检索结果-南通市图书馆

Competitive adsorption and mobility sequence of heavy metals in urban soils of southeastern China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2006年第2期18卷 329-333页

作者： ZHANG Ming-kui FANG Li-ping HUANG Chang-yong department of natural resource Sciences College of Natural Resource and Environmental Sciences Zhejiang University Hangzhou 310029 China

Heavy metals can be introduced into urban soils at the same time. Therefore, their selective retention and competitive adsorption by the soils become of major importance in determining their availability and movement throughout the soil. In this study, the availability and mobility of six heavy metals in eight urban soils collected from different cities of Zhejiang Province, southeastern China were assessed using distribution coefficients（Kd） and retardation factor（Rf）. The results showed that there were great differences in the Kd and Rfamong the tested soils. The adsorption sequences were Cr〉Pb〉Cu〉Cd〉Zn〉Ni, and the Kd decreased with increasing levels of metal addition. Ni generally has the lowest Rf values followed closely by Cd, and Zn whereas Cr and Pb reached the highest values. The results suggest that Ni and Zn have the highest mobility associated to the lowest adsorption, Cr and Pb present the opposite behavior. Correlation analysis indicates that soil pH, CaCO3 content, and cation exchange capacity （CEC） are key factors controlling the solubility and mobility of the metals in the urban soils.

关键词： competitive adsorption mobility sequence heavy metal urban soil

Smart Gas Sensors:Recent Developments and Future Prospective

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第3期17卷 55-86页

作者： Boyang Zong Shufang Wu Yuehong Yang Qiuju Li Tian Tao Shun Mao College of environmental Science and Engineering Biomedical Multidisciplinary Innovation Research InstituteShanghai East HospitalState Key Laboratory of Pollution Control and Resource ReuseTongji University1239 Siping RoadShanghai 200092People’s Republic of China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092People’s Republic of China Microbiome Medicine Center Department of Laboratory MedicineZhujiang HospitalSouthern Medical UniversityGuangzhou 510280People’s Republic of China

Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,*** the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated *** electronicand optoelectronic gas sensors have been developed for high-performancesmart gas *** the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas *** review highlights recent advances of smart gassensors in diverse *** structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are ***,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are ***,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.

关键词： Smart gas sensor Electronic sensor Optoelectronic sensor Flexible and wearable sensor Artificial intelligence

Impact of exclosures on wood biomass production and fuelwood supply in northern Ethiopia

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2019年第2期30卷 629-637页

作者： Wolde Mekuria Mastewal Yami Mitiku Haile Kindeya Gebrehiwot Emiru Birhane International Water management Institute(IWMI) International Institute of Tropical Agriculture(IITA) department of Land resource management and environmental Protection Mekelle University Faculty of environmental Sciences and natural resource management Norwegian University of Life Sciences

In the Ethiopian highlands, communal grazing lands are one of the major land uses, and are source of livelihood for the rural people. Free and uncontrolled grazing in the communal grazing lands is the dominant grazing system. The traditional uncontrolled and free grazing system has caused severe degradation of the grazing lands. As a result, communities have started to establish exclosures and support the restoration of degraded communal grazing lands. Studies have shown that exclosures are effective to restoring degraded communal grazing lands and improving ecosystem services. However, studies that investigate the changes in aboveground biomass following the establishment of exclosures and compare it with fuelwood demand of the beneficiaries in our study area is lacking. Therefore, our study aimed at:(1) quantifying yearly biomass accumulation in exclosures and compare it to fuelwood demand of households that manage the exclosures;(2) assessing household energy sources and their consumption levels. To monitor changes in biomass production with over time, replicated(n = 3) 5 and10 year-old exclosures were sampled. To investigate fuelwood sources and consumption patterns, household surveys, key informant interviews and focus group discussion were conducted. Our results demonstrated that total biomass production increased with exclosure age. In both exclosure, biomass production from Vachellia etbaica was significantly(p \ 0.05) greater than that from ***. Average daily fuelwood consumption per person was(0.63 ± 0.2) kg day^(-1). This means that the total biomass(27.5 Mg year^(-1)) obtained from 114.6 ha of exclosures covers only 9.4% of yearly fuelwood demand of the residents who manage the sampled exclosures. Nearly all respondents(95%) confirmed that they travel more than10 km day^(-1) to gather fuelwood from surrounding degraded forest patches. We recommend plantings of fast growing native tree species within exclosures and around homesteads to provide

关键词： Biomass Ethiopia Exclosures Fuel wood Tigray Woody species

Distribution and temporal variability of the solar resource at a site in south-east Norway

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2016年第4期10卷 375-381页

作者： Muyiwa S. ADARAMOLA department of Ecology and natural resource management NorwegianUniversity of Life Sciences As 1430 Norway

