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Impacts of environmental conditions on woody plant diversity,structure and regeneration in forest patches of Guna Mountain:Este District,South Gondar Zone,Ethiopia
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作者 DILNESSA Gashaye ZERIHUN Woldu +1 位作者 SILESHI Nemomissa ENYEW Adgo 《Journal of Mountain Science》 SCIE CSCD 2023年第7期1940-1953,共14页
Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,str... Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,structure and regeneration in forest patches of Guna Mountain:the case of Este District,South Gondar Zone,north-west Ethiopia.A total of 71 square sample plots(400 m~2 each) were established at 10 transects laid in five forest patches of the study area to collect vegetation data including the abundance of species,height and diameter at breast height(DBH).Environmental data including available potassium,available phosphorus,cation exchange capacity,soil texture,electrical conductivity,soil acidity,total nitrogen,organic matter,organic carbon,sodium adsorption ratio,exchangeable sodium percentage,bulk density,aspect,elevation,slope,latitude and longitude data were collected in the same plots.A correlation analysis between vegetation and environmental data was performed using rcorr(x) function in package Hmisc in R Programming Language.The most pronounced impacts were observed in altitude,grazing and pH,positively and silt,sand,electrical conductivity and cation exchange capacity,negatively.In addition,strong and significant impacts on plant structure were also observed due to the variation in soil texture and p H.The difference in aspect,sand and slope also impacted plant regeneration.The study showed that environmental parameters influence the diversity,structure and regeneration of woody plants.These parameters can be considered in the rehabilitation of the vegetation cover and conservation efforts of the rare woody species.Conservation measures that can minimalize the negative influences of environmental conditions can be applied through collaboration with communities around the forest patches. 展开更多
关键词 ALTITUDE Human disturbance environmental condition Plant diversity Plant structure VEGETATION
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Robust Damage Detection and Localization Under Complex Environmental Conditions Using Singular Value Decomposition-based Feature Extraction and One-dimensional Convolutional Neural Network
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作者 Shengkang Zong Sheng Wang +3 位作者 Zhitao Luo Xinkai Wu Hui Zhang Zhonghua Ni 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第3期252-261,共10页
Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of ci... Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical structures.This paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well removed.Hence,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental datasets.The first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC. 展开更多
关键词 Ultrasonic guided waves Singular value decomposition Damage detection and localization environmental and operational conditions One-dimensional convolutional neural network
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Spatial and historical distribution of organic phosphorus driven by environment conditions in lake sediments 被引量:3
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作者 Changwei Lü Jiang He Bing Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第2期32-41,共10页
The chemistry of sedimentary organic phosphorus(OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with enviro... The chemistry of sedimentary organic phosphorus(OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both Na OH-OP(OP extracted by Na OH) and Re-OP(residual OP) in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of Lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many ways.The drivers are mainly precipitation and temperature, governing organic matter(OM)production, degradation rate and transportation in the watershed. Over a long temporal dimension(4000 years), the vertical distributions of Re-OP and Na OH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution. 展开更多
关键词 Organic phosphorus Spatial and historical distribution environmental conditions SEDIMENT LAKE
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Impact of direct and indirect heating systems in broiler units on environmental conditions and flock performance
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作者 Shaun Smith Joseph Meade +3 位作者 James Gibbons Kevina Mc Gill Declan Bolton Paul Whyte 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第11期2588-2595,共8页
