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Thermodynamic transport mechanism of water freezing-thawing in the vadose zone in the alpine meadow of the Tibet Plateau

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Journal of Groundwater Science and Engineering 2022年第3期10卷 302-310页

作者： Gang Qiao Feng-dan Yu Wen-ke Wang Jun Zhang Hua-qing Chen Key Laboratory of Groundwater and Ecology in Arid and Semi-arid CGSXi’an 710054China Observation and research station of Groundwater and Ecology in Yulin Shaanxi DNRYulin 719053Shaanxi ProvinceChina School of Water Conservancy and Environment Chang’an UniversityXi’an 710054China

High altitude,cold and dry climate,strong solar radiation,and high evapotranspiration intensity have created an extremely fragile ecological and geological environment on the Tibet *** the heat in the vadose zone is primarily generated by the external solar radiation energy,and evapotranspiration is contingent on the consumption of vadose heat,the intensity of evapotranspiration is associated with the intensity of solar radiation and the heat budget in the vadose ***,the spatial and temporal variation of heat budget and thermodynamic transfer process of the vadose zone in the frigid region are not clear,which hinders the revelation of the dynamic mechanism of evapotranspiration in the vadose zone in the frigid *** the moisture content of the vadose zone in the alpine regions being the research object,the paper conducts in-situ geothermal observation tests,takes meteorological characteristics into consideration,and adopts the method of geothermal gradient and numerical computation to analyse the temporal and spatial variation rule of heat budget and thermodynamic transmission process of the vadose zone in the high and cold *** results show there is a positive correlation between air temperature,ground temperature,and water content of the vadose zone in both thawing and freezing *** to the change law of geothermal gradient,the thermodynamic transfer process of the vadose zone has four stages:slow exothermic heating,fast endothermic melting,slow endothermic cooling,and fast exothermic *** the surface down,the moisture freezing rate of the vadose zone is slightly higher than the melting *** is of great significance for understanding the evapotranspiration dynamic process of the vadose zone and protecting and rebuilding the ecological and geological environment in the high and cold regions.

关键词： Freeze-thaw action Thermodynamic Evapotranspiration Moisture in the vadose zone Tibet plateau

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Reflectance signature on sunlit crown of conifers

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Science China(technological Sciences) 1997年第6期40卷 623-630页

作者：王锦地李小文项月琴 Institute of Remote Sensing Application Chinese Academy of Sciences Beijing 100101 China Experimental station for Agro-ecology and Technique Institute of Geography Chinese Academy of Sciences Beijing 100101 China

Based on the field measurements of the reflected radiation distribution on sunlit crown surface and crown structure, the analytical approximation model of path-scattering of light in a homogeneous layer is applied to the calculation of the reflectance signature of sunlit crown. The reflectance on the sunlit crown surface is considered as the weighted sum of the direct-to-hemisphere reflectance and the hemisphere-to-hemisphere reflectance. The validation results show that the calculated reflectance signature fits the field measurement very well This paper presents details of the validation and the feasibility of the model application to nonuniform medium, such as tree crown canopies.

关键词： canopy structure path-scattering radiation reflectance signature.

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Experimental research on bond strength of deformed GFRP rebars with different surface configurations

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Journal of Harbin Institute of Technology(New Series) 2009年第4期16卷 469-474页

作者：郝庆多王言磊欧进萍 Harbin Quality Supervising Central station of Construction Engineering School of Civil Engineering Harbin Institute of Technology School of Civil and Hydraulic Engineering Dalian University of Technology

Based on the Canadian Standards Association(CSA) criterion,experiments on 30 pull-out specimens were conducted to study the bond strength of deformed GFRP rebars with 8 different surface *** rebar was embedded in a 150 mm concrete cube,and the test embedded length was four times of the rebar *** between the mode of failure,the average bond strength and the average bond strength-slip for each rebar was *** show that the failure mode of all specimens is the shearing off or desquamation of ribs,no splitting cracks appear on the cube *** bond stress of deformed GFRP rebars mainly depends on the mechanical interaction between the ribs of the bar and the surrounding concrete,and the bond strength of deformed GFRP rebars is improved *** optimal rib spacing is less than 2.5 times of the rebar diameter,and the rib height is more than 3% of the rebar diameter.

