Microwave-assisted

微波辅助
  • 文章类型: Journal Article
    本研究旨在研究在昭通褐煤样品盐酸化学浸出过程中,添加氟化钠(NaF)并利用超声波和微波能量辅助对灰分去除效率的影响。云南,中国。对昭通褐煤样品进行了化学浸出,云南,中国,在实验时间条件下(30-120分钟),温度(55-95°C),微波功率(240-800W),超声波功率(25-100%),和NaF添加浓度(0.2-1.2M)。NaF的添加大大提高了褐煤灰分的去除效率。在优化条件下,NaF的加入使褐煤灰分去除率从25%提高到65.27%。微波辅助褐煤脱灰可以显著提高脱灰效率,对褐煤的微观结构调控具有积极意义。超声波辅助除灰可以降低煤粉燃尽温度,提高煤的燃烧性能。
    This study was aimed at investigating the effects of adding sodium fluoride (NaF) and using the assistance of ultrasonic and microwave energy on the removal efficiency of ash content during the hydrochloric acid (HCl) chemical leaching process of lignite samples from Zhaotong, Yunnan, China. Chemical leaching was conducted on lignite samples from Zhaotong, Yunnan, China, under the experimental conditions of time (30-120 min), temperature (55-95 °C), microwave power (240-800 W), ultrasonic power (25-100%), and NaF addition concentration (0.2-1.2 M). The addition of NaF greatly improved the removal efficiency of ash content from lignite. Under optimized conditions, the addition of NaF increased the removal rate of ash content from lignite from 25% to 65.27%. The microwave-assisted deashing of lignite can significantly improve the deashing efficiency, with positive implications for the microstructure regulations of lignite. Ultrasonic-assisted deashing can lower the temperature for coal powder burnout and enhance the combustion performance of coal.
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  • 文章类型: Journal Article
    本研究针对稀土熔融电解渣(RMES)中氟化稀土元素转化为羟基化稀土元素的困难问题,提出采用微波辅助常压碱浸方法处理RMES。研究了RMES在微波辅助常压碱浸条件下的浸出行为,并确定了最佳反应条件。在反应温度为150℃的条件下,NaOH初始浓度为60%,NaOH与炉渣的质量比为4:1,微波功率为700W,反应时间120min,搅拌速度为300r/min,氟化稀土的转化率达到99.17%。通过浸出动力学分析,得到了微波辅助常压碱浸工艺的表观速率方程,计算得到的表观活化能为54.872kJ/mol,这是12.458kJ/mol,比使用常规加热进行浸出时达到的(67.33kJ/mol)低。
    This study focuses on the difficulty of converting fluorinated rare earth elements into hydroxylated rare earth elements in rare earth melt electrolysis slag (RMES) and proposes the use of a microwave-assisted atmospheric alkaline leaching method for the treatment of RMES. The leaching behavior of RMES under microwave-assisted atmospheric alkaline leaching was studied, and the optimal reaction conditions were determined. Under the conditions of a reaction temperature of 150 °C, initial NaOH concentration of 60 %, NaOH-to-slag mass ratio of 4:1, microwave power of 700 W, reaction time of 120 min, and stirring speed of 300 r/min, the conversion rate of fluorinated rare earths reached 99.17 %. The apparent rate equation of the microwave-assisted atmospheric alkaline leaching process was obtained by leaching kinetic analysis, and the apparent activation energy under this process was calculated to be 54.872 kJ/mol, which was 12.458 kJ/mol lower than that achieved when conventional heating was used for leaching (67.33 kJ/mol).
