TX-100与MBI复配体系对Q235钢的缓蚀性能

目的 通过分析曲拉通（TX-100）与2-巯基苯并咪唑（MBI）复配体系在酸性介质中对Q235钢的缓蚀情况,获得缓蚀效果最佳条件,如两者的配比、浓度等,分析其缓蚀效果和机理。方法 采用静态失重法对缓蚀剂的缓蚀性能进行了初步判定,用极化曲线法和交流阻抗法进一步研究缓蚀机理和效率,通过SEM和XPS对不同情况下的碳钢进行表面形貌观察和表面成分分析,采用综合分析法研究混合缓蚀剂对碳钢表面的缓蚀机理。结果 保持混合缓蚀剂总浓度2×10?4 mol/L,TX-100和MBI以不同摩尔比混合时,随着TX-100摩尔分数α(TX-100)的增加,缓蚀效率增大。当α(TX-100)=50%时,缓蚀效果达到90%,继续增大α(TX-100),缓蚀效率减小。当TX-100和MBI等摩尔混合时,随着总浓度的增大,缓蚀效率增大。当达到2×10?4 mol/L时,再增大缓蚀剂的总浓度,缓蚀效率没有明显增大,且达到90%以上。分析表明,两种缓蚀剂TX-100和MBI之间存在分子间相互作用,使其在Q235钢表面形成致密牢固的保护层,且混合物属于控制阴极反应为主的混合型抑制剂。结论 经过优选TX-100和MBI混合缓蚀剂的配比和浓度,降低了MBI的用量和缓蚀剂的应用成本,同时为金属防腐奠定了理论基础。     

Electro-magneto temperature-dependent vibration analysis of functionally graded-carbon nanotube-reinforced piezoelectric Mindlin cylindrical shells resting on a temperature-dependent,orthotropic elastic medium

Vibration smart control analysis of a temperature-dependent functionally graded-carbon nanotube-reinforced piezoelectric cylindrical shell embedded in an orthotropic elastic medium is investigated. The mixture law is used for obtaining the material properties of the structure. The structure is subjected to a 2D magnetic field. Considering the first-order shear deformation theory, the motion equations are obtained. Based on an analytical method and differential quadrature method, the frequency is calculated. The effects of applied voltage, magnetic field, volume percent, and distribution type of carbon nanotubes, temperature, orthotropic elastic medium, and length to radius ratio of the shell are shown on system frequency.     

中深孔爆破一次成井技术研究与应用

目前中深孔爆破一次成井普遍存在断面小、深度低的特点。一般深度都控制在12 m以内，20 m左右一次爆破成型的盲、天溜井案例较少，且多为失败案例。但随着科技进步，设备更新，开采分段逐渐严格，天溜井施工工艺要求也逐渐增大。为保证中深孔爆破的安全与高效，试验、研究中深孔爆破一次成井技术，从爆破设计、参数、设备选型等方面，实施了一种高效的中深孔爆破一次成井实例，对一次成井施工技术的研究具有重要意义。     

基于SpringBoot框架的中长期水文预报系统设计与开发

鉴于中长期水文预报能有效为宏观防洪形势分析和水资源管理提供科学依据,提出了Java环境下基于SpringBoot框架开发的中长期水文预报系统。该系统集成了包含随机森林、支持向量机、小波分析、贝叶斯模型平均等多种模型方法的Python模型库以提高开发效率;采用了基于RabbitMQ技术的异种语言调用与基于RESTful技术的轻量级接口设计以降低系统响应时间。并搭建了全国主要江河流域共10个断面的中长期水文预报系统作为示例进行分析,实现了中长期水文预报业务化运行,可为同类系统开发提供参考示范。     

钠水反应试验系统中小泄漏钠水反应氢气分布特性

蒸汽发生器是钠冷快堆的关键设备之一，其传热管破裂引发的钠水反应会产生大量氢气及热量，危害钠冷快堆的安全运行。本文基于VOF多相流模型，在钠水反应试验系统内开展中小泄漏钠水反应工况的数值分析，获得了高压反应釜内氢气在钠水反应下的三维空间分布特性和迁移特性。结果表明：高压反应釜内氢气的迁移特性受钠液流速影响，氢气在整个循环环路的迁移特性主要受水泄漏量控制。通过设置灵敏度为0.005 ppm的氢计，获得了环路不同区域检测到氢气的最快特征时间。     

温轧温度对中碳Cr-Mo钢组织性能的影响

通过SEM、EBSD和拉伸试验研究了温轧温度对中碳Cr-Mo钢组织演变和力学性能的影响。结果表明:较高温轧温度有利于Cr-Mo钢组织的均匀分布,当轧制温度从500 ℃增加到600 ℃时,铁素体晶粒尺寸由0.424 μm增加到0.490 μm,晶粒尺寸差别不断减小,屈服强度由1380 MPa下降至1062 MPa,在550 ℃轧制试验钢的塑性最好,强塑积最高,为5816 MPa·%。     

