检索结果-南通市图书馆

Supported Recyclable Metal-free Frustrated Lewis Pair Catalyst for Catalytic Hydrogenation of Substituted Pyridines to Piperidines

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2024年第4期40卷 682-689页

作者： MA Shaohua tang Zhiyong CAS Key Laboratory for Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P.R.China University of Chinese Academy of Sciences Beijing100049P.R.China

The construction of heterogeneous frustrated Lewis pairs(FLPs)catalysts is crucial for realizing highly efficient and recyclable pyridines catalytic *** this work,we prepared a recyclable heterogenous FLPs catalyst CMP-BF with conjugated microporous polymer CMP-ethynyl as the support via self-catalyzed 1,1-carboboration reaction with commercial Lewis acid B(C_(6)F_(5))_(3).The as-synthesized CMP-BF demonstrates superior heterogenous catalytic hydrogenation performance(conversion>99%),and considerable stability(84%conversion after three cycles)in recyclable hydrogenation of 2,*** work provides insights into the fabrication and catalytic application of recyclable heterogenous FLP catalysts.

关键词： Pyridine hydrogenation Frustrated Lewis pair Conjugated microporous polymer

Homological Transfer between Additive Categories and Higher Differential Additive Categories

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 Mathematica Sinica,English Series 2024年第5期40卷 1325-1344页

作者： Xi tang Zhao Yong HUANG School of Science Guilin University of Aerospace TechnologyGuilin 541004P.R.China Department of Mathematics Nanjing UniversityNanjing 210093P.R.China

Given an additive category C and an integer n≥*** higher differential additive category consists of objects X in C equipped with an endomorphism ϵ_(X)satisfying ϵ_(X)^(n).Let R be a,finite-dimensional basic algebra over an algebraically closed field and T the augmenting functor from the category of finitely generated left R-modules to that of finitely generated left R/(t^(n))-*** is proved that a finitely generated left R-module M isτ-rigid(respectively,(support)τ-tilting,almost completeτ-tilting)if and only if so is T(M)as a left R[t]/(t^(n))-***,R isτm-selfinjective if and only if so is R[t]/(t^(n)).

关键词： Higher differential objects Wakamatsu tilting subcategories G_(ω)-projective modules sup-portτ-tilting modules τ_(m)-selfinjective algebras precluster tilting subcategories

Key-Part Attention Retrieval for Robotic Object Recognition

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第3期29卷 644-655页

作者： Jierui Liu Zhiqiang Cao Yingbo tang State KeyLaboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of SciencesBeijing100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

The ability to recognize novel objects with a few visual samples is critical in the robotic *** methods mainly concern the recognition of inter-category objects,however,the object recognition fromdifferent sub-classes within the same category remains challenging due to their similar *** thispaper,we propose a key-part attention retrieval solution to distinguish novel objects of different sub-classesaccording to a few samples without ***,an object encoder,including convolutional neuralnetwork with attention and key-part aggregation,is designed to generate object attention map and extract theobject-level embedding,where object attention map from the middle stage of the backbone is used to guide thekey-part ***,to overcome the non-differentiability drawback of key-part attention,the objectencoder is trained in a two-step scheme,and a more stable object-level embedding is *** this basis,the potential objects are located from a scene image by mining connected domains of the attention *** the embedding of each potential object and embeddings from support data,the recognition of thepotential objects is *** effectiveness of the proposed method is verified by experiments.

关键词： key-part attention retrieval robotic object recognition

A supramolecular self-assembly material based on cucurbituril and cationic TPE as ultra-sensitive probe of energetic pentazolate salts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第5期35卷 69-76页

作者： Boan tang Jingxiang Zhong Shutao Wang Shiyu Zhou Yongxing tang Wei Huang School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

The successful synthesis of the pentazolate anion(cyclo-N-5)has been a great breakthrough in the field of energetic ***,the detection methods for these energetic materials based on the pentazolate anion are quite ***,two fluorescent probes for cyclo-N-5anion were *** 1(TPE2N)was synthesized with a tetraphenylethylene functionalized by two cationic groups which can generate strong electrostatic interactions with pentazolate anion and result in specific fluorescent *** 2 was designed based on sensor 1 and supramolecular cucurbit[7]uril(CB[7]).The unique structural features of CB[7]provide sites for the interaction between the cations and N-5anion in its cavity,which would generate a platform for the detection and enhance the recognition *** titration calorimetry(ITC)experiment and fluorescence titration experiment indicate the binding molar ratio between sensor 1 with CB[7]is 1:*** sensors display typical aggregation-induced emission(AIE)features and good *** sensors demonstrate excellent sensitivity to pentazole hydrazine salt with high enhancement constant(sensor 1:1.34×10^(6);sensor 2:3.78×10^(6))and low limit of detection(LOD:sensor 1=4.33μM;sensor 2=1.54μM).The formation of an AIE-based supramolecular sensor effectively improves the sensitivity to *** addition,the probes also have good selectivity of N-5anion *** research would shed some light on the design of novel fluorescent sensors to detect pentazolate-based molecules and provides an example of supramolecular chemistry combined with fluorescent probes.

