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Modeling of Gate Tunneling Current for Nanoscale MOSFETs with High-k Gate Stacks
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作者 王伟 孙建平 顾宁 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第7期1170-1176,共7页
A quantum model based on solutions to the Schrodinger-Poisson equations is developed to investigate the device behavior related togate tunneling current for nanoscale MOSFETs with high-k gate stacks. This model can mo... A quantum model based on solutions to the Schrodinger-Poisson equations is developed to investigate the device behavior related togate tunneling current for nanoscale MOSFETs with high-k gate stacks. This model can model various MOS device structures with combinations of high-k dielectric materials and multilayer gate stacks,revealing quantum effects on the device performance. Comparisons are made for gate current behavior between nMOSFET and pMOSFET high- k gate stack structures. The results presented are consistent with experimental data, whereas a new finding for an optimum nitrogen content in HfSiON gate dielectric requires further experimental verifications. 展开更多
关键词 high- k gate current quantum model
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High- and Ultrahigh-pressure Metamorphism and Retrogressive Textures of Gneiss in the Donghai Area——Evidence from gneisses in drillhole ZK2304 被引量:12
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作者 LIU Fulai, XU Zhiqin, XU Huifen and YANG Jingsui Institute of Geology, CAGS, 26 Baiwanzhuang Rd., Beijing 100037 Zhu Xiling 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1999年第3期300-315,370,共17页
In the gneisses from the drillhole ZK2304 of the Donghai area, there have been preserved high- and ultrahigh-pressure metamorphic mineral assemblages, a series of complicated retrogressive textures and relevant metamo... In the gneisses from the drillhole ZK2304 of the Donghai area, there have been preserved high- and ultrahigh-pressure metamorphic mineral assemblages, a series of complicated retrogressive textures and relevant metamorphic reactions. In addition to garnet, jadeititic-clinopyroxene and rutile, other peak stage (M2) minerals in some gneisses include phengite, aragonite and coesite or quartz pseudomorphs after coesite. The typical peak-stage mineral assemblages in gneisses are characterized by garnet + jadeitic-clinopyroxene + rutile + coesite, garnet + jadeitic-clinopyroxene + phengite + rutile ± coesite and garnet + jadeitic-clinopyroxene + aragonite + rutile ± coesite. The grossular content (Gro) in garnet is high and may reach 50. 1 mol%. The SiO2 content of phengite ranges from 54.37% to 54.84% with 3.54-3.57 p.f.u. Quartz pseudomorphs after coesite occur as inclusions in garnet.The gneisses of the Donghai area have been subjected to multistage recrystallization and exhibit a closewise P-T evolutional path characterized by the near-isothermal decompression. The inclusion assemblage (Hb+Ep+Bi+Pl+Qz) within garnet and other minerals has recorded a pre-peak stage (Mi) epidote amphibole fades metamorphic event. High- and ultrahigh-pressure peak metamorphism (M2) took place at T=750-860℃ and P>2.7 GPa. The symplectitic assemblages after garnet, jadeitic-clinopyroxene and rutile imply a near-isothermal decompression metamorphism (M3, M4) during the rapid exhumation. Several lines of evidence of petrography and metamorphic reactions indicate that both gneisses and eclogites have experienced ultrahigh-pressure metamorphism in the Donghai area. This research may be of great significance for an in-depth study of the metamorphism and tectonic evolution in the Su-Lu ultrahigh-pressure metamorphic belt. 展开更多
