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Search Results: 1 - 10 of 29777 matches for " Kang Xue-Ya "
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Synthesis and Electrochemical Characterizations of Zinc-doped LiFePO4/C by Carbothermal Reduction
HUA Ning, WANG Chen-Yun, KANG Xue-Ya, Tuerdi, HAN Ying
无机材料学报 , 2010, DOI: 10.3724/sp.j.1077.2010.10105
Abstract: Alien atom doping has been adopted to modify the electrochemical performance of olivine type LiFePO4 for cathode material. Here, we report that zinc-doping can improve the performance of LiFePO4/C immensely by a simple method. LiFePO4/C and Zn-doped LiFePO4/C cathode materials were firstly synthesized by carbothermal reduction method. Physical-chemical characterizations were done by X-ray diffraction, scanning electron microscope and transmittance electron microscope. Electrochemical behavior of the cathode materials were analyzed by using cyclic voltammetry, and galvanostatic measurements were employed to characterize the reaction of lithium ion insertion and de-insertion. ICP and XRD analyses indicate that Zn ions were sufficiently doped in LiFePO4 and did not alter its crystal structure. During de-intercalation and intercalation process of lithium ions, the doped zinc atoms protect the LiFePO4 crystal from shrink. Consequently, the conductivity is enhanced after doping. It is noted that zinc ions doping can improve performance of LiFePO4, especially on the aspect of stable cycle-life at higher C rate.
The first principles and experimental study on Mn-doped LiFePO4
Mn掺杂LiFePO4的第一性原理研究

Dou Jun-Qing,Kang Xue-Ya,Tuerdi Wumair,Hua Ning,Han Ying,
窦俊青
,康雪雅,吐尔迪· 吾买尔,华宁,韩英

物理学报 , 2012,
Abstract: The electronic structures of pure and Mn-doped LiFePO4 are studied using density functional theory (DFT). The results demonstrate that the pure LiFePO4 has a band gap of 0.725 eV, while the 25% Mn doped LiFe0.75Mn0.25PO4 has the smallest band gap (0.469 eV), and the weakest Fe---O and Li---O bond, which indicates that the electronic conductivity and the ionic conductivity of the doped LiFePO4 are improved due to doping. On the other hand, the experimental results also show that the LiFe0.75Mn0.25PO4 has the best electrochemical performance and it delivers a very high capacity of 158 mAh? g-1 and a high energy density of 551 Wh·kg-1.
Microwave Sintering of ZnO Varistor Ceramics
ZnO压敏陶瓷的微波烧结

KANG Xue-Ya,CHANG Ai-Min,HAN Ying,WANG Tian-Diao,TAO Ming-De,TU Ming-Jin,
康雪雅
,常爱民,韩英,王天雕,陶明德,涂铭旌

无机材料学报 , 1998,
Abstract: ZnO nanopowders prepared by the Sol-Gel method were sintered by microwave. The microstructure of the material was analysed by XRD and SEM. The I - V properties of varistor weremeasured by a stabilized dc power source. Compared with the conventional sintering, microwavesintering promptes grain growth and shortenes sintering time. When grain sizes are the same, thetemperature of microwave sintering can be lower than that of conventional sinering. Microwavesintering has the ability to enhance the density of ZnO varistor ceramic and to obtain good electricpropertises. Hence, microwave sintering is a newly effective method for processing ZnO varistorceramic .
MAGMATISM OF GALC-ALKALINE SERIES IN THE BEISHAN REGION OF GANSU PROVINCE AND ITS RELATION TO PLATE TECTONICS
甘肃北山区的钙碱系列岩浆活动及其与板块构造的关系

LIU Xue-ya,
刘雪亚

地球学报 , 1984,
Abstract: According to the recent investigations, the plutonic granitoid batholites of the Late Paleozoic occur widely in the Beishan region, while the Early Paleozoic and the Mesozoic granite intrusions are developed a little. From the Ordovician to Permian periods, persistent magmatic activities resulted in volcanic rocks on different scales. The mixed volcanic formations of effusive and explosive eruptions predominate the northern Beishan region, while the southern part is characterized by explosive formation. The magmatites of various types are generally distributed along the E-W trending folds and faults. Most of the granitoid batholites are complex intrusive massives as a result of superposed magmatism. The magmatites of this region are similar to those of Hercynian orogenic belt in southwest Europe.The Paleozoic epigenetic metamorphic zones of various facies series with linear feature are widespread in the region. The low-medium pressure metamorphic rocks of greenschist facies and epidote-amphibolite facies are outcropped mainly in the northern part. The prehnite-pumpellyite facies of low temperature and katametamorphism are distributed in some areas of the central Beishan. The medium pressure greenschist facies and dynamo-meta-morphic mylonite and cataclasite are widely exposed in the southern part. In the light of isotopic age determination, the high tide of metamorphism took place in the Carboniferous period. The endogenic mineralizations of Fe, Cu, W, Au, Pb, Zn, Nb and Ta in the region are obviously related to calcalkaline magmatic activities.According to the studies of tectonics, the central Beishan occurred as a median massif in the Paleozoic, which is called the Mazongshan Rise. Both the Mazongshan Rise and the Central Tianshan-Mujunkum massif bear a lot of similarities in the time of cratonization and the nature of covers. The southward subduction activities happened two times in the Middle and Late Paleozoic along the northern Beishan. To the south of the Rise, there is a subduction zone and a collision zone underthrusting to the north at the same time.To summarize, the whole Beishan region is part of the Kazakhstanian plate. Its magmatism, metamorphism and endogenic mineralizations are immediately related to subduction activities of plates.
A High-Resolution Method for 2D DOA Estimation
一种新的二维角度估计的高分辨算法

