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Influence of introducing Zr,Ti,Nb and Ce elements on externally solidified crystals and mechanical properties of high-pressure die-casting Al–Si alloy
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作者 Junjie Li Wenbo Yu +5 位作者 Zhenyu Sun Weichen Zheng Liangwei Zhang Yanling Xue Wenning Liu Shoumei Xiong 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期147-153,共7页
High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress aro... High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties. 展开更多
关键词 aluminium alloy high-pressure die-casting externally solidified crystals non-heat treatment
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Nano-scale Reinforcements and Properties of Al-Si-Cu Alloy Processed by High-Pressure Torsion
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作者 DONG Ying WU Siyuan +4 位作者 HE Ziyang LIANG Chen CHENG Feng HE Zuwei QIAN Chenhao 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第5期1253-1259,共7页
To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu allo... To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic. 展开更多
关键词 Al-Si-Cu alloy high-pressure torsion nano-scale reinforcements ternary eutectic
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Experimental and Finite Element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite
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作者 Seyed Mohammad Reza Abtahi Saeid Ansari Sadrabadi +4 位作者 Gholam Hosein Rahimi Gaurav Singh Hamid Abyar Daniele Amato Luigi Federico 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1783-1806,共24页
Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necess... Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed. 展开更多
关键词 high-pressure pipeline composite repair ASME PCC-2 ISO 24817
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Security and Privacy in Solar Insecticidal Lamps Internet of Things:Requirements and Challenges
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作者 Qingsong Zhao Lei Shu +3 位作者 Kailiang Li Mohamed Amine Ferrag Ximeng Liu Yanbin Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期58-73,共16页
Solar insecticidal lamps(SIL) can effectively control pests and reduce the use of pesticides. Combining SIL and Internet of Things(IoT) has formed a new type of agricultural IoT,known as SIL-IoT, which can improve the... Solar insecticidal lamps(SIL) can effectively control pests and reduce the use of pesticides. Combining SIL and Internet of Things(IoT) has formed a new type of agricultural IoT,known as SIL-IoT, which can improve the effectiveness of migratory phototropic pest control. However, since the SIL is connected to the Internet, it is vulnerable to various security issues.These issues can lead to serious consequences, such as tampering with the parameters of SIL, illegally starting and stopping SIL,etc. In this paper, we describe the overall security requirements of SIL-IoT and present an extensive survey of security and privacy solutions for SIL-IoT. We investigate the background and logical architecture of SIL-IoT, discuss SIL-IoT security scenarios, and analyze potential attacks. Starting from the security requirements of SIL-IoT we divide them into six categories, namely privacy, authentication, confidentiality, access control, availability,and integrity. Next, we describe the SIL-IoT privacy and security solutions, as well as the blockchain-based solutions. Based on the current survey, we finally discuss the challenges and future research directions of SIL-IoT. 展开更多
关键词 CHALLENGES Internet of Things(IoT) privacy and security security requirements solar insecticidal lamps(SIL)
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Evaluation of the Insecticidal Effects of Aqueous Extracts of the Leaves of:Erythrophleum guineense and Uvaria chamae against Caryedon serratus Ol.(Coleoptera,Bruchidae),an Insect Pest of Groundnut Grains in the Republic of Guinea
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作者 Aboubacar Safi Sylla Adama Moussa Sakho +1 位作者 Aboubacar Diallo Abdoulaye Keita 《Journal of Environmental Science and Engineering(A)》 CAS 2024年第6期199-206,共8页