关键词 GNEISS high- and ultrahigh-pressure metamorphism retrogressive texture drillhole Donghai area
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Comparison of Diurnal,Seasonal and Solar Cycle Variations of High-latitude,Mid-latitude and Low-latitude Ionosphere 被引量:1
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作者 K G RATOVSKY J K SHI +1 位作者 A V OINATS E B ROMANOVA 《空间科学学报》 CAS CSCD 北大核心 2014年第2期143-153,共11页
Comparison of regular(diurnal,seasonal and solar cycle)variations of high-latitude,mid-latitude and low-latitude ionospheric characteristics has been provided on basis of local empirical models of the peak electron de... Comparison of regular(diurnal,seasonal and solar cycle)variations of high-latitude,mid-latitude and low-latitude ionospheric characteristics has been provided on basis of local empirical models of the peak electron density and the peak height.The local empirical models were derived from the hand-scaled ionogram data recorded by DPS-4 digisondes located at Norilsk(69°N,88°E),Irkutsk(52°N,104°E)and Hainan(19°N,109°E)for a 6-year period from December,2002 to December,2008.The technique used to build the local empirical model is described.The primary focus is diurnal-seasonal behavior under low solar activity and its change with increasing solar activity.Both common and specific features of the high-latitude(Norilsk),mid-latitude(Irkutsk)and low-latitude(Hainan)regular variations were revealed using their local empirical models. 展开更多
关键词 high- mid-and low-latitude ionosphere Local model DIURNAL seasonal and solar activity behavior
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Phase control of magnetron sputtering deposited Gd_2O_3 thin films as high-κ gate dielectrics 被引量:1
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作者 岳守晶 魏峰 +3 位作者 王毅 杨志民 屠海令 杜军 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第3期371-374,共4页
Gd2O3 thin films as high-κ gate dielectrics were deposited directly on Si(001) substrates by magnetron sputtering at a pressure of 1.3 Pa and different temperatures. X-ray diffraction results revealed that all the ... Gd2O3 thin films as high-κ gate dielectrics were deposited directly on Si(001) substrates by magnetron sputtering at a pressure of 1.3 Pa and different temperatures. X-ray diffraction results revealed that all the films grown from 450 to 570 ℃ were crystalline, and the Gd2O3 thin films consisted of a mixture of cubic and monoclinic phases. The growth temperature was a critical parameter for the phase constituents and their relative amount. Low temperature was favorable for the formation of cubic phase while higher temperature gave rise to more monoclinic phase. All the Gd2O3 thin films grown from different temperatures exhibited acceptable electrical properties, such as low leakage current density (JL) of 10-5 A/cm^2 at zero bias with capacitance equivalent SiO2 thickness in the range of 6-13 nm. Through the comparison between films grown at 450 and 570 ℃, the existence of monoclinic phase caused an increase in JL by nearly one order of magnitude and a reduction of effective dielectric constant from 17 to 9. 展开更多
