The cross section of the process e + e − → π + π − has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The ...measurement is based on an integrated luminosity of about 88 pb − 1 , of which 62 pb − 1 represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed. Published by the American Physical Society 2024
The paper describes a method of the charged particle identification, developed for the CMD-3 detector, installed at the VEPP-2000 e+e− collider. The method is based on application of boosted decision ...trees classifiers, trained for the optimal separation of electrons, muons, pions and kaons in the momentum range from 100 to 1200MeV/c. The input variables for the classifiers are linear combinations of the energy depositions of charged particles in 12 layers of the liquid xenon calorimeter of the CMD-3. The event samples for training of the classifiers are taken from the simulation. Various issues of the calorimeter strip channels response simulation and their calibration are considered. Application of the method is illustrated by the examples of separation of the e+e−(γ) and π+π−(γ) final states and of selection of the K+K− final state at high energies.
The article proves the promising nature of using functionalized magnetic nano particles in extraction of metals from process solutions and in treatment of industrial effluents. The experimental ...copper extraction from solutions using a magnetic nanosorbent made of lipoic acid-functionalized magnetite is described. Sorption efficiency is determined as function of the initial concentration of solutions as compared with non-functionalized nano-size magnetite. The copper-bearing sedimentation mechanism includes chemosorption at active centers of lipoic acid, adsorption at clean magnetite surface and re-crystallization of sorbate in intrinsic copper-bearing phases. The phase composition of copper in the sediments is examined, and the copper extractability is illustrated. The conditioning technology is proposed for copper-bearing solutions. The stage-wise use of the magnetic nanosorbent enables process solution purification up to the maximum allowable concentration at simultaneous production of a concentrate suitable for hydrometallurgical processing.
The article presents measurements of the plasma parameters of a helicon discharge using optical diagnostic methods on the PN-3 installation. The composition of the diagnostic complex is described. ...The methods for measuring plasma parameters, including emission spectroscopy and laser-induced fluorescence, and methods for processing measurement results are considered. The results of measurements of the plasma parameters of a helicon discharge using optical diagnostic methods are presented. The measurements are carried out in experiments to study the dependence of the parameters of the helicon discharge plasma on the value of magnetic induction and the magnetic field profile under the antenna. Argon is used as the working gas. The radial distribution of the electron temperature for different parts of the plasma column is measured by optical emission spectroscopy. The laser-induced fluorescence method using the 3d
2
G
9/2
and 4p
2
F
7/2
states to determine the local concentration of the singly charged Ar II ion is applied. On the basis of the results of the work, the optimal value of the magnetic field under the HF antenna, which was 900–1000 G, and the configuration of the magnetic field of the setup, a magnetic trap, are determined from the viewpoint of the plasma column profile and plasma density.
Patients with developmental disorders often harbour sub-microscopic deletions or duplications that lead to a disruption of normal gene expression or perturbation in the copy number of ...dosage-sensitive genes. Clinical interpretation for such patients in isolation is hindered by the rarity and novelty of such disorders. The DECIPHER project (https://decipher.sanger.ac.uk) was established in 2004 as an accessible online repository of genomic and associated phenotypic data with the primary goal of aiding the clinical interpretation of rare copy-number variants (CNVs). DECIPHER integrates information from a variety of bioinformatics resources and uses visualization tools to identify potential disease genes within a CNV. A two-tier access system permits clinicians and clinical scientists to maintain confidential linked anonymous records of phenotypes and CNVs for their patients that, with informed consent, can subsequently be shared with the wider clinical genetics and research communities. Advances in next-generation sequencing technologies are making it practical and affordable to sequence the whole exome/genome of patients who display features suggestive of a genetic disorder. This approach enables the identification of smaller intragenic mutations including single-nucleotide variants that are not accessible even with high-resolution genomic array analysis. This article briefly summarizes the current status and achievements of the DECIPHER project and looks ahead to the opportunities and challenges of jointly analysing structural and sequence variation in the human genome.
