Design of Hierarchical NiCo@NiCo Layered Double Hydroxide Core–Shell Structured Nanotube Array for High‐Performance Flexible All‐Solid‐State Battery‐Type Supercapacitors

A novel hierarchical nanotube array (NTA) with a massive layered top and discretely separated nanotubes in a core–shell structure, that is, nickel–cobalt metallic core and nickel–cobalt layered double hydroxide shell (Ni?Co@Ni?Co LDH), is grown on carbon fiber cloth (CFC) by template‐assisted electrodeposition for high‐performance supercapacitor application. The synthesized Ni?Co@Ni?Co LDH NTAs/CFC shows high capacitance of 2200 F g^?1 at a current density of 5 A g^?1, while 98.8% of its initial capacitance is retained after 5000 cycles. When the current density is increased from 1 to 20 A g^?1, the capacitance loss is less than 20%, demonstrating excellent rate capability. A highly flexible all‐solid‐state battery‐type supercapacitor is successfully fabricated with Ni?Co LDH NTAs/CFC as the positive electrode and electrospun carbon fibers/CFC as the negative electrode, showing a maximum specific capacitance of 319 F g^?1, a high energy density of 100 W h kg^?1 at 1.5 kW kg^?1, and good cycling stability (98.6% after 3000 cycles). These fascinating electrochemical properties are resulted from the novel structure of electrode materials and synergistic contributions from the two electrodes, showing great potential for energy storage applications.     

Layered NiFe-LDH/MXene nanocomposite electrode for high-performance supercapacitor

Layered double hydroxide (LDH) is potentially excellent supercapacitor (SC) materials, but the low conductivity and easy agglomeration limit the further improvement of their electrochemical properties. Therefore, LDHs are requisite to grow on some conductive substrates to produce high-performance SC. In this paper, the conductive two-dimensional (2D) transition metal carbides, nitrides and carbonitrides (called MXene) were explored as the substrate to directly deposit NiFe-LDH nanosheets by a one-step hydrothermal method, then a three-dimensional (3D) porous NiFe-LDH/MXene electrode was obtained. The morphology and electrochemical performance of the composite electrodes were analyzed and investigated. The results show that the NiFe-LDH/MXene electrode has larger specific capacitance (720.2 F/g) than NiFe-LDH (465 F/g), and the capacitance of the composite electrode retained 86% after 1000 cycles (only 24% for NiFe-LDH), showing excellent cycle stability. The improved electrochemical performance of the composites is caused by the stable sheet-like structure of NiFe-LDH during charge-discharge time and the conductive network formed by the MXene, which can accelerates electron transport. In addition, the asymmetric SC based on NiFe-LDH/MXene positive electrode display a power density of 758.27 W/kg at an energy density of 42.4 Wh/Kg. These results indicate the NiFe-LDH/MXene composites can be applied as the novel candidate of high-performance SC electrodes.     

Ni catalysts derived from Mg–Al layered double hydroxides for hydrogen production from landfill gas conversion

A layered double hydroxide (LDH) precursor with a hydrotalcite-like structure containing Ni/Mg/Al cations was prepared. A series of Ni catalysts containing mixed-oxides and spinel phases were then obtained through thermal treatment of the LDH precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), and temperature-programmed reduction (TPR) revealed that the LDH derived Ni catalysts have well-dispersed nickel phases upon reduction. The thermal treatment temperatures have noticeable effects on the specific surface area, pore volume, phase transformation, particle size, and reducibility of the catalysts. Thermal treatment temperatures up to 700 °C promote the generation of mesopores which facilitate an increase in specific area and pore volume. Beyond 700 °C sintering occurs, mesopores collapse, and specific area and pore volume decrease. High thermal treatment temperatures favor the phase transformation to spinel solid solutions and the particle size growth. Metal-support interaction is enhanced but reducibility is hindered due to the formation of spinel solid solution phases. The LDH derived Ni catalysts were tested for landfill gas conversion at 750 °C and have shown excellent activity and stability in terms of methane conversion. At gas hourly space velocity (GHSV) of 240,000 h⁻¹ and pressure of 1 atm, 81% methane conversion was achieved during a 48 h test period without apparent catalyst deactivation.     

高强度铝合金7075的温成形性能(英文)

对铝合金板料7075在加热状态下的成形性能进行研究。首先,通过单向拉伸试验得到不同温度以及不同应变速率下的应力—应变关系。然后,通过极限拉伸比(LDR)试验和极限拱顶高(LDH)试验对其在不同温度下的拉伸性能和胀形性能进行研究。最后,对不同温度下成形后材料的力学性能进行研究。结果表明:7075铝合金的拉伸和胀形性能在140~220°C均得到较大提升;当温度高于260°C时,由于成形温度对板料热处理状态的影响,成形性能和成形后材料的力学性能均出现下降趋势。     

