外来杂草之所以能在传入地产生危害，与它们所具有的某些特性和当地缺乏环境阻力密切相关。
This is closely related to certain characteristics of the exotic weeds and to lack of environmental resistance.
结论当人体的环境压力增加时，经面罩提供大于咽鼓管通气阻力的正压呼吸可以预防耳气压伤的发生。
Conclusions When environmental pressure was added, positive pressure breathing higher than the ventilative resistance of the Eustachian tube could prevent ear barotraumas.
试验研究表明，该除尘器具有除尘效率高、阻力低的特点，在劳动保护及环境保护领域可以推广应用。
The results show that the collecting efficiency of this collector is high and the resistance is low, so it can be spreaded and applied in the field of Labour safety and environmental protection.
此换热器空气阻力大，空气预热温度不高，风机压头高，环境噪声大，风机振动大、易损坏。
The recuperators have high air resistance , low air preheating temperature and high fan pressure head , and fan has much noise to environment and are apt to break down with vibration .
低滚动阻力轮胎提供很少在潮湿环境中的抓地力。
Low-rolling resistance tires offer very little grip in wet conditions.
员工，尤其是中年员工承受着来自心理、生理与环境的多重压力，并转为资产重组的阻力。
The workers, especially the middle - aged workers, have to be under heavy pressure from psychology, physiology and environment, which may change into resistance.
方法：在不同负压条件下对空气过滤器的过滤效率和阻力、舱内环境指标和使用者生理参数进行测试。
Method the filter efficiency, pressure, capabilities of inner environment and physiological parameters of the user were tested in different negative pressure conditions.
结果表明，能使绿洲扩大的主要条件是低纬度、小尺度，并具有低水汽、较高温度的环境以及较小气孔阻力的植被。
The results indicate: lower latitude, smaller horizontal scale, lower humidity and some vegetation with small stoma resistance are good to develop oasis.
前瞻性人格是指个体不受情境阻力的制约，主动采取行动以改变其外部环境的倾向性。
Proactive personality is defined as a disposition of being relatively unconstrained by situational forces, and toward taking action to influence one's environment.
究其原因有内部的管理问题也有外部环境的阻力，但落后就要挨打是一个不争的现实。
There are internal management question and external environment element which leaded to this situation, but it is no doubt that the one who falling behind would be oppressed.
其缺点是沉管过程中大量挤土，沉管阻力较大，对周围环境造成不利影响。
Its disadvantage is that it presses a large range of soil while sinking the pipe, inducing high resistatance and bring negative effects to surrounding environment.
这些变化对心脏血流量、周围血管阻力和内环境稳态可能产生一定影响，使机体耐力下降。
These changes may have some influences on volume of blood flow of heart, resistance of peripheral blood vessels and stabilization of homeostasis, and the results could decrease stamina of the body.
这些变化对心脏血流量、周围血管阻力和内环境稳态可能产生一定影响，使机体耐力下降。
These changes may have some influences on volume of blood flow of heart, resistance of peripheral blood vessels and stabilization of homeostasis, and the results could decrease stamina of the body.
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