核电站弯管流量计的应用案例

介绍弯管流量计在三门核电一回路流量测量中的应用,并与常规弯管流量计进行对比分析。     

热电厂的节能改造

介绍了蒸汽计量中采用弯管流量的独特优点,分析了弯管流量计取代孔板流量计,在热工计量中更加安全、节能、提高效益。     

基于Ansys Fluent及正交试验的90°弯管冲蚀影响因素分析

管道系统在物料运输过程中,受固体颗粒的冲蚀,常导致管道弯头失效。应用Ansys Fluent软件进行90°弯管冲蚀模拟,得出入口流速、颗粒质量流量、颗粒粒径、管道直径、弯径比均会影响90°弯管冲蚀率。采用正交试验方法分析得到冲蚀影响因素主次顺序为:入口流速颗粒质量流量弯径比管道直径颗粒粒径;通过方差分析得出,入口流速、颗粒质量流量对弯管冲蚀率的影响高度显著,入口流速、颗粒质量流量、颗粒粒径间交互作用不显著。     

微型弯管中双重乳液流体动力学特性的可视化实验研究

设计并搭建了双重乳液液滴在微型弯管中流动的可视化实验装置,动态观测了双重乳液液滴在微型弯管中的界面演化过程,研究了不同弯管角度和外液相流量对双重乳液液滴变形程度的影响,分析了双重乳液在弯管中的流型演化规律。研究结果表明:弯管角度越大,液滴受到的离心力就越大,双重乳液液滴的变形程度就相应增加;随着外流体流量的增大,液滴所受到的剪切力和离心力就增大,从而加剧了液滴的变形程度。     

气力输送系统中弯管磨损分析及应对措施

在气力输送系统中，设置弯管的主要作用是改变输送物料的运动方向，可为气力输送路径布置提供极大的灵活性。但也导致系统压力降增加，弯管磨损，以及物料破碎率增加。从物料在弯管内运动形式的角度，分析了影响弯管磨损的因素。从弯管设计的角度，提出了避免或减少弯管磨损的措施。     

百重7井区蒸汽驱试验计量系统现场应用分析

百口泉采油厂百重七井区稠油油藏已经开采多年,已经进入了蒸汽驱的试验阶段。本文主要对百重七蒸汽驱试验采用的两种计量方式,即系统孔板流量计和弯管流量计进行研究,分析影响流量计计量准确度的因素,包括流体特性、仪表性能、环境条件等方面,找出提高测量准确度的具体措施。     

输送速度对气力输送管道弯管磨损的影响

通过弯管磨损试验，建立了磨损率与输送速度之间的函数关系；验证了输送速度对弯管工作寿命和输送量的影响；介绍了弯管内磨损分布情况。依据侵蚀深度和弯管工作寿命结果，推出了弯管磨损速度与输送速度之间函数关系。     

基于fluent不同角度弯管持液率的计算

天然气运输过程当中,由于弯管处的阻力所造成的局部能量损失,以及重力的作用,造成气体携液能力的降低,本文将通过workbench建立不同角度弯管的模型,采用龙岗集输管道001-1至001-7段的管道参数,应用fluent数值模拟,模拟得到进出口气液的体积流量,计算持液率,研究不同角度弯管对气体持液率的影响。     

气力输送中弯管压力降的研究

讨论了气力输送中弯管的压力损失,详细阐述了输送过程中各种参数,如输送气速、料气比和弯管弯曲半径、弯管结构及形状对气力输送压降和输送能力的影响,指出不同的物料在弯管结构选择上也应不同。     

弯管塑性极限载荷研究进展

弯管形状和受载复杂，是管系中的薄弱环节，因此弯管塑性极限载荷的研究在学术和工程上都有重要意义。本文介绍了弯管塑性极限载荷的研究现状、存在的问题及发展趋势。     

Kinetics of phase separation in polyurethane/polystyrene semi-1 interpenetrating polymer networks. 2. Microscopy observations and theoretical approach

The phase separation process of in-situ polyurethane/polystyrene semi-1 interpenetrating polymer networks has been followed by optical microscopy completed by image analysis. The final morphology has been examined by scanning electron microscopy, and its relation to the phase separation process has been established. When phase separation occurs before gelation of the medium, polystyrene is dispersed both as large and small noduli in the polyurethane network; a polyurethane-rich interphase separates the noduli from the matrix. These observations explain the previous results on the turbidity of such systems measured by light transmission. In the opposite cases, no visible phase separation is observed on the micrographs. The thermodynamics of the phase separation process has also been examined.     

