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Downwash airflow distribution pattern of hexa-copter unmanned aerial vehicles

International Journal of agricultural and Biological Engineering 2024年第4期17卷 24-34页

作者： Dengeru Yallappa Ramasamy Kavitha Allimuthu Surendrakumar Kannan Balaji Balakrishnan Suthakar Ayyasamy Paramasivam Mohan Kumar Yathendranaik Ravi Narayananaik Ashoka Kumar Kavan department of Farm machinery and Power Engineering Agricultural Engineering College and Research InstituteTamil Nadu Agricultural UniversityCoimbatore

In recent times,the use of vertical take-off and landing(VTOL)multi-rotor Unmanned Aerial Vehicle(UAVs)for spraying chemical pesticides against weeds and pests has recently become *** current aerial spray application research is primarily focused on examining the influence of UAV spraying parameters such as flight height,travel speed,rotor configuration,droplet size,payload and wind *** downwash airflow velocity generated by the UAV rotor propeller has a significant impact on the droplet deposition process.A test rig was developed to measure the downwash airflow pattern generated by the rotor propeller of a *** this investigation,a six-rotor electric autonomous UAV sprayer was used to investigate the parameters and distribution laws of downwash airflow *** downwash airflow velocity was measured using portable anemometers mounted on the test rig at radial positions viz.,0 m,0.5 m,1 m,1.5 m and 2 m,perpendicular to(X)and parallel to the UAV’s flight direction(Y).The experiment was conducted at three levels of hover height,viz.,1 m,2 m and 3 m(Z)and three levels of payload,viz.,0 kg,5 kg,and 10 *** special downwash airflow distribution pattern was analysed using the Python programming language(Version 3.7).Results show that the downwash airflow velocity generated by the radial position of the UAV rotor is evenly distributed on the rotating loop and the standard deviation of the downwash airflow velocity is less than 0.5 m/*** maximum downwash airflow velocity of 13.8 m/s was observed below the rotor at 10 kg payload capacity,1 m hover height(Z),and 0.5 m in the *** minimum downwash wind field of 0.3 m/s was observed at 0 kg pay load capacity,1 m height,and 2 m in the *** downwash airflow velocity along each position in the radial direction of the rotor increases initially and then *** downwash airflow distribution results helps in mounting of spray nozzle configuration to drone sprayer which helps to

关键词： downwash air payload rotor propeller flight height distribution analysis flight direction

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Coupling Co2P nanoparticles onto N,P-doped biomass-derived carbon as efficient electrocatalysts for flexible Zn–air batteries

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Rare Metals 2024年第10期43卷 4982-4991页

作者： Shu-Qi Li Kang Sun Yan-Yan Liu Shu-Ling Liu Jing-Jing Zhou Wen-Bo Zhang Yi-Hang Lu Xiang-Meng Chen Xiao-Peng Wang Bao-Jun Li Jian-Chun Jiang College of Science Henan Agricultural University department of Chemistry Tsinghua University College of Chemistry Zhengzhou University Institute of Chemical Industry of forest Products National Engineering Lab for Biomass Chemical UtilizationKey and Open Lab on Forest Chemical EngineeringChinese Academy of ForestryState Forestry Administration

Catalysts for oxygen conversion play an important role in energy storage and conversion technologies such as metal-air *** highly active stable,and low-cost catalysts is critical for further implementation of the above ***,an efficien oxygen electrocatalyst with Co2P nanoparticles （NPs）coupling onto N,P-doped porous carbon nanosheets（Co2P@NPAC） derived from cotton stalk is successfully designed and prepared via activation,hydrothermal treatment,and pyrolysis *** excellent properties of electrical conductivity,mass transfer,and synergistic integration between Co2P and N,P-doped carbon endow Co2P@NPAC composite with superior oxygen reduction reaction/oxygen evolution reaction （ORR/OER） ***2P@NPAC catalyst achieves ORR activity with half-wave potential of 0.85 V and high OER activity with overpotential of 261 mV at 10 mA·*** flexible Zn-air batteries （ZABs） based on Co2P@NPAC catalyst revea outstanding performances with a high open-circuit voltage（1.38 V）,a peak power density of (75 mW·cm-2),and a low charge-discharge voltage gap （0.74 V,～200 cycles）The flexible ZABs express the stable discharge-charge voltage gap at various bending *** work provides interesting inspiration for the ingenious design of efficien carbon electrocatalysts from biomass with potential application of energy storage and conversion devices.

