Electrical Properties of Conductive Two-Component Xerographic Developer

Xerographic development with a conductive two-component magnetic brush depends on the electrical properties of a developer mixture consisting of insulative toner particles and conductive carrier beads. The electric field driving toner deposition onto an image receiver is affected by the carrier bead conductivity, toner concentration, magnetic field strength, developer thickness, and developer agitation due to the relative motion between the developer and image receiver. To elucidate the dependence of the electrical properties on these parameters, the measurements on an electroded cell of developer under conditions simulating magnetic brush development systems are described. The measurements provide insight into the solid area and line development process with conductive xerographic developer.     

Ultrafast response of As-implanted GaAs photoconductors

The photoconductive response of an optoelectronic switch fabricated from GaAs implanted with arsenic ions is measured to have a duration as short as 0.7 ps and a relaxation time as fast as 0.5 ps. The switching efficiency and relaxation time of the photoswitches using the As-implanted GaAs substrates are determined to be comparable to photoconductive devices employing GaAs grown by low-temperature molecular-beam epitaxy (LT-GaAs). For high dc-bias values, persistent photocurrent tails from transient leakage currents are found to be very prominent in bulk GaAs devices that were implanted with 10¹⁶ cm^-2 arsenic ions at 200 keV. This behavior has been determined to arise from substrate leakage current underneath the thin implanted layer, which recrystallizes and exhibits, as does LT-GaAs, arsenic-precipitate formation after annealing. In order to reduce this leakage current, multiple ion dosages with various implantation energies have been implemented. An epitaxial GaAs layer has also been implanted with arsenic ions, isolated from its semi-insulating substrate, and bonded onto a fused silica wafer in order to verify that the persistent tail response from the photoconductive switches was not actually due to the implanted region of the GaAs     

Simulation of toner depositing process in Xerographic image studies

A novel concept of insulative magnetic brush (IMB) development which exhibits excellent reproduction of solid-area images while maintaining an IMB line image reproduction capability is discussed. The process is based on a simulation of the profile of the electric field in the development zone, the behaviour of toner in the development gap, and the balance of charges in the developer in a two-component magnetic brush development system     

A Theoretical Study of the Mechanics of a Xerographic Cleaning Blade

The use of a polymeric blade is common in removing the residual toner from the imaging surface in xerography. The cleaning action of such a blade is influenced by its local deformation in the contacting region. A nonlinear beam theory approach is presented for studying the deformation of a xerographic cleaning blade. Both the straight and tip regions of the blade are examined. The parameters studied include the normal load, the ratio of tangential and normal forces (the coefficient of friction , ?), the blade tip angle, blade inclination angle, Young's modulus, Poisson's ratio, blade length, and thickness. The effect of these parameters on the size of the contacting region is presented. The critical ratio ?c and the critical inclination angle which determine blade curl-under and curl-up are discussed. The maximum blade inclination angle which governs the tip stability is predicted. Cleaning performance criteria for planning and local curl-unders are developed in terms of the pressure in the contacting region. Agreement of the analytical findings with the available experimental data is good.     

温差电材料Bi_(0.5)Sb_(1.5)Te_3双掺杂调控及热电性能研究

采用真空熔炼及热压方法制备Ga和Na共掺杂Bi0.5Sb1.5Te3热电材料。利用X射线衍射(XRD)技术对样品的物相结构进行了表征。在300~500K测量温度范围内,共掺杂样品的Seebeck系数均低于Bi0.5Sb1.5Te3的Seebeck系数,并随着Ga掺杂量的增加,Seebeck系数逐渐减小。共掺杂使样品的载流子浓度增加,从而有效地提高了材料的电导率。所有共掺杂样品的热导率都大于Bi0.5Sb1.5Te3的热导率,在Na掺杂浓度不变的情况下,随着Ga掺杂浓度的增加,热导率逐步增加,Na0.04Bi0.5Sb1.46-xGaxTe3(x=0.12)样品具有高电导率的同时,Seebeck系数和热导率的损失不是很大,材料的热电性能得到了改善,在300~475K测量温度范围内的热电性能优值与Bi0.5Sb1.5Te3相比较均有所提高,325K时的最大ZT值为1.4。     

An Experimental and Theoretical Study of the Flow of Xerographic Developer Powders from Small Hoppers

An experimental and theoretical study is presented which characterizes the flow of xerographic developer powders out of small hoppers. A small hopper in this reference is defined as one having a maximum height of 12 in. Two walls of the hopper converge at the gate and the remaining two walls are parallel to each other. The flow is studied as a function of the gate opening, hopper angle, particle size, the total height of the particulate material in the hopper, and the angle of repose. Experimental results are presented for particle diameters between 100 ? and 600 ?. A theory is presented to predict flow rates. The predicted functional dependence agrees very well with the observations. The predicted flow rates are about 3.75 times higher than the observed ones. It is suggested that this is due to a resistive force originating in particle interactions. Inclusion of this correction factor in the theory results in very good agreement between theoretical predictions and experimental observations.     

Thermoelectric properties of p-type Bi0.5Sb1.5Te3 compounds fabricated by spark plasma sintering

P-type thermoelectric Bi_0.5Sb_1.5Te₃ compounds were prepared by the spark plasma sintering method with temperature ranges of 300–420^∘C and powder sizes of ∼75 μm, 76–150 μm, 151–250 μm. As the sintering temperature increased, the electrical resistivity and thermal conductivity of the compound were greatly changed due to an increase in the relative density. The Seebeck coefficient and electrical resistivity were varied largely with decreasing the powder size. Subsequently, the compound sintered at 380^∘C with the powders of ∼75 μm showed the maximum figure-of-merit of 2.65 × 10⁻³K⁻¹ and the bending strength of 73 MPa.     

