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The [4+2] Cycloaddition of 2-Pyrone in Total Synthesis

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Chinese Journal of Chemistry 2019年第9期37卷 946-976页

作者： quan Cai Department of Chemistry and Research Center for Molecular Recognition and Synthesis Fudan University220 Handan Rd.Shanghai 200433China

Diels-Alder reaction is one of the most important reactions in organic synthesis and has witnessed great achievements in total syntheses of complex natural *** this review,we will focus on the [4+2] cycloaddition that utilizes 2-pyrone as the diene *** advances of its applications in the total syntheses of natural products in the past fifty years will be discussed here.

关键词： Cycloaddition 2-Pyrone Total Synthesis

Bibliometric analysis of UAV swarms

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Journal of Systems Engineering and Electronics 2022年第2期33卷 406-425页

作者： JIANG Yangyang GAO Yan SONG Wenqi LI Yue quan quan Beihang University Library Beijing 100191China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Projects on unmanned aerial vehicle(UAV) swarms have been initiated in a big way in the last few years, especially from 2015 to 2016. As a result, the number of related works on UAV swarms has been on the rise, with the rate of growth dramatically accelerating since 2017. This research conducts a bibliometric analysis of robotics swarms and UAV swarms to answer the following questions:(i) Disciplines mentioned in the UAV swarms research.(ii) The future development trends and hotspots in the UAV swarms research.(iii) Tracking related outcomes in the UAV swarms research.

关键词： unmanned aerial vehicle(UAV)swarm bibliometric mapping knowledge domain

Aerial refueling scheduling of multi-receiver and multi-tanker under spatial-temporal constraints for forest firefighting

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Chinese Journal of Aeronautics 2024年第5期37卷 71-91,I0001页

作者： Jing HUANG Jiaqi XING Jinrui REN quan quan Youmin ZHANG Department of Information and Control Engineering Xi’an University of TechnologyXi’an 710048China Jiujiang Measuring Test Technology Research Institute Jiujiang 332000China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Automation Xi’an University of Posts&TelecommunicationsShaanxiXi’an 710121China Department of Mechanical Industrial and Aerospace EngineeringConcordia UniversityMontreal H3G 1M8Canada

Forest fires pose a significant threat to human life and property,so the utilization of unmanned aircraft systems provides new ways for forest *** the constrained load capacities of these aircraft,aerial refueling becomes crucial to extend their operational time and *** order to address the complexities of firefighting missions involving multi-receiver and multi-tanker deployed from various airports,first,a fuel consumption calculation model for aerial refueling scheduling is established based on the receiver ***,two distinct methods,including an integrated one and a decomposed one,are designed to address the challenges of establishing refueling airspace and allocating tasks for *** methods aim to optimize total fuel consumption of the receivers and tankers within the aerial refueling scheduling *** optimization problem is established as nonlinear optimization models along with *** integrated method seamlessly combines refueling rendezvous point scheduling and tanker task allocation into unified *** has a complete solution space and excels in optimizing total fuel *** decomposed method,through the separation of rendezvous point scheduling and task allocation,achieves a reduced computational ***,this comes at the cost of sacrificing optimality by excluding specific feasible ***,numerical simulations are carried out to verify the feasibility and effectiveness of the proposed *** simulations yield insights crucial for the practical engineering application of both the integrated and decomposed methods in real-world *** comprehensive approach aims to enhance the efficiency of forest firefighting operations,mitigating the risks posed by forest fires to human life and property.

关键词： Aerial refueling Scheduling Planning Spatial-temporal constraint Firefighting

Prospects of utilization of inter-subspecific heterosis between indica and japonica rice

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Journal of Integrative Agriculture 2020年第1期19卷 1-10页

作者： ZHANG Gui-quan Guangdong Provincial Key Laboratory of Plant Molecular Breeding State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources/College of AgricultureSouth China Agricultural University

The Asian cultivated rice(Oryza sativa L.) grown worldwide is divided into two subspecies, indica and japonica. It is well known that the heterosis of inter-subspecies is usually stronger than that of intra-subspecies. Since the 1970 s, indica hybrid rice, an intra-subspecific hybrid rice, has being widely used in China and even in the world. However, the inter-subspecific hybrid rice between indica and japonica is still unavailable. The major obstacle is the hybrid sterility of the inter-subspecies. In recent decades, the genetic and molecular basis of indica-japonica hybrid sterility was understood more and more clearly. Some breeding approaches for overcoming inter-subspecific hybrid sterility were proposed and used to develop the indicajaponica hybrid rice. The updated understanding will offer new approaches for development of breeding lines for overcoming indica-japonica hybrid sterility, which facilitates developing of inter-subspecific hybrid rice.

