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H-Bonded Liquid Crystalline Polymer Network Materials

Chemical Research in Chinese Universities 2001年第Z1期17卷 89-90页

作者： lin hong-cheu Department of Materials Science and Engineering National Chiao Tung University Institute of Chemistry Academia Sinica Institute of Chemistry Academia Sinica

Side-chain copolymers, poly(mOBA-co-mStilb)s, composed of proton acceptors (stilbazoles) and proton donors (benzoic acids) connected to polyacrylate backbone with different methylene spacer lengths (m = 6 and 10) were prepared in different donor/acceptor molar ratios. The H-bonded copolymeric networks were formed once they were synthesized, and showed more homogenous phase than the physical-blended supramolecular networks consisting of donor and acceptor homopolymers, i.e.H-bonded blends of PmOBA and PmStilb. In order to compare the effects of the backbone connection of these H-bonded copolymers and blends, we also built monomer-monomer and polymer-monomer H-bonded complexes of similar structures (shown in Fig. 1). DSC, POM, and powder XRD studies reveal that the copolymers (m = 10)with mole fractions of benzoic acids between 0.33-0.83 show the smectic A (SMA) phase with layer spacing values between 42.22A-50.47A (increases with higher H-bonded crosslinking density between benzoic acids and stilbazoles), while for m = 6, liquid crystalline behavior still can be observed at 0.89 molar fraction of benzoic acids. However, on the basis of powder XRD study it is found that the d spacing values of H-bonded copolymers with m = 6 in the SmA phase increase with higher molar ratios of benzoic acids, which is agreed with the formation of microphase separation due to the hydrogen bonds of benzoic acids connected themselves from the same backbone. The isotropization temperatures of the H-bonded copolymers and blends increase as the molar ratios of benzoic acids increase, while the higher crosslinking density of the H-bonded copolymeric networks and blends can stabilize the liquid crystalline phase.

关键词： Polymer Network benzoic acids crosslinking density supramolecular networks microphase separation powder XRD crystalline behavior similar structures crystalline phase molar fraction hydrogen bonds

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Grain refinement of 5A06 aluminum alloy welds caused by tungsten inert gas welding arc characteristics under Ar-He alternating gas supply conditions:a coupled method of water-cooled copper plate test/numerical simulation

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Journal of Iron and Steel Research International 2024年第3期31卷 767-777页

作者： hong-bin Dai Jian Miao Jia-xin lin School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and *** the tungsten inert gas(TIG)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change *** FLUENT software was used to numerically simulate the characteristics of the TIG arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were *** with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIG arc has obvious dynamic characteristics under the condition of Ar-He alternating gas *** unique dynamic TIG arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply Grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property

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Chinese Journal of Electronics 2024年第3期33卷 683-693页

作者： Jiamei LIU lin TAN hong XU PLA Strategic Support Force Information Engineering University

Deoxys-BC is the primitive tweakable block cipher of the Deoxys family of authenticated encryption *** on existing related-tweakey boomerang distinguishers,this paper improves the boomerang attacks on 11-round Deoxys-BC-256 and 13-round Deoxys-BC-384 by the optimized key guessing and the precomputation *** transfers a part of subtweakey guess in the key-recovery phase to the precomputation resulting in a significant reduction of the overall time *** 11-round Deoxys-BC-256,we give a related-tweakey boomerang attack with time/data/memory complexities of 2218.6/2125.7/2125.7,and give another attack with the less time complexity of2215.8and memory complexity of 2120 when the adversary has access to the full *** 13-round Deoxys-BC-384,we give a related-tweakey boomerang attack with time/dat a/memory complexities of 2k-96+2157.5/2120.4/*** the key size k=256,it reduces the time complexity by a factor of 231compared with the previous 13-round boomerang *** addition,we present two new related-tweakey boomerang distinguishers on 11-round Deoxys-BC-384 with the same probability as the best previous distinguisher.

