Near-infrared (NIR)spectroscopy is a highly efficient and non-destructive technology applied in many areas. The measured spectra, however, are susceptible to shift due to various external interferences, resulting in biased analytical results. Time-shifts in NIR spectra are typical phenomena of continuously shifting spectra with measuring time, which is common in practical applications. In this study, a new method for modeling the time-shift NIR spectra was proposed, in which the shifting signal was divided into shifting background and sample-dependent shifts, and then corrected by continuous wavelet transform (CWT)and semi-supervised parameter-free calibration enhancement (SS-PFCE),respectively. The efficiency of the method was evaluated by modeling 1941 time-shift NIR spectra of soil samples collected in Yunnan Province (China)in 2019 and 2020 to predict the soil organic matter (SOM)content. The spectra taken in 2019 were calibrated (Root mean squared error of prediction (RMSEP)= 6.7 g/kg,R-2 = 0. 76)and a large deviation was observed in predicting the spectra taken in 2020 (RMSEP = 31. 3 g/kg,R-2 = 0. 50). After CWT treatment, the prediction of spectra measured in 2020 was significantly promoted by predicting the spectra (RMSEP = 11.6 g/kg,R-2 = 0. 66),and the prediction was further improved by SS-PFCE (RMSEP = 8. 3 g/kg,R-2 = 0. 67). The results indicated that CWT and SS-PFCE were efficient for eliminating the shifting background and sample-related shifts in time-shift NIR spectra, respectively.

为了考察环境条件对爆珠力学性能的影响,通过测试不同环境条件下爆珠的质量、压破强度、压破形变率和弹性指数,提出了爆珠样品的适宜环境条件.结果表明:①爆珠和爆珠滤棒在"温度(22±1)℃、相对湿度(60±2)％"的环境下调节48 h能够达到温湿度平衡.②爆珠的压破强度、压破形变率和弹性指数在40％～60％相对湿度范围和10～40℃温度范围内略有差异,但差异的程度与样品差异有较大关系.极限温度条件(低于10℃,高于40℃)对爆珠的力学性能有较大的影响,低温冷冻后爆珠的力学性能不可恢复.③爆珠的力学性能在爆珠生产、爆珠滤棒加工和爆珠卷烟加工各环节的温湿度条件下均没有较大差异.

穿流回转干燥机目前大多采用直线型抄板的形式,其作用仅为物料抄动用,不具备内部物料混合作用,这使得物料因转筒内部风场分布不均导致干燥不均匀加剧,基于EDEM仿真软件,采用Hertz-Mindlin with JKR模型表征颗粒的接触力,对颗粒物料在穿流回转干燥机中的混合分散情况进行模拟,并运用后处理网格划分方法来直观展现回转干燥机中物料的分布情况.结果证明,优化后的抄板能有效提高穿流回转干燥机内部物料的混合度,提升物料干燥均匀度.

高压水射流清洗技术相比传统的化学方法清洗,具有安全、高效、低成本、环保等特点.本文从高压水射流在农产品、水产品、食品加工企业方面的应用展开综述,展望了高压水射流清洗技术的发展前景.

为提升瓜尔胶作为增稠剂在乳状液中的增稠效果,本文采用三因素三水平的正交试验考察了影响瓜尔胶水溶液溶解效果的因素.以溶解温度、溶解时间、搅拌时间为变量,瓜尔胶水溶液粘度为响应值,实验得出最佳溶解工艺为:搅拌6min后置于20℃条件下溶解90min.以实验得出的最佳溶解工艺配制瓜尔胶水溶液,配置水包油型乳状液,考察连续相中瓜儿胶的添加量对乳状液稳定性的影响,以显微镜观察法、离心分层法进行分析,实验得出当瓜尔胶添加量为连续相的1.5％时,能显著提升此乳状液体系的稳定性.

壳聚糖及其改性材料在降低卷烟烟气有害成分方面具有重要的作用.本文综述了壳聚糖及其改性材料在降低卷烟烟气有害成分如重金属离子、自由基、挥发性羰基化合物、酚类物质等方面的最新研究进展,并对降低卷烟烟气有害成分工作的研究方向和研究重点进行展望,以期为卷烟烟气有害成分的去除以及低危害卷烟产品的开发提供有益参考.

近红外光谱技术(NIR)是一种高效的现代分析技术,其有快速、非破坏性、无试剂分析、安全及同时测定多种维分测定等特点,在多个领域得到了日益广泛的应用.本文着重介绍了近红外光谱技术在物料混合均匀度检测的方法及应用进展.

In order to promote the efficiency and precision in determining the strength of cigarette capsules,a ten-channel capsule strength tester was designed based on mechanical compression method. The tester was mainly composed of a ten-channel mechanical compression device,a pressure and displacement data acquisition unit,a slave computer for data processing and control,and a host computer for human-computer interaction. The mechanical compression device exerted an evenly distributed vertical pressure on the capsules,the pressure data were acquired via pressure sensors. The strength of capsule was characterized with the breakdown strength and magnitude of deformation. The precision and stability of the tester was validated as well. The results showed that:1)The tester could automatically test the capsules of 2.8 or 3.5 mm in diameter. 2)The test precision was up to 0.02 N with good repeatability. There existed no significant differences in capsule strength and deformation measurements between the designed tester and an imported one. The designed tester provides an efficient test method for the quality control of cigarette capsules.

液膜以其传质速率高、选择好、低成本和低能耗等特点,成为分离、纯化与浓缩溶质的有效手段.主要简述了液膜分离技术的基本原理和分类,介绍了近年来国内外应用液膜分离技术去除和回收废水中重金属方面的研究进展.

This article describes the near-infrared spectroscopy to detect milk protein, fat, minerals, and mass fraction of melamine, and identification of adulterated milk powder and brand identity applications. Finally, looking to the applications prospect of near-infrared spectroscopy in non-destructive testing of powder milk.

Using dropline separation, tangent skimming, and triangulation to estimate the area of an overlapping chromatographic peak might contribute to a large deviation. It is easy, however, to eliminate these errors caused by geometric segmentation using three-way data analysis (second-order tensor decomposition) algorithms. This method of chromatographic analysis has many advantages: automation, anti-interference, high accuracy in the resolution of overlapping chrom- atographic peaks. It even makes the final goal of analytical chemistry achievable without the aid of complicated separation procedures. The core of this method is the process of utilizing useful information and building models through chemometric algorithms. Three-way chromatographic data set can be divided into trilinear dataset and nontrilinear dataset, correspondingly, three-way data analysis (second-order tensor decomposition) algorithms can be divided into trilinear algorithms and nontrilinear algorithms. In this paper, three-way calibration used in liquid chromatography for complex chemical systems in the last decade is reviewed, and focused on sample pretreatment, auxiliary algorithms, the combination and comparison of correction algorithms.