检索结果-南通市图书馆

On the Innovation,Design,Construction,and Experiments of OMEGA-Based SSPS Prototype:The Sun-Chasing Project

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第5期36卷 90-101页

作者： Baoyan duan Yiqun Zhang Guangda Chen Ze Zhao Jianwei Mi Xun li lin Yang Xi li Research Institute on Mechatronics Xidian UniversityXi’an 710071China Research Institute of Antenna Xidian UniversityXi’an 710071China

This study systematically introduces the development of the world’s first full-link and full-system ground demonstration and verification system for the OMEGA space solar power satellite(SSPS).First,the OMEGA 2.0 innovation design was ***,field-coupling theoretical models of sunlight concentration,photoelectric conversion,and transmitting antennas were established,and a systematic optimization design method was ***,a beam waveform optimization methodology considering both a high beam collection efficiency and a circular stepped beam shape was ***,a control strategy was developed to control the condenser pointing toward the sun while maintaining the transmitting antenna toward the ***,a high-efficiency heat radiator design method based on bionics and topology optimization was ***,a method for improving the rectenna array’s reception,rectification,and direct current(DC)power synthesis efficiencies is ***,high-precision measurement technology for high-accuracy beam-pointing control was ***,a smart mechanical structure was designed and ***,the developed SSPS ground demonstration and verification system has the capacity for sun tracking,a high concentration ratio,photoelectric conversion,microwave conversion and emission,microwave reception,and rectification,and thus satisfactory results were obtained.

关键词： OMEGA-SSPS Full-link and full-system Beam collection efficiency Circular stepped beam shape Smart structure Field coupling theoretical model `Beam pointing control

Effect of yttrium on catalytic performance of Y-doped TiO_(2) catalysts for propane dehydrogenation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第5期42卷 962-971,I0005页

作者： liyu Hou liming Xia Ruipeng Zhou Jianmei li Renjie li Zhen Zhao Guimei Yuan Aijun duan State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang110034China

Defective bulk catalysts based on TiO_(2) have superior catalytic performance for propane dehydrogenation(PDH).The oxygen vacancy concentration and the number of active sites on the catalyst surface can be effectively tuned by doping metal in TiO_(2).Herein,yttrium(Y)-doped titanium dioxide(nY/TiO_(x))catalysts were in-situ synthesized via the coprecipitation method to study the effect of rare earth metal Y doping on the structure of TiO_(2) and the catalytic performance for *** results demonstrate that Ydoped TiO_(2) exhibits higher catalytic activity,propylene selectivity and stability than bare TiO_(2).Full characterizations with X-ray diffraction(XRD),high-resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS),infrared spectroscopy of pyridine adsorption(Py-IR),temperature-programmed desorption of ammonia(NH_(3)-TPD),H_(2) temperature-programmed reduction(H_2-TPR),and Raman techniques on these catalysts reveal that Y^(3+)can enter TiO_(2) lattice,and the lattice stability of the catalyst can be enhanced by replacing Ti^(4+)to form Y-O-Ti ***,the introduction of an appropriate amount of Y can obviously promote the PDH reaction by adjusting the acidity of the catalyst,improving the release capacity of TiO_(2) lattice oxygen and increasing the formation of active ***,excessive Y doping will lead to pore clogging,and the exposure of active sites will be reduced,resulting in the degradation of catalytic performance.

关键词： Propane dehydrogenation Anatase Lattice defects Coordinatively unsaturated Ti cations Oxygen vacancy Rare earths

Human-robot object handover:Recent progress and future direction

在线全文

学校读者我要写书评

暂无评论

Biomimetic Intelligence & Robotics 2024年第1期4卷 1-13页

作者： Haonan duan Yifan Yang Daheng li Peng Wang Institute of Automation Chinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Centre for Artificial Intelligence and Robotics Hong Kong Institute of Science and InnovationChinese Academy of SciencesHong Kong 999077China

Human-robot object handover is one of the most primitive and crucial capabilities in human-robot *** is of great significance to promote robots to truly enter human production and life scenarios and serve human in numerous *** progressions in the field of human-robot object handover have been made by *** article reviews the recent literature on human-robot object *** this end,we summarize the results from multiple dimensions,from the role played by the robot(receiver or giver),to the end-effector of the robot(parallel-jaw gripper or multi-finger hand),to the robot abilities(grasp strategy or motion planning).We also implement a human-robot object handover system for anthropomorphic hand to verify human-robot object handover *** review aims to provide researchers and developers with a guideline for designing human-robot object handover methods.

