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RNA解旋酶DDX5:细菌性炎症反应的调节器

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中国兽医科学 2024年第6期54卷 852-852页

作者： Jian Xu li-yuan liu fei-Jie Zhi Yin-Juan Song Zi-Hui Zhang Bin li Fu-Ying Zheng Peng-Cheng Gao Su-Zi Zhang yu-yu Zhang Ying Zhang Ying Qiu Bo jiang Yong-Qing li Chen Peng yue-Feng Chu State Key Laboratory for Animal Disease Control and Prevention College of Veterinary Medicine Lanzhou University Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences Lanzhou China. National Key Laboratory of Veterinary Public Health College of Veterinary Medicine China Agricultural University Beijing China. College of Veterinary Medicine Xinjiang Agricultural University Urumqi China. State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences University of Chinese Academy of Sciences Shanghai China. Institute of Animal Husbandry and Veterinary Medicine Beijing Academy of Agriculture and Forestry Sciences Beijing China. National Key Laboratory of Veterinary Public Health College of Veterinary Medicine China Agricultural University Beijing China. pengchenea@***. State Key Laboratory for Animal Disease Control and Prevention College of Veterinary Medicine Lanzhou University Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences Lanzhou China. chuyuefeng@***.

细菌性感染是威胁动物和人类健康的重要原因之一,国际著名医学杂志《柳叶刀》发表的一项研究表明,金黄色葡萄球菌、大肠杆菌、肺炎链球菌、支原体等33种常见细菌感染是2019年全球人类第二大死亡原因,与全球八分之一的死亡有关,减少细菌... 详细信息

细菌性感染是威胁动物和人类健康的重要原因之一,国际著名医学杂志《柳叶刀》发表的一项研究表明,金黄色葡萄球菌、大肠杆菌、肺炎链球菌、支原体等33种常见细菌感染是2019年全球人类第二大死亡原因,与全球八分之一的死亡有关,减少细菌感染已成为全球公共卫生的优先事项。研制细菌感染防控技术和制定有效防控策略,离不开对细菌致病和免疫机制的深度解析。病原菌与宿主间存在双向、动态、复杂的相互作用,其中甲基化、泛素化等表观遗传修饰在病原菌与宿主互作的过程中发挥了重要作用.

关键词：细菌感染防控技术细菌性感染免疫机制肺炎链球菌防控策略金黄色葡萄球菌 RNA解旋酶

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基于多电平变流器模块的直流输电系统控制

电网与清洁能源 2024年第9期40卷 47-53页

作者：刘威于飞董霜沙志成李可军山东电力工程咨询院有限公司山东大学电气工程学院

为了保证直流输电系统在发生三相短路故障时输电电压的稳定性，有效控制输电系统的运行，该文提出了基于多电平变流器模块（modular multilevel converter,MMC）的直流输电系统运行控制方法。利用反并联二极管与并联电容来设计多电平变... 详细信息

为了保证直流输电系统在发生三相短路故障时输电电压的稳定性，有效控制输电系统的运行，该文提出了基于多电平变流器模块（modular multilevel converter,MMC）的直流输电系统运行控制方法。利用反并联二极管与并联电容来设计多电平变流器模块，获得交流等效电感，保证换流站交直流量与有功功率相同，明确换流站内功率情况；将该模块与前馈解耦补偿项相结合，运用PI获得电流内环运行控制器的输入值，实现电流解耦，增强直流电压的稳定控制，提高输电系统抗扰动性能；通过修正与控制环节获得对应参考值，以及最佳运行控制结果。通过实验表明：设计的模块既能保证输电系统在正常工作状态下平稳运行，也能在发生故障时将影响控制在安全范围内，保证电力系统输电稳定。

关键词：系统运行控制 PI控制器直流输电系统有功功率模块化多电平变流器 MMC

基于冬小麦高光谱图像的天然气微泄漏胁迫区域提取

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光谱学与光谱分析 2024年第3期44卷 770-776页

作者：李辉刘姁升蒋金豹陈绪慧张帅唐珂赵新伟杜兴强玉龙飞雪中国四维测绘技术有限公司北京100086 鄂尔多斯应用技术学院内蒙古鄂尔多斯017000 中国矿业大学(北京)地球科学与测绘工程学院北京100083 生态环境部卫星环境应用中心北京100094 中国资源卫星应用中心北京100094

