不同掺杂对Yb半导的（Ba,Sr）TiO3系PTCR材料性能的影响

研究了不同掺杂方式对ＰＴＣＲ材料电学性能的影响,结果表明,Ｙｂ一次掺杂ＢａＴｉＯ３电阻变化“Ｕ”型曲线,低阻区为０．１ｍｏｌ％～０．３ｍｏｌ％,其移峰效率为３～５℃／ｍｏｌ。二次单一掺杂Ｙｂ提高电阻率,降低对升阻比,二次单一掺杂Ｍｎ提高电阻率与升阻经,二次Ｙｂ,Ｍｎ共掺杂可降低电阻率,提高升阻比,并探讨了二者配合作用的机理,Ｙｂ：Ｍｎ＝１：１效果最佳。     

半导体钛酸锶陶瓷烧结新工艺的研究

为了获得电阻率低的ＳｒＴｉＯ_３陶瓷,本文采用两种方法制造还原气氛进行烧结,一是通氮气＋Ｃ,另一是用石墨粉埋覆陶瓷片,烧成之后,测试这两种方法下瓷片的收缩情况,密度大小及其电阻率,实验证明石墨粉埋烧的各种性能良好,电阻率也比较低,简化了工艺设备及工艺。     

Investigation of the dependency of the upper critical magnetic field on the content x in Y1−xYbx/2Gdx/2Ba2Cu3O7−y superconducting structures

The Y_1−xYb_x/2Gd_x/2Ba₂Cu₃O_7−y superconducting samples for x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 were prepared by using the solid-state reaction technique. Resistivity measurements of the samples were performed in QD–PPMS system under different magnetic fields up to 5 T in zero fields cooling regime. Using the resistivity data, the upper critical magnetic field H_c2(0) at T = 0 K for 50% of R_n was calculated by the extrapolation H_c2(T) to the temperature T = 0 K. The coherence length in T = 0 K were calculated from H_c2(0) and the effects of x in the composition on both the coherence length and the upper critical magnetic field were examined. The results showed that H_c2(0) varied from 84.05 to 122.26 T with the content x. The upper critical magnetic field in the temperature T = 0 K slightly decreased with increasing the content x. Using the content x, the upper critical magnetic field can be controlled and this can be used in the superconductivity applications.     

Superconducting properties of zinc substitution in Tl-2223 phase

The effect of partial replacement of copper by zinc in Tl₂Ba₂Ca₂Cu₃O_10−δ superconductor phase is studied. Superconducting samples of the nominal composition Tl₂Ba₂Ca₂Cu_3−xZn_xO_10−δ with x ranging from 0 to 0.6 are prepared under normal pressure by a one step of solid-state reaction technique. The samples are characterized by using X-ray powder diffraction, scanning electron microscope (SEM) and EDX. The X-ray data indicate that the partial replacement of Cu²⁺ions by Zn²⁺ions does not influence the tetragonal structure of the samples, and the lattice parameters a and c vary according to the difference in the ionic radii of Cu and Zn. The superconducting parameters, such as superconducting transition temperature T_c, critical current density J_c and irreversibility field B_ir are calculated from electrical resistivity and AC-magnetic susceptibility measurements.     

铝掺杂氧化锌晶须/环氧树脂抗静电性能研究

采用新的铝掺杂方法,降低了氧化锌晶须的本体电阻率;研究了铝掺杂对氧化锌晶须电阻率的影响。含20%掺量的氧化铝使氧化锌晶须的表面电阻率从107~108Ω降低到1·6×106Ω,体积电阻率从108~109Ω·cm降低到7·1×105Ω·cm;研究了铝掺杂氧化锌晶须对环氧树脂抗静电性能的影响,铝掺杂氧化锌晶须的添加量为8%,使涂层的表面电阻降低到7·2×1010Ω。     

Investigation of water electrical parameters as a function of measurement frequency using cylindrical capacitive sensors

In this study electrical properties of different water liquids at frequency range of 100–2000 Hz are investigated by using the short invasive and non-invasive cylindrical capacitive sensors (CCSs). Operation of the capacitance measurement module for such probes is based on the auto balancing bridge method. Comparison of the measured capacitances and measured resistances for different water liquids shows decrease by increasing the frequency. In another study the dielectric constant of distilled water, mineral water, tap water and salt water are measured. The effects of the frequency on the resistivity, permittivity and conductance of the different water liquids are also investigated.     

混掺钢屑铁砂水泥砂浆压敏性研究

在砂浆中混掺钢屑和铁砂两种工业废弃料,制备得到环保低成本的水泥基复合材料,在测定其抗压强度的基础上采用交流两电极法研究其导电性能和压敏性能,并分析研究了混掺掺量、弹塑性荷载、不同加载速率以及冲击荷载等对其压敏性的影响。试验结果表明,随着导电材料掺量增加,试件压敏性更加明显。加载速率越大,试件电阻率变化越大;冲击荷载数值对瞬间电阻率与卸载后电阻率均有较大影响。     

Effect of Ce on the Aging of AlMgSi Alloy by Resistance Measurement

ＥｆｆｅｃｔｏｆＣｅｏｎｔｈｅＡｇｉｎｇｏｆＡｌＭｇＳｉＡｌｌｏｙｂｙＲｅｓｉｓｔａｎｃｅＭｅａｓｕｒｅｍｅｎｔ￥ＸｕＹｕｅｈｕａｎｇ（徐约黄），ＷａｎｇＳｈａｏｌｉｎｇ（王绍苓），ＴｉａｎＳｈａ（田沙），ＤｕＦｅｎｇｍｕ（杜凤牡），ＺｈｏｕＸｉａｏ...     

低电阻油层成因及其研究方法：以辽河油田为例

低电阻油层主要有两种储集层类型:一种是粉砂岩储集层;另一种是含粘土矿物的砂岩储集层.在这两种储集层中,由于强烈的毛细管作用和极大的内表面积形成的高含水饱和度使含烃储集层的电阻率与纯水层相似.在分析了辽河油田锦16块低电阻率油层的地质特点后,提出了识别低电阻油层的基本方法:从分析油藏的形成条件和储集层的岩性特征入手,利用测井信息结合岩心分析资料识别低电阻油层.