scholarly journals Na2MoO2−δF4+δ – a perovskite with a unique combination of atomic orderings and octahedral tilts

2015 ◽  
Vol 51 (84) ◽  
pp. 15469-15471 ◽  
Author(s):  
Hajime Ishikawa ◽  
Irene Munaò ◽  
Bela E. Bode ◽  
Zenji Hiroi ◽  
Philip Lightfoot
Keyword(s):  
Unique Combination ◽  
System P ◽  
Anion Site ◽  
A Site

Na2MoO2−δF4+δ represents the first example of a perovskite exhibiting simultaneous A-site, B-site and anion site order, together with a complex tilt system.

scholarly journals The molybdenum centre of native xanthine oxidase. Evidence for proton transfer from substrates to the centre and for existence of an anion-binding site

1978 ◽  
Vol 175 (3) ◽  
pp. 869-878 ◽  
Author(s):  
S Gutteridge ◽  
S J Tanner ◽  
R C Bray
Keyword(s):  
Xanthine Oxidase ◽  
Anion Binding ◽  
Hydrogen Atoms ◽  
Substrate Molecule ◽  
Strongly Coupled ◽  
Exchange Processes ◽  
Turnover Process ◽  
Anion Site ◽  
A Site

The observation by Bray & Knowles [Proc. R. Soc. London Ser. A (1968) 302, 351–353] of direct transfer, during the catalytic reaction, of hydrogen atoms from substrate molecules to the enzyme xanthine oxidase was reinvestigated. The experimental phenomenon and its basic interpretation were confirmed and extended. In the reduced functional enzyme, molybdenum(V) interacts with two enzyme-bound protons, which are exchangeable with solvent protons. One of these is coupled to the metal with AHav. 1.4mT and the other with AHav. 0.3mT. The molecule also contains a site for the binding of anions, presumably as ligands of molybdenum. This is shown by effects of nitrate ions on the e.p.r. spectra. The spectra of the nitrate and 1-methylxanthine complexes of the reduced enzyme are very similar to one another, and are designated Rapid type-1 spectra. It is concluded that, in the Michaelis complex, the substrate molecule occupies the anion site, probably being bound to molybdenum via the nitrogen in its 9-position. During the turnover process, hydrogen from the substrate C-8 position, after transfer to the enzyme, appears as the proton more strongly coupled to molybdenum. This proton then exchanges with solvent deuterium with a rate constant of 27s-1, at pH 8.2 and 12 degrees C. It has been confirmed that substrate molecules occupying the anion site do not interfere with observation of the transfer and exchange processes.

I Speak in the Third Person

Post-Mandarin ◽  
2017 ◽  
Author(s):  
Ben Tran
Keyword(s):  
Educational System ◽  
Social Group ◽  
Cultural Translation ◽  
Grammatical Category ◽  
The Third ◽  
System P ◽  
Third Person ◽  
Exam System ◽  
A Site ◽  
The Third Person

Focusing on Khái Hưng’s Nửa chừng xuân [In the Midst of Spring], Chapter 4 examines how the author addressed the cultural translation of Europe’s first-person grammatical category, a significant marker of modern Vietnamese literature, into Vietnam’s Confucian sociolinguistic order. The chapter suggests that the cultural translation of Western individualism into the Vietnamese language was a site of gendered discrepancies and differences. In particular, the chapter examines how the colonial government’s implementation of a French educational system in place of the preexisting mandarin exam system affected women, a social group that had been excluded from the precolonial educational system.

Singing “The Internationale”

2016 ◽  
Author(s):  
Xiaomei Chen
Keyword(s):  
Status Quo ◽  
Cultural Performance ◽  
Construction Of Knowledge ◽  
System P ◽  
The Status ◽  
Chinese Intellectuals ◽  
A Site

This chapter examines the preoccupation of Chinese intellectuals, translators, writers, and performers with the power of voice and sound by analyzing the prominent role of “The Internationale” throughout the changing landscape of Chinese cultural performance. It traces how “The Internationale” evolved from its French and Soviet roots into a Chinese nationalist song and how it became a rally song to mobilize the Chinese masses, preserving its popularity through political vicissitudes up until the postsocialist era. Despite the song’s historical involvement in the construction of revolutionary discourse, “The Internationale” has retained its function as a song of memory and of counterculture for manipulating the very revolutionary beliefs it had helped promote. As a site of sonic construction of knowledge and power, “The Internationale” embodies and manifests complex and paradoxical impulses, which can at once legitimize and challenge the status quo and its authoritarian system.

