Three-in-one fire-retardant poly(phosphate)-based fast ion-conductor for all-solid-state lithium batteries

The development of flame retardant or nonflammable electrolytes is the key to improve the safety of lithium batteries,owing to inflammable organic solvents and polymer matrix in common liquid and polymer electrolytes regarded as the main cause of battery fire.Herein,a series of solid-state polyphosphate oligomers(SPPO)as a three-in-one electrolyte that integrated the roles of lithium salt,dissociation matrix,and flame retardant were synthesized.The well-designed SPPO electrolytes showed an optimal ionic conductivity of 5.5×10^(-4)S cm-1at 30℃,an acceptable electrochemical window up to 4.0 V vs.Li/Li+,and lithium ion transference number of 0.547.Stable Li-ion stripping/plating behavior for 500 h of charge-discharge cycles without internal short-circuit in a Li|SPPO|Li cell was confirmed,together with outstanding interface compatibility between the SPPO electrolyte and lithium foil.The optimal Li|SPPO|LiFePO4cell presented good reversible discharge capacity of 149.4 mA h g-1at 0.1 C and Coulombic efficiency of 96.4%after 120 cycles.More importantly,the prepared SPPO cannot be ignited by the lighter fire and show a limited-oxygen-index value as high as 35.5%,indicating splendid nonflammable nature.The SPPO could be a promising candidate as a three-in-one solid-state electrolyte for the improved safety of rechargeable lithium batteries.

帕博利珠单抗对晚期非小细胞肺癌患者T淋巴细胞亚群的影响及疗效观测

背景与目的本研究旨在探究非小细胞肺癌患者应用帕博利珠单抗治疗前后外周血淋巴细胞亚群的变化及临床意义。方法选取2015年1月-2020年12月至青岛大学附属医院及潍坊市人民医院行帕博利珠单抗治疗的32例非小细胞肺癌的患者为观察组,另外选取同期30例健康查体者为对照组。治疗前、治疗后第1、2、4周期,采用流体细胞术检测患者外周血淋巴细胞亚群水平的变化。结果非小细胞肺癌患者治疗前的CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)指标较对照组明显下降(P<0.05),CD8^(+)水平明显升高(P<0.05);应用帕博利珠单抗治疗1个周期后,淋巴细胞亚群较免疫治疗前的变化未见明显统计学差异;治疗2周期后CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)数值较治疗前升高(P>0.05),CD8^(+)指标较治疗前下降(P<0.05);治疗4周期后CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)数值较治疗前得到显著改善(P<0.05),CD8^(+)指标较治疗前明显下降(P<0.05);疗效达到疾病稳定(stable disease,SD)/部分缓解(partial response,PR)患者在治疗过程中,第4周期的CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)数值较治疗前升高(P<0.05),CD8^(+)指标较治疗前降低(P<0.05);疗效达到疾病进展(progressive disease,PD)患者在治疗过程中,淋巴细胞亚群变化较治疗前均没有明显统计学差异(P>0.05)。同时本文通过分析显示,程序性死亡受体配体1(programmed cell death ligand 1,PD-L1)表达与否及病理学类型对免疫治疗效果的影响不明显。通过多因素分析显示,同时观察CD3^(+)、CD4^(+)、CD8^(+)的变化对预测免疫治疗效果更有意义。结论帕博利珠单抗可以调节非小细胞肺癌患者T淋巴细胞亚群的变化,改善患者机体的免疫状态,且未见明显不良反应,同时治疗过程中监测淋巴细胞亚群变化可预测免疫治疗效果。

疫情防控常态下肺癌早筛的现状及进展

肺癌是我国发病率最高的恶性肿瘤。早发现早鉴别出有症状的肺癌患者和及时从高危人群中筛选出无症状患者需要多方面配合。目前,尽管已经联合影像学、血清学、基因组学、蛋白质组学等手段对可疑肺癌进行筛查,但仍存在漏诊、误诊等问题。同时,新型冠状病毒肺炎(corona virus disease 2019, COVID-19)流行病的蔓延给肺癌早筛带来了新的挑战。在疫情防控常态化下,肺癌早筛工作应该做出相应改变:提高人群防癌控癌意识、加强就诊流程管理、提高肿瘤检出效率、优化检测技术并合理利用互联网和大数据平台。联合多种筛查方法建立一种理想的肺癌早筛模式,保证疫情防控常态下肺癌早筛工作既精简又高效。

Cold atmospheric-pressure air plasma treatment of C6 glioma cells:effects of reactive oxygen species in the medium produced by the plasma on cell death

An atmospheric-pressure air plasma is employed to treat C6 glioma cells in vitro. To elucidate on the mechanism causing cell death and role of reactive species （RS） in the medium produced by the plasma, the concentration of the long-lived RS such as hydrogen peroxide, nitrate, and ozone in the plasma-treated liquid （phosphate-buffered saline solution） is measured. When vitamin C is added to the medium as a ROS quencher, the viability of C6 glioma cells after the plasma treatment is different from that without vitamin C. The results demonstrate that reactive oxygen species （ROS） such as H2O2, and O3 constitute the main factors for inactivation of C6 glioma cells and the reactive nitrogen species （RNS） may only play an auxiliary role in cell death.

