The new SPASCHARM experiment for systematic studies of polarization phenomena in strong interactions is under construction now at IHEP, Protvino. The technical beam runs for the experiment first ...stage are planned for the Fall 2016 and Spring 2017. At this stage, the polarization measurements will be carried out with unpolarized hadronic beams of various compositions (π±, K±, p, antiprotons), using the polarized target. The universal large acceptance experimental set-up is capable detecting and identification most charged and neutral particles and reconstructing a large number of resonances produced in beam interactions at polarized proton target, and later on at the second stage, in collisions of polarized proton and antiproton beams with fixed targets of various materials. The large acceptance and wide data acquisition bandwidth would provide the capabilities for simultaneous data accumulation for a number of physics analyses from the measurements of single-spin asymmetries in inclusive and exclusive reactions to reconstructions of final state hyperon polarizations and spin density matrix elements for vector mesons in a wide range of kinematic variables (pT, xF).
Analytical and numerical methods of solving inverse problems for logarithmic and Newtonian potentials are investigated. The following contact problem in the case of a Newtonian potential is ...considered: In a domain Ω{Ω:−l≤x,y≤l,H−φ(x,y)≤z≤H} there are sources with density ρ(x,y) that perturb the Earth’s gravitational field. Here φ(x,y) is a nonnegative compactly supported function with a support Ω=−l,l2, 0≤φ(x,y)≤H. It is required to simultaneously restore the depth H of the contact surface z=H, the density ρ(x,y) of the sources, and the function φ(x,y). Methods of simultaneous determination based on nonlinear models of potential theory are developed in this paper. The following basic information is used in case of a Newtonian potential: (1) values of the gravity field and its first and second derivatives; (2) values of the gravity field at different heights. A method of simultaneous recovery of the functions ρ(x,y), φ(x,y) and the constant H in analytical form is demonstrated. Iterative methods for the simultaneous recovery are constructed. The efficiency of the numerical methods is demonstrated on model examples.
The degassing of Allende carbonaceous chondrite (CV3 type) was studied using a setup specially designed for this purpose. The experiments involved stepwise heating (without gas accumulation) and ...isothermal annealing of meteorite samples with the composition of released gases determined through gas chromatography methods in the temperature range from 200 to 800°C. To account for sorbed water, degassing at 50 and 110°C was additionally analyzed. The Raman and IR spectra of both the primary Allende substance and the substance after its annealing at three temperatures (200, 500, and 800°C) were obtained. These spectra were used to trace the thermal transformation of the substance of the meteorite’s parent body and estimate the maximum temperature of metamorphism. The results were compared with the degassing of the Murchison carbonaceous chondrite of another type (CM2).
The rapid progress in mass-market applications of metal-ion batteries intensifies the development of economically feasible electrode materials based on earth-abundant elements. Here, we report on a ...record-breaking titanium-based positive electrode material, KTiPO
F, exhibiting a superior electrode potential of 3.6 V in a potassium-ion cell, which is extraordinarily high for titanium redox transitions. We hypothesize that such an unexpectedly major boost of the electrode potential benefits from the synergy of the cumulative inductive effect of two anions and charge/vacancy ordering. Carbon-coated electrode materials display no capacity fading when cycled at 5C rate for 100 cycles, which coupled with extremely low energy barriers for potassium-ion migration of 0.2 eV anticipates high-power applications. Our contribution shows that the titanium redox activity traditionally considered as "reducing" can be upshifted to near-4V electrode potentials thus providing a playground to design sustainable and cost-effective titanium-containing positive electrode materials with promising electrochemical characteristics.
Hard carbon is the most prospective anode material for sodium-ion batteries with outstanding electrochemical performance. However, the type of reaction associated with charge storage is a subject of ...contentious deliberations within the scientific society. We examined the pseudocapacitive behavior of glucose-derived hard carbon with different porosity by detailed linear sweep voltammetric analysis which demonstrated the presence of three distinct processes occurring during Na+-deinsertion. A combination of pseudocapacitive-intercalation-pseudocapacitive behavior for all synthesized hard carbons is proposed. Obtained results differ drastically from the behavior demonstrated by graphite/Li cell, soft carbon/Na cell and pure Na metal plating.
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•LSV analysis were applied to study Na+ (de)insertion mechanism in hard carbon.•“Sloping” part of the charge/discharge curve refers to pseudocapacitive prosess.•Low-voltage “plateau” is predominantly intercalation-type process.•Third step of the charge storage mechanism (at ∼20 mV) was observed and investigated.•Pseudocapacitive-intercalation-pseudocapacitive mechanism is proposed.
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