浅论食品添加剂的安全性

介绍了食品添加剂的定义、分类和作用 ,分析了国内外食品添加剂的现状、发展前景及存在的问题 ,综述了食品添加剂的安全性问题及监督管理办法。     

新型瓶罐回收机的创新设计

以新型的机构实现瓶罐的分类回收及破坏的功能,在设计过程中采用了模块化设计的思想,引入AVR单片机控制系统来完成对各功能的智能控制.     

基于递阶质量屋的多属性灰色模糊评价系统研究

质量功能配置中的顾客需求权重以及设计要求权重的获取是产品配置的关键环节.在层次分析法的基础上,应用递阶质量屋方法优化了各因素的权重值,针对出现的模糊语言,利用模糊数对定性指标进行量化,并将灰色系统理论引入设计方案的多属性模糊优选,提出了一种基于递阶质量屋的灰色关联与模糊优选评价方法.该方法综合考虑相关模糊因素交叉耦合后的影响,对方案优劣进行整体比较.实例证明,该方法能够处理复杂的、多层次的、且信息不够完全的问题,评价方法客观准确,可操作性强,能够得到符合客观实际的结果.     

基于改进PSO算法的自适应均衡算法

传统的自适应均衡算法存在收敛速度慢,稳定性差、均衡效果不理想等缺点,从而使自适应均衡器在高速光纤通信系统中的应用受到限制.具有梯度搜索因子的Grads-PSO算法,结合了传统数值优化方法在计算速度和计算精度上的优势,将梯度法引入粒子群算法中.在梯度搜索因子的指导下,PSO算法的运算过程显得更加有规则,从而提高了算法的收敛速度和运算精度.因此,本文提出将改进PSO算法用作自适应均衡器均衡算法.通过仿真实验表明,改进PSO算法具有收敛速度快,计算精度高的优点,将其作为自适应均衡器的控制算法可收到很好的均衡效果,优于传统的控制算法.     

An automatic parameter calibration method for the SWAT model in runoff simulation

Runoff simulation is highly significant for hydrological monitoring, flood peak simulation, water resource management, and basin protection. Runoff simulation by distributed hydrological models, such as the soil and water assessment tool (SWAT) model which is the most widely used, is becoming a hotspot for hydrological forecasting research. However, parameter calibration is inefficient and inaccurate for the SWAT model. An automatic parameter calibration (APC) method of the SWAT model was developed by hybrid of the genetic algorithm (GA) and particle swarm optimization (PSO). Multi‐station and multi‐period runoff simulation and accuracy analysis were conducted in the basin of the Zhangjiang River on the basis of this hybrid algorithm. For example, in the Yaoxiaba Station, the calibration results produced an R² of 0.87 and Nash Sutcliffe efficiency (NSE) index of 0.85, while verification results revealed an R² of 0.83 and NSE of 0.83. Results of this study show that the proposed method can effectively improve the efficiency and simulation accuracy of the model parameters. It can be concluded that the feasibility and applicability of GA‐PSO as an APC method for the SWAT model were confirmed via case studies. The proposed method can provide theoretical guidance for many hydrological research fields, such as hydrological simulation, flood prevention, and forecasting.     

断层模型约束反演在MTH地区煤层横向预测中应用研究

利用相干体确定断层平面的走向特征,在剖面上采用井点处断点引导小断层解释,准确落实其空间位置,并建立精细的断层模型,在此基础上,利用断层约束反演技术,进行煤层的横向预测。MTH地区实例表明,基于断层模型约束反演技术的煤层横向预测方法,可精细描述煤层变薄带、分叉合并带、厚度变化等赋煤状态。     

高钒高速钢碳化钒形态的数值化分析

针对碳化钒的不同形态,设计出定量分析软件,并利用形状因子K,实现了高钒高速钢不同碳化物形态数值化处理,当K介于0.785～1.000之间碳化钒形态为团球状;K≤0.223,碳化钒呈开花状.高钒高速钢当碳含量达到4.2%时,K为0.86和当量直径D为0.78μm,碳化物呈团球状均匀分布.     

Effect of Ce(3+) on soluble microbial products production in anaerobic granular sludge digestion

Upflow anaerobic sludge bed reactors fed on glucose were used to investigate the effects of Ce(3+) on soluble microbial products (SMP) production, which is the majority of the residual chemical oxygen demand present in the effluent. It was found that Ce(3+) concentration of 0.05 mg/L had no significant effect on the amount of SMP production, whereas that of 1 mg/L led to the increase in SMP production. The molecular-weight distribution and carbohydrate analysis indicated that an increase in SMP production may be partly attributed to the release of extracellular polymeric substances (EPS) into the bulk solution resulted from cerium toxicity, and the nucleic acids analysis suggested that increased cell lysis also contributed to SMP accumulation in the presence of Ce(3+). The increase in SMP production in the presence of Ce(3+) is possibly a consequence of the release of EPS and increased cell lysis due to cerium toxicity.     

Statistically uniform intra-block refresh algorithm for very low delay video communication

This paper focuses on the mechanism underlying the overall delay of a real-time video communication system from the time of capture at the encoder to the time of display at the decoder. A detailed analysis is presented to illustrate the delay problem. We then describe a statistically uniform intra-block refresh scheme for very low delay video communication. By scattering intra-blocks uniformly into continuous frames, the overall delay is significantly decreased, and object changes in the scene could be presented to the end user instantly. For comparison, the overall delay and the peak signal-to-noise ratio (PSNR) performance are tested. The experiment results show that an average of approximately 0.1 dB PSNR gain on average is obtained relative to random intra-macroblock refresh algorithm in H.264 JM, and the end-to-end delay performance is significantly improved.