自制电磁振子替代电动音叉演示李萨如图形

本文设计了一种新型电磁振子，并分析其工作原理，激光通过此装置产生两个相互垂直的简谐振动，其合成振动的图形投影在大屏幕上，具有稳定、清晰的特点。

一种基于固体传声原理的通信装置研究

在进行某种水下金属管内作业时,由于现场条件的限制,潜水员在管中只能用敲击信号进行通信,效率低下。为解决通信问题,设计了一种基于固体传声原理的通信装置,该装置采用电磁式振子,通过振动管壁,使管内人员听管外人员的口令。本文对通信装置结构进行了设计,并对作业管的管内声场进行了仿真研究,最后通过试验对其传音效果进行验证。

单相多铁性材料中静态与动态磁电效应研究新进展

多铁性材料是一类新型多功能材料,其中磁有序与铁电序共存,且序参量之间存在非平庸的相互耦合效应。这使其具有巨大的工业应用前景并蕴含着丰富和有趣的基础物理问题。本文首先简要回顾多铁性材料研究的历史,重点介绍由磁有序引起的新型多铁性材料的实验和理论的新进展。随后,我们系统地概述多铁性材料中演生的一类新的元激发(即电磁振子)的物理特性以及当前对其产生机制的理解。最后,我们总结了多铁性材料研究中尚未解决的技术问题,并展望了多铁性材料的发展趋势。

Effects of Fe_(2)O_(3) content on microstructure and mechanical properties of CaO-Al_(2)O_(3)-SiO_(2) system

The effects of Fe2O3 content on the microstructure and mechanical properties of the CaO-Al2O3-SiO2 system were investigated by differential thermal analysis（DTA）, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, electron spin resonance（ESR）, and Mssbauer spectroscopy. The results show that the addition of Fe2O3 does not affect the main crystalline phase in the prepared glasses, but it reduces the crystallisation peak temperature, increases the crystallisation activation energy, and reduces the crystal granularity. The ESR results indicate that Fe2O3 can promote crystallization, as it leads to the phase separation of the CaO-Al2O3-SiO2 system due to axial distortion. Moreover, Fe2O3 alters the network structure of the CaO-Al2O3-SiO2 system, allowing Fe3＋ to enter octahedral sites that exhibit higher symmetry than tetrahedral sites. All of these factors are favourable to increasing the bending strength. The Mssbauer results reveal that there are two types of coordination for both Fe3＋ and Fe2＋ and the bending strength of the CaO-Al2O3-SiO2 system increases with the amount of six-coordinate Fe3＋. The increasing interaction between Fe3＋ and Fe2＋ can also enhance the bending strength of the CaO-Al2O3-SiO2 system. The microhardness of the CaO-Al2O3-SiO2 system was determined to be HV 896.9 and the bending strength to be 217 MPa under the heat treatment conditions of nucleation temperature of 700 °C and nucleation time of 2 h, crystallization temperature of 910 °C and crystallization time of 3 h.

Effects of BYHW Decoction and Its Effective Constituents on the Fluidity of the Cell Membrane in a Stroke-Modeled Rat Brain

With in vitro spin labeling electron spin resonance (ESR) spectroscopy, we have studied the effects of Bu Yang Huan Wu (BYHW) decoction and its effective constituents such as astragaloside IV ferulic acid, chuanxiongzine, rutin, chlorogenic acid, 9,10 dimethoxy pterocarpane 7 O β D glucoside, calycosin, formononetin, calycosin 7 O glucoside, paeoniflorin, paeonal and quercein on the cell membrane fluidity of a rat brain which was modeled after the dual cervical arteries were intercepted and released for realizing an ischemia reperfusion injury which was selected as a brain stroke model. Our results indicated that the cell membrane fluidity in the model group decreased approximately 8% compared with the control group, and after brain cells were incubatied with species, the membrane fluidity could be recovered closely to the control level depending on the BYHW decoction and its different constituents. As the membrane fluidity is a very sensitive biological index which reflectsd the cell status, our method will be useful to study the molecular mechanism of tradition Chinese medicine (TCM) and its combination recipe.

