4.1 The work satisfaction of hospital researchers is at a satisfactory level
According to the data analysis, the overall job satisfaction score of researchers in S Hospital is 3.64, which is between 3-4, reaching the satisfaction level. Through factor analysis, it is found that the job satisfaction of researchers in S Hospital is composed of six dimensions: self-efficacy, scientific research system, scientific research management, salary and welfare, leadership factors and colleague relationship. The average score of satisfaction of the six dimensions is between 3.42 and 3.85, which indicates that the researchers in S hospital have a high job satisfaction.
4.2 Analysis of influencing factors on job satisfaction of Hospital researchers
The salary and welfare is one of the factors that affect the job satisfaction of hospital researchers. The Pearson correlation analysis shows that the correlation coefficient between salary and welfare and overall job satisfaction reaches 0.6, which indicates that salary and welfare have a significant positive impact on overall job satisfaction. This is consistent with the results of Cabelkova I [17-20]et al. The difference analysis found that different ages, education, working years, professional titles and job categories all had statistically significant differences in salary and welfare satisfaction, and the above research results all indicated that salary and welfare had an impact on the job satisfaction of hospital researchers.
The results of data analysis show that compared with the five dimensions of self-efficacy and scientific research system, the satisfaction degree of salary and welfare is the lowest (3.42 ± 0.57), and the difference analysis shows that the researchers with low education background, professional title and short working years have the lowest satisfaction on salary and welfare. According to Maslow's hierarchy of needs theory , salary and welfare are the necessary conditions to realize their basic needs. When the basic needs cannot be met, the satisfaction can not be improved, and the enthusiasm and efficiency of scientific research work are difficult to improve.
The scientific research system has the greatest influence on the hospital researchers' work satisfaction. The results of multiple linear regression analysis show that when six dimensions are taken as independent variables and overall job satisfaction is taken as dependent variables, the fitting degree reaches 99.1%, which indicates that the explanatory power of each variable is very high and that each dimension has a certain degree of influence on overall satisfaction. According to the standardized coefficient, the research system has the greatest impact on the job satisfaction of researchers. Scientific research system mainly includes relevant systems of promotion, professional title evaluation and appointment, performance assessment and other aspects of hospital scientific research personnel, which is the "baton" of scientific research activities  and also the main way to identify the achievements of scientific research personnel. The data analysis found that the satisfaction of scientific researchers in S Hospital was (3.68±0.82) in job promotion, (3.70±0.72) in performance assessment, (3.71±0.72) in title evaluation and recruitment, and (3.70±0.68) in the overall scientific research system, indicating that the scientific researchers were satisfied with the scientific research system of the hospital.
The age of researchers has an impact on job satisfaction. The results showed that researchers aged 30-39 and over 50 had the lowest overall job satisfaction, while those aged 40-49 had the highest overall job satisfaction, followed by those aged under 29. Combined with the difference analysis of the results, it is found that there are also differences in the satisfaction of researchers of different age groups on scientific research management, salary and benefits.
To be specific, researchers aged between 40 and 49 are basically at a stable stage in both family and work, have made certain achievements in the field of scientific research, and have a certain academic level and status. They have less pressure on scientific research, less pressure on life and work, and are more likely to have satisfaction and satisfaction in scientific research work；Researchers aged 29 and under have just entered their jobs, and most of them are unmarried or married and have no children. They have little family pressure, and they are interested in exploring and seeking knowledge in medical scientific research. They also have more time and energy to engage in scientific research and are easily satisfied with scientific research work；The reason for the low satisfaction of researchers in the age group of 30-39 is that most of them facing the promotion, the problem such as marriage, raising children, supporting the elderly, the situation has a certain restrictions on their scientific research work, make they don't have enough time and energy to understand the recent developments in related field, can't clear research direction, multiple pressure affects their scientific research job satisfaction；Over the age of 50 researchers continue to engage in scientific research is largely because the love for the scientific research work, the reason for their low satisfaction may be that they are limited by their age when applying for certain projects, but there are also some people who may be due to the decrease of their energy in scientific research as they grow older.
Improve the salary and welfare level of researchers. Material reward is not only one of the essential conditions to meet the physiological needs of researchers, but also a kind of affirmation to their scientific research work. Those engaged in medical scientific research are mainly highly educated talents with a master's degree or above, who tend to have a higher achievement orientation [25-26]. When their physical needs are satisfied, they pursue higher needs. Therefore, hospitals need to establish a more fair, just and reasonable salary and welfare system, establish a good incentive mechanism[27,28], and practically improve the treatment level of scientific researchers, so as to reduce their economic pressure and improve their enthusiasm for scientific research. In addition, we can also take spiritual incentive measures[29-30], such as hospital leaders care about and attach importance to scientific research personnel, and set up all kinds of inspiring scientific research honorary titles, so as to enhance the satisfaction and sense of achievement of scientific research personnel, so as to improve the efficiency of scientific research.
Change the concept of scientific research management, establish and improve the scientific research management system. Research  shows that there is a positive relationship between scientific research work satisfaction and scientific research performance. Scientific research work is a crucial link in the development of hospitals, and the work satisfaction of researchers affects the overall scientific research level of hospitals .In addition to completing heavy clinical work, researchers also need to invest a lot of time and energy to carry out scientific research. Therefore, the hospital should change its concept in scientific research management, adhere to the principle of "people-oriented", emphasize the performance of scientific research, and pay attention to the needs of scientific researchers. Hospital leaders and policy makers need to make efforts to design and implement strategies that can alleviate the work pressure of researchers and balance their work and family life , so as to solve their worries, protect their rights and interests, continuously improve their work satisfaction, and ultimately promote the overall scientific research level of the hospital.
Targeted measures should be taken for researchers with low satisfaction. the satisfaction of researchers is jointly affected by their subjective consciousness and objective environment . Therefore, hospital managers should take into account the differences between different groups when improving their satisfaction. For 30-39 scientific research personnel, the hospital can be understand by conducting seminars and other forms of difficulties and requirements of their current work, to take targeted measures to help them to solve difficulties, can also provide more learning resources and independent space for researchers by improving the hospital research platform, library system, updating laboratory equipment, setting up study rooms, etc, create a strong academic atmosphere, through the promotion of soft and hard conditions to improve their scientific research satisfaction.For researchers aged 50 and over, appropriate preferential policies should be adopted to apply for research projects according to their own abilities and needs. Seminars can also be held so that outstanding researchers with rich experience and outstanding scientific research achievements can impart experience, skills and solve doubts to young researchers, so as to improve the satisfaction of researchers and improve the overall scientific research level of the hospital.