Determination of charge states of single swift heavy projectiles by high-energy delta-electrons

The effective charge state is an important particle parameter which is required for the calculation of many effects concerning the interaction between radiation and matter such as an estimate of the radial dose of swift heavy projectiles, stopping power and so on. A new method for the determination of effective charge states of heavy ions is based on the measurement of the number of high-energy delta-electrons which are ejected from a target by the penetrating ion. These electrons are detectable with a CCD-detector and their number can be correlated to the effective charge state of the projectile for known particle velocities. This method is even applicable to operation with single swift heavy ions within statistical bounds.     

Investigation of proton-proton short-range correlations via the 12C(e,e'pp) reaction

We investigated simultaneously the 12C(e,e'p) and 12C(e,e'pp) reactions at Q2=2 (GeV/c)2, xB=1.2, and in an (e, e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics, with a missing momentum greater than the Fermi momentum of nucleons in a nucleus and far from the delta excitation, short-range nucleon-nucleon correlations are predicted to dominate the reaction. For (9.5+/-2)% of the 12C(e,e'p) events, a recoiling partner proton was observed back-to-back to the 12C(e,e'p) missing-momentum vector, an experimental signature of correlations.     

The wittig reaction of non-stabilized phosphorus ylides and aromatic aldehydes. Studies on erythro and threo β-hydroxyphosphonium salts and the promotion of stereochemical drift by synergism between diastereomers

In deprotonation studies with isomerically pure $\text{erythro}$-3 and $\text{threo}$-3, “retro-Wittig” reaction was only detected for $\text{erythro}$-3. Mixtures of $\text{erythro}$-3 and $\text{threo}$-3, under lithium salt-free conditions, undergo stereochemical drift because of synergism between diastereomeric oxaphosphetanes $\text{cis}$-2 and $\text{trans}$-2 during their decomposition to alkenes.     

Quark-hadron duality in neutron (3He) spin structure

We present experimental results of the first high-precision test of quark-hadron duality in the spin-structure function g_{1} of the neutron and 3He using a polarized 3He target in the four-momentum-transfer-squared range from 0.7 to 4.0 (GeV/c);{2}. Global duality is observed for the spin-structure function g_{1} down to at least Q;{2}=1.8 (GeV/c);{2} in both targets. We have also formed the photon-nucleon asymmetry A1 in the resonance region for 3He and found no strong Q2 dependence above 2.2 (GeV/c);{2}.     

Inner mantles and iterated HOD

We present a class forcing notion $\mathbb{M}(\eta )$, uniformly definable for ordinals η, which forces the ground model to be the ηth inner mantle of the extension, in which the sequence of inner mantles has length at least η. This answers a conjecture of Fuchs, Hamkins, and Reitz [1] in the positive. We also show that $\mathbb{M}(\eta )$ forces the ground model to be the ηth iterated $\mathbf{HOD}$ of the extension, where the sequence of iterated $\mathbf{HOD}$s has length at least η. We conclude by showing that the lengths of the sequences of inner mantles and of iterated $\mathbf{HOD}$s can be separated to be any two ordinals you please.     

A method for C2 acylation of 1,3-indandiones

The 1,3-indandione scaffold is an important structural motif used in the preparation of a large number of industrial chemical and pharmaceutical compounds. However, few approaches allow for the direct C2 acylation on these building blocks. A method was developed using DMAP and EDCI, which is mild in reactivity, covers a diverse range of carboxylic acid acylating agents, is compatible with electron releasing and withdrawing substituents on the 1,3-indandione partner, and performs well in a polar aprotic solvent (for solubility reasons) This method cleanly afforded twenty five different products in yields of 32–96%.     

Pushing the Upper Limit of Nucleophilicity Scales by Mesoionic N-Heterocyclic Olefins

A series of mesoionic, 1,2,3-triazole-derived N-heterocyclic olefins (mNHOs), which have an extraordinarily electron-rich exocyclic CC-double bond, was synthesized and spectroscopically characterized, in selected cases by X-ray crystallography. The kinetics of their reactions with arylidene malonates, ArCH=C(CO₂Et)₂, which gave zwitterionic adducts, were investigated photometrically in THF at 20 °C. The resulting second-order rate constants k₂(20 °C) correlate linearly with the reported electrophilicity parameters E of the arylidene malonates (reference electrophiles), thus providing the nucleophile-specific N and s_N parameters of the mNHOs according to the correlation lg k₂(20 °C)=s_N(N+E). With 21<N<32, the mNHOs are much stronger nucleophiles than conventional NHOs. Some mNHOs even excel the reactivity of mono- and diacceptor-substituted carbanions. It is exemplarily shown that the reactivity parameters thus obtained allow to calculate the rate constants for mNHO reactions with further Michael acceptors and predict the scope of reactions with other electrophilic reaction partners including carbon dioxide, which gives zwitterionic mNHO-carboxylates. The nucleophilicity parameters N correlate linearly with a linear combination of the quantum-chemically calculated methyl cation affinities and buried volumes of mNHOs, which offers a valuable tool to tailor the reactivities of strong carbon nucleophiles.     

On the Function and Structure of Synthetically Modified Porins

The attachment of modulators to a trimeric porin ion channel was investigated (see picture of the trimer with a crown ether modulator (orange)). The interplay of modulator and protein is essential for the conformational heterogeneity of the hybrid channel. Single‐site attachment in large pores is not sufficient to change the electrophysiological characteristics of the pores—such change requires additional noncovalent interactions or second‐site attachments.