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CONFINED LAMELLA FORMATION IN CRYSTALLINE-CRYSTALLINE POLY(ETHYLENE OXIDE)-b-POLY(ε-CAPROLACTONE) DIBLOCK COPOLYMERS

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Chinese Journal of Polymer Science 2013年第9期31卷 1260-1270页

作者： fei-fei xue xue-si Chen Li-jia An Sergio S. Funari Shi-chun Jiang School of Materials Science and Engineering Tianjin University State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences HASYLAB at DESY

The real time and in situ investigation of the crystallization process and structure transitions of asymmetric crystalline-crystalline diblock copolymers from the melt was performed with synchrotron simultaneous SAXS/WAXS. The asymmetric poly（ethylene oxide）-b-poly（ε-caprolactone） diblock copolymers were chosen for the present study. It was shown that the short blocks crystallized later than the long blocks and final lamellar structure was formed in all of the asymmetric diblock copolymers. The final lamellar structure was confirmed by AFM observation. The SAXS data were analyzed with different methods for the early stage of the crystallization. The Guinier plots indicated that there were no isolated domains formed before the formation of lamellae in the asymmetric diblock copolymers during the crystallization process. Debye- Bueche plots implied the formation of correlated domains during crystallization.

关键词： PEO-b-PCL diblock copolymers Synchrotron simultaneous SAXS/WAXS Polymer crystallization Confinedlamella formation.

Novel Incentive Scheme to Motivate Flexible Customers for Phase Balancing

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CSEE Journal of Power and Energy Systems 2022年第4期8卷 1048-1059页

作者： Lurui Fang Kang Ma Furong Li fei xue Xi'an Jiaotong-liverpool University Suzhou 215123Chin University of Bath BathUK

Phase imbalance is a significant and widespread problem in low voltage(LV,415V)*** paper develops a novel incentive scheme that encourages flexible customers to engage in phase *** the technical side,this incentive scheme is based on a centralized control algorithm utilizing the inherent fexibility of customers'AC/DC converters to achieve phase balancing at the substation side of LV *** the incentive side,first,this paper calculates the benefits from phase *** then defines a rebalancing contribution index that quantifies the flexible customer's contribution to addressing the predominant imbalance-induced consequence,e.g,capacity wastes,and energy *** to the contribution indices and the benefits,the incentive scheme rewards flexible customers correspondingly and guides them to prioritize the predominant consequence of phase *** studies demonstrate that:1)the remunerations paid to the flexible customers primarily depends on their contributions to addressing the predominant imbalance-induced consequences for the network in question;2)the incentive scheme does not discriminate against small/medium-sized flexible customers who are dedicated to phase balancing,thus promoting inclusiveness.

关键词： Competition-based contribution index low voltage incentive scheme phase imbalance power distribution

A 3-D numerical simulation of the characteristics of open channel flows with submerged rigid vegetation

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Journal of Hydrodynamics 2021年第4期33卷 833-843页

作者： Jun-tao Ren xue-fei Wu Ting Zhang School of Environment and Resource Southwest University of Science and TechnologyMianyang621010China

This paper applies the Flow-3D to investigate the impacts of different flow discharge and vegetation scenarios on the flow velocity (including the longitudinal, transverse and vertical velocities). After the verification by using experimental measurements, a sensitivity analysis is conducted for the vegetation diameter, the vegetation height and the flow discharge. For the longitudinal velocity, the greatest impact on the flow structure originates from the vegetation diameter, rather than the discharge. The vegetation height, however, determines the inflection point of the vertical distribution. Comparing the transverse velocities at two positions in the vegetated area, i.e., the upstream and the downstream, a symmetric pattern is identified along the water depth. The same pattern is also observed for the vertical velocity regardless of the flow or vegetation scenario, including both transverse and vertical fluid circulation patterns in the vegetated area. Moreover, the larger the vegetation diameter is, the more evident these patterns become. The upper circulation occurs near the vegetation canopy. These findings regarding the circulations along the transverse and vertical directions in the vegetated region shed light on the 3-D flow structure through the submerged vegetation.

关键词： Submerged rigid vegetation longitudinal velocity transverse velocity vertical velocity open channel

Implementation of New OPAL Tables in Eggleton's Stellar Evolution Code

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Chinese Journal of Astronomy and Astrophysics 2007年第2期7卷 245-250页

作者： xue-fei Chen Christopher A. Tout National Astronomical Observatories / Yunnan Observatory CAS Kunming 650011 Institute of Astronomy The Observatories Madingley Road Cambridge CB3 0HA England Centre for Stellar and-Planetary Astrophysics Schooi of Mathematics.~Mona-shUniversityClaytonVictoria 3800 Australia

Based on previous works of OPAL, we construct a series of opacity tables for various metaUicities Z = 0, 0.00001, 0,00003, 0.0001, 0.0003, 0.001, 0.004, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08 and 0.1. These tables can be easily used in Eggleton＇s stellar evolution code in place of the old tables without changing the code. The OPAL tables are used for log10 （T/K）〉 3.95 and Alexander＇s for log10 （T/K）〈 3.95. At log10 （T/K） = 3.95, the two groups＇ data fit well for all hydrogen mass fractions. Conductive opacities are included by reciprocal addition according to the formulae of Yakovlev and Urpin. A comparison of 1 and 5 M⊙ models constructed with the older OPAL tables of Iglesias and Rogers shows that the new opacities have most effect in the late stages of evolution, the extension of the blue loop during helium burning for intermediate-mass and massive stars.

