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Ice has been suggested to have played a significant role in the origin of life partly owing to its ability to concentrate organic molecules and promote reaction efficiency. However, the techniques for studying organic molecules in ice are absorption‐based, which limits the sensitivity of measurements. Here we introduce an emission‐based method to study organic molecules in water ice: the phosphorescence displays high sensitivity depending on the hydration state of an organic salt probe, acridinium iodide (ADI). The designed ADI aqueous system exhibits phosphorescence that can be severely perturbed when the temperature is higher than 110 K at a concentration of the order of 10−5 M, indicating changes in hydration for ADI. Using the ADI phosphorescent probe, it is found that the microstructures of water ice, i.e., crystalline vs. glassy, can be strongly dictated by a trace amount (as low as 10−5 M) of water‐soluble organic molecules. Consistent with cryoSEM images and temperature‐dependent Raman spectral data, the ADI is dehydrated in more crystalline ice and hydrated in more glassy ice. The current investigation serves as a starting point for using more sensitive spectroscopic techniques for studying water‐organics interactions at a much lower concentration and wider temperature range. [ABSTRACT FROM AUTHOR]

Electric field measurement techniques based on Rydberg atoms have proven to have unique advantages in high sensitivity and have drawn wide attention in microwave electric field metrology and communication. The Rydberg states employed for microwave sensing are usually excited by two- or three-step laser irradiation. It leads to the Rydberg atoms being populated by some specific magnetic quantum number states determined by the laser polarization configurations, whose further coupling to another Rydberg state is also constrained by the microwave polarization. Based on a three-laser optical excitation, we demonstrate this effect on the microwave spectra of the 85Rb transitions 41F7/2 → 42D5/2 and 41F7/2 → 41G7/2 at various combining polarization configurations. It shows a strong polarization dependence on the microwave spectrum and then affects the sensitivity of Rydberg atom-based microwave field sensing. Advisable polarization schemes for higher sensitivity are suggested by the two types of transitions. [ABSTRACT FROM AUTHOR]

We firstly generalize the fuzzy way-below relation on an L-poset, and consider its continuity by means of this relation. After that, we introduce a kind of stratified L-generalized convergence structure on an L-poset. In terms of that, L-fuzzy Scott topology and fuzzy Scott topology are considered, and the properties of fuzzy Scott topology are discussed in detail. At last, we investigate the Scott convergence of stratified L-filters on an L-poset, and show that an L-poset is continuous if and only if the Scott convergence on it coincides with the convergence with respect to the corresponding topological space.

The corrosion failure behavior of 7005 aluminum alloy is a critical issue in the durability studies of vessels operating. In this study, the corrosion behavior of aluminum alloy 7005‐T4 in 3.5 wt% NaCl solution with pH 2, pH 4, and pH 6 was investigated by surface observation, electrochemical, and mechanical testing. The experiment results that the corrosion susceptibility is more at a solution of pH 2 compared with that at pH 4 and pH 6. The maximum depth and width of corrosion pits increase linearly with aggravation of corrosion. In addition, the probability distribution of the corrosion pit depth in each corrosion environment, which generally follows a Lognormal distribution, is statistically analyzed. The tendency of stress−strain curves at the elastic−plastic transition stage indicated that corrosion has an effect on mechanical performance, and revealed that corrosion promotes the advance of the plastic deformation stage. Fractography indicated the presence of a quasi‐cleavage zone beneath the corrosion layer. The results provide theoretical guidance for safe service and design guidelines for 7005 aluminum alloy. [ABSTRACT FROM AUTHOR]

The Rydberg atom-based microwave electric field sensor has high sensitivity for weak RF-field detection. Selection of Rydberg states with larger electric dipole moment is beneficial to enhance the sensitivity, and we choose Rydberg states with its principal quantum number up to n ∼ 80. We study the probe laser transmission response to a microwave field for these chosen high Rydberg states at room temperature. It agrees well with theoretical simulation based on an optical Bloch equation with considered microwave-atom interaction and Doppler broadening effect. In our experiment, the microwave sensing sensitivity based on 85 Rb transition | 78 S 1 / 2 ⟩ → | 78 P 3 / 2 ⟩ arrives at 5.102(49) nV cm − 1 Hz − 1 / 2 at 1 kHz. [ABSTRACT FROM AUTHOR]