关键词 Gd2O3 thin film rare earth oxide high-κ gate dielectric magnetron sputtering
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The effectiveness of a high-fidelity teaching simulation based on an NLN/Jeffries simulation in the nursing education theoretical framework and its influencing factors 被引量:2
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作者 Fen-Fen Zhu Li-Rong Wu 《Chinese Nursing Research》 CAS 2016年第3期129-132,共4页
Objective: To investigate the effectiveness of a high-fidelity teaching simulation based on an NLN/Jeffries simulation in the nursing education theoretical framework and its influencing factors. Methods: A high-fide... Objective: To investigate the effectiveness of a high-fidelity teaching simulation based on an NLN/Jeffries simulation in the nursing education theoretical framework and its influencing factors. Methods: A high-fidelity teaching simulation on clinical nursing practices using intelligent human analogues was conducted with 200 students, and The Simulation Design Scale, and the Student Satisfaction and Self-Confidence in Learning Scale developed by the National League for Nursing were used to evaluate the training effectiveness and its influencing factors. Results: For the high-fidelity teaching simulation, students gave scores of 4.36± 0.54 points for satisfaction and 4.33 ± 0.46 points for Self-Confidence. The students highly rated the five dimensions of teaching design, i.e., teaching objectives/information, assistance/support for students, problem solving, guided feedback, and fidelity. The teaching design was closely correlated with the satisfaction of the high-fidelity teaching simulation and self-efficacy, and the dimensions of teaching objectives/informa- tion and assistance/support for students were particularly strong predictors of teaching effectiveness. Conclusions: A high-fidelity teaching simulation based on Jeffries' theoretical framework improved student satisfaction with the simulation and their Self-Confidence. In planning simulations, teachers should take into account five characteristics, i.e., teaching objectives/information on simulation education, assistance/support for students, problem solving, guided reflection, and fidelity, to achieve better teaching effectiveness. 展开更多
关键词 Jeffries simulation in nursing education high-?delity simulation education Teaching design Teaching satisfaction Self-ef?cacy
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Materials Design on the Origin of Gap States in a High-κ/GaAs Interface
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作者 Weichao Wang Cheng Gong +3 位作者 Ka Xiong Santosh K.C. Robert M.Wallace Kyeongjae Cho 《Engineering》 SCIE EI 2015年第3期372-377,共6页
Given the demand for constantly scaling micro- electronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf(Zr)O2, in order to minimize current... Given the demand for constantly scaling micro- electronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf(Zr)O2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant (high-κ) dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remotephonon scattering, and dielectric-charge trapping.Ⅲ-Ⅴ and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf(Zr)O2/Ⅲ-Ⅴ(Ge) has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding configurations at Hf(Zr)O2/Ⅲ-Ⅴ(Ge) interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize first- principle calculations to investigate the interface between HfO2 and GaAs. Our study shows that As--As dimer bonding, Ga partial oxidation (between 3+ and 1+) and Ga- dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation. 展开更多
