Comparison of methods of parameric correction for evaluating metamerism

In practice, most metameric pairs do not achieve colorimetric equality for a set of reference conditions. These parameric pairs are composed of a residual color difference and a metameric difference. Three techniques have been used to correct this residual color difference: an additive correction in L*a*b*, a multiplicative correction in XYZ (recommended by the CIE), and parameric decomposition where the batch's spectrum is adjusted. Parameric decomposition can be viewed as batch correction using three “colorants” (process primaries) where the color‐mixing model is linear in reflectance. Most often, Cohen and Kappauf's Matrix R technique is used where the primaries are color matching functions. Alternative primaries were derived from a Munsell Book of Color and an automotive paint system using principal component analysis (PCA) and independent component analysis (ICA). 1,152 parameric pairs about 24 color centers were synthesized using the paint system and Kubelka–Munk turbid‐media theory. Each parameric pair was corrected to a metameric pair using these methods. Spectral accuracy was evaluated by comparing the corrected spectra to metameric reference spectra calculated using Kubelka–Munk batch correction. The Matrix R technique had the worst spectral accuracy under the reference conditions while both PCA and ICA had similar and reasonable accuracy. The special index of metamerism, change in illuminant, was calculated for each parameric pair using these various correction techniques to achieve colorimetric equality. The Matrix R and CIE‐recommended multiplicative techniques were statistically significantly worse than parameric decomposition using Munsell Book of Color PCA and ICA and automotive ICA process primaries. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 293–303, 2007     

铁含量测定方法比较研究

依次以2,2’-联吡啶和1,10-菲啰啉为显色剂,研究了对应的测定铁含量的光度法的灵敏度、线性范围及常见阳离子的干扰倍数。结果显示,对干扰离子Cu2+、Ni2+及Zn2+而言,2,2’-联吡啶分光光度法的抗干扰能力较强;在回归方程线性相关系数相同的前提下,1,10-菲啰啉光度法灵敏度较高,2,2’-联吡啶分光光度法的线性范围较宽。研究结果对在一定条件下,更合理地选用测定方法,有一定的指导意义。     

Comparison of 4 methods of evaluating protein quality in vegetable sources

This study compares the practical value of the following methods: protein efficiency ratio (PER), blood urea concentration in rats (BUC), relative nutritive value (RNV), and predicted protein value (PPV) to evaluate the protein quality of 41 diets of plant origin. Results demonstrated low correlations between PER and RNV (r = 0.66), PER and PPV (r = 0.53), RNV and PPV (r = 0.54), whereas there was a high negative correlation between PER and BUC (r = -0.89). These different procedures can be useful and valid for distinct and well-defined objectives, but the evaluation of results must be made in accordance with the purpose of the experiment. In assessing the protein quality of foodstuffs, it is therefore recommended that mathematical computer models be developed which take into account the cybernetic system of the amino acid metabolism. This would definitely reduce the actual need of expensive long-term biological assays.     

3种磷含量测定方法的比较

目的比较3种A群脑膜炎球菌多糖蛋白结合物中磷含量测定方法的差异,为今后方法的选择及进一步优化提供参考。方法对《中国药典》三部(2010版)附录中的磷测定法(方法1)、高分子结合物含量测定法(方法 2)、文献中的磷测定法(方法 3)这3种方法的标准曲线、测定磷酸二氢钾对照品中磷含量、测定A群多糖、A群衍生物、A群结合物中磷含量以及标准曲线增加两个低浓度点的差异进行比较。结果不同人员采用同一方法绘制的标准曲线的斜率(b)的变异系数(CV)均小于10%,相关系数(r2)均在0.995以上,CV值在0~0.23%之间,其中方法 2标准曲线b值的CV值小于1%,且r2值与其他两种方法相比更稳定;3种方法测定同一份磷酸二氢钾对照品的结果与理论值相比,相对误差均在10%以下,其中方法 2的相对误差最小,为5.73%;3种方法测定A群多糖、A群衍生物、A群结合物中磷含量的CV值均小于10%;3种方法的标准曲线增加两个低浓度点后,b值及r2值的CV值均小于10%,与原标准曲线近似。结论 3种方法测定磷含量的标准曲线均具有良好的线性,不同操作人员的测定结果无明显差异,其中方法2测定A群脑膜炎球菌多糖、A群脑膜炎球菌多糖衍生物及A群脑膜炎球菌多糖蛋白结合物中的磷含量时,稳定性较好,操作简便易行。     

