大豆田除草剂使用与变迁

简要论述了大豆田除草剂品种使用与变迁,并介绍了若干新品种。     

地沟油与食用油理化指标的对比分析

根据食用动植物油脂检测的国家标准方法,对比分析了地沟油和食用油的感官指标,碘价、折光率、过氧化值、酸值和电导率等理化指标。结果表明,与食用油相比,地沟油的酸值和电导率明显增大,酸值和电导率可以作为鉴定地沟油的指标。     

黄连木油物理化学特性分析与评价

采用国家标准方法,研究黄连木油脂的物理化学特性。结果表明,黄连木油的比重为0.9043,吸光度为7.9250,折光指数为1.4725,碘值为95.42,不皂化物含量为4.53%,皂化价为148.9921,酸价为25,水份及挥发物含量为0.56%。通过与其它植物油进行比较分析,认为黄连木油的碘值、水分及挥发物含量和矿物柴油相近,基本符合《柴油机燃料调合用生物柴油(BD100)》的标准,适合做生物柴油的生产原料。     

溢油污染发生后的物理和化学修复技术

目前溢油污染已经严重影响到人类的健康和生存质量,威胁到人类的可持续发展。溢油污染事件发生后,应当组织专业人员对泄漏油品采取有效控制、可靠回收,并采用适宜的物理和化学环境修复技术应急处理溢油污染,对于控制污染面积、保证溢油环境污染修复效果具有重要的意义。     

Influence of Polydimethylsiloxane on the Degradation of Soybean Oil at Frying Temperature

Soybean oils treated with 5, 10, 25, 50, and 100 ppb polydimethylsiloxane (PDMS) and a control soybean oil (no PDMS) were heated at 180 °C for 48 h. The decomposition of linoleate (18:2) and tocopherols was monitored. The degradation of 18:2 and both γ- and δ-tocopherols followed pseudo first-order kinetics. For 25 ppb PDMS (the concentration necessary to form a PDMS monolayer on the air-oil interface) and greater concentrations, 18:2 degradation decreased at a rate comparable to the control. However, for the samples with 25 ppb or more PDMS, there was a subsequent increase in the rate of 18:2 degradation during the 48 h of heating period. The same trend seen for 18:2 degradation also was observed for the rates of degradation of both γ- and δ-tocopherols; but, for the tocopherols the treatment with 10 ppb PDMS also decreased the rate of degradation. For those PDMS treatments in which a subsequent increase in degradation rates were observed, the rates of degradation after the change were similar to the rate of degradation in the control oil. In general, the time that the changes in rates occurred increased with the PDMS concentrations. The occurrence of these changes was attributed to decreases in the concentrations of tocopherols or PDMS such that the protective effects were lost.     

环氧大豆油对软PVC性能影响的研究

研究了环氧大豆油对软聚氯乙烯(PVC)性能的影响。实验表明,铅盐和有机锡的热稳定性较好,单独使用硬脂酸钙、硬脂酸锌、环氧大豆油或不足量的有机锡热稳定剂时,PVC样品很快变色。环氧大豆油与硬脂酸钙、硬脂酸锌、有机锡热稳定剂并用时,环氧大豆油具有很好的协同效应;但环氧大豆油和硬脂酸钙、硬脂酸锌不能简单替代有机锡稳定剂。热重分析证明了不同热稳定剂的效果。作为辅助增塑剂,环氧大豆油用量应低于5份。     

探究石油加工过程中油田化学剂的影响及对策

石油加工是我国发展的重要经济项目,而对于加工过程中化学剂的添加必不可少,不仅是提升工作效率的方式,同时也是稳定原油质量的方法。但在实际工程中部分化学剂残留对原油质量产生了影响,针对这一现象做出研究,分析其影响方式并提出建议对策。     

