Broadband, high-power optical frequency combs covering visible to near-infrared spectral range.

Optical frequency combs (OFCs) have become essential tools in a wide range of metrological and scientific research fields. However, in the reported literature, OFCs that cover the visible spectral range have a limited bandwidth and pulse energy. These drawbacks limit their potential applications, such as high-signal-to-noise ratio spectroscopic measurements. In this work, we demonstrate a broadband, high-power optical frequency comb covering the visible to near-infrared range (550 nm to 900 nm) with a high average power of approximately 300 mW. This is accomplished by the power scaling of optical pulses from a fully stabilized Er:fiber comb, coherent spectral broadening and finally the utilization of a PPLN's χ(2) nonlinearity. The broadband, high-power, fully stabilized visible OFCs showcased in this work offer reliable laser sources for high-precision spectroscopic measurements, imaging, and comparisons of optical clocks.

Observations reveal vertical transport induced by submesoscale front.

Submesoscale fronts, with horizontal scale of 0.1-10 km, are key components of climate system by driving intense vertical transports of heat, salt and nutrients in the ocean. However, our knowledge on how large the vertical transport driven by one single submesoscale front can reach remains limited due to the lack of comprehensive field observations. Here, based on high-resolution in situ observations in the Kuroshio-Oyashio Extension region, we detect an exceptionally sharp submesoscale front. The oceanic temperature (salinity) changes sharply from 14 °C (34.55 psu) to 2 °C (32.7 psu) within 2 km across the front from south to north. Analysis reveals intense vertical velocities near the front reaching 170 m day-1, along with upward heat transport up to 1.4 × 10-2 °C m s-1 and salinity transport reaching 4 × 10-4 psu m s-1. The observed heat transport is much larger than the values reported in previous observations and is three times as that derived from current eddy-rich climate models, whereas the salinity transport enhances the nutrients concentration with prominent implications for marine ecosystem and fishery production. These observations highlight the vertical transport of submesoscale fronts and call for a proper representation of submesoscale processes in the next generation of climate models.

Investigation and research on elderly people's willingness to combine medical and health care and related factors in coastal cities in eastern China.

Background: The problem of global aging was becoming increasingly prominent. At present, the empty nest and miniaturization of family structure reduce the function of home-based elderly care. Methods: A questionnaire survey was conducted on 347 elderly people in multiple communities and nursing homes in eastern coastal cities of China, and 13 institutional staff members of eight nursing institutions that carried out the medical-nursing integration model were interviewed as the research objects. The survey mainly focuses on the basic characteristics of the elderly, the family support system, and the acceptance of medical care and health care. The influencing factors were screened by t test, univariate analysis and multivariate logistic regression analysis. SPSS software was used to test the reliability and validity of the questionnaire, and the Crobach's was 0.792, which can be considered that the questionnaire had good internal reliability. The classification of the questionnaire was reasonable, the reliability of the questionnaire was high, and the internal consistency of the scale was high. According to KMO and Bartlett test, KMO = 0.826, χ2 = 853.731, the degree of freedom was 36, and the P value was 0.000. Results: The proportion of male and female respondents was 48.1% and 51.9% respectively. Multivariate logistic regression analysis results showed that gender had no statistical significances on the degree of support for combine medical and health care in the elderly (P > 0.05). The results showed that gender, age, marital status, medical insurance type and old-age insurance type had little effect on the support of the combination of medical care and health care for the elderly (P > 0.05). Compared with the control group with education below primary school, the elderly with bachelor's degree or above are more willing to support the combination of medical care and health (P < 0.05). The registered residence type is more obvious than that of the urban residents (P < 0.05). Compared with the enterprise employees in the control group, the elderly who were employed as migrant workers before retirement were more willing to support the combination of medical care and health (P < 0.05). From the perspective of family monthly income, the elderly with family income ≥10,000 RMB have more obvious support for the combination of medical care and health than the elderly with family monthly income <3,000 RMB in the control group (P < 0.05). In terms of the degree of understanding, the degree of understanding and support in different degrees are significantly higher than that in the control group (P < 0.05). Conclusion: Through multivariate logistic regression analysis, education level, registered residence, pre-retirement occupation and family income are more obvious for the elderly to support medical care and health. It is necessary to increase investment in elderly activity centers, actively carry out activities.