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Suppression of pheromone biosynthesis and mating behavior by RNA interference of pheromone gland-specific fatty acyl reductase in Maruca vitrata

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Insect Science 2022年第4期29卷 1135-1144页

作者： Wook Hyun cha Dae-Weon Lee Department of Biosafety Kyungsung UniversityBusanRepublic of Korea Metabolomics Research Center for Functional Materials Kyungsung UniversityBusanRepublic of Korea

In moths,various enzymes,such as fatty acid synthases,fatty acyl desaturases,and fatty acyl reductases(FARs),are involved in pheromone *** particular,pheromone gland-specific FAR(pgFAR)plays an important role in converting the functional group from carboxylic to alcohol during pheromone biosynthesis.A novel pgFAR of Maruca vitrata,Mvi-pgFAR,was identified through transcriptome sequencing of its pheromone *** investigate the involvement of Mvi-pgFAR in pheromone biosynthesis,Mvi-pgFAR was cloned from the pheromone gland and suppressed by RNA interference(RNAi).Mvi-pgFAR harbored several conserved motifs related to NAD(P)H-binding,N-glycosylation,and adenosine/guanosine triphosphate *** analysis revealed that Mvi-pgFAR with other lepidopteran pgFARs formed an independent ***-pgFAR was specifically expressed only in the pheromone *** real-time polymerase chain reaction showed that the diurnal expression levels of Mvi-pgFAR in the pheromone gland were the highest at 2 h before the *** primarily confirming Mvi-pgFAR suppression by RNAi,(E,E)-10,12-hexadecadienal(E10E12-16:Ald),a major sex pheromone component,was quantified by gas *** Mvi-pgFAR was successfully suppressed,E10E12-16:Ald production was reduced by up to half of that of the control,and the mating rate was subsequently *** results demonstrate that Mvi-pgFAR downregulation can suppress mating behavior by changing the relative sex pheromone component ratio,suggesting that Mvi-pgFAR can be used as a novel control target.

关键词： (EE)-10,12-hexadecadienal gas chromatography Maruca viruta pgFAR RNAi sex pheromone

Mechanical properties of cotton fabric reinforced geopolymer composites at 200-1000℃

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Journal of Advanced Ceramics 2014年第3期3卷 184-193页

作者： Thamer ALOMAYRI les VICKERS Faiz U.A.SHAIKH It-Meng LOW Department of Imaging&Applied Physics Curtin UniversityGPO Box U1987PerthWA 6845Australia Department of Physics Umm Al-Qura UniversityMakkah 21955Saudi Arabia Department of Civil Engineering Curtin UniversityGPO Box U1987PerthWA 6845Australia

Geopolymer composites containing woven cotton fabric(0-8.3 wt%)were fabricated using the hand lay-up technique,and were exposed to elevated temperatures of 200℃,400℃,600℃,800℃and 1000℃.With an increase in temperature,the geopolymer composites exhibited a reduction in compressive strength,flexural strength and fracture *** heated above 600℃,the composites exhibited a significant reduction in mechanical *** also exhibited brittle behavior due to severe degradation of cotton fibres and the creation of additional porosity in the *** images verified the existence of voids and small channels in the composites due to fibre degradation.

关键词： geopolymer composites microstructures mechanical properties fracture toughness

干旱胁迫对白枪杆幼苗生长生物量及C、N、P化学计量特征的影响

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四川农业大学学报 2024年第2期42卷 397-404页

作者：张梅叶澜李树萍茶晓飞董琼西南林业大学西南地区生物多样性保育国家林业和草原局重点实验室/西南山地森林资源保育与利用教育部重点实验室昆明650224

【目的】研究不同干旱胁迫程度对白枪杆幼苗生长、生物量积累与分配,以及不同器官C、N、P积累与分配,探究白枪杆对不同干旱环境的适应性。【方法】以1 a生白枪杆幼苗实生苗为试验材料,研究干旱胁迫处理分别是对照(CK)、轻度干旱胁迫(LS... 详细信息

