Kinetics

动力学
  • 文章类型: Journal Article
    衰老导致消化道功能的变化,但年龄对营养物质消化和吸收的影响尚不清楚。本研究的目的是研究两种类似于奶油干酪的高蛋白乳制品的体外消化(24%w/w蛋白质,20%w/w脂质),酪蛋白与乳清蛋白的比例相反,80:20(WP-20),和20:80(WP-80)。使用了INFOGEST提出的适用于一般老年人群(≥65岁)的新静态消化模型,以及协议的标准版本。在每种产品的两种模型之间比较了蛋白水解和脂解的动力学,在消化的胃和肠阶段。在这两种奶油奶酪中,在胃期结束时,老年人的蛋白质水解程度(DH-P)显着低于年轻人(WP-20为-19%,WP-80为-44%),并且在肠期结束时(WP-20为-16%,WP-80为-20%)。在WP-20消化结束时,老年人的脂质水解程度(DH-L)也显着低于年轻人(-30%),但有趣的是,WP-80的情况并非如此(测量了类似的DH-L)。在两种消化条件下,WP-80释放的游离脂肪酸也比WP-20释放的更快:肠道消化5分钟后,WP-80的DH-L已经≈32%,而WP-20的DH-L为14%。这归因于酪蛋白与乳清蛋白的比例相反,导致形成不同的凝胶结构,从而导致胃肠道中不同的解构模式。这项研究强调了一个事实,即仔细考虑成分是至关重要的,结构,和食物的消化率,以开发适合老年人群特定需求的产品。
    Ageing leads to changes in the functionality of the digestive tract but the effect of age on digestion and absorption of nutrients remains unclear. The objective of this study was to investigate in vitro the digestion of two high-protein dairy products similar to cream cheese (24 % w/w proteins, 20 % w/w lipids) with opposite casein to whey protein ratios, 80:20 (WP-20), and 20:80 (WP-80). The new static digestion model adapted to the general older adult population (≥65 y.) proposed by INFOGEST was used, as well as the standard version of the protocol. Kinetics of proteolysis and lipolysis were compared between both models for each product, in the gastric and intestinal phases of digestion. In both cream cheeses, the degree of protein hydrolysis (DH-P) was significantly lower for older adults than for young adults at the end of the gastric phase (-19 % for WP-20, and -44 % for WP-80), and at the end of the intestinal phase (-16 % for WP-20, and -20 % for WP-80). The degree of lipid hydrolysis (DH-L) was also significantly lower for older adults than for young adults at the end of the digestion for WP-20 (-30 %), but interestingly it was not the case for WP-80 (similar DH-L were measured). Free fatty acids were also released faster from WP-80 than from WP-20 in both digestion conditions: after 5 min of intestinal digestion DH-L was already ≈32 % for WP-80 against 14 % for WP-20. This was attributed to the opposite casein to whey protein ratios, leading to the formation of different gel structures resulting in different patterns of deconstruction in the gastrointestinal tract. This study highlights the fact that it is essential to carefully consider the composition, structure, and digestibility of foods to develop products adapted to the specific needs of the older adult population.
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  • 文章类型: Journal Article
    应变碳环结构单元的合成与药物化学有关,和亚甲基环丁烷在当前的合成技术中尤其具有挑战性。仔细检查[1.1.1]推进剂和二硼试剂的反应性,发现双(儿茶酚)二硼(B2cat2)可以在室温下在几分钟内产生双(硼化)亚甲基环丁烷。该反应构成了通过特殊的非极性烃活化B-B键的第一个例子,也是第一次用硼亲电活化推进剂。包括原位NMR动力学和DFT计算在内的机理研究表明,二硼部分可以通过与推进剂的倒σ键配位而直接活化。并揭示DMF参与二硼酸酯中间体的稳定而不是B-B键的活化。这些结果为二硼和推进剂化学提供了新的可能性,并进一步发展了基于推进剂菌株释放的亚甲基环丁烷的合成。
    The synthesis of strained carbocyclic building blocks is relevant for Medicinal Chemistry, and methylenecyclobutanes are particularly challenging with current synthetic technology. Careful inspection of the reactivity of [1.1.1]propellane and diboron reagents has revealed that bis(catecholato)diboron (B2cat2) can produce a bis(borylated) methylenecyclobutane in a few minutes at room temperature. This reaction constitutes the first example of B-B bond activation by a special apolar hydrocarbon and also the first time that propellane is electrophilically activated by boron. Mechanistic studies including in situ NMR kinetics and DFT calculations demonstrate that the diboron moiety can be directly activated through coordination with the inverted sigma bond of propellane, and reveal that DMF is involved in the stabilization of diboronate ylide intermediates rather than the activation of the B-B bond. These results enable new possibilities for both diboron and propellane chemistry, and for further developments in the synthesis of methylenecyclobutanes based on propellane strain release.
