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MECHANISM-TRANSFORMATION SYNTHESIS AND CHARACTERIZATION OF POLY(STYRENE-b-2-ETHYL-2-OXAZOLINE) DIBLOCK COPOLYMER

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Chinese Journal of Polymer Science 1999年第2期17卷 145-150页

作者： Sheng-qing Xu Han-ying Zhao Tao Tang bao-tong huang Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China 中科院长春应用化学所吉林长春

By mechanism-transformation (anionic --> cationic) poly(styrene-6-2-ethyl-2-oxazoline) diblock copolymer, PS-b-PEOx, was synthesized in two steps. The first step is the polymerization of styrene block capped with ethylene oxide and its tosylation; the second step is the cationic ring-opening polymerization of 2-ethyl-2-oxazoline. The products were thoroughly characterized by various methods, such as H-1-NMR, IR, DMA, TEM and SAXS. The results show that the copolymer obtained possesses high molecular weight and narrow molecular weight distribution.

关键词： diblock copolymer mechanism-transformation polymerization 2-ethyl-2-oxazoline styrene characterization

Morphological and Structural Studies of sPS/aPS Blends

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Chinese Chemical Letters 1998年第4期9卷 407-410页

作者： Sheng Qing XU Bin CHEN Yang LIU He Sheng CHEN bao tong huang(Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022) Changchun Inst. of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

The morphology and structure of the syndiotactic polystyrene (sPS)/atactic polystyrene (aPS) blends with various compositions have been studied by means of DSC, optical microscopy, SAXS, and WAXD. The results show that aPS is miscible with amorphous region of sPS. There is no macroscopic evidence that aPS forms separated domains in the blends. The decrease in crystallinity of sPS in the blends implies segregation of the aPS to the interfibrillar regions of the spherulites of sPS. The constancy of interlamellar distance and melting points indicates that the fibrillar structural units of sPS is unchanged on addition of aPS to sPS, and the unchanging parameters of the sPS unit cells mean that aPS does not enter the unit cells of sPS.

关键词： blend syndiotactic polystyrene compatibility structure

Hybrid treatment of varied orthodontic appliances for a patient with skeletal class II and temporomandibular joint disorders:A case report and review of literature

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World Journal of Clinical Cases 2024年第2期12卷 431-442页

作者： tong Lu Li Mei bao-Chao Li Zi-Wei huang huang Li Department of Orthodontics Nanjing Stomatological HospitalThe Affiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008Jiangsu ProvinceChina Discipline of Orthodontics Department of Oral ScienceFaculty of DentistryUniversity of OtagoDunedin 9016New Zealand

BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a *** TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and *** SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and *** treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep ***,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep *** the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her *** careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her ***,the improved facial appearance and relatively stable occlusion were *** 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was *** TMD screening and monitoring is of great clinical importance in the TMD susceptible *** treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

关键词： Temporomandibular disorder Skeletal class II Deep overbite Dual bite Invisible mandibular advancement appliance Case report

Forced boiling of nonazeotropic immiscible mixture in a supercapillary microchannel array for ultra-high heat flux removal with chip junction temperature below 85℃

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Science China(Technological Sciences) 2024年第5期67卷 1364-1380页

作者： SUN Bo bao YuChen TIAN tong LI Ji School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Laboratory of Advanced Thermal Management Technologies School of Engineering ScienceUniversity of Chinese Academy of SciencesBeijing100049China

In this study,a structure-optimized two-phase microchannel heat sink with sintered submicron nucleation sites was developed and *** copper-based microchannels had a rectangular cross-section with an equivalent hydraulic diameter of 222μ*** subcooled flow boiling characteristics were comprehensively compared between pure HFE-7100 and a non-azeotropic,immiscible binary mixture of HFE-7100 and water,considering heating areas of 1 and 5 cm^(2).The total heating power input to the test section were 100–1500 and 250–3000 W for a 1 and 5 cm^(2)heat source,respectively,with a flow rate ranging from 50 to150 L/*** to pure HFE-7100,the non-azeotropic immiscible binary mixture of HFE-7100/water in the sintered porous microchannels exhibited a much higher overall heat transfer coefficient and lower power *** maintain the junction temperature of a high power electronic chip below 85℃,the proposed supercapillary microchannel heat sink could effectively dissipate the heat flux of 1275 W/cm^(2)over 1 cm^(2)heat source and 500 W/cm^(2)over 5 cm^(2)heat *** addition,the volume ratio of the binary mixture strongly influence the two-phase flow heat transfer *** optimal volume ratio exist in terms of the thermal resistance–pumping power minimization(HFE-7100:water=2:8 is recommended in this study).The findings of this investigation on the flow boiling properties of non-azeotropic immiscible mixtures help fill a gap in the related field.

