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Hydrothermal treatment of rice straw for carbohydrate production 稻草水热处理生产碳水化合物的研究
Q4 Chemistry Pub Date : 2023-06-05 DOI: 10.5564/mjc.v24i50.2425
Enkhtur Munkhbat, Z. Lei
 This study focused on the effect of hydrothermal (HT) treatment at 180 – 210 °C for holding 0 - 15 min on the solubilization of rice straw and the changes of HT residue. The optimum treatment conditions for the highest solubilization and solid reduction of rice straw was 210 °C for holding 0 min. Under this condition, the extraction yield and total organic carbon (TOC) concentration of the HT liquid part were the highest, about 44% and 7850 mg/L, respectively. The dry residue showed that the HT conditions above 200 °C for holding a short time were more efficient, which was confirmed by FT-IR and the changes of surface morphology under microscope. The reactor headspace could be an important factor because HT treatment with a lower headspace (HTp210-0(15)) yielded more soluble carbohydrate under the test conditions. Also, energy input calculated based on the 1 ton removed hemicellulose (extraction yield) in the headspace experiments proved this finding.
本研究重点研究了180–210°C水热处理0–15分钟对稻草增溶作用和HT残留量的影响。稻草溶解率和固形物还原率最高的最佳处理条件为210℃保温0分钟。在此条件下,HT液部分的提取率和总有机碳浓度最高,分别约为44%和7850 mg/L。干燥残留物表明,在200°C以上的高温条件下保持短时间更有效,FT-IR和显微镜下表面形态的变化证实了这一点。反应器顶部空间可能是一个重要因素,因为在测试条件下,用较低顶部空间(HTp210-0(15))进行的HT处理产生了更多的可溶性碳水化合物。此外,基于顶部空间实验中1吨去除的半纤维素(提取产率)计算的能量输入证明了这一发现。
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引用次数: 0
Monte Carlo and DFT calculations on the corrosion inhibition efficiency of some benzimide molecules 某些苯并胺分子缓蚀效率的蒙特卡罗和DFT计算
Q4 Chemistry Pub Date : 2023-06-05 DOI: 10.5564/mjc.v24i50.2435
D. Mamand, Y. H. Azeez, H. Qadr
Calculations using density functional theory (DFT) and Monte Carlo methods were performed on 2-methylbenzimidazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole, benzotriazole, and benzimidazole to determine their corrosion inhibition efficiency. The molecular structure was optimized geometrically using DFT calculations at the B3LYP/6– 311 G++(d,p) and b2plypd3/aug-cc-pvdz basis set level in protonated and non-protonated species in gas and water. In this study, HOMO, LUMO, bandgap, ionization energy, electronegativity, hardness, softness, electrophilicity and nucleophilicity, electron transfer, back donation energy and condensed Fukui indices are used to assess a molecule's local reactivity. Theoretical investigations can precisely establish the geometrical dimensions of a molecule and correctly explain the quantum properties of inhibitors. The mechanism of interaction between inhibitors and metal surfaces in a specified molecule is studied using molecular dynamics. The benzimidazole functional groups absorbed energy linearly on metal surfaces, with quantum characteristics determined using density functional theory and an ab initio technique. Importantly, the findings of this conceptual model are consistent with the corrosion inhibition efficiency of earlier experimental investigations.
