燃料电池交流阻抗是燃料电池发电性能的关键数据,进行燃料电池的交流阻抗测试可以识别有问题的燃料电池组件和其在组装过程中产生的偏差。完成不同频率下的交流阻抗测试后,即可得到燃料电池的电化学阻抗谱。I TECH I T8900A电子负载可...燃料电池交流阻抗是燃料电池发电性能的关键数据,进行燃料电池的交流阻抗测试可以识别有问题的燃料电池组件和其在组装过程中产生的偏差。完成不同频率下的交流阻抗测试后,即可得到燃料电池的电化学阻抗谱。I TECH I T8900A电子负载可以简化测量过程,本文将介绍使用I TECH电子负载和其他通用设备实现交流阻抗测试的方法。展开更多
In-bore yaw of a projectile in a gun tube has been shown to result in range loss if the yaw is significant. An attempt was made to determine if relationships between in-bore yaw and projectile First Maximum Yaw(FMY) w...In-bore yaw of a projectile in a gun tube has been shown to result in range loss if the yaw is significant. An attempt was made to determine if relationships between in-bore yaw and projectile First Maximum Yaw(FMY) were observable. Experiments were conducted in which pressure transducers were mounted near the muzzle of a 155 mm cannon in three sets of four. Each set formed a cruciform pattern to obtain a differential pressure across the projectile. These data were then integrated to form a picture of what the overall pressure distribution was along the side of the projectile. The pressure distribution was used to determine a magnitude and direction of the overturning moment acting on the projectile. This moment and its resulting angular acceleration were then compared to the actual first maximum yaw observed in the test. The degree of correlation was examined using various statistical techniques. Overall uncertainty in the projectile dynamics was between 20% and 40% of the mean values of FMY.展开更多
文摘燃料电池交流阻抗是燃料电池发电性能的关键数据,进行燃料电池的交流阻抗测试可以识别有问题的燃料电池组件和其在组装过程中产生的偏差。完成不同频率下的交流阻抗测试后,即可得到燃料电池的电化学阻抗谱。I TECH I T8900A电子负载可以简化测量过程,本文将介绍使用I TECH电子负载和其他通用设备实现交流阻抗测试的方法。
文摘In-bore yaw of a projectile in a gun tube has been shown to result in range loss if the yaw is significant. An attempt was made to determine if relationships between in-bore yaw and projectile First Maximum Yaw(FMY) were observable. Experiments were conducted in which pressure transducers were mounted near the muzzle of a 155 mm cannon in three sets of four. Each set formed a cruciform pattern to obtain a differential pressure across the projectile. These data were then integrated to form a picture of what the overall pressure distribution was along the side of the projectile. The pressure distribution was used to determine a magnitude and direction of the overturning moment acting on the projectile. This moment and its resulting angular acceleration were then compared to the actual first maximum yaw observed in the test. The degree of correlation was examined using various statistical techniques. Overall uncertainty in the projectile dynamics was between 20% and 40% of the mean values of FMY.
