Since the speed of light is constant, knowing how far away such a "standard candle" is ( calculated from its apparent brightness seen from Earth) is to know how long ago it exploded.

By gauging the redshift and apparent brightness of a large number of supernovae located at a variety of distances, researchers can create a record of the universe's expansion.

藉由调校大量位于不同距离的超新星红移和表观亮度，研究人员可造出一组宇宙膨胀的记录。

The distance to such an object can be worked out by comparing its apparent brightness with its known, absolute brightness.

通过比较表观亮度和已知的绝对亮度，即可得出该天体和我们的距离。

Deferring to historical custom, astronomers, measure the apparent brightness of stars through the magnitude scale, a very confusing way.

按照历史习惯，天文学家用星等标这种容易使人混淆的方法来度量恒星的视亮度。

The corresponding concept for apparent brightness is generally called a number count.

而视亮度的相应概念通常叫作计数。

Effect of chemical component, preparation conditions on the performance of the phosphor was studied by using TG-DTG, XRD and phosphor relative brightness meter.

借助TG，XRD，荧光粉相对亮度仪、荧光分光光度仪等手段系统研究了合成过程中原料化学组成及配比、合成条件对磷酸钡钙∶铈、锰发光性能的影响。

Development of new type of dampproof and brightening agent

新型防潮上光剂的研制

Development of new type of dampproof and brightening agent covered tunnels(ⅲ);

新型防潮上光剂的研制被覆坑道（Ⅲ类）；

The variety of paper brightening agent and its utilization

造纸增白剂的种类与应用

Application of membrane technology to production of brightening agent

膜技术在增白剂生产中的应用

Study on a new type of dyeing brightening agent in leather

一种新型皮革染色增艳剂的助染性研究

Result Method of Several Type of Liquid Optical Brightening Agent Test

几种液体增白剂性能试验

Introduce the result of several type of liquid Optical Brightening Agent ( OBA) test, commend the test method of OBA use for coating color.

介绍了几种液体增白剂的性能试验结果，及用于铜版纸涂料中的液体增白剂的选择试验方法。

The plating solution has good brightening and leveling power at high and middle current density area and the permitted solution temperature is up to 40 ℃ better than that for the dye-type process.

该工艺中、高电流密度区光亮整平性好，允许液温可达40℃，优于染料型工艺。

The results indicated that the mixture of fluorescent whitening agents, which were self-made, have a good brightening effect and can be used to whiten the polyester/ cotton fabric with one-step process.

实验表明：论文所研制的复配荧光增白剂具有良好的应用性能，可以使涤棉混纺织物通过一浴一步法增白工艺获得优异的增白效果。

The influences of main categories of optical brightener in the market on whiteness, detergency and fabric brightening effect of laundry powder were examined.

研究了用于洗衣粉的主要类型增白剂对粉体白度、去污性能和织物增白3个方面的影响。

The acting principle of flour brightener and the effective factors of brightening effect were analysed. The reasonable addition level of brightener and adding methods were put forward.

通过对面粉增白剂作用原理和增白效果影响因素的分析，提出面粉增白剂的合理用量及添加方法。

A Study on the Measurement of the Brightening Effect of Fluorescent Brightener on Paper sheet-fed single colour perfector

纸张染色测定荧光增白剂增白强度的方法研究单张纸双面单色胶印机

Influences of optical brighteners on whiteness, detergency and fabric brightening effect of laundry powder

荧光增白剂对洗衣粉白度与去污及织物增白的影响

Application of Flour Brightener and Effective Factors of Brightening Effect

面粉增白剂的应用及增白效果的影响因素

The results showed that the dyeing brightening agent can brighten and deepen direct and acid dyes, but it has no effect on metal complex dyes and its brightening effect disappears after being baked.

结果表明此种新型染色增艳剂对酸性和直接染料具有很好的增深、增艳作用，对金属络合染料没有增艳作用，烘干后使用增艳效果消失。