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An approach for formation design and flight performance prediction based on aerodynamic formation unit:Energy-saving considerations

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Chinese Journal of Aeronautics 2024年第3期37卷 77-91页

作者： Nanxuan qiao Tielin MA Xiangsheng WANG Jie WANG Jingcheng FU Pu XUE School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Institute of Unmanned System Beihang UniversityBeijing 100191China Key Laboratory of Advanced Technology of Intelligent Unmanned Flight System Ministry of Industry and Information TechnologyBeijing 100191China School of Transportation Science and Engineering Beihang UniversityBeijing 102206China Beijing Institute of Space Long March Vehicle Beijing 100076China

The performance improvement of swarm drones through aerodynamic shape optimization may be challenging due to folded size constraints imposed by the specific launch approach.However,fixed-wing aircraft swarms can benefit from formation flight in terms of energy consumption.This study introduces the concept of the"aerodynamic formation unit",which consists of two or three aircraft that form an inseparable unit of the formation.Considering the Unmanned Aerial Vehicle(UAV)distribution and wingtip vortex interference in the formation,two typical aerodynamic formation units are optimized by the variable-fidelity aerodynamic optimization method based on space mapping.The aerodynamic characteristics of the formation UAVs that affect flight performance,such as lift-to-drag ratio(L/D ratio)and static stability are analyzed by Computational Fluid Dynamics(CFD)simulations.The L/D ratio(cruising condition)of the following aircraft can be increased by 22.8%and 57.5%in the optimal units that involve two and three aircraft respectively.Moreover,this study conducts several CFD simulations for multi-aircraft formations formed by the units,which show that the average L/D ratio of the formation can be improved by more than 19%.These results verify the feasibility and effectiveness of the"aerodynamic formation unit"concept and the optimization framework for formation parameters.

关键词： Formation flight CFD Aerodynamic formation unit Wingtip vortices Foldable tandem-wing aircraft

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Integrated Frequency-constrained Scheduling Considering Coordination of Frequency Regulation Capabilities from Multi-source Converters

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 261-274页

作者： Jiaming Li Ying qiao Zongxiang Lu Wei Ma Xin Cao Rongfu Sun the Department of Electrical Engineering Tsinghua UniversityBeijing 100084China the China Suntien Green Energy Limited Company Shijiazhuang 050011China the State Grid Jibei Electric Power Company Beijing 100054China

As the proportion of renewable energy(RE)increases,the inertia and the primary frequency regulation(FR)capability of the power system decrease.Thus,ensuring frequency security in the scheduling model has become a new technical requirement in power systems with a high share of RE.Due to a shortage of conventional synchronous generators,the frequency support of multi-source converters has become an indispensable part of the system frequency resources,especially variable-speed wind turbine generation(WTG)and battery energy storage(BES).Quantitative expression of the FR capability of multi-source converters is necessary to construct frequency-constrained scheduling model.However,the frequency support performance of these converter-interfaced devices is related to their working states,operation modes,and parameters,and the complex coupling of these factors has not been fully exploited in existing models.In this study,we propose an integrated frequency-constrained scheduling model considering the coordination of FR capabilities from multi-source converters.Switchable FR control strategies and variable FR parameters for WTG with or without reserved power are modeled,and multi-target allocation of BES capacity between tracking dispatch instruction and emergency FR is analyzed.Then,the variable FR capabilities of WTG and BES are embedded into the integrated frequency-constrained scheduling model.The nonlinear constraints for frequency security are precisely linearized through an improved iteration-based strategy.The effectiveness of the proposed model is verified in a modified IEEE 24-bus standard system.The results suggest that the coordinated participation of BES and WTG in FR can effectively reduce the cost of the scheduling model while meeting frequency security constraints.

