The construction of dams for intercepting and storing water has altered surface water distributions, landsea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir prop...The construction of dams for intercepting and storing water has altered surface water distributions, landsea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir properties through the land surface and hydrological models can lead to water storage simulation and extraction errors. This impact is particularly evident in many artificial reservoirs in China. The study aims to comprehensively assess the spatiotemporal distribution and trends of water storage in medium and large reservoirs(MLRs) in Chinese mainland during 1950-2016, and to investigate the gravity,displacement, and strain effects induced by the reservoir mass concentration using the load elasticity theory. In addition, the impoundment contributions of MLRs to the relative sea level changes were assessed using a sea-level equation. The results show impoundment increases in the MLRs during1950-2016, particularly in the Yangtze River(Changjiang) and southern basins, causing significant elastic load effects in the surrounding areas of the reservoirs and increasing the relative sea level in China's offshore. However, long-term groundwater estimation trends are overestimated and underestimated in the Yangtze River and southwestern basins, respectively, due to the neglect of the MLRs impacts or the uncertainty of the hydrological model's output(e.g., soil moisture, etc.). The construction of MLRs may reduce the water mass input from land to the ocean, thus slowing global sea level rise. The results of the impact of human activities on the regional water cycle provide important references and data support for improving the integration of hydrological models, evaluating Earth's viscoelastic responses under longterm reservoir storage, enhancing in-situ and satellite geodetic measurements, and identifying the main factors driving sea level changes.展开更多
The effects of various metal ions (Na+, K+, Ca2+, Mg2+, Al3+, Co2+) and anions (Cl–, SO2-4 and CH3COO–) on two cellulases were investigated. Fitting of the data to Michaelis-Menten kinetics showed that Al3+ noncom-p...The effects of various metal ions (Na+, K+, Ca2+, Mg2+, Al3+, Co2+) and anions (Cl–, SO2-4 and CH3COO–) on two cellulases were investigated. Fitting of the data to Michaelis-Menten kinetics showed that Al3+ noncom-petitively inhibited cellulase (Km = 22.68 g/L;Vmax = 0.269 mg/min at 5.0 mmol/L AlCl3) and Mg2+ competitively inhibited cellulase (Km = 50.0 g/L;Vmax = 0.434 mg/min at 10.0 mmol/L MgCl2) Different metal ions increased or decreased inhibition of cellulase activity slightly below 1 mmol/L and strongly over 10 mmol/L. The results indicated that filter paper activeity (FPA) was suitable for analysis of enzymatic saccharification with various lignocellulosic substrates whereas crude cellulase was suitable for applications in the biomass industry. Some metal ions were proved to inhibit cellulase reversibly.展开更多
Ratoon is the stub or root of a perennial plant that is commonly retained after harvest to produce a following crop.This paper presents a review of ratoon cotton in relation to a broader framework that has been examin...Ratoon is the stub or root of a perennial plant that is commonly retained after harvest to produce a following crop.This paper presents a review of ratoon cotton in relation to a broader framework that has been examining perennialization of agriculture for the benefit of ecology and economy.Cotton is botanically indeterminate,but has been treated as an annual after domestication,yet the habit of perenniality is retained and the plants begin to resprout after the first harvest.In some cropping systems,this tendency is exploited using the“ratooning”practice(i.e.growing one or more crops on the rootstock of the first).Ratooning has declined for various reasons such as an increase in the prevalence of pests and diseases and overwintering risk.However,ratooning has many benefits such as no annual tillage before sowing,a well-established root system,and high yield.The three methods of ratooning offer flexibility to balance the environmental and economic benefits in agriculture.The greatest environmental benefits arise from perennial ratoon cropping of semi-wild cotton,and the greatest economic benefit is obtained from biannually cropping modern annual cultivars.However,an optimum solution would be provided by perennial cropping annual cultivars.To realize both environmental and economic benefits,research is needed in the following main areas:preventing the buildup of pests and diseases,breeding the most suitable cotton cultivars for ratooning,and developing light and simplified cultivation(LSC)systems for ratoon cultivation.展开更多
We give a recursive algorithm to compute the multivariable Zassenhaus formula e^X1+X2+…+Xn=e^X1eX2…e^Xn∏∞k=2e^Wk and derive an effective recursion formula of Wk.