关键词： Cotton stalk Flexible Zn–air batteries N,P-doped activated carbon Oxygen reduction reaction

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The storage and utilization of carbohydrates in response to elevation mediated by tree organs in subtropical evergreen broad-leaved forests

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forest Ecosystems 2024年第1期11卷 52-61页

作者： Bin Xu Xueli Jiang Yingying Zong G.Geoff Wang Fusheng Chen Zhenyu Zhao Xiangmin Fang Key Laboratory of National forestry and Grassland Administration on forest Ecosystem Protection and Restoration of Poyang Lake Watershed College of ForestryJiangxi Agricultural UniversityNanchang330045China Jiulianshan National Observation and Research Station of Chinese forest Ecosystem College of ForestryJiangxi Agricultural UniversityNanchang330045China department of forestry and Environmental Conservation Clemson UniversityClemsonSC29634USA

Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate climate change *** effect of elevation on tree growth may depend on organ ***,the allocation patterns of nonstructural and structural carbohydrates(NSCs and SCs,respectively)in different tree organs and their response to elevation remain *** selected four dominant tree species,Schima superba,Castanopsis eyrei,Castanopsis fargesii and Michelia maudiae,along an elevation gradient from 609 to 1,207 m in subtropical evergreen broad-leaved forests and analyzed leaf,trunk,and fine root NSCs,carbon(C),nitrogen(N)and phosphorus(P)concentrations and the relative abundance of *** NSCs increased initially and then decreased,and trunk NSCs increased with increasing ***,root NSCs decreased with increasing *** relative abundance of SCs in leaves and trunks decreased,while the relative abundance of root SCs increased with increasing *** significant correlations between SCs and NSCs in leaves were detected,while there were negative correlations between SCs and NSCs in trunks,roots,and all *** partitioning analysis indicated that plant C/N and C/P were the main predictors of changes in SCs and *** results suggest that tree organs have divergent responses to elevation and that increasing elevation will inhibit the aboveground part growth and enhance the root growth of trees.A tradeoff between the C distribution used for growth and storage was confirmed along the elevation gradient,which is mainly manifested in the"sink"organs of *** results provide insight into tree growth in the context of global climate change scenarios in subtropical forest ecosystems.

关键词： Nonstructural carbohydrates Structural carbohydrates Elevation Subtropical evergreen broad-leaved forests Tree organs

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Resistance and resilience of soil biological indicators:A case study with multi-walled carbon nanotube

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Pedosphere 2024年第3期34卷 664-675页

作者： Shagufta YASMEEN Nintu MANDAL Anupam DAS Pritam GANGULY Sanjay KUMAR Rajiv RAKSHIT department of Soil Science and agricultural Chemistry Bihar Agricultural UniversitySabourBhagalpur 813210(India) department of Agronomy Bihar Agricultural UniversitySabourBhagalpur 813210(India)