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  • 文章类型: Journal Article
    股骨髋臼撞击综合征(FAIS)可引起髋关节疼痛和软骨唇损伤,可通过非手术或手术治疗。蹲下运动需要较大的髋关节屈曲度,并支持许多日常和运动任务,但可能会导致髋关节撞击并引起疼痛。以前尚未研究过物理治疗师主导的护理和关节镜对下蹲过程中生物力学的差异影响。这项研究探讨了在物理治疗师主导的干预下治疗的FAIS患者在下蹲时运动学和时间12个月变化的差异(个性化髋关节治疗,PHT)和关节镜检查。
    在多中心注册的FAIS参与者的子样本(n=36),务实,双臂优势随机对照试验在基线下蹲期间和随机分配至PHT(n=17)或关节镜(n=19)后12个月进行了三维运动分析.时间序列和峰值树干的变化,骨盆,和髋关节生物力学,研究了治疗组之间的下蹲速度和最大深度。
    在PHT组和关节镜组之间没有检测到12个月变化的显着差异。与基线相比,关节镜组随访时蹲下较慢(下降:平均差-0.04m·s-1(95CI[-0.09~0.01]);上升:-0.05m·s-1[-0.11~0.01]%)。在组间或组内未检测到深蹲深度的差异。调整速度后,与基线相比,随访时两个治疗组的躯干屈曲均更大(下降:PHT7.50°[-14.02至-0.98]%;上升:PHT7.29°[-14.69至0.12]%,关节镜16.32°[-32.95至0.30]%)。与基线相比,两个治疗组均显示前骨盆倾斜减少(下降:PHT8.30°[0.21-16.39]%,关节镜-10.95°[-5.54至16.34]%;上升:PHT-7.98°[-0.38至16.35]%,关节镜-10.82°[3.82-17.81]%),髋关节屈曲(下降:PHT-11.86°[1.67-22.05]%,关节镜-16.78°[8.55-22.01]%;上升:PHT-12.86°[1.30-24.42]%,关节镜-16.53°[6.72-26.35]%),和膝关节屈曲(下降:PHT-6.62°[0.56-12.67]%;上升:PHT-8.24°[2.38-14.10]%,关节镜-8.00°[-0.02至16.03]%)。与基线相比,PHT组在随访时在深蹲过程中表现出更多的pi屈(-3.58°[-0.12至7.29]%)。与基线相比,两组在随访时都表现出较低的外髋屈曲力矩(下降:PHT-0.55N·m/BW·HT[%][0.05-1.05]%,关节镜-0.84N·m/BW·HT[%][0.06-1.61]%;上升:PHT-0.464N·m/BW·HT[%][-0.002至0.93]%,关节镜-0.90N·m/BW·HT[%][0.13-1.67]%)。
    探索性数据表明,在12个月的随访中,PHT或髋关节镜检查在引起躯干变化方面均不优越,骨盆,或下肢生物力学。两种治疗方法都可能引起运动学和力矩的变化,然而,这些变化的影响是未知的。
    澳大利亚新西兰临床试验注册中心参考:ACTRN12615001177549。审判登记2015年2月11日。
    UNASSIGNED: Femoroacetabular impingement syndrome (FAIS) can cause hip pain and chondrolabral damage that may be managed non-operatively or surgically. Squatting motions require large degrees of hip flexion and underpin many daily and sporting tasks but may cause hip impingement and provoke pain. Differential effects of physiotherapist-led care and arthroscopy on biomechanics during squatting have not been examined previously. This study explored differences in 12-month changes in kinematics and moments during squatting between patients with FAIS treated with a physiotherapist-led intervention (Personalised Hip Therapy, PHT) and arthroscopy.
