1) deviation factor
偏差系数,畸变系数
2) distortion coefficient
畸变系数
1.
The distortion coefficients were used to correct the distortion points,and the parameters of the camera were estimated.
针对视觉测量中摄像机镜头畸变对精度的影响问题,提出一种基于平行直线求解镜头畸变系数及摄像机标定的方法。
3) Deviation factor
偏差系数
1.
With a drop in formation pressure, the parameters which closely related to the flow coefficient of the exponential deliverability equation are varied, such as gas deviation factor, gas viscosity, reservoir permeability, effective thickness and so on.
随着地层压力的下降,与指数式产能方程流动系数密切相关的参数,如天然气偏差系数、天然气粘度、气层渗透率、有效厚度等都是变化的。
2.
On the basis of analysis of the raw materials,using the fineness modulus of aggregate mixture,the deviation factor of synthetic gradation and objective gradation as technical indexes,the best aggregate ratio is attained through the application of computer operations.
在骨料原材料分析的基础上,以合成级配与目标级配的偏差系数、骨料混合料的细度模数作为技术指标,通过计算机应用程序的运算,获得定量化的骨料最佳级配。
4) bias factor
偏差系数
1.
A bias factor is commonly used to account for the effect of differences in failure criteria on reliability of pile foundations.
为了评估不同失效准则对基桩可靠度的影响,传统的方法是引入失效准则偏差系数。
2.
For this purpose,a bias factor defined with respect to S-lgt criterion is introduced;and one.
为此,以S-lgt失效准则为基准,引进了失效准则的偏差系数的概念,根据一组实测钻孔桩数据对另外6种失效准则的偏差系数进行了评估,进而进行了可靠度分析。
3.
The friction factor between the prestressed wires and the metallic corrugated pipes and the bias factor of pipleline are determinated.
通过对某立交桥现浇后张预应力混凝土箱梁预应力钢束的摩擦损失试验 ,测试并理论计算了预应力的摩擦损失 ,推导了该桥预应力钢束与金属波纹管之间的摩擦系数和管道偏差系数 ,指出现行《公桥规》以及当前设计工作中有关预应力摩擦损失计算的不足 ,并提出相关建
5) variation coefficient
变差系数
1.
The optimum design example shows that the variation coefficient of load torque acting on cutting head is decreased 13.
优化设计实例表明,截割头的负载转矩变差系数减小了13。
2.
The Analysis shows that the bigger the variation coefficient of dependent variable,the bigger the mean square error of regression equation when the multiple correlation coefficient(or correlation coefficient) is definite.
分析表明,复相关系数(或相关系数)一定时,倚变量的变差系数越大,回归方程的均方误差就越大;回归分析时,应对回归方程的误差进行分析。
3.
Mathematical expectation,variation coefficient and probability density function were analyzed or simulated to investigate the variation trend and characteristics of daily precipitation in the area.
利用重庆地区4个气象台站(沙坪坝、开县、万州、酉阳)1961~2000年的40 a观测资料,通过计算、拟合日降水的数学期望、变差系数及分布函数,对重庆地区日降水变化趋势及变化特征进行分析,从而进一步了解重庆气候变化情况。
6) coefficient of variation
变差系数
1.
Through the histogram method and Kolmogorov test,it was obtained that the sensitivity coefficient of variation for D6-2 artillery primer and mechanical explosive devices approximated the normal distribution of(0.
变差系数是进行火工品可靠性设计的重要参数之一。
2.
The results show that the rainfall isogram in the area of Beijing has been densified by the urbanization, and then the annual rainfall has been increased as well; which makes the change of the coefficient of variation of urban rainfall is larger than those of the suburbs.
分析表明,城市化使北京地区降雨量等值线加密、年雨量增加,使城区雨量变差系数变化大于郊区。
3.
Based on the date of Chaohu river network of waterways area 8 survey station of many year materials,The relations between,its flood peak and the year of the largest flood runoff one day is established,its corresponding coefficient of variation Cv value is calculated and the distribution rule and origin of the Cv value is analyzed.
通过对巢湖水系河网区8个测站多年资料,建立其洪峰与年最大一日洪量关系,计算其对应变差系数Cv值。
补充资料:阀门技术注重流量系数和气蚀系数
阀门的流量系数和气蚀系数是阀的重要参数,这在先进工业国家生产的阀门资料中一般均能提供。我国生产的阀门基本上没有这方面资料,因为取得这方面的资料需要做实验才能提出,这是我国和世界先进水平的阀门差距的重要表现之一。
3.1、阀门的流量系数
3.1、阀门的流量系数
阀门的流量系数是衡量阀门流通能力的指标,流量系数值越大,说明流体流过阀门时的压力损失越小。
按KV值计算式
式中:KV—流量系数
Q—体积流量m3/h
ΔP—阀门的压力损失bar
P—流体密度kg/m3
3.2、阀门的气蚀系数
用气蚀系数δ值,来选定用作控制流量时,选择什么样的阀门结构型式。
式中:H1—阀后(出口)压
H2—大气压与其温度相对应的饱和蒸气压力之差m
ΔP—阀门前后的压差m
各种阀门由于构造不同,因此,允许的气蚀系数δ也不同。如图所示。如计算的气蚀系数大于容许气蚀系数,则说明可用,不会发生气蚀。如蝶阀容许气蚀系数为2.5,则:
如δ>2.5,则不会发生气蚀。
当2.5>δ>1.5时,会发生轻微气蚀。
δ<1.5时,产生振动。
δ<0.5的情况继续使用时,则会损伤阀门和下游配管。
阀门的基本特性曲线和操作特性曲线,对阀门在什么时候发生气蚀是看不出来的,更指不出来在那个点上达到操作极限。通过上述计算则一目了然。所以产生气蚀,是因为液体加速流动过程中通过一段渐缩断面时,部分液体气化,产生的气泡随后在阀后开阔断面炸裂,其表现有三:
(1)发生噪声
(2)振动(严重时可造成基础和相关构筑物的破坏,产生疲劳断裂)
(3)对材料的破坏(对阀体和管道产生侵蚀)
再从上述计算中,不难看出产生气蚀和阀后压强H1有极大关系,加大H1显然会使情况改变,改善方法:
a.把阀门安装在管道较低点。
b.在阀门后管道上装孔板增加阻力。
c.阀门出口开放,直接蓄水池,使气泡炸裂的空间增大,气蚀减小。
综合上述四个方面的分析、探讨,归纳起来对闸阀、蝶阀主要特点和参数列表便于选用。两个重要参数在阀门运用中 。
说明:补充资料仅用于学习参考,请勿用于其它任何用途。
参考词条