blast loading with consideration

Jun WU,Xuemei LIU

期刊论文

Design and modeling of a novel soft parallel robot driven by endoskeleton pneumatic artificial muscles

期刊论文

一种基于特征模板和CNN-BiLSTM-CRF的网络安全实体识别方法

Ya QIN, Guo-wei SHEN, Wen-bo ZHAO, Yan-ping CHEN, Miao YU, Xin JIN

期刊论文

Analysis of load and adaptability of disc cutters during shield tunneling in soft–hard varied strata

期刊论文

Risk stratification system for skin and soft tissue infections after allogeneic hematopoietic stem cell

期刊论文

Design and experiment of a novel pneumatic soft arm based on a deployable origami exoskeleton

期刊论文