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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    

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    

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    

Petroleum pitch derived hard carbon via NaCl-template as anode materials with high rate performance for

《化学科学与工程前沿(英文)》 doi: 10.1007/s11705-024-2430-4

摘要: Sodium-ion batteries (SIBs) have garnered significant interest in energy storage due to their similar working mechanism to lithium ion batteries and abundant reserves of sodium resource. Exploring facile synthesis of a carbon-based anode materials with capable electrochemical performance is key to promoting the practical application of SIBs. In this work, a combination of petroleum pitch and recyclable sodium chloride is selected as the carbon source and template to obtain hard carbon (HC) anode for SIBs. Carbonization times and temperatures are optimized by assessing the sodium ion storage behavior of different HC materials. The optimized HC exhibits a remarkable capacity of over 430 mAh·g–1 after undergoing full activation through 500 cycles at a density of current of 0.1 A·g–1. Furthermore, it demonstrates an initial discharge capacity of 276 mAh·g–1 at a density of current of 0.5 A·g–1. Meanwhile, the optimized HC shows a good capacity retention (170 mAh·g–1 after 750 cycles) and a remarkable rate ability (166 mAh·g–1 at 2 A·g–1). The enhanced capacity is attributed to the suitable degree of graphitization and surface area, which improve the sodium ion transport and storage.

关键词: petroleum pitch     hard carbon     sodium-ion batteries     high rate     recyclable template    

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    

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    

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    

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    

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    

Online soft measurement for wastewater treatment system based on hybrid deep learning

《环境科学与工程前沿(英文)》 2024年 第18卷 第2期 doi: 10.1007/s11783-024-1780-y

摘要:

● A hybrid model is proposed to overcome limitations of single model with time series.

关键词: Prediction model     Soft measurement     CNN-BNLSTM-AM model     TPE optimization algorithm    

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    

Crack evolution of soft–hard composite layered rock-like specimens with two fissures under uniaxial compression

《结构与土木工程前沿(英文)》 2021年 第15卷 第6期   页码 1372-1389 doi: 10.1007/s11709-021-0772-2

摘要: Acoustic emission and digital image correlation were used to study the spatiotemporal evolution characteristics of crack extension of soft and hard composite laminated rock masses (SHCLRM) containing double fissures under uniaxial compression. The effects of different rock combination methods and prefabricated fissures with different orientations on mechanical properties and crack coalescence patterns were analyzed. The characteristics of the acoustic emission source location distribution, and frequency changes of the crack evolution process were also investigated. The test results show that the damage mode of SHCLRM is related to the combination mode of rock layers and the orientation of fractures. Hard layers predominantly produce tensile cracks; soft layers produce shear cracks. The first crack always sprouts at the tip or middle of prefabricated fractures in hard layers. The acoustic emission signal of SHCLRM with double fractures has clear stage characteristics, and the state of crack development can be inferred from this signal to provide early warning for rock fracture instability. This study can provide a reference for the assessment of the fracture development status between adjacent roadways in SHCLRM in underground mines, as well as in roadway layout and support.

关键词: soft−hard composite layered rock mass     double cracks     crack evolution     acoustic emission     digital image correlation    

Organosilane surfactant-assisted synthesis of mesoporous SSZ-39 zeolite with enhanced catalytic performance in the methanol-to-olefins reaction

Hao Xu, Chi Lei, Qinming Wu, Qiuyan Zhu, Xiangju Meng, Daniel Dai, Stefan Maurer, Andrei-Nicolae Parvulescu, Ulrich Müller, Fengshou Xiao

《化学科学与工程前沿(英文)》 2020年 第14卷 第2期   页码 267-274 doi: 10.1007/s11705-019-1845-9

摘要: SSZ-39 zeolite with AEI framework structure is a good catalyst candidate for the methanol-to-olefins (MTO) reaction. However, the diffusion limitation and coke formation often results in fast deactivation of the SSZ-39 zeolite catalyst. One solution for this challenge is to introduce mesoporosity in the SSZ-39 zeolite. Herein, we report the synthesis of mesoporous SSZ-39 zeolite using an organosilane surfactant, , -dimethyl- -(3-(trimethoxysilyl)propyl)octan-1-aminium chloride, as a mesopore template and , -dimethyl- -2,6-dimethylpiperidinium as a micropore template. The obtained zeolites were characterized by X-ray diffraction, N sorption, scanning electron microscopy, temperature programmed desorption of ammonia, and magic angle spinning nuclear magnetic resonance of Al. The results show that the mesoporous SSZ-39 zeolite has high crystallinity, meso/microporosity, high surface area, cuboid morphology, and abundant acidic sites. More importantly, this mesoporous SSZ-39 zeolite exhibits enhanced catalyst lifetime in the MTO reaction due to the presence of mesoporosity for fast mass transfer, compared with a conventional SSZ-39 zeolite without mesoporosity.

关键词: SSZ-39 zeolite     mesopores     organosilane surfactant     MTO reaction     soft template     mass transfer    

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    

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    

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 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

Petroleum pitch derived hard carbon via NaCl-template as anode materials with high rate performance for

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

Online soft measurement for wastewater treatment system based on hybrid deep learning

期刊论文

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

期刊论文

Crack evolution of soft–hard composite layered rock-like specimens with two fissures under uniaxial compression

期刊论文

Organosilane surfactant-assisted synthesis of mesoporous SSZ-39 zeolite with enhanced catalytic performance in the methanol-to-olefins reaction

Hao Xu, Chi Lei, Qinming Wu, Qiuyan Zhu, Xiangju Meng, Daniel Dai, Stefan Maurer, Andrei-Nicolae Parvulescu, Ulrich Müller, Fengshou Xiao

期刊论文

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

期刊论文

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

期刊论文