In principle,nature reserves are managed and controlled according to the core area and the general control area.At present,there is no relevant design specification for the design system of patrol road in various prot...In principle,nature reserves are managed and controlled according to the core area and the general control area.At present,there is no relevant design specification for the design system of patrol road in various protected areas.This paper analyzed the factors to be considered in determining the grade,horizontal and vertical design indicators,and cross section indicators of the patrol road in the protected area,and came up with the corresponding design indicators and parameters,so as to provide a certain reference for the subsequent patrol road design.展开更多
The study looks at the carbon reserves of bamboo forests in China from 2004 to 2018.The temporal and spatial variation characteristics of the carbon reserves of bamboo forests in China were analyzed.It enriches the re...The study looks at the carbon reserves of bamboo forests in China from 2004 to 2018.The temporal and spatial variation characteristics of the carbon reserves of bamboo forests in China were analyzed.It enriches the research field of bamboo forest carbon reserve change at the national level.The bamboo forest carbon reserves of 20 provinces in China were estimated by using the calculation method of bamboo forest biomass and bamboo forest soil organic matter carbon reserves,and the temporal and spatial variation characteristics of bamboo forest carbon reserves in China were analyzed by GIS spatial analysis method.The results are as follows:(1)the carbon reserves of bamboo forests in China during 2004-2008,2009-2013 and 2014-2018 were 707.08 Tg C,802.83 Tg C and 845.05 Tg C respectively,with an average annual growth rate of 1.95%.Fujian,Jiangxi,Zhejiang,Hunan,Sichuan and Guangdong account for 78.01%-78.80% of the total bamboo forest carbon storage in China.(2)From 2004 to 2008,the carbon reserves of bamboo biomass in China were 380.63 Tg C-454.92 Tg C,accounting for 52.64%-52.91% of the total carbon reserves;The carbon storage of soil organic matter is 342.39 Tg C-406.33 Tg C,accounting for 47.01%-47.36% of the total carbon storage.(3)The spatial distribution of bamboo forest carbon reserves in China shows a high-high,low-low correlation trend.The relevant provinces are Zhejiang,Fujian,Guangdong and Jiangxi,which are concentrated in the southern provinces of China.The low-low related provinces are Inner Mongolia,Hebei and Liaoning,which are concentrated in the northern provinces of China.In the future,China’s bamboo forest carbon reserves will increase steadily.Bamboo forest carbon reserves are concentrated in southern provinces.China should further improve the level of spatial agglomeration and give full play to the role of bamboo forest carbon sink.展开更多
With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased.In this context, the problem of light pollution has attracted ...With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased.In this context, the problem of light pollution has attracted wide attention.Previous studies have revealed that light pollution can affect biological living environments, human physical and mental health, astronomical observations and many other aspects.Therefore, organizations internationally have begun to advocate for measures to prevent light pollution, many of which are recognized by the International Dark-Sky Association(IDA).In addition to improving public awareness, legal protections, technical treatments and other means, the construction of Dark Sky Reserves(DSR) has proven to be an effective preventive measure.So far, as a pioneer practice in this field, the IDA has identified 11 DSRs worldwide.Based on the DA requirements for DSRs, this paper utilizes NPP-VIIRS nighttime light data and other multi-source spatial data to analyze possible DSR sites in China.The land of China was divided into more than ten thousand 30 km × 30 km fishnets, and constraint and suitable conditions were designated, respectively, as light and cloud conditions, and scale, traffic and attractiveness conditions.Using a multiple criteria evaluation, 1443 fishnets were finally selected as most suitable sites for the construction of DSRs.Results found that less than 25% of China is not subject to light pollution, and less than 13% is suitable for DSR construction, primarily in western and northern areas, including Tibet, Xinjiang, Qinghai, Gansu and Inner Mongolia.展开更多
Analyzes on solid potassium mineral reserves calculation methods and existing problems of chaerhan salt lake,t with many parameters comparison solid potassium mineral reserves calculation results are reliable。
National nature reserves are an important part of classification management on ecological protection in China. Taking the national nature reserves of Jilin Province as examples, this paper introduced the stability ind...National nature reserves are an important part of classification management on ecological protection in China. Taking the national nature reserves of Jilin Province as examples, this paper introduced the stability index by referring to the intensity model of landuse and land-cover change(LUCC), and analyzed the overall stability of land-use and land-cover(LULC) in the study area from the time interval level and land category level. The stability of LULC in different types of nature reserves was tracked and identified by extracting land-use change trajectory, and the land-use change trajectory was divided into three types: stable type, sub-stable type and unstable type. The impact of LUCC on regional ecosystem services was studied by using hotspot analysis and gravity center analysis. The results showed that: 1) The LULC in the study area was stable on the whole, and the proportion of stable land area reached 86.08%. The intensity of LUCC showed an increasing trend in recent 20 years, and the conversion of cultivated land and construction land was active in continuous time interval. 