复合型水性丙烯酸树脂乳液的制备和性能

采用低玻璃化转变温度、高分子量的丙烯酸树脂乳液与高玻璃化转变温度、低分子量的丙烯酸树脂分散体混合的方式,制备了无交联剂水性丙烯酸树脂复合乳液,用于彩印包装纸与塑料薄膜的热复合。以丙烯酸、丙烯酸丁酯、苯乙烯、丙烯酸羟乙酯等为原料,采用种子乳液聚合法制备了相对分子质量(1.48~1.84)×10^(5)、玻璃化转变温度(T_(g))﹣20~﹣40℃的丙烯酸酯乳液。以丙烯酸、丙烯酸丁酯、苯乙烯、α-甲基苯乙烯、马来酸单酯等为原料,采用本体聚合法制备了相对分子质量(1.34~1.65)×10^(4)、T_(g) 20~45℃、软化点80~105℃的固体树脂,进一步采用自乳化方法将固体树脂制备成树脂水分散体。考察了不同Tg的丙烯酸酯乳液与水分散体以不同比例混配后的乳液混合体的性能。研究结果表明,T_(g)为﹣27.6℃的丙烯酸酯乳液与Tg为28.2℃固体树脂的分散体以质量比8:2混合后,用于PET膜-黑色印刷纸的热复合,剥离强度达到5.6 N/25 mm,持粘性达270 h,可以充分满足覆膜材料的附着力和耐压纹等性能要求。

Identification and characterization of FpRco1 in regulating vegetative growth and pathogenicity based on T-DNA insertion in Fusarium pseudograminearum

Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.

A universal multifunctional dual cation doping strategy towards stabilized ultra-high nickel cobalt-free lithium layered oxide cathode

Ultra-high nickel cobalt-free lithium layered oxides are promising cathode material for lithium-ion batteries(LIBs)because of their relatively high capacity and low cost.Nevertheless,the high nickel content would induce bulk structure degradation and interfacial environment deterioration,and the absence of Co element reduces the lithium diffusion kinetics,severely limiting the performance liberation of this kind of cathodes.Herein,a multifunctional Ti/Zr dual cation co-doping strategy has been employed to improve the lithium storage performance of LiNi_(0.9)Mn_(0.1)O_(2)(NM91)cathode.On the one hand,the Ti/Zr co-doping weakens the Li^(+)/Ni^(2+)mixing through magnetic interactions due to the inexistence of unpaired electrons for Ti^(4+)and Zr^(4+),increasing the lithium diffusion rate and suppressing the harmful coexistence of H1 and H2 phases.On the other hand,they enhance the lattice oxygen stability because of the strong Ti-O and Zr-O bonds,inhibiting the undesired H3 phase transition and lattice oxygen loss,improving the bulk structure and cathode-electrolyte interface stability.As a result,the Ti/Zr co-doped NM91(NMTZ)exhibits a 91.2%capacity retention rate after 100 cycles,while that of NM91 is only82.9%.Also,the NMTZ displays better rate performance than NM91 with output capacities of 115 and93 mA h g^(-1)at a high current density of 5 C,respectively.Moreover,the designed NMTZ could enable the full battery to deliver an energy density up to 263 W h kg^(-1),making the ultra-high nickel cobaltfree lithium layered oxide cathode closer to practical applications.

Unlocking the potential of ultra-thin two-dimensional antimony materials:Selective growth and carbon coating for efficient potassium-ion storage

