Al2O3/Cr3C2/(W,Ti)C复合材料化学相容性分析

应用热力学原理计算分析了Al2O3/Cr3C2/(W,Ti)C复合陶瓷材料体系中各组分间化学反应的可能性.结果表明,在1800℃范围内各组分间不会发生化学反应.并通过Al2O3/Cr3C2/(W,Ti)C复合陶瓷材料的热压烧结制备进行了实验验证.     

脲醛树脂基高分子材料改性研究

本文简要介绍了脲醛树脂基高分子材料的基本生产工艺流程,探索玻璃纤维、纳米蒙脱土、丁腈橡胶粉以及玉米淀粉种类和用量对脲醛树脂基高分子材料耐电击穿性能的影响。实验结果表明,选用玻璃纤维作为增强剂对脲醛树脂基高分子材料的耐电击穿强度影响最为明显,纳米蒙脱土次之,玉米淀粉的加入对脲醛树脂基高分子材料的耐电击穿强度影响不明显,而丁腈橡胶的加入对脲醛树脂基高分子材料的耐电击穿强度有明显的下降趋势,改性后的脲醛树脂基高分子材料的耐电击穿强度能超过17KV/mm,最佳耐压时间在100s以上。     

Mach—Zehnder干涉型光纤弱磁场传感器稳定性的研究

近年来,Mach—zehnder干涉型光纤弱磁场传感器的研究和应用获得了很大的发展,但是,外界环境因素的干扰始终影响着传感器的稳定性。本文选择直流相位跟踪法来保证传感器的稳定性,给出了理论阐述和具体电路。结果表明,该方法很好的消除了外界环境因素的干扰,保证了传感器的稳定性。     

响应面优化低糖滇红奶茶的配方

目的 通过响应面法优化低糖滇红奶茶的配方。方法 以滇红茶、全脂奶粉、零卡糖为主要原料,通过单因素分析结合响应面实验设计优化滇红奶茶配方,并分析产品的理化及卫生指标。结果 优化配方为：滇红茶汁50%、全脂奶粉15%、零卡糖10%、乳化剂0.22%、稳定剂0.2%,此时感官评分为87.83。滇红奶茶浅棕色稳定性好、质地均匀、浓稠恰当、细腻滑润无杂质,甜味适中茶香味与奶香香味协调无异味,经测定蛋白质含量(5.99±0.06)%、脂肪含量(3.38±0.02)%、茶多酚含量(320.6±2.25) mg/kg,微生物指标符合国家标准。结论 本研究开发了一种低糖健康的滇红奶茶,为滇红茶的深加工提供一定的实验依据。     

涡流发生器在流体机械流动控制中应用研究进展

从实验测量和数值计算两个方面对涡流发生器流动控制的基础研究和应用研究进行评述,介绍了涡流发生器在流体机械流动控制中的应用及其取得的主要研究成果,最后指出了涡流发生器发展存在的问题和发展方向.     

激光法合成纳米金刚石的高分辨电镜研究

在常温常压下,采用脉冲激光作用循环的石墨悬浮液,收集并烘干得到样品B,另一部分用高氯酸进行酸煮提纯提到样品A.对样品A、B分别进行高分辨电子显微镜（HRTEM）和显微拉曼光谱（Micro-Raman）分析.结果表明,部分石墨经激光作用后转变成了具有多重孪晶结构特征的、尺寸为5 nm的金刚石颗粒,同时还得到了非晶碳.高分辨电子显微镜照片证明,石墨转变成纳米金刚石的机理为快速成核长大过程.     

Editable Supercapacitors with Customizable Stretchability Based on Mechanically Strengthened Ultralong MnO2 Nanowire Composite

Although some progress has been made on stretchable supercapacitors, traditional stretchable supercapacitors fabricated by predesigning structured electrodes for device assembling still lack the device‐level editability and programmability. To adapt to wearable electronics with arbitrary configurations, it is highly desirable to develop editable supercapacitors that can be directly transferred into desirable shapes and stretchability. In this work, editable supercapacitors for customizable shapes and stretchability using electrodes based on mechanically strengthened ultralong MnO₂ nanowire composites are developed. A supercapacitor edited with honeycomb‐like structure shows a specific capacitance of 227.2 mF cm^?2 and can be stretched up to 500% without degradation of electrochemical performance, which is superior to most of the state‐of‐the‐art stretchable supercapacitors. In addition, it maintains nearly 98% of the initial capacitance after 10 000 stretch‐and‐release cycles under 400% tensile strain. As a representative of concept for system integration, the editable supercapacitors are integrated with a strain sensor, and the system exhibits a stable sensing performance even under arm swing. Being highly stretchable, easily programmable, as well as connectable in series and parallel, an editable supercapacitor with customizable stretchability is promising to produce stylish energy storage devices to power various portable, stretchable, and wearable devices.     

