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Flexible Gradient Poly(ether-ester)from the Copolymerization of Epoxides and c-Caprolactone Mediated by a Hetero-bimetallic Complex

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Chinese Journal of Polymer Science 2021年第8期39卷 1013-1019,I0007页

作者： wei-min ren Hong-Juan Gao Tian-Jun Yue State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024China

Copolymerization is a commonly employed method for optimizing the properties of polymer *** ether segments into polyesters main chain to obtain polyether-polyester copolymers is an effective strategy to realize the integration of multiple properties of polyester and polyether,and to develop more high-performance,multi-purpose polymer ***,the synthesis of poly(ether-ester)s is accessible by employing the biphenyl-linked heterodinuclear salen Cr-AI complex in the presence of PPNCI for the copolymerization of epoxides and£-caprolactone(CL).Monitoring the copolymerization process reveals that catalyst 1 exhibited good performance for the copolymerization of epoxides and CL,affording copolymers with a gradient sequence *** dynamic thermomechanical analysis(DMA)study indicates the obtained poly(ether-ester)s possess enhanced flexibility compared with the block copolymers or blend of PPO and PCL homopolymers with the same *** study provides a theoretical basis for the preparation of high-performance polymer materials.

关键词： Lactone Epoxide Copolymerization Poly(ether-ester)copolymer Dynamic mechanical analysis

Mechanism-inspired Design of Heterodinuclear Catalysts for Copolymerization of Epoxide and Lactone

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Chinese Journal of Polymer Science 2020年第9期38卷 950-957,I0006页

作者： wei-min ren Rui-Jing Wang Bai-Hao ren Ge-Ge Gu Tian-Jun Yue State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024China

Polyesters,as a class of high-performance and versatile polymer materials,often suffer from some drawbacks,such as hydrophobicity and brittleness due to their single structure ***,modifications have attracted much attention for enhancing their desirable properties,of which one efficient way is incorporating the aliphatic polyether segment into the main chain of the ***,this approach is of much challenge because the obtained polyesters are problematic in either low alternating degree or low molecular ***,we describe an efficient strategy to incorporate polyether fragment into polyester by developing a novel Co-Al based heterodinuclear complex for mediating the copolymerization of propylene oxide(PO)withε-caprolactone(CL).The tracking experiments reveal that PO and CL convert into the polymer chain throughout the polymerization ***,the linear increase in the molecular weight with conversion of CL indicates the controllable nature of the *** competition polymerization,offering the monomer reactivity ratios of rCL=0.96 and rPO=1.04,suggests that the tendency of self-propagation or incorporation of monomers is nearly ***,the obtained polymers with different ether contents exhibit tunable thermal properties with enhanced decomposition temperature for the polymer with higher ether *** newly developed heterodinuclear complex for new polymerization provides an idea to synthesize new functional polymeric materials.

关键词： Heterodinuclear catalysis Polyester-polyether copolymer Lactone Epoxide Copolymerization

Epstein-Barr virus-encoded small RNAs in idiopathic orbital inflammatory pseudotumor tissues: a comparative case series

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International Journal of Ophthalmology(English edition) 2017年第8期10卷 1268-1272页

作者： min-wei ren Yi Du Shan ren Cheng-Ye Tang Jian-Feng He Department of Ophthalmology the First Affiliated Hospital of Guangxi Medical University Department of Ophthalmology Liuzhou People's Hospital

AIM： To investigate the positive rate and types of cells that express Epstein-Barr virus-encoded small RNAs （EBERs） and to determine the distribution of EBER-expressing cells in idiopathic orbital inflammatory pseudotumor （IOIP） tissues. METHODS： We retrospectively examined 40 archived paraffin specimens from two teaching hospitals in Southern China between January 2007 and January 2015 that were pathologically determined to exhibit IOIP. Eleven concurrent paraffin specimens of thyroid-associated ophthalmopathy （TAO） composed the control group. In situ hybridization was performed to detect EBERs. Immunohistochemistry was employed to detect CD3, CD20, Vimentin, and smooth muscle actin （SMA）, and the positive rate, types of positive cells, and distribution and location of EBERs were evaluated. RESULTS： The positive expression rate of EBERs was 47.5% （19/40） in the IOIP group, which was significantly higher than that in the TAO group [0 （0/11）, P=-0.011]. in the IOIP group, the lymphocyte infiltrative subtype, fibrotic subtype, and mixed subtype exhibited EBER-positive rates of 57.1% （12121）, 12.5% （118）, and 54.5% （6/11）, respectively, and no significant differences were found between these subtypes （P=0.085）. Positive signals of EBERs were mainly present in medium-small lymphocytes between or around follicles and in the nuclei of activated immunoblasts （14/19）. CONCLUSION： The positive rate, types, and distribution of EBER-expressing cells in IOIP have been *** findings are conducive for a better understanding of the underlying mechanisms of Epstein-Barr virus infection in IOIP pathogenesis.

