[en] This article discuses the application of anti-cosmic ray γ spectrometer with low background level on water sample measurement. In this paper, a water standard source is used to efficiency calibration, and the difference of detection efficiency of water samples of different shapes is compared. The detection limit of the water samples measured by the anti-cosmic ray γ spectrometer is compared with other gamma spectrometers. Results when γ energy E < 130 keV, the detection efficiency of marlin cup (ϕ 17 cm × H 17 cm) is lower than the cylinder (ϕ 7.0 cm × 7.5 cm) for water samples. When E > 130 keV, the detection efficiency of marlin cup is higher than the cylinder sample. The detection limit of marlin cup measured by anti-cosmic γ spectrometer was one magnitude lower than that of cylinder water samples. The detection limit of the anti-cosmic γ spectrometer for the same water sample is one magnitude lower than that of the common γ spectrometer. The detection limit of radionuclides such as ¹⁴⁴Ce, ¹³⁷Cs and ⁶⁰Co in the samples of marlin cup water without pretreatment is 3.07 × 10^-2 Bq/L, 3.67 × 10^-3 Bq/L and 3.7 × 10^-3 Bq/L, directly measured by anti-cosmic γ spectrometer. Conclusion the anti-cosmic γ spectrometer can be used for the measurement of water samples with low radioactivity. Its advantage is that it can reduce pretreatment time, shorten sample measurement cycle, greatly reduce detection limit and improve measurement accuracy. (authors)

[en] The ω- and ρ-meson tensor couplings to nucleons in a derivative scalar coupling model for finite nuclei are investigated. The influences of the tensor couplings on the binding energies per nucleon, the root-mean-square charge radii, spin-orbit splittings and single particle energies are discussed. The obtained results show that the spin-orbit splittings for finite nuclei are more sensitive to the ω-meson tensor coupling

[en] In an electromagnetically induced transparency system, the atoms have long-lived coherence compared to the cavity lifetime and interact nonadiabatically with the laser fields. We show that the high frequency fluctuations of both the intensities and the intensity difference can be squeezed below the shot noise limit due to the nonadiabatic effects. This noise squeezing can be used to enhance the precision in the short time measurements based on the intensities or the intensity difference. (fundamental areas of phenomenology(including applications))

[en] Objective: To analyze the radionuclides contents and estimate the internal dose for the raw water with a high level of total α activity in some sites of a region, and to provide the reasonable explanations and possible solutions. Methods: The total α activity concentration and radionuclide analysis were determined according to the current domestic relevant standards. The international formula was used for the internal irradiation dose estimation. Results: Based on the measured total α level, the average annual effective dose of internal irradiation for residents who have been drinking the raw water in this area for long time was averaged to be 0.09 mSv and the maximum dose might exceed the recommended drinking water dose level (0.1 mSv/a). The total α activity in the drinking water was mainly contributed by U and ²²⁶Ra, and the internal radiation dose came mainly from ²²⁶Ra. However, the ²²⁶Ra content in the drinking water did not exceed the guidance level recommended by WHO. Conclusion: The high radioactivity level of total α in the groundwater in this area may be related to the geological structure of the area. The natural radioactive nuclides in the aquifer rock may dissolve into and are concentrated during the formation of groundwater, which eventually result in the high total α level in the groundwater. (authors)

[en] We present a mechanism for double transparency in an optomechanical system. This mechanism is based on the coupling of a moving cavity mirror to a second mechanical oscillator. Due to the purely mechanical coupling and the radiation pressure, three pathways are established for excitations of the probe photons into the cavity photons. Destructive interference occurs at two different frequencies, leading to double transparency to the probe field. It is the coupling strength between the mechanical oscillators that determines the locations of the transparency windows. Moreover, the normal splitting appears for the generated Stokes field and the four-wave mixing process is inhibited on resonance. (paper)

[en] The aim of this study was to investigate the effects of two different external carbon sources (acetate and ethanol) on the nitrous oxide (N₂O) emissions during denitrification in biological nutrient removal processes. Results showed that external carbon source significantly influenced N₂O emissions during the denitrification process. When acetate served as the external carbon source, 0.49 mg N/L and 0.85 mg N/L of N₂O was produced during the denitrificaiton processes in anoxic and anaerobic/anoxic experiments, giving a ratio of N₂O-N production to TN removal of 2.37% and 4.96%, respectively. Compared with acetate, the amount of N₂O production is negligible when ethanol used as external carbon addition. This suggested that ethanol is a potential alternative external carbon source for acetate from the point of view of N₂O emissions. (paper)

[en] This paper proposes a novel form of multimode nonlinear interactions by using a near-resonantly dressed atomic ensemble in an optical cavity. Due to quantum interference, a pair of collective fields come into the bilinear interactions, whose strengths are proportional to the population difference between dressed states which are coupled to the collective fields. By such an interaction, it is possible to obtain perfect multimode squeezing and collective Einstein-Podolsky-Rosen (EPR) entanglement in the cavity output. (classical areas of phenomenology)

[en] We examine the quantum correlation between the Mollow sidebands in the collective resonance fluorescence from a strongly driven ensemble of two-level atoms. By using the criterion proposed by Shchukin and Vogel, we show that non-Gaussian entanglement exists between the two separated sidebands. The responsible mechanism is traced to the spontaneous parametric process, in which the nonclassical correlation is established. This suggests that the collective resonance fluorescence provides a continuous source for the non-Gaussian entangled light and thus has great potentials for various applications in quantum information and quantum computation. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

[en] The aims of this study were twofold. Firstly, the denitrificaion performance in deep-bed denitrificaiton filter (DBDF), serving as the advanced total nitrogen (TN) and total phosphorus (TP) removal technology, was evaluated. Secondly, the effect of dissolved oxygen (DO) into the DBDF on both the denitrificaion performance and the external carbon source addition was investigated. The operational results over eight months demonstrated good TN removal efficiency (87.8%) in the studied full-scale plant, in which 70.7% and 17.1% of TN were removed in the pre-denitrifation in oxidation ditch and post-denitrifation in DBDF, respectively. The DO concentration was inversely related to both the external carbon source dosage and the nitrate removed in DBDF. A dose of 3.60Kg methane (97%) was required to remove 1Kg nitrate, with approximately 26.2% of methane dosed was depleted by the DO in DBDF influent. It is suggested to take some measures to eliminate or mitigate the waterfall reoxygenation at process configurations before the DBDF, which is expected to save the cost of external carbon source. (paper)

[en] To determine if radiopharmaceutical waste can be cleared or decay-in-storage is effective for its disposal, we have evaluated the extent of this problem in low level radioactive waste involving "9"9Tc"m over a 10 half-life cycle of decay-in-storage by identifying the residual radionuclides in our dry waste using a multi-channel γ-ray spectrum analyzer. Radionuclides were identified by the presence of characteristic photopeaks of each isotope in the γ-ray spectrum and quantified by region of interest analysis. Although all radionuclide activity concentrations were lower that their clearance level after the decay-in-storage cycle long-lived radioisotopes "1"3"7Cs, "1"5"5Eu, "1"2"3Te"m and "1"5"4Eu were observed in "9"9Tc"m waste. "1"3"7CS and "1"5"5Eu can be the radionuclidic impurities during "9"9Mo preparations. "1"2"3Te"m and "1"5"4Eu may be the decay products from the radionuclidic impurities. Short decay-in-storage cannot decrease the activity of long-lived radionuclides greatly. So to control the nuclear purity of radiopharmaceutical is important, which can prevent the disposal of the radiopharmaceutical waste from becoming complicated. (authors)