The aim of this study is to evaluate the insecticidal potential of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae on Caryedon serratus Ol.(Coleoptera,Bruchidae),an insect pest of groundnut... The aim of this study is to evaluate the insecticidal potential of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae on Caryedon serratus Ol.(Coleoptera,Bruchidae),an insect pest of groundnut grains in the Republic of Guinea.To do this,tests on their insecticidal efficacy were carried out separately on groups of 8 bruchids using concentrations of aqueous extracts from their leaves in jars each containing 20 g of groundnut.The mortality of the bruchids and the impact of their aqueous extracts were observed and recorded for 96 h and 120 days after infestation,followed by a test of the germinative power of the seeds.Concentrations(C1)of aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae applied to 20 g of groundnut resulted in bruchid mortality of 86.99%and 78.82%of each plant respectively.At the same doses,the treated seeds were not attacked during 4 months’storage.The germination rate of groundnut seeds at the start and end of the experiment was 97.65%and 93.60%respectively.Thus,aqueous extracts of the leaves of Erythrophleum guineense and Uvaria chamae can be considered as an alternative bio-insecticide against pests in groundnut storage shops. 展开更多
关键词 insecticidal effect Erythrophleum guineense Uvaria chamae Caryedon serratus Ol
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Numerical Simulation Analysis of the Transformer Fire Extinguishing Process with a High-Pressure Water Mist System under Different Conditions 被引量:1
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作者 Haowei Yao Youxin Li +7 位作者 Kefeng Lv Dong Wang Jinguang Zhang Zhenyu Zhan Zhenyu Wang Huaitao Song Xiaoge Wei Hengjie Qin 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期733-747,共15页
To thoroughly study the extinguishing effect of a high-pressure water mist fire extinguishing system when a transformer fire occurs,a 3D experimental model of a transformer is established in this work by employing Fir... To thoroughly study the extinguishing effect of a high-pressure water mist fire extinguishing system when a transformer fire occurs,a 3D experimental model of a transformer is established in this work by employing Fire Dynamics Simulator(FDS)software.More specifically,by setting different parameters,the process of the highpressure water mist fire extinguishing system with the presence of both diverse ambient temperatures and water mist sprinkler laying conditions is simulated.In addition,the fire extinguishing effect of the employed high-pressure water mist system with the implementation of different strategies is systematically analyzed.The extracted results show that a fire source farther away fromthe centerline leads to a lower local temperature distribution.In addition,as the ambient temperature increases,the temperature above the fire source decreases,while the temperature and the concentrationof theupperflue gas layer bothdecrease.Interestingly,after thehigh-pressurewatermist sprinkler begins to operate,both the temperature distribution above the fire source and the concentration of the flue gas decrease,which indicates that the high-pressure water mist system plays the role of cooling and dust removal.By comparing various sprinkler laying methods,it is found that the lower sprinkler height has a better effect on the temperature above the fire source,the temperature of the upper flue gas layer,and the concentration of the flue gas.Moreover,when the sprinkler is spread over thewhole transformer,the cooling effect on both the temperature above the fire source and the temperature of the upper flue gas layer is good,whereas the change in the concentration of the flue gas above the fire source is not obvious compared to the case where the sprinkler is not fully spread. 展开更多
关键词 Transformer fire high-pressure water mist TEMPERATURE flue gas concentration
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The discovery of TiO_(2)-Ⅱ,the α-PbO_(2)-structured high-pressure polymorph of rutile,in the Suizhou L6 chondrite 被引量:1
