排序方式: 共有35条查询结果,搜索用时 9 毫秒
1.
Chao Huangfu Liang Fu Yuzhi Li Xueling Li Haijun Du Jianshan Ye 《Electroanalysis》2013,25(9):2238-2243
In the present work, a sensitive, facile and disposable sensing platform for trace analysis of heavy metal ions was developed at the Bi modified graphene‐poly(sodium 4‐styrenesulfonate) composite film screen printed electrode (GR/PSS/Bi/SPE). The GR/PSS/Bi/SPE improved sensitivity and linearity due to the functionalization of graphene with negatively charged PSS providing more absorbing sites. The detection limit of the GR/PSS/Bi/SPE is found to be 0.042 µg L?1 for Cd2+ and 0.089 µg L?1 for Pb2+ with linear responses of Cd2+ and Pb2+ in the range of 0.5–120 µg L?1. Finally, the practical application was confirmed in real water with satisfactory results. 相似文献
2.
Study of total ionizing dose radiation effects on enclosed gate transistors in a commercial CMOS technology 下载免费PDF全文
This paper studies the total ionizing dose radiation effects on MOS
(metal-oxide-semiconductor) transistors with normal and enclosed gate
layout in a standard commercial CMOS (compensate MOS) bulk process.
The leakage current, threshold voltage shift, and transconductance of
the devices were monitored before and after $\gamma $-ray
irradiation. The parameters of the devices with different layout
under different bias condition during irradiation at different total
dose are investigated. The results show that the enclosed layout not
only effectively eliminates the leakage but also improves the
performance of threshold voltage and transconductance for NMOS
(n-type channel MOS) transistors. The experimental results also
indicate that analogue bias during irradiation is the worst case for
enclosed gate NMOS. There is no evident different behaviour observed
between normal PMOS (p-type channel MOS) transistors and enclosed
gate PMOS transistors. 相似文献
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采用交替沉积磁控溅射工艺制备了超薄多层的FeCoB SiO2 磁性纳米颗粒膜 .利用x射线衍射仪、扫描探针显微镜、透射电子显微镜分析了薄膜的微结构和形貌特征 .采用振动样品磁强计、四探针法、微波矢量分析仪及谐振腔法测量薄膜试样的磁电性能和微波复磁导率 .重点对SiO2 介质相含量、薄膜微结构对电磁性能产生重要影响的机理做了分析和探讨 .结果表明 :这类FeCoB SiO2 磁性纳米颗粒膜具有良好的软磁性能和高频电磁性能 ,2GHz时的磁导率 μ′高于 70 ,可以应用于高频微磁器件或微波吸收材料的设计 相似文献
5.
Single-pulse chaos are studied for a functionally graded materials rectangular plate. By means of the global perturbation method, explicit conditions for the existence of a Silnikov-type homoclinic orbit are obtained for this system, which suggests that chaos are likely to take place. Then, numerical simulations are given to test the analytical predictions. And from our analysis, when the chaotic motion occurs, there are a quasi-period motion in a two-dimensional subspace and chaos in another two-dimensional supplementary subspace. 相似文献
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The global bifurcations in mode of a nonlinear forced dynamics of suspended cables are investigated with the case of the 1:1
internal resonance. After determining the equations of motion in a suitable form, the energy phase method proposed by Haller
and Wiggins is employed to show the existence of the Silnikov-type multi-pulse orbits homoclinic to certain invariant sets
for the two cases of Hamiltonian and dissipative perturbation. Furthermore, some complex chaos behaviors are revealed for
this class of systems. 相似文献
8.
A variational approach is used to study the ground state of a bound polaron in a spherical quantum dot under an external electric field. The binding energy of the hydrogenic impurity state is calculated by taking the interaction of an electron with both the confined longitudinal optical phonons and the surface optical phonons into account. The interaction between impurity and longitudinal optical phonons has also been considered to obtain the binding energy of a bound polaron. It shows that the polaron effects give significant corrections to the binding energy and its Stark energy shift. The external electric field increases the phonon contributions to the binding energy. 相似文献
9.
We studied the growing process of Ge dots on silicon substrates covered with an ultrathin silicon dioxide buffer layer which was formed with simple chemical procedure. Uniform and densely packed (1011 cm−2) quantum dots (QDs) were obtained by optimizing the growth parameter with the MBE method. The influence of temperature, coverage, as well as the post-annealing process, on the epitaxial and non-epitaxial nanodots formation was evaluated. Nano-sized high density quantum dots were also realized with different growing conditions, whose structural and growing mechanism were discussed under the help of SEM and RHEED results. 相似文献
10.
Bei-Xi Jia Qian-Qian Huangfu Feng-Xiao Ren Lu Jia Yan-Bing Zhang Hong-Min Liu 《Natural product research》2015,29(9):800-806
This article marks the first report on high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD) and quadruple time-of-flight mass spectrometry (Q-TOF/MS) for the identification and quantification of main bioactive constituents in Baeckea frutescens. In total, 24 compounds were identified or tentatively characterised based on their retention behaviours, UV profiles and MS fragment information. Furthermore, a validated method with good linearity, sensitivity, precision, stability, repeatability and accuracy was successfully applied for simultaneous determination of five flavonoids and one chromone in different plant parts of B. frutescens collected at different harvest times, and their dynamic contents revealed the appropriate harvest times. The established HPLC-DAD-Q-TOF/MS using multi-bioactive markers was proved to be a validated strategy for the quality evaluation on both raw materials and related products of B. frutescens. 相似文献