Electrochemical behavior of a titanium electrode in hydrazine solutions

The kinetics of the establishment of the oxidation-reduction potential of a titanium electrode upon contact with hydrazine was studied in different media: H2SO4, NaOH, and Na2SO4. It was found that the nature of the potential shift depends little on the medium. The initial potential determines the rate of potential displacement upon contact with hydrazine, which is explained by the different condition of the electrode's surface

Transition frequency shifts with fine structure constant variation for Fe II: Breit and core-valence correlation correction

Transition frequencies of Fe II ion are known to be very sensitive to variation of the fine structure constant \alpha. The resonance absorption lines of Fe II from objects at cosmological distances are used in a search for the possible variation of \alpha in cause of cosmic time. In this paper we calculated the dependence of the transition frequencies on \alpha^2 (q-factors) for Fe II ion. We found corrections to these coefficients from valence-valence and core-valence correlations and from the Breit interaction. Both the core-valence correlation and Breit corrections to the q-factors appeared to be larger than had been anticipated previously. Nevertheless our calculation confirms that the Fe II absorption lines seen in quasar spectra have large q-factors of both signs and thus the ion Fe II alone can be used in the search for the \alpha-variation at different cosmological epochs.Comment: 7 pages, submitted to Phys. Rev.

Critical Behavior of the Conductivity of Si:P at the Metal-Insulator Transition under Uniaxial Stress

We report new measurements of the electrical conductivity sigma of the canonical three-dimensional metal-insulator system Si:P under uniaxial stress S. The zero-temperature extrapolation of sigma(S,T -> 0) ~\S - S_c\^mu shows an unprecidentedly sharp onset of finite conductivity at S_c with an exponent mu = 1. The value of mu differs significantly from that of earlier stress-tuning results. Our data show dynamical sigma(S,T) scaling on both metallic and insulating sides, viz. sigma(S,T) = sigma_c(T) F(\S - S_cT^y) where sigma_c(T) is the conductivity at the critical stress S_c. We find y = 1/znu = 0.34 where nu is the correlation-length exponent and z the dynamic critical exponent.Comment: 5 pages, 4 figure

Threshold Laws for the Break-up of Atomic Particles into Several Charged Fragments

The processes with three or more charged particles in the final state exhibit particular threshold behavior, as inferred by the famous Wannier law for (2e + ion) system. We formulate a general solution which determines the threshold behavior of the cross section for multiple fragmentation. Applications to several systems of particular importance with three, four and five leptons (electrons and positrons) in the field of charged core; and two pairs of identical particles with opposite charges are presented. New threshold exponents for these systems are predicted, while some previously suggested threshold laws are revised.Comment: 40 pages, Revtex, scheduled for the July issue of Phys.Rev.A (1998

Conductivity of Metallic Si:B near the Metal-Insulator Transition: Comparison between Unstressed and Uniaxially Stressed Samples

The low-temperature dc conductivities of barely metallic samples of p-type Si:B are compared for a series of samples with different dopant concentrations, n, in the absence of stress (cubic symmetry), and for a single sample driven from the metallic into the insulating phase by uniaxial compression, S. For all values of temperature and stress, the conductivity of the stressed sample collapses onto a single universal scaling curve. The scaling fit indicates that the conductivity of si:B is proportional to the square-root of T in the critical range. Our data yield a critical conductivity exponent of 1.6, considerably larger than the value reported in earlier experiments where the transition was crossed by varying the dopant concentration. The larger exponent is based on data in a narrow range of stress near the critical value within which scaling holds. We show explicitly that the temperature dependences of the conductivity of stressed and unstressed Si:B are different, suggesting that a direct comparison of the critical behavior and critical exponents for stress- tuned and concentration-tuned transitions may not be warranted