关键词 high-mobility device high-κ/Ⅲ-Ⅴ interface interfacial gap states first-principle calculations
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Differential Effects of Voluntary Ethanol Consumption on Dopamine Output in the Nucleus Accumbens Shell of Roman High- and Low-Avoidance Rats: A Behavioral and Brain Microdialysis Study
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作者 Maria G. Corda Giovanna Piras +1 位作者 Maria A. Piludu Osvaldo Giorgi 《World Journal of Neuroscience》 2014年第3期279-292,共14页
The Roman high(RHA) and low-Avoidance (RLA) rats were selectively bred for rapid vs poor acquisition of two-way active avoidance behavior. These lines differ in numerous behavioral traits, with RLA rats being more fea... The Roman high(RHA) and low-Avoidance (RLA) rats were selectively bred for rapid vs poor acquisition of two-way active avoidance behavior. These lines differ in numerous behavioral traits, with RLA rats being more fearful/anxious than RHA rats, and the latter being novelty-seekers and showing larger intake of, and preference for, addictive substances including ethanol (ETH). Moreover, several differences in central dopaminergic, serotonergic, and GABAergic functions have been reported in these two lines. Since those neural systems are involved in the regulation of ETH consumption, it was considered of interest to investigate: 1) the differences in ETH intake and preference between RHA and RLA rats, 2) the effects of ETH on DA release in the shell of the nucleus accumbens (AcbSh) using brain microdialysis. ETH solutions of increasing concentrations (2% - 10%) were presented on alternate days in a free choice with water. To examine ETH intake and preference stability, animals were subsequently switched to daily presentations of 10% ETH for 10 consecutive days. RHA rats consumed significantly larger amounts of ETH and displayed higher ETH preference than did RLA rats throughout the acquisition and maintenance phases. Following chronic exposure to ETH the animals were habituated to a restricted access to ETH schedule (2% ETH, 2 h per day × 4 days) before surgical implantation of a dialysis probe in the AcbSh. Under these experimental conditions, voluntary ETH intake (2%, 1 h, p.o.) produced a significant increase in accumbal DA output in RHA rats but not in their RLA counterparts. Finally, the i.p. administration of ETH (0.25 g/kg) to na?ve Roman rats produced a significant increment in accumbal DA output only in RHA rats. These results indicate that the mesolimbic dopaminergic system of RHA rats is more responsive to the effects of ETH than that of RLA rats. 展开更多
关键词 ROMAN high- and Low-Avoidance RATS VOLUNTARY Ethanol Consumption Mesolimbic Dopaminergic System Nucleus Accumbens Shell Novelty-Seeking Behavior
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Study on Mechanical Properties of High Fine Silty Basalt Fiber Shotcrete Based on Orthogonal Design