This study compared the impact of three indirect heating systems to direct gas flame heaters on a selection of flock performance and environmental indicators in commercial broiler units. No statistically significant d... This study compared the impact of three indirect heating systems to direct gas flame heaters on a selection of flock performance and environmental indicators in commercial broiler units. No statistically significant differences(P≥0.05) were found in flock mortality rates, bird weight, water consumption, stress response, carbon dioxide, ammonia, temperature, relative humidity, litter quality, within-flock Campylobacter levels or mean Campylobacter counts when flock data from any of the three indirect heating systems were compared to flocks reared in houses with direct heating systems. Differences in litter quality were observed between upper and lower litter layers in all houses, regardless of heating type, which may have implications for bird health and welfare. Carbon dioxide concentrations in houses with direct heating systems were significantly higher than those in houses with indirect heating systems during the first 10 days of bird life(P≤0.05). This was due to the increased use of heating systems during this period of the flock cycle. Differences in CO2 concentrations had no effect on flock performance, possibly due to the fact that concentrations did not exceed known safe levels. A statistically significant increase in stress response was observed in birds as a result of partial depopulation(thinning) within houses, irrespective of heating system type used(P≤0.05). Stress associated with thinning may have consequences for bird welfare and food safety. In conclusion, the results of our study suggest that indirect heating systems do not appear to negatively impact on flock performance, stress response, within-flock Campylobacter levels or mean Campylobacter counts and do not appear to significantly alter environmental conditions within broiler houses when compared to houses equipped with direct heating systems. Indirect systems are a viable alternative for heating broiler houses in terms of flock performance, bird welfare and food safety. 展开更多
关键词 litter quality WELFARE stress poultry production CAMPYLOBACTER environmental conditions
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Environmental Conditions Determining the Timing of the Lifetime Maximum Intensity of Tropical Cyclones over the Western North Pacific and Their Frequency of Occurrence
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作者 秦晓昊 山口宗彦 +1 位作者 碓氷典久 广濑成章 《Journal of Tropical Meteorology》 SCIE 2022年第1期1-11,共11页
Environmental conditions determining the timing of the lifetime maximum intensities of tropical cyclones(TCs)are investigated for the TCs over the western North Pacific during the period 2008-2017.The results show tha... Environmental conditions determining the timing of the lifetime maximum intensities of tropical cyclones(TCs)are investigated for the TCs over the western North Pacific during the period 2008-2017.The results show that the land controls the timings of the lifetime maximum intensities in 42% of the TCs over this basin,indicating that accurate track forecasts are beneficial for TC intensity forecasts.With respect to other TCs that are not affected by the land(i.e.,Ocean-TCs),the timings of their lifetime maximum intensities are determined by multiple oceanic factors.In particular,interactions between TCs and cold-core eddies occur in a large proportion(nearly 60%)of Ocean-TCs at or shortly after the times of their lifetime maximum intensities,especially in strong TCs(categories 4 and 5),suggesting that a consideration of the above interactions is necessary for improving TC intensity forecasting skills.In addition,unfavorable oceanic heat content conditions become common as the latitude increases over 25°N,influencing half of the Ocean-TCs.Strong vertical wind shear contributes detrimentally to the atmospheric environment in 17% of the TCs over this basin,especially in moderate and weak TCs.In contrast,neither the maximum potential intensity nor the humidity in the middle level of the atmosphere plays dominant roles when TCs turn from their peak intensities to weakening. 展开更多
关键词 environmental conditions lifetime maximum intensity tropical cyclones frequency of occurrence
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Do the Environmental Approval Conditions Enable the Best Practice EIA Follow-up and Hence Strengthen the EIA System?An Indian Case Study Analysis
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作者 A K A Rathi 《Macro Management & Public Policies》 2022年第2期10-19,共10页