关键词： heterosis reproductive isolation hybrid sterility genetic basis molecular mechanism subspecies hybrid rice

A Note on Integral Structures in Some Locally Algebraic Representations of GL_(2)

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Acta Mathematica Sinica,English Series 2021年第1期37卷 59-72页

作者： Yong quan HU Morningside Center of Mathematics Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190P.R.China Chinese Academy of Sciences University of Chinese Academy of SciencesBeijing 100049P.R.China

In the p-adic local Langlands correspondence for GL2(Qp),the following theorem of Berger and Breuil has played an important role:the locally algebraic representations of GL2(Qp)associated to crystabelline Galois representations admit a unique unitary *** this note,we give a new proof of the weaker statement that the locally algebraic representations admit at most one unitary completion and such a completion is automatically *** proof is purely representation theoretic,involving neither(ψ,Γ)-module techniques nor global *** F is a finite extension of Qp,we also get a simpler proof of a theorem of Vignéras for the existence of integral structures for(locally algebraic)special series and for(smooth)tamely ramified principal series.

关键词： Invariant norm diagram

On Modeling Drilling Load in Lunar Regolith Simulant

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Chinese Journal of Mechanical Engineering 2018年第1期31卷 41-52页

作者： Qi-quan quan Chong-Bin Chen Zong-quan Deng Jun-Yue Tang De-Wei Tang State Key Laboratory of Robotics and System Harbin Institute of Technology

Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.

关键词： Lunar regolith drilling Lunar regolith simulant Drill-simulant interaction Screw conveyance

Synthesis of Copper Oxalate Nanorods by a Simple One-step Solid-state Chemical Reaction Method

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Chemical Research in Chinese Universities 2005年第2期21卷 134-136页

作者： CAOYa-li JIADian-zeng LIULang XIAODing-quan XINXin-quan InstituteofAppliedChemistry XinjiangUniversityUrumqi830046P.R.China DepartmentofMaterialsScience SichuanUniversityChengdu610064P.R.China StateKeyLaboratoryofCoordinationChemistry NanjingUniversityNanjing210093P.R.China

Copper oxalate nanorods were successfully prepared by means of a simple one-step solid-state reaction method with the assistance of a suitable surfactant, polyethylene glycol 400. The product with uniform rod-like morphology was characterized by XRD, TEM and SEM. The formational mechanism of the rod-like structure was also preliminary discussed.

关键词： Nanorod Nanostructure Solid-state reaction Copper oxalate

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道路桥梁钻孔灌注桩施工技术研究

价值工程 2025年第1期44卷 36-38页

作者：范志泉龙岩交通建设集团有限公司龙岩364000

钻孔灌注桩因其适应性强、成本合理、施工便捷,在公路桥梁、港口等工程领域得到广泛应用。然而,其成桩过程复杂,影响质量的因素众多,因此需要严格控制每一环节并全面考虑各种影响因素。本文通过研究东山大桥道路桥梁工程的灌注桩施工,... 详细信息

钻孔灌注桩因其适应性强、成本合理、施工便捷,在公路桥梁、港口等工程领域得到广泛应用。然而,其成桩过程复杂,影响质量的因素众多,因此需要严格控制每一环节并全面考虑各种影响因素。本文通过研究东山大桥道路桥梁工程的灌注桩施工,深入对比分析了旋挖成孔和冲击成孔两种方式的技术特性、工效及成本,旨在为类似工程提供有益参考。通过综合比较不同施工方案,可结合工程需求、施工条件和经济效益,选出最佳方案,进而提升工程质量,降低成本并缩短工期。

关键词：钻孔灌注桩旋挖成孔冲击成孔施工方案

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Fully enclosed hybrid electromagnetic-triboelectric nanogenerator to scavenge vibrational energy

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Nano Research 2016年第8期9卷 2226-2233页

作者： Ting quan Ya Yang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences National Center for Nanoscience and Technology Beijing 100083 China

We propose a fully enclosed hybrid nanogenerator consisting of five elec- tromagnetic generators （EMGs） and four triboelectric nanogenerators （TENGs）. Under a vibration frequency of 15.5 Hz, one TENG can deliver a high output voltage of approximately 24 V and a low output current of approximately 24 μA, whereas one EMG can deliver a low output voltage of approximately 0.8 V and a high output current of approximately 0.5 mA. By integrating five rectified EMGs in series and four rectified TENGs in parallel, the hybrid nanogenerator can be used to charge a home-made Li-ion battery from 1 to 1.9 V in 6.3 h. By using the hybrid nanogenerator to scavenge the vibrational energy produced by human hands, a temperature-humidity sensor can be sustainably powered by the nanogenerator, which is capable of charging the 200 ~F system power capacitor from 0 to 2 V in 15 s, and sustainably power the sensor in 29 s.

关键词： hybrid nanogenerator electromagnetic triboelectric vibration energy Li-ion battery