Forebrain excitatory neuron-specific loss of Brpf1 attenuates excitatory synaptic transmission and impairs spatial and fear memory

Bromodomain and plant homeodomain(PHD)finger containing protein 1(Brpf1)is an activator and scaffold protein of a multiunit complex that includes other components involving lysine acetyltransferase(KAT)6A/6B/7.Brpf1,KAT6A,and KAT6B mutations were identified as the causal genes of neurodevelopmental disorders leading to intellectual disability.Our previous work revealed strong and specific expression of Brpf1 in both the postnatal and adult forebrain,especially the hippocampus,which has essential roles in learning and memory.Here,we hypothesized that Brpf1 plays critical roles in the function of forebrain excitatory neurons,and that its deficiency leads to learning and memory deficits.To test this,we knocked out Brpf1 in forebrain excitatory neurons using CaMKIIa-Cre.We found that Brpf1 deficiency reduced the frequency of miniature excitatory postsynaptic currents and downregulated the expression of genes Pcdhgb1,Slc16a7,Robo3,and Rho,which are related to neural development,synapse function,and memory,thereby damaging spatial and fear memory in mice.These findings help explain the mechanisms of intellectual impairment in patients with BRPF1 mutation.

A 30-year overview of sodium-ion batteries

Sodium-ion batteries(NIBs)have emerged as a promising alternative to commercial lithium-ion batteries(LIBs)due to the similar properties of the Li and Na elements as well as the abundance and accessibility of Na resources.Most of the current research has been focused on the half-cell system(using Na metal as the counter electrode)to evaluate the performance of the cathode/anode/electrolyte.The relationship between the performance achieved in half cells and that obtained in full cells,however,has been neglected in much of this research.Additionally,the trade-off in the relationship between electrochemical performance and cost needs to be given more consideration.Therefore,systematic and comprehensive insights into the research status and key issues for the full-cell system need to be gained to advance its commercialization.Consequently,this review evaluates the recent progress based on various cathodes and highlights the most significant challenges for full cells.Several strategies have also been proposed to enhance the electrochemical performance of NIBs,including designing electrode materials,optimizing electrolytes,sodium compensation,and so forth.Finally,perspectives and outlooks are provided to guide future research on sodium-ion full cells.

Thickening progression mechanism of silica fume-oil well cement composite system at high temperatures

This work studied the thickening progression mechanism of the silica fume-oil well cement composite system at high temperatures(110-180.C)in order to provide a theoretical guidance for the rational application of silica fume in the cementing engineering.Results showed that silica fume seldom affected the thickening progression of oil well cement slurry at 110-120.C,but when temperature reached above130.C,it would aggravate the bulging degree of thickening curves and significantly extend the thickening time,meanwhile causing the abnormal“temperature-based thickening time reversal”and“dosage-based thickening time reversal”phenomena in the range of 130-160.C and 170-180.C respectively.At 130-160.C,the thickening time of oil well cement slurry was mainly associated with the generation rate of calcium hydroxide(CH)crystal.The introduced silica fume would be attracted to the cement minerals'surface that were hydrating to produce CH and agglomerate together to form an“adsorptive barrier”to hinder further hydration of the inner cement minerals.This“adsorptive barrier”effect strengthened with the rising temperature which extended the thickening time and caused the occurrence of the“temperature-based thickening time reversal”phenomenon.At 170-180.C,the pozzolanic activity of silica fume significantly enhanced and considerable amount of C-S-H was generated,thus the“temperature-based thickening time reversal”vanished and the“dosage-based thickening time reversal”was presented.

