前后比

研究了几种典型的反射板形状对基站天线前后比特性和水平面辐射方向图的影响，仿真得到了满足基站天线双频辐射要求的最佳反射板形状。

The effect of several kinds of reflector on the front to back ratio and horizontal plane radiation pattern of base-station antenna is simulated , and the best reflector is obtained , which meets the radiation demands of dual-band base-station antenna .

以二频道为例，分析了小尺寸八木天线前后比F／B的窄带性及展宽频带的方法。

With TV channel 2 as example , narrow performance of small size Yagi antenna front-to-back ratio F / B and method used to expand the F / B bandwidth has been analyzed .

治疗组能够显著改善肺功能，VC、FEV1、FEV1%治疗前后比有极显著差异（P<0.01），与对照组比有显著差异（P<0.05）。

In the treatment group , pulmonary function was improved and VC , FEV 1 and FEV 1 % were changed greatly ( P < 0.01 ) with marked difference as compared with the control group ( P < 0.05 ) .

第四，我们提出了渐变槽天线定向增益增强的设计方法。我们同时研究了具有高增益，高前后比和宽带的Yagi形双锥形槽（DTSA）天线。

Forth , we present a design technique for directional gain enhancement in low profile tapered slot antennas ; we study along a yagi-like dual tapered slot antenna ( DTSA ) which features high gain , high front-to-back ratio and broadband characteristics with a short taper profile .

我知道你们在所谓的假期前后比平时还忙。

I know you 're busier around the so-called holidays than you are during the times when it 's week after week of regular work .

蜂窝移动通信系统中的基站天线通常由直线阵列加反射板构成，而反射板的形状主要影响天线的前后比特性及水平面辐射方向图。

In the cellular mobile communication system , the base-station antenna often consists of a linear array antenna backed by a reflector , and the reflector mainly affects the characteristic of front-to-back ratio and the radiation pattern in the horizontal plane .

使人惊奇的是，Mn／Ni耦合体系的居里温度在吸附氧前后都比相应Ni薄膜的要低，与一般预期的结果相反。

Strikingly the Curie temperature ( Tc ) of Mn / Ni film before and after the oxygen absorption is lower than that of the bare Ni film , whereas the opposite result would be generally expected .

并试验研究了不同转速、齿数工况的封严效果，探讨了篦齿前后压比与泄漏系数的变化关系。

The relations between pressure ratio and leaking coefficient were also explored .

小旋涡出现位置和旋涡大小与热边界端面的传热量和封严段前后压比有关。

The location and size of the small eddy depend on the heat flux on the wall of the heating boundary and the pressure ratio .

选择膨胀前后密度比、流场湍流强度、射流交汇处距喷嘴出口的距离作为评价指标，定义模糊打分的评价方法。

We select the density ratio which before expansion to after expansion , turbulence intensity in flow field and the distance from jet junction position to nozzle exit as the evaluation index , definite the method of fuzzy marking .

用TPR、TPD表征了催化剂的表面性质，测定了酸改性前后海泡石的比表面及孔径分布，并与活性进行了关联。

The surface properties of the alloys were characterized by TPR and TPD . The specific surface area and distribution of pore diameter were determined , and were correlated with the activity of the samples .

方案中的评价函数是网络进行路由优化前后开销的比。

The evaluation function value in the scheme is the ratio of the network overhead before route optimization to that after route optimization .

主要概述了电极各组分配比、电极孔率、正极前后膜厚度比与电性能的关系。

The relationship between the electrochemical performance and different composition , porosity of electrodes and thickness ratio of front and rear positive electrode was reviewed .

定义了激光光束衍射远场光斑压缩前后的能量比以及能量密度比来衡量超衍射极限激光光束的质量。

The ratio of the power and the ratio of the power density are firstly defined to evaluate the quality of the beam beyond the diffraction limits .

文中报道了研究的试验装置，快速老化模式以及老化前后空燃比、起燃温度、起燃时间等特性的台架试验结果。

Air / Fuel ratio property , light-off temperature property and light-off time property tested on bench before and after the fast aging are described in this paper .