Soil ecosystem is experiencing stresses due to climate change,and soil inhabitants try to demonstrate their inherent resistance and resilience against those *** of nanomaterials as agricultural inputs could bring shifts in resistance and resilience patterns of soil microbes and associated enzymes,especially under short-term heat *** this background,the impacts of multi-walled carbon nanotube(MWCNT)on the resistance and resilience of soil biological indicators were *** incubation experiment was conducted with varied MWCNT concentrations(0,50,100,250,and 500 mg kg-1soil)for 90 d after 24-h heat stress at 48±2?C to assess the impacts of MWCNT on soil enzyme activities and microbial populations vis-à-vis their resistance and resilience indices under short-term exposure to heat *** activities were reduced after exposure to heat *** indices of enzyme activities were enhanced by MWCNT application on day 1 after heat stress,whereas there was no recovery of enzyme activities after 90-d *** soil enzyme activities,resistance index values of soil microbial populations followed the similar trend and were improved by MWCNT ***-walled carbon nanotube has the potential to improve resistance indices of soil enzyme activities and microbial populations under heat stress,although they could not recover to their original state during periodical incubation after heat *** study helps to understand the relative changes of biological indicators under MWCNT and their ability to withstand heat stress.

关键词： enzyme activity heat stress microbial population nanomaterial recovery

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Relating estimates of wood properties of birch to stem form, age and species

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Journal of forestry Research 2024年第3期35卷 1-11页

作者： Grace Jones Maria Ulan Mateusz Liziniewicz Johan Lindeberg Stergios Adamopoulos Teagasc forestry Development department Ashtown Research CentreDublin 15 D15DY05Ireland Research Institutes of Sweden(RISE) GoteborgSweden The forest Research Institute of Sweden(Skogforsk) Ekebo 225026890SvalovSweden department of forestry and Wood Technology Linnaeus University35195VaxjoSweden department of forest Biomaterials and Technology Swedish University of Agricultural SciencesBox 700875007 UppsalaSweden

Birch has long suffered from a lack of active forest management,leading many researchers to use mate-rial without a detailed management *** collected from three birch(Betula pendula Roth,*** Ehrh.)sites in southern Sweden were analyzed using regression analysis to detect any trends or differences in wood proper-ties that could be explained by stand history,tree age and stem *** sites were genetics trials established in the same *** of acoustic velocity(AV)from non-destructive testing(NDT)and predicted AV had a higher correlation if data was pooled across sites and other stem form factors were considered.A subsample of stems had radial profiles of X-ray wood density and ring width by year created,and wood density was related to ring number from the pith and ring *** seemed likely that wood density was negatively related to ring width for both birch *** models had slight improvements if site and species were included,but only the youngest site with trees at age 15 had both birch *** paper indicated that NDT values need to be considered separately,and any predictive models will likely be improved if they are specific to the site and birch species measured.

关键词： Acoustic velocity Non-destructive testing Predictive models Regression analysis Wood density

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The effect of abiotic stresses on plant C:N:P homeostasis and their mitigation by silicon

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The Crop Journal 2024年第2期12卷 340-353页

作者： Milton Garcia Costa Renato de Mello Prado Luiz Fabiano Palaretti Jonas Pereira de Souza Júnior department of agricultural Production Science School of Agricultural and Veterinarian SciencesSão Paulo State UniversityJaboticabalBrazil

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus(C:N:P), leading to biochemical and physiological alterations and reductions in yield. Silicon(Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources(water, light, nutrients, and toxic elements), strategically employ Si to maintain C:N:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating C:N:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on C:N:P homeostasis, as well as the role of Si in preserving C:N:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining C:N:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation.

关键词： Nutritional stoichiometry Elemental stoichiometry Beneficial element Environmental stresses Nutritional efficiency Carbon use efficiency agricultural sustainability

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Are gender inclusiveness and rural transformation interlinked?The case of Bangladesh

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Journal of Integrative Agriculture 2024年第6期23卷 2112-2126页

作者： Maria Fay Rola-Rubzen Mohammad Jahangir Alam Jon Marx Sarmiento Ismat Ara Begum Al Amin Al Abbasi Subrata Saha UWA School of Agriculture and Environment The University of Western AustraliaPerth 6009Australia department of Agribusiness and Marketing Bangladesh Agricultural UniversityMymensingh-2202Bangladesh department of agricultural Economics Bangladesh Agricultural UniversityMymensingh-2202Bangladesh

