Plastic straining and concomitant microstructure recrystallization of Ni-Cu alloy in the undercooled condition

Microstructure and microtexture of rapidly solidified undercooled Ni-Cu alloys were investigated. The characteristic undercooling of Ni80Cu20 alloy was determined as 45K, 90K and 160K. Dendrite deformation due to rapid solidification led to strong deformation microtexture. Due to recrystallization upon annealing after recalescence, many subgrains were formed in the microstructure. Further, annealing the quenched alloy at 900°, new microtextures and subgrains were formed, which was due to recrystallization and dislocation network rearrangement. The results of comparative experiment proved the recrystallization mechanism of the microstructure refinement in the non-equilibrium solidification structure of the undercooled binary alloy

Optical control of the interface between gold surface and blood cell samples

The optical properties of blood (spectra of the extinction coefficient, k, refractive index, n, etc.) carry important diagnostic information and are usually monitored using bulk samples. In this work, attention is drawn to the interface between the blood volume and the surface of glass or thin gold films on it, where the refractive index may differ from the bulk one. We draw attention to the relationship between two effects – SPR and TIR. It is shown that if the named effects are measured for two different external media 0 and 1 with different refractive indices, then the values of the angles SPR and TIR will be linearly related by the empirical formula SPR1=SPR0+TIR1- TIR0)*K, where the coefficient K depends on the thickness of the transition layer di between the surface and the volume of the liquid medium (suspension). Numerical calculation of K (di) for gold films shows that K = 1.6 at di = 0 and monotonically decreases to 0.01 with an increase in di to 300 nm (and further to 0). Measurement of the angular dependences of reflection, R(), on (1) 100% hematocrit blood samples, (2) hemolyzed samples and (3) washed erythrocytes with dilutions with a buffer solution. It was shown that all samples exhibit a minimum SPR, but the TIR angle can be measured only for blood samples with destroyed membranes (hemolyzed), buffer solution and plasma. The n-value for hemolyzed blood is 1.3505, which is indicative of a low hemoglobin content in the sample. At the same time, di for a sample of 100% hematocrit was 60-105 nm, which indicates a strong deformation of erythrocytes in the form of polyhedrocytes and their dense packing after centrifugation. Washing the cells with a buffer increases di to 280 nm and more and practically eliminates blood cells from the SPR sensitivity region. The reason for this may be that in the blood of 100% hematocrit, erythrocytes are in the form of polyhedrocytes tightly adhering to the gold surface, while as a result of washing and diluting with a buffer solution, the cells relax back into discocytes. As a result, the containing hemoglobin erythrocyte cytoplasm moves away from the surface at a distance di> 300 nm into the suspension volume and leaves the area of the enhanced plasmon-polariton field.

Study on Deformation Evolution Characteristics of Reverse-Dip Rock Slope under the Influence of Rainfall

In Southwestern China, there exists deep river valleys and abundant rainfall, which leads to a large number of reverse-dip rock slopes. In order to investigate the evolution characteristics of toppling deformation of reverse-dip slope under the influence of rainfall, and a typical reverse-dip slope was taken as an engineering case. Firstly, the temporal and spatial evolution nephogram of toppling displacement under different rainfall was obtained based on the discrete surface displacement monitoring data of bank slope. Then, taking bank slope, gully buffer zone, and development degree of bank slope as development characteristics based on geological field survey, afterward, the evolution characteristics in different strong deformation zones were analyzed by superimposing the development characteristic partition and the spatial and temporal displacement nephogram. The results showed that the horizontal displacement mainly occurred on the right front and middle rear of the bank slope while large vertical displacement occurred on the middle of the bank slope under the influence of rainfall. As the rainfall increased to the maximum, the toppling deformation reached the peak, and vertical displacement was more sensitive to the rainfall than horizontal displacement. After the superposition, the largest strong deformation zone was located in the middle and rear part of the bank slope, which is characterized by medium and high slope and mature stage and 50 m gully buffer zone. This paper explores the deformation and failure process of reverse-dip rock slope considering the change of rainfall through real displacement monitoring data and focuses on the real deformation evolution law of each characteristic zone combined with different development characteristics partition.

Crustal Cracks in Areas of Active Deformation: Correlation of GPS and Seismic Anisotropy

<p>Seismic anisotropy in the upper crust can be observed from shear-wave split- ting. It is closely related to crack distribution, orientation and density via the orientation of fast polarisation and the delay time between the two perpendic- ular components of the original shear-wave. Since stress variations can a ect crustal cracks, they should change shear-wave splitting. Another observable result of variations in stress can be deformation measured by GPS (Global Positioning System). Although there are as yet few publications linking these di erent methods, some have suggested an alignment of fast direction with maximum horizontal compressive stress and maximum horizontal compressive strain. We examine whether we can observe this or a di erent relation of seis- mic anisotropy to strain and stress changes in three di erent settings. We performed shear-wave splitting analyses of local earthquakes and baseline and strain calculations around Taupo caldera (New Zealand), Aso caldera (Japan), and around an area on the Raukumara peninsula (New Zealand) associated with slow slip on the Hikurangi subduction interface. Both anisotropy and deformation vary with time in all three regions, but the time variations do not strongly correlate with each other. We suggest that a strong deformation signal observed at Taupo caldera might have a regional, non-volcanic source, and small variations in shear-wave splitting cannot be linked to variations in GPS time series or baselines. At Aso caldera strong deformation seems to be directly related to volcanic activity. Seismic anisotropy also shows a change, but at a slightly di erent time than the GPS signal. On the Raukumara peninsula, the strong deformation associated with slow slip does not show up as a variation in seismic anisotropy, although variations in shear-wave splitting do exist in this area. Overall, we observe an alignment of fast direction with either maximum horizontal compressive strain or stress or both for a subset of time periods and stations. In addition, there is a contribution of structure to the observed anisotropy. We conclude that deformation and seismic anisotropy cannot always be linked in a straightforward way. Instead, shear-wave splitting may be connected to smaller scale processes than can be detected by the current densities of the GPS networks.</p>

