Si

骨坏死
  • 文章类型: Journal Article
    由于它的许多好处,包括高比容量,低压高原,和丰富的供应,硅基阳极材料是取代石墨阳极的有力竞争者。然而,硅具有导电性差等缺点,在放电过程中突然的体积变化,和固体电解质界面(SEI)膜在循环过程中的持续增长,这将导致电极容量迅速下降。用碳或金属氧化物涂覆硅的外部是解决上述问题的流行方法。鉴于上述内容,在这项工作中使用了液相方法和静电纺丝技术来创建Si@MnO@CNFs双层涂覆的硅基阳极材料。因为经过深思熟虑的设计,MnO和C两侧包覆硅纳米颗粒,显著降低其在循环过程中的体积效应。此外,氧化锰具有出色的电化学动力学和出色的理论容量。碳纳米纤维\'最外层增加材料的导电性和稳定复合材料的结构,减少音量效应。在2Ag-1下进行1100次循环后,本工作中制备的复合负极材料仍能保持994.4mAhg-1的高容量。这项研究提供了一种不寻常的硅和MnO组合,这可能为硅基复合材料在锂离子电池中的应用开辟了道路。
    Due to its many benefits, including high specific capacity, low voltage plateau, and plentiful supplies, silicon-based anode materials are a strong contender to replace graphite anodes. However, silicon has drawbacks such as poor electrical conductivity, abrupt volume changes during the discharge process, and continuous growth of the solid electrolyte interfacial (SEI) film during cycling, which would cause the electrode capacity to degrade quickly. Coating the silicon\'s exterior with carbon or metal oxide is a popular method to resolve the above-mentioned problems. In light of those above, the liquid-phase approach and electrostatic spinning technique were used in this work to create Si@MnO@CNFs bilayer-coated silicon-based anode materials. Because of the well-thought-out design, MnO and C bilaterally coat the silicon nanoparticles, significantly reducing their volume effect during cycling. Furthermore, manganese oxide has outstanding electrochemical kinetics and an excellent theoretical capacity. The carbon nanofibers\' outermost layer increases the material\'s conductivity and stabilizes the composite material\'s structure, reducing the volume effect. After 1100 cycles at 2 A g-1, the composite anode material prepared in this work can still maintain a high capacity of 994.4 mAh g-1. This study offers an unusual combination of silicon and MnO that might set the way for the application of silicon-based composites in lithium-ion batteries.
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  • 文章类型: Journal Article
    镉污染严重威胁着食品安全和人类健康。最大限度地减少植物对Cd的吸收和增强植物对Cd的耐受性对于提高作物产量和减少对人类的危害至关重要。在这项研究中,我们设计了三种Cd浓度胁迫处理(Cd1:0.20mg·kg-1,Cd2:0.60mg·kg-1和Cd3:1.60mg·kg-1)和两种叶面硅(Si)处理(CK:不喷涂任何材料,和Si:叶面Si喷施)进行土壤Cd胁迫的盆栽实验。结果表明,喷施Si可使糙米中Cd含量降低4.79~42.14%。施硅使净光合速率(Pn)提高1.77-4.08%,气孔导度(Gs)5.27-23.43%,蒸腾速率(Tr)为2.99-20.50%,胞间二氧化碳(CO2)浓度(Ci)为6.55-8.84%。叶面喷施Si可显著提高水稻叶片中超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性,分别提高9.84-14.09%和4.69-53.09%,分别,丙二醛(MDA)含量降低7.83-48.72%。总之,叶面喷施硅保护水稻冠层叶片的光合作用和抗氧化系统,是降低糙米中Cd含量的有效方法。
    Cadmium (Cd) pollution is a serious threat to food safety and human health. Minimizing Cd uptake and enhancing Cd tolerance in plants are vital to improve crop yield and reduce hazardous effects to humans. In this study, we designed three Cd concentration stress treatments (Cd1: 0.20 mg·kg-1, Cd2: 0.60 mg·kg-1, and Cd3: 1.60 mg·kg-1) and two foliar silicon (Si) treatments (CK: no spraying of any material, and Si: foliar Si spraying) to conduct pot experiments on soil Cd stress. The results showed that spraying Si on the leaves reduced the Cd content in brown rice by 4.79-42.14%. Si application increased net photosynthetic rate (Pn) by 1.77-4.08%, stomatal conductance (Gs) by 5.27-23.43%, transpiration rate (Tr) by 2.99-20.50% and intercellular carbon dioxide (CO2) concentration (Ci) by 6.55-8.84%. Foliar spraying of Si significantly increased the activities of superoxide dismutase (SOD) and peroxidase (POD) in rice leaves by 9.84-14.09% and 4.69-53.09%, respectively, and reduced the content of malondialdehyde (MDA) by 7.83-48.72%. In summary, foliar Si spraying protects the photosynthesis and antioxidant system of rice canopy leaves, and is an effective method to reduce the Cd content in brown rice.