    UNASSIGNED: A subsample (n = 36) of participants with FAIS enrolled in a multi-centre, pragmatic, two-arm superiority randomised controlled trial underwent three-dimensional motion analysis during squatting at baseline and 12-months following random allocation to PHT (n = 17) or arthroscopy (n = 19). Changes in time-series and peak trunk, pelvis, and hip biomechanics, and squat velocity and maximum depth were explored between treatment groups.
    UNASSIGNED: No significant differences in 12-month changes were detected between PHT and arthroscopy groups. Compared to baseline, the arthroscopy group squatted slower at follow-up (descent: mean difference -0.04 m∙s-1 (95%CI [-0.09 to 0.01]); ascent: -0.05 m∙s-1 [-0.11 to 0.01]%). No differences in squat depth were detected between or within groups. After adjusting for speed, trunk flexion was greater in both treatment groups at follow-up compared to baseline (descent: PHT 7.50° [-14.02 to -0.98]%; ascent: PHT 7.29° [-14.69 to 0.12]%, arthroscopy 16.32° [-32.95 to 0.30]%). Compared to baseline, both treatment groups exhibited reduced anterior pelvic tilt (descent: PHT 8.30° [0.21-16.39]%, arthroscopy -10.95° [-5.54 to 16.34]%; ascent: PHT -7.98° [-0.38 to 16.35]%, arthroscopy -10.82° [3.82-17.81]%), hip flexion (descent: PHT -11.86° [1.67-22.05]%, arthroscopy -16.78° [8.55-22.01]%; ascent: PHT -12.86° [1.30-24.42]%, arthroscopy -16.53° [6.72-26.35]%), and knee flexion (descent: PHT -6.62° [0.56- 12.67]%; ascent: PHT -8.24° [2.38-14.10]%, arthroscopy -8.00° [-0.02 to 16.03]%). Compared to baseline, the PHT group exhibited more plantarflexion during squat ascent at follow-up (-3.58° [-0.12 to 7.29]%). Compared to baseline, both groups exhibited lower external hip flexion moments at follow-up (descent: PHT -0.55 N∙m/BW∙HT[%] [0.05-1.05]%, arthroscopy -0.84 N∙m/BW∙HT[%] [0.06-1.61]%; ascent: PHT -0.464 N∙m/BW∙HT[%] [-0.002 to 0.93]%, arthroscopy -0.90 N∙m/BW∙HT[%] [0.13-1.67]%).
    UNASSIGNED: Exploratory data suggest at 12-months follow-up, neither PHT or hip arthroscopy are superior at eliciting changes in trunk, pelvis, or lower-limb biomechanics. Both treatments may induce changes in kinematics and moments, however the implications of these changes are unknown.
    UNASSIGNED: Australia New Zealand Clinical Trials Registry reference: ACTRN12615001177549. Trial registered 2/11/2015.