Gender inclusiveness is important in the rural transformation process of Bangladesh as rural women play key roles in both agricultural and non-agricultural *** inclusiveness also leads to gender *** empirically evaluate relationships between rural transformation and gender inclusiveness in *** consider three rural transformation indicators:high-value commodities’share in agricultural output values,non-farm employment’s share in rural labor employment,and non-agricultural GDP’s share in total *** capturing gender inclusiveness include the per capita rural income of males and females,ratio of investments into gender programs,female access to education,access to healthcare,employment participation,land ownership,and asset *** test the effect of the difference in per capita rural income of males and females and the ratio of their incomes and check for the robustness of the gender variables across different model *** 128 district-level observations from 32 districts of Bangladesh across four time periods(2000,2005,2010 and 2016),we use both ordinary least squares and fixed effects panel regression *** find that female land and asset ownership and access to education and healthcare are robust determinants of various stages of rural ***,our results suggest that improving women’s ownership of land and assets and investing in women’s education and healthcare will likely contribute to a more inclusive rural transformation.

关键词： rural transformation Bangladesh gender inclusiveness investments on women

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Antifertility effects of quinestrol in male lesser bandicoot rat, Bandicota bengalensis, and potential in managing rodent population under field conditions

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Integrative Zoology 2024年第1期19卷 108-126页

作者： Ajooni SIDHU Neena SINGLA department of Zoology Punjab Agricultural UniversityLudhianaPunjabIndia

Integrating fertility control techniques using steroid hormones after lethal control can help reduce post control rebuildup of rodent *** current study is thefirst to assess the antifertility effects of quinestrol in male lesser bandicoot rat,Bandicota bengalensis which is the predominant rodent pest species in Southeast *** in different groups were fed bait containing 0.00%,0.01%,0.02%,and 0.03%quinestrol for 10 days in laboratory and evaluated immediately,and 15,30,and 60 days after treatment discontinuation for effect on reproduction and other antifertility *** of 0.03%quinestrol treatment for 15 days was also observed in managing rodent populations in groundnut *** resulted in average consumption of 19.53±1.80,67.63±5.50,and 246.67±1.78 mg/kg bwt active ingredient by three treated groups of rats,*** reproduction was observed in female rats mated with male rats treated with 0.03%quinestrol,even 30 days after cessation of ***-mortem examination showed a significant(P<0.0001)effect of treatment on organ weights(testis,cauda epididymis,seminal vesicles,and prostate gland)and different sperm parameters(sperm motility,sperm viability,sperm count,and sperm abnormality)in the cauda epididymalfluid with partial reversibility after 60 days.A significant(P<0.0001)effect of quinestrol on the histomorphology of testis and cauda epididymis was observed,suggesting its effect on *** cell association and cell count in seminiferous tubules did not fully recover within 60 days of stopping *** of the effects of quinestrol treatment in groundnutfields showed greater reductions in rodent activity infields treated with 2%zinc phosphide followed by 0.03%quinestrol treatment as compared tofields treated with 2%zinc phosphide *** concludes that quinestrol has the potential to reduce fecundity and post control rebuildup of *** populations,but long-term studies

关键词： antifertility Bandicota bengalensis field evaluation quinestrol reversibility

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Why ecosystem characteristics predicted from remotely sensed data are unbiased and biased at the same time-and how this affects applications

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forest Ecosystems 2024年第1期11卷 24-31页

作者： Goran Ståhl Terje Gobakken Svetlana Saarela Henrik J.Persson Magnus Ekstrom Sean P.Healey Zhiqiang Yang Johan Holmgren Eva Lindberg Kenneth Nystrom Emanuele Papucci Patrik Ulvdal Hans OleØrka Erik Næsset Zhengyang Hou Håkan Olsson Ronald E.McRoberts department of forest Resource Management Swedish University of Agricultural Sciences90183UmeåSweden Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesÅsNorway USDA forest Service Rocky Mountain Research StationOgdenUTUSA The Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry UniversityBeijing100083China department of forest Resources University of MinnesotaSt.PaulMNUSA

