The investigation of soil total nitrogen (STN) holds significant importance in the preservation and sustainability of Earth's ecosystems. The Qinghai-Tibet Plateau (QTP), renowned as the world's most expansive plateau and characterized by its exceptionally delicate ecosystem, demands an in-depth exploration of its STN content. In this study, we use a machine learning approach to extrapolate point-scale measured STN stocks to the entire QTP and calculated STN storage from 0 to 2 m.
View Article and Find Full Text PDFThe source region of the Yellow River (SRYR) is located at the edge of the Qinghai-Tibet Plateau (QTP), which is completely covered by frozen ground. Due to relatively higher temperatures, the frozen ground in the SRYR is particularly fragile and susceptible to the impacts of global climate change. This study discusses the maximum freeze depth (MFD) of frozen ground in the SRYR, including analysis of measured data at the stations, comparison of simulation models, and projection of future changes.
View Article and Find Full Text PDFThe Tibetan Plateau (TP) is experiencing extensive permafrost degradation due to climate change, which seriously threatens sustainable water and ecosystem management in the TP and its downstream areas. Understanding the evolution of permafrost is critical for studying changes in the water cycle, carbon flux, and ecology of the TP. In this study, we mapped the spatial distribution of permafrost and active layer thickness (ALT) at 1 km resolution for each decade using empirical models and machine learning methods validated with borehole data.
View Article and Find Full Text PDFZhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi
September 2002
Objective: To study the usage of viral load and CD4+ cell count methods in evaluating the effects of clinical treatment in HIV infected people.
Methods: Totally 73 cases of HIV infected persons were studied with clinical observation and laboratory examinations, six cases were treated with cocktail therapy, 36 cases with chinese herbs and the other 31 cases were untreated.
Results: The results indicated that the viral load levels in cocktail therapy group were significantly lower than the other two groups within 3 months and then kept at very low level.