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  • 文章类型: Journal Article
    本文研究了以氨甲基膦酸(AMPA)为吸附剂的氧化石墨烯从水溶液中吸附钍的动力学研究。首先,使用TEM对AMPA-GO吸附剂进行了表征,XRD,和FTIR方法。实验以两种间歇和连续模式进行。在批处理模式下,研究了在不同pH(1-4)下的吸附动力学,温度(298-328K),初始浓度(50-500mgL-1),和剂量(0.1-2gL-1)。结果表明,钍吸附动力学符合拟一级动力学模型,吸附反应是吸热的。在pH为3,吸附剂用量为0.5gL-1,温度为328K时,观察到对钍离子的最大实验吸附容量为138.84mgg-1。结果表明,AMPA-GO吸附剂可以使用7次,吸附容量变化可接受。在连续条件下,进料流量的影响(2-8mLmin-1),初始浓度(50-500mgL-1),和柱床高度(2-8厘米)进行了调查。使用Thomas分析了连续数据,Yoon-Nelson,和Bohart-Adams模特.色谱柱的实验数据与Thomas,和Yoon-Nelson模型.研究结果表明,使用功能化的氧化石墨烯吸附剂具有很大的去除水溶液中钍的能力。
    This article investigated the kinetic studies of thorium adsorption from an aqueous solution with graphene oxide functionalized with aminomethyl phosphonic acid (AMPA) as an adsorbent. First, the AMPA-GO adsorbent was characterized using TEM, XRD, and FTIR methods. Experiments were performed in two batch and continuous modes. In batch mode, adsorption kinetics were studied in different pH (1-4), temperature (298-328 K), initial concentration (50-500 mg L-1), and dosages (0.1-2 g L-1). The results showed that thorium adsorption kinetic follows pseudo-first-order kinetic model and that the adsorption reaction is endothermic. The maximum experimental adsorption capacity of thorium ions was observed 138.84 mg g-1 at a pH of 3, adsorbent dosage of 0.5 g L-1, and a temperature of 328 K. The results showed that AMPA-GO adsorbent can be used seven times with an acceptable change in adsorption capacity. In continuous conditions, the effect of feed flow rate (2-8 mL min-1), initial concentration (50-500 mg L-1), and column bed height (2-8 cm) was investigated. The continuous data was analyzed using the Thomas, Yoon-Nelson, and Bohart-Adams models. The experimental data of the column were well matched with the Thomas, and Yoon-Nelson models. The research results showed that the use of functionalized graphene oxide adsorbents has a great ability to remove thorium from aqueous solutions.
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  • 文章类型: Journal Article
    四甲基氢氧化铵(TMAH),这是一种用于电子工业的化学品,被归类为威胁水生生态系统和人类健康的有害物质(HAZMAT第8类)。因此,许多研究试图使用各种治疗方法去除TMAH,包括先进的氧化过程,如臭氧,UV,或者芬顿氧化。然而,先前的研究表明TMAH去除的动力学速率较低。在这种情况下,我们提出了通过将冷等离子体(CP)工艺与高碘酸盐氧化相结合来替代TMAH降解的方法。至于TMAH去除的动力学,动力学常数提高了5倍(对于40.56和2.2W,为0.1661和0.0301,分别),因为CP系统的电功率从2.2增加到40.56W。当同时使用4mM高碘酸盐时,40.56WCP系统的动力学常数比2WCP系统进一步增加了54倍(1.6250)。因此,集成CP/高碘酸盐系统的TMAH去除效率(29.5%)是2WCP系统(14.4%)的2倍。集成CP/高碘酸盐体系的这种优异的TMAH降解能力在pH10和25°C时变得明显。总的来说,综合CP/高碘酸盐系统有望成为有效控制有害TMAH化学品的可行管理选择。
    Tetramethylammonium hydroxide (TMAH), which is a chemical used in the electronic industry, is classified as a hazardous material (HAZMAT class 8) that threatens aquatic ecosystems and human health. Consequently, numerous studies have attempted to remove TMAH using various treatment methods, including advanced oxidation processes such as ozone, UV, or Fenton oxidation. However, prior research has indicated a low kinetic rate of TMAH removal. In this context, we proposed an alternative to TMAH degradation by combining a cold plasma (CP) process with periodate oxidation. As for the kinetics of TMAH removal, the kinetic constant was improved by 5 times (0.1661 and 0.0301 for 40.56 and 2.2 W, respectively) as the electric power of a CP system increased from 2.2 to 40.56 W. The kinetic constant of a 40.56 W CP system further increased by 54 times (1.6250) than a 2 W CP system when 4 mM periodate was used simultaneously. As a result, the integrated CP/periodate system represented 2 times higher TMAH removal efficiency (29.5%) than a 2 W CP system (14.4%). This excellent TMAH degradation capability of the integrated CP/periodate system became pronounced at pH 10 and 25 °C. Overall, the integrated CP/periodate system is expected to be a viable management option for effectively controlling hazardous TMAH chemicals.
