基于黑曲霉固态发酵的绿豆皮降解及理化特性提升机理

本试验研究了黑曲霉固态发酵对绿豆皮特性的影响,并对降解机理进行探究,结果表明黑曲霉固态发酵能有效提升绿豆皮制粉特性和功能特性,所得绿豆皮粉体积平均径减小8.53倍,比表面积增大32.46倍。阳离子交换能力、胆酸钠吸附能力及葡萄糖吸附能力均有明显提升,依次提升1.11倍、1.18倍和1.17倍。黑曲霉对绿豆皮的降解,先降解木质素与半纤维素,再降解纤维素。主要通过破坏纤维素、半纤维素及木质素的化学键,降解长链结构为短链结构,破坏结晶区结构,降低相对结晶度,进而破坏绿豆皮结构,使其变得疏松多孔,让绿豆皮易被粉碎为粒径更小、比表面积更大的粉体,具有更好的物质交换效率,提升绿豆皮的理化特性。     

高熔体强度聚丙烯中长支链结构的分析与表征方法新进展

高熔体强度聚丙烯(high melt strength polypropylene,HMSPP)是具有较高熔体强度和弹性、在熔融拉伸时存在应变硬化现象的一种新型聚丙烯材料。近年来,对长支链(LCB)型HMSPP (LCB-HMSPP)的研发引起了学术界和工业界的广泛关注。在利用各种方法和工艺制备LCB-HMSPP之后,所得聚合物是否具有长支链结构,长支链的化学组成、密度及链长度等拓扑结构信息,都需要通过各种仪器分析与表征方法对其进行定性或定量验证。本文着重对傅里叶变换红外光谱(FTIR)法、核磁共振碳谱(¹³C NMR)法、凝胶渗透色谱(GPC)及其联用方法、流变学表征法和结晶行为表征法在LCB-HMSPP中LCB链结构分析与表征中的研究新进展进行总结和评述,介绍了这些方法各自的优缺点和适用性并对这些方法进行了对比,最后对用于LCB-HMSPP中LCB链结构的分析与表征方法研究的未来发展及应用前景进行了展望。     

水热法制备3D花球状Bi2SiO5及其光催化油酸酯化反应

化石燃料资源的枯竭和环境污染等问题,使寻找生物燃料等可持续、可再生能源成为世界关注的焦点。本文通过简单水热法制备3D花球状Bi₂SiO₅,并用于在模拟太阳光照射下油酸与甲醇的光催化酯化反应。为了解Bi₂SiO₅催化剂的物理、化学和光学性质,采用X射线衍射（XRD）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）、高分辨率透射电子显微镜（HRTEM）、氨-程序升温脱附（NH₃-TPD）和紫外-可见漫反射光谱（UV-vis DRS）对其进行表征,且通过傅里叶变换红外光谱（FTIR）分析反应产物成分组成。酯化反应产物油酸甲酯的产率通过¹H NMR进行定量分析,计算过程简单、结果精确可靠。在模拟太阳光照射下,最优反应条件为：醇油比为12∶1、催化剂用量为5%（质量分数）、反应温度为70℃、光照反应时间为6h,油酸甲酯产率为28.8%。核磁共振氢谱（¹H NMR）分析结果显示油酸甲酯选择性高达100%,且催化剂循环3次后油酸甲酯产率仍可达26.8%,稳定性强。电子自旋共振（ESR）测试表明,Bi₂SiO₅光催化酯化反应过程中存在羟基自由基（·OH）和超氧基自由基（·O{}_{\mathrm{2}}^{-}）。基于Bi₂SiO₅首次用于光催化酯化反应,为解释其具有催化活性的原因,提出了其光催化酯化反应机理。     

基于Regression GAN的原油总氢物性预测方法

针对生成对抗网络（Generative adversarial network,GAN）不适用于原油物性回归预测的问题,本文提出一种回归生成对抗网络（Regression GAN,RGAN）结构,该结构由生成模型G、判别模型D及回归模型R组成.通过判别模型D与生成模型G间的对抗学习,D提取原油物性核磁共振氢谱（1H NMR）谱图的潜在特征.首层潜在特征是样本空间的浅层表示利于解决回归问题,采用首层潜在特征建立回归模型R,提高了预测的精度及稳定性.通过增加条件变量和生成样本间的互信息约束,并采用回归模型R的MSE损失函数估计互信息下界,生成模型G产生更真实的样本.实验结果表明,RGAN有效地提高了原油总氢物性回归预测精度及稳定性,同时加快了生成模型的收敛速度,提高了谱图的生成质量.     

NMR核磁共振在线分析在常减压装置的应用

利用NMR核磁共振在线分析仪对中石化某公司常减压装置的原油、初顶油、常顶油、常一线油、常三线油、减三线油等进行快速分析,分析数据实时反馈到DCS,为建立实时优化打下基础,分析数据重复性和再现性好,分析结果稳定可靠,利于降低人工成本.     