关键词： Battery energy storage(BES) wind turbine generation(WTG) frequency regulation(FR) frequency security power system scheduling

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二氧化碳加氢制甲醇过程中铜基催化剂活性位点研究进展

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化工进展 2023年第S1期42卷 287-298页

作者：时永兴林刚孙晓航蒋韦庚乔大伟颜彬航江苏华电句容发电有限公司江苏镇江212413 清华大学化学工程系北京100084

二氧化碳加氢制甲醇反应研究对解决能源紧缺和环境问题具有重要意义。以Cu/ZnO/Al_(2)O_(3)为代表的铜基催化剂因其反应活性高、成本低廉而备受关注,受限于催化剂中Cu物种的电子结构多样性与表征技术的发展水平,铜基催化剂的真实活性位... 详细信息

二氧化碳加氢制甲醇反应研究对解决能源紧缺和环境问题具有重要意义。以Cu/ZnO/Al_(2)O_(3)为代表的铜基催化剂因其反应活性高、成本低廉而备受关注,受限于催化剂中Cu物种的电子结构多样性与表征技术的发展水平,铜基催化剂的真实活性位点、反应机理尚不清楚。本文综述了二氧化碳加氢制甲醇过程中铜基催化剂活性位点的研究进展,并结合原位表征技术的研究进展对其反应机理进行综述。研究人员结合多种先进表征手段确定了活性位点的结构和组成,同时揭示了不同催化剂结构对反应性能的影响。通过原位表征技术的应用,可以实时观察反应过程中催化剂的结构变化,揭示了反应关键步骤和催化剂的作用方式。未来可以结合更多原位表征技术和计算模拟方法,探索催化剂微观结构和反应机理,以更高的反应性能制备绿色甲醇。

关键词：二氧化碳加氢甲醇合成铜基催化剂活性位点原位表征技术

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Deep learning-based optical aberration estimation enables offline digital adaptive optics and super-resolution imaging

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Photonics Research 2024年第3期12卷 474-484页

作者： CHANG qiao HAOYU CHEN RUN WANG TAO JIANG YUWANG WANG DONG LI Department of Automation Tsinghua UniversityBeijing 100084China Institute for Brain and Cognitive Sciences Tsinghua UniversityBeijing 100084China National Laboratory of Biomacromolecules New Cornerstone Science LaboratoryCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Optical aberrations degrade the performance of fluorescence microscopy.Conventional adaptive optics(AO)leverages specific devices,such as the Shack–Hartmann wavefront sensor and deformable mirror,to measure and correct optical aberrations.However,conventional AO requires either additional hardware or a more complicated imaging procedure,resulting in higher cost or a lower acquisition speed.In this study,we proposed a novel space-frequency encoding network(SFE-Net)that can directly estimate the aberrated point spread functions(PSFs)from biological images,enabling fast optical aberration estimation with high accuracy without engaging extra optics and image acquisition.We showed that with the estimated PSFs,the optical aberration can be computationally removed by the deconvolution algorithm.Furthermore,to fully exploit the benefits of SFE-Net,we incorporated the estimated PSF with neural network architecture design to devise an aberration-aware deeplearning super-resolution model,dubbed SFT-DFCAN.We demonstrated that the combination of SFE-Net and SFT-DFCAN enables instant digital AO and optical aberration-aware super-resolution reconstruction for live-cell imaging.

关键词： optics resolution enable

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Identifying the geographical origin and processing technology of Moyao(Myrrh) on the basis of near-infrared spectroscopy combined with chemometrics

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Journal of Traditional Chinese Medicine 2024年第3期44卷 505-514页

作者： XU Ningning YAN Ganming XU Fengjie DENG Linfeng qiao Xinjiang LU Changzheng CHENG Shaomin TCM Diagnosis Institute College of Traditional Chinese MedicineJiangxi University of Chinese Medicine TCM Processing Institute Pharmaceutical CollegeJiangxi University of Chinese medicine School of Electronic Information and Artificial Intelligence Shaanxi University of Science and Technology Jiangzhong Pharmaceutical Co. Ltd. Jiangxi Guhan Refined Chinese Herbal Pieces Co. Ltd.

OBJECTIVE: To evaluate the quality of Moyao(Myrrh) in the identification of the geographical origin and processing of the products. METHODS: Raw Moyao(Myrrh) and two kinds of Moyao(Myrrh) processed with vinegar from three countries were identified using near-infrared(NIR) spectroscopy combined with chemometric techniques. Principal component analysis(PCA) was used to reduce the dimensionality of the data and visualize the clustering of samples from different categories. A classical chemometric algorithm(PLS-DA) and two machine learning algorithms [K-nearest neighbor(KNN) and support vector machine] were used to conduct a classification analysis of the near-infrared spectra of the Moyao(Myrrh) samples, and their discriminative performance was evaluated. RESULTS: Based on the accuracy, precision, recall rate, and F1 value in each model, the results showed that the classical chemometric algorithm and the machine learning algorithm obtained positive results. In all of the chemometric analyses, the NIR spectrum of Moyao(Myrrh) preprocessed by standard normal variation or Multivariate scattering correction combined with KNN achieved the highest accuracy in identifying the geographical origins, and the accuracy of identifying the processing technology established by the KNN method after first-order derivative pretreatment was the best. The best accuracy of geographical origin discrimination and processing technology discrimination were 0.9853 and 0.9706 respectively. CONCLUSIONS: NIR spectroscopy combined with chemometric technology can be an important tool for tracking the origin and processing technology of Moyao(Myrrh) and can also provide a reference for evaluations of its quality and the clinical use.