Insights on advanced g‐C_(3)N_(4)in energy storage:Applications,challenges,and future

Graphitic carbon nitride(g‐C_(3)N_(4))is a highly recognized two‐dimensional semiconductor material known for its exceptional chemical and physical stability,environmental friendliness,and pollution‐free advantages.These remarkable properties have sparked extensive research in the field of energy storage.This review paper presents the latest advances in the utilization of g‐C_(3)N_(4)in various energy storage technologies,including lithium‐ion batteries,lithium‐sulfur batteries,sodium‐ion batteries,potassium‐ion batteries,and supercapacitors.One of the key strengths of g‐C_(3)N_(4)lies in its simple preparation process along with the ease of optimizing its material structure.It possesses abundant amino and Lewis basic groups,as well as a high density of nitrogen,enabling efficient charge transfer and electrolyte solution penetration.Moreover,the graphite‐like layered structure and the presence of largeπbonds in g‐C_(3)N_(4)contribute to its versatility in preparing multifunctional materials with different dimensions,element and group doping,and conjugated systems.These characteristics open up possibilities for expanding its application in energy storage devices.This article comprehensively reviews the research progress on g‐C_(3)N_(4)in energy storage and highlights its potential for future applications in this field.By exploring the advantages and unique features of g‐C_(3)N_(4),this paper provides valuable insights into harnessing the full potential of this material for energy storage applications.

Elafibranor:A promising treatment for alcoholic liver disease,metabolic-associated fatty liver disease,and cholestatic liver disease

Liver diseases pose a significant threat to human health.Although effective therapeutic agents exist for some liver diseases,there remains a critical need for advancements in research to address the gaps in treatment options and improve patient outcomes.This article reviews the assessment of Elafibranor's effects on liver fibrosis and intestinal barrier function in a mouse model of alcoholic liver disease(ALD),as reported by Koizumi et al in the World Journal of Gastroenterology.We summarize the impact and mechanisms of Elafibranor on ALD,metabolic-associated fatty liver disease,and cholestatic liver disease based on current research.We also explore its potential as a dual agonist of PPARα/δ,which is undergoing Phase III clinical trials for metabolic-associated steatohepatitis.Our goal is to stimulate further investigation into Elafibranor's use for preventing and treating these liver diseases and to provide insights for its clinical application.

In situ observation of the phase transformation kinetics of bismuth during shock release

A time-resolved x-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth.Results reveal a retarded transformation from the shock-induced Bi-Ⅴphase to a metastable Bi-Ⅳphase during the shock release,instead of the thermodynamically stable Bi-Ⅲphase.The emergence of the metastable Bi-Ⅳphase is understood by the competitive interplay between two transformation pathways towards the Bi-Ⅳand Bi-Ⅲ,respectively.The former is more rapid than the latter because the Bi-Ⅴto B-Ⅳtransformation is driven by interaction between the closest atoms while the Bi-Ⅴto B-Ⅲtransformation requires interaction between the second-closest atoms.The nucleation time for the Bi-Ⅴto Bi-Ⅳtransformation is determined to be 5.1±0.9 ns according to a classical nucleation model.This observation demonstrates the importance of the formation of the transient metastable phases,which can change the phase transformation pathway in a dynamic process.

