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Enhanced VOC emission with increased temperature contributes to the shift of O_(3)-precursors relationship and optimal control strategy 被引量:2
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作者 Fangqi Qu Yuanjie Huang +11 位作者 Yemin Shen Genqiang Zhong Yan Xu Lingling Jin Hongtao Qian Chun Xiong Fei Zhang Jiasi Shen Bingye Xu Xudong Tian Zhengning Xu Zhibin Wang 《Journal of Environmental Sciences》 2025年第4期218-229,共12页
Assessing the impact of anthropogenic volatile organic compounds(VOCs)on ozone(O_(3))formation is vital for themanagement of emission reduction and pollution control.Continuousmeasurement of O_(3)and the major precurs... Assessing the impact of anthropogenic volatile organic compounds(VOCs)on ozone(O_(3))formation is vital for themanagement of emission reduction and pollution control.Continuousmeasurement of O_(3)and the major precursorswas conducted in a typical light industrial city in the YRD region from 1 May to 25 July in 2021.Alkanes were the most abundant VOC group,contributing to 55.0%of TVOCs concentration(56.43±21.10 ppb).OVOCs,aromatics,halides,alkenes,and alkynes contributed 18.7%,9.6%,9.3%,5.2%and 1.9%,respectively.The observational site shifted from a typical VOC control regime to a mixed regime from May to July,which can be explained by the significant increase of RO_(x)production,resulting in the transition of environment from NOx saturation to radical saturation with respect to O_(3)production.The optimal O_(3)control strategy should be dynamically changed depending on the transition of control regime.Under NOx saturation condition,minimizing the proportion of NOx in reduction could lead to better achievement of O_(3)alleviation.Under mixed control regime,the cut percentage gets the top priority for the effectiveness of O_(3)control.Five VOCs sources were identified:temperature dependent source(28.1%),vehicular exhausts(19.9%),petrochemical industries(7.2%),solvent&gasoline usage(32.3%)and manufacturing industries(12.6%).The increase of temperature and radiation would enhance the evaporation related VOC emissions,resulting in the increase of VOC concentration and the change of RO_(x)circulation.Our results highlight determination of the optimal control strategies for O_(3)pollution in a typical YRD industrial city. 展开更多
关键词 O_(3)pollution Volatile organic compounds Photochemical box model Source apportionment Optimal O_(3)control strategies
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Machine Learning-Based Online Monitoring and Closed-Loop Controlling for 3D Printing of Continuous Fiber-Reinforced Composites 被引量:1
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作者 Xinyun Chi Jiacheng Xue +6 位作者 Lei Jia Jiaqi Yao Huihui Miao Lingling Wu Tengfei Liu Xiaoyong Tian Dichen Li 《Additive Manufacturing Frontiers》 2025年第2期90-96,共7页
Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exa... Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exacerbates this challenge by rendering the process vulnerable to environmental changes and unexpected factors,resulting in defects and inconsistent product quality,particularly in unmanned long-term operations or printing in extreme environments.To address these issues,we developed a process monitoring and closed-loop feedback control strategy for the 3D printing process.Real-time printing image data were captured and analyzed using a well-trained neural network model,and a real-time control module-enabled closed-loop feedback control of the flow rate was developed.The neural network model,which was based on image processing and artificial intelligence,enabled the recognition of flow rate values with an accuracy of 94.70%.The experimental results showed significant improvements in both the surface performance and mechanical properties of printed composites,with three to six times improvement in tensile strength and elastic modulus,demonstrating the effectiveness of the strategy.This study provides a generalized process monitoring and feedback control method for the 3D printing of continuous fiber-reinforced composites,and offers a potential solution for remote online monitoring and closed-loop adjustment in unmanned or extreme space environments. 展开更多
关键词 Continuous fiber-reinforced composites 3D printing Computer vision Machine learning Defect detection Feedback control
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La_(2)O_(3)、Y_(2)O_(3)协同对Fe/FeAl_(2)O_(4)金属陶瓷显微结构和力学性能的影响
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作者 胡修勇 张福顺 常宏涛 《稀有金属与硬质合金》 北大核心 2026年第1期49-56,82,共9页
基于对稀土协同强化金属陶瓷机制的认知不足问题,本研究通过X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)及电子探针微区分析(EPMA)等,系统探讨了La_(2)O_(3)、Y_(2)O_(3)双掺杂对Fe/FeAl_(2)O_(4)金属陶瓷微观结构以及力学性能的耦合... 基于对稀土协同强化金属陶瓷机制的认知不足问题,本研究通过X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)及电子探针微区分析(EPMA)等,系统探讨了La_(2)O_(3)、Y_(2)O_(3)双掺杂对Fe/FeAl_(2)O_(4)金属陶瓷微观结构以及力学性能的耦合作用。结果表明:La^(3+)优先固溶于FeAl_(2)O_(4)晶格,而Y^(3+)主要富集于晶界形成玻璃网状结构。与未掺杂稀土相比,当La_(2)O_(3)、Y_(2)O_(3)质量分数分别为0.2%和0.5%时,FeAl_(2)O_(4)相的平均晶粒尺寸由28.56 nm降低至27.03 nm。此时材料综合性能最优:相对密度为99.96%,维氏硬度为3766 HV,抗弯强度为138.9 MPa,较未掺杂稀土的样品分别提高4.1%、12.3%和18.6%。机理分析表明,双稀土协同效应促使La-Y-Si-O复合硅酸盐原位生成,La-Y-Si-O相以棒状微晶的形态,通过钉扎效应抑制晶粒粗化,促进相对密度提升,从而提升力学性能。本研究为稀土改性金属陶瓷提供了新的设计策略。 展开更多
关键词 铁基金属陶瓷 稀土协同掺杂 La_(2)O_(3) Y_(2)O_(3) 晶界调控 弥散强化 力学性能
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基于电射流打印的Ti_(3)C_(2)MXene基柔性气体传感器的制备及其性能研究
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作者 王云帆 孙蕾 +3 位作者 王春静 张鹏亚 焦泽霖 张文磊 《化工新型材料》 北大核心 2026年第1期151-155,160,共6页
传统气体传感器加载敏感材料多采用电极表面直接滴涂方式,该方法存在材料加载量难以精确控制、重复性差等问题。为解决上述问题开发了基于电射流打印制备柔性气体传感器的新方法,自主搭建了低成本电射流打印装置,配制了以Ti_(3)C_(2)MX... 传统气体传感器加载敏感材料多采用电极表面直接滴涂方式,该方法存在材料加载量难以精确控制、重复性差等问题。为解决上述问题开发了基于电射流打印制备柔性气体传感器的新方法,自主搭建了低成本电射流打印装置,配制了以Ti_(3)C_(2)MXene材料为基础的功能墨水,讨论了打印条件对Ti_(3)C_(2)MXene基功能墨水打印图形尺寸的影响。在Ti_(3)C_(2)MXene功能墨水中加入气敏材料In_(2)O_(3),在聚对苯二甲酸乙二醇酯柔性叉指电极上通过电射流打印制备了柔性气体传感器并测试了其灵敏度。结果表明:采用0.3%Ti_(3)C_(2)MXene/7%PEO(聚氧化乙烯)溶液作为电射流打印的功能墨水,可以保证在开启电压较小的同时形成分辨率较高的图形;在施加电压2500V,打印距离1mm,注射泵流速300nL/min,基板移动速度300mm/min的锥射流打印条件下,沉积的图形规整有序、直径均匀,尺寸为(2.56±0.32)μm;柔性气体传感器灵敏度较高。 展开更多
关键词 Ti_(3)C_(2)MXene 功能墨水 电射流打印 可控加载 气体传感器
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Monolithically 3D-nanoprinted millimeter-scale lens actuator for dynamic focus control in optical systems
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作者 Florian Lux Aybuke Calikoglu Çağlar Ataman 《Advanced Photonics Nexus》 2025年第4期140-153,共14页
Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found im... Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found important applications in endomicroscopy and biomedical imaging.The potential of this versatile tool for monolithic manufacturing of dynamic micro-opto-electro-mechanical systems(MOEMSs),however,has not yet been sufficiently explored.This work introduces a 3D-nanoprinted lens actuator with a large optical aperture,optimized for remote focusing in miniaturized imaging systems.The device integrates orthoplanar linear motion springs,a self-aligned sintered micro-magnet,and a monolithic lens,actuated by dual microcoils for uniaxial motion.The use of 3D nanoprinting allows complete design freedom for the integrated optical lens,whereas the monolithic fabrication ensures inherent alignment of the lens with the mechanical elements.With a lens diameter of 1.4 mm and a compact footprint of 5.74 mm,it achieves high mechanical robustness at resonant frequencies exceeding 300 Hz while still providing a large displacement range of 200μm(±100μm).A comprehensive analysis of optical and mechanical performance,including the effects of coil temperature and polymer viscoelasticity,demonstrates its advantages over conventional micro-electro-mechanical system actuators,showcasing its potential for next-generation imaging applications. 展开更多
关键词 micro-electro-mechanical system scanner two-photon polymerization 3D nanoprinting dynamic focus control electromagnetic actuation
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超高温等离子体热处理调控Al_(2)O_(3)-TiCN复合陶瓷刀具表面形貌及力学性能的研究
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作者 钟世凯 刘玥 +2 位作者 毛新涛 韩泉泉 宰守刚 《工具技术》 北大核心 2026年第2期21-29,共9页
提出一种基于大功率强磁旋热等离子体(MRTP)超高温装备的新型高温瞬态处理技术,利用其快速升温与超高温场特性,对Al_(2)O_(3)-TiCN复合陶瓷车刀片进行高温短时热处理(1900℃~2150℃,15~60 s),探究表面形貌演化、致密化行为及其与力学性... 提出一种基于大功率强磁旋热等离子体(MRTP)超高温装备的新型高温瞬态处理技术,利用其快速升温与超高温场特性,对Al_(2)O_(3)-TiCN复合陶瓷车刀片进行高温短时热处理(1900℃~2150℃,15~60 s),探究表面形貌演化、致密化行为及其与力学性能的关联。结合SEM、XRD与力学性能及密度测试,揭示等离子体能量输入对相变行为及缺陷演化的协同作用规律。结果表明:通过超高温等离子技术表面处理Al_(2)O_(3)-TiCN复合陶瓷刀片,工艺参数为1900℃-30 s时,复合陶瓷刀具材料的综合性能最好,处理后试样断裂韧性K_(IC)为9.68 MPa·m^(1/2),提升40.5%,而维氏硬度HV为23.11 GPa,基本无衰减。研究结果为等离子体改性技术在陶瓷刀具中的应用提供了理论与实验依据。 展开更多
关键词 超高温等离子体 Al_(2)O_(3)-TiCN复合陶瓷 表面形貌调控
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长三角地区PM_(2.5)和O_(3)健康风险及其联防联控分区研究
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作者 宋晓伟 韩越梅 +5 位作者 郝永佩 程鹏 朱晓东 孔媛 高宁馨 李思思 《环境科学研究》 北大核心 2026年第2期493-505,共13页
为评估长三角地区PM_(2.5)和O_(3)短期暴露的健康风险,并破解区域复合污染联防联控精准分区管理的难题,本文分析了2015−2023年长三角地区PM_(2.5)和O_(3)污染特征及其健康风险,并通过量化复合污染健康指数(CPHI),构建了以城市为节点、... 为评估长三角地区PM_(2.5)和O_(3)短期暴露的健康风险,并破解区域复合污染联防联控精准分区管理的难题,本文分析了2015−2023年长三角地区PM_(2.5)和O_(3)污染特征及其健康风险,并通过量化复合污染健康指数(CPHI),构建了以城市为节点、以城市间复合污染的相似性为权重的复杂网络,同时应用Girvan-Newman社区发现算法(GN算法)划分联防联控分区,并在各分区内识别关键城市节点以支撑分区内差异化协同治理。结果表明:①得益于近年来大气污染治理成效显著,2015−2023年长三角地区PM_(2.5)年均浓度下降38.31%;而O_(3)年均浓度波动上升11.15%,主要与前期防控重点差异及新型冠状病毒感染疫情影响有关。PM_(2.5)与O_(3)的浓度峰值分别出现在冬季(62μg/m^(3))和夏季(117μg/m^(3)),二者峰值差异由不同的人为活动与自然因素共同驱动。PM_(2.5)与O_(3)污染严重区域均集中在长三角北部地区,南部地区污染较低。②2015−2023年长三角地区归因于PM_(2.5)污染的早逝人数显著下降,无锡市等城市降幅(66%)较大,而归因于O_(3)污染的早逝人数波动上升,芜湖市等城市增幅(25791%)较大。③基于GN算法的社区划分结果,将长三角地区划分为5个复合污染特征相似的联防联控区(北部分区、中西分区、中东分区、西南分区和东南分区)。各分区关键城市节点的差异化治理策略为,无锡市、嘉兴市等关键通道城市强化跨市协同治理,无锡市、苏州市等高效枢纽城市可率先实施减排示范,而滁州市、六安市等边缘城市应聚焦本地源治理。研究显示,长三角地区PM_(2.5)和O_(3)污染特征及健康风险具有明显的时空分异特征,且基于城市间CPHI时间序列所划分的联防联控分区及其关键节点识别,可为长三角地区精细化协同治理提供科学的决策依据。 展开更多
