光度

Amounts of the glycyrrhizic acid were determined by ultraviolet spectrophotometry at 252 nm wavelengh. Result The best extraction conditions from decoct method were that amount of affusion wate was 200 mL, extract 2 times, boiling time was 5 min, crash time was 20 s.

利用正交试验4因素3水平选择最佳提取条件(包括加水量、提取次数、煮沸时间、粉碎时间、溶剂量、振荡时间、氨水浓度)，用紫外分光光度法在252 nm波长处测定甘草酸含量。

To examine the capacity of alkaline resistance of Albizzia julibrissin Durazz seedlings,the contents of MDA,soluble sugar and proline,and the activity of POD and SOD in Albizzia julibrissin durazz tree body were measured by means of visible spectrophotometry.

为检测合欢幼苗的抗碱胁迫能力，文章试验利用可见分光光度法测定了碱胁迫下合欢幼苗体内的丙二醛、可溶性糖、脯氨酸含量及POD、SOD活性，分析这些生理指标在不同处理浓度、不同处理时间下的变化规律，探求碱胁迫下合欢幼苗的抗逆生理机制。

To explore physiological mechanism of how alkaline stress affects the growth of the Albizzia julibrissin Durazz seedlings, the concentrations of malonaldehyde, soluble sugar and proline, and the physiological indexes as peroxidase and superoxide dismutase were measured by means of visible spectrophotometry.

为探求碱胁迫影响合欢幼苗生长的生理机制，采用可见分光光度法测定合欢幼苗体内丙二醛含量、可溶性糖含量、脯氨酸含量及过氧化氢酶、超氧化物歧化酶活性等生理指标。

The transmission spectrum and the absorption spectrum of alcohol shows that the characteristic absorption peak shifts with alcoholicity due to the molecular configuration. A multiple regression model was established based on the position, the intensity and the shape of the characteristic absorption peak, and used to detect alcoholicity. The predictive results show a linear relationship between predicted values and real values in sonic range, and can be used as a means to detect the alcoholicity.

通过对酒精透射光谱和吸收光谱的研究发现，其特征吸收峰随浓度不同发生漂移，从分子结构能级角度对其做了定性解释；根据部分稳定的特征吸收峰处不同波长点的吸光度，利用最小二乘法建立了多元线性回归模型，运用此模型实现了根据特征吸收峰波长的位置、强度、形状来预测酒精浓度，测定数据与样品浓度之间在一定范围呈良好的线性关系。

The total molecular optical rotatory power depends on the algebraic sum of rotations of all helices existed in the molecular structure .

化合物的总旋光方向是由分子结构中所有螺旋旋光度的代数和所决定。

According to the helix theory , the algebraic sum value of all rotations of dihedral angle helix is equal to zero in the structure of 1,3-disubstituted cyclohexane derivatives.

按照螺旋理论，1，3-二取代环已烷衍生物的结构中存在的二面角螺旋旋光度代数和为零，不应具有旋光性，但是它们却是光学活性的。

Different functional group also brings different influence for the absorbance of alkali metal.

有机物官能团上的差异也将对碱金属元素的吸光度产生不同的影响。

A method for the determination of aloin and aloe-emodim in aloe vera was established based on multi-wavelength linear regression spectrophotometry in wavelength range of 350-450nm with a regression equation.

依据芦荟苷与芦荟大黄素的光谱特征，选择350-450nm为测定波长范围，用多波长直线回归分光光度法同时测定芦荟中芦荟苷和芦荟大黄素含量。

The stability of aloin decreased with the increase of temperature and heating time. However, the absorbency of aloin did not change with time under room temperature (20℃). The aloin was sensitive to light, and the aloe juice showed a yellowish green sediment in 2 hours after exposed to sunlight. The stability of aloin declined when the pH value arose. The aloe juice was more stable under lower concentration of sodium chloride and sucrose.

结果表明：加热的温度越高，时间越长，芦荟苷的热稳定性越差，而在室温下(20℃)芦荟苷的吸光度基本不随时间改变；芦荟苷具有光敏性，在太阳光照射下，2小时后便出现黄绿色沉淀物；芦荟溶液随着pH的升高，其稳定性下降；低浓度的氯化钠和蔗糖对芦荟汁液稳定性的维持比高浓度的效果明显。

MAIN OUTCOME MEASURES: The ratio of absorbance value between ALP and total protein.

主要观察指标：碱性磷酸酶与总蛋白的吸光度值。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。