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  • 文章类型: Journal Article
    口腔癌占印度所有癌症相关死亡的50-70%,在全球最常见的癌症中排名第六。大约90%的口腔恶性肿瘤在组织学上是由鳞状细胞引起的,因此被称为口腔鳞状细胞癌。有机聚阳离子被称为生物多胺,例如,腐胺(放),亚精胺(Spd),精胺(Spm)对细胞增殖至关重要,包括基因表达控制,核酸内切酶介导的DNA片段的调节,和DNA损伤抑制。较高的Spm和Spd水平已被鉴定为用于检测各种癌症中的肿瘤发展的癌症生物标志物。目前的研究利用单宁酸,多酚化合物,作为还原剂和封端剂,通过一步微波辅助合成制造AuNP。制造的TA@AuNP用作纳米探针,用于PBS中多胺的比色感测。当将TA@AuNP添加到多胺中时,多胺中的胺基通过氢键或静电相互作用与TA@AuNP的酚基相互作用。这些相互作用导致TA@AuNP的聚集,导致TA@AuNP的表面等离子体共振(SPR)带从530nm红移到560nm。发现纳米探针在低浓度下对Spm具有高度特异性。TA@AuNPs能够在人工唾液样品中成功检测到Spm。在使用智能手机应用程序记录感测过程的RGB值时,发现当纳米粒子由于Spm的存在而聚集时,R值的强度下降,表明TA@AuNPs由于与多胺的相互作用而聚集。
    Oral cancer accounts for 50%-70% of all cancer-related deaths in India and ranks sixth among the most frequent cancers globally. Roughly 90% of oral malignancies are histologically arise from squamous cells and are therefore called oral squamous cell carcinoma. Organic polycations known as biogenic polyamines, for example, putrescine (Put), spermidine (Spd), and spermine (Spm), are vital for cell proliferation, including gene expression control, regulation of endonuclease-mediated fragmentation of DNA, and DNA damage inhibition. Higher Spm and Spd levels have been identified as cancer biomarkers for detecting tumour development in various cancers. The current study utilises tannic acid, a polyphenolic compound, as a reducing and capping agent to fabricate AuNPs via a one-step microwave-assisted synthesis. The fabricated TA@AuNPs were utilised as a nanoprobe for colourimetric sensing of polyamines in PBS. When TA@AuNPs are added to the polyamine, the amine groups in polyamines interact with the phenolic groups of TA@AuNPs via hydrogen bonding or electrostatic interactions. These interactions cause the aggregation of TA@AuNPs, resulting in a red shift of the Surface Plasmon Resonance band of TA@AuNPs from 530 nm to 560 nm. The nanoprobe was found to be highly specific for Spm at low concentrations. TA@AuNPs were able to detect Spm successfully in artificial saliva samples. On recording the RGB values of the sensing process using a smartphone app, it was found that as the nanoparticles aggregated due to the presence of Spm, the intensity of theR-value decreased, indicating the aggregation of TA@AuNPs due to interaction with the polyamine.
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  • 文章类型: Journal Article
    我们描述了一种微波辅助,不含甲醇和乙酸,廉价的SDS-PAGE蛋白快速染色方法。只有柠檬酸,苯甲酸,使用考马斯亮蓝G-250(CBG)。微波照射缩短了检测时间,和蛋白质在清晰的背景下在30分钟内显示出来,固定2分钟和染色12分钟后。通过使用这个协议,获得了与常规甲醇/乙酸方法相当的谱带强度。
    We describe a microwave-assisted, methanol and acetic acid-free, inexpensive method for rapid staining of SDS-PAGE proteins. Only citric acid, benzoic acid, and Coomassie brilliant blue G-250 (CBG) were used. Microwave irradiation reduced the detection duration, and proteins in a clear background were visualized within 30 min of destaining, after 2 min of fixing and 12 min of staining. By using this protocol, comparable band intensities were obtained to the conventional methanol/acetic acid method.