The environmental approval for a project is generally granted with a set of terms and conditions to the project proponent.The environmental clearance(EC)letters for 33 infrastructure projects were examined for the rel... The environmental approval for a project is generally granted with a set of terms and conditions to the project proponent.The environmental clearance(EC)letters for 33 infrastructure projects were examined for the relevance,adequacy,and enforceability of the EC conditions.Using the basic tenets of the EIA process,it is found that the long list of irrelevant,inadequate,and unenforceable conditions is greenwash and unsuited for best practice EIA follow-up,hence meeting the EIA objectives.The conditions should be directed at measuring the environmental performance of the project to catalyze achieving sustainability targets.The conditions for stringent supervision and frequent inspection of the site activities in the construction phase could help ensure the implementation of the proposed mitigation measures for infrastructure projects.A comprehensive environmental impact assessment framework may use the principles of the ABC analysis to prioritize the properly specified EC conditions,resource allocation,and stakeholder engagement for the best practice EIA follow-up and hence strengthen the EIA system. 展开更多
关键词 Decision-making EIA report EIA review environmental clearance environmental clearance conditions
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Study of Intelligent Approaches to Identify Impact of Environmental Temperature on Ultrasonic GWs Based SHM:A Review
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作者 Saqlain Abbas Zulkarnain Abbas +1 位作者 Xiaotong Tu Yanping Zhu 《Journal on Artificial Intelligence》 2023年第1期43-56,共14页
Structural health monitoring(SHM)is considered an effective approach to analyze the efficient working of several mechanical components.For this purpose,ultrasonic guided waves can cover long-distance and assess large ... Structural health monitoring(SHM)is considered an effective approach to analyze the efficient working of several mechanical components.For this purpose,ultrasonic guided waves can cover long-distance and assess large infrastructures in just a single test using a small number of transducers.However,the working of the SHM mechanism can be affected by some sources of variations(i.e.,environmental).To improve the final results of ultrasonic guided wave inspections,it is necessary to highlight and attenuate these environmental variations.The loading parameters,temperature and humidity have been recognized as the core environmental sources of variations that affect the SHM sensing mechanism.Environmental temperature has the most significant influence on SHM results.There is still a need for extensive research to develop such a damage inspection approach that should be insensitive to environmental temperature variations.In this framework,the current research study will not only illuminate the effect of environmental temperature through different intelligent approaches but also suggest the standard mechanism to attenuate it in actual ultrasonic guided wave based SHM.Hence,the work presented in this article addresses one of the open research challenges that are the identification of the effect of environmental and operating conditions in practical applications of ultrasonic guided waves and impedance-based SHM. 展开更多
关键词 Structural health monitoring ultrasonic guided waves environmental and operating conditions thermal sensitivity
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Differential Expression of Genes Related to Fruit Development and Capsaicinoids Synthesis in Habanero Pepper Plants Grown in Contrasting Soil Types
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作者 Eduardo Burgos-Valencia Federico García-Laynes +4 位作者 Ileana Echevarría-Machado Fatima Medina-Lara Miriam Monforte-González JoséNarváez-Zapata Manuel Martínez-Estévez 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期151-183,共33页
Habanero pepper(Capsicum chinense Jacq.)is a crop of economic relevance in the Peninsula of Yucatan.Its fruits have a high level of capsaicinoids compared to peppers grown in other regions of the world,which gives the... Habanero pepper(Capsicum chinense Jacq.)is a crop of economic relevance in the Peninsula of Yucatan.Its fruits have a high level of capsaicinoids compared to peppers grown in other regions of the world,which gives them industrial importance.Soil is an important factor that affects pepper development,nutritional quality,and capsaicinoid content.However,the effect of soil type on fruit development and capsaicinoid metabolism has been little understood.This work aimed to compare the effect of soils with contrasting characteristics,black soil(BS)and red soil(RS),on the expression