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Isolation performances and optimization of triple quasi-zero stiffness isolators

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 124-141页

作者： Yuntian Zhang Guangnan Zhu qingjie cao School of Astronautics Harbin Institute of TechnologyHarbin 150001China

In this paper,triple quasi-zero stiffness(QZS)passive vibration isolators whose restoring force curve has a three-stage softening effect are proposed.Multi-coupled SD oscillators with three independent geometrical parameters are used as negative stiffness mechanisms to achieve QZS characteristics at the origin and symmetrical positions on both sides of the origin.Isolation performances of different triple QZS isolators are analyzed to show influences of the selection of QZS regions away from the origin on the range of isolation regions.Pareto optimizations of system parameters are carried out to get a larger range of small restoring force regions and small stiffness regions.Isolation performances of two triple QZS isolators are discussed to show the influence of different Pareto optimization solutions through the comparisons with single and double QZS isolators.Results showed that triple QZS isolators have both the advantages of single and double QZS isolators which results in better isolation performances under both small and large excitation amplitudes.An improvement in isolation performances for triple QZS isolators is found with the decrease in average stiffness due to the appearance of two symmetrical QZS regions away from the origin.Larger displacements of QZS regions away from the origin result in better isolation performances when excitation amplitude is large,and triple QZS characteristics are similar to double QZS isolators at this time.Smaller restoring forces of QZS regions away from the origin lead to better isolation performances when excitation amplitude is small,and triple QZS characteristics are similar to single QZS isolators at this moment.Compared with the decrease in average stiffness,the improvement of isolation performances shows a hysteresis phenomenon due to the difference between static and dynamic characteristics.

关键词： triple quasi-zero stiffness vibration isolation Pareto optimization force transmissibility geometrical nonlinear

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Effects of simulated gut pH environment on bacterial composition and pheromone production of Dendroctonus valens

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Insect Science 2024年第1期31卷 225-235页

作者： qingjie cao Yu Zhao Tuuli-Marjaana Koski Huiping Li Jianghua Sun College of Forestry Hebei Agricultural UniversityBaodingHebei ProvinceChina State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina College of Life Science/Hebei Basic Science Center for Biotic Interactions Institute of Life Science and Green DevelopmentHebei UniversityBaodingHebei ProvinceChina

Bark beetles are an economically and ecologically important insect group,with aggregation behavior and thus host colonization success depends on pheromone-mediated communication.For some species,such as the major invasive forest pest in China,red turpentine beetle(Dendroctonus valens),gut microbiota participates in pheromone production by converting tree monoterpenes into pheromone products.However,how variation in gut microenvironment,such as pH,affects the gut microbial composition,and consequently pheromone production,is unknown.In this study,we fed wild caught D.valens with 3 different pH media(main host diet with natural pH of 4.7;a mildly acidic diet with pH 6 mimicking the beetle gut pH;and highly acidic diet with pH 4),and measured their effects on the gut pH,bacterial community and production of the main aggregation and anti-aggregation pheromone(verbenone).We further tested the verbenone production capacity of 2 gut bacterial isolates in different pH environments(pH 6 and 4).Compared to natural state or main host diet,feeding on less acidic diet(pH 6)diluted the acidity of the gut,whereas feeding on highly acidic diet(pH 4)enhanced it.Both changes in gut pH reduced the abundance of dominant bacterial genera,resulting in decreased verbenone production.Similarly,the highest pheromone conversion rate of the bacterial isolates was observed in pH mimicking the acidity in beetle gut.Taken together,these results indicate that changes in gut pH can affect gut microbiota composition and pheromone production,and may therefore have the potential to affect host colonization behavior.

关键词： Dendroctonus valens gut bacteria gut pH verbenone

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The effect of inactivation of aldehyde dehydrogenase on pheromone production by a gut bacterium of an invasive bark beetle,Dendroctonus valens

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Insect Science 2023年第2期30卷 459-472页

作者： qingjie cao Tuuli-Marjaana Koski Huiping Li Chi Zhang Jianghua Sun College of Forestry Hebei Agricultural UniversityBaodingHebei ProvinceChina College of Life Science Institute of Life Science and Green DevelopmentHebei UniversityBaodingHebei ProvinceChina State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina Rural Energy and Environment Agency Ministry of AgricultureandRural AffairsBeijingChina

