[en] The strong interaction, one of the indispensable pillars of the Standard Model of particle physics, poses challenges at low energies because of the phase transition and the confinement nature of its underlying theory, quantum chromodynamics. Therefore, unveiling the emergent dynamics of its degrees of freedom at low energies, hadrons, and their interactions are of the essence at the low-energy precision frontier of the Standard Model. In this thesis, we pursue a model-independent and high-precision description of the low-energy hadronic effects in the anomalous magnetic moment of the muon (g-2)${}_{\mathrm{\mu <!--\; ??\; -->}}$ and the rare leptonic decay of the neutral pion π${}^0$ → e${}^{+}$e${}^{-<!--\; ???\; -->}$. The approach is based on a synergy between general principles of the S-matrix, dispersion relations, low-energy theorems, and perturbative quantum chromodynamics. In the first part, we investigate hadronic vacuum polarization in the muon (g-2)${}_{\mathrm{\mu <!--\; ??\; -->}}$, including the contributions from the 3π and π${}^0$γ channels. The 3π channel, which constitutes the second-largest exclusive contribution to hadronic vacuum polarization and its uncertainty, is addressed using a dispersive representation of the γ* → 3π amplitude. In a similar manner, we study the reaction e${}^{+}$e${}^{-<!--\; ???\; -->}$ → π${}^0$γ based on a dispersive representation of the underlying π${}^0$ → γγ* transition form factor. The more involved pion-pole contribution to hadronic light-by-light scattering is discoursed in the second part. It is unambiguously defined by the doubly-virtual pion transition form factor. We report on a reconstruction of it from the available data, using a dispersive representation that accounts for all the low-lying singularities, reproduces the correct high- and low-energy limits, and proves suitable for the evaluation of the (g-2)${}_{\mathrm{\mu <!--\; ??\; -->}}$ loop integral. In the final part, we present a feasible formalism to reexamine the dilepton decay π${}^0$ → e${}^{+}$e${}^{-<!--\; ???\; -->}$: the loop integral of the reduced amplitude is expressed in terms of the standard one-loop functions, yielding a two-dimensional integral representation suitable for the numerical treatment with the dispersively reconstructed pion transition form factor.

[en] Bacterial infection and loosening of orthopedic implants remain two disastrously postoperative complications. Angiogenesis is critical important to facilitate implant osseointegration in vivo. TiO₂ nanotubes arrays (NTAs) with proper dimensions possess good osseointegration ability. Accordingly, the present work incorporated copper (Cu) into TiO₂ NTAs (Cu-Ti-O NTAs) to enhance their antibacterial ability and angiogenesis activity, which was realized through anodizing magnetron-sputtered TiCu coatings with different Cu contents on pure titanium (Ti). Our results show ordered Cu-Ti-O NTAs can be produced under proper Cu content (< 15.14%) in TiCu coatings. The NTAs possess excellent long-term antibacterial ability against Staphylococcus aureus (S. aureus), which may be ascribed to sustained release of Cu²⁺. The cytotoxicity of Cu-Ti-O NTAs to endothelial cells (ECs) could be negligible and can even promote cell proliferation as revealed by live/dead staining and MTT. Meanwhile, Cu-Ti-O NTAs can up-regulate nitric oxide (NO) synthesis and vascular endothelial growth factors (VEGF) secretion of ECs on the sample surfaces compared with that of pure TiO₂ NTAs (control). Furthermore, the angiogenic activity is also enhanced in ionic extracts of Cu-Ti-O NTAs compared with the control. The excellent long-term antibacterial ability and favorable angiogenic activity render Cu-Ti-O NTAs to be promising implant coatings. - Highlights: • Cu-Ti-O NTAs possess long-term antibacterial ability against Staphylococcus aureus. • Cu-Ti-O NTAs can up-regulate nitric oxide synthesis and vascular endothelial growth factors secretion of endothelial cells. • Cu-Ti-O NTAs can enhance in vitro angiogenesis activity of endothelial cells.

[en] The synergism between red tetrazolium (RT) and uracil (Ur) on the corrosion of cold rolled steel (CRS) in H₂SO₄ solution is first investigated by weight loss, potentiodynamic polarization, and atomic force microscope (AFM). Effects of inhibitor concentration (25-500 mg l^-1), temperature (20-50 deg. C), and acid concentration (1.0-5.0 M) on synergism are discussed systematically. The results reveal that RT has a moderate inhibitive effect, and its adsorption obeys the Freundlich adsorption isotherm. For Ur, it has a poor effect. However, incorporation of RT with Ur significantly improves the inhibition performance, and produces synergistic inhibition effect.

[en] The adsorption and inhibition effect of 6-benzylaminopurine (BAP) on cold rolled steel (CRS) in 1.0 M HCl at 25-50 deg. C was studied by weight loss and potentiodynamic polarization methods. The results showed that BAP was a good inhibitor in 1.0 M HCl, and the inhibition efficiency (IE) increased with the inhibitor concentration. The adsorption of BAP on the CRS surface obeyed the Langmuir adsorption isotherm equation. Both thermodynamic parameters (adsorption heat ΔH⁰, adsorption free energy ΔG⁰ and adsorption entropy ΔS⁰) and kinetic parameters (apparent activation energy E_a and pre-exponential factor A) were calculated and discussed. Polarization curves showed that BAP acted as a mixed-type inhibitor in hydrochloric acid. Good agreement between weight loss and polarization methods was obtained. The adsorbed film on CRS surface containing optimum dose of BAP was investigated by Fourier transform infrared spectroscopy (FTIR) and atomic force microscope (AFM). Quantum chemical calculation was applied to elucidate the adsorption mode of the inhibitor molecule onto steel surface. Depending on the results, the inhibitive mechanism was proposed from the viewpoint of adsorption theory.