关键词： Epstein-Barr virus Epstein-Barr virus-encoded small RNAs thyroid eye disease Graves' ophthalmopathy idiopathic orbital inflammatory disease

Highly active bifunctional salenTi(Ⅳ) catalysts for asymmetric cyanosilylation of aldehydes and TMSCN

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Chinese Chemical Letters 2011年第11期22卷 1285-1288页

作者： Ye Qian Wen wei min ren Xiao Bing Lu State Key Laboratory of Fine Chemicals Dalian University of Technolog3 Dalian 116024 China

A novel enantiopure salen ligand bearing a diphenylphosphine oxide on the 3-position of one aromatic ring was synthesized and combined with Ti（Oi-Pr）_4 as a monometallic bifunctional catalyst for asymmetric cyanosilylation reaction of aldehydes with tnmethylsilyl cyanide（TMSCN）.The catalyst system exhibited excellent activity and moderate *** addition of TMSCN to 4-nitrobenzaldehyde in the presence of 1 mol%catalyst loading could complete within 10 min at ambient temperature. An intramolecularly cooperative catalysis was observed in this system wherein the central metal Ti（Ⅳ） is suggested to play a role of Lewis acid to activate aldehydes while the appended diphenylphosphine oxide worked as Lewis base to activate TMSCN.

关键词： Cyanohydnn Bifunctional catalyst Salen TMSCN Diphenylphosphine oxide

Inter-well internal resonance analysis of rectangular asymmetric cross-ply bistable composite laminated cantilever shell under transverse foundation excitation

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1353-1370页

作者： Lele ren wei ZHANG Yufei ZHANG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanics Guangxi UniversityNanning 530004China Beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures College of Mechanical EngineeringBeijing University of TechnologyBeijing 100124China

The chaotic dynamic snap-through and complex nonlinear vibrations are investigated in a rectangular asymmetric cross-ply bistable composite laminated cantilever shell,in cases of 1:2 inter-well internal resonance and primary *** transverse foundation excitation is applied to the fixed end of the structure,and the other end is in a free *** first-order approximate multiple scales method is employed to perform the perturbation analysis on the dimensionless two-degree-of-freedom ordinary differential motion control *** four-dimensional averaged equations are derived in both polar and rectangular coordinate *** from the obtained frequency-amplitude and force-amplitude response curves,a detailed analysis is conducted to examine the impacts of excitation amplitude,damping coefficient,and tuning parameter on the nonlinear internal resonance characteristics of the *** nonlinear softening characteristic is exhibited in the upper stable-state,while the lower stable-state demonstrates the softening and linearity *** simulation is carried out using the fourth-order Runge-Kutta method,and a series of nonlinear response curves are *** the excitation amplitude further elucidates the global bifurcation and chaotic dynamic snap-through characteristics of the bistable cantilever shell.

关键词： bistable composite laminated cantilever shell inter-well internal resonance primary resonance chaotic dynamic snap-through complex nonlinear vibration

Normalized Solution for p-Kirchhoff Equation with a L2-supercritical Growth

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 414-429页

作者： Zhi-min ren Yong-yi LAN School of Sciences Jimei UniversityXiamen 361005China

In this paper,we investigate the following p-Kirchhoff equation{∫R^(N)|u|^(2)dx=ρ,(a+b)∫RN(|Δu}^(p)+|u|^(p))dx)(-Δpu+|u|^(p-2u)=|u|^(s-2)u+μu,x∈R^(N),where a>0,b≥0,p>0 are constants,constants,p*=N-P/Np is the ... 详细信息

关键词： p-Kirchhoff equation normalized solution mountain-pass lemma

A Feature Selection Method Based on Hybrid Dung Beetle Optimization Algorithm and Slap Swarm Algorithm

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Computers, Materials & Continua 2024年第8期80卷 2979-3000页

