SiC nanoparticles incorporation in electroless NiP-Graphene oxide nanocomposite coatings

The presence of SiC nanoparticles within the Graphene oxide (GO) incorporated electroless deposited NiP layers (NiP-GO) on carbon steel substrate was studied in this work. The effect of co-deposition of GO nanoplatelets and/or SiC nanoparticles on the morphology and structure of the heat-treated NiP coatings were investigated by scanning electron microscope and X-ray diffraction, respectively. The results revealed that the heat-treated NiP and NiP–SiC coatings consisted of Ni and Ni₃P phases, whereas the NiP-GO also contains the intermediated Ni₂P and Ni₁₂P₅ metastable phases due to the incomplete precipitation of Ni₃P. Such metastable phases are significantly decreased by the incorporation of SiC nanoparticles in NiP-GO coatings. The mechanical properties of the coatings were characterized by microhardness measurement and “pin on disk” wear test. The corrosion tests were conducted in aqueous 3.5 %wt NaCl using electrochemical measurement for Ni–P, NiP-GO, NiP–SiC, and NiP-GO-xSiC coatings. By co-deposition of SiC nanoparticles, the hardness of NiP-GO is significantly increased and the wear loss is reduced, especially at a high sliding distance during the wear test. The corrosion behavior of the NiP-GO coatings containing different amounts of SiC nanoparticles has been investigated.     

香肠整体营养价值评价与包装正面标签应用研究进展

为促进我国消费者对香肠的合理消费与饮食健康，引导企业生产营养健康的香肠，利用《中国食物成分表》（第1册第2版）的16 种香肠及其营养素数据，构建富含营养素食物（nutrient-rich foods，NRF9.3）模型，评价香肠整体营养价值，并借鉴瑞典的锁孔（Keyhole）标识和英国的多交通灯信号标签进行相应的包装正面（front of package，FOP）标签应用探索。结果表明：除了儿童肠、火腿肠外，14 种香肠的NRF9.3＜0，每100 kcal的推荐性营养素含量均低于限制性营养素，对人体的营养价值较低，适合采用总结指示体系和特定营养素体系的FOP标签进行标示；因此，居民日常应限制香肠摄入，建议对脂肪、盐含量超标的香肠采用红色交通灯信号标签提醒消费者，对NRF9.3＞0的香肠实施单一的健康选择标识推荐消费者选购。     

Effect of Ni and SAPO-34 co-additive on enhancing hydrogen storage performance of MgH2

The hydrogen storage performances of MgH₂ improved by the addition of Ni and SAPO-34 were studied in detail. The mixture of MgH₂ with Ni and SAPO-34 was a physical reaction as shown by the X-ray diffraction (XRD) results. The SAPO-34 and Ni were uniformly distributed on the surface of MgH₂. The thermodynamic and kinetic properties of 90MgH₂/5Ni/5SAPO-34 were investigated by differential scanning calorimetry (DSC) and pressure-composition-isothermal (PCI) methods. The results showed that the dehydrogenation activation energy of 90MgH₂/5Ni/5SAPO-34 decreased by 64.3 kJ/mol compared with that of MgH₂. In addition, the relationship between the value of dehydrogenation heat and hydrogen content was also investigated by in-situ calorimetry. The enthalpy value of each sample in the dehydrogenation processes were calculated by in-situ calorimetry measurement. The dehydrogenation enthalpies of as-milled MgH₂ and 90MgH₂/5Ni/5SAPO-34 were 63.2 kJ/mol H₂ and 53.6 kJ/mol H₂, respectively. Thus, the co-doping of Ni and SAPO-34 contributed significantly to decrease the thermodynamic stability and improve the hydrogen sorption kinetic properties of MgH₂.     

