Hydrogen Sulfide Splitting into Hydrogen and Sulfur through Off-Field Electrocatalysis.

Hydrogen sulfide (H2S), a toxic gas abundant in natural gas fields and refineries, is currently being removed mainly via the Claus process. However, the emission of sulfur-containing pollutants is hard to be prevented and the hydrogen element is combined to water. Herein, we report an electron-mediated off-field electrocatalysis approach (OFEC) for complete splitting of H2S into H2 and S under ambient conditions. Fe(III)/Fe(II) and V(II)/V(III) redox mediators are used to fulfill the cycles for H2S oxidation and H2 production, respectively. Fe(III) effectively removes H2S with almost 100% conversion during its oxidation process. The H+ ions are reduced by V(II) on a nonprecious metal catalyst, tungsten carbide. The mediators are regenerated in an electrolyzer at a cell voltage of 1.05 V, close to the theoretical potential difference (1.02 V) between Fe(III)/Fe(II) and V(II)/V(III). In a laboratory bench-scale plant, the energy consumption for the production of H2 from H2S is estimated to be 2.8 kWh Nm-3 H2 using Fe(III)/Fe(II) and V(II)/V(III) mediators and further reduced to about 0.5 kWh Nm-3 H2 when employing well-designed heteropolyacid/quinone mediators. OFEC presents a cost-effective approach for the simultaneous production of H2 and elemental sulfur from H2S, along with the complete removal of H2S from industrial processes. It also provides a practical platform for electrochemical reactions involving solid precipitation and organic synthesis.

Optical feedback frequency locking: impact of directly reflected field and responding strategies.

The challenges presented by the directly reflected field in optical feedback cavity-enhanced spectroscopy systems serve as substantial obstacles, introducing additional complexity to existing systems and compromising their sensitivity, as the underlying mechanisms of its adverse effects remain not fully understood. This study aims to address this issue by introducing a comprehensive analytical model. Additionally, frequency locking can be achieved by decreasing the feedback rate, the laser's linewidth enhancement factor, and the directly reflected field, and by increasing the refractive index of the gain medium, the length of the laser's resonant cavity, the electric field reflectivity of the laser's output facet, and the resonant field. These parameters can affect the feedback coupling rate pre-factor, and for a resonant cavity with a length of 0.394 m, optical feedback can only be established when the feedback coupling rate pre-factor is less than 1.05 × 109. Through experimental validation, we successfully confirm the effectiveness of the proposed solution in eliminating the detrimental effects of the directly reflected field. Importantly, this suppression is achieved without compromising other aspects of the system's performance. The research findings not only offer the potential to optimize various cavity-enhanced spectroscopy systems that rely on optical feedback but also show promising applications in advancing the development of high-purity spectrum diode lasers utilizing optical feedback from an external high-finesse cavity.

Perspectives of Chinese New Nurses Regarding Successful Transition: A Qualitative Study.

BACKGROUND: Transition issues have been discussed for many decades, yet little is known about successful transition expectations in the context of Chinese culture. PURPOSE: This article was designed to describe the expectations of newly graduated nurses in China regarding successful transition. METHODS: A qualitative, descriptive study design was employed, and a purposive sampling method was used to recruit interviewees. All of the one-to-one conversations were held in a quiet room to ensure privacy. All of the interviews were transcribed and then analyzed using thematic analysis. RESULTS: Nineteen new nurses were recruited from seven tertiary hospitals and participated in the in-depth interview process. Transition success, that is, "professional metamorphosis," was revealed through the four themes of "being competent in nursing work," "establishing a professional identity," "establishing comfortable interpersonal relationships," and "achieving balance between work and life." CONCLUSIONS/IMPLICATIONS FOR PRACTICE: Chinese new nurses expect their successful transition to achieve a professional metamorphosis in many aspects. A successful transition is not only a journey of professionalization but also a process of socialization. New nurses expect to achieve both maturity in their work and wisdom in life. The results of this study provide a greater understanding of transition issues in the context of Chinese culture. Thus, support and strategies cannot be limited to interventions designed to improve working competence but should be individualized to help new nurses achieve a smooth transition.

The effects of clinical learning environment and career adaptability on resilience: A mediating analysis based on a survey of nursing interns.