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  • 文章类型: Journal Article
    将二氧化碳(CO2)催化转化为增值化学品至关重要,从稀薄大气中捕获二氧化碳的成本是巨大的挑战。一种有前途的策略是将吸附和转化一步结合起来,例如应用碱性溶液,可以选择性地减少碳酸盐(CO32-)作为CO2吸附的后果。由于这个系统的复杂性,控制氢化的机理细节尚未深入研究。在这里,以Ru/TiO2催化剂为探针,阐明了CO32-活化机理,其中通过热力学和动力学研究,建立了紧凑的Langmuir-Hinshelwood反应模型,该模型表明CO32-氢化的总体速率受HCOO-内特定的C-O键断裂基本步骤控制,Ru表面主要被CO32-或HCOO-覆盖在独立条件下。这一假设得到了可忽略的动力学同位素效应(kH/kD≈1)的进一步支持,CO32-和HCOO-氢化反应势垒的相似性(ΔH®hydr,Na2CO3和ΔH288hydr,HCOONa)和熵的非变化(ΔS288hydr≈0)。更有趣的是,溶液的碱度肯定像剑中的两面,可以促进CO2的吸附,同时在CO32-加氢过程中抑制催化。
    Catalytic conversion of carbon dioxide (CO2) into value-added chemicals is of pivotal importance, well the cost of capturing CO2 from dilute atmosphere is super challenge. One promising strategy is combining the adsorption and transformation at one step, such as applying alkali solution that could selectively reduce carbonate (CO32-) as consequences of CO2 adsorption. Due to complexity of this system, the mechanistic details on controlling the hydrogenation have not been investigated in depth. Herein, Ru/TiO2 catalyst was applied as a probe to elucidate the mechanism of CO32- activation, in which with thermodynamic and kinetic investigations, a compact Langmuir-Hinshelwood reaction model was established which suggests that the overall rate of CO32- hydrogenation was controlled by a specific C-O bond rupture elementary step within HCOO- and the Ru surface was mainly covered by CO32- or HCOO- at independent conditions. This assumption was further supported by negligible kinetic isotope effects (kH/kD ≈ 1), similarity on reaction barriers of CO32- and HCOO- hydrogenation (ΔH‡hydr,Na2CO3 and ΔH‡hydr,HCOONa) and a non-variation of entropy (ΔS‡hydr ≈ 0). More interestingly, the alkalinity of the solution is certainly like a two sides in a sword and could facilitate the adsorption of CO2 while hold back catalysis during CO32- hydrogenation.
