The kinematic viscosity of Fe-Mn-c melts is measured with Mn contents of 5.0, 7.5, 10.0, 12.0, 15.0, 17.5, 20.0, and 25.0 wt % and ccontents of 0.4 to 2.2 wt %. The kinematic viscosity is measured using damped torsio...
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The kinematic viscosity of Fe-Mn-c melts is measured with Mn contents of 5.0, 7.5, 10.0, 12.0, 15.0, 17.5, 20.0, and 25.0 wt % and ccontents of 0.4 to 2.2 wt %. The kinematic viscosity is measured using damped torsional vibrations of a crucible with a melt upon the heating and subsequent cooling of the samples. The temperatures at which the characteristics of the viscous flow change and the liquid-liquid structural transition occurs in Fe-Mn-c melts are determined using the results from measuring the kinematic viscosity.
The surface adhesion between c. elegans and the agar plates on which they are commonly grown has yet to be accurately quantified. c. elegans is a scientifically important species of nematode whose simple structure all...
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The surface adhesion between c. elegans and the agar plates on which they are commonly grown has yet to be accurately quantified. c. elegans is a scientifically important species of nematode whose simple structure allowed the first mapping of the complete nervous system in a multicellular organism. One of the current topics of research in the c. elegans community is the investigation of neuronal function in locomotion. Models of locomotion are used in these studies to aid in determination of the functions of specific neurons involved in locomotion. The adhesion force plays a critical role in developing these models. This paper presents the experimental determination of the adhesion energy of a representative sample of c. elegans. Adhesion energy was determined by a direct pull-off technique. In this approach, nematodes are anesthetized to prevent movement and secured to a small load cell before an agar plate is slowly brought into contact with the specimen and then removed. The maximum tensile force is then fit to a JKR-type adhesion model, which assumes that the nematode is a cylinder in order to determine the adhesion energy. Repeated adhesions are also investigated to determine the importance of drying on the measured adhesion force. From these experiments, the adhesion energy was found to be W =4.94 +/- 1.19 mJ/m(2). Limited experiments on the rol-6 cuticle mutant found a lower adhesion energy W =2.65 +/- 1.16 mJ/m(2) for these animals.
In this paper, co3O4/NiO/ccomposites were prepared by in situ co-precipitation and heat treatment with Zn/co-ZIF-derived N-doped porous carbon as carbon matrix. The structure and constituent of co3O4/NiO/ccomposites...
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In this paper, co3O4/NiO/ccomposites were prepared by in situ co-precipitation and heat treatment with Zn/co-ZIF-derived N-doped porous carbon as carbon matrix. The structure and constituent of co3O4/NiO/ccomposites were detected by the X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and other test methods. The result showed that Nico-LDH nanosheets grew evenly on the surface of porous carbon matrix. co3O4/NiO/ccomposites retained the dodecahedral shape of the carbon matrix. Electrochemical performance was investigated through electrochemical workstation and LAND-cT2001A battery test system. The results showed that the co3O4/NiO/c electrode has a higher initial discharge specificcapacity of 1673.0 mA h g(-1) at 0.1 A g(-1), and it could still maintain the discharge specificcapacity of 1167.8 mA h g(-1) after 100 cycles. The co3O4/NiO/c showed a high reversible capacity of 812.3 mA h g(-1) after 500 cycles at 0.5 A g(-1). The co3O4/NiO/c electrode exhibited excellent lithium storage performance, which can be attributed to the unique functionalities of the ternary components: NiO and co3O4 can guarantee high specificcapacity, while the carbon matrix can improve the conductivity and the stability of the structure. Therefore, co3O4/NiO/ccomposite was expected to be anode material for lithium storage equipment.
Herein, we report the effects of the catalyst support surface chemical/physical state of commercially available high -surface-area carbons on the electrochemical performance of Pt/c electrocatalysts synthesized using ...
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Herein, we report the effects of the catalyst support surface chemical/physical state of commercially available high -surface-area carbons on the electrochemical performance of Pt/c electrocatalysts synthesized using carbons as the support for platinum nanoparticles (Pt-NPs). A series of Pt/c electrocatalysts were synthesized through a microwave-assisted polyol process. The support carbons and the Pt/ccatalysts were characterized for their structural characteristics including crystallinity, microstructure (morphology and particle size distribution), physical surface area, porosity, thermal behavior, and surface chemical state. Evaluation of the electrocatalytic performances and durability parameters of the Pt/ccatalysts was performed through cyclic voltammetry and an accelerated stress test (AST). The results showed that the support carbons have similar physical properties except for the amounts and types of oxygen-containing surface functional groups. The Pt/ccatalysts supported on the carbon with a higher surface oxygen content were found more durable during the AST, as compared to their corresponding counterparts supported on the carbon with a lower surface oxygen content. This was attributed to the presence of oxygen functional groups that may function as the active sites for the nucleation of new Pt-NPs, hence inhibiting Ostwald ripening to some extent. This study provides valuable catalyst support selection criteria and synthesis parameters at different pressures.
The carbonaceous residue (coke) formed on HZSM-5 during the conversion of methanol to gasoline was studied by 13 c n.m.r. spectroscopy using cross-polarization and magic angle spinning and by e.p.r. spectroscopy. Meas...
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The carbonaceous residue (coke) formed on HZSM-5 during the conversion of methanol to gasoline was studied by 13 c n.m.r. spectroscopy using cross-polarization and magic angle spinning and by e.p.r. spectroscopy. Measurements were made on samples with different coke contents and on samples from which some external coke had been removed by treatment with an oxygen plasma. It was found that the amount of carbon visible by n.m.r. differed from that expected from the measured coke contents and that the ratio of these amounts varied with the degree of coking. We concluded that the n.m.r.-visible carbon was most probably composed of methyl-substituted polycyclic aromatic hydrocarbons, the degree of methyl substitution and ring condensation changing with the coke content. It was inferred that these methyl-substituted polycyclic aromatics were present in the channels of the zeolite whereas the coke invisible to n.m.r. could be highly condensed polycyclic aromatics or “graphitic” structures on the external surfaces of the zeolite crystals. It appears that initial coke formation is internal and that external coke forms at latter stages in the deactivation process.