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  • 文章类型: Journal Article
    本研究旨在合成和表征氟比洛芬衍生物,并评估其镇痛作用,术后和慢性炎性疼痛模型的抗炎和胃保护活性。氟比洛芬衍生物是通过使用涉及酯化的三步工艺生产的,酰肼生产,和希夫碱,每个修饰了不同的羧基。所有新合成的氟比洛芬衍生物(NS5-NS8)均通过1HNMR表征,13CNMR,19FNMR和HR-ESI-MS,手术后,在建立良好的体内动物模型中确定了炎性疼痛和致溃疡活性。为了评估术后和炎性疼痛,使用各种剂量的化合物[1、3、10和30mg/kg(bwt)],而在100和150mg/kg(bwt)的剂量下评估了它们的致溃疡潜力。在急性和重复测试中,不同剂量的衍生物显着降低了切口损伤相关的疼痛(p<0.001),同时降低了phologicagent诱导的炎症反应。胃组织学和生化特征表明,与阿司匹林和氟比洛芬相比,合成的衍生物没有引起溃疡的潜力。此外,对接显示这些化合物的酰肼部分在COX-2结合位点内的相互作用中至关重要.因此,合成的化合物具有很强的镇痛和抗炎作用,引起溃疡的风险低。这些属性使它们成为治疗与炎症和疼痛相关的病理性病症的潜在有价值的治疗剂。由RamaswamyH.Sarma沟通。
    Present research was designed to synthesize and characterize the flurbiprofen derivatives and to evaluate their analgesic, anti-inflammatory and gastro-protective activities in post-operative and chronic inflammatory pain models. Flurbiprofen derivatives were produced by using three-step processes involving esterification, hydrazide production, and schiff base, each of which modified a different carboxyl group. All the newly synthesized flurbiprofen derivatives (NS5-NS8) were characterized by 1H NMR,13C NMR,19F NMR and HR-ESI-MS, and the post-operative, inflammatory pain and ulcerogenic activities were determined in well-established in-vivo animal models. To evaluate post-operative and inflammatory pain, various doses of compounds [1, 3, 10, and 30 mg/kg (bwt)] were used, while their ulcerogenic potential was assessed at doses of 100 and 150 mg/kg (bwt). The incisional damage linked pain was significantly (p < 0.001) reduced by derivatives at different doses in both the acute and repeated tests with decreased response of phologistic agent-induced inflammation. The stomach histology and biochemical features demonstrate that the synthesized derivatives have no potential to cause ulcerogenicity as compared to aspirin and flurbiprofen. Furthermore, docking shows that the hydrazide moiety of these compounds is crucial in interacting within COX-2 binding site. Therefore, the synthesized compounds exhibit strong analgesic and anti-inflammatory effects and a low risk of causing ulcers. These attributes render them potentially valuable therapeutic agents for the treatment of pathological disorders associated with inflammation and pain.Communicated by Ramaswamy H. Sarma.
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  • 文章类型: Journal Article
    在这项工作中,一系列的海胆状Ce(HCOO)3纳米团簇是通过一个容易和可扩展的微波辅助方法通过改变辐照时间合成,并研究了结构-性质关系。反应时间的优化是基于结构表征和电化学性能,Ce(HCOO)3-210s样品在1Ag-1的电流密度下显示出高达132Fg-1的比电容。这是由于最佳的介孔分层结构和结晶度有利于其导电性,提供丰富的Ce3+/Ce4+活性位点,促进电解质离子的运输。此外,制备了基于Ce(HCOO)3//AC的非对称超级电容器,提供14.78Whkg-1的最大能量密度和15168Wkg-1的相当高的功率密度。在3Ag-1下进行10,000次连续充放电循环后,ASC设备保留了其初始比电容的81.3%。这种海胆状Ce(HCOO)3的优异的综合电化学性能为实际的超级电容器应用提供了重要的前景。
    In this work, a series of urchin-like Ce(HCOO)3 nanoclusters were synthesized via a facile and scalable microwave-assisted method by varying the irradiation time, and the structure-property relationship was investigated. The optimization of the reaction time was performed based on structural characterizations and electrochemical performances, and the Ce(HCOO)3-210 s sample shows a specific capacitance as high as 132 F g-1 at a current density of 1 A g-1. This is due to the optimal mesoporous hierarchical structure and crystallinity that are beneficial to its conductivity, offering abundant Ce3+/Ce4+ active sites and facilitating the transportation of electrolyte ions. Moreover, an asymmetric supercapacitor based on Ce(HCOO)3//AC was fabricated, which delivers a maximum energy density of 14.78 Wh kg-1 and a considerably high power density of 15,168 W kg-1. After 10,000 continuous charge-discharge cycles at 3 A g-1, the ASC device retains 81.3% of its initial specific capacitance. The excellent comprehensive electrochemical performance of this urchin-like Ce(HCOO)3 offers significant promise for practical supercapacitor applications.