【目的】研究不同干旱胁迫程度对白枪杆幼苗生长、生物量积累与分配,以及不同器官C、N、P积累与分配,探究白枪杆对不同干旱环境的适应性。【方法】以1 a生白枪杆幼苗实生苗为试验材料,研究干旱胁迫处理分别是对照(CK)、轻度干旱胁迫(LS)、中度干旱胁迫(MS)和重度干旱胁迫(SS)对白枪杆幼苗生长、生物量的积累量与分配、根冠比、各器官C、N、P含量及化学计量特征的分析和各器官C、N、P的积累和分配规律等指标测定。【结果】随干旱胁迫程度的上升,白枪杆幼苗的苗高和地径的增长量显著降低(P<0.05)。叶片、茎和根的生物量及总生物量、叶片生物量占比降低,茎和根生物量占比和根冠比降低。白枪杆幼苗C、N和P的积累量随干旱胁迫程度的上升呈下降趋势;与适宜的水分处理相比,白枪杆幼苗各器官的C∶N均呈先下降后上升的趋势,叶片和根的C∶P呈先下降后上升的趋势;白枪杆幼苗各器官N∶P低于14,表明生长主要受N限制。【结论】白枪杆幼苗生长及生物量和C、N、P含量及化学计量特征对不同干旱胁迫程度的响应有差异,主要表现在随干旱胁迫程度的上升,白枪杆幼苗的苗高、地径增长量呈下降趋势,生物量的分配也倾向于地下部分,干旱胁迫处理下不利于白枪杆幼苗的生长,生物量的积累减少,C、N和P的积累量降低。

关键词：白枪杆干旱生长 C∶N∶P 适应策略

基于FDM的PTFE/PEEK多孔轴承保持架材料制备与摩擦学性能研究

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塑料科技 2024年第6期52卷 16-21页

作者：王文文刘洁赵训茶汤超刘鹏山东劳动职业技术学院山东济南250022 山西农业大学信息科学与工程学院山西晋中030800 山东省农业科学院山东济南250100

采用熔融沉积成型(FDM)工艺制备了聚四氟乙烯/聚醚醚酮(PTFE/PEEK)二元复合多孔材料,并围绕材料的微观结构与宏观摩擦学性能及二者之间的映射机制展开研究。结果表明:基于FDM工艺制备的PTFE/PEEK多孔材料成孔效果良好且随着NaCl质量分... 详细信息

采用熔融沉积成型(FDM)工艺制备了聚四氟乙烯/聚醚醚酮(PTFE/PEEK)二元复合多孔材料,并围绕材料的微观结构与宏观摩擦学性能及二者之间的映射机制展开研究。结果表明:基于FDM工艺制备的PTFE/PEEK多孔材料成孔效果良好且随着NaCl质量分数提高,多孔试样的孔隙更为密集。PTFE/PEEK多孔材料的含油率与孔隙率变化成正比,NaCl质量分数为53%时,材料的油保持率最高,所有试样的油保持率均高于90%。干摩擦条件下,PTFE的加入在一定程度上改善了材料的摩擦学性能;贫油润滑状态下,NaCl含量为63%的6#试样摩擦系数最低,多孔结构的供油、含油能力与PTFE的润滑性相结合,可赋予复合材料优异的摩擦学性能。本研究为PEEK基多孔轴承保持架材料的成型与应用提供了参考。

关键词：轴承保持架熔融沉积成型聚醚醚酮聚四氟乙烯摩擦学性能

Alarm cue induces an antipredator morphological defense in juvenile Nicaragua cichlids Hypsophrys nicaraguensis

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Current Zoology 2010年第1期56卷 36-42页

作者： Maria E.ABATE Andrew G. ENG les KAUFMAN Department of Biology Boston University Department of Neurosurgery University of Pennsylvania

Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficient to also induce morphological defenses has received little attention. Cichlids are characterized by a high level of morphological plasticity during development, and the few species that have been tested do exhibit defensive behaviors when exposed to alarm cues released from the damaged skin of conspecifics. We utilized young juvenile Nicaragua cichlids Hypsophrys nicaraguensis to test if the perception of predation risk from alarm cue （conspecific skin extract） alone induces an increased relative body depth which is a defense against gape-limited predators. After two weeks of exposure, siblings that were exposed to conspecific alarm cue increased their relative body depth nearly double the amount of those exposed to distilled water （control） and zebrafish Danio rerio alarm cue. We repeated our measurements over the last two weeks （12 and 14） of cue exposure when the fish were late-stage juveniles to test if the rate of increase was sustained; there were no differences in final dimensions between the three treatments. Our results show that 1） the Nicaragua cichlid has an innate response to conspecific alarm cue which is not a generalized response to an injured fish, and 2） this innate recognition ultimately results in developing a deeper body at a stage of the life history where predation risk is high [Current Zoology 56 （1）： 36-42, 2010].