Quality of life after pancreatic surgery

BACKGROUND Pancreatic surgery is challenging owing to the anatomical characteristics of the pancreas.Increasing attention has been paid to changes in quality of life(QOL)after pancreatic surgery.AIM To summarize and analyze current research results on QOL after pancreatic surgery.METHODS A systematic search of the literature available on PubMed and EMBASE was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Relevant studies were identified by screening the references of retrieved articles.Studies on patients’QOL after pancreatic surgery published after January 1,2012,were included.These included prospective and retrospective studies on patients'QOL after several types of pancreatic surgeries.The results of these primary studies were summarized inductively.RESULTS A total of 45 articles were included in the study,of which 13 were related to pancreaticoduodenectomy(PD),seven to duodenum-preserving pancreatic head resection(DPPHR),nine to distal pancreatectomy(DP),two to central pancre-atectomy(CP),and 14 to total pancreatectomy(TP).Some studies showed that 3-6 months were needed for QOL recovery after PD,whereas others showed that 6-12 months was more accurate.Although TP and PD had similar influences on QOL,patients needed longer to recover to preoperative or baseline levels after TP.The QOL was better after DPPHR than PD.However,the superiority of the QOL between patients who underwent CP and PD remains controversial.The decrease in exocrine and endocrine functions postoperatively was the main factor affecting the QOL.Minimally invasive surgery could improve patients’QOL in the early Core Tip:This review summarizes and analyzes current research results on quality of life(QOL)after pancreatic surgery.The article covers the discussion and analysis of the QOL of various pancreatic surgeries.Which kind of surgical procedure has better QOL is controversial.The long-term benefits on QOL of minimally invasive surgery over open surgery are contro-INTRODUCTION The pancreas,located in the retroperitoneum,is a glandular organ with endocrine and exocrine functions.It can be divided into four main parts:Head,neck,body,and tail.Pancreatic surgery can be divided into pancreaticoduoden-ectomy(PD),duodenum-preserving pancreatic head resection(DPPHR),distal pancreatectomy(DP),central pancre-atectomy(CP),and total pancreatectomy(TP).Pancreatic surgery is challenging due to the organ’s complex anatomical structure,peripheral vascularity,and intractable postoperative complications.Following the standardization of surgical steps and improvements in relevant medical techniques and surgical instruments,the safety of pancreatic surgery has significantly improved.Perioperative morbidity,mortality,and other related indicators have become more acceptable.However,owing to the organ’s essential role in digestion,absorption,and blood glucose regulation,changes in the quality of life(QOL)of patients after pancreatic surgery have attracted the attention of surgeons.More patients with non-malignant pancreatic diseases are willing to undergo surgical treatment because of the acceptable safety.In this case,from the perspective of the patient postoperatively,the significance of rehabilitation reflects the traditional perioperative outcome and QOL[1].The QOL is a new concept that extends beyond health.Although there is no consensus on its conception[2],we can consider it a multi-dimensional architecture that incorporates objective and individual subjective views of aspects of one’s physical,psychological,and social well-being[3-5].It includes evaluating physical health,and many subscales,such as emotion,job,culture,family,sociability,economy,cognition,happiness,sex,and some symptoms[6].Since people have realized the importance of QOL,many QOL scales have emerged,including the European Organization for Research and Treatment of Cancer QLQ-C30,European Quality of Life 5-dimension,36-item Short,etc.However,it is challenging to follow up on patients’QOL once they are discharged from the hospital.Consequently,most relevant studies had small sample sizes or lacked long-term follow-up results.Moreover,a summary of studies on QOL after pancreatic surgery is lacking.This study assessed the QOL in patients who underwent PD,DPPHR,DP,CP and TP.We conducted this study to describe the existing findings on the QOL after pancreatic surgery to make it easier for surgeons and patients to decide on a surgical approach.In addition,we attempted to identify controversial results to encourage further targeted research.

Helicobacter pylori,esophageal precancerous lesions,and proton pump inhibitor overuse

This article reviews the cohort study published in the World Journal of Gastroenterology,which reported low rates of Helicobacter pylori(H.pylori)infection among esophageal cancer(EC)patients,coupled with proton pump inhibitor(PPI)overuse.These findings suggest a potential protective role of H.pylori against EC and indicate a possible association between PPI use and increased cancer risk.In light of these findings,our article examines the complex relationship between H.pylori and esophageal precancerous lesions,exploring the potential underlying mechanisms.We also address growing concerns regarding PPI overuse,including its potential effects on cancer therapy efficacy and the risk of drug interactions.Ultimately,this article highlights the urgent need for further research to evaluate the safety and efficacy of PPIs in cancer patients and to better understand their broader implications.

Influences of the Fresh Air Volume on the Removal of Cough-Released Droplets in a Passenger Car of a High-Speed Train Using CFD

The spread and removal of pollution sources,namely,cough-released droplets in three different areas(front,middle,and rear areas)of a fully-loaded passenger car in a high-speed train under different fresh air flow volume were studied using computational fluid dynamics(CFD)method.In addition,the structure of indoor flow fields was also analysed.The results show that the large eddies are more stable and flow faster in the air