Crustal Cracks in Areas of Active Deformation: Correlation of GPS and Seismic Anisotropy

<p>Seismic anisotropy in the upper crust can be observed from shear-wave split- ting. It is closely related to crack distribution, orientation and density via the orientation of fast polarisation and the delay time between the two perpendic- ular components of the original shear-wave. Since stress variations can a ect crustal cracks, they should change shear-wave splitting. Another observable result of variations in stress can be deformation measured by GPS (Global Positioning System). Although there are as yet few publications linking these di erent methods, some have suggested an alignment of fast direction with maximum horizontal compressive stress and maximum horizontal compressive strain. We examine whether we can observe this or a di erent relation of seis- mic anisotropy to strain and stress changes in three di erent settings. We performed shear-wave splitting analyses of local earthquakes and baseline and strain calculations around Taupo caldera (New Zealand), Aso caldera (Japan), and around an area on the Raukumara peninsula (New Zealand) associated with slow slip on the Hikurangi subduction interface. Both anisotropy and deformation vary with time in all three regions, but the time variations do not strongly correlate with each other. We suggest that a strong deformation signal observed at Taupo caldera might have a regional, non-volcanic source, and small variations in shear-wave splitting cannot be linked to variations in GPS time series or baselines. At Aso caldera strong deformation seems to be directly related to volcanic activity. Seismic anisotropy also shows a change, but at a slightly di erent time than the GPS signal. On the Raukumara peninsula, the strong deformation associated with slow slip does not show up as a variation in seismic anisotropy, although variations in shear-wave splitting do exist in this area. Overall, we observe an alignment of fast direction with either maximum horizontal compressive strain or stress or both for a subset of time periods and stations. In addition, there is a contribution of structure to the observed anisotropy. We conclude that deformation and seismic anisotropy cannot always be linked in a straightforward way. Instead, shear-wave splitting may be connected to smaller scale processes than can be detected by the current densities of the GPS networks.</p>

DETERMINATION OF CONCENTRATION AND EXTRACTION OF VANADYLPORPHYRIN COMPLEXES FROM OIL OF OIL-AND-GAS REGION «NORTH BUZACHI»

For the extraction of vanadylporphyrin complexes from oils of the oil-and-gas bearing region «North Buzachi» at 20 °C, N-N-Dimethylformamide (DMF) was used as an extractant, which shows a good isolating ability of porphyrin complexes into fractions with increasing the polarity. In the visible region the electronic spectra of metalporphyrin concentrates isolated from oil differ slightly and have two intense absorption bands at 573 nm and 534 nm, corresponding to vanadylporphyrin complexes, and at 550 nm, related to nickel porphyrins. According to the calculation method of graphical extrapolation, using the Lambert-Ber formula, content of nickel porphyrins in the extract is 11 times less than vanadylporphyrins. In the FT-IR spectra of porphyrinates, strong deformation vibrations of C-H-pyrrole fragments were detected in the absorption area 809.27 and 3024.79 cm-1, which indicate the presence of vanadium (IV) porphyrinate in the isolated fraction.

A non-Archimedean analogue of Teichmüller space and its tropicalization

In this article we use techniques from tropical and logarithmic geometry to construct a non-Archimedean analogue of Teichmüller space$$\overline{{{\mathcal {T}}}}_g$$ T ¯ g whose points are pairs consisting of a stable projective curve over a non-Archimedean field and a Teichmüller marking of the topological fundamental group of its Berkovich analytification. This construction is closely related to and inspired by the classical construction of a non-Archimedean Schottky space for Mumford curves by Gerritzen and Herrlich. We argue that the skeleton of non-Archimedean Teichmüller space is precisely the tropical Teichmüller space introduced by Chan–Melo–Viviani as a simplicial completion of Culler–Vogtmann Outer space. As a consequence, Outer space turns out to be a strong deformation retract of the locus of smooth Mumford curves in $$\overline{{\mathcal {T}}}_g$$ T ¯ g .

Laser pulse-electron beam synergy effect on electron self-injection and higher energy gain in laser wakefield accelerators

A new scheme for injection and acceleration of electrons in wakefield accelerators is suggested based on the co-action of a laser pulse and an electron beam. This synergy leads to stronger wakefield generation and higher energy gain in the bubble regime. The strong deformation of the whole bubble leads to electron self-injection at lower laser powers and lower plasma densities. To predict the practical ranges of electron beam and laser pulse parameters an interpretive model is proposed. The effects of altering the initial electron beam position on self-trapping of plasma electrons are studied. It is observed that an ultra-short (25 fs), high charge (340 pC), 1 GeV electron bunch is produced by injection of a 280 pC electron beam in the decelerating phase of the 75 TW laser driven wakefield.