宰后早期猪肉、牛肉和鸡肉中能量代谢及蛋白质磷酸化

目的:探讨畜禽肉宰后能量代谢的差异及其可能的原因。方法:于宰后45 min测定鸡肉、灰白(pale soft exudative,PSE)猪肉、正常猪肉和牛肉中糖原、ATP/ADP/AMP含量及乳酸脱氢酶(lactate dehydrogenase,LDH)活性,并提取肌浆和肌原纤维蛋白进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfatepolyacrylamide gel electrophoresis,SDS-PAGE)和液相色谱-串联质谱鉴定,分析各组肉的磷酸化水平差异。结果:牛肉中糖原含量显著高于其他组(P0.05),正常猪肉组糖原和ATP含量显著高于PSE猪肉组和鸡肉组(P0.05),而PSE猪肉组的LDH活性显著高于其他组(P0.05);肌浆蛋白SDS-PAGE ProQ染色表明,宰后45 min PSE猪肉组中6个条带的磷酸化水平显著低于正常猪肉组(P0.05),而另有6个条带的磷酸化水平显著高于正常猪肉组(P0.05)。牛肉组和鸡肉组中分别有3个和1个条带的磷酸化水平偏低,1个条带和8个条带的磷酸化水平明显偏高。而肌原纤维蛋白电泳表明,牛肉中大部分蛋白质的磷酸化水平处于最高值,而鸡肉组处于最低值,猪肉介于两者之间;PSE猪肉组中7个条带的磷酸化水平显著低于正常猪肉(P0.05);6个条带的磷酸化水平显著高于正常猪肉(P0.05)。结论:宰后异质肉的形成受宰后糖原和ATP消耗速率、LDH活性的影响,同时与肌肉中糖酵解酶的磷酸化水平有关。     

Phytochemistry, traditional uses and pharmacology of Eugenia jambolana Lam. (black plum): A review

Eugenia jambolana Lam. (syn. Syzigium cumini (L.) SKEELS; S. jambolana DC; Family: Myrtaceae), commonly known as black plum or Jamun is a plant native to India. Annually the trees produce oblong or ellipsoid fruits (berries). They are green when raw and purplish black when fully ripe. The ripe fruits are sweetish sour to taste and are used to prepare health drinks, squashes, juices, jellies and wine. Studies have shown that the berries contain carbohydrates, minerals and the pharmacologically active phytochemicals like flavonoids, terpenes, and anthocyanins. Jamun is a plant with known ethnomedicinal uses. Before the discovery of insulin, Jamun was useful in the treatment of diabetes and is an integral part in the various alternative systems of medicine. Scientific studies have shown that the various extracts of Jamun possess a range of pharmacological properties such as antibacterial, antifungal, antiviral, anti-genotoxic, anti-inflammatory, anti-ulcerogenic, cardioprotective, anti-allergic, anticancer, chemopreventive, radioprotective, free radical scavenging, antioxidant, hepatoprotective, anti-diarrheal, hypoglycemic and antidiabetic effects. The present paper reviews these aspects and also addresses the lacunas in the existing knowledge.     

乳酸脱氢酶高产菌株的选育及条件研究

以植物乳酸短杆菌RS2-2(Lactobacillus plantarum)为出发菌株,经紫外线、亚硝基胍单独处理和复合处理,获得1株乳酸脱氢酶高产菌株U-N-B14,通过优化实验对该菌株生产乳酸脱氢酶的营养要求和发酵条件进行了研究,优化后的发酵培养基组成为(g/L):酵母膏10,麦芽糖12,乙酸铵4,K2HPO44,NaCl 8,吐温80 2mL/L。发酵条件是:培养温度30℃,pH值6.5,培养时间24 h,接种量8%。在此条件下,1.5 m3罐中试生产的乳酸脱氢酶产量可达1 497 U/g。     

胭脂红阴离子插层Mg/Al-LDH晶体结构的研究

用液相共沉淀法制备胭脂红插层Mg/Al双氢氧化物,对产物晶化成核以及胭脂红阴离子插层的机理进行探讨,对不同条件下晶化成核LDH的晶体结构、晶面生长选择性和晶粒尺寸等结构参数进行分析比较,得出不同反应条件对晶体形成的影响规律。根据LDH层间距和胭脂红离子的几何尺度,推算出胭脂红阴离子在双氢氧化物层间的配置方式为单层平卧。     

LDH的制备及其对水环境中低含量磷的吸附研究

用共沉淀法制备了Mn-Fe-LDH、Mg-Mn-LDH、Ca-Fe-LDH,采用环境扫描电镜和傅立叶变换红外光谱仪对材料进行分析,研究其对水中磷酸根的吸附性能和机制。结果表明,材料孔隙结构发达,是良好的吸附材料;与吸附前的LDH相比,吸附后的3种材料红外光谱都出现了P-O振动吸收峰,从而验证了有磷酸根离子作为附加阴离子进入LDH层间;材料用量1 mL,处理质量浓度2 mg/L的40 mL磷溶液,处理时间1 h,此时Mn-Fe-LDH、Mg-Mn-LDH、Ca-Fe-LDH对磷的去除率分别达到了97.41%、82.41%和97.00%;共存离子对材料的除磷效果有不同程度的影响。