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作者 Jinxing Wang Yingjie Yang +5 位作者 Xiaolin Yang Huazhe Jiao Qi Wang Liuhua Yang Jianxin Yu Fengbin Chen 《Journal of Renewable Materials》 EI 2023年第8期3351-3370,共20页
In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strengt... In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strength growth characteristics of HFS-BFRS were analyzed.And thefitting equation of compressive strength growth characteristics of HFS-BFRS under the synergistic effect of multiple factors was given.And based on the orthogonal experimental method,the effects on the compressive strength,splitting tensile strength andflex-ural strength of HFS-BFRS under the action of different levels of influencing factors were investigated.The effect of three factors on the mechanical properties of HFS-BFRS,3,and 28 d,respectively,was revealed by choosing the colloidal sand ratio(C/H),basaltfiber volume fraction(BF Vol)and naphthalene high-efficiency water reducing agent(FDN)as the design variables,combined with indoor tests and theoretical analysis.The results show that the sensitivity of the three factors on compressive strength andflexural strength is C/H>FDN>BF Vol,and split-ting tensile strength is BF Vol>FDN>C/H.Finally,thefitting ratio of HFS-BFRS was optimized by the factor index method,and the rationality was verified by thefield test.For thefluidity of HFS-BFRS,the slump can be improved by 139%under the action of 1.2%FDN,which guarantees the pump-ability of HFS-BFRS. 展开更多
关键词 Solid wastes recycling high-fine silt basaltfiber total solid waste shotcrete orthogonal design
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氮化硼填充导热绝缘复合材料的研究进展 被引量:21
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作者 秦丽丽 王占京 +4 位作者 侯君 瞿雄伟 张立群 Saeed Z Beckry A 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2013年第9期175-178,共4页
近来,通过添加导热填料制备高导热绝缘聚合物基复合材料成为学者们研究的热点。文中综述了以氮化硼(BN)为填料的导热塑料、导热橡胶的研究现状。发现对无机填料进行表面处理,可以提高基体与填料间的相容性,减小两者间的热传导阻力;采用... 近来,通过添加导热填料制备高导热绝缘聚合物基复合材料成为学者们研究的热点。文中综述了以氮化硼(BN)为填料的导热塑料、导热橡胶的研究现状。发现对无机填料进行表面处理,可以提高基体与填料间的相容性,减小两者间的热传导阻力;采用多模式的填料以适当的比例混杂填充聚合物基体,可以使填料间接触面积增大,从而有效提高聚合物基体的热导率。文中还简述了填充型导热复合材料的导热机理和典型理论模型,并提出了提高复合材料导热性的关键所在。 展开更多
关键词 氮化硼 导热绝缘 复合材料 导热机理 导热模型
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环路热管复合毛细芯的孔结构优化与性能研究 被引量:12
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作者 徐计元 邹勇 程林 《中国电机工程学报》 EI CSCD 北大核心 2012年第23期70-74,152,共5页
采用不同粒度的造孔剂制备了孔隙特性优化布置的环路热管双层复合结构毛细芯。研究了复合结构毛细芯的导热系数及其整体毛细抽吸性能。实验结果表明:孔隙率相同的情况下,毛细芯的导热系数随着平均孔径的降低及孔径分布的集中而降低。通... 采用不同粒度的造孔剂制备了孔隙特性优化布置的环路热管双层复合结构毛细芯。研究了复合结构毛细芯的导热系数及其整体毛细抽吸性能。实验结果表明:孔隙率相同的情况下,毛细芯的导热系数随着平均孔径的降低及孔径分布的集中而降低。通过控制复合结构毛细芯内外层的孔隙特性可调节毛细芯的整体导热系数分布。双层复合结构毛细芯的整体毛细抽吸性能介于相应单层毛细芯的抽吸性能之间,其整体毛细抽吸性能主要取决于内层的孔隙特性。考虑到复合毛细芯的导热系数布置、整体毛细抽吸性能和气体渗透率等因素,采用内层小孔径而外层孔径较大的复合毛细芯结构可实现环路热管毛细芯整体性能的优化。 展开更多
关键词 环路热管 复合毛细芯 导热系数 毛细抽吸性能 造孔剂
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氮化铝填充导热复合材料导热性能的有限元分析 被引量:11
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作者 高智芳 刘进立 王笃金 《塑料工业》 CAS CSCD 北大核心 2014年第11期63-67,共5页
采用有限元方法分析了氮化铝(Al N)填料粒径、含量以及树脂种类等因素对复合材料导热性能的影响。模拟结果显示:填料体积分数小于20%时,导热系数的模拟结果和试验结果接近,在高填充时,导热系数模拟结果低于试验结果,但是变化趋势和试验... 采用有限元方法分析了氮化铝(Al N)填料粒径、含量以及树脂种类等因素对复合材料导热性能的影响。模拟结果显示:填料体积分数小于20%时,导热系数的模拟结果和试验结果接近,在高填充时,导热系数模拟结果低于试验结果,但是变化趋势和试验结果一致;低填充量时填料粒径对导热系数影响不大,高填充时,大粒径填料可以增强复合材料导热系数;树脂本身的导热性能越高,复合材料的导热性能越好。 展开更多
关键词 导热高分子复合材料 有限元模拟 导热系数
