Carbonaceous microsphere-based superabsorbent polymer as filler for coating of NPK fertilizer: Fabrication,properties, swelling,and nitrogen release characteristics

Recently, the use of controlled release fertilizers in agriculture has resulted in huge benefits in plant growth and cultivation. Superabsorbent polymer (SAP)-coated fertilizers have the added advantage in retaining water in soil after irrigation and also reduce the nutrient release rate from soil in a controlled manner. This study aimed to produce a nitrogen–phosphorus–potassium (NPK) fertilizer coated with superabsorbent carbonaceous microspheres polymer (SPC) by inverse suspension polymerization method with water-retention and controlled release properties. Two sets of experiments were conducted: (1) three different weight percentages and (2) different materials. NPK coated with SPC showed increasing water-retention ability with respect to carbon microsphere percentages and retains >80% water at the 30th day of experiment compared with pure NPK and NPK coated with SAP. The slow release behavior of all samples was investigated by induced coupled plasma mass spectrometry spectrometry and results showed that NPK coated with SAP and SPC has a low release rate with <50% nutrient release compared with uncoated NPK at the 30th day. The release mechanism kinetics of NPK coated with SAP and SPC were studied based on the Kosmeyer–Peppas model. The mechanisms approached Fickian diffusion-controlled release as the n value for both samples was less than 0.5. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48396.     

Polymer brush coatings for combating marine biofouling

A variety of functional polymer brushes and coatings have been developed for combating marine biofouling and biocorrosion with much less environmental impact than traditional biocides. This review summarizes recent developments in marine antifouling polymer brushes and coatings that are tethered to material surfaces and do not actively release biocides. Polymer brush coatings have been designed to inhibit molecular fouling, microfouling and macrofouling through incorporation or inclusion of multiple functionalities. Hydrophilic polymers, such as poly(ethylene glycol), hydrogels, zwitterionic polymers and polysaccharides, resist attachment of marine organisms effectively due to extensive hydration. Fouling release polymer coatings, based on fluoropolymers and poly(dimethylsiloxane) elastomers, minimize adhesion between marine organisms and material surfaces, leading to easy removal of biofoulants. Polycationic coatings are effective in reducing marine biofouling partly because of their good bactericidal properties. Recent advances in controlled radical polymerization and click chemistry have also allowed better molecular design and engineering of multifunctional brush coatings for improved antifouling efficacies.     

汽车外饰件色差日常控制与管理浅谈

为保证整车外观颜色的一致性,提高客户的满意度,将外饰件与车身色差控制在很小范围内,制定系统而有效的评价标准与管理办法尤为重要。结合现生产,从实际情况出发,对控制车身色差问题做系统分析,并运用SPC统计方法对日常色差进行监控管理,有效抑制了色差问题的发生。     

Statistical testing for sufficient control chart performances during monitoring of grouped processes

With ISO 7870-8, a standardized application of charting techniques for short runs and small mixed batches was presented in 2017. Similar to various scientific approaches, it requires that sample values from grouped processes follow nearly identical distributions. In practice, however, there tend to be differences between distribution parameters. Moreover, equal parameters do not ensure that distributions are properly aligned to the center line and control limits of the chart. These facts can lead to undesired control chart performances which can be expressed by average run lengths (ARL) during in-control and out-of-control conditions. In this work, a statistical test for sufficient control chart performances during monitoring of grouped processes based on preliminary samples is proposed. Control chart performances are defined as sufficient when they deviate within acceptable ranges from usual performances during single process monitoring in mass production. The ARL resulting from estimated distributions and planned production sequences is used as test statistic and calculated via the Markov chain approach. Exemplary tests are executed for scenarios with individuals and cumulated sum (CUSUM) charts. A simulative determination of error rates resulting from the ARL-based testing demonstrates its effectiveness in testing for sufficient control chart performances compared to an indirect testing with Levene's test and a one-way analysis of variance (ANOVA).     

基于数据驱动的全流程模锻生产过程专家系统

阐述了我国锻造生产线现状,介绍了国内外统计过程控制研究和应用的概况,指出在我国锻造生产环境中实施统计过程控制所面临的困难。基于工序单元采用约束理论对锻造生产过程进行分析,寻求瓶颈环节或关键环节作为监控重点;将质量管理工具SPC分析方法应用于锻造生产过程,实时监控瓶颈环节或关键环节,通过局部优化最终得到整个生产过程的稳定;根据模锻生产的特征以及SPC分析方法中定义的5大影响因素搭建专家知识库,利用主流的机器学习算法进行知识的获取。基于以上研究,设计基于数据驱动的全流程模锻生产过程专家系统,用以实现模锻生产过程全流程的实时监控、稳定性分析以及生产过程的优化。     

传统质量工具在软件质量保证中的应用

软件的质量问题是目前我国软件企业面临的最大问题之一.分析当前导致软件质量无法保证的原因,提出能力成熟度模型(CMM)与传统质量工具集成的思想,建立了以CMM为框架,集合传统质量工具的软件质量保证新模式,并对具体应用提出解决方案.为提高软件效率、保证软件质量和使顾客满意提供支持.     

精细化工过程控制技术的重要发展趋势

分析了精细化工生产过程的特点及其控制需求,阐明了精细化工过程控制技术的现状与主要发展趋势,包括精细化工过程的集成控制、自动批量生产控制、优化控制、生产工况和生产质量的综合性统计过程控制以及生产过程的综合性安全保护控制等。重点论述了精细化工过程控制技术领域应着重研究的两项重要课题,一为统计过程控制技术,研究和开发适合精细化工过程间歇生产特点的多变量统计控制方法,即多向、非线性、多尺度、多种分布、自适应统计过程控制方法,提高精细化工过程的工况监控和质量控制水平;二为研究和应用防护层分析与设计、非正常工况管理等综合性安全保护控制工程技术,提高精细化工过程的安全控制水平。     

商务群替代小交换机的方案及实现

本文介绍了用中兴ZXJ10交换机的商务群功能替代厂内部模拟小交换机的实现方案,描述了实现方案的具体施工过程和交换机数据系统的设置方法和步骤,以达到改善整个厂内部通话的目的。     

浅谈SPC在汽车涂装中的应用

采用SPC质量工具,对促进剂的用量进行分析和控制,从而在保证涂装质量的前提下,降低磷化渣废弃物处理成本。