Antimony-based anodes have attracted wide attention in potassium-ion batteries due to their high theoretical specific capacities(∼660 mA h g^(-1))and suitable voltage platforms.However,severe capacity fading caused by huge volume change and limited ion transportation hinders their practical applications.Recently,strategies for controlling the morphologies of Sb-based materials to improve the electrochemical performances have been proposed.Among these,the two-dimensional Sb(2D-Sb)materials present excellent properties due to shorted ion immigration paths and enhanced ion diffusion.Nevertheless,the synthetic methods are usually tedious,and even the mechanism of these strategies remains elusive,especially how to obtain large-scale 2D-Sb materials.Herein,a novel strategy to synthesize 2D-Sb material using a straightforward solvothermal method without the requirement of a complex nanostructure design is provided.This method leverages the selective adsorption of aldehyde groups in furfural to induce crystal growth,while concurrently reducing and coating a nitrogen-doped carbon layer.Compared to the reported methods,it is simpler,more efficient,and conducive to the production of composite nanosheets with uniform thickness(3–4 nm).The 2D-Sb@NC nanosheet anode delivers an extremely high capacity of 504.5 mA h g^(-1) at current densities of 100 mA g^(-1) and remains stable for more than 200 cycles.Through characterizations and molecular dynamic simulations,how potassium storage kinetics between 2D Sb-based materials and bulk Sb-based materials are explored,and detailed explanations are provided.These findings offer novel insights into the development of durable 2D alloy-based anodes for next-generation potassium-ion batteries.

Technique of Earthworms Restoring Soil in Greenhouse Cultivation

The production environment of greenhouse cultivation is relatively closed,the multiple cropping index is high,the management of fertilizationwatering and pesticideapplication isblindtosomeextent,andthe phenomenonofcontinuous cropping isalsocommonSoilquali-ty affects the sustainable development of greenhouse cultivation.Earthworm is a ubiquitous invertebrate organism in soil,an important part of soil system,a link between terrestrial organisms and soil organisms,an important link in the small cycle of soil material organisms,and plays an important role in maintaining the structure and function of soil ecosystem.Different ecotypes of earthworms are closely related to their habi-tats(soil layers)and food resource preferences,and then affect their ecological functions.The principle of earthworm regulating soil function is essentially the close connection and interaction between earthworm and soil microorganism.Using different ecotypes of earthworms and bio-logical agents to carry out combined remediation of greenhouse cultivation soil is a technical model to realize sustainable development of green-house cultivation.

PsERF1B-PsMYB10.1-PsbHLH3 module enhances anthocyanin biosynthesis in the flesh-reddening of amber-fleshed plum (cv. Friar) fruit in response to cold storage

Flesh-reddening usually occurs in the amber-fleshed plum(Prunus salicina Lindl.)fruit during cold storage but not during ambient storage direct after harvest.It is not clear how postharvest cold signal is mediated to regulate the anthocyanin biosynthesis in the forming of flesh-reddening yet.In this study,anthocyanins dramatically accumulated and ethylene produced in the‘Friar’plums during cold storage,in comparison with plums directly stored at ambient temperature.Expression of genes associated with anthocyanin biosynthesis,as well as transcription factors of PsMYB10.1,PsbHLH3,and PsERF1B were strongly stimulated to upregulated in the plums in the period of cold storage.Suppression of ethylene act with 1-methylcyclopropene greatly suppressed flesh-reddening and downregulated the expression of these genes.Transient overexpression and virus-induced gene silencing assays in plum flesh indicated that PsMYB10.1 encodes a positive regulator of anthocyanin accumulation.The transient overexpression of PsERF1B,coupled with PsMYB10.1 and PsbHLH3,could further prompt the anthocyanin biosynthesis in a tobacco leaf system.Results from yeast two-hybrid and luciferase complementation assays verified that PsERF1B directly interacted with PsMYB10.1.PsERF1B and PsMYB10.1 enhanced the activity of the promoter of PsUFGT individually,and the enhancement was prompted by the co-action of PsERF1B and PsMYB10.1.Overall,the stimulation of the PsERF1B-PsMYB10.1-PsbHLH3 module mediated cold signal in the transcriptomic supervision of the anthocyanin biosynthesis in the‘Friar’plums.The results thereby revealed the underlying mechanism of the postharvest alteration of the flesh phenotype of‘Friar’plums subjected to low temperature.

Proton pitch angle distributions in the Martian induced magnetosphere: A survey of Tianwen-1 Mars Ion and Neutral Particle Analyzer observations

The pitch angle distributions of ions and electrons can be affected by various processes;thus,they can serve as an important indicator of the physical mechanisms driving the dynamics of space plasmas.From observations from the Mars Ion and Neutral Particle Analyzer onboard the Tianwen-1 orbiter,we calculated the pitch angle distributions of protons in the Martian induced magnetosphere by using information from the magnetohydrodynamically simulated magnetic field,and we statistically analyzed the spatial occurrence pattern of different types of pitch angle distributions.Even though no symmetrical features were seen in the dataset,we found the dominance of the field-aligned distribution type over the energy range from 188 to 6232 eV.Maps of the occurrence rate showed the preferential presence of a trapped-like distribution at the lower altitudes of the surveyed nightside region.Although our results are more or less restricted by the adopted magnetic field,they indicate the complexity of the near-Mars proton pitch angle distributions and infer the possibility of wave–particle interactions in the Martian induced magnetosphere.