关键词 PM_(2.5) O_(3) 长三角地区 健康风险 复杂网络 区域联防联控
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Adaptations in mitochondrial quality control and interactions with innate immune signaling within skeletal muscle:A narrative review
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作者 Priyanka Khemraj Anastasiya Kuznyetsova David A.Hood 《Journal of Sport and Health Science》 2026年第1期27-39,共13页
Skeletal muscle health and function are essential determinants of metabolic health,physical performance,and overall quality of life.The quality of skeletal muscle is heavily dependent on the complex mitochondrial reti... Skeletal muscle health and function are essential determinants of metabolic health,physical performance,and overall quality of life.The quality of skeletal muscle is heavily dependent on the complex mitochondrial reticulum that contributes toward its unique adaptability.It is now recognized that mitochondrial perturbations can activate various innate immune pathways,such as the nucleotide-binding oligomerization domain(NOD)-like receptor protein 3(NLRP3)inflammasome complex by propagating inflammatory signaling in response to damage-associated molecular patterns(DAMPs).The NLRP3 inflammasome is a multimeric protein complex and is a prominent regulator of innate immunity and cell death by mediating the activation of caspase-1,pro-inflammatory cytokines interleukin-1βand interleukin-18 and pro-pyroptotic protein gasdermin-D.While several studies have begun to demonstrate the relationship between various mitochondrial DAMPs(mtDAMPs)and NLRP3 inflammasome activation,the influence of various metabolic states on the production of these DAMPs and subsequent inflammatory profile remains poorly understood.This narrative review aimed to address this by highlighting the effects of skeletal muscle use and disuse on mitochondrial quality mechanisms including mitochondrial biogenesis,fusion,fission and mitophagy.Secondly,this review summarized the impact of alterations in mitochondrial quality control mechanisms following muscle denervation,aging,and exercise training in relation to NLRP3 inflammasome activation.By consolidating the current body of literature,this work aimed to further the understanding of innate immune signaling within skeletal muscle,which can highlight areas for future research and therapeutic strategies to regulate NLRP3 inflammasome activation during divergent metabolic conditions. 展开更多
关键词 Mitochondrial quality control Innate immune signaling NLRP3 inflammasome Exercise Skeletal muscle disuse
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等离子体协同S型Bi@Bi_(2)S_(3)/CeO_(2)复合纤维可控合成及CO_(2)光还原
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作者 曹铁平 李跃军 孙大伟 《硅酸盐学报》 北大核心 2026年第1期184-194,共11页
