Nuclear multifragmentation in
d
(4.4 GeV) + Au collision was studied with the 4π setup FASA installed at the external beam of the Dubna Nuclotron. Data obtained are analyzed within the statistical ...model of multifragmentation. It is found that the kinetic energy spectra of intermediate mass fragments deviate from the predicted ones. It is explained by the collective flow caused by the thermal expansion of fragmenting nucleus.
In the article, ways of increasing wear resistance of rolling mills bearing units under conditions of sliding friction are studied. The working surfaces of these details need the surface hardening. ...Since the details of the bearing units are traditionally made of 45 grade steel, we have studied the features of the formation of the structure and properties of the steel of this grade after plasma hardening without surface reflow. Variation of microstructure depending on hardening regimes was investigated. The microstructure of the steel in the hardening zone was studied by X-ray diffraction and metallographic methods. The possibility of increasing the operational properties of rolling mills bearing units using of plasma hardening of rubbing surfaces was shown.
The results of study of spontaneous fruit size and shape mutants and inheritance of these traits in tomato are given and genetic processes are explained. It is concluded that the diversity of tomato ...fruit shape and weight in the collection is due mainly to mutations of genes—diameter of fruit width and diameter of height joined into an ovate cluster.
The paper is devoted to the experimental determination of the space-time characteristics for the target multifragmentation in p(8.1 GeV)+Au collisions. The experimental data on the fragment charge ...distribution and kinetic energy spectra are analyzed within the framework of the statistical multifragmentation model. It is found that the partition of hot nuclei is specified after expansion of the target spectator to a volume equal to V{sub t}=(2.9{+-}0.2)V{sub o}, with V{sub o} as the volume at normal density. However, the freezeout volume is found to be V{sub f}=(11{+-}3)V{sub o}. At freezeout, all the fragments are well separated and only the Coulomb force should be taken into account. The results are in accordance with a scenario of spinodal disintegration of hot nuclei.
Abstract
Background
The barnacles are a group of >2,000 species that have fascinated biologists, including Darwin, for centuries. Their lifestyles are extremely diverse, from free-swimming larvae to ...sessile adults, and even root-like endoparasites. Barnacles also cause hundreds of millions of dollars of losses annually due to biofouling. However, genomic resources for crustaceans, and barnacles in particular, are lacking.
Results
Using 62× Pacific Biosciences coverage, 189× Illumina whole-genome sequencing coverage, 203× HiC coverage, and 69× CHi-C coverage, we produced a chromosome-level genome assembly of the gooseneck barnacle Pollicipes pollicipes. The P. pollicipes genome is 770 Mb long and its assembly is one of the most contiguous and complete crustacean genomes available, with a scaffold N50 of 47 Mb and 90.5% of the BUSCO Arthropoda gene set. Using the genome annotation produced here along with transcriptomes of 13 other barnacle species, we completed phylogenomic analyses on a nearly 2 million amino acid alignment. Contrary to previous studies, our phylogenies suggest that the Pollicipedomorpha is monophyletic and sister to the Balanomorpha, which alters our understanding of barnacle larval evolution and suggests homoplasy in a number of naupliar characters. We also compared transcriptomes of P. pollicipes nauplius larvae and adults and found that nearly one-half of the genes in the genome are differentially expressed, highlighting the vastly different transcriptomes of larvae and adult gooseneck barnacles. Annotation of the genes with KEGG and GO terms reveals that these stages exhibit many differences including cuticle binding, chitin binding, microtubule motor activity, and membrane adhesion.
Conclusion
This study provides high-quality genomic resources for a key group of crustaceans. This is especially valuable given the roles P. pollicipes plays in European fisheries, as a sentinel species for coastal ecosystems, and as a model for studying barnacle adhesion as well as its key position in the barnacle tree of life. A combination of genomic, phylogenetic, and transcriptomic analyses here provides valuable insights into the evolution and development of barnacles.
We have investigated resistivity changes introduced on the high-resistivity p-type silicon wafer by the irradiation with deuteron beam with an energy of 4.4GeV performed in the NUCLOTRON ...superconducting accelerator. Two contactless techniques were used for the measurements of resistivity changes: namely the microwave split post dielectric resonator (SPDR) technique and capacitance measurements in the frequency domain. The first technique allows resistivity measurements in the plane of the wafer, while the second one in the direction perpendicular to the wafer. The resistivity map obtained with the SPDR technique enabled us to obtain a permanent fingerprint of the accelerator beam intensity profile. It has been shown that after the irradiation, the material resistivity increased to ∼3.9×105Ωcm in the wafer region exposed to the maximum beam intensity. Complementary studies of the properties and concentrations of radiation deep-level defects were performed by the high-resolution photo-induced current transient spectroscopy (HRPITS). These studies have shown that the irradiation of the high resistivity silicon with 4.4-GeV deuterons results in the formation of several types of deep-level defects responsible for the charge compensation.
Multifragmentation of the system
α +
197
Au
has been studied at incident energies of 1 and 3.6 GeV/nucleon with the new 4π setup, “FASA”. A very high mean IMF multiplicity of 〈
M〉
IMF
=5.1 ± 0.8 is ...observed at the higher incident energy. Applying the statistical multifragmentation model of Gross, a breakup density
ϱ
ϱ
0
of about
1
7
is deduced from the relative velocity between two IMFs at large relative angles. The excitation energy increases from 4.5 MeV/nucleon at the lower beam energy to 5.5 MeV/nucleon at the higher beam energy. The time difference between the emission of two IMFs is less than 100 fm/c, justifying to call this process a simultaneous breakup.
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