美国公共图书馆对民众的生活和工作具有重要作用,但近年来出现了较大的使用波动情况。本文以皮尤美国公共图书馆服务调研中用户陈述的使用变化原因为样本,基于质性分析工具Nvivo和SPSS Text Analytics对原因内容进行主题提取,借助Pajek...美国公共图书馆对民众的生活和工作具有重要作用,但近年来出现了较大的使用波动情况。本文以皮尤美国公共图书馆服务调研中用户陈述的使用变化原因为样本,基于质性分析工具Nvivo和SPSS Text Analytics对原因内容进行主题提取,借助Pajek和VOSviewer构建主题间的语义关联网络并实现可视化展示,在对主题关联网络社区划分的基础上总结归纳当前美国民众公共图书馆使用习惯变化的原因。首先,儿童及青少年的教育、传统资源和服务以及便利性是增加公共图书馆使用的主要原因;而互联网和信息技术、家庭生活方式的改变及对电子资源和服务需求增多,是导致民众减少使用的主要因素。其次,信息技术的作用具有双重性,图书馆的免费网络服务和技能培训增加了其使用,而高收入和高学历用户也因信息技术的便捷减少了前往公共图书馆的次数。最后,公共图书馆应利用信息技术创新其无线和移动服务方式,丰富基于信息技术的教育培训和社区活动,增加不同层次的用户黏性。同时,本文发现使用习惯变化反映出美国民众的分层现象,未来笔者将展开民众属性特征与原因主题的关联分析,以期得到更加深入的研究结论。展开更多
Vegetation restoration has been proposed as an effective method for increasing both plant biomass and soil carbon(C) stocks. In this study, 204 publications(733 observations) were analyzed, focusing on the effects of ...Vegetation restoration has been proposed as an effective method for increasing both plant biomass and soil carbon(C) stocks. In this study, 204 publications(733 observations) were analyzed, focusing on the effects of vegetation restoration on soil organic carbon(SOC) in China. The results showed that SOC was increased by 45.33%, 24.43%, 30.29% and 27.98% at soil depths of 0–20 cm, 20–40 cm, 40–60 cm and > 60 cm after vegetation restoration, respectively. Restoration from both cropland and non-cropland increased the SOC content. The conversion of non-cropland was more efficient in SOC accumulation than the conversion of cropland did, especially in > 40 cm layers. In addition, the conversion to planted forest led to greater SOC accumulation than that to other land use did. Conversion period and initial SOC content extended more influence on soil C accumulation as the main factors after vegetation restoration than temperature and precipitation did. The SOC content significantly increased with restoration period after long-term vegetation restoration(> 40 yr), indicating a large potential for further accumulation of carbon in the soil, which could mitigate climate change in the near future.展开更多
Land use changes are regarded as landscape pattern change driven by many interactive natural and social-economic factors. Different combination of physical geographical elements induced the difference of spatio-tempor...Land use changes are regarded as landscape pattern change driven by many interactive natural and social-economic factors. Different combination of physical geographical elements induced the difference of spatio-temporal pattern of land use change. There are four physical geographical regions in Mongolian Autonomou County of Qian Gorlos of Jilin Province. Based on spatial analysis and statistical analysis, we conclude that the primary pattern of land use and the tendency of land use changes are all different in four physical geographical regions. During 1987 – 1996, the dominant land use change processes were from grassland or forest to arableland, from unused land to paddy and grassland to unused land. Though land use change is mainly affected by social and economic condition in short period, the composite characters of physical geographical elements controls land use dynamic process. The relationship between land use dynamic process and the character of physical geographical units differ in different regions. Possible human impacts on land use change are explored with application of buffer areas of series distance along main roads and radius around main settlements. A few models are built to describe the relationship between land use spatial change rates and distance to road and settlements. According to our result, the relationship with the proximity to roads was a negative liner function, with the change rate decreasing rapidly when moving away from roads. Within a distance of less 7.5km from main traffic lines, land use changes occur red more. The bulk of grassland was apt to be opened up for cultivation around the settlements and the transformation from dryland to paddy occurred within the distance of 1km away from settlements.展开更多
Main goal of this paper is to discuss specific problem which is occurring during the creation of modem complex soRware systems, particularly at the design stage. Many of modem architectural styles are promoting buildi...Main goal of this paper is to discuss specific problem which is occurring during the creation of modem complex soRware systems, particularly at the design stage. Many of modem architectural styles are promoting building composite software systems compounded with reusable and flexible units. Because of high speed of contemporary software system evolution which is related to initial process changes, it is very significant to have ability to do related refactoring tasks. Sometimes, when structure if software system is monolithic, modification process takes a long time and in worse cases it is impossible. On the other hand flexible composite systems are easy to govern. Our work is related to complex process decomposition into small simple sub-processes at the architectural level of designing stage.展开更多
