19 resultados para Halkin, Theodore, 1924-
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
A new species, Axianassa sinica, from the Beibu Gulf (Gulf of Tonkin), northern South China Sea, is described and illustrated. The new species is readily distinguished from A. australis Rodrigues & Shimizu, 1992, by its acute rostrum, merus of pereopod 1 with a tooth distally on lower margin and an elongated telson.
Resumo:
Development of shear bands in saturated soils is a multi-stage process based on the theoretical and numerical investigations in this paper. The soil is initially in homogenous shear strain state, and the instability can be characterized by a dimensionless number D. The inhomogenous distribution of shear strains appears when D>1, and the shear band will initiate and develop gradually. Numerical solutions show that only single shear band that is finally formed in the central region of the specimen even several disturbances (distributed along the specimen) appear in the beginning.
Resumo:
采用简单的有机一无机混合的溶胶一凝胶方法制备了折射率在一定范围内可调的波导材料,并利用其制备了平面波导环形谐振腔器件。波导结构呈现倒脊形,其制备工艺首先是利用感应耦合等离子体刻蚀技术(ICP)在二氧化硅衬底上刻蚀波导结构的凹槽,然后再沉积波导薄膜。利用光谱仪对器件的传输特性进行了测量,观测到具有10dB对比度,自由光谱范围0.182nm周期性谐振现象,结合环形谐振腔的传输特性,得到环形腔具有较低的传输损耗1.7dB/cm。同时对环形谐振腔的温度特性进行了测量,得出波导材料的热光系数为-1.54×10^-4
Resumo:
The anuran tribe Paini, family Dicroglossidae, is known in this group only from Asia. The phylogenetic relationships and often the taxonomic recognition of species are controversial. In order to stabilize the classification, we used approximately 2100bp o
Resumo:
研究了黄鳝在不同温度、不同体重下的摄食速度,得到在17~20℃范围内,3组不同体重的黄鳝关 于摄食速度与温度关系的回归方程:V=enTb。由此可看出:在一定温度范围内,摄食速度随温度的上升而增大,而 相对摄食速度随体重的增大而减小。根据回归方程还可推测不同温度、不同体重下黄鳝的摄食量。
Resumo:
<正> 人体内侵袭水蛭病是一种危害人体健康的寄生虫病。在Craig和Faust的“临床寄生虫学”一书中列举了Masterman(1908)和Manson(1903)报道的由于出血过多和喉、气管阻塞导致死亡的例子。Messioger(1924)报道的一妇女因声带受侵袭而产生痉挛性咳嗽和脉搏跳动微弱以及Woolnougb(1928)报道的一三岁和另一十岁半的澳大利亚女孩阴道因水蛭咬伤而出血不止。此病在我国南方广大农村也很普遍,最早金大雄(1941,1949)报道过贵州省和云南省人鼻中发现的水蛭。湖北省兴山县张
Resumo:
Detailed X-ray photoelectron spectroscopy (XPS) depth profiling measurements were performed across the back n-layer/transparent conducting oxide (n/TCO) inter-faces for superstrate p-i-n solar cells to examine differences between amorphous silicon (a-Si:H) and microcrystalline silicon (mu c-Si:H) n-layer materials as well as TCO materials ZnO and ITO in the chemical, microstructural and diffusion properties of the back interfaces. No chemical reduction of TCO was found for all variations of n-layer/TCO interfaces. We found that n-a-Si:H interfaces better with ITO, while n-mu c-Si:H, with ZnO. A cross-comparison shows that the n-a-Si:H/ITO interface is superior to the n-mu c-Si:H/ZnO interface, as evidenced by the absence of oxygen segregation and less oxidized Si atoms observed near the interface together with much less diffusion of TCO into the n-layer. The results suggest that the n/TCO interface properties are correlated with the characteristics of both the n-layer and the TCO layer. Combined with the results reported on the device performance using similar back n/TCO contacts, we found the overall device performance may depend on both interface and bulk effects related to the back n/TCO contacts. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
水印检测是数字水印技术的一个关键步骤,但是目前所提出的绝大多数水印检测算法既不具备赖以支撑的理论基础,其检测性能也不是优化的.利用数字水印的不可感知特性,应用弱信号检测理论进行水印检测的研究.首先从图像小波变换系数的统计特性出发,利用广义高斯分布(GGD)来建立小波细节子带系数的统计分布模型;然后针对水印嵌入强度未知的情况,将水印检测问题转化为非高斯噪声中具有未知参数的确定性信号的检测,在弱信号条件下提出一种离散小波变换(DWT)域图像水印的优化盲检测算法.检测性能分析表明,该检测算法能够实现恒虚警率水印检测.实验结果验证了检测性能理论分析的有效性和实际性能的优越性.
Cobalt loss from Co-ZrO2 catalyst for fischer-tropsch synthesis in continuously stirred tank reactor
Resumo:
MicroRNA(miRNA)是一类大小为19—24个核苷酸的非编码RNA,它们通过与靶基因的信使RNA(mRNA)结合在转录后水平调节靶基因的表达,因而在广泛的生物学过程中发挥重要作用。首先从miRNA的获得和鉴定两方面对目前miRNA发现工作进行了概括,然后分析和总结了近年来人源miRNA发现工作的现状,最后提出有关新miRNA发现工作的新想法。
Resumo:
以连续5 a不同CO2浓度处理的长白赤松和红松幼苗为对象,采用CFU(活细胞计数)菌落计数法研究了大气CO2浓度对幼苗非根际土壤微生物数量的影响。结果表明:高浓度CO2(700μmol.mol-1和500μmol.mol-1)处理对长白赤松和红松幼苗非根际土壤细菌数量具有显著的(p<0.01)抑制作用,对真菌数量亦有抑制作用。大气CO2浓度升高对红松幼苗非根际土壤放线菌数量具有抑制作用(p<0.05),而对长白赤松幼苗土壤放线菌数量没有明显的影响。
Resumo:
通过添加不同比例的粉煤灰对城市污泥进行钝化,对钝化污泥的pH值、养分含量及重金属含量变化以及各配比人工土壤的持水性能进行了研究,评价其用于无土排岩场生态修复的可行性.结果表明,当粉煤灰与污泥以Ⅲ(1∶1)和Ⅱ(2∶1)配比时,人工土壤持水性能高于对照(草甸棕壤),以Ⅳ(1∶2)配比时,持水性接近于对照;粉煤灰钝化污泥中养分含量极其丰富,处于高肥力水平,随着粉煤灰添加量的增加,人工土壤的养分含量呈现降低趋势;粉煤灰钝化污泥人工土壤中除了Ⅲ(1∶1)中Ni含量较高,为187.67 mg.kg-1外,各处理中重金属Cd、Pb、Cu、Zn、Cr含量都显著低于国家农用标准(GB 4284-84、GB 8173-87).