精细化工的先驱:Sir William Henry Perkin与合成染料

William Henry Perkin爵士是一位著名的有机化学家,也是有机化学工业先驱。他一生品行端正,为后世之楷模。关于Perkin的外文传记颇多,而中文文献较少。本文查阅并梳理了相关的文献,对Perkin成长的时代背景、科学贡献、人物生平和对后代的影响进行了描述,以求对化学教育和个人成长提供启发和借鉴。

Effects of constant light and dark conditions on the locomotor activity,body mass,and body temperature rhythms of Eurasian Tree Sparrows(Passer montanus)

Light is an essential environmental cue influencing the endogenous circadian clocks that regulate behavioral and physiological processes in animals.Despite extensive research on the circadian rhythms of avian behavior and physiology,the mechanisms by which they adapt and adjust to abnormal photoperiod conditions,such as artificial light,have yet to be fully elucidated.Here,the circadian rhythms of the body mass,activity,and core and peripheral body temperatures of the Eurasian Tree Sparrow(Passer montanus,ETS)-a diurnal passerine-were examined under three different lighting conditions:constant light(LL),constant darkness(DD),and normal light-dark cycles(LD).Our results showed that the activity,body mass,core,tarsometatarsus,and eye temperatures of the ETSs varied significantly with treatment,time,and the interaction between treatment and time;however,there was no significant change in body mass in response to the interaction between time and treatment.Under LD conditions,the ETSs exhibited significant circadian rhythms in activity and core,tarsometatarsus,and eye temperatures.Under LL conditions,only the core temperature exhibited significant rhythmicity.Under DD conditions,there were no significant circadian rhythms in activity,body mass,and eye temperature;however,the core and tarsometatarsus temperatures remained rhythmic.Our results indicate that the core body temperature rhythm of ETS is endogenous and can be maintained under abnormal photoperiods.In contrast,the activity and body surface temperature,uncoupled from the core body temperature under abnormal photoperiod conditions,strongly depend on light.These results differ from those of other diurnal avian species,suggesting a unique coping mechanism of ETS in response to an abnormal photoperiod.

A comparison study of prevalence,awareness,treatment and control rates of hypertension and associated factors among adults in China and the United States based on national survey data

Objective:This study compared the prevalence,awareness,treatment and control of hypertension and associated factors in China and the United States(US).Methods:Adult data from nationally representative samples were derived from the Chronic Disease and Risk Factors Surveillance in 2010 and 2013 in China and the National Health and Nutrition Examination Survey in 2010 and 2013 in the US.Multivariable logistic and Poisson regression analysis were conducted to assess associations of the four outcomes with body weight status and behavioral factors.Results:Age-standardized prevalence rates of hypertension was 35.7%(95%confidence interval[CI]:35.4%to 36.1%)in 2010 and 29.8%(95%CI:29.4%to 30.2%)in 2013 in China,and 35.3%(95%CI:33.6%to 37.1%)in 2010 and 37.9%(95%CI:36.0%to 39.7%)in 2013 in the US.Among hypertensive participants,the age-standardized rates of treatment were 18.4%(95%CI:17.9%to 1&9%)in 2010 and 23.8%(95%CI:23.1%to 24.6%)in 2013 in China and 54.5%(95%CI:50.3%to 5&7%)in 2010 and 50.9%(95%CI:46.5%to 55.3%)in 2013 in the US;the age-standardized hypertension control rates were 3.2%(95%CI:3.0%to 3.5%)and 5.7%(95%CI:5.3%to 6.0%)in 2010 and 2013 in China and 50.6%(95%CI:46.2%to 55.0%)and 55.3%(95%CI:50.3%to 60.3%)in the US.Obesity was significantly associated with prevalence,awareness and control rates in both countries.Different from the US,obesity was negatively associated with hypertension control in China.Conclusion:Hypertension prevalence in China is similar to that in the US,but the control rate in China was significantly lower.Obesity was a critical risk factor for poor hypertension control in China.