针对传统光催化剂载流子复合严重、CO_(2)吸附活化不足的难题,通过静电纺丝-水热两步法合成了Bi@Bi_(2)S_(3)/CeO_(2)复合纤维。扫描电子显微镜与透射电子显微镜揭示,Bi_(2)S_(3)以不同形貌构筑于CeO_(2)纤维表面,原位生成的Bi纳米颗粒... 针对传统光催化剂载流子复合严重、CO_(2)吸附活化不足的难题,通过静电纺丝-水热两步法合成了Bi@Bi_(2)S_(3)/CeO_(2)复合纤维。扫描电子显微镜与透射电子显微镜揭示,Bi_(2)S_(3)以不同形貌构筑于CeO_(2)纤维表面,原位生成的Bi纳米颗粒均匀锚定在Bi_(2)S_(3)表面,形成独特的三维立体结构。X射线光电子能谱与电子顺磁共振谱证实,Bi_(2)S_(3)与CeO_(2)通过S型异质结实现载流子定向分离,高活性电子保留在Bi_(2)S_(3)导带用于CO_(2)还原,强氧化空穴留存于CeO_(2)价带驱动水氧化;Bi纳米颗粒的表面等离子体共振(SPR)效应使可见光吸收能力增强,同时可为体系分流更多高活性电子。在模拟太阳光照下,Bi@Bi_(2)S_(3)/CeO_(2)复合纤维生成CO速率达14.58μmol·g^(-1)·h^(-1)(选择性72%),是纯CeO_(2)纳米纤维的10倍,同时有部分CH4生成(5.68μmol·g^(-1)·h^(-1))。5次循环后活性仍保持90%以上。通过分级结构设计,协同S型异质结与SPR效应,为解决CeO_(2)基催化剂的性能瓶颈,实现CO_(2)光还原提供了“结构-界面-组分”三重调控的新模式。 展开更多
关键词 表面等离子体共振 S型异质结 Bi@Bi_(2)S_(3)/CeO_(2)复合纤维 可控合成
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Fe_(3)O_(4)/TiO_(2)核壳结构的制备及其对染料废水的光催化降解性能研究
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作者 高树会 王楠楠 +1 位作者 彭佃钦 朱孟龙 《工业催化》 2026年第1期80-84,共5页
根据Fe_(3)O_(4)包覆TiO_(2)原理,制备了Fe_(3)O_(4)/TiO_(2)核壳结构,并利用X射线衍射对其进行表征,以染料废水为模型分子对其光催化降解性能研究。结果表明,以m(Fe_(3)O_(4))∶m(TiO_(2))=1∶2时制备的Fe_(3)O_(4)+2TiO_(2)作为催化剂... 根据Fe_(3)O_(4)包覆TiO_(2)原理,制备了Fe_(3)O_(4)/TiO_(2)核壳结构,并利用X射线衍射对其进行表征,以染料废水为模型分子对其光催化降解性能研究。结果表明,以m(Fe_(3)O_(4))∶m(TiO_(2))=1∶2时制备的Fe_(3)O_(4)+2TiO_(2)作为催化剂,在催化剂用量2500 mg·L^(-1)、染料废水溶液浓度40 mg·L^(-1)、pH值为3.0和反应时间250 s的最优条件下,对染料废水降解率可达100%。Fe_(3)O_(4)与TiO_(2)之间形成最佳协同效应时,Fe_(3)O_(4)有效增强了光生电子-空穴分离,增强了TiO_(2)光催化性能,提供更多活性位点,扩大了催化接触面积,提升了整体催化性能,达到高效降解染料废水的效果。 展开更多
关键词 水污染防治工程 Fe_(3)O_(4)/TiO_(2)核壳结构 染料废水 光催化降解
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维生素D_(3)辅助布地奈德吸入气雾剂对小儿支气管哮喘TLR4/NF-κB信号通路的影响
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作者 杜兰 《临床合理用药》 2026年第1期27-30,共4页
目的 分析维生素D_(3)辅助布地奈德吸入气雾剂对小儿支气管哮喘Toll样受体4(TLR4)/核转录因子-κB(NF-κB)信号通路的影响。方法 选取2022年5月—2024年12月黄骅市中医医院收治的支气管哮喘患儿86例开展研究,以密封信封抽签法随机分为... 目的 分析维生素D_(3)辅助布地奈德吸入气雾剂对小儿支气管哮喘Toll样受体4(TLR4)/核转录因子-κB(NF-κB)信号通路的影响。方法 选取2022年5月—2024年12月黄骅市中医医院收治的支气管哮喘患儿86例开展研究,以密封信封抽签法随机分为辅助组(n=43)和参考组(n=43)。参考组予以布地奈德吸入气雾剂治疗,辅助组在参考组基础上增加维生素D_(3)治疗,2组均持续给药14 d。比较2组疾病控制率,症状、体征改善时间,治疗前后TLR4、NF-κB蛋白表达水平、免疫指标。结果 辅助组疾病控制率为93.02%,高于参考组的76.74%(χ^(2)=4.440,P=0.035)。辅助组胸闷、憋喘、咳嗽、肺部湿啰音改善时间短于参考组(P<0.01)。治疗14 d后,2组TLR4、NF-κB蛋白表达水平低于治疗前,且辅助组低于参考组(P<0.01);2组CD_(3)^(+)、CD4^(+)、CD4^(+)/CD8^(+)高于治疗前,CD8^(+)低于治疗前,且辅助组高/低于参考组(P<0.05或P<0.01)。结论 维生素D_(3)辅助布地奈德吸入气雾剂可有效控制支气管哮喘患儿病情,促进症状体征改善,调节TLR4/NF-κB信号通路,提高免疫功能。 展开更多
关键词 支气管哮喘 小儿 维生素D_(3) 布地奈德吸入气雾剂 TOLL样受体4 核转录因子-ΚB 疾病控制率 免疫功能
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Control Efficacy of Validamycin A·(0.2 Billion Spores/ml) Paenibacillus polymyxa DN-1 3% AS for Rice Sheath Blight
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作者 胡飞 苏卫华 +4 位作者 李昌春 周子燕 胡本进 徐丽娜 郑进国 《Agricultural Science & Technology》 CAS 2016年第11期2615-2618,共4页
With validamycin A.(0.2 billion spores/ml) Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for' rich sheath blight were in... With validamycin A.(0.2 billion spores/ml) Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for' rich sheath blight were investigated. The results of two- year test showed that when the application amount was in the range of 45-90 g.a.i/ hm^2, the field efficacy of validamycin A-(0.2 billion spores/ml) P. polymyxa DN-1 3% AS in the initial infection stage of rich sheath blight (Le., the diseased plant rate was below 5%) reached 80.38%-89.06%, and that in the peak infection stage (i.e., the diseased plant rate was higher than 10%) reached only 41.12%-53.26%. The field efficacy of validamycin A.(0.2 billion spores/ml) P. polymyxa DN-1 3% AS at the early onset of rich sheath blight was significantly better than that at the onset, so that the application time of validamycin A .(0.2 billion spores/ml) P. polymyxa DN-1 3% AS should be appropriately brought forward in the prevention and control of rice sheath blight. 展开更多