Globally, solar energy is expected to play a significant role in the changing face of energy economies in the near future. However, the variability of this resource has been the main barrier for solar energy development in most locations around the world. This paper investigated the distribution and variability of solar radiation using the a 10-year （2006 to 2015） data collected at Sorhs meteor- ological station located at latitude 59° 39＇ N and longitude 10° 47＇E, about 93.3 m above sea level （about 30 km from Oslo）, in south-eastern part of Norway. It is found that on annual basis, the total number of days with a global solar radiation of less than 1 kWh/（m2.d） is 120 days while the total number of days with an expected global solar radiation greater than 3 kWh/（m2.d） is 156 days （42.74%） per year. The potential energy output from a horizontally placed solar collector in these 156 days is approximately 75% of the estimated annual energy output. In addition, it is found that the inter-annual coefficient of variation of the global solar radiation is 4.28%, while that of diffuse radiation is 4.96%.

关键词： coefficient of variation global solar radiation,diffuse ratio albedo PV energy systems

Forests,atmospheric water and an uncertain future: the new biology of the global water cycle

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2018年第3期5卷 236-257页

作者： Douglas Sheil Faculty of environmental Sciences and natural resource management(MINA) Norwegian University of Life Sciences (NMBU)

Theory and evidence indicate that trees and other vegetation influence the atmospheric water-cycle in various *** influences are more important, more complex, and more poorly characterised than is widely *** there is little doubt that changes in tree cover will impact the water-cycle, the wider consequences remain difficult to predict as the underlying relationships and processes remain poorly characterised. Nonetheless, as forests are vulnerable to human activities, these linked aspects of the water-cycle are also at risk and the potential consequences of large scale forest loss are severe. Here, for non-specialist readers, I review our knowledge of the links between vegetation-cover and climate with a focus on forests and rain(precipitation). I highlight advances, uncertainties and research opportunities. There are significant shortcomings in our understanding of the atmospheric hydrological cycle and of its representation in climate models. A better understanding of the role of vegetation and tree-cover wil reduce some of these shortcomings. I outline and il ustrate various research themes where these advances may be *** themes include the biology of evaporation, aerosols and atmospheric motion, as well as the processes that determine monsoons and diurnal precipitation cycles. A novel theory—the ‘biotic pump’—suggests that evaporation and condensation can exert a major influence over atmospheric dynamics. This theory explains how high rainfall can be maintained within those continental land-masses that are sufficiently forested. Feedbacks within many of these processes can result in non-linear behaviours and the potential for dramatic changes as a result of forest loss(or gain): for example, switching from a wet to a dry local climate(or visa-versa). Much remains unknown and multiple research disciplines are needed to address this: forest scientists and other biologists have a major role to *** ideas, methods and data offer opportun

关键词： Biotic pump Climate Condensation Evaporation Ice-nucleation Transpiration GCM Vapour Water-cycle

Sediment contribution from different geologic formations and land uses in an Iranian small watershed,case study

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2017年第2期32卷 210-220页

作者： Seyed Hamidreza Sadeghi Saeed Najafi Alireza Riyahi Bakhtiari department of Watershed management Engineering Faculty of Natural ResourcesTarbiat Modares University department of environmental Sciences Faculty of Natural ResourceTarbiat Modares University

Many intra and extra problems occurred due to unsustainable human use of natural resources leading to increasing sediment loads in the ***,few studies have been comprehensively conducted in progressing countries to prioritize sediment sources from different points of views,particularly in some countries like Iran where such valuable information is essential for proper watershed resources *** present study was therefore planned to assess the importance of potential sediment sources viz.,spatial sources(geologic units) and source types(land use units) in sediment yield in Idelo watershed as one of the important sub-watersheds of Sefidrood large Watershed in Zanjan Province,Iran,using composite *** addition,the results of the sediment fingerprinting approach were compared with those of field measurement data obtained from studying soil erosion types(viz.,sheet,rill and gully erosion).Toward this attempt,16 tracers were detected in different geologic units and land uses and the sediment yielded at the watershed *** results showed that the composite fingerprints of the different geologic units comprising As,N,Cu,Zn,OC and Co tracers could correctly distinguish 86% of the sediment source *** red gypsiferous marl contributed 85 percent in sediment *** regard to source types,the optimum composite fingerprint encompassed only N and Cu and provided a discriminatory efficiency of 90%.Besides that,the rangelands with 48.8% study area coverage had a significant contribution of 88% in sediment *** field measurements confirmed the reliability of results of fingerprinting approach in apportioning watershed scale sediment sources on the base of consistency of the two sets of *** was also understood from the results,besides successful applicability of composite fingerprinting in assessing the provenance of the sediment yielded at the watershed outlet that the geologic formations and land use types played differe

关键词： Composite fingerprinting Multivariate mixing model Soil erosion Spatial sources Source types

Invasion syndromes:hypotheses on relationships among invasive species attributes and characteristics of invaded sites

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Arid Land 2013年第3期5卷 275-283页

