主要动力

The understanding of the asymptotic behavior of dynamical systems is one of the most important problems of modern mathematical physics.

理解动力系统的渐近行为是研究无穷维动力系统的主要内容，也是当代数学物理的重要问题之一。

As magin use is to arrange the position of all the mational axle box and transrnit the power and the motion to all the main axle by the electrical machinery or the power pants .

三组合机床主轴箱设计，按专用要求进行设计，由通用零件组成，其主要作用是根据被加工零件的要求，安排各主轴位置并将动力和运动由电机或动力部件传给各主轴，使之得到要求的转速，机床主轴箱选用400*400，用中间传动轴带动主轴传动。

The utility model is characterized in that a commonly used escalator which is formed by a plurality of active rundles and handrails is assembled on a vehicle, and the drive force of the escalator is suppplied by the vehicle through the mechanical transmission system; a mechanical transmission system is added in the vehicle and the mechanical transmission system mainly transmit the dynamic energy to the escalator carried on the vehicle, the rundles and the handrails can move in positive or opposite direction synchronously; a hydraulic power transmission system is added in the vehicle, and then the hydraulic power transmission system mainly transmit the dynamic energy to the escalator carried on the vehicle as well as related hydraulic power transmission devices or facilities; the whole vehicle-carrying escalator is supported by the supporting facilities, or the whole vehicle-carrying escalator moves upwards and downwards taking the axle direction which movably connects the lower end and the tail end of the vehicle as center.

其主要技术特征是：将主要由若干节活动梯级、扶手带等组成的现代所通常使用的自动扶梯安装在机动车上，并使自动扶梯的主动力部分由机动车通过机械传动系统供给；在机动车上增加机械传动系统，该机械传动系统主要向所载的自动扶梯传递动能，并使自动扶梯的梯级和扶手带能够同步正向或反向运动；在机动车上增加液压传动系统，该液压传动系统主要向车载自动扶梯的相关液压传动装置或设施传递动能，并在机动车的液压传动作用下，使支撑设施支撑整体车载自动扶梯，或使车载的自动扶梯以下端与机动车末端活动连接的轴向为中心整体升、降运动。

In recent years, the researches in mathematical biology which modeled by normal differential equations are mainly concentrated on two branches: 1 continuous biological dynamical systems; 2 impulsive semi-dynamical systems.

生物数学中以生物动力系统为基础的研究近年来得到了长足的发展，其中以微分方程为模型的研究工作主要集中在连续动力系统和脉冲动力系统上。

The gas is fed to at least one gas consuming prime mover of the LNG carrier.

这些气体被用与LNG运输船的至少一个主要的动力设备，LNG运输船的的动力就由这些动力设备提供。

Established in the PSAT in the various subsystems model, the final connection, operation, and that concrete results of its analysis of text using different conditions in the simulation study, a major analysis of the dynamic performance of electric vehicles, to verify matching power systems meet the requirements of dynamic performance indicators.

在PSAT中建立起各个子系统的模型，最后连接、运行，得出具体的结果并对其进行分析，文中在采用不同工况下进行了仿真研究，主要分析了电动汽车的动力性能，以验证匹配的动力系统符合所要求的动力性能指标。

In order to understand the dynamic property of extradosed cable-stayed, built up its plane continous rigid-frame model and compared with each other, concluded that the former is more complex due to the remarkable coupling effect of cable, pylons and box-girder. The dynamic property of box-girder decide the dynamic property of the bridge, whose whole structure is comparative rigid. This paper indicated that the bridge is not attribute to flexible structure, because its basic free vibration cycle is more shorter than the cable-stayed bridge.

为了更好的理解矮塔斜拉桥的动力特性，还建立了平面梁单元的连续刚构模型，并与平面梁单元的矮塔斜拉模型进行了对比分析，结果表明，矮塔斜拉模型由于索、塔、梁的高阶振型耦合显著，其振型较连续刚构复杂，灵江大桥的动力特性主要由主梁的动力特性决定，其结构整体刚度较大，基本自振周期较斜拉桥短，不属于柔性结构。

According to calculation of obstacle degree, the obstacle factor of sustainable land use was analyzed in detail. The factors such as per capita agricultural gross output value, per unit area yield of grain, reed land rate, agricultural land rate and degree of townish are the main obstacle factor ofKey words: land use; sustainability; obstacle degree; The Yellow River Delta

研究结果表明：在34个因子中人均农业总产值、粮食单产、芦苇地占地率、农业用地率、城镇化水平是黄河三角洲可持续土地利用的主要障碍因素，其中芦苇地占地率在1996年以后始终是第一障碍因素，而人均农业总产值的限制主要出现在1998年之前，之后对可持续土地利用未构成障碍；粮食单产和农业用地率的影响主要出现在1996年以后；林草覆盖率、公顷耕地农机总动力和农村电气化水平在一半以上的年份对可持续土地利用构成障碍；在1994年之前，农民人均收入障碍度较大，是主要的障碍因素。

Researches on fluid dynamic performance of aquatic sports equipment in China were started early, mainly involving with the aerodynamic characteristics of sailboats, sailboards and wind sails, the propulsive char-acteristics of the propeller of racing boats and leather rowboats, the propulsive characteristics of swimming flaps, etc.

我国的水上运动器材的流体动力性能研究起步较早，主要涉及到帆船、帆板、风帆的空气动力特性和船体水动力性能，赛艇、皮划艇桨叶推进特性，蹼泳板的推进性能等等。

The main products has: ZQ drill pipe power tongs series, QT Series Casing power tongs, FYZ series air-cooled hydraulic, pneumatic winch series, XYQ tubing power tongs series, ZQ-100 suspended or devices.

主要产品有：ZQ钻杆动力钳系列，QT套管动力钳系列，FYZ风冷液压系列，气动绞车系列，XYQ油管动力钳系列，ZQ-100吊升装置等。

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。