2) The stability of LULC in forest ecological reserves and wildlife reserves in the eastern part of Jilin Province was the highest, while that in inland wetland reserves and geological relic reserves in the central and western part of Jilin Province was lower.3) The LUCC in national nature reserves not only changed the value of its own ecosystem service function, but also affected the ecosystem service function of the whole region. The combination of intensity analysis and land-use change trajectory was used to identify the characteristics of stability of LULC in nature reserves, which was conducive to deeply understand the process of LUCC in national nature reserves and provided reasonable suggestions for regional ecological protection.展开更多
Excessive rainfall provides a favorable condition for field mold infection of plants, which triggers field mold(FM) stress. If FM stress occurs during the late maturation stage of soybean seed, it negatively affects s...Excessive rainfall provides a favorable condition for field mold infection of plants, which triggers field mold(FM) stress. If FM stress occurs during the late maturation stage of soybean seed, it negatively affects seed yield and quality. To investigate the responses of soybean seed against FM stress and identify the underlying biochemical pathways involved, a greenhouse was equipped with an artificial rain producing system to allow the induction of mold growth on soybean seed. The induced quality changes and stress responses were revealed on the levels of both transcriptome and metabolome. The results showed that soybean seeds produced under FM stress conditions had an abnormal and inferior appearance, and also contained less storage reserves, such as protein and polysaccharide. Transcriptional analysis demonstrated that genes involved in amino acid metabolism, glycolysis, tricarboxylic acid, β-oxidation of fatty acids, and isoflavone biosynthesis were induced by FM stress. These results were supported by a multiple metabolic analysis which exhibited increases in the concentrations of a variety of amino acids, sugars, organic acids, and isoflavones, as well as reductions of several fatty acids. Reprogramming of these metabolic pathways mobilized and consumed stored protein, sugar and fatty acid reserves in the soybean seed in order to meet the energy and substrate demand on the defense system, but led to deterioration of seed quality. In general, FM stress induced catabolism of storage reserves and diminished the quality of soybean seed in the field. This study provides a more profound insight into seed deterioration caused by FM stress.展开更多
The concentrations of five metals(Cu, Pb, Zn, Cd and Hg) were measured in sediments obtained before and after the establishment of Techeng Island Special Marine Reserves(TCISMR) in Zhanjiang Bay to evaluate the ecolog...The concentrations of five metals(Cu, Pb, Zn, Cd and Hg) were measured in sediments obtained before and after the establishment of Techeng Island Special Marine Reserves(TCISMR) in Zhanjiang Bay to evaluate the ecological risk of heavy metals. The results showed that average values of potential ecological risk indexes of heavy metals at all stations increased slightly from 32.09 to 30.54 after establishment of TCISMR. Optimal semivariance simulation showed that the contents of five heavy metals have strong spatial correlations in August 2010(before), while this correlations weakened in April 2013(after establishment of TCISMR), suggesting that the main sources of heavy metals changed. The Hakanson Risk Index(HRI) values in Donghai levee, central and southern parts of Zhanjiang harbor were high up to 60.13 and 46.46, respectively. And Zhanjiang Bay Channel, the areas around special marine reserves, the artificial reef areas and mangrove areas at south of Techeng Island are the areas with low ecological risk and high ecological value, which should be treated as the prior ecological protection areas. Our study provided a priority control pattern of heavy metal pollution in TCISMR, which greatly benefits the sustainable development and resource protection in Zhanjiang Bay.展开更多
A study was conducted to estimate the forest cover change, quantify and map tree above-ground carbon stock using Remote sensing and GIS techniques together with forest inventory. Landsat images of 1980, 1995 and 2010 ...A study was conducted to estimate the forest cover change, quantify and map tree above-ground carbon stock using Remote sensing and GIS techniques together with forest inventory. Landsat images of 1980, 1995 and 2010 acquired during dry season were used in the estimation of cover changes. Supervised image classification using Maximum Likeli-hood Classifier was performed in ERDAS Imagine software to analyze the images and further analysis was performed in Arc GIS 9.3 software. Stratified sampling procedure was used to select concentric inventory plots in Pugu Forest Reserve (PFR) and Kazimzumbwi Forest Reserve (KFR). Plots were laid according to NAFORMA, and the tree parameters in each sampling plot were collected. A Microsoft Excel spreadsheet was used to compute the above-ground bio- mass for each plot using an empirical equation relating wood basic density and tree height. The above-ground carbon was calculated using a conversion factor of 0.49. Geostatistical method in ArcGIS was used to analyze and map carbon. Results revealed that for the periods 1980-1995 and 1995-2010, Closed Forest in PFR decreased by 4.5% and 25.3% respectively, while for KFR, Closed Forest decreased by 11.9% and 31.3% respectively. The mean carbon density for PFR and KFR were respectively 5.72 tC/ha and 0.98 tC/ha while carbon stocks were 14 730.41 tC and 7 206.46 tC re- spectively. The revealed low carbon densities were attributable to decline in area under Closed Forest in the two Forest Reserves. The study recommends concerted efforts to enhance proper management of the forests so that the two forest reserves may contribute to REDD initiatives.展开更多
