维生素的分析方法研究进展

本文对维生素的分析方法进行了综述。维生素的分析方法主有高效液相色谱、荧光分析法、紫外-可见分光光度法和流动注射化学发光分析法等。     

化学发光法测定水中痕量铬(Ⅵ)

本文介绍了流动注射化学发光分析法测定水样中痕量铬(Ⅵ)的新方法。关于液相化学发光分析的研究和应用在我国已初步开展,是一种高灵敏度的分析方法。但在无机物的分析方面限制很大,一个重要原因是能产生化学发光的物质不多,因此仅有少数无机离子能够利用这类方法测定,而铬(Ⅵ)就是其中的一种离子。本实验用鲁米诺作为化学发光     

流动注射化学发光分析法的应用进展

综述了近几年来流动注射化学发光分析法的研究进展,展望了流动注射化学发光分析法的发展动向.     

流动注射化学发光技术在农药残留检测中的应用

简述了流动注射化学发光技术的基本原理、实验装置及其与免疫分析、高效液相色谱、固相光谱、红外等分析技术联用在农药残留检测方面的应用。讨论了流动注射化学发光技术存在的问题和发展趋势。指出这种新型有效的自动微量化分析技术在食品和环境中的农药残留检测方面已经取得了一定进展，但还存在一些问题需要不断改进。     

流动注射化学发光法测定洗涤用品中的甲醛

基于在酸性介质中,甲醛能够增敏高锰酸钾氧化茚三酮的化学发光反应,结合流动注射技术,建立了测定洗涤用品中的甲醛的化学发光分析方法。结果表明,甲醛质量浓度在10μg/mL～100μg/mL内,与发光强度呈良好的线性关系;对50μg/mL甲醛标准溶液连续进样7次测定,相对标准偏差为1.49%,该方法的检出限为0.637μg/mL。     

双(2,4,6-三氯苯基)草酸酯化学发光反应及其在分析化学中的应用

评述了近年来双（２，４，６－三氯苯基）草酸酯化学发光反应在分析化学领域中的应用和进展，尤其详述了这一反应体系用作液相色谱和流动注射分析检测技术的原理和应用。     

Luminol-H2O2化学发光体系测定水中对叔丁基苯酚

采用流动注射技术研究了在碱性条件下,Luminol-H2O2与对叔丁基苯酚的化学发光行为,对影响化学发光强度的诸因素进行了优化,建立了流动注射化学发光法测定对叔丁基酚的新方法.方法的检出限为4×10-8g/L,线性范围为2.0×10-6～1×10-4g/L,对10-5g/L对叔丁基进行11次平行测定,相对标准偏差为1.45%.该法用于测定废水中对叔丁基苯酚的含量,结果令人满意.     

多巴胺与牛血清白蛋白相互作用的流动注射-化学发光法研究

采用流动注射-化学发光法研究了多巴胺与牛血清白蛋白的相互作用。根据流动注射-化学发光模型,给出了不同温度下多巴胺与牛血清白蛋白的结合常数、结合位点数和热力学参数。结果表明,多巴胺与牛血清白蛋白可能形成1∶1复合物,结合常数在104数量级。热力学参数表明该反应为自发吸热熵增加的过程,主要作用力为疏水作用力。     

岩白菜素抗氧化活性的分子光谱法测定

以自由基清除法,结合流动注射-化学发光法、紫外-可见分光光度法和荧光光谱法等分子光谱技术对岩白菜素进行抗氧化活性研究。以岩白菜素清除率为指标,以经典抗氧化剂维生素C作为对照,测得清除率紫外-可见分光光度法为98.10%、荧光光谱法为98.22%、流动注射-化学发光法为97.87%;对超氧阴离子的清除,测得清除率紫外分光光度法为75.20%、荧光光谱法为73.15%、流动注射-化学发光法为79.67%,岩白菜素对羟自由基的清除IC_(50)为0.73 ng/mL,对超氧阴离子清除IC_(50)为1.18 ng/mL,且抗氧化活性均优于经典抗氧化剂维生素C。结果表明,岩白菜素具有良好的抗氧化能力,为岩白菜属植物抗氧化活性的开发提供理论依据和实验参考。     

分子印迹流动注射化学发光测定胞嘧啶核苷

以胞嘧啶核苷为目标分子,合成对其有专一性识别的分子印迹聚合物(MIP)。在酸性条件下,利用HCl-KMn O4-HCHO发光体系,结合流动注射化学发光(FI-CL)分析方法,创建对胞嘧啶核苷测定有特异性识别的MIP-FI-CL分析方法,其线性范围为8×10-5~1×10-3mol/L,检出限为4×10-5mol/L。利用此方法测定复杂样品中胞嘧啶核苷的含量,结果令人满意。     

Numerical and experimental analysis of resin flow and cure in resin injection pultrusion (RIP)

This work presents the results of modeling, numerical simulation, and experimental study of resin flow and heat transfer in the resin injection pultrusion (RIP) process. A control volume/finite element method (CV/FEM) was used to solve the flow governing equations, together with heat transfer and chemical reaction models. Resin viscosity, degree of cure, and fiber stack compressibility and permeability were measured in order to understand their influences on the process. An analytical flow model has also been develped based on the one‐dimensional flow approximation for the resin flow in the injection die. A high‐pressure small‐taper injection die was tested with different line speeds. Experimental data were used to verify the simulation results and the analytical solutions.     