浮法玻璃表面的理化特征

从浮法玻璃成形工艺的特点出发,论述了浮法玻璃表面渗锡以及渗锡分布特征,浮法玻璃表面化学成分的变化特征,浮法玻璃表面物理性质的变化特征。     

Chemical Characterization of a High‐Oleic Soybean Oil

High‐oleic low‐linolenic acid soybean oil (HOLLSB, Plenish^®) is an emerging new oil with projections of rapid expansion in the USA. HOLLSB has important technological advantages, which are expected to drive a gradual replacement of commodity oils used in food applications such as soybean oil. A key technological advantage of HOLLSB is its relatively high oxidation stability. This oxidation stability is the result of a favorable fatty acid composition, high (76%) oleic acid, low linoleic (6.7%), and alpha‐linolenic (1.6%) acids, and high concentration of tocopherols (936 ppm) after refining, enriched with the gamma‐homolog (586 ppm). A detailed analysis of the fatty acid composition of this HOLLSB by gas chromatography–mass spectrometry allowed the identification and structural determination of 9‐cis‐heptadecenoic acid (or 17:1n‐8). To our knowledge, this is the first time 9‐cis‐heptadecenoic acid has been unequivocally reported in soybean oil. This unusual fatty acid component has the potential to be used as a single authenticity marker for the quantitative assessment of soybean oil. The Rancimat induction period (IP) of Plenish^® (16.1 hours) was higher than those of other commercially available high‐oleic oils, such as canola (13.4 hours), and Vistive^® Gold (10 hours), a different variety of soybean oil. Plenish^® showed the same IP as high‐oleic sunflower oil. Plenish^® shows a modest increase in oxidation stability with the external addition or relatively high concentrations of tocopherols. The characteristic high oxidative stability of Plenish^® may be further enhanced with the use of nontocopherol antioxidants.     

Correlation Between Dielectric Properties and Chemical Changes in Soybean Oil Derivatives

Dielectric properties of soybean oil derivatives were measured at frequency bands from 10⁵ to 10⁷ Hz at different temperatures. Relaxation times τ, activation enthalpies δH, and entropy changes δS for dielectric relaxation were calculated and related to the chemical changes of the samples. It was found that dielectric properties can be used in differentiating between epoxidized and nonepoxidized oils, and can help in distinguishing these kinds of oils and formoxy-hydroxy derivatives.     

煤转化对炼油化工行业竞争力浅析

论述了我国发展煤转化的必要性并分析了我国煤转化产业所处阶段。指出目前煤转化对炼油化工的影响较小,即使将来也只是石油化工的有益补充。     

环氧大豆油改性白炭黑对天然橡胶性能的影响

采用环氧大豆油(ESO)对白炭黑进行改性,研究ESO改性白炭黑对天然橡胶(NR)性能的影响。结果表明:采用ESO对白炭黑进行改性,ESO分子成功接枝到白炭黑粒子上;ESO改性白炭黑可以降低NR混炼胶的门尼粘度和动态模量,改善其加工性能;提高NR硫化胶的物理性能,降低NR硫化胶60℃时的损耗因子(tanδ)值、提高0℃时的tanδ值,从而降低动态生热、提高抗湿滑性能。     

Physical Properties of Soybean Oleogels and Oil Migration Evaluation in Model Praline System

The present study examined the physical properties of soybean oleogels and commercial confectionery filling fats and evaluated the oil migration properties in model praline systems. Soybean oleogels were prepared using different oleogelators namely monoglyceride (MAG oleogels) and a mixture of sorbitan tri‐stearate (STS) with lecithin (50:50) (Lec‐STS oleogels). Both MAG oleogels and Lec‐STS oleogels demonstrated a flat solid fat content (SFC) profile with zero SFC at 40 °C. At low temperature, MAG oleogels and Lec‐STS oleogels demonstrated a non‐flowing gel‐like property due to the ability of the oleogelator to entrap liquid oil. In addition, oleogels also showed thixotropic behavior indicating the possible capability to prevent migration of filling fats to coatings and also good flow ability during pumping though manufacturing equipment. The textural property of oleogels also did not change significantly upon storage indicating good structural stability. When used as in a model praline system, oleogels demonstrated a migration delaying property.     

