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science China Chemistry 2008年第2期51卷 152-157页

作者： LIU Bo1,2, SHI MinMin1,2, YANG LiGong1,2, CHEN HongZheng1,2 & wang Mang1,2 1 State Key Lab of Silicon Materials, department of polymer science and Engineering, Zhejiang university, Hangzhou 310027, China 2 Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Zhejiang university, Hangzhou 310027, China 1. State Key Lab of Silicon Materials Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China 2. Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education Zhejiang University Hangzhou 310027 China

A novel organic electron acceptor, N,N′-dipyrimidinyl-3,4,9,10-perylene-tetracarboxylic diimide (DMP), was designed and synthesized. The molecular structure was characterized by FTIR spectrum and elemental analysis. By cyclic voltammetry measurements, DMP was found to possess a lower LUMO energy level than N,N′-diphenyl-3,4,9,10-perylene-tetracarboxylic diimide due to the stronger electron-withdrawing pyrimidinyl group than the phenyl group. Fluorescence quenching is observed in a dual-layer film consisting of a DMP layer and a C60 layer and was attributed to the charge transfer at the interface due to the energy level offset between DMP and C60.

关键词： perylene diimide LUMO charge transfer fluorescence quenching

SYNTHESIS AND FREE RADICAL RING-OPENING polymerIZATION OF 2-METHYL-AND 2-METHYL-9-n-BUTYL-(-7-METHYLENE-1,4,6-TRIOXA-SPIRO (4, 4)NONANE)

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Chinese Journal of polymer science 1989年第3期7卷 232-238页

作者：潘才元王寅 department of Materials science and Engineering University of Science and Technology of China. Hefei

This paper describes the synthesis and free radical ring-opening polymerization of 2-methyl-and 2-methyl-9-n-butyl (-7-methylene-1, 4, 6-trioxaspiro (4, 4) nonane). The structures of the two polymers were verified by IR, 'H and ^(13)C NMR spectra. The substituent on 9-position of 7-methylene-trioxaspiro (4, 4) nonane affects the structure of polymer and polymerization activity. The polymerization mechanism is discussed.

关键词： 2-Mehyl-7-methylene-trioxaspiro (4, 4) nonane 2-Mehyl-9-n-butyl-7-methylene-trioxaspiro (4, 4) nonane free radical ring-opening polymerization, Substituent effect Steric hindrance

Transparent partial page migration between CPU and GPU

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Frontiers of Computer science 2020年第3期14卷 1-13页

作者： shiqing ZHANG Zheng QIN Yaohua YANG Li SHEN Zhiying wang department of Computer science National University of Defense TechnologyChangsha 410073China

Despite the increasing investment in integrated GPU and next-generation interconnect research,discrete GPU connected by PCIe still account for the dominant position of the market,the management of data communication between CPU and GPU continues to ***,the programmer explicitly controls the data transfer between CPU and *** simplify programming and enable systemwide atomic memory operations,GPU vendors have developed a programming model that provides a single,virtual address space for accessing all CPU and GPU memories in the *** page migration engine in this model automatically migrates pages between CPU and GPU on *** meet the needs of high-performance workloads,the page size tends to be *** by low bandwidth and high latency interconnects compared to GDDR,larger page migration has longer delay,which may reduce the overlap of computation and transmission,waste time to migrate unrequested data,block subsequent requests,and cause serious performance *** this paper,we propose partial page migration that only migrates the requested part of a page to reduce the migration unit,shorten the migration latency,and avoid the performance degradation of the full page migration when the page becomes *** show that partial page migration is possible to largely hide the performance overheads of full page *** with programmer controlled data transmission,when the page size is 2MB and the PCIe bandwidth is 16GB/sec,full page migration is 72.72×slower,while our partial page migration achieves 1.29×*** the PCIe bandwidth is changed to 96GB/sec,full page migration is 18.85×slower,while our partial page migration provides 1.37×***,we examine the performance impact that PCIe bandwidth and migration unit size have on execution time,enabling designers to make informed decisions.

