直流蒸汽发生器建模与仿真研究

以B&W公司直流蒸汽发生器（OTSG）为对象，基于仿真支撑软件APROS平台中的基本模块，建立了图形化的直流蒸汽发生器模型；利用不同的APROS两相流计算模型进行仿真，对比分析后选取六方程计算模型；将2种模拟工况下的仿真结果与压降和传热系数经验关系式的计算结果进行对比，根据对比结果修正模型的压降和传热系数；将设定工况下的稳态及动态仿真结果与国内外实验数据对比，验证了本文模型的准确性。      

弥散型核燃料热导率计算模型研究

The effective thermal conductivity (ETC) of dispersion fuels plays an important role in nuclear reactor safety analysis and fuel performance evaluation. In this study, based on the theory of porous body, considering the relativity of dispersion particle distributions, an ETC model of dispersion fuels was proposed and validated. The effect of porosity, fuel volume fraction and fuel-matrix thermal conductivity ratio on the ETC were investigated. The results show that the ETC decreases along with the increasing of fuel volume fraction and porosity; the higher the fuel-matrix thermal conductivity ratio is, the less the effect of fuel volume fraction on the ETC of dispersion fuel is.     

Spectral radiance reconstruction from trichromatic camera responses based on orthogonal test and regularized algorithm

Reconstruction of spectral information based on multi‐channel image system is a significant problem in color reproduction, detection, and recognition. A spectral radiance reconstruction from trichromatic digital camera responses is researched in this article. The mapping relationship between the trichromatic imaging system response and the incident spectral radiance is analyzed. Then, in order to remove the ill‐posedness of the problem, a regularized constraint solution model of spectral radiance reconstruction matrix is established. And the spectral radiance can be reconstructed by spectral radiance reconstruction matrices and trichromatic imaging system response. Finally, the spectral radiance reconstruction matrix is estimated by the system radiometric calibration experiment. The input radiance is offered by a LCD display. A 3‐factor and 9‐level orthogonal test is designed for the calibration experiment, and a test set of 24 colors is used for precision analysis. The results show that the average relative mean error of our method is 8.69%, it is lower than that of Wiener filtering method by 2.84%. The method can reconstruct spectral radiance information effectively.     

Cyclic thermal shock resistance of h-BN composite ceramics with La2O3–Al2O3–SiO2 addition

The effects of La₂O₃–Al₂O₃–SiO₂ addition on the thermal conductivity, coefficient of thermal expansion (CTE), Young's modulus and cyclic thermal shock resistance of hot-pressed h-BN composite ceramics were investigated. The samples were heated to 1000 °C and then quenched to room temperature with 1–50 cycles, and the residual flexural strength was used to evaluate cyclic thermal shock resistance. h-BN composite ceramics containing 10 vol% La₂O₃–Al₂O₃ and 20 vol% SiO₂ addition exhibited the highest flexural strength, thermal conductivity and relatively low CTE, which were beneficial to the excellent thermal shock resistance. In addition, the viscous amorphous phase of ternary La₂O₃–Al₂O₃–SiO₂ system could accommodate and relax thermal stress contributing to the high thermal shock resistance. Therefore, the residual flexural strength still maintained the value of 234.3 MPa (86.9% of initial strength) after 50 cycles of thermal shock.     

Effects of the joining process on the microstructure and properties of liquid-phase-sintered SiC-SiC joints formed with Ti foil

The joining of liquid-phase sintered SiC (LPS-SiC) ceramics was conducted using spark plasma sintering (SPS), through solid state diffusion bonding, with Ti-metal foil as a joining interlayer. Samples were joined at 1400 °C, under applied pressures of either 10 or 30 MPa, and with different atmospheres (argon, Ar, vs. vacuum). It was demonstrated that the shear strength of the joints increased with an increase in the applied joining pressure. The joining atmosphere also affected on both the microstructure and shear strength of the SiC joints. The composition and microstructure of the interlayer were examined to understand the mechanism. As a result, a SiC-SiC joining with a good mechanical performance could be achieved under an Ar environment, which in turn could provide a cost-effective approach and greatly widen the applications of SiC ceramic components with complex shape.     