作者： Lora B PERKINS Robert S NOWAK department of natural resource management South Dakota State UniversityBrookings SD 57007USA department of natural resources & environmental Science University of NevadaReno NV 89557USA

As invasion science accepts that there is no single causal factor for biological invasion, the identification of groups of traits that are often associated, or ＂syndromes＂, is a logical move forward. Invasion syndromes are proposed to identify suites of site conditions （biotic and environmental） that render a site vulnerable to invasion by different types of invaders. This paper proposed four invasion syndromes which relate invader attributes （competitive ability, niche construction, phenotypic plasticity, and phenological niche separation） to the biotic characteristics （biodiversity and enemies） and environmental conditions （resource abundance and fluctuation） of invaded sites. The four invasion syndromes described in this paper are a development of hypotheses of how the many factors that influence species invasion might be associated. Invasion Syndrome 1 proposes that sites with relatively high resource abundance and high diversity should be vulnerable to invasion by species with high competitive ability. Invasion Syndrome 2 hypothesizes that sites with relatively low resource abundance and low diversity should be vulnerable to invasion by species with niche construction ability. Invasion Syndrome 3 postulates that sites with moderate or fluctuating resources and moderate diversity should be vulnerable to invasion by species with high phenotypic plasticity. Invasion Syndrome 4 hypothesizes that species introduced into a site where it has phenological niche separation from natives will not have to contend with interference from the biotic community at a site （diversity or natural enemies） and may invade where ever site environmental conditions suit its life history. Further work is needed to support, contradict, or refine these hypotheses and almost certainly will identify more invasion syndromes.

关键词： non-native competitive ability niche construction ecosystem engineering phenotypic plasticity phenological niche separation

Characterization of mean stem density,fibre length and lignin from two Acacia species and their hybrid

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2018年第2期29卷 540-546页

作者： Asif Javed Muhammad Seong Siang Ong Wickneswari Ratnam School of environmental and natural resource Sciences Faculty of Science and TechnologyUniversiti Kebangsaan department of Forestry and Range management University of Agriculture Faisalabad

The objective of this study was to compare the wood properties related to wood pulp quality of two widely planted Acacia species *** mangium *** Acacia auriculiformis *** *** their *** insoluble lignin content(Klason),mean stem density and fibre length differed considerably among the species and *** possessed a high percent of lignin content compared to *** and the Acacia ***,mean stem density of *** was higher than *** and the *** length of heartwood tissues was generally shorter than that of sapwood *** hybrid had longer fibres than the parent *** was negatively correlated with mean stem ***,the wood properties of the hybrid were superior to its parent *** significant intraspecific variation observed for wood properties of Acacia species could be used in breeding superior hybrids combining desirable traits of the two *** thedifficulty involved in accurately measuring the lignin content compared to mean stem density,selection for plants with low lignin content can be achieved by indirect selection of high mean stem density.

关键词： Acacia mangium × Acacia auriculiformis hybrid Fibre length Indirect selection Lignin content Mean stem density

Exclosures restored the density and root colonization of arbuscular mycorrhizal fungi in Tigray, Northern Ethiopia

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2017年第1期6卷 339-350页

作者： Emiru Birhane Kide Mogos Gebremedihin Tewodros Tadesse Mengsteab Hailemariam Negasi Solomon department of Land resources management and environmental protection Mekelle UniversityPO Box 231MekelleEthiopia Faculty of environmental Sciences and natural resource management Norwegian University of Life SciencesPO Box 50031432ÅsNorway department of natural resource Economics and management Mekelle UniversityPO Box 231MekelleEthiopia

Introduction:Exclusion of grazing animals and tree plantations were among the methods used for the restoration of degraded lands in tropical semiarid *** can foster secondary forest succession by improving soil conditions and modifying microclimate for understory *** paper compared the arbuscular mycorrhizal fungi(AMF)spore density,root colonization of woody plants and soil chemical properties under exclosure with increasing age,and grazing land at different slope ***:The study was conducted in northern Ethiopia from 12 exclosure sites paired each with adjacent grazing land in total from 24 sites with four treatments replicated three *** the entire study,216 plots were examined of which 108 were in exclosures and 108 in communal grazing *** were four age classes and three slope positions in each of the land *** soil and root samples were collected using nested plots measuring 100m2 from four sides of 1763 plants for spore enumeration and root *** for chemical properties were collected from the four corners and center of 5 m×5 m ***:All the 61 woody plant species that belong to 41 families were colonized by *** density and root colonization were significantly higher in exclosures as compared to grazing land and increased with increasing ages of *** slope had significantly higher spore density and root colonization than middle and upper *** chemical properties were significantly higher in the exclosure,oldest age of exclosure,and foot slope position(except P).AMF spore density and root colonization were significantly positively correlated with soil chemical ***:Exclosures are helpful to restore the AMF spore density and root colonization of woody species and soil fertility.

关键词： Spore density Root colonization Age of exclosure Slope position