引起因素

It has been frequently assumed, but not proved, that the majority of the migrants in what has come to be called the Great Migration came from rural areas and were motivated by two concurrent factors: the collapse of the cotton industry following the boll weevil boll weevil: n.

通常认为，但没有证实，这一被称作大迁徙运动中的多数的移民者来自农村，并且他们被两种共同存在的因素所驱动－开始于1898年的由棉铃虫害导致的棉花工业的垮掉和1914年一战爆发引起的欧洲移民的终止导致的北方对劳力的需求增多。

But if investors do not demand for cash bonus, you can choose dividend re-investment way to avoid being idle cash dividend, to avoid inflation and other factors arising from the devaluation of the currency.

但是，如果投资者不要求现金红利，您可以选择红利再投资方式，以避免被闲置现金股利，以避免通货膨胀和货币贬值引起的其他因素。

But ought to see, build the bitter fleabane break out of the career to exhibit as bourg, a lot of adverse elements subsequently and grow, its influence rate is older and older, manacling the hands or feet that bourg builds badly, the abidance that restricting bourg construction develops, ought to cause each various height to take seriously.

但是应当看到，随着村镇建设事业的蓬勃发展，许多不利因素随之而增长，其影响程度愈来愈大，严重束缚着村镇建设的手脚，制约着村镇建设的持续发展，应当引起各层各级的高度重视。

In this paper we combining connecting tunnel project of Subway Line 4 at Xidan-lingjing bystreet in Beijing. To aim at the difficulties of building large-span connecting tunnels in the fine sand layer, through roads and underground pipelines, construction nearby buildings and other project difficulties. Using theoretical analysis, numerical simulation, field tests and other research methods to comprehensive and systemic research the stratum deformation mechanism and process control techniques of shallow excavation method, and a series of results were obtained. Firstly, use the stochastic media theory to analyze the stratum deformation mechanism, concretely analyze the analytic equation of surface horizontal displacement and deformation which were caused by the excavation of single-hole and double-hole tunnel, and further discussion on ground settlement, vertical deformation, surface horizontal displacement and horizontal deformation. Analyzing the main influence factors of surface displacement, and combined with practical work to proof the theory which was applied to shallow buried single-hole tunnel in fine sand layer was scientific.

本文结合北京地铁四号线西单～灵境胡同渡线隧道工程，针对在粉细砂地层中修建大跨渡线隧道，下穿道路和地下管线，临近建筑物施工等工程难点，利用理论分析、数值模拟、和现场监测等多种研究手段，对浅埋暗挖隧道地层变位机理及控制技术，深入地进行全面和系统的研究，并取得以下成果：(1)引入随机介质理论，对地层变位机理进行了分析，具体分析了单、双孔隧道开挖引起的地表位移及变形的解析方程，并深入探讨了地表沉降、垂直变形、地表水平位移和水平变形的特点，同时分析了影响地表位移的主要因素，并结合工程实例，佐证该理论应用于粉细砂地层浅埋暗挖单孔地铁隧道的科学性。

If the exclusion of genetic factors, this situation may be due to its cambium layer caused by the uneven pigment secretion.

若排除遗传因素，此情况可能是由于其生发层色素分泌不均引起的。

The characteristics of WSA detector are analyzed and tested.Three factors which can induce the image distortion,the charge cloud size which collected by WSA,the capacitive coupling between different electrodes and the performance of electronics,are discussed.

对研制出的楔条形阳极探测器进行了性能分析与实验测试，分析了引起成像畸变的三个重要因素：到达阳极的电子云半径大小、阳极的电容耦合效应和电子读出电路的性能。

The capillarity coefficient and sorptivity are two important parameters to characterize the water absorption of building materials.

非饱和建筑材料的毛细吸水过程既是造成材料性能劣化的重要因素，又是有害物质进入材料内部、引起钢筋锈蚀的主要载体。

Objective To analyze the risk factors of root caries.

目的 分析引起根面龋的危险因素。

Through the inversion based on finite element analysis, it is revealed that the transient temperature rise on the case body,as a result of firing heat impact,is a key factor dominating the residual deformation and extraction resistance of the cartridge case. The distribution of transient temperature increment on case body is also obtained.

通过有限元反演计算，揭示了筒体上热冲击引起的瞬态温升是决定药筒残余变形和抽壳阻力的一个关键因素，得到了筒体瞬态温度增量分布规律。

On this foundation, the factor that discussed shadow castanet form and control are politic, right the defect that causes by strip steel temperature, through laminar flow refrigeration is obtained good the discussion that the strategy of board form made a focal point.

在此基础上，讨论了影响板形的因素和控制策略，并对由带钢温度引起的缺陷，经过层流冷却获得良好板形的策略做了重点的讨论。

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。