关键词： Pentazolate anion Explosives detection Aggregation-induced emission(AIE) Host-guest interaction

A Least-squares-based Iterative Method with Better Convergence for PF/OPF in Integrated Transmission and Distribution Networks

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 953-962页

作者： Kunjie tang Shufeng Dong Yonghua Song College of Electrical Engineering Zhejiang UniversityHangzhou 310027China State Key Laboratory of Internet of Things for Smart City and Department of Electrical and Computer Engineering University of MacaoMacao SARChina IEEE

The limitations of the conventional master-slavesplitting(MSS)method,which is commonly applied to power flow and optimal power flow in integrated transmission and distribution(I-T&D)networks,are first *** that the MSS method suffers from a slow convergence rate or even divergence under some circumstances,a least-squares-based iterative(LSI)method is *** with the MSS method,the LSI method modifies the iterative variables in each iteration by solving a least-squares problem with the information in previous iterations.A practical implementation and a parameter tuning strategy for the LSI method are ***,a LSI-PF method is proposed to solve I-T&D power flow and a LSIheterogeneous decomposition(LSI-HGD)method is proposed to solve optimal power *** experiments demonstrate that the proposed LSI-PF and LSI-HGD methods can achieve the same accuracy as the benchmark ***,these LSI methods,with appropriate settings,significantly enhance the convergence and efficiency of conventional ***,in some cases,where conventional methods diverge,these LSI methods can still converge.

关键词： Fixed-point theory integrated transmission and distribution networks least-squares-based iterative method master-slave-splitting method optimal power flow power flow

Large magnetostriction of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites in a wide temperature range

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4期42卷 705-709页

作者： Hehe Ding Yangguang Shi Shaolong tang MIIT Key Laboratory of Aerospace Information Materials and Physics Department of Applied PhysicsNanjing University of Aeronautics and AstronauticsNanjing210016China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China

We report the magnetostrictive performance of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy *** of M?ssbauer spectra and the XRD results indicate that the easy magnetic direction of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)compound is alongdirection with spontaneous magnetostrictionλ111 of1900 ***-oriented Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites with particle volume fractions of20 vol%-55 vol%were *** measurements demonstrate that the composite is highly *** raw material cost of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)is about 85%of that of the Terfenol-D(Tb_(0.3)Dy_(0.7)Fe_(2))***_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites possess comparable magnetostriction with those composites made of Tb_(0.3)Dy_(0.7)Fe_(2)*** room temperature,the magnetostrictionλ_Ⅱof the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composite reaches 420 ppm at a low field of 80 kA/m and about1000 ppm at 239 kA/*** addition,the composite exhibits a large saturation magnetostrictionλ_Ⅱover1200 ppm from 300 to 100 K,suggesting its potential applications as a low-cost magnetostrictive material in a wide temperature ***,the current study offers an opportunity to widen the operating temperature range of the magnetostrictive composite.

关键词： Magnetostrictive composite Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93) Wide temperaturerange Laves phase Rare earths

在线全文

学校读者我要写书评

暂无评论

先进压缩空气储能系统的基础研究与应用进展

Engineering 2024年第3期34卷 246-269页

作者： xinjing Zhang Ziyu Gao Bingqian Zhou Huan Guo Yujie Xu Yulong Ding Haisheng Chen Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Birmingham Centre for Energy Storage&School of Chemical Engineering University of BirminghamBirmingham B152TTUK