关键词 Validamycin A-(0.2 billion spores/roll P. polymyxa DN-1 3% AS Rice sheath blight Initial infection stage Peak infection stage control efficacy
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基于PLC的HL-3装置活动孔栏位移控制系统的设计 被引量:1
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作者 许婕 蔡立君 +4 位作者 刘健 卢勇 李云峰 罗山 黄文玉 《核聚变与等离子体物理》 北大核心 2025年第3期324-331,共8页
为了实现HL-3装置活动孔栏位移的自动化控制,基于PLC和步进电机的应用原理,设计了活动孔栏位移自动控制系统。选用两相混合式步进电机,采用S7-1200PLC作为步进电机控制器。通过运动轴组态,并运用PLC-open运动功能块实现了对活动孔栏驱... 为了实现HL-3装置活动孔栏位移的自动化控制,基于PLC和步进电机的应用原理,设计了活动孔栏位移自动控制系统。选用两相混合式步进电机,采用S7-1200PLC作为步进电机控制器。通过运动轴组态,并运用PLC-open运动功能块实现了对活动孔栏驱动步进电机的开环速度控制和位置控制。同时完成了人机界面交互,实现了对HL-3装置活动孔栏位移实时显示、参数设置、自动反馈控制和阈值报警等功能。该系统已成功投入到HL-3装置放电实验运行中。自此系统投入运行以来的结果表明,所设计的控制系统能够满足控制要求,完成了预期目标。 展开更多
关键词 HL-3主机 活动孔栏 PLC 步进电机驱动 控制系统
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2020珠峰高程测量BDS-3数据质量分析 被引量:2
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作者 杨强 党亚民 +2 位作者 蒋光伟 马新莹 孙洋洋 《导航定位学报》 北大核心 2025年第2期20-27,共8页
2020年珠峰高程测量首次以国产北斗卫星导航系统(BDS)接收机为核心装备,获取了北斗三号全球卫星导航系统(BDS-3)高精度观测数据。为了确保成果的可靠性,利用天宝(Trimble)接收机对国产接收机BDS-3观测结果进行检核。针对珠峰地形环境限... 2020年珠峰高程测量首次以国产北斗卫星导航系统(BDS)接收机为核心装备,获取了北斗三号全球卫星导航系统(BDS-3)高精度观测数据。为了确保成果的可靠性,利用天宝(Trimble)接收机对国产接收机BDS-3观测结果进行检核。针对珠峰地形环境限制导致全球卫星导航系统(GNSS)观测网形不佳、峰顶GNSS观测时间短等难题,提出三级控制策略相结合的GNSS观测网数据处理方案,通过构建地区GNSS基准网、局部GNSS控制网和峰顶联测网,在极其有限的珠峰观测时段内最大化地优化提取高质量GNSS观测数据。为了验证BDS-3观测数据的精度,对比全球定位系统(GPS)和BDS-3数据解算结果,并检核GNSS数据处理与分析软件(GPAS)/加米特(GAMIT)2种软件的BDS解算结果,结果表明,BDS-3处理结果精度与GPS成果精度相当,高程方向精度均优于2 cm,坐标差异均优于1 cm,验证了本次珠峰测高BDS-3观测成果的精度和可靠性。 展开更多
关键词 珠穆朗玛峰 数据处理 全球卫星导航系统(GNSS)控制网 高程测量 北斗三号全球卫星导航系统(BDS-3) 质量评估
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SINGULAR PERTURBATION APPROACH TO MOVING MASS CONTROL OF BUOYANCY-DRIVEN AIRSHIP IN 3-D SPACE 被引量:1
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作者 吴小涛 Claude H Moog 胡跃明 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第4期343-352,共10页
The attitude control problem and the guidance problem are solved in 3-D for a buoyancy-driven airship actuated by the combined effects of an internal air bladder which modulates the airshiprs net weight and of two mov... The attitude control problem and the guidance problem are solved in 3-D for a buoyancy-driven airship actuated by the combined effects of an internal air bladder which modulates the airshiprs net weight and of two moving masses which modulate its center of mass. A simple and clear modeling is introduced to derive the 8 degree of freedom (DOF) mathematical model. Nonlinear control loops are derived through maximal feedback linearization with internal stability for both dynamics in the longitudinal plane and in the lateral plane. Based on a singular perturbation approach, the superposition of these two control actions in the longitudinal plane and in the lateral plane is shown to achieve the control of the dynamics in 3-D space. The simulations of the airship tracking specified attitude, moving direction and speed in 3-D space are presented. 展开更多
