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Unraveling molecular-level mechanisms of reactive facet of carbon nitride single crystals photocatalyzing overall water splitting

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Rare Metals 2020年第12期39卷 1353-1355页

作者： Cong-Yong Wang chen-huai Yang Zhi-cheng Zhang Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Department of Chemistry National University of SingaporeSingapore 117543Singapore Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of ScienceTianjin University&Collaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China

Despite the reactive facets play a vital role in designing highly efficient photocatalysts,it has long been a tremendous challenge to reveal the principle that reactive facets favor photocatalysis at the molecular ***... 详细信息

关键词： splitting catalysis designing

Universal cooling patterns of the butterfly wing scales hierarchy deduced from the heterogeneous thermal and structural properties of Tirumala limniace(Lepidoptera:Nymphalidae,Danainae)

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Insect Science 2022年第6期29卷 1761-1772页

作者： Chu-Fei Tang Fan-Fan Li Ye Cao huai-jian Liao Institute of Leisure Agriculture Jiangsu Academy of Agricultural SciencesNanjingChina Key Laboratory of Urban Agriculture Ministry of Agriculture and Rural AffairsShanghaiChina

The radiative cooling of butterfly wing scales hierarchy has great value in understanding how poikilotherms adapt to the environment and developing bionic ***,it remains unclear what the cooling system is like and how the vari-ation of hierarchy affects the cooling ***,the correlation between the variations of the structure and emissivity of scale hierarchy is thoroughly investigated in Tirumala limniace(Cramer,1775),whose thermal properties are highly heteroge-neous among different wings and regions but similar between males and ***-terns were deduced from the biological and model simulation *** scale hierarchy varies at the micro-to nanolevel on both surface and section,correspond-ing to the variating *** on wing veins and margins have large nanostruc-tured units with small lumens and are distinctly thickened,which bring extraordinarily high *** variations of light and dark scales,respectively,lead to the high emissivity of the middle region of wings and the front ***,the elevation of the inner surface area and the thickness of the chitin is the key to enhancing the cooling *** the first time,the effects of the variation of hierarchy toward emissivity of the mid-infrared spectrum are systematically *** is demonstrated that wing scales integrally differentiate in coping with the heterogeneous cooling needs,which may benefit in balancing multifunctions and the development toward the adap-tation to the abiotic *** study provides insights into the comprehensive thermoregulation system of butterflies and the further development of radiative cooling materials.

关键词： butterfly emissivity heterogeneous hierarchy radiative cooling wing scales

阿仑膦酸钠/壳聚糖/聚乙烯醇复合水凝胶膜的制备与表征

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中国组织工程研究 2025年第22期29卷 4720-4730页

作者：胡晨姜莹陈佳乔光伟董文马坚宁夏医科大学总医院口腔颌面外科宁夏回族自治区银川市750004 徐州市口腔医院口腔颌面外科江苏省徐州市221000 宁夏医科大学总医院口腔医院正畸科宁夏回族自治区银川市750004

背景:骨质疏松症是牙种植治疗的高风险因素,制备缓释阿仑膦酸钠的组织工程支架应用于骨质疏松患者口腔种植手术是当前口腔骨组织工程研究热点。目的:制备阿仑膦酸钠/壳聚糖/聚乙烯醇复合水凝胶膜,表征其缓释性能。方法:(1)采用物理交联... 详细信息

