Calcium cyanurate is synthesized by reacting calcium chloride with potassium cyanate following a solid‐state reaction. The formation of the new compound Ca3(O3C3N3)2 (CCY), which occurs by the ...cyclotrimerization of cyanate ions, was examined thermoanalytically and the crystal structure was determined by single‐crystal structure analysis. The structure of CCY is closely related to the structure of the well‐known oxoborate β‐BaB2O4 (BBO). Second harmonic generation (SHG) measurements on crystal powders show a higher SHG efficiency for CCY than for BBO by about one order of magnitude.
The alkaline‐earth cyanurate Ca3(O3C3N3)2 (CCY) was produced in a solid‐state metathesis reaction through the cyclotrimerization of cyanate ions. The crystal structure of CCY is closely related to the structure of β‐BBO. Crystalline CCY promises to be amongst the most efficient frequency doubling materials.
Research in various populations has shown that, starting early in childhood, individuals often demonstrate resilience in the face of stress and adversity. Against the experience of minority stress, ...LGBT people mount coping responses and most survive and even thrive despite stress. But research on resilience in LGBT populations has lagged. In this commentary, I address 2 broad issues that I have found wanting of special exploration in LGBT research on resilience: First, I note that resilience, like coping, is inherently related to minority stress in that it is an element of the stress model. Understanding resilience as a partner in the stress to illness causal chain is essential for LGBT health research. Second, I explore individual- versus community-based resilience in the context of minority stress. Although individual and community resilience should be seen as part of a continuum of resilience, it is important to recognize the significance of community resilience in the context of minority stress.
Electrochemical Cobalt‐Catalyzed C−H Activation Sauermann, Nicolas; Meyer, Tjark H.; Ackermann, Lutz
Chemistry : a European journal,
November 2, 2018, Letnik:
24, Številka:
61
Journal Article
Recenzirano
Carbon–heteroatom bonds represent omnipresent structural motifs of the vast majority of functionalized materials and bioactive compounds. C−H activation has emerged as arguably the most efficient ...strategy to construct C−Het bonds. Despite of major advances, these C−H transformations were largely dominated by precious transition metal catalysts, in combination with stoichiometric, toxic metal oxidants. Herein, we discuss the recent evolution of cobalt‐catalyzed C−H activations that enable C−Het formations with electricity as the sole sustainable oxidant until May 2018.
The recent merger of cobalt‐catalyzed C−H activation with electrosynthesis has enabled C−Het and C−Het formations with electricity as the sustainable oxidant.
Electrochemistry enabled C−H/N−H functionalizations at room temperature by external oxidant‐free cobalt catalysis. Thus, the sustainable cobalt electrocatalysis manifold proceeds with excellent ...levels of chemoselectivity and positional selectivity, and with ample scope, thus allowing electrochemical C−H activation under exceedingly mild reaction conditions at room temperature in water.
Electro Co: Cobalt‐catalyzed C−H/N−H functionalizations were accomplished in H2O at 23 °C without toxic metal oxidants by using electricity. This sustainable cobalt electrocatalysis manifold proceeds with excellent levels of chemoselectivity and positional selectivity, and with ample scope.
► Effects of graphite surface modification by oxygen treatment on anode performance. ► Estimation of graphite morphology changes by density functional theory (DFT). ► Absolute and relative extents of ...basal plane and “non-basal plane surface” areas. ► Correlation of
C
irr to change of quantitative amounts of graphitic surfaces is shown. ► Correlation of Raman spectra, DFT calculations and electrochemical performance.
For graphitic carbons as anode materials in lithium ion batteries, the morphology and chemistry of the graphite surface have a significant impact on the formation of the solid electrolyte interphase (SEI), the corresponding irreversible charge losses, and the overall electrochemical anode performance. In this work the effects of graphite surface modification, induced by an elevated temperature treatment, on the SEI formation are discussed in details. Morphology changes due to burn-off of carbon are investigated by Raman spectroscopy and nitrogen adsorption measurements, which are not only used to calculate the BET specific surface area but also for the estimation of the absolute and relative extents of the basal plane surface area and the “non-basal plane surface” area. In particular, the relation of the first cycle irreversible charge loss to the change of surface morphology, especially to the quantitative amounts of the different types of surfaces is highlighted.
