[Multi-Element Detection in Molten Steel with Laser-Induced Breakdown Spectroscopy].

On-line element content detection in iron and steel industry is one of the key techniques to ensure the quality in iron and steel metallurgy. Laser Induced Breakdown Spectroscopy (LIBS) has been applied to on-line components detection in molten steel. We have built LIBS system for components detection of molten steel in laboratory. The system consists of a Q-switched Nd∶YAG laser (repetition rate 10 Hz, wavelength 1 064 nm, pulse length 10 ns, pulse energy about 120 mJ), high frequency induction furnace (temperature 1 600 ℃), spectrometer (wavelength range 186～310 nm, spectral resolution 0.1 nm), laser focusing and spectral signal collecting system. Multi-elements were detected in molten steel with the application of deep-UV detector coating and solarization resistant fibers. According to the calibration curves of C, S, Mn and Cr, the limit of detections are 169, 15, 58.9 and 210 µg·g-1 respectively. The R-squares of calibration curves of C, S, Mn, and Cr are better than 0.96 by using appropriate analytical lines and reference lines. At the same time, through the comparison of different elements, we find the best calibration curve of different element need different delay conditions.

[Development of a High Spectral Resolution UV Flat-Field Spectrograph].

As an important optical splitting element, grating is used in many different spectrometers and spectrographs. Spherical varied-line-spacing grating (SVLSG) is easily combined with array detectors to get a wide wavelength range of spectrums in one time, because it can focus the spectrums in approximately a plane. Therefore, it's widely used in many spectral instruments. We usually only know the central groove density of a commercial grating and its mounting parameters, while its line spacing parameters are unknown. Moreover, the mounting parameters are optimized within the whole using wavelength range of the grating. However, in most circumstances only part of the wavelength range is used. Therefore, the mounting parameters are not optimized for the needed wavelength range. Under this condition, in this article we developed a method based on the focusing theory of the flat-field grating and the mounting parameters the manufacture provided to deduce the line spacing parameters of the grating. With these parameters, we can optimize the detector position according to the wavelength range we need and ray tracing can be done to test the optical system. In this article we developed a high spectral resolution ultraviolet spectrograph, covering a wavelength range of 230-280 nm. The grating used in this spectrograph has a central groove density of 1 200 lines x mm(-1) and a designed wavelength range of 170-500 nm. We deduced the line spacing parameters of the grating and optimized the detector mounting parameters. Hollow cathode lamps of different elements were used to calibrate the spectrograph and test the spectral resolution of it. Wavelength calibration of the spectrograph has been done with the parameter fitting method, and the calibration accuracy is better than 0.01 nm. Results show the spectral resolution of the spectral graph is about 0.08 nm at 280.20 nm.

[The auto-focusing remote laser-induced breakdown spectroscopy system].

The present paper presents an auto-focus laser-induced breakdown spectroscopy (LIBS) remote measuring system. This system contains a Schwarzschild telescope, which consists of a convex mirror and a concave mirror. The two spherical mirrors are coaxially placed. The convex mirror is mounted on a motorized linear translation stage. With this motorized linear translation stage, the convex mirror can move along the optical axis to change the spacing between the convex mirror and the concave mirror. Therefore the focal length can be adjusted to focus the laser on samples at different distances and collect the plasma spectra. The advantages of the telescope system include, firstly, the light path of laser focusing and spectra signal collection is the same, which make it easier for mounting and collimation; secondly, the light path of the telescope uses total reflection type, which is fit for the detection in ultra-violate region; finally, the telescope consists of only two spherical mirrors which are relatively easier to manufacture. Within the translation range of the motorized linear translation stage, the focal length of the telescope in this paper can be adjusted from 1.5 to 3.6 m. The diameter of the focusing spot varies from 0.5 to 1.0 mm. Utilizing this telescope system, LIBS experiments were conducted using copper sample. And the characteristic lines of Cu element (Cu I 223.01 nm, Cu I 224.43 nm) obtained are used for the auto focusing. By investigating the relation of the area of spectral lines covered and the spacing between the mirrors, the optimal laser focusing location was obtained. The LIBS experiment results show that the system functions well, fulfilling the demand of remote ablation of sample and LIBS spectral measuring, and the telescope is able to auto-focus the laser on samples at different position to perform remote LIBS experiment.

[Laser-induced breakdown spectroscopy system for elements analysis in high-temperature and vacuum environment].

Laser-induced breakdown spectroscopy (LIBS) is one of the most promising technologies to be applied to metallurgical composition online monitoring in these days. In order to study the spectral characters of LIBS spectrum and to investigate the quantitative analysis method of material composition under vacuum and high temperature environment, a LIBS measurement system was designed and set up which can be used for conducting experiments with high-temperature or molten samples in different vacuum environment. The system consists of a Q-switched Nd : YAG laser used as the light source, lens with different focus lengths used for laser focusing and spectrum signal collecting, a spectrometer used for detecting the signal of LIBS spectrums, and a vacuum system for holding and heating the samples while supplying a vacuum environment. The vacuum was achieved and maintained by a vacuum pump and an electric induction furnace was used for heating the system. The induction coil was integrated to the vacuum system by attaching to a ceramic sealing flange. The system was installed and testified, and the results indicate that the vacuum of the system can reach 1X 10(-4) Pa without heating, while the heating temperature could be about 1 600 degreeC, the system can be used for melting metal samples such as steel and aluminum and get the LIBS spectrum of the samples at the same time. Utilizing this system, LIBS experiments were conducted using standard steel samples under different vacuum or high-temperature conditions. Results of comparison between LIBS spectrums of solid steel samples under different vacuum were achieved, and so are the spectrums of molten and solid steel samples under vacuum environment. Through data processing and theoretical analyzing of these spectrums, the initial results of those experiments are in good agreement with the results that are presently reported, which indicates that the whole system functions well and is available for molten metal LIBS experiment under vacuum environment.

