Characteristics of the Permafrost Structure on the Fildes Peninsula, King George Island, Antarctica

Based on the data from the pitting, geoelectrical prospectings, temperature measuring, and the divided layers frost-heaving instruments, this paper, first, discusses the structure features of active layers in this region, and proves the presence of the bowlshaped frost table in the stone circles area. Second, it analyses the temperature distributive rule in the active layer, meantime, according to the vertical-profile parameters of granularity, clay mineral, salt content and resistivities, it also discusses the different features of permafrost structure and their control actions on the periglacial landform development between high and low places. It suggests that the four-layer structure should exist in the permafrost region (including under-bedrock), that is, active layer, frost sand and gravels layer, frost volcanic rock permeated by sea water, and frost volcanic rock unpermeated by sea water. Finally, the permafrost table and its vertical gradient are deduced.     

2000年被美国《应用力学评论》列为核心期刊的中国期刊名单

复合材料学报固体力学学报 :英文版 (华中科技大学 )应用数学和力学 :英文版 (上海大学 )中国海洋工程 :英文版力学进展 声学学报 :英文版中国航空学报 :英文版 应用力学学报 (西安交通大学 )机械强度 (郑州 ) 计算力学学报 (大连理工大学 )非线性科学与数值模拟通讯 :英文版 机械工程学报 :英文版北京理工大学学报北京理工大学学报 :英文版中国矿业大学学报计算数学 :英文版航空学报 大连理工大学学报河海大学学报华中理工大学学报水动力学研究与进展 :Ｂ辑 ,英文版上海交通大学学报 :英文版上海交通大学学报上海大学学报 :英文版热科…     

氩-碳-硅等离子体热力学性质和输运系数计算

计算了广温度范围(300—30000 K)和广压力范围(0.1—10 atm, 1 atm=101.325 k Pa)下,不同混合物比例、碳和硅蒸气浓度的局域热力学平衡(LTE)和化学平衡(LCE)的氩-碳-硅等离子体组分、热力学性质和输运系数.等离子体气相平衡组分使用质量作用定律计算,同时凝聚相组分采用相平衡的方法计算.输运系数的计算包括黏度、电导率和热导率,使用拓展到高阶近似的Chapman-Enskog方法.采用文献中较新的数据得到了较为准确的碰撞积分,导出了Ar-C-Si等离子体的输运系数.结果表明,在相变温度以下,凝聚态物种的引入导致Ar-C-Si等离子体的热力学性质、输运系数与纯Ar等离子体接近,在相变温度点则会产生不连续点.压力、碳/硅蒸气浓度和比例对等离子体热力学性质和输运系数具有较大影响.最终计算值与文献数据对比符合良好,有望为氩-碳-硅等离子体传热流动数值模拟提供基础数据.     

Growth and Characterization of GaAs／A1GaAs Thue-Morse Quasicrystal Photonic Bandgap Structures

One-dimensional quasicrystal structures composed of Ⅲ-Ⅴ semiconductor GaAs/AlGaAs multilayers in deterministic Thue-Morse (TM) sequences have been grown by using gas-source molecular beam epitaxy to investigate both the structural and the photonic bandgap properties. The x-ray measurements show that this aperiodic system exhibits obvious periodic spatial correlations, from which the precise thickness of the constitutive layers could be determined. Transmission and reflection measurements experimentally demonstrated plenty of photonic bandgaps with traditional or fractal features existing in those quasicrystal structures, which are in good agreement with the transfer matrix simulations. The diversity of this TM system makes it a good candidate for photonic device applications.     

InGaAs Photodetectors Cut-off at 1.9μm Grown by Gas-Source Molecular Beam Epitaxy

Using a linear graded Inx Ga1-xAs as the buffer layer, positive-intrinsic-negative wavelength-extended In0.6 Ga0.4As photodetectors with 50% cut-off wavelength of 1.9μm at room temperature were grown by using gas-source molecular beam epitaxy, and their performance over a wide temperature range has been extensively investigated. The detectors show typical dark current at bias voltage 50mV and the resistance-area product R0A of 7nA/765Ωcm^2 and 31pA/404kΩcm^2 at 290K and 210K, respectively. The thermal activation energy of the dark current in the temperature range 250-350K is 0.488 eV.     

美国《数学评论》2000年收录中国期刊名单

安徽师大学报：自然科学版宝鸡文理学院学报：自然科学版北京大学学报：自然科学版北京理工大学学报北京理工大学学报：英文版北京师范大学学报：自然科学版逼近论及其应用：新辑,英文版长沙电力学院学报：自然科学版长沙交通学院学报重庆师范学院学报：自然科学版纳粹教学与应用数学（西北大学）大连理工大学学报代数集刊：英文版（北京）电子科技大学学报东北大学学报：自然科学版乐北师大学报：自然科学版东北数学：英文版（吉林大学）东南大学学报东南大学学报：英文版非线性科学与数值模拟通讯：英文版福建师范大学学报：自然科学版福…     

南极乔治王岛菲尔德斯半岛的冻土结构特征研究

本文根据坑探、物探、测温、分层冻胀仪等资料分析,讨论了本区活动层的结构特征,论证了石环区碗状冻结面的存在,分析了活动层温度的分布规律以及粒度、粘土矿物、含盐量和电阻率等垂向剖面参数反映的高低不同地势间冻土结构的差异及其对冰缘地貌发育的控制作用,继而提出了本区冻土(包括下覆基岩)具有的4层结构,最后,推算了冻土上限及其垂直变化梯度。