kinetic model

动力学模型
  • 文章类型: Journal Article
    在本文中,Ce和Pd掺杂对污染物的去除效果和活化能(CO,C3H6和NO)通过使用表征方法和构建的动力学方程进行了比较分析。此外,还讨论了水对NSR工艺的影响机理。结果表明:(1)与Ce掺杂相比,Pd掺杂有效地提高了催化剂低温段(150-250°C)中CO(80%)和C3H6(71%)的去除,而Ce掺杂表现出优异的NO低温转化率。(2)LaKMnPdO3催化剂的反应活化能为9784kJ/mol,显著低于LaKMnCeO3催化剂。(3)H2O的存在对LaKMnPdO3催化剂对NOx的储存性能具有重要的增强作用,但降低了NO的催化还原。它为有效处理日益严重的颗粒物和臭氧污染问题提供了解决方案。
    In this paper, the removal effects and activation energy of Ce and Pd doping on pollutants (CO, C3H6, and NO) were comparatively analyzed by using characterization methods and constructed kinetic equations. Furthermore, the problems of the water influence mechanism on the NSR process were also discussed. The results show the following: (1) Pd doping effectively improves the removal of CO (80%) and C3H6 (71%) in the low-temperature section of the catalyst (150-250 °C) compared to Ce doping, while Ce doping exhibits excellent low-temperature conversion of NO. (2) The reaction activation energy of the LaKMnPdO3 catalyst was 9784 kJ/mol, which was significantly lower than that of the LaKMnCeO3 catalyst. (3) The presence of H2O has an important enhancement effect in the storage performance of the LaKMnPdO3 catalyst for NOx but decreases the catalytic reduction of NO. It provides a solution for the effective treatment of the increasing problems of particulate matter and ozone pollution.
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  • 文章类型: Journal Article
    鲜切萝卜在储存过程中易受品质损失和微生物污染,导致保质期短。这项研究调查了光动力技术(PDT)对在4°C下储存10d的鲜切萝卜的影响,并开发了适当的模型来预测保质期。结果表明,姜黄素介导的PDT维持感官可接受性,颜色,和坚定,体重减轻,通过使多酚氧化酶和过氧化物酶失活来增加样品的抗坏血酸和总酚,从而提高抗氧化能力和质量。PDT后样品中的总细菌计数显著(p<0.05)减少了2.01logCFUg-1,并且与对照相比,它们的保质期延长了6天。为了准确预测保质期,建立了基于微生物生长的动力学模型,在减肥的同时,b*值,坚定,通过相关性分析,选择抗坏血酸作为开发基于质量的预测模型的代表性属性。建模结果表明,基于抗坏血酸的预测模型最适合PDT处理的样品,而基于细菌生长的改进的Gompertz模型对于对照和次氯酸钠处理的样品是最好的。这项研究表明,PDT有望延长鲜切萝卜的保质期,用关键指标建立预测模型可以提供更可靠的货架期估计。
    Fresh-cut radishes are susceptible to quality loss and microbial contamination during storage, resulting in a short shelf life. This study investigated the effects of photodynamic technology (PDT) on fresh-cut radishes stored at 4 °C for 10 d and developed appropriate models to predict the shelf life. Results showed that curcumin-mediated PDT maintained sensory acceptability, color, and firmness, decreased weight loss, and increased ascorbic acid and total phenolics of samples by inactivating polyphenol oxidase and peroxidase, resulting in improved antioxidant capacity and quality. The total bacteria count in samples was significantly (p < 0.05) reduced by 2.01 log CFU g-1 after PDT and their shelf life was extended by 6 d compared to the control. To accurately predict the shelf life, the kinetic models based on microbial growth were established, while weight loss, b* value, firmness, and ascorbic acid were selected as representative attributes for developing quality-based prediction models through correlation analysis. Modeling results showed prediction models based on ascorbic acid best fitted PDT-treated samples, while the modified Gompertz model based on bacteria growth was the best for control and samples treated by sodium hypochlorite. This study suggests that PDT is promising in extending the shelf life of fresh-cut radishes, and using critical indexes to establish the prediction model can provide a more reliable shelf-life estimation.