谐振传感系统的稳定性理论分析、设计与仿真

分析了谐振传感系统的稳定性条件 ,并根据稳定性误差得到了稳定性能指标 .在理论的基础上 ,对谐振传感系统作了具体设计 ,得到了以振子的振动速度作为输出以稳定系统的频率的设计思想 ,以及增加AGC环节以稳定振幅并获得较理想的正弦波的设计思想 .建立了振子电磁耦合模型 ,并对整个系统进行了仿真 。

Temperature-Dependent Formation of Redox Sites in Molybdenum Trioxide Studied by Electron Paramagnetic Resonance Spectroscopy

The formation and qualification of redox sites in transition metal oxides are always the active fields related to electronics, catalysis, sensors, and energy-storage units. In the present study, the temperature dependence of thermal reduction of MoO3 was surveyed at the range of 350℃ to 750℃. Upon reduction, the formed redox species characterized by EPR spectroscopy are the MoVion and superoxide anion radical (O2-) when the reduction was induced at the optimal temperature of 300-350℃. When heating-up from 350℃, the EPR signals started to decline in amplitude. The signals in the range of 400-450℃ decreased to half of that at 350℃, and then to zero at ~600℃. Further treatment at even higher temperature or prolonged heating time at 500℃ caused more reduction and more free electrons were released to the MoO3 bulk, which results in a delocalized means similar to the antiferromagnetic coupling. These data herein are helpful to prepare and study the metal-oxide catalysts.

Identification of Superoxide O2^- during KNO3-NaNO2-NaNO3 Salt by Electron UV-Vis Absorption Spectroscopy Thermal Decomposition of Molten Paramagnetic Resonance and

On account of excellent thermal physical properties, molten nitrates/nitrites salt has been widely employed in heat transfer and thermal storage industry, especially in concentrated solar power system. The thermal stability study of molten nitrate/nitrite salt is of great importance for this system, and the decomposition mechanism is the most complicated part of it. The oxide species O2^2- and O2^- were considered as intermediates in molten KNO3-NaNO3 while hard to been detected in high temperature molten salt due to their trace concentration and low stability. In this work, the homemade in situ high temperature UV- Vis instrument and a commercial electron paramagnetic resonance were utilized to supply evidence for the formation of superoxide during a slow decomposition process of heat transfer salt （HTS, 53 wt% KNO3/40 wt% NaNO2/7 wt% NaNO3）. It is found that the superoxide is more easily generated from molten NaNO2 compared to NaNO3, and it has an absorption band at 420-440 nm in HTS which red shifts as temperature increases. The band is assigned to charge-transfer transition in NaO2 or KO2, responsible for the yellow color of the molten nitrate/nitrite salt. Furthermore, the UV absorption bands of molten NaNO2 and NANO3 are also obtained and compared with that of HTS.

Detoxification of chromium-containing slag by Achromobacter sp.CH-1 and selective recovery of chromium

Based on the principle of bacterial leaching and bacterial metallurgy,a novel technology for the detoxification of chromium-containing slag by Achromobacter sp.CH-1 and chromium recovery was proposed.Strain CH-1 cell morphology before and after Cr(Ⅵ) reduction was observed with a scanning electron microscope(SEM),and the reduction product is found to adhere to terminals of CH-1 cells.Energy-dispersive X-ray(EDX) and electron paramagnetic resonance(EPR) analyses reveal that the main component of the reduction product is Cr(Ⅲ).Furthermore,small and large-scale demonstration projects reveal that Achromobacter sp.can be used to detoxify chromium-containing slag and to selectively recover chromium by using this novel technique.Chromium recovery rate increases with decreasing particle sizes of chromium-containing slag and slagheap height.Chromium recovery rates in 10 t/batch and 20 t/batch of on-site demonstration projects for chromium-containing slag detoxification are more than 90%.

Dynamics analysis of vibration process in Particle Impact Noise Detection

Particle Impact Noise Detection (PIND) test is a reliability screening technique for hermetic device that is prescribed by MIL-PRF-39016E. Some test conditions are specified, although MIL-PRF-39016E did not specify how to obtain these condi- tions. This paper establishes the dynamics model of vibration process based on first order mass-spring system. The corresponding Simulink model is also established to simulate vibration process in optional input excitations. The response equations are derived in sinusoidal excitations and the required electromagnetic force waves are computed in order to obtain a given vibration and shock accelerations. Last, some simulation results are given.