关键词： Ciphers Memory management Complexity theory Encryption Time complexity

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Positive definiteness of real quadratic forms resulting from the variable-step L1-type approximations of convolution operators

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Science China Mathematics 2024年第2期67卷 237-252页

作者： hong-lin Liao Tao Tang Tao Zhou School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Division of Science and Technology BNU-HKBU United International CollegeZhuhai 519087China SUSTech International Center for Mathematics Shenzhen 518055China NCMIS&LSEC Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

The positive definiteness of real quadratic forms with convolution structures plays an important rolein stability analysis for time-stepping schemes for nonlocal operators. In this work, we present a novel analysistool to handle discrete convolution kernels resulting from variable-step approximations for convolution *** precisely, for a class of discrete convolution kernels relevant to variable-step L1-type time discretizations, weshow that the associated quadratic form is positive definite under some easy-to-check algebraic conditions. Ourproof is based on an elementary constructing strategy by using the properties of discrete orthogonal convolutionkernels and discrete complementary convolution kernels. To our knowledge, this is the first general result onsimple algebraic conditions for the positive definiteness of variable-step discrete convolution kernels. Using theunified theory, we obtain the stability for some simple nonuniform time-stepping schemes straightforwardly.

关键词： discrete convolution kernels positive definiteness variable time-stepping orthogonal convolution kernels complementary convolution kernels

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A ratiometric fluorescent probe for hypoxanthine detection in aquatic products based on the enzyme mimics and fluorescence of cobalt-doped carbon nitride

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Food Science and Human Wellness 2024年第2期13卷 879-884页

作者： Xin Wang Chengyi hong Zhengzhong lin Zhiyong Huang College of Ocean Food and Biological Engineering Jimei UniversityXiamen 361021China

A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 *** the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by *** result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.

关键词： Co doped g-C_(3)N_(4) Ratiometric fluorescent probe Hypoxanthine Freshness Aquatic products

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Compressed Data Separation via ℓ_(q)-Split Analysis with ℓ_(∞)-Constraint

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1655-1673页

作者： Ming Yang Gu Song Li Jun hong lin School of Mathematical Science Zhejiang UniversityHangzhou310027P.R.China Center for Data Science Zhejiang UniversityHangzhou310027P.R.China

In this paper,we study compressed data separation(CDS)problem,i.e.,sparse data separation from a few linear random *** propose the nonconvex ℓ_(q)-split analysis with ℓ_(∞)-constraint and 0 详细信息

In this paper,we study compressed data separation(CDS)problem,i.e.,sparse data separation from a few linear random *** propose the nonconvex ℓ_(q)-split analysis with ℓ_(∞)-constraint and 0

关键词： Data separation ℓ_(q)-split analysis Dantzig selector frames restricted isometry property compressed sensing

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Non-volatile dynamically switchable color display via chalcogenide stepwise cavity resonators

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Opto-Electronic Advances 2024年第1期7卷 16-27页

作者： Kuan Liu Zhenyuan lin Bing Han Minghui hong Tun Cao School of Optoelectronic Engineering and Instrumentation Science Dalian University of TechnologyDalian 116024China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361102China Institute of Laser Engineering Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic *** trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying ***,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity *** device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost *** switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively *** color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase ***,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far *** minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) *** switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,***,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.

关键词： tunable color displays Fabry-Pérot cavity resonators color printing chalcogenide materials

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Pulmonary embolism secondary to acute anterior ST-elevation myocardial infarction:a case report

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World Journal of Emergency Medicine 2024年第2期15卷 139-141页

作者： lin Yuan hong Li Yuhong Mi Ying Liang Emergency Critical Center Beijing Anzhen HospitalCapital Medical UniversityBeijing 100029China

Thrombophilia denotes a condition,whether acquired or hereditary,characterized by increased susceptibility to hypercoagulation.[1]This condition was first described in 1965,coinciding with the discovery of an inherited predisposition to venous thromboembolism(VTE)in patients deficient in antithrombin III.[2]While arterial and venous thromboses are common in hospitalized patients,acute myocardial infarction(AMI)and pulmonary embolism(PE)stand out as ***,theoccurrenceof AMI complicated by PE is exceedingly rare,especially when considering cases where paradoxical embolism originating from a patent foramen ovale is *** report presents a case of AMI complicated with PE.A comprehensive understanding of the pathophysiology of this rare yet critical condition is important for ensuring prompt diagnosis and treatment.