Decarbonization of the electric power sector is essential for sustainable ***-carbon generation technologies,such as solar and wind energy,can replace the CO_(2)-emitting energy sources(coal and natural gas plants).As a sustainable engineering practice,long-duration energy storage technologies must be employed to manage imbalances in the variable renewable energy supply and electricity *** air energy storage(CAES)is an effective solution for balancing this mismatch and therefore is suitable for use in future electrical systems to achieve a high penetration of renewable energy *** study introduces recent progress in CAES,mainly advanced CAES,which is a clean energy technology that eliminates the use of fossil fuels,compared with two commercial CAES plants at Huntorf and McIntosh which are conventional ones utilizing fossil *** CAES include adiabatic CAES,isothermal CAES,liquid air energy storage,supercritical CAES,underwater CAES,and CAES coupled with other *** principles and configurations of these advanced CAES technologies are briefly discussed and a comprehensive review of the state-of-the-art technologies is presented,including theoretical studies,experiments,demonstrations,and *** comparison and discussion of these CAES technologies are summarized with a focus on technical maturity,power sizing,storage capacity,operation pressure,round-trip efficiency,efficiency of the components,operation duration,and investment *** application trends were *** paper presents a comprehensive reference for developing novel CAES systems and makes recommendations for future research and development to facilitate their application in several areas,ranging from fundamentals to applications.

关键词： Compressed air energy storage Fundamentals Applications Technological parameters Comparison

Cronkhite-Canada syndrome with esophagus involvement and sixyear follow-up:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第8期30卷 984-990页

作者： Yu-Chen tang Department of Endocrinology The First Affiliated Hospital of Ningbo UniversityNingbo 315000Zhejiang ProvinceChina

BACKGROUND Cronkhite-Canada syndrome(CCS)is a rare,noninherited disease characterized by gastrointestinal polyposis with diarrhea and ectodermal *** polyps are distributed through the whole digestive tract,and they are common in the stomach and colon but very uncommon in the *** SUMMARY Here,we present a case of a 63-year-old man with skin hyperpigmentation accompanied by diarrhea,alopecia,and loss of his *** data indicated anemia,hypoalbuminemia,hypocalcemia,hypokalemia,and positive fecal occult *** showed numerous polyps scattered throughout the digestive tract,including the *** was treated with nutritional support and glucocorticoids with remission of his *** Comprehensive treatment led by hormonal therapy can result in partial or full remission of clinical *** should be individualized for each patient according to their therapy *** endoscopy is necessary for assessing mucosal disease activity and detecting malignant transformation.

关键词： Cronkhite-Canada syndrome Gastrointestinal polyposis Hormonal therapy Prognosis Case report

U-Pb zircon ages and petrogeochemistry and tectonic implications of gabbro and granite in southwest Lahad Datu area of Sabah, Malaysia

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 Oceanologica Sinica 2024年第2期43卷 94-110页

作者： Zhigang Zhao Wu tang Shixiang Liu Huafeng tang Pujun Wang Zhiwen Tian China National Offshore Oil Corporation(CNOOC)Research Institute Co. Ltd.Beijing 100028China College of Earth Sciences Jilin UniversityChangchun 130061China

The southwest Lahad Datu felsic rocks were previously thought to have formed in the late Triassic as part of the microcontinental crystalline *** on U-Pb ages,geochemistry,and the Hfisotopes of zircon from the southeastern Sabah gabbro and granite,in this study,the tectonic properties of the Sabah area during the Triassic were *** weighted average U-Pb zircon ages of the gabbro and granite samples were determined to be(230.9±2.5)Ma and(207.1±3.3)Ma,*** granite had SiO_(2) contents of 66.54%-79.47%,low TiO_(2) contents of 0.08%-0.3%,Al_(2)O_(3) contents of 10.97%-16.22%,Na_(2)O contents of 5.91 %-6.39%,and low K_(2)O contents of 0.15%-0.65%.The chondrite-normalized rare earth element(REE) patterns exhibit light REE enrichment,with right-sloping *** primitive mantle-normalized trace element spider diagrams exhibit Th,U,La,Sr,and Zr enrichment and Nb,Ta,P and Ti depletions,i.e.,the geochemical characteristics of typical island arc igneous *** tectonic discriminant diagram indicates that the granite is a volcanic arc *** Hf isotopic an alysis of gabbro zircon revealed that the zircons have ε_(Hf)(t)values of 12.08-16.24(mean of 14.32) and two-stage model ages(t_(DM2)) of 223-491 Ma(mean of 347 Ma).This indicates that the diagenetic magma of the gabbro was mainly derived from melting of newly formed crustal *** ophiolite in southeast Sabah has existed since the early Late *** crystalline basement granite in southeastern S abah was emplaced lasted from late Triassic to early *** on previous studies and global plate reconstruction models,it is speculated that the southeastern Sabah granite may have been formed in an island arc setting,i.e.,where the oceanic crust of the Paleo-Tethys Ocean collided with the oceanic crust of the Panthalassa Ocean.

关键词： Sabah early late Triassic ophiolite granite tectonic properties