扫描隧道显微镜钨针尖的制备与表征

采用直流电化学刻蚀方法制备扫描隧道显微镜钨针尖,研究了电化学刻蚀过程中NaOH溶液浓度、钨丝浸入长度和刻蚀电压对针尖形貌的影响。通过扫描电子显微镜(SEM)测量针尖曲率半径和针尖纵横比值,以表征针尖的尺寸和形状;通过能谱仪(EDS)分析针尖表面成分,以表征表面清洁度;通过场发射显微镜(FEM)得到Fowler-Nordheim (F-N)曲线来检测针尖发射性能。实验结果表明,当溶液浓度为2 mol/L、钨丝浸入长度为4 mm、刻蚀电压为3 V时,可以得到曲率半径约为100 nm、纵横比值为13的针尖,且表面无钨的氧化层。FEM结果显示当对针尖施加500 V的负偏压时,针尖可以稳定发射50 nA量级的电流,且针尖性能具有良好的一致性。     

Enhanced hydrogen storage performance of three-dimensional hierarchical porous graphene with nickel nanoparticles

Three-dimensional hierarchical porous graphene with nickel nanoparticles (3DHPG-Ni) was synthesized through electrostatic assembly method with the assistance of poly (methyl methacrylate) (PMMA) template and subsequent removal of PMMA template by calcination. The morphology, microstructure and hydrogen adsorption properties of 3DHPG-Ni nanocomposites were examined in detail. The obtained 3DHPG-Ni nanocomposite exhibited hierarchical porous structure composed of macro-, meso- and micropores, high specific surface area (925 m² g^?1), large pore volume (0.58 cm³ g^?1) and excellent hydrogen storage capacity. Under the pressure of 5 bar, 3DHPG-Ni nanocomposite showed a maximum hydrogen capacity of 4.22 wt% and 1.95 wt% at 77 K and 298 K, respectively, demonstrating that the as-prepared 3DHPG-Ni nanocomposite was supposed to be a promising material with outstanding properties for practical applications in the field of hydrogen storage. The three-dimensional hierarchical porous structure, evenly distributed Ni nanoparticles and hydrogen spillover effect were responsible for the enhanced hydrogen storage capacities.     

Compiler compatible 5.66 Mb/mm2 8T 1R1W register file in 14 nm FinFET technology

1-read/1-write (1R1W) register file (RF) is a popular memory configuration in modern feature rich SoCs requiring significant amount of embedded memory. A memory compiler is constructed using the 8T RF bitcell spanning a range of instances from 32 b to 72 Kb. An 8T low-leakage bitcell of 0.106 μm² is used in a 14 nm FinFET technology with a 70 nm contacted gate pitch for high-density (HD) two-port (TP) RF memory compiler which achieves 5.66 Mb/mm² array density for a 72 Kb array which is the highest reported density in 14 nm FinFET technology. The density improvement is achieved by using techniques such as leaf-cell optimization (eliminating transistors), better architectural planning, top level connectivity through leaf-cell abutment and minimizing the number of unique leaf-cells. These techniques are fully compatible with memory compiler usage over the required span. Leakage power is minimized by using power-switches without degrading the density mentioned above. Self-induced supply voltage collapse technique is applied for write and a four stack static keeper is used for read Vmin improvement. Fabricated test chips using 14 nm process have demonstrated 2.33 GHz performance at 1.1 V/25 °C operation. Overall V_min of 550 mV is achieved with this design at 25 °C. The inbuilt power-switch improves leakage power by 12x in simulation. Approximately 8% die area of a leading 14 nm SoC in commercialization is occupied by these compiled RF instances.     

Determining most effective structural form of nickel-cobalt catalysts for dry reforming of methane

In this study, catalytic activity of carbon dioxide reforming of methane was investigated over nickel-cobalt catalysts in various structural forms. Catalytic activity tests were performed at the temperatures of 600–800 °C in a micro-flow quartz reactor. SEM-EDX, XRD and XPS studies were also performed to understand the surface morphology of the catalysts. The results showed that 8 wt%Ni-2wt.%Co on wash-coated MgO over monolithic structure led to highest catalytic performances with CH₄ and CO₂ conversions of 83% and 89% respectively as well as H₂/CO ratio of 0.95 at 750 °C. SEM-EDX and XPS results of catalyst spent at 750 °C also showed considerable amount of coke formation; however, the use of 3% oxygen in the feed suppressed the coke formation significantly. The catalyst was stable for 48 h in the presence of O₂ (3%) added feed at the temperature of 750 °C.     

