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1.
Fiber production from inorganic industrial solid wastes is an effective waste management strategy. Because of cost considerations, most enterprises generally use local solid wastes as raw materials to produce fibers. In this study, we explored the feasibility of producing fibers using fly ash and magnesium slag. The results show that the melting temperature of the blends composed of fly ash, magnesium slag, and a small amount of calcined dolomite first decreased and then increased with an increase in acidity coefficient (Mk) from 1.0 to 2.4. The samples could form a eutectic system in the Mk range of 1.4–1.8, and therefore have a relatively low melting temperature in this Mk range. Fly ash could react with magnesium slag and calcined dolomite to form akermanite, gehlenite-magnesium, and anorthite at temperatures close to the melting temperature; therefore, these crystalline phases were the main reaction products formed in the samples with Mk values lower than 1.80. Anorthite reacted further with some Na-containing and Si-containing spieces to produce labradorite. Thus, the content of anorthite and labradorite rapidly increased and they became the major crystal phases in the blend samples with Mk values greater than 1.80. MAS-NMR spectroscopic analysis revealed that the network structure of the melts depended on the ratio of bridging oxygen to non-bridging oxygen; a high ratio of bridging oxygen to non-bridging oxygen could lead to the formation of a dense network structure in the melt. The blends of fly ash and magnesium slag can be used to produce wool fibers and continuous fibers. In addition, the suitable temperature ranges for the production of both types of fibers were determined. The drawing temperature for continuous fiber production depended on the degree of polymerization and structure of the melt. 相似文献
2.
Peter K. Windsor Stephen P. Plassmeyer Dominic S. Mattock Jonathan C. Bradfield Erika Y. Choi Bill R. Miller III Byung Hee Han 《International journal of molecular sciences》2021,22(6)
Deposition of amyloid β (Aβ) fibrils in the brain is a key pathologic hallmark of Alzheimer’s disease. A class of polyphenolic biflavonoids is known to have anti-amyloidogenic effects by inhibiting aggregation of Aβ and promoting disaggregation of Aβ fibrils. In the present study, we further sought to investigate the structural basis of the Aβ disaggregating activity of biflavonoids and their interactions at the atomic level. A thioflavin T (ThT) fluorescence assay revealed that amentoflavone-type biflavonoids promote disaggregation of Aβ fibrils with varying potency due to specific structural differences. The computational analysis herein provides the first atomistic details for the mechanism of Aβ disaggregation by biflavonoids. Molecular docking analysis showed that biflavonoids preferentially bind to the aromatic-rich, partially ordered N-termini of Aβ fibril via the π–π interactions. Moreover, docking scores correlate well with the ThT EC50 values. Molecular dynamic simulations revealed that biflavonoids decrease the content of β-sheet in Aβ fibril in a structure-dependent manner. Hydrogen bond analysis further supported that the substitution of hydroxyl groups capable of hydrogen bond formation at two positions on the biflavonoid scaffold leads to significantly disaggregation of Aβ fibrils. Taken together, our data indicate that biflavonoids promote disaggregation of Aβ fibrils due to their ability to disrupt the fibril structure, suggesting biflavonoids as a lead class of compounds to develop a therapeutic agent for Alzheimer’s disease. 相似文献
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4.
为解决系统模型误差、外部干扰以及执行器故障引起的双星编队轨道控制精度低、稳定性差问题,设计一种基于观测器的抗干扰容错线性二次型调节器(LQR)控制策略。首先,根据编队双星相对运动动力学模型,设计基于双比例积分自适应律的增广观测器,同时实现对系统状态、间歇故障与快速时变故障、可建模干扰的快速精确估计,并采用H∞优化技术抑制不可建模干扰对控制系统的影响。其次,采用Lyapunov稳定性理论,保证动态误差系统渐近稳定。然后,在控制器中引入未知动态估计信息的前馈补偿项,设计闭环反馈抗干扰容错LQR控制律。最后实验结果表明,相比文献中控制方法,本文所提方法的编队卫星相对位置控制精度提高49.93%,验证了所设计的抗干扰容错LQR控制律的优越性,能够为双星编队构形保持提供精确控制策略。 相似文献
5.
针对频域法构造小波滤波器方法较少、稳定性无法保证、逼近精度不高等问题,基于天牛须搜索算法提出了一种小波滤波器直接频域逼近方法。首先根据小波滤波器电路的基本要求设计逼近有理式,然后加入电路实现所需的稳定性、正实性和初值为零的约束条件,建立小波滤波器逼近的频域优化模型。再以高斯小波和Marr小波为例,使用天牛须搜索算法求解频域逼近的数学模型得到滤波器有理式参数。在时域和频域上分别将该方法和其他频域方法进行对比,仿真和计算结果表明在相同条件下,频域逼近法具有更优的效果,五阶高斯小波和七阶Marr小波的逼近均方误差仅为3.446 8×10~(-4)和7.346 2×10~(-4)。 相似文献
6.
