国家自然科学基金委员会(National Natural Science Foundation of China,简称NSFC)自1986年成立以来,秉承引导科学发展,服务学科管理的宗旨,在吸收借鉴多国科学基金学科布局和申请导向方式的基础上,形成了现有学科布局和申请代码体系....国家自然科学基金委员会(National Natural Science Foundation of China,简称NSFC)自1986年成立以来,秉承引导科学发展,服务学科管理的宗旨,在吸收借鉴多国科学基金学科布局和申请导向方式的基础上,形成了现有学科布局和申请代码体系.科学基金的申请导向方式主要是以学科申请代码引导为主(如面上、青年、地区科学基金项目的申请及所有项目的归口管理)、指南引导为辅(如重点、重大、重大研究计划及联合基金等项目申请).展开更多
The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentr...The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentrations of Hg （CK, Hg25, Hg50, and Hg100, denoted as 0, 25, 50, and 100 mg Hg/kg dry soil, respectively） were incubated for 28 days. Soil denitrification enzyme activity （DEA） was measured at day 3, 7 and 28. The abundances and community structures of two denitrification concerning genes, nirS （cd1-nitrite reductase gene） and nosZ （nitrous oxide reductase gene）, were analyzed using real-time PCR and denaturing gradient gel electrophoresis （DGGE）. Results showed that soil DEA was significantly stimulated in the treatments of Hg25 and Hg50 compared with others at day 7. Meanwhile, no difference in the abundances of soil nirS and nosZ was found between Hg spiked treatments and CK, except the lower abundance of nirS （P 〈 0.05） in the Hg added treatments compared with that in the CK at day 28. The community structures of denitrifiers based on nirS gene presented obvious change at day 7 along with the Hg additions, however, no variation was found in all treatments based on the nosZ gene. The results indicated that Hg （Hg25 and Hg50） had a strongly short-term stimulation on soil DEA, and nirS gene is more sensitive than nosZ gene to Hg stress.展开更多
Identifying the factors that influence the heavy metal contents of soil could reveal the sources of soil heavy metal pollution.In this study,a categorical regression was used to identify the factors that influence soi...Identifying the factors that influence the heavy metal contents of soil could reveal the sources of soil heavy metal pollution.In this study,a categorical regression was used to identify the factors that influence soil heavy metals.First,environmental factors were associated with soil heavy metal data,and then,the degree of influence of different factors on the soil heavy metal contents in Beijing was analyzed using a categorical regression.The results showed that the soil parent material,soil type,land use type,and industrial activity were the main influencing factors,which suggested that these four factors were important sources of soil heavy metals in Beijing.In addition,population density had a certain influence on the soil Pb and Zn contents.The distribution of soil As,Cd,Pb,and Zn was markedly influenced by interactions,such as traffic activity and land use type,industrial activity and population density.The spatial distribution of soil heavy metal hotspots corresponded well with the influencing factors,such as industrial activity,population density,and soil parent material.In this study,the main factors affecting soil heavy metals were identified,and the degree of their influence was ranked.A categorical regression represents a suitable method for identifying the factors that influence soil heavy metal contents and could be used to study the genetic process of regional soil heavy metal pollution.展开更多
文摘国家自然科学基金委员会(National Natural Science Foundation of China,简称NSFC)自1986年成立以来,秉承引导科学发展,服务学科管理的宗旨,在吸收借鉴多国科学基金学科布局和申请导向方式的基础上,形成了现有学科布局和申请代码体系.科学基金的申请导向方式主要是以学科申请代码引导为主(如面上、青年、地区科学基金项目的申请及所有项目的归口管理)、指南引导为辅(如重点、重大、重大研究计划及联合基金等项目申请).
基金supported by the Natural Science Foundation of China (No. 41020114001, 50921064)the Ministry of Sciences and Technology (No. 2009AA06Z402,2008ZX07209-006-04)the CAS/SAFEA International Partnership Program for Creative Research Teams of"Ecosystem Processes and Services"
文摘The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentrations of Hg （CK, Hg25, Hg50, and Hg100, denoted as 0, 25, 50, and 100 mg Hg/kg dry soil, respectively） were incubated for 28 days. Soil denitrification enzyme activity （DEA） was measured at day 3, 7 and 28. The abundances and community structures of two denitrification concerning genes, nirS （cd1-nitrite reductase gene） and nosZ （nitrous oxide reductase gene）, were analyzed using real-time PCR and denaturing gradient gel electrophoresis （DGGE）. Results showed that soil DEA was significantly stimulated in the treatments of Hg25 and Hg50 compared with others at day 7. Meanwhile, no difference in the abundances of soil nirS and nosZ was found between Hg spiked treatments and CK, except the lower abundance of nirS （P 〈 0.05） in the Hg added treatments compared with that in the CK at day 28. The community structures of denitrifiers based on nirS gene presented obvious change at day 7 along with the Hg additions, however, no variation was found in all treatments based on the nosZ gene. The results indicated that Hg （Hg25 and Hg50） had a strongly short-term stimulation on soil DEA, and nirS gene is more sensitive than nosZ gene to Hg stress.
基金This research was supported by the National Natural Science Foundation of China(Grant Nos.41771510 and 41271478)the Science and Technology Service Network Initiative(STS)from the Chinese Academy of Sciences(No.KFJ-STS-ZDTP-007)In addition,the authors would like to thank professor Yucheng Chen of South-west University for helping us to analyze the data.
文摘Identifying the factors that influence the heavy metal contents of soil could reveal the sources of soil heavy metal pollution.In this study,a categorical regression was used to identify the factors that influence soil heavy metals.First,environmental factors were associated with soil heavy metal data,and then,the degree of influence of different factors on the soil heavy metal contents in Beijing was analyzed using a categorical regression.The results showed that the soil parent material,soil type,land use type,and industrial activity were the main influencing factors,which suggested that these four factors were important sources of soil heavy metals in Beijing.In addition,population density had a certain influence on the soil Pb and Zn contents.The distribution of soil As,Cd,Pb,and Zn was markedly influenced by interactions,such as traffic activity and land use type,industrial activity and population density.The spatial distribution of soil heavy metal hotspots corresponded well with the influencing factors,such as industrial activity,population density,and soil parent material.In this study,the main factors affecting soil heavy metals were identified,and the degree of their influence was ranked.A categorical regression represents a suitable method for identifying the factors that influence soil heavy metal contents and could be used to study the genetic process of regional soil heavy metal pollution.
