浅谈“水源空调“在丹东市的推广使用

本文通过对“水源空调”的介绍,结合丹东市的地质情况,分析论证其在我市推广使用的可行性。     

助催化剂对TiCl_4/MgCl_2催化丙烯高温聚合的影响

研究了助催化剂种类(三甲基铝、三异丁基铝、三正己基铝、三乙基铝和甲基铝氧烷)及其含量对无内、外给电子体的TiCl4/MgCl2催化剂催化丙烯高温(100℃)聚合性能的影响,并用结晶分级分析、示差扫描量热和凝胶渗透色谱等方法分析了所得聚丙烯的结晶熔融行为和微观结构。实验结果表明,聚合温度从70℃升至100℃时,TiCl4/MgCl2催化剂的定向能力基本不变;100℃聚合时,以烷基化能力较弱的三异丁基铝为助催化剂时TiCl4/MgCl2催化剂的活性最高,而采用烷基化能力最强的三甲基铝为助催化剂时TiCl4/MgCl2催化剂的活性最低;100℃聚合时,助催化剂的种类对TiCl4/MgCl2催化剂的定向能力影响很小。     

Effect of specimen size and loading conditions on spalling of concrete

Different qualities of concrete have been fire tested using different geometries of the specimens as well as different load levels and load configurations. The main objective with the study was to examine a test methodology consisting of a full‐scale test and different small scale‐tests for determining the probability of spalling and the amount of spalling of fire exposed concrete structures. A reference specimen was defined as a one‐sided fire exposed slab with the dimensions 1800 × 1200 mm² giving an exposed area of 1500 × 1200 mm². A number of concrete qualities with different probabilities for spalling, were tested using the reference specimen. These tests showed that the reference specimens worked well giving the expected test results. Small specimens were manufactured in different shapes with the same concrete as the one used in the reference tests. These small specimens were tested either at the same time as the reference specimens in the large furnace or afterwards on a small‐scale furnace where the fire exposed surface was 450 × 360 mm². The test results clearly show the increased probability and the increased amount of spalling by using external compressive loading. The results also show that by using pre‐stress through bars or wires the load can be lost due to heating of the bars/wires which results in a decreased amount of spalling. The boundary of the specimen also affects the amount of spalling. The spalling around the edges was in all tests less than the spalling on the central parts of the exposed area. It could also be noted that the spalling did not pass completely through any of the specimens. The reason for this is probably that the water/vapour could migrate out from the unexposed surface of the specimen. Copyright © 2006 John Wiley & Sons, Ltd.     

超稠油生产重交通道路石油沥青工艺探讨

超稠油的密度大、粘度高、轻油收率低、酸值高，沥青组成分布不合理，生产沥青困难。探索合适的超稠油生产沥青的加工工艺，不但可以解决超稠油加工困难问题，而且增加了生产道路沥青产品的原料资源。试验及生产证明，采用调和、预处理-蒸馏等工艺加工超稠油能够生产出合格的重交通道路石油沥青产品。     

Biaxiale Ermüdung reibrührgeschweißter Strukturelemente

Biaxial fatigue of friction stir welded stiffened panels Within the framework of the European WelAir project, cruciform specimens made from stiffening FSW overlap joints were fatigued in the DLR biaxial test rig. To resemble the loading situation of pressurized fuselage structures, proportional loading without any phase shift, but with different load ratios λ between the loading components in both directions was applied.Natural crack initiation and subsequent crack growth were governed by the stiffness gradient caused by introducing the stringer. Cracks initiated and propagated at run‐in and run‐out locations in a direction perpendicular to the weld seam. The shortest fatigue life was observed for uniaxial loading in welding direction (λ = 0). An additional stress component perpendicular to the joint line (λ > 0) resulted in a higher number of cycles to failure. Similar to single stringer panels, increasing the load ratio also increased the number of cycles to failure for FSW clip‐stringer structural members, but additionally gives a different location of the fatal crack.     

ESR Refining Potential for Titanium Alloys using a CaF2‐based Active Slag

Since the end of the Cold War and due to the needs to produce titanium more cost‐efficient and thus more attractive for its civilian use, the electroslag remelting (ESR) process has become an increasingly important topic of international research programmes, because titanium and titanium aluminides can be chemically refined by ESR in some degree. Using ESR, titanium turnings from machining steps and scrap from foundries can be remelted, refined and provided as secondary titanium for the market at relatively favourable prices. This article investigates the removability of the main impurities out of titanium and titanium‐aluminium alloys by electroslag remelting using the active slag system CaF₂‐Ca‐(CaO). Thermochemical and kinetic aspects of the ESR process are considered.