作者： wei Liu Tengteng ren School of Information Science and Engineering Shenyang Ligong UniversityShenyang110158China

Feature Selection(FS)is a key pre-processing step in pattern recognition and data mining tasks,which can effectively avoid the impact of irrelevant and redundant features on the performance of classification *** recent years,meta-heuristic algorithms have been widely used in FS problems,so a Hybrid Binary Chaotic Salp Swarm Dung Beetle Optimization(HBCSSDBO)algorithm is proposed in this paper to improve the effect of *** this hybrid algorithm,the original continuous optimization algorithm is converted into binary form by the S-type transfer function and applied to the FS *** combining the K nearest neighbor(KNN)classifier,the comparative experiments for FS are carried out between the proposed method and four advanced meta-heuristic algorithms on 16 UCI(University of California,Irvine)*** evaluation metrics such as average adaptation,average prediction accuracy,and average running time are chosen to judge and compare the *** selected dataset is also discussed by categorizing it into three dimensions:high,medium,and low *** results show that the HBCSSDBO feature selection method has the ability to obtain a good subset of features while maintaining high classification accuracy,shows better optimization *** addition,the results of statistical tests confirm the significant validity of the method.

关键词： Feature selection dung beetle optimization KNN transfer function HBCSSDBO

Finite-size-induced non-Hermitian phase transitions in real space

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 105-111页

作者： Hongfei Wang Biye Xie wei ren Department of Physics International Center for Quantum and Molecular StructuresShanghai UniversityShanghai 200444China School of Science and Engineering The Chinese University of Hong KongShenzhen 518172China

While non-Hermiticity provokes intriguing phenomena without Hermitian counterparts, e.g., the skin effect and the breakdown of bulk-boundary correspondence, attracting extensive attention both in fundamental physics and device engineering, the role of finite sizes therein remains elusive. Here, we propose a class of finite-size-induced non-Hermitian phase transitions, relying upon higher-order topological invariants associated with real-space wave functions. The phase diagrams for general non-Hermitian chiral models are further acquired to demonstrate our topological definition. Such phase transitions are elucidated qualitatively by an effective intercell coupling alteration that depends on finite sizes in respective directions. Besides, we mimic these phenomena by analogizing the circuit Laplacian in finite-size electric circuits with nonreciprocal couplings. The resultant admittance spectra agree with our theoretical predictions. Our findings shed light on the finite-size mechanism of non-Hermitian topological phase transitions and pave the way for applications in switching and sensing.

关键词： non-Hermitian phase transitions finite-size effects higher-order topological invariants

Is the Cape Stone Forest in Shantou City formed by wave erosion? A comparison of the pedestal rocks on the coasts and the mountains of Queshi in eastern Guangdong, China

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Journal of Mountain Science 2024年第5期21卷 1447-1463页

作者： CHEN min WANG wei School of Geography South China Normal UniversityGuangzhou 510631China

Cape Stone Forest is a group of granite rock pillars(pedestal rocks) towering over Shilin Lake, on the southern shore of Shantou Bay in eastern Guangdong, China. The rock pillars were previously identified as sea stacks because they have marine notch-like concave sidewalls at their base, and more importantly, the lake is immediately adjacent to the bay, which is exposed to the open sea. However, rock pillars similar in shape and size can also be found at the top of Queshi Mountain, which is only about 300 meters northwest of the lake and about 85 meters above sea level. Therefore, the marine origin of Cape Stone Forest is seriously questioned. In this study, 3D imagery and drone technology were used to collect data in the investigations without direct manual measurements in the water or on the mountain. It shows that the concave sidewalls of the rock pillars in the lake and on the mountains occur at different heights and are exposed to different directions, while a natural sea stack on Mayu Island at the mouth of Shantou Bay has a horizontal notch parallel to the sea level, although the granite rock of the sea stack is the same as that of the lake and the mountains. The eastern side of the island, where the sea stack is located, is exposed to the open sea but blocks large waves for the rock pillars in the lake. Therefore, the origin of Cape Stone Forest cannot be explained by wave-based mechanisms. The only satisfactory explanation that takes into account all the field evidence is that the narrow rock pillars of the lake and mountain were formed by chemical weathering that penetrated closely the spaced joints of the granite rock, and the notch-like concave sidewalls were formed by more effective chemical weathering at the base of the pillars.

关键词： Pedestal rock Granite Closely spaced joints Wave erosion Chemical weathering