The paper deals with the rapid growing twin surpluses and surging foreign exchange reserves in China’s international accounts withessed in recent years.It observes the characteristics of the phenomenon against the st...The paper deals with the rapid growing twin surpluses and surging foreign exchange reserves in China’s international accounts withessed in recent years.It observes the characteristics of the phenomenon against the standard economic theory and empirical experiences.Then it offers explanation factors:the combined effects of processing trade and foreign direct investments,China’s opening development model underpinned by the intra-product specialization of the contemporary globalization era,and the undervalued exchange rate for the Chinese currency.展开更多
Purpose:Fully integrating its e-reserves service into the university’s course management system has become the primary design goal of the innovative e-reserves service system at Shanghai Jiao Tong University(SJTU)Lib...Purpose:Fully integrating its e-reserves service into the university’s course management system has become the primary design goal of the innovative e-reserves service system at Shanghai Jiao Tong University(SJTU)Library.Design/methodology/approach:Through blending library and information service into the teaching and learning process,SJTU Library has effectively combined its reserves service into the user learning environment.The main metadata model and the design of various interfaces of the e-reserves service system are introduced.Findings:E-reserves has been integrated into the course management system.Users can directly access relevant resources when they browse the customized course page.It is more convenient for teachers to add reserves items,and the added items can be made available simultaneously on SJTU Library’s resource discovery platform automatically.Research limitations:At present,e-reserves items are mainly books,and more other types of reserves materials are needed to be provided.Some relevant copyright issues should be addressed.Practical implications:Using a series of interface interactions,the e-reserves service has been integrated into the university’s course management system.It is convenient for students to access customized e-reserves service during their learning process.Originality/value:We achieved interconnection between the e-reserves and the university’s course management system.Information on the e-reserves Web page is automatically updated.SJTU Library provides customized e-reserves service in the course management system.展开更多
Ministry of Geology and Mineral Reserves resently declared that verified reserves of 12 min-eral species are the foremost in the world.These minerals are rare-earths、 gypsum、 titanium、 tantalum、 tungsten、 benton...Ministry of Geology and Mineral Reserves resently declared that verified reserves of 12 min-eral species are the foremost in the world.These minerals are rare-earths、 gypsum、 titanium、 tantalum、 tungsten、 bentonite、tin、 mirabilite、 barite、 magnesite、 antimony、 graphite.In addition,vanadium、molvbdenium and coal,etc.seven kind of mineral reserves take second place in the world.展开更多
1.The Status of Major Mineral Reserves in ChinaSince 1949 162 kinds of minerals and thousands of mining area have been found out in geo-logical exploration,and 149 kinds have been proved reserves.Estimated potential c...1.The Status of Major Mineral Reserves in ChinaSince 1949 162 kinds of minerals and thousands of mining area have been found out in geo-logical exploration,and 149 kinds have been proved reserves.Estimated potential cost of 45 kindsonly of major minerals may be more than one billion RMB(?).China is the one of the great-nations of mineral resources in the world.But the distribution in respect of mineral species is not so ideal as expected.According to theirreserves the minerals can be classified as follows.展开更多
As a significant inducement during the development of oil and gas,the role of remaining recoverable reserves is more observable especially in the later phase of development of oilfield.Depended on the production decli...As a significant inducement during the development of oil and gas,the role of remaining recoverable reserves is more observable especially in the later phase of development of oilfield.Depended on the production decline method in petroleum reservoir engineering,a new model of predicting recoverable and remaining recoverable reserves has been展开更多
