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1.
自行研制的等离子体针在大气压下通过介质阻挡放电产生的等离子体,再由喷嘴处安装的漏斗形装置聚焦形成针状等离子体. 然后对针状等离子体的基本特性和杀Enterococcus faecalis(E. faecalis)菌进行了研究,E. faecalis菌是一种引起完善充填根管再感染的主要微生物. 当等离子体针功率为5—28?W时,对等离子体的温度进行了测量,表明它不同于其他热杀菌方式. 通过改变等离子体针内电极末端注入的氧气量,发现适当的氧气量,不仅增加等离子体内含氧粒子的浓度而且对等离子体的长度影响也不明显. 实验表明最佳参数为功率15?W,0.1?m3·h-1氦和2.5%氧气,间距12?mm,处理时间30 s. 为了找出杀菌的关键粒子,进一步比较了大气压下的等离子体针的发射光谱与agar(琼脂)2?mm下的光谱并找出关键粒子.
关键词:
大气压等离子体
介质阻挡放电
E. faecalis菌')" href="#">E. faecalis菌
光谱 相似文献
2.
Zhi-Gang Luo Xiao-Lin Chen Xiang Liu Shi-Lin Zhu 《The European Physical Journal C - Particles and Fields》2009,60(3):403-411
Stimulated by recent observations of the excited bottom–strange mesons B
s1 and B
s2*, we calculate the semileptonic decays
, which is relevant for the exploration of the potential of searching these semileptonic decays in experiment. 相似文献
3.
Junfeng Sun Dongsheng Du Yueling Yang 《The European Physical Journal C - Particles and Fields》2009,60(1):107-117
The B
c
→J/ψ
π, η
c
π decays are studied with the perturbative QCD approach. It is found that the form factors
and
for the B
c
→J/ψ, η
c
transitions and the branching ratios are sensitive to the parameters ω, v, f
J/ψ
and
, where ω and v are the parameters of the charmonium wave functions for a Coulomb potential and the harmonic-oscillator potential, respectively,
and f
J/ψ
and
are the decay constants of the J/ψ and η
c
mesons, respectively. The large branching ratios and the clear signals of the final states make the B
c
→J/ψ
π, η
c
π decays the prospective channels for measurements at the hadron colliders. 相似文献
4.
Characterization of the high—voltage pulsed discharge plasma of ammonia by emission spectroscopy 下载免费PDF全文
We have used optical emission spectroscopy to characterize the high-voltage pulsed discharge of ammonia.Ammonia was highly dissociated in the discharge at low pressures.More atomic nitrogen was generated as compared to the discharge of nitrogen gas at the same pressure of 0.8kPa.We discuss the elimination of the oxygen impurity in the ammonia discharge,and we estimate the time-dependent atomic excitation temperature and the electron density from the measured spectra. 相似文献
5.
研究了十甲基环五硅氧烷(D5)的电子回旋共振等离子体沉积的SiCOH薄膜中Si—OH基团对介电性能和漏电流的影响.结果表明Si—OH含量的增大会导致介电常数k的增大、漏电流的降低和介电色散的增强.由于Si—OH结构的强极化补偿了薄膜密度减小带来的介电常数降低,导致总的介电常数k增大.高Si—OH含量下漏电流的降低是由于封端的Si—OH基团降低了薄膜中Si—O网络的连通概率p而导致网络电导下降的缘故.介电色散的增强与Si—OH封端结构的快极化过程有关.改变放电参数以提高电子能量,从而提高源的电离程度,使更多的Si—OH基团断裂并通过缩合反应形成Si—O—Si网络,可以进一步降低薄膜的介电常数.
关键词:
SiCOH薄膜
Si—OH结构
介电性能
ECR放电等离子体 相似文献
6.
Yu-Ming Wang M. Jamil Aslam Cai-Dian Lü 《The European Physical Journal C - Particles and Fields》2009,59(4):847-860
The exclusive weak decay of Λ
b
→Λ
γ and Λ
b
→Λ
l
+
l
− are investigated in the Appelquist–Cheng–Dobrescu model, which is an extension of the standard model in the presence of universal
extra dimensions. Employing the transition form factors obtained in the light-cone sum rules, we analyze how the invariant-mass
distribution, the forward–backward asymmetry and the polarization asymmetry of the Λ baryon of these decay modes can be used to constrain the only additional free parameter with respect to the standard model,
namely, the radius, R, of the extra dimension. Our results indicate that the Kaluza–Klein modes can lead to approximately 25% suppression of the
branching ratio of Λ
b
→Λ
γ; however, their contributions can bring about 10% enhancement to the decay rate of Λ
b
→Λ
l
+
l
−. It is shown that in the present scenario the zero position of the forward–backward asymmetry of Λ
b
→Λ
μ
+
μ
− is sensitive to the compactification parameter R, while the measurement of polarizations of Λ baryon in the Λ
b
decays are not a useful tool to provide any valuable information for the universal extra-dimension model. 相似文献
7.
