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Mechanism of nanoparticle aggregation in gas-liquid microfluidic mixing

Chinese Chemical Letters 2024年第4期35卷 376-381页

作者： Hongxia li Xiyang Wang Du Qiao jiahao li Weiping Zhu Honglin li Key Laboratory for Precision&Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116023China Shanghai Key Laboratory of New Drug Design School of PharmacyEast China University of Science and TechnologyShanghai 200237China

Using gas-liquid segmented micromixers to prepare nanoparticles that have a homogeneous particle size, controllable shape, and monodispersity advantages. Although nanoparticle aggregation within a microfluid has been shown to be affected by the shear effect, the shear effect triggering conditions in gasliquid two-phase flow is unclear and the aggregation behavior of nanoparticles under the shear effect is difficult to predict, resulting in uncontrollable physical and chemical properties of nanoparticle aggregates. In this study, a numerical simulation of nanoparticle aggregation in gas-liquid two-phase flow under the shear effect is performed using the CFD-DEM method. Then, the effects of total flow rate,gas-liquid two-phase flow ratio, and particle volume fraction on particle aggregation were analyzed to achieve control of particle aggregation shape and size. Meanwhile, the triggering mechanism of the shear effect and the mechanism of the shear effect on the aggregation of nanoparticles were clarified. The results show that increasing the total flow rate or decreasing the gas-liquid two-phase flow rate ratio can induce the shear effect, which reduces the particle aggregation size and makes the morphology tend to be spherical. Moreover, increasing the particle volume fraction, and total flow rate or decreasing the gas-liquid two-phase flow rate ratio also increases the number of particle collisions and induce interparticle adhesion. Hence, particle adhesion and the shear effect compete with each other and together affect particle aggregation.

关键词： Microfluidic Gas-liquid segmented micromixer Nanoparticle aggregation Shear effect Numerical calculation

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Influence of Al_(2)O_(3)/SiO_(2) Ratio on the Structure and Properties of Na^(+)/K^(+)Ion Exchange Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) Glasses

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 606-612页

作者：吴建磊 CHEN Junzhu TIAN Xiaokun li jiahao GAO Wenkai YUE Yunlong 康俊峰 School of Materials Science and Engineering University of JinanJinan 250022China CDGM GLASS Co.LTD Chengda 610199China

In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were *** results showed that,with increasing Al_(2)O_(3)/SiO_(2) ratio,the simple structural units Q_(1) and Q_(2) transformed into highly aggregated structural units Q_(3) and Q_(4),indicating the increase of polymerization degree of glass ***,the coefficient of thermal expansion decreased from 9.23×10^(-6)℃^(-1) to 8.88×10^(-6)℃^(-1).The characteristic temperatures such as melting,forming,softening and glass transition temperatures increased with the increase of Al_(2)O_(3)/SiO_(2) ratio,while the glasses working temperature range became *** increasing Al_(2)O_(3)/SiO_(2) ratio and prolonging ion-exchange time enhanced the surface compressive stress(CS)and depth of stress layer(DOL).However,the increase of ion exchange temperature increased the DOL and decreased the CS affected by stress *** was a good linear relationship between stress relaxation and surface compressive *** strengthening significantly improved the hardness of glasses,which reached the maximum value of(622.1±10)MPa for sample with Al_(2)O_(3)/SiO_(2) ratio of 0.27 after heat treated at 410℃for 2 h.

关键词： network structure viscosity ion exchange aluminosilicate glass

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Carbon Emission Factors Prediction of Power Grid by Using Graph Attention Network

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Energy Engineering 2024年第7期121卷 1945-1961页

作者： Xin Shen jiahao li YujunYin Jianlin Tang Weibin lin Mi Zhou Measurement Center Yunnan Power Grid Co.Ltd.Kunming650000China Electric Power Research Institute China Southern Power Grid Co.Ltd.Guangzhou510530China Guangdong Provincial Key Laboratory of Intelligent Measurement and Advanced Metering of Power Grid Guangzhou510530China

Advanced carbon emission factors of a power grid can provide users with effective carbon reduction advice,which is of immense importance in mobilizing the entire society to reduce carbon *** method of calculating node carbon emission factors based on the carbon emissions flow theory requires real-time parameters of a power ***,it cannot provide carbon factor information *** address this issue,a prediction model based on the graph attention network is *** model uses a graph structure that is suitable for the topology of the power grid and designs a supervised network using the loads of the grid nodes and the corresponding carbon factor *** network extracts features and transmits information more suitable for the power system and can flexibly adjust the equivalent topology,thereby increasing the diversity of the *** input and output data are simple,without the power grid *** demonstrated its effect by testing IEEE-39 bus and IEEE-118 bus systems with average error rates of 2.46%and 2.51%.