化学需氧量测定方法的研究与探讨

化学需氧量是评价水体有机物污染的重要指标之一,是常规分析测试的主要项目。阐述了标准回流法中催化剂、掩蔽剂、消解方法、氧化剂方面的研究,探讨了分光光度法、电化学法、动力学法、流动注射分析法、相关系数法、原子吸收法等测定方法的发展研究,同时,介绍了COD在线自动监测,提出了化学需氧量测定方法的趋势,为环境监测工作提供有利价值。     

Role of vacuum pressure and port locations on flow front control for liquid composite molding process

In this paper, the influence of air pressure gradients at the flow front, due to presence of two air vents under different vacuum pressures, is investigated for Liquid Composites Molding (LCM) Processes such as Resin Transfer Molding (RTM) and Vacuum Assisted Resin Transfer Molding (VARTM). An analytical mode introduced to predict the pressure distribution. It is suggested that the air press variation along the flow front can be used to control the flow front progress during the injection molding processes. The parametric studies identify a simple relationship that captures the most important process physics, which in prat can be implemented for flow front control.     

Application of The Splitting Approach to Solve Population Balance Equations in Chemical Processes

Different processes in chemical industries deal with particles and multiphase flow. In such processes, particle or bubble size distribution (PSD) influences the final product quality and also process design. On the other hand, solutions to the dominant hydrodynamic and thermo‐kinetic equations ignoring these distributions will make it impossible to accurately simulate these processes. Solutions to population balance equations (PBE's) are needed to attain the PSD. One of the most common methods for the solution of a PBE is the classes method (CM). However, as this method requires a large number of classes to give a reasonable result, it needs a huge amount of calculations and time. To overcome this problem, in this paper, a variant of the CM is proposed in which particles in different classes are transformed to new classes in two steps with the application of the operator splitting technique. In the first step, the particles are aggregated and broken up to form three parallel types of groups, namely: groups formed from aggregated particles, groups formed from broken‐up particles, and finally, a group formed from non‐altered particles. In the second step, these parallel groups are combined to redefine classes for the next time step. Finally, results of this method, which could be called the parallel groups classes method (PGCM), for different coalescence and breakage kernels are compared with those obtained using the analytical solution and the CM. Excellent agreement of the results from the PGCM with the analytical solution reveals its effectiveness and accuracy; which will give it an advantage over the CM.     

Novel flow injection synthesis of iron oxide nanoparticles with narrow size distribution

A novel synthesis method based on a flow injection technique was developed and the synthesis of magnetite nanoparticles was performed to demonstrate the concept. The technique consisted of continuous or segmented mixing of reagents under laminar flow regime in a capillary reactor. Different schemes of the flow injection synthesis were evaluated and the continuous mode was found to be more advantageous for the synthesis of the iron oxide particles. The material was characterised by X-ray diffraction, thermal analysis, electron microscopy, and magnetic susceptometry. The obtained magnetite nanoparticles had a narrow size distribution in the range 2-7 nm. The influence of chemical parameters and conditions on properties of the material was investigated.     

注塑制品熔接痕的自动识别

通过对注塑模充模过程中熔接痕形成机理的数学分析，给出了一个结合流动模拟数值实现过程的熔接痕自动识别算法，结合计算机图形学知识，利用计算机自动实现了注塑成型中熔接痕的起始、发展和形成。该算法可预测复杂制件的熔接痕位置，并适用于气体辅助注射成型和反应注射成型。最后通过一个算例验证了该算法的实用性。     

A STUDY OF NON-NEWTONIAN FLOW AND HEAT TRANSFER OVER A NON-ISOTHERMAL WEDGE USING THE HOMOTOPY ANALYSIS METHOD

The thermoconvective boundary layer flow of a generalized third-grade viscoelastic power-law non-Newtonian fluid over a porous wedge is studied theoretically. The free stream velocity, the surface temperature variations, and the injection velocity at the surface are assumed variables. A similarity transformation is applied to reduce the governing partial differential equations for mass, momentum, and energy conservation to dimensionless, nonlinear, coupled, ordinary differential equations. The homotopy analysis method (HAM) is employed to generate approximate analytical solutions for the transformed nonlinear equations under the prescribed boundary conditions. The HAM solutions, in comparison with numerical solutions (fourth-order Runge-Kutta shooting quadrature), admit excellent accuracy. The residual errors for dimensionless velocity and dimensionless temperature are also computed. The influence of the “power-law” index on flow characteristics is also studied. The mathematical model finds important applications in polymeric processing and biotechnological manufacture. HAM holds significant promise as an analytical tool for chemical engineering fluid dynamics researchers, providing a robust benchmark for conventional numerical methods.     

流动注射双光束光度法测水中的硅

本文采用了一套流动注射分析一双光束分光光度装置，研究了工业用水中硅含量测定的实验条件，建立了一种新的分析方法，精密度和准确性良好，分析灵敏度提高近一倍，设备简简单，分析速度快，方便易行，扩大了双光束分光光度的应用范围。     

Theoretical evaluation of carbon monoxide and hydrocarbon reduction by secondary-air injection

In order to evaluate the effects of various factors upon the performance of a thermal reactor with secondary-air injection which reduces carbon monoxide (CO) and hydrocarbon emitted from combustion engines, analytical studies were carried out for a model in which one-dimensional flow of gas is assumed. Effects of factors such as gas temperature, injection rate of secondary air, residence time and air/fuel ratio of the engine have been examined by chemical kinetics, taking 20 chemical species and 52 elementary reactions into consideration. The oxidation rate of CO and methane (CH₄) becomes high when the gas temperature after air injection exceeds about 900 K. For a given gas temperature, there exists an appropriate range for the quantity of injection air in which CO, CH₄ and formaldehyde can be reduced effectively. This range can be widened by either raising the gas temperature or prolonging the residence time. By increasing the air/fuel ratio of the engine, CO and CH₄ emitted from the reactor tend to decrease. These results explain reasonably well the phenomena formerly observed experimentally.