BACKGROUND: The resilience education of intern nursing students has significant implications for the development and improvement of the nursing workforce. The clinical internship period is a critical time for enhancing resilience. AIMS: To evaluate the resilience level of Chinese nursing interns and explore the effects of factors affecting resilience early in their careers, focusing on the mediating roles of career adaptability between clinical learning environment and resilience. METHODS: The cross-sectional study design was adopted. From March 2022 to May 2023, 512 nursing interns in tertiary care hospitals were surveyed online with the Connor-Davidson Resilience Scale, the Clinical Learning Environment Scale for Nurse and the Career Adapt-Abilities Scale. Structural equation modelling was used to clarify the relationships among these factors. Indirect effects were tested using bootstrapped confidence intervals. RESULTS: The nursing interns showed a moderately high level of resilience [M (SD) = 70.15 (19.90)]. Gender, scholastic attainment, scholarship, career adaptability and clinical learning environment were influencing factors of nursing interns' resilience. Male interns with good academic performance showed higher levels of resilience. Career adaptability and clinical learning environment positively and directly affected their resilience level (ß = 0.62, 0.18, respectively, p < .01). Career adaptability was also positively affected by the clinical learning environment (ß = 0.36, p < .01), and mediated the effect of clinical learning environment on resilience (ß = 0.22, p < .01). CONCLUSION: Clinical learning environment can positively affect the resilience level of nursing interns. Career adaptability can affect resilience directly and also play a mediating role between clinical learning environment and resilience. Thus, promotion of career adaptability and clinical teaching environment should be the potential strategies for nursing interns to improve their resilience, especially for female nursing interns with low academic performance.

Optical feedback noise-immune cavity-enhanced optical heterodyne molecular spectrometry for sub-Doppler-broadened detection of C2H2: publisher's note.

This publisher's note contains a correction to Opt. Lett.49, 202 (2024)10.1364/OL.507004.

Optical feedback noise-immune cavity-enhanced optical heterodyne molecular spectrometry for sub-Doppler-broadened detection of C2H2.

A novel, to the best of our knowledge, noise-immune cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS) has been developed, utilizing optical feedback for laser-to-cavity locking with a common distributed-feedback diode laser. The system incorporates active control of the feedback phase and feedforward control of the laser current, allowing for consecutive laser frequency detuning by scanning a piezoelectric transducer (PZT) attached to the cavity. To enhance the fidelity of the spectroscopic signal, wavelength-modulated (wm) NICE-OHMS is implemented. Benefiting from the optical feedback, a modulation frequency of 15 kHz is achieved, surpassing the frequencies typically used in traditional NICE-OHMS setups. Then, the sub-Doppler-broadened wm-NICE-OHMS signal of acetylene at 1.53 µm is observed. A seven-fold improvement in signal to noise ratio has been demonstrated compared to NICE-OHMS alone and a limit of detection of 6.1 × 10-10cm-1 is achieved.

The transition issue among new nurses in China: A mediation model analysis.

AIM: To explore the impact and interrelated pathway of work environment, career adaptability, and social support on the transition process and outcomes among new nurses. BACKGROUND: The transition issue affecting new nurses has been discussed for many decades. However, the exact interplay of various factors influencing the transition process and outcomes needs further exploration. METHODS: A cross-sectional, descriptive survey design was employed, and a convenient sample of 1628 new nurses from 22 tertiary hospitals in China was surveyed between November 2018 and October 2019. Mediation model analysis was used to analyze the data, and the STROBE checklist was used to report the study. FINDINGS: The transition status mediated the effects of work environment, career adaptability and social support, and had a significantly positive influence on their intention to remain and job satisfaction. Among the influencing factors, the work environment had the most significant positive impact on both the intention to remain and job satisfaction. CONCLUSION: Work environment was found to be the most significant factor affecting both the transition status and outcomes of new nurses. The transition status played an important mediating role between the influencing factors and the transition outcomes, whereas career adaptability was found to mediate the impact of social support and work environment in the transition process. IMPLICATIONS FOR NURSING AND NURSING POLICIES: The results underscore the critical role of the work environment and demonstrate the mediating effects of transition status and career adaptability in the transition process of new nurses. Therefore, dynamic evaluation of the transition status should serve as the foundation for developing targeted supportive interventions. Such interventions should also focus on enhancing career adaptability and fostering a supportive work environment to facilitate the transition of new nurses.

Self-calibrated NICE-OHMS based on an asymmetric signal: theoretical analysis and experimental validation.

