药剂复配对B型烟粉虱增效作用测定

采用试管药膜法,测定了阿维菌素、氟虫腈等7种药剂及相关混配对B型烟粉虱的毒力及增效作用.结果显示:在7种药剂中阿维菌素和氟虫腈对烟粉虱显示了较高毒力,LC50值分别为1.122 9、3.081 3 mg/L,毒力倍数较毒死蜱分别为125.0和45.6;在新烟碱类药剂中啶虫脒对烟粉虱的毒力最高,LC50值为7.1195 mg/L;啶虫脒和阿维菌素1:5和1:10的质量浓度比混配LC50值分别为1.3881、1.0647mg/L,显示了一定的相加作用;啶虫脒币口氟虫腈1:2和1:4的混配LC50值分别为3.765 3、1.5831mg/L,其中1:4混配共毒系数达到了219.79,显示了较高的增效作用;啶虫脒和毒死蜱1:4和1:8混配的LC50值分别为21.813、25.730 mg/L,共毒系数分别为135.68、177.16,有较高的增效作用.     

不同发酵时间对酵母发酵的影响

将酵母菌进行36、72、108h液体发酵后,检测其发酵液中残糖量、酒精含量、总酸和氨基酸态氮含量变化情况,为酵母菌液体发酵最佳时间提供科学依据。结果表明:酵母发酵36、72、108h后,发酵液中残糖量分别为:18.75、10.37、5.42g/L;酒精含量分别为:酒精度分别为2.07%、4.62%、7.93%;产总酸分别为:3.17、5.14、5.11g/L;氨基酸态氮分别为0.46、0.87、0.85g/L。结论:酵母发酵液中各指标含量会随着发酵时间的变化而变化,由此可知酵母菌在不同发酵时间产生的代谢产物量不同。     

90%杀单·乙酰甲可湿性粉剂的分析方法

利用反相高效液相色谱外标法检测90%杀单·乙酰甲可湿性粉剂,结果表明:杀虫单与乙酰甲胺磷的线性相关系数分别为0.9998、0.9998,标准偏差分别为0.064、0.12;变异系数分别为0.78%、0.91%;回收率分别为99.02%～100.29%、99.67%,100.09%。     

丙环唑和苯醚甲环唑复配对水稻纹枯病的联合毒力

通过在活体稻苗上对水稻纹枯病进行复配药剂筛选,发现丙环唑和苯醚甲环唑(质量比分别为1:5、1:3、1:1、3:1、5:1)复配剂的共毒系数CTC值分别为128.91、82.66、156.89、87.35和111.73,综合增效作用和经济效益两方面考虑,两者1:1配比最佳.     

秦岭链霉菌发酵产物的抗菌活性

离体试验结果表明:质量浓度为2 000 mg/L时,秦岭链霉菌发酵产物对玉米大斑病菌、小麦根腐病菌菌丝生长抑制率分别为100%、80.39%;对枯草芽孢杆菌、蜡状芽孢杆菌的抑菌圈直径分别为24、23 mm.盆栽试验表明:在6000 mg/L下,对小麦白粉病菌、黄瓜霜霉病菌和番茄灰霉病菌的保护效果分别为76.1%、63.9%和61.1%.治疗效果分别为70.8%、59.7%和66.9%.田问试验结果表明:在10000 mg/L下,小麦白粉病菌、黄瓜霜霉病菌和番茄灰霉病菌防治效果分别为52.73%、64.98%和74.95%.     

牦牛皮胶原蛋白的提取及其性能分析

以牦牛皮为原料,提取了酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC),并对胶原蛋白分子的结构和性能进行了分析。结果表明:ASC和PSC的提取率分别为54%±0.18%和78%±0.42%;UV、FTIR及电泳分析结果表明:ASC和PSC具有完整的三股螺旋结构,符合Ⅰ型胶原蛋白的结构特征;氨基酸分析发现:ASC和PSC含有丰富的亚氨基酸,其含量分别为264.1和276.6残基/1000残基;热稳定性分析表明:ASC和PSC热变性温度(Td)分别为37.5、41.5℃,热收缩温度分别为62.5、70.0℃,证明PSC的热稳定性高于ASC;SEM结果表明:ASC和PSC表面为松散、不规则的纤维网形态;自组装实验结果显示:两者具有一定的成纤维能力,自组装产物的D-周期分别为(68.2±5)nm、(69.3±3)nm,且PSC比ASC的组装速度快。     