关键词： unified memory data communication page migration partial page migration

Securing offshore resources development: A mathematical investigation into gas leakage in long-distance flexible pipes

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Petroleum science 2024年第4期21卷 2734-2744页

作者： Xiang-An Lu Liang-Liang Jiang Jian-Sheng Zhang Min-Gui wang Guangling College of Yangzhou university department of Chemical and Petroleum Engineering University of Calgary department of Energy and Power Engineering Tsinghua University

Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development. Under high pressure conditions, small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space, incurring annular pressure build-up and/or production of acidic environment, which poses serious challenges to the structure and integrity of the flexible pipes. Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature, annular structure, external temperature. In a long-distance gas flexible pipe, moreover, gas permeation exhibits non-uniform features, and the gas permeated into the annular space flows along the metal gap. To assess the complex gas transport behavior in long-distance gas flexible pipes, a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes, the diffusion of gas in the inner liner, and the gas seepage in the annular space under varying permeable properties of the annulus. In addition, the effect of a variable temperature is accounted. A numerical calculation method is accordingly constructed to solve the coupling mathematical equations. The annular permeability was shown to significantly influence the distribution of annular pressure. As permeability increases, the annular pressure tends to become more uniform, and the annular pressure at the wellhead rises more rapidly. After annular pressure relief followed by shut-in, the pressure increase follows a convex function. By simulating the pressure recovery pattern after pressure relief and comparing it with test results, we deduce that the annular permeability lies between 123 and 512 m D. The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.

关键词： Offshore resources development Transport security Long-distance flexible pipes Gas leakage Heat and mass transfer model Finite difference calculation

How to select heterogeneous CO_(2)reduction electrocatalyst

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Nano Research Energy 2024年第1期3卷 38-77页

作者： Ji Shen Dingsheng wang department of Chemistry Tsinghua UniversityBeijing 100084China

As an important part of carbon neutralization,carbon dioxide electroreduction reaction(CO_(2)RR)can convert CO_(2)into high value-added chemicals and fuels to realize the recycling of carbon resources and solve the problem of environmental ***,exploring the element species and surface structure of the catalyst plays a central role in improving the performance of the catalyst,enhancing the CO_(2)conversion efficiency and forming C1 and C_(2+)***,we summarize the recent progress in the selective regulation of CO_(2)RR reaction products by different *** particular,we emphasize the structure-property relationship of CO_(2)RR by the microenvironment of metal center and substrate,heteroatom doping,hydrogen bond network of metal-free polymer,and construction of heterogeneous catalytic *** the same time,the recent advances for the identification of CO_(2)RR active sites and mechanistic studies on the process of reducing CO_(2)conversion to different products are reviewed,as well as a comprehensive review to the final ***,we outline the inevitable challenges faced by CO_(2)RR and present our own recommendations aimed at contributing to CO_(2)resource utilization.

关键词： CO_(2)RR C_(1)product C_(2+)product electrocatalyst electrochemical performances

Structural disruption of melanin-like polymers with boosted UV protection

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science China Chemistry 2024年第5期67卷 1653-1663页

作者： Zhen Yang Xianheng wang Wanjie Bai Zikun Zou Haoxing Wu Yiwen Li department of Radiology Huaxi MR Research CenterFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceNational Clinical Research Center for GeriatricsWest China HospitalSichuan UniversityChengdu 610041China College of polymer science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

Manipulating the energy structure of materials represents an efficient way to regulate their light absorption behaviors. For example, constructing donor-acceptor(D-A) structures to increase the polarizability and reduce the energy bandgap of local molecules has been widely used in the field of organic photovoltaics with ordered structures. Remarkably, even in disordered and chaotic systems such as melanin-like polydopamine(PDA), visible and near-infrared light absorption can be significantly improved using this strategy. However, there has been a noticeable dearth of research on the ultraviolet(UV) light absorption regulation of bioinspired polymers with disordered and chaotic architectures by tailoring the D-A microstructures. In this study, a series of benzoheterocyclic molecules with strong electron-donating features screened by molecular simulation calculations were involved in disrupting the D-A structures within PDA. The destruction of D-A structures promoted the increase of the energy band gap and finally boosted the UV absorption of PDA. The resulting PDA nanoparticles with enhanced UV absorption were further employed to fabricate UV shielding composite films to protect the growth of plants from harmful UV radiation. This research may open up new avenues for structural disruption of bioinspired polymers for enhanced photoprotection applications.