of genes related to the development of fruits,and capsaicinoid synthesis using a transcriptomic analysis of the habanero pepper fruits.Plants growing in RS had bigger fruits and higher expression of genes related to floral development,fruit abscission,and softening which suggests that RS stimulates fruit development from early stages until maturation stages.Fruits from plants growing in BS had enrichment in metabolic pathways related to growth,sugars,and photosynthesis.Besides,these fruits had higher capsaicinoid accumulation at 25 days post-anthesis,and higher expression of genes related to the branched-chain amino acids metabolism(ketol-acid reductisomerase KARI),pentose phosphate pathway and production of NADPH(glucose-6-phosphate-1-dehydrogenase G6PDH),and proteasome and vesicular traffic in cells(26S proteasome regulatory subunit T4 RPT4),which suggest that BS is better in the early stimulation of pathways related to the nutritional quality and capsaicinoid metabolism in the fruits. 展开更多
关键词 Capsicum chinense jacq soil types plant growth environmental conditions fruit quality capsaicinoid metabolism TRANSCRIPTOME
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Effects of environmental variations on the abundance of western winter-spring cohort of neon flying squid(Ommastrephes bartramii) in the Northwest Pacific Ocean 被引量:10
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作者 YU Wei CHEN Xinjun +2 位作者 CHEN Yong YI Qian ZHANG Yang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第8期43-51,共9页
During 1995-2011, annual production of winter-spring cohort of Ommastrephes bartramii for Chinese squidjigging fishery has greatly fluctuated, which is closely related to the environmental conditions on the spawning a... During 1995-2011, annual production of winter-spring cohort of Ommastrephes bartramii for Chinese squidjigging fishery has greatly fluctuated, which is closely related to the environmental conditions on the spawning and fishing grounds. To better understand how squid recruitment and abundance were infuenced by ocean environmental conditions, biological and physical environmental variables including sea surface temperature (SST), SST anomaly (SSTA), chlorophyll a (Chl a) concentration and the Kuroshio Current were examined during years with the highest (1999), intermediate (2005), and lowest (2009) catches. Catch per unit effort (CPUE) of the squid-jigging vessels was used as an indicator of squid abundance. The results indicated that high SST and Chl a concentration on the spawning ground in 1999 resulted in favorable incubation and feeding conditions for squid recruitment. Whereas the suitable spawning zone (SSZ) in 2009 shifted southward and coincided with low SST and Chl a concentration, resulting in a reduction in the squid recruitment. The small difference of SSZ area in the three years suggested the SSZ provided limited influences on the variability in squid recruitment. Furthermore, high squid abundance in 1999 and 2005 was associated with warm SSTA on the fishing ground. While the cool SSTA on the fishing ground in 2009 contributed to adverse habitat for the squid, leading to extremely low abundance. It was inferred that strengthened intensity of the Kuroshio force generally yielded favorable environmental conditions for O. bartramii. Future research are suggested to focus on the fundamental research oil the early life stage of O. bartramii and mechanism of how the ocean-climate variability affects the squid abundance and spatial distribution by coupling physical model with squid biological process to explore transport path and abundance distribution. 展开更多
关键词 Ommastrephes bartramii environmental conditions RECRUITMENT ABUNDANCE Northwest Pacific Ocean
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Chemometric study of spatial variations of environmental and ecological characteristics in the Zhujiang River (Pearl River) Estuary and adjacent waters 被引量:5
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作者 SONG Xingyu HUANG Liangmin +4 位作者 ZHANG Jianlin YIN Kedong LIU Sheng TAN Yehui YIN Jianqiang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第4期60-74,共15页
Chemometric approach based on principal component analysis(PCA) was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River(Pearl River) Estuary and adjacent... Chemometric approach based on principal component analysis(PCA) was utilized to examine the spatial variances of environmental and ecological characteristics in the Zhujiang River(Pearl River) Estuary and adjacent waters(ZREAW) in the South China Sea. The PCA result shows that the ZREAW can be divided into different zones according to the principal components and geographical locations of the study stations,and indicates that there are distinct regional variances on environmental features and the corresponding phytoplankton biomass and community structures among different areas. The spatial distribution of ecological features was implied to be influenced by various degrees of the different water resources,such as the Pearl River discharges,the coastal current and the oceanic water from the South China Sea. The variation of the biomass maximum zone and the complex impacts on the spatial distributions of phytoplankton biomass and production were also evaluated. 展开更多
