نتایج جستجو برای: metal cluster
تعداد نتایج: 395377 فیلتر نتایج به سال:
Compounds with M—C(sp2) or N—C(sp) bonds show a reactivity different from that of metal—alkyl complexes. This paper describes some reactions of transition metal acetylides, which are characterised by electrophilic additions to the s—carbon. Cycloaddition to olef ins has given cyclobutenyl, butadienyl and allylic derivatives, while reactions with tropylium and arenediazonium salts generate new t...
A mathematical model was developed for ionic conduction in amorphous oxide films. The model is based on a hypothesized “defect cluster” mechanism in which both metal and oxygen ions are involved in transport. Defect clusters are created by inward displacement of oxygen ions around an oxygen vacancy‐like defect in response to the vacancy's electric field. Metal ions are assumed to migrate easily...
Nitrogenase enzymes have evolved complex iron-sulfur (Fe-S) containing cofactors that most commonly contain molybdenum (MoFe, Nif) as a heterometal but also exist as vanadium (VFe, Vnf) and heterometal-independent (Fe-only, Anf) forms. All three varieties are capable of the reduction of dinitrogen (N(2)) to ammonia (NH(3)) but exhibit differences in catalytic rates and substrate specificity uni...
We present an analysis of a 50 orbit HST ACS observation of the M87 globular cluster system. We use the extraordinary depth of this dataset to test whether the colors and magnitudes show evidence for a mass-metallicity relation in globular cluster populations. We find only a weak or absent relation between the colors and magnitudes of the metal poor subpopulation of globular clusters. The weakn...
The assembly of ultrasmall metal nanoclusters (NCs) is of interest to both basic and applied research as it facilitates the determination of cluster structures and the customization of cluster physicochemical properties. Here we present a facile and general approach to assemble noble metal NCs by selectively inducing electrostatic interactions between negatively-charged metal NCs and divalent c...
Music in general and the music industry in particular have been understudied subjects in the field of geography. The relatively scarce amount of literature on music industries has concentrated its attention on companies operating inside the industry, and on popular music. There is a gap in the knowledge on the networking processes of individuals inside the music industry and the geographical dy...
Hydrated trivalent rare earth metal ions containing yttrium and all naturally abundant lanthanide metals are formed using electrospray ionization, and the structures and reactivities of these ions containing 17-21 water molecules are probed using blackbody infrared radiative dissociation (BIRD) and infrared action spectroscopy. With the low-energy activation conditions of BIRD, there is an abru...
The plant metallothionein2 from Cicer arietinum (chickpea), cic-MT2, is known to coordinate five divalent metal ions such as Zn(II) or Cd(II), which are arranged in a single metal thiolate cluster. When the Zn(II) form of the protein is titrated with Cd(II) ions in the presence of sulfide ions, an increased Cd(II) binding capacity and concomitant incorporation of sulfide ions into the cluster a...
The globular cluster Ω Centauri (NGC 5139) is the most massive and brightest cluster in our Galaxy. It has also a moderately high mass to light ratio (3.6) and an anomalous flattening (0.83) for a globular cluster. This cluster is also very interesting because it is one of a few examples of globular clusters with a measurable spread in the metal abundance (see Da Costa & Willumsen 1981, Norris ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید