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Chinese Journal of Polymer Science 2021年第4期39卷 397-416,I0004页

作者： feng Cai yu-Xuan Chen Wen-Zhong Wang hai-feng yu Department of Materials Science and Engineering and Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of EngineeringPeking UniversityBeijing 100871China

The great potential of liquid-crystalline block copolymers(LCBCs)containing photoresponsive mesogens toward novel applications in photonics and nanotechnology has been attracting increasing attention,due to the combination of the inherent property of microphase separation of block copolymers and the hierarchically-assembled structures of liquid-crystalline polymers(LCPs).The periodically ordered nanostructures in bulk film of LCBCs can be acquired by supramolecular cooperative motion,derived from the interaction between liquid-crystalline elastic deformation and microphase separation,which are able to improve physical properties of polymer film toward advanced functional ***,various micro/nano-patterned structures have been fabricated via light manipulation of photoresponsive LCBCs with good reproducibility and mass *** to recent developments in synthesis and polymerization techniques,diverse azobenzene-containing LCBCs have been designed,resulting in the creation of a wide variety of novel *** review illustrates recent progresses in macroscopic regulation of hierarchical nanostructures in LCBCs towards functional *** existing challenges are also discussed,showing perspectives for future studies.

关键词： Liquid-crystalline block copolymers Microphase separation Hierarchical nanostructures Functional materials

UV-Vis-NIR Light-deformable Shape-memory Polyurethane Doped with Liquid-crystal Mixture and GO towards Biomimetic Applications

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Chinese Journal of Polymer Science 2022年第2期40卷 166-174页

作者： Peng Zhang feng Cai Guo-Jie Wang hai-feng yu School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Institute of New Structural Materials School of Materials Science and Engineeringand Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationPeking UniversityBeijing 100871China

Nature has been inspiring material researchers to fabricate biomimetic functional devices for various applications, and shape-memory polymer materials(SMPMs) have received tremendous attention since the promising intelligent materials possess more advantages over others for the fabrication of biomimetic functional devices. As is well-known, SMPMs can be stimulated by heat, electricity, magnetism, pH, solvent and light. From the viewpoint of practical applications, ultraviolet(UV)-visible(Vis)-near infrared(NIR) light-responsive SMPMs are undoubtedly more advantageous. However, up to now, UV-Vis-NIR light-deformable SMPMs by combining photothermal and photochemical effects are still rarely reported. Here we designed a UV-Vis-NIR light-deformable SMP composite film via incorporating a liquid crystal(LC) mixture and graphene oxide(GO) into a shape-memory polyurethane matrix. The elongated composite films exhibited interesting photomechanical bending deformations with different light-triggered mechanisms,(1) photochemically induced LC phase transition upon UV exposure,(2) photochemically and photothermally induced LC phase transition upon visible-light irradiation,(3) photothermally triggered LC phase transition and partial stress relaxation upon low-intensity NIR exposure. All the deformed objects could recover to their original shapes by high-intensity NIR ***, the biomimetic circadian rhythms of acacia leaves and the biomimetic bending/spreading of fingers were successfully achieved, which could blaze a way in the field of biomimetic functional devices due to the excellent light-deformable and shape-memory properties of the SMP composite films.

关键词： UV-Vis-NIR Light-deformable Shape-memory Liquid-crystal Biomimetic functional device

Fabrication of Al air-bridge on coplanar waveguide

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Chinese Physics B 2018年第10期27卷 216-218页

作者： Zhen-Chuan Jin hai-Teng Wu hai-feng yu Yang yu National Laboratory of Solid State Microstructures School of PhysicsNanjing UniversityNanjing 210093China

Superconducting coplanar waveguide（CPW） can be widely used as two-dimensional（2 D） resonator, transmission line or feedline, providing an important component for superconducting quantum circuit which is a promising candidate for quantum information processing. Due to the discontinuities and asymmetries in the ground planes, CPW usually exhibits the spurious resonance, which is a common source of decoherence in circuit quantum electrodynamics experiments. To mitigate the spurious resonance, we fabricated superconducting aluminum air-bridges on Nb CPW. The fabricated airbridges are approximately 3 m high and up to 120 m long. Compared with other methods, the fabrication procedures of our air-bridges are simpler, and the air-bridge can withstand strong ultrasound.

关键词： air-bridge fabrication superconducting coplanar waveguide

Early Versus Delayed Laparoscopic Cholecystectomy for Acute Cholecystitis with Mild Pancreatitis

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Current Medical Science 2020年第5期40卷 937-942页

作者： Lu WANG hai-feng yu Tong GUO Peng XIE Zhi-wei ZHANG Ya-hong yu Department of Biliopancreatic Surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Critical Medicine Yueyang First People's HospitalYueyang 414000China

The safety and feasibility of early laparoscopic cholecystectomy(LC)for acute cholecystitis with mild pancreatitis were explored.A total of 973 patients with acute pancreatitis,including 651 mild cases and 322 moderate or severe cases were retrospectively studied from July 2014 to December 2018 in our *** 426 mild pancreatitis cases with acute cholecystitis were enrolled in this study,of which 328 patients underwent LC during the same-admission(early LC group),and 98 patients underwent LC a period of time after conservative treatment(delayed LC group).Clinical characteristics,operative findings and complications were recorded and followed *** two groups were comparable in age,gender,the grade of American Society of Anesthesiologist(ASA),biochemical findings and Balthazar computer tomography(CT)rating(P>0.05).The operation interval and hospital stay in early LC group were significantly shorter than in delayed LC group(5.83+1.62 vs.41.3618.44 days;11.38+2.43 vs.16.49+3.48 days,P<0.01).There was no significant difference in the average operation time between the two *** preoperative biliary related events recurred in early LC group but there were 21 cases of preoperative biliary related events in delayed LC group(P<0.01).There was no significant difference in conversion rate(3.85 vs.5.10%,P=0.41)and surgical complication rate(3.95 vs.4.08%,P-0.95)between early LC group and delayed LC *** the postoperative follow-up period of 375 cases,biliary related events recurred in 4 cases in early LC group and 3 cases in delayed LC group(P=0.37).The effect of early LC during the same-admission is better than delayed LC for acute cholecystitis with mild pancreatitis.

关键词： acute cholecystiti mild pancreatitis laparoscopic cholecystectomy

Manipulation of superconducting qubit with direct digital synthesis

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Chinese Physics B 2019年第9期28卷 78-82页

作者： Zhi-yuan Li hai-feng yu Xin-Sheng Tan Shi-Ping Zhao Yang yu National Laboratory of Solid State Microstructures School of PhysicsNanjing UniversityNanjing 210093China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

We investigate the XY control and manipulation of the superconducting qubit state using direct digital synthesis(DDS)for the microwave pulse signal *** decoherence time, gate fidelity, and other qubit properties are measured and carefully characterized, and compared with the results obtained by using the traditional mixing technique for the microwave pulse *** particular, the qubit performance in the state manipulation with respect to the sampling rate of DDS is *** results demonstrate that the present technique provides a simple and effective method for the XY control and manipulation of the superconducting qubit *** applications of the technique for the possible future scalable superconducting quantum computation are discussed.

关键词： superconducting qubit direct digital synthesis arbitrary waveform generator

nfluences of superheat and cooling intensity on macrostructure and macrosegregation of duplex stainless steel studied by thermal simulation

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Journal of Iron and Steel Research International 2021年第9期28卷 1125-1132页

作者： Hong-gang Zhong Xiang-ru Chen Yan-jie Liu Zhi-qiang Wei hai-feng yu Qi-jie Zhai Center for Advanced Solidification Technology Shanghai UniversityShanghai200444China Shanghai Institute of Materials Genome Shanghai200444China Research Institute Baoshan Iron&Steel Co.Ltd.Shanghai200431China

The influences of superheat and cooling intensity on macrostructure and macrosegregation of one new kind duplex stainless steel(DSS)were *** simulation equipment was applied to prepare samples,which could reproduce the industrial processes of DSS manufactured by a vertical continuous slab *** and macrosegregation were analyzed using the digital single lens reflex and laser-induced breakdown spectroscope(LIBSOPA-200),*** percentage of both chill zone and center equiaxed zone increases with the superheat decreasing,while that of the columnar zone *** is only equiaxed grain existing as the superheat is 10 and 20℃.The lower the superheat is,the coarser the gain size *** cooling intensity in mold could remarkably decrease the chill zone length and refine the grains in chill zone and center equiaxed *** influences of cooling intensity on macrosegregation are greater than those of *** macrosegregation of Si,Mn and Cr is slightly dependent on superheat,while that of Cu,Mo and Ni changes greatly with superheat increasing.

