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921.
结合三维动态测点优化布置的有效独立法(EFI3)和改进的一维有效独立法,提出同时考虑双向测点优化布置的有效独立法(EFI2)。采用二维空间相互正交方向的节点振型作为输入,根据模态振型最大线性无关性和较大能量分布原则,EFI2法将同时优化双向的测点布置。以某大跨越特高压输电塔为工程背景,运用EFI2法优化其顺导线和横导线向加速度测点布置,并选用两种评估标准分析测点布置的优化效果。结果表明:对同时考虑空间二维振动的大跨越特高压输电塔结构,EFI2法能得到较为理想的测点布置方案。 相似文献
922.
LI JinHua PAN YongXin LIU QingSong QIN HuaFeng DENG ChengLong CHE RenChao & YANG XinAnKey Laboratory of the Earth’s Deep Interior Institute of Geology Geophysics Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing Franco-Chinese Biomineralization Nano-structures Laboratory State Key Laboratory of Lithospheric Evolution Chinese Academy of S... 《科学通报(英文版)》2010,55(1):38-44
The magnetic properties of magnetosome magnetite are of interdisciplinary interest because magnetosomes are potential carriers of natural remanent magnetization and paleoenvironment, as well as novel nano-biomaterials in biotechnological and biomedical applications. We carried out magnetic and electron transmission microscopy analyses of fresh Magnetospirillum magneticum AMB-1 whole cells and isolated magnetosomes. Results revealed that AMB-1 synthesized single-domain magnetite magneto-somes, which are arra... 相似文献
923.
A preliminary study of chronology for a newly-discovered ancient city and five archaeological sites in Lop Nor,China 总被引:1,自引:0,他引:1
YIDILISI Abuduresule 《科学通报(英文版)》2010,55(1):63-71
In the past century, it has long been debated in the archeological, historical, geographical, and many other related communities where the capital of the Luolan and Shanshan states was in the Lop Nor region. This paper presents three AMS radiocarbon ages from a newly-discovered ancient city at about 6.3 km to the northwest of the Xiaohe Graveyard, and fifteen new radiocarbon ages from the Loulan (LA), LE, Qieerqiduke, Milan, and Tuyin sites in Lop Nor. The new investigation shows that the age of newly-disco... 相似文献
924.
The polyaniline coated multi-walled carbon nanotubes (PANI/CNTs) composites were synthesized by in situ polymerization. The microstructure and component of the composites were characterized by scanning electron microscope (SEM), Fourier transfer infrared spectroscopy (FTIR), X-ray diffraction (XRD), and N2 adsorption BET. The electrochemical performances of the samples were tested by cyclic voltammogram (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge. The results showed... 相似文献
925.
Data from the CASN (Capital Area Seismograph Network), NSNC (National Seismograph Network of China), and IRIS (Incor-porated Research Institutions for Seismology) are compared with data from a temporary North China Seismic Array to obtain the background orientation of the horizontal crustal principal compressive stress at NE 95.1°±15.4° in North China. Data are corrected for disturbances of faults and irregular tectonics, and are used to constrain the fast SKS polarization at NE 110.2°±15.8° in North China. Individual station analyses suggests that there is consistently more than 10° difference between the polarizations of fast shear-wave in the crust and those of fast SKS phases. Azimuthally anisotropic phase velocities of Rayleigh waves at different periods also indicate an orientation change for fast velocity with depth. It suggests the crust-mantle coupling in North China follows neither the simple decoupling model nor the strong coupling model. Instead, it is possibly some inhomogeneous combination of two models or some gradual-change model of physical characteristics. This study shows that anisotropy in the crust and mantle could be multiply characterized more correctly and crust-mantle coupling could be analyzed further, if increasing near-field shear-wave splitting data that indicate crustal anisotropy, combined with the azimuthal anisotropy of Rayleigh waves, besides the result of SKS splitting travelling through lithosphere and surface GPS measurements. 相似文献
926.
