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。

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.

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.

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。

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.

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.

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.

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.

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.

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。

IPCC第六次评估报告:多年冻土碳循环及其对气候变暖响应的新认识

Carbon cycling in terrestrial ecosystems is an important factor that affects the level and accumulation rate of global atmospheric greenhouse gases and determines the stability of the global climate.From 2010 to 2019,31%of CO_(2) emissions caused by human activities were absorbed by vegetation in terrestrial ecosystems and 23%by the ocean,while the remaining 46%accumulated in the atmosphere.However,as the climate continues to warm。

Parametrising historical Chinese courtyard-dwellings:An algorithmic design framework for the digital representation of Siheyuan iterations based on traditional design principles

Many Beijing Siheyuan,a type of Chinese vernacular housing with significant cultural value,have been lost in recent years.Preserving the few remaining has become a necessity,but many contemporary architects lack an understanding of their design principles.Based on a historical analysis deriving from Fengshui theory,the Gongchens Zuofa Zeli ancient construction manual,and craftsmen's experience,this paper describes a parametric algorithm capable of producing Siheyuan variants within a 4D CAD environment which by transforming the original design principles into an algorithm contributes to an understanding of Siheyuan typology and their preservation.This algorithm was implemented in a virtual scripting environment to generate accurate virtual counterparts of historical orextant Siheyuan houses revealing the tacit computational rules underlying traditional Chinese architecture.

Modulation of hot regions in waveguide-based evanescent-field-coupled localized surface plasmons for plasmon-enhanced spectroscopy

Coupling efficiency between the localized surface plasmons(LSPs) of metal nanoparticles(NPs) and incident light dominates the sensitivities of plasmon-based sensing spectroscopies and imaging techniques, e.g., surfaceenhanced Raman scattering(SERS) spectroscopy. Many endogenous features of metal NPs(e.g., size, shape,aggregation form, etc.) that have strong impacts on their LSPs have been discussed in detail in previous studies.Here, the polarization-tuned electromagnetic(EM) field that facilitates the LSP coupling is fully discussed.Numerical analyses on waveguide-based evanescent fields(WEFs) coupled with the LSPs of dispersed silver nanospheres and silver nano-hemispheres are presented and the applicability of the WEF-LSPs to plasmon-enhanced spectroscopy is discussed. Compared with LSPs under direct light excitation that only provide 3–4 times enhancement of the incidence field, the WEF-LSPs can amplify the electric field intensity about 30–90 times(equaling the enhancement factor of 10~6–10~8 in SERS intensity), which is comparable to the EM amplification of the SERS"hot spot" effect. Importantly, the strongest region of EM enhancement around silver nanospheres can be modulated from the gap region to the side surface simply by switching the incident polarization from TM to TE, which widely extends its sensing applications in surface analysis of monolayer of molecule and macromolecule detections. This technique provides us a unique way to achieve remarkable signal gains in many plasmon-enhanced spectroscopic systems in which LSPs are involved.

Macroporous composite capacitive bioanode applied in microbial fuel cells

Interfacial electron transfer between electroactive biofilm and the electrode was crucial step for microbial fuel cells(MFCs).A three-dimensional multilayer porous sponge coating with nitrogen-doped carbon nanotube/polyaniline/manganese dioxide(S/N-CNT/PANI/MnO2)electrode has been developed for MFC anode.Here,the S/N-CNT/PANI/MnO2 anode can function as a biocapacitor,able to store electrons generated from the degradation of organic substrate under the open circuit state and release the accumulated electrons upon requirement.Thus,the mismatching of the production and demand of the electricity can be overcome.Comparing with the sponge/nitrogen-doped carbon nanotube(S/N-CNT)bioanode,S/N-CNT/PANI/MnO2 capacitive bioanode displays a strong interaction with the microbial biofilm,advancing the electron transfer from exoelectrogens to the bioanode.The maximum power density of MFC with S/N-CNT/PANI/MnO2 capacitive bioanode is 1019.5 mW/m^2,which is 2.2 and5.8 times as much as that of S/N-CNT/MnO2 bioanode and S/N-CNT bioanode(470.7 mW/m^2 and176.6 mW/m^2),respectively.During the chronoamperometric experiment with 60 min of charging and 20 min of discharging,the S/N-CNT/PANI/MnO2 capacitive bioanode was able to store 10743.9 C/m^2,whereas the S/N-CNT anode was only able to store 3323.4 C/m^2.With a capacitive bioanode,it is possible to use the MFC simultaneously for production and storage of electricity.