关键词： Human-robot interactions Object handover

In vivo haploid induction in cauliflower,kale,and broccoli

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第9期66卷 1823-1826页

作者： Guixiang Wang Mei Zong Shuo Han Hong Zhao Mengmeng duan Xin liu ning Guo Fan liu State Key Laboratory of Vegetable Biobreeding Beijing Key Laboratory of Vegetable Germplasm ImprovementBeijing Vegetable Research CenterBeijing Academy of Agriculture and Forestry SciencesBeijing100097China

Brassica oleracea (family Brassicaceae) represents a group of economically valuable vegetables cultivated worldwide,including cabbage (var. capitata), cauliflower (var. botrytis),broccoli (var. italica), and kale (var. acephala). These crops are typically self-incompatible and require vernalization for flowering, thereby contributing to their long growth cycles.

关键词： breeding crops thereby

Combination of methylthio-chemistry with living crystallization-driven self-assembly toward uniformπ-conjugated nanostructures with antibacterial activity,surface tailorability,tunable morphology and dimension

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第7期67卷 2341-2352页

作者： Chuyu duan Binbin Xu Ruru li Xiaoyu Huang Shaoliang lin Chun Feng Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

living crystallization-driven self-assembly(CDSA)provides robust access to uniformπ-conjugated nanostructures(CNSs)from block copolymers(BCPs)containing a crystallineπ-conjugated segment with controlled dimension,morphology and composition,which show appealing applications in biomedicine,photocatalysis and *** further expand the application spectrum of these CNSs,the development of facile strategies toward diverse CNSs with varying structures/functionalities is highly ***,BCPs consisting of oligo(p-phenylene ethynylene)-b-poly(polypropyl-3-methanethiol acrylate)(OPE_(9)-bPMTPA35and OPE_(9)-b-PMTPA_(58);the subscript represents the number of repeat unit of each block)consisting of a crystallineπ-conjugated core-forming OPE_(9)segment and a corona-forming PMTPA block are *** efficient“click-type”alkylation of methylthio groups,OPE_(9)-b-PMTPA with varying contents of sulfonium unit is *** ribbon-like micelles with different widths and lengths can then be generated in a controlled manner via the self-seeding approach of living ***,negatively charged polymeric and Ag nanoparticles can be immobilized on sulfonium/methylthio-containing shells by taking advantage of electrostatic attraction and coordination interaction,***,the ribbon-like micelles with positively charged shells exhibit antibacterial activity against *** the ease of modification of PMTPA-based shell and attractive opto-electronic/photocatalytic properties ofπ-conjugated units,the combination of methylthio-chemistry and living CDSA opens a new avenue to generate multi-functional CNSs for widespread applications from biomedicine to photocatalysis.

关键词： crystallization-driven self-assembly block copolymer π-conjugated nanostructure methylthio-chemistry

Engineering and dynamics of heterogeneous catalysts via metal single atoms as promoters/precursors

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2547-2565页

作者： Jiwei li Junli Xu Jingyun Yang Zitao duan Zhun Zhang Haifeng Xiong State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province Xiamen 361102China

Metal single-atom catalysts(SACs) have emerged as a focal point of research, captivating the scientific community due to their distinctive electronic properties and unparalleled catalytic prowess in the realm of heterogeneous catalysis. However, their significance transcends their role as mere active sites. Recent investigations have illuminated the multifaceted capabilities of metal single atoms as catalyst promoters and precursors, paving the way for the engineering of highly efficient heterogeneous catalysts. Single-atom promoters not only enhance the stabilization of active metals and tailor the support material, but regulate the reactive interfacial structure, eventually tuning the catalytic performance. Furthermore, SACs were also used as catalyst precursors to design new catalyst active sites. During the pretreatment or catalytic reaction, the structure of the metal single sites is changed significantly and transformed into the new and more active state, which improve the adsorption and reactive ability of reactants or intermediates. In this critical review, we comment the recent development of metal SACs used as catalyst promoters/precursors in engineering heterogeneous catalysts, including thermal catalysis and electrocatalysis. Furthermore, the dynamic evolution of the SACs during the pretreatment or catalytic reaction is also discussed. Finally, we provide our insight to potentially guide the future development on this emerging field.