Semiochemical-based management strategies are important for controlling bark beetles,such as invasive Red Turpentine Beetle(Denroctonus valens),the causal agent for mass mortality of pine trees(Pinus spp.)in China.It has been previously shown that the pheromone verbenone regulates the attack density of this beetle in a dose-dependent manner and that the gut bacteria of D.valens are involved in verbenone production.However,molecular functional verification of the role of gut bacteria in the pheromone production of D.valens is still lacking.To better understand the molecular function of gut bacterial verbenone production,we chose a facultative anaerobic gut bacterium(Enterobacter xiangfangensis)of D.valens based on its strong ability to convert cis-verbenol to verbenone,as shown in our previous study,and investigated its transcriptomics in the presence or absence of cis-verbenol under anaerobic conditions(simulating the anoxic environment in the beetle's gut).Based on this transcriptome analysis,aldehyde dehydrogenase(ALDH1)was identified as a putative key gene responsible for verbenone production and was knocked-down by homologous recombination to obtain a mutant E.xiangfangensis strain.Our results show that these mutants had significantly decreased the ability to convert the monoterpene precursor to verbenone compared with the wild-type bacteria,indicating that ALDH1 is primarily responsible for verbenone conversion for this bacterium species.These findings provide further mechanistic evidence of bacterially mediated pheromone production by D.valens,add new perspective for functional studies of gut bacteria in general,and may aid the development of new gene silencing-based pest management strategies.

关键词： aldehyde dehydrogenase Dendroctonus valens gut bacteria mutants transcriptome verbenone

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Development of an Integrated Disposable Device for SARSCoV-2 Nucleic Acid Extraction and Detection

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Biomedical and Environmental Sciences 2024年第6期37卷 639-646页

作者： Jing Ma Yanzhe Hao Meiling Hou Xiaoshan Zhang Jingduan Liu Haodi Meng Jiangbo Chang Xuejun Ma Jihua Liu qingjie Ying Xianhua Wang Hongxia Li Yuxi cao Xiaoguang Zhang National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China Beijing Runbio Biotechnology Development Co. LtdBeijing 100106China Beijing Beta Technology Co. LtdBeijing 101318China Jiangsu Qitian Gene Biotechnology Co. LtdWuxi 214135JiangsuChina

Objective To develop a highly sensitive and rapid nucleic acid detection method for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods We designed,developed,and manufactured an integrated disposable device for SARS-CoV-2 nucleic acid extraction and detection.The precision of the liquid transfer and temperature control was tested.A comparison between our device and a commercial kit for SARS-Cov-2 nucleic acid extraction was performed using real-time fluorescence reverse transcription polymerase chain reaction(RT-PCR).The entire process,from SARS-CoV-2 nucleic acid extraction to amplification,was evaluated.Results The precision of the syringe transfer volume was 19.2±1.9μL(set value was 20),32.2±1.6(set value was 30),and 57.2±3.5(set value was 60).Temperature control in the amplification tube was measured at 60.0±0.0°C(set value was 60)and 95.1±0.2°C(set value was 95)respectively.SARS-Cov-2 nucleic acid extraction yield through the device was 7.10×10^(6) copies/mL,while a commercial kit yielded 2.98×10^(6) copies/mL.The mean time to complete the entire assay,from SARS-CoV-2 nucleic acid extraction to amplification detection,was 36 min and 45 s.The detection limit for SARS-CoV-2 nucleic acid was 250 copies/mL.Conclusion The integrated disposable devices may be used for SARS-CoV-2 Point-of-Care test(POCT).

关键词： An integrated disposable device SARS-Cov-2 Nucleic acid detection

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Bifurcation and dynamic response analysis of rotating blade excited by upstream vortices

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Applied Mathematics and Mechanics(English Edition) 2016年第9期37卷 1251-1274页

作者： Dan WANG Yushu CHEN M.WIERCIGROCH qingjie cao School of Astronautics Harbin Institute of Technology Centre for Applied Dynamics Research School of Engineering University of AberdeenKing's College

A reduced model is proposed and analyzed for the simulation of vortexinduced vibrations （VIVs） for turbine blades. A rotating blade is modelled as a uniform cantilever beam, while a van der Pol oscillator is used to represent the time-varying characteristics of the vortex shedding, which interacts with the equations of motion for the blade to simulate the fluid-structure interaction. The action for the structural motion on the fluid is considered as a linear inertia coupling. The nonlinear characteristics for the dynamic responses are investigated with the multiple scale method, and the modulation equations are derived. The transition set consisting of the bifurcation set and the hystere- sis set is constructed by the singularity theory and the effects of the system parameters, such as the van der Pol damping. The coupling parameter on the equilibrium solutions is analyzed. The frequency-response curves are obtained, and the stabilities are determined by the Routh-Hurwitz criterion. The phenomena including the saddle-node and Hopf bifurcations are found to occur under certain parameter values. A direct numerical method is used to analyze the dynamic characteristics for the original system and verify the va- lidity of the multiple scale method. The results indicate that the new coupled model is useful in explaining the rich dynamic response characteristics such as possible bifurcation phenomena in the VIVs.

