降凝剂BEM降低原油凝点的机理探讨

研究了从大原油和冀东原油分离出的蜡（含2％相应的胶质）用降凝剂BEM处理后X射线衍射图的变化和几种原油以降凝剂BEM处理后蜡晶尺寸的变化及加剂原油经析蜡高峰区的泵剪切后蜡晶尺寸的变化,X射线衍射数据证实降凝剂通过共晶作用改变蜡晶的结构,蜡晶尺寸的变化说明,降凝剂使原油的蜡晶变大,进而降低原油的凝点,剪切破坏蜡晶的结构是剪切引起原油凝点上升的主要原因。     

可完全生物降解材料的应用进展

介绍了可生物降解材料的降解机理和特点,综述了化学合成型、天然高分子型和微生物合成型可完全生物降解材料的研究现状及其在各个领域的最新应用进展。     

可降解温敏型共聚物PLGA-PEG-PLGA的合成及辐照法分子量调整

合成了不同嵌段的可降解的温敏型聚乙交酯丙交酯-聚乙二醇-聚乙交酯丙交酯共聚物（DL—lactide—co—glycolide-b-ethylene glycol—b—DL—lactide—co—glycolide，PLGA-PEG—PLGA）。用红外、核磁共振、凝胶渗透色谱等表征了其化学结构、分子量及分子量分布，研究了其相变过程。用辐照法成功地进行了PLGA—PEG—PLGA分子量调整。实验结果表明，在反应温度150℃催化剂辛酸亚锡0．04g反应8h，5．08g乙交酯与12．61g丙交酯（摩尔比为1：2）的条件下，产物溶于水后得到的水凝胶具有明显的相变过程。不同分子量的共聚物相变温度不同，在同定聚乙二醇分子量且共聚物溶液浓度相同条件下，共聚物中丙交酯与乙交酯比例越高，共聚物分子量越大，相同浓度下的分子量越大的共聚物形成的溶胶，凝胶转变温度越低，凝胶-溶胶转变温度越高。当辐照20kGy样品的分子量分布最大，从而改变凝胶的相变温度。     

Fabrication of a biodegradable Fe-Mn-Si alloy by field assisted sintering

Biodegradable metals are emerging as novel implant materials by overcoming the drawbacks of the existing materials used commercially. This work investigates the suitability of Fe-35Mn-5Si as a biodegradable implant by examining its mechanical and corrosion behavior. The processing involves High Energy Ball Milling (HEBM) followed by Spark Plasma Sintering (SPS) and heat treatment at optimized conditions to develop a single-phase austenitic alloy. The heat-treated (HT) samples exhibited low magnetic susceptibility of 3.47x10⁻⁷ due to the austenitic phase formation. Yield strength of 500 MPa, UTS of 712 MPa, Young’s modulus of 110 GPa, and hardness of 380 HV along with 9.5% elongation was obtained in the optimized samples, which are comparable to Ti alloy and 316L stainless steel metallic implants. The corrosion tests yielded degradation rates of 0.025 mm/year for the alloy in standard Hank’s solution. This alloy could pave the way for the fabrication of low-cost biodegradable implants using the simple powder metallurgy route.     

Multidimensional Proton Nuclear Magnetic Resonance Relaxation Morphological and Chemical Spectrum Graphics for Monitoring and Characterization of Polyunsaturated Fatty-Acid Oxidation

Polyunsaturated fatty acids (PUFA) are components of many commercial products such as edible oils, foods, cosmetics, medication, and in biological systems such as phospholipids of cellular membranes. Although PUFA aggregates are important functional components, they are also related to system degradation, because PUFA are susceptible to oxidation via their multiple double bonds and allylic carbons. Current technologies are not effective in characterizing the morphological and chemical structural domains of saturated, monounsaturated fatty acids (MUFA) and PUFA materials, or how the morphological structures of fatty acids, at the mesomolecular, nanomolecular, and molecular levels, affect their oxidation mechanisms. In this article, the ¹H low-field (LF) NMR energy relaxation time technology is proposed as a tool to analyze PUFA oils undergoing thermal oxidation. This technology generates two-dimensional (2D) chemical and morphological spectra using a primal-dual interior method for the convex objectives (PDCO) optimization solver for computational processing of the energy relaxation time signals T₁ (spin–lattice) and T₂ (spin–spin). The 2D graphical maps of T₁ vs. T₂ generated for butter, rapeseed oil, soybean oil, and linseed oil show that the different degrees of unsaturation of fatty-acid oils affect their chemical and morphological domains, which influences their oxidative propensity. The technology of the ¹H LF-NMR energy relaxation time proved to be an effective tool to characterize and monitor PUFA oxidation.     

Characterisations of cassava starch and poly(butylene adipate-co-terephthalate) blown film with silicon dioxide nanocomposites

Films with high permeability are necessary for the packaging of agricultural products that respire to avoid anoxic conditions. This research developed and characterised bioplastic nanocomposite films with enhanced permeation and increased strength. Thermoplastic starch (TPS) was compounded with silicon dioxide (SiO₂) and blended with poly (butylene adipate-co-terephthalate) (PBAT) to produce bioplastic PBAT/TPS blend films via blown-film extrusion. Different SiO₂ contents (0.5%–1%) were dispersed in the matrices, causing interaction via hydrogen bonding with the TPS phase. SiO₂ at 1% significantly improved melting of the polymer blends, giving increasing amorphous ratios of the polymeric films. Microstructures and surface topography indicated voids between incompatible components and porous structures that improved permeation. Increasing SiO₂ content linearly enhanced oxygen and water vapour permeability by up to 39% and 16%, respectively. Tensile strength and elongation at break increased and decreased up to 40% and 32%, respectively, indicating increased rigidity due to adding solid nanoparticles to 1%. Migration phenomena of the film components, that is molecules with diol structures and silicon compounds depended on types of simulant and microstructures that induced swelling and release of the compounds. Film permeabilities increased, thereby facilitating air and humidity flow through the packaging.     

Addressing the slow corrosion rate of biodegradable Fe-Mn: Current approaches and future trends

The movement towards the commercialization of biodegradable Fe has been hampered by the perceived slow degradation rate of the metal in physiological environments. The introduction of Fe-Mn alloys offers promise due to its significantly improved biocorrosion rates, excellent biocompatibility, and non-magnetic properties. However, the issue of slow corrosion rates persists in this alloy and its future hinges on addressing this issue. This short review report presents the current approaches to address this problem, the challenges concerning Fe-Mn corrosion, and some future techniques that may improve the degradation rate of Fe-Mn alloys.     

核磁共振法研究原油降凝剂F21分子结构与性能之间关系

用核磁共振氢谱和碳谱研究了乙烯－醋酸乙烯酯三元共聚物型原油降凝剂Ｆ２１的分子结构与性能之间的关系。研究结果表明共聚物中醋酸乙烯酯含量和支化度对原油凝固点降低有很大影响，找出了使青海、高尚堡、渤海三种原油凝固点下降７－１４℃的最佳分子结构，发现乙烯平均序列长度为８．３即乙烯链段平均含１６．７个碳原子时，共聚物对原油的降凝效果最好。     

油田污水处理系统的除氧与封层隔氧研究

本文在室内条件下研究了曝氧水中Na_2SO_3除氧效果与搅拌速度、温度的关系,考察了不同密封材料液体石蜡、柴油、机油、原油等在不同温度和搅拌速度下对油田污水的隔氧作用,发现在温度较高时,以原油的密封效果为最好。