To examine the eukaryotic biodiversity of aquatic ecosystems in the Qiantang River,China,eukaryotic microbes in the river were investigated using 18S rRNA gene sequencing during the breeding season(July to August 2018...To examine the eukaryotic biodiversity of aquatic ecosystems in the Qiantang River,China,eukaryotic microbes in the river were investigated using 18S rRNA gene sequencing during the breeding season(July to August 2018).Four distinct distribution patterns(1.Jiande;2.Tonglu and Fuyang;3.Jiubao;4.Yanguan)of the microbial community and their potential effects on fishery activities were observed.Results show lower abundances of Dinophyta and Fungi and higher abundances of Cryptophyta and Chlorophyta in Tonglu and Fuyang than those in the other three sections.In addition,the reserves(Tonglu and Fuyang)destabilized the original eukaryotic microbial co-occurrence network.Among all the environmental factors measured,nitrogen(nitrite,nitrate,ammonium),water temperature and total chlorophyll a acted as major driving factors that controlled the eukaryotic microbial distribution.Furthermore,the existence of some algae(e.g.,Chrysophyceae,Cryptophytes,and Chlorophyceae)and fungi(e.g.,Rhizophydium)in Tonglu and Fuyang was beneficial to juvenile fish growth and water quality,although some detrimental species(e.g.,Aphanomyces)needed attention.This study provides further insights into the sustainable protection and utilization of rivers.展开更多
The construction of nature reserves plays an essential role in protecting natural resources and the ecological environment,especially the conservation of rare and endangered species,which also has a vital function in ...The construction of nature reserves plays an essential role in protecting natural resources and the ecological environment,especially the conservation of rare and endangered species,which also has a vital function in maintaining the ecological security of the national territory.China has built up a comprehensive network of nature reserves after waves of development,but there are still many problems with the management of nature reserves,such as the definition of boundaries,zoning theory,zoning methods,and legal protection.The definition of boundaries is a tool for effective management of nature reserves,but achieving scientific and effective boundary definition is a difficult problem for the construction and management of reserves.It is also a problem that must be solved to achieve sustainable development.This paper compared three fundamental theories of the conservation of species in nature reserves,namely island biogeography,metapopulation,and landscape ecology,from connotations,applications and advantages,and disadvantages,and discussed the progress of theoretical research to provide valuable references for the definition and planning of effective boundaries of nature reserves.展开更多
Most scholars believe that FDI inflow has a direct impact on China’s foreign exchange reserve,while others hold that FDI is mainly invested in the form of physical capital and technology,and therefore does not direct...Most scholars believe that FDI inflow has a direct impact on China’s foreign exchange reserve,while others hold that FDI is mainly invested in the form of physical capital and technology,and therefore does not directly contribute to China’s foreign exchanges reserve accumulation.This paper points out that both effects,direct and indirect,should be considered when assessing FDI’s contribution to foreign exchange reserves.Result shows that from 1986 to 2007,FDI contributed 50%to foreign exchange reserves and the direct effect dominant before 2003 was surpassed by indirect effect after 2001 as the major source of the contribution.展开更多
Due to engineering technology and development costs,a considerable amount of proven oil and gas resources in China are difficult to develop,becoming reserves difficult to produce.Based on the successful development of...Due to engineering technology and development costs,a considerable amount of proven oil and gas resources in China are difficult to develop,becoming reserves difficult to produce.Based on the successful development of some domestic oil and gas reserves difficult to recover,this article summarizes the"four in one"petroleum engineering synergetic management model to promote the effective development of these reserves.This model draws on the essence of management theories,such as system theory,cybernetics and synergetic theory,and proposes the development idea of value creating and sharing for this type of reserves.By adopting the new management method of mechanism synergy,speciality synergy,process synergy and industrial chain synergy,this model effectively overcomes the decentralization of management responsibility,different management objectives,great risks of engineering and technological innovation,and the large number of uncertain factors in project construction,and can stimulate the vitality and power of active coordination of project participants,to effectively realize the synergetic innovation of engineering technology and synergetic cost reduction of the whole chain,reduction of the balanced oil price of the project,and dispersion of the project investment risk.By adopting this model,a large proportion of difficult-to-produce reserves have been liberated,realizing the effective utilization of the difficult-to-produce oil and gas resources,and making the reserves an important supplement to ensure national energy security.展开更多
文摘In principle,nature reserves are managed and controlled according to the core area and the general control area.At present,there is no relevant design specification for the design system of patrol road in various protected areas.This paper analyzed the factors to be considered in determining the grade,horizontal and vertical design indicators,and cross section indicators of the patrol road in the protected area,and came up with the corresponding design indicators and parameters,so as to provide a certain reference for the subsequent patrol road design.