关键词： vortex-induced vibration van der Pol oscillator dynamic response tran-sition set singularity theory bifurcation phenomenon

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Volatiles produced by bacteria alleviate antagonistic effects of one associated fungus on Dendroctonus valens larvae

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Science China(Life Sciences) 2017年第8期60卷 924-926页

作者： Shanshan Wang Fangyuan Zhou Bo Wang Dandan Xu qingjie cao Min Lu Jianghua-Sun State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute of Health Sciences Anhui UniversityHefei 230039China Shandong Provincial Key Laboratory of Applied Microbiology Ecology InstituteShandong Academy of SciencesJinan 250014China Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesXishuangbanna 666303China

Dear Editor,Microbes play important roles in various symbiotic systems(Douglas,2015;Xing et al.,2017;Zhu and Wu,2016;Xu et al.,2016a).In the symbiosis formed by bark beetles and microbial associates,beetles formed symbiotic relationships with some fungi including mutualistic and antagonistic ones(Cheng et al.,2015;Lu et al.,2016;Scott et al.,2008),and these interactions,indirectly affected by a third or even fourth participator in a community context,may change from antagonistic ones to mutualistic ones.For example,associated bacterial volatiles can alleviate antagonistic

关键词：拮抗作用挥发物 Douglas 细菌真菌幼虫共生系统共生关系

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基于双流Transformer结构的多能计算机断层扫描成像投影数据去噪方法

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激光与光电子学进展 2024年第8期61卷 399-408页

作者：欧阳顺馨史再峰孔凡宁张丽丽曹清洁天津大学微电子学院天津300072 天津师范大学数学科学学院天津300387 天津市成像与感知微电子技术重点实验室天津300072

多能计算机断层扫描(Computed tomography,CT)技术可以更加精确地分辨出人体组织对不同能量X射线光子的吸收情况,是医学成像领域的重要发展方向。为了解决因量子噪声等非理想效应加重导致重建图像质量急剧退化的问题,提出了一种基于移... 详细信息

多能计算机断层扫描(Computed tomography,CT)技术可以更加精确地分辨出人体组织对不同能量X射线光子的吸收情况,是医学成像领域的重要发展方向。为了解决因量子噪声等非理想效应加重导致重建图像质量急剧退化的问题,提出了一种基于移位窗口多头自注意力机制的双流Transformer网络结构。该结构利用移位窗口Transformer和局部增强窗口Transformer分别提取投影数据的全局和局部特征,充分利用投影数据的非局部自相似性以保留投影数据的内部结构;然后通过残差卷积融合提取的特征;最后使用带有非局部全变分的混合损失函数来监督网络模型的训练,提升该网络模型对投影数据内部细节的敏感程度。实验结果表明,所提方法处理后的重建图像峰值信噪比(PSNR)值、结构相似性(SSIM)值和特征相似度(FSIM)值分别达到37.7301 dB、0.9944和0.9961。与目前先进的多能CT去噪方法相比,所提方法在去除低剂量多能CT投影数据噪声的同时,可保留更多的细节特征,有利于后续的精确诊断。

关键词：图像处理计算机断层扫描成像低剂量卷积神经网络 Transformer网络

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妊娠期糖尿病对母鼠肠道菌群的影响

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中国微生态学杂志 2024年第4期36卷 408-413页

作者：曹少锋范青杰李明王业忠梅璐郑州大学第五附属医院消化内科河南郑州450014 大连医科大学基础医学院微生态学教研室

目的探究母鼠妊娠期糖尿病(gestational diabetes mellitus,GDM)对其肠道微生态的影响,从微生物角度对GDM的早期预防与早期治疗提供参考。方法利用高脂饮食联合腹腔注射链脲佐菌素构建GDM模型,采用16S rRNA基因高通量测序技术剖析GDM... 详细信息

