认识导电度

胶印技术发展到今天应该算是很成熟了,但是在实际印刷生产过程中还是经常会发生许多故障,例如:同一批次的印件,纸张、油墨、橡皮布、润版液、印刷机不变,温度、湿度及操作人员等也没有任何变化,而印刷质量却发生了很大的变化,其中,一个重要原因就是通常不被人们注意的润版液导电度的变化,即在对浓缩的润版液稀释时加入水中的电解质成分发生了变化.

1号机凝结水导电度间断性超标的原因分析及调整

通过对国电靖远发电有限公司1号机组凝结水导电度运行中经常超标的原因进行分析，找出影响凝结水导电度的原因，提出预防和解决办法，为机组的安全经济运行提供可靠保证。

加热器疏水氢导电度在300MW供热机组上的改造与应用

本文介绍氢导电度的技术原理,以漳山电厂300MW机组热网加热器为研究对象,通过对加热器疏水进行氢导电度的改造与检测,提高疏水、蒸汽品质,降低机组发生保护动作跳机的几率。

储层含油饱和度评价新方法及其应用

储层岩石含流体饱和度的确定涉及面广、影响因素多、确定难度大,在实际油气藏评价中,需要发展一套实用可靠的饱和度计算方法。在阿尔奇公式的应用中,通常把岩石当成岩石骨架、孔隙和孔隙流体(油气和水)3个组成部分。然而,在多数情况下,油的电性特征与地层的岩石骨架类似,都为电流的不良导体,那么,如果将油成分视为不导电的岩石骨架一部分,则岩石总可认为是充满水的,此时,由阿尔奇公式导出的孔隙度为岩石的含水孔隙度。以该思路为指导,并结合孔隙度测井方法,可以推导出一套岩石饱和度计算公式和可动油评价方法。更进一步,通过实验室岩石毛管压力曲线和油藏中自由水面以上的高度,可标定出不同类型储层的含水饱和度,以此作为测井饱和度计算的检验和校正。将上述方法应用于中东Mishrif厚壳蛤颗粒灰岩饱和度解释和储层评价中,取得了很好的效果。

图形电镀铜层厚度的均匀性——辅助电极的位置在图形的周边缘

要获得精细导线PCB的蚀刻的高质量其关键因素就是确保镀铜厚度图形表面的均匀性。现就为达到良好的图形电镀厚度的方法的进行讨论。现将BGA的图形分隔成小部分面积和活化致密的面积。在BGA图形的电流分布是通过拉普拉斯方程式和精密的伏特计装置解决数值的模拟分析来解决。这种模拟方法测定电流密度分布是很有效的，而决定的因素却是图形密度和电镀溶液导电度。为获得镀层的均匀性，通过设置辅助凸状电极在每个BGA图形的边缘，辅助凸状电极吸收电流有助于集中于分散图形。这种图形的一般位置是在接近放置在BGA图形的边缘，于是采用辅助凸状电极，使电流集中稀少分散图形，使接近BGA图形边缘电流减少。电流分布是通过辅助凸状电极距离和高度而变化的。采用或选择最佳的辅助凸状电极位置变化，其厚度层的最小误差可以达到3．37％。

Effect of sintering temperature and holding time on structure and properties of Li_(1.5)Ga_(0.5)Ti_(1.5)(PO_4)_(3)electrolyte with fast ionic conductivity

Li1.5Ga0.5Ti1.5(PO4)3(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects of sintering temperature and holding time on relative density,phase composition,microstructure,bulk conductivity,and total conductivity.In the impedance test under frequency of 1-10~6 Hz,the bulk conductivity of the samples increased with increasing sintering temperature,and the total conductivity first increased and then decreased.SEM results showed that the average grain size in the ceramics was controlled by the sintering temperature,which increased from(0.54±0.01)μm to(1.21±0.01)μm when the temperature changed from 750 to 950°C.The relative density of the ceramics increased and then decreased with increasing temperature as the porosity increased.The holding time had little effect on the grain size growth or sample density,but an extended holding time resulted in crack generation that served to reduce the conductivity of the solid electrolyte.

