不同介质中聚四氟乙烯复合材料的摩擦磨损性能

分别在碱液、水、油和干摩擦条件下考察了碳纤维和玻璃纤维填充聚四氟乙烯复合材料的摩擦磨损性能。利用SEM观察了不同介质中磨损面和对摩面的形貌,并探讨了其磨损机理。结果表明,不同介质中摩擦系数的大小关系是μ干>μ水或油>μ碱,磨损率是W水>W干>W碱或油。水、碱和油都不同程度地阻止了转移膜的形成。碱液和油具有很好的冷却与润滑作用,摩擦系数低,磨损小;然而水分子降低了填料和基体的界面粘接强度,造成犁削和磨粒磨损加重。     

芒硝法生产硫酸钾工艺的模拟与分析

硫酸钾生产工艺中,钾离子转化率和能耗是二个最重要的指标,过去由于缺少可靠的电耗计算模,对能耗只能停留在定性分析上,本文利用ＰＨＥＥＳ软件,对各种芒硝法工艺路线进行了稳态模拟,给出了理论转化率和理论能耗之间的定量指标。通过发现,随着转化率的提高,能耗随之大幅度增长,由此得出结论不要片面追求高转化率,应综合考虑转化订与能耗的关系,达到优选之目的,能过模拟分析,为新工艺的研究和开发提供理论指导。     

挥发性强电解质混合溶剂体系的汽液平衡研究

本文报导了101.3 kPa下HCL+H_2O+CH_3aOH体系汽液平衡的实测结果。在对H_2O+CH_3OH混合溶剂中HCI的电离情况进行研讨,并求得HCl在该混合溶剂中亨利常数的基础上,从二元体系的性质出发,用笔者扩展的Pitzer(1980年)模型预测了HCl+H_2O+CH_3OH体系的汽液平衡,得到与实测数据极为一致的结果。     

正丁醇—水—氯化钙体系液液平衡的测定和预测

测定了298．15K和323．15K下氯化钙在1％－2％（质量分数）范围内的正丁醇－水体液液平衡。应用作者提出的强电解质混合溶剂体系过量自由焓模型（1994年）,仅用二元信息回归出参数,对该体系的平衡双液相联结线和盐浓度分布进行预测,所得结果与实测相一致。     

Double pull specimen more suitable for measuring bond-slip relationship of FRP-to-concrete interface

A new "conceptual" design named "double pull" specimen was proposed in order to measure the bond-slip (δ-τ) relationship of fiber reinforced polymer (FRP)-to-concrete interface more accurately. A finite element analysis (FEA) was performed for preliminarily evaluating the suitability of the proposed conceptual double pull specimen. Through the FEA, it was indicated that the FRP-to-concrete interface of the proposed conceptual specimen might subject to a much higher load level than that of the most commonly used simple shear specimen, showing a great potential for measuring δ-τ relationship more accurately. In the light of the conceptual specimen, a kind of "practical" double pull specimen was developed and proved to be more suitable for measuring δ-τ relationship through an exploratory experimental study with 20 specimens. Consequently, an experimental program with 10 double pull specimens was performed for measuring the ultimate slip δ_u which was difficult to capture by using the existing specimens. It is shown that the range of δ_u is 0.31-0.52 mm based on the test results. The suggestion for improving the measure method is also put forward.     

粒径对K2Ti6O13大孔陶瓷的制备及性能影响

以K2Ti6O13晶须、K2CO3和TiO2为原料,通过调变K2Ti6O13晶须的粒径,采用不同尺寸晶须间的混合,制备了孔结构可调的K2Ti6O13大孔陶瓷,考察了陶瓷的纯水通量和机械强度与K2Ti6O13晶须粒径及不同尺寸晶须间的配比关系。研究结果表明,随着K2Ti6O13晶须粒径的减小,K2Ti6O13陶瓷体积密度增大,开孔率和纯水通量随之减小,机械强度逐渐升高。当采用中位粒径为7.50 μm 和1.60 μm的K2Ti6O13晶须以质量比为3:1的比例为原料时,陶瓷物料间形成了大晶须与中细颗粒的搭接,得到了最佳的综合性能,相应的机械强度为42.8±0.2 MPa,开孔率为36.4%,纯水通量为2366 L.m-2.h-1.MPa-1,在分子筛膜领域具有良好的应用前景。     

原位合成的介孔TiO2-B/锐钛微粒:改善的锂离子电池阳极材料（英文）

Mesoporous TiO2-B/anatase microparticles have been in-situ synthesized from K2Ti2O5 without template. The TiO2-B phase around the particle surface accelerates the diffusion of charges through the interface, while the anatase phase in the core maintains the capacity stability. The heterojunction interface between the main polymorph of anatase and the trace of TiO2-B exhibits promising lithium ion battery performance. This trace of 5%(by mass) TiO2-B determined by Raman spectra brings the first discharge capacity of this material to 247 mA·h·g?1, giving 20%improvement com-pared to the anatase counterpart. Stability testing at 1 C reveals that the capacity maintains at 171 mA·h·g?1, which is better than 162 mA·h·g?1 for single phase anatase or 159 mA·h·g?1 for TiO2-B. The mesoporous TiO2-B/anatase microparticles also show superior rate performance with 100 mA·h·g?1 at 40 C, increased by nearly 25%as compared to pure anatase. This opens a possibility of a general design route, which can be applied to other metal oxide electrode materials for rechargeable batteries and supercapacitors.     

利用外源氢气纯化升级沼气的研究进展

沼气发酵过程存在产气速率低和甲烷浓度低两个普遍问题。从甲烷生成的反应机理来看,如果提供充足的氢气,能够把沼气中的CO2成分转化为CH4,既提高了甲烷的产量,又提高了甲烷的浓度。介绍了最近国内外在这个方向上的探索性研究成果。实验表明,利用外源氢气确实可以纯化升级沼气,在一定条件下还可以达到生物甲烷的品质(即CH4浓度高于95%)。分析了这项技术实用化需要解决的两个关键问题:强化H2气液传质及获取廉价氢源。最后,对这个方向进行了展望,并提出了一个光电催化产氢与厌氧发酵产甲烷耦合的设想方案。     

以学生视角看化工热力学课程的教与学

化工热力学是公认难教和难学的一门课程。文章以独特的学生视角,从内部和外部因素对化工热力学课程难学的原因进行剖析,并针对课程内容抽象、公式繁杂等难题,从课程学习及知识应用方面阐述了化工热力学课程学习的心得体会,提出“追本溯源”“化繁为简”的学习方法,为化工热力学课程的教与学提供参考。     

乙醇-水-盐体系汽液平衡

用改进的Ｏｔｈｍｅｒ汽液平衡釜在０．１０１３ＭＰａ下测定了乙醇水氯化钙、醋酸钾体系在恒盐摩尔分率下的汽液平衡数据。用Ｆｕｒｔｅｒ方程、修正的Ｆｕｒｔｅｒ方程、拟二元模型及溶剂化模型对实验数据进行关联，取得良好结果，其中乙醇水氯化钙体系实验数据用修正的Ｆｕｒｔｅｒ方程关联，所得汽相平均偏差为０．０１２４。