Transfronteriza

2017 ◽  
Author(s):  
Michelle Téllez
Keyword(s):  
Trade Agreement ◽  
Community Formation ◽  
Twin Cities ◽  
Collective Consciousness ◽  
The North ◽  
Feminist Politics ◽  
System P ◽  
Mexico Border ◽  
A Site ◽  
Geographical Space

This chapter examines how women border dwellers are responding to transnational processes and the effects of neoliberal policies, such as the North American Free Trade Agreement (NAFTA), by focusing on woman-centered activism projects as well as innovative forms of political organizing and community formation at the U.S./Mexico border. Building on the idea of transfronterismo, or transborderness, the chapter suggests that the actual border should be seen not just as a site of passage but also as a site for gendered transformation where a politicized transfronteriza identity can emerge. It looks specifically at the transborder space of the twin cities of Tijuana and San Diego and the work of the La Colectiva Feminista Binacional (Binational Feminist Collective, CFB). It probes the lives and experiences of the men and women of the maquiladora industry and shows that the construction of a politicized transfronteriza identity is determined by three factors: a shared geographical space, a collective consciousness based on mutual experiences and solidarity, and a feminist politics that looks at women's rights as fundamental to challenging the system.

Eels Under Standing Wave Conditions

1982 ◽  
Vol 40 ◽  
pp. 492-495
Author(s):  
O.L. Krivanek ◽  
J. TaftØ
Keyword(s):  
Standing Wave ◽  
Wave Conditions ◽  
Set Up ◽  
A Site ◽  
Complex Crystal

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.

Head Size and DNA Content in Bacteriophage T4

1972 ◽  
Vol 30 ◽  
pp. 200-201
Author(s):  
Fred Eiserling ◽  
A. H. Doermann ◽  
Linde Boehner
Keyword(s):  
Electron Microscopy ◽  
Dna Content ◽  
Bacteriophage T4 ◽  
Head Size ◽  
Virus Particles ◽  
Altered Protein ◽  
A Cell ◽  
Bacterial Viruses ◽  
A Site ◽  
Protein Shell

The control of form or shape inheritance can be approached by studying the morphogenesis of bacterial viruses. Shape variants of bacteriophage T4 with altered protein shell (capsid) size and nucleic acid (DNA) content have been found by electron microscopy, and a mutant (E920g in gene 66) controlling head size has been described. This mutant produces short-headed particles which contain 2/3 the normal DNA content and which are non-viable when only one particle infects a cell (Fig. 1).We report here the isolation of a new mutant (191c) which also appears to be in gene 66 but at a site distinct from E920g. The most striking phenotype of the mutant is the production of about 10% of the phage yield as “giant” virus particles, from 3 to 8 times longer than normal phage (Fig. 2).

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

Comparison of TEM and STM observations of small silver clusters on different carbon supports

1990 ◽  
Vol 48 (4) ◽  
pp. 264-265
Author(s):  
Bernd Tesche ◽  
Tobias Schilling
Keyword(s):  
Vibration Isolation ◽  
Pyrolytic Graphite ◽  
Carbon Film ◽  
Silver Clusters ◽  
Carbon Supports ◽  
Stacking Order ◽  
System P ◽  
High Resolution Tem ◽  
High Degree ◽  
Degree Of Order

The objective of our work is to determine:a) whether both of the imaging methods (TEM, STM) yield comparable data andb) which method is better suited for a reliable structure analysis of microclusters smaller than 1.5 nm, where a deviation of the bulk structure is expected.The silver was evaporated in a bell-jar system (p 10−5 pa) and deposited onto a 6 nm thick amorphous carbon film and a freshly cleaved highly oriented pyrolytic graphite (HOPG).The average deposited Ag thickness is 0.1 nm, controlled by a quartz crystal microbalance at a deposition rate of 0.02 nm/sec. The high resolution TEM investigations (100 kV) were executed by a hollow-cone illumination (HCI). For the STM investigations a commercial STM was used. With special vibration isolation we achieved a resolution of 0.06 nm (inserted diffraction image in Fig. 1c). The carbon film shows the remarkable reduction in noise by using HCI (Fig. 1a). The HOPG substrate (Fig. 1b), cleaved in sheets thinner than 30 nm for the TEM investigations, shows the typical arrangement of a nearly perfect stacking order and varying degrees of rotational disorder (i.e. artificial single crystals). The STM image (Fig. 1c) demonstrates the high degree of order in HOPG with atomic resolution.

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