动力减振实验装置的结构设计与研制

介绍动力减振实验装置的结构、实验的方法、步验与数据处理。实验结果表明所采用的设计方法是合理的、可行的。     

Mechanical behavior of a near α titanium alloy under dynamic compression: Characterization and modeling

Dynamic compression tests under strain rates from 870 s^?1 to 2100 s^?1 were conducted for a near α Ti–8Al–1Mo–1V titanium alloy with equiaxed microstructure. Compression behavior, adiabatic shearing and band microstructure were investigated via characterization and calculation. The results demonstrate that all dynamic constitutive curves exhibited obvious stress fluctuation phenomenon with double increase-decrease changing stages at the primary stage of compression. The dislocation multiplication theory can be used to explain this phenomenon. After the stress fluctuation period, work hardening coexisted with the thermal softening, resulting in the slow hardening tendency in constitutive curves. J-C model was utilized to quantify the dynamic constitutive curves. The deviations between the predicted and experimental curves under high strain rates may be attributed to the over-consideration of thermal softening effect in J-C model. Adiabatic shearing band (ASB) began to form under the strain rate of 2100 s^?1. A total shearing strain of 8.1 within ASB achieved in 8.9 μs, corresponding to a local strain rate of about 9.1 × 10⁵ s^?1 and is over 430 times of the macro strain rate. Post annealing was conducted on ASB before EBSD characterization. Due to the static recrystallization during annealing, the α phase within ASB generally presented as ultra-fine grains less than 1 μm in diameter.     

Berry相因子与主纤维丛的关系及其拓扑性质

用纤维丛理论描述Ｂｅｒｒｙ相因子。将Ｂｅｒｒｙ相位作为联络１－形式及相应参数空间的曲率２－形式。利用Ａｔｉｙａｈ－Ｓｉｎｇｅｒ指数定理。讨论了Ｂｅｒｒｙ相因子的拓扑性质及其与反常之间的关系。     

绝热过程不宜看作多方过程的特例

证明绝热过程不是多方过程,并消除因用PV~r=C分析绝热过程问题而引起的困惑。     

Stern-Gerlach实验的绝热演化与Berry相因子

给出了Ｓｔｅｒｎ－Ｇｅｒｌａｃｈ实验在绝热演化过程中的Ｂｅｒｒｙ相因子．     

量子微腔中暗态原子粒子数转移的绝热条件

为了明确量子微腔中粒子数转移的绝热条件，本文利用准绝热近似方法详细地讨论了量子微腔中单模驻波场与简并三能级原子相互作用的动力学演化，定量地研究了实现粒子数经由暗态在两激发态间绝热转化的条件     

Dynamic response characteristic of 7N01/7A01/7050 aluminium multilayer plate at high strain rate

The correlations between the structures, fracture behavior and dynamic shear property were investigated for 7050 to 7N01 layer of 7N01/7A01/7050 multilayer plate with different thickness ratio fabricated by hot rolling bonding. is The results showed that when thickness ratio of 7050 to 7N01 layer was 1 and 7050 layer was backplane, the absorbed energy of the multilayer plate was 39% higher than that of 7050 alloy. The excellent energy absorbing ability of 7N01/7A01/7050 multilayer plate is attributed to the blunted cracks in 7A01 interlayer, the enhanced 7050 layer by decreasing of secondary cracks and the delaying dynamic failure of 7050 layer.     

关于压强对N_2O_42NO_2反应体系影响的再讨论

在利用反应体系说明压强对化学平衡影响的实验中，当推压活塞时，体系将出现由浅→深→浅的颜色变化．就这种色变产生的原因，本文提出了新的解释，即主要是由于体系的温度变化所致．并由此阐明该实验不适宜说明压强化学平衡的影响．     

微波吸收材料测量的Rv方法的一点注释

本文对微波暗室中吸收材料的测量方法——RV 方法的应用条件作了细致的讨论,证明了这种方法只有在满足的条件下才可应用。并提出了新的计算法——R_E 方法,实验结果证明该方法是可行的和有效的。     

大体积混凝土绝热温升表达式的推导与试验分析

由固体热传导理论可知,大体积混凝土绝热温升仅与其中的水泥水化放热规律有关。在化学反应过程中,温度对化学反应速率的影响服从Arrhenius方程。因此,根据水泥恒温水化放热规律和水泥水化放热行为的温度效应,可以预测任意温度条件下任一时刻水化放热总量,进而推导出大体积混凝土绝热温升表达式。试验验证采用10 mm木胶板内衬100 mm聚苯乙烯泡沫板和3 mm胶合板模拟绝热状态。最后得出大体积混凝土绝热温升表达式可以用双曲函数或复合指数函数表达,而因双曲函数形式上要比复合指数函数简单,建议使用双曲函数表达式。