天空地数字农业管理系统框架设计与构建建议

数据正在成为基础性战略资源。构建以天空地大数据为关键要素的数字农业管理系统,对于建设数字中国、推进农业高质量发展、抢占全球农业制高点具有重要意义。本研究围绕农业农村部提出的天空地数字农业管理系统建设任务,从农业信息技术学科出发,首先给出了天空地数字农业的科学内涵,阐述了其与传统数字农业的异同点,理清了天空地数字农业管理系统在资源调查、生产调度、灾害监测、市场预警、决策服务的五大核心功能;其次,重点阐述了天空地数字农业管理系统的关键任务,即一个观测体系(天空地一体化的数字农业观测体系)、四个数字化(农业资源权属、生产过程、灾害监测和市场预警)、一个管理平台(农业生产、加工、经营、管理、服务等全产业链的天空地数字农业管理平台);然后,明确提出了天空地数字农业管理系统在标准规范研制、关键技术与装备研发、系统集成与平台开发三方面的科技创新重点任务;最后,针对天空地数字农业管理系统建设的复杂性和系统性,从规划设计、科技创新、资源共享、多方参与、应用领域拓展等方面提出了发展建议。

贵阳市府社区老年人群的中医体质分析

目的通过对贵阳市府社区的650例60岁及以上老年人群进行中医体质调查,分析不同性别、不同年龄组老年人群的中医体质类型特点,从而为中医体质辨证在老年人群疾病防治、中医养生保健、宣传教育等方面提供流行病学调查数据支持。方法通过社区中医师一对一采集基本个人信息、调查问卷及量表的形式进行中医体质辨识。结果单一体质316人,阴虚质、平和质和痰湿质为前三位,其中阴虚质92人,平和质78人,痰湿质63人;复合体质334人,前三位依次是阴虚痰湿60人,气虚阴虚56人,阴虚血瘀51人。不同性别、不同年龄组分布构成比不同,差异具有统计学意义(P<0.001)。结论通过本次对贵阳市府社区老年人人群进行中医体质辨识流行病学调查,揭示了贵阳市府社区老年人群的中医体质类型分布规律,有助于把握老年人体质特点,对调整体质偏颇,提高老年人健康素质具有重要的实用价值。

Research-training needs of clinical nurses: A nationwide study among tertiary hospitals in China

Objective: This study aimed to evaluate Chinese tertiary hospital nurses' research output,research ability,and their related training needs regarding scientific research methodology and analyze the relations among them.Methods: A nationwide survey was conducted in China on a large sample of tertiary hospital nurses (n =27,335) recruited from 22 provinces,autonomous regions,and municipalities.A validated,self-designed questionnaire,consisted of a common questionnaire,the Science Research Skills Self-Rating Questionnaire (SRSQ) and the Scientific Research Training Needs Questionnaire (SRTNQ) were used to assess nurses' research output,self-rated research skills and research-training needs.Results: The nurses' scientific research participation rates (with 4.13%,7.85%,5.35%,and 2.04% in research projects,research attendance,papers published,and patent,respectively) and their self-rated research skills 25.00 (12.50,37.50) were very low.However,the research training needs were relatively high 53.12(37.50,75.00).Significant differences in research participation rates (research projects,research attendance,papers published,and patent),scientific research skills,and research-training needs were determined by age,highest education level,nursing experience,employment,technical title,administrative post,and clinical tutoring experience (P< 0.05).Female and male nurses had different research participation rates (only research projects and studies published) and scientific research skills (P < 0.05).Positive correlations were observed among research output,scientific research skills,and researchtraining needs (P < 0.01).Conclusions: Nurses' scientific research participation and self-rated research ability were below the optimal despite that they had relatively high research-training needs.Nurses should be provided further research training with tailored content to their characteristics and capacity.

