汽车内空气污染研究综述

汽车在现代社会中扮演着重要的角色,同时,车内污染也可能是现代社会中人体健康的最主要的威胁之一.世界各国对汽车内的污染开展了不少研究,研究结论表明:汽车行驶在尾气排放"隧道"的中央,车内的人受害最重,加之汽车内置材料可能释放出的有害气体,内外夹击的车内污染会给人体健康带来严重威胁.污染物包括可吸入颗粒物、霉菌、种类繁多的化学物质.污染与汽车的型号、使用年限、燃料、交通拥挤状况、天气和海拔高度等诸多因素有关.为了减少污染带来的危害,一些健康驾驶的建议被提出.     

厦门市老年体育工作的现状及对策

对厦门市老年体育工作的政策保障、经费来源、组织与指导、城乡结对共建、宣传和对外交流方面的调研发现,厦门市老年体育工作存在着各行业老体协服务功能退化,健身辅导员和社会体育指导员未能发挥应有作用,社区老年人体育场地设施使用受限、利用率较低,专业服务人员少、相关科研机构缺失,缺乏非政府组织的积极参与等问题。为实现"健康老龄化"的目标,厦门市应加大对体育非政府组织的指导,加强社区对老年体育的组织、协调、管理、凝聚、整合和服务功能,建立各级社会体育健身指导员的考核奖惩、登记注册等制度,开放社区教育系统体育场地,树立示范老年体育指导站(点),提升服务老年体育工作的专业水平和能力,加强对老年人体育健身活动的科学指导。     

Extraction and characterization of highly pure alumina (α, γ, and θ) polymorphs from waste beverage cans: A viable waste management approach

The recycling and recovery of important materials from inexpensive feedstock has now become an intriguing area and vital from commercial and environmental viewpoints. In the present work, extraction of different single phases of alumina (α, γ, θ-Al₂O₃) having high purity (>99.5 %) from locally available waste beverage cans (～95 % Al) through facile precipitation route calcined at distinct temperatures has been reported. The optimization of process technology was done by a variety of different synthesis parameters, and the production cost was estimated between 84.47-87.45 USD per kg of alumina powder. The as prepared alumina fine particles have been characterized using different sophisticated techniques viz. TG-DTA, WD-XRF, XRD, FT-IR, SEM, DLS-based particle size analysis (PSA) with zeta (ζ) potential measurement and UV–Visible Spectroscopy. X-ray diffractogram confirms the formation of γ-, θ-, and α-alumina at 500–700 °C, 900–1000 °C, and 1200 °C respectively and crystallite size, crystallinity, strain, dislocation density, and specific surface area were measured using major X-ray diffraction peaks which varies with temperature. The SEM studies showed that the as prepared alumina particles were agglomerated, irregular-shaped with particle size (0.23–0.38 µm), pore size, and porosity were calculated from SEM image. ζ-potentials at different pH values as well as isoelectric point (IEP) of α, γ, and θ alumina were calculated in an aqueous medium which changes with temperature. The direct band gap (E_g) energies were found between 4.09 and 5.19 eV of alumina obtained from different calcination temperatures. The synthesized materials can be used in sensors, ceramics, catalysis, and insulation applications.     

教育筑就“中国梦”——深入学习贯彻习近平总书记关于教育的重要论述

教育乃民生之重、立国之本。当今世界,各国之间激烈的经济和科技竞争,归根到底是教育的竞争、人才的竞争。人才成就＂中国梦＂,教育培养更全面健康的人才具有其深刻理论渊源和现实必要性,是实现中国梦的力量源泉。党的十八大以来,习近平总书记关于教育工作的重要论述精辟阐释了立德树人的根本任务,坚持以人为本、全面实施素质教育的战略主题,为新时期教育工作提出了新要求,即教育为实现中华民族复兴的＂中国梦＂担当重大历史使命。     

增广独立成分分析用于果汁饮料中防腐剂的快速测定

采用正交设计法配制16组包含苯甲酸钠、山梨酸钾、对羟基苯甲酸甲酯钠3种防腐剂水性混合样品,分别测其紫外-可见(UV)光谱.果汁样品通过离心,取上清溶液,稀释一定的倍数测定其UV光谱.将果汁样品紫外光谱数据与模拟水样光谱融合得到增广光谱矩阵,采用独立成分分析(ICA)提取增广光谱矩阵中独立组分(IC)的浓度轮廓,将实际样品中3种防腐剂以外的其他成分作为背景加以扣除,以模拟标准样品3种防腐剂对应的浓度轮廓回归分析得到3种防腐剂测定的独立成分回归(ICR)模型,实际样品中防腐剂的IC值代入ICR模型预测得到相应防腐剂含量.将浓度IC轮廓进行最小二乘回归分析得到与其对应的光谱轮廓,可用作防腐剂与作为其他成分的背景信号的定性分析.方法用于市售某柠檬饮料中防腐剂测试分析,ICR模型的线性相关系数(R)均在0.99以上,测定结果与采用高效液相色谱法相当.     