In this paper we report a wave-function visualization of the core-induced interaction of a non-hydrogenic Rydberg atom in an electric field and its resultant redistribution of the spectral line intensities. The energy levels and oscillator strengths are calculated based on an effective potential where the radial part of the wavefunction is expanded in a B-spline basis. The calculation is in good agreement with the experimental measurements of the absorption spectrum of sodium atoms in an electric field of F = 840 V/cm, both below and above the saddle point [E.sub.sp]. The visualization of the wavefunction for the eigenstates can help us to see how they stem from the interaction between two or more red and blue hydrogenic states. An approximate localized symmetry close to the atomic core is also observed in the wavefunctions, which accounts for the alternation of oscillator strengths in the experiment. Key words: Rydberg atom, Stark effect, oscillator strength, symmetry. Nous presentons ici une visualisation par la fonction d'onde de l'interaction induite par le coeur d'un atome de Rydberg non hydrogenique dans un champ electrique, ainsi que la redistribution des intensites des raies spectrales qui s'ensuit. Nous calculons les niveaux d'energie et les forces d'oscillateur a partir d'un potentiel effectif, avec la partie radiale de la fonction d'onde ecrite dans une base B spline. Le calcul est en bon accord avec les valeurs experimentales du spectre d'absorption d'atomes de sodium dans un champ electrique de F = 840 V/cm, a la fois sous et au dessus du point de selle [E.sub.sp]. La visualisation des fonctions d'onde des etats propres peut nous aider a voir comment elles emergent d'une interaction entre deux ou plus d'etats hydrogeniques rouges et bleus. Nous observons aussi dans la fonction d'onde une symetrie locale approximative pres du coeur atomique, ce qui explique l'alternance des forces d'oscillateur dans l'experience. [Traduit par la Redaction] Mots-cles : atome de Rydberg, effet Stark, force d'oscillateur, symetrie. PACS Nos.: 32.60.+i, 32.70.Cs, 32.80.Fb., 1. Introduction Ever since the pioneering work on the Stark spectra of alkali metal atoms by Zimmerman et al. [1], the effect of an electric field on non-hydrogenic atoms in [...]

We have demonstrated a Rydberg atom-based two-band communication with the optically excited Rydberg state coupled to another pair of Rydberg states by two microwave fields, respectively. The initial Rydberg state is excited by a three-color electromagnetically-induced absorption in rubidium vapor cell via cascading transitions, with all of them located in infrared bands: a 780 nm laser servers as a probe to monitor the optical transmittancy via transition 5 S 1 / 2 → 5 P 3 / 2 , 776 nm and 1260 nm lasers are used to couple the states 5 P 3 / 2 and 5 D 5 / 2 and states 5 D 5 / 2 and 44 F 7 / 2 . Experimentally, we show that two channel communications carried on the two microwave transitions influence each other irreconcilably, so that they cannot work at their most sensitive microwave-optical conversion points simultaneously. For a remarkable communication quality for both channels, the two microwave fields both have to make concessions to reach a common microwave-optical gain. The optimized balance for the two microwave intensities locates at E MW 1 = 6.5   mV / cm and E MW 2 = 5.5   mV / cm in our case. This mutual exclusive influence is theoretically well-explained by an optical Bloch equation considering all optical and microwave field interactions with atoms. [ABSTRACT FROM AUTHOR]

This paper aims to further study the new kind of ordered fuzzy group named ordered L-group, which is put forward in literature [20]. Some algebraic properties of ordered L-groups, such as the relationship between elements, the equivalent characterizations and the products of these groups are discussed. Following that, the properties of substructures including characterization theorems, the convexity, the products of (normal) subgroups maintain the original substructure, along with the properties of ordered L-group homomorphisms are explored. The discussion of ordered fuzzy groups in this paper is from the perspective of fuzzy binary operation, which is different from the commonly method that just discuss the fuzzification of substructures in the research of fuzzy algebra. It can better reflect the essence of fuzzy groups logically just like that of classical groups. [ABSTRACT FROM AUTHOR]