[EUV flat field grating spectrometer and performance measurement].

A high-resolution extreme ultraviolet (EUV) spectrometer has been developed to diagnose the magnetically confined plasmas. A holographic spherical varied line spacing concave grating which provides a flat focal plane is used as the diffraction element working with the grazing incidence angle of 3 degrees. The nominal groove density is 1200 lines x mm(-1). A deeply cooled back-illuminated CCD camera is used as the spectra detector and a mechanical shutter is used to control the time of exposure. It covers the wavelength range of 5-50 nm with the CCD cameral moving along the spectra focal plane to cover different wavelength range interested. Spectrometer design is presented and it was tested by a Penning discharge light source. By the wavelength calibration, the actual parameters of the optical system were calculated and the wavelength accuracy is 0.003 nm. Results show that the spectral resolution is about 0.015 nm at 20 nm with the width of entrance slit opened at 30 microm, which agrees with the design goal.

[Measuring method of spatial and spectral distribution of hollow cathode lamp].

In the present paper, the authors propose a method to measure the spatial and spectral distribution of hollow cathode lamp by imaging spectrometer. A push-broom convex grating imaging spectrometer based on Offner system is presented, with wavelength range 400-1 000 nm, field angle 22 degrees and spectral resolution 2-3 nm. The spatial distribution of Hg hollow cathode lamp was measured for the first time; this gives the spatial intensity distribution for different wavelengths and spectral distribution at different positions, with high spatial and spectral resolution. Also the hyperspectral data under different working current condition was obtained in order to analyze the differences of the distribution. It will be a powerful tool for the spatial and spectral properties measurement of hollow cathode lamps and other kinds of light sources.

Effect of continuous nursing care based on the IKAP theory on the quality of life of patients with chronic obstructive pulmonary disease: A randomized controlled study.

OBJECTIVE: To explore the effect of continuous nursing care based on the Information, Knowledge, Attitude, and Practice (IKAP) theory on the quality of life of patients with chronic obstructive pulmonary disease (COPD). METHODS: This study is a randomized control trial. COPD patients attending the Affiliated Hospital of Inner Mongolia Medical University, China between July 1 and October 31, 2017 were eligible. Following random assignment of participants to either the intervention group or control group, 70 patients (35 in each group) were included in the final sample. The intervention group received nursing care based on the Information, Knowledge, Attitude, and Practice theory, while the control group received standard nursing care. Data were collected before the intervention, 1 month after the intervention, and three months after the intervention. The St. George's Respiratory Questionnaire (SGRQ) was used to measure quality of life. RESULTS: Three months after the intervention, there were significant differences in the total SGRQ score (20.29 ±â€Š10.03 vs 30.14 ±â€Š12.52) and in the three SGRQ dimensions between the intervention group and the control group (P < .05). A repeated-measures analysis of variance showed that the total SGRQ score and the scores for impact and symptoms had a significant time effect (P < .001), that the total SGRQ score and the score for symptoms had a significant interaction effect (P < .05), and that the impact dimension had a significant group effect (P = .042). Pairwise comparisons of the data for the intervention group showed that there were significant differences between the pre-intervention and 1 month after intervention scores as well as between pre-intervention and three months after intervention, for the total SGRQ scores and the scores for impact and symptoms(P < .001). In terms of the impact dimension, there was a significant difference in the intervention group between 1 month after intervention and 3 months after intervention (P = .016). CONCLUSION: Continuous nursing care based on Information, Knowledge, Attitude, and Practice theory improved quality of scores at 3 months after intervention among COPD patients. Given limitations of the study, future large-scale studies are needed to validate our results.

Factors associated with post-traumatic stress disorder of nurses exposed to corona virus disease 2019 in China.

Quantitative studies using validated questionnaires on post-traumatic stress disorder (PTSD) of Nurses exposed to corona virus disease 2019 (COVID-19) in China are rare and the baseline PTSD must first be evaluated before prevention. This study aimed to investigate the factors potentially involved in the level of PTSD of Nurses exposed to COVID-19 in China.In this cross-sectional study, male and female Nurses (n = 202) exposed to COVID-19 from HuBei China were included in the final sample. The PTSD Checklist-Civilian (PCL-C) questionnaire and Simplified Coping Style Questionnaire (SCSQ) were used for evaluation. Multivariate stepwise linear regression analysis and spearman correlation test were performed to assess the association between various factors associated with PTSD.The incidence of PTSD in Nurses exposed to COVID-19 was 16.83%, the PCL-C score was 27.00 (21.00-34.00), and the highest score in the three dimensions was avoidance dimension 9.50 (7.00-13.25); multivariable stepwise linear regression analysis showed that job satisfaction and gender were independently associated with lower PCL-C scores (both P < .001); PCL-C scores were correlated with positive coping (r = -0.151, P = .032), negative coping (r = 0.154, P = .029).Nurses exposed to COVID-19 from HuBei China with job satisfaction, male and positive coping had low PCL-C scores which necessitate reducing the PTSD level by ways of improving job satisfaction, positive response, and strengthening the psychological counseling of female nurses in order to reduce the risk of psychological impairment.