关键词： microchannel sintered powder coating submicron nucleation cavities nonazeotropic immiscible ultra-high heat flux

d-Orbital steered FeN_(4)moiety through N,S dual-site adjustation for zinc-air flow battery

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Journal of Energy Chemistry 2024年第5期92卷 8-15页

作者： Chunzhu bao Mingwei tong Xueli Li Zhonghua Xiang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

The implementation of pristine covalent organic polymer(CO_(2)P)with well-defined structure as air electrode may spark fresh vitality to rechargeable zinc-air flow batteries(ZAFBs),but it still remains challenges in synergistically regulating their electronic states and structural porosity for the great device ***,we conquer these issues by exploiting N and S co-doped graphene with COP rich in metal-ligand nitrogen to synergistically construct an effective catalyst for oxygen reduction reaction(ORR).Among them,the N and S co-doped sites with high electronegativity properties alter the number of electron occupations in the d orbital of the iron centre and form electron-transfer bridges,thereby boosting the selectivity of the ORR-catalysed four-electron ***,the introduction of COP materials aids the formation of pore interstices in the graphene lamellae,which both adequately expose the active sites and facilitate the transport of reactive *** from the synergistic effect,as-prepared catalyst exhibits excellent half-wave potentials(E_(1/2)=912 mV)and stability(merely 8.8%drop after a long-term durability test of 50000 s).Further,ZAFBs assembled with the N/SG@CO_(2)P catalyst demonstrate exceptional power density(163.8 mW cm^(-2))and continuous charge and discharge for approximately 140 h at 10 mA cm^(-2),outperforming the noble-metal benchmarks.

关键词： Nitrogen/sulfurdual sites Metal-coordinated nitrogen sites Covalent organic polymer Oxygen reduction reaction Zn-airflow battery

An isolated symmetrical 2T2R cell enabling high precision and high density for RRAM-based in-memory computing

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Science China(Information Sciences) 2024年第5期67卷 287-294页

作者： Yaotian LING Zongwei WANG Yuhang YANG Lin bao Shengyu bao Qishen WANG Yimao CAI Ru huang School of Integrated Circuits Beijing Advanced Innovation Center for Integrated Circuits Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

In-memory computing(IMC), leveraging emerging memories, holds significant promise in overcoming memory limitations and improving energy efficiency. However, the prevailing IMC array structure based on serially connected transistors and memory cells(1T1R/2T2R), along with the signed weight mapping scheme, can lead to asymmetrical weight sensing issues(AWS) due to electrical asymmetry within the1T1R/2T2R structure, particularly in highly scaled cells where the transistor's resistance becomes significant. In this paper, we propose and fabricate an electrically symmetric memory cell based on a physically isolated 2T2R structure for IMC. This design aims to enhance the precision and density of RRAM-based IMC arrays. The 2T2R cells are manufactured using the back-end-of-line(BEOL) process of a commercial40 nm technology platform. The feasibility of this design is verified through measured and simulated results,showcasing its capability to address the issue of AWS. Compared to conventional 2T2R cells, this design achieves a considerably smaller transistor footprint without compromising accuracy, while also improving integration density by 42.2%. These innovative memory cell advancements have the potential to further advance high-energy-efficient IMC technology.

关键词： RRAM 2T2R multi-level storage weight asymmetry in-memory computing

Elevational and temporal patterns of pollination success in distylous and homostylous buckwheats(Fagopyrum)in the Hengduan Mountains

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Plant Diversity 2024年第5期46卷 661-670页

作者： Ling-Yun Wu Shuang-Quan huang Ze-Yu tong Faculty of Resources and Environmental Science Hubei UniversityWuhan 430062China Institute of Evolution and Ecology School of Life SciencesCentral China Normal UniversityWuhan 430079China

