响应面法优化黄芪多糖的提取工艺研究

为优化对黄芪多糖提取工艺.根据单因素实验结果,选取实验因素与水平,根据Box - Benhnken的试验设计原理,采用三因素三水平的响应面分析法,以获得多元二次线性回归方程,以多糖得率为响应值的响应面和等高线.结果表明,提取黄芪多糖最佳工艺条件:料水比1:13,提取温度94 ℃,提取时间64 min.在此条件下,黄芪多...     

星点设计-响应面法优化麦冬总黄酮提取工艺及其抗氧化活性的研究

在单因素试验的基础上,利用星点设计-响应面法来优化酶提取法提取麦冬总黄酮的提取工艺,同时利用DPPH法和Fenton法测定总黄酮提取液清除1,1-二苯基-2-三硝基苯肼自由基和羟基自由基的能力.结果表明麦冬总黄酮酶提取法的最佳提取工艺条件:酶用量为46.61 mg,酶解时间为4.14 h,酶解温度为55.56℃,提取率...     

响应面法优化黄连-罗汉果药对中降糖成分的超声提取工艺研究

本文优化了黄连-罗汉果药对中发挥降血糖作用的主要指标性有效成分小檗碱型生物碱、多糖和罗汉果皂苷的超声提取工艺。利用响应面法考察超声提取时间、料液比例、超声温度与超声功率对提取效果的影响。最佳提取条件为将黄连、罗汉果细粉浸泡于1∶30倍量的水中,置于75℃、400 W的恒温超声仪中提取23 min,提取3次,得到的提取液中三种指标成分质量总和最高,其中小檗碱型生物碱、多糖和罗汉果皂苷的提取率分别为22.70%、31.16%、16.55%。该提取工艺简单高效,预测性良好,有利于促进黄连、罗汉果合用发挥降血糖功效的开发利用。     

基于多指标评价法的蒲公英提取工艺优化

以超声提取法提取蒲公英有效成分,选择总黄酮、咖啡酸、绿原酸和菊苣酸为评价指标,结合AHP-CRITIC法计算各指标权重;在单因素试验的基础上,利用Box-Behnken法优化蒲公英超声提取工艺。实验结果表明超声提取法提取蒲公英的最优提取工艺参数为：液料比5∶1,甲醇浓度60%,提取时间26 min,在此工艺条件下预测综合评分为73.26,验证实验所得综合评分为74.13±2.63,RSD为3.55%。本研究优化的蒲公英超声提取工艺适合于蒲公英中总黄酮、咖啡酸、绿原酸和菊苣酸的提取,其工艺稳定、可靠,可为蒲公英资源的开发和利用提供参考。     

响应面优化制备花生壳纤维素及其对罗丹明B的吸附性能

以废花生壳为原料制备了花生壳纤维素吸附剂并将其用于去除水中水中罗丹明B(Rhodamine B,RhB)染料。采用Box-Behnken Design(BBD)响应面法(RSM)法对制备条件进行了优化,筛选出获得吸附效果最佳的花生壳纤维素的制备条件。系统考察了溶液的pH值,初始浓度、吸附时间以及溶液离子强度对其吸附性能的影响。结果表明:pH=4时,花生壳纤维素对RhB的吸附效果最佳,饱和吸附容量q_m为166.7 mg·g^-1;与RSM模型预测值吻合。吸附过程可在30 min内达到平衡,符合准二级动力学模型。吸附容量随着溶液离子强度的增大而减小,说明其吸附是以静电作用为主的吸附过程。10次循环使用后花生壳纤维素对RhB的吸附效率仍能保持91%以上,表明该材料可以多次循环使用,是潜在的高效吸附材料。     

响应面法优化牦牛骨胶原蛋白的提取工艺研究

近年来,胶原蛋白由于自身的功能特性而日益成为人们关注的热点。本文以牦牛骨为原料,采用胃蛋白酶酸酶法提取胶原蛋白。考察了固液比、胃蛋白酶采用响应面实验优化,得到最佳酶解条件为固液比为1∶28 g·mL^-1、胃蛋白酶用量为0.4 g·L^-1、提取时间为12.5 h,在此条件下提取率为35.88%。     

响应面法优化微波提取翻白草总黄酮

利用响应面法研究了翻白草总黄酮的微波辅助提取工艺.在单因素试验的基础上,以乙醇体积分数、液固比、提取温度、微波时间为自变量,总黄酮的得率为响应值,研究各因素及其交互作用对黄酮得率的影响.结果表明其最佳提取条件是:乙醇体积分数55%、液固比32 m L/g、温度82℃、微波时间10 min.此条件下,翻白草中黄酮的提取率为6.96 mg/g,与理论预测值基本吻合.     