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作者 Xiande Xie Xiangping Gu Ming Chen 《Acta Geochimica》 EI CAS CSCD 2023年第1期1-8,共8页
We report the discovery of TiO_(2)-Ⅱ in the unmelted rock of the shocked Suizhou L6 chondrite.Natural TiO_(2)-Ⅱ was previously found in ultrahigh-pressure metamorphic and mantle-derived rocks,terrestrial impact stru... We report the discovery of TiO_(2)-Ⅱ in the unmelted rock of the shocked Suizhou L6 chondrite.Natural TiO_(2)-Ⅱ was previously found in ultrahigh-pressure metamorphic and mantle-derived rocks,terrestrial impact structures,and tektite.Our microscopic,Raman spectroscopic,electron microprobe and transmission electron microscopic investigations have revealed:(1) All observed TiO_(2)-Ⅱ grains are related with ilmenite and pyrophanite;(2) TiO_(2)-Ⅱ occurs as needle-and leaf-shaped inclusions in llmenite and patch-,tape-shaped body in pyrophanite;(3)The composition of TiO_(2)-Ⅱ is identical with that of its precursor rutile;(4) The Raman spectrum of TiO_(2)-Ⅱ is in good agreement with that of natural and synthesized α-PbO_(2)-type TiO_(2);(5) TiO_(2)-Ⅱ occurs mainly in the form of well-ordered nano-domains and small mis-orientation among the domains can be observed.(6) All electron diffraction reflections from TiO_(2)-Ⅱ can be indexed to α-PbO_(2)structure in space group Pbcn with lattice parameters of a=4.481 ?,b=5.578 A and c=4.921 A;(7) The exsolution inclusions of rutile from host ilmenite are mostly connected with an alternation process along the lamellar twinning plane of ilmenite induced by shockinduced high pressure and high temperature;(8) The P-T regime of 20-25 GPa and 1000 ℃ estimated for the Suizhou unmelted rock is suitable for phase transition of rutile into TiO_(2)-Ⅱ phase. 展开更多
关键词 RUTILE TiO_(2)-Ⅱ high-pressure polymorph Shock metamorphism Suizhou meteorite
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Preparation of Amide-Containing Insecticidal Derivatives from the Renewable Natural Productβ-Pinene
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作者 Jiulong Wang Yanqing Gao +5 位作者 Xiaoping Rao Zongde Wang Shibin Shang Zhanqian Song Hongyan Si Shengliang Liao 《Journal of Renewable Materials》 SCIE EI 2023年第5期2368-2380,共13页
The preparation of bioactive derivatives from the renewable natural product pinene is a hot research topic in the deep processing and utilization of pinene.In this study,β-pinene was used to develop novel molecules a... The preparation of bioactive derivatives from the renewable natural product pinene is a hot research topic in the deep processing and utilization of pinene.In this study,β-pinene was used to develop novel molecules as a promising new precursor of insecticide.A series of amide-containing derivatives ofβ-pinene were synthesized and characterized.The insecticidal activities of these derivatives against Mythimna separate and Semiaphis heraclei were tested.The structure characterization results showed that the characterization data of amide-containing derivatives were in full agreement with their proposed structures.The insecticidal activities evaluation results indicated that amide-containing derivatives exhibited weak insecticidal activity against Mythimna separate,but exhibited moderate to good insecticidal activity against Semiaphis heraclei.After testing for 72 h,the corrected mortality against Semiaphis heraclei of compounds 5c,5e,5f,5 h,5j,and 5 m was 100%at 1000 mg/L.The structure-activity relationship analysis results showed that the introduction of an amide group into the structure of derivatives improved their insecticidal activity against Semiaphis heraclei.Meanwhile,the amide-containing derivatives containing the F and NO_(2) substituted benzene ring might improve their insecticidal activity against Semiaphis heraclei.This study will be helpful for the high value-added utilization of the natural renewable resourceβ-pinene and the development of novel insecticides. 展开更多
关键词 TURPENTINE PINENE derivative AMIDE insecticidal activity
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Chemical Composition of Different Extracts of Conyza bonariensis: Insecticidal and Nematicidal Activities