基金supported by the Yunnan Provincial Education Department Scientific Research Fund Project(Grant No.2023Y0803)the National Natural Science Foundation of China(Grant No.72264035)。
文摘The study looks at the carbon reserves of bamboo forests in China from 2004 to 2018.The temporal and spatial variation characteristics of the carbon reserves of bamboo forests in China were analyzed.It enriches the research field of bamboo forest carbon reserve change at the national level.The bamboo forest carbon reserves of 20 provinces in China were estimated by using the calculation method of bamboo forest biomass and bamboo forest soil organic matter carbon reserves,and the temporal and spatial variation characteristics of bamboo forest carbon reserves in China were analyzed by GIS spatial analysis method.The results are as follows:(1)the carbon reserves of bamboo forests in China during 2004-2008,2009-2013 and 2014-2018 were 707.08 Tg C,802.83 Tg C and 845.05 Tg C respectively,with an average annual growth rate of 1.95%.Fujian,Jiangxi,Zhejiang,Hunan,Sichuan and Guangdong account for 78.01%-78.80% of the total bamboo forest carbon storage in China.(2)From 2004 to 2008,the carbon reserves of bamboo biomass in China were 380.63 Tg C-454.92 Tg C,accounting for 52.64%-52.91% of the total carbon reserves;The carbon storage of soil organic matter is 342.39 Tg C-406.33 Tg C,accounting for 47.01%-47.36% of the total carbon storage.(3)The spatial distribution of bamboo forest carbon reserves in China shows a high-high,low-low correlation trend.The relevant provinces are Zhejiang,Fujian,Guangdong and Jiangxi,which are concentrated in the southern provinces of China.The low-low related provinces are Inner Mongolia,Hebei and Liaoning,which are concentrated in the northern provinces of China.In the future,China’s bamboo forest carbon reserves will increase steadily.Bamboo forest carbon reserves are concentrated in southern provinces.China should further improve the level of spatial agglomeration and give full play to the role of bamboo forest carbon sink.
基金Under the auspices of the National Natural Science Foundation of China(No.41871162)
文摘With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased.In this context, the problem of light pollution has attracted wide attention.Previous studies have revealed that light pollution can affect biological living environments, human physical and mental health, astronomical observations and many other aspects.Therefore, organizations internationally have begun to advocate for measures to prevent light pollution, many of which are recognized by the International Dark-Sky Association(IDA).In addition to improving public awareness, legal protections, technical treatments and other means, the construction of Dark Sky Reserves(DSR) has proven to be an effective preventive measure.So far, as a pioneer practice in this field, the IDA has identified 11 DSRs worldwide.Based on the DA requirements for DSRs, this paper utilizes NPP-VIIRS nighttime light data and other multi-source spatial data to analyze possible DSR sites in China.The land of China was divided into more than ten thousand 30 km × 30 km fishnets, and constraint and suitable conditions were designated, respectively, as light and cloud conditions, and scale, traffic and attractiveness conditions.Using a multiple criteria evaluation, 1443 fishnets were finally selected as most suitable sites for the construction of DSRs.Results found that less than 25% of China is not subject to light pollution, and less than 13% is suitable for DSR construction, primarily in western and northern areas, including Tibet, Xinjiang, Qinghai, Gansu and Inner Mongolia.
