离线式带钢双面翻转检查站方案设计及实践

针对某酸轧机组检查站穿带困难、检查效率低、产生废品多、故障率高的问题,开发了一种离线式带钢双面检查站。该检查站新增了带钢翻转装置,将在入口分切剪处完成定尺剪切的带钢试样由两侧压板夹紧,中间可升降皮带机落下,翻转装置将带钢试样张紧,并翻转90°或者180°,实现带钢的双面检查。皮带机两侧布置有可升降、可横移的活动操作平台,检测人员站在平台上对带钢进行打磨检查,可同时对带钢上下表面进行检测。由于缩短了带钢的传输距离,有效减少了其他擦划伤的影响,提高了带钢表面质量检测准确性。     

Preparation of magnetic zeolite/chitosan composite using silane as modifier for adsorption of Cr(VI) from aqueous solutions

This study aimed to prepare an efficient, cost-effective, and separable magnetic zeolite/chitosan composite (MZFA/CS) adsorbent from solid waste to deal with the water pollution of Cr(VI). The MZFA/CS was characterized by X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM) techniques. Then, the effect of pH, temperature, initial concentration of Cr(VI) ions, and contact time was considered in the study. For a sorbent dose of 0.1 g in 50 mL of a Cr(VI) solution, at a contact time of 30 min, temperature of 30°C, and a pH of 3, an adsorption capacity (q_e) of 16.96 mg g⁻¹ was achieved. Adsorption kinetics and isotherm data obtained for all adsorption systems were well-fitted by pseudo-second-order and Langmuir models, respectively. The thermodynamic study suggested that the adsorption process is spontaneous and endothermic in nature. In summary, the adsorbent with better separability (Ms = 16.83 emu g⁻¹) and adsorbability was successfully fabricated.     

核磁共振磷谱法测定乳制品中的酪蛋白含量

基于插值法建立乳制品中酪蛋白的核磁共振磷谱定量检测方法。结果表明，该方法的检出限为0.38 g/L（信噪比（RSN）=3），定量限为1.25 g/L（RSN=10）；在5.00～35.00 g/L质量浓度范围内线性良好，相关系数R2大于0.999；加标回收率在91.94%～105.10%范围区间；日内精密度在0.65%～1.40%范围区间；日间精密度在1.40%～1.80%范围区间。对市售不同乳制品中酪蛋白含量进行检测，该方法与GB 31638—2016《酪蛋白》测定结果误差在±5%以内，满足方法可行性对比分析验证要求。该方法相比常规方法样品前处理简单、定量准确性高，大大缩短了检测时间，且有更广泛的适用性，满足乳制品中酪蛋白快速定量检测的要求。     

Magnetic Assembly of a Multifunctional Guidance Conduit for Peripheral Nerve Repair

Nerve growth conduits are designed to support and promote axon regeneration following nerve injuries. Multifunctionalized conduits with combined physical and chemical cues, are a promising avenue aimed at overcoming current therapeutic barriers. However, the efficacious assembly of conduits that promote neuronal growth remains a challenge. Here, a biomimetic regenerative gel is developed, that integrates physical and chemical cues in a biocompatible “one pot reaction” strategy. The collagen gel is enriched with magnetic nanoparticles coated with nerve growth factor (NGF). Then, through a remote magnetic actuation, highly aligned fibrillar gel structure embedded with anisotropically distributed coated nanoparticles, combining multiple regenerating strategies, is obtained. The effects of the multifunctional gels are examined in vitro, and in vivo in a 10-mm rat sciatic nerve injury model. The magneto-based therapeutic conduits demonstrate oriented and directed axonal growth, and improve nerve regeneration in vivo. The study of multifunctional guidance scaffolds that can be implemented efficiently and remotely provides the foundation to a novel therapeutic approach to overcome current medical obstacles for nerve injuries.     

Microstructure,tribological behavior and magnetic properties of Fe−Ni−TiO2 composite coatings synthesized via pulse frequency variation

The Fe−Ni−TiO₂ nanocomposite coatings were electrodeposited by pulse frequency variation. The results showed that the nanocomposite with a very dense coating surface and a nanocrystalline structure was produced at higher frequencies. By increasing the pulse frequency from 10 to 500 Hz, the iron and TiO₂ nanoparticles contentswere increased in expense of nickel content. XRD patterns showed that by increasing the frequency to 500 Hz, an enhancement ofBCC phase was observed and the grain size of deposits was reduced to 35 nm. The microhardness and the surface roughness were increased to 647 HV and 125 nm at 500 Hz due to the grain size reduction and higher incorporation of TiO₂ nanoparticles into the Fe−Ni matrix (5.13 wt.%). Moreover, the friction coefficient and wear rate values were decreased by increasing the pulse frequency;while the saturation magnetization and coercivity values of the composite deposits were increased.     

