牛奶中褪黑素含量的检测方法

褪黑素作为一种多功能活性因子,在畜牧生产中具有十分重要的作用。近年来,有关天然高褪黑素奶的研究大规模开展,对奶中褪黑素含量测定需求也有所增加。目前比较常见的褪黑素检测方法有气相色谱法（GC）、气相色谱-质谱联用法（GC-MS）、高效液相色谱法（HPLC）、高效液相色谱-质谱联用法（LC-MS）、放射免疫测定法（RIA）、酶联免疫吸附测定法（ELISA）、紫外分光光度法（UV）。本文从原理、特点及优缺点等方面对这几种方法展开介绍,并对各方法的应用进行简单的比较,为后续相关研究与应用提供一定参考。     

突发性环境污染事故应急监测的速度保障

针对突发性环境事故如何保证应急监测速度的问题，从应急监测前准备工作及应急监测运行期两方面进行说明，为保障应急监测速度提供了切实可行的方法和步骤。     

Automatic Measuring Method of Eyeglass Lens Power

A method of measuring eyeglass lens power is proposed. A position detector and 3 beams of ray are used to measure the prismatic, spherical and astigmatic powers. Based on the method, an automatic focimeter with simple structure can be developed. The measure errors of prismatic and spherical powers are analyzed, from which it is concluded that the precision of the position detector is the key to the method.     

Experimental Study of Multifunctional Acid to Deliquesce Stratum-jam

Aiming at the oneness of acid to deliquesce stratum-jam applied in scene at the present time,which is incapable of deliquescing complex dirty simultaneously,this article confects a new multifunctional O/W acid.This acid is an emulsified mixture containing 15% hydrochloric acid as its extro-posture,high dissolved oil as its internal state under the function of some proper exterior active reagent.It is composed of 0.5%OP-10,0.5%Span80,0.2%Tween80,0.06%imidazole and 0.01%twelve-alcohol,and the content of oil is equal to the acid content.It can be indicated that this acid has good ability of resolving mineral(CaCO_3,MgCO_3) and organic compound(mainly colloidal bitumen) when it was poured into the stratum,so that it can deliquesce oleic stratum-jam,resume and improve the penetrability of stratum,boost the ability of liquid flowing up.     

Dropwise Condensation Heat Transfer Coefficient on the Horizontal Circular Surface with Radial Gradient Surface Energy

A theoretical model is developed for the dropwise condensation heat transfer on the horizontal circular surface with radial gradient surface energy based on the heat transfer model of individual condensate drop and the size distribution model of condensate drop on homogeneous condensation surface.The effect of variation of contact angle on the gradient surface on condensation heat transfer and condensate drop size distribution is taken account of in this model.The theoretical calculation method was obtained to predict the dropwise condensation heat transfer coefficient on the horizontal circular surface with radial gradient surface energy under various wall subcooled temperature,contact angle profile on wall surface,and working fluid.The effects of surface energy gradient,wall subcooled temperature,and thermophysical properties of condensate on the condensation heat transfer are discussed respectively.The calculation results show that the condensation heat transfer coefficient increases slightly with the increase of wall subcooled temperature.As latent heat and surface tension increasing,the condensation heat transfer coefficient increases.A larger surface energy gradient induces a larger condensation heat transfer coefficient.     

Filtering Construct of Adaptive Filter Grou Pwith Multi-scale Decomposition

The principle and method of the adaptive filter and the filtering with wavelet transform were analyzed, and the model and method of adaptive filtering with wavelet transforms for the transient signal was established. The separated noise of signal by the multi-scale decomposition of wavelet transforms, was the input signal of adaptive filter, and accordingly the optimal filtering method of signal-noise decomposition was realized. By the adaptive filter grou Pbased on the wavelet transform, the optimal filtering to the multi-noise of signal is achieved at the same time, and the method presented in this paper has the excellent filtering capability. Examples of application demonstrate that this method presented is excellent to realize the optimal estimate to the valuable signal and noise of the transient signal in the same frequency segment.     

Experiment on Activation of Black Soil by Electro-hydraulic Impulse

The activation of black soil (analog the lignite) by electro-hydraulic impulse is proposed. The abundant insoluble nitrogen, phosphorus, potassium and other organic elements in black soil are activated as the green fertilizer by this way. The new method is provided for activating sludge produced by treating wastewater. For several kinds of black soil, the experiment result indicates that electro-hydraulic impulse increases the percentage of absorbable nitrogen by 1 to 4 times and the percentage of insoluble organic elements by 4 times, which is a valuable reference to sludge treatment.     

Design for Precision Measurement System Based on Machine Vision

It is difficult to measure the geometric quantity of small parts in finishing, assembling and measuring, because it's easy to break the workpieces' surface and alter their position by means of traditional contact measuring methods.There are some non contact measurers, such as,light feeler pin and interference microscope etc., because of it's high price and strict working conditions,so it's difficult to promote them in widely use. Precision measurement system based on machine vision has the advantages of non contact measuring as well as high performance and low price. Some problems, such as light source, algorithm of edge fitting, auto focusing,are discussed.