Phosphorus(P)is a finite natural resource and is increasingly considered to be a challenge for global sustainability.Agriculture in China plays a key role in global sustainable P management.Rhizosphere and soil-based ...Phosphorus(P)is a finite natural resource and is increasingly considered to be a challenge for global sustainability.Agriculture in China plays a key role in global sustainable P management.Rhizosphere and soil-based P management are necessary for improving P-use efficiency and crop productivity in intensive agriculture in China.A previous study has shown that the future demand for phosphate fertilizer by China estimated by the LePA model(legacy phosphorus assessment model)can be greatly reduced by soil-based P management(the building-up and maintenance approach).The present study used the LePA model to predict the phosphate demand by China through combined rhizosphere and soil-based P management at county scale under four P fertilizer scenarios:(1)same P application rate as in 2012;(2)rate maintained same as 2012 in low-P counties or no P fertilizer applied in high-P counties until targeted soil Olsen-P(TPOlsen)level is reached,and then rate was the same as P-removed at harvest;(3)rate in each county decreased to1–7 kg ha^(-1) yr^(-1) after TPOlsen is reached in low-P counties,then increased by 0.1–9 kg ha^(-1) yr^(-1) until equal to P-removal;(4)rate maintained same as 2012 in low-P counties until TPOlsen is reached and then equaled to P-removal,while the rate in high-P counties is decreased to 1–7 kg ha^(-1) yr^(-1) until TPOlsen is reached and then increased by 0.1–9 kg ha^(-1) yr^(-1)until equal to P-removal.Our predictions showed that the total demand for P fertilizer by whole China was 693 Mt P2O5and according to scenario 4,P fertilizer could be reduced by 57.5%compared with farmer current practice,during the period 2013–2080.The model showed that rhizosphere P management led to a further 8.0%decrease in P fertilizer use compared with soil-based P management.The average soil Olsen-P level in China only needs to be maintained at 17 mg kg^(-1) to achieve high crop yields.Our results provide a firm basis for government to issue-relevant policies for sustainable P management in China.展开更多
The hydrogen evolution reaction(HER)is a promising way to produce hydrogen,and the use of non-precious metals with an excellent electrochemical performance is vital for this.Carbon-based transition metal catalysts hav...The hydrogen evolution reaction(HER)is a promising way to produce hydrogen,and the use of non-precious metals with an excellent electrochemical performance is vital for this.Carbon-based transition metal catalysts have high activity and stability,which are important in reducing the cost of hydrogen production and promoting the development of the hydrogen production industry.However,there is a lack of discussion regarding the effect of carbon components on the performance of these electrocatalysts.This review of the literature discusses the choice of the carbon components in these catalysts and their impact on catalytic performance,including electronic structure control by heteroatom doping,morphology adjustment,and the influence of self-supporting materials.It not only analyzes the progress in HER,but also provides guidance for synthesizing high-performance carbon-based transition metal catalysts.展开更多
[Objective] The aim was to analyze the characteristics of environmental Kuznets curve (EKC) and assess air quality in Qingdao City. [Method] The EKC characteristics of Qingdao from 1996 to 2008 were studied based on a...[Objective] The aim was to analyze the characteristics of environmental Kuznets curve (EKC) and assess air quality in Qingdao City. [Method] The EKC characteristics of Qingdao from 1996 to 2008 were studied based on air pollutant discharge indices, air pollution indices and economic data from the environmental quality reports and statistics yearbooks of Qingdao, and the air quality of Qingdao City was assessed. [Result] With the increase of GDP per capita, the total discharge of industrial waste gases improved remarkably, and its EKC showed inverted U type. Meanwhile, the discharge of SO2, industrial fumes and industrial dusts decreased on the whole, and the EKC of sulfur dioxide and industrial fumes was close to inverted N type. In addition, air pollution composite index also showed decrease trend, and its EKC showed inverted N type. In recent 13 years, the concentration of SO2, particles and NO2 in ambient air of Qingdao City showed decrease trend on the whole, especially particles. In addition, PM10 has replaced SO2 as the primary pollutant since 2001, and air pollution type has changed from coal smoke pollution to mixed mode pollution of coal smoke and motor vehicle. The mitigation of air pollution in Qingdao City could be attributed to the implementation of industrial waste gas management by the governments of Qingdao City. [Conclusion] The study could provide theoretical foundations for the establishment of environmental policies in Qingdao City.展开更多
In this paper,it gives the definition of the category of ■-sets and bi-induced maps whose true value set is a Locale,a complete Heyting algebra.In this category it defines the L_b-monomorphisms and the L_b-epimorphis...In this paper,it gives the definition of the category of ■-sets and bi-induced maps whose true value set is a Locale,a complete Heyting algebra.In this category it defines the L_b-monomorphisms and the L_b-epimorphisms.Especially,it gives the definition,the judgmental theorem of L_b-coequalizers.Furthermore,it defines L_b-regular epimorphisms and proves the judgmental theorem.At the end it concludes a result:the category of ■-sets and bi-induced maps is finitely cocomplete.展开更多
The effects of instilled silica have been studied on the serum-phospholipid (PL), lipid peroxide (LPO) and histopathology of rat lung up to 140 days from the first day of instillation. Silica induced relatively higher...The effects of instilled silica have been studied on the serum-phospholipid (PL), lipid peroxide (LPO) and histopathology of rat lung up to 140 days from the first day of instillation. Silica induced relatively higher serum-PL throughout the experiment. The level of LPO also increased appreciably. They presented positive linear correlation. The early lesion was acute alveolitis with silica particles. These lesions became silicotic nodules on the 30th day, which then were enlarged gradually and fused by fibrosis. Alveolar macrophages (AM) were activated and surface structure was damaged. These results indicate that instilled sillca can induce lipid peroxidation of cell membrane and selective accumulation of lung PL展开更多