Анализ состояния безопасности дорожного движения в Республике Казахстан

The article presents the results of the study of the road traffic safety on the automobile roads of the Republic of Kazakhstan. We performed the analysis of the main indicators, specifying the state of the road traffic safety on the automobile roads of the republican significance of the Republic of Kazakhstan. In many regulatory acts, such as “The Priority Action Plan for Improving the Road Traffic Safety of the Republic of Kazakhstan for 2017–2020”, developed with the support of the Asian Development Bank, and in the “National Concept of Road Traffic Safety” project as well , developed by the Interdepartmental Research Institute called “The Academy of Law Enforcement Agencies” of the General Prosecutor’s Office of the Republic of Kazakhstan, the urgent need to improve road traffic safety is clearly pointed. At the same time, it is necessary to have the information about the extent of the existing problem in the field of road traffic safety, which is ensured by the constant consideration and analysis of the statistical indicators, as well as by planning appropriate measures aimed at correcting the situation and achieving planned indicators in the framework of, for example, the national concept of road traffic safety. Currently, statistics on road traffic accidents, occurring in Kazakhstan, are published by the Committee on Statistics of the Republic of Kazakhstan and the Committee on Legal Statistics and Special Accounting. However in the current situation, this is not enough, especially since the ARC MIID of the Republic of Kazakhstan outlined the program of actions aimed at eliminating the existing shortcomings in the field of the road traffic safety and significant improving its indicators. The analytical investigation of the status of the road traffic safety on the roads of the Republic of Kazakhstan was carried out. This will become a kind of starting point in the consistent work in this direction, which will provide the interested parties, first of all the experts, with the high-quality and reliable information about the main figures, characterizing the state of safety of the road users. Based on objective accident data, it is possible to take the effective measures aimed at improving the situation on the roads of the Republic of Kazakhstan.В статье представлены результаты исследования безопасности дорожного движения и проведен анализ основных показателей, определяющих состояние безопасности дорожного движения на автомобильных дорогах республиканского значения Казахстана. Во многих распорядительных документах, таких, например, как «Приоритетный план действий по повышению безопасности дорожного движения в Республике Казахстан на 2017–2020 годы», разработанном при поддержке Азиатского банка развития, а также в проекте «Национальная концепция безопасности дорожного движения», подготовленном Межведомственным научно-исследовательским институтом «Академия правоохранительных органов» Генеральной прокуратуры Республики Казахстан, четко указана острая необходимость повышения безопасности дорожного движения. В то же время необходимо иметь информацию о масштабах существующей проблемы в области безопасности дорожного движения, что обеспечивается постоянным изучением и анализом статистических показателей, а также планированием соответствующих мер, направленных на исправление ситуации и достижение запланированных показателей в рамках, например, Национальной концепции безопасности дорожного движения. В настоящее время статистика дорожно-транспортных происшествий, происходящих в стране, публикуется Комитетом по статистике Республики Казахстан и Комитетом по правовой статистике и специальному учету. Однако в сложившейся ситуации этого недостаточно, тем более что Министерство индустрии и инфраструктурного развития Республики Казахстан наметило программу действий, направленную на устранение существующих недостатков в области безопасности дорожного движения и значительное улучшение ее показателей. Проведено аналитическое исследование состояния безопасности дорожного движения. Это станет своего рода отправной точкой в последовательной работе в данном направлении, которая предоставит заинтересованным сторонам, в первую очередь экспертам, качественную и достоверную информацию об основных показателях, характеризующих состояние безопасности участников дорожного движения. Исходя из объективных данных о ДТП, можно принять эффективные меры, направленные на улучшение ситуации на дорогах Республики Казахстан

Scaling of the Conductivity with Temperature and Uniaxial Stress in Si:B at the Metal-Insulator Transition

Using uniaxial stress to tune Si:B through the metal-insulator transition we find the conductivity at low temperatures shows an excellent fit to scaling with temperature and stress on both sides of the transition. The scaling functions yield the conductivity in the metallic and insulating phases, and allow a reliable determination of the temperature dependence in the critical regions on both sides of the transition

Electric dipole moments of Hg, Xe, Rn, Ra, Pu, and TlF induced by the nuclear Schiff moment and limits on time-reversal violating interactions

We have calculated the atomic electric dipole moments (EDMs) induced in ^{199}Hg, ^{129}Xe, ^{223}Rn, ^{225}Ra, and ^{239}Pu by their respective nuclear Schiff moments S. The results are (in units 10^{-17}S(e {fm}^{3})^{-1}e cm): d(^{199}Hg)=-2.8, d(^{129}Xe)=0.38, d(^{223}Rn)=3.3, d(^{225}Ra)=-8.5, d(^{239}Pu)=-11. We have also calculated corrections to the parity- and time-invariance-violating (P,T-odd) spin-axis interaction constant in TlF. These results are important for the interpretation of atomic and molecular experiments on EDMs in terms of fundamental P,T-odd parameters.Comment: 16 page

Myostatin Inhibition in Muscle, but Not Adipose Tissue, Decreases Fat Mass and Improves Insulin Sensitivity

Myostatin (Mstn) is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Mstn−/− mice have a dramatic increase in muscle mass, reduction in fat mass, and resistance to diet-induced and genetic obesity. To determine how Mstn deletion causes reduced adiposity and resistance to obesity, we analyzed substrate utilization and insulin sensitivity in Mstn−/− mice fed a standard chow. Despite reduced lipid oxidation in skeletal muscle, Mstn−/− mice had no change in the rate of whole body lipid oxidation. In contrast, Mstn−/− mice had increased glucose utilization and insulin sensitivity as measured by indirect calorimetry, glucose and insulin tolerance tests, and hyperinsulinemic-euglycemic clamp. To determine whether these metabolic effects were due primarily to the loss of myostatin signaling in muscle or adipose tissue, we compared two transgenic mouse lines carrying a dominant negative activin IIB receptor expressed specifically in adipocytes or skeletal muscle. We found that inhibition of myostatin signaling in adipose tissue had no effect on body composition, weight gain, or glucose and insulin tolerance in mice fed a standard diet or a high-fat diet. In contrast, inhibition of myostatin signaling in skeletal muscle, like Mstn deletion, resulted in increased lean mass, decreased fat mass, improved glucose metabolism on standard and high-fat diets, and resistance to diet-induced obesity. Our results demonstrate that Mstn−/− mice have an increase in insulin sensitivity and glucose uptake, and that the reduction in adipose tissue mass in Mstn−/− mice is an indirect result of metabolic changes in skeletal muscle. These data suggest that increasing muscle mass by administration of myostatin antagonists may be a promising therapeutic target for treating patients with obesity or diabetes