牛乳粉中氯霉素残留分析标准物质的定值方法研究及应用

目的 建立一种基于液相色谱-串联质谱法的牛乳粉中氯霉素残留分析基体标准物质定值方法,并以此法用于该标准物质的均匀性、稳定性检验及定值.方法 牛乳粉加水复原后,用乙酸乙酯提取,经正己烷除脂,再用乙酸乙酯萃取,同位素内标法定量测定.结果 氯霉素在0.4～4.0ng/mL范围内线性关系良好,相关系数达0.999,平均回收率为...     

基于升沉补偿平台多缸同步的控制策略研究

为保证升沉补偿平台的上平台在6个液压缸运动过程中始终处于相对平稳状态,提出一种将广义预测控制与相邻交叉耦合控制相结合的控制策略,实现对平台6个液压缸的位置同步控制。采用广义预测控制作为每个液压伺服通道的位置控制器,加入相邻交叉耦合同步控制方式,使每个液压伺服通道的液压缸考虑与其相邻两通道液压缸之间的同步误差,获得新的控制量,对6个液压缸进行同步控制;利用MATLAB进行仿真。结果表明：系统响应速度快,具有较好的位置控制和同步控制性能;将基于广义预测控制的相邻交叉耦合同步控制方法应用于升沉补偿平台,简化了控制器结构,协调6个液压伺服通道,在一定程度上减小了负载扰动对平台稳定性的影响。     

核桃膳食化-从膳食结构需求角度浅析核桃仁全利用

核桃油是重要的木本粮油,具有较高的营养价值和良好的保健功能活性,但易产生氧化哈败等问题,其化学组成和制备方法对核桃油的氧化稳定性具有重要影响。本文综述了核桃油中脂肪酸、酚类化合物、植物甾醇、角鲨烯等组分的种类、含量及功能作用,并对核桃油的抗炎、抗氧化、抗肿瘤、免疫调节、神经保护等生物活性进行了分析,对常见制备方法和工艺创新的优缺点进行了综述,分析了核桃油化学组成和制备方法对核桃油氧化稳定性的影响,并对核桃油的功能活性、高效制备技术和专用品种加工适宜性等研究方向进行了展望,以期为核桃油产品的开发利用提供参考。

     

Unraveling the Origin of Enhanced K+ Storage of Carbonaceous Anodes Enabled by Nitrogen/Sulfur Co-Doping

N-doped carbons, as promising anode materials for energy storage, are generally modified by the additional heteroatoms (B, P, and S) doping to further promote the electrochemical performance. However, the promotion mechanism by such additional doping, especially its interplay with N-containing species, remains unclear. Herein, by adopting N/S co-doped carbon as a model system, it is found that S-doping can significantly improve the content of pyridinic-N, i.e., the most energetically favorable N type for K⁺ storage. Theoretical calculations reveal that such S-induced pyridinic-N improvement possibly originates from its catalytic effect that can facilitate the transition from edge quaternary-N to pyridinic-N. The resultant high content of pyridinic-N, together with the additional S species, ensures abundant active sites for K⁺ storage. Accordingly, the N/S co-doped carbon anode delivers both a high reversible capacity (422.9 mA h g⁻¹ at 0.05 A g⁻¹) and an impressive cyclic stability (249.6 mA h g⁻¹ at 1 A g⁻¹ over 4000 cycles). Moreover, in/ex situ characterizations further verify the merits of N/S co-doped carbon from the perspective of compositional evolution and structural stability. This study unravels the origin of enhanced K⁺ storage by N/S co-doping, which also helps to understand the synergistic effects of other heteroatoms co-doping systems.     