关键词： melanin-like polymers polydopamine D-A structure UV absorption photoprotection

Shape Memory polymer Composites:4D Printing,Smart Structures,and Applications

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Research 2024年第3期2023卷 319-343页

作者： Shiyu Yan Fenghua Zhang Lan Luo Linlin wang Yanju Liu Jinsong Leng Centre for Composite Materials and Structures Harbin Institute of Technology(HIT)No.2 Yikuang StreetHarbin 150000People's Republic of China department of Astronautic science and Mechanics Harbin Institute of Technology(HIT)No.92 West Dazhi StreetHarbin 150000People's Republic of China.

Shape memory polymers (SMPs) and their composites (SMPCs) are smart materials that can be stably deformed and then return to their original shape under external stimulation, thus having a memory of their shape. Three-dimensional (3D) printing is an advanced technology for fabricating products using a digital software tool. Four-dimensional (4D) printing is a new generation of additive manufacturing technology that combines shape memory materials and 3D printing technology. Currently, 4D-printed SMPs and SMPCs are gaining considerable research attention and are finding use in various fields, including biomedical science. This review introduces SMPs, SMPCs, and 4D printing technologies, highlighting several special 4D-printed structures. It summarizes the recent research progress of 4D-printed SMPs and SMPCs in various fields, with particular emphasis on biomedical applications. Additionally, it presents an overview of the challenges and development prospects of 4D-printed SMPs and SMPCs and provides a preliminary discussion and useful reference for the research and application of 4D-printed SMPs and SMPCs.

关键词： composites printing Smart

Injection of a Self-propelled polymer into a Small Circular Cavity

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Chinese Journal of polymer science 2024年第6期42卷 886-894页

作者： Chao wang Yan-Li Zhou Xiao Yang Fan Wu Meng-Bo Luo department of Physics Taizhou UniversityTaizhou318000China department of Physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active polymer Injection Dynamics Simulation

Recent Developments of Photodeformable polymers:From Materials to Applications

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Research 2024年第2期2023卷 729-752页

作者： Shuting Kong Hailan wang Eethamukkala Ubba Yuxin Xiao Tao Yu Wei Huang Frontiers science Center for Flexible Electronics(FSCFE) Shaanxi Institute of Flexible Electronics(SIFE)Northwestern Polytechnical University127 West Youyi RoadXian 710072China OMC Research Laboratory.department of Chemistry School of Advanced SciencesVITVelloreTamilnaduIndia Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Nanjing Tech University(NanjingTech)30 South Puzhu RoadNanjing 211816China State Key Laboratory of Organic Electronics and Information Displays&Institute of Advanced Materials(IAM) Nanjing University of Posts and Telecommunications9 Wenyuan RoadNanjing 210023China

Photodeformable polymer materials have a far influence in the fields of flexibility and *** stimulation energy is converted into mechanical energy through molecular *** kinds of photodeformable polymer materials,liquid crystalline polymer(LCP)photodeformable materials have been a hot topic in recent *** such as azobenzene,a-cyanostilbene,and 9,10-dithiopheneanthracene have been widely used in LCP,which are helpful for designing functional molecules to increase the penetration depth of light to change physical *** to the various applications of photodeformable polymer materials,there are many excellent reports in intelligent *** this review,we have systematized LCP containing azobenzene into 3 categories depending on the degree of crosslinking liquid crystalline elastomers,liquid crystalline networks,and linear *** structural,typical polymer materials and their applications are *** issues faced and future directions to be developed for photodeformable polymer materials are also summarized.

关键词： properties. field. crystalline