Venera-11 and Venera 12: Preliminary estimates for the wind speed and turbulence in the atmosphere of Venus

The methods and results of measurements for wind speed and atmospheric turbulence in the clouds of Venus are described, and compared with earlier results. The distribution of wind speed obtained from the data of Venera 12 is in good conformity with the data of the preceding Venera and Pioneer probes, indicating the existence of a constant and powerful zonal movement of the troposphere

Hacking commercial quantum cryptography systems by tailored bright illumination

The peculiar properties of quantum mechanics allow two remote parties to communicate a private, secret key, which is protected from eavesdropping by the laws of physics. So-called quantum key distribution (QKD) implementations always rely on detectors to measure the relevant quantum property of single photons. Here we demonstrate experimentally that the detectors in two commercially available QKD systems can be fully remote-controlled using specially tailored bright illumination. This makes it possible to tracelessly acquire the full secret key; we propose an eavesdropping apparatus built of off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photodiodes to detect single photons. We believe that our findings are crucial for strengthening the security of practical QKD, by identifying and patching technological deficiencies.Comment: Revised version, rewritten for clarity. 5 pages, 5 figures. To download the Supplementary information (which is in open access), go to the journal web site at http://dx.doi.org/10.1038/nphoton.2010.21

Revealing Network Connectivity From Dynamics

We present a method to infer network connectivity from collective dynamics in networks of synchronizing phase oscillators. We study the long-term stationary response to temporally constant driving. For a given driving condition, measuring the phase differences and the collective frequency reveals information about how the oscillators are interconnected. Sufficiently many repetitions for different driving conditions yield the entire network connectivity from measuring the dynamics only. For sparsely connected networks we obtain good predictions of the actual connectivity even for formally under-determined problems.Comment: 10 pages, 4 figure

Thermal stability of a laser-clad NiCrBSi coating hardened by frictional finishing

Frictional treatment decreases surface roughness of a NiCrBSi laser coating and increases its microhardness and abrasive wear resistance. Even after softening annealing at 900 °C, the coating subjected to frictional treatment preserves its advantage in hardness and wear resistance over the original clad coating. Annealing at 1000 °C after frictional treatment ensures less effective growth of the hardness and wear resistance of the coating as compared to annealing of the undeformed coating due to the limited precipitation of large Cr23C6 carbides on the deformed surface, which form a wear-resistant framework. © 2017 Author(s).Russian Foundation for Basic Research, RFBR: 16-38-00452-mol-a01201375904108692015Federal Agency for Scientific Organizations: 01201463331Federal Agency for Scientific OrganizationsUral Branch, Russian Academy of Sciences, UB RAS: 15-9-12-45The study was financially supported by the Russian Foundation for Basic Research (RFBR), grant No. 16-38-00452-mol-a, by the Foundation for Assistance to Small Innovative Enterprises (FASIE), project UMNIK No. 108692015; the work was done within the Complex Program of UB RAS, project No. 15-9-12-45, within the state order for IES UB RAS, No. 01201375904 and within the state order of The Federal Agency for Scientific Organizations (FASO Russia) on the subject “Structure”, No. 01201463331. The experimental research was done on the equipment installed at the Plastometriya Collective Use Center of IES UB RAS

Effect of frictional treatment on the microstructure and surface properties of low-carbon steel

The microstructure of annealed low-carbon (0.17 wt% C) steel subjected to frictional treatment with a sliding hard-alloy indenter is studied by EBSD analysis, as well as its micromechanical characteristics. It has been found that frictional treatment results in high dispersity of the structure in the steel surface, down to the submicro- and nanocrystalline state. Instrumented microindentation has revealed that, under all the loads, the values of the contact elastic modulus E ∗ of low-carbon (0.17 wt% C) steel after frictional treatment are lower than those in the initial annealed state. Particularly, the mean value of E ∗ decreases from 208 to 168 GPa under a load of 1 gf on the indenter, from 213 to 176 GPa under a load of 25 gf and from 204 to 155 GPa under a load of 200 gf. It is for the first time that the effect of a decrease in the elastic modulus is observed for a carbon steel subjected to frictional treatment. It also follows from the microindentation data that frictional treatment increases the capability of the surface of annealed low-carbon (0.17 wt% C) steel to withstand higher contact loads prior to plastic deformation. © 2018 Author(s)

Increasing the resistance of a NiCrBSi coating to heat wear by means of combined laser heat treatment

Testing of NiCrBSi coatings formed by gas-powder laser cladding and combined laser heat treatment, including laser cladding and high-temperature annealing, were conducted under conditions of sliding friction on the Kh12M steel according to the pin-on-disk scheme. The combined processing resulting in the formation of large carbides and chromium borides in the coatings is shown to increase their wear resistance by a factor of 1.8 at sliding velocities of 6.1 and 9.3 m/s, when there is significant frictional heating of the friction surfaces. © 2018 Author(s)