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作者 Kodjo Adande Kodjo Eloh +2 位作者 Oudjaniyobi Simalou Marie-France Bakaï Pierluigi Caboni 《American Journal of Analytical Chemistry》 CAS 2023年第2期95-120,共26页
C. bonariensis (L.) Cronq. known as hairy fleabane was first described in Argentina but it is now widely spread through most warmer regions of Europe, Africa, Asia, the Caribbean and Central America. In this work, a c... C. bonariensis (L.) Cronq. known as hairy fleabane was first described in Argentina but it is now widely spread through most warmer regions of Europe, Africa, Asia, the Caribbean and Central America. In this work, a chemical analysis by liquid and gas chromatography coupled with mass spectrometry of the whole plant, aerial part, flowers and roots extracts of C. bonariensis harvested in Togo (West Africa) was carried out. Two acetylenic compounds Lachnophyllum ester and limonene were identified as the main components of essential oils while Lachnophyllum and Matricaria lactones were dominant in chloroform extracts. Based on the plant chemical compositions, essential oils and chloroform extracts were tested on cowpea weevil Callosobruchus maculatus adults which are considered as one of the most cosmopolitan pests of stored beans, and on freshly hatched second-stage juveniles of root-knot nematode Meloidogyne incognita. Results showed that the whole plant essential oil demonstrated an LC<sub>50/24h</sub> value of 1.75 μL oil/L air on C. maculatus while at 3.91 μL oil/L air, it showed 100% mortality. Furthermore, the plant root chloroform extracts partitioned in diethyl ether-hexane mixture showed the strongest nematicidal activity with an LC<sub>50/72h</sub> value of 0.47 mg/mL. Our findings suggest that the widely diffused plant C. bonariensis and its acetylenic constituents could be considered as potent botanical insecticidal and nematicidal agents. 展开更多
关键词 Conyza bonariensis insecticidal Activity Nematicidal Activity Callosobruchus maculatus Meloidogyne incognita
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A new transition metal diphosphideα-MoP_(2) synthesized by a high-temperature and high-pressure technique
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作者 刘晓磊 于振海 +9 位作者 李建福 徐真真 周春银 董朝辉 张丽丽 王霞 余娜 邹志强 王晓丽 郭艳峰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期563-567,共5页
Monoclinicα-MoP_(2),with the OsGe2-type structure(space group C2/m,Z=4)and lattice parameters a=8.7248(11)Å,b=3.2322(4)Å,c=7.4724(9)Å,andβ=119.263°,was synthesized under a pressure of 4~GPa at a ... Monoclinicα-MoP_(2),with the OsGe2-type structure(space group C2/m,Z=4)and lattice parameters a=8.7248(11)Å,b=3.2322(4)Å,c=7.4724(9)Å,andβ=119.263°,was synthesized under a pressure of 4~GPa at a temperature between 1100℃and 1200℃.The structure ofα-MoP_(2) and its relationship to other transition metal diphosphides are discussed.Surprisingly,the ambient pressure phase orthorhombicβ-MoP_(2)(space group Cmc21)is denser in structure thanα-MoP_(2).Room-temperature high-pressure x-ray diffraction studies exclude the possibility of phase transition fromβ-MoP_(2) to α-MoP_(2),suggesting thatα-MoP_(2) is a stable phase at ambient conditions;this is also supported by the total energy and phonon calculations. 展开更多
关键词 high-pressure synthesis monoclinic MoP_(2) crystal structure
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Insecticidal Activity and Physicochemical Characterization of Nanoparticles from Foliar Extract of Capsicum chinense
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作者 Arnoldo E.Alfaro-Corres Daniel Gonzalez-Mendoza +5 位作者 Esau Ruiz-Sanchez Carlos Ail-Catzin Benjamin Valdez-Salas Federico Gutierrez-Miceli Arturo Reyes-Ramirez Jacques Fils Pierre 《Journal of Renewable Materials》 EI 2023年第11期3933-3943,共11页
