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121.
We report the synthesis, characterisation and self-assembly of a nanoscopic Fe24 cluster using an organic dendrimer as a molecular substrate for building up well-defined molecular nanostructures. 相似文献
122.
After conjugation to vancomycin (Van), chemically stable and highly magnetic anisotropic FePt magnetic nanoparticles (approximately 4 nm) become water-soluble and capture E. coli at 15 cfu mL(-1). 相似文献
123.
杨宏伟 《高等学校计算数学学报》2001,23(3):273-280
1 引 言考虑非齐次守恒律方程ut+f(u) x =g(u) , -∞ 0 ,(1 .1 )u(x,0 ) =u0 (x) , -∞ 0 , (1 .5)g∈ C3且 g是 Lipschitz连续的 ,Lipschitz系数为 L . (1 .6 )对于一般守恒律齐次方程 ,粘性解逼近熵解的收敛阶为 O(ε ) [1 ] .在 f严格凸的条件下 ,其收敛速度可以提高到 O(ε|lnε|+ε) [2 ] ,[3] .本文考虑具有条件 (1 .5) (1 .6 )的非齐次方程(1 .1 ) ,在较广泛的一类初值条件下… 相似文献
124.
可见光谱法研究核酸酶P1与氯化铜(Ⅱ)的相互作用 总被引:1,自引:0,他引:1
首次采用VIS与酶活性测定的方法,研究了溶液中核酸酶P1与无机氯化铜(Ⅱ)(CuCl2)的直接相互作用。结果发现:在水溶液中核酸酶P1活性中心的Zn(Ⅱ)离子可被外加氯化铜(CuCl2)中的Cu(Ⅱ)部分诱导、交换出来,而Cu(Ⅱ)进入酶的活性中心,形成相应“Cu(Ⅱ)-P1”酶衍生物,并随着溶液pH值的变化,形成酶的衍生物结构亦随之变化,相应地也影响了酶的催化活性。 相似文献
125.
1 IntroductionProjecting a single frequency lfringe pattern upon an Object and observing itsdeformation from a different view angle has been a common method for various threedimensional shape measurement techniques. An autpmatic analysis of the fringepatterns is normally carried out either by the FOurier transform method[IJ or by phasestepping['] of the fringe patterns. HOWever, these techniques have a disadvantage ofprincipal importance, the so-called indetedrinaCy tO a factor Of Zap, or … 相似文献
126.
Coplanar Phase Shifters Based on Ferroelectric Thin Films 总被引:2,自引:0,他引:2
Chunlin Fu Fusheng Pan Hongwei Chen Shucheng Feng Wei Cai Chuanren Yang 《International Journal of Infrared and Millimeter Waves》2007,28(3):229-235
Barium strontium titanate (Ba0.6Sr0.4TiO3, short for BST) thin films were prepared by RF-magnetron sputtering. The dielectric tunability, loss tangent, remanent polarization
(2Pr) and coercive electric field (Ec) of the BST films are respectively 29.5%, 0.013, 2.29 μC/cm2 and 22.27 kV/cm at 1 kHz and 20 V. The designed coplanar waveguide (CPW) phase shifter consists of 56 same sections. It is
shown that the fabricated lines of electrodes are smooth and the widths at the tip of bottom electrodes are about 5 μm. At
the central frequency of 28 GHz and a bias voltage of 20 V, the figure of merit is approximately 13°/dB. 相似文献
127.
Shihui Jiao Guangsheng Pang Hongwei Liang Yan Chen Shouhua Feng 《Journal of nanoparticle research》2007,9(4):605-610
Nanoparticles and nanorods of CuSb2O6 are prepared by hydrothermal method and its high temperature α-phase is stabilized at room temperature. The average size
of the nanoparticles is ca. 13.7 nm. The nanorods, with a width of ca. 20 nm and an aspect ratio of ca. 5, are the agglomerates
composing of smaller nanoparticles with an average size of ca. 8.3 nm. Compared with the high temperature α-phase of bulk
sample at 400 K, the lattice of nanophases elongated in ab plane and compressed along c direction. The CuSb2O6 nanoparticles exhibit predominant paramagnetic phenomenon. The difference in magnetic properties of the nanoparticles and
nanorods indicates the interfacial interaction of agglomerated nanoparticles. 相似文献
128.
Hongwei Yang Wanchun Tang Xiangkun Kong 《International Journal of Infrared and Millimeter Waves》2007,28(7):547-556
In this paper, shift operator finite-difference time-domain (SO-FDTD) method is applied for the calculation of the dispersive
medium. The high efficiency and accuracy of this method is verified by calculating the reflection of the plane electromagnetic
wave impinging on a non-magnetized plasma slab with different electron density distributions. The results show that the average
electron density only determines overall trends of the reflection, and different distributions affect the oscillating process
of the reflection. If the average electron density maintains the same, the distribution of electron density with homogenous
or inhomogeneous alternation will sharply take effects on the reflection. And magnitude of alternation of electron density
affects the incident frequency directly when the reflection tends to uniform. 相似文献
129.
Jingchang Sun Hongwei Liang Jianze Zhao Ziwen Zhao Guotong Du 《Applied Surface Science》2007,253(11):5161-5165
ZnO films were deposited on c-plane Al2O3 substrates by pulsed laser deposition. The etching treatments for as-grown ZnO films were performed in NH4Cl aqueous solution as a function of NH4Cl concentration and etching time. It was found that NH4Cl solution is an appropriate candidate for ZnO wet etching because of its controllable and moderate etching rate. The influence of etching treatment on the morphology, optical and electrical properties of the ZnO films has been investigated systematically by means of X-ray diffraction, atomic force microscope, photoluminescence and Hall effect. The results indicated that the surface morphology and optical properties of the films were highly influenced by etching treatment. 相似文献
130.
为什么教师在课堂上多次强调的问题,学生在学习中却屡屡犯错?学生为什么会提出一些非常简单的问题,甚至存在明显错误的思路和方法?难道仅仅是记忆力不好,学习不专注等因素造成的吗?其实教师有一定的责任.以往一节课基本上是教师一人唱“独角戏”,这种“牵着鼻子走”的教学模式,学生学到的只是这个问题的“是什么”、“为什么”和“怎么做”.一些需要学生一步一步深入思考的问题,却都是教师代替学生“解决”了. 相似文献