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  • 文章类型: Journal Article
    已经开发了多种策略来增强锂离子电池(LIB)中的Si基阳极的循环稳定性。尽管在提高硅基阳极的循环稳定性方面取得了重大进展,低的初始库仑效率(ICE)仍然是其商业应用的重大挑战。在这里,用石墨烯(G)包裹基于沥青的碳(C)包覆的Si纳米颗粒(NPs),以获得具有11.3m2g-1的小比表面积(SSA)的Si@C/G复合材料,从而在500mAg-1下产生91.2%的高ICE。此外,石墨烯和来自低成本石油沥青的软碳的综合利用强烈促进了导电性,结构稳定性,和SiNP的反应动力学。因此,合成的Si@C/G的Si负载量为54.7%,可提供大的可逆容量(500mAg-1时为1191mAhg-1),超过200次循环的长循环寿命(容量保持率为87.1%),和优越的倍率能力(952mAhg-1在1500mAg-1)。当与全电池中的自制LiNi0.8Co0.1Mn0.1O2(NCM811)阴极耦合时,它显示了一个有前途的循环稳定性为200次循环。这项工作提出了一种具有商业应用的硅基阳极材料制造的创新方法。
    A variety of strategies have been developed to enhance the cycling stability of Si-based anodes in lithium-ion batteries. Although significant progress has been made in enhancing the cycling stability of Si-based anodes, the low initial Coulombic efficiency (ICE) remains a significant challenge to their commercial application. Herein, pitch-based carbon (C) coated Si nanoparticles (NPs) were wrapped by graphene (G) to obtain Si@C/G composite with a small specific surface area of 11.3 m2g-1, resulting in a high ICE of 91.2% at 500 mA g-1. Moreover, the integrated utilization of graphene and soft carbon derived from the low-cost petroleum pitch strongly promotes the electrical conductivity, structure stability, and reaction kinetics of Si NPs. Consequently, the synthesized Si@C/G with a Si loading of 54.7% delivers large reversible capacity (1191 mAh g-1at 500 mA g-1), long cycle life over 200 cycles (a capacity retention of 87.1%), and superior rate capability (952 mAh g-1at 1500 mA g-1). When coupled with a homemade LiNi0.8Co0.1Mn0.1O2(NCM811) cathode in a full cell, it exhibits a promising cycling stability for 200 cycles. This work presents an innovative approach for the manufacture of Si-based anode materials with commercial application.
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  • 文章类型: Journal Article
    SI手册对它认为无量纲的数量的处理,与相关的第一单元,要求某些物理量被视为简单的数字。由此产生的正式系统消除了这些数量的性质,并将它们排除在数量演算提供的超过数值计算的重要好处之外,即,有时可以防止不同单位和不同数量的意外混淆。我提出了一种更好的治疗方法,即从SI手册中删除那些与无量纲治疗中的常见做法相冲突的处方,特别是以种类区分的非SI无量纲单位的定义和使用。
    The SI brochure\'s treatment of quantities that it regards as dimensionless, with the associated unit one, requires certain physical quantities to be regarded as simply numbers. The resulting formal system erases the nature of these quantities and excludes them from important benefits that quantity calculus provides over numerical value calculations, namely, that accidental confusion of different units and different kinds of quantities is sometimes prevented. I propose a better treatment that entails removing from the SI brochure those prescriptions that conflict with common practices in the treatment of dimensionless quantities, especially the definition and use of non-SI dimensionless units that are distinguished by kind.