关键词 principal component analysis spatial variations environmental conditions ecological distribution PHYTOPLANKTON Zhujiang River (Pearl River) Estuary
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Adsorption behavior of imidacloprid pesticide on polar microplastics under environmental conditions:critical role of photo-aging
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作者 Weiyi Liu Ting Pan +2 位作者 Hang Liu Mengyun Jiang Tingting Zhang 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2023年第4期13-26,共14页
The photo-aging behavior of microplastics(MPs)in natural environment has become a global concern.The ultraviolet radiation has enough energy to change the polymer structure and physicalchemical properties of MPs.Less ... The photo-aging behavior of microplastics(MPs)in natural environment has become a global concern.The ultraviolet radiation has enough energy to change the polymer structure and physicalchemical properties of MPs.Less attention has focused on the interactions of the photo-aged polar and biodegradable MPs with organic pollutants.This work investigated the structural properties of aged polar polyamide(PA)MPs and biodegradable polylactic acid(PLA)MPs exposed to ultraviolet irradiation and their adsorption behavior and mechanism for neonicotinoid insecticide imidacloprid(IMI).The results showed that the MPs had extensive changes in surface morphology and chemical properties after photo-aging.The C–N bond of PA MPs was disrupted to form more carbonyl groups.The oxygen-containing functional groups on the surface of aged PLA MPs were broken and generated relatively smaller molecules.The adsorption capacity of IMI on PA MPs decreased by 19.2%,while the adsorption capacity of IMI on PLA MPs increased by 41.2%after photo-aging.This depended on the natural structure of the MPs and their ability to absorb ultraviolet light.The electrostatic interactions,hydrogen bonds,van der Waals interactions,and polar-polar interactions were the main adsorption mechanisms of IMI on MPs.High initial solution pH and low ionic strength favored the adsorption of IMI by altering charge distribution on the MPs surface.The formation of the humic acid-IMI complexes decreased the concentration of IMI in the water phase and further decreased the adsorption on MPs.These results are enlightening for a scientific comprehension of the environmental behavior of the polar MPs. 展开更多
关键词 Microplastics Neonicotinoid insecticide Photo-aging adsorption environmental conditions
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Research on in-situ condition preserved coring and testing systems 被引量:19
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作者 He-Ping Xie Tao Liu +12 位作者 Ming-Zhong Gao Ling Chen Hong-Wei Zhou Yang Ju Feng Gao Xiao-Bo Peng Xiong-Jun Li Rui-Dong Peng Ya-Nan Gao Cong Li Zhi-Qiang He Ming-Qing Yang Zhi-Yu Zhao 《Petroleum Science》 SCIE CAS CSCD 2021年第6期1840-1859,共20页
As shallow resources are increasingly depleted,the mechanics'theory and testing technology of deep insitu rock has become urgent.Traditional coring technologies obtain rock samples without retaining the in-situ en... As shallow resources are increasingly depleted,the mechanics'theory and testing technology of deep insitu rock has become urgent.Traditional coring technologies obtain rock samples without retaining the in-situ environmental conditions,leading to distortion of the measured parameters.Herein,a coring and testing systems retaining in-situ geological conditions is presented:the coring system that obtains in-situ rock samples,and the transfer and testing system that stores and analyzes the rocks under a reconstructed environment.The ICP-Coring system mainly consists of the pressure controller,active insulated core reactor and insulation layer and sealing film.The ultimate bearing strength of 100 MPa for pressurepreservation,temperature control accuracy of 0.97%for temperature-retained are realized.CH_(4)and CO permeability of the optimized sealing film are as low as 3.85 and 0.33 ppm/min.The average tensile elongation of the film is 152.4%and the light transmittance is reduced to 0%.Additionally,the pressure and steady-state temperature accuracy for reconstructing the in-situ environment of transfer and storage system up to 1%and±0.2 is achieved.The error recorded of the noncontact sensor ring made of lowdensity polymer is less than 6%than that of the contact test.The system can provide technical support for the deep in-situ rock mechanics research,improving deep resource acquisition capabilities and further clarifying deep-earth processes. 展开更多