茶藨子农药和医药生物活性研究进展

综述了近年来茶藨子(Ribes L.)国内外农药和医药生物活性研究方面的进展,主要包括化学成分、生物活性、应用概况,并对它的发展趋势和应用前景作综展望。     

Vinyl monomers bearing chromophore moieties and their polymers. VI. Synthesis and photochemical behavior of acrylic monomer bearing phenoxazine moiety and its polymer

An acrylic monomer having phenoxazine moiety, i.e., N-acryloylphenoxazine (APO), has been synthesized by dehydrochlorination of N-(3-chloropropionyl)phenoxazine with 1,5-diazabicyclo[5.4.0]undec-5-ene in dimethyl sulfoxide. The monomer can be polymerized with AIBN as an initiator. The photochemical behavior, including the fluorescence and photosensitizing properties of this monomer and its polymer, has been studied. It has been recorded that the absorption spectrum of polymer P(APO) displays a few blue shifts compared with its monomer APO. It has also been observed that the fluorescence emission intensity of the monomer is dramatically lower than that of its polymer at the same chromophore concentration. This may be ascribed to the charge transfer interacting between the coexisting electron-accepting acrylic carbon-carbon double bond and the electron-donation phenoxazine moiety in APO, intramolecularly or intermolecularly on excitation. The fluorescence of the APO polymer, which does not have carbon-carbon double bond, can be quenched by electron-deficient unsaturated nitriles and esters, clarifying that the electron-deficient carbon-carbon double bond does play an important role for the fluorescence quenching of the monomer. Thus, we term such phenomena as structural self-quenching effect, differing from the concentrational self-quenching effect, which is caused mainly by concentrational factors. The fluorescence quenching of P(APO) by C₆₀ has also been demonstrated. The formation of the charge transfer complex of P(APO) with C₆₀ in the ground state is revealed by the upward deviation from the linearity of the Stern-Volmer plot. APO can act as a photoinitiator to sensitize the photopolymerization of vinyl monomers such as acrylonitrile in dimethyl formamide and pursued kinetically. From the ultraviolet analysis of the PAN sensitized by APO, it is proved that APO not only sensitizes the photopolymerization of AN, but also incorporates in the PAN chain. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:481–489, 1997     

Characterization of Cure Profile of Anaerobic Adhesives by Real-Time FT-IR Spectroscopy. I. Effect of Transition Metal Dithiolate Complexes

A model acrylic adhesive formulation consisting of triethylene glycol dimethacrylate (TRIEGMA) monomer, cumene hydroperoxide (CHP), o-benzoic sulfimide (saccharin or BS) and with or without a metal dithiolate catalyst has been made to study kinetics and mechanism of the anaerobic polymerization. In these studies, a real-time FT-IR spectroscopic (RT/FT-IR) technique has been used to study anaerobic cure profiles at room temperature. The catalytic effect of several transition metal dithio complexes for redox-initiated acrylate polymerization has been studied. The dithiolates used in these studies include the dithiocarbamate, xanthate dithiophosphate complexes of copper, nickel and zinc systems. Copper diacetylacetonate was also studied for comparison of its catalytic reactivity. A syner-gistic effect of copper dithiolate catalyst and saccharin was observed. The effects of catalyst concentration, metal and ligand type, and co-initiator on cure profiles have been monitored in a real-time mode.     

Modified wheat flour–natural rubber blends. II

Effect of cyanoethylation of starch on the properties of starch xanthide–NR vulcanizates has been studied. Significant improvements in compounding, tensile modulus, tensile strength, and retention of wet strength of the vulcanizates have been recorded. Equilibrium swelling of vulcanizates by water is also greatly suppressed. The role of cyanoethylation of starch in imparting such specific effects has been analyzed in the light of the polarity of the cyanoethyl group and its effect in lowering the critical yield stress of the modified starch for efficient dispersive mixing in NR matrix.     