Relation of the energy content of fats and proteins as an indicator of energy-protein potential of population diets

The protein-calorie (Po/o) and the protein value (NDpCalo/o) have been proposed as indices to evaluate the potentiality of diets to meet protein and calorie needs of a given population. The fat-calorie to protein-calorie ratio (G/P) is presented as a complementary index, considering the possibility that the values of Po/o and NDpCalo/o can be adequate but that the energy density of the diets is too low, as might be the case in many rural communities of the developing countries. On the basis of the evidence discussed in this paper, the G/P ratio estimated as adequate is 2.5, and values lower than 2 can be considered as nutritionally unacceptable.     

Comparison of methods for evaluating bond strength between concrete substrate and repair materials

This investigation was aimed at studying the effect of test methods on bond strength between concrete substrate and repair material. Four test methods with cementitious or modified-cementitious repair materials, and two surface roughnesses were studied. The methods used were pull-off, slant shear, splitting prism and a new direct shear named Bi-Surface shear test. While the coefficient of variation (COV) for each type of test was acceptable, the bond strengths from some tests were up to eight times larger than those obtained from others. It is imperative that the bond tests be selected such that they represent the state of stress the structure is subjected to in the field. The new test method was easy to carry out and had reasonable results and can be developed by further investigations.     

腈纶含油率检验方法对比

使用索氏萃取法、红外光谱分析法、紫外分光光度法对腈纶短纤维含油率进行了测定,对其结果进行了假设检验分析,并比较了3种方法。结果表明:3种方法测定3．20 dtex×102 mm,6．00 dtex×102 mm, 2．78 dtex×64 mm腈纶短纤维的含油率分别为0．358％-0．365％,0．534％～0．550％,0．401％～0．410％; 假设检验分析表明,3种方法均接受假设,其检验水平一致;3种方法各有特点,在进行含油率测试时,可根据条件和需要,合理选择分析方法。     

Comparison of different methods for the determination of the oil content in oilseeds

The investigation and assessment of the oil content of oilseeds are important criteria, especially for the oil milling trade. Standard methods for the determination of the oil content of oilseeds are very time consuming, with extraction periods of 4 to 8 h. Three different oilseeds—rapeseed, sunflower, and soybean—are extracted by supercritical fluid extraction (SFE), accelerated solvent extraction, microwave-assisted extraction, solid fluid vortex extraction, and Soxtherm, and the results are compared with the result of the German Fat Science Society (DGF) standard method B-I 5 (87). Besides, the extracts are analyzed regarding the content of tocopherols as a parameter for mild extraction conditions and the content of diglycerides and free fatty acids as parameters for the content of more polar lipids. The results of the determination of the oil content under optimal conditions are comparable with the results of the DGF standard method B-I 5 (87). There are no significant differences between the different methods. The content of tocopherols is dependent upon the extraction method and the type of oilseed. The highest content is obtained by SFE. The content of diglycerides and free fatty acids varied according to the oilseed.     

煤制气甲烷化过程能量利用评价方法比较

针对煤制气托普索甲烷化工艺中的典型反应装置和非反应装置,采用能量衡算法和有效能分析法,选定相关的计算基准,比较不同方法,同时对照比较了Aspen Plus的模拟计算结果。研究表明:在进行焓差计算中,平均热容法、统一基准焓法和统一热值法计算结果接近,后两者计算过程简单清晰,但Aspen Plus计算结果有较大差距;在计算物流焓时,3种方法计算结果各不相同,但统一基准焓法可与Aspen Plus的计算值相统一;在进行有效能分析中,化学有效能计算基准采用龟山-吉田模型,可与统一基准热值法相统一,便于比较。     

Comparison of the direct and indirect wide-line nuclear magnetic resonance methods for determining solid fat content

A direct method of measuring the solid fat content by wide-line nuclear magnetic resonance (NMR) was compared with the conventional indirect wide-line NMR procedure. The direct method is based on the use of variable gate widths available on the Newport Analyser Mk IIIA. The results obtained for four different fats using the direct method did not differ significantly from those of the indirect method. As the direct method required additional measurements, was somewhat more complex theoretically and gave more variable results because of the weaker signal obtained at the wide gate, no real advantage could be found for its use.     