The polarization of a bremsstrahlung photon during the processes ee
± → (eγ)e
± and ep → (eγ)p is calculated for peripheral kinematics in the high-energy limit, where the cross section does not decrease with the incident
energy. When the initial electron is unpolarized (longitudinally polarized), the final photon can be linearly (circularly)
polarized. The Stokes parameters of the photon polarization are calculated as a function of the kinematical variables of the
process: the energy of the recoil particle, the energy fraction of the scattered electron, and the polar and azimuthal angles
of the photon. The numerical results are given in the form of tables for typical values of the relevant kinematic variables.
The text was submitted by the authors in English. 相似文献
8.
J. Ryckebusch W. Van Nespen 《The European Physical Journal A - Hadrons and Nuclei》2004,20(3):435-441
Differential cross-sections for exclusive 16O(e,epp)14C processes are computed within a distorted-wave framework which includes central short-range correlations and intermediate
excitations. The cross-sections are compared to high-resolution data from the MAMI facility at Mainz for a central energy and momentum transfer of
MeV and
MeV, respectively. A fair agreement between the numerical calculations and data is reached when using spectroscopic information extracted from a 15N
C experiment. The comparison between the calculations and the data provides additional evidence that short-range correlations exclusively affect nucleon pairs with a small center-of-mass momentum residing in a relative S state.Received: 3 September 2003, Revised: 2 December 2003, Published online: 18 June 2004PACS:
24.10.-i Nuclear-reaction models and methods - 21.60.-n Nuclear-structure models and methods - 25.30.Fj Inelastic electron scattering to continuum 相似文献
9.
电子原子散射中的S,T,U参数可用来描述散射前后自旋状态的变化,研究精细结构水平上的散射激发振幅之间的关系,进而揭示电子原子碰撞过程中电子自旋-轨道耦合以及电子-电子交换等自旋相关效应.采用扭曲波玻恩近似计算了钠原子受电子散射S→P跃迁中的S,T,U参数,分析了多种入射能(2.2—60 eV)的电子与钠原子激发S→P跃迁过程的S,T,U参数随散射角的分布,其中对10 eV入射能的Sp参数与已报道实验数据符合一致.结果表明,较低能电子入射下的S,T,U参数随散射角的分布幅度和起伏都比较明显,入射能大于40 eV的电子入射,S,T,U参数的散射角分布变化很小.
关键词:
散射激发
S')" href="#">S
T')" href="#">T
U参数')" href="#">U参数
散射振幅
自旋相关效应 相似文献
10.
We reconsider the utility of the radiative decay B→γℓν with an energetic photon in the final state for determining parameters of the B-meson light-cone distribution amplitude. Including 1/m
b
power corrections and radiative corrections at next-to-leading logarithmic order, we perform an improved analysis of the
existing BABAR data. We find a provisional lower limit on the inverse moment of the B meson distribution amplitude, λ
B
, which, due to the inclusion of radiative and power corrections, is significantly lower than the previous result. More data
with large photon energy are, however, required to obtain reliable results, as should become available in the future from
SuperB factories. 相似文献
11.
把一维q变形振子的结论推广到D维q变形振子体系,得到了D维q变形振子体系的哈密顿算符形式,并求出了其本征值和在坐标象中的本征函数.结果显示,这是一个非线性振子. 相似文献
12.
N × N集成光开关阵列模型 总被引:9,自引:8,他引:1
报道了由2N个1 × N 多模干涉马赫-曾德尔光开关组成的N × N光开关阵列结构,分析了这种结构的开关阵列优势和局限性.用场传输矩阵方法建立了1 × N多模干涉光开关的光场传输方程.给出了光开关阵列从任一输入端输入、从任一输出端输出时阵列开关的工作条件.在上述原理及理论基础上分析了4×4光开关阵列的结构和工作条件. 相似文献
13.
14.
测量了CdTe太阳电池器件从50kHz至1MHz频率范围的电容-电压特性,计算了吸收层的载流子浓度和空间电荷区的位置,电容-电压特性测试结果出现两个峰,峰特征与测试频率有关,用多结模型进行模拟分析,解释了实验结果.测量了电池从220K至300K的变温暗电流-电压特性,得出电池的反向暗饱和电流密度J0和二级管理想因子A,分析了J0,A随测量温度的变化,并讨论了电池器件的电流特性.
关键词:
CdTe太阳电池
电流-电压特性
电容-电压特性 相似文献
15.