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  • 文章类型: Journal Article
    厌氧氨氧化反应同时利用氨和亚硝酸盐作为底物;然而,高亚硝酸盐浓度作为反应的强抑制剂。在这项研究中,在使用不同生物质载体的连续饲喂试验中,分别评估了NO2-和游离亚硝酸(FNA)的抑制作用。在pH7.6下,进水NO2浓度增加,其中FNA不太可能影响anammox活性。使用含有固定化厌氧氨氧化菌的聚乙二醇(PEG)凝胶载体进行的连续测试表明,当反应器中NO2--N浓度为350mgL-1(FNA≤0.06mgL-1)时,抑制率为13%。反应器中NO2-浓度与抑制率呈线性增加关系。通过在容易形成FNA的pH6.4下增加进水NO2-浓度来评估FNA的抑制作用,证明FNA与抑制率之间的关系可以拟合为S形曲线,FNA的50%抑制浓度(IC50)为0.88mgL-1。使用表面含有厌氧氨氧化细菌的聚乙烯醇载体进行的类似测试显示出与PEG凝胶载体相同的趋势,FNA的IC50为0.70mgL-1。这些结果表明,FNA对anammox活性的抑制作用大于NO2-。对这两个因素的评估有助于确定稳定应用厌氧氨氧化工艺的重要操作指标。
    The anammox reaction simultaneously utilizes ammonia and nitrite as substrates; however, high nitrite concentrations act as strong inhibitors of the reaction. In this study, inhibition by NO2- and free nitrous acid (FNA) was separately evaluated in continuous feeding tests using different biomass carriers. The influent NO2- concentration was increased under pH 7.6, where FNA is less likely to affect anammox activity. A continuous test using polyethylene glycol (PEG) gel carriers containing immobilized anammox bacteria showed that the inhibition ratio was 13% when the NO2--N concentration in the reactor was 350 mg L-1 (FNA ≤0.06 mg L-1). The relationship between NO2- concentration in the reactor and inhibition ratio increased linearly. Evaluation of the inhibitory effect of FNA by increasing the influent NO2- concentration at pH 6.4, where FNA is easily formed, demonstrated that the relationship between FNA and inhibition ratio could be fitted to a sigmoid curve, and the 50% inhibitory concentration (IC50) of FNA was 0.88 mg L-1. A similar test performed using polyvinyl alcohol carriers containing anammox bacteria on their surface showed the same trend as the PEG gel carriers, with the IC50 for FNA at 0.70 mg L-1. These results indicate that the inhibitory effect of FNA on anammox activity was greater than that of NO2-. The evaluation of these two factors helped identify important operational indicators of the stable application of anammox processes.
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  • 文章类型: Journal Article
    缀合反应是抗体-药物缀合物(ADC)制造过程中的中心步骤。取决于所选择的缀合化学,该反应产生不同缀合的亚物种的异质和复杂混合物。通过机械动力学模型对缀合反应的参数化提供了增强有价值的反应知识并确保过程稳健性的机会。这项研究为半胱氨酸缀合的ADC模态位点特异性和链间二硫键缀合的缀合反应引入了通用的建模框架。进行了涉及不同马来酰亚胺官能化有效载荷的各种共轭动力学,而受控的渐进有效载荷进料被用来减缓共轭,便于对反应机理进行更详细的研究。用还原反相(RP)色谱法分析动力学数据,这可以很容易地实现对具有不同药物与抗体比率的ADC的准确表征,提供单克隆抗体(mAb)的单链的缀合轨迹。然后基于多个标准开发和选择缀合机制的可能动力学模型。当将建立的模型校准到涉及不同有效载荷的动力学时,缀合率被确定为有效载荷特异性的。还可以得出关于两种模式的动力学可比性的进一步结论。一个校准模型用于初始浓度的示例性计算机筛选,为深入理解ADC开发中的缀合过程提供有价值的见解。
    The conjugation reaction is the central step in the manufacturing process of antibody-drug conjugates (ADCs). This reaction generates a heterogeneous and complex mixture of differently conjugated sub-species depending on the chosen conjugation chemistry. The parametrization of the conjugation reaction through mechanistic kinetic models offers a chance to enhance valuable reaction knowledge and ensure process robustness. This study introduces a versatile modeling framework for the conjugation reaction of cysteine-conjugated ADC modalities-site-specific and interchain disulfide conjugation. Various conjugation kinetics involving different maleimide-functionalized payloads were performed, while controlled gradual payload feeding was employed to decelerate the conjugation, facilitating a more detailed investigation of the reaction mechanism. The kinetic data were analyzed with a reducing reversed phase (RP) chromatography method, that can readily be implemented for the accurate characterization of ADCs with diverse drug-to-antibody ratios, providing the conjugation trajectories of the single chains of the monoclonal antibody (mAb). Possible kinetic models for the conjugation mechanism were then developed and selected based on multiple criteria. When calibrating the established model to kinetics involving different payloads, conjugation rates were determined to be payload-specific. Further conclusions regarding the kinetic comparability across the two modalities could also be derived. One calibrated model was used for an exemplary in silico screening of the initial concentrations offering valuable insights for profound understanding of the conjugation process in ADC development.