This work was carried out to evaluate the insecticidal effect of mono,bi and trimetallic nanoparticles(NPs)from leaf extract of habanero pepper(Capsicum chinense Jacq.)on the red flour beetle(Tribolium castaneum herbs... This work was carried out to evaluate the insecticidal effect of mono,bi and trimetallic nanoparticles(NPs)from leaf extract of habanero pepper(Capsicum chinense Jacq.)on the red flour beetle(Tribolium castaneum herbst.)and cotton mealybug(Phenacoccus solenopsis Tinsley).The results showed that Cu NPs,Cu/Mn NPs and Zn/Cu NPs had high insecticidal effect against T.castaneum(63%-80% mortality after 96 h).The Cu NPs and Zn/Cu NPs showed also insecticidal effect against P.solenopsis,but to a lesser extent(20%–28% after 96 h).With regards to the physicochemical characterization,Cu NPs had a zeta potential of 21.1 mV,whereas Cu/Mn NPs and Zn/Cu NPs exhibited zeta potentials of 200 mV.The polydispersity index(PDI)values for Cu NPs,Cu/Mn NPs,and Zn/Cu NPs were 10.1,29.16,and 14.34,respectively.The TF-IR spectra of the NPs varied from 600 to 4000 cm−1.The EDX weight percentages showed the presence of Cu(0.29%–2.4%),Mn(1.4%),and Zn(2.6%)in Cu/Mn NPs and Zn/Cu NPs,respectively. 展开更多
关键词 Phytonanoparticles botanical insecticide pest control agronanotechnology
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High-pressure new phases of V–N compounds
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作者 时旭含 李志慧 +4 位作者 刘媛媛 王元元 刘冉 胡阔 姚震 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期560-565,共6页
The high-pressure diagram of V–N compounds is enriched by proposed seven new stable high-pressure phases.The P-1-VN_4with the armchair N-rich structure may be quenched to ambient conditions.The formed N–N covalent b... The high-pressure diagram of V–N compounds is enriched by proposed seven new stable high-pressure phases.The P-1-VN_4with the armchair N-rich structure may be quenched to ambient conditions.The formed N–N covalent bond plays an important role for the structural stability of N-chain.The charge transfer results in a V–N ionic bond interaction,which further improves the stability of N-chain structure.The P-1-VN_4,P4mnc-VN_8,and Immm-VN_(10)with the outstanding detonation properties have potential application in explosive field. 展开更多
关键词 high-pressure N-rich V–N compounds phase diagram STABILITY DFT calculation
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Evaluation of the Insecticidal Activity of Powders of Ageratum conyzoide L. Leaves and Roots of Securidaca longepedunculata Fresen on the Germination Rate of Cowpea Infected with Callosobruchus maculatus
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作者 Mohamed Diogo Bangoura Aboubacar Diallo +2 位作者 Adama Moussa Sakho Amadou Youssouf Bah Abdoulaye Keita 《Journal of Environmental Science and Engineering(A)》 2023年第4期127-138,共12页
Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus ma... Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus maculatus. The commonly used control strategy is essentially based on chemicals whose use is toxic, expensive and restrictive. In the search for alternatives to chemical control, this work was undertaken to evaluate the insecticidal potential of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots. Powder toxicity and insecticidal efficacy tests were performed separately on groups of 20 Callosobruchus maculatus using 3 doses of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots in jars each containing 100 g cowpea. The mortality of Callosobruchus maculatus and the impact of powders were noted respectively for 96 h and 4 months after infestation. The germination capacity of the treated seeds was assessed at the start of the study. Doses of 1 and 8 g of Ageratum conyzoides leaf powders and Securidaca longepedunculata roots were applied respectively to every 100 g of cowpea and led to 100% mortality of Callosobruchus maculatus. At these same doses, more than half of the treated seeds were attacked during the 4 months of storage. Germination tests have shown that powders of Ageratum conyzoides leaves and roots of Securidaca longepedunculata have no negative effect on the germination power of cowpea seeds. Therefore, they could be considered as excellent bio-insecticides that socio-professional strata (farmers and warehouse workers) can use in the fight against cowpea insects intended for storage. 展开更多
关键词 ETHNOBOTANY insecticidal activity COWPEA Ageratum conyzoides Securidaca longepedunculata Callosobruchus maculatus.