Ergodic Rate Analysis on Applying Antenna Selection in D2D Communication Underlaying Cellular Networks

By reusing the spectrum of a cellular network, device-to-device(D2D) communications is known to greatly improve the spectral efficiency bypassing the base station(BS) of the cellular network. Antenna selection is the most cost efficient scheme for interference management, which is crucial to D2D systems. This paper investigates the achievable rate performance of the D2D communication underlaying the cellular network where a multiple-antenna base station with antenna selection scheme is deployed. We derive an exact closed-form expression of the ergodic achievable rate. Also, using Jensen's inequality, two pairs of upper and lower bounds of the rate are derived and we validate the tightness of the two sets of bounds. Based on the bounds obtained, we analyze the ergodic achievable rate in noise-limited scenario, interference-limited high SNR scenario and larger-scale antenna systems. Our analysis shows that the presence of D2D users could be counter-productive if the SNR at cellular UE is high. Further analysis shows that the relationship between the ergodic rate and the number of antennas it positive, but keeps decreasing as the antenna number increasing. These show the inefficiency of antenna selection in D2D interference management.

Consensus-Based Distributed Control with Communication Time Delays for Virtual Synchronous Generators in Isolate Microgrid

A consensus-based distributed control method of coordinated VSGs with communication time delays in isolate microgrid is proposed. When time delays are considered in communication, there are some effects on frequency restoration and active power output allocation. In the control structure, only local information exchange is needed, while the final frequency can be controlled to the nominal value and the VSGs can automatically share loads according to their rated values. An AC microgrid with three VSGs and some loads is implemented. The proposed control strategy is verified by MATLAB/ Simulink simulation results.

Simultaneous recovery of phosphorus and nitrogen from liquid digestate by vacuum membrane distillation with permeate fractional condensation

A vacuum membrane distillation(VMD)process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate.The polytetrafluoroethylene(PTFE)membrane flux could reach 6000 g·m-2·h-1 with the rejection efficiency of total phosphorus(TP)over 0.99,under the condition of flowrate being 120 L·h-1 and temperature being 40°C.Membrane fouling occurred with a film of organics and microorganism deposited on the surface of the membrane.Membrane flux could be reversed after the membrane was rinsed by water.Higher feed temperature and flowrate could improve the membrane flux,while hardly affect the rejection efficiency of total phosphorus.The concentration of TP could reach 1600 mg·L-1 after membrane distillation,which is about 5 times of that in initial liquid digestate.On the downstream of the membrane,some of the permeate vapor was condensed under the vacuum condition and most of water was collected here.The remaining vapor enriched with total nitrogen(TN)was compressed and pumped to the atmospheric condition to condense.The TN concentration in atmospheric condensate was as high as 7000 mg·L-1 with the process separation factor for ammonia being enhanced to 114.

Arabidopsis WRKY1 promotes monocarpic senescence by integrative regulation of flowering,leaf senescence,and nitrogen remobilization

Monocarpic senescence,characterized by whole-plant senescence following a single flowering phase,is widespread in seed plants,particularly in crops,determining seed harvest time and quality.However,how external and internal signals are systemically integrated into monocarpic senescence remains largely unknown.Here,we report that the Arabidopsis thaliana transcription factor WRKY1 plays essential roles in multiple key steps of monocarpic senescence.WRKY1 expression is induced by age,salicylic acid(SA),and nitrogen(N)deficiency.Flowering and leaf senescence are accelerated in the WRKY1 overexpression lines but are delayed in the wrky1 mutants.The combined DNA affinity purification sequencing and RNA sequencing analyses uncover the direct target genes of WRKY1.Further studies show that WRKY1 coordinately regulates three processes in monocarpic senescence:(1)suppressing FLOWERING LOCUS C gene expression to initiate flowering,(2)inducing SA biosynthesis genes to promote leaf senescence,and(3)activating the N assimilation and transport genes to trigger N remobilization.In summary,our study reveals how one stress-responsive transcription factor,WRKY1,integrates flowering,leaf senescence,and N remobilization processes into monocarpic senescence,providing important insights into plant lifetime regulation.