[en] Cerium is often used to simulate the corrosion behavior and transformation behavior of actinides such as uranium and plutonium, and its oxidation kinetics in water vapor has not been reported. In this study, the oxidation kinetics of cerium at high temperature in water vapor was studied by means of a thermogravimetric analyzer. The kinetics curve was obtained and the reaction process was discussed. The oxidation kinetics of cerium in water vapor conform to the rule of three-stage oxidation, and the main products after the reaction are CeO₂ and hydrogen. (authors)

[en] Objective: To assess the feasibility of the log file-based three-dimensional independent dose verification system for the quality assurance of clinical radiotherapy. Methods: The statistical values of the percentage depth dose, off-axis curves and output factor calculated by the Mobius system were statistically compared with the measured data by three-dimensional water tank. The three-dimensional independent dose verification in clinical radiotherapy plan and the acceleratr log file-based three-dimensional dose verification during the treatment were performed in 17 patients with nasopharyngeal cancer. The accuracy of dose calculation and reconstruction of Mobius system was assessed. A statistical analysis was performed on the intra-fractional γ pass rate (3%/3mm) for each patient to evaluate the stability of intra-fractional radiotherapy. Results: The percentage depth dose, off-axis curve and output factor statistically calculated by the Mobius system matched well with the data measured by three-dimensional water tank. The dose-volume histogram (DVH) parameters between the target area and organ at risk during clinical radiotherapy plan were statistically compared in 17 patients with nasopharyngeal cancer. The maximum deviation was -2.16% for the three-dimensional independent dose verification in the clinical radiotherapy plan, and 0.18 Gy for the accelerator log file-based three-dimensional dose verification. The average γ pass rate for 17 nasopharyngeal cancer patients was 99.26%, and the maximum deviation of intra-fractional radiotherapy was below 0.5%. Conclusions: The function of dose reconstruction and independent calculation of the Mobius system yeilds the same accuracy with the treatment planning system, which can quickly perform three-dimensional independent dose verification in the clinical radiotherapy plan and accelerator log file-based three-dimensional dose verification throughout the treatment, thereby guarantting and providing the safe and reliable technical support for clinical treatment. (authors)

[en] In order to obtain the decay data of the short-lived nuclide ¹⁴⁴La, the ¹⁴⁴La samples with high abundance and high activity need to be prepared. In present paper, a separation method was established based on the twice delay separation method, in which the ¹⁴⁴Ba-¹⁴⁴La was separated in 15 s by HDEHP extraction with SISAK separation system, and the newly grown ¹⁴⁴La was separated by P204 extraction chromatographic column at 20 s. The effects of extraction time, concentration of extraction agent and medium condition on the extraction ratio were studied in detail, and the process of rapid radiochemical separation of ¹⁴⁴La from the fission products was established. The process takes about 50 s, and the chemical recovery rate of ¹⁴⁴La is about 75%. (authors)

[en] The ionic beam which exhibits a Kapchinsky-Vladimirsky distribution is studied in this paper. Not only the halo is found, but also the ionic radial density which has changed is discovered when the ionic beam is in accelerator channels. By delay feedback control method, the halo is removed. Moreover as long as the proper parameters are chosen, the density uniformity can be found at beam's center. (authors)

[en] Highlights: • The efficiency of the MNITG at arbitrary power is analytically derived. • A universal bound on the efficiency of the MNITG with broken time-reversal symmetry and the arbitrary power is obtained. • Some system-specific characteristics are discussed and uncovered. • The broken time-reversal symmetry provides the physically allowed degrees of freedom for tuning the performance of heat devices. - Abstract: We investigate the performance at arbitrary power of minimally nonlinear irreversible thermoelectric generators (MNITGs) with broken time-reversal symmetry within linear irreversible thermodynamics, and the efficiency of MNITGs at arbitrary power is analytically derived. Furthermore, a universal bound on the efficiency of thermoelectric generators (TGs) with broken time-reversal symmetry and the arbitrary power is obtained. Some system-specific characteristics are discussed and uncovered. A large efficiency at arbitrary power can also be achieved via the cooperative mechanism between the system parameters. Our results indicate that the broken time-reversal symmetry provides the physically allowed degrees of freedom for tuning the performance of thermoelectric devices, and the physical trade-off region between the efficiency and the power output can also offer the appropriate space for optimizing the performance of TGs.

[en] The perturbation to conformal invariance and the numerical algorithm of Hamiltonian systems with disturbed forces under variational discretization are studied in this paper. Based on the discrete difference variational principles, the discrete Hamiltonian equations (variational integrators) for dynamical systems are obtained in the undisturbed and the disturbed cases, respectively. The determining equations of perturbation to conformal invariance are established for disturbed Hamiltonian systems. The exact invariants of Noether type led by conformal invariance for an undisturbed Hamiltonian system are derived. For disturbed discrete Hamiltonian systems, the condition of perturbation to conformal invariance leading to adiabatic invariants is proposed. Two examples are considered: a simple harmonic oscillator and the Kepler problem. The dynamical analysis is given by using the numerical results.