采用密度泛函理论(DFT)和蒙特卡罗方法计算了2-甲基苯并咪唑、2-巯基苯并咪唑、2-氨基苯并咪唑、苯并三唑和苯并咪唑的缓蚀效率。通过DFT计算,在气体和水中的质子化和非质子化物质的B3LYP/6 - 311 G++(d,p)和b2plypd3/ augg -cc-pvdz基集水平上对分子结构进行几何优化。在本研究中,利用HOMO、LUMO、带隙、电离能、电负性、硬度、柔软度、亲电性和亲核性、电子转移、背给能和浓缩福井指数来评价分子的局部反应性。理论研究可以精确地建立分子的几何尺寸,并正确地解释抑制剂的量子特性。用分子动力学方法研究了抑制剂与特定分子中金属表面相互作用的机理。苯并咪唑官能团在金属表面上线性吸收能量,其量子特性使用密度泛函理论和从头算技术确定。重要的是,这个概念模型的发现与早期实验研究的缓蚀效率是一致的。
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引用次数: 0
Message from the Editor-in-Chief 总编辑寄语
Q4 Chemistry Pub Date : 2022-12-23 DOI: 10.5564/mjc.v23i49.2450
J. Temuujin
No abstract in English
无英文摘要
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引用次数: 0
Wound-healing activity of polyhexamethyleneguanidine hydrochloride hydrogel and extract of Bergenia crassifolia on thermal burn simulation 聚六亚甲基胍水凝胶及山楂提取物在热烧伤模拟中的创面愈合活性
Q4 Chemistry Pub Date : 2022-12-23 DOI: 10.5564/mjc.v23i49.2049
S. Stelmakh, O. Ochirov, M. Grigor’eva, A. Tykheev, S. Lebedeva, V. Okladnikova, S. Zhamsaranova
The results of a study of the wound healing activity of a composition based on the hydrogel of polyhexamethylene guanidine hydrochloride and Bergenia crassifolia extract, under conditions of modeling thermal burns in laboratory animals (rats), are presented. It was found that the composition affects the change in the summary antioxidant and leukocyte activity towards the normalization of these indicators. Morphological analysis of the slices showed that, under the influence of a polyhexamethylene guanidine hydrogel composition and B.crassifolia extract, healing proceeds more intensively than in the control group and is manifested by a smaller thickness of the leukocyte-necrotic scab, accelerated epithelization, and complete closure of the skin defect.
介绍了在实验室动物(大鼠)热烧伤模型条件下,基于聚六亚甲基胍盐酸盐和厚叶Bergenia提取物水凝胶的组合物的伤口愈合活性的研究结果。研究发现,该成分影响总抗氧化和白细胞活性的变化,使这些指标正常化。切片的形态学分析表明,在聚六亚甲基胍水凝胶组合物和厚叶B.crassifolia提取物的影响下,愈合进行得比对照组更为强烈,表现为白细胞坏死结痂厚度更小,上皮化加速,皮肤缺损完全闭合。
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引用次数: 0
Preparation of catalyst from natural montmorillonite mineral and its application in the synthesis of carbon nanosphere 天然蒙脱石制备催化剂及其在碳纳米球合成中的应用
Q4 Chemistry Pub Date : 2022-12-23 DOI: 10.5564/mjc.v23i49.2430
Altantuya Ochirkhuyag, Ulambayar Rentsennorov, Davaabal Batmunkh, Oyun-Erdene Gendenjamts, E. Odbaatar, Tserendagva Tsend-Ayush, J. Temuujin
In developed countries, nanoparticles derived from natural minerals and high-purity chemicals both are widely studied, while in developing countries like Mongolia, the natural minerals-based nanoparticles have more interest because of the low production cost and applicability of domestic natural minerals for their production. For the synthesis of natural mineral-based nanomaterials, it is important first to define the chemical composition and physical structure of local minerals and their possible processing route. We employed an environmentally friendly alkaline leaching procedure to recover silica from the clay mineral at 90°C for 24 hours. We applied an organic surfactant (CTAB) and a simple coprecipitation approach to form iron-doped silica nanoparticles. Consequently, we used iron-doped silica nanoparticles as a substrate and catalyst for the synthesis of carbon nanosphere at 750 °C for 1 hour in an argon and acetylene gas atmosphere. As a result, vast quantities of superhydrophobic carbon nanospheres (CNS) were obtained. The physicochemical properties of nanosilica substrate, non-functionalized carbon nanosphere, and functionalized carbon nanosphere (CNS) samples were characterized using XRD, XRF, SEM, EDS, TEM, and FTIR spectrometer. Iron-doped mineral-derived nanosilica particles demonstrated high catalytic efficiency and the potential to produce a large amount of value-added carbon nanospheres. Superhydrophobic CNS can be used in a variety of applications, particularly drug delivery; however, to use CNS in both aqueous and non-aqueous media, the superhydrophobic properties of CNS can be modified using different oxidizers. The changes in hydrophobicity of the CNS were examined and suggested possible oxidizing agents.
