向东南的

Therefore, the moist potential vorticity analysis associated with the mesoscale convective system was researched in the paper, so as to reveal the moist potential characteristics of mesoscale convective system in typhoon circulation. The results showed that, during the generation stage, convective instability characterized by MPV1 was a favorable condition for forming MCS, while the vorticity which was caused by the slantwise isentropic surface and the vertical shear of the horizontal wind characterized by MPV2 was an inspiring mechanism. The specific process was that, the atmosphere exhibited the feature of strong convective instability at the low level of convection areas and the southeast areas, which included plenty of erratic energy. The slantwise ascended the stream transfer the erratic energy to northwest, where the stratification stability was small. As decreased, the cyclonic vorticity increased. On the other hand, the vorticity caused by the slantwise isentropic surface and the vertical shear of the horizontal wind inspired the release of convective instability and as a result that the MCS formed. During the development stage, the cyclonic vorticity increased quickly with the persistent decreasing of . Meanwhile, the inclination of isentropic linewas bigger than the absolute momentum line at middle level, which exhibited the feature of conditional symmetric instability , then the conditional symmetric instability was forced to release by the vorticity resulted from the slantwise isentropic surface and the vertical shear of horizontal wind, and the MCS developed.

结果表明，在对流形成阶段，MPV1即对流不稳定为MCS的形成提供背景不稳定条件，由MPV2即湿等熵面的倾斜和水平风的垂直切变而引起的涡旋发展作为强迫机制：MCS形成的区域及东南区域中低层是强对流不稳定层，蕴含丰富的不稳定能量，倾斜上升运动把对流不稳定区具有强不稳定能量的暖湿空气向西北中层的中性层结区输送，由于的减小，气旋性涡度增强，有利于形成对流，另一方面，由于湿等熵面倾斜和低空急流加强而引起的涡旋发展作为一种强迫机制激发对流不稳定能量得到释放，从而形成对流；在对流系统地发展阶段，由于低层的对流不稳定性进一步减弱，进一步减小，气旋性涡度进一步增强，有利于MCS的增强，中层等θe 线的倾斜度比绝对动量M 等值线的倾斜度大，对应有条件对称不稳定区域，满足条件对称不稳定条件，在湿等熵面倾斜和台风低空急流作用下引起的涡旋发展强迫对称不稳定能量释放，从而使得对流得以维持和加强。

The established models in which annual precipitation was incorporated as the principal variable indicate a very closely correlation between forest productivity and its corresponding climatic factors,allowing to simulate distribution pattern of actual forest productivity effectiv...

结果表明：在所构建的模型中，除海拔高度与净生产力的相关模型外，其它模型均有较高的实用价值，模型的拟合曲线变化，基本反映了中国森林现实生产力的地理分布格局；中国森林生产力的分布格局主要取决于气候环境中的水热条件，水分条件是决定中国大部分地区森林生产力水平和地理分布格局的主导因素；根据7个GCMs大气环流模型预测合成的2030年的气候情景，研究气候变化对中国森林生产力影响的结果是：气候变化并没有改变中国森林第一性生产力的地理分布格局，即从东南向西北森林生产力递减趋势不变，但不同地域的森林生产力有不同程度的增加。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。