关键词： Continuous casting Solidification Thermal simulation Duplex stainless steel Macrosegregation

Guanidinium Iodides-based Ionic Liquids: Synthesis and Application for Dye-sensitized Solar Cells(DSSCs)

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Chemical Research in Chinese Universities 2009年第1期25卷 40-42页

作者： ZHENG Ren-feng WU Mao-cheng DUAN hai-feng ZHANG yu WEI Xiao LUO Xu-yang LIN Ying-jie College of Chemistry Jilin University Changchun 130012 P. R. China

A series of guanidinium ionic liquids（GILs） was designed, synthesized, and used as electrolytes for dye-sensitized solar cells（DSSCs）. The effect of electrolytes containing GILs on the photovoltaic performance of DSSCs was investigated. It is demonstrated that these GILs are promising for being used as electrolytes for DSSCs and a conversion efficiency of 4.1% can be obtained under AM 1.5 sun light irradiation.

关键词： Guanidinium ionic liquid Dye-sensitized solar cells(DSSCs) Electrolyte

Theoretical Studies on the Structures and Reactions of Halocarbenoids(Ⅰ)Structures and Stability of Chlorocarbenoid CHCl_2

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Chemical Research in Chinese Universities 1997年第3期13卷 256-261页

作者： Li LI Ji-hai, feng Sheng-yu,Liu Wei (Chemical College,Shandong University,Jinan, 250100) SHANDONG UNIV CHEM COLLJINAN 250100PEOPLES R CHINA

The chlorocarbenoid , CHCl2Li , was studied by means of ab initio molecular or- bital theory. Three equilibrium structures and two isomerization transition states were located. The calculations showed that the three-membered ring structure is the most stable. The 'classical tetrahedral' structure is not the local minimum on the potential energy surface.

关键词： Chlorocarbenoid isomeric structure Ab initio molecular orbital calcu- lation

A colorimetric chemosensor based on new water-soluble PODIPY dye for Hg^(2+) detection

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Chinese Chemical Letters 2015年第10期26卷 1241-1245页

作者： Xin-Dong Jiang hai-feng yu Jiu-Li Zhao Chang-Liang Sun Ying Xie Lin-Jiu Xiao College of Applied Chemistry Key Laboratory of Rare-Earth Chemistry and Applying Liaoning Province Shenyang University of Chemical Technology Center of Physical and Chemistry Test Shenyang University of Chemical Technology

The phosphorus-containing PODIPY 1 as a chemosensor can detect Hg^2＋ by a color change from pink to violet red without the use of any instrumentation. PODIPY 1 was selective to Hg^2＋ with a remarkable absorption change, and addition of other relevant metal ions caused almost no absorption change. The new PODIPY dye 1 was sensitive to various concentrations of Hg^2＋. The energy gap between the HOMO and LUMO of the metal complex 1–Hg^2＋ is smaller than that of chemosensor 1, which is in good agreement with the red shift in the absorption observed upon treatment of 1 with Hg^2＋. The 1-based test strips were easily fabricated and low-cost, useful in practical and efficient Hg^2＋test kits.

关键词： PODIPY Hg^2+ Colorimetric DFT Chemosensor

Plastic characterization of metals by combining nanoindentation test and finite element simulation

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Transactions of Nonferrous Metals Society of China 2013年第8期23卷 2368-2373页

作者： Yong MA Ying ZHANG hai-feng yu Xiang-yu ZHANG Xue-feng SHU Bin TANG Research Institute of Surface Engineering Taiyuan University of Technology Taiyuan 030024 China Research Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 China

Materials with the same elastic modulus E and representative stress and strain （σr,εr） present similar indentation-loading curves, whatever the value of strain hardening exponent n. Based on this definition, a good approach was proposed to extract the plastic properties or constitutive equations of metals from nanoindentation test combining finite element simulation. Firstly, without consideration of strain hardening, the representative stress was determined by varying assumed representative stress over a wide range until a good agreement was reached between the computed and experimental loading curves. Similarly, the corresponding representative strain was determined with different hypothetical values of strain hardening exponent in the range of 0-0.6. Through modulating assumed strain hardening exponent values to make the computed unloading curve coincide with that of the experiment, the real strain hardening exponent was acquired. Once the strain hardening exponent was determined, the initial yield stress ay of metals could be obtained by the power law constitution. The validity of the proposed methodology was verified by three real metals： AISI 304 steel, Fe andA1 alloy.

关键词： nanoindentation finite element simulation representative stress representative stain initial yield stress