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反演二维瞬态热传导问题随温度变化的导热系数 被引量:12
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作者 周焕林 徐兴盛 +1 位作者 李秀丽 陈豪龙 《应用数学和力学》 CSCD 北大核心 2014年第12期1341-1351,共11页
基于边界元法反演二维瞬态热传导问题随温度变化的导热系数.采用Kirchhoff变换将非线性的控制方程转变为线性方程.边界元法用于构建二维瞬态热传导问题的数值分析模型.将反演参数作为优化变量,测点温度计算值与测量值之间的残差平方和... 基于边界元法反演二维瞬态热传导问题随温度变化的导热系数.采用Kirchhoff变换将非线性的控制方程转变为线性方程.边界元法用于构建二维瞬态热传导问题的数值分析模型.将反演参数作为优化变量,测点温度计算值与测量值之间的残差平方和作为优化目标函数.引入复变量求导法求解目标函数的梯度矩阵,梯度正则化法用于优化目标函数获得反演结果.探讨时间步长、测点数量和随机偏差对反演结果的影响.减小步长、增加测点数量收敛速度加快.降低了随机偏差,计算结果更精确.算例证明了算法的有效性与稳定性. 展开更多
关键词 边界元法 反问题 瞬态热传导 导热系数 梯度正则化法
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Effective thermal and electrical conductivity of graphite nanoplatelet composites 被引量:1
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作者 周晓锋 张小松 周建成 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期158-161,共4页
The relationship between the thermal/electrical conductivity enhancement in graphite nanoplatelets (GNPs) composites and the properties of filling graphite nanoplatelets is studied. The effective thermal and electri... The relationship between the thermal/electrical conductivity enhancement in graphite nanoplatelets (GNPs) composites and the properties of filling graphite nanoplatelets is studied. The effective thermal and electrical conductivity enhancements of GNP-oil nanofluids and GNP-polyimide composites are measured. By taking into account the particle shape, the volume fraction, the thermal conductivity of filling particles and the base fluids, the thermal and electrical conductivity enhancements of GNP nanofluids are theoretically predicted by the generalized effective medium theory. Both the nonlinear dependence of effective thermal conductivity on the GNP volume fraction in nanofhiids and the very low percolation threshold for GNP-polyimide composites are well predicted. The theoretical predications are found to be in reasonably good agreement with the experimental data. The generalized effective medium theory can be used for predicting the thermal and electrical properties of GNP composites and it is still available for most of the thermal/electrical modifications in two-phase composites. 展开更多
关键词 graphite nanoplatelet nanofluids thermalconductivity electrical conductivity percolation threshold
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Mo/AlN金属陶瓷微波吸收材料的制备与性能表征 被引量:2
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作者 程继贵 梁槟星 +3 位作者 董洁 蔡艳波 顾瑞 夏永红 《功能材料》 EI CAS CSCD 北大核心 2007年第A08期3041-3044,共4页
以Mo与AlN为原料,复合氧化物为烧结助剂,通过常规的成形烧结工艺制备出了Mo含量为30%~40%(质量分数)的Mo/AlN金属陶瓷烧结体。对烧结体的微观结构进行观测,并对其导热系数及力学性能等进行了测试分析,采用矢量网络分析仪对其... 以Mo与AlN为原料,复合氧化物为烧结助剂,通过常规的成形烧结工艺制备出了Mo含量为30%~40%(质量分数)的Mo/AlN金属陶瓷烧结体。对烧结体的微观结构进行观测,并对其导热系数及力学性能等进行了测试分析,采用矢量网络分析仪对其反射衰减率进行测量,并与纯AlN材料进行了对比。结果表明:通过采用适当的烧结助剂,在1750℃下无压烧结,可以获得相对密度高于98%的Mo/AlN金属陶瓷复合材料烧结体。该烧结体的抗弯强度与导热系数随着Mo含量的增加而提高,含40%Mo(质量分数)试样的抗弯强度和导热系数分别为531.4MPa和156.1W/m.K:不同Mo含量Mo/AlN试样在不同的频段内出现宽频吸收,其中含40%Mo(质量分数)的试样在14~18GHz频率内呈现较宽的吸收频段,最大反射衰减量为-22dB。 展开更多
关键词 Mo/AlN金属陶瓷吸波材料 无压烧结 反射衰减量 导热系数 抗弯强度
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纳米尺度材料有效导热率的界面效应 被引量:1
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作者 韩亚芬 夏新林 +1 位作者 李东辉 谈和平 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2013年第7期68-71,共4页
