Challenges and approaches of single-crystal Ni-rich layered cathodes in lithium batteries

High energy density and high safety are incompatible with each other in a lithium battery, which challenges today’s energy storage and power applications. Ni-rich layered transition metal oxides(NMCs) have been identified as the primary cathode candidate for powering next-generation electric vehicles and have been extensively studied in the last two decades, leading to the fast growth of their market share, including both polycrystalline and single-crystal NMC cathodes. Single-crystal NMCs appea...     

Direct and green repairing of degraded LiCoO2 for reuse in lithium-ion batteries

Traditional recycling processes of LiCoO₂ rely on destructive decomposition, requiring high-temperature roasting or acid leaching to extract valuable Li and Co, which have significant environmental and economic concerns. Herein, a direct repairing method for degraded LiCoO₂ using a LiCl–CH₄N₂O deep eutectic solvent (DES) was established. The DES is not used to dissolve LiCoO₂ but directly serves as a carrier for the selective replenishment of lithium and cobalt. Replenishment of lithium restores LiCoO₂ at different states of charge to a capacity of 130 mAh/g (at 0.1 C rate), while replenishing the cobalt increases the capacity retention rate of 90% after 100 cycles, which is comparable to pristine LiCoO₂. The DES is collected and reused multiple times with a high repair efficiency. This process reduces energy consumption by 37.1% and greenhouse gas emissions by 34.8% compared with the current production process of LiCoO₂, demonstrating excellent environmental and economic viability.     

Applications of chemical imaging techniques in paleontology

Chemical imaging techniques, based on a combination of microscopy and spectroscopy, are designed to analyse the composition and spatial distribution of heterogeneous chemical complexes within a sample. Over the last few decades, it has become an increasingly popular tool for characterizing trace elements, isotopic information and organic biomarkers (molecular biosignatures) found in fossils. Here, we introduce the analytical principle of each technique and the interpretation of the chemical signals, followed by a review of the main applications of these techniques in paleontology. We also demonstrate that each technique is associated with pros and cons, and the current limitations and obstacles associated with the use of each specific technique should be taken into account before being applied to fossil samples. Finally, we propose that, due to the rapid advances in the available technology and overall trends towards more multi-disciplinary studies in paleontology, chemical imaging techniques can be expected to have broader applications in paleontology in the near future.     

Structural evolution of protein-biofilms: Simulations and experiments

The control of biofilm formation is a challenging goal that has not been reached yet in many aspects. One unsolved question is the role of van der Waals forces and another is the importance of mutual interactions between the adsorbing and the adsorbed biomolecules ("critical crowding"). In this study, a combined experimental and theoretical approach is presented, which fundamentally probes both aspects. On three model proteins-lysozyme, α-amylase, and bovine serum albumin-the adsorption kinetics is studied experimentally. Composite substrates are used enabling a separation of the short- and the long-range forces. Although usually neglected, experimental evidence is given for the influence of van der Waals forces on the protein adsorption as revealed by in situ ellipsometry. The three proteins were chosen for their different conformational stabilities in order to investigate the influence of conformational changes on the adsorption kinetics. Monte Carlo simulations are used to develop a model for these experimental results by assuming an internal degree of freedom to represent conformational changes. The simulations also provide data on the distribution of adsorption sites. By in situ atomic force microscopy we can also test this distribution experimentally, which opens the possibility to, e.g., investigate the interactions between adsorbed proteins.     

The changing rôle of the symbol in the evolution of chemical notation

Computer techniques are indispensable for storing and retrieving information on the seven million different chemical substances now known, and will become increasingly important as their number and complexity grow. A necessary prerequisite is the unambiguous representation of molecular structure in terms of symbols suitable for computer usage. This article reviews the development of chemical symbolism from its inception in the ancient civilizations to its use in modern notational systems.     

突发事件演化的耗散结构判断模型研究

运用熵和耗散结构对突发事件演化进行分析,明确突发事件演化过程符合耗散结构非线性及动态变化的特性,据此对经典布鲁塞尔器(Brusselator)模型进行转义处理,建立突发事件演化的耗散结构判断模型。依据模型构建正负熵指标体系,判断事件演化的受控性是否满足耗散结构的有序平衡状态。最后依据事故资料,对2013年某输油管道泄漏事故进行分析,分析结果与实际事故的发展过程具有良好的吻合性,可为突发事件的应急决策提供有益的借鉴。     

Generation of nitric oxide gradients in microfluidic devices for cell culture using spatially controlled chemical reactions

In this paper, we develop a microfluidic device capable of generating nitric oxide (NO) gradients for cell culture using spatially controlled chemical reactions. NO plays an essential role in various biological activities, including nervous, immune, and cardiovascular systems. The device developed in this paper can control NO gradients without utilizing expensive and hazardous high purity NO gas sources or direct addition of NO donors. Consequently, the device provides an efficient, cost-effective, robust, and stable platform to generate NO gradients for cell culture studies. In the experiments, NO gradients are first characterized using a NO-sensitive fluorescence dye, and cell experiments using aortic smooth muscle cells are conducted. The results demonstrate that the device can alter the intracellular NO concentrations and further affect the Ca²⁺ concentration oscillation for the cells. The device developed in this paper provides a powerful platform for researchers better study the biological roles of NO and its spatial distribution using in vitro cell models with minimal instrumentation.     