文摘Analyzes on solid potassium mineral reserves calculation methods and existing problems of chaerhan salt lake,t with many parameters comparison solid potassium mineral reserves calculation results are reliable。
基金Under the auspices of National Natural Science Foundation of China(No.42071255)。
文摘National nature reserves are an important part of classification management on ecological protection in China. Taking the national nature reserves of Jilin Province as examples, this paper introduced the stability index by referring to the intensity model of landuse and land-cover change(LUCC), and analyzed the overall stability of land-use and land-cover(LULC) in the study area from the time interval level and land category level. The stability of LULC in different types of nature reserves was tracked and identified by extracting land-use change trajectory, and the land-use change trajectory was divided into three types: stable type, sub-stable type and unstable type. The impact of LUCC on regional ecosystem services was studied by using hotspot analysis and gravity center analysis. The results showed that: 1) The LULC in the study area was stable on the whole, and the proportion of stable land area reached 86.08%. The intensity of LUCC showed an increasing trend in recent 20 years, and the conversion of cultivated land and construction land was active in continuous time interval. 2) The stability of LULC in forest ecological reserves and wildlife reserves in the eastern part of Jilin Province was the highest, while that in inland wetland reserves and geological relic reserves in the central and western part of Jilin Province was lower.3) The LUCC in national nature reserves not only changed the value of its own ecosystem service function, but also affected the ecosystem service function of the whole region. The combination of intensity analysis and land-use change trajectory was used to identify the characteristics of stability of LULC in nature reserves, which was conducive to deeply understand the process of LUCC in national nature reserves and provided reasonable suggestions for regional ecological protection.
基金supported by the National Natural Science Foundation of China(31971853)the National Key Research and Development Program of China(2016YFD0300209)the Science Fund for Distinguished Young Scholars of Sichuan,China(20JCQN0155)。
文摘Excessive rainfall provides a favorable condition for field mold infection of plants, which triggers field mold(FM) stress. If FM stress occurs during the late maturation stage of soybean seed, it negatively affects seed yield and quality. To investigate the responses of soybean seed against FM stress and identify the underlying biochemical pathways involved, a greenhouse was equipped with an artificial rain producing system to allow the induction of mold growth on soybean seed. The induced quality changes and stress responses were revealed on the levels of both transcriptome and metabolome. The results showed that soybean seeds produced under FM stress conditions had an abnormal and inferior appearance, and also contained less storage reserves, such as protein and polysaccharide. Transcriptional analysis demonstrated that genes involved in amino acid metabolism, glycolysis, tricarboxylic acid, β-oxidation of fatty acids, and isoflavone biosynthesis were induced by FM stress. These results were supported by a multiple metabolic analysis which exhibited increases in the concentrations of a variety of amino acids, sugars, organic acids, and isoflavones, as well as reductions of several fatty acids. Reprogramming of these metabolic pathways mobilized and consumed stored protein, sugar and fatty acid reserves in the soybean seed in order to meet the energy and substrate demand on the defense system, but led to deterioration of seed quality. In general, FM stress induced catabolism of storage reserves and diminished the quality of soybean seed in the field. This study provides a more profound insight into seed deterioration caused by FM stress.
基金jointly funded by the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (No.2013K0011)the State Oceanic Administration Key Laboratory of Sea area Management Technology Fund (No.201711)+2 种基金the Guangdong MEPP Fund (No.GDOE [2019]A46)the GDNRC (No.[2020]067)the South China Sea Branch Secretary fund (No.1673)。
文摘The concentrations of five metals(Cu, Pb, Zn, Cd and Hg) were measured in sediments obtained before and after the establishment of Techeng Island Special Marine Reserves(TCISMR) in Zhanjiang Bay to evaluate the ecological risk of heavy metals. The results showed that average values of potential ecological risk indexes of heavy metals at all stations increased slightly from 32.09 to 30.54 after establishment of TCISMR. Optimal semivariance simulation showed that the contents of five heavy metals have strong spatial correlations in August 2010(before), while this correlations weakened in April 2013(after establishment of TCISMR), suggesting that the main sources of heavy metals changed. The Hakanson Risk Index(HRI) values in Donghai levee, central and southern parts of Zhanjiang harbor were high up to 60.13 and 46.46, respectively. And Zhanjiang Bay Channel, the areas around special marine reserves, the artificial reef areas and mangrove areas at south of Techeng Island are the areas with low ecological risk and high ecological value, which should be treated as the prior ecological protection areas. Our study provided a priority control pattern of heavy metal pollution in TCISMR, which greatly benefits the sustainable development and resource protection in Zhanjiang Bay.
