近红外光谱分析技术在肥料成分分析中的应用及前景

近红外光谱是一种快速、无损、可实现多组分同时测定的分析技术。本文简要介绍了近红外光谱的发展、测量原理、技术特点．并对近年来近红外光谱技术在肥料成分分析中的应用及前景进行了总结。近红外光谱在肥料成分分析中的应用范围比较狭窄,主要集中在两个方面：一是利用近红外反射光谱（NIRS）分析技术快速测定各种畜禽粪便主要肥料成分含量;二是应用近红外光谱技术在土壤及土壤肥料学科中的应用;只有极少量的关于混合（复合）肥料的研究。随着近红外光谱技术的不断成熟,除了应用范围将不断拓宽之外,相信对于目前较为空白的应用机理的研究也将越来越深入、细致及严谨。     

高职院校《光谱分析技术》理实一体化课程教学设计

《光谱分析技术》是高职院校工业分析与检验专业的专业核心课程。以可见分光光度法为例,对学习内容、学习者情况进行了科学分析,从教学目标、教学方法、教学媒体、教学过程及考核方法等方面进行了教学设计,并运用以任务为驱动、以项目为载体、“教一学一做一评”四位一体的教学方法调动学生的学习积极性,充分发挥学生的主体作用和教师的主导作用,提升了学生的职业核心能力和创新意识,取得了较好的教学效果。     

波谱分析的内在统一性和差异性及教学效果

根据波谱分析课程特点及教学实践中遇到的一些问题,提出在教学实践中应强调波谱分析方法的统一性和差异性,从而使学生快速领会不同波谱分析方法的特征,提高识图、理图能力,并取得了良好的教学效果。     

建设北京电子能谱中心,开展优质特色服务

该文介绍了清华大学北京电子能谱中心以完善规章制度作为实验室规范管理的保证;与国际接轨,参加ISO/TCL国际标准比对,从而提高分析水平;提高服务层次,扩大服务范围,建设国内一流实验室的基本情况。     

Effect of creatine supplementation on phosphocreatine resynthesis,inorganic phosphate accumulation and pH during intermittent maximal exercise

In this study, we examined the effect of creatine ingestion on muscle power output, muscle phosphocreatine resynthesis, inorganic phosphate and pH during repeated brief bouts of maximal exercise. Nine healthy males performed maximal plantar flexion before and after creatine ingestion (20 g ·day -1 for 6 days). The experimental protocol consisted of five 8 s bouts (bouts 1-5) interspersed with 30 s recovery, followed by bouts 6 (8 s) and 7 (16 s) separated by 1 and 2 min, respectively. Muscle phosphocreatine, inorganic phosphate and pH were estimated every 16 s by 31 P magnetic resonance spectroscopy. After creatine ingestion, muscle power output increased by ~5% ( P ? 0.05) from bouts 3 to 7 and muscle phosphocreatine resynthesis increased ( P ? 0.05) during 10 min recovery. The higher phosphocreatine concentration observed after only 30 s of recovery was accompanied by lower inorganic phosphate accumulation and higher pH. Strong correlations were found between exercise power restoration and the corresponding pre-exercise phosphocreatine and inorganic phosphate concentrations and muscle pH after creatine ingestion. The better maintenance of muscle power output observed after creatine ingestion was attributed to a higher rate of phosphocreatine resynthesis, lower accumulation of inorganic phosphate and higher pH.     

Diethyl oxalate as a new potential conservation product for decayed carbonatic substrates

This note shows the first results of a study concerning the development of a new method for the consolidation of decayed carbonatic matrices. On the basis of the results achieved with ammonium oxalate, the authors tested a different mechanism to crystallize calcium oxalate phases in calcium carbonate substrate using diethyl oxalate solution. Raman spectroscopy provided a significant analytical support on the study of diethyl oxalate hydrolysis allowing to monitor the reaction and to suppose the occurrence of a reaction intermediate. The investigation of the newly-formed calcium oxalate phases after the reaction of diethyl oxalate with calcite powder allowed to verify the reactivity of the proposed solution and to highlight the crystallization of caoxite, an uncommon calcium oxalate phase.     

N-TiO2溶胶的低温制备及紫外光谱分析

采用钛酸四正丁酯为前驱体低温制备N掺杂TiO2纳米溶胶,并利用紫外-可见光谱对其分子结构及光学性能进行了表征研究.     

Neural network and principal component regression in non-destructive soluble solids content assessment: a comparison

Visible and near infrared spectroscopy is a non-destructive, green, and rapid technology that can be utilized to estimate the components of interest without conditioning it, as compared with classical analytical methods. The objective of this paper is to compare the performance of artificial neural network (ANN) (a nonlinear model) and principal component regression (PCR) (a linear model) based on visible and shortwave near infrared (VIS-SWNIR) (400–1000 nm) spectra in the non-destructive soluble solids content measurement of an apple. First, we used multiplicative scattering correction to pre-process the spectral data. Second, PCR was applied to estimate the optimal number of input variables. Third, the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models. The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN. Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR.     

紫外可见分光光度法测定铜及铜合金抛光液中的硝酸根

研究了紫外可见分光光度计在301.7nm处测定铜及铜合金抛光液中硝酸根的浓度。方法的线性范围为0.9662—9.6621g/L,适合于该类型抛光液中硝酸根的检测。该方法快速简便、准确度高、精密度好。     

游泳运动员短时间高强度间歇训练中肌氧含量及相关指标的变化特征

目的：：探讨游泳运动员短时间高强度间歇训练过程中肌肉氧参数动态变化特征和规律,以及训练前后的血乳酸( LA)、心率( HR)、主观疲劳感觉( RPE)变化及相关性。方法：随机选取山东省游泳运动员(n=15)采用短时间高强度间歇训练模式,全力蹬踏功率自行车30秒、休息120秒、重复进行3次为一组、共2组,组间休息3-4分钟。连续监测受试者短时间高强度间歇训练过程中股外侧肌组织肌氧参数变化;每次全力蹬踏30秒后即刻测试受试者RPE;整个训练过程中实时同步监测HR,并于每次全力蹬踏30秒后即刻读取并记录受试者HR;分别在训练前后即刻取受试者指尖血10μL,测试LA值。结果：(1)全力蹬踏功率自行车过程中股外侧肌组织氧合血红蛋白含量( CHbO2)和局部组织肌氧饱和度( TOI)迅速下降、肌组织还原血红蛋白( CHb )迅速上升;(2)两组短时间高强度间歇训练后LA、HR、RPE都分别显著高于训练前(P<0.01);(3)训练前后的LA、HR、RPE之间具有高度相关性(P<0.01)。结论：(1)可通过近红外光谱技术监控短时间高强度间歇训练过程中肌组织中CHbO2、CHb、TOI动态变化趋势;(2)在短时间高强度间歇训练过程中,可以通过LA、HR、RPE直接有效地监控训练的强度。