关键词： Predict carbon factors graph attention network prediction algorithm power grid operating parameters

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High-throughput discovery of highly selective reversible hMAO-B inhibitors based on at-line nanofractionation

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1772-1786页

作者： Yu Fan Jincai Wang Jingyi Jian Yalei Wen jiahao li Hao Tian Jacques Crommen Wei Bi Tingting Zhang Zhengjin Jiang Institute of Pharmaceutical Analysis/Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research/International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Ministry of Education(MOE)of China/College of Pharmacy Jinan UniversityGuangzhou 510632China KU Leuven-University of Leuven Pharmaceutical AnalysisDepartment of Pharmaceutical and Pharmacological SciencesLeuven 3000Belgium Laboratory of Analytical Pharmaceutical Chemistry Department of Pharmaceutical SciencesCIRMUniversity of LiegeLiege B-4000Belgium Department of Neurology the First Affiliated Hospital of Jinan University/Clinical Neuroscience Institutethe First Affiliated Hospital of Jinan UniversityGuangzhou 510630China

Human monoamine oxidase B(hMAO-B)has emerged as a pivotal therapeutic target for Parkinson's *** to adverse effects and shortage of commercial drugs,there is a need for novel,highly selective,and reversible hMAO-B inhibitors with good blood-brain barrier *** this study,a high-throughput at-line nanofractionation screening platform was established with extracts from Chuanxiong Rhizoma,which resulted in the discovery of 75 active compounds,including phenolic acids,volatile oils,and phthalides,two of which were highly selective novel natural phthalide hMAO-B inhibitors that were potent,selective,reversible and had good blood‒brain *** docking and molecular dynamics simulations elucidated the inhibition ***(IC_(50)=103 nmol/L;SI=645)and neocnidilide(IC_(50)=131 nmol/L;SI=207)demonstrated their excellent potential as hMAO-B *** offset the limitations of deactivating enzymes associated with irreversible hMAO-B inhibitors such as *** SH-SY5Y cell assays,sedanolide(EC_(50)=0.962μmol/L)and neocnidilide(EC_(50)=1.161μmol/L)exhibited significant neuroprotective effects,comparable to the positive drugs rasagiline(EC_(50)=0.896μmol/L)and safinamide(EC_(50)=1.079μmol/L).These findings underscore the potential of sedanolide as a novel natural hMAO-B inhibitor that warrants further development as a promising drug candidate.

关键词： Human monoamine oxidase B inhibitors High-throughput screening At-linenanofractionation Parkinson's disease Cellular neuroprotection Traditional Chinese medicines(TCMs)

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凹槽结构对离心泵空化特性的影响

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华中科技大学学报(自然科学版) 2024年第7期52卷 139-144页

作者：赵伟国张栩杨良李家豪兰州理工大学能源与动力工程学院兰州理工大学甘肃省流体机械及系统重点实验室

以低比转速离心泵为研究对象，提出一种叶片前缘布置凹槽结构的空化抑制方法．结合修正的SST k-ω湍流模型和Z-G-B空化模型对离心泵进行数值模拟，并将试验与模拟进行对比分析．结果发现：凹槽结构提升了离心泵的断裂扬程，降低了临界... 详细信息

以低比转速离心泵为研究对象，提出一种叶片前缘布置凹槽结构的空化抑制方法．结合修正的SST k-ω湍流模型和Z-G-B空化模型对离心泵进行数值模拟，并将试验与模拟进行对比分析．结果发现：凹槽结构提升了离心泵的断裂扬程，降低了临界空化余量；在不同的空化阶段降低了漩涡强度，优化了周围流场的流动状态，诱发相对高压并改善涡量场；减少了各空化余量下离心泵的空泡体积，降低了多个监测点压力脉动主频幅值．凹槽结构有效限制离心泵空化发展，使离心泵的运行更加稳定．

关键词：离心泵空化特性凹槽结构数值模拟压力脉动

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Bioinspired polysaccharide-based nanocomposite membranes with robust wet mechanical properties for guided bone regeneration

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National Science Review 2024年第3期11卷 215-226页

作者： Jian-Hong Xiao Zhen-Bang Zhang jiahao li Si-Ming Chen Huai-ling Gao YinXiu liao Lu Chen ZiShuo Wang YiFan Lu YuanZhen Hou HengAn Wu DuoHong Zou Shu-Hong Yu Department of Chemistry New Cornerstone Science Laboratory Institute of Biomimetic Materials&Chemistry Anhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials&Chemistry Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of China Department of Dental Implant Center Stomatologic Hospital and College Key Laboratory of Oral Diseases Research of Anhui Province Anhui Medical University CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics CAS Center for Excellence in Complex System Mechanics University of Science and Technology of China Department of Oral Surgery College of Stomatology National Clinical Research Center for Oral DiseasesShanghai Key Laboratory of Stomatology Shanghai Research Institute of Stomatology Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Institute of Innovative Materials(I2M) Department of Chemistry Department of Materials Science and Engineering Southern University of Science and Technology