Reproductive strategies of sexually dimorphic plants vary in response to the ***,we ask whether the sexual systems of Fagopyrum species(i.e.,selfing homostylous and out-crossing distylous)represent distinct adaptive strategies to increase reproductive success in changing alpine *** answer this question,we determined how spatial and temporal factors(e.g.,elevation and peak flowering time)affect reproductive success(i.e.,stigmatic pollen load)in nine wild Fagopyrum species(seven distylous and two homostylous)among 28 populations along an elevation gradient of 1299-3315 m in the Hengduan Mountains,southwestern *** also observed pollinators and conducted hundreds of hand pollinations to investigate inter/intra-morph compatibility,self-compatibility and pollen limitation in four Fagopyrum species(two distylous and two homostylous).We found that Fagopyrum species at higher elevation generally had bigger flowers and more stigmatic pollen loads;lateflowering individuals had smaller flowers and lower pollen *** pollen deposition was more variable in distylous species than in homostylous *** seed set was not pollenlimited in all species,we found that fruit set was much lower in distylous species,which rely on frequent pollinator visits,than in homostylous species capable of autonomous *** findings that pollination success increases at high elevations and decreases during the flowering season suggest that distylous and homostylous species have spatially and temporally distinct reproductive strategies related to environment-dependent pollinator activity.

关键词： Biodiversity hotspot Elevation gradient Fagopyrum Stigmatic pollen load Temporal pattern

Influence and optimization of swirler parameters on elbow wear of deep coal fluidization pipeline transportation system

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Friction 2024年第7期12卷 1408-1433页

作者： Shaodi ZHAO Jiusheng bao Shirong GE Zhongbin WANG Yan YIN Congguang huang School of Mechanical and Electrical Engineering China University of Mining and TechnologyXuzhou 221116China School of Mechanical Electronic and Information Engineering China University of Mining and Technology-BeijingBeijing 100083China Frontier Scientific Research Center for Fluided Mining of Deep Underground Resources China University of Mining and TechnologyXuzhou 221008China

Elbow wear is a major threat to the multiphase pipeline transportation industry,which has a negative impact on the stable operation of the transportation *** order to find the wear reduction methods of elbows in the fluidization pipeline transportation system for 2000-meter-deep coal resources,the swirler was installed upstream of the elbows,and wear simulations and tests of three kinds of elbows were carried *** results showed that the maximum wear rate(MWR)of elbows increased and then decreased along the elbow *** to the different directions of gravity,the heavy wear position(HWP)of the horizontal-vertical(H-V)elbow was in front of the vertical-horizontal(V-H)*** the downstream portion of the horizontal-horizontal(H-H)elbow was still a horizontal pipe,the HWP of the H-H elbow almost covered the whole *** swirler placed upstream of the elbows could make the particles at the elbow move to the intrados of the elbows,resulting in less collision between the particles and the extrados of the elbows,thus reducing the wear of the *** wear reduction effects of swirlers on three different elbows were favorably connected with the guide vane angle(GVA)and negatively correlated with the guide vane length(GVL),decreased first and then increased as the guide vane height(GVH)increased,and were little affected by the guide vane number(GVN)and the guide vane thickness(GVT).The mathematical models between the MWR of the elbows and guide vane parameters were *** bench tests,the wear reduction effect of three kinds of elbows under the optimal guide vane parameters was 58.4%,76.9%,and 78.6%,*** errors between the bench test results and the simulation results were around 10%.

关键词： pipe elbow erosion wear spiral flow swirler guide vane parameters particle collision

Temperature-controlled DCP Fluorescent Probe Based on Hydrogel-immobilized Quantum Dots Composite

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 931-936页

作者：童伊琳杨坤 HAN Xuecai YU Kan bao Jiaqi Faculty Information Science and Technology Wenhua CollegeWuhan 430074China State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430074China Yangtze Optical Fibre and Cable Joint Stock Limited Company Wuhan 430074China

A composite was created by incorporating the quantum dot-enhanced SiO_(2)nanoparticles within this *** on this composite,a temperature-controlled fluorescent probe for DCP was developed.A meticulous examination of this probe revealed its attributes and factors affecting its *** using temperature modulation,the probe was adept at detecting DCP concentrations ranging between 1.0×10^(-6)and 9.0×10^(-6)mol/*** a probe offers remarkable selectivity,repeatability,and robust stability,so that the detection of DCP can be carried out at different temperatures,and a fast,reliable,sensitive and low-cost intelligent detection method is realized.

关键词： temperature-controlled fluorescent probe hydrogel-immobilized quantum dots composite DCP