活性稀释剂对环氧豆油丙烯酸酯光固化体系的影响

用环氧豆油与丙烯酸反应制备出环氧豆油丙烯酸酯预聚物,研究了活性稀释剂的组成、配比对紫外光固化速率、固化膜性能及施工性能的影响,并利用红外光谱对涂料光固化前后的结构进行了表征。结果表明:活性稀释剂的加入量以30%为宜,当其配比为10%苯乙烯,20%三羟甲基丙烷三丙烯酸酯时,光固化速率较快,固化膜无色透明,表面光滑平整,其硬度达到3H,且具有较好的柔韧性和附着力。     

物理化学强化对再生混凝土收缩性能影响

根据《混凝土用再生粗骨料》(GB/T 25177-2010),废弃混凝土经简单破碎、一次颗粒整形和二次颗粒整形后分别制得II类再生粗骨料、准I类再生粗骨料和I类再生粗骨料,并将三类再生粗骨料在浓度6%的有机硅烷防水剂中进行24h化学浸渍处理,得到三类物理化学强化再生粗骨料。分别研究不同品质物理化学强化再生粗骨料和不同取代率(ф_z=0、50%、100%)取代天然骨料对再生混凝土的收缩性能的影响。结果显示:再生粗骨料混凝土收缩性能为:SA-SI再生粗骨料混凝土FA-SI再生粗骨料混凝土SBA-SI再生粗骨料混凝土,且均优于普通混凝土;SBA-SI、FA-SI和SA-SI再生粗骨料混凝土的收缩率均随着ф_z的增大而减小。     

工科物理化学开放式教学的几点探讨

针对工科学生感性认识强、动手能力强的特点,在物理化学理论教学中运用了开放式教学模式,具体为:引入开放性的应用教学案例、教学辅导材料与考查方式,设置开放性提问并将授课内容与科研实践相结合。这种教学方式可以改变以教师为中心的传统教学模式,充分发挥学生的主观能动性,可以有效地促进学习效率,激发学习兴趣,并有益于学生创新能力的培养。     

城市垃圾焚烧飞灰物化特性动态分析

以某一垃圾焚烧电厂2017年内不同时期产生的焚烧飞灰为研究对象,对其进行较系统性、动态的物化特性分析。结果表明:焚烧飞灰粉体白度约46、密度约1.88 g/cm~3、颗粒的粒径D50、D90分别约为25μm与76μm。粉体颗粒无固定的形态结构,其中可见针状结构、板片结构与方柱状颗粒。焚烧飞灰中存在氯化钾(KCl)、氯化钠(NaCl)、氧化钙(CaO)、碳酸钙(CaCO_3)等,其主体元素含量分布特征为钙(Ca)>氯(Cl)>钠(Na)>钾(K)>硅(Si)>锌(Zn),同时垃圾焚烧飞灰中含多种重金属元素,且重金属在所检样品中的量化顺序是铅(Pb)>铜(Cu)>铬(Cr)>镉(Cd)。本课题工作可为垃圾焚烧飞灰固废的多元化、绿色化、资源化的利用提供积极的技术支撑与理论指导。     

油井管材料的腐蚀特性研究综述

由于原油特性、采油方式的不同,油田采出液中通常会存在各种腐蚀性离子及酸性气体。比如具有腐蚀性的阴离子(Cl~-、SO_4~(2-)、CO_3~(2-))、易结垢性阳离子(Ca~(2+)、Mg~(2+))、酸性气体(CO_2、H_2S)等。这些离子、酸性气体的存在及浓度变化,在温度与压力的作用下,影响管材的电化学腐蚀行为,造成油井套材料不同程度的腐蚀。针对常用油井管材料在不同影响因素条件下腐蚀行为展开论述,通过对比在不同影响因素下油井管材料的腐蚀规律,得到不同影响因素下的腐蚀特点,为防腐措施的选择、石油安全生产提供理论依据。