关键词： deformed GFRP rebars concrete bond strength pull-out test rib spacing rib height optimalsurface configuration

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Deployment of wireless sensor network in dispersed renewable energy sources for increasing efficiency of power distribution networks

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Journal of Modern Power Systems and Clean Energy 2015年第4期3卷 610-618页

作者： Theodoros A.TSIFTSIS Paschalis C.SOFOTASIOS Nick PAPANIKOLAOU Michael I.LOUPIS technological Educational Institute(T.E.I.)of Central Greece 35100 LamiaGreece Tampere University of Technology 33101 TampereFinland Democritus University of Thrace Kimmeria67100 XanthiGreece

In this work,a novel performance analysis method for evaluating the robustness of emerging power distribution networks(PDNs),which involve deployable renewable energy sources,is *** is realized with the aid of the outage probability(OP)criterion in the context of cooperative communications,which is widely considered in modern wireless communication *** main usefulness of this method is that it allows the involved components to communicate to each-other by means of a robust and flexible wireless sensor network *** this context,any conventional medium voltage(MV)bus of the PDN is represented as a wireless relay node where data signals gathered from each MV bus can be forwarded reliably to a control station for the subsequent *** received signals at wireless nodes are decoded and then forwarded to ensure minimal errors and maximal robustness at the receiving *** considered OP analysis denotes the probability that the power of a received information signal drops below a pre-defined threshold which satisfies the acceptable Quality of Service requirements of a reliable signal *** this end,simple closed-form expressions are proposed for the OP of a regenerative cooperative-based PDN in the presence of various multipath fading effects,which degrade information signals during wireless *** offered results are rather simple and provide meaningful insights for the design and deployment of smart grid systems.

关键词： Smart grid Cooperative communications(CCs) Power distribution network(PDN) Outage probability Renewable energy source(RES) Wireless sensor network(WSN)

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Changes in soil carbon sequestration and soil respiration following afforestation on paddy fields in north subtropical China

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Journal of Plant Ecology 2013年第3期6卷 240-252页

作者： Jun Cui Rongjuan Zhang Naishun Bu Huabin Zhang Boping Tang Zhaolei Li Lifeng Jiang Jiakuan Chen Changming Fang Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection Yancheng Teachers UniversityYancheng 224002P.R.China Coastal Ecosystems research station of Yangtze River Estuary Ministry of Education Key Laboratory for Biodiversity and Ecological EngineeringInstitute of Biodiversity ScienceFudan UniversityShanghai 200433P.R.China

Aims Although many studies have reported net gains of soil organic carbon(SOC)after afforestation on croplands,this is uncertain for Chinese paddy rice ***,we aimed to evaluate the effects of affores-tation of paddy rice croplands on SOC sequestration and soil respiration(R).Such knowledge would improve our understanding of the efctive-ness of various land use options on greenhouse gas mitigation in *** The investigation was conducted on the Chongming Island,north subtropical *** sites were reclaimed from coastal salt marshes in the 1960s,and soils were homogeneous with simple land use:*** stocks and R,levels were monitored over one year in a paddy rice cropland,an evergreen and a deciduous broad-leaved plantation established on previous paddy fields and a reference fal-low land site never *** incubation of soil under fast-changing temperatures was used to compare the temperature sensitivity(Q10)of SOC decomposition across land *** Findings After 15-20 years of afforestation on paddy fields,SOC concentra-tion only slightly increased at the depth of 0--5 cm but decreased in deeper layers,which resulted in a net loss of SOC stock in the top *** increase of sOC was observed during the rice-growing period in croplands but not in afforested soils,suggest-ing a stronger SOC sequestration by paddy rice ***,SOC sequestered under cropping was more labile,as indicated by its higher contents of dissolved organic carbon and microbial ***,paddy soils had higher annual R,than afforested soils;R,abruptly increased after paddy fields were drained and plowed and remained distinctively high throughout the dry farming *** incubation revealed that paddy soils had a much higher Q10 of SOC decomposition than afforested *** that tem-perature was the primary controller of R,in this region,it was con-cluded that despite the stronger SOC sequestration by paddy rice cropp

