Assessing the dynamics of human activity intensity and its natural and socioeconomic determinants in Qinghai-Tibet Plateau

Investigating the spatiotemporal variation of human activity intensity and its determinants is a crucial basis for further revealing the mechanism of human-environment interaction and optimizing the human development mode.In this study,the human activity intensity on the Qinghai-Tibet Plateau(QTP)from 1990 to 2020 was measured based on the quantitative model of land use data and the actual regional background,and the under-lying natural and socioeconomic determinants were investigated using spatial econometric methods.The results demonstrate that(1)the human activity intensity in QTP has increased by 11.96%,and there are differences in different spatial scales;the areas with high human activity intensity are distributed in the Hehuang Valley where Xining City and its surrounding areas are located,as well as the One-River and Two-River Area where Lhasa City and surrounding areas are located.(2)Human activity intensity has significant positive spatial spillover,suggesting that local changes will cause changes in the same direction in adjacent areas.(3)The human activ-ity intensity in QTP is affected by various determinants.Concerning socioeconomic factors,the economic level has no significant impact on the human activity intensity in QTP,which differs from the general regional law.Both urbanization and traffic conditions have a significant positive effect,and the impact intensity continues to increase.Concerning natural factors,topographic relief has a significant positive effect;the impacts of temper-ature and vegetation coverage have changed from insignificant to a significant positive effect;the impacts of precipitation and river network density have not been verified;there is no linear relationship between altitude and human activity intensity in the entire QTP,while it exists in local regions.Finally,this study proposes three policy implications for the realization of a more harmonious human-environment relationship in QTP.

Evaluation of the sustainable development level of countries along the Belt and Road and its impact factors:Empirical analysis based on the Super-efficiency slacks-based measure and Tobit measure models

Sustainable development is an important component of the Belt and Road Initiative(BRI)and is of great significance for evaluating the levels of sustainable development of countries along this route(henceforth,BRI countries).Therefore,this study aims to identify the factors that influence the levels of sustainable development of BRI countries in a reasonable and objective manner.Eventually,this study employs the super efficiency slacks-based measure(Super-SBM)model,which considers unexpected outputs to measure the level of sustainable development of BRI countries.The dynamic change and composition of the sustainable development level of these countries are calculated using the global Malmquist-Luenberger index.Furthermore,the Tobit model is used to identify the factors influencing the level of sustainable development of BRI countries in general and in various categories.The empirical results suggest the following points.(a)The overall level of sustainable development of BRI countries is low,whereas those of high-income and middle-and high-income countries are relatively high.(b)The overall sustainable development levels of BRI countries declined to a certain extent in 2008 owing to the effect of the financial crisis,.However,the sustainable development level of other countries,barring low-income countries,has gradually increased since 2011.(c)Since 2008,technological progress has replaced technical efficiency as the main driving force behind the improvement of the sustainable development level of BRI countries.(d)A U-shaped relationship is observed between the economic and sustainable development levels of these countries.(e)The level of science and technology and the proportion of renewable energy consumption can promote the sustainable development of these countries.Moreover,a negative correlation exists between the level of opening to the outside world and that of sustainable development of countries that mainly export resource-based products and are dominated by labor-intensive export industries.Barring low-income countries,the energy structure plays an effective role in improving the level of sustainable development.Finally,the study presents suggestions for China in the process of coping with the sustainable development of relevant countries during its promotion of the BRI.

Establishment of the Determination Methods of Total Anthraquinone Content in Different Processed Products of Rhubarb

[Objectives]Ultraviolet spectrophotometry was established for the determination of total content of anthraquinone in different processed products of rhubarb.[Methods]Emodin was used as the control substance,and its color was developed by magnesium acetate methanol solution with the concentration of 1%,the absorbance was determined at the wavelength of 516 nm,the content of total anthraquinone in different processed products of rhubarb was determined to compare the content differences.[Results]The regression equation was y=0.0452 x+0.0015,R 2=0.9991.Emodin had a good linear range in the concentration of 0.98-23.52μg/mL,with high accuracy,good repeatability and stable detection results.This method revealed the content changes of total anthraquinone in rhubarb before and after processing.[Conclusions]This method could be used as the quality control method of different processed products of rhubarb,and provided reference for the comprehensive development and utilization of rhubarb resources in the future.

《男性氧化应激性不育:特发性男性不育症的专业术语建议和临床实践指南》解读

由美国生殖医学中心牵头,全球27个国家的生殖领域专家共同参与编写并于2019年发表了《男性氧化应激性不育:特发性男性不育症的专业术语建议和临床实践指南》[Male Oxidative Stress Infertility(MOSI):Proposed Terminology and Clinical Practice Guidelines for Management of Idiopathic Male Infertility,以下简称《MOSI实践指南》]。指南阐述了氧化应激(oxidative stress,OS)致男性不育的病理生理学、MOSI概念的提出、诊断及治疗。本文通过对《MOSI实践指南》的重要章节进行解读,以期为临床医师提供参考。