Land property in the post socialist countries was rebuilt in the beginning of the 1990s. The process went in different way in all of the post-socialist countries. The result of the privatization of agricultural land w...Land property in the post socialist countries was rebuilt in the beginning of the 1990s. The process went in different way in all of the post-socialist countries. The result of the privatization of agricultural land was a fragmented, direct or indirect smallholder ownership structure in most of the new member states of the EU. The land, partly or totally was given back to the owners and inheritors of land reforms following the war. It means that considerable proportion of the land is cultivated by tenants, the fragmented estate structure decreases the efficiency and the increasing rental fees further destroy the profitability and competitiveness of farming. Regarding to the competitiveness of agriculture, Poland showed a developing tendency after the accession, but Hungary suffers from serious problems. Applying descriptive statistics between the changes of land use and land ownership during the research relation analysis, emphasizing the effect in competitiveness of the land price and a land rent, the paper tries to identify the main differences and similarities in land use and property structure, and their effects on the agricultural competitiveness based on the FADN data base, since 2004-2007.展开更多
Due to their ecological disadvantages, many mountain regions have experienced land-use abandonment and shrub encroachment on former grassland at higher altitudinal zones--especially during recent decades of urbanizati...Due to their ecological disadvantages, many mountain regions have experienced land-use abandonment and shrub encroachment on former grassland at higher altitudinal zones--especially during recent decades of urbanization. But does this trend also apply to the hinterland of urban settlements？ By using the Southern Colombian example of Popay^n, a medium-sized city located in the Northern Andes, we can show that the landscape changes observed between 1989 and 2010 can hardly be related to agricultural abandonment. Hypsometric variations of land-cover change indicate that, until 2001, woods or shrubland expanded faster at the lower altitudinal range adjacent to the city than at the more remote higher zones. In contrast, after 2001 grassland areas increased on former woods or shrnbland at all altitudinal belts. Both periods thus present developments that can be interpreted as the result of land-use expansion below 2000 m asl and land-use persistence in the tierrafrla of the mountain city＇s hinterland.展开更多
Soil harbors remarkably stabilize bacterial communities at the phylum level. However, no two soils have exactly the same structure of bacterial phyla. The structure of microbial community is strongly influenced by the...Soil harbors remarkably stabilize bacterial communities at the phylum level. However, no two soils have exactly the same structure of bacterial phyla. The structure of microbial community is strongly influenced by the type of land-use through changes in soil attributes. Using high-throughput pyrosequencing and quantitative polymerase chain reaction techniques, soil microbial community structures were investigated along a land-use gradient of 100- and 27-year farmlands, a 33-year Pinus forest, a 28-year poplar forest, and a 21-year shrubland, as well as a native desert from which all cultivated systems were converted. The results revealed that the dominant phylotypes in the native soil comprised primarily of Alphaproteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes, accounting for 〉 71.4% of the total bacterial 16S rRNA sequence reads. Changes in land-use led to a significant decrease in these dominant phylotypes down to 33.4%. In contrast, the phylotypes with low abundance, such as Acidobaeteria, Chloroflexi, Nitrospira, and Gammaproteobaeteria, increased sharply from 4.5%-5.9% in the native soil to 20.9% 30.2% of the total 16S rRNA gene sequences in the cultivated soils except for the soil from the shrubland. These contrasting changes in the major taxa appear to be correlated with the changes in soil attributes. For instance, bacterial and archaeal amoA genes were found to be 960- and 3 800-fold more abundant in the soil from the 100-year farmland than the native soil. The changes in numerically less dominant nitrifying phylotypes are consistent with soil inorganic nitrogen dynamics. Quantification of the 16S rRNA genes demonstrated that bacteria and archaea were about two to three orders of magnitude more abundant in the cultivated soil than in the native soil. Hence, land-use type affects the soil bacterial community structure, which has profound consequences on ecosystem function.展开更多
