NH3-H2O-LiBr三元混合溶液性能的实验研究

对NH3-H2O-LiBr三元工质进行了压力-温度热力平衡特性的试验测量研究,给出了温度在20℃-80℃之间,压力达到3MPa的压力-温度特性曲线.并对NH3-H2O-LiBr三元混合工质的循环特性做了初步研究.实验中,参数的测量采用静态法.氨、水、溴化锂的质量配比为1:1:1.     

浸渍冷冻用多元载冷剂的凝固点实验研究

通过实验手段测试了乙醇、氯化钠、水构成的多元载冷剂的凝固点温度,分析了各组分彼此间的影响以及葡萄糖、蛋白质作为添加剂对混合溶液凝固点的影响。通过实验得到了适合不同温度区间使用的载冷剂质量浓度组成:-20℃以上区域:乙醇5%~15%,氯化钠5%~20%;-20℃~-30℃区域:乙醇23%~25%,氯化钠14%~18%;-30℃~-40℃区域:乙醇37%~40%,氯化钠12%~14%;-40℃~-46℃区域:乙醇40%~55%,氯化钠9%~12%。实验结果表明:乙醇溶液加入氯化钠后,溶液的凝固点都有大幅下降;同等浓度的氯化钠溶液,随着乙醇加入的浓度增大,凝固点降低;氯化钠在乙醇水溶液中的溶解的饱和度随着乙醇水溶液质量浓度增加而减小;加入蛋白质可以使溶液凝固点降低1~2℃,葡萄糖对溶液凝固点的影响不明显。     

四丁基溴化铵相变蓄冷材料热物性实验研究

通过实验对四丁基溴化铵(TBAB)溶液的蓄冷结晶过程进行了测试,结果表明TBAB溶液的凝固温度随其浓度的改变而改变,在25%~45%的浓度范围内,其凝固温度位于5.8~9.3℃范围内.选取相变温度适宜、相变过程稳定、浓度为40%的TBAB溶液,向其添加硼砂成核剂,测试其相变温度和相变潜热,测试结果表明质量浓度为2%的硼砂在不影响TBAB溶液凝固温度的情况下可以降低其结晶过冷度2.4℃.采用示差扫描量热仪(DSC)测试TBAB溶液的熔解潜热为187.030kJ/kg.因此TBAB溶液是一种高效的空调蓄冷材料.     

CO_2/R290应用于复叠制冷低温环路浓度配比实验研究

在复叠制冷实验台上对由CO_2/R290组成的不同配比的二元混合制冷剂进行了低温循环性能实验.实验结果表明,随着CO_2含量增大,二元混合物的压比减小,制冷量增大,耗功减少,COP增加,制冷速率增大.但随着CO_2含量增大,二元混合物的排气温度也升高,当CO_2在混合物中的组分达到71%时,蒸发温度为-61℃时,压缩机的排气温度接近115℃.因此,混合物中CO_2含量不宜超过71%.混合物中R290降低了CO_2凝固点温度,同时也降低了CO_2较高的冷凝压力,对扩展CO_2在低温区域的应用很有益处.     

温敏凝胶流变性能动力学研究

应用动态流变实验测定了温敏共聚物的流体特性,分析其在溶胶-凝胶转变过程共聚物溶液随温度变化形成凝胶机理。以室内合成的四元共聚物溶液为基础,采用动态流变实验测定了该共聚物溶液在不同温度、浓度下的剪切模量和损耗模量的变化,确定了凝胶特性,并与试管倒置法比较了凝胶温度。实验结果表明,临界温度为143℃,在一定浓度下(高于接触浓度C*),低于此温度共聚物溶液具有一般粘性流体特性;高于此温度可形成凝胶网络结构;溶液在测试温度(65～240℃)内,其损耗角从56.27°逐渐变为31.04°,溶液体系从粘性流体逐渐到粘弹性流体过渡;说明该溶液在一定浓度下具有温敏特性。     

Ti-Si-C三元系组元化学位稳定性相图

收集并计算了Ti-SI-C三元系在1200度温度下各组元化合物的热力学数据,利用Ti-SI-C三元系在该温度下的平衡相图以及对碳化物未知热力学数据所做的估算,计算该三元系中各组元化学位并作出的相应的化学位稳定性相图。     