Yang Xue-ya,Chen Bai-xiao,
杨雪亚
,陈伯孝

电子与信息学报 , 2010,
Abstract: A high-resolution algorithm for 2D DOA estimation is proposed to reduce the computational complexity of traditional high-resolution methods. The objective function of the optimization issue based on norm constraint is developed firstly. Then the sparse solution corresponding to the received data along the azimuth dimension is deduced by solving the minimization problem using the iteration algorithm, then it is used to obtain the angular frequencies in which azimuth and elevation angles are coupled, and signals of different angular frequencies are separated. Finally, the sparse solution relating to each signal is obtained to get the elevation angle and then compute the corresponding azimuth angle. A modified method is presented to overcome the blind angular region problem occurred in the algorithm. Compared with the traditional high-resolution methods, the proposed method has lower SNR threshold and simple procedure to achieve high precision with lower sidelobe level. Numerical simulation results verify the effectiveness of the method.
MESOZOIC AND CENOZOIC MAGMATIC ACTIVITIES OF CONTINENTAL MARGIN AND ISLAND ARCS IN EAST ASIA AND PLATE TECTONICS
亚洲东部陆缘及岛弧区中—新生代的岩浆活动与板块构造

LIU Xue-ya,WANG Quan,
刘雪亚
,王荃

地球学报 , 1983,
Abstract: In the geological evolution of the coastal region of the Pacific Ocean inEast Asia during the Mesozoic and Cenozoic eras, two outstanding characteristics can be recognized, i. e., the appearance of well-known magmatic beltscomposed of widely developed igneous rocks, and the formation of a seriesof fault-depressed basins, including fringing seas, marginal seas and some interior basins. The former contain various kinds of endogenous minerals whilethe latter are abundant in energy resources. According to recent studies, wesuggest that the formation of these huge magmatic zone and basins is theresults of deep melting and partial division and extension caused by subduction, when convergence between the Pacific Ocean and the Eurasian platestook place since the Mesozoic era. There are three associations of intrusive and eruptive rocks in East Asia.The first one consists of basic and ultrabasic complex developed during theearly geosynclinal stage or under mid-ocean ridge conditions and submarinebasic pillow lava accompanied with radiolarian siliceous rock and graywacke.Besides forming oceanic crust and marginal sea floor, this ophiolite association sometimes occurs as narrow stripes in orogenic belts; also it may appearin a flysch formation as allochthonous rock, thus constituting an ophiolitemelange zone.Two roughly parallel ophiolitic or ophiolite-melange zones arediscovered in East Asia:the interior ophiolite belt distributed intermittently inKoryak Range, Sikhote-Alin Mountains, the islands of Sakhalin, Hokkaido,Honshu and Shikoku, as well as Nadanhada Range and the coastal region ofFujian Province is mainly of late-Palaeozoic to early Mesozoic age; the exteinal melange belt is of Mesozoic age and appears in eastern Kamchatka,the Shimanto zone of Southeastern Japan, coast mountains in Taiwan Province of China, Luzon, etc. The second association developed along the continental active margin orisland-arc zone and belonging to intermediate acid calc-alkali series is madeup of diorite, granodiorite, basalt, andesite, dacite, liparite, etc. The Mesozoicrocks of this type can be found along the coast of Okhotsk sea, the Sikho-te-Alin, Laoye Mountain and Zhangguangcai Mountain, Japan, Korea, andfujian and Zhejiang provinces of China. The isotopic age of the intrusiverocks is 62-214 m. y. (in Fujian), 68-225 m. y. (in Korea), or 50-95 m. y. (inSouthwestern Japan), obviously indicating that the rocks get younger fromNW to SE. The volcanic rocks in East China occur chiefly in the upper Jurassic and Cretaceous formation, showing isotopic age of 70-140 m. y. The Cenozoic rocks of this association appear in an external belt in Kamchatka, Kurileislands, Ryukyu islands, Luzon and other places, with the intensity of magmatic activities weaker than those of the Mesozoic. These two age groups ofigneous association are found respectively at the western side of the twoophiolite zones mentioned above, thus forming two notable "pair belts". The third association which is
TECTONICS OF THE LONGSHOUSHAN ANCIENT RIFT AND HEXI CORRIDOR
龙首山古裂谷带及河西走廊的大地构造

