A.1 Principal

The absorbance of a series of standard Pt-Co color calibration solutions is measured at 373 nm by spectral photometer and standard calibration curve is made. The absorbance spectrum of industrial lineal alkylbenzene is similar to that of Pt-Co color solution. Measure the absorbance of sample liquid the same wave length as that of standard solution, and calculate the hazen value via calibration curve.

Hazen: unit of color, the color of an aqueous solution containing 1mg of Pt (K2PtCl6) and 2 mg of Co (CoCl2·6H2O)per litre.

A.2 Chemical reagent

A.2.1 K2PtCl6

A.2.2 CoCl2 · 6H2O

A.2.3 Hydrochloric acid, G.R. ρ20=1.19

A.3 Apparatas

Pippette the stock solution into 10 cm cell, measure the absorbance at 373 nm, 430 nm, 455 nm, 480 nm, 510 nm by specturmphotometer (A.3.1), respectively. The test value shall be in accordance with the range specified in Table 1.

A.3.1 Spectrophotometer, capable of measure the transparency at 373 nm, 430 nm, 455 nm, 480 nm, 510 nm, up to reading 0.005.

爱是一种热情、一种自我牺牲的道德情感。教师对教育事业和学生的热爱，是基于对革命事业的高度责任感，认识到少年儿童是祖国的未来，认识到教师肩负的重任。

A.3.2 Glass cell 1 cm, 5 cm, 10 cm.

A.4 Procedure

A.4.1 Preparation of Pt-Co standard stock solution

中职教育不同于普通高校教育，前者更加注重增强学生的实践能力。其教育的目的不仅是培养学生的学习兴趣，更是切实提高学生的专业技能，并使他们形成一套具体解决职业中问题的方法。运用实践教学法能为学生创造更多的实践机会，让学生主动体验职业中遇到的各种问题，使他们在实践中主动学习，积极探索，学习技能，加深理解，进而提高他们对课本知识的实际运用能力。

Ordinary laboratory apparatus and

A.4.3 Test of standard

Use semi micro burette, when measure precisely the light color under 15 Hazen, to pipette carefully the stock solution according to volume specified in Table 3, into 100 mL volumetric flasks, respectively, dilute to the mark with water. These 15 flasks form the standard calibration solutions.

Weigh 1.245 g of K2PtCl6 (A.2.1) and 1.000 g of CoCl2 · 6H2O (A.2.2) into a beaker, add 100 mL of water to dissolve. Then, add 100 mL of Hydrochloric acid (A.2.3)to beaker to dissolve the solid completely. Quantitatively transfer the solution to a 1,000 mL volumetric flask, make up to volume with water, shake well.

Table 1. The allowed range of transparency and absorbance of color stock solution with 500 Hazen

Wave length (nm) Transparency Absorbance 430 0.759～0.776 0.110～0.120 455 0.716～0.741 0.130～0.145 480 0.759～0.785 0.105～0.120 510 0.861～0.881 0.055～0.065

A.4.2 Preparation of Pt-Co standard calibration solution

Transfer appropriate volume of stock solution according to Table 2. to 100 mL volumetric flasks, respectively, dilute to the mark with water. These are standard calibration solutions.

Table 2. Standard calibration solution

?

3)建立“强护表高韧性整体支护法”，通过支护构件均化预应力在围岩表面的分布，降低部分应力差，避免局部产生更大的应力差导致的大变形，形成预应力均匀分布的整体延伸型支护结构。

Table 3. Standard calibration solution with light color

1 0.20 9 1.80

在144株大肠埃希菌菌株中（表3），可见B2群菌株占最大比例41.0%（59/144），其次分别为F群、B1群和E群，分别占16.7%（24/144）、13.9%（20/144）和13.2%（19/144）。

Measure the absorbance of prepared solution at 373nm against water, use 1 cm or 5 cm cell (use 5 cm cell for solutions Hazen ＜100; otherwise, use 1 cm cell.). Draw a calibration graph, Hazen as X-axis and Absorbance as y-axis.

A.4.4 Test of sample

中国酒业协会副理事长刘秀华在交流会上表示，随着科技进步的迅猛发展，白酒产业作为具有几千年历史的传统产业，其智能化进程迫在眉睫。正是在这关键时期，中国酒业协会牵头实施了中国白酒“158计划”。该项目以实现中国白酒企业“自动化控制，机械化生产”为总体目标，在制曲机械化、发酵工艺机械化、窖泥生产机械化等诸多领域开展研究，取得了诸多显著的科研成果。今天行业在小曲与麸曲生产上已经完全采用机械化、自动化进行生产；大曲从原料的筛选到粉粹成型已经机械化、自动化；酒醅从出糟到蒸馏入醅也实现了机械化；而大曲的发酵，及酒醅在窖池、罐、缸中发酵的机械化进程仍有待研究。

Fill the cell with sample liquid, light colored sample in 5 cm cell and dark colored in 1 cm cell. Measure the absorbance at 373 nm against water. Find the corresponding hazen on the curve as the sample color.

A.5 Precision

The absolute difference between two independent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will not exceed the repeatability limit (r) in more than 5% of cases. R expected to be less than 8.