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Evaluation of the Efficacy of an Aloe barbadensis Based Biological Insecticide against Pests of Abelmochus esculentus for Promoting Ecological Agriculture (Far-North, Cameroon)
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作者 Mba Félicité Obono Laurentine Naoutissa +1 位作者 Samuel Ntamack Augustin Goudoum 《Agricultural Sciences》 2024年第5期590-603,共14页
Chemical insecticides have been considered as a means to combat crop pests. Although their effectiveness is evident, their impact on the environment is increasingly being discussed. The aim of this study is to determi... Chemical insecticides have been considered as a means to combat crop pests. Although their effectiveness is evident, their impact on the environment is increasingly being discussed. The aim of this study is to determine the agro-ecological potential of a biological insecticide (C<sub>25</sub>H<sub>32</sub>O<sub>12</sub>) based on Aloe barbadensis in a Sahelian context. For this purpose, a completely randomized block experimental design with 3 replications and 4 treatments was set up to experiment with Aloe barbadensis as a bioinsecticide against pests of Abelmoschus esculentus. However, data were collected using an observation and parameter monitoring grid. This includes the cultivation of Abelmoschus esculentus, soil preparation, seeding and watering, plot labeling, preparation of the bioinsecticide (selection and preparation of raw materials, grinding of Aloe barbadensis miller and extraction of the crude bioinsecticide, quantification of treatment doses and dilution, and obtaining the formulated bioinsecticide), plant watering, plant treatment, and finally parameter monitoring. The results obtained reveal that the level of damage is significantly high in the control treatment T0 (63%) compared to the other treatments, with 29% for treatment T1, 7% for T2, and 1% for T3, implying a strong action capability of this insecticide against pests of Abelmoschus esculentus. Therefore, it can be concluded that for a normal growing season of Abelmoschus esculentus, this biological insecticide should be sprayed 12 times. Furthermore, this biological insecticide is unique in that it does not inflict any gastric toxicity on the pests, which gives it the characteristic of being a repellent. It is a biological insecticide whose efficacy period has been tested, with a minimum duration of 21 days. In conclusion, this formulated bioinsecticide based on Aloe barbadensis demonstrates significant efficacy against pests of Abelmoschus esculentus. In the future, we will consider experimenting with its effectiveness against pests of other plants. 展开更多
关键词 ALOE Biological insecticide PESTS Agro-Ecological
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Laboratory evaluation of toxicity of selected insecticides against egg and larval stages of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)
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作者 BUSNOOR Abhishek V. WADASKAR R.M. +5 位作者 FAND Babasaheb B. TAMBE V.J. PILLAI T. MAHULE D.J. NAGRARE V.S. PRASAD Y.G. 《Journal of Cotton Research》 CAS 2024年第1期15-28,共14页
Background The cryptic nature of pink bollworm Pectinophora gossypiella(Saunders)larvae enables its reduced vul-nerability to insecticidal control.Further,the development of resistance against Bacillus thuringiensis(B... Background The cryptic nature of pink bollworm Pectinophora gossypiella(Saunders)larvae enables its reduced vul-nerability to insecticidal control.Further,the development of resistance against Bacillus thuringiensis(Bt)toxins posed a serious threat to transgenic cotton cultivation.This necessitated determining the critical timing of spray applications on the control effectiveness.This study assessed the influence of egg age(freshly laid vs.three-day-old)and the loca-tion of larvae(directly exposed to the insecticide residues on the boll rind vs.burrowed inside the bolls)on insecticide control efficacy.Results The results revealed a significant decrease in the ovicidal activity of tested insecticides with an increase in the age of eggs from one day old to three days old(paired t-test,P<0.05).The larvae directly exposed to the insec-ticide residues on the boll rind were more susceptible(>80%mortality)than the larvae exposed after they had bur-rowed inside the bolls(<49%mortality).The inhibitory effects of tested insecticides on developmental biology were more pronounced in the experiment on pre-larval release insecticide treatment compared with insecticide treatment given post-larval release and entry inside the bolls.Conclusion Egg age influences the insecticide susceptibility,as does the larval location,directly exposed vs bur-rowed inside the bolls.Older eggs and the larvae that had burrowed inside the green bolls of cotton were relatively less susceptible to the insecticide treatments.The toxic effects of insecticides on egg and larval stages were primar-ily ephemeral.These findings are significant for devising a comprehensive strategy for pink bollworm management on a sustainable basis. 展开更多