关键词： embolism infarction acute

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Efficient synthesis of bottle-brush polymers enabled by selective photoactivation strategy in NIR-induced PET-RAFT polymerization

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Science China Chemistry 2024年第7期67卷 2353-2361页

作者： Hao Zha lin Cheng Zuowei Wang Chao Liu Chunyan hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Bottle-brush polymers possessing densely grafted side chains have special properties that are distinct from linear ***,an efficient method for preparing bottle-brush polymers based on a selective photoactivation strategy in the photoinduced electron/energy transfer reversible addition-fragmentation chain transfer(PET-RAFT)polymerization was developed.A methacrylate monomer 2-(2-(dodecylthiocarbonothioylthio)propionate)ethyl methacrylate(DTPEMA)containing a 2-(dodecylthiocarbonothioylthio)propionate(DTP)unit with a secondary R group was *** the unique selectivity of metal naphthalocyanine photocatalyst zinc 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine(ZnTtBNc)toward trithiocarbonate with tertiary R group,the PET-RAFT polymerization of DTPEMA catalyzed by ZnTtBNc was performed under near infrared(NIR)light(λ_(max)=760 nm)irradiation at room temperature,using 4-cyano-4-[(dodecylsulfanylthiocarbonyl)-sulfanyl]pentanoic acid(CDTPA)with a tertiary R group as a chain transfer agent(CTA).Proton nuclear magnetic resonance(1H NMR)and gel permeation chromatography(GPC)results demonstrated that the DTP units in the side chains were inert during the *** grafting poly(methyl acrylate)(PMA)from PDTPEMA via thermal-initiated RAFT polymerization,welldefined P(DTPEMA-g-PMA)bottle-brush polymers could be ***,the film prepared from the bottle-brush polymer exhibited excellent scratch self-healing property due to the interlocking of side chains.

关键词： bottle-brush polymers PET-RAFT polymerization selective photoactivation scratch self-healing

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Optimizing near-carbon-free nuclear energy systems:advances in reactor operation digital twin through hybrid machine learning algorithms for parameter identification and state estimation

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Nuclear Science and Techniques 2024年第8期35卷 177-203页

作者： Li‑Zhan hong He‑lin Gong hong‑Jun Ji Jia‑Liang Lu Han Li Qing Li Paris Elite Institute of Technology Shanghai Jiao Tong UniversityShanghai 200240China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610041China

Accurate and efficient online parameter identification and state estimation are crucial for leveraging digital twin simulations to optimize the operation of near-carbon-free nuclear energy *** previous studies,we developed a reactor operation digital twin(RODT).However,non-differentiabilities and discontinuities arise when employing machine learning-based surrogate forward models,challenging traditional gradient-based inverse methods and their *** study investigated deterministic and metaheuristic algorithms and developed hybrid algorithms to address these *** efficient modular RODT software framework that incorporates these methods into its post-evaluation module is presented for comprehensive *** methods were rigorously assessed based on convergence profiles,stability with respect to noise,and computational *** numerical results show that the hybrid KNNLHS algorithm excels in real-time online applications,balancing accuracy and efficiency with a prediction error rate of only 1%and processing times of less than 0.1 ***,algorithms such as FSA,DE,and ADE,although slightly slower(approximately 1 s),demonstrated higher accuracy with a 0.3%relative L_2 error,which advances RODT methodologies to harness machine learning and system modeling for improved reactor monitoring,systematic diagnosis of off-normal events,and lifetime management *** developed modular software and novel optimization methods presented offer pathways to realize the full potential of RODT for transforming energy engineering practices.

关键词： Parameter identification State estimation Reactor operation digital twin Reduced order model Inverse problem

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