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<jats:p>Copper sulfate pentahydrate is investigated by terahertz time-domain spectroscopy. It is shown that the terahertz absorption coefficients are correlated with the particle size of the samples, as well as the heating rates of the ambient temperature. Furthermore, the water molecules of copper sulfate pentahydrate can be quantitatively characterized due to the high sensitivity of the terahertz wave to water molecules. Based on such results, the status of water incorporated in mineral opal is also characterized using terahertz time-domain spectroscopy. It indicates that terahertz technology can be considered as an efficient method to detect the dehydration of minerals.</jats:p>

<jats:p>From the perspective of error compensation in the sampling process, a digital calibration algorithm was studied for the processing of spectral data in dual-comb spectroscopy. In this algorithm, dynamic adaptation to phase fluctuations maintained constant measurement results of spectral line positions and intensities. A mode-resolved broadband absorption spectrum was obtained over the full-spectral range of the comb with a Hertz linewidth of radio frequency comb mode. The measured spectrum spanned over 10 THz, which covered the multiplexed absorption regions of mixed gases, such as CO<jats:sub>2</jats:sub> and N<jats:sub>2</jats:sub>O. The calibrated interferograms were also capable of direct coherent averaging in the time domain. The transmittance obtained deviated from the theoretical calculation by no more than 2% in the whole spectral span.</jats:p>

<jats:p>Both the negativity of Wigner function and the phase sensitivity of an SU(1,1) interferometer are investigated in this paper. In the case that the even coherent state and squeezed vacuum state are input into the interferometer, the Heisenberg limit can be approached with parity detection. At the same time, the negativity volume of Wigner function of detection mode comes entirely from the input state and varies periodically with the encoding phase. In addition, the negativity volume of Wigner function is positively correlated with the phase sensitivity of the SU(1,1) interferometer. The positive correlation may mean that the non-classicality indicated by negative Wigner function is a kind of resource that can verify some related research results of phase estimation.</jats:p>

<jats:p>We fabricated a silver ion emitter based on the solid state electrolyte film of RbAg<jats:sub>4</jats:sub>I<jats:sub>5</jats:sub> prepared by pulsed laser deposition. The RbAg<jats:sub>4</jats:sub>I<jats:sub>5</jats:sub> target for PLD process was mechano-chemically synthesized by high-energy ball milling in Ar atmosphere using <jats:italic>β</jats:italic>-AgI and RbI as raw materials. The ion-conducting properties of RbAg<jats:sub>4</jats:sub>I<jats:sub>5</jats:sub> were studied by alternating current (AC) impedance spectroscopy and the ionic conductivity at room temperature was estimated 0.21 S/m. The structure, morphology, and elemental composition of the RbAg<jats:sub>4</jats:sub>I<jats:sub>5</jats:sub> film were investigated. The Ag<jats:sup>+</jats:sup> ion-conducting property of the prepared superioni-conductor film was exploited for ion–beam generation. The temperature and accelerating voltage dependences of the ion current were studied. Few nA current was obtained at the temperature of 196 °C and the accelerating voltage of 10 kV.</jats:p>

<jats:p>High energy <jats:italic>γ</jats:italic>-rays can be used in many fields, such as nuclear waste transmutation, flash photographics, and astrophysics. The <jats:sup>13</jats:sup>C(<jats:inline-formula> <jats:tex-math><?CDATA ${\rm{p}},\gamma $?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">p</mml:mi> <mml:mo>,</mml:mo> <mml:mi>γ</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_060706_ieqn5.gif" xlink:type="simple" /> </jats:inline-formula>)<jats:sup>14</jats:sup>N resonance reaction was used to generate high energy and mono-energetic <jats:italic>γ</jats:italic>-rays in this work. The thick-target yield of the 9.17-MeV <jats:italic>γ</jats:italic>-ray from the resonance in this reaction was determined to be (4.7±0.4)<jats:inline-formula> <jats:tex-math><?CDATA $\times {10}^{-9}\gamma $?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>9</mml:mn> </mml:mrow> </mml:msup> <mml:mi>γ</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_060706_ieqn6.gif" xlink:type="simple" /> </jats:inline-formula>/proton, which was measured by a HPGe detector. Meanwhile, the angular distribution of 9.17-MeV <jats:italic>γ</jats:italic>-ray was also determined. The absolute efficiency of HPGe detector was calibrated using <jats:sup>56</jats:sup>Co and <jats:sup>152</jats:sup>Eu sources with known radioactive activities and calculated by GEANT4 simulation.</jats:p>

<jats:p>High intensity <jats:italic>γ</jats:italic>-ray source can be obtained through resonance reaction induced by protons. In this work, the possibility of using such high intensity MeV-range <jats:italic>γ</jats:italic>-ray source to transmute nuclear waste is investigated through Mont Carlo simulation. <jats:sup>197</jats:sup>Au(<jats:italic>γ</jats:italic>, n)<jats:sup>196</jats:sup>Au experiment is performed to obtain the transmutation rate and compared with the simulation result. If the current of the proton beam is 10 mA at the resonance energy of 441 keV, with the <jats:italic>γ</jats:italic> photons emitted from <jats:sup>7</jats:sup>Li(p, <jats:italic>γ</jats:italic>)<jats:sup>8</jats:sup>Be, then the corresponding transmutation yield for <jats:sup>129</jats:sup>I in 2<jats:italic>π</jats:italic> direction can reach 9.4×10<jats:sup>9</jats:sup> per hour. The result is compared with that of LCS <jats:italic>γ</jats:italic>-ray source.</jats:p>