ZnO Nanoplatelets with Controlled Thickness: Atomic Insight into Facet-Specific Bimodal Ligand Binding Using DNP NMR

Colloidal nanoplatelets (NPLs) and nanosheets with controlled thickness have recently emerged as an exciting new class of quantum-sized nanomaterials with substantially distinct optical properties compared to 0D quantum dots. Zn-based NPLs are an attractive heavy-metal-free alternative to the so far most widespread cadmium chalcogenide colloidal 2D semiconductor nanostructures, but their synthesis remains challenging to achieve. The authors describe herein, to the best of their knowledge, the first synthesis of highly stable ZnO NPLs with the atomically precise thickness, which for the smallest NPLs is 3.2 nm (corresponding to 12 ZnO layers). Furthermore, by means of dynamic nuclear polarization-enhanced solid-state ¹⁵N NMR, the original role of the benzamidine ligands in stabilizing the surface of these nanomaterials is revealed, which can bind to both the polar and non-polar ZnO facets, acting either as X- or L-type ligands, respectively. This bimodal stabilization allows obtaining hexagonal NPLs for which the surface energy of the facets is modulated by the presence of the ligands. Thus, in-depth study of the interactions at the organic–inorganic interfaces provides a deeper understanding of the ligand–surface interface and should facilitate the future chemistry of stable-by-design nano-objects.     

核磁共振方法研究油水过渡带驱替特征

目前,利用常规手段难以对低含油饱和度油水过渡带进行开采,利用气驱及化学驱方式开采仍具有开发潜力,但对于不同类型的油水过渡带,其开发机理不明确。开展4组天然岩心驱替实验,利用核磁共振技术研究不同类型油水过渡带中剩余油的启动机理和主要分布状态,在此基础上研究油水过渡带的开发特征。实验结果表明,气驱开发方式更适用于低渗岩心;化学驱的乳化及降低表面张力作用对小孔隙中剩余油有较好的动用程度,提高采收率效果显著。     

聚乙烯亚胺氨基化磁性氧化石墨烯的制备及其对活性艳红X-3B的吸附

使用改性hummers法制备出氧化石墨烯(GO),通过水热法在GO上生长磁性CoFe₂O₄,再使用聚乙烯亚胺(PEI)进行氨基改性,制备出聚乙烯亚胺氨基化磁性氧化石墨烯(PEI-MGO)。使用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对PEI-MGO的结构和微观形貌进行表征。结果表明:纳米级尖晶石相CoFe₂O₄均匀分散于GO上,且氨基改性成功。探讨了PEI-MGO对水体中活性艳红X-3B的吸附性能。结果表明:在活性艳红X-3B初始质量浓度为150mg/L、体积为100mL、吸附剂质量为0.04g、pH值为1、吸附时间为60min时达到平衡,平衡吸附量为361.15mg/g。PEI-MGO对活性艳红X-3B的饱和吸附量为470.58mg/g。磁分离和磁回收研究表明,PEI-MGO能快速从水体中分离,回收率为98.6%。     

Multi-field coupling thermo-acoustic radiation using free-standing nano-thin films in a static magnetic field

Abstract

Thermo-acoustic radiation from nano-thin film has been widely reported these years. In this paper, a static magnetic field is introduced to enhance the acoustic power in the multi-field thermo-acoustic generation. The coupled thermo-acoustic system in a static magnetic field shares the same acoustical unit with very few additional components. In the presence of a static magnetic field, thin-film vibration is excited instead of being still in the classical thermo-acoustic system. Not surprisingly, a steady magnetic field has very little impact on the thermo-acoustic generation system when a constant amplitude sinusoidal current is introduced. The oscillation perpendicular to the nano-thin film is driven by the electromagnetic force. The system response of thermo-acoustics and magneto-acoustics can be generally matched when suitable parameters are introduced. The acoustical pressure output can be significantly improved in the presence of a static magnetic field although more electrical input power should be provided in the multi-field thermo-acoustic system. Evidently, the coupled multi-field acoustical system is able to handle more electrical power input and the power input can be more easily dissipated relatively. The results show that the acoustic response of this new multi-filed coupled system can be significantly improved as compared to the classical system without magnetic effects.