基于3D打印技术的锂离子电池正极墨水的制备与性能研究

三元镍钴锰酸锂材料(LiNi_0.5Co_0.2Mn_0.3O₂)因其优异的能量密度,较大的理论容量,被视为最具潜力的锂离子电池正极材料,本文旨在制备出适用于3D打印技术的性能优良的锂离子正极墨水.利用扫描电子显微镜(SEM)、四探针测试仪、ANSYS R15.0软件模拟分析等,探究了石墨混合、增稠剂含量、三元材料固含量、烧结温度、挤压压力等因素对3D打印锂离子正极电极性能及电极墨水流动特性的影响.结果表明：当添加质量分数为15%的石墨后,三元材料电极的电阻率为18.33 kΩ·cm,比未添加时降低65%,电极导电性能提升;当烧结温度为400 ℃时,三元材料平整致密,电极导电性能优良;三元镍钴锰酸锂材料固含量为52%、增稠剂含量为4%时,正极墨水粘度适中,挤压压力为0.5 MPa时打印出的细棒状电极表面光滑平整,成形性优良.     

高浓度CO2在MEA溶液中平衡溶解度的实验研究

采用气液搅拌平衡装置,通过酸碱滴定和皂泡流量计测定了高浓度CO2在不同MEA溶液中的平衡溶解度。利用正交实验设计方法,考察了温度、CO2分压力、MEA质量浓度等因素对CO2平衡溶解度的影响。结果表明,在实验参数选定范围内,影响MEA中CO2平衡溶解度的因素主次顺序为：CO2分压力〉MEA质量浓度〉温度;MEA溶液中CO2的平衡溶解度随压力的增大而增大,随MEA质量浓度的增大而减小,随温度的增大而减小。     

气相分压对Co-Ni-Sb三元热电材料体系相平衡和相稳定性的影响

依据Co-Ni-Sb三元系凝聚态的热力学优化评估和气相组分的热力学数据,利用Thermo-calc软件从热力学角度分析了气相压力对该体系中二元和三元体系的相平衡和相稳定性的影响。结果表明,气相压力减小到一定程度,Co-Ni、Co-Sb、Ni-Sb和Co-Ni-Sb体系中的化合物发生分解,出现气-液-固三相平衡区;计算的三相平衡温度-压力图(T-P图)表明各化合物都存在发生分解的临界压力和临界温度,在临界压力之上或临界温度以下,凝聚相间保持与常压下基本相同的相平衡关系。通过真空条件下Ni/ηCoSb3三元扩散偶测定的Co-Ni-Sb三元系1 073K等温截面,验证了计算的相平衡关系。研究结果为制备含Ni方钴矿热电材料ηCoSb3的工艺设计提供了热力学参考。     

R32/R134a和R407C用于变浓度热泵系统的实验

为了解决R32/R134a应用于变浓度热泵系统存在的排气温度过高问题,提出使用三元混合工质R407C用于该系统中.以R32/R134a和R407C作为工质在变浓度容量调节热泵系统中进行了吸气压力不变时的变浓度实验.实验结果表明,R407C在本系统中变浓度范围低于R32/R134a,但R407C的排气温度和耗功均低于R32/R134a,具有良好的变浓度调节潜力.     

Weakly strict equilibria in finite normal form games

In this paper we introduce the weakly strict equilibrium for (mixed extensions of) finiten-person games. For those games we prove that our new concept is a strict refinement of the undominated Nash equilibrium concept. We show that their set of weakly strict equilibria is nonempty and coincides with their set of strict equilibria (when the latter is also non-empty) and we study the relation between our refinement and other noncooperative concepts.We thank Xunta de Galicia for financial support through project XUGA20702B93     

产业技术溢出水平与集群结构的关联分析

依据设计的产业技术溢出系数模型,明确了影响产业技术溢出水平的各因素之间的相互关系,分析了不同结构的产业集群中由于技术溢出所导致的收益分配状况,得出了高技术溢出水平适合于无领导企业的产业集群,低技术溢出水平适合于存在领导企业的产业集群的结论;给出了具体的技术溢出水平取值范围;同时,也为构建产业集群技术创新机制提供了实用性对策思路.     