First observation of mesospheric and thermospheric winds by a Fabry-Perot interferometer in China 总被引:3,自引:0,他引:3
Wei Yuan JiYao Xu RuiPing Ma Qian Wu GuoYing Jiang Hong Gao Xiao Liu SunZheng Chen 《科学通报(英文版)》2010,55(35):4046-4051
A Fabry-Perot interferometer, funded by the Meridian Project in China, was deployed at the Xinglong station (40.2°N,117.4°E) of the National Astronomical Observatories in Hebei Province, China. The instrument has been operating since April 2010, measuring mesospheric and thermospheric winds. The first observational data of winds at three heights in the mesosphere and thermosphere were analyzed, demonstrating the capacity of this instrument to aid basic scientific research. The wavelengths of three airglow emissions were OH892.0, OI 557.7, and OI 630.0 nm, which corresponded to heights of 87, 98, and 250 km, respectively. Three 38-day data sets of horizontal winds, from April 5, 2010 to May 12, 2010, show clear day-to-day variations at the same height. The minimum and maximum meridional winds at heights of 87, 98, and 250 km were –16.5 to 8.7 m/s, –24.4 to 15.9 m/s, and –43.6 to 1.5 m/s. Measurements of zonal winds were –5.4 to 7.6 m/s, 2.3 to 23.0 m/s, and –22.6 to 49.3 m/s. The average data from the observations was consistent with the data from HWM93. The wind data at heights of 87 and 98 km suggest a semi-diurnal oscillation, clearly consistent with HWM93 results. Conversely there was a clear discrepancy between the observations and the model at 250 km. In general, this Fabry-Perot interferometer is a useful ground-based instrument for measuring mesospheric and thermospheric winds at middle latitudes. 相似文献
927.
LEE Jun-Hee PARK Su-A PARK KoEun KIM Jae-Hyun KIM Kyung-Shik LEE Jihye Kim WanDoo 《科学通报(英文版)》2010,55(1):94-98
In this paper, we design and fabricate a 3D scaffold using rapid prototyping (RP) technology for tissue engineering. The scaffold should have a three-dimensional interconnected pore network. We fabricate a polycaprolactone (PCL) scaffold with interconnecting pores and uniform porosity for cell ingrowth using a 3D plotting system. In order to keep the three dimensional shape under mechanical loading while implanted, we design an oscillating nozzle system to increase elastic modulus and yield strength of PCL ... 相似文献
928.
An allowable generalized quantum gate (introduced by Long, Liu and Wang) has the form of U = Σ
k=0
d−1
c
k
U
k
, where U
k’s are unitary operators on a Hilbert space H and |Σ
k=0
d−1
c
k
|⩽1 and |c
k
|⩽1 (0⩽k⩽d−1). In this work we consider a kind of AGQGs, called restricted allowable generalized quantum gates (RAGQGs), satisfying
0 < Σ
k=0
d−1|c
k
|⩽1. Some properties of the set RAGQG(H) of all RAGQGs on H are established. Especially, we prove that the extreme points of RAGQG(H) are exactly unitary operators on H and that B(H)=R
+
RAGQG(H). 相似文献
929.
DeKun Wang XiaoHong Jiang ChunMei Zhao ZhiHua Wang Hua Wang ZuLiang Du 《科学通报(英文版)》2010,55(6):478-483
Self-organized dithieno [3,2-b:2',3'-d] thiophene-2,5-dicarboxylic acid (A) and dithieno [2,3-b:3',2'-d] thiophene-2,5-dicarboxylic acid (B) films were prepared through solvent-induced order-disorder transition method.The arrangement of the two molecules on substrates were observed by atomic force microscopy (AFM),which demonstrated that A was arranged orderly in a certain angle on mica,while B was flat-flying on mica.The optical and conductance properties in micro region of these two compound films were ch... 相似文献
930.
Flow visualization experiments are conducted in water tunnel for low aspect ratio cropped wings at low Reynolds number. The experimental results show that the model sweep angle Λ influences the formation and development of the leading-edge vortex. For wings with Λ =0°, the dominant flow structure is transverse vortex. When Λ≥26°, the dual vortex structure can be observed at some angles of attack, and it is confirmed that the dual vortex is a special structure for flow over low aspect ratio wing at low Reyno... 相似文献