28%苯甲·嘧菌酯悬浮种衣剂的高效液相色谱分析

采用高效液相色谱法测定28%苯甲.嘧菌酯悬浮种衣剂中苯醚甲环唑和嘧菌酯的质量分数,使用C18反相柱和紫外可变波长检测器,以乙腈+水为流动相,用外标法对有效成分进行分析和定量。苯醚甲环唑和嘧菌酯的标准偏差分别为:0.04、0.09;变异系数分别为:0.50%、0.40%;平均回收率分别为:99.0%、98.8%。     

应用化学发光免疫分析法测定CA125

目的 评价化学发光免疫分析法测定CA125辅助诊断卵巢癌的临床应用价值。方法 分别用Lumiassay~(TM)与ACS:180试剂测定卵巢癌61例,非卵巢癌21例。正常对照67例,并与RlA进行对照。结果 Lumiassay~(TM)、ACS:180与RIA测定CA125的灵敏度分别为86.9％、86.9％和80.3％;特异度分别为95.5％、97.0％和92.5％;阳性预测值分别为94.6％、96.4％和90.7％;阴性预测值分别为88.9％、89.0％和83.9％;准确度分别为91.4％、92.2％和86.7％。Lumiassay~(TM)与ACS:180有高度的一致性和相关性;Lumiassay~(TM)、ACS:180与RIA一致性与相关性略低。结论 化学发光免疫分析法测定CA125辅助诊断卵巢癌具有较高的灵敏度、特异度与临床价值,在3种方法的对比中,Lumiassay~(TM)ACS:180有着高度的相关性,优于RIA。     

20%噻嗪酮·杀扑磷乳油的液相色谱分析

本文叙述了采用高效液相色谱法即以甲醇+水(78:22)为流动相,C18柱和紫外检测器同柱一次分离测定混剂中的噻嗪酮和杀扑磷.结果表明:噻嗪酮、杀扑磷的标准偏差分别为0.0265和0.0122;变异系数分别为0.174%和0.242%;平均回收率分别为99.68%和99.67%;线性相关系数分别为0.9994和0.9996.     

30%吡唑醚菌酯·克菌丹悬浮剂的高效液相色谱分析

采用高效液相色谱法测定30%吡唑醚菌酯·克菌丹悬浮剂中吡唑醚菌酯和克菌丹的质量分数。使用反相C_(18)柱,采用紫外可变波长检测器,流动相为乙腈和水,采用外标法进行定性和定量检测。结果表明该方法中吡唑醚菌酯和克菌丹线性相关系数分别为0.999 5和0.999 2,标准偏差分别为:0.09、0.16;变异系数分别为:1.73%、0.63%;平均回收率分别为:99.57%、99.78%。     

The prediction of clay contents in oil shale using DRIFTS and TGA data facilitated by multivariate calibration

The prediction of clay content in oil shale is important for the optimisation of oil shale processing conditions and process feasibility. The multivariate calibration technique of partial least squares regression (PLSR) was implemented in order to predict clay content in oil shale samples taken from the Stuart oil shale deposit, Queensland, Australia. The calibration data used were the diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS) spectra of 34 oil shale samples. DRIFTS data from another set of 20 oil shale samples were used for model validation. The data pre-processing includes the use of derivatives facilitated by the Savitsky-Golay nine-points’ method. A four components model was constructed and it showed a root mean square error of calibration (RMSEC) of 4.79% and a root mean square error of prediction (RMSEP) of 4.35%. TGA data sets were also used to construct a calibration model, which produced less accurate results than DRIFTS. DRIFTS, when combined with multivariate calibration, provided an accurate in situ method of evaluating clay content in oil shale. Clay content measured using XRD was used as a reference.     