丝胶枸杞保健饮料的研制

以丝胶蛋白和枸杞提取液为原料,采用单因素实验和正交试验,确定丝胶枸杞饮料中主原料的优化配方为:枸杞浸出物为10%、丝胶蛋白1.0%、柠檬酸为0.10%、阿斯巴甜为0.050%;所制得的饮料色泽呈淡黄色,有枸杞的清香味,具有抗菌、促进肠胃道消化、抗氧化等功效,是一款有开发前景的保健饮料。     

Paper spray mass spectrometry and PLS-DA improved by variable selection for the forensic discrimination of beers

Paper spray mass spectrometry (PS-MS) combined with partial least squares discriminant analysis (PLS-DA) was applied for the first time in a forensic context to a fast and effective differentiation of beers. Eight different brands of American standard lager beers produced by four different breweries (141 samples from 55 batches) were studied with the aim at performing a differentiation according to their market prices. The three leader brands in the Brazilian beer market, which have been subject to fraud, were modeled as the higher-price class, while the five brands most used for counterfeiting were modeled as the lower-price class. Parameters affecting the paper spray ionization were examined and optimized. The best MS signal stability and intensity was obtained while using the positive ion mode, with PS(+) mass spectra characterized by intense pairs of signals corresponding to sodium and potassium adducts of malto-oligosaccharides. Discrimination was not apparent neither by using visual inspection nor principal component analysis (PCA). However, supervised classification models provided high rates of sensitivity and specificity. A PLS-DA model using full scan mass spectra were improved by variable selection with ordered predictors selection (OPS), providing 100% of reliability rate and reducing the number of variables from 1701 to 60. This model was interpreted by detecting fifteen variables as the most significant VIP (variable importance in projection) scores, which were therefore considered diagnostic ions for this type of beer counterfeit.     

城市水循环健康的评价方法及其应用——以邯郸市主城区为例

健康良性的水循环是实现区域可持续发展的基本保障。为客观诊断邯郸市水循环健康状况,选用综合指数法对其主城区2005～2016年水循环进行了健康评价,并采用模糊模式识别法和集对分析法进行对比验证。结果表明：邯郸市主城区因受到重工业城市背景和产业结构不合理的影响,城市水循环状态为亚健康;随着邯郸市产业结构的调整和水利民生政策的落实,其水循环健康状况逐年好转,2016年已达健康状态。三种评价方法的结果趋势基本一致,说明评价指标体系的构建较为合理,评价方法也较为适用。可见,研究结果为区域水资源综合管理的进一步优化以及社会经济的高质量发展提供了技术参考。     

Determination of melamine in milk-based products and other food and beverage products by ion-pair liquid chromatography-tandem mass spectrometry

This paper describes a fast method for the sensitive and selective determination of melamine in a wide range of food matrices, including several milk-based products. The method involves an extraction with aqueous 1% trichloroacetic acid before the injection of the 10-fold diluted extract into the liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) system, using labelled melamine as the internal standard. As melamine is present in aqueous media in the cationic form, the chromatographic separation in reversed-phase LC requires the use of anionic ion-pair reagents, such as tridecafluoroheptanoic acid (THFA). This allows a satisfactory chromatographic retention and peak shape in all the types of food samples investigated. The method has been validated in six food matrices (biscuit, dry pasta and four milk-based products) by means of recovery experiments in samples spiked at 1 and 5 mg kg⁻¹. Average recoveries (n = 5) ranged from 77% to 100%, with excellent precision (RSDs lower than 5%) and limits of detection between 0.01 and 0.1 mg kg⁻¹. In addition, accuracy and robustness of the method was proven in different soya-based matrices by means of quality control (QC) sample analysis. QC recoveries, at 1 and 2.5 mg kg⁻¹, were satisfactory, ranging from 79% to 110%. The method developed in this work has been applied to the determination of melamine in different types of food samples. All detections were confirmed by acquiring two MS/MS transitions (127 > 85 for quantification; 127 > 68 for confirmation) and comparing their ion intensity ratio with that of reference standards. Accuracy of the method was also assessed by applying it to a milk-based product and a baking mix material as part of an EU proficiency test, in which highly satisfactory results were obtained.     

加快微灌技术推广应用和健康发展的对策和建议

本文研究了我国微灌（滴灌、微喷灌、涌泉灌）技术发展现状及存在的问题,分析了我国的农业特点,根据微灌技术推广应用的亲身实践经验和体会,提出了加快微灌技术推广应用和健康发展的对策和建议：（1）国家要加大科技投资,加强应用基础研究和技术创新,研究适合我国农业特点的微灌技术,并加大示范区建设以推广较为成熟的示范模式（;2）政府要加强引导,必要时通过政府行为,促进专门人员或组织进行统一灌溉、公司或个人对土地进行统一种植,为微灌技术的规模化推广应用创造条件;（3）强化设计和施工管理以确保工程合格,建立有效的工程后期管护机制并配套齐全灌溉管理技术使工程发挥应有作用,提高微灌工程的经济效益,确保农民的增收,充分调动农民使用微灌技术的积极性;（4）建立有效的技术服务体系。