Characterisation of fly ashes. Potential reactivity as alkaline cements

A representative group of Spanish fly ashes has been characterised in order to determine its capacity for being alkali activated and give place to a material with cementitious properties. The characterisation studies have been carried out through chemical analysis, laser granulometry, Blaine, BET, particle size distribution, XRD and ²⁹Si MAS NMR. Compressive mechanical strength test was used to determine the reactivity of the fly ashes as alkaline binders. The results obtained have demonstrated that all investigated fly ashes are suitable to be alkali activated. Additionally it has also been demonstrated that the key factors of their potential reactivity are: the reactive silica content, the vitreous phase content and the particle size distribution.     

Caspase-14—From Biomolecular Basics to Clinical Approach. A Review of Available Data

Caspase-14 is a unique member of the caspase family—a family of molecules participating in apoptosis. However, it does not affect this process but regulates another form of programmed cell death—cornification, which is characteristic of the epidermis. Therefore, it plays a crucial role in the formation of the skin barrier. The cell death cycle has been a subject of interest for researchers for decades, so a lot of research has been done to expand the understanding of caspase-14, its role in cell homeostasis and processes affecting its expression and activation. Conversely, it is also an interesting target for clinical researchers searching for its role in the physiology of healthy individuals and its pathophysiology in particular diseases. A summary was done in 2008 by Denecker et al., concentrating mostly on the biotechnological aspects of the molecule and its physiological role. However, a lot of new data have been reported, and some more practical and clinical research has been conducted since then. The majority of studies tackled the issue of clinical data presenting the role of caspase in the etiopathology of many diseases such as retinal dysfunctions, multiple malignancies, and skin conditions. This review summarizes the available knowledge on the molecular and, more interestingly, the clinical aspects of caspase-14. It also presents how theoretical science may pave the way for medical research. Methods: The authors analyzed publications available on PubMed until 21 March 2021, using the search term “caspase 14”.     

Pyrolysis and combustion of cellulose. VIII. Thermally initiated reactions of phosphonomethyl amide flame retardants

Several N-(phosphonomethyl) amides have previously been reported to act as particularly effective flame retardants for cellulose. It has also been demonstrated previously that the efficiency of a flame retardant on cellulose frequently parallels its ability to phosphorylate cellulosic hydroxyls at elevated temperatures. This study of the hydrolysis and alcoholysis reactions of N-(phosphonomethyl) amides establishes their unique reactivity. An explanation for this high reactivity is proposed on the basis of intramolecular assistance of the attack of water or alcohols at phosphorus by the carbonyl oxygen of the amide moiety.     

A mathematical model of the melting of polymeric materials in extruders. Investigation of the form of the interface and of melt velocity profiles

Conclusions The form of the interface in the melting of a polymer in an extruder has been studied. It has been found that it differs considerably from right-angled, and melting of the polymer takes place over its entire curvolinear surface.The three components of polymer melt velocity have been constructed: The change in these both over the cross-sectional area of the extruder screw and also along its length has been noted.In the liquid phase of the polymer, an intense circulation of the melt takes place in the transverse plane of the screw channel.Translated from Khimicheskie Volokna, No. 5, pp. 40–42, September–October, 1984.     

Interaction of supercritical carbon dioxide with polymers. I. Crystalline polymers

Supercritical fluid (SCF) technology involving carbon dioxide is recently receiving wide attention due to its vast potential application in various fields such as cleaning, extraction, synthesis, etc., in addition to its environmental benefits. To fully exploit the use of SCFs in new technologies, it is important to understand how SCFs interact with materials. To this end, we have undertaken a systematic study involving a wide pressure and temperature range to investigate the interaction of supercritical carbon dioxide (SC CO₂) with nine different crystalline polymers, namely, substituted and unsubstituted polyethylene (four varieties), polypropylene, nylon 66, poly(ethylene terephthalate), poly(oxymethylene), and poly(vinylidine fluoride). Critical factors such as changes in appearance and weight, temperature, pressure and time of the supercritical fluid treatment, and dimension of samples have been observed. The influence of SC CO₂ on the thermal properties of treated polymers has been investigated through TGA analysis. Further, changes in the mechanical properties such as yield strength, ultimate elongation, and modulus of elasticity of the investigated crystalline polymers were also observed. A discussion has been included to show the possible implications of the observed changes in realizing various applications. © 1996 John Wiley & Sons, Inc.