Systematic Identification of the Light-quality Responding Anthocyanin Synthesis-related Transcripts in Petunia Petals

Previous studies have shown that high light intensity can induce anthocyanin synthesis(AS)in petunia plants.To identifywhich kind of light quality plays a role in inducing such metabolic process,and what transcripts participate in controlling it,we carried out whole-transcriptome sequencing and analysis of petunia petals treated with different light-quality conditions.Among the red and white light treatments,a total of 2205 differentially expressed genes and 15,22,and 20 differentially expressed circRNAs,miRNAs,and lncRNAs,were identified respectively.The AS-related genes,including the structural genes CHSj,F3H,F35H,DFR,and ANS,and the regulatory genes AN4,DPL,PHZ and MYBx were found to be downregulated under red light condition compared with their levels under white light condition.Furthermore,the light photoreceptor Cryptochrome 3(CRY3)and a series of light-dependent genes,such as PIF,HY5,andBBXs,were also determined to respond to the light treatments.The anthocyanin contents in early petunia petals under red light were significantly lower than that under white and blue light.The results of qRT-PCR further confirmed the expression pattern of some AS-related and light-response genes in response to different light quality.Yeast two-hybrid results showed that the key elements in the light signal pathway,HY5 can interact with BBX19,BBX24 and BBX25.And PHZ,the important AS regulator can induce anthocyanin synthesis in response to blue light quality fromtransient expression analysis in petunia petals.These findings presented here not only deepen our understanding of how light quality controls anthocyanin synthesis,but also allow us to explore potential target genes for improving pigment production in petunia flower petals.

Sn-based Intermetallic Compounds for Li-ion Batteries: Structures, Lithiation Mechanism, and Electrochemical Performances

On account of the lower theoretical capacity of the traditional graphite,the development of reliable anode materials with high capacity and energy density for application in lithium-ion batteries(LIBs)is zealously pursued to meet the ever-increasing power demands for portable mobile devices or(hybrid)electronic vehicles.

Economic evaluation of cervical cancer screening strategies in urban China

Objective:This study evaluated the feasibility of different cervical cancer screening strategies in urban China.Methods:A Markov model was constructed to simulate a hypothetical cohort of 100,000 females aged 30-59 years in a 20-year period.Screening strategies included liquid-based cytology(LBC)every three years,human papillomavirus(HPV)DNA testing every three and five years,respectively,and a combination of HPV DNA testing and LBC(HPV+LBC)every three and five years,respectively.Model outcomes included cumulative incidence over 20 years,cumulative risk of cervical cancer,costs,life year saved(LYS),quality-adjusted life years(QALYs)and benefits.The cost-effectiveness ratios(CERs),incremental cost-effectiveness ratios(ICERs),costutility ratios(CURs),and benefit-cost ratios(BCRs)were used as outcomes in the health economic evaluation analysis.Univariate sensitivity analyses were performed to examine the stability of the results.Results:The cumulative incidence of the five screening strategies ranged from 833.02 to 1,158.07 cases per100,000 females.HPV DNA testing was most effective in reducing the cumulative risk of cervical cancer,saving life years and QALYs and gaining benefits.The CERs of HPV DNA testing every three and five years,and LBC every three years were considered to be very cost-effective if they were below China's GDP per capita.The CERs of HPV+LBC were considered to be cost-effective if they were below three times GDP per capita.The incremental cost-effectiveness analysis showed that HPV DNA testing every three and five years,LBC every three years and HPV+LBC every five years were dominant strategies.Conclusions:The findings of this study indicated that HPV DNA testing every five years or LBC every three years should be recommended in urban China.

Amphiphilic small molecular mates match hydrophobic drugs to form nanoassemblies based on drug-mate strategy

Nanomedicine has made great progress in the targeted therapy of cancer. Here, we established a novel drug-mate strategy by studying the formulation of nanodrugs at the molecular level. In the drug-mate combination, the drug is a hydrophobic drug that is poorly soluble in water, and the mate is an amphiphilic small molecule (SMA) that has both hydrophilic and lipophilic properties. We proposed that the hydrophobic drug could co-assemble with a suitable SMA on a nanoscale without additive agents. The proof-ofconcept methodology and results were presented to support our hypothesis. We selected five hydrophobic drugs and more than ten amphiphilic small molecules to construct a library. Through molecular dynamic simulation and quantum chemistry computation,we speculated that the formation of nanoassemblies was related to the binding energy of the drug-mate, and the drug-mate interaction must overcome drug-drug interaction.Furthermore, the obtained SF/VECOONa nanoassemblieswas selected as a model, which had an ultra-high drug loading content (46%), improved pharmacokinetics, increased bioavailability, and enhanced therapeutic efficacy. In summary, the drug-mate strategy is an essential resource to design exact SMA for many hydrophobic drugs and provides a reference for the design of a carrier-free drug delivery system.