The currently predominant Taylor principles should be disregarded in the study of plastic deformation of metals

The original Taylor principles offer identical intergranular strain equilibrium without stress equilibrium in metals during deformation. In reality, however, the stress and strain equilibria are maintained individually for different grains. As key points, the principles have become a prerequisite predominantly in the current theories, which unreasonably indicate that strains instead of stresses induce grain deformation despite reaching the stress equilibrium by complicated combinations of the activation of slip systems or other crystallographic mechanism via different approaches. Real intergranular equilibria can be traced if mechanical interactions together with the external loading are considered step by step. In this work, several penetrating and non-penetrating slips were used to obtain the necessary elastic and plastic strain tensors of different grains in a natural manner. Without the Taylor principles, the stress and strain equilibria can be reached naturally, simply, easily, reasonably, and individually without complicated calculations. Results of the experimental observation conformed with the predicted deformation texture when certain important engineering stress conditions are included in the simulation. Therefore, the Taylor principles for plastic deformation of polycrystalline metals should now be disregarded.     

On the structure of the set of perfect equilibria in bimatrix games

Summary In this paper attention is focussed on the structure of the set of perfect equilibria. It turns out that the structure of this set resembles the structure of the Nash equilibrium set. Maximal Selten subsets are introduced to take the role of maximal Nash subsets. It is found that the set of perfect equilibria is the finite union of maximal Selten subsets. Furthermore it is shown that the dimension relation for maximal Nash subsets can be extended to faces of such sets. As a result a dimension relation for maximal Selten subsets is derived.     

高耸烟囱定向爆破动态平衡的原理与应用

为了控制复杂环境下,受风及外壁钢结构爬梯载荷影响的高耸烟囱定向爆破方向,基于动态平衡设计原理,采取了偏口补偿平衡纠偏方法和合理的切口参数设计来调整烟囱倾倒瞬间的倾覆力矩方向,使不对称载荷的烟囱在倾倒过程中处于相对的动态平衡状态,确保了不对称载荷下的高耸烟囱定向倾倒的准确性,其设计方法和参数可供同类工程参考。     

高耸烟囱定向爆破动态平衡的原理与应用

为了控制复杂环境下,受风及外壁钢结构爬梯载荷影响的高耸烟囱定向爆破方向,基于动态平衡设计原理,采取了偏口补偿平衡纠偏方法和合理的切口参数设计来调整烟囱倾倒瞬间的倾覆力矩方向,使不对称载荷的烟囱在倾倒过程中处于相对的动态平衡状态,确保了不对称载荷下的高耸烟囱定向倾倒的准确性,其设计方法和参数可供同类工程参考。     

Phase diagram of the Mg-O system at a pressure of 2 GPa

Thermodynamic calculation and experimental studies of the phase quilibria in the Mg-O system have been performed and the system phase diagram at a pressure of 2 GPa has been constructed. The system is characterized by the existence of just one eutectic equilibrium at 1100 K, in which magnesium, MgO magnesium oxide, and a liquid phase take part.     

有流量附加约束的动态交通网络平衡问题

在抽象空间上研究了有流量附加约束的动态交通网络的平衡问题,将这种附加约束等价的当作路径的新增阻抗,并给出了基于这个条件下的Wardrop用户平衡的变分不等式表达。这事实上是提供了计算这种平衡配流的另一种方法。此外,所研究的问题更接近现实的有路径流量限制的情形,还得出了相应的动态平衡性质。     

Internal oxidation and local equilibrium

Abstract

Local equilibrium principles can provide boundary conditions for modeling internal oxidation. For example at the moving boundary between the oxidized and oxide free regions, the principles require that average concentrations and matrix concentrations are equal and strongly suggest that “enrichment” of the oxidized region with solute will not occur. Instead, depletion of solute is always predicted for dilute alloys. Also, a flux of solute from the internally oxidized region toward the free surface is always predicted except in the limiting case of a zero solubility limit.     

Adsorption of copper from the sulphate solution of low copper contents using the cationic resin Amberlite IR 120

The possibilities for ammonium ions removal from aqueous solutions by natural and NaCl pretreated Bulgarian clinoptilolite from Beli plast deposit were studied. Experiments were carried out using batch method. The adsorption of NH₄⁺ was investigated as a function of the solution pH, dosage of adsorbent, initial ammonium concentration and temperature. The results clearly showed that the treatment with NaCl improved both the adsorption capacity and the removal efficiency of natural clinoptilolite. The equilibrium experimental data for adsorbed NH₄⁺ ions on clinoptilolite samples were correlated better by the Langmuir isotherm model. The maximum adsorption capacities for ammonium ions shown by natural and pretreated clinoptilolites (CL_Na and CL_Na(t)) were 7.85, 12.29 and 18.40 mg/g, respectively. The results indicated a significant potential of the natural and conditioned clinoptilolites as adsorbents for ammonium removal.