Research on Fiber Optic Surface Plasmon R esonance.Biosensors:A Review

Due to the benefits of the high sensitivity,real-time response,no labeling requirement,and good selectivity,fiber optic sensors based on surface plasmon resonance(SPR)have gained popularity in biochemical sensing in recent years.The current research on such sensors is hot in enhancing sensitivity,improving detection accuracy,and achieving the detection of biochemical molecules.The goal of this work is to present a thorough overview of recent developments in the optical fiber SPR biosensor research.Firstly,it explores the basic principles and sensing structures of optical fiber SPR biosensors,focusing on four aspects.Subsequently,this paper introduces three fiber optic surface plasmon biosensors:SPR,localized surface plasmon resonance(LSPR),and long-range surface plasmon resonance(LRSPR).Each concept is explained from the perspective of the basic principles of fiber optic SPR biosensors.Furthermore,a classification of fiber optic SPR biosensors in health monitoring,food safety,environmental monitoring,marine detection,and other applications is introduced and analyzed.Eventually,this paper summarizes the current research directions of SPR biosensors.Meanwhile,it provides a prospective outlook on how fiber optic SPR sensors will develop in the future.

Effectiveness of machine learning at modeling the relationship between Hi-C data and copy number variation

Copy number variation(CNV)refers to the number of copies of a specific sequence in a genome and is a type of chromatin structural variation.The development of the Hi-C technique has empowered research on the spatial structure of chromatins by capturing interactions between DNA fragments.We utilized machine-learning methods including the linear transformation model and graph convolutional network(GCN)to detect CNV events from Hi-C data and reveal how CNV is related to three-dimensional interactions between genomic fragments in terms of the one-dimensional read count signal and features of the chromatin structure.The experimental results demonstrated a specific linear relation between the Hi-C read count and CNV for each chromosome that can be well qualified by the linear transformation model.In addition,the GCN-based model could accurately extract features of the spatial structure from Hi-C data and infer the corresponding CNV across different chromosomes in a cancer cell line.We performed a series of experiments including dimension reduction,transfer learning,and Hi-C data perturbation to comprehensively evaluate the utility and robustness of the GCN-based model.This work can provide a benchmark for using machine learning to infer CNV from Hi-C data and serves as a necessary foundation for deeper understanding of the relationship between Hi-C data and CNV.

Does the continuous wetting of the Tibetan Plateau contribute to the accelerated degradation of permafrost?

Global warming is causing the Tibetan permafrost to degrade, as evidenced by rising ground temperatures, thicker active layer thickness, thinner permafrost layer, and melting underground ice, etc.(Ran et al., 2018;Wang et al., 2020).The degradation of permafrost not only profoundly alters the carbon cycling processes in high-altitude ecosystems,thereby influencing the regional climate system, but also affects landscape hydrological connectivity。

Droplet Laplace valve-enabled glaucoma implant for intraocular pressure management

Glaucoma,the leading cause of irreversible blindness worldwide,is closely linked to aqueous overaccumulation and elevated intraocular pressure(IOP).For refractory glaucoma,aqueous shunts with valves are commonly implanted for effective aqueous drainage control and IOP stabilization.However,existing valved glaucoma implants have the disadvantages of inconsistent valve opening/closing pressures,poor long-term repeatability due to their reliance on moving parts,and complex architectures and fabrication processes.Here,we propose a novel valving concept,the droplet Laplace valve(DLV),a three-dimensional printable moving-parts-free microvalve with customizable and consistent threshold valving pressures.The DLV uses a flow discretization unit governed by capillarity,comprising a droplet-forming nozzle,and a separated reservoir to digitize continuous flow into quantifiable droplets.Unlike the classic one-time-use Laplace valves,the DLV's unique design allows for its reusability.The opening pressure is adjustable by varying the nozzle size,like the classic Laplace valves(following the Young–Laplace equation),while the closing pressure can be modified by tuning the separation distance and the reservoir size.Various DLVs with customizable opening pressures from 5 to 11 mmHg have been demonstrated,with opening/closing pressure differences suppressed down to<0.5 mmHg(<0.15 mmHg under the best conditions).Thanks to its moving-parts-free nature and digitized flow properties,the DLV shows a highly repeatable valving performance(<1.7%,1000 cycles)and a predictable linear flow rate–pressure correlation(R2>0.99).Preliminary ex vivo validation in an enucleated porcine eye confirms the DLV's efficiency in aqueous shunting and prompt IOP stabilization.The DLV technology holds great promise in glaucoma implants for IOP management and various microsystems for flow control.