基金supported by the National Natural Science Foundation of China (No.42274110 and 42374106)long-term monitoring project in the Three Gorges Reservoir area (the National Natural Science Foundation of China,No.41874090 and 41504065)。
文摘The construction of dams for intercepting and storing water has altered surface water distributions, landsea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir properties through the land surface and hydrological models can lead to water storage simulation and extraction errors. This impact is particularly evident in many artificial reservoirs in China. The study aims to comprehensively assess the spatiotemporal distribution and trends of water storage in medium and large reservoirs(MLRs) in Chinese mainland during 1950-2016, and to investigate the gravity,displacement, and strain effects induced by the reservoir mass concentration using the load elasticity theory. In addition, the impoundment contributions of MLRs to the relative sea level changes were assessed using a sea-level equation. The results show impoundment increases in the MLRs during1950-2016, particularly in the Yangtze River(Changjiang) and southern basins, causing significant elastic load effects in the surrounding areas of the reservoirs and increasing the relative sea level in China's offshore. However, long-term groundwater estimation trends are overestimated and underestimated in the Yangtze River and southwestern basins, respectively, due to the neglect of the MLRs impacts or the uncertainty of the hydrological model's output(e.g., soil moisture, etc.). The construction of MLRs may reduce the water mass input from land to the ocean, thus slowing global sea level rise. The results of the impact of human activities on the regional water cycle provide important references and data support for improving the integration of hydrological models, evaluating Earth's viscoelastic responses under longterm reservoir storage, enhancing in-situ and satellite geodetic measurements, and identifying the main factors driving sea level changes.
文摘The effects of various metal ions (Na+, K+, Ca2+, Mg2+, Al3+, Co2+) and anions (Cl–, SO2-4 and CH3COO–) on two cellulases were investigated. Fitting of the data to Michaelis-Menten kinetics showed that Al3+ noncom-petitively inhibited cellulase (Km = 22.68 g/L;Vmax = 0.269 mg/min at 5.0 mmol/L AlCl3) and Mg2+ competitively inhibited cellulase (Km = 50.0 g/L;Vmax = 0.434 mg/min at 10.0 mmol/L MgCl2) Different metal ions increased or decreased inhibition of cellulase activity slightly below 1 mmol/L and strongly over 10 mmol/L. The results indicated that filter paper activeity (FPA) was suitable for analysis of enzymatic saccharification with various lignocellulosic substrates whereas crude cellulase was suitable for applications in the biomass industry. Some metal ions were proved to inhibit cellulase reversibly.
基金This work was supported by the National Natural Science Foundation of China[31571600]National Key R&D Program of China[2016YFD0101413].
文摘Ratoon is the stub or root of a perennial plant that is commonly retained after harvest to produce a following crop.This paper presents a review of ratoon cotton in relation to a broader framework that has been examining perennialization of agriculture for the benefit of ecology and economy.Cotton is botanically indeterminate,but has been treated as an annual after domestication,yet the habit of perenniality is retained and the plants begin to resprout after the first harvest.In some cropping systems,this tendency is exploited using the“ratooning”practice(i.e.growing one or more crops on the rootstock of the first).Ratooning has declined for various reasons such as an increase in the prevalence of pests and diseases and overwintering risk.However,ratooning has many benefits such as no annual tillage before sowing,a well-established root system,and high yield.The three methods of ratooning offer flexibility to balance the environmental and economic benefits in agriculture.The greatest environmental benefits arise from perennial ratoon cropping of semi-wild cotton,and the greatest economic benefit is obtained from biannually cropping modern annual cultivars.However,an optimum solution would be provided by perennial cropping annual cultivars.To realize both environmental and economic benefits,research is needed in the following main areas:preventing the buildup of pests and diseases,breeding the most suitable cotton cultivars for ratooning,and developing light and simplified cultivation(LSC)systems for ratoon cultivation.
基金the National Natural Science Foundation of China (Grant No. 11531004)Simons Foundation (Grant No. 523868).
文摘We give a recursive algorithm to compute the multivariable Zassenhaus formula e^X1+X2+…+Xn=e^X1eX2…e^Xn∏∞k=2e^Wk and derive an effective recursion formula of Wk.