关键词： land use soil organic matter(SOC) temperature sensitivity Q_(10) Chongming Island

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Effect of Humic Acid, Mycorrhiza Inoculation, and Biochar on Yield and Water Use Efficiency of Flax under Newly Reclaimed Sandy Soil

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Agricultural Sciences 2014年第14期5卷 1427-1432页

作者： Bakry Ahmed Bakry Omar Maghawry Ibrahim Abdelraouf Ramadan Eid Elham Abdelmoneim Badr Field Crops research Department National Research Centre Dokki Egypt Plant Production Department Arid Lands Cultivation Research Institute City of Scientific Research and Technological Applications (SRTA-City) New Borg El-Arab Egypt Water Relations and Field Irrigation Department National Research Center Giza Egypt

In order to examine the application of different soil and foliar organic fertilizers as well as biofertilizing flax under sandy soil conditions, two field experiments were carried out at the research and Production station of the National research Centre (NRC), Al Nubaria district, El-Behaira Governorate, Egypt during 2012/2013 and 2013/2014 winter seasons. The trials aimed to study the effect of humic acid (HA) as low cost natural fertilizer, inoculation with mycorrhiza, and biocharcoal on on yield, quality and water use efficiency of flax variety (Amon) under newly reclaimed sandy soil. The treatments consisted of HA (25 kg/feddan), inoculation with mycorrhiza (1 kg/ feddan), and biochar (4 tons/feddan) and all the combinations among the treatments. Results showed that the treatment combination of (humic acid + mycorrhiza + biochar) was significantly superior compared to all the other treatments in number of capsules/plant, biological yield/plant (g), seed yield/plant (g), seed yield (kg/feddan), straw yield (tons/feddan), oil percent (%), and oil yield (kg/feddan). However, it gave the highest fruiting zone length (cm) but not significantly different from (mycorrhiza + biochar) and (humic acid + biochar), also it gave the highest seed index (g) but not significantly different from humic acid and (humic acid + mycorrhiza). The treatment combination of (humic acid + biochar) gave the highest plant height (cm), technical stem length (cm), and number of branches/plant.

关键词： Flax Humic Acid Biochar Mycorrhiza Water Use Efficiency

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The Influence of Housing Prices on Urban Competitiveness:Review and Prospects

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Chinese Journal of Urban and Environmental Studies 2019年第3期7卷 40-52页

作者： NI Pengfei ZHANG Yangzi CAO Qingfeng National Academy of Economic Strategy Chinese Academy of Social Sciences China Everbright Group Post-Doctoral Scientific research Workstation China Everbright Center Tsinghua University Applied Economics Postdoctoral Mobile station Modern Economic and Management Institute Tianjin University of Finance and Economics

To examine the impact of housing prices on urban competitiveness, we first sort out the relevant literature on the compositions and performances of urban competitiveness. The internal compositions of urban competitiveness include factor endowments and industrial development. The external manifestations include market size, economic growth and productivity. Additionally,from the perspectives of urban economics and new economic geography, the theoretical basis of housing price’s impact on urban competitiveness is analyzed. On this basis, we analyze the mechanism and direction of housing price’s impact on urban competitiveness. The results show that most of the existing researches pay attention to the impact of housing prices on urban competitiveness through economic growth, industrial structure or production factors. However,there are differences in the specific direction of influence, and there is no research that considers the relationship of multiple influences.

关键词： Housing price urban competitiveness urban economics new economic geography

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research on the resource utilization of Baosteel steel slag as concrete material

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Baosteel Technical research 2009年第4期3卷 9-13页

作者： JIN Qiang HE Hongzhu YANG Gang ZHANG Chao WANG Youqin research Center of Metallurgical Slag SBMCC Shanghai 200941 China Shanghai Building Material Market Administration station Shanghai 200941 China

The utilization of steel slag has been a worldwide issue for a long time. Attention is increasingly being paid to the technological innovation and development of steel slag. Aiming at the development of environmentally friendly steel slag concrete materials and their use in a recyclable economy ,Baosteel has recently been conducting research on and using many new building materials, including steel slag powder concrete, steel slag pervious concrete, steel slag counter weight concrete and so on. In this way, steel slag has been turned from a kind of solid waste into a value-added material. The technology of steel slag utilization has been enriched and developed,while a new model of using Baosteel steel slag in a recyclable economy has also been explored and practised.