天然气在能源结构中逐渐占据重要地位。由于天然气管道和储气库常年埋藏于地下,无氧腐蚀、自然灾害、注入井和管道口松懈等因素会导致气体发生泄漏。在地下储存天然气大规模泄漏之前确定泄漏点的位置并做出早期判断和预警十分必要。以... 详细信息

天然气在能源结构中逐渐占据重要地位。由于天然气管道和储气库常年埋藏于地下,无氧腐蚀、自然灾害、注入井和管道口松懈等因素会导致气体发生泄漏。在地下储存天然气大规模泄漏之前确定泄漏点的位置并做出早期判断和预警十分必要。以冬小麦为研究对象,采集4期高光谱图像数据,融合其图像、空间、时相特征,探寻天然气胁迫下冬小麦胁迫范围半径和时长之间的关系,并间接探测天然气微泄露点。一方面对连续统去除后的冬小麦高光谱图像数据进行连续小波变换并利用CWT_(mexh)指数[CWT_(mexh)=CW_(770)^(2)/(1-CW_(487))×CW_(550)]对高光谱胁迫组图像进行微泄露点信息提取,另一方面提取高光谱图像数据的PCA特征,基于SVM分类器提取天然气胁迫区域。最后将天然气微泄露识别结果进行数学形态学分析,并利用最小二乘对胁迫区域进行圆曲线拟合,探索天然气泄漏胁迫半径与胁迫天数的关系。结果表明:(1)CWT_(mexh)指数应用到成像高光谱数据表现出较好的识别性能;(2)SVM分类器可基于光谱差异性特征识别冬小麦胁迫区域,分类精度较好,最大分类精度可以达到99.25%,Kappa系数为0.97,且识别精度随天然气胁迫持续而增加;(3)冬小麦受胁迫区域半径和通气天数呈现强烈的线性相关。因此,结果表明,在冠层尺度和低空尺度通过高光谱遥感监测地表植被间接识别天然气微泄漏点具有可行性,可以预测地下天然气微泄漏随着时间变化引起的胁迫区域变化。该工作为星载高光谱遥感监测地下储存天然气泄漏点提供科学依据,为以后的工程应用提供技术支持。

关键词：天然气微泄漏冬小麦高光谱图像空间特征

Experimental Investigation of Disturbing the Flow Field on the Vortex-Induced Vibration of Deepwater Riser Fitted with Gas Jetting Active Vibration Suppression Device

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China Ocean Engineering 2020年第3期34卷 341-351页

作者： li Peng jiang Zhen-xing liu yu WANG yu GUO Hai-yan WANG fei ZHANG Yong-bo College of Civil Engineering and Architecture Shandong University of Science and TechnologyQingdao 266590China shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation Qingdao 266590China College of Engineering Ocean University of ChinaQingdao 266100China National Oceanographic Center of Qingdao Qingdao 266071China

An experimental investigation on the disturbance effect of jet-type active vibration suppression device on vortexinduced vibration of deep-sea riser was carried out in the wave-flow combined *** vibration suppression device was designed in which the jet pipe was horizontally fixed to the front end of the *** varying three different excitation spacings and multi-stage outflow velocities,the influence law of the dominant frequency,dimensionless displacement and other dynamic response parameters was studied under different excitation spacings,and the mechanism and sensitive characteristics of the disturbance suppression were *** results indicate that the variation of excitation spacing makes gas curtain enter the strong disturbed flow region at different velocities and angles,and the coupling relationship between excitation spacing and reduced velocity is the key factor to enter the strong disturbed flow region to achieve the optimal disturbance *** the strong disturbed flow region,the influence of gas curtain on the dominant frequency is obviously affected by the flow velocity,while the vibration displacement is stable at the same amplitude and is weakly affected by the flow *** curtain can effectively disturb the formation of vortex shedding,destroy the strong nonlinear coupled vibration of the riser,and achieve better vibration suppression *** the weak disturbed flow region,the vortex length of the riser tail is prolonged,the strong nonlinear coupled vibration of the riser is gradually restored,and the vibration suppression effect of the device gradually decreases.