As an ultra-sensitive detection technique, the noise-immune cavity enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) technique has great potential for assessment of the concentration of trace gases. To determine gas concentrations at the ppt or lower level with high accuracy, it is desirable that the technique exhibits self-calibration (or calibration-free) capabilities. Although being sensitive, NICE-OHMS has so far not demonstrated any such ability. To remedy this, this paper provides a self-calibrated realization of NICE-OHMS that is based on a switching of the feedback target of the DeVoe-Brewer (DVB) locking procedure from the modulation frequency of the frequency modulation spectroscopy (FMS) to the cavity length, which creates an asymmetrical signal whose form and size can be used to unambiguously assess the gas concentration. A comprehensive theoretical model for self-calibrated NICE-OHMS is established by analyzing the shift of cavity modes caused by intracavity absorption, demonstrating that gas absorption information can be encoded in both the laser frequency and the NICE-OHMS signal. To experimentally verify the methodology, we measure a series of dispersion signals under different levels of absorbance using a built experimental setup. An instrument factor and the partial pressure are obtained by fitting the measured signal through theoretical expressions. Our results demonstrate that fitted values are more accurate for higher partial pressures than for lower. To improve on the accuracy at low partial pressures, it is shown that the instrument factor obtained by fitting the signal at large partial pressures (in this case, above 7.8 µTorr) can be set to a fixed value for all fits. By this, the partial pressures can be assessed with a relative error below 0.65%. This technique has the potential to enable calibration-free ultra-sensitive gas detection.

Simple technique of coupling a diode laser into a linear power buildup cavity for Raman gas sensing.

We report a novel, to the best of our knowledge, and simple technique to lock a 642 nm multi-quantum well diode laser to an external linear power buildup cavity by directly feeding the cavity reflected light back to the diode laser for enhancement of gas Raman signals. The dominance of the resonant light field in the locking process is achieved by reducing the reflectivity of the cavity input mirror and thus making the intensity of the directly reflected light weaker than that of the resonant light. Compared with traditional techniques, stable power buildup in the fundamental transverse mode TEM00 is guaranteed without any additional optical elements or complex optical arrangements. An intracavity exciting light of 160 W is generated with a 40 mW diode laser. Using a backward Raman light collection geometry, detection limits at the ppm level are achieved for ambient gases (N2, O2) with an exposure time of 60 s.

Optical-feedback cavity-enhanced absorption spectroscopy for OH radical detection at 2.8†µm using a DFB diode laser.

We report the development of an optical-feedback cavity-enhanced absorption spectroscopy (OF-CEAS) instrument for OH detection at 2.8 µm using a DFB diode laser. Two different approaches, symmetry analysis and wavelength modulation, were performed to achieve laser frequency locking to the cavity mode. Compared with the symmetry analysis method, the wavelength modulation method continuously locked the laser frequency to the cavity mode and eliminated decoupling the laser from the cavity mode. A detection sensitivity of 1.7×10-9 cm-1 was achieved in a 25 s sampling time and was about 3 times better than that of the symmetry analysis method. The corresponding OH detection limit was ∼ 2×108 molecule/cm3. Further improvement can be achieved by using higher reflectivity mirrors and other high-sensitivity approaches, such as frequency modulation spectroscopy and Faraday rotation spectroscopy.

Fiber pigtailed DFB laser-based optical feedback cavity enhanced absorption spectroscopy with a fiber-coupled EOM for phase correction.

A novel technique for performing fiber pigtailed DFB laser and linear Fabry-Pérot cavity based optical feedback cavity enhanced absorption spectroscopy (OF-CEAS) is proposed. A fiber-coupled electro-optic modulator (f-EOM) with x-cut y-propagation LiNbO3 waveguide is employed, instead of PZT used in traditional OF-CEAS, to correct the feedback phase, which improves the compactness and applicability of OF-CEAS. Through the efficient and real-time control of the feedback phase by actively changing the input voltage of the f-EOM, a good long-term stability of the signal has been achieved. Consequently, a detection sensitivity down to 7.8×10-10 cm-1, better than the previous by PZT based OF-CEAS, has been achieved over the integration time of 200 s, even by use of a cavity with moderate finesse of 2850.

Six 19,20-epoxycytochalasans from endophytic Diaporthe sp. RJ-47.

Two new cytochalasins, deacetyl-19-epi-cytochalasin P1 (1), deacetyl-19,20-epoxycytochalasin D (2) were isolated from the endophytic fungus Diaporthe sp. RJ-47, along with four known compounds deacetyl-5,6-dihydro-7-oxo-19,20-epoxycytochalasin C (3), 19,20-epoxycytochalasin Q (4), 19,20-epoxycytochalasin C (5) and deacetyl-19,20-epoxy cytochalasin C (6). Their structures were unambiguously elucidated on the basis of the comprehensive analysis of extensive spectroscopic data. The antimicrobial effects of these compounds were evaluated.

Boosting Electrochemical Water Oxidation on NiFe (oxy) Hydroxides by Constructing Schottky Junction toward Water Electrolysis under Industrial Conditions.