低渗致密砂岩气藏SEC储量评估实例分析--以A气田JS气藏为例

在对气藏的地质特征、开发历程以及生产规律充分了解的基础上,确定合理的评估方法、递减率及初始产量等参数的取值,可合理评价气藏的SEC储量,为气藏储量评估提供方法指导。     

Effects of Nonthermal Plasma Technology on Functional Food Components

Understanding the impact of nonthermal plasma (NTP) technology on key nutritional and functional food components is of paramount importance for the successful adoption of the technology by industry. NTP technology (NTPT) has demonstrated marked antimicrobial efficacies with good retention of important physical, chemical, sensory, and nutritional parameters for an array of food products. This paper presents the influence of NTPT on selected functional food components with a focus on low‐molecular‐weight bioactive compounds and vitamins. We discuss the mechanisms of bioactive compound alteration by plasma‐reactive species and classify their influence on vitamins and their antioxidant capacities. The impact of NTP on specific bioactive compounds depends both on plasma properties and the food matrix. Induced changes are mainly associated with oxidative degradation and cleavage of double bonds in organic compounds. The effects reported to date are mainly time‐dependent increases in the concentrations of polyphenols, vitamin C, or increases in antioxidant activity. Also, improvement in the extraction efficiency of polyphenols is observed. The review highlights future research needs regarding the complex mechanisms of interaction with plasma species. NTP is a novel technology that can both negatively and positively affect the functional components in food.     

管状带式输送机在线纠扭托辊的研究与应用

管状带式输送机是一种新型环保的散状物料连续输送设备,在运行过程中受各种因素影响,头、尾过渡段经常会跑偏,管状段经常会扭转,常规停机调偏纠扭方法已不能胜任复杂路线长距离管带机稳定运行的要求。为适应市场发展趋势,设计人员分析了管带机扭转原因,结合纠扭基本原理及常规纠扭方法,新开发出一种在线(不停机)纠扭托辊并投入项目应用。     

选择性絮凝-柱浮选回收钼精选尾矿中的微细粒辉钼矿

针对某钼精选尾矿细泥含量大、辉钼矿嵌布粒度微细的特点,提出选择性絮凝-柱浮选新工艺,即先将钼精选尾矿进行选择性絮凝,采用高效的微细粒分选的设备旋流-静态微泡浮选柱进行分选,解决了该钼精选尾矿中微细粒辉钼矿的回收问题。利用浮选柱半工业试验系统,考察处理量、分散剂用量、捕收剂用量、絮凝剂用量、起泡剂用量和抑制剂用量等因素对浮选指标的影响,并优化工艺和操作参数条件,在此基础上进行连选试验。研究结果表明:采用选择性絮凝-柱浮选工艺,在浮选柱"一粗三精一扫"闭路流程的情况下,可获得钼精矿钼品位为34.40%、铜精矿铜品位为16.83%,钼回收率为73.97%、铜回收率为67.48%的良好指标。该技术的研究为钼精选尾矿中微细粒辉钼矿的回收提供了新思路。     

Changes in physicochemical properties and DNA quality of milk as affected by different heat treatments

The effects of three common heat treatments (pasteurisation, boiling and autoclaving) on milk physicochemical properties and DNA quality were investigated. Milk composition, colour and pH value varied significantly during the heating process. The heat treatment also affected the DNA quality of the milk and, in particular, reduced the content of both mitochondrial DNA (mtDNA) and nuclear DNA (nDNA). These reached their lowest values when autoclaving was conducted, but the content of nDNA was never greater than that of mtDNA. The physicochemical and DNA quality changes in milk are crucial factors in any authentication process using polymerase chain reaction (PCR)‐based methods.