We present a theoretical and experimental investigation of the improvement and determination of the sensitivity of Rydberg atom-based microwave RF sensor. An optical Bloch equation has been set up based on the configuration that two-color cascading lasers exciting atom to highly Rydberg state and a microwave RF coupling this Rydberg state to its adjacent neighbor. The numerical simulation shows that the sensitivity of the atomic RF sensor is correlated with the amplitude strengths of the applied two lasers and the RF itself. It also depends on the frequency detuning of the coupling laser, which induces an asymmetrically optical splitting. The coupling laser frequency fixing at the shoulder of the stronger one is more favorable for a higher sensitivity. Accordingly, we perform an experimental demonstration for the optimization of all these parameters and the sensitivity is improved to 12.50(04) nVcm − 1 ·Hz − 1 / 2 . [ABSTRACT FROM AUTHOR]

Photoionization dynamics of bounded electrons in the ground state, the first and second excited states of a hydrogen atom, triggered by ultrashort near-infrared laser pulses, have been investigated in a transition regime ( γ ∼ 1 ) that offers both multiphoton and tunneling features. Significant differences in spectral characteristics are found between the three low-energy states. The H( 2 s ) ionization probability is larger than the H( 2 p ) value with a special oscillating structure, but both are much greater than the ground state H( 1 s ) in a wide range of laser intensities. By comparing the momentum spectrum and angular distributions of low-energy photoelectrons released from these degenerate states, we find the H( 2 p ) state shows a stronger long-range Coulomb attraction force than the H( 2 s ) state on account of the difference in the initial electron wave packet. Furthermore, analysis of the photoelectron momentum distributions sheds light on both the first and second excited states with a symmetrical intercycle interference structure in a multicycle field but an intracycle interference of an asymmetric left-handed or right-handed rotating spectrum in a few-cycle field. By analyzing photoelectron spectroscopy, we identify the parity characteristics of photoelectrons in different energy intervals and their corresponding above-threshold single-photon ionization (ATSI) or above-threshold double-photon ionization (ATDI) processes. We finally present the momentum distributions of the electrons ionized by laser pulses with different profiles and find the carrier-envelope phase (CEP) is a strong factor in deciding the rotating structure of the emission spectrum, which provides a new method to distinguish the CEP of few-cycle pulses. [ABSTRACT FROM AUTHOR]

The involvement of spinal NR2B, a N-methyl-D-aspartate (NMDA) receptor subunit, in the therapeutic effect of electro-acupuncture (EA) on chronic visceral hyperalgesia was investigated. Chronic visceral hyperalgesia was induced using an irritable bowel syndrome (IBS) model in rats. Graded colorectal distention (CRD) stimuli at strengths of 20, 40, 60 and 80 mmHg were applied, and behavioral tests were performed to measure the abdominal withdrawal reflex (AWR) in response to the CRD stimuli and assess the severity of the visceral hyperalgesia. Rats were randomly divided into four groups: normal intact (control) group, IBS model (model) group, EA-treated IBS rats (EA) group and sham EA-treated IBS rats (sham EA) group. For the EA treatment, electric stimuli were applied through needles inserted into two acupoints [Zu-san-li (ST-36) and Shang-ju-xu (ST-37)] in both hind limbs, while the sham EA treatment consisted of only the insertion of needles into these same acupoints without an application of electric stimuli. Our results showed that AWR scores of the model group responding to CRD stimuli of 20, 40, 60 and 80 mmHg were significantly increased. These increased scores subsequently decreased following EA treatment (P < 0.05) compared with those for the other groups. The expression of NR2B in the superficial laminae (SDH, laminae I and II), nucleus proprius (NP, laminae III and IV), neck of the dorsal horn (NECK, laminae V and VI) and central canal region (lamina X) at thoracolumbar (T13-L2) and lumbosacral (L6-S2) segmental level significantly increased in the model group versus the control group (P < 0.05) and significantly decreased after EA treatment (P < 0.05). There were no significant changes in neither AWR scores nor expression of the NR2B subunit in these spinal regions after the sham EA treatment. These results confirm that EA can relieve chronic visceral hyperalgesia in IBS model rats and suggest that such an effect is possibly mediated through the downregulation of the NR2B subunits of NMDA at the spinal level. Keywords: Chronic visceral hyperalgesia, Irritable bowel syndrome, Electro-acupuncture, NMDA receptor, NR2B, Spinal cord, Author(s): Hongping Liu[sup.1], Yuhua Zhang[sup.1], Debo Qi[sup.1] and Weimin Li[sup.1] Introduction Visceral hyperalgesia is a pathological state in which the sensory threshold of pain decreases or the sense of pain [...]