采用SSR和RAPD标记研究黄瓜属（葫芦科）的系统发育关系

野黄瓜Cucumis hystrix（2n=24）是在亚洲发现的第一个染色体基数为12的黄瓜属物种。这一发现对现行的以染色体基数和地理分布为基础的黄瓜属分类系统提出了质疑。采用SSR和RAPD两种分子标记对黄瓜属22份不同类型材料的亲缘关系进行了研究。结果表明，野黄瓜C.hystrix与黄瓜C.sativus var.sativus（2n=14）间的遗传距离（SSR:0.59，RAPD:0.57）小于其与甜瓜C.melo var.melo（2n=24）间的距离（SSR:0.87，RAPD:0.70）。SS     

浅析上市公司信息披露中存在的问题及对策

分析了上市公司会计信息披露中存在的问题，指出我国上市公司信息披露制度的建立，一方面保护了投资者的合法权益，另一方面可使上市公司资产发挥最佳。就目前我国上市公司的信息披露尚欠规范，严重阻碍了证券公司从无效市场向有效市场的发展，给证券市场的正常运作带来诸多不利影响等问题进行讨论。在研究分析的基础上，就如何改善会计信息披露状况，有助于推动我国证券市场高效健康发展提出了相应的对策。     

A microfluidic cell for studying the formation of regenerated silk by synchrotron radiation small- and wide-angle X-ray scattering

A tube-in-square-pipe microfluidic glass cell has been developed for studying the aggregation and fiber formation from regenerated silk solution by in-situ small-angle X-ray scattering using synchrotron radiation. Acidification-induced aggregation has been observed close to the mixing point of the fibroin and buffer solution. The fibrous, amorphous material is collected in a water bath. Micro-wide-angle X-ray scattering of the dried material confirms its β-sheet nature.     

水蒸气蒸馏——免试剂离子色谱法测定氧化锌物料中氟和氯

文章采用水蒸气蒸馏法分离富集氧化锌中氟、氯阴离子,并用免试剂淋洗液发生器产生的KOH溶液梯度淋洗,Ion Pac AS19型阴离子分离柱分离,电导法对其检测。实验表明,该前处理方法可消除物料中大量共存离子的干扰及避免对色谱柱的污染,在设定的色谱条件下,氟离子和氯离子具有很好的线性和重现性以及较低的检测限,检出限(S/N=3)分别为4.5mg/kg和5mg/kg。     

Concurrent shear stress and chemical stimulation of mechano-sensitive cells by discontinuous dielectrophoresis

Microfluidic platforms enable a variety of physical or chemical stimulation of single or multiple cells to be examined and monitored in real-time. To date, intracellular calcium signalling research is, however, predominantly focused on observing the response of cells to a single mode of stimulation; consequently, the sensitising/desensitising of cell responses under concurrent stimuli is not well studied. In this paper, we provide an extended Discontinuous Dielectrophoresis procedure to investigate the sensitising of chemical stimulation, over an extensive range of shear stress, up to 63 dyn/cm², which encompasses shear stresses experienced in the arterial and venus systems (10 to 60 dyn/cm²). Furthermore, the TRPV4-selective agonist GSK1016790A, a form of chemical stimulation, did not influence the ability of the cells'' to remain immobilised under high levels of shear stress; thus, enabling us to investigate shear stress stimulation on agonism. Our experiments revealed that shear stress sensitises GSK1016790A-evoked intracellular calcium signalling of cells in a shear-stimulus dependent manner, as observed through a reduction in the cellular response time and an increase in the pharmacological efficacy. Consequently, suggesting that the role of TRPV4 may be underestimated in endothelial cells—which experience high levels of shear stress. This study highlights the importance of conducting studies at high levels of shear stress. Additionally, our approach will be valuable for examining the effect of high levels of shear on different cell types under different conditions, as presented here for agonist activation.     

