Effect of particle sizes on in-vitro calcium and magnesium binding capacity of prepared dietary fibers

Microscopic examination showed a change on the surface structure of dietary fibers (DF) from rice straw (RS) and sugarcane bagasse (SB) by alkaline hydrogen peroxide (AHP) treatment. Effect of particle size on in-vitro binding of calcium (Ca) and magnesium (Mg) of AHP-RS, AHP-SB and Solka Floc® 900 (SF) were evaluated. Total bound Ca and Mg decreased with particle size reduction (P<0.05) for all types of DF. Ca and Mg (82–95%) were released from AHP-RS and AHP-SB by acid washing but only 53–60% Mg was removed from SF. There were strong correlations between water holding capacity, oil binding capacity and particle density and total bound Ca and Mg for all DF samples.     

Effects of MFC-modified GCC as Filler on the Opacity of Pulp Handsheets

Microfibrillated cellulose (MFC) was obtained by mechanical grinding of different pulps. MFC-modified ground calcium carbonate (GCC) was prepared in two different ways, designated MFC-GCC composite filler and MFC-GCC flocs filler. The opacity of pulp handsheets loaded with MFC-modified GCC was measured. The effects of MFC originated from different pulps, pretreatment method, and filler modification on the opacity of handsheets loaded with MFC-modified GCC were discussed. The results show that MFC originated from alkaline peroxide mechanical pulp (APMP) was optimal for improving the opacity of the handsheets and PFI grinding pretreatment for MFC provided a denser structure in the corresponding MFC_APMP-GCC floc filler while enzyme pretreatment was more effective in increasing the opacity of the filled paper. Under the experimental conditions, the opacity of handsheets increased from 81.0% to 82.7% when the unmodified GCC was replaced by an equivalent amount of MFC_APMP-GCC composite filler, while other properties were unchanged.     

Comparative study of coal,natural gas,and coke-oven gas based methanol to olefins processes in China

Traditional olefins production mainly depends on oil. In view of the short supply of oil, feedstocks are expanded to coal, natural gas, coke-oven gas, and methanol in China. In this paper, a comparative study of alternative olefins production is conducted from aspects of techno-economic feasibility and environmental friendliness. Results show that coal-to-olefins has a significant cost advantage. However, it suffers from low energy efficiency and serious CO₂ emissions. To address these problems, this study proposes and analyses coal-to-olefins with CO₂ capture, coal and natural gas-to-olefins, and coal and coke-oven gas-to-olefins. The two co-feed systems ensure great reduction of CO₂ emissions and significant improving energy efficiency. They should be actively developed in regions with rich coal and gas. While in regions with rich coal and lean gas, coal-to-olefins with CO₂ capture should be developed in large scale. This paper also provides several suggestions on planning these olefins production routes in China.     

Paper-Mill Waste Reinforced Nanofluidic Membrane as High-Performance Osmotic Energy Generators

Nanofluidic membranes consisting of 2D materials and polymers are considered promising candidates for harvesting osmotic energy from river estuaries owing to their unique ion channels. However, micron-scale polymer chains agglomerate in the nanochannels, resulting in steric hindrance and affection ion transport. Herein, a nanofluidic membrane is designed from MXene and xylan nanoparticles that are derived from paper-mill waste. The demonstrated membrane reinforced by paper-mill waste has the characteristics of green, low-cost, and outstanding performance in mechanical properties and surface-charge-governed ionic transport. The MXene/carboxmethyl xylan (CMX) membrane demonstrates a high surface charge (ζ-potential of −44.3 mV) and 12 times higher strength (284.96 MPa) than the pristine MXene membrane. The resulting membrane shows intriguing features of high surface charge, high ion selectivity, and reduced steric hindrance, enabling it high osmotic energy generation performance. A potential of the nanofluidic membrane is ≈109 mV, the corresponding current of up to 2.73 µA, and the output power density of 14.52 mW m⁻² are obtained under a 1000-fold salt concentration gradient. As the electrolyte pH increases, the power density reaches 56.54 mW m⁻². This works demonstrate that CMX nanoparticles can effectively enhance the properties of the nanofluidic membrane and provide a promising strategy to design high-performance nanofluidic devices.     