关键词： deepwater riser vortex-induced vibration(VIV) active vibration suppression jet-type excitation spacing disturbance flow

Objectness Region Enhancement Networks for Scene Parsing

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Journal of Computer Science & Technology 2017年第4期32卷 683-700页

作者： Xin-yu Ou Ping li He-fei ling Si liu Tian-jiang Wang School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China Institute of Information Engineering Chinese Academy of Sciences Beijing 100091 China Cadres Online Learning Institute of yunnan Province Yunnan Open University Kunming 650223 China

Semantic segmentation has recently witnessed rapid progress, but existing methods only focus on identifying objects or instances. In this work, we aim to address the task of semantic understanding of scenes with deep learning. Different from many existing methods, our method focuses on putting forward some techniques to improve the existing algorithms, rather than to propose a whole new framework. Objectness enhancement is the first effective technique. It exploits the detection module to produce object region proposals with category probability, and these regions are used to weight the parsing feature map directly. 'Extra background' category, as a specific category, is often attached to the category space for improving parsing result in semantic and instance segmentation tasks. In scene parsing tasks, extra background category is still beneficial to improve the model in training. However, some pixels may be assigned into this nonexistent category in inference. Black-hole filling technique is proposed to avoid the incorrect classification. For verifying these two techniques, we integrate them into a parsing framework for generating parsing result. We call this unified framework as Objectness Enhancement Network (OENet). Compared with previous work, our proposed OENet system effectively improves the performance over the original model on SceneParse150 scene parsing dataset, reaching 38.4 mIoU (mean intersection-over-union) and 77.9% accuracy in the validation set without assembling multiple models. Its effectiveness is also verified on the Cityscapes dataset.

关键词： objectness region enhancement black-hole filling scene parsing instance enhancement objectness region proposal

Zn 对免热处理铸造铝硅系合金显微组织与力学性能的影响

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铸造 2024年第9期73卷 1243-1247页

作者：李明常博文刘志中李宇飞刘家懿康明姜正鳌海装沈阳局驻沈阳地区第四军事代表室辽宁沈阳110022 中国机械总院集团沈阳铸造研究所有限公司高端装备铸造技术全国重点实验室辽宁沈阳110022 中国机械总院集团沈阳铸造研究所有限公司辽宁沈阳110022 沈阳铸研科技有限公司辽宁沈阳110022

研究了Zn元素含量分别为0.5wt%、1.0wt%、和1.5wt%时,对Al-Si-Mn-Mg免热处理铸造铝合金的显微组织和力学性能影响。通过变质处理,观察到不同的微观组织。结果表明,随着Zn元素含量的提高,合金的抗拉强度及屈服强度增加,伸长率降低。同时... 详细信息

研究了Zn元素含量分别为0.5wt%、1.0wt%、和1.5wt%时,对Al-Si-Mn-Mg免热处理铸造铝合金的显微组织和力学性能影响。通过变质处理,观察到不同的微观组织。结果表明,随着Zn元素含量的提高,合金的抗拉强度及屈服强度增加,伸长率降低。同时发现,随着Zn元素含量的提升,合金的变质效果出现不同程度的下降。

关键词：显微组织铝合金铸造铝合金合金化免热处理

A High-Strength and Biodegradable Zn–Mg Alloy with Refined Ternary Eutectic Structure Processed by ECAP

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Acta Metallurgica Sinica(English Letters) 2020年第9期33卷 1191-1200页

作者： He Huang Huan liu li-sha Wang yu-Hua li Solomon-Oshioke Agbedor Jing Bai Feng Xue Jing-Hua jiang College of Mechanics and Materials Hohai UniversityNanjing 210000China Ocean and Coastal Engineering Research Institute Nantong 226300China College of Materials Science and Engineering Southeast UniversityNanjing 211189China Suqian Research Institute of Hohai University Suqian 223800China

