木粉疏水改性对HDPE基木塑复合材料性能的影响

采用一种操作简便且易于工业推广的方法对木粉进行疏水改性，具体过程为：将3种可热聚合的单体，即甲基丙烯酸甲酯（MMA）、甲基丙烯酸丁酯（BMA）和苯乙烯（St）均匀喷洒在木粉上，经过预热处理后，与配方中其他组分，如高密度聚乙烯（HDPE）和马来酸酐接枝聚乙烯（MAPE）等通过高速混合机混合均匀，采用双螺杆挤出机造粒后，注射制备木塑复合材料（WPC）样条，测试其力学性能。另外，考察了疏水改性对WPC接触角、维卡软化温度、洛氏硬度、吸水性能、热性能的影响规律。结果表明：疏水改性后WPC的接触角增大，木粉和HDPE的界面相容性改善，力学性能得到明显提高。其中，当MMA、BMA和St的添加量为3%时，WPC的力学性能最好，与疏水改性前相比，弯曲强度分别提高了17.3%、26.3%和27.5%，弯曲模量分别提高了24.4%、24.4%和26.0%，冲击强度分别提高了54.7%、57.7%和60.5%。 此外，疏水改性后WPC的维卡软化温度、洛氏硬度、耐水性和耐热性也得到改善。     

Effect of Temperature and Strain Rate on the Hot Deformation Behaviour of Ferritic Stainless Steel

Metals and Materials International - The flow behaviour and microstructure characteristics of a ferritic stainless steel were investigated using plain strain compression test on a Gleeble 3500...     

An Artificial Skyrmion Platform with Robust Tunability in Synthetic Antiferromagnetic Multilayers

Magnetic skyrmions are topologically nontrivial spin structures, and their existence in ferromagnetically coupled multilayers has been widely reported with a disordered arrangement. Here, a nucleation scenario of ordered skyrmions in nanostructured synthetic antiferromagnetic (SAF) multilayers is proposed and experimentally demonstrated using direct magnetization imaging, indirect magnetometer and magnetoresistance measurement, and micromagnetic simulation. Instead of relying on Dzyaloshinskii–Moriya interaction, the antiferromagnetic interlayer exchange coupling in the SAF multilayers fulfills the role of nucleation and stabilization of skyrmions. The robustness of the proposed skyrmion nucleation scenario is examined against temperature from 4.5 to 300 K and device size from 400 to 1200 nm. Interestingly, these synthetic skyrmions still behave well with a size less than 100 nm. The higher stability than generic magnetic domains can be attributed to topological protection. The results thus provide an artificial skyrmion platform to meet the functional needs of high density and designable arrangement in magnonic and spintronic applications.     

SiO2对邯郸球团矿抗压强度的影响

抗压强度是球团矿的重要指标,直接影响高炉内炉况顺行及生产指标。改变球团矿的化学成份,球团矿微观结构也将受到影响,矿物结构发生改变,对球团矿的抗压强度也有不同的影响。本试验采用邯钢生产现场所用的邯邢精粉、安徽精粉、沙河精粉、燕山矿粉等五种矿粉进行造球,利用偏光显微镜等检测手段对不同矿粉的球团矿的抗压强度进行研究。从试验结果分析得出:SiO_2含量在3%时抗压强度最强,在7%时抗压强度最差。     

安徽省凤阳县焦台陈含金石墨矿物质组份研究

本文通过详细的镜下光、薄片鉴定、电子探针分析、单矿物分析、物相分析等手段查明了安徽省凤阳县焦台陈含金石墨矿中矿石的化学组成、矿石中的主要矿物,对其特征做了详尽的描述,并对主要矿物石墨的粒级分布及其镶嵌特征做了认真分析,阐明了影响石墨回收的矿物学因素。     

基于滑模的运载器主动段俯仰通道姿控系统设计

与传统比例-积分-微分（PID）控制方法相比，滑模控制（SMC）方法可以比较容易地将不确定性纳入控制器设计中，从而增强系统的鲁棒性。探索了SMC技术在运载器主动段姿态控制中的工程应用，首先通过分析基于趋近律的SMC系统，提出了降低不连续切换项系数的需求，然后研究了基于干扰上界的SMC方法。三通道小偏差仿真结果验证了两种方法的控制效果，表明第2种控制器的鲁棒性更好，稳态误差小，同时发动机喷管摆角需求较小。     

Controlled enzymatic hydrolysis on characteristic and antioxidant properties of soybean protein isolate-maltodextrin conjugates

This study aimed to investigate the effect of limited hydrolysis on conformational and antioxidant properties of soy protein isolate-maltodextrin (SPI-Md) conjugates. Extrinsic fluorescence analysis showed unfolding of the protein molecule and exposure of hydrophobic groups in SPI-Md conjugate hydrolysates. Free amino acid analysis showed that, the contents of hydrophobic amino acids in SPI-Md conjugates increased after hydrolysis. The contents of leucine, isoleucine, phenylalanine increased from 0.32, 0.30 and 0.54 to 1.36, 1.86 and 2.60, respectively, when the hydrolysis degree (DH) gradually increased from 0% to 5.7%. The FT-IR spectrum showed that C = O absorption of the amide group formed by glycosylation continued unabated after limited hydrolysis (DH 2.9%). The glycated SPI products showed good reducing power and superior resistance to lipid oxidation (34%, 12 mg mL^?1), whereas the limit hydrolysates (DH 2.9%) of SPI-Md conjugates showed more ef?cient radical-scavenging capacity (89.5%, at 12 mg mL^?1) and iron-chelation activity (91.3%, at 12 mg mL^?1). Results of this study indicated that, slight enzymatic hydrolysis (DH 0–2.9%) could help partially unfolding the globular structure of SPI-Md conjugates without deteriorating amide bonds and had a positive effect on their antioxidant properties.     

Safe preparation of beefy meaty peptide with Bacillus subtilis

Preparation of flavour peptides with microorganisms is an attractive choice for its large-scale production. However, beefy meaty peptide (BMP), as a research hotspot in the field of umami peptide, has been studied in few microorganisms, and furthermore, the safe preparation of BMP has not yet been reported. In this study, multi-copy BMP (8BMP) was successfully expressed and produced in the ‘generally recognized as safe’ Bacillus subtilis (B. subtilis). Firstly, 8BMP with the potentially intense umami was screened out based on molecular docking analysis. Then, it was successfully expressed in the B. subtilis 168 and verified through sensory evaluation. Finally, the scaling capacity of 8BMP was evaluated in a 5-L fermenter, with the highest yield (0.84 g L⁻¹) 6.4 times than that of shake flask, which is conductive for industrial production of BMP and other food peptides.     

非调制双色红外测温误差实时补偿方法研究

针对环境温度变化对双色红外测温准确度的影响,基于双色比色红外测温原理,分析了非调制双色红外测温的误差来源,提出一种新的快门式非调制双色红外测温方法。在光路中增加快门及其控制模块,控制快门闭合,将测得系统偏移作为补偿项,补偿实际测温时因温度变化给测量带来的误差。仿真结果表明,在600～1 100℃的测温范围内,长时间使用的无快门非调制红外双色测温的精度严重劣化,而快门式非调制双色红外测温的准确度大幅提高,可达到±0.5%。