Soil nutrient content and nutrient balances in newly-built solar greenhouses in northern China

Soil nutrient content and nutrient balances in newly-built solar greenhouses in the southern part of China??s Loess Plateau were investigated over two consecutive years. Farmers applied manure and inorganic fertilizers at average annual rates of 1,907?kg?N ha^?1, 1,601?kg?P₂O₅?ha^?1 and 1,742?kg?K₂O?ha^?1. Manure accounted for 65?% of the total N input, 57?% of the total P input and 55?% of the total K input. The average annual nutrient surpluses were 1,374?kg?N?ha^?1, 1,468?kg?P₂O₅?ha^?1 and 881?kg?K₂O?ha^?1. Soil organic matter, total N, available P, available K and electrical conductivity (EC) increased significantly across time in the topsoil (0?C20?cm depth), but not in the subsoil (20?C100?cm depth). The nitrate?CN concentrations (mg?N?kg^?1) of the 0?C100?cm depth increased by 163?C336?% over 2?years. The average accumulation of nitrate?CN (kg?N?ha^?1) of the 0?C100?cm depth increased by 241?% and leveled out at 511?kg?N?ha^?1; and it was 1,015?kg?N?ha^?1 in the 0?C200?cm depth. In conclusion, over-fertilization led to large nutrient surpluses in the soil of newly-built greenhouses.     

凝血酶原复合物中肝素含量测定的两种方法的比较

目的对凝血酶原复合物(prothrombin complex concentrate,PCC)中肝素含量测定的发色底物法和经典的硫酸鱼精蛋白中和肝素凝固法进行比较。方法对本公司制备的8批PCC实验样品,分别采用发色底物法和凝固法测定肝素含量,比较两种方法检测结果的差异和测定重复性。结果凝固法、发色底物法重复性均良好,凝固法检测有20%的误差,发色底物法CV在3.5%~9.2%之间;两种方法样品检测值的差值与均值比在4.4%~29.2%之间,检测值的相关系数为0.407,而仅选取用组分Ⅲ沉淀制备样品时,检测值的相关系数为0.938。结论凝血酶原复合物中肝素含量测定的两种方法中,发色底物法与经典的硫酸鱼精蛋白中和肝素凝固法相比,定量更精确,适用性更强。     

Squash yield, nutrient content and soil fertility parameters in response to methods of fertilizer application and rates of nitrogen fertigation

Two field experiments were conducted to evaluate squash yield and nutrient content in response to different fertigation nitrogen (N) rates and method of fertilizer N application. The following treatments were studied in a randomized complete block design with four replications: zero N (N0), 50 (N1), 100 (N2) and 150 (N3) mg l^–3 N concentration in the irrigation water (IW) (fertigation treatments) and a soil application treatment (NS) equivalent to the N2 treatment. Irrigation was applied to replenish 80% of the Class A pan evaporation twice a week. Compared to the control (N0), shoot dry matter and yield were increased by all fertigation N rates and by the soil application treatment. However, soil application gave a lower yield than the equivalent fertigation N rate, indicating the comparative advantage of fertigation. The lowest fertigation N rate was adequate to give the highest yield in the first season, while in the second season a higher rate was necessary to achieve the maximum yield. The growth and fruit yield were higher in the second season as a result of the more favorable climatic conditions. Regression relationships indicate that the yield and the shoot dry weight were related to the fertigation N rates by polynomial quadratic relationships. The response to N in the second season was greater, as indicated by the steeper positive slope. The fruit yield was linearly related to both fruit number and fruit size in both seasons. N contents in shoots increased with N addition and were higher in both fruit and shoot during fruiting with the fertigation method. Soil salinity slightly increased with N application, especially in the top 15 cm, but remained low and acceptable for normal plant growth. Soil P increased mainly in the top soil following phosphoric acid application to all plots. Restricted P movement to deeper soil is attributed to the expected precipitation and/or sorption reactions with Ca and Mg in calcareous soils. It can be concluded that fertigation is more effective than soil application in increasing the yield and with fertigation lower N rates would be adequate to produce higher yield, thus lowering fertilization cost and minimizing environmental impact of over-fertilization.     