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  • 文章类型: Journal Article
    通过三乙氧基硅烷(TEOS)和柠檬酸(CA)的一步水热法制备了一种新型的碳化聚合物点。由碳化聚合物点(CPD)制成的传感器在室温下对氨表现出优异的气体传感性能。Si,O-共掺杂的CPD在室温下表现出优异的氨传感性能,包括1ppm的低实际检测限(pLOD)(Ra/Rg:1.10,1ppm),响应/恢复时间短(30/36s,1ppm),高耐湿性(当相对湿度从30%变为80时,波动小于5%),高稳定性(120天后初始反应波动小于5%),可靠的重复性,和其他干扰气体的高选择性。通过控制实验和原位红外光谱研究了气敏机理,表明Si,O-共掺杂实质上改善了CPD的电子转移能力,并且协同地支配了CPD的优异的氨感测性质。这项工作提出了一种构建新型高性能,用于气体传感的单组分碳化聚合物点。
    A new type of carbonized polymer dot was prepared by the one-step hydrothermal method of triethoxylsilane (TEOS) and citric acid (CA). The sensor made from carbonized polymer dots (CPDs) showed superior gas sensing performance toward ammonia at room temperature. The Si, O-codoped CPDs exhibited superior ammonia sensing performance at room temperature, including a low practical limit of detection (pLOD) of 1 ppm (Ra/Rg: 1.10, 1 ppm), short response/recovery time (30/36 s, 1 ppm), high humidity resistance (less than 5% undulation when changing relative humidity to 80 from 30%), high stability (less than 5% initial response undulation after 120 days), reliable repeatability, and high selectivity against other interferential gases. The gas sensing mechanism was investigated through control experiments and in situ FTIR, indicating that Si, O-codoping essentially improves the electron transfer capability of CPDs and synergistically dominates the superior ammonia sensing properties of the CPDs. This work presents a facile strategy for constructing novel high-performance, single-component carbonized polymer dots for gas sensing.
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  • 文章类型: Journal Article
    背景:在2023年,美国经历了最高记录的自杀人数,超过5万人死亡。在精神疾病领域,抑郁症是最常见的问题,影响15%至17%的人口,并携带约15%的显著自杀风险。然而,不是每个抑郁症患者都有自杀念头.虽然“自杀性抑郁症”不是临床诊断,它可以在日常生活中观察到,强调意识的必要性。
    目的:本研究旨在研究动力学,情感音调,以及r/Depressionsubreddit中帖子中讨论的主题,特别关注也参与过r/SuicideWatch社区的用户。目的是使用自然语言处理技术和模型来更好地了解具有潜在自杀意念的用户抑郁的复杂性,目的是改善自杀的干预和预防策略。
    方法:存档的帖子是从2019年到2022年的r/Depression和r/SuicideWatchReddit社区中提取的,最终数据集超过150,000个帖子,由大约25,000个独特的重叠用户提供。对这些职位进行了广泛和全面的混合方法,包括趋势和生存分析,探索2个子reddits中用户的动态。BERT系列模型从数据中提取特征用于情感和主题分析。
    结果:2020年8月16日,r/SuicideWatch的帖子计数超过了r/Depression。2020年从r/Depression到r/SuicideWatch的过渡时间最短,只持续了26天。悲伤是r/Depression社区中重叠用户中最普遍的情绪。此外,身体活动的变化,消极的自我观点,自杀念头被认为是最常见的抑郁症状,都与失望的情绪基调表现出较强的正相关。此外,除了自杀念头外,“在学校和工作中与抑郁和动机作斗争”(12%)成为讨论最多的话题,根据用户对自杀意念的倾向对用户进行分类。
    结论:我们的研究强调了在r/Depression和r/SuicideWatch等在线社区中使用自然语言处理技术探索与心理健康挑战相关的语言标记和模式的有效性。这些见解提供了不同于以往研究的新颖观点。在未来,使用这些技术将有可能进一步完善和优化机器分类,这可能导致更有效的干预和预防策略。
    BACKGROUND: In 2023, the United States experienced its highest- recorded number of suicides, exceeding 50,000 deaths. In the realm of psychiatric disorders, major depressive disorder stands out as the most common issue, affecting 15% to 17% of the population and carrying a notable suicide risk of approximately 15%. However, not everyone with depression has suicidal thoughts. While \"suicidal depression\" is not a clinical diagnosis, it may be observed in daily life, emphasizing the need for awareness.