Thermal performance investigation of a single medium temperature phase change microcapsule used for wind power absorption and heat storage system

Phase change microcapsules have a wide application in the heat storage system. The medium temperature heat storage systems such as medium temperature solar thermal plants, waste heat recovery systems and wind power absorption systems. In order to analyse the effects of configuration parameters and materials on phase change heat transfer process in a single medium temperature microcapsule, an enthalpy-transforming model was applied to trace the location of the solid-liquid interface and obtain the liquid fraction at different time in the melting process. Based on this model, the effects of particle size, the effects of wall thickness, the effects of wall materials and different medium temperature phase change materials were analyzed. The numerical results show that the larger particle size has a longer melting time, the melting time of 50 μm particle size and 250 μm particle size is 0.036 s and 2.48 s, respectively. In addition, the melting time of microcapsules with different wall thicknesses from the 1μm to 9μm is the same i.e., 0.14 s. Therefore, the wall thickness has little effect on the melting time of microcapsules. Besides, the microcapsule with the erythritol as inner material and the polystyrene as wall material has the longest melting time. Furthermore, the thermal conductivity of the wall materials is the main factor affecting the melting time. Moreover, the product of latent heat and density of phase change material is the main factor of the melting time.     

内燃机冷却系统中应用纳米流体强化传热研究综述

内燃机工作时依赖冷却系统将多余热量及时带走以保证燃烧室核心部件及润滑油膜的正常工作温度。常规内燃机冷却介质导热系数偏低,而新一代强化传热工质纳米流体具有明显提升的传热性能,应用于内燃机冷却系统有利于强化内燃机传热及提高热管理性能。且由于纳米流体的传热性能受纳米粒子的种类、大小、浓度、形状等因素影响,可以通过改变这些因素控制内燃机冷却水腔的传热量。综述了国内外研究者针对纳米流体导热系数与对流换热性能开展的试验测试、理论分析和计算机模拟研究工作,以及纳米流体应用于内燃机冷却系统中强化传热的进展,最后指出当前研究工作的不足及未来工作方向。     

Performance assessment of food safety management systems in animal-based food companies in view of their context characteristics: A European study

Recurrently the question arises if efforts in food safety management system (FSMS) have resulted in effective systems in animal-based food production systems. The aim of this study was to gain an insight in the performance of FSMS in European animal-based food production companies in view of their typical context characteristics. Hundred European companies (from Belgium, Spain, The Netherlands, Greece, Italy, and Hungary) varying in company size, and producing different types of fresh and processed animal-derived products (dairy, beef/lamb, poultry, and pork) were assed using a diagnostic instrument. Results indicated that most participating companies adapted adequately their food safety management systems to the riskiness of their context characteristics resulting in rather good safety output scores. Only a small group have overall basic systems and operate in a moderate or moderate-high risk context, which was reflected in lower safety output scores. Companies tend to invest first in the control strategies whereas assurance activities such as verification and validation seem to require more time and effort to achieve advanced levels. Our study demonstrated that also small and medium enterprises managed to have advanced systems, and achieve a good safety output. However, their typical organisational characteristics such as less resources (educated staff, laboratory facilities, time), more restricted formalisation (restricted use of procedures and formal meetings), limited information systems, but more stable workforce, might require more tailored support from government and/or branch organisations to develop towards advanced systems in the case of high-risk products and processes. More in-depth studies to successful SMEs could give insight in best practices to improve FSMS performance.     

Heat transfer analysis for particle–fluid suspension thermomagnetohydrodynamic peristaltic flow with Darcy–Forchheimer medium

This theoretical analysis explores the effect of heat and mass transfer on particle–fluid suspension for the Rabinowitsch fluid model with the stiffness and dynamic damping effects through Darcy–Brinkman–Forchheimer porous medium. In this study, we also incorporate slip and transverse magnetic field effects. Using low Reynolds number, to neglect inertial forces and to keep the pressure constant during the flow, channel height is used largely as compared with the ratio of length of the wave. A numerical technique is used to solve flow governing system of differential equations. Particular attention is paid to viscous damping force parameter, stiffness parameter, and rigidity parameter; also, the numerical data for thermal profile, momentum, and concentration distribution are presented graphically. Outcomes are deliberated in detail for different fluid models (thinning, thickening, and viscous models). It is found that velocity profile increases for greater values of viscous damping effect and stiffness and rigidity parameter for shear thinning, but conflicting comportment is showed for thickening nature model. Viscous dissipation effects increases the thermal profile for all cases of fluid models. The scope of the present article is valuable in explaining the blood transport dynamics in small vessels while considering the important wall features with chemical reaction characteristics. The current analysis has extensive applications in biomedical engineering field, that is, peristaltic pumps.