Phase, magnetism and thermal conductivity of glass ceramics from iron ore tailings

In order to develop the applications of ore tailings, the glass ceramics were prepared by using a conventional melting-quenching-sintering process. The phase component, microstructures, magnetic properties and thermal conductivities of the prepared glass ceramics were investigated by using X-ray diffractometer, scanning electron microscopy, vibrating sample magnetometer and thermophysical properties tester, respectively. The results show that orthorhombic olivine-type phase and triclinic sunstone-type phase formed when the glass was annealed at 700 oC, the concentration of olivine-type and sunstone-type phases decreased, the spinel-type cubic phase occurred and the amount increased when the annealing temperatures increased. The magnetic properties from the cubic spinel ferrites were detected in the glass ceramics, and the related saturation magnetization increased with the annealing temperature increasing. The porous glass ceramics with magnetic property showed much lower thermal conductivity, compared with the non-magnetic porous glass-ceramic and the dense glass-ceramics.

Theoretical Calculation of Energy Spectrum of YGG:Cr^(3+)and Thermal Shifts of Its R-Lines

With the strong-field scheme and trigonal bases, the complete d3 energy matrix in a trigonally distorted cubic-field has been constructed. By diagonalizing this matrix, the energy spectrum of YGG：Cr^3＋ at normal pressure and low temperature has been calculated. The g factor of the ground-state has been evaluated in terms of the energy spectrum. At the same time, by using the wavefunctions obtained from diagonalizing the complete d^3 energy matrix and Thermal Shifts theory, we calculate the thermal shifts of the sharp lines of YGG：Cr^3＋ and determine the relevant parameters. The calculated results are all in good agreement with the optical-spectrum and EPR experimental data. It is demonstrated that the obtained wavefunctions and the values of parameters are reasonable.

Effects of Vanadium Oxidation Number on Light Olefins Selectivity of FCC Catalyst

Effects of vanadium on light olefins selectivity of FCC catalysts were investigated with vanadium having different oxidation numbers （hereinafter abbreviated as Oxnum）. Molecular modeling studies showed that vanadium with low Oxnum could affect the chemical conversion of large-size hydrocarbon molecules. However, the vanadium deposited on equilibrium catalyst bad high Oxnum because of the oxidation reaction taking place in the regenerator, so an activation method to reduce vanadium Oxnum named ＂selective activation＂ was introduced. It was proved by means of Electron Paramagnetic Resonance （EPR） and Temperature-Programmed Reduction （TPR） methods that the vanadium Oxnum was decreased, when the catalyst was activated. The molecular modeling studies are consistent well with the lab evaluation results. The light olefins selectivity of activated equilibrium catalysts was better than that achieved by the inactivated catalysts. Similar results were observed with the lab vanadium-contaminated catalyst. The light olefins selectivity of the catalyst was optimized when the vanadium Oxnum was close to 2 （VO）.

Light Emission Characteristics of Metal/Insulator/Metal and Metal/Insulator/Si Tunnel Junctions Mediated by Surface Plasmon-polaritons

The Au/Al2O3/Al metal/insulator/metal junction(MIMJ) and Au/SiO2/Si metal/insulator/Si junction(MISJ) have been constructed successfully. The light emission of these junctions was mediated by surface plasmon-polaritons(SPPs) under surface roughness. The light emission from MISJ was more uniform and stable than that from MIMJ. The light power of MISJ was about 2~3 orders higher than that of MIMJ. The light emission spectrum of MISJ was analyzed especially. In the spectrum, there was one main peak located at the wavelength of 610 nm^640 nm, which was mainly due to the couple of SPP with the surface roughness at the Au/air and Au/SiO2 interfaces. A weak peak located at the shorter wavelength region in the spectrum was also found, which was caused by the direct radiation of doped-Si plasma oscillation.

Complete response to radiation therapy of orbital metastasis from hepatocellular carcinoma

The incidence of hepatocellular carcinoma(HCC)is increasing in the United States,and 50%-75%o patients with HCC will develop metastatic disease Orbital metastases from HCC are extremely rare.We report the case of a 52-year-old male with known metastatic HCC,who presented with severe proptosis and diplopia.An orbital mass was identified on magnetic resonance imaging(MRI)and confirmed to have hypermetabolic activity on positron emission tomography/computed tomography.He received a palliative course of external beam radiation therapy to the right orbit.Intensity modulated radiation therapy (IMRT)was used to allow sparing of critical norma tissues in close proximity to the tumor.One month after completion of IMRT to 58 Gray in 30 fractions delivered over 6 wk,the patient had a complete clinical,radiologic(MRI)and symptomatic response The patient continues to have local control in the orbi 1.7 years after therapy completion.All critical norma structures were kept below the tolerance dose using IMRT,and no toxicities were observed.

