Soil water is one of the most important components in hydrological cycle. The stable hydrogen and oxygen isotopes in soil water have been increasingly used in the ecological, environment and hydrological research. In view of different techniques for extracting soil water, there is significant difference in theδD andδ18 O composition. This paper presents a method for analyzing hydrogen and oxygen isotopes in soil water by using elemental analyzer and isotope ratio mass spectrometry with accelerated solvent extraction for sample pretreatment. The conditions are: extraction solvent: dichloromethane, temperature: 100 ℃, pressure of 10. 3 MPa, static time:10 min. The samples were extracted three times, and with cycle values of four, four and three, respectively. Comparing with the added water, the deuterium and oxygen isotope values in the extracted soil water enrich 2. 12‰-4. 58‰ and 0. 17‰-0. 93‰, respectively. The reproducibility of replicate extractions of soil water is around ±0. 89‰ for δD and ±0. 37‰ for δ18 O.

Objective To design simulated pulmonary air embolism demonstration model,so as to solve the problem of pathological anatomy of pulmonary air embolism in experiment teaching. Methods According to the principle of the disturbance of local blood circulation and air embolism, we designed a pulmonary air embolism model. We took 223 school nursing students as the object of this study,and randomly divided them into 2 groups:animal experiment teaching group and model control group,then we compared the teaching effect between the two groups. Result The test scores of students in the animal experiment teaching group were higher than control group (P<0.05) . Conclusion The use of simulated pulmonary air embolism demonstration model teaching can improve the students’experimental test scores,and can be repeatedly used,stimulate students' study interest,reduce the cost of teaching,and improve the teaching quality.

Objective:To investigate the quality of humanistic care for nursing students in Hebei province and to analyze its influencing factors.Methods:The humanistic care quality assessment scale of nursing students was designed and used as the research tool. A questionnaire survey was conducted among 2 693 nursing students from 11 medical colleges and universities in Hebei province and the results were analyzed. SPSS 21.0 was used for statistical analysis. Measurement data were expressed by (mean±standard deviation). The single factor analysis of variance and independent sample t-test were used for comparative study, and the multiple linear regression method was used to analyze the influencing factors. Results:The total Cronbach's coefficient of the scale was 0.966, and the Cronbach's coefficient of each dimension was 0.780-0.959, proving that the scale could be used. The data showed that the overall quality of humanistic care of nursing students in Hebei province was (119.70 ± 15.35), and the overall score rate was 85.50%. Among them, the comparison results of education background, grade, participation in volunteer activities, personality, the degree of concern of surrounding people, family atmosphere, and whether the teacher mentioned humanistic care were statistically significant ( P<0.05). Conclusion:The quality of humanistic care for nursing students in Hebei province is at a relatively high level. Colleges and universities can provide targeted education according to the current situation and influencing factors, create a good humanistic classroom atmosphere for nursing students, encourage nursing students to actively participate in humanistic practice, and improve the quality of humanistic care for nursing students.