The practical deployment of promising NiFe-based oxygen evolution reaction (OER) electrocatalysts is heavily limited due to the constrain in both stability and activity under industrial conditions. Herein, a 3D free-standing NiFe(oxy)hydroxide-based electrode with Schottky junction is constructed, in which NiFe(oxy)hydroxide (NiFe(OH)x ) nanosheets are chemically assembled on the top of metal-like Ni3 S2 scaffold that are in situ formed on commercial Ni mesh. Such an assembly enhances the binding strength of each components, promotes the charge transfer across the interfaces, and modulates the electronic and nanostructural features of NiFe(OH)x . Consequently, the electrode delivers current densities of as high as 500 and 1000 mA cm-2 for OER at overpotentials of only 248 and 270 mV with long-term stability in 1 m KOH. When it was paired with a NiMo hydrogen evolution cathode in a practical two-electrode system, a current density of 1000 mA cm-2 is achieved at a low cell voltage of ≈1.61 V at 80 °C in 30% KOH without losing performance for at least 1500 h. This is the best performance reported thus far for alkaline water electrolysis under industrial conditions, demonstrating its great potential for practical applications.

Optical feedback linear cavity enhanced absorption spectroscopy.

A simple and universal technique for performing optical feedback cavity enhanced absorption spectroscopy with a linear Fabry-Pérot cavity is presented. We demonstrate through both theoretical analysis and experiment that a diode laser can be sequentially stabilized to a series of cavity modes without any influence from the direct reflection if the feedback phase is appropriately controlled. With robust handling of the feedback phase and help from balanced detection, a detection limit of 1.3 × 10-9 cm-1 was achieved in an integration time of 30 s. The spectrometer performance enabled precision monitoring of atmospheric methane (CH4) concentrations over a time period of 72 h.

Newly graduated nurses' perceptions of work environment: A cross-sectional study in China.

AIM: To assess the attitudes of newly graduated nurses in China toward their work environment and identify the factors affecting their perception. BACKGROUND: Newly graduated nurses are the primary supply to cover the nursing shortage, but their stressful transition into clinical work has contributed to high turnover for decades. Although serving as a source of stress, the work environment can also be a source of support for new nurses. METHODS: A total of 2361 new nurses at 31 tertiary hospitals in 20 provinces were surveyed from June to November 2018, using the Chinese version of the Practice Environment Scale-Nursing Work Index. Basic information and their perception about work environment were collected. RESULTS: New nurses rated their work environment with an overall score of 84.67 (12.85). Multiple linear regression identified that education level, monthly income, hospital type and location, participation (or not) in standardized training programmes and having (or not) a mentor/preceptor were factors significantly associated with their perception of the work environment. CONCLUSION: The perception of newly graduated nurses in China was mainly positive overall. Nursing managers may take full advantage of factors affecting the perception of work environment to support newly graduated nurses better, to help their retention and transition.

Effects of psychosocial factors on posttraumatic growth among lung cancer patients: A structural equation model analysis.

OBJECTIVE: The purpose of this study was to investigate how locus of control, coping strategies, emotion regulation strategies and social support affect posttraumatic growth. METHODS: A cross-sectional study design was adopted. A convenience sample of 540 patients with lung cancer was recruited from November 2016 to July 2017 at two tertiary grade A hospitals in China. The participants completed a series of questionnaires. Structural equation modelling was used to explore the effects of psychosocial factors on posttraumatic growth. RESULTS: Social support had a direct positive effect on posttraumatic growth (ß = 0.318, SE = 0.071, BC 95% CI = 0.252/0.390), and it also had indirect effects on posttraumatic growth (ß = 0.112, SE = 0.023, BC 95%CI = 0.088/0.135) through mediating psychological factors. Coping strategies and the cognitive reappraisal emotion regulation strategy were the main mediating variables, explaining approximately 73.1% of the indirect effect between social support and posttraumatic growth. CONCLUSIONS: Our study suggests that Chinese lung cancer survivors can show relatively high posttraumatic growth. There are many mediating paths between social support and posttraumatic growth. These results may help healthcare professionals to identify the psychosocial factors that may benefit lung cancer patients and develop interventions to promote posttraumatic growth.

Palm-Sized Laser Spectrometer with High Robustness and Sensitivity for Trace Gas Detection Using a Novel Double-Layer Toroidal Cell.