关键词 Deep mining In-situ environmental conditions In-situ condition preserved coring and testing In-situ transfer Deep-earth processes ICP-Coring In-situ condition-preserved coring
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How behavioral plasticity enables foraging under changing environmental conditions in the social wasp Vespula germanica (Hymenoptera: Vespidae) 被引量:2
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作者 Sabrina Moreyra Mariana Lozada 《Insect Science》 SCIE CAS CSCD 2021年第1期231-237,共7页
The foraging strategy at abundant resources of the social wasp Vespula germanica includes scanning in the direction of the nest while memorizing resource-specific landmarks and contextual cues.In the present study,we ... The foraging strategy at abundant resources of the social wasp Vespula germanica includes scanning in the direction of the nest while memorizing resource-specific landmarks and contextual cues.In the present study,we sought to explore wasps'behavioral plasticity on foraging trips to resources whose location and composition changed after a single visit.We evaluated how contextual modifications of food displacement and replacements 60 cm apart from the original site,affect re-orientation for re-finding previously memorized food resources.The results showed that wasps detected and collected the resource faster when more changes were introduced on the following visit.If returning foragers discovered several modifications on both the location and the kind of resource,they collected food more rapidly from the displaced dish,than if only a single parameter in the environment had been changed.These findings illustrate the grade of behavioral plasticity in V.germanica while foraging on abundant resources,which may contribute to the understanding of the prodigious invasive success of this species in anthropized environments. 展开更多
关键词 behavioral plasticity environmental conditions FORAGING invasive insects LEARNING social wasps
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Carbon Geochemistry of Gas Hydrate-associated Sediments in the Southwestern Taiwan Basin 被引量:2
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作者 LEI Huaiyan YANG Yufeng +1 位作者 Selvaraj KANDASAMY SHI Chunxiao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第1期333-341,共9页
Marine gas hydrates, one of the largest methane reservoirs on Earth, may greatly affect the deep sea sedimentary environment and biogeochemistry; however, the carbon geochemistry in gas hydrate-bearing sediments is po... Marine gas hydrates, one of the largest methane reservoirs on Earth, may greatly affect the deep sea sedimentary environment and biogeochemistry; however, the carbon geochemistry in gas hydrate-bearing sediments is poorly understood. In this study, we investigated the carbon variables in sediment core 973-3 from the southwestern Taiwan Basin in the South China Sea to understand the effect of environmental factors and archaeal communities on carbon geochemistry. The carbon profiles suggest the methanogenesis with the incerase of dissolved inorganic carbon (DIC) and high total organic carbon (TOC) (mean = 0.46%) originated from terrigenous organic matter (mean j13CToc value of -23.6%0) driven by the abundant methanogen 'Methanosaeta and Methanomicrobiales'. The active anaerobic oxidation of methane is characterized by the increase of DIC and inorganic carbon (IC), and the depleted δ13CIC, coupled with the increase of TOC and the decrease of δ13Croc values owing to the methanotroph 'Methanosarcinales/ANME' in 430-840 cm. Environmental factors and archaeal communities in core 973-3 are significantly correlated to carbon variables owing to methane production and oxidation. Our results indicate that the carbon geochemical characteristics are obviously responding to the formation and decomposition of gas hydrates. Furthermore, pH, Eh and grain size, and Methanosaeta greatly affect the carbon geochemistry in gas hydrate-associated sediments. 展开更多
关键词 southwestern Taiwan Basin carbon geochemistry environmental conditions ARCHAEA gashydrate
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Numerical experiments of HAB inducement in Qingdao adjacent coastal area 被引量:2
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作者 LIU Xuehai LI Ruixiang YUAN Yeli 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2010年第5期109-120,共12页