Photo-Ionization of Hydrogen Atom in a Circularly Polarized Standing Electromagnetic Wave

Applying time-independent non-perturbative formalism to the photo-ionization of hydrogen atom immersed in a strong circularly polarized standing electromagnetic wave, we calculate the shift of energy levels and the distortion of wave functions for the hydrogen atom, the ionization cross section induced by the standing wave, and the angular distribution of photoelectrons and obtain some interesting results.

Transalkylation of Multi-secbutylbenzenes with Benzene over Hierarchical Beta Zeolite

A hierarchical beta zeolite synthesized by quasi-solid phase conversion method was characterized by BET, scanning electron microscope （SEM）, transmission electron microscope （TEM）, X-ray diffraction （XRD）, temperature-programmed desorption of ammonia （NH3-TPD）, 27A1 and 295i magic angle spinning nuclear magnetic resonance （27A1 and 29Si MAS NMR）, and its catalytic performance was compared with that of conventional microporous beta zeolite for liquid phase transalkylation of multi-secbutylbenzenes （MSBBs） with benzene. The results indicate that the hierarchical beta zeolite consists of nanosized crystals with a meso/ microporous structure and has stronger acid strength than the microporous beta zeolite. The higher conversion oftri-secbutylbenzene （TSBB） and selectivity ofsec-butylbenzene （SBB） are achieved on hierarchical beta zeolite than microporous beta zeolite, while the conversion of di-secbutylbenzene （DSBB） is slightly higher. The improvement of catalytic performance over hierarchical beta zeolite can be ascribed to the presence of mesopores, nanosized crystals and stronger acidity.

Theoretical Studies of Energy Spectra and g Factors of Cr3＋-Doped YAl3（BO3）4

With the strong-field scheme and trigonal bases, by diagonalizing the complete d^3 energy matrix in a trigonally distorted cubic-field, the energy spectra and wavefunctions of YAl3（BO3）4：Cr^3＋ have been calculated. The rates of change of levels with respect to various parameters and the contributions to levels from various parameters are calculated, and the physical origins of various levels or splittings have been clearly and quantitatively shown. By using the wavefunctions obtained from diagonalizing the complete energy matrix, the g factors of the ground state of YAl3 （BO3 ）4;Cr^3＋ have been evaluated. The calculated results are in good agreement with the optical-spectral and EPR experimental data. It is demonstrated that the bonding between Cr^3＋ and ligands （O^2-） is ionic.

Theoretical Studies of g Factors and Defect Structures for Cubic, Tetragonal, and Orthorhombic Fe^＋ Centers in Alkali Halides MX （M=Li, Na; X = F, C1）

The EPR 9 factors for cubic, tetragonal and orthorhombic Fe^＋ centers in alkali halides MX （M= Li, Na; X = F, CI） are calculated from second-order perturbation formulas of g factors based on cluster approach for 3d^7 ions in three symmetries. From calculations, the g factors of these Fe^＋ centers in MX crystals are reasonably explained and the defect structural data for the tetragonal and orthorhombic Fe^＋ centers are estimated. The results are discussed.

IR, 1H NMR, Electronic Properties and Conductivity Studies of N1 ,N4-Bis（Diphme）Benzene-l,4-Diamine Chloride Zirconium （IV） [{（Ar）2NC6H5N（Ar）2}ZrCl4] （Ar = C6H5）

A range of new compounds such as N1,N4-bis（diphenylmethlene）benzene-l,4-diamine zirconium （IV） chloride [{（Ar）2NC6HsN（Ar）z}ZrCl4] （Ar = C6H5） complex counting the chelating amine and chloride in position trans have been prepared. Well-defined NI,N4-bis（diphenylmethlene）benzene-l,4-diamine zirconium （IV） chloride [{（Ar）2NC6H5N（Ar）2}ZrCl4] （Ar = C6H5） was obtained by stoichiometric addition of {（Ar）2NC6H5N（Ar）2} （Ar = C6H5） and {ZrC14} in ethanol at reflex temperature. IR, 1H NMR, electronic properties using hyperchem program study has been improved for this compound such as bond distance, and this compound was also defined as electric conductivity which proves to be useful for conductively compound.