采用自行设计的评价指标体系即液膜溶胀率、黑液处理前后吸光比、乳液55℃超声破乳率3个指标来研究评价稀型乳状液膜法处理制浆黑液的效果是完全可行的。

It is totally feasible to study and evaluate the results of pulping black liquor treated by dilute emulsion liquid membrane process through dissolving-expanding ratio , absorption ratio and deemulsification ratio .

最后通过信杂比改善因子对该算法性能进行分析，得出杂波抑制后的信杂比较杂波抑制前的信杂比有较大提高，且杂波抑制前后信杂比成近似线性关系。

At last , the signal-to-clutter improvement factor is used to analyze the performance of the algorithm , and signal-to-clutter ratio obtained after clutter suppression has been improved greatly than that before clutter suppression .

结果中下部胸椎发生楔形骨折概率较高，即使发生爆裂骨折，其椎体前后缘压缩比常较大。

Results The incidence of wedge fractures in the middle and lower thoracic spine was comparatively high while during the occurrence of burst fractures in the thoracic segments the ratio between the compression ratio of the anterior and posterior height is comparatively high .

饲料报酬与日增重基本一致，前后期I组比II组分别提高了1.79%和6.11%。

It is the same with daily gain , feed conversion ratio of group I increased by 1.79 % and 6.11 % over group ⅱ in former and latter periods respectively .

这一现象也为氮溶前后样品XPS强度比的比值所证实。

Two kinds of species coexist in monolayer with constant ratio , which have also been confirmed by XPS experiment for samples before and after extraction .

向日极光弧则主要出现在子夜前后，子夜前比子夜后多，极向和天顶比赤道侧多。除向日极光弧外，其它形态的极光在中山站的出现情况与Kp指数相关。

And except for the transpolar arcs , the appearance frequences of other three kinds of aurora are related with Kp index .

利用离子背散射分析了激光再结晶前后InP化学计量比的变化，结果表明：采用SiO2保护膜后较好地抑制了InP组分的分解。

Analysis of the stoichiometrical rate of InP by Rutherford backscattering spectrometry shows that the decomposition of InP is greatly suppressed by using a SiO2 encapsulant .

通过比较POD控制器安装前后低频振荡阻尼比的变化和时域仿真说明了该设计方法的有效性，且适用于大规模电力系统。

Both the comparison results of the low frequency oscillation damping ratios before and after the POD controller is installed and the time-domain simulation results show that the proposed approach is effective and is suitable to large scale power systems .

导出适用于合成孔径雷达（SAR）的基本方程，用于决定回波信号功率、检测前后的信噪比、平均发射功率和噪声等效后向散射系数。

The basic synthetic aperture radar ( SAR ) equations , which are used to determine the echo power , the signal to noise ratio before and after detection , the average transmission power and the noise equated σ° have been derived in detail .

制动衬片摩擦性能对轻型货车前后制动力之比的影响

Influence of Friction Characteristic of the Braking Linings on Braking Force Distribution of Light Truck

为了有效制动和改善轿车制动稳定性，讨论了摩擦材料的摩擦系数与制动减速度和前后制动力分配比的关系。

For effective braking and improving the braking stability , the correlation between friction factor of brake lining and deceleration are discussed .

鉴于1996年前后劳动收入占比呈明显相异趋势，分别对1996年之前和之后两个时期的数据进行模型拟合。

As the labor income share showed a different trend before and after 1996 , model fitting is break up into two periods .

本文研究了制动衬片摩擦性能&热衰退性能、速度和压力相关性对轻型货车鼓式制动器前后制动力之比的影响及其规律。

In this paper , the influence of friction charateristic of brake linings on braking force distribution of light truck are analysed and discussed ;

结果表明，实施缓存限制策略前后，分布式模型比集中式模型均有更好的性能。

Simulation result showed that the distributed model was more efficient than the central model no matter it worked under buffer-restricted policy or not .

二个飞行员座位在座舱内前后串列，后座比前座略高提供更多的视野。

Two pilot seats are located in tandem in the cockpit , with the rear seat higher than the front seat to give better view .