Eugene Metakovsky Laura Pascual Patrizia Vaccino Viktor Melnik Marta Rodriguez-Quijano Yulia Popovych Sabina Chebotar William John Rogers 《International journal of molecular sciences》2021,22(4)
The Gli-B1-encoded γ-gliadins and non-coding γ-gliadin DNA sequences for 15 different alleles of common wheat have been compared using seven tests: electrophoretic mobility (EM) and molecular weight (MW) of the encoded major γ-gliadin, restriction fragment length polymorphism patterns (RFLPs) (three different markers), Gli-B1-γ-gliadin-pseudogene known SNP markers (Single nucleotide polymorphisms) and sequencing the pseudogene GAG56B. It was discovered that encoded γ-gliadins, with contrasting EM, had similar MWs. However, seven allelic variants (designated from I to VII) differed among them in the other six tests: I (alleles Gli-B1i, k, m, o), II (Gli-B1n, q, s), III (Gli-B1b), IV (Gli-B1e, f, g), V (Gli-B1h), VI (Gli-B1d) and VII (Gli-B1a). Allele Gli-B1c (variant VIII) was identical to the alleles from group IV in four of the tests. Some tests might show a fine difference between alleles belonging to the same variant. Our results attest in favor of the independent origin of at least seven variants at the Gli-B1 locus that might originate from deeply diverged genotypes of the donor(s) of the B genome in hexaploid wheat and therefore might be called “heteroallelic”. The donor’s particularities at the Gli-B1 locus might be conserved since that time and decisively contribute to the current high genetic diversity of common wheat. 相似文献
7.
Md Saifur Rahman Md Badrul Alam Young Kyun Kim Mst Hur Madina Ismail Fliss Sang Han Lee Jin Cheol Yoo 《International journal of molecular sciences》2021,22(10)
In this study, we investigate the immunomodulatory effects of a novel antimicrobial peptide, YD1, isolated from Kimchi, in both in vitro and in vivo models. We establish that YD1 exerts its anti-inflammatory effects via up-regulation of the Nrf2 pathway, resulting in the production of HO-1, which suppresses activation of the NF-κB pathway, including the subsequent proinflammatory cytokines IL-1β, IL-6, and TNF-α. We also found that YD1 robustly suppresses nitric oxide (NO) and prostaglandin E2 (PGE2) production by down-regulating the expression of the upstream genes, iNOS and COX-2, acting as a strong antioxidant. Collectively, YD1 exhibits vigorous anti-inflammatory and antioxidant activity, presenting it as an interesting potential therapeutic agent. 相似文献
8.
Kyunghee Kim Jisue Kim Hyoungseob Kim Gun Yong Sung 《International journal of molecular sciences》2021,22(4)
Owing to the prohibition of cosmetic animal testing, various attempts have recently been made using skin-on-a-chip (SOC) technology as a replacement for animal testing. Previously, we reported the development of a pumpless SOC capable of drug testing with a simple drive using the principle that the medium flows along the channel by gravity when the chip is tilted using a microfluidic channel. In this study, using pumpless SOC, instead of drug testing at the single-cell level, we evaluated the efficacy of α-lipoic acid (ALA), which is known as an anti-aging substance in skin equivalents, for skin tissue and epidermal structure formation. The expression of proteins and changes in genotyping were compared and evaluated. Hematoxylin and eosin staining for histological analysis showed a difference in the activity of fibroblasts in the dermis layer with respect to the presence or absence of ALA. We observed that the epidermis layer became increasingly prominent as the culture period was extended by treatment with 10 μM ALA. The expression of epidermal structural proteins of filaggrin, involucrin, keratin 10, and collagen IV increased because of the effect of ALA. Changes in the epidermis layer were noticeable after the ALA treatment. As a result of aging, damage to the skin-barrier function and structural integrity is reduced, indicating that ALA has an anti-aging effect. We performed a gene analysis of filaggrin, involucrin, keratin 10, integrin, and collagen I genes in ALA-treated human skin equivalents, which indicated an increase in filaggrin gene expression after ALA treatment. These results indicate that pumpless SOC can be used as an in vitro skin model similar to human skin, protein and gene expression can be analyzed, and it can be used for functional drug tests of cosmetic materials in the future. This technology is expected to contribute to the development of skin disease models. 相似文献
9.
研究了一种生态多孔纤维棉(EPFC)的生物挂膜性能,并将其应用于脱氮反应器中,考察不同DO水平与装置设计(填充率、孔密度)对脱氮效果的影响。结果表明,EPFC是一种良好的生物挂膜材料。DO含量对反应器脱氮效果影响显著,在ρ(DO)=10~11 mg/L、HRT=5 d时NH4+-N去除率最高97.41%;TN去除率在ρ(DO)=9~10 mg/L、HRT=4 d时最高45.52%。对装置设计进行优化后,发现反应器BR5脱氮效果最好,其填料填充率为2/3、孔密度为5.2个/cm2;优化运行条件为ρ(DO)=9~10 mg/L、HRT=5 d,NH4+-N与TN去除率分别可达98.59%和59.93%。可为EPFC进一步应用于生物脱氮工艺如生物接触氧化法、序批式活性污泥法工艺等提供思路。 相似文献
10.
新疆准噶尔盆地南缘高探1井于白垩系清水河组测试获日产原油1213 m3/d、天然气32.17×104m3,创整个盆地单井日产量最高纪录,充分证实了南缘油气勘探潜力巨大[1]。为此,2019年,新疆油田在南缘共部署了875 km2三维地震采集项目,采用了井震联合采集技术、井炮源驱动技术、有线仪器+无线节点+有线连续采集技术、宽频单点接收技术、光纤表层调查技术等,高效、高质量完成了野外地震采集,地震资料品质得到了较好的提高,初步形成了适合南缘山前带的地震采集技术,为南缘山前带油气勘探和和下一步增储建产储备了相关的配套技术,该技术也可为国内其它探区山前带地震采集提供借鉴。 相似文献