关键词： Moyao () geographical origin near-infrared spectroscopy processing technology

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Nitrogen‑Doped Magnetic‑Dielectric‑Carbon Aerogel for High‑Efficiency Electromagnetic Wave Absorption

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Nano-Micro Letters 2024年第1期16卷 313-327页

作者： Shijie Wang Xue Zhang Shuyan Hao Jing qiao Zhou Wang Lili Wu Jiurong Liu Fenglong Wang Key Laboratory for Liquid‑Solid Structural Evolution and Processing of Materials Ministry of Education Shandong UniversityJinan 250061People’s Republic of China School of Mechanical Engineering Shandong UniversityJinan 250061People’s Republic of China Shenzhen Research Institute of Shandong University Shenzhen 518057GuangdongPeople’s Republic of China

Carbonbased aerogels derived from biomass chitosan are encountering a flourishing moment in electromagnetic protection on account of lightweight,controllable fabrication and versatility.Nevertheless,developing a facile construction method of component design with carbon-based aerogels for high-efficiency electromagnetic wave absorption(EWA)materials with a broad effective absorption bandwidth(EAB)and strong absorption yet hits some snags.Herein,the nitrogen-doped magnetic-dielectric-carbon aerogel was obtained via ice template method followed by carbonization treatment,homogeneous and abundant nickel(Ni)and manganese oxide(MnO)particles in situ grew on the carbon aerogels.Thanks to the optimization of impedance matching of dielectric/magnetic components to carbon aerogels,the nitrogen-doped magnetic-dielectric-carbon aerogel(Ni/MnO-CA)suggests a praiseworthy EWA performance,with an ultra-wide EAB of 7.36 GHz and a minimum reflection loss(RLmin)of−64.09 dB,while achieving a specific reflection loss of−253.32 dB mm−1.Furthermore,the aerogel reveals excellent radar stealth,infrared stealth,and thermal management capabilities.Hence,the high-performance,easy fabricated and multifunctional nickel/manganese oxide/carbon aerogels have broad application aspects for electromagnetic protection,electronic devices and aerospace.

关键词： Electromagnetic wave absorption Wide bandwidth Dielectric-magnetic synergy Multifunction

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Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation

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National Science Review 2024年第2期11卷 155-167页

作者： Peng He Meng-Yang Hu Jin-Hong Li Tian-Zhang qiao Yi-Lin Lu Shou-Fei Zhu Frontiers Science Center for New Organic Matter State Key Laboratory and Institute of Elemento-Organic Chemistry Nankai University

Iron catalysts are ideal transition metal catalysts because of the Earths abundant, cheap, biocompatible features of iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively,and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.

关键词： spin effect spin-delocalization spin crossover iron-catalysis alkyne hydrosilylation

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Effects of Different Light Qualities on the Growth Characteristics of Populus trinervis

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 1043-1056页

作者： Jiaqi Li Zhensheng qiao Dan Zong Chengzhong He Key Laboratory for Forest Genetics and Tree Improvement and Propagation in Universities of Yunnan Province Southwest Forestry UniversityKunmingChina Key Laboratory of Biodiversity Conservation in Southwest China State Forestry AdministrationSouthwest Forestry UniversityKunmingChina Key Laboratory for Forestry Resources Conservation and Utilization in the Southwest Mountains of China Ministry of EducationSouthwest Forestry UniversityKunmingChina