关键词 buoyancy-driven AIRSHIP nonlinear control 3-D singular perturbation
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Nominal Model-Based Sliding Mode Control with Backstepping for 3-Axis Flight Table 被引量:11
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作者 刘金琨 孙富春 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第1期65-71,共7页
Based on nominal model, a novel global sliding mode controller (GSMC) with a new control scheme is proposed for a practical uncertain servo system. This control scheme consists of two combined controllers, One is th... Based on nominal model, a novel global sliding mode controller (GSMC) with a new control scheme is proposed for a practical uncertain servo system. This control scheme consists of two combined controllers, One is the global sliding mode controller for practical plant, the other is the integral backstepping controller for nominal model. Modeling error between practical plant and nominal model is used to design GSMC. The steady-state control accuracy can be guaranteed by the integral backstepping control law, and the global robustness can be obtained by GSMC. The stability of the proposed controller is proved according to the Lyapunov approach. The simulation results both of sine signal and step signal tracking for 3-axis flight table are investigated to show good position tracking performance and high robustness with respect to large and parameter changes over all the response time. 展开更多
关键词 nominal model sliding mode control backstepping control robust control 3-axis flight table
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Design and Reliability Analysis of DP-3 Dynamic Positioning Control Architecture 被引量:4
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作者 王芳 万磊 +1 位作者 姜大鹏 徐玉如 《China Ocean Engineering》 SCIE EI 2011年第4期709-720,共12页
As the exploration and exploitation of oil and gas proliferate throughout deepwater area, the requirements on the reliability of dynamic positioning system become increasingly stringent. The control objective ensuring... As the exploration and exploitation of oil and gas proliferate throughout deepwater area, the requirements on the reliability of dynamic positioning system become increasingly stringent. The control objective ensuring safety operation at deep water will not be met by a single controller for dynamic positioning. In order to increase the availability and reliability of dynamic positioning control system, the triple redundancy hardware and software control architectures were designed and developed according to the safe specifications of DP-3 classification notation for dynamically positioned ships and rigs. The hardware redundant configuration takes the form of triple-redundant hot standby configuration including three identical operator stations and three real-time control computers which connect each other through dual networks. The function of motion control and redundancy management of control computers were implemented by software on the real-time operating system VxWorks. The software realization of task loose synchronization, majority