    OBJECTIVE: This study aims to examine the dynamics, emotional tones, and topics discussed in posts within the r/Depression subreddit, with a specific focus on users who had also engaged in the r/SuicideWatch community. The objective was to use natural language processing techniques and models to better understand the complexities of depression among users with potential suicide ideation, with the goal of improving intervention and prevention strategies for suicide.
    METHODS: Archived posts were extracted from the r/Depression and r/SuicideWatch Reddit communities in English spanning from 2019 to 2022, resulting in a final data set of over 150,000 posts contributed by approximately 25,000 unique overlapping users. A broad and comprehensive mix of methods was conducted on these posts, including trend and survival analysis, to explore the dynamic of users in the 2 subreddits. The BERT family of models extracted features from data for sentiment and thematic analysis.
    RESULTS: On August 16, 2020, the post count in r/SuicideWatch surpassed that of r/Depression. The transition from r/Depression to r/SuicideWatch in 2020 was the shortest, lasting only 26 days. Sadness emerged as the most prevalent emotion among overlapping users in the r/Depression community. In addition, physical activity changes, negative self-view, and suicidal thoughts were identified as the most common depression symptoms, all showing strong positive correlations with the emotion tone of disappointment. Furthermore, the topic \"struggles with depression and motivation in school and work\" (12%) emerged as the most discussed topic aside from suicidal thoughts, categorizing users based on their inclination toward suicide ideation.
    CONCLUSIONS: Our study underscores the effectiveness of using natural language processing techniques to explore language markers and patterns associated with mental health challenges in online communities like r/Depression and r/SuicideWatch. These insights offer novel perspectives distinct from previous research. In the future, there will be potential for further refinement and optimization of machine classifications using these techniques, which could lead to more effective intervention and prevention strategies.
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  • 文章类型: Journal Article
    改性沥青结合料在沥青路面中仍然被认为是重要的。然而,由于储存稳定性问题,各种改性剂的综合使用受到限制。此外,尽管利用了各种方法来评估粘结剂的储存稳定性,但缺乏对每种方法中沥青粘结剂分离程度的详细分析。因此,进行了综合分析,以评估用粒状橡胶改性剂(CRM)和苯乙烯-异戊二烯-苯乙烯(SIS)改性的沥青结合料的储存稳定性,利用基于四种混合方法(A:高剪切混合方法,B:低速搅拌法,C:高剪切混合法+低混合法,D:低速搅拌法+低混合法)。为生产改性沥青结合料,CRM的比例为每种粘合剂的5%和10%,并且将10%SIS添加到所有粘合剂中。这项研究的结果传达了(1)改性剂的添加导致G*/sinδ在不同的混合方法增加,但是使用混合方法(C和D)相对较长的时间导致较低的G*/sinδ,指示次优性能;(2)通过多次应力蠕变恢复(MSCR),Jnr和%rec的流变特性表现出与G*/sinδ评估相似的趋势,突出了改进的弹性恢复与更高的改性剂含量;(3)储存稳定性评估显示一致的趋势在高剪切混合组(A和C),而低速混合组(B和D)表现出升高的分离指数(SI),表明对改性条件的敏感性;(4)使用MSCR方法的评估表明,在3.2kPa载荷下的%rec对于粘合剂储存稳定性的敏感评估是有效的,并且Jnr在变化的载荷下显示出有限的灵敏度,提倡%rec以进行精确评估;(5)尽管允许进行各种测试,实现一致的结果仍然具有挑战性。未来的研究应探索各种改性剂和最佳评估方法,以增强对粘合剂行为和分离动力学的了解。