景天三七总多酚提取工艺的优化及活性研究

采用超声提取景天三七中的多酚,并利用Box-Behnken响应面法对影响景天三七总多酚提取率的因素(液料比、乙醇浓度、超声时间、超声温度)进行了优化,并以DPPH自由基和ABTS自由基清除能力为评价指标,研究景天三七总多酚体外抗氧化活性.结果显示,最佳的提取条件为乙醇浓度63％,液料比36:1(mL·g-1),超声温度...     

响应面法优化大孔树脂固定化黑豆过氧化物酶的研究

从陕北小粒黑豆中提取的过氧化物酶经过分离纯化后,用大孔树脂吸附法对其进行固定化研究,从8种树脂中优选出固定化效果较好的LXD-762型树脂,然后通过单因素实验和响应面优化实验对其固定化条件进行优化。结果表明,在振荡速度150r/min、吸附时间4.2h、酶液浓度0.25mg/m L、吸附温度35℃的优化条件下,固定化效果最好,固定化率可达94.35%。     

木蹄多糖提取工艺研究

通过对木蹄多糖提取得率有影响的子实体粉末颗粒大小、料水比、提取温度和提取时间进行的单因素研究,其中对料水比、提取温度和提取时间3个因素采用应用响应面法进行了优化,确定了木蹄子实体多糖的最佳提取工艺条件：子实体粉末颗粒60目,料水比1：42．92,提取温度88．92℃,提取时间3．92h,多糖得率达到5．68％。     

基于自适应蒙特卡洛法评定测量不确定度程序开发与应用

进行了基于自适应蒙特卡洛法评定测量不确定度的程序开发与应用。基于Python语言,设计开发自适应蒙特卡洛法评定测量不确定度程序,包含评定过程框架、自定义变量名称模块、过程参数关联计算模块以及蒙特卡洛法采样计算模块。程序界面简洁,操作简单,计算准确,适用于任意多个独立变量、任意多个过程参数及单一被测量的数学模型,为利用自适应蒙特卡洛法评定测量不确定度提供了方便。     

Uncertainty of measurement for summed masses: application to controlled substances

Because sentences for drug possession depend on the mass of the seized drug, testing laboratories must often determine the summed mass of numerous items submitted under a single case. One common practice for this purpose is to continue analyzing and weighing samples until a legal threshold is passed, at which point it is important to inform the court whether the summed mass is significantly above the threshold, or only marginally so. This paper develops a means for estimating the uncertainty of the summed mass for the common situation where the readability, d, of the balance dominates the uncertainty. It is seen that for all sample sizes the uncertainty, UM, is given by the remarkable simple expression UM = (d/2) × [N + SQRT(3N)] + N × CCE, where N is the number of items and CCE is the absolute value of the calibration check error. In most instances, this can be further simplified to UM = N × d.     

自由基浓度测定方法的再验证及其在煤化学中应用

对前人建立的标准曲线法测煤中自由基浓度进行优化,以DPPH标准样品和基准样品的二次积分面积比值为新参数,结果显示新参数标准曲线法的实测值与理论值相对误差都在5%以内;重复性、复现性实验的相对标准偏差都小于3%。将新参数标准曲线法用于分析不同煤化程度煤和新疆黑山煤(HS)沥青质的自由基浓度,发现随着煤化程度增加,其煤中自由基浓度逐渐增大,从低阶褐煤的8.531×10~(17)/g上升到高阶无烟煤3.37899×10~(19)/g;而在HS煤液化过程中,随着加氢液化温度的升高,其沥青质自由基浓度逐渐下降,从290℃的1.5793×10~(18)/g降到450℃的7.410×10~(17)/g,沥青质自由基浓度变化趋势与其产率变化趋势相一致。     

Effects of injection angle on the measurement of surface tension coefficient by drop weight method

The drop weight method for surface tension measurement is based on the weight of drops detached from a nozzle. The original idea was based on a postulate introduced by Tate (On the Magnitude of a Drop of Liquid Formed Under Different Circumstances, Philos. Mag. 27, 176–180, 1864), assuming that the weights of an ideal pendant drop and a detached ideal drop are identical, and that this weight is equal to the surface force that holds a drop attached to the nozzle. To consider the real volume of a drop that detaches from a nozzle, the method required a correction factor. Harkins and Brown suggested such correction factors for vertical injection from a nozzle. In this study, a correction factor for injection at different angles is presented and some of the hydrodynamic effects on surface tension measurement based on the drop weight method are studied. In addition, a model is introduced for the detachment time of drops in directions other than the vertical direction     