Remotely sensed data are frequently used for predicting and mapping ecosystem characteristics,and spatially explicit wall-to-wall information is sometimes proposed as the best possible source of information for ***,wall-to-wall information typically relies on model-based prediction,and several features of model-based prediction should be understood before extensively relying on this type of *** such feature is that model-based predictors can be considered both unbiased and biased at the same time,which has important implications in several areas of *** this discussion paper,we first describe the conventional model-unbiasedness paradigm that underpins most prediction techniques using remotely sensed(or other)auxiliary *** this point of view,model-based predictors are typically ***,we show that for specific domains,identified based on their true values,the same model-based predictors can be considered biased,and sometimes severely *** suggest distinguishing between conventional model-bias,defined in the statistical literature as the difference between the expected value of a predictor and the expected value of the quantity being predicted,and design-bias of model-based estimators,defined as the difference between the expected value of a model-based estimator and the true value of the quantity being *** show that model-based estimators(or predictors)are typically design-biased,and that there is a trend in the design-bias from overestimating small true values to underestimating large true ***,we give examples of applications where this is important to acknowledge and to potentially make adjustments to correct for the design-bias *** argue that relying entirely on conventional model-unbiasedness may lead to mistakes in several areas of application that use predictions from remotely sensed data.

关键词： Bias Model-based inference Design-based inference

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Is there hybridization between 2 species of the same genus in sympatry?——The genetic relationships between Anoplophora glabripennis,Anoplophora chinensis,and putative hybrids

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Insect Science 2024年第2期31卷 633-645页

作者： Haiwen Qin Huachao Xu Arnaud Capron Ilga Porth Mingming Cui Melody A.Keena Xiaofang Deng Juan Shi Richard C.Hamelin Sino-French Joint Laboratory for Invasive forest Pests in Eurasia Department of ForestBejing Forestry UniversityBejingChina department of forest and Conservation Sciences The University of British ColumbiaVancouverCanada College of forestry and Biotechnology Zhejiang A&F UniversityHangzhouChina department of Wood and forest Sciences Laval UniversityQuebecCanada 5 Department of AgricultureNorthern Research StationUSDA Forest ServiceHamdenConnecticutUSA Changchun Landscape Plant Conservation Station Bureau of Forestry and Landscaping of ChangchunChangchunChina

Anoplophora glabripennis(Asian longhorn beetle,ALB)and Anoplophora chinensis(Citrus longhorn beetle,CLB)are native forest pests in China;they have become important international quarantine *** are found using the same Salix aureopendula host tree of Cixi,Zhejiang province,*** this host tree,we collected additional beetles that appeared to be morphologically intermediate between ALB and *** using a stereoscope,we observed that there were several bumps on the base of the elytra,which was inconsistent with ALB,which typically has a smooth elytral base,but was more like CLB,which has numerous short tubercles on the elytral *** their sympatry and intermediate morphology,we hypothesized that these may represent ALB×CLB *** studied the genomic profiles for 46 samples(ALB,CLB,and putative hybrids)using genotyping-by-sequencing(GBS)providing a reduced representation of the entire *** principal component analyses on the 163 GBS-derived single nucleotide polymorphism data,we found putative hybrids tightly clustered with ALB,but genetically distinct from the CLB ***,our initial hybrid hypothesis was not supported by genomic ***,while mating experiments between adult ALB and CLB were successful in 4 separate years(2017,2018,2020,and 2021),and oviposition behavior was observed,no progeny was *** employed population genomic analysis and biological hybridization experiments,we conclude that the putative hybrids represent newly discovered morphological variants within *** approach further confirmed the advantage of genome-wide information for Anoplophora species assignment in certain ambiguous classification cases.

关键词： Anoplophora chinensis Anoplophora glabripenni sg enotyping-bysequencing invasive pest mating putative hybrid

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