近红外光谱的ELM校正模型测定柴油凝点

为了简便、快速地测定柴油凝点,建立了一个基于ELM算法的近红外光谱校正模型。首先选择KS法按4:1划分样本集,并以"一阶导数+矢量归一化"方法进行光谱预处理;以校正集数据训练ELM模型并进行参数优化后,代入测试集光谱数据完成预测。通过136个柴油样品数据建模验证,结果表明用近红外光谱的ELM校正模型测定柴油凝点是完全可行的,且其准确度、稳健性和速度均优于PLSR模型和LS-SVM模型。     

A Direct GPC Calibration for Low Molecular Weight Polybutadiene,Employing Dual Detectors

Abstract

The calibration of gel permeation chromatograph (GPC) for a given polymer type is usually done by running well-characterized polymer samples of the same type. The available polystyrene and polyglycol standards with molecular weights below 5000 do not give parallel calibration curves, and the points for polystyrene are not on an extension of the higher-molecular-weight portion of the curve. In order to check the calibration in this low molecular-weight region and to establish an independent curve for polybutadiene, a polybutadiene sample prepared by a-methylstyrene tetramer-Na₂ initiation was chromatographed. In doing this, dual detection was used, consisting of a differential refractometer, and an ultraviolet absorption spectrophotometer.

The UV signal from the spectrophotometer was assumed to represent the tetramer portion of the polymer, and its percentage was calculated at each volume increment, using externally determined response factors. This percentage and the tetramer molecular weight gives the molecular weight of the polymer eluting at each volume increment. After correction for the aromatic portion of the polymer, these data and the points obtained with the polybutadiene standards were found to give a reasonable calibration curve for the entire range. The present paper describes the application of this technique to the examination of low molecular-weight polybutadiene.     

Molar mass analysis of polyamides-11 and -12 by size exclusion chromatography in HFiP

The SEC analysis of polyamide-11 and polyamide-12 can be conducted free of association and aggregation phenomena when hexafluoroisopropanol + 0.05 mol/L potassium trifluoroacetate are used as the mobile phase. The calibration of the SEC system can be conducted in different ways. As stationary phases non-polar polystyrene and polar perfluoro silicagel were tested. The investigations showed that the polystyrene gel exhibits hydrophobic interactions with the polyamides while with the silicagel selective interactions were not found. Investigating different options for SEC calibration it was found that conventional PMMA calibration does not yield correct results. The universal calibration approach based on PMMA calibration did not work either. Correct molar masses were obtained when the PMMA calibration curve was corrected with data from polyamide blends using a simplex algorithm. Alternatively, calibration can be conducted with broadly distributed polyamides that were first fully characterized by SEC-MALLS. The resulting molar mass distributions for different sets of polyamides were compared with molar masses that were determined directly by SEC-MALLS and excellent correlation was obtained.     

Influence of the short‐chain branch length on the calibration of temperature rising elution fractionation systems

The effects of short‐chain branch (SCB) length on the calibration of temperature rising elution fractionation (TREF) were examined. Samples of ethylene–hexene, ethylene–octene, and a novel polyolefin produced using Eastman Chemical Company's Gavilan catalyst technology were used to prepare TREF calibration curves. Preparative TREF was used to collect fractions of the materials based on their crystallizability, and the branching frequencies of the fractions were determined by NMR. Calibration curves were generated by plotting the branching frequency as a function of the TREF elution temperature. The results indicate that the calibration curves shift to lower TREF elution temperatures as the length of the SCB increases from methyl to butyl to hexyl. Other factors that may contribute to this shift include chain microstructural differences from variations in catalyst structure and process conditions. The shift can be decreased by plotting the data in “number of branches per 1000 backbone carbons” versus TREF elution temperature instead of the more traditional “number of branches per 1000 total carbons.” These data indicate that the branch type must be known a priori to calculate SCB averages and SCB distributions and that unique calibration curves exist for copolymers made using different α‐olefin comonomers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 722–728, 2003     

付立叶变换近红外光谱法快速测定烟叶中叶黄素和β-胡萝卜素含量

应用高效液相色谱法测定烟叶中叶黄素和β-胡萝卜素含量,采用偏最小二乘法的近红外预测模型,建立了应用近红外光谱技术快速测定烟叶中类胡萝卜素含量的分析方法。方法的相关系数分别为0.9909和0.9861。     

Novel,Rapid Identification,and Quantification of Adulterants in Extra Virgin Olive Oil Using Near‐Infrared Spectroscopy and Chemometrics

