Plasmonic coupling-enhanced in situ photothermal nanoreactor with shape selective catalysis for C-C coupling reaction

Carbon-carbon (C-C) coupling reactions represent one of the most powerful tools for the synthesis of complex natural products, bioactive molecules developed as drugs and agrochemicals. In this work, a multifunctional nanoreactor for C-C coupling reaction was successfully fabricated via encapsulating the core-shell Cu@Ni nanocubes into ZIF-8 (Cu@Ni@ZIF-8). In this nanoreactor, Ni shell of the core-shell Cu@Ni nanocubes was the catalytical active center, and Cu core was in situ heating source for the catalyst by absorbing the visible light. Moreover, benefiting from the plasmonic resonance effect between Cu@Ni nanocubes encapsulated in ZIF-8, the absorption range of nanoreactor was widened and the utilization rate of visible light was enhanced. Most importantly, the microporous structure of ZIF-8 provided shape-selective of reactant. This composite was used for the highly shape-selective and stable photocatalysed C-C coupling reaction of boric acid under visible light irradiation. After five cycles, the nanoreactor still remained high catalytical activity. This Cu@Ni@ZIF-8 nanoreactor opens a way for photocatalytic C-C coupling reactions with shape-selectivity.

     

The influence of cryogenic rolling on a transformation-induced plasticity steel

ABSTRACT

Here, a novel cryogenic rolling plus intercritical annealing process was applied to a transformation-induced plasticity (TRIP) steel with a low chemical composition of carbon and manganese. Compared with traditional cold rolling, obvious grain refinement was observed, due to a high amount of dislocations retained. In addition, austenite volume fraction was increased, because of a unique nucleation mechanism. Subjected to cryogenic rolling, strength and ductility were increased, due to the enhanced austenite stability, which provided continuous and active TRIP effect. Consequently, tensile strength was increased to 1030?MPa, and elongation was increased to 38.2%. Thus, a great mechanical combination was obtained in a steel with a relatively low chemical composition with carbon and manganese, only by cryogenic rolling process.     

Hybrid-triggered fault detection filter design for networked Takagi–Sugeno fuzzy systems subject to persistent heavy noise disturbance

In the network environment, the single time-triggered scheme wastes limited bandwidth resources due to all the sampled data are transmitted to the networks, and the single event-triggered scheme may increase system error because of ignoring factors such as changes in network utilization. To reduce the design conservatism, this paper is concerned with the hybrid-triggered L₁ fault detection filter design for a class of nonlinear networked control systems (NCSs) described by Takagi–Sugeno (T-S) fuzzy model. Taking the effects of time-triggered scheme and event-triggered scheme into consideration simultaneously, we construct a fuzzy fault detection system. New results on stability and L₁ performance are proposed for fuzzy fault detection system by exploiting the Lyapunov–Krasovskii functional and by means of the integral inequality method. Specially, attention is focused on the design of fault detection filter that guarantees a prescribed L₁ noise attenuation level . Finally, two examples are presented to demonstrate the effectiveness of the proposed method.     

Effects of Agaricus bisporus on gel properties of chicken myofibrillar protein

The gel-forming ability of myofibrillar protein (MP) is highly correlated with the characteristics of emulsified meat products. Incorporation of Agaricus bisporus (Ab) powder into MP gels may enhance its gel properties to facilitate the development of a novel and safe meat product. Therefore, this study investigated the effects of Ab powder on gel strength, water holding capacity (WHC), texture, rheological behaviour, LF-NMR spin–spin relaxation (T₂), microstructure and protein secondary structure of the MP gel system. The results indicated that the gel strength, WHC, G' value and G" value were significantly improved when the addition of Ab powder increased from 0% to 6% (P < 0.05). Meanwhile, the T₂ relaxation time was shortened, and free water was transformed into immobilised water. The texture of the gel was improved when 1%–4% Ab powder was added compared to the control. Furthermore, Ab filled in the gel network and promoted the unfolding of MP α-helix and the formation of MP β-sheet during the thermal denaturation of MP, leading to a dense aggregated network structure. The study suggested that Ab could be a promising ingredient in improving chicken MP's gel properties and developing fat-reduced meat products.     

基于热力学的自然风压分析方法

从热力学的角度出发，考虑巷道热力因素对风流的影响，导出自然风压的计算方法。     

PQAAM聚合物的制备及其絮凝性能研究

以环氧氯丙烷和二乙胺为原料 ,合成一种聚季铵盐 :采用过硫酸铵、异丙醇氧化还原引发体系 ,以聚季铵盐与丙烯酰胺为原料 ,合成了PQAAM聚合物 ,研究了聚季铵盐浓度、异丙醇浓度、原料配比对反应的影响。并证明了PQAAM对细粒煤的具有絮凝作用 ,是一种优良的阳离子型絮凝剂。     

凹凸棒石黏土脱色剂对航空煤油脱色研究

介绍了凹凸棒石黏土作为脱色剂,对航空煤油脱色.通过正交实验研究了活化酸度、焙烧温度、AlCl3加入量、脱色剂的用量和脱色时间对航空煤油脱色的影响.结果表明,经6%的硫酸酸化和450℃焙烧处理后的凹凸棒石黏土,加入1%AlCl;,制备的脱色剂脱色效果最佳,可使航空煤油的脱色率达到98.3%.     

膨胀石墨的尺寸效应及其对油吸附的影响

用不同粒度的石墨在相同条件下酸化、高温膨胀，可获得膨胀倍数不同的膨胀石墨。通过扫描电镜及X射线衍射等观察膨胀石墨结构，证实在生产条件如酸氧化工艺、膨胀温度等相同时，鳞片石墨的粒度越大则膨胀倍数越高，对油的吸附性能越好。     

煤中全硫测定方法的探讨

煤炭中全硫的分析，采用高温燃烧中和法进行测定，其中所用氧气采用纯氧瓶来供氧。因此，在试验中有很多不便。本文通过大量试验，从理论和实践中提出了直接以空气中氧来代替目前所用氧气钢瓶是完全可行的。