We assessed 12-month prevalence and incidence data on sexual victimization in 5 federal surveys that the Bureau of Justice Statistics, the Centers for Disease Control and Prevention, and the Federal ...Bureau of Investigation conducted independently in 2010 through 2012. We used these data to examine the prevailing assumption that men rarely experience sexual victimization. We concluded that federal surveys detect a high prevalence of sexual victimization among men-in many circumstances similar to the prevalence found among women. We identified factors that perpetuate misperceptions about men's sexual victimization: reliance on traditional gender stereotypes, outdated and inconsistent definitions, and methodological sampling biases that exclude inmates. We recommend changes that move beyond regressive gender assumptions, which can harm both women and men.
Cytoplasmic male sterility (CMS) is a common feature encountered in plant species. It is the result of a genomic conflict between the mitochondrial and the nuclear genomes. CMS is caused by ...mitochondrial encoded factors which can be counteracted by nuclear encoded factors restoring male fertility. Despite extensive work, the molecular mechanism of male sterility still remains unknown. Several studies have suggested the involvement of respiration on the disruption of pollen production through an energy deficiency. By comparing recent works on CMS and respiratory mutants, we suggest that the "ATP hypothesis" might not be as obvious as previously suggested.
We present results for the isovector electromagnetic form factors of the nucleon computed on the coordinated lattice simulations ensembles with Nf=2+1 flavors of O(a)-improved Wilson fermions and an ...O(a)-improved vector current. The analysis ncludes ensembles with four lattice spacings and pion masses ranging from 130 up o 350 MeV and mainly targets the low-Q2 region. In order to remove any bias rom nsuppressed excited-state contributions, we investigate several source-sink eparations between 1.0 and 1.5 fm and apply the summation method as well as xplicit two-state fits. The chiral interpolation is performed by applying covariant hiral perturbation theory including vector mesons directly to our form factor data, hus avoiding an auxiliary parametrization of the Q2 dependence. At the physical oint, we obtain μ=4.71(11)stat(13)sys for the nucleon isovector magnetic moment, in good agreement with the experimental value and ⟨r2M⟩=0.661(30)stat(11)sys fm2 for the corresponding square radius, again in good agreement with the alue inferred from the ep-scattering determination Bernauer et al., Phys. Rev. ett. 105, 242001 (2010) of the proton radius. Our estimate for the isovector electric charge radius, ⟨r2E⟩=0.800(25)stat(22)sys fm2, however, is in slight tension with the larger value inferred from the aforementioned ep-scattering data, while being in agreement with the value derived from the 2018 CODATA average for the proton charge radius.
This study examined the effects of minority stress on the physical health of lesbians, gay men, and bisexuals (LGBs). Participants (
N
= 396) completed baseline and one year follow-up interviews. ...Exposure to stress and health outcomes were assessed with two methods: a subjective self-appraisal method and a method whereby two independent judges externally rated event narratives using standardized criteria. The odds of experiencing a physical health problem at follow-up were significantly higher among LGBs who experienced an externally rated prejudice event during the follow-up period compared to those who did not. This association persisted after adjusting for experiences of general stressful life events that were not related to prejudice. Self-appraised minority stress exposures were not associated with poorer physical health at 1-year follow-up. Prejudice-related stressful life events have a unique deleterious impact on health that persists above and beyond the effect of stressful life events unrelated to prejudice.
The preparation of tungsten iodides in large quantities is a challenge because these compounds are not accessible using an easy synthesis method. A new, remarkably efficient route is based on a ...halide exchange reaction between WCl6 and SiI4. The reaction proceeds at moderate temperatures in a closed glass vessel. The new compounds W3I12 (W3I8⋅2 I2) and W3I9 (W3I8⋅1/2
I2) containing the novel W3I8 cluster are formed at 120 and 150 °C, and remain stable in air. W3I12 is an excellent starting material for the synthesis of other metal‐rich tungsten iodides. At increasing temperature these trinuclear clusters undergo self‐reduction until an octahedral tungsten cluster is formed in W6I12. The synthesis, structure, and an analysis of the bonding of compounds containing this new trinuclear tungsten cluster are presented.
A halide exchange reaction between WCl6 and SiI4 yields a new stable tungsten iodide W3I12 (W3I8⋅2 I2) with the W3I8 cluster (see picture), which can be used in the synthesis of other tungsten iodides. The synthesis and the structure and bonding situation of compounds with this new trinuclear cluster are presented.
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