voting and fault detection were presented in details. A hierarchical software architecture was planed during the development of software, consisting of application layer, real-time layer and physical layer. The behavior of the DP-3 dynamic positioning control system was modeled by a Markov model to analyze its reliability. The effects of variation in parameters on the reliability measures were investigated. The time domain dynamic simulation was carried out on a deepwater drilling rig to prove the feasibility of the proposed control architecture 展开更多
关键词 DP-3 dynamic positioning system reliability triple redundancy motion control redundancy management
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Role of 3'-untranslated region translational control in cancer development, diagnostics and treatment 被引量:6
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作者 Andrii Vislovukh Thaiz Rivera Vargas +1 位作者 Anna Polesskaya Irina Groisman 《World Journal of Biological Chemistry》 CAS 2014年第1期40-57,共18页
The messenger RNA 3'-untranslated region(3'UTR)plays an important role in regulation of gene expres-sion on the posttranscriptional level. The 3'UTR con-trols gene expression via orchestrated interactionbe... The messenger RNA 3'-untranslated region(3'UTR)plays an important role in regulation of gene expres-sion on the posttranscriptional level. The 3'UTR con-trols gene expression via orchestrated interactionbetween the structural components of mRNAs(cis-ele-ment) and the specific trans-acting factors(RNA bind-ing proteins and non-coding RNAs). The crosstalk ofthese factors is based on the binding sequences and/or direct protein-protein interaction, or just functionalinteraction. Much new evidence that has accumulatedsupports the idea that several RNA binding factors canbind to common mRNA targets: to the non-overlappingbinding sites or to common sites in a competitive fash-ion. Various factors capable of binding to the sameRNA can cooperate or be antagonistic in their actions.The outcome of the collective function of all factorsbound to the same mRNA 3'UTR depends on manycircumstances, such as their expression levels, affinity to the binding sites, and localization in the cell, which can be controlled by various physiological conditions. Moreover, the functional and/or physical interactions of the factors binding to 3'UTR can change the character of their actions. These interactions vary during the cell cycle and in response to changing physiological condi-tions. Abnormal functioning of the factors can lead to disease. In this review we will discuss how alterations of these factors or their interaction can affect cancer development and promote or enhance the malignant phenotype of cancer cells. Understanding these altera-tions and their impact on 3'UTR-directed posttran-scriptional gene regulation will uncover promising new targets for therapeutic intervention and diagnostics. We will also discuss emerging new tools in cancer di-agnostics and therapy based on 3'UTR binding factors and approaches to improve them. 展开更多
关键词 Translational control 3 -untranslated region MICRORNAS RNA binding proteins CANCER
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