基于Design-Expert软件对原子吸收光谱仪工作参数优化

将响应表面试验设计方法(RSM)应用于原子吸收光谱仪工作参数优化,以铜元素为目标化合物,结合Design-Expert软件进行数据处理.结果表明,单因素试验最佳工作条件:仪器灯电流15 m A,仪器吸喷速率7 m L/min,仪器乙炔气流量3.00 L/min.中心组合试验结果表明:当吸喷速率为7 m L/min、乙炔气流量为2.25 L/min、灯电流为10 m A时,仪器灵敏度最好.     

Adiabatic multi-step separation method and its application to coupled oscillators

Extension of the adiabatic approach to a multi-step separation method is presented. This method step by step reduces the multi-dimensional Schrödinger equation to the effective equations of lower dimensions. The reduction procedure allows to take advantage of multi-level hierarchy of various physical systems. The multi-step separation method is applied in the calculation of vibrational energies of coupled oscillators. The new method is found to be very effective and accurate.     

New translation method for STOs and its application to calculation of overlap integrals

A new translation method for Slater‐type orbitals (STOs) is proposed involving exact translation of the regular solid harmonic part of the orbital followed by the series expansion of the residual spherical part in powers of the radial variable. The method is positively tested in the case of the overlap integral, showing good rate of convergence and great numerical stability under wide changes in the relevant molecular parameters. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 73: 333–340, 1999     

正交试验结合响应面法优化诃子多糖提取工艺

采用正交试验结合响应面法优化诃子多糖的提取工艺,以诃子多糖的提取率为指标,以固液比、提取温度、提取时间和提取次数为因素,正交试验初步筛选工艺参数,响应面法做进一步优化.结果表明,多糖提取的最佳工艺条件为固液比1∶28,提取温度69℃,提取时间1h,提取次数3次,各项指标相对误差均小于2%,应用响应面法可减少诃子多糖提取时间.     

New translation method for STOs and its application to calculation of two-center two-electron integrals

The new translation method for Slater-type orbitals (STOs) previously tested in the case of the overlap integral is extended to the calculation of two-center two-electron molecular integrals. The method is based on the exact translation of the regular solid harmonic part of the orbital followed by the series expansion of the residual spherical part in powers of the radial variable. Fair uniform convergence and stability under wide changes in molecular parameters are obtained for all studied two-center hybrid, Coulomb, and exchange repulsion integrals. Ten-digit accuracy in the final numerical results is achieved through multiple precision arithmetic calculation of common angular coefficients and Gaussian numerical integration of some of the analytical formulas resulting for the radial integrals. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 91–100, 2000     

Multivariate Optimization of Pb2+ Adsorption onto Ethiopian Low-Cost Odaracha Soil Using Response Surface Methodology

Lead pollution is a severe health concern for humankind. Utilizing water contaminated with lead can cause musculoskeletal, renal, neurological, and fertility impairments. Therefore, to remove lead ions, proficient, and cost-effective methods are imperative. In this study, the Odaracha soil which is traditionally used by the local community of the Saketa District was used as a novel low-cost technology to adsorb lead ions. Odaracha adsorbent was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption process followed the batch adsorption experiment. The response surface method was implemented to derive the operating variables’ binary interaction effect and optimize the process. According to the study’s experimental result, at optimum experimental conditions Odaracha adsorbent removes 98.17% of lead ions. Based on the result of the central composite design model, the Pb²⁺ ion removal efficiency of Odaracha was 97.193%, indicating an insignificant dissimilarity of the actual and predicted results. The coefficient of determination (R²) for Pb²⁺ was 0.9454. According to the factors’ influence indicated in the results of the central composite design model, all individual factors and the interaction effect between contact time and pH has a significant positive effect on lead adsorption. However, other interaction effects (contact time with dose and pH with dose) did not significantly influence the removal efficiency of lead ions. The adsorption kinetics were perfectly fitted with a pseudo-second-order model, and the adsorption isotherm was well fitted with the Freundlich isotherm model. In general, this study suggested that Odaracha adsorbent can be considered a potential adsorbent to remove Pb²⁺ ions and it is conceivable to raise its effectiveness by extracting its constituents at the industrial level.