    Modified asphalt binders are still considered important in asphalt pavement. However, the comprehensive use of various modifiers is limited due to storage stability issues. Moreover, there is a scarcity of detailed analyses regarding the degree of separation for asphalt binders among each method despite the utilization of various methods to assess the storage stability of binders. Therefore, a comprehensive analysis was conducted to assess the storage stability of asphalt binder modified with a crumb rubber modifier (CRM) and styrene-isoprene-styrene (SIS), utilizing five evaluation factors following the ASTM D7173 guidelines based on four mixing methods (A: high-shear mixing method, B: low-speed agitating method, C: high-shear mixing method + low mixing method, D: low-speed agitating method + low mixing method). To produce the modified asphalt binder, the proportions of the CRM were 5% and 10% for each binder, and 10% SIS was added to all binders. The results in this study convey that (1) the addition of the modifier led to an increase in G*/sin δ with different mixing methods, but using mixing methods (C and D) for a relatively long time resulted in a lower G*/sin δ, indicating suboptimal performance; (2) through the multiple stress creep recovery (MSCR), rheological properties of Jnr and % rec exhibited trends similar to G*/sin δ evaluation, highlighting an improved elastic recovery with a higher modifier content; (3) storage stability assessment revealed consistent trends in high-shear mixing groups (A and C), while low-speed mixing groups (B and D) exhibited an elevated separation index (SI), suggesting a sensitivity to modification conditions; (4) evaluation using the MSCR method indicated that % rec with a 3.2 kPa load is effective for the sensitive assessment of binder storage stability and Jnr showed a limited sensitivity across varying loads, advocating for % rec for precise evaluation; and (5) despite permitting various tests, achieving consistent results remains challenging. Future research should explore diverse modifiers and optimal evaluation methods to enhance knowledge of binder behavior and separation dynamics.
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  • 文章类型: Journal Article
    NISTonaChip(NOAC)计划的中心思想是,可以开发测量技术,通过创建部署和通常小型化的标准,使“在国家计量研究所之外”进行计量。这些标准,当基于自然的基本属性时,可以直接追溯到国际单位制,称为SI。NIST还在开发基于量子的SI可追溯性标准,称为QSI,或基于量子的国际单位制。具体来说,本文将涵盖NIST在热力学计量学领域的努力,以开发NOAC压力标准,真空和温度测量。
    The NIST on a Chip (NOAC) program\'s central idea is the idea that measurement technology can be developed to enable metrology to be performed \"outside the National Metrology Institute\" by the creation of deployed and often miniaturized standards. These standards, when based on fundamental properties of nature, are directly tracible to the international system of units known as the SI. NIST is also developing quantum-based standards for SI traceability known as QSI, or Quantum based International System of units. Specifically, this paper will cover NIST efforts in the area of thermodynamic metrology to develop NOAC standards for pressure, vacuum and temperature measurements.