A new, rapid Fourier transform near infrared (FT‐NIR) spectroscopic procedure is described to screen for the authenticity of extra virgin olive oils (EVOO) and to determine the kind and amount of an adulterant in EVOO. To screen EVOO, a partial least squares (PLS1) calibration model was developed to estimate a newly created FT‐NIR index based mainly on the relative intensities of two unique carbonyl overtone absorptions in the FT‐NIR spectra of EVOO and other mixtures attributed to volatile (5280 cm^?1) and non‐volatile (5180 cm^?1) components. Spectra were also used to predict the fatty acid (FA) composition of EVOO or samples spiked with an adulterant using previously developed PLS1 calibration models. Some adulterated mixtures could be identified provided the FA profile was sufficiently different from those of EVOO. To identify the type and determine the quantity of an adulterant, gravimetric mixtures were prepared by spiking EVOO with different concentrations of each adulterant. Based on FT‐NIR spectra, four PLS1 calibration models were developed for four specific groups of adulterants, each with a characteristic FA composition. Using these different PLS1 calibration models for prediction, plots of predicted vs. gravimetric concentrations of an adulterant in EVOO yielded linear regression functions with four unique sets of slopes, one for each group of adulterants. Four corresponding slope rules were defined that allowed for the determination of the nature and concentration of an adulterant in EVOO products by applying these four calibration models. The standard addition technique was used for confirmation.     

Application of the SIMS Method in Studies of Cr Segregation in Cr-Doped CoO: I, Aspects of Quantitative Analysis

Aspects of calibration of intensities of SIMS secondary ions vs concentration as well as sputtering time vs depth are considered for Cr-doped CoO. Advantages and limitations of the SIMS method in quantitative analysis of segregation-induced concentration profiles in oxide crystals are discussed. The studies indicate a substantial effect due to charging the surface during sputtering. The depth calibration was performed by using the Ta₂O₅/Ta system as a standard. Good depth resolution was revealed. The calibration dependence of Cr intensities on concentration is characterized by a wide scatter of data caused by charging the surface. Very good shape reproducibility of the intensity ratio vs depth profiles was revealed. Therefore, normalized intensity ratios can be used for calibration.     

Determination of hexane residues in vegetable oils with FTIR spectroscopy

The FTIR spectroscopy method was developed for the determination of hexane residues in palm and groundnut (peanut) oils. The method was based on horizontal attenuated total reflectance with a ZnSe crystal at 45° at room temperature, and partial least squares (PLS) statistics were used to derive calibration models. The accuracy of the method was comparable to that of the AOCS Method Ca 3b-87, with coefficients of determination (R ²) of 0.9866 and 0.9810 for palm and groundnut oils, respectively, and SE of calibration of 3.83 and 4.91, respectively. The calibration models were validated, and the R ² of validation and the SE of prediction computed. The SD of the difference for repeatability for the method was comparable to that for the standard AOCS method when used for palm and groundnut oils. With its speed and ease of data manipulation by computer software, FTIR spectroscopy has an advantage over present chemical methods, which require preparation of the oil using toxic solvents before GC.     

Simultaneous determination of molecular weight and crystallinity of recycled HDPE by infrared spectroscopy and multivariate calibration

An attempt of correlating molecular weight (M_n) of recycled high‐density polyethylene (HDPE) as measured by size‐exclusion chromatography (SEC) with diffuse reflectance near and mid‐infrared spectroscopy (NIR/MIR) was made by means of multivariate calibration. The spectral data obtained was also used to extract information about the degree of crystallinity of the recycled resin. Differential scanning calorimetry (DSC) was used as the reference method. Partial least‐squares (PLS) calibration was performed on the MIR and NIR spectral data for prediction of M_n. Four PC factors described fully the PLS models. The root‐mean‐square error of prediction (RMSEP) obtained with MIR data was 360, whereas a RMSEP of 470 was achieved when calibration was carried out on the diffuse reflectance NIR data. A PLS calibration for prediction of degree of crystallinity was performed on the NIR data in the 1100–1900‐nm region, but the ability of prediction of this model was poor. However a PLS calibration in the region 2000–2500 nm yield better results. Four PC factors explained the most of the variance in the spectra and the RMSEP was 0.4 wt %. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 321–327, 2002