<jats:p>In this work, we mainly investigate the NH<jats:sub>3</jats:sub> molecular multiphoton ionization process by using the photoelectron velocity map imaging technique. Under the condition of femtosecond laser (wavelength at 800 nm), the photoelectron images are detected. The channel switching and above-threshold ionization (ATI) effect are also confirmed. The kinetic energy spectrum (KES) and the photoelectron angular distributions (PADs) are obtained through the anti-Abel transformation from the original images, and then three ionization channels are confirmed successfully according to the Freeman resonance effect in a relatively low laser intensity region. In the excitation process, the intermediate resonance Rydberg states are <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{C}}}^{\sim }{}^{1}{\rm{A}}_{1}^{^{\prime} }$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">C</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>∼</mml:mo> </mml:mrow> </mml:msup> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant="normal">A</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>′</mml:mo> </mml:mrow> <mml:mprescripts /> <mml:none /> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> </mml:mmultiscripts> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_063201_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> (6 + 2 photons process), <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{B}}}^{\sim }{}^{1}{\rm{E}}^{^{\prime\prime} }$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">B</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>∼</mml:mo> </mml:mrow> </mml:msup> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant="normal">E</mml:mi> </mml:mrow> <mml:none /> <mml:mrow> <mml:mo>″</mml:mo> </mml:mrow> <mml:mprescripts /> <mml:none /> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> </mml:mmultiscripts> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_063201_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> (6 + 2 photons process) and <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{C}}}^{\sim }{}^{1}{\rm{A}}_{1}^{^{\prime} }$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">C</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>∼</mml:mo> </mml:mrow> </mml:msup> <mml:mmultiscripts> <mml:mrow> <mml:mi mathvariant="normal">A</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>′</mml:mo> </mml:mrow> <mml:mprescripts /> <mml:none /> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> </mml:mmultiscripts> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_063201_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> (7 + 2 photons process), respectively. At the same time, we also find that the photoelectron angular distributions are independent of laser intensity. In addition, the electrons produced by different processes interfere with each other and they can produce a spider-like structure. We also find ac-Stark movement according to the Stark-shift-induced resonance effect when the laser intensity is relatively high.</jats:p>

<jats:p>The pressure broadening in the far wings, where the sodium Na (<jats:inline-formula> <jats:tex-math> <?CDATA $3{\rm{p}}\leftarrow 3{\rm{s}}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>3</mml:mn> <mml:mi mathvariant="normal">p</mml:mi> <mml:mo>←</mml:mo> <mml:mn>3</mml:mn> <mml:mi mathvariant="normal">s</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_063202_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>) resonance line is perturbed by ground lithium Li (2s) atoms, has been theoretically analyzed. The NaLi potential–energy curves and the transition dipole moments are constructed by using a reliable <jats:italic>ab initio</jats:italic> data points to carry out the reduced-absorption coefficients <jats:inline-formula> <jats:tex-math> <?CDATA ${k}_{r}(\nu,T)$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>k</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>r</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>ν</mml:mi> <mml:mo>,</mml:mo> <mml:mi>T</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_063202_ieqn4.gif" xlink:type="simple" /> </jats:inline-formula>. This quantum-mechanical investigation have demonstrated that the NaLi profile spectra show a satellite future in the red wing at wavelength <jats:italic>λ</jats:italic> =685 nm in the temperature range 4000 K–1.8×10<jats:sup>4</jats:sup> K. The computation could also exhibit a second satellite, in the blue wing, near the wavelength <jats:italic>λ</jats:italic> =574 nm beyond 6000 K and a third peak located at <jats:italic>λ</jats:italic> =490 nm which begins to appear at 1.8×10<jats:sup>4</jats:sup> K.</jats:p>

<jats:p>The interaction between neon and x-ray free-electron lasers with different laser parameters is systematically studied by solving a set of coupled rate equations. As an example, the evolution of 1s<jats:sup>1</jats:sup>2s<jats:sup>2</jats:sup>2p<jats:sup>6</jats:sup> configuration is given under different incident photon numbers, pulse widths, and photon energies. We have also determined all of the charge-state populations as a function of three laser pulse parameters by averaging over time. The result shows that the variations of these charge-state populations demonstrate a pattern when the pulse width is shorter than 10 fs: some of the charge-states decrease rapidly, while the others rise but remain relatively constant for pulse width larger than 10 fs. The variation of the average charge with three parameters has also obtained. The average charge decreases for a pulse width shorter than 10 fs but remains basically unchanged for a pulse width longer than 10 fs.</jats:p>

<jats:p>Sub-ppmv level detection of hydrogen sulphide (H<jats:sub>2</jats:sub>S) using a 1.578-<jats:inline-formula> <jats:tex-math><?CDATA ${\rm{\mu }}{\rm{m}}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">μ</mml:mi> <mml:mi mathvariant="normal">m</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_063301_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> distributed feedback tunable diode laser combining with wavelength modulation spectroscopy and second harmonic detection scheme is reported. A home-developed novel compact dense-pattern multipass gas cell with an effective optical path length of 29.37 m is used to improve sensitivity and reduce sample volume. Detection parameters are optimized, including modulation frequency and amplitude. The analysis of Allan variance shows that a minimum detectable concentration 60 ppbv is obtained with a lock-in time constant of 10 ms, and a detection limit of 13 ppbv can be achieved by average in 300 s. The demonstrated H<jats:sub>2</jats:sub>S sensor has a strong penitential application in natural gas process for regulating and controlling H<jats:sub>2</jats:sub>S concentration.</jats:p>