关键词 Bioefficacy COTTON insecticidES Pink bollworm Pectinophora gossypiella Timings of spray
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Geographical Distribution of Arboviruses, Aedes aegypti and Aedes albopictus Vectors and Their Resistance to Insecticides in Africa: A Systematic Review
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作者 Shoukrat Ohuwa Toyin Bello Abdou Azaque Zoure +6 位作者 Abdoul Karim Ouattara Dogfounianalo Somda Christelle Nadembega Dorcas Obiri-Yeboah Moussa Namountougou Abdoulaye Diabate Jacques Simpore 《Advances in Entomology》 2024年第4期249-274,共26页
Background & Objectives: Epidemics of arboviruses such as Dengue, Chikungunya and Zika have been recorded in recent years indicating that Aedes aegypti and Aedes albopictus are both important and very active vecto... Background & Objectives: Epidemics of arboviruses such as Dengue, Chikungunya and Zika have been recorded in recent years indicating that Aedes aegypti and Aedes albopictus are both important and very active vectors in Africa. For vector control, insecticides are on the front line, unfortunately, reported resistance jeopardizes the effectiveness of this strategy. The objective of this review was to determine the geographical distribution and insecticide resistance mechanisms of Ae. aegypti and Ae. Albopictus in Africa. Methods: A systematic review of the literature in scientific databases (PubMed, Google Scholar, ScienceDirect, Hinari) allowed us to identify relevant articles on the geographical distribution of Aedes aegypti, Aedes albopictus and arboviral diseases. On the other hand, studies related to insecticides used in vector control against Aedes, associated resistances and their molecular and metabolic mechanisms. Results: A total of 94 studies met the inclusion criteria for this search. Aedes aegypti is reported in most of Africa, and Aedes albopictus in part. There is a re-emergence and outbreak of Arbovirus epidemics in West and Central Africa. The insecticides used were organochlorines, carbamates, organophosphates and pyrethroids. In Aedes, target site insensitivity and metabolic resistance would be the 2 main mechanisms of resistance to these insecticides. Interpretation & Conclusion: Resistance has been recorded in all four major classes of insecticides recommended by WHO for vector control and eradication. New vector control methods such as the use of plant extracts with larvicidal and adulticidal activities, advanced modern biotechnology techniques, and nanobiotechnology need to be developed. 展开更多
关键词 AEDES ARBOVIRUS insecticide Resistance Molecular and Metabolic Mechanisms AFRICA
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The Entomological Efficacy of Piperonyl Butoxide (PBO) Combined with a Pyrethroid in Insecticide-Treated Nets for Malaria Prevention: A Village-Based Cohort Study Prior to Large-Scale Deployment of New Generation Mosquito Nets in Burkina Faso
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作者 Aristide S. Hien Samina Maiga +9 位作者 Koama Bayili Adissa Y. Ouattara Dieudonné D. Soma Richard Bationo Georges Benson Meda Delphine O. Karama Tiecoura Camara Georges Anicet Ouedraogo Roch K. Dabiré Abdoulaye Diabaté 《Advances in Entomology》 2024年第3期224-248,共25页
The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that in... The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance. 展开更多
关键词 Pyrethroid Resistance Permethrin + PBO ITNs Permethrin ITN Bionomic Data insecticide Susceptibility Data Burkina Faso
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Insecticidal Activities of Extracts from Brucea javanica (L.) Merr. Callus 被引量:4
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作者 曾宪儒 曾涛 +1 位作者 黎柳锋 韩美丽 《Agricultural Science & Technology》 CAS 2008年第4期141-143,共3页
[Objective] The research aimed to lay a foundation for the screening of cell lines producing secondary metabolites of Brucea javanica(L.)Merr.[Method] The insecticidal activities of the extracts from branch and 3 diff... [Objective] The research aimed to lay a foundation for the screening of cell lines producing secondary metabolites of Brucea javanica(L.)Merr.[Method] The insecticidal activities of the extracts from branch and 3 different types of calluses of Brucea javanica(L.)Merr.was detected through methods of leaf disc and potted seedlings against the diamond back moth.[Result] Extracts from four kinds of Brucea javanica(L.)Merr.tissues assumed both the activities of antifeedant and oviposition deterrency against the diamond back moth.Antifeedant effect of extracts was in turn the callus C< callus B< callus A< branches.Oviposition deterrency activity of the extracts was in turn the callus A> branch > callus B>callus C.The insecticidal activities of callus A and B were higher than that of the callus C.[Conclusion] The results show that insecticidal activity of callus and its growth rate is inversely proportional. 展开更多
关键词 Brucea javanica(L.)Merr. CALLUS insecticidal ACTIVITIES Plutella XYLOSTELLA L.