An Individual Nanocube‐Based Plasmonic Biosensor for Real‐Time Monitoring the Structural Switch of the Telomeric G‐Quadruplex

Promoted by the localized surface plasmon resonance nanotechnology, a simple and sensitive plasmonic aptamer nanosensor (nanoaptasensor) on an individual Au@Ag core‐shell nanocube (Au@Ag NC) has been proposed for real‐time monitoring of the formation process of G‐quadruplex structures and label‐free analysis of potassium ions (K⁺). In particular, the analysis of the thermodynamic parameters indicates that there are two types of binding states accompanied with a remarkable change of free energy (ΔG) in the sequential folding process of telomere DNA sequence. This nanoaptasensor has raised promising applications in monitoring the dynamic process of the structural switch of the G‐quadruplex.     

纤维素微纤丝改性方式对胶原纤维复合膜性能的影响

利用金属-多酚网络（metal-polyphenol network，MPN）和不同程度羧基化改性制备的纤维素微纤丝（cellulose microfibrils，CMF）与胶原纤维（collagen fiber，CF）共混制成复合膜，探究CMF改性方式对复合膜性能的影响。结果表明：MPN改性的CMF能使复合膜抗氧化性能提高51.49%，断裂延伸率和阻光性也有显著提高；MPN和高含量羧甲基共同改性的CMF能最大程度降低MPN对复合膜机械强度的影响；MPN和高含量羧乙基共同改性的CMF能使复合膜对水蒸气和氧气的阻隔能力分别提高1.30 倍和3.48 倍。扫描电子显微镜和红外光谱分析表明不同方式改性的CMF与CF之间是物理交联且具有良好的相容性，从而为提高复合膜的性能以更好地应用到食品包装领域提供了一种新手段。     

Synthesis of copper indium sulfide nanoparticles by solvothermal method

Single crystalline CuInS₂ particles with a chalcopyrite structure and a size of 7–10 nm were prepared by a convenient solvothermal reaction, and characterized by XRD, XPS, TEM (HR-TEM) and UV–vis absorption spectroscopy. The as-synthesized nanoparticles can be redispersed in organic solvents, which will facilitate the practical application of these nanoparticles under organic-solution conditions. The growth of the CuInS₂ is regarded to involve the formation and decomposition of Cu²⁺-thiourea complexes, the reduction of Cu²⁺ and a slow supply of In³⁺ ions in the crystallization solution.     

Bioremediation of acid-rock drainage by sulphate-reducing prokaryotes: A review

Acid-rock drainage (ARD) is a widespread environmental problem that causes adverse effects to the quality of ground water and surface water through acidification, high concentration of the iron, sulphate, and elevated levels of soluble toxic metals. Active treatment technologies are often expensive and require regular attention resulting in increased overall costs due to operation and maintenance expenses. One of the effective treatment methods is to use sulphate-reducing prokaryotes (SRP) in bioreactors. They offer advantages such as high metal removal at low pH, stable sludge, very low operation costs, and minimal energy consumption. Sulphide precipitation is the desired mechanism of contaminant removal; however, many mechanisms including adsorption and precipitation of metal carbonates and hydroxides also occur in passive bioreactors. Several factors influencing the performance of the bioreactors are reviewed. The fundamental biochemical and microbiological reactions that occurs in the bioreactors has been dealt in detail. The present review presents performance of bioreactors, chemical characterisation of organic substrates for successful treatment of ARD. Moreover, design parameters, longevity and future scope of the study on bioreactors is also discussed in this review.     

非硅系PU革离型纸原纸的开发

在实验室条件下,针对非硅系PU革离型纸最重要的三个性能:强度、耐热性和纸膜结合强度,对增强剂的用量进行了三因素四水平的正交实验,对耐热剂某金属氧化物的用量进行了优化,并探讨了纸膜结合强度对原纸的平滑度和孔隙率的特殊要求。结果表明:增强剂的最佳添加量为CS用量为1.5%,PAE用量为0.8%,CPAM用量为0.06%,耐热剂某金属氧化物的最佳用量为6%;原纸的平滑度相对于孔隙率而言,对纸膜结合强度的影响更显著。     

木片浸渍程度数学建模

在对木片成分进行合理划分和假设的基础上,建立了计算木片浸渍程度的数学模型.结果表明,木片浸渍程度数学模型计算结果和实际测定结果线性符合良好,可用以表达液体向木片内部浸渍的程度.木片浸渍程度数学模型中无体积项,计算过程不受木片形状的影响.