LIU Xue-ya,WANG Quan,
刘雪亚
,王荃

地球学报 , 1993,
Abstract: On the basis of recent investigations in Gansu Province and tectono-Stratigraphical analysis the authors consider that there is a Proterozoic rift of WNW trend along the Longshoushan Mountains on the southern margin of the Alxa massif. The Dunzigou Group and Hanmushan Group of closed lagoon facies or neritic facies were deposited in the rift during the Middle-Late Proterozoic. Along the rift a series of ultramafic-mafic intrusions conlainning Ni-Cu ore deposits are scattered in the area of Jinchuang. The whole Hexi Corridor of Gansu Province may be divided into two halves. The eastern half is an orogenic zone along the southern continental margin of the Alxa massif and consists of the Yongchang-Wuwei miogeocline and the Lenglongling-Gulang eugeocline from north to south. In the Early Paleozoic, it belonged to the North China-Korea Paleoplate. The western half is a part of the northern Qilian eugeocline and belonged to the Qaidam-Qilian paleoplate in the Early Paleozoic. The suture line between the two halves lies from Gaotai to Minle. Through the authors' repeated investigations, the tectonic evolution of the Qilian Mts, and Hexi Corridor between the two paleoplates has been established. At least seven tectonostratigraphic terranes can be recongnized in this region. Among them, the northermost one occurs on the southwestern margin of the North China-Korea Paleoplate, and the other six terranes occur on the northern-continental margin of the Qaidam massif.
PALEOPLATE TECTONICS IN NEI MONGGOL OF CHINA
中国内蒙古中部的古板块构造

WANG Quan,LIU Xue-ya,LI Jin-yi,
王荃
,刘雪亚,李锦轶

地球学报 , 1991,
Abstract: 基于近年的研究,笔者认为内蒙古南部华北地台北缘有二条东西走向的元古代裂谷带,并分别沉积了泻湖相或浅海相的渣尔泰群和白云鄂博群。白云鄂博群中部炭质白云岩中铅的同位素年龄为1500Ma。沿二裂谷带在阴山和燕山零星出露一系列碱性火山岩和侵入体。裂谷带以北的古生代造山带中,识别出6条蛇绿岩带,以及至少5个增生地体。介于西伯利亚和华北二地台间的古生代洋盆,因多次向两侧陆缘带俯冲,终于在二叠纪晚期导致华夏古陆与安加拉古陆的碰撞。其间的缝合线位于林西至索伦敖包一带。内蒙古及其邻区大地构造演化的研究表明,西伯利亚地台南缘与中新生代的亚洲东部陆缘甚为相似,而华北地台北缘则与北美的科迪勒拉山系大体相似。从华北与西伯利亚的分裂到二者的重新拼合构成一个巨大而完整的威尔逊旋回。
Enhancing thermoelectric figure-of-merit by low-dimensional electrical transport in phonon-glass crystals
Xue-Ya Mi,Xiaoxiang Yu,Kai-Lun Yao,Xiaoming Huang,Nuo Yang,Jing-Tao Lü
Physics , 2015, DOI: 10.1021/acs.nanolett.5b01491
Abstract: Low-dimensional electronic and glassy phononic transport are two important ingredients of highly-efficient thermoelectric material, from which two branches of the thermoelectric research emerge. One focuses on controlling electronic transport in the low dimension, while the other on multiscale phonon engineering in the bulk. Recent work has benefited much from combining these two approaches, e.g., phonon engineering in low-dimensional materials. Here, we propose to employ the low-dimensional electronic structure in bulk phonon-glass crystal as an alternative way to increase the thermoelectric efficiency. Through first-principles electronic structure calculation and classical molecular dynamics simulation, we show that the $\pi$-$\pi$ stacking Bis-Dithienothiophene molecular crystal is a natural candidate for such an approach. This is determined by the nature of its chemical bonding. Without any optimization of the material parameter, we obtain a maximum room-temperature figure of merit, $ZT$, of $1.48$ at optimal doping, thus validating our idea.
产妇高龄对新生儿出生缺陷及生后并发症的影响
Effect of advanced maternal age on birth defects and postnatal complications of neonates

王睁, 李利, 雷雪丫, 薛瑾, 米弘瑛
WANG Zheng
, LI Li, LEI Xue-Ya, XUE Jin, MI Hong-Ying

- , 2016, DOI: 10.7499/j.issn.1008-8830.2016.11.006
Abstract:
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