Wild animals use their habitat according to ecological pressures such as predation, resource availability or tempera- ture, yet little is known about how individuals use their environment in semi free-ranging conditio...Wild animals use their habitat according to ecological pressures such as predation, resource availability or tempera- ture, yet little is known about how individuals use their environment in semi free-ranging conditions. We assessed whether a semi-free ranging group of Tonkean macaques Macaca tonkeana used its wooded parkland in a heterogeneous way. GIS and GPS were used to determine whether individuals adjusted their behaviors according to variation in environmental constraints over time of day and the course of a year. We demonstrated that social and resting activities occurred in high altitude areas and areas with a high density of bushes, whereas the group foraged in areas where the density of bushes and grass was low. In general, the animals used areas exposed to the sun that were not on a slope. Semi-free ranging Tonkean macaques seemed to behave like their wild counterparts in terms of activity budget, land use per activity and thermoregulation展开更多
文摘美国公共图书馆对民众的生活和工作具有重要作用,但近年来出现了较大的使用波动情况。本文以皮尤美国公共图书馆服务调研中用户陈述的使用变化原因为样本,基于质性分析工具Nvivo和SPSS Text Analytics对原因内容进行主题提取,借助Pajek和VOSviewer构建主题间的语义关联网络并实现可视化展示,在对主题关联网络社区划分的基础上总结归纳当前美国民众公共图书馆使用习惯变化的原因。首先,儿童及青少年的教育、传统资源和服务以及便利性是增加公共图书馆使用的主要原因;而互联网和信息技术、家庭生活方式的改变及对电子资源和服务需求增多,是导致民众减少使用的主要因素。其次,信息技术的作用具有双重性,图书馆的免费网络服务和技能培训增加了其使用,而高收入和高学历用户也因信息技术的便捷减少了前往公共图书馆的次数。最后,公共图书馆应利用信息技术创新其无线和移动服务方式,丰富基于信息技术的教育培训和社区活动,增加不同层次的用户黏性。同时,本文发现使用习惯变化反映出美国民众的分层现象,未来笔者将展开民众属性特征与原因主题的关联分析,以期得到更加深入的研究结论。
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05060104)
文摘Vegetation restoration has been proposed as an effective method for increasing both plant biomass and soil carbon(C) stocks. In this study, 204 publications(733 observations) were analyzed, focusing on the effects of vegetation restoration on soil organic carbon(SOC) in China. The results showed that SOC was increased by 45.33%, 24.43%, 30.29% and 27.98% at soil depths of 0–20 cm, 20–40 cm, 40–60 cm and > 60 cm after vegetation restoration, respectively. Restoration from both cropland and non-cropland increased the SOC content. The conversion of non-cropland was more efficient in SOC accumulation than the conversion of cropland did, especially in > 40 cm layers. In addition, the conversion to planted forest led to greater SOC accumulation than that to other land use did. Conversion period and initial SOC content extended more influence on soil C accumulation as the main factors after vegetation restoration than temperature and precipitation did. The SOC content significantly increased with restoration period after long-term vegetation restoration(> 40 yr), indicating a large potential for further accumulation of carbon in the soil, which could mitigate climate change in the near future.
基金the auspices of the Knowledge Innovation Project of the Chinese Academy of sciences (KZCXI - Y - 02)the Key Ninth Five-Year P
文摘Land use changes are regarded as landscape pattern change driven by many interactive natural and social-economic factors. Different combination of physical geographical elements induced the difference of spatio-temporal pattern of land use change. There are four physical geographical regions in Mongolian Autonomou County of Qian Gorlos of Jilin Province. Based on spatial analysis and statistical analysis, we conclude that the primary pattern of land use and the tendency of land use changes are all different in four physical geographical regions. During 1987 – 1996, the dominant land use change processes were from grassland or forest to arableland, from unused land to paddy and grassland to unused land. Though land use change is mainly affected by social and economic condition in short period, the composite characters of physical geographical elements controls land use dynamic process. The relationship between land use dynamic process and the character of physical geographical units differ in different regions. Possible human impacts on land use change are explored with application of buffer areas of series distance along main roads and radius around main settlements. A few models are built to describe the relationship between land use spatial change rates and distance to road and settlements. According to our result, the relationship with the proximity to roads was a negative liner function, with the change rate decreasing rapidly when moving away from roads. Within a distance of less 7.5km from main traffic lines, land use changes occur red more. The bulk of grassland was apt to be opened up for cultivation around the settlements and the transformation from dryland to paddy occurred within the distance of 1km away from settlements.
文摘Main goal of this paper is to discuss specific problem which is occurring during the creation of modem complex soRware systems, particularly at the design stage. Many of modem architectural styles are promoting building composite software systems compounded with reusable and flexible units. Because of high speed of contemporary software system evolution which is related to initial process changes, it is very significant to have ability to do related refactoring tasks. Sometimes, when structure if software system is monolithic, modification process takes a long time and in worse cases it is impossible. On the other hand flexible composite systems are easy to govern. Our work is related to complex process decomposition into small simple sub-processes at the architectural level of designing stage.
