γγ→tcˉ+ctˉ\gamma\gamma \to t\bar{c}+c\bar{t} in a supersymmetric theory with an explicit R-parity violation

We studied the process $\gamma\gamma \to t\bar{c}+c\bar{t}$ in a $R_{p}$ violating supersymmetric Model with the effects from both B- and L-violating interactions. The calculation shows that it is possible to detect a $R_{p}$ violating signal at the Next Linear Collider. Information about the B-violating interaction in this model could be obtained under very clean background, if we take the present upper bounds for the parameters in the supersymmetric $\rlap/ R_{p}$ interactions. Even if we can not detect a signal of $\rlap/R_{p}$ in the experiment, we may get more stringent constraints on the heavy-flavor $\rlap/R_{p}$ couplings.Comment: 16 pages, 6 figure

Life fingerprints of nuclear reactions in the body of animals

Nuclear reactions are a very important natural phenomenon in the universe. On the earth, cosmic rays constantly cause nuclear reactions. High energy beams created by medical devices also induce nuclear reactions in the human body. The biological role of these nuclear reactions is unknown. Here we show that the in vivo biological systems are exquisite and sophisticated by nature in influence on nuclear reactions and in resistance to radical damage in the body of live animals. In this study, photonuclear reactions in the body of live or dead animals were induced with 50-MeV irradiation. Tissue nuclear reactions were detected by positron emission tomography (PET) imaging of the induced beta+ activity. We found the unique tissue "fingerprints" of beta+ (the tremendous difference in beta+ activities and tissue distribution patterns among the individuals) are imprinted in all live animals. Within any individual, the tissue "fingerprints" of 15O and 11C are also very different. When the animal dies, the tissue "fingerprints" are lost. The biochemical, rather than physical, mechanisms could play a critical role in the phenomenon of tissue "fingerprints". Radiolytic radical attack caused millions-fold increases in 15O and 11C activities via different biochemical mechanisms, i.e. radical-mediated hydroxylation and peroxidation respectively, and more importantly the bio-molecular functions (such as the chemical reactivity and the solvent accessibility to radicals). In practice biologically for example, radical attack can therefore be imaged in vivo in live animals and humans using PET for life science research, disease prevention, and personalized radiation therapy based on an individual's bio-molecular response to ionizing radiation

Poly[[aqua­(μ2-oxalato)(μ2-2-oxido­pyridinium-3-carboxylato)holmium(III)] monohydrate]

In the title complex, {[Ho(C2O4)(C6H4NO3)(H2O)]·(H2O)}n, the HoIII ion is coordinated by three O atoms from two 2-oxidopyridinium-3-carboxylate ligands, four O atoms from two oxalate ligands and one water mol­ecule in a distorted bicapped trigonal-prismatic geometry. The 2-oxidopyridin­ium-3-carboxylate and oxalate ligands link the HoIII ions into a layer in (100). These layers are further connected by inter­molecular O—H⋯O hydrogen bonds involving the coordinated water mol­ecules to assemble a three-dimensional supra­molecular network. The uncoordin­ated water mol­ecule is involved in N—H⋯O and O—H⋯O hydrogen bonds within the layer

Poly[bis­(4,4′-bipyridine)(μ3-4,4′-dicarboxybiphenyl-3,3′-di­carboxyl­ato)iron(II)]

In the polymeric title complex, [Fe(C16H8O8)(C10H8N2)2]n, the iron(II) cation is coordinated by four O atoms from three different 4,4′-dicarboxybiphenyl-3,3′-di­carboxyl­ate ligands and two N atoms from two 4,4′-bipyridine ligands in a distorted octa­hedral geometry. The 4,4′-dicarboxybiphenyl-3,3′-di­carboxyl­ate ligands bridge adjacent cations, forming chains parallel to the c axis. The chains are further connected by inter­molecular O—H⋯N hydrogen bonds, forming two-dimensional supra­molecular layers parallel to (010)

High SNR Gain by Stochastic Resonance in a Tristable System

We report that the signal-to-noise ratio (SNR) can be improved by the stochastic resonance (SR) in a tristable system. The system is driven by Gaussian white noise and a sinusoidal signal, and studied by using the second-order Runge-Kutta method. We find that the SNR gain exhibits the stochastic resonance behavior, and greatly exceeds unity on some occasions. This result is the latest development of the tristable stochastic resonance, and has potential applications in the signal detection, processing and communications.  DOI: http://dx.doi.org/10.11591/telkomnika.v11i12.371

Measuring the Determinants of Student Satisfaction in Practical Teacher Training Education Program in China

Despite extensive research on student satisfaction in HEIs, notable gaps exist in investigating the profound impact of practical teacher training in education programs, particularly in China. This study examines the relationships between student satisfaction and its predictors in practical teacher training among Chinese undergraduates. Results show that expectation, perceived administrative service quality, perceived teaching quality, and perceived value are significant predictors of student satisfaction. However, image and teacher-student interaction have no significant relationships with student satisfaction. The six constructs represent 49% of the variance in student satisfaction. These findings indicate the necessity for enhanced management of practical teacher training programs