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Synthesis and Insecticidal Activity of Derivants of 3,13-Ester Mesaconitine 被引量:5
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作者 王晓东 袁小红 +3 位作者 杨海君 侯大斌 王惠 许源 《Agricultural Science & Technology》 CAS 2009年第3期3-6,共4页
[Objective] The experiment aimed to explore the relations between structure of aconitine, aconitine derivatives and insecticide. [Method] The aconitine derivatives such as 3-acetyl mesaconitine, 3-propionyl mesaconiti... [Objective] The experiment aimed to explore the relations between structure of aconitine, aconitine derivatives and insecticide. [Method] The aconitine derivatives such as 3-acetyl mesaconitine, 3-propionyl mesaconitine, 3-acetyl-13-Benzoyl-mesaconitine and 3-propionyl-13-Benzoyl-mesaconitine were synthesized by mesaconitine with acetic anhydride or propionic anhydride and their insecticidal activities were also determined. [Result] When the concentration was 500 mg/L, the insecticidal activities of mesaconitine against Nilaparvata legen and Aphis were 50% and 30% respectively while the insecticidal activities of 3-acetyl mesaconitine, 3-propionyl mesaconitine, 3-acetyl-13-Benzoyl-mesaconitine and 3-propionyl-13-Benzoyl-mesaconitine against Aphis medicagini were 40%, 30%, 30% and 20% respectively at 500 mg/L. [Conclusion] After hydroxyl esterification, the insecticidal activity of mesaconitine was declined and the existence of hydroxyl at 3rd position in mesaconitine played very important influences on insecticidal activity. 展开更多
关键词 MESACONITINE DERIVATIVE STRUCTURE insecticidal activity
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Insecticidal Activities of Alkaloids Extracted from Poisonous Plants
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作者 刘海峰 全炳武 李翔国 《Plant Diseases and Pests》 CAS 2010年第6期64-67,共4页
[Objective] Insecticidal activities of alkaloids extracted from 12 poisonous plants in Changbai Mountain were studied in the paper,to provide the basis for development and utilization of poisonous plants in Changbai M... [Objective] Insecticidal activities of alkaloids extracted from 12 poisonous plants in Changbai Mountain were studied in the paper,to provide the basis for development and utilization of poisonous plants in Changbai Mountain.[Method] Leaf disc method was used to study the effects of alkaloids extracted from 12 poisonous plants on the growth and development of 3-5 instars of cabbage worm (Pieris rapae) and their antifeedant activities.[Result] The effects of alkaloids extracted from different poisonous plants on the growth and development of cabbage worm were also different.Five treatments of alkaloids extracted from Sophora flavescens,Datura stramonium L.,Arisaema amurense Maxim.,Veratum dahuricum Loes.and Tripterygium regelii Spragne et Takeda made the weight of test insects gradually decrease and finally die;the alkaloid treatments of Pueraria lobata (Willd.) Ohwi,Aconitum kusnezoffii Reichb.,Cimicifuga dahurica (Turcz.) Maxim.and Corydalis ambigua Schleeht.could make cabbage worm pupate ahead of time,but the pupa state was deformed;the antifeedant rates of cabbage worm after the treatments of P.lobata,A.kusnezoffii,C.dahurica,A.amurense,V.dahuricum and C.ambigua for 48 h were all over 90%,and the antifeedant rates of C.dahurica and C.ambigua were the highest as 100%.[Conclusion]The reports on the insecticidal activities of five poisonous plants including P.lobata,A.kusnezoffii,C.dahurica,C.ambigua and A.amurense are rare,and they have important values on the development of botanical pesticides. 展开更多
关键词 Poisonous plant ALKALOID insecticidal activity Antifeedant rate
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