Polysaccharide-based membranes with excellent mechanical properties are highly desired. However, severe mechanical deterioration under wet conditions limits their biomedical applications. Here, inspired by the structural heterogeneity of strong yet hydrated biological materials, we propose a strategy based on heterogeneous crosslink-and-hydration（HCH） of a molecule/nano dual-scale network to fabricate polysaccharide-based nanocomposites with robust wet mechanical properties. The heterogeneity lies in that the crosslink-and-hydration occurs in the molecule-network while the stress-bearing nanofiber-network remains unaffected. As one demonstration, a membrane assembled by bacterial cellulose nanofiber-network and Ca2+-crosslinked and hydrated sodium alginate molecule-network is designed. Studies show that the crosslinked-and-hydrated molecule-network restricts water invasion and boosts stress transfer of the nanofiber-network by serving as interfibrous bridge. Overall, the molecule-network makes the membrane hydrated and flexible; the nanofiber-network as stress-bearing component provides strength and *** HCH dual-scale network featuring a cooperative effect stimulates the design of advanced biomaterials applied under wet conditions such as guided bone regeneration membranes.

关键词： bioinspiration heterogeneous crosslink-and-hydration dual-scale network nanocomposite membrane wet mechanical properties guided bone regeneration

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华北泥河湾盆地铺路哺乳动物群的磁性地层学定年

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地球物理学报 2024年第1期67卷 225-240页

作者：李嘉皓刘平高显丽中国科学院大学地球与行星科学学院北京100049 中国科学院大学地球与行星科学学院计算地球动力学重点实验室北京100049 中国科学院大学北京燕山地球关键带国家野外科学观测研究站北京101408

华北泥河湾盆地的晚新生代河湖相沉积地层,产出了十分丰富的旧石器和哺乳动物化石,记录了早期人类活动以及晚上新世以来哺乳动物群的演化过程.作为广义泥河湾动物群之一,铺路动物群化石点位于盆地内的壶流河东侧,含有晚上新世及早更新... 详细信息

华北泥河湾盆地的晚新生代河湖相沉积地层,产出了十分丰富的旧石器和哺乳动物化石,记录了早期人类活动以及晚上新世以来哺乳动物群的演化过程.作为广义泥河湾动物群之一,铺路动物群化石点位于盆地内的壶流河东侧,含有晚上新世及早更新世哺乳动物化石.本文结合生物地层学和岩石地层学,对含铺路哺乳动物化石的河湖相沉积物,进行详细的岩石磁学及高分辨率的磁性地层学研究,旨在对铺路哺乳动物群进行精确定年.结果表明,铺路剖面河湖相沉积物的磁性矿物主要为磁铁矿、磁赤铁矿和赤铁矿,平均粒度以准单畴为主.铺路剖面河湖相沉积物记录了布容正极性时(Brunhes normal chron)早期、松山负极性时(Matuyama reverse chron)、高斯正极性时(Gauss normal chron)和吉尔伯特负极性时(Gilbert reverse chron)晚期,铺路动物群产出在留尼旺(Réunion)地磁漂移之前,凯纳(Kaena)负极性亚时之后,年代约为3.0~2.2 Ma.本研究结果将广义泥河湾动物群的年代下限延至约3.0 Ma.此外,结合泥河湾盆地古气候学及古环境学研究结果,表明在上新世与更新世过渡期间,泥河湾动物群的演化受气候环境变化的影响,更适应干旱寒冷的生存环境.

关键词：泥河湾盆地磁性地层学泥河湾动物群铺路动物群晚上新世

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身份与责任:航天工程师的伦理冲突探析

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自然辩证法通讯 2024年第3期46卷 102-110页

作者：张恒力李嘉豪李昂北京航空航天大学马克思主义学院北京100191 北京林业大学纪委办监察处北京100083

航天工程探索在逐步实现人类未来梦想征程中推进新兴技术创新与发展的同时,高风险的技术特征带来各种潜在的风险和伦理挑战。作为航天工程重要主体的航天工程师,承载着国家人、职业人和企业人等多重身份,面临责任要求冲突的道德困境,通... 详细信息

航天工程探索在逐步实现人类未来梦想征程中推进新兴技术创新与发展的同时,高风险的技术特征带来各种潜在的风险和伦理挑战。作为航天工程重要主体的航天工程师,承载着国家人、职业人和企业人等多重身份,面临责任要求冲突的道德困境,通过积极伦理等视阈,深度剖析道德困境的突出表征与技术根源,基于我国航天工程历史进程,明晰我国航天工程发展的道德原则和价值理想,以期更好地推动我国航天工程事业向善良性发展。