在发达国家,从天然矿物和高纯度化学品中提取的纳米颗粒都得到了广泛的研究,而在蒙古等发展中国家,基于天然矿物的纳米颗粒因其生产成本低且适用于国内天然矿物而更受关注。对于天然矿物基纳米材料的合成,重要的是首先确定局部矿物的化学组成和物理结构及其可能的加工路线。我们采用了一种环保的碱性浸出程序,在90°C下24小时从粘土矿物中回收二氧化硅。我们应用有机表面活性剂(CTAB)和简单的共沉淀方法来形成铁掺杂的二氧化硅纳米颗粒。因此,我们使用铁掺杂的二氧化硅纳米颗粒作为基底和催化剂,在氩气和乙炔气氛中,在750°C下合成碳纳米球1小时。结果,获得了大量的超疏水碳纳米球(CNS)。使用XRD、XRF、SEM、EDS、TEM和FTIR光谱仪对纳米二氧化硅基底、非功能化碳纳米球和功能化碳纳米球(CNS)样品的物理化学性质进行了表征。铁掺杂矿物衍生的纳米二氧化硅颗粒表现出高催化效率和生产大量增值碳纳米球的潜力。超疏水性中枢神经系统可用于多种应用,特别是药物递送;然而,要在水性和非水性介质中使用CNS,可以使用不同的氧化剂来改变CNS的超疏水特性。检测了中枢神经系统疏水性的变化,并提出了可能的氧化剂。
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引用次数: 0
Effect of various transition metal ions on mordanting stage of yak wool bleaching process 不同过渡金属离子对牦牛毛漂白过程媒染阶段的影响
Q4 Chemistry Pub Date : 2022-10-26 DOI: 10.5564/mjc.v23i49.2138
Dashjargal Arildii, Otgontsetseg Ranaajav, Odonchimeg Genenbat, Amarzaya Bazarvaani, Sarangerel Davaasambuu
Yak wool is a smooth, warm, and durable natural protein-structured fiber that could compete with cashmere and other high-end protein-structured fibers on the market. However, it suffers from drawing consumers’ attention due to the lack of color due to the shortfall of the yak wool bleaching technology. Herein, we studied the applicability of various transition metals, i.e., copper (II), cobalt (II), iron (II), and nickel (II) salts, as a mordanting reagent based on their effect on the hydrogen peroxide decomposition reaction and the morphological and mechanical properties of the bleached yak wool with the presence of these transition metal. Our study suggested that the iron (II) ion was the most efficient reagent for the mordant bleaching since it provided less fiber damage, relatively high strength, and elongation to the bleached yak wool with good whiteness, while the Cu (II) was the least favorable agent for the yak wool bleaching process.