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  • 文章类型: Journal Article
    一种高性能的电极材料,持久耐用,和低成本的超级电容器长期以来一直是学术界和工业界的期望。在所有影响电极材料电化学性能和循环稳定性的因素中,形貌和内在结构特征是最重要的。在这项研究中,利用Ce3+和-COOH基团设计了一种新型的3D花状Ce(COOH)3电极材料,并通过一锅微波辅助方法制备。通过SEM对样品的形貌和结构特征进行了分析,EDS,TEM,XRD,FT-IR,XPS,N2吸附/解吸技术,并在三电极结构中研究了电化学行为。Ce(COOH)3电极在1Ag-1时具有140Fg-1的出色比电容,高于许多其他先前报道的Ce基电极。此外,它提供了高速率的能力,保留其初始电容的60%时,电流密度放大20倍。戏剧性地,Ce(COOH)3电极具有超高的循环稳定性,60,000次循环后的电容保持率为107.9%,据我们所知,这是报道的Ce-有机化合物电极中耐久性最高的。优异的电化学性能归因于其固有的晶体结构和独特的形貌。这项工作表明,3D花状Ce(COOH)3具有用于超级电容器应用的巨大潜力,并且可以扩展简便且可扩展的合成策略以生产其他金属-有机复合电极。
    An electrode material with high performance, long durability, and low cost for supercapacitors has long been desired in academia and industry. Among all the factors that affect the electrochemical performance and cycling stability of electrode materials, the morphology and intrinsic structure characteristics are the most important. In this study, a novel 3D flower-like Ce(COOH)3 electrode material was designed by taking advantage of the Ce3+ and -COOH groups and fabricated by a one-pot microwave-assisted method. The morphology and structure characteristics of the sample were examined by SEM, EDS, TEM, XRD, FT-IR, XPS, N2 adsorption/desorption techniques, and the electrochemical behaviors were investigated in a three-electrode configuration. The Ce(COOH)3 electrode presents an excellent specific capacitance of 140 F g-1 at 1 A g-1, higher than many other previously reported Ce-based electrodes. In addition, it delivers high rate capability that retains 60% of its initial capacitance when the current density is magnified 20 times. Dramatically, the Ce(COOH)3 electrode exhibits an ultra-high cycling stability with capacitance retention of 107.9% after 60,000 cycles, which is the highest durability among reported Ce-organic compound electrodes to the best of our knowledge. The excellent electrochemical performance is ascribed to its intrinsic crystal structure and unique morphology. This work indicates that the 3D flower-like Ce(COOH)3 has significant potential for supercapacitor applications and the facile and scalable synthesis strategy can be extended to produce other metal-organic composite electrodes.
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  • 文章类型: Journal Article
    美罗培南是目前临床应用最常见的碳青霉烯类药物。在工业上,最终的合成步骤的特征在于以间歇方式与氢气和Pd/C进行非均相催化氢化。所需的高质量标准很难满足,并且需要特定条件来去除两个保护基团[即,同时对硝基苄基(pNB)和对硝基苄氧羰基(pNZ)]。三相气-液-固系统使得该步骤困难且不安全。近年来小分子合成新技术的引入为过程化学开辟了新的领域。在这种情况下,我们已经研究了使用微波(MW)辅助流动化学的美罗培南氢解作为具有工业前景的新技术。反应参数(催化剂用量,T,P,停留时间,流量)在温和条件下研究了从间歇过程到半连续流的过程,以确定它们对反应速率的影响。停留时间(840s)和循环数(4)的优化使我们能够开发出一种新颖的方案,与批量生产相比,该方案将反应时间减半(14分钟与30分钟),同时保持相同的产品质量。使用这种半连续流技术的生产率提高补偿了产量略低的情况(70%与74%)以批量模式获得。
    Meropenem is currently the most common carbapenem in clinical applications. Industrially, the final synthetic step is characterized by a heterogeneous catalytic hydrogenation in batch mode with hydrogen and Pd/C. The required high-quality standard is very difficult to meet and specific conditions are required to remove both protecting groups [i.e., p-nitrobenzyl (pNB) and p-nitrobenzyloxycarbonyl (pNZ)] simultaneously. The three-phase gas-liquid-solid system makes this step difficult and unsafe. The introduction of new technologies for small-molecule synthesis in recent years has opened up new landscapes in process chemistry. In this context, we have investigated meropenem hydrogenolysis using microwave (MW)-assisted flow chemistry for use as a new technology with industrial prospects. The reaction parameters (catalyst amount, T, P, residence time, flow rate) in the move from the batch process to semi-continuous flow were investigated under mild conditions to determine their influence on the reaction rate. The optimization of the residence time (840 s) and the number of cycles (4) allowed us to develop a novel protocol that halves the reaction time compared to batch production (14 min vs. 30 min) while maintaining the same product quality. The increase in productivity using this semi-continuous flow technique compensates for the slightly lower yield (70% vs. 74%) obtained in batch mode.