Laser-produced plasma helium-like titanium Kα x-ray source and its application to Rayleighben-Taylor instability study 下载免费PDF全文
Several experiments are performed on the ShenGuang-II laser facility to investigate an x-ray source and test radiography concepts. X-ray lines emitted from laser-produced plasmas are the most practical means of generating these high intensity sources. By using a time-integrated space-resolved keV spectroscope and pinhole camera, potential helium-like titanium Kα x-ray backlighting (radiography) line source is studied as a function of laser wavelength, ratio of pre-pulse intensity to main pulse intensity, and laser intensity (from 7.25 to ~11.3× 1015 W/cm2). One-dimensional radiography using a grid consisting of 5 μm Au wires on 16 μm period and the pinhole-assisted point projection is tested. The measurements show that the size of the helium-like titanium Kα source from a simple foil target is larger than 100 μm, and relative x-ray line emission conversion efficiency ξx from the incident laser light energy to helium-like titanium K-shell spectrum increases significantly with pre-pulse intensity increasing, increases rapidly with laser wavelength decreasing, and increases moderately with main laser intensity increasing. It is also found that a gold gird foils can reach an imaging resolution better than 5-μm featured with high contrast. It is further demonstrated that the pinhole-assisted point projection at such a level will be a novel two-dimensional imaging diagnostic technique for inertial confinement fusion experiments. 相似文献
16.
Marisílvia Donadelli 《Indian Journal of Physics》2011,85(1):27-32
The ratio of the ψ′ over the J
ψ production cross section in the dielectron channel has been measured in $
\sqrt s
$
\sqrt s
= 200 GeV p + p collisions with the PHENIX detector at RHIC. The analysis is based on fitting of the dielectron invariant mass spectra in
the area around the J
ψ and ψ′ signals in order to extract a ratio ψ′ over J
ψ of 0.019 ± 0.005 (stat) ± 0.002 (sys) and a fractional feed-down contribution to J
ψ from ψ′ of 8.6 ± 2.5%. 相似文献
17.
Jeong Ho Ryu Hyong Sik Won Youn-Gon Park Sang Hyun Kim Won Young Song Hideo Suzuki Chulsoo Yoon 《Applied Physics A: Materials Science & Processing》2009,95(3):747-752
Rare-earth-doped oxynitride or nitride compounds have been reported to be photoluminescent and may then serve as new phosphors
because of their good thermal and chemical stabilities. In this work, Eu2+-doped β-SiAlON phosphor with a composition of Eu
x
Si6−z
Al
z
O
z
N8−z
(x=0.018, z=0.23) was prepared by gas-pressured solid state reaction. The crystallinity and particle morphology of the prepared phosphor
were characterized. The Stokes shift and zero-phonon line were calculated mathematically and estimated from the spectral data.
The temperature dependence of photoluminescence was measured from 25 to 250°C. The prepared Eu2+-doped β-SiAlON green phosphor showed superior thermal quenching property compared to silicate (SrBaSiO4:Eu2+) green phosphor. The white light-emitting diode (LED) back-lighting unit (BLU) using the prepared β-SiAlON:Eu2+ green phosphor exhibited higher color gamut than a commercial silicate phosphor. 相似文献
18.
Extensive dynamical \begin{document}$N/D$\end{document} ![]()
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calculations are conducted in the study of \begin{document}$S_{11}$\end{document} ![]()
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channel low energy \begin{document}$\pi N$\end{document} ![]()
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scatterings, based on various phenomenological model inputs of left cuts at the tree level. The subtleties of the singular behavior of the partial wave amplitude, at the origin of the complex \begin{document}$s$\end{document} ![]()
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plane, are analysed in detail. Furthermore, it is found that the dispersion representation for the phase shift, \begin{document}$\delta$\end{document} ![]()
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, must be modified in the case of \begin{document}$\pi N$\end{document} ![]()
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scatterings. An additional contribution from the dispersion integral exists, which approximately cancels the contribution of the two virtual poles located near the end points of the segment cut, induced by \begin{document}$u$\end{document} ![]()
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channel nucleon exchanges. With limited reliance on the details of the dynamical inputs, the subthreshold resonance \begin{document}$N^*(890)$\end{document} ![]()
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survives. 相似文献
19.
Zhi-Gang Wang 《The European Physical Journal C - Particles and Fields》2008,58(2):245-250
We study the final-state rescattering effects in the decay B
0→η
c
K
*. The numerical results indicate that the corrections are comparable with the contribution from the naive factorizable amplitude,
and the total amplitudes can accommodate the experimental data. 相似文献
20.
A general formalism for double and triple spin correlations of the reaction
is developed for the case of collinear kinematics. A complete polarization experiment allowing one to reconstruct all four
amplitudes describing this process is suggested. Furthermore, the spin observables of the inelastic charge-exchange reaction
(pp)(1
S
0 are analyzed in collinear kinematics within the single pN-scattering mechanism involving the subprocess pn → Δ0
p. The full set of spin observables, related to the polarization of one or two initial particles and one final particle, is
obtained in terms of three invariant amplitudes of the reaction pd → Δ(pp)(1
S
0) and the transition form factor d → (pp)(1
S
0). A complete polarization experiment for the reaction
(pp)(1
S
0) is suggested which allows one to determine three independent combinations of the four amplitudes of the elementary subprocess
.
The text was submitted by the authors in English. 相似文献