为了研究界面效应对纳米尺度材料内声子热输运的影响,利用格子波尔兹曼法模拟二维矩形结构二氧化硅纳米材料内声子热输运,模拟过程考虑了边界面散射对声子平均自由程的影响.结果表明,相对镜反射的情况,漫反射界面明显降低了纳米尺度材... 为了研究界面效应对纳米尺度材料内声子热输运的影响,利用格子波尔兹曼法模拟二维矩形结构二氧化硅纳米材料内声子热输运,模拟过程考虑了边界面散射对声子平均自由程的影响.结果表明,相对镜反射的情况,漫反射界面明显降低了纳米尺度材料的导热率,边界面存在界面效应;随着镜反射因子的减小,材料的有效导热率降低;提高纳米尺度固体材料界面的粗糙度,界面热阻增强,有助于降低导热率. 展开更多
关键词 格子玻尔兹曼方法 纳米尺度 声子输运 界面效应 导热率
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底部真空负压浸渗工艺制备β-SiC_p/Al电子封装材料 被引量:2
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作者 谢斌 王晓刚 +1 位作者 华小虎 易大伟 《铸造》 CAS CSCD 北大核心 2013年第10期953-957,共5页
摘要:针对国内目前sic/A1在产业化中存在的诸多问题,选用W20和w60的β-SiC粉体,采用模压成型制备SiC预制体,并通过底部真空负压浸渗工艺制备了致密度为96%~98%、体积分数为55%~72%的β-SiCp/Al复合材料。XRD、SEM、CT和CTE... 摘要:针对国内目前sic/A1在产业化中存在的诸多问题,选用W20和w60的β-SiC粉体,采用模压成型制备SiC预制体,并通过底部真空负压浸渗工艺制备了致密度为96%~98%、体积分数为55%~72%的β-SiCp/Al复合材料。XRD、SEM、CT和CTE测试分析表明:所制备的复合材料中存在MgAl20。尖晶石相,没有发现Al4C3脆性相;复合材料组织均匀,存在少量浸渗缺陷,孔洞较少;SiC体积分数为72%的复合材料在常温热度下的热膨胀系数为6.91×10-6/K,热导率为164.8W/(m·K),而sic体积分数为65%的复合材料的热膨胀系数为7.31×10-6/K,热导率为172.7W/(m.K)。 展开更多
关键词 无压浸渗 β-SiCp AL复合材料 热膨胀系数 热导率
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导热石墨烯/聚合物纳米复合材料研究进展 被引量:2
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作者 董丽娜 周文英 +1 位作者 睢雪珍 王子君 《现代塑料加工应用》 CAS 北大核心 2015年第4期61-63,共3页
探讨了超声剥离石墨烯/聚合物纳米复合材料研究进展,介绍了石墨烯的结构、用量、表面改性、长径比对聚合物纳米复合材料的热导率及其他性能的影响,论述了石墨烯与其他碳填料的协同效应对聚合物热导率及其他物理性能的影响。所得结论为... 探讨了超声剥离石墨烯/聚合物纳米复合材料研究进展,介绍了石墨烯的结构、用量、表面改性、长径比对聚合物纳米复合材料的热导率及其他性能的影响,论述了石墨烯与其他碳填料的协同效应对聚合物热导率及其他物理性能的影响。所得结论为制备综合性能优良的石墨烯/聚合物纳米复合材料提供有益参考。 展开更多
关键词 石墨烯 导热聚合物 表面改性 导热性 述评
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玻化微珠再生保温混凝土配合比优化设计 被引量:5
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作者 陈春红 朱平华 田斌 《混凝土与水泥制品》 北大核心 2014年第4期67-70,共4页
考虑再生混凝土综合性能,选取再生粗、细骨料取代率、水胶比和玻化微珠掺量作为关键影响因素,以抗压强度、抗折强度、保温性能和抗冻性能作为评价指标,设计了再生混凝土配合比正交试验,并运用功效系数法进行了分析。结果表明,水胶比对... 考虑再生混凝土综合性能,选取再生粗、细骨料取代率、水胶比和玻化微珠掺量作为关键影响因素,以抗压强度、抗折强度、保温性能和抗冻性能作为评价指标,设计了再生混凝土配合比正交试验,并运用功效系数法进行了分析。结果表明,水胶比对再生混凝土的抗压强度和抗冻性能影响最大;随着再生粗、细骨料取代率增大,混凝土的力学强度下降;玻化微珠掺量的增加会降低再生混凝土的力学强度,但对其保温性能具有明显的改善作用。通过验证试验发现,只要合理配置,可以配制28d抗压强度达到20MPa、导热系数为0.34 W/(m·K)的玻化微珠再生保温混凝土墙体材料。 展开更多
关键词 再生混凝土 配合比 优化设计 功效系数法 导热系数
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预焙铝电解槽三维槽帮形状的模拟计算 被引量:5
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作者 崔喜风 邹忠 +2 位作者 张红亮 李劼 徐宇杰 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2012年第3期815-820,共6页
应用APDL语言设计一种新型的三维槽帮形状计算算法,通过循环调用前处理、求解和后处理模块,自动调整三维槽帮表面节点坐标,实现铝电解槽三维槽帮形状的计算。选择成熟的180kA铝电解槽作为研究算例,在有限元软件ANSYS的平台上建立四分之... 应用APDL语言设计一种新型的三维槽帮形状计算算法,通过循环调用前处理、求解和后处理模块,自动调整三维槽帮表面节点坐标,实现铝电解槽三维槽帮形状的计算。选择成熟的180kA铝电解槽作为研究算例,在有限元软件ANSYS的平台上建立四分之一槽电热模型,并引入热接触来描述熔体与槽帮、阳极和阴极等之间的对流传热,进行三维槽帮的数值仿真研究。采用这种三维计算方法可以更加真实的考虑铝电解槽的结构和工艺参数情况,电热耦合计算又将电场对热场的影响考虑在内,更加符合实际情况。研究结果表明:该算法得到的槽帮形状与实测结果基本一致,同时验证铝电解槽槽帮在小面厚度大于大面厚度,而在角部处槽帮最厚的规律。该方法可为新型铝电解槽设计提供技术支撑。 展开更多
关键词 铝电解槽 3D槽膛内形 电热耦合计算 热接触 有限元
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(Sm_(0.7)Yb_(0.3))_2Ce_2O_7陶瓷的热膨胀系数及热导率 被引量:1
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作者 马建辉 郭鹏 张红松 《硅酸盐通报》 CAS CSCD 北大核心 2014年第8期2133-2137,共5页
以Sm2O3、Yb2O3和CeO2为原材料,采用固相反应法制备了(Sm0.7Yb0.3)2Ce2O7陶瓷材料,用X射线衍射(XRD分析了其相结构,采用扫描电子显微镜(SEM)和电子能谱(EDS)分析其显微组织和元素组成,用推杆膨胀法和激光脉冲法测试了其热膨胀系数和热... 以Sm2O3、Yb2O3和CeO2为原材料,采用固相反应法制备了(Sm0.7Yb0.3)2Ce2O7陶瓷材料,用X射线衍射(XRD分析了其相结构,采用扫描电子显微镜(SEM)和电子能谱(EDS)分析其显微组织和元素组成,用推杆膨胀法和激光脉冲法测试了其热膨胀系数和热导率。结果表明,所制备的(Sm0.7Yb0.3)2Ce2O7具有典型的萤石结构,其微观组织致密,晶界清晰。Yb3+离子较小的离子半径使其热膨胀系数低于Sm2Ce2O7,基质原子与取代原子之间质量及尺寸之间的差别,使其具有比Sm2Ce2O7更低的热导率,该材料有潜力用作新型热障涂层表面陶瓷层材料。 展开更多
关键词 热障涂层 稀土铈酸盐 热膨胀系数 热导率
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