目的探究母鼠妊娠期糖尿病(gestational diabetes mellitus,GDM)对其肠道微生态的影响,从微生物角度对GDM的早期预防与早期治疗提供参考。方法利用高脂饮食联合腹腔注射链脲佐菌素构建GDM模型,采用16S rRNA基因高通量测序技术剖析GDM对妊娠期母鼠肠道微生态的影响。结果 GDM造模后,母鼠肠道菌群发生显著改变,肠道菌群物种多样性显著增加,肠道中厚壁菌门和拟杆菌门比例显著降低,乳杆菌和链球菌相对丰度有下降的趋势,Dubosiella、 Lachnospiraceae_NK4A136_group和Allobaculum等多种条件致病菌丰度有增加的趋势。结论 GDM会导致妇女肠道微生态失衡,增加机体血糖代谢负担,需及时监测和采取有效的干预措施。

关键词：妊娠期糖尿病肠道菌群母鼠 16S rRNA高通量测序

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基于高密度电测法的西沙东岛地下淡水透镜体识别

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资源科学 2024年第3期46卷 635-646页

作者：韩冬梅曹国亮蔡砥柱宋献方邢子浩孟庆杰中国地质调查局海口海洋地质调查中心海口571127 中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室北京100101 中国科学院大学资源与环境学院北京100049 中国地质大学(北京)水利部地下水保护重点实验室(筹) 北京100083 中国地质大学(北京)水资源与环境学院北京100083

[目的]珊瑚岛地下淡水透镜体是维持岛上居民生产生活、生态涵养所必需的重要资源。准确识别珊瑚岛地下淡水透镜体的形态,揭示地下淡水补给机制,是珊瑚岛地下水资源评价的重要基础,对实现科学管理海岛地下水资源至关重要。[方法]本文以... 详细信息

[目的]珊瑚岛地下淡水透镜体是维持岛上居民生产生活、生态涵养所必需的重要资源。准确识别珊瑚岛地下淡水透镜体的形态,揭示地下淡水补给机制,是珊瑚岛地下水资源评价的重要基础,对实现科学管理海岛地下水资源至关重要。[方法]本文以西沙群岛的东岛为研究对象,结合水文地质调查,对高密度电阻率法实测剖面数据进行反演解译,基于电阻率和地下水总溶解固体浓度关系识别了咸淡水界面。[结果]①根据高密度电阻率法反演电阻率首次识别了西沙东岛地下淡水透镜体发育特征,该方法在西沙珊瑚岛具有较好的适用性;②东岛淡水透镜体主要发育于岛屿西北和南侧沙堤,厚度较薄,仅3~7m,局部地区甚至无地下淡水;③东岛地下咸淡水界面形态说明沙堤以内植被根系吸水是造成淡水透镜体较薄的主要原因,植被分布对东岛地下淡水资源具有重要影响。[结论]在保护西沙珊瑚岛生态系统的前提下,适当减少人工椰树林种植面积,可有效增加岛屿降雨形成的地下淡水资源,有利于发挥珊瑚岛地下淡水透镜体对岛屿水安全的保障作用。

关键词：珊瑚岛淡水透镜体高密度电法咸淡水界面西沙东岛

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锥辊平盘形立磨的辊套夹角和R角对工况的影响分析

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水泥 2024年第3期 59-61页

作者：曹庆杰王双志张伯超康春生冀东水泥滦州有限责任公司河北唐山063708 唐山冀东水泥股份有限公司河北唐山064000

在熟料单位产品综合电耗中,原料系统占比在1/3以上,电耗的影响很多,其中锥辊平盘形立磨辊套大端外R角半径如果没有进行合理定制,会导致粉磨设备效率未达最佳状态,造成熟料单位产品综合电耗上升。本文就滦州公司辊套小端夹角在15°、13... 详细信息

在熟料单位产品综合电耗中,原料系统占比在1/3以上,电耗的影响很多,其中锥辊平盘形立磨辊套大端外R角半径如果没有进行合理定制,会导致粉磨设备效率未达最佳状态,造成熟料单位产品综合电耗上升。本文就滦州公司辊套小端夹角在15°、13°和大端外R角半径在R40、R80、R60时,粉磨做功效率、能耗方面和相关选型因素的一些研究与实践工作进行了叙述、总结。

关键词：立磨辊套R角辊套夹角工况

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