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  • 文章类型: Journal Article
    最近对极化子的兴趣激增,引发了有关暗态在强光物质耦合现象中的作用的基本问题。这里,我们通过控制限制在Fabry-Pérot腔中的堆叠的CdSe纳米片的数量来系统地改变暗态的相对数量。我们发现发射光谱随着纳米片数量的增加而显著变化,主要发射强度从较低的极化子分支逐渐移动到多种暗态。通过基于动力学模型的伴随计算,这种转变是通过暗态流形对激发的熵捕获而合理化的,而由于局部无序而导致的弱暗态色散解释了它们的非零发射。我们的结果指出了暗态浓度与腔嵌入量子发射器的光学和动力学性质的相关性,具有玻色-爱因斯坦凝聚物形成的分支,极化子激射,基于极化子的量子转导方案,和极化子化学。
    The recent surge of interest in polaritons has prompted fundamental questions about the role of dark states in strong light-matter coupling phenomena. Here, we systematically vary the relative number of dark states by controlling the number of stacked CdSe nanoplatelets confined in a Fabry-Pérot cavity. We find the emission spectrum to change significantly with an increasing number of nanoplatelets, with a gradual shift of the dominant emission intensity from the lower polariton branch to a manifold of dark states. Through accompanying calculations based on a kinetic model, this shift is rationalized by an entropic trapping of excitations by the dark state manifold, while a weak dark state dispersion due to local disorder explains their nonzero emission. Our results point toward the relevance of the dark state concentration to the optical and dynamical properties of cavity-embedded quantum emitters with ramifications for Bose-Einstein condensate formation, polariton lasing, polariton-based quantum transduction schemes, and polariton chemistry.
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  • 文章类型: Journal Article
    过氧化物和高价金属的协同作用在废水处理中引起了越来越多的关注。然而,过氧化物如何与活性金属物种相互作用以增强反应性仍不清楚。在这里,我们报道了过乙酸(PAA)和高锰酸盐(VII)对微污染物的协同氧化,并重新审视潜在的机制。与单独的Mn(VII)相比,PAA-Mn(VII)系统对磺胺甲恶唑(SMX)的降解效率显着提高了28倍。广泛的淬火实验和电子自旋共振(ESR)分析揭示了PAA-Mn(VII)系统中超出Mn(III)的意外Mn(V)和Mn(VI)的产生。Mn中间体的利用效率使用2,2'-偶氮-双(3-乙基苯并噻唑啉)-6-磺酸盐(ABTS)进行量化,结果表明,PAA可以提高活性锰(Mn)物种的电子转移效率,从而加速了微污染物的降解。密度泛函理论(DFT)计算表明,Mn中间体可以与低能隙的PAA的O1配位,提高Mn中间体的氧化能力和稳定性。建立了基于第一性原理的动力学模型来模拟PAA-Mn配合物的时间依赖性浓度曲线,并量化了PAA-Mn(III)配合物(50.8至59.3%)和PAA-Mn(Ⅴ/Ⅵ)配合物(40.7至49.2%)的贡献。PAA-Mn(VII)系统可以抵抗复杂基质成分的干扰(例如,氯化物和腐殖酸),导致实际废水的高效率。这项工作为PAA与反应性锰物种的相互作用提供了新的见解,以加速微污染物的氧化,有利于其在废水处理中的应用。
    Synergistic actions of peroxides and high-valent metals have garnered increasing attentions in wastewater treatment. However, how peroxides interact with the reactive metal species to enhance the reactivity remains unclear. Herein, we report the synergistic oxidation of peracetic acid (PAA) and permanganate(Ⅶ) towards micropollutants, and revisit the underlying mechanism. The PAA-Mn(VII) system showed remarkable efficiency with a 28-fold enhancement on sulfamethoxazole (SMX) degradation compared to Mn(Ⅶ) alone. Extensive quenching experiments and electron spin resonance (ESR) analysis revealed the generation of unexpected Mn(V) and Mn(VI) beyond Mn(III) in the PAA-Mn(VII) system. The utilization efficiency of Mn intermediates was quantified using 2,2\'-azino-bis(3-ethylbenzothiazoline)-6-sulfonate (ABTS), and the results indicated that PAA could enhance the electron transfer efficiency of reactive manganese (Mn) species, thus accelerating the micropollutant degradation. Density functional theory (DFT) calculations showed that Mn intermediates could coordinate to the O1 of PAA with a low energy gap, enhancing the oxidation capacity and stability of Mn intermediates. A kinetic model based on first principles was established to simulate the time-dependent concentration profiles of the PAA-Mn complexes and quantify the contributions of the PAA-Mn(III) complex (50.8 to 59.3 %) and the PAA-Mn(Ⅴ/Ⅵ) complex (40.7 to 49.2 %). The PAA-Mn(VII) system was resistant to the interference from complex matrix components (e.g., chloride and humic acid), leading to the high efficiency in real wastewater. This work provides new insights into the interaction of PAA with reactive manganese species for accelerated oxidation of micropollutants, facilitating its application in wastewater treatment.