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  • 文章类型: Journal Article
    这项研究探索了溶胀预处理作为解决与2,2,6,6-四甲基哌啶-1-氧基自由基(TEMPO)介导的氧化纳米纤维素制备过程相关的高成本和污染的解决方案的应用。结果表明,溶胀使纤维显著膨胀,同时保持纤维素的聚合度(DP)(约95%)。纤维素的天然晶体结构和氢键在溶胀后被破坏,导致结晶度和微晶尺寸的减小,以及分子间O6-H-O3含量的降低。使用连续的一级反应动力学模型成功地拟合了有或没有溶胀的纤维素纤维的TEMPO介导的氧化过程。拟合结果表明,溶胀显着降低了TEMPO介导的氧化活化能,并提高了反应速率。在三个膨胀系统中,NaOH/硫脲/水体系的促进作用最佳。因此,溶胀处理能够显著减少30%的催化剂剂量的TEMPO介导的氧化,同时保持竞争性的反应速率,产量,和产品性能。较低的催化剂用量有助于降低成本和对环境的影响,促进TEMPO介导的氧化过程的工业应用。
    This study explored the application of swelling pretreatment as a solution to the high cost and contamination associated with the process of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation for nanocellulose preparation. The results demonstrated that swelling significantly expanded the fibers while preserving the degree of polymerization (DP) of cellulose (approximately 95 %). The native crystal structure and hydrogen bonding of cellulose were disrupted after swelling, leading to a reduction in crystallinity and crystallite size, and the decrease of bonding energy and content of intermolecular O6-H⋯O3\'. The TEMPO-mediated oxidation processes of cellulose fibers with or without swelling were successfully fitted using a consecutive first-order reaction kinetic model. The fitting results indicated that swelling significantly reduced the activation energy of TEMPO-mediated oxidation and enhanced the reaction rate. Among three swelling systems, the NaOH/thiourea/water system exhibited the optimal promotion effect. Consequently, the swelling treatment enables a significant reduction of 30 % in the catalyst dose for the TEMPO-mediated oxidation while preserving a competitive reaction rate, yield, and product performance. Lower catalyst dosage helps to reduce cost and environmental impact, facilitating the industrial application of the TEMPO-mediated oxidation process.
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  • 文章类型: Journal Article
    四氢生物蝶呤,通过生物合成和人体自我再生获得的最关键的酶辅因子之一。在这个过程中,它经历氧化和去质子化,形成醌-二氢生物蝶呤,然后互变异构产生双氢生物蝶呤。本研究使用理论计算介绍了每个阶段的热力学和动力学性质。在隐式溶剂模型中使用Born-Haber循环确定氧化还原电位和pKa值。使用时间依赖性密度泛函理论从计算的吸收光谱表征氧化还原代谢物。互变异构步骤的速率常数是使用Eyring的过渡状态理论计算的,结合Wigner的隧道校正。N3原子被认为是H3B+最可能的去质子化位点。阐明了中间体的光谱特性,突出关键的电子转换。互变异构步骤通过振动弯曲模式发生,和隧道校正显着提高反应速率。这些发现为四氢生物蝶呤再生的热力学和动力学提供了全面的理解,帮助调节其生物活性。
    Tetrahydrobiopterin, one of the most crucial enzymatic cofactors acquired through biological synthesis and self-regeneration in the human body. During this process, it undergoes oxidation and deprotonation, forming quinonoid-dihydrobiopterin, which then tautomerizes to yield dihydrobiopterin. This study presents the thermodynamic and kinetic properties of each stage using theoretical calculations. Redox potentials and pKa values are determined using the Born-Haber cycle in implicit solvent models. Redox metabolites are characterized from calculated absorption spectra using time-dependent density functional theory. Rate constants for tautomerization steps are computed using Eyring\'s Transition State Theory, incorporating Wigner\'s tunneling correction. The N3 atom is identified as the most probable deprotonation site for H3B+. Spectral properties of intermediates are elucidated, highlighting key electronic transitions. Tautomerization steps occur through vibrational bending modes, and tunneling corrections significantly increase reaction rates. These findings provide a comprehensive understanding of the thermodynamics and kinetics of tetrahydrobiopterin regeneration, aiding in the modulation of its biological activity.