牦牛毛是一种光滑、保暖、耐用的天然蛋白质结构纤维,可以与市场上的羊绒和其他高端蛋白质结构纤维竞争。然而,由于牦牛毛漂白技术的不足,其颜色不足,难以引起消费者的注意。在此,我们研究了各种过渡金属,即铜(II)、钴(II),铁(II)和镍(II)盐,作为媒介试剂的适用性,基于它们对过氧化氢分解反应的影响以及这些过渡金属存在下漂白牦牛毛的形态和机械性能。我们的研究表明,铁离子是最有效的媒介漂白剂,因为它对漂白的牦牛毛具有良好的白度,纤维损伤小,强度和伸长率较高,而铜离子是最不利于牦牛毛漂白的试剂。
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引用次数: 0
Homolytic B–Cl bond dissociation energies of chloroborane-type molecules 氯硼烷型分子的均相B–Cl键离解能
Q4 Chemistry Pub Date : 2022-08-19 DOI: 10.5564/mjc.v23i49.2016
Wen-guan Lu, Robert J. O’Reilly
This study reports accurate gas-phase homolytic B–Cl bond dissociation energies, obtained using the benchmark-quality W1w thermochemical protocol, for a set of 25 chloroborane-type molecules (known herein as the BCl25BDE dataset). The BDEs of these species differ by as much as 136.5 kJ mol-1 at 298 K, with (BH2)2BCl having the lowest BDE (388.5 kJ mol-1 at 298 K) and (CH3)HBCl having the highest (525.1 kJ mol-1 ).  Using the W1w BDEs as reference values, the accuracy of a diverse set of more economical DFT procedures (which may be applied to the study of molecules sufficiently large that the use of benchmark-quality methods such as W1w is rendered computationally prohibitive) have been investigated. As a result of this analysis, the most accurate methods for the computation of B–Cl BDEs are ωB97/A'VQZ (MAD = 3.0 kJ mol-1 ) and M06/A'VTZ (MAD = 3.2 kJ mol-1 ). The double-hybrid functional DSD-PBEP86 in conjunction with the A'VQZ basis set (MAD = 4.0 kJ mol-1 ) was found to give the lowest largest deviation (LD = 6.4 kJ mol-1 ) of any of methods considered in this assessment study.
本研究报告了一组25个氯硼烷型分子(本文称为BCl25BDE数据集)使用基准质量W1w热化学方案获得的准确气相均裂B–Cl键离解能。这些物种在298K下的BDE差异高达136.5kJ mol-1,其中(BH2)2BCl的BDE最低(298K下为388.5kJ mol-1),(CH3)HBCl的BDE。使用W1w BDE作为参考值,研究了一组更经济的DFT程序的准确性(该程序可用于研究足够大的分子,从而使W1w等基准质量方法的使用在计算上变得禁止)。根据该分析,计算B–Cl BDE的最准确方法是ωB97/a'VQZ(MAD=3.0 kJ mol-1)和M06/a'VTZ(MAD=3.2 kJ mol-2)。在本评估研究中考虑的任何方法中,双杂交函数DSD-PBEP86与A’VQZ基集(MAD=4.0 kJ mol-1)的偏差最小(LD=6.4 kJ mol-2)。
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引用次数: 2
Development technology of starter cultures using lactic acid bacteria isolated from fermented Camel milk with cholesterol lowering ability 降胆固醇骆驼乳乳酸菌发酵剂的研制技术
Q4 Chemistry Pub Date : 2022-05-30 DOI: 10.5564/mjc.v23i49.1404
Sarengaole Bayinjirigala, Tsend-ayusha Chuluunbat, Jirigala Bayin, B. Menghe
The aim of the study is to develop a technology of starter cultures for fermented milk using new strains of lactic acid bacteria isolated from Mongolian traditional fermented camel milk. “Khoormog” samples are collected from Inner Mongolia, China. Totally 230 Lactobacillus strains are isolated and screened by acid-, bile- tolerance, lactose decomposition and acid production ability. The cholesterol lowering abilities and adhesiveness on Caco-2 are evaluated. The top 2 strains are identified as Lactobacillus plantarum. These 2 strains are prepared as the starter cultures in milk fermentation. The development technology of starter cultures is studied.