Comparison of the effects of Mg–6Zn and titanium on intestinal tract in vivo

To evaluate the ability of Mg–6Zn to replace titanium nails in the reconstruction of the intestinal tract in general surgery, we compared the Mg–6Zn and titanium implants with respect to their effects on rat’s intestinal tract by biochemical, radiological, pathological and immunohistochemical methods. The results indicated that Mg–6Zn implants started to degrade at the third week and disintegrate at the fourth week. No bubbles appeared, which may be associated with intestinal absorption of the Mg–6Zn implants. Pathological analyses (containing liver, kidney and cecum tissues) and biochemical measurements, including serum magnesium, creatinine, blood urea nitrogen, glutamic–pyruvic–transaminase and glutamic–oxaloacetic–transaminase proved that degradation of Mg–6Zn did not harm the important organs, which is an improvement over titanium implants. Immunohistochemical results showed that Mg–6Zn could enhance the expression of transforming growth factor-β₁. Mg–6Zn reduced the expression of tumor necrosis factor at different stages. In general, our study demonstrates that the Mg–6Zn alloy had good biocompatibility in vivo and performed better than titanium at promoting healing and reducing inflammation. It may be a promising candidate for stapler pins in intestinal reconstruction.     

Collaborative Design of Hollow Nanocubes,In Situ Cross‐Linked Binder,and Amorphous Void@SiOx@C as a Three‐Pronged Strategy for Ultrastable Lithium Storage

Although silicon‐based materials are ideal candidate anodes for high energy density lithium‐ion batteries, the large volumetric expansion seriously damages the integrity of the electrodes and impedes commercial processes. Reasonable electrode design based on adjustable structures of silicon and strong binders prepared by a facile method is still a great challenge. Herein, a three‐pronged collaborative strategy via hollow nanocubes, amorphous Void@SiO_x@C, and in situ cross‐linked polyacrylic acid and d ‐sorbitol 3D network binder (c‐PAA‐DS) is adopted to maintain structural/electrode integrality and stability. The all‐integrated c‐PAA‐DS/Void@SiO_x@C electrode delivers excellent mechanical property, which is attributed to ductility of the c‐PAA‐DS binder and high adhesion energy between Void@SiO_x@C and c‐PAA‐DS calculated by density functional theory. Benefiting from the synergistic effect of accommodation of the hollow structure, protection of outer carbon shell, amorphous Void@SiO_x@C, and strong adhesive c‐PAA‐DS binder, c‐PAA‐DS/Void@SiO_x@C shows excellent electrochemical performance. Long cycling stability with a reversible capacity of 696 mAh g^?1 is obtained, as well as tiny capacity decay after 500 cycles at 0.5 A g^?1 and high‐rate performance. The prelithiated Void@SiO_x@C||LiNi_0.5Co_0.2Mn_0.3O₂ (NCM523) full cell is also assembled and shows a reversible capacity of 157 mAh g^?1 at 0.5 C, delivering an excellent capacity retention of 94% after 160 cycles.     

Grain‐Boundary “Patches” by In Situ Conversion to Enhance Perovskite Solar Cells Stability

The power conversion efficiency of organic–inorganic hybrid perovskite solar cells has increased rapidly, but the device stability remains a big challenge. Previous studies show the grain boundary (GB) can facilitate ion migration and initiate device degradation. Herein, methimazole (MMI) is employed for the first time to construct a surface “patch” by in situ converting residual PbI₂ at GBs. The resultant MMI–PbI₂ complex can effectively suppress ion migration and inhibit diffusion of the metal electrodes. The origin of the surface “patch” effect and their working mechanisms are investigated experimentally and theoretically at the microscopic level. It hence demonstrates a simple and effective method to prolong the device stability in the context of GB engineering, which could be extensively applied to perovskite‐based optoelectronics.