Populus trinervis is native to China and plays an irreplaceable role in maintaining the ecological balance of boreal and temperate forests.P.trinervis mainly grows in high-altitude areas.At present,there are limited studies on the response of P.trinervis to different light qualities,so it is necessary to investigate the photosynthetic physiological changes of P.trinervis in different light environments.In our study,P.trinervis was grown for 8 months under light filtered by three different colored films.The three treatments were blue film,green film,and white plastic film.The effects of blue(B),green(G),and white(W)light on photosynthetic pigment content,absolute growth,photosynthetic parameters,soluble sugar content,and chlorophyll fluorescence parameters were studied,respectively.Compared to the Wtreatment,the chlorophyll a and b,carotenoids,total chlorophyll content(a+b),absolute growth of seedling height,net photosynthetic rate(PN),water use efficiency(WUE),total soluble sugars,sucrose,and nonphotochemical quenching(NPQ)of P.trinervis were significantly increased under B treatment.Meanwhile,chlorophyll a and b,carotenoids,total chlorophyll(a+b),transpiration rate(Tr),intercellular CO2 concentration(Ci),stomatal conductance(gs),absolute growth of seedling height and leaf length,reducing sugar,total soluble sugar content,and NPQ were significantly increased under G treatment.The results showed that the absolute growth and chlorophyll content of P.trinervis were increased under B light,while the sugar and photosynthetic parameters were increased under G light.Additional studies may look into how B light impacts absolute growth and promotional mechanisms,as well as how G light affects the accumulation of sugar levels.

关键词： Blue light green light white light photosynthetic pigment soluble sugar

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A case report of bilateral lateral ventricle calcified pseudoneoplasm of the neuraxins

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Chinese Neurosurgical Journal 2024年第1期10卷 67-72页

作者： Xiaolong qiao Yinan Chen Ying Ji Chaoshi Niu Chuandong Cheng Anhui University of Science and Technology HuainanAnhui 232001People’s Republic of China Department of Neurosurgery The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of China1st Tianehu RoadHefeiAnhui 230031People’s Republic of China

Background Calcifying pseudoneoplasm of the neuraxis(CAPNON)is indeed a rare central nervous system lesion that can occur in central nervous system(CNS).Due to its infrequency and limited literature reports,it is challenging to diagnose and manage CAPNON.Case presentation In this intriguing study,we embarked on a quest to uncover the story of a 16-year-old girl who experienced bothersome headaches.Through advanced imaging techniques like computed tomography(CT)and magnetic resonance imaging(MRI),we glimpsed a delicate calcified growth within the lateral ventricles’posterior horn.Motivated by our unwavering commitment to solving mysteries,we embarked on a surgical journey that not only freed the young patient from her ailment but also shed light on the true nature of her puzzling adversary—a remarkable CAPNON.Conclusions For patients with CAPNON who have multiple or non-respectable lesions,the primary goal is to alleviate symptoms.After alleviating the symptoms with partial resection,close monitoring of any residual lesions is essential.If there is no evidence for disease progression,a strategy of continued close observation is appropriate.

关键词： CAPNON Imaging Pathology Operation

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Supramolecular Thermally Activated Delayed Fluorescence Materials via Through-Space Charge Transfer

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CCS Chemistry 2024年第5期6卷 1165-1173页

作者： Yuqian Wang Ruicong Feng Yang Yu qiao Song Shenzhen Grubbs Institute Southern University of Science and TechnologyShenzhen 518055 Department of Chemistry Southern University of Science and TechnologyShenzhen 518055

Thermally activated delayed fluorescence(TADF)polymeric materials based on through-space charge transfer(TSCT)have emerged as a highly studied topic in recent years.However,the construction of TSCT TADF materials via a supramolecular approach is still a big challenge.In this work,we report the noncovalent synthesis of TSCT TADF materials using a cyclic peptide-based bottle-brushed supramolecular polymer as a scaffold.By bringing the TSCT donor and acceptor in close proximity in space using the supramolecular scaffold,distinctive TADF emission in both solution and solid states could be achieved.Furthermore,the TADF system could be utilized as a sensitizer to coassemble with fluorescence acceptors to build thermally assisted fluorescence systems,resulting in color-tunable delayed fluorescence with high efficiency and color purity.Our findings provide a facile yet effective approach to designing and fabricating TSCT TADF materials,which might hold great potential for applications in the fields of organic light-emitting diode,bioimaging,and sensing.

关键词： supramolecular chemistry cyclic peptide thermally activated delayed fluorescence throughspace charge transfer thermally assisted fluorescence

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