接枝型阳离子淀粉絮凝剂对石材废水的絮凝降浊性能与机理研究

混凝/絮凝工艺是去除废水中悬浮胶体颗粒、降低浊度的有效手段.本研究以一种常见的天然高分子材料——淀粉为原材,以丙烯酰胺和甲基丙烯酰氧乙基三甲基氯化铵为共聚单体,采用接枝共聚技术,开发了一系列接枝链分布相同、但电荷密度及平均接枝链链长不同的接枝型阳离子淀粉改性絮凝剂:淀粉接枝共聚丙烯酰胺-聚甲基丙烯酰氧乙基三甲基氯化铵(St-G).并以一种具有高浊度特征的行业废水——石材废水为研究对象,详细讨论了St-G的结构因素(电荷密度与平均接枝链链长)及环境因素(絮凝剂投加量和pH等)对其絮凝性能的影响,结合絮凝后上清液Zeta电位、絮体结构的动态监测结果以及扩展DLVO(Derjguin-Landau-Verwey-Overbeek)胶体稳定理论等,详细探究了其絮凝机理.研究结果表明,St-G对石材废水的絮凝性能明显优于传统无机混凝剂聚合氯化铝,St-G对石材废水的除浊作用主要是电荷碎片机制为主导,且与黏结架桥作用协同作用的结果.随着St-G电荷密度的增加,其浊度去除率增加而对应最佳絮凝剂用量减少,且絮体破碎后恢复因子增加;而絮体尺寸、絮体生长速度及其破碎因子均与St-G平均接枝链链长呈正相关.扩展DLVO理论结果也表明,St-G与石材废水胶体颗粒间总相互作用能为负值,且与电荷密度呈负相关,其中电荷密度最大的St-G1总相互作用能最低,最易发生电中和混凝作用,具有最佳的降浊效果.综上可知,St-G的制法安全简便、降浊效果显著、绿色环保且价格低廉,在石材加工等行业废水处理中有着良好的应用前景.

TransPolymer: a Transformer-based language model for polymer property predictions

Accurate and efficient prediction of polymer properties is of great significance in polymer design.Conventionally,expensive and time-consuming experiments or simulations are required to evaluate polymer functions.Recently,Transformer models,equipped with self-attention mechanisms,have exhibited superior performance in natural language processing.However,such methods have not been investigated in polymer sciences.Herein,we report TransPolymer,a Transformer-based language model for polymer property prediction.Our proposed polymer tokenizer with chemical awareness enables learning representations from polymer sequences.Rigorous experiments on ten polymer property prediction benchmarks demonstrate the superior performance of TransPolymer.Moreover,we show that TransPolymer benefits from pretraining on large unlabeled dataset via Masked Language Modeling.Experimental results further manifest the important role of self-attention in modeling polymer sequences.We highlight this model as a promising computational tool for promoting rational polymer design and understanding structure-property relationships from a data science view.

Highly efficient electrocatalytic nitrogen fixation enabled by the bridging effect of Ru in plasmonic nanoparticles

Plasmon-generated hot electrons show great potential for driving chemical reactions.The utilization efficiency of hot electrons is highly dependent on the interaction of the electronic states at the interfaces between plasmonic nanoparticles and other materials/molecules.Strong interaction can produce new hybridized electron states,which permit direct hot-electron transfer,a more efficient transfer mechanism.However,Au usually has very weak interaction with most molecules because of its inertness,which makes direct hot-electron transfer impossible.Herein,the improvement of the hot-electron transfer efficiency from Au to N_(2)is demonstrated by introducing a Ru bridging layer.Both the N_(2)fixation rate and Faradic efficiency(FE)are enhanced by the excitation of plasmons.The enhancement of the N_(2)fixation rate is found to arise from plasmon-generated hot electrons.Theoretical calculations show that the strong interaction of the Ru electronic states with the N_(2)molecular orbitals produces new hybridized electronic states,and the Ru d electrons also strongly couple with the Au sp electrons.Such a bridging role of Ru makes direct hot-electron transfer from Au to N_(2)possible,improving the FE of nitrogen fixation.Our findings demonstrate a new approach to increasing the utilization efficiency of plasmonic hot electrons for chemical reactions and will be helpful to the design of plasmonic catalysts in the future.

