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1.
肿瘤热疗用Fe3O4磁性纳米粒的制备及表征   总被引:2,自引:0,他引:2  
用化学共沉淀法制备用于肿瘤磁流体热疗的Fe3O4磁性纳米粒子并对其进行表征。运用透射电子显微镜、X射线衍射分析、扫描电子显微镜、能谱分析及图像分析等技术进行特性研究;在高频交变磁场下观察Fe3O4纳米磁流体的体外升温情况。制备的Fe3O4磁性纳米粒子属尖晶石型铁氧体、圆形,粒径20nm左右。其不同浓度的磁流体在高频交变磁场下可升温至37℃~56℃。  相似文献   

2.
在磁场条件下,用水热法制备了尖晶石型锰锌铁氧体粉末。利用X射线衍射、X射线光电子能谱和高锰酸钾分光光度法,对铁氧体粉末的微观结构、表面原子信息和锰的平均价态进行了研究。研究表明,在水热条件为:180℃4h外加磁场的条件下制备的物质没有新相产生,在内加磁晶和外加磁场的条件下得到的铁氧体样品,有一部分锌进入了尖晶石的B位。  相似文献   

3.
根据磁性液体特殊的结构组成及磁场中所呈现的奇异特性,利用自行搭建的场致热效应实验装置,通过控制电流换向器,磁场迅速左右换向,致使磁性液体中磁性颗粒磁矩的取向迅速改变,并通过调节直流电源输入电压,控制磁场强度,使磁性液体处于不同强度的换向磁场下,由此探索磁性液体场致热效应规律及分析机制。实验结果表明,处于变化磁场中的磁性液体具有热效应,其温度将随时间的推移而升高,其升温速率与磁场强度及磁极换向频率呈正相关。这将提供一种特殊磁场下诱导磁性液体实现"肿瘤热疗"的新方法。  相似文献   

4.
以硫酸亚铁、硫酸锰和硫酸锌为原料,采用碳酸盐共沉淀法制备了Mn1–xZnxFe2O4(x=0,0.2,0.4,0.5和0.6)铁氧体微粉。通过TGA-DSC、XRD和SEM等测试手段,分析其物相、微观结构和形貌,并用振动样品磁强计(VSM)测量其室温磁滞回线,重点探讨了锰锌铁氧体前驱粉在热处理过程中发生的反应。磁性能测试表明,随着Zn2+含量的增加,锰锌铁氧体微粉的比饱和磁化强度先增加后降低,当x(Zn2+)=0.2时,微粉的比饱和磁化强度最大,为84.24A·m2·kg–1。  相似文献   

5.
温敏锰锌铁氧体材料是一种具有较低居里温度的铁氧体材料,由于其反应灵敏、工作稳定,在温敏开关中作为关键材料得到了广泛的推广和应用。本文通过研究温敏锰锌铁氧体材料的组成与居里温度的关系,发现在一定温度范围内,在其它原材料配方比例不变的情况下,材料的居里温度在一定比例含量范围内随着氧化铁含量的增加而升高,平均增长比率为氧化铁含量每增加1%,居里温度升高6.35℃。  相似文献   

6.
简要介绍了锰锌铁氧体的传统制备方法和工艺流程,综述了近年来制备锰锌铁氧体的新工艺,最后根据目前的研究现状,探讨了锰锌铁氧体制备工艺优化的发展方向.  相似文献   

7.
简要介绍了锰锌铁氧体的传统制备方法和工艺流程,综述了近年来制备锰锌铁氧体的新工艺,最后根据目前的研究现状,探讨了锰锌铁氧体制备工艺优化的发展方向。  相似文献   

8.
Fe~(2+)对纳米软磁锰锌铁氧体生成反应催化作用研究   总被引:1,自引:1,他引:0  
以ZnSO4·7H2O,FeCl3·6H2O和MnSO4为原料,采用液相沸腾回流法,成功地制备出了纳米锰锌铁氧体。本文着重研究了Fe2+对纳米锰锌铁氧体生成反应的催化作用;研究了在反应前驱物中对锰、锌元素实施补偿的可能性。研究表明,Fe2+对纳米锰锌铁氧体生成反应有催化作用,且在pH低于9.6时,催化作用明显;pH=9.6时,补偿Mn可行。  相似文献   

9.
废旧电池水热法制备镍掺杂纳米晶锰锌铁氧体   总被引:1,自引:0,他引:1  
以废旧碱性锌锰电池为原料,采用水热法制备了镍掺杂的纳米晶锰锌铁氧体。用XRD、TEM和VSM,就镍掺杂量对锰锌铁氧体的相结构和磁性能的影响进行了研究。结果表明:镍掺杂的摩尔分数为0~2%时,均可制得具有尖晶石结构的纳米晶锰锌铁氧体。最佳x(Ni2+)为1.5%,此时镍掺杂锰锌铁氧体的Ms、Mr和Hc分别为3.6432×105A/m,2.5088×104A/m和2.388×103A/m。  相似文献   

10.
采用传统陶瓷制备工艺制备了NiCuZn铁氧体材料。研究了V2O5、MoO3掺杂对NiCuZn铁氧体材料的微观形貌、直流叠加性能、温度稳定性的影响。研究表明,适量添加V2O5、MoO3可增加铁氧体材料晶界非磁性相的厚度,提高退磁场Hd;从而降低铁氧体材料的磁导率在直流叠加磁场作用下的下降速度。适量添加V2O5、MoO3可调整材料的晶粒尺寸及气孔、晶界等非磁性相的含量;进而改变饱和磁化强度、磁各向异性场、退磁场对材料磁导率的影响权重,最终达到调整材料温度系数的目的。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

13.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

14.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

15.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

16.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

17.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

18.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

19.
This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.  相似文献   

20.
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.  相似文献   

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