Genetic variability of Sargassum liebmannii on the coast of Jalisco in the central Mexican Pacific revealed by molecular markers and morphological traits

BackgroundSargassum liebmannii is widely distributed throughout rocky, coastal upwelling areas in the tropical Mexican Pacific. This brown algae is of great environmental and industrial importance. However, no information is available that documents the genetic or phenotypic variability of the species, which is needed to determine how it may react to environmental variation related to climate change. In this study, S. liebmannii specimens were collected from the coast of Jalisco, Mexico, and molecular and morphological characterization was conducted. Intraspecific variability was estimated according to the study areas.ResultsThe inter-simple sequence repeat (ISSR) markers indicated a polymorphism percentage of 95%. The Shannon index and Nei index showed relatively low values among the populations (0.3569 and 0.081, respectively). On the other hand, the genetic differentiation coefficient indicated inter- and intrapopulation values of 36.69% and 63.31%, respectively. The Jaccard similarity coefficient was used to determine the degree of similarity among individuals by geographical area. The morphological characteristics and environmental variables that were used to correlate phenotypes and genotypes indicated that S. liebmannii showed low genetic flow because of the presence of geographical barriers due to substrate that was not optimal for algal development.ConclusionsThe ISSR markers were useful for detecting genetic differences among S. liebmannii individuals. The results indicate that a coupled genotypic-phenotypic study is beneficial for documenting the variation present in the little-studied algal species. These studies may be used in future research to clarify taxonomic controversies while generating additional genomic information.How to cite: Jung-Kim HW, Hernández-Herrera RM, Enciso-Padilla I, et al. Genetic variability of Sargassum liebmannii on the coast of Jalisco in the central Mexican Pacific revealed by molecular markers and morphological traits. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.08.003     

天山北缘侏罗系地层热历史演化及其地质意义：磷灰石裂变径迹和镜质体反射率证据

对天山北缘石场．玛纳斯、安集海河和四棵树河地区18个样品进行了磷灰石裂变径迹年龄测定，同时测定了中生界地层10件裂变径迹样品相应煤层的镜质体反射率。结果表明地层由老到新镜质体反射率逐渐增加，磷灰石裂变径迹中值年龄逐渐降低。石场．玛纳斯地区，下部三叠系煤层镜质体反射率R。值较低，为0．56％，磷灰石裂变径迹中值年龄较大，为125．3±9．1Ma；八道湾组煤层R。为0．53％～0．64％，磷灰石裂变径迹中值年龄介于81．3±4．7～87．8±5．9Ma；上部西山窑组煤层R。最高，达到0．81％，磷灰石裂变径迹中年龄较低，为44．0±5．4—11．8±1．8Ma；相同层位，东部石场．玛纳斯一带R。比西部四棵树地区高，磷灰石裂变径迹年龄刚好相反。磷灰石裂变径迹模拟结果表明中生界三叠系、下侏罗统地层的埋藏深度相对较浅，上覆沉积持续的时间到晚侏罗世到早白垩世基本上已经结束，然后保持在基本不变的深度，直至中新世，不整合在三叠系之下的花岗岩的模拟结果也支持这样的认识。晚侏罗世一早白垩世的冷却降温事件可能是地温梯度变化和隆升作用的共同结果；中侏罗统地层埋藏增温过程持续时间较长，在玛纳斯地区直至渐新世末期。所有样品中磷灰石裂变径迹模拟都记录了10Ma左右的快速冷却过程，近4—5kin的地壳表层物质被剥蚀，平均剥蚀速率400—500m／Ma。这一剥蚀过程应该与天山地区的快速隆升，以及向北的冲断推覆作用相对应。天山地区山前带的变形应不早于10Ma，这一认识与野外地质证据一致。     

中小企业内外创新网络协同演化与能力提升

当前对创新网络研究多是把企业看作网络中的一个节点,而忽略了个体内部与网络之间的互动演化,企业内部创新管理仍是一个黑箱。文章提出从外部开放度和内部要素参与度两个维度来研究内外网络的协同演化,并通过一个纵向案例研究来分析创新能力的提升机制。随着整体外部创新网络的发展,企业内部要素参与度逐渐增加,并形成了一个内部创新网络体系,这种内外创新网络之间的演化学习和协同互动是提升企业创新能力的关键。     

植物多倍体基因组的形成与进化

多倍化是植物进化变异的自然现象，也是促进植物发生进化改变的重要力量。在被子植物中，约 70％的种类在进化史中曾发生过一次或多次多倍化的过程。目前的研究结果表明，自然界绝大多数多倍体是通过未减数配子的融合而形成的，并且很多多倍体种是通过多次独立的多倍化过程而重复发生的。由多倍化所导致的重复基因在多倍体基因组中可能有三种不同的命运，即：保持原有的功能、基因沉默或分化并执行新的功能。多倍化以后，重复基因组的进化动态则主要表现在染色体重排和“染色体二倍化”、不同基因组之间的相互渗透、以及核-质之间的相互作用等方面。     

模块化组织价值创新:路径及其演化

作为市场中一种新兴的制度安排,模块化组织彰显了价值创新的优越性。模块化组织价值创新路径是组织成长方式、战略方案和实施途径选择匹配的集合。本文首先识别了模块化组织价值创新的三种路径——竞合互动、价值对流和模块操作路径,并对比了三种路径的价值创新要素及创新效率。基于此,构建了模块化组织价值创新路径演化模型,路径演化沿着"竞合互动路径→价值对流路径→模块操作路径"的方向。最后,以美邦集团26年的发展历程为纵向案例研究,实证剖析了价值创新路径的演化过程。