背景:骨质疏松症是牙种植治疗的高风险因素,制备缓释阿仑膦酸钠的组织工程支架应用于骨质疏松患者口腔种植手术是当前口腔骨组织工程研究热点。目的:制备阿仑膦酸钠/壳聚糖/聚乙烯醇复合水凝胶膜,表征其缓释性能。方法:(1)采用物理交联法制备不同质量比(壳聚糖与聚乙烯醇的质量比分别为3∶7、5∶5、7∶3)的壳聚糖/聚乙烯醇复合水凝胶膜与单纯的壳聚糖、聚乙烯醇水凝胶膜,通过表征水凝胶膜的形貌、水接触角、力学性能、溶胀率与细胞相容性筛选适宜的水凝胶膜作为阿仑膦酸钠的载体。(2)制备含0,0.4,1.2,2.0 mg/L阿仑膦酸钠的单纯壳聚糖/聚乙烯醇复合水凝胶膜,将大鼠骨髓间充质干细胞分别与4组水凝胶膜共培养,通过CCK-8法与CD44免疫荧光染色检测水凝胶膜的细胞相容性。将载药壳聚糖/聚乙烯醇复合水凝胶膜浸泡于PBS中,采用紫外可见分光光度法检测复合水凝胶膜的药物释放性能。结果与结论:(1)表征结果显示,随着水凝胶膜中聚乙烯醇质量的增加,水凝胶膜的结构密度增加、孔隙率减少,水接触角(均在90°以内)、断裂伸长率与抗压强度增大,平衡溶胀率降低,对大鼠骨髓间充质干细胞的增殖均无影响,单纯壳聚糖水凝胶膜可促进大鼠骨髓间充质干细胞的黏附,3∶7、5∶5比例复合水凝胶膜不影响大鼠骨髓间充质干细胞的黏附,单纯聚乙烯醇水凝胶膜、7∶3比例复合水凝胶膜抑制大鼠骨髓间充质干细胞的黏附,综合以上结果,选择5∶5复合水凝胶膜作为阿仑膦酸钠的载体。(2)CCK-8检测结果显示,含0.4,1.2 mg/L阿仑膦酸钠组复合水凝胶膜无细胞毒性;CD44免疫荧光染色结果显示,含0.4 mg/L阿仑膦酸钠组复合水凝胶膜不影响大鼠骨髓间充质干细胞的黏附,含1.2,2.0 mg/L阿仑膦酸钠组复合水凝胶膜抑制大鼠骨髓间充质干细胞的黏附;含0.4,1.2,2.0 mg/L阿仑膦酸钠的壳聚糖/聚乙烯醇复合水凝胶膜在最初6 h内爆发性释放阿仑膦酸钠,此后均匀稳定地释放阿仑膦酸钠,释放时间达96 h以上。(3)结果表明,5∶5比例的壳聚糖/聚乙烯醇复合水凝胶膜具有良好的理化性能、细胞相容性,可以作为阿仑膦酸钠的缓释载体。

关键词：阿仑膦酸钠壳聚糖聚乙烯醇水凝胶复合水凝胶膜种植体

Organocatalytic asymmetric[2+2] cycloaddition of alkynes with quinones

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Science China Chemistry 2023年第8期66卷 2292-2299页

作者： huai-Ri Sun Lan Yang Yu Li Le Yu Bo-Bo Gou Atif Sharif Qing-Song jian Jie chen Ling Zhou Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry&Materials ScienceNorthwest UniversityXi’an710127China

A chiral phosphoric acid catalyzed enantioselective[2+2] cycloaddition of alkynylindols or alkynylnaphthols with quinones is disclosed.A class of functionalized cyclobutenes with excellent yields,diastereo-and enantioselectivities were prepared under mild reaction conditions(70 examples,up to 99%yield,99%ee,all>50:1 dr).Mechanistic studies revealed that a dearomatization of indole or naphthol occurred to initiate the cycloaddition,followed by an intramolecular Michael addition with in situ generated allene-iminium or vinylidene-quinone methide *** competitive[2+3] cycloaddition was prevented in this catalytic *** interesting central to axial chirality conversion via a rearrangement process was realized during transformation of the product.

关键词： organocatalysis [2+2]cycloaddition asymmetric catalysis alkynes cyclobutenes

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Experimental Study on Flow Boiling Heat Transfer Characteristics of Microencapsulated Phase Change Material Suspension

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Journal of Thermal Science 2023年第4期32卷 1547-1557页

作者： TAN Zhenyu LI Xunfeng huai Xiulan chenG Keyong chen Junlin Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Nanjing Institute of Future Energy System Nanjing211135China

Due to its core phase change characteristics,microencapsulated phase change material(MPCM)can make many base fluids have better heat transfer *** this paper,the flow boiling heat transfer characteristics of fluorinated liquid-based microencapsulated phase change material suspension(MPCMS)through vertical transparent quartz channel were *** effects of MPCM core phase change temperature and suspension flow velocity on boiling heat transfer coefficient and critical heat flux were discussed,*** results show that the appropriate concentration of MPCMS can enhance both the boiling heat transfer coefficient and the critical heat *** strengthening effect becomes weak with the increase of suspension flow *** maximum strengthening rates of critical heat flux appear at 0.05 m/s,which are 25%(MPCMS(70℃)),16%(MPCMS(58℃))and 10%(MPCMS(28℃)).The phase change temperature of the MPCM core has important effects on the boiling heat transfer coefficient and the critical heat *** results showed that the MPCM with core phase change temperature higher than the boiling temperature of base fluid has the best enhancement *** bubble behavior in vertical tube with different heat flux can be observed by high-speed photography *** particle core phase change in MPCMS inhibits the aggregation of bubbles and forms many small bubbles to enhance heat *** work lays a foundation for further exploring the industrial application of MPCMS.