关键词： single-atom catalysts single-atom promoter single-atom precursor dynamic evolution

Surgical techniques to prevent delayed gastric emptying after pancreaticoduodenectomy

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2024年第5期23卷 449-457页

作者： Peng duan Lu Sun Kai Kou Xin-Rui li Ping Zhang Department of Hepatobiliary and Pancreatic Surgery General Surgery Centerthe First Hospital of Jilin UniversityChangchun 130021China Department of Dental Implantology Hospital of StomatologyJilin UniversityChangchun 130021China

Background: Delayed gastric emptying(DGE) is one of the most common complications after pancreaticoduodenectomy(PD). DGE represents impaired gastric motility without significant mechanical obstruction and is associated with an increased length of hospital stay, increased healthcare costs, and a high readmission rate. We reviewed published studies on various technical modifications to reduce the incidence of DGE. Data sources: Studies were identified by searching Pub Med for relevant articles published up to December 2022. The following search terms were used: “pancreaticoduodenectomy”, “pancreaticojejunostomy”, “pancreaticogastrostomy”, “gastric emptying”, “gastroparesis” and “postoperative complications”. The search was limited to English publications. Additional articles were identified by a manual search of references from key articles. Results: In recent years, various surgical procedures and techniques have been explored to reduce the incidence of DGE. Pyloric resection, Billroth II reconstruction, Braun's enteroenterostomy, and antecolic reconstruction may be associated with a decreased incidence of DGE, but more high-powered studies are needed in the future. Neither laparoscopic nor robotic surgery has demonstrated superiority in preventing DGE, and the use of staplers is controversial regarding whether they can reduce the incidence of DGE. Conclusions: Despite many innovations in surgical techniques, there is no surgical procedure that is superior to others to reduce DGE. Further larger prospective randomized studies are needed.

关键词： Pancreaticoduodenectomy Delayed gastric emptying Postoperative complications Surgical techniques

Influences of chemical reactions on polysulfide reduction reaction process on promotor surface in li-S batteries

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2712-2718页

作者： Yufeng Luo Zhenhan Fang Zixin Hong Shaorong duan Haitao liu Hengcai Wu Qunqing li Yuegang Zhang Shoushan Fan Wenhui duan Jiaping Wang Tsinghua-Foxconn Nanotechnology Research Center Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China Frontier Science Center for Quantum Information Tsinghua UniversityBeijing 100084China

Polar promotors have been proven effective in catalyzing the polysulfide(PS)reduction reaction(PSRR)process in lithium-sulfur(li-S)***,the promotor surface tends to be poisoned due to the accumulation of insoluble discharging products of lithium disulfide(li_(2)S_(2))and lithium sulfide(li_(2)S)during li-S battery ***,we investigate the detailed PSRR mechanism on the surface of manganese sulfides(MnS)as a representative promoter by performing in-situ Raman mapping *** catalytic ability of MnS enables thorough electrochemical reduction of PSs to li_(2)S_(2) and li_(2)S on the MnS *** generated li_(2)S_(2) and li_(2)S then adsorb the dissolved PSs via chemical reactions among sulfur species during the subsequent PSRR *** phenomenon mitigates promotor poisoning and continuously improves the reversible ***,the assembled li-S cell demonstrates excellent electrochemical performance after introducing a conductive interlayer containing a thin piece of carbon nanotube film and MnS promotors.

关键词： promotors polysulfides chemical reactions catalytic ability in-situ Raman measurements

Abelmoschus manihot polysaccharide fortifies intestinal mucus barrier to alleviate intestinal inflammation by modulating Akkermansia muciniphila abundance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第9期14卷 3901-3915页

作者： Yumeng Wang Chengxi li Jianping li Shu Zhang Qinyu Zhang Jinao duan Jianming Guo Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization Nanjing University of Chinese MedicineNanjing 210023China Jiangsu Key Laboratory for High Technology Research of TCM Formulae Nanjing University of Chinese MedicineNanjing 210023China

The intestinal mucus barrier is an important line of defense against gut *** to this barrier brings bacteria into close contact with the epithelium,leading to intestinal ***,its restoration is a promising strategy for alleviating intestinal *** study showed that Abelmoschus manihot polysaccharide(AMP)fortifies the intestinal mucus barrier by increasing mucus production,which plays a crucial role in the AMP-mediated amelioration of ***-10-deficient mouse models demonstrated that the effect of AMP on mucus production is dependent on ***,bacterial depletion and replenishment confirmed that the effects of AMP on IL-10 secretion and mucus production were mediated by Akkermansia *** findings suggest that plant polysaccharides fortify the intestinal mucus barrier by maintaining homeostasis in the gut *** demonstrates that targeting mucus barrier is a promising strategy for treating intestinal inflammation.

关键词： Plant polysaccharide Abelmoschus manihot Intestinal inflammation Mucus barrier Interleukin 10 Gut microbiota A.muciniphila Mucin 2