文摘Land property in the post socialist countries was rebuilt in the beginning of the 1990s. The process went in different way in all of the post-socialist countries. The result of the privatization of agricultural land was a fragmented, direct or indirect smallholder ownership structure in most of the new member states of the EU. The land, partly or totally was given back to the owners and inheritors of land reforms following the war. It means that considerable proportion of the land is cultivated by tenants, the fragmented estate structure decreases the efficiency and the increasing rental fees further destroy the profitability and competitiveness of farming. Regarding to the competitiveness of agriculture, Poland showed a developing tendency after the accession, but Hungary suffers from serious problems. Applying descriptive statistics between the changes of land use and land ownership during the research relation analysis, emphasizing the effect in competitiveness of the land price and a land rent, the paper tries to identify the main differences and similarities in land use and property structure, and their effects on the agricultural competitiveness based on the FADN data base, since 2004-2007.
基金funded by the Austrian Science Fund (FWF) [Project No. P24692]
文摘Due to their ecological disadvantages, many mountain regions have experienced land-use abandonment and shrub encroachment on former grassland at higher altitudinal zones--especially during recent decades of urbanization. But does this trend also apply to the hinterland of urban settlements？ By using the Southern Colombian example of Popay^n, a medium-sized city located in the Northern Andes, we can show that the landscape changes observed between 1989 and 2010 can hardly be related to agricultural abandonment. Hypsometric variations of land-cover change indicate that, until 2001, woods or shrubland expanded faster at the lower altitudinal range adjacent to the city than at the more remote higher zones. In contrast, after 2001 grassland areas increased on former woods or shrnbland at all altitudinal belts. Both periods thus present developments that can be interpreted as the result of land-use expansion below 2000 m asl and land-use persistence in the tierrafrla of the mountain city＇s hinterland.
基金Supported by the National Natural Science Foundation of China (No.91025021)the Knowledge Innovation Programs of the Chinese Academy of Sciences (Nos.KSCX2-EW-G-16-02 and KSCX2-YW-G-074-02)the E-Science Program of the Chinese Academy of Sciences (No.INFO-115-D01-Z006)
文摘Soil harbors remarkably stabilize bacterial communities at the phylum level. However, no two soils have exactly the same structure of bacterial phyla. The structure of microbial community is strongly influenced by the type of land-use through changes in soil attributes. Using high-throughput pyrosequencing and quantitative polymerase chain reaction techniques, soil microbial community structures were investigated along a land-use gradient of 100- and 27-year farmlands, a 33-year Pinus forest, a 28-year poplar forest, and a 21-year shrubland, as well as a native desert from which all cultivated systems were converted. The results revealed that the dominant phylotypes in the native soil comprised primarily of Alphaproteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes, accounting for 〉 71.4% of the total bacterial 16S rRNA sequence reads. Changes in land-use led to a significant decrease in these dominant phylotypes down to 33.4%. In contrast, the phylotypes with low abundance, such as Acidobaeteria, Chloroflexi, Nitrospira, and Gammaproteobaeteria, increased sharply from 4.5%-5.9% in the native soil to 20.9% 30.2% of the total 16S rRNA gene sequences in the cultivated soils except for the soil from the shrubland. These contrasting changes in the major taxa appear to be correlated with the changes in soil attributes. For instance, bacterial and archaeal amoA genes were found to be 960- and 3 800-fold more abundant in the soil from the 100-year farmland than the native soil. The changes in numerically less dominant nitrifying phylotypes are consistent with soil inorganic nitrogen dynamics. Quantification of the 16S rRNA genes demonstrated that bacteria and archaea were about two to three orders of magnitude more abundant in the cultivated soil than in the native soil. Hence, land-use type affects the soil bacterial community structure, which has profound consequences on ecosystem function.
文摘Wild animals use their habitat according to ecological pressures such as predation, resource availability or tempera- ture, yet little is known about how individuals use their environment in semi free-ranging conditions. We assessed whether a semi-free ranging group of Tonkean macaques Macaca tonkeana used its wooded parkland in a heterogeneous way. GIS and GPS were used to determine whether individuals adjusted their behaviors according to variation in environmental constraints over time of day and the course of a year. We demonstrated that social and resting activities occurred in high altitude areas and areas with a high density of bushes, whereas the group foraged in areas where the density of bushes and grass was low. In general, the animals used areas exposed to the sun that were not on a slope. Semi-free ranging Tonkean macaques seemed to behave like their wild counterparts in terms of activity budget, land use per activity and thermoregulation