文摘A study was conducted to estimate the forest cover change, quantify and map tree above-ground carbon stock using Remote sensing and GIS techniques together with forest inventory. Landsat images of 1980, 1995 and 2010 acquired during dry season were used in the estimation of cover changes. Supervised image classification using Maximum Likeli-hood Classifier was performed in ERDAS Imagine software to analyze the images and further analysis was performed in Arc GIS 9.3 software. Stratified sampling procedure was used to select concentric inventory plots in Pugu Forest Reserve (PFR) and Kazimzumbwi Forest Reserve (KFR). Plots were laid according to NAFORMA, and the tree parameters in each sampling plot were collected. A Microsoft Excel spreadsheet was used to compute the above-ground bio- mass for each plot using an empirical equation relating wood basic density and tree height. The above-ground carbon was calculated using a conversion factor of 0.49. Geostatistical method in ArcGIS was used to analyze and map carbon. Results revealed that for the periods 1980-1995 and 1995-2010, Closed Forest in PFR decreased by 4.5% and 25.3% respectively, while for KFR, Closed Forest decreased by 11.9% and 31.3% respectively. The mean carbon density for PFR and KFR were respectively 5.72 tC/ha and 0.98 tC/ha while carbon stocks were 14 730.41 tC and 7 206.46 tC re- spectively. The revealed low carbon densities were attributable to decline in area under Closed Forest in the two Forest Reserves. The study recommends concerted efforts to enhance proper management of the forests so that the two forest reserves may contribute to REDD initiatives.
文摘The paper deals with the rapid growing twin surpluses and surging foreign exchange reserves in China’s international accounts withessed in recent years.It observes the characteristics of the phenomenon against the standard economic theory and empirical experiences.Then it offers explanation factors:the combined effects of processing trade and foreign direct investments,China’s opening development model underpinned by the intra-product specialization of the contemporary globalization era,and the undervalued exchange rate for the Chinese currency.
基金supported by the Scientific and Research Innovation Project of Shanghai Municipal Education Commission
文摘Purpose:Fully integrating its e-reserves service into the university’s course management system has become the primary design goal of the innovative e-reserves service system at Shanghai Jiao Tong University(SJTU)Library.Design/methodology/approach:Through blending library and information service into the teaching and learning process,SJTU Library has effectively combined its reserves service into the user learning environment.The main metadata model and the design of various interfaces of the e-reserves service system are introduced.Findings:E-reserves has been integrated into the course management system.Users can directly access relevant resources when they browse the customized course page.It is more convenient for teachers to add reserves items,and the added items can be made available simultaneously on SJTU Library’s resource discovery platform automatically.Research limitations:At present,e-reserves items are mainly books,and more other types of reserves materials are needed to be provided.Some relevant copyright issues should be addressed.Practical implications:Using a series of interface interactions,the e-reserves service has been integrated into the university’s course management system.It is convenient for students to access customized e-reserves service during their learning process.Originality/value:We achieved interconnection between the e-reserves and the university’s course management system.Information on the e-reserves Web page is automatically updated.SJTU Library provides customized e-reserves service in the course management system.
文摘Ministry of Geology and Mineral Reserves resently declared that verified reserves of 12 min-eral species are the foremost in the world.These minerals are rare-earths、 gypsum、 titanium、 tantalum、 tungsten、 bentonite、tin、 mirabilite、 barite、 magnesite、 antimony、 graphite.In addition,vanadium、molvbdenium and coal,etc.seven kind of mineral reserves take second place in the world.
文摘1.The Status of Major Mineral Reserves in ChinaSince 1949 162 kinds of minerals and thousands of mining area have been found out in geo-logical exploration,and 149 kinds have been proved reserves.Estimated potential cost of 45 kindsonly of major minerals may be more than one billion RMB(?).China is the one of the great-nations of mineral resources in the world.But the distribution in respect of mineral species is not so ideal as expected.According to theirreserves the minerals can be classified as follows.