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  • 文章类型: Journal Article
    开发用于氧还原反应(ORR)的低成本单原子电催化剂是非常需要的,但仍然是一个巨大的挑战。优于传统技术,据报道,微波辅助策略可快速生产高质量的Fe/N/C单原子催化剂(SAC),具有大大提高的反应速率和显着降低的能耗。合成的催化剂表现出优异的ORR性能,正半波电位高达0.90V,0.76s-1的高周转频率,以及令人满意的稳定性,在9000次循环中损失的半波电位仅为27mV(比损失107mV的Pt/C好得多)和良好的耐甲醇性。构造的水性和柔性全固态Zn空气电池(ZAB)的开路电压为1.56和1.52V,分别,高于基于20%Pt/C的那些(即,1.43和1.38V,分别)。令人印象深刻的是,它们提供235mWcm-2的峰值功率密度,超过Pt/C(即,186mWcm-2),与有史以来最好的Fe/N/C基ZAB相当。
    The development of low-cost single-atom electrocatalysts for oxygen reduction reaction (ORR) is highly desired but remains a grand challenge. Superior to the conventional techniques, a microwave-assisted strategy is reported for rapid production of high-quality Fe/N/C single-atom catalysts (SACs) with profoundly enhanced reaction rate and remarkably reduced energy consumption. The as-synthesized catalysts exhibit an excellent ORR performance with a positive half-wave potential up to 0.90 V, a high turnover frequency of 0.76 s-1 , as well as a satisfied stability with a lost half-wave potential of just 27 mV over 9000 cycles (much better than that of Pt/C with 107 mV lost) and good methanol resistance. The open-circuit voltages of as-constructed aqueous and flexible all-solid-state Zn-air batteries (ZABs) are 1.56 and 1.52 V, respectively, higher than those of 20% Pt/C-based ones (i.e., 1.43 and 1.38 V, respectively). Impressively, they afford a peak power density of 235 mW cm-2 , which exceeds that of Pt/C (i.e., 186 mW cm-2 ), and is comparable to the best ones of Fe/N/C-based ZABs ever reported.
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  • 文章类型: Journal Article
    聚合物是许多行业的基本组成部分,可以与许多其他材料和组件共轭,以获得大量产品。生物材料在药物制剂开发中的应用已被广泛研究。组织工程,和生物医学领域。然而,许多聚合物的天然形式有关于微生物污染的局限性,易感性,溶解度,和稳定性。化学或物理改性可通过调整聚合物的性质以满足若干要求来克服这些限制。聚合物改性是跨学科的,切割传统材料,物理学,生物学化学,医学,和工程限制。几十年来,微波辐射已成为驱动和促进化学改性反应的成熟技术。该技术允许容易的温度和功率控制以有效地执行合成方案。此外,微波辐射有助于绿色和可持续化学。在这一贡献中,描述了微波辅助聚合物改性,特别关注它们在开发几种新型剂型中的应用。
    Polymers are a fundamental part of numerous industries and can be conjugated with many other materials and components to have a vast array of products. Biomaterials have been extensively studied for their application in pharmaceutical formulation development, tissue engineering, and biomedical areas. However, the native form of many polymers has limitations concerning microbial contamination, susceptibility, solubility, and stability. Chemical or physical modifications can overcome these limitations by tailoring the properties of polymers to meet several requirements. The polymer modifications are interdisciplinary, cutting across conventional materials, physics, biology, chemistry, medicine, and engineering limitations. Microwave irradiation has become a well-established technique for a few decades to drive and promote chemical modification reactions. This technique allows ease of temperature and power control to perform the synthesis protocols efficiently. Additionally, microwave irradiation contributes to green and sustainable chemistry. In this contribution, microwave-assisted polymer modifications were described with a special focus on their application in developing several novel dosage forms.
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