Many existing systems are written in c and are not re-entrant or thread safe. Sometimes these systems are required in a context for which they were not first designed, possibly meaning they now need to be re-entrant. ...
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Many existing systems are written in c and are not re-entrant or thread safe. Sometimes these systems are required in a context for which they were not first designed, possibly meaning they now need to be re-entrant. This article introduces a program that filters c source code, modifying shared resources (the global variables) to make the code re-entrant: 'virtualizing' the code. The code is then compiled as normal. This approach allows programmatic virtualization with little cost at runtime. copyright (c) 2007 John Wiley & Sons, Ltd.
We describe a production quality implementation of Scheme. Its design, and therefore the program, is based around objects although it is written in c, a language not specifically intended for object-oriented programmi...
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We describe a production quality implementation of Scheme. Its design, and therefore the program, is based around objects although it is written in c, a language not specifically intended for object-oriented programming. This was a fortuitous choice as it allowed us to recover from a design mistake that was not discovered until implementation time. Moreover, as we designed the program around objects and were not constrained by a strict object-oriented notation, this created a program that others have found easy to understand, extend and tune for improved performance.
Despite its maturity and popularity, the c programming language still lacks tool support for reliably performing even simple refactoring, browsing, or analysis operations. This is primarily due to identifier scope com...
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Despite its maturity and popularity, the c programming language still lacks tool support for reliably performing even simple refactoring, browsing, or analysis operations. This is primarily due to identifier scope complications introduced by the c preprocessor. The cScout refactoring browser analyses complete program families by tagging the original identifiers with their precise location and classifying them into equivalence classes orthogonal to the c language's namespace and scope extents. A web-based user interface provides programmers with an intuitive source code analysis and navigation front-end, while an SQL-based back-end allows more complex source code analysis and manipulation. cScout has been successfully applied to many medium and large-sized proprietary and open-source projects identifying thousands of modest refactoring opportunities. (c) 2009 Elsevier B.V. All rights reserved.
作者：
chen, L.Yao, X.cen, S.Wang, S.Tsinghua Univ
Sch Aerosp Engn Dept Engn Mech Beijing 100084 Peoples R China Tsinghua Univ
Sch Aerosp Engn Ctr High Performance Comp Beijing 100084 Peoples R China Natl Univ Def Technol
Coll Aerosp & Mat Engn State Key Lab Adv Ceram Fibers & Composites Changsha 410073 Hunan Peoples R China
In this paper, impact damage behaviours of c/Sic rigid-felt titanium alloy three-layered plate under normal impact are investigated. First, low velocity impact experiment of the three-layered plate is performed by mea...
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In this paper, impact damage behaviours of c/Sic rigid-felt titanium alloy three-layered plate under normal impact are investigated. First, low velocity impact experiment of the three-layered plate is performed by means of a drop weight impact apparatus. Second, the finite element model of the three-layered plate is established using a damage constitutive model;also, the influences of the initial kinetic energy (the initial velocity and the mass of the impactor) on stress distributions and damage patterns of the three-layered plate are analysed. Finally, the energy dissipation mechanisms and failure characterizations of the three-layered plate are discussed;also, the agreements of physical variables and damage morphologies between experimental and numerical results validate the reliability of numerical simulation. The results will play an important role in designing and evaluating advanced thermal protection structure.
Brown adipose tissue is important for maintaining energy homeostasis and adaptive thermogenesis in rodents and humans. As disorders arising from dysregulated energy metabolism, such as obesity and metabolic diseases, ...
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Brown adipose tissue is important for maintaining energy homeostasis and adaptive thermogenesis in rodents and humans. As disorders arising from dysregulated energy metabolism, such as obesity and metabolic diseases, have increased, so has interest in the molecular mechanisms of adipocyte biology. Using a functional screen, we identified cyclin c (cycc), a conserved subunit of the Mediator complex, as a novel regulator for brown adipocyte formation. siRNA-mediated cycc knockdown (KD) in brown preadipocytes impaired the early transcriptional program of differentiation, and genetic KO of cycccompletely blocked the differentiation process. RNA sequencing analyses of cycc-KD revealed a critical role of cycc in activating genes co-regulated by peroxisome proliferator activated receptor gamma (PPAR alpha) and ccAAT/enhancer-binding protein alpha (c/EBP alpha). Overexpression of PPAR gamma(2) or addition of the PPAR gamma ligand rosiglitazone rescued the defects in cycc-KO brown preadipocytes and efficiently activated the PPAR gamma-responsive promoters in both WT and cycc-KO cells, suggesting that cycc is not essential for PPAR gamma transcriptional activity. In contrast, cycc-KO significantly reduced c/EBP alpha-dependent gene expression. Unlike for PPAR gamma, overexpression of c/EBP alpha could not induce c/EBP alpha target gene expression in cycc-KO cells or rescue the cycc-KO defects in brown adipogenesis, suggesting that cycc is essential for c/EBP alpha-mediated gene activation. cycc physically interacted with c/EBP, and this interaction was required for c/EBP alpha transactivation domain activity. consistent with the role of c/EBP alpha in white adipogenesis, cycc-KD also inhibited differentiation of 3T3-L1 cells into white adipocytes. Together, these data indicate that cycc activates adipogenesis in part by stimulating the transcriptional activity of c/EBP alpha.
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