文摘As a significant inducement during the development of oil and gas,the role of remaining recoverable reserves is more observable especially in the later phase of development of oilfield.Depended on the production decline method in petroleum reservoir engineering,a new model of predicting recoverable and remaining recoverable reserves has been
基金Supported by the Fisheries Species Conservation Program of the Agricultural Department of China(Nos.171821303154051044,17190236)the Natural Science Foundation of Zhejiang Province(No.LQ20C190003)+1 种基金the Natural Science Foundation of Ningbo Municipality(Nos.2019A610421,2019A610443)the K.C.Wong Magna Fund of Ningbo University。
文摘To examine the eukaryotic biodiversity of aquatic ecosystems in the Qiantang River,China,eukaryotic microbes in the river were investigated using 18S rRNA gene sequencing during the breeding season(July to August 2018).Four distinct distribution patterns(1.Jiande;2.Tonglu and Fuyang;3.Jiubao;4.Yanguan)of the microbial community and their potential effects on fishery activities were observed.Results show lower abundances of Dinophyta and Fungi and higher abundances of Cryptophyta and Chlorophyta in Tonglu and Fuyang than those in the other three sections.In addition,the reserves(Tonglu and Fuyang)destabilized the original eukaryotic microbial co-occurrence network.Among all the environmental factors measured,nitrogen(nitrite,nitrate,ammonium),water temperature and total chlorophyll a acted as major driving factors that controlled the eukaryotic microbial distribution.Furthermore,the existence of some algae(e.g.,Chrysophyceae,Cryptophytes,and Chlorophyceae)and fungi(e.g.,Rhizophydium)in Tonglu and Fuyang was beneficial to juvenile fish growth and water quality,although some detrimental species(e.g.,Aphanomyces)needed attention.This study provides further insights into the sustainable protection and utilization of rivers.
基金Supported by the Central Universities Basic Research Operations Project(JS2019HGXJ0027).
文摘The construction of nature reserves plays an essential role in protecting natural resources and the ecological environment,especially the conservation of rare and endangered species,which also has a vital function in maintaining the ecological security of the national territory.China has built up a comprehensive network of nature reserves after waves of development,but there are still many problems with the management of nature reserves,such as the definition of boundaries,zoning theory,zoning methods,and legal protection.The definition of boundaries is a tool for effective management of nature reserves,but achieving scientific and effective boundary definition is a difficult problem for the construction and management of reserves.It is also a problem that must be solved to achieve sustainable development.This paper compared three fundamental theories of the conservation of species in nature reserves,namely island biogeography,metapopulation,and landscape ecology,from connotations,applications and advantages,and disadvantages,and discussed the progress of theoretical research to provide valuable references for the definition and planning of effective boundaries of nature reserves.
文摘Most scholars believe that FDI inflow has a direct impact on China’s foreign exchange reserve,while others hold that FDI is mainly invested in the form of physical capital and technology,and therefore does not directly contribute to China’s foreign exchanges reserve accumulation.This paper points out that both effects,direct and indirect,should be considered when assessing FDI’s contribution to foreign exchange reserves.Result shows that from 1986 to 2007,FDI contributed 50%to foreign exchange reserves and the direct effect dominant before 2003 was surpassed by indirect effect after 2001 as the major source of the contribution.
文摘Due to engineering technology and development costs,a considerable amount of proven oil and gas resources in China are difficult to develop,becoming reserves difficult to produce.Based on the successful development of some domestic oil and gas reserves difficult to recover,this article summarizes the"four in one"petroleum engineering synergetic management model to promote the effective development of these reserves.This model draws on the essence of management theories,such as system theory,cybernetics and synergetic theory,and proposes the development idea of value creating and sharing for this type of reserves.By adopting the new management method of mechanism synergy,speciality synergy,process synergy and industrial chain synergy,this model effectively overcomes the decentralization of management responsibility,different management objectives,great risks of engineering and technological innovation,and the large number of uncertain factors in project construction,and can stimulate the vitality and power of active coordination of project participants,to effectively realize the synergetic innovation of engineering technology and synergetic cost reduction of the whole chain,reduction of the balanced oil price of the project,and dispersion of the project investment risk.By adopting this model,a large proportion of difficult-to-produce reserves have been liberated,realizing the effective utilization of the difficult-to-produce oil and gas resources,and making the reserves an important supplement to ensure national energy security.