In this study, the microstructure, mechanical properties and corrosion behaviors of a Zn–1.6 Mg(wt%) alloy during multipass rotary die equal channel angle pressing(RD-ECAP) processing at 150 °C were systematically investigated. The results indicated that a Zn + Mg2 Zn11 + MgZn2 ternary eutectic structure was formed in as-cast Zn–Mg alloy. After ECAP, the primary Zn matrix turned to fine dynamic recrystallization(DRX) grains, and the network-shaped eutectic structure was crushed into fine particles and blended with DRX grains. Owing to the refined microstructure, dispersed eutectic structure and dynamically precipitated precipitates, the 8 p-ECAP alloy possessed the optimal mechanical properties with ultimate tensile strength of 474 MPa and elongation of 7%. Moreover, the electrochemical results showed that the ECAP alloys exhibited similar corrosion rates with that of as-cast alloys in simulated body fluid, which suggests that a high-strength Zn–Mg alloy was successfully developed without sacrifice of the corrosion resistance.

关键词： Zn–Mg alloy Equal channel angular pressing Eutectic structure Mechanical property Corrosion behavior

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侧链衍生季铵盐型氯胺的合成及抗菌应用

应用化学 2024年第7期41卷 966-975页

作者：李令东张颂伟张维伦刘鹏飞于江际鸣周豪大连理工大学精细化工国家重点实验室盘锦124221 大连理工大学化工海洋与生命学院盘锦124221

以5,5-二甲基海因(DMH)为原料,设计合成了一系列侧链衍生的季铵盐型氯胺抗菌剂(10-14),表征了前体和氯胺结构。以大肠杆菌(***)和金黄葡萄球菌(***)为模式菌株,以三甲基季铵盐氯胺1为对照,初步测试了氯胺10-14的抗菌活性。结果表明,氯胺... 详细信息

以5,5-二甲基海因(DMH)为原料,设计合成了一系列侧链衍生的季铵盐型氯胺抗菌剂(10-14),表征了前体和氯胺结构。以大肠杆菌(***)和金黄葡萄球菌(***)为模式菌株,以三甲基季铵盐氯胺1为对照,初步测试了氯胺10-14的抗菌活性。结果表明,氯胺10-13抗菌能力随侧链变长先增强后减弱,其中三丁基季铵盐氯胺12对***和***的杀灭对数(KL)值分别为1.07±0.09和6.49,表现出这一系列中相对更优的抗菌活性,这可能是12达到了分子触杀所需的最佳亲疏水平衡状态,与菌体细胞膜作用更强所致。此外,携羟乙基侧链氯胺14实现了对***和***全杀,展现了10-14中最出色的抗菌性能,这可能和氯胺分子更易穿透菌体细胞膜有关。本工作制备的一系列高活性季铵盐氯胺抗菌剂,为更高效离子型氯胺抗菌剂的设计研发提供了参考借鉴。

关键词：季铵盐型氯胺多步合成抗菌活性亲疏水平衡侧链衍生物

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Scaled-up synthesis of defect-rich layered double hydroxide monolayers without organic species for efficient oxygen evolution reaction

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Green Energy & Environment 2022年第5期7卷 975-982页

作者： Haoyuan Chi Jingwen Dong Tian li sha Bai ling Tan Jikang Wang Tianyang Shen Guihao liu lihong liu Luyi Sun yufei Zhao yu-fei Song State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing100875China Polymer Program Institute of Materials Science and Department of Chemical&Biomolecular EngineeringUniversity of ConnecticutStorrsConnecticut06269USA Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing100029China

The scaled-up synthesis of organic-free monolayer nanomaterials is highly desirable,especially in obtaining green energy by *** this study,a method for the scaled-up synthesis of the series of monolayer layered double hydroxides(LDHs)without the addition of organic solvents is reported via the separate nucleation and aging steps *** resulting monolayer LDHs with the thicknesses of less than 1 nm showed a narrow thickness distribution.X-ray absorption fine-structure revealed that monolayer NiFe-LDH nanosheets have a number of oxygen and metal vacancies *** a practical application,monolayer NiFe-LDH nanosheets containing defects showed an enhanced electrocatalytic water oxidation activity compared with that of bulk *** functional theory calculations uncovered that excellent catalytic activity is attributed to vacancies *** proposed method is an economical and universally applicable strategy for the scaled-up production of monolayer LDHs.

关键词： process synthesis monolayer