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  • 文章类型: Journal Article
    氯化乙烯(CEs)污染的地下水的生物修复在实际修复项目中引起了越来越多的关注。然而,在底物和环境因素的约束下,微生物代谢过程的建模是不充分的。这项研究开发了一种新的动力学模型,其中结合了逻辑模型和Dual-Monod动力学,以表示受控制的微生物生长与CE污染的地下水中生物可利用的底物之间的相互作用。所提出的模型是基于离散的观察,以模拟在基质和环境条件的约束下的微生物生长,减少模型所需的观测数据量。同时,提出的模型引入了两个新的动力学参数,微生物生长的有效比生长速率和实际自限系数,简化了独立参数的数量。还开发了一种基于拟牛顿算法的参数估计方法。基于假设数据对模型进行了验证,实验结果,和发布的数据集,证明了地下水系统中微生物生长和PCE顺序生物降解的成功模拟(*E<0.3)。监测持续时间和采样时间表对估计生物参数有重大影响,当来自极低底物浓度或微生物生长下降时期的数据参与参数估计时,会引起很大的误差。研究表明,所提出的动力学模型提供了一个新的见解来表达微生物种群生长的局限性,由于可用的底物和环境因素,并希望在受CE污染的实际场所中应用。
    The bioremediation of chlorinated ethenes (CEs) contaminated groundwater is attracting increasingly attention in practical remediation projects. However, modelling of microbial metabolic processes under the constraints of substrate and environmental factors is inadequate. This study developed a new kinetic model, which incorporated the logistic model and Dual-Monod kinetic to represent the interaction between the controlled microbial growth and the bioavailable substrates in CE-contaminated groundwater. The proposed model was based on discrete observations to simulate microbial growth under the constraints of substrate and environmental conditions, reducing the amount of observational data required for the model. Meanwhile, the proposed model introduced two new kinetic parameters, the effective specific growth rate μeff and the real self-limiting coefficient of microbial growth keff,sl, to simplified the number of independent parameters. A parameter estimation method based on the quasi-Newton\'s algorithm for the proposed model was also developed. The model was validated based on the hypothetical data, experimental results, and a published dataset, demonstrated the successful simulation of microbial growth and the sequential biodegradation of PCE in groundwater systems (*E < 0.3). The monitoring duration and the sampling schedule have significant impacts on estimating the biological parameters, and large errors would be induced when the data from the periods of extremely low substrate concentration or microbial growth decline were involved in parameter estimation. The research suggested that the proposed kinetic model provided a new insight to express the limitation of microbial population growth due to the available substrates and environmental factors, and is hoping to be applied in actual CE-contaminated sites.
