Population dynamics parameters and stock status of Squaliobarbus curriculus (Richardson, 1846) were analyzed from May to September 2021 in the Lanxi section of Qiantang River. FiSAT II software program was used. The g...Population dynamics parameters and stock status of Squaliobarbus curriculus (Richardson, 1846) were analyzed from May to September 2021 in the Lanxi section of Qiantang River. FiSAT II software program was used. The growth coefficient K = 0.21 year<sup>–1</sup>, asymptomatic length L<sub>∞</sub> = 39.48 cm, and age at theoretical zero-length t<sub>0</sub> = –0.74 years were estimated. The von Bertalanffy growth function was calculated as L<sub>t</sub> = 39.48[1 – e<sup>–</sup><sup>0.21(t + 0.74)</sup>]. The growth curve for weight had an inflection at 5.86 years, corresponding to 29.61 cm in standard length and 372.29 g in weight. The natural mortality rate (M), the fishing mortality rate (F), and the total mortality rate (Z) were calculated as 0.51, 0.61, and 1.12 year<sup>–1</sup>, respectively. The exploitation ratio (E) was 0.54, which is greater than the value of 0.5 suggested by Gull (1971), indicating a probable state of overdevelopment. The annual average stock number and biomass of S. curriculus in the Lanxi section of Qiantang River were 31.86 × 10<sup>6</sup> individuals and 3656.82 t, respectively.展开更多
China's higher education has entered the popularization stage,which coincides with the 14th Five-Year Plan and the process of educational modernization.As a"short board"in the development of higher educa...China's higher education has entered the popularization stage,which coincides with the 14th Five-Year Plan and the process of educational modernization.As a"short board"in the development of higher education in the western region,the higher education in Lanxi should accurately understand the basic characteristics of the popularization stage of higher education and firmly grasp new opportunities for future development[1].On the basis of interpreting the development needs and policy opportunities of national higher education in the new era,the government in Lanxi needs to renew school-running ideas,clarify school-running development goals,deepen the reform of school-running system,promote the modernization of higher education governance system,strengthen the cultivation of collaborative ability and the construction of characteristic disciplines in its higher education,improve the quality of personnel training and the social contribution of human resources,as well as run a satisfactory education for the people.展开更多
The identification of dominant driving factors for different ecosystem services(ESs)is crucial for ecological conservation and sustainable development.However,the spatial heterogeneity of the dominant driving factors ...The identification of dominant driving factors for different ecosystem services(ESs)is crucial for ecological conservation and sustainable development.However,the spatial heterogeneity of the dominant driving factors affecting various ESs has not been adequately elucidated,particularly in ecologically fragile regions.This study employed the integrated valuation of ESs and trade-offs(InVEST)model to evaluate four ESs,namely,water yield(WY),soil conservation(SC),habitat quality(HQ),and carbon storage(CS),and then to identify the dominant driving factors of spatiotemporal differentiation of ES and further to characterize the spatial heterogeneity characteristics of the dominant driving factors in the eco-fragile areas of the upper Yellow River,China from 2000 to 2020.The results demonstrated that WY exhibited northeast-high and northwest-low patterns in the upper Yellow River region,while high values of SC and CS were distributed in central forested areas and a high value of HQ was distributed in vast grassland areas.The CS,WY,and SC exhibited decreasing trends over time.The most critical factors affecting WY,SC,HQ,and CS were the actual evapotranspiration,precipitation,slope,and normalized difference vegetation index,respectively.In addition,the effects of different factors on various ESs exhibited spatial heterogeneity.These results could provide spatial decision support for eco-protection and rehabilitation in ecologically fragile areas.展开更多
文摘Population dynamics parameters and stock status of Squaliobarbus curriculus (Richardson, 1846) were analyzed from May to September 2021 in the Lanxi section of Qiantang River. FiSAT II software program was used. The growth coefficient K = 0.21 year<sup>–1</sup>, asymptomatic length L<sub>∞</sub> = 39.48 cm, and age at theoretical zero-length t<sub>0</sub> = –0.74 years were estimated. The von Bertalanffy growth function was calculated as L<sub>t</sub> = 39.48[1 – e<sup>–</sup><sup>0.21(t + 0.74)</sup>]. The growth curve for weight had an inflection at 5.86 years, corresponding to 29.61 cm in standard length and 372.29 g in weight. The natural mortality rate (M), the fishing mortality rate (F), and the total mortality rate (Z) were calculated as 0.51, 0.61, and 1.12 year<sup>–1</sup>, respectively. The exploitation ratio (E) was 0.54, which is greater than the value of 0.5 suggested by Gull (1971), indicating a probable state of overdevelopment. The annual average stock number and biomass of S. curriculus in the Lanxi section of Qiantang River were 31.86 × 10<sup>6</sup> individuals and 3656.82 t, respectively.
文摘China's higher education has entered the popularization stage,which coincides with the 14th Five-Year Plan and the process of educational modernization.As a"short board"in the development of higher education in the western region,the higher education in Lanxi should accurately understand the basic characteristics of the popularization stage of higher education and firmly grasp new opportunities for future development[1].On the basis of interpreting the development needs and policy opportunities of national higher education in the new era,the government in Lanxi needs to renew school-running ideas,clarify school-running development goals,deepen the reform of school-running system,promote the modernization of higher education governance system,strengthen the cultivation of collaborative ability and the construction of characteristic disciplines in its higher education,improve the quality of personnel training and the social contribution of human resources,as well as run a satisfactory education for the people.
基金Under the auspices of National Natural Science Foundation of China (No.41977402,41977194)。
文摘The identification of dominant driving factors for different ecosystem services(ESs)is crucial for ecological conservation and sustainable development.However,the spatial heterogeneity of the dominant driving factors affecting various ESs has not been adequately elucidated,particularly in ecologically fragile regions.This study employed the integrated valuation of ESs and trade-offs(InVEST)model to evaluate four ESs,namely,water yield(WY),soil conservation(SC),habitat quality(HQ),and carbon storage(CS),and then to identify the dominant driving factors of spatiotemporal differentiation of ES and further to characterize the spatial heterogeneity characteristics of the dominant driving factors in the eco-fragile areas of the upper Yellow River,China from 2000 to 2020.The results demonstrated that WY exhibited northeast-high and northwest-low patterns in the upper Yellow River region,while high values of SC and CS were distributed in central forested areas and a high value of HQ was distributed in vast grassland areas.The CS,WY,and SC exhibited decreasing trends over time.The most critical factors affecting WY,SC,HQ,and CS were the actual evapotranspiration,precipitation,slope,and normalized difference vegetation index,respectively.In addition,the effects of different factors on various ESs exhibited spatial heterogeneity.These results could provide spatial decision support for eco-protection and rehabilitation in ecologically fragile areas.