基金supported by the Double First-Class Financial Capital in China(NDYB2018-4)the Scientific Research Start-up Fund of the Autonomous Region Human Resources and Social Security Department in 2018,China(for Haigang Li)+1 种基金the Project of Grassland Talent,China(for Haigang Li)the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-328017493/GRK 2366(International Research Training Group“Adaptation of Maize-based Food–Feed–Energy Systems to Limited Phosphate Resources”)。
文摘Phosphorus(P)is a finite natural resource and is increasingly considered to be a challenge for global sustainability.Agriculture in China plays a key role in global sustainable P management.Rhizosphere and soil-based P management are necessary for improving P-use efficiency and crop productivity in intensive agriculture in China.A previous study has shown that the future demand for phosphate fertilizer by China estimated by the LePA model(legacy phosphorus assessment model)can be greatly reduced by soil-based P management(the building-up and maintenance approach).The present study used the LePA model to predict the phosphate demand by China through combined rhizosphere and soil-based P management at county scale under four P fertilizer scenarios:(1)same P application rate as in 2012;(2)rate maintained same as 2012 in low-P counties or no P fertilizer applied in high-P counties until targeted soil Olsen-P(TPOlsen)level is reached,and then rate was the same as P-removed at harvest;(3)rate in each county decreased to1–7 kg ha^(-1) yr^(-1) after TPOlsen is reached in low-P counties,then increased by 0.1–9 kg ha^(-1) yr^(-1) until equal to P-removal;(4)rate maintained same as 2012 in low-P counties until TPOlsen is reached and then equaled to P-removal,while the rate in high-P counties is decreased to 1–7 kg ha^(-1) yr^(-1) until TPOlsen is reached and then increased by 0.1–9 kg ha^(-1) yr^(-1)until equal to P-removal.Our predictions showed that the total demand for P fertilizer by whole China was 693 Mt P2O5and according to scenario 4,P fertilizer could be reduced by 57.5%compared with farmer current practice,during the period 2013–2080.The model showed that rhizosphere P management led to a further 8.0%decrease in P fertilizer use compared with soil-based P management.The average soil Olsen-P level in China only needs to be maintained at 17 mg kg^(-1) to achieve high crop yields.Our results provide a firm basis for government to issue-relevant policies for sustainable P management in China.
文摘The hydrogen evolution reaction(HER)is a promising way to produce hydrogen,and the use of non-precious metals with an excellent electrochemical performance is vital for this.Carbon-based transition metal catalysts have high activity and stability,which are important in reducing the cost of hydrogen production and promoting the development of the hydrogen production industry.However,there is a lack of discussion regarding the effect of carbon components on the performance of these electrocatalysts.This review of the literature discusses the choice of the carbon components in these catalysts and their impact on catalytic performance,including electronic structure control by heteroatom doping,morphology adjustment,and the influence of self-supporting materials.It not only analyzes the progress in HER,but also provides guidance for synthesizing high-performance carbon-based transition metal catalysts.
基金Supported by Soft Scientific Project(2009RKA185)Project of Educational Commission of Shandong Province(J08WB04)
文摘[Objective] The aim was to analyze the characteristics of environmental Kuznets curve (EKC) and assess air quality in Qingdao City. [Method] The EKC characteristics of Qingdao from 1996 to 2008 were studied based on air pollutant discharge indices, air pollution indices and economic data from the environmental quality reports and statistics yearbooks of Qingdao, and the air quality of Qingdao City was assessed. [Result] With the increase of GDP per capita, the total discharge of industrial waste gases improved remarkably, and its EKC showed inverted U type. Meanwhile, the discharge of SO2, industrial fumes and industrial dusts decreased on the whole, and the EKC of sulfur dioxide and industrial fumes was close to inverted N type. In addition, air pollution composite index also showed decrease trend, and its EKC showed inverted N type. In recent 13 years, the concentration of SO2, particles and NO2 in ambient air of Qingdao City showed decrease trend on the whole, especially particles. In addition, PM10 has replaced SO2 as the primary pollutant since 2001, and air pollution type has changed from coal smoke pollution to mixed mode pollution of coal smoke and motor vehicle. The mitigation of air pollution in Qingdao City could be attributed to the implementation of industrial waste gas management by the governments of Qingdao City. [Conclusion] The study could provide theoretical foundations for the establishment of environmental policies in Qingdao City.
基金Foundation item： Supported by the National Natural Science Foundation of China（10871137）
文摘In this paper,it gives the definition of the category of ■-sets and bi-induced maps whose true value set is a Locale,a complete Heyting algebra.In this category it defines the L_b-monomorphisms and the L_b-epimorphisms.Especially,it gives the definition,the judgmental theorem of L_b-coequalizers.Furthermore,it defines L_b-regular epimorphisms and proves the judgmental theorem.At the end it concludes a result:the category of ■-sets and bi-induced maps is finitely cocomplete.
文摘The effects of instilled silica have been studied on the serum-phospholipid (PL), lipid peroxide (LPO) and histopathology of rat lung up to 140 days from the first day of instillation. Silica induced relatively higher serum-PL throughout the experiment. The level of LPO also increased appreciably. They presented positive linear correlation. The early lesion was acute alveolitis with silica particles. These lesions became silicotic nodules on the 30th day, which then were enlarged gradually and fused by fibrosis. Alveolar macrophages (AM) were activated and surface structure was damaged. These results indicate that instilled sillca can induce lipid peroxidation of cell membrane and selective accumulation of lung PL
