—The results of investigations of the flora of small rivers within the city of Saratov (Elshanka, Nazarovka, Pervaya Gusel’ka, and Vtoraya Gusel’ka) are presented. The species composition of aquatic ...plants of the streams studied is represented by 37 macrophyte species belonging to 23 genera, 17 families, and three divisions (Charophyta, Polypodiophyta, and Magnoliophyta). The families Potamogetonaceae, Cyperaceae, and Lemnaceae predominate by the number of represented species. The values of the Menchinik index indicate that the greatest floristic diversity is characteristic of the Elshanka and Nazarovka rivers (3.1 and 3.4, respectively). The species composition of aquatic plants of the studied rivers within the urban area has a low similarity coefficient with the flora of rivers with relatively low anthropogenic load. Hydrophytes are the most numerous ecological group (22 species). According to the Paley–Kownacki dominance index, among the macrophytes of the rivers studied, most species are subdominant (57.28%) (
Potamogeton perfoliatus, Typha angustifolia, Lemna trisulca,
etc.); 37.18% (
Phragmites australis, Potamogeton pectinatus, Lemna minor, Ceratophyllum demersum
) belong to dominants, and the rest (11.54%) are defined as subdominants of the first order. Exceptional predominance is characteristic of
Ceratophyllum demersum
and
Phragmites australis,
which acted as dominants in all rivers studied. A significant part of the rivers is characterized by a low degree of overgrowth by hydrophilous vegetation, from slightly overgrown to not overgrown. The main types of distribution of aquatic and riparian-water vegetation are belted and fragmentary. Macrophyte communities are characterized by a simplified structure (one- or two-tiered), with absolute predominance of one plant species and the presence of two to four associated species with low values of projective coverage. The results of our calculations of indices (macrophyte index for small rivers (
S
m
), Indice Biologique Macrophytique in Riviere (
IBMR
)) based on the structural parameters of macrophytes showed that the rivers studied have a satisfactory ecological status.
Non-catalytic conversion of 4-oxoalkane-1,1,2,2-tetracarbonitriles in the presence of water leads to the formation of a mixture of fluorescent 4-cyano-2-oxo-1,2-dihydropyridine-3-carboxamides and ...2-oxo-1,2-dihydropyridine-3,4-dicarbonitriles in equal proportions. This transformation was explained, spectral-luminescence properties were investigated, and fluorescence quantum yield was measured.
Tune Measurement System of the SKIF Booster Belikov, O. V.; Bekhtenev, E. A.; Dementev, E. N. ...
Physics of particles and nuclei letters,
08/2023, Letnik:
20, Številka:
4
Journal Article
Recenzirano
Tune measurement system developed in Budker Institute of Nuclear Physics for the Booster of the SKIF project provides fast and accurate measurements of fractional part of betatron tunes during ...Booster acceleration cycle. Resonance excitation of betatron oscillations with help of radio frequency (RF) pulses feeding to the kiker electrodes is used in the system. The minimal tune measurement time is 1.3 ms, which allows having tunes measurement data for each phase of the Booster accelerating cycle. The system can perform up to 256 measurements during 400 ms time interval of Booster energy ramping. The tune measurement accuracy is better than 0.001
f
0
, where
f
0
is Booster revolution frequency.
A
bstract
We present the study of the decay
J/ψ
→
ρπ
. The results are based on of 5.2 million
J/ψ
events collected by the KEDR detector at the VEPP-4M collider. The branching fractions are measured ...to be
B
(
J/ψ
→
ρπ
) = (2
.
072 ± 0
.
017 ± 0
.
062) ∙ 10
−
2
and
B
(
J/ψ
→
π
+
π
−
π
0
) = (1
.
878 ± 0
.
013 ± 0
.
051) ∙ 10
−
2
, where the first uncertainties are statistical and the second systematic. Our results are more precise than the previous relative measurements.
The Budker Institute of Nuclear Physics has been designing two accelerator facilities of the MegaScience class 1, 2. It is planned to use the same bipolar power supplies sources for corrector magnets ...in both projects. These power supplies must provide an output current of 6 and 12 A and output voltage up to 100 V. Identical power-supply sources will be used both for slow orbit correction and for fast orbit feedback. As a result, the power-supply sources must provide the high stability of output current (at least 0.01%) and adequate bandwidth (at least 1k Hz). The project must allow for the fast replacement of a failed power-supply source.
When creating accelerators and storage-ring installations in a compact space, there is not always enough space for all the necessary magnet elements. In this case, we can reduce the number of ...correctors if we shunt magnet coils by a special bypass module, which can take some of the current away 1. This paper describes this type of bypass module, which can recuperate energy taken to the electrical grid.
The reaction of 4-halo-3-hydroxyfuro3,4-
c
pyridin-1(3
H
)-ones with acyclic and alicyclic secondary amines in ethyl acetate afforded the corresponding 3-(dialkylamino)-4-halofuro3,4-
c
pyridin-1(3
H
...)-ones in a few minutes.
Within the program “Ecosystems of the Siberian Arctic Seas,” carried out by Shirshov Institute of Oceanology, Russian Academy of Sciences since 2007, studies of the water structure and spatial ...variability of the parameters of the carbonate system have been performed, and the intensity and direction of the carbon dioxide flux over the continental slope of the Laptev Sea and in the Vilkitsky Strait in September 2018 have been calculated. The presence of several main water masses that govern the water structure in the study area is shown. A strong spatial variability of the parameters of the carbonate system of seawater, determined by complexes of physical and chemical–biological processes, has been revealed. The intensity and direction of the carbon dioxide flux at the water–atmosphere boundary were calculated, which range from –12 to 4 mmol m
–2
day
–1
. It was revealed that the investigated area of the outer shelf and continental slope of the Laptev Sea is an emitter of carbon dioxide into the atmosphere as of September 2018. Conversely, the area of the Vilkitsky Strait, is a CO
2
sink zone.
Based on the reaction of available adducts of tetracyanoethylene (TCNE) and aromatic ketones (4-aryl-4-oxoalkane-1,1,2,2-tetracarbonitriles) with hydrogen chloride, several aryl substituted ...2-halogencinchomeronic dinitriles were synthesized. We found that aryl substituted derivatives, in contrast to alkyl substituted ones, possess an intensive solid state fluorescence. The relationship between the chemical structures and photophysical properties of these compounds was investigated.
The methods of absorption electronic and NMR spectroscopy were used to study the processes of complexation during the interaction of molecules of unsubstituted indoline spiropyran with aluminum ...salts. The mechanism of formation and structure of complexes of two types has been established. Negative photochromism of the complex of the merocyanine form of spiropyran with aluminum ions was found. The stability of metal complexes to the action of various agents has been investigated.