关键词： Alarm substance Inducible defense Phenotypic plasticity Cichlid Chemical cue Antipredator

Recent progress on in situ characterizations of electrochemically intercalated transition metal dichalcogenides

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Nano Research 2019年第9期12卷 2126-2139页

作者： Sajad Yazdani Milad Yarali Judy J. cha Department of Mechanical Engineering and Materials Science Yale UniversityNew HavenCT 06511USA Energy Sciences Institute Yale University West CampusWest HavenCT 06516USA

Layered transition metal dichalcogenides(TMDCs)have been extensively studied owing to their unique physical and chemical *** van der Waals(vdW)interact!ons betwee n the stacki ng layers of TMDCs allow intercalati on of various species including mono vale nt alkali,divale nt alkaline earth and multivale nt metal ions,zero-vale nt transiti on metals,as well as orga nic molecules,all of which can drastically alter fun dame ntal properties of the *** urge to understa nd the phe nomena and the desire to exploit them for applicati ons have inspired a great deal of investigations.A large portion of the mystery has been unveiled over the past decade of intense research;however,many questions remain open and require further *** review is concerned with investigations on structural and electronic evolution of TMDCs drive n by electrochemically con trolled in tercalati ***,we aim to survey the rece nt adva nces and experime ntal platforms for mon itoring the in tercalati on processes in situ by utilizi ng nano *** additi on,several in quiries and prospects are outlined in a broader con text for future ave nues of studies.

关键词： transition metal dichalcogenides electrochemical intercalation in situ characterizations transmission electron microscopy(TEM) magnetotransport measurements

Do farmers care about climate change? Evidence from five major grain producing areas of China

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Journal of Integrative Agriculture 2019年第6期18卷 1402-1414页

作者： SONG Chun-xiao LIU Rui-feng les Oxley MA Heng-yun College of Economics and Management Henan Agricultural UniversityZhengzhou 450002P.R.China Department of Economics and Finance University of WaikatoHamilton 3240New Zealand

Using a logistic model,this paper empirically investigated farmers’perception of climate change and its determinants based on a field survey of 1 350 rural households across five major grain producing provinces in *** results show:i)There is an apparent difference in perception levels for long-term temperature and precipitation ***,57.4%of farmers perceived the long-term temperature change correctly,but only 29.7%of farmers perceived the long-term precipitation change correctly;ii)The factors influencing the farmers’perceptions are almost completely different between precipitation and temperature,the former are mostly agriculture related,while latter are mostly non-agriculture related,except for farm size;and iii)Farmers are not expected to pay more attention to long-term precipitation changes over the crop growing seasons,because less than 30%of farmers can correctly perceive long-term precipitation ***,to improve the accuracy of farmers’perceptions of climate change,the government is recommended to:i)enhance education and training programs;ii)speed up land transfer and expand household land farm size;iii)develop farmer cooperative organizations;iv)invest more in agricultural infrastructure,specifically in major grain producing regions;and v)improve the agricultural environment and increase farming income.

关键词： China major grain producing areas determinants climate change perception irrigation areas

“Standby” EMT and “immune cell trapping” structure as novel mechanisms for limiting neuronal damage after CNS injury

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Neural Regeneration Research 2014年第23期9卷 2032-2035页

作者： Jong-Ho cha Kyu-Won Kim SNU-Harvard Neuro Vascular Protection Research Center College of Pharmacy Seoul National University Department of Molecular Medicine and Biopharmaceutical Sciences Graduate School of Convergence Science and Technology and College of Medicine or College of PharmacySeoul National University

The central nervous system （CNS） contains the two most important organs, the brain and spinal cord, for the orchestration of the mental and physical activities of life. Because of its importance, the human body has evolved barrier systems to protect CNS tissue from the external environment. This barrier is a membrane composed of tightly apposed cells and is selectively permeable to specific molecules by way of membrane transporters.

关键词： EMT and immune cell trapping Standby CNS structure as novel mechanisms for limiting neuronal damage after CNS injury cell

Physical investigation on the behaviours of voussoir beams

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 516-527页

作者： chaoshi Hu Derek Apel les Jozef Sudak Wei Victor Liu Zhaoyuan Chu School of Mining and Petroleum Engineering Department of Civil and Environmental EngineeringUniversity of AlbertaEdmontonT6G 1H9Canada Department of Mechanical and Manufacturing Engineering University of CalgaryCalgaryT2N 1N4Canada Anhui Yitong Construction Consulting and Management Ltd.YuexiAnqing246000China

It is important to understand the behaviour of voussoir beams in the design of underground *** are a large number of discrepancies between the re sults obtained by differe nt researchers so *** resolve these discrepancies,physically testing the stress distribution at the mid span and abutment of voussoir beam is the *** this paper,a simple two-block voussoir beam was built with loading *** displacement and strain of the voussoir beam were measured by a digital image correlation *** strain distribution along the joints of voussoir beams was firstly ***,the relationship between transverse load and midspan displacement of voussoir beam was *** is found that the stress distributions at the midspan and abutment are different both in shape and *** stress distribution is changing as the loading changes as well.

关键词： Voussoir beam Stress distribution Image correlation