A three-dimension ecological dynamic model was established to numerically study the relationship of HAB and environmental conditions.The numerical experiments showed that the growth of diatom,the dominant HAB specie,w... A three-dimension ecological dynamic model was established to numerically study the relationship of HAB and environmental conditions.The numerical experiments showed that the growth of diatom,the dominant HAB specie,was mainly restricted by phosphate and silicate.If the concentrations of phosphate and silicate reach 17-25 μg/L and 300-375 μg/L respectively,the water is in a state of eutrophication.When phosphate and silicate up to 26-32 μg/L and 350-500 μg/L respectively,HAB could be induced.The major regions of HAB occurrence are Jiaozhou Bay mouth,coastal bays,and coastal area from Maidao to Shilaoren.To avoid HAB occurrence,concentration of phosphate and silicate should not exceed 17-20 μg/L and 300 μg/L as a whole.Reasonable control of pollutant discharge is a key point to prevent water eutrophication and HAB occurrence. 展开更多
关键词 HAB numerical model marine ecosystem dynamics environmental condition
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Some Considerations in Design and Construction of the Wei-Liu Water Supplying Submarine Pipeline 被引量:1
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作者 Fan Yunlin and Chang Dezhi Associate Professor, Dept. of Ocean Eng., Tianjin University Engineer, Construction Committee of Weihai City, Shandong Province 《China Ocean Engineering》 SCIE EI 1991年第4期499-506,共8页
The Wei- Liu water supplying submarine pipeline is at present the longest one of the kind in China. It is about 4 kilometers long from Weihai City to Liugong Island in Shandong province. It took only half a year to de... The Wei- Liu water supplying submarine pipeline is at present the longest one of the kind in China. It is about 4 kilometers long from Weihai City to Liugong Island in Shandong province. It took only half a year to design and construct it. The project was of a high economic efficiency and some practical experiences were achieved. In this paper a general introduction to the design and construction of this pipeline is presented and such problems as the stability of the pipeline in very soft clay, design of curved slide for launching and estimation of dragging forces are expounded. 展开更多
关键词 submarine pipeline design laying method stability analysis route selection environmental conditions
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ANALYSIS OF “BIMODAL PATTERN” STORM ACTIVITY CHARACTERISTICS OF THE BAY OF BENGAL 被引量:1
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作者 段旭 段玮 林志强 《Journal of Tropical Meteorology》 SCIE 2017年第2期191-201,共11页
Storms that occur at the Bay of Bengal(Bo B) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the... Storms that occur at the Bay of Bengal(Bo B) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the Bo B are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the Bo B storm activity, and the "bimodal period" of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the"bimodal pattern"storm activity in the Bo B. The analysis on sea surface temperature(SST) shows that the SSTs of all the year around in the Bo B area meet the conditions required for the generation of tropical cyclones(TCs). However,the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a "two-peak"storm activity pattern. The genesis potential index(GPI) quantifies and reflects the environmental conditions for the generation of the Bo B storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms. 展开更多
关键词 storm of BoB "bimodal pattern" activity characteristics cause analysis environmental conditions GPI index
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GENERATION AND DEVELOPMENT OF MESOSCALE CLOUD ON HEAVY RAIN BELT ON THE PERIPHERY OF TYPHOON 9608 (Herb) 被引量:1
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作者 李志楠 张明英 +1 位作者 郑新江 赵亚民 《Journal of Tropical Meteorology》 SCIE 2001年第1期102-112,共11页