利用真空固态反应合成高质量二维过渡金属二硫化物晶体及其应用

二维过渡金属二硫化物(TMD)晶体由于其结构的多样性和独特的性质备受关注。真空固态反应法是生长高质量二维TMD晶体的一种强有力工具,此方法大大推动了基于二维TMD晶体的基础研究和应用探索。在这篇综述中,我们总结了在真空系统中生长高质量二维TMD晶体的方法,并讨论了影响二维TMD晶体尺寸、质量、形态和多型性的因素。我们还简要讨论了二维TMD晶体的物理性质及各种应用。最后,对真空固态反应法在二维TMD晶体生长中的应用进行了展望。     

Polymer electrolytes and interfaces in solid-state lithium metal batteries

The polymer electrolyte based solid-state lithium metal batteries are the promising candidate for the high-energy electrochemical energy storage with high safety and stability. Moreover, the intrinsic properties of polymer electrolytes and interface contact between electrolyte and electrodes have played critical roles for determining the comprehensive performances of solid-state lithium metal batteries. In this review, the development of polymer electrolytes with the design strategies by functional units adjustments are firstly discussed. Then the interfaces between polymer electrolyte and cathode/anode, including the interface issues, remedy strategies for stabilizing the interface contact and reducing resistances, and the in-situ polymerization method for enhancing the compatibilities and assembling the batteries with favorable performances, have been introduced. Lastly, the perspectives on developing polymer electrolytes by functional units adjustment, and improving interface contact and stability by effective strategies for solid-state lithium metal batteries have been provided.     

Synergistic effect of ionic liquid and organo-functional silane on the preparation of silica based hybrid ionogels as solid-state electrolyte for Li-ion batteries

Having excellent safety and potentially high energy density, solid-state electrolytes can be used in large-scale energy storage applications instead of flammable and volatile organic solvent-based electrolytes. Aerogels are notable candidates for solid-state electrolytes due to their low density, high porosity, high specific surface area, stable thermal behavior, and ultralow dielectric constant. In this work, Li-doped silica ionogels were synthesized by the two-step sol-gel method by using trifunctional organosilane Methyltrimethoxysilane (MTMS), as silica co-precursor along with conventional precursor TEOS. In addition, 1,3-Butylmethylimidazolium bis(trifluorosulfonyl)imide (BMIMTFSI) was selected as an ionic liquid to provide ion mobility throughout the solid skeleton. The synthesized hybrid ionogels were characterized by FTIR, SEM, BET, and TGA analyzes. It was observed that the specific surface areas of the obtained ionogels varied between 685 and 725 m²/g. To examine the effect of Li⁺ ion concentration on ion conductivity, electrolyte solutions have prepared in different concentrations (0.5 ~ 2 M). The Li⁺ ion conductivity of the ionogel prepared with 2 M of Li⁺ ion solution (M-IGE-2) was determined as 4.06 × 10⁻⁴ S/cm by Potentiostatic EIS measurement and it possessed 3.3V of electrochemical stability.     

Double cation (KMg)3+ co-substitution to regulate negative thermal expansion property of ln2W3O12

To improve the negative thermal expansion (NTE) performance of ln₂W₃O₁₂, a novel series of NTE (KMg)_xln_2-xW₃O₁₂ ceramics were fabricated via the solid-state method. The effects of (KMg)³⁺ substitution on the phase composition, microstructure and thermal expansion property of the ln₂W₃O₁₂ ceramics were characterized using X-ray diffraction (XRD), Raman spectrometer (Raman), X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), transmission electron microscope (TEM) and thermal mechanical analyzer (TMA). Results indicate that (KMg)³⁺ can partially replace In³⁺ in In₂W₃O₁₂ and form a new phase K_xMg_xln_2-xW₃O₁₂ with monoclinic symmetry. For x = 0.5, pure monoclinic (KMg)_0.5ln_1.5W₃O₁₂ ceramics is prepared and shows strong NTE. Its coefficient of thermal expansion is −7.89 × 10⁻⁶ °C⁻¹ in 30–700 °C, in addition, no phase transition was observed over the entire testing temperature range. These research results indicate that double cations co-substitution is an effective strategy to improve the NTE property of ln₂W₃O₁₂ through crystal structure modulation. This strategy could be extended to the performance modulation of other NTE materials.     

Integrated Target-Based and Phenotypic Screening Approaches for the Identification of Anti-Tubercular Agents That Bind to the Mycobacterial Adenylating Enzyme MbtA

Iron is essential for the pathogenicity and virulence of Mycobacterium tuberculosis, which synthesises salicyl-capped siderophores (mycobactins) to acquire this element from the host. MbtA is the adenylating enzyme that catalyses the initial reaction of mycobactin biosynthesis and is solely expressed by mycobacteria. A 3200-member library comprised of lead-like, structurally diverse compounds was screened against M. tuberculosis for whole-cell inhibitory activity. A set of 846 compounds that inhibited the tubercle bacilli growth were then tested for their ability to bind to MbtA using a fluorescence-based thermal shift assay and NMR-based Water-LOGSY and saturation transfer difference (STD) experiments. We identified an attractive hit molecule, 5-hydroxyindol-3-ethylamino-(2-nitro-4-trifluoromethyl)benzene ( 5 ), that bound with high affinity to MbtA and produced a MIC₉₀ value of 13 μm . The ligand was docked into the MbtA crystal structure and displayed an excellent fit within the MbtA active pocket, adopting a binding mode different from that of the established MbtA inhibitor Sal-AMS.