Discovery and characterization of novel paramyxoviruses from bat samples in China

Many paramyxoviruses are responsible for a variety of mild to severe human and animal diseases.Based on the novel discoveries over the past several decades,the family Paramyxoviridae infecting various hosts across the world includes 4 subfamilies,17 classified genera and 78 species now.However,no systematic surveys of bat paramyxoviruses are available from the Chinese mainland.In this study,13,064 samples from 54 bat species were collected and a comprehensive paramyxovirus survey was conducted.We obtained 94 new genome sequences distributed across paramyxoviruses from 22 bat species in seven provinces.Bayesian phylodynamic and phylogenetic analyses showed that there were four different lineages in the Jeilongvirus genus.Based on available data,results of host and region switches showed that the bat colony was partial to interior,whereas the rodent colony was exported,and the felines and hedgehogs were most likely the intermediate hosts from Scotophilus spp.rather than rodents.Based on the evolutionary trend,genus Jeilongvirus may have originated from Mus spp.in Australia,then transmitted to bats and rodents in Africa,Asia and Europe,and finally to bats and rodents in America.

层级蜂窝结构面内压缩行为研究:有限元模拟和理论分析

要本文研究了具有三角形子结构的二阶层级蜂窝结构(SHT)的面内压缩特性.在此过程中,正六边形蜂窝结构的细胞壁被替换成两层等边三角形作为子结构。研究结果表明,有限元(FE)模拟和理论分析结果具有良好的一致性.为了展现SHT优越的压缩性能,我们将其与不同种类蜂窝结构的压缩性特性进行了比较.在不同的加载速度下,SHT展现出三种变形模式,并定性获得了模式转换的临界速度.此外,本文还进一步讨论了加载速度和相对密度对压缩平台应力和能量吸收能力的影响.

The Hutong neighbourhood grammar:A procedural modelling approach to unravel the rationale of historical Beijing urban structure

Hutong neighbourhoods,composed of Chinese courtyard dwellings(Siheyuan),are historically and socially significant urban spaces that embody the traditional Chinese way of life and philosophy.As part of the national heritage,there is an increasing research interest in Hutong neighbourhoods,many of which are facing oblivion.This study presents a formal grammar for Hutong neighbourhood generation.This research investigates traditional principles of urban planning of ancient Beijing,based on examples on the historical map Qianlong Jingcheng Quantu,to derive the lost design rules.These rules are used to build up a procedural modelling framework,which reveals the development of Beijing’s urban structure from the Yuan(1271–1368)to the Qing(1644–1911)dynasty.Our findings present a grammar incorporated into the procedural modelling framework to parametrically generate Hutong neighbourhoods,which replicates the morphological characteristics of historic cases.It contributes to the understanding of the generation of Hutong neighbourhoods.In support of heritage sustainability,this grammar can be implemented in a computational environment by visual scripting that enables the generation of new instances of Hutong neighbourhoods,both real and virtual.

A Fluorescein Derivative Chemosensor Combined with Triplet-Triplet Annihilation Upconversion System for Ratiometric Sensing of Cysteine

A derivative of fluorescein,fluorescein O,O-diacrylate(FODA),was utilized in a triplet-triplet annihilation upconversion(TTA-UC)system to develop a composite ratiometric chemosensor capable of detecting cysteine(Cys).FODA acted as both the probe for Cys and the energy acceptor for upconversion(UC)emission,thereby making UC a responsive signal to Cys.In addition,the phosphorescence signal of the sensitizer in the TTA-UC system remained constant and did not respond to Cys,making it an ideal internal reference signal for constructing a ratiometric sensor.Through this simple strategy,traditional fluorescent probes can be combined with TTA-UC system to establish a ratiometric sensing platform,which can be applied in more scenarios due to the longer wavelength excitation.

股权结构、创新投资和创新产出——基于创业板上市公司数据的实证研究

创新是竞争优势的源泉,创新投资是企业实现自主创新的基础。股权结构对公司资源的配置、管理效率和议事规则有着重要影响,从而左右着企业创新投资的效率。已有的文献多集中于创新投资方面,对创新产出较少关注。本文探究了股权结构对创新投资和创新产出的影响,通过多元回归模型和调节变量的回归模型的分析,揭示股权结构、创新投资和企业创新产出的内在联系。实证发现.企业创新投资和创新产出呈正相关,表明样本公司创新是有效率的;以股权分散度衡量的股权结构与企业创新产出呈负相关,同时股权分散度对创新投资和创新产出具有负向的调节效应。这说明股权越分散,对管理层的监督越缺乏,管理层的代理问题越严重,企业的创新产出越低。