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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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  • 文章类型: Journal Article
    电力变压器的寿命,主要由其固体绝缘的条件决定,当矿物油是这些机器中的冷却剂时,在各种操作条件下是众所周知的。然而,有一种趋势是用可生物降解的液体代替这种油,尤其是酯类;因此,了解固体绝缘与这些流体的老化是至关重要的。目前可用的数据不允许在市场上可获得的酯中选择最佳酯,因为每一项研究都适用不同的条件,无法比较结果。因此,本文分析了以下五种最有前途的商业酯对牛皮纸和热升级牛皮纸的降解:向日葵,油菜籽,大豆,棕榈,和合成。材料在130、150和170°C下进行加速热老化,并通过其聚合度和降解动力学模型的获得来评估论文的完整性。在这项工作中研究了广泛的材料,接受了相同的治疗,允许比较酯,揭示了替代流体影响的显著差异。向日葵,油菜籽,大豆酯提供了最好的纸张保护,即,在150°C的测试中,牛皮纸的聚合度用这些液体降低了71%,与矿物油减少83%相比,用棕榈酯减少79%,和75%的减少与合成酯。此外,获得了不同的动力学模型来预测降解;结论是Emsley模型提供了最佳拟合。此外,发现一种类型的纸张的介电流体的行为不能外推,这只在广泛的研究中值得注意。
    The lifespan of an electrical transformer, primarily determined by the condition of its solid insulation, is well known under various operating conditions when mineral oil is the coolant in these machines. However, there is a trend toward replacing this oil with biodegradable fluids, especially esters; therefore, an understanding of the ageing of solid insulation with these fluids is essential. Currently available data do not allow for the selection of the best ester among those available on the market, as each study applies different conditions, making it impossible to compare results. Thus, this paper analyses the degradation of Kraft and Thermally Upgraded Kraft papers with the following five most promising commercial esters: sunflower, rapeseed, soybean, palm, and synthetic. The materials underwent accelerated thermal ageing at 130, 150, and 170 °C, and the integrity of the papers was evaluated through their polymerisation degree and the obtaining of the degradation kinetic models. The wide range of materials studied in this work, which were subjected to the same treatments, allows for a comparison of the esters, revealing significant differences in the impact of the alternative fluids. Sunflower, rapeseed, and soybean esters provided the best paper protection, i.e., the degree of polymerisation of Kraft paper in the tests at 150 °C decreased by 71% with these fluids, compared to the 83% reduction with mineral oil, 79% reduction with palm ester, and 75% reduction with synthetic ester. Furthermore, different kinetic models were obtained to predict the degradation; it was concluded that the Emsley model provides the best fit. Additionally, it was found that the behaviour of a dielectric fluid with one type of paper cannot be extrapolated, which is only noticeable in broad-scope studies.
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  • 文章类型: Journal Article
    了解纳米颗粒(NPs)穿过细胞质膜后的降解在药物递送设计和细胞毒性评估中至关重要。然而,由于缺乏定量模型,控制可降解动力学的关键因素仍不清楚。在这项研究中,银纳米粒子(AgNPs)的亚细胞成像用于确定AgNPs的细胞内转移,单粒子ICP-MS用于跟踪降解过程。随后开发了细胞动力学模型来描述摄取,转让,和AgNPs的降解行为。我们的模型表明,AgNPs的细胞内降解效率远高于通过模拟测试确定的效率,NPs的降解受细胞因子的影响很大。具体来说,Ca或Zn的缺乏主要降低了NPs的动力学溶解,而钙缺乏也导致NP转移的延迟。强烈揭示了这些动力学参数的生物学意义。我们的模型表明,大多数内化的AgNPs溶解,产生的离子被迅速净化。Ag离子的释放在很大程度上取决于微泡介导的途径。通过改变AgNPs的涂层和尺寸,模型结果表明,尺寸影响了NPs向降解过程的转移,而涂层影响降解动力学。总的来说,我们开发的模型为理解和预测NPs的物理化学性质和周围环境对纳米毒性和治疗效果的影响提供了有价值的工具.
    Understanding the degradation of nanoparticles (NPs) after crossing the cell plasma membrane is crucial in drug delivery designs and cytotoxicity assessment. However, the key factors controlling the degradable kinetics remain unclear due to the absence of a quantification model. In this study, subcellular imaging of silver nanoparticles (AgNPs) was used to determine the intracellular transfer of AgNPs, and single particle ICP-MS was utilized to track the degradation process. A cellular kinetic model was subsequently developed to describe the uptake, transfer, and degradation behaviors of AgNPs. Our model demonstrated that the intracellular degradation efficiency of AgNPs was much higher than that determined by mimicking testing, and the degradation of NPs was highly influenced by cellular factors. Specifically, deficiencies in Ca or Zn primarily decreased the kinetic dissolution of NPs, while a Ca deficiency also resulted in the retardation of NP transfer. The biological significance of these kinetic parameters was strongly revealed. Our model indicated that the majority of internalized AgNPs dissolved, with the resulting ions being rapidly depurated. The release of Ag ions was largely dependent on the microvesicle-mediated route. By changing the coating and size of AgNPs, the model results suggested that size influenced the transfer of NPs into the degradation process, whereas coating affected the degradation kinetics. Overall, our developed model provides a valuable tool for understanding and predicting the impacts of the physicochemical properties of NPs and the ambient environment on nanotoxicity and therapeutic efficacy.
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