关键词： flow boiling enhancement flow visualization suspension microencapsulated phase change material

Second-order interference of two independent photons with different spectra

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Chinese Physics B 2019年第10期28卷 345-353页

作者： Yu Zhou jian-Bin Liu huai-Bin Zheng Hui chen Fu-Li Li Zhuo Xu MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter Department of Applied PhysicsXi’an Jiaotong UniversityXi’an 710049China Electronic Materials Research Laboratory Key Laboratory of the Ministry of Education (MOE)& International Center for Dielectric ResearchSchool of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049China The Key Laboratory of Weak Light Nonlinear Photonics(Nankai University) Tianjin 300457China

The second-order interference of two independent photons with different spectra in a Shih-Alley/Hong-Ou-Mandel interferometer is studied in Feynman's path integral theory. There is a second-order interference pattern for photons with different spectra if the photons are indistinguishable for the employed detection system. The conditions to observe the second-order temporal beating with photons of different spectra are analyzed. The influence of the response time of the detection system on the observed second-order interference pattern is also discussed. It is a direct result of that measurement in quantum mechanics is dependent on the employed measuring apparatus. The results are helpful to understand the physics of two-photon interference in different schemes.

关键词： two-photon interference Feynman's path integral theory Hong-Ou-Mandel interferometer

Robust Control for Discrete-Time T-S Fuzzy Singular Systems

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Journal of Systems Science & Complexity 2021年第4期34卷 1345-1363页

作者： chen jian YU Jinpeng School of Information and Control Engineering Qingdao University of TechnologyQingdao 266520China School of Automation Qingdao UniversityQingdao 266071China

This paper deals with the robust admissibility and state feedback stabilization problems for discrete-time T-S fuzzy singular systems with norm-bounded *** introducing a new approximation technique,the initial membership functions are conveniently expressed in piecewiselinear functions with the consideration of the approximation *** utilizing the piecewise-linear membership functions,the fuzzy weighting-based Lyapunov function and the use of auxiliary matrices,the admissibility of the systems is determined by examining the conditions at some sample *** conditions can be reduced into the normal parallel distributed compensation ones by choosing special values of some slack ***,the authors design the robust state feedback controller to guarantee the closed-loop system to be *** examples are provided to illustrate the advantage and effectiveness of the proposed method.

关键词： Admissible discrete-time singular systems piecewise-linear membership functions state feedback T-S fuzzy models

Terahertz Emission of Ferromagnetic Ni-Fe Thin Films Excited by Ultrafast Laser Pulses

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Chinese Physics Letters 2012年第6期29卷 265-267页

作者： SHEN jian ZHANG huai-Wu LI Yuan-Xun State Key Laboratory of Electronic Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054

It is believed that the ultrafast demagnetization process in ferromagnetic film is intrinsically a thermal effect,which is induced by ultrafast laser *** present experimental evidence that such ultrafast demagnetization of the NiFe thin film can radiate electromagnetic waves in the terahertz *** also demonstrate that the magnitude of the terahertz electromagnetic pulse emitted from ferromagnetic films alter pulsed laser excitation can be tuned by the Gilbert damping factor α,which is conventionally used to describe damping of GHz precession motion of *** damping factors are obtained by varying the normal metal film adjacent to the magnetic film via spin *** measured radiated electric field in the far field is found to be proportional to the Gilbert damping factor.

关键词： pumping film magnetic

Solidification microstructure of Ti-43Al alloy by twin-roll strip casting

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China Foundry 2023年第2期20卷 99-107页

作者： Yang chen Guo-huai Liu Ye Wang Zhao-dong Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China College of Material Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150080China

As a near-net-shape technology,the twin-roll strip casting(TRC)process can be considered to apply to the fabrication of TiAl alloy ***,the control of the grain distribution is very important in strip casting because the mechanical properties of strips are directly determined by the solidification microstructure.A three-dimensional(3D)cellular automation finite-element(CAFE)model based on ProCAST software was established to simulate the solidification microstructure of Ti-43Al ***,the influence of casting temperature and the maximum nucleation density(nmax)on the solidification microstructure was investigated in *** simulation results provide a good explanation and prediction for the solidification microstructure in the molten pool before leaving the kissing *** and simulated microstructure show the common textureorientation in the columnar grains ***,the microstructure evolution of the Ti-43Al alloy was analyzed and the solidification phase transformation path during the TSC process was determined,i.e.,L→L+β→β→β+α→α+γ+β/B2 phase under a faster cooling rate and L→L+β→β→β+α→γ+lamellar(α_(2)+γ)+β/B2 phase under a slower cooling rate.

关键词： TiAl alloy simulation microstructure strip casting solidification