本研究的目的是利用从蒙古传统发酵骆驼奶中分离的新型乳酸菌,开发发酵乳发酵剂培养技术。“Khoormog”样本采集于中国内蒙古。从乳酸杆菌的耐酸性、胆汁耐受性、乳糖分解能力和产酸能力等方面筛选出230株乳酸杆菌。评估了降低胆固醇的能力和对Caco-2的粘附性。前2个菌株被鉴定为植物乳杆菌。这两个菌株被制备为牛奶发酵中的起始培养物。对发酵剂培养基的开发技术进行了研究。
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引用次数: 0
A quantum chemical study of the interaction of carboxylic acids with DMSO 羧酸与DMSO相互作用的量子化学研究
Q4 Chemistry Pub Date : 2022-05-27 DOI: 10.5564/mjc.v23i49.1407
Mu Ren, Ao Rigele, Na Shun, Narantsogt Natsagdorj
Quantum chemical computational methods, which use quantum mechanics and molecular dynamics theory, have developed rapidly in the past few decades, and quantum chemical computation has penetrated almost all fields of chemistry. Hydrogen bonds are ubiquitously common weak intermolecular interactions. Moreover, the bonding mechanism of hydrogen bonds is considered to be different from that of chemical bonding. Because of the difficulty of experimental studies, a more accurate calculation of hydrogen bonding from theory is a more convenient and direct method to understand hydrogen bonding. Density functional theory (DFT) is the most widely used general function in quantum chemical calculations, giving accurate results for most chemical systems. In this paper, the geometries of the hydrogen-bonded dimer complex of acetic acid and DMSO was structurally optimized and potential energy surface was determined. The geometries of four related hydrogen-bonded dimer complexes were fully optimized using the M06-2X/6-311++G (3d, 2p) exchange-correlation functional with DFT-D3(BJ) empirical dispersion correction. We found that hydrogen bonding is a mixture of electrostatic interactions and covalent bonding, and that hydrogen bonding is a kind of force with different percentages of electrostatic and covalent character, rather than a special force independent of chemical bonding. Thus, more clearly defining our inherent classification of forces between substances provides a new perspective for our future study of weak interactions such as hydrogen bonding.
利用量子力学和分子动力学理论的量子化学计算方法在过去几十年中发展迅速,量子化学计算几乎渗透到化学的所有领域。氢键是普遍存在的弱分子间相互作用。此外,氢键的键合机理被认为与化学键合的键合机制不同。由于实验研究的困难,从理论上更准确地计算氢键是理解氢键的一种更方便、更直接的方法。密度泛函理论(DFT)是量子化学计算中应用最广泛的通用函数,为大多数化学系统提供了准确的结果。本文对乙酸和二甲基亚砜氢键二聚物的几何结构进行了优化,并确定了其势能面。使用M06-2X/6-311++G(3d,2p)交换相关函数和DFT-D3(BJ)经验色散校正,对四种相关氢键二聚体配合物的几何结构进行了充分优化。我们发现氢键是静电相互作用和共价键的混合物,氢键是一种具有不同百分比静电和共价性质的力,而不是一种独立于化学键的特殊力。因此,更明确地定义我们对物质之间作用力的固有分类,为我们未来研究氢键等弱相互作用提供了一个新的视角。
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引用次数: 0
Efficiency of KOH-activated carbon for removal of heavy metal pollution from water KOH活性炭去除水中重金属污染的效果
Q4 Chemistry Pub Date : 2022-05-27 DOI: 10.5564/mjc.v23i49.1406
N. Byamba-Ochir, Nazgul Muratbyek, Narangarav Tumen-Ulzii, Ariunaa Alyeksandr, Nasantogtokh Oyunchimeg
The study to reduce heavy metals pollution from water using the KOH-activated carbon was studied the factors affecting the adsorption capacities of Cu(II) and Pb(II), in particular, initial metals concentration, pH of the solution, and contact time in static conditions. Using X-ray photoelectron spectroscopy and FTIR analysis to determine the elemental composition and surface functional groups of the activated carbon surface, the presence of oxygen-related functional groups was observed. The maximum adsorption capacities were 135.8 mg g-1 and 31.0 mg g-1 for removal of lead and copper solutions with the initial concentration of 300 mg L-1 of metal at 318 K, respectively. The removal percentage was found to be higher for Pb (II) when compared with Cu (II).
研究了koh活性炭在静态条件下对Cu(II)和Pb(II)吸附能力的影响因素,特别是初始金属浓度、溶液pH和接触时间。利用x射线光电子能谱和FTIR分析测定活性炭表面的元素组成和表面官能团,观察到氧相关官能团的存在。在318 K条件下,初始金属浓度为300 mg L-1时,对铅和铜的最大吸附量分别为135.8 mg g-1和31.0 mg g-1。与Cu (II)相比,Pb (II)的去除率更高。
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引用次数: 0
期刊
Mongolian Journal of Chemistry
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