[en] We have studied the oxygen-isotope effects on T_c and in-plane penetration depth λ_ab(0) in an optimally doped three-layer cuprate Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_10+y (T_c∼107 K). We find a small oxygen-isotope effect on T_c (α_O=0.019), and a substantial effect on λ_ab(0) [Δλ_ab(0)/λ_ab(0)=2.5±0.5%]. The present results along with the previously observed isotope effects in single-layer and double-layer cuprates indicate that the isotope exponent α_O in optimally doped cuprates is small while the isotope effect on the in-plane effective supercarrier mass is substantial and nearly independent of the number of the CuO₂ layers. A plausible pairing mechanism is proposed to explain the isotope effects, high-T_c superconductivity, and tunneling spectra in a consistent way

[en] We present the results of the oxygen isotope effect study in colossal magnetoresistive manganate La_1-xCa_xMnO_3+y using electron paramagnetic resonance (EPR). We observed strong isotope effects on EPR intensity and linewidth which can be explained by a model where a bottlenecked spin relaxation takes place from the exchange-coupled constituent Mn⁴⁺ ions via the Mn³⁺ Jahn-Teller ions to the lattice. For x = 0.2 the ferromagnetic exchange energy J exhibits a ¹⁶O/¹⁸O oxygen isotope effect of ∝-10%. The observed isotope effects suggest the presence of Jahn-Teller polarons in these materials. We also report the results of the similar study in cuprate superconductors La_2-xSr_xCuO₄. Experiments showed large oxygen isotope effect on EPR linewidth. It was found that isotope effect is strong in samples with small Sr doping and decreases with Sr concentration increase. These results provide the first microscopic evidence for the polaronic charge carriers in the cuprate superconductors. (orig.)

[en] Objective: To study the expression of OCT-4 in tumor tissues of cervical cancer patients with different radiosensitivity, and to explore the effect of OCT-4 knockdown on radiosensitivity of human cervical squamous carcinoma Siha cells and its mechanism. Methods: Real-time PCR and Western-blot were used to determine the mRNA and protein expression of OCT-4, respectively, in tumor tissues of cervical cancer patients with different radiosensitivity. The Siha cells were transfected with 0CT-4-SiRNA to construct the OCT-4 knockdown cell line (OCT-4 SiRNA group). The control group and NC transfection group were also set up. The Siha cells in each group were exposed to different doses of X-ray. The MTT assay and colony formation assay were used to evaluate cell proliferation and colony formation ability in each group, respectively. Flow cytometry was used to assess apoptosis and cell cycle in each group. Western blot was used to measure the expression of cleaved caspase-3 and p-Akt in each group. Results: With the decrease in radiosensitivity of patients with cervical cancer, the mRNA and protein expression of OCT-4 in tumor tissues were significantly increased (P < 0.05). Compared with the control group and the NC group, the OCT-4 SiRNA group had a significantly increased cell proliferation inhibition rate, significantly weaker colony formation ability, significantly enhanced apoptosis and cell cycle inhibition, significantly higher expression of cleaved caspase-3, and significantly lower expression of p-Akt after exposure to different doses of X-ray (all P < 0.05). Conclusions: OCT-4 expression is negatively correlated with the radiosensitivity of patients with cervical cancer. OCT-4 knockdown enhances the radiosensitivity of human cervical squamous carcinoma Siha cells by promoting the expression of cleaved caspase-3 and inhibiting the expression of p-Akt. (authors)

[en] Typical failures of in-core neutron flux instrumentation system based on the movable fission chamber during installation and commissioning, such as detector stucking, spiral tube dislocation, accumulated position error, measuring mode abnormality, motor driver failure and selection abnormality of the selector, are summarised, analysed from different aspects to the extent of primary causes based on working principle and engineering experience, and concluded with solutions and precautions. (authors)

[en] Phosphomolybdic acid zirconium loaded on silocone (ZrMoPP-SiO₂) adsorbent was synthesized by two-step method. The characterizations of the adsorbents were investigated by XRF, SEM, TEM, XRD, BET and XPS methods. The effects of both competitive ions and acidity on cesium adsorption of ZrMoPP-SiO₂ were also studied. The adsorption follows a typical Langmuir model and a pseudo second-order kinetic model. After adsorption of cesium, there is cesium peak on XPS of ZrMoPP-SiO₂, which means ZrMoPP-SiO₂ has great adsorption of cesium. Five co-existing cations and the change of acidity don't affect adsorption ability of ZrMoPP-SiO₂. Results show that ZrMoPP-SiO₂ has certain industrial application prospect. (authors)

[en] We present numerical calculations of the nuclear spin-lattice relaxation (R_s) rate in the superconducting state of pure indium and slightly underdoped n-type cuprate Pr_0.91LaCe_0.09CuO_4-y. By properly taking into account electron-phonon coupling, our calculated R_s for the conventional s-wave superconductor, indium, is in quantitative agreement the experimental data with a clear Hebel-Slichter peak. In contrast, the absence of the Hebel-Slichter peak in the R_s data of Pr_0.91LaCe_0.09CuO_4-y can be explained by either d-wave or highly anisotropic s-wave gap symmetry. Thus, the absence of the Hebel-Slichter peak does not necessarily argue against an s-wave gap symmetry in this electron-doped cuprate. -- Highlights: → Nuclear spin-lattice relaxation rate in electron-doped Pr_0.91LaCe_0.09CuO_4-y. → The absence of the Hebel-Slichter peak agrees with either d-wave or anisotropic s-wave. → The gap symmetry in slightly underdoped n-type cuprates is of highly anisotropic s-wave.

[en] Using a numerical computational method, quasiprobability distributions of new kinds of even and odd nonlinear coherent states (EONLCS) are investigated. The results show that the distributions of the new even nonlinear coherent states (NLCS) are distinct from those of the new odd NLCS and imply that the new EONLCS always exhibit some different nonclassical effects. Finally, with the aid of newly introduced intermediate coordinate-momentum representation in quantum optics, the tomograms of the new EONLCS are calculated. This is a new way of obtaining the tomogram function

[en] We discuss quantum fluctuation in excited states (named thermo number states) of mesoscopic LC circuits at a finite temperature. By introducing the coherent thermo state into the thermo field dynamics pioneered by Umezawa and using the natural representation of thermo squeezing operator we can concisely derive the fluctuation. The result shows that the noise becomes larger when either temperature or the excitation number increases

[en] In this paper by virtue of the technique of integration within an ordered product (IWOP) of operators and the intermediate coordinate-momentum representation in quantum optics, we derive the normal ordering and antinormal ordering products of the operator (fQ + gP)ⁿ when n is an arbitrary integer. These products are very useful in calculating their matrix elements and expectation values and obtaining some useful mathematical formulae. Finally, the applications of some new identities are given. (classical areas of phenomenology)

[en] Based on the entangled state representation and a bosonic phase operator formalism, we tackle with Cooper-pair number-phase quantization for the inductance coupling circuit including Josephson junctions, and then investigate how Josephson current equations change due to the presence of the coupling inductance and obtain bosonic operator Faraday formula, as well as the corresponding number-phase uncertainty relation