增安型稀土永磁同步电动机tE时间的研究

针对增安型稀土永磁同步电动机的关键防爆参数tE,在综合考虑了集肤效应和散热因素等的基础上,提出REPMSM转子tE的理论计算,并对一台增安型REPMSM-RSMAg250-6进行计算,计算结果与试验结果接近,验证了该计算方法的正确性。     

CuCr50Te/Cu双层触头材料烧结变形的研究

本文通过对不同相对密度下Cu及CuCr50Te粉末压制材料在1050℃烧结时收缩率的测定,分析了CuCr50Te/Cu双层触头材料产生烧结变形的原因。通过选择适当的压制压力,减少Cu层与CuCr50Te层材料之间的烧结收缩率差别,解决了烧结变形问题。同时还提出了粉末压烧材料的相对密度与收缩率的经验关系方程,并根据实验结果进行了验证。     

CuCr50 Te/Cu双层触头材料烧结变形的研究

本文通过对不同相对密度下Cu及CuCr50Te粉末压制材料在1050℃烧结时收缩率的测定，分析了CuCr50Te/Cu双层触头材料产生烧结变形的原因。通过选择适当的压制压力，减少Cu层与CuCr50Te层材料之间的烧结收缩率差别，解决了烧结变形的问题。同时还提出了粉末压烧材料的相对密度与收缩率的经验关系方程，并根据实验结果进行了验证。     

热压法制备P型Bi2Te3基温差电材料研究

以P型赝二元Bi2Te3-Sb2Te3体系温差电材料区熔晶棒为前驱体,采用真空热压烧结法制备材料样品。测试热压前后材料样品性能,测试结果表明:热压样品较区熔材料具有更高的致密度和机械强度,改善了Bi2Te3基温差电材料易沿解理面发生劈裂的现象;同时,热压工艺促使了材料内部晶体结构和载流子浓度的变化,引起材料电导率的降低和塞贝克系数的改变,导致材料热导率显著降低。综合考虑材料各项性能参数,热压材料的热电优值基本与区熔材料相当,但前者的力学强度明显优于后者,在实际使用中将占有明显的优势。     

微量Te对Cu-30CrTe合金触头材料抗焊接性的影响

使用光学显微镜和扫描电镜（sEM）观察熔铸Cu-30crTe、Cu-30Cr烧结粉末冶CuCr25等三种触头材料经真空扩散焊后的室温拉伸断口及焊接结合区纵断面的显微组织。三种触头材料具有不同的断裂特征,熔铸Cu-30crTe材料焊接结合面的显微组织明显不同于烧结cuCr25;同时参考X射线光电子能谱（XPS）表面分析结果,对添加微量Te改进触头材料抗焊接性的机理和评判原则进行了讨论。     

Bi2Te3基温差发电组件的热应力和结构参数选择

温差电材料性能决定了温差发电组件(TEM)的发电功率及转换效率,而在使用过程中由于环境因素的影响,对其机械性能也提出了一定的要求.热压法制备的Bi2Te3基温差电材料密度和强度均有提高,缓解了区熔法制备的Bi2Te3基温差电材料在平行于晶体方向上易发生解理破坏的问题,但还不能完全避免.通过分析Bi2Te3基温差电材料沿...     

Ag掺杂对Bi2(Te0.95Se0.05)3薄膜热电功率因子的影响

采用瞬间蒸发技术在温度为473 K的玻璃基体上沉积了厚度为800 nm的Ag掺杂Bi2(Te0.95Se0.05)3热电薄膜.利用X射线衍射(XRD)技术对薄膜的物相结构进行表征,采用表面粗糙度测量仪测定薄膜厚度,薄膜的电阻率采用四探针法在室温下进行测量,在室温下对薄膜的Seebeck系数进行表征.Ag的掺杂浓度为0....     

Improvement of the figure-of-merit by formation of crystallographic texture in Bi2Te3-based thermoelectric compounds

Coarse powders of 200∼300 μm size and fine powders below 45 μm size were blended with various ratios, and then synthesized by spark plasma sintering method. The use of coarse powders was beneficial to improve the crystallographic orientation and addition of fine powders reduced the voids existing between coarse powders. When 20 wt% of fine powders were blended with coarse powders, the sintered compound exhibited the maximum figure-of-merit.     

High-order non-linear circuit elements: Circuit-theoretic properties

Highei- and mixed-order non-linear circuit elements have been introduced to provide a logically complete formulation for non-linear circuit theory. In this paper, we analyse the circuit-theoretic properties of these elements, including reciprocity, passivity and losslessness. We have derived necessary and sufficient conditions for a higher- or mixed-order n-port element to be reciprocal or antireciprocal. We have shown that under very mild assumptions, most non-linear higher-order 2-terminal elements are active and not lossless. Finally, we show that the number of lossless linear higher-order 2-terminal elements far exceeds that of the passive linear elements.     

Dielectric mixtures: electrical properties and modeling

A review of the current state of understanding of dielectric mixture properties, and approaches to use numerical calculations for their modeling are presented. It is shown that interfacial polarization can yield different non-Debye dielectric responses depending on the properties of the constituents, their concentrations and geometrical arrangements. Future challenges on the subject are also discussed.     

Silicon carbide: its nonabrasive electrical properties andapplications

Silicon carbide (SiC) has been around for over a century. However, only in the past two to three decades has its semiconducting properties been sufficiently studied and applied. Its many advantages, with its ability to withstand high temperatures being the most prominent, are making silicon carbide a choice for new applications and an improved substitute for traditional electronic materials     

Correction to: Piezoelectric and elastic properties of relaxor-like PZT:Ba ceramics

Journal of Electroceramics - The original version of this article unfortunately contained a mistake. The copyright line was incorrect in the HTML version of this article. The copyright line should...