关键词： energy-saving environmentally friendly properties steel slag concrete resource utilization application research

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Atmospheric HONO formation during and after the Spring Festival holidays in a coastal city of China

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Journal of Environmental Sciences 2023年第5期127卷 251-263页

作者： Xue Ni Cuizhi Sun Yongyun Zhang Baoling Liang Shengzhen Zhou Guangdong Lan Jun Zhao School of Atmospheric Sciences Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studiesand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yat-sen UniversityZhuhai 519082China Guangdong Provincial Observation and research station for Climate Environment and Air Quality Change in the Pearl River Estuary Zhuhai 519082China Key Laboratory of Tropical Atmosphere-Ocean System Ministry of EducationZhuhai 519082China

Nitrous acid(HONO)is an important source of hydrogen oxides(HOx),which affects air quality,the atmospheric oxidation capacity,and human ***,we present ambient measurements of the HONO concentrations in Zhuhai,a coastal city in Southern China,from February 7 to March 15,*** campaign was classified into two periods during(P1)and after(P2)the Spring Festival *** average HONO mixing ratio during P2(1.19±0.85 ppbv)was much higher than that during P1(0.24±0.18 ppbv),likely due to the contribution of homogeneous HONO *** nighttime,the heterogeneous conversion rate during P2(0.0089/hr)was considerably higher than that during P1(0.0057/hr),suggesting a higher heterogeneous NO_(2) conversion ***,the heterogeneous NO_(2) conversion was the dominant way during P1 with a high percentage of 88%,while comparable ratios of heterogeneous and homogeneous formation were found(54%vs.46%)during P2,indicating that the homogeneous formation was also important during *** daytime,homogeneous reaction was the major known pathway,with a contribution of 16%during P1 and 27%during P2,leaving large unknown HONO sources which reasonably correlated with the photo-enhanced NO_(2) *** case scenarios were additionally explored,showing that there might be a primary emission source during one scenario(February 17-18)and vehicle emissions might be the major unknown HONO source for another scenario(March 3–5).The results suggest that large unknown daytime sources still exist which need more future ambient and laboratory studies.

关键词： Nitrous acid Nocturnal and daytime budget Heterogeneous conversion Homogeneous formation Coastal area

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AN ADAPTIVE-WEIGHTED TWO-DIMENSIONAL DATA AGGREGATION ALGORITHM FOR CLUSTERED WIRELESS SENSOR NETWORKS

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Journal of Electronics(China) 2013年第6期30卷 525-537页

作者： Zhang Junhu Zhu Xiujuan Peng Hui School of Information Science & Technology Qingdao University of Science & Technology College of Computer Engineering Qingdao Technological University School of Information Renmin University of China

In this paper,an Adaptive-Weighted Time-Dimensional and Space-Dimensional(AWTDSD) data aggregation algorithm for a clustered sensor network is proposed for prolonging the lifetime of the network as well as improving the accuracy of the data gathered in the *** contains three phases:(1) the time-dimensional aggregation phase for eliminating the data redundancy;(2) the adaptive-weighted aggregation phase for further aggregating the data as well as improving the accuracy of the aggregated data; and(3) the space-dimensional aggregation phase for reducing the size and the amount of the data transmission to the base *** utilizes the correlations between the sensed data for reducing the data transmission and increasing the data accuracy as *** result shows that AWTDSD can not only save almost a half of the total energy consumption but also greatly increase the accuracy of the data monitored by the sensors in the clustered network.

关键词： Data aggregation Adaptive-weighted aggregation Clustered Wireless Sensor Networks(WSNs) Linear regression Data accuracy Energy consumption Lempel-Ziv-Welch (LZW)

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