关键词： radiative transfer- stars evolution - stars general

Effect of Working Position on Vertical Motion Straightness of Open Hydrostatic Guideways in Grinding Machine

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Chinese Journal of Mechanical Engineering 2017年第1期30卷 46-52页

作者： ZHA JUn WANG Zhiwei xue fei CHEN Yaolong State Key Laboratory for Manufacturing Systems Engineering Xi 'an Jiaotong University Xi 'an 710049 China College of Mechanical and Electronic Engineering Shandong University of Science and Technology Qingdao 266590 China

Hydrostatic guideways have various applications in precision machine tools due to their high motion accuracy. The analysis of motion straightness in hydrostatic guideways is generally ignoring the external load on the slider. A variation force also exists, caused by the different working positions, together with the dead load of the slider and that of other auxiliary devices. The effect of working position on vertical motion straightness is investigated based on the equivalent static model, considering the error averaging effort of pressured oil film in open hydrostatic guideways. Open hydrostatic guideways in LGF1000 are analyzed with this approach. The theoretical results show that the slider has maximum vertical motion straightness when the working position is closer the guiderail of Y axis. The vertical motion straightness reaches a minimum value as the working position is located at the center of the two guiderails on the Y axis. The difference between the maximum and minimum vertical motion straightness is 34.7%. The smaller vertical motion straightness is attributed to the smaller spacing of the two pads centers, along the Y direction. The experimental results show that the vertical motion straightness is 4.15 μm/1200 mm, when the working position is located in the middle of the Xbeam, and 5.08 pro/1200 mm, when the working position is approaching the Y guiderails, denoting an increase of 18.3%. The changing trends of the measured results validate the correctness of the theoretical model. The research work can be used to reveal the variation law of accuracy of the open hydrostatic guideways, under different working positions, to predict the machining precision, and provides the basis for an error compensation strategy for gantry type grinding machines.

关键词： open hydrostatic guideways error averaging vertical motion straightness working position

VBMq： pursuit baremetal performance by embracing block I/O parallelism in virtualization

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Frontiers of Computer Science 2018年第5期12卷 873-886页

作者： Diming ZHANG fei xue Hao HUANG Shaodi YOU Faculty of Computer Science and Technology Nanjing University Nanjing 210023 China College of Computer Science and Engineering Jiangsu University of Science and Technology Zhenjiang 212003 China College of Engineering and Computer Science Australian National University Canberra 2600 Australia Data61-CSIRO Australian National University Canberra 2600 Australia

Barely acceptable block I/O performance prevents virtualization from being widely used in the HighPerformance Computing field. Although the virtio paravirtual framework brings great I/O performance improvement, there is a sharp performance degradation when accessing high-performance NAND-flash-based devices in the virtual machine due to their data parallel design. The primary cause of this fact is the deficiency of block I/O parallelism in hypervisor, such as KVM and Xen. In this paper, we propose a novel design of block I/O layer for virtualization, named VBMq. VBMq is based on virtio paravirtual I/O model, aiming to solve the block I/O parallelism issue in virtualization. It uses multiple dedicated I/O threads to handle I/O requests in parallel. In the meanwhile, we use polling mechanism to alleviate overheads caused by the frequent context switches of the VM＇s notification to and from its hypervisor. Each dedicated I/O thread is assigned to a non-ovedapping core to improve performance by avoiding unnecessary scheduling. In addition, we configure CPU affinity to optimize I/O completion for each request. The CPU affinity setting is very helpful to reduce CPU cache miss rate and increase CPU efficiency. The prototype system is based on Linux 4.1 kernel and QEMU 2.3.1. Our measurements show that the proposed method scales graciously in the multi-core environment, and provides performance which is 39.6x better than the baseline at most, and approaches bare-metal performance.