复杂储层连通孔隙度评价与渗透率定量计算方法

复杂储层中普遍存在孔隙度相近而渗透率差异较大的现象。为了揭示其原因,采用铸体薄片、核磁共振、CT扫描成像等实验评价孔隙的连通性。连通孔隙度是渗透率的一个主要贡献参数。因此,从岩石孔隙空间的导电机理出发,以导电孔隙度为桥梁,建立连通孔隙度的计算模型,并分析十二种不同类型岩石中连通孔隙度与总孔隙度的函数关系;基于连通孔隙度的计算模型,建立普适性的核磁共振T_(2)模型;以石灰岩储层为例,在相近孔隙度条件下,从不同类型岩石渗透率之间的差异出发,推导、建立孔隙度指数模型,得到孔隙度指数的分布范围。基于普适性的核磁共振T_(2)模型,可将石灰岩储层渗透率预测的平均绝对误差从20.41mD降至0.83mD。该方法具有一定的理论价值和实际意义。

含微量Ni、Zr、RE的新型铜基电接触材料组织与性能研究

在铜基体中添加Ni、Zr、RE微量元素使铜基体合金化,制得新型铜基触头材料。该材料组织均匀,晶粒细小。经过冷加工至0.86 mm时,Ni含量为1%(质量分数,下同)样品的抗拉强度可达600 MPa,硬度HV达158,冷加工性能良好;经过导电性能测试,Ni含量为0.5%样品的相对导电度(IACS)达到75.4%,导电性能良好。

浅谈电选技术用于生产洁净煤

本文介绍了一种目前在我国选煤生产实践中还不曾应用的新型电造技术的分选原理和用子生产洁净煤的可行性。应用此选煤技术将会把我国煤炭分选技术提高到一个新水平。

水—氢—氢冷却的发电机的水系统特点

引进型３００ＭＷ、６００ＭＷ发电机经国产化后，已经投运了好我台。发电机定子水冷系统是发电机的辅助系统，一般由汽机专业管理，然而汽机、电气两个专业都不太注意。对定子水冷系统的技术特点还没有完全消化，或者还没有理解原设计的意图，作者在这方面进行了较广范围的调研，并总结了一些实践经验。

Arc erosion behaviors of AgSnO_2 contact materials prepared with different SnO_2 particle sizes

To clarify the effect of SnO2 particle size on the arc erosion behavior of AgSnO2 contact material, Ag?4%SnO2 (mass fraction) contact materials with different sizes of SnO2 particles were fabricated by powder metallurgy. The microstructure of Ag?4%SnO2 contact materials was characterized, and the relative density, hardness and electrical conductivity were measured. The arc erosion of Ag?4%SnO2 contact materials was tested, the arc duration and mass loss before and after arc erosion were determined, the surface morphologies and compositions of Ag?4%SnO2 contact materials after arc erosion were characterized, and the arc erosion mechanism of AgSnO2 contact materials was discussed. The results show that fine SnO2 particle is beneficial for the improvement of the relative density and hardness, but decreases the electrical conductivity. With the decrease of SnO2 particle size, Ag?4%SnO2contact material presents shorter arc duration, less mass loss, larger erosion area and shallower arc erosion pits.

Electrical and mechanical properties of Cu-Cr-Zr alloy aged under imposed direct continuous current

The Cu-Cr-Zr alloys were aged at different temperatures for different time with different current densities. The results show that both the electrical conductivity and hardness are greatly improved after being aged with current at a proper temperature. The electrical conductivity increases approximately linearly with increasing current density while the hardness remains constant. The microstructure observation reveals that a much higher density of dislocations and nanosized Cr precipitates appear after the imposition of current, which contributes to the higher electrical conductivity and hardness. The mechanism is related with three factors： 1） Joule heating due to the current, 2） migration of mass electrons, 3） solute atoms, vacancies, and dislocations promoted by electron wind force.

一种基于开关函数的电压源逆变器仿真模型

针对现有电压源逆变器(VSI)仿真模型的弊端,在详细分析120度导电模式下VSI的换相过程的基础上,提出了一种基于开关函数思想的120度导电模式下VSI仿真模型,并给出了仿真波形,证明了这种仿真模型的有效性.

