Practical Application of the Probabilistic‐Statistical Model of the Suspension Separation in Hydrocyclones

An effective practical approach that allows not only a significant reduction in the scope of practical experiments in the course of studying suspension separation processes in hydrocyclones, but also makes it possible to assess the intensity of random components of the processes and define the interrelation between such components and hydrodynamics of flows in a hydrocyclone is presented. Within the frames of the developed probabilistic‐statistical model of suspension separation in hydrocyclones on the basis of statistical self‐similarity properties, a relationship was found between determined and random components of the processes. This allowed transitioning from three‐parameter probability density functions for suspension particles in hydrocyclones to two‐parameter functions; thus significantly improving the efficiency of practical application of the developed model.     

磁流变阻尼器抑制转子系统振动试验

针对大型旋转机械通过临界转速时振动过大及运行中故障频发等问题,搭建转子试验台,模拟启停机过程和碰摩、不对中故障。不改变原有支撑形式,安装自主设计的磁流变阻尼器,在不停机的情况下,试验研究阻尼器抑制转子通过临界转速时振动过大及各类故障振动。试验结果表明,阻尼器可以有效抑制转子系统临界转速附近的振动,降幅在60%以上;转子发生碰摩或不对中故障时,阻尼器可以降低其高倍频振动。     

Supramolecular Glyco‐nanoparticles Toward Immunological Applications

Glyco‐mimicking nanoparticles (glyco‐NPs) with Förster resonance energy transfer (FRET) donor and acceptor groups formed via dynamic covalent bond of benzoboroxole and sugar from two complementary polymers are prepared. The glyco‐NPs are proved to be quite stable under physiological conditions but sensitive to pH. So the glyco‐NPs can be internalized by dendritic cells with integrity and nontoxicity and then dissociate within the acidic organelles. This particle dissociation is directly observed and visualized in vitro, for the first time via the FRET measurements and fluorescent microscopy. This feature makes controlled release of drug or protein by glyco‐NPs possible, i.e., when model antigen Ovalbumin is loaded in the glyco‐NPs, the released Ovalbumin in dendritic cells stimulates T cells more efficiently than the free Ovalbumin itself as a result of the enhanced antigen processing and presentation. Thus, the results enlighten a bright future of the glyco‐NPs in immunotherapy.     

A novel bio‐based phthalonitrile resin derived from catechin: synthesis and comparison of curing behavior with petroleum‐based counterpart

The development of bio‐based thermosetting resins with good thermal stability can potentially afford sustainable polymers as replacements for petroleum‐based polymers. We report a practical route to a novel catechin‐based phthalonitrile resin precursor (CA‐Ph), which contains free phenolic hydroxyl groups that result in ‘self‐curing’ at elevated temperatures to afford a thermostable polymer. Comparison of the performance of this CA‐Ph resin with that of a conventional petroleum‐based bisphenol A phthalonitrile resin (BPA‐Ph; containing 5 wt% of the curing agent 4,4′‐diaminodiphenylsulfone) revealed that CA‐Ph exhibits a lower melting point and curing temperature. Cured CA‐Ph resin retains 95% of its weight at 520 °C under a nitrogen atmosphere, which compares favorably with results obtained for BPA‐Ph resin that retains 95% of its weight at a lower temperature of 484 °C. Kinetic results indicated that the curing reactions of both CA‐Ph and BPA‐Ph systems follow an autocatalytic mechanism. These results suggest that catechin is a useful bio‐based feedstock for the preparation of self‐curing and thermally stable phthalonitrile resins for advanced technological applications. © 2017 Society of Chemical Industry     

Automated classification of simulated wind field patterns from multiphysics ensemble forecasts

In this study, we have proposed an automated classification approach to identify meaningful patterns in wind field data. Utilizing an extensive simulated wind database, we have demonstrated that the proposed approach can identify low‐level jets, near‐uniform profiles, and other patterns in a reliable manner. We have studied the dependence of these wind profile patterns on locations (eg, offshore vs onshore), seasons, and diurnal cycles. Furthermore, we have found that the probability distributions of some of the patterns depend on the underlying planetary boundary layer schemes in a significant way. The future potential of the proposed approach in wind resource assessment and, more generally, in mesoscale model parameterization improvement is touched upon in this paper.     