关键词： high-performance parallelism paravirtual I/O

Sources, enrichment mechanisms, and resource effects of rare metal elements-enriched geothermal springs in Xizang, China

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Science China Earth Sciences 2024年第11期67卷 3476-3499页

作者： fei xue Hongbing TAN Xiying ZHANG Jinbao SU School of Earth Sciences and Engineering Hohai UniversityNanjing 211100China Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes Qinghai Institute of Salt LakesChinese Academy of SciencesXining 810008China School of Oceanology Hohai UniversityNanjing 210024China

Rare metals such as lithium(Li), rubidium(Rb), and cesium(Cs) are strategically crucial mineral resources for the development of emerging industries in China. Ensuring a stable long-term supply of these resources is essential. The geothermal systems in Xizang, China are well-developed, with a wide distribution of various types. Most high-temperature geothermal systems in Xizang are exceptionally enriched in rare metal elements(RMEs) and have the potential to become a new source of rare metals to secure China's strategic mineral resource supply in the future. A close relationship also exists between the geothermal system and the special salt lake resources on the Tibetan Plateau. Geothermal springs thus play a key role in the migration and enrichment of RMEs from deep to shallow parts of the crust, in the transition between endogenous and exogenous mineralization, and source-to-sink processes. However, the mechanisms of element enrichment and evolution in these springs have not been systematically discussed, and many theoretical issues remain to be investigated. Based on summarizing and analyzing previous research, this study employs hydrochemical and isotopic geochemistry methods to investigate typical geothermal springs across Xizang and explore the anomalous enrichment mechanism of RMEs, and the resource effects of geothermal springs. Comprehensive analysis shows that the total dissolved solids(TDS) and hydrochemical types of geothermal springs are similar to those of major geothermal fields worldwide, but the Tibetan springs are abnormally rich in Li(averaging5.48 mg/L), Rb(averaging 0.75 mg/L), and Cs(averaging 3.58 mg/L), which are hundreds to thousands of times more concentrated than natural waters. The distribution of these enriched geothermal springs is controlled by the Yarlung Zangbo suture zone and the extended N-S trending rifts, especially in the intersection zone of the two, where the geothermal springs are the most enriched. Based on the spatial distr

关键词： Geothermal springs Rare metal elements Enrichment mechanisms Salt lakes Tibetan Plateau

High-temperature oxidation behavior of 9Cr‒5Si‒3Al ferritic heat-resistant steel

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International Journal of Minerals,Metallurgy and Materials 2020年第9期27卷 1244-1250页

作者： Jun-jun Yan xue-fei Huang Wei-gang Huang College of Materials Science and Engineering Sichuan UniversityChengdu 610065China

To improve the oxidation properties of ferritic heat-resistant steels,an Al-bearing 9Cr‒5Si‒3Al ferritic heat-resistant steel was *** then conducted cyclic oxidation tests to investigate the high-temperature oxidation behavior of 9Cr‒5Si and 9Cr‒5Si‒3Al ferritic heat-resistant steels at 900 and 1000℃.The characteristics of the oxide layer were analyzed by X-ray diffraction,scanning electron microscopy,and energy dispersive *** results show that the oxidation kinetics curves of the two tested steels follow the parabolic law,with the parabolic rate constant kp of 9Cr‒5Si‒3Al steel being much lower than that of 9Cr‒5Si steel at both 900 and 1000℃.The oxide film on the surface of the 9Cr‒5Si alloy exhibits Cr2MnO4 and Cr2O3 phases in the outer layer after oxidation at 900 and 1000℃.However,at oxidation temperatures of 900 and 1000℃,the oxide film of the 9Cr‒5Si‒3Al alloy consists only of Al2O3 and its oxide layer is thinner than that of the 9Cr‒5Si *** results indicate that the addition of Al to the 9Cr‒5Si steel can improve its high-temperature oxidation resistance,which can be attributed to the formation of a continuous and compact Al2O3 film on the surface of the steel.

关键词： ferritic heat-resistant steel high-temperature oxidation oxidation kinetics aluminum

Terrain-influenced wind flow of the Qitai radio telescope site

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Journal of Mountain Science 2023年第11期20卷 3173-3185页

作者： HE fei-long XU Qian WANG Na xue fei WANG Hui Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China University of Chinese Academy of Sciences Beijing 100049China

The wind environment of a site is one of the important factors affecting the observation performance of large aperture and high-performance radio *** the relationship between the effects of different terrains on wind flow is important to optimize the wind environment of the *** terrain of the Qitai radio telescope(QTT)site located in east Tianshan Mountains at an elevation of about 1800 m was used to study the wind flow in the adjacent zone of antenna based on numerical *** area from 600m south to 600m north of the antenna is defined as the antenna adjacent zone,and three groups of boundaries with different terrains are set up upstream and downstream,*** the zone where the antenna is located is a slope terrain,in order to verify the influence of terrain on the wind flow and to clarify the relationship between the influence of boundary terrain on the wind flow,a control group of horizontal terrain is *** simulation results show that the wind flow is mainly influenced by the *** highest elevation of the upstream and downstream boundary terrains affects the basic wind *** upstream boundary terrain has a greater impact on wind flow than the downstream boundary *** addition,the wind speed profile index obtained by numerical simulation is smaller than the actual index for the wind from ***,the wind speed at the upper level(about 100 m)obtained by inversion based on the measured wind speed at the bottom(about 10 m)is also smaller than the actual wind speed.

关键词： Radio telescope site Terrain Wind flow characteristic Numerical simulation