真空电弧纳米流体颗粒沉降及悬浮稳定性探讨

具有高度悬浮稳定性的纳米流体在工业应用上,才可确保纳米化的独特性与应用价值。本文旨在以自行发展的真空电弧纳米流体合成系统所制备出的纳米流体,探讨纳米流体中悬浮颗粒的沉降及悬浮稳定性。文中将分析此系统的主要制程参数对所合成Cu及Ti纳米流体悬浮稳定性的影响,如峰质电流、崩溃电压及放电幅等。针对所制备出的纳米流体检测其平均粒径、粒径分布、形貌特性、pH值、接口电位、沉降性及材料结构等特征,同时观察及量测静置时间与上述纳米流体特性变化的关连性。经由长时间检测纳米流体中颗粒的沉降及悬浮性变化,以验证此真空电弧纳米流体合成系统在所不同的制程参数条件下,所产出纳米流体的悬浮稳定性。

Continuous changes in electrical conductivity of sodium aluminate solution in seeded precipitation

The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pair. The results show that the electrical conductivity of sodium aluminate slurry linearly decreases with increasing aluminum hydroxide addition. Moreover, both the electrical conductivity of slurry and the difference in electrical conductivity between sodium aluminate solution and slurry remarkably decline in the first 60 min before gradually increasing in the preliminary 10 h and finally reaching almost the same level after 10 h. In low Na2 O concentration solution the activities of Na OH and Na Al（OH）4 in seeded precipitation are high, which can enlarge the difference in conductivity between slurry and solution. Additionally, more ion pairs exist in solution in preliminary seeded precipitation, and the adsorption of Na＋Al（OH）4- on seed surface is likely to break the equilibrium of ion pair formation and to decrease the difference in conductivity in preliminary seeded precipitation.

Precipitation behavior and properties of a new high strength Al-Zn-Mg-Cu alloy

The microstructure and the associated hardness, strength and electrical conductivity of a new Al-Zn-Mg-Cu alloy during one-step ageing treatment were systematically studied. The results show that the electrical conductivity of the alloy increased continuously with increasing ageing temperature and ageing time. At the early stage of ageing, the hardness and strength of the alloy increased rapidly and then reached the peak value. When aged at 120 °C, the hardness and strength maintained at high level for a long time after the peak value. The main precipitations are GPI zones, GPII zones and metastable η′ phase. GPI and GPII zones are found in the alloy after ageing for 24 h at 120 °C, which indicates that some stable GP zones can exist through the ageing process. When aged at 160 °C, the hardness and strength decreased rapidly after the peak value. The precipitation process is significantly promoted compared with that aged at 120 °C. Both GPI zones and GPII zones disappeared after ageing for 1 h at 160 °C. The main precipitates are η′ phase when aged at 160 °C for 1 h. The main precipitates are η phase when the ageing time prolongs to 24 h.

SIMULATION OF TV SELF-GUIDED WEAPON

A comprehensive model of the air-to-ground TV self-guided missile is built, including a sensor model, an overload control model, and an auto-pilot and guidance model, etc. By the 3D simulation of the missile trajectory, the evaluation index, such as the kill probability, the hit precision can be obtained. The effects of various jamming factors on the hit accuracy are analyzed. Simulation results prove that the validity of the model and also effectively support the decision making for a practical attack.

Mechanical properties,electrical conductivity and microstructure of CuCrZr alloys treated with thermal stretch process

CuCrZr alloys were treated with the thermal stretch process at various temperatures from 100 to 300℃.The results reveal that the thermal stretch process is successfully developed to manufacture the precipitation hardening CuCrZr alloys with a good combination of microhardness and electrical conductivity.By increasing the tensile elongations at each temperature from 100 to 300℃,the microhardness increases whereas the electrical conductivity decreases slightly.Cr-containing precipitate phases with a Nishiyama-Wasserman orientation relationship to the copper matrix were observed by TEM.The achievement of high micro-hardness and acceptable electrical conductivity in the thermal stretch treated alloys is ascribed to the interactions of the heteroatom solution,dislocation increment,grain refinement and dispersive precipitation effect.