Typhoon-induced heavy rains are mostly studied from the viewpoint of upper-level westerly troughs. It is worthwhile to probe into a case where the rain is caused by tropical cyclone system, which is much heavier. Duri... Typhoon-induced heavy rains are mostly studied from the viewpoint of upper-level westerly troughs. It is worthwhile to probe into a case where the rain is caused by tropical cyclone system, which is much heavier. During August 3 ~ 5, 1996, an unusually heavy rainstorm happened in the southwest of Hebei province. It was caused by 3 mesoscale convective cloud clusters on the periphery of a tropical cyclone other than the direct effects of a westerly trough. Generating in a weak baroclinic environment that is unstable with high energy, the cloud clusters were triggered off for development by unstable ageostrophic gravity waves in the low-level southeast jet stream on the periphery of the typhoon. There was a vertical circulation cell with horizontal scale close to 1000 km between the rainstorm area and westerly trough in northeast China. As shown in a computation of the Q vector of frontogenesis function, the circulation cell forms a mechanism of transforming energy between the area of interest and the westerly trough system farther away in northeast China. Study of water vapor chart indicates that high-latitude troughs in the northeast portion of the rain migrate to the southeast to enhance anti-cyclonic divergence in upper-level convection over the area of heavy rain and cause rain clusters, short-lived otherwise, to develop vigorously. It is acting as an amplifier in this case of unusually strong process of rain. 展开更多
关键词 TYPHOON mesoscale convective cloud cluster environmental condition analysis of water vapor imagery
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Effect of Different Combined Treatments on Tomato Seedling Growth in High-temperature Season 被引量:2
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作者 Caixia MA Ke LIU +1 位作者 Yiming ZHANG Jiqing WANG 《Agricultural Biotechnology》 CAS 2018年第3期32-35,40,共5页
The study on raising of strong tomato seedlings in high-temperature season is of great practical significance,because high-temperature condition in summer and autumn causes excessive growth of tomato seedlings easily.... The study on raising of strong tomato seedlings in high-temperature season is of great practical significance,because high-temperature condition in summer and autumn causes excessive growth of tomato seedlings easily. ‘Fenniya'variety was selected as an experimental material,an orthogonal experiment was designed with rhizospheric temperature( A),light intensity( B) and nutrient salt concentration( C) as three factors which were designed with three levels,so as to study the effects of different treatments on root activity,strong seedling index,hypocotyl length and average internode length. The results showed that the most important factor for tomato seedling's root activity,hypocotyl length and internode length was nutrient salt concentration. In terms of effect on seedling index,substrate temperature should be reduced properly,to avoid excessive shading. It was primarily determined that the effects of three factors on the raising of strong tomato seedlings ranked as factor C,factor B and factor A from high to low; and the screened optimal seedling raising conditions were the rhizospheric temperature at( 3 + 1)℃,the shading rate of( 50 + 5) % and the EC value of( 5. 0 + 0. 5) mS/cm. 展开更多
关键词 TOMATO Hole tray seedling matrix Orthogonal experiment design environmental conditions
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Performance of Desiccant-Based Cooling Systems in Hot-Humid Climates: A Review
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作者 Maatouk Khoukhi Omar Al Khatib 《Energy Engineering》 EI 2021年第4期875-909,共35页
This paper reviews the principle and application of the thermally activated desiccant cooling systems with their capability to perform efficiently in hot-humid climates.The paper first introduces the continuous increa... This paper reviews the principle and application of the thermally activated desiccant cooling systems with their capability to perform efficiently in hot-humid climates.The paper first introduces the continuous increase of thermal comfort required in building and their relation with the consumption of conventional energy sources.The importance of desiccant cooling technology and its applications has been introduced as well.The energy and environmental issues with the conventional energy supply and the demand with the environmental problems and conditions mainly related to indoor air quality have been also discussed in the second chapter of this paper.The third part of this paper deals with different techniques and systems applied for cooling and dehumidification including the principles of solid and liquid desiccant applications.Indeed,these systems perform well in hothumid climates.The result of a case study of the solid desiccant cooling system combined with solar energy for the desiccant wheel regeneration has been presented in the last chapter in this paper to show the capability of these systems once well applied in a hot-humid climate. 展开更多
关键词 Desiccant cooling energy performance thermal comfort environmental condition solar energy
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