A palm-sized laser spectrometer has been developed for detecting trace gases based on tunable diode laser absorption spectroscopy in combination with a novel double-layer toroidal cell. With the benefit of a homemade electronic system and compact optical design, the physical dimensions of the sensor are minimized to 24 × 15× 16 cm3. A toroidal absorption cell, with 84 reflections in 2 layers for an effective optical path length of 8.35 m, was used to enhance the absorption signals of gaseous species. A homemade electronic system was designed for implementing a distributed feedback (DFB) diode laser controller, an analog lock-in amplifier, data acquisition, and communication. Calibration-free scanned wavelength modulation spectroscopy was employed to determine the concentration of the gas and reduce the random fluctuations from electronical noise and mechanical vibration. The measurement of CH4 in ambient air was demonstrated using a DFB laser at 1.653 µm. The rise time and fall time for renewing the gas mixture are approximately 16 and 14 s, respectively. Vibration and temperature tests have been carried out for verifying the performance of the spectrometer, and standard deviations of 0.38 ppm and 0.11 ppm for 20 ppm CH4 at different vibration frequencies and temperatures, respectively, have been determined. According to the Allan deviation analysis, the minimum detection limit for CH4 can reach 22 ppb at an integration time of 57.8 s. The continuous measurement of atmospheric CH4 for 2 days validated the feasibility and robustness of our laser spectrometer, providing a promising laser spectral sensor for deploying in unmanned aerial vehicles or mobile robots.

Developing and validating the transition status scale for newly graduated nurses in China.

AIM: The present study aimed to develop and examine the psychometric properties of the Transition Status Scale for Newly Graduated Nurses. METHODS: Three phases were conducted: Phase I involved a qualitative research to explore and establish the potential items pool; Phase II reduced the items using the item analysis with a sample of 73 nurses. Phase III evaluated the psychometric properties of the final scale. Data from 814 valid questionnaires were analysed using exploratory factor analysis and confirmatory factor analysis. RESULTS: Five factors, including 'Interpersonal integration', 'Profession-related positive emotion', 'Competence for nursing work', and 'Active coping strategies', 'Balance between work and life', accounted for 68.87% of total variance. Cronbach's α was 0.891. Confirmatory factor analysis indicated acceptable model fitness. CONCLUSIONS: The Transition Status Scale for Newly Graduated Nurses has good psychometric properties. It can be used to measure the transition status conveniently and effectively. IMPLICATIONS FOR NURSING MANAGEMENT: The assessment result with the Transition Status Scale for Newly Graduated Nurses can provide information about the transition status of new nurses, thereby providing reference to guide the specific nursing interventions to smooth the transition process. It can also work as an alternative instrument to compare the effectiveness of different transition programs.

[AuAg26(SR)18S]- Nanocluster: Open Shell Structure and High Faradaic Efficiency in Electrochemical Reduction of CO2 to CO.

For atomically precise metal nanoclusters, distinctive molecular architectures and promising applications are urgently required to be intensively explored. Herein, we have first reported the open shell structure of the [AuAg26(S-Adm)18S]- nanocluster and its application in the electrochemical reduction of CO2. The X-ray crystal structure of the AuAg26 nanocluster is composed of a AuAg12 icosahedron kernel and a Ag14(SR)18S open shell. The shell includes a Ag6(SR)3S, a Ag5(SR)6, and three Ag(SR)3 motifs. It is the first time twisty propeller-like Ag5(SR)6 and trefoil-like Ag6(SR)3S motifs in metal nanoclusters have been observed. Due to the novel open shell configuration of Ag14(SR)18S, four triangular facets of the kernel are exposed. The AuAg26 nanocluster shows excellent catalytic activity in the electrochemical reduction of CO2 to CO. The Faradaic efficiency of CO is up to 98.4% under -0.97 V. The electrochemical in situ infrared study and DFT calculations demonstrate that the open shell structure of the AuAg26 nanocluster is beneficial to the forming of intermediate COOH* in the electrochemical reduction of CO2 to CO.

Implementation of the toroidal absorption cell with multi-layer patterns by a single ring surface.

We developed a type of toroidal multi-pass cell with multi-layer patterns based on the off-axis model. The effective path length of the original toroidal multi-pass cell is extended several roundtrips in comparison with the single-layer pattern, since the inner surface of the toroidal multi-pass cell is more efficiently utilized. The light pattern has been achieved by using the simple ring surface, which is easy to fabricate. The exact analytical equations for the design of the toroidal multi-pass cell were derived based on analytical vector calculations. A series of numerical ray tracing simulations is presented, and the maximum theoretical optical path length that can be reached is 30 m with a setup of 5 cm column radius. Furthermore, two practical spot patterns are demonstrated with a path length of 8.3 m for a two-layer pattern and 10 m for a three-layer pattern, with respective effective volumes of 63 mL and 94 mL. Furthermore, the fringe effect is substantially reduced to less than 0.5% by the usage of our designed mask.