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  • 文章类型: Journal Article
    本研究旨在评价改性纳米零价铁(SAS-nZVI)对柠檬酸(CA)对铅镉复合污染土壤化学淋洗的影响。将合成的SAS-nZVI用作浸出助剂,以提高CA化学浸出对土壤重金属(HMs)的去除率。SAS-nZVI剂量等各种因素的影响,研究了洗脱温度和洗脱时间。同时,评价了化学淋洗对土壤基本理化性质和HMs形态的影响。结果表明,当SAS-nZVI投加量为2.0g/L时,浸出温度为25°C,浸出时间为720分钟,土壤中Pb和Cd的最大去除率分别为77.64%和97.15%。使用洗脱和解吸动力学模型(Elovich模型,双常数模型,扩散模型)。SAS-nZVI-CA对土壤中Pb和Cd的洗脱和解吸过程与双常数模型拟合较好,表明Pb和Cd的解吸动力学过程是非均相扩散过程,洗脱过程受扩散因素控制。用SAS-nZVI-CA浸出后,土壤的理化性质变化不大,HMs在土壤中的流动性和毒性降低,浸出废液中HMs含量降低。可以得出结论,SAS-nZVI提高了CA从土壤中提取Pb和Cd的效率,将化学浸出技术造成的土壤损害降至最低,并缓解了与处理浸出废液相关的挑战。
    This study aimed to evaluate the effect of modified nanoscale zero-valent iron (SAS-nZVI) on chemical leaching of lead and cadmium composite contaminated soil by citric acid (CA). The synthesized SAS-nZVI was used as a leaching aid to improve the removal rate of soil heavy metals (HMs) by CA chemical leaching. The effects of various factors such as SAS-nZVI dosage, elution temperature and elution time were studied. At the same time, the effect of chemical leaching on the basic physical and chemical properties of soil and the morphology of HMs was evaluated. The results show that when the SAS-nZVI dosage is 2.0 g/L, the leaching temperature is 25 °C, and the leaching time is 720 min, the maximum removal rates of Pb and Cd in the soil are 77.64% and 97.15% respectively. The experimental results were evaluated using elution and desorption kinetic models (Elovich model, double constant model, diffusion model). The elution and desorption process of Pb and Cd in soil by SAS-nZVI-CA fitted well with the double-constant model, indicating that the desorption kinetic process of Pb and Cd is a heterogeneous diffusion process, and the elution process is controlled by diffusion factors. After leaching with SAS-nZVI-CA, the physical and chemical properties of the soil changed little, the mobility and toxicity of HMs in the soil were reduced, and the HMs content in the leaching waste liquid was reduced. It can be concluded that SAS-nZVI enhances the efficiency of CA in extracting Pb and Cd from soil, minimizes soil damage resulting from chemical leaching technology, and alleviates the challenges associated with treating leaching waste liquid.
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  • 文章类型: Journal Article
    为了有效地利用红松种子鳞片的资源,一种林业废物,对提取的严格研究,净化,稳定性,并对来自这些种子鳞片的原花青素进行了自由基清除能力。动力学模型表明,在超声条件下,原花青素含量在0.5h内达到2.66mg/g。最佳储存参数包括黑暗,4°C,和pH4。混合物的聚合度以及高,低聚合物组分的聚合度分别为4.89,7.42和3.07,低聚合物组分表现出最高的自由基清除活性。通过HPLC-QE-MS/MS,1HNMR,和FT-IR分析,我们鉴定了原花青素B1,原花青素B2,(-)-表儿茶素,和聚合三聚体酯。红松原花青素具有较高的分子量,复杂的内部分子结构,和值得称赞的稳定性,结晶需要升高的温度。因此,来自红松种子鳞片的原花青素已成为非常有前途的新型天然抗氧化剂。
    To efficiently harness resources from Pinus koraiensis seed scales, a type of forestry waste, rigorous studies on the extraction, purification, stability, and free radical scavenging capacity of the proanthocyanidins derived from these seed scales were conducted. Kinetic models showed that under ultrasonic conditions, the proanthocyanidins content reached 2.66 mg/g within 0.5 h. The optimal storage parameters include darkness, 4 °C, and pH 4. The degrees of polymerization of the mixture and the high- and low-polymer components were 4.89, 7.42 and 3.07, respectively, with the low-polymer component exhibiting the highest radical scavenging activity. Through HPLC-QE-MS/MS, 1H NMR, and FT-IR analyses, we identified proanthocyanidin B1, proanthocyanidin B2, (-)-epicatechin, and polymeric trimer esters. The Pinus koraiensis proanthocyanidins exhibited a high molecular weight, a complex internal molecular structure, and commendable stability, with crystallization requiring elevated temperatures. Therefore, the proanthocyanidins from Pinus koraiensis seed scales have emerged as highly promising novel natural antioxidants.
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