Inhibition of growth and metastasis of triple-negative breast cancer targeted by Traditional Chinese Medicine Tubeimu in orthotopic mice models

Objective： Triple-negative breast cancer（TNBC） is highly invasive and metastatic, which is in urgent need of transformative therapeutics. Tubeimu（TBM）, the rhizome of Bolbostemma paniculatum（Maxim.） Franquet, is one of the Chinese medicinal herbs used for breast diseases since the ancient times. The present study evaluated the efficacy, especially the anti-metastatic effects of the dichloromethane extract of Tubeimu（ETBM） on TNBC orthotopic mouse models and cell lines.Methods： We applied real-time imaging on florescent orthotopic TNBC mice model and tested cell migration and invasion abilities with MDA-MB-231 cell line. Digital gene expression sequencing was performed and Kyoto Encyclopedia of Genes and Genomes（KEGG） analysis applied to explore the pathways influenced by ETBM.Moreover, quantitative real-time polymerase chain reactions（q RT-PCR） and Western blot were delivered to confirm the gene expression changes.Results： ETBM exhibited noticeable control on tumor metastasis and growth of TNBC tumors with no obvious toxicity. In compliance with this, it also showed inhibition of cell migration and invasion in vitro. Its impact on the changed biological behavior in TNBC may be a result of decreased expression of integrin β1（ITGβ1）, integrin β8（ITGβ8） and Rho GTPase activating protein 5（ARHGAP5）, which disabled the focal adhesion pathway and caused change in cell morphology.Conclusions： This study reveals that ETBM has anti-metastatic effects on MDA-MB-231-GFP tumor and may lead to a new therapeutic agent for the integrative treatment of highly invasive TNBC.

Birds and plastic pollution:recent advances

Plastic waste and debris have caused substantial environmental pollution globally in the past decades,and they have been accumulated in hundreds of terrestrial and aquatic avian species.Birds are susceptible and vulnerable to external environments;therefore,they could be used to estimate the negative effects of environmental pollution.In this review,we summarize the effects of macroplastics,microplastics,and plastic-derived additives and plastic-absorbed chemicals on birds.First,macroplastics and microplastics accumulate in different tissues of various aquatic and terrestrial birds,suggesting that birds could suffer from the macroplastics and microplastics-associated contaminants in the aquatic and terrestrial environments.Second,the detrimental effects of macroplastics and microplastics,and their derived additives and absorbed chemicals on the individual survival,growth and development,reproductive output,and physiology,are summarized in different birds,as well as the known toxicological mechanisms of plastics in laboratory model mammals.Finally,we identify that human commensal birds,long-life-span birds,and model bird species could be utilized to different research objectives to evaluate plastic pollution burden and toxicological effects of chronic plastic exposure.

Inner-outer decomposition of wall shear stress fluctuations in turbulent channels

Fluctuating wall shear stress in turbulent channel flows is decomposed into small-scale and large-scale components.The large-scale fluctuating wall shear stress is computed as the footprints of the outer turbulent motions,and the small-scale one is obtained by subtracting the large-scale one from the total,which fully remove the outer influences.We show that the statistics of the small-scale fluctuating wall shear stress is Reynolds number independent at the friction Reynolds number larger than 1000,while which is Reynolds number dependent or the low-Reynolds-number effect exists at the friction Reynolds number smaller than 1000.Therefore,a critical Reynolds number that defines the emergence of universal small-scale fluctuating wall shear stress is proposed to be 1000.The total and large-scale fluctuating wall shear stress intensities approximately follow logarithmic-linear relationships with Reynolds number,and empirical fitting expressions are given in this work.