关键词：航天工程积极伦理学伦理冲突

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含氟流体助熔华南基底片麻岩的实验研究:对稀土成矿花岗岩成因的制约

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大地构造与成矿学 2024年第2期48卷 213-231页

作者：李嘉豪丁兴刘军锋于津海中国科学院广州地球化学研究所同位素地球化学国家重点实验室广东广州510640 长安大学地球科学与资源学院陕西西安710064 中国科学院深地科学卓越创新中心广东广州510640 南京大学地球科学与工程学院江苏南京210023

为了明确含氟流体对花岗岩源区岩浆过程中稀土元素地球化学行为的影响,本文采用华南代表性的高稀土片麻岩和低稀土片麻岩作为初始物质,与~4%的流体(纯水、1.5 mol/L HF、1.0 mol/L NaF)在0.8 GPa、1000℃的条件下开展了流体助熔的部分... 详细信息

为了明确含氟流体对花岗岩源区岩浆过程中稀土元素地球化学行为的影响,本文采用华南代表性的高稀土片麻岩和低稀土片麻岩作为初始物质,与~4%的流体(纯水、1.5 mol/L HF、1.0 mol/L NaF)在0.8 GPa、1000℃的条件下开展了流体助熔的部分熔融实验。实验结果表明,所有片麻岩的熔融程度达到40%以上,残余矿物组合主要为斜长石+石英+斜方辉石±单斜辉石+钛铁矿+磷灰石±黑云母。部分熔融产生的熔体的成分主要为花岗闪长质‒花岗质,总体具有高氟(0.11%~0.27%)、高水(0.38%~1.86%)和A2型花岗岩的特征;其中,高稀土片麻岩部分熔融形成的熔体为钾玄质和准铝质,而低稀土片麻岩熔融形成的熔体偏高钾钙碱性和强过铝质。在微量元素蛛网图上,两者均表现为富集K、Rb、Th、Ce、Sm、Y、Yb等元素,亏损Ba、Nb、Ta、Zr、Hf、Ti等元素;稀土元素配分曲线则表现为右倾、负Eu异常的特征。相对于原岩,含氟流体助熔会强化熔体中Si、K、Na、Rb、Sr、Ba、Th、U、LREE和F的富集,并增加熔体的La_(N)/Yb_(N)值。同时,实验也证实片麻岩部分熔融形成的熔体的稀土元素含量主要受原岩控制,高稀土片麻岩更易于熔出稀土元素初始富集的熔体;相对于原岩,各类流体助熔均会造成稀土元素在熔体中不同程度的富集,其中,含HF流体助熔最高可富集稀土46%~49%(近1.5倍富集)。我们因此认为在华南LREE型和HREE型成矿花岗岩形成过程中,含F流体发挥重要的作用。此外,本文也提出了一种新的A2型花岗岩形成机制,即含F流体助熔地壳基底岩石,这很好地解释了华南晚中生代大规模分布的与稀土、稀有金属及氟成矿相关的陆内A2型花岗岩的形成。

关键词：部分熔融流体助熔含氟流体稀土元素花岗岩片麻岩

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通道剪枝与知识蒸馏相结合的轻量化SAR目标检测

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测绘学报 2024年第4期53卷 712-723页

作者：黄启灏靳国旺熊新王丽美李佳豪信息工程大学地理空间信息学院河南郑州450001 河南城建学院测绘与城市空间信息学院河南平顶山467000

轻量化SAR目标检测方法对快速检测SAR影像中的地物目标具有重要意义。针对轻量化检测方法精度不高的问题,设计了一种通道剪枝与知识蒸馏相结合的轻量化SAR目标检测方法。该方法通过对复杂网络中批归一化层的缩放因子γ进行稀疏化训练,... 详细信息

轻量化SAR目标检测方法对快速检测SAR影像中的地物目标具有重要意义。针对轻量化检测方法精度不高的问题,设计了一种通道剪枝与知识蒸馏相结合的轻量化SAR目标检测方法。该方法通过对复杂网络中批归一化层的缩放因子γ进行稀疏化训练,判别对应特征通道的重要程度,进而裁剪次要通道,并在微调训练后将其作为教师网络,构造知识蒸馏框架指导轻量模型训练,提高轻量模型的检测精度。采用YOLOv5-6.1算法搭建了检测框架,并在重组的MSAR和SSDD多类目标数据集上进行了训练和检测试验,结果表明该方法能够在保持模型体积仅3.73 MB的轻量化条件下,提升SAR目标检测精度,验证了本文方法的有效性。

关键词： SAR 目标检测轻量化通道剪枝知识蒸馏

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