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  • 文章类型: Journal Article
    自交不亲和(SI)是防止开花植物自体受精和近亲繁殖的重要机制。柑橘表现出受包含S-RNase基因和多个S-基因座F-box(SLF)基因的多态性S基因座调节的SI。有文献记载,S-RNase作为雌蕊S决定簇发挥作用,但是没有直接证据表明与S-RNase密切相关的SLF基因在柑橘中作为花粉S决定簇。这项研究组装了两种柚子(柑橘)植物的基因组,获得了三个新的完整且注释良好的S单倍型,并在S基因座上分离出36个SLF或SLF样等位基因。138个SLF的系统发育分析表明,SLF基因分为12种类型,包括六种具有不同或缺失等位基因的类型。此外,转化实验证实,保守的S6-SLF7a蛋白可以通过识别迷你柑橘植物(S7S8和S8S29,FortunellaHindsii)中的非自身S8-RNase来导致SI向自身相容性的转变,柑橘基因功能研究的模型植物。体外测定证明了不同S单倍型的SLF与Skp1-Cullin1-F-box亚基CgSSK1蛋白之间的相互作用。这项研究提供了直接证据,表明SLF控制柑橘的花粉功能,展示其在“非自我识别”SI系统中的作用。
    Self-incompatibility (SI) is a crucial mechanism that prevents self-fertilization and inbreeding in flowering plants. Citrus exhibits SI regulated by a polymorphic S-locus containing an S-RNase gene and multiple S-locus F-box (SLF) genes. It has been documented that S-RNase functions as the pistil S determinant, but there is no direct evidence that the SLF genes closely linked with S-RNase function as pollen S determinants in Citrus. This study assembled the genomes of two pummelo (Citrus grandis) plants, obtained three novel complete and well-annotated S-haplotypes, and isolated 36 SLF or SLF-like alleles on the S-loci. Phylogenetic analysis of 138 SLFs revealed that the SLF genes were classified into 12 types, including six types with divergent or missing alleles. Furthermore, transformation experiments verified that the conserved S6-SLF7a protein can lead to the transition of SI to self-compatibility by recognizing non-self S8-RNase in \'Mini-Citrus\' plants (S7S8 and S8S29, Fortunella hindsii), a model plant for citrus gene function studies. In vitro assays demonstrated interactions between SLFs of different S haplotypes and the Skp1-Cullin1-F-box subunit CgSSK1 protein. This study provides direct evidence that SLF controls the pollen function in Citrus, demonstrating its role in the \'non-self recognition\' SI system.
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  • 文章类型: Journal Article
    地下水是各种用途的主要水源。因此,含水层污染对人类健康和环境构成严重威胁。确定含水层的高度易受污染的地区是必要的,以实施适当的补救措施,从而确保地下水的可持续性。本文旨在加强地下水脆弱性评估(GWVA),以有效地管理含水层质量。这项研究的重点是Moulouya盆地的ElOrjane含水层,摩洛哥,由于橄榄厂废水,它面临着显著的降解。地下水脆弱性图(GVM)是使用DRASTIC生成的,农药DRASTIC,SINTACS,和SI方法。为了评估拟议改进的有效性,安装了24个压力计来测量硝酸盐浓度,地下水污染的常见指标。这项研究旨在通过合并新的图层来增强GWVA,比如土地利用,并在综合敏感性分析的基础上调整参数率。结果表明,所产生的GVM和测量的硝酸盐浓度之间的Pearson相关值(PCV)显著增加。例如,在添加土地利用层并使用Wilcoxon方法调整参数速率后,DRASTIC方法的PCV从0.42提高到0.75。这些发现为准确评估具有类似危害和水文条件的地区的地下水脆弱性提供了宝贵的见解,特别是在半干旱和干旱地区。它们有助于改善地下水和环境管理实践,确保含水层的长期可持续性。
    Groundwater serves as a primary water source for various purposes. Therefore, aquifer pollution poses a critical threat to human health and the environment. Identifying the aquifer\'s highly vulnerable areas to pollution is necessary to implement appropriate remedial measures, thus ensuring groundwater sustainability. This paper aims to enhance groundwater vulnerability assessment (GWVA) to manage aquifer quality effectively. The study focuses on the El Orjane Aquifer in the Moulouya basin, Morocco, which is facing significant degradation due to olive mill wastewater. Groundwater vulnerability maps (GVMs) were generated using the DRASTIC, Pesticide DRASTIC, SINTACS, and SI methods. To assess the effectiveness of the proposed improvements, 24 piezometers were installed to measure nitrate concentrations, a common indicator of groundwater contamination. This study aimed to enhance GWVA by incorporating new layers, such as land use, and adjusting parameter rates based on a comprehensive sensitivity analysis. The results demonstrate a significant increase in Pearson correlation values (PCV) between the produced GVMs and measured nitrate concentrations. For instance, the PCV for the DRASTIC method improved from 0.42 to 0.75 after adding the land use layer and adjusting parameter rates using the Wilcoxon method. These findings offer valuable insights for accurately assessing groundwater vulnerability in areas with similar hazards and hydrological conditions, particularly in semi-arid and arid regions. They contribute to improving groundwater and environmental management practices, ensuring the long-term sustainability of aquifers.
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