Disrupting Intracellular Iron Homeostasis by Engineered Metal-Organic Framework for Nanocatalytic Tumor Therapy in Synergy with Autophagy Amplification-Promoted Ferroptosis

Metal-organic frameworks (MOFs) featuring good biocompatibility and tunable microstructures are developed to generate reactive oxygen species (ROS) for nanocatalytic therapy. However, the relatively low catalytic activity of MOF and intracellular ion homeostasis, a self-protective mechanism to resist the intracellular accumulation of metal ions, results in the undesirable efficacy of tumor therapy. Herein, a therapeutic strategy is introduced of breaking intracellular iron homeostasis for nanocatalytic therapy in synergy with autophagy amplification-promoted ferroptosis, based on etched MOF nanocatalyst (denoted COS@MOF), which is self-etched by thiamine pyrophosphate (TPP) and further modified with autophagy agonist chitosan oligosaccharides (COS). Such self-etched MOF exhibit an open cavity structure that is more conducive to adsorbing reactive molecules and producing more active sites, and an enhanced Fe(II)/Fe(III) ratio, reinforcing catalytic activity for ROS generation. The catalytic process of COS@MOF can be accelerated by overexpressed endogenous hydrogen sulfide (H₂S) within colorectal tumors which reduces Fe³⁺ into more active Fe²⁺. In vitro and in vivo results demonstrate that COS@MOF amplifies autophagy to break iron homeostasis for facilitating ROS production to promote ferroptosis, achieving synergetic nanocatalytic/ferroptosis tumor therapy. This study provides a promising paradigm to elevate MOF-based catalytic performance in synergy with autophagy amplification-promoted ferroptosis for enhanced therapeutic efficacy.     

基于深度强化学习的户内变电站通风降噪优化设计

针对户内变电站运行发热导致温度过高引发安全风险，以及采取相关散热措施可能导致噪声扰民的问题，提出一种基于有限元仿真和深度强化学习的户内变电站进风口设计参数优化方法。以此对户内变电站通风系统进风口位置大小进行优化设计，使其获得最优通风降噪效果。首先，通过有限元分析法对其温度场、流体场和声场进行仿真建模；然后，基于大量仿真数据，采用卷积神经网络建立温度和噪声的预测模型；最后，考虑噪声约束，利用基于最大熵强化学习框架的SAC算法，以变电站室内温度最低为目标对进风口设计参数进行优化求解。研究结果表明，经过优化后的进风口设计方案能够有效降低变电站室内温度，同时使噪声满足国家规范要求。     

3D printing of alumina ceramic heat sink with mini-channels for thermal management

Thermal management has become one of the most challenging issues for high-power, integrated, and miniaturized electronic devices. In this paper, an alumina ceramic heat sink with mini-channels was fabricated using a digital light processing 3D printing technology. Microstructures of the ceramic were investigated by scanning electron microscopy. A proper flow rate of water in the mini-channels was figured out for efficient cooling by infrared thermal imaging and micro-thermocouple characterizations. The ceramic heat sink was further integrated with a high-power laser diode module; cooling performance was evaluated by investigating the thermal resistance of the ceramic heat sink and the optoelectronic property of the laser diode module. Results indicated that the laser diode module could be operated at high driving power of 115.6 W. This study provided a new strategy for a highly efficient thermal management of electronic devices and highlighted the technical potential of ceramic heat sink with more compact coolant channels.     

Review on the Binders for Sustainable High-Energy-Density Lithium Ion Batteries: Status,Solutions, and Prospects

The upsurging demand for electric vehicles and the rapid consumption of lithium-ion batteries (LIBs) calls for LIBs to possess high energy density and resource sustainability. The former requires the usage of electroactive materials with high capacity and the maximum amount within the fixed electrode volume. The latter essentially creates a closed-loop circulation scenario for electroactive materials. In all aspects, binders are of practical significance in bonding electroactive materials, maintaining electrode integrity and detaching electrode slurry from the current collector. Currently, the key role of binders in enhancing the electrochemical behavior of sustainable high-capacity electroactive materials has been recognized. Meanwhile, binders that are designed for easy and cost-effective recycling of electroactive materials are gradually reported. Herein, recently developed binders that hold promises in establishing sustainable high-energy-density LIBs are summarized. The role of binder in facilitating easy separation of electroactive materials are first highlighted. Subsequently, special attention is paid to conductive binders, contributing to less battery chemistries and higher energy density of electrode. Additionally, progress of emerging binders in high-capacity electroactive materials are also reviewed. It is believed that the advances in binders will open up opportunities for establishing a sustainable high-energy-density battery economy.