掺混肥料检验方法的改进

由于掺混肥属于定向非随机不均匀物料,为使养分分析结果具有代表性,重现性好,提出掺混肥料取样方法的改进措施,选择可封闭式或关闭式采样探子;采用四角取样法进行取样;采用多次重新缩分的分样方式进行样品缩分;试样制备时保留至少200~250 g样品。用此方法对掺混肥取样分析,可获得较好的结果。     

磷酸二铵产品养分含量的定量估算

论述磷酸二铵产品中的物相组成 ,并对其含量进行定量估算 ,计算值与产品的实际检测结果很接近。最后分析了浓磷酸中的杂质含量对磷酸二铵产品总养分的影响     

内标法与外标法测定餐具洗涤剂中甲醇含量的分析比较

对GB 9985—2000中内标法测定餐具洗涤剂中甲醇含量的方法进行了改进,并比较了内标法和外标法在测定洗涤剂中甲醇含量的差异。通过向洗涤剂样品中加入异丁醇内标液,用75%乙醇定容到一定体积,经0.45μm针式微孔滤膜过滤,DB-FFAP色谱柱分离,火焰离子化检测器(FID)检测,内标法和外标法分别计算洗涤剂中甲醇的含量。实验得到方法的检出限为0.5 mg/L,内标法和外标法的相对标准偏差(RSD)分别为0.4%~0.9%和0.6%~1.2%,平均回收率分别为100%~102%和95%~99%。结果表明,采用内标法和外标法的定量方式获得的结果均能满足检测要求,但内标法的精密度和回收率优于外标法。     

DAP产品总养分的影响因素及控制方法

分析磷酸中固形物、阴离子和阳离子等杂质对磷酸二铵产品总养分的影响。阐述调整产品总养分的措施,主要采取锥形槽式沉降法和平底槽式沉降法澄清磷酸,以降低含固量,提高产品总养分;采用配浆法提高含固量和添加硫酸、石膏的方式降低产品总养分。并对其可行性、有效性和准确性进行探讨。     

两种Lowry法检测百日咳疫苗原液蛋白含量的比较

目的比较《中国药典》三部(2015版)收录的两种Lowry法测定百日咳疫苗原液蛋白定量的差异,为原液蛋白准确定量和新版药典Lowry法的适用性确认提供依据。方法 9个实验室分别按照现行药典收录的两种Lowry法,对4家15批百日咳疫苗原液蛋白含量进行测定。并与凯氏定氮法检测结果进行比较。结果方法 1(未经酸沉淀Lowry法)实验室内测定结果的变异系数(CV)均值在1.7%~8.9%之间,实验室间测定结果的CV值在3.9%~9.3%之间;方法 2(酸沉淀Lowry法)实验室内测定结果的CV均值在3.6%~7.4%之间,实验室间测定结果的CV值在3.9%~18.1%之间。同一样品两种方法测定结果差异有统计学意义(P0.001),结果呈相关性(R2=0.944 9)。在与部分样品测得的凯氏定氮法结果的比较中,方法 1差异有统计学意义(P0.001),方法 2差异无统计学意义(P0.05)。结论所有样品采用同一种Lowry方法测定时所得结果实验室内和实验室间一致性较好,采用方法 2测定结果明显低于方法 1,更接近凯氏定氮法结果真实值,表明酸沉淀对Lowry法百日咳原液蛋白定量有显著影响。与Lowry方法 1相比,Lowry方法 2更能准确反映百日咳疫苗原液的真实蛋白含量,且精密度、适用性均符合要求。