The results of the studies on the use of collector reagents in the form of a reverse microemulsion (RME) of the water-in-oil type (i.e., water droplets are suspended in the oil phase) for the ...flotation extraction of lead and zinc minerals are presented. Lead and zinc concentrates and a lead–zinc ore are used as the initial samples for flotation. The concentration of galena in the lead concentrate is 74.7%, and the concentration of sphalerite in the zinc concentrate is 78.7%. Basic collector reagents in the composition of the RME are potassium butyl xanthate (PBX) and kerosene. A nonionic surfactant (NSA) is used to stabilize the RME. Casein is used as additives to the main reagents to eliminate the negative effect of osmotic pressure upon preparing the RME. The transformation of casein to the active soluble form is carried out using sodium sulfide. The particle size in the reverse microemulsion is 12.38 nm. The following options for supplying reagents to the flotation pulp are studied in flotation tests: RME, RME + foaming agent, and potassium butyl xanthate + foaming agent. A T-92 reagent is used as the foaming agent. The consumption of PBX in the composition of the RME and in the classical supply is 26 g/t. The results of laboratory tests show that the method of supplying flotation reagents in the form of an RME leads to an increase both in the flotation rate of lead and zinc sulfides and in their recovery into a foam product. Tests with the use of an RME in the collective flotation cycle of a lead–zinc ore show an increase in the extraction of lead into the total concentrate by 10.8% and zinc by 38.5% in comparison with the classical supply of reagents (collector + foaming agent) in addition to an increase in the flotation rate. An increased selectivity of the action of an RME in relation to zinc sulfides in comparison with lead sulfides is noted. The flotation rate coefficient of sphalerite is 7.8-fold higher when compared to galena. The gain in the extraction into the total zinc concentrate is also higher and is 16.78%, while the gain into the lead concentrate is 1.9% under the same conditions.
This paper proposes a method for quickly estimating the average flotation capacity of minerals according to the kinetic experiment without finding the flotation spectrum at which the first moments of ...distribution are calculated by the coefficients of the polynomial approximation of the logarithmic form of the kinetics. Using the example of copper-nickel ore, it is shown that the application of this method is effective in the multiparameter problem of comparative assessment of reagents. The ten parameters assessed included the average floatability of the target minerals (chalcopyrite and pentlandite), pyrrhotite and rock; the flotation selectivity coefficients of target minerals relative to pyrrhotite and rock; and the levels of copper and nickel losses from bulk flotation tailings. A visual representation of the interdependencies of parameters is achieved using diagrams showing the effect of flotation reagents on groups of parameters: average flotation, selectivity coefficients, metal losses, and selectivity relative to rock. The influence of butyl xanthate, Aeroflot, diesel fuel, and waste rock depressants—carboxymethyl cellulose (CMC) and acidified water glass (with a total consumption of 130 g/t collectors, 5–10 g/t diesel fuel, 200 g/t CMC, acidified water glass—500 g/t)—on the estimated parameters under conditions of collective flotation is determined. It is found that the addition of Aeroflot and diesel fuel to the main reagent collector xanthate increases the selectivity of pentlandite and chalcopyrite flotation relative to pyrrhotite and rock-forming component. The introduction of acidified liquid glass into the reagent mode increases the selectivity of the flotation of nickel and copper sulfides relative to the rock. CMC additives impair the selectivity of copper flotation. The quantitative effects of each individual parameter are taken into account in the integral rating assessment of the prospects of using reagent combinations for copper-nickel ore in terms of a set of ten parameters. The proposed method can be further used for a mass comparative evaluation of flotation reagents.
The results of a study of three methods for determining the phase of signals from a heterodyne microwave interferometer are presented: phase calculation by processing digitized signals using software ...methods; direct phase measurement with an AD8302 detector; and phase measurements by quadrature detection. The results of phase measurements obtained by these methods are compared. The values of errors of each method are estimated and ways to minimize them are considered.
A
bstract
The cross section of the process
e
+
e
−
→ ηπ
+
π
−
is measured using the data collected with the CMD-3 detector at the VEPP-2000 collider in the center-of-mass energy range from 1
.
1 to 2
....
0 GeV. The decay mode
η → γγ
is used for
η
meson reconstruction in the data sample corresponding to an integrated luminosity of 78
.
3 pb
−
1
. The energy dependence of the
e
+
e
−
→ ηπ
+
π
−
cross section is fitted within the framework of vector meson dominance in order to extract the Γ(
ρ
(1450)
→ e
+
e
−
)
B
(
ρ
(1450)
→ ηπ
+
π
−
) and the Γ(
ρ
(1700)
→ e
+
e
−
)
B
(
ρ
(1700)
→ ηπ
+
π
−
) products. Based on conservation of vector current, the analyzed data are used to test the relationship between the
e
+
e
−
→ ηπ
+
π
−
cross section and the spectral function in
τ
−
→ ηπ
−
π
0
ντ
decay. The
e
+
e
−
→ ηπ
+
π
−
cross section obtained with the CMD-3 detector is in good agreement with the previous measurements.
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