Process and joint quality of ultrasonic vibration enhanced friction stir lap welding

In order to improve the process effectiveness and joint quality, ultrasonic vibrations were integrated with friction stir lap welding. Effect of ultrasonic exertion on the process and joint quality of AA 6061-T6 were investigated. Upon ultrasonic exertion, joints owned larger effective lap width, shorter hooks and improved strength. Weld fracture mode changed from a ductile–brittle mixed mode to a more ductile mode while the fracture path shifted from lap interface to beyond the stir zone. Material flow and interface defects were characterised using lap welded dissimilar aluminium alloy joints. Ultrasonic vibration improved the material flow and reduced the interfacial defects. Variations in failure load of joints were found in accordance with the variations in material flow and interfacial defects.     

On‐the‐Spot Immobilization of Quantum Dots,Graphene Oxide,and Proteins via Hydrophobins

Class I hydrophobin Vmh2, a peculiar surface active and versatile fungal protein, is known to self‐assemble into chemically stable amphiphilic films, to be able to change wettability of surfaces, and to strongly adsorb other proteins. Herein, a fast, highly homogeneous and efficient glass functionalization by spontaneous self‐assembling of Vmh2 at liquid–solid interfaces is achieved (in 2 min). The Vmh2‐coated glass slides are proven to immobilize not only proteins but also nanomaterials such as graphene oxide (GO) and quantum dots (QDs). As models, bovine serum albumin labeled with Alexa 555 fluorophore, anti‐immunoglobulin G antibodies, and cadmium telluride QDs are patterned in a microarray fashion in order to demonstrate functionality, reproducibility, and versatility of the proposed substrate. Additionally, a GO layer is effectively and homogeneously self‐assembled onto the studied functionalized surface. This approach offers a quick and simple alternative to immobilize nanomaterials and proteins, which is appealing for new bioanalytical and nanobioenabled applications.     

采油树平板闸阀柔性密封圈结构优化设计

为了提高采油树平板闸阀密封圈的密封性能,在泛塞封的基础上,设计一种密封圈本体唇边开有锯齿状凸起的新型柔性密封结构;运用有限元分析方法模拟密封圈的工作状况,分析柔性密封结构特性参数对密封圈密封性能的影响,获得不同柔性密封圈结构参数下密封面间接触应力分布规律,并对新型密封结构进行优化。结果表明:密封面间最大接触应力随唇边锯齿数量、唇边夹角度数的增大而增大,随唇谷夹角度数的增大而减小;新型密封结构选择锯齿数量为3、唇边夹角为20°、唇谷夹角为30°的特性参数时,其最大接触应力比常规Y形密封圈提高了15倍;新型柔性密封结构的密封圈与阀杆、阀盖壁面间接触应力比常规Y形密封圈有显著提高,提高了密封圈的密封性能。     

四川盆地高石梯-磨溪地区下二叠统气源示踪

以天然气、烃源岩及储层沥青的地球化学特征为主要依据,通过天然气-天然气、储层沥青-烃源岩、天然气-烃源岩3个方面对比,深入探讨四川盆地高石梯-磨溪地区下二叠统天然气来源。研究表明,四川盆地高石梯-磨溪地区下二叠统天然气主要来源于筇竹寺组泥岩。其5项证据分别为:下二叠统天然气乙烷碳同位素小于-30.5‰,甲、乙烷碳同位素倒转是由高演化程度烃源岩所致;多数下二叠统天然气与龙王庙组天然气特征最为相似;GS18,NC1井下二叠统天然气特征与寒武系相似,说明上下层气源一致;高石梯-磨溪地区下二叠统储层沥青地球化学特征与筇竹寺组泥岩最为相似;筇竹寺组泥岩主要为下二叠统供气,这一认识符合干酪根油气生成理论和同位素分馏规律。