One-step potentiostatic electrodeposition of Ni–Se–Mo film on Ni foam for alkaline hydrogen evolution reaction

Exploring efficient, abundant, low-cost and stable materials for hydrogen evolution reaction (HER) is highly desired but still a challenging task. Herein, Ni–Se–Mo electrocatalysts supported on nickel foam (NF) substrate were synthesized by a facile one-step electrodeposition method. The Ni–Se–Mo film presents high electrocatalytic activity and stability toward HER, with a low overpotential of 101 mV to afford a current density of 10 mA cm⁻² in 1.0 M KOH medium. Such excellent HER performance of Ni–Se–Mo film induced by the synergistic effects from Mo-doped Ni–Se film leads to the fast electron transfer. This work provides the validity of interface engineering strategy in preparing highly efficient transition metal chalcogenides based HER electrocatalysts.     

Effect of Ni loading on SBA-15 synthesized from palm oil fuel ash waste for hydrogen production via CH4 dry reforming

The successful synthesis of SBA-15 using silica source extracted from palm oil fuel ash (POFA) was proven with the presence of mesostructure characteristics as evidenced by low angle XRD, N₂ adsorption-desorption isotherms and TEM. Different amounts of Ni were loaded on the synthesized SBA-15(POFA) using the impregnation method at 80 °C. The influence of Ni loading over the Ni/SBA-15(POFA) physiochemical properties and CO₂ reforming of CH₄ (CRM) were investigated in a stainless steel fixed-bed reactor at 800 °C and atmospheric pressure with 1:1 CO₂:CH₄ volumetric feed composition. An increment in Ni loading on SBA-15(POFA) from 1 to 5 wt% decreased the BET surface area and crystallinity of catalyst as proven by N₂ adsorption–desorption and XRD analysis. The catalytic performance of CRM followed the sequence of 3 wt% > 5 wt% > 2 wt% > 1 wt% -Ni/SBA-15(POFA). This result was owing to the even distribution of Ni and good Ni–O–Si interaction of 3 wt% Ni/SBA-15(POFA) as proved by TEM, FTIR and XPS. Lowest H₂/CO ratio and catalyst activity and stability of 1 wt% Ni/SBA-15(POFA) were due to the weaker Ni–O–Si interaction and small amount of basic sites that favor the reverse water gas shift (RWGS) reaction and carbon formation. The recent finding indicates that a quantity as small as 3 wt% Ni loaded onto SBA-15(POFA) could elicit outstanding catalytic performance in CRM, which was comparable with 10 wt% Ni loading catalysts reported in literature.     

Ni(OH)2与不同碳质材料复合制备超级电容器电极材料研究进展

超级电容器具有功率密度大、寿命长、生产成本低等优点,被认为是最有发展前途的储能系统之一。然而,超级电容器的低能量密度阻碍了其实际应用。由于存储的能量与CV2成正比,可以通过增加材料的电容"C"或操作电压窗口"V"或两者同时增加来提高超级电容器的能量密度。然而具有宽电位窗口的有机电解质离子往往电导率差,成本高,容易引起环境问题。因此为改善能量密度,应采用高比电容的电极材料,故而设计出具有高比电容的适合电极材料就成为研究热点。Ni(OH)2作为超级电容器电极材料,具有理论容量大、成本低、天然丰富、易于合成等优点,近年来备受关注。但由于Ni(OH)2导电率低、比表面积小,其容量劣化严重。碳质材料作为双电层超级电容器的电极材料,其能量存储机制取决于电极表面的电解质离子吸附和解离,具有导电率好、原料丰富、成本较低、电化学稳定性高等优点而应用广泛。因此,有必要将高导电碳质材料引入Ni(OH)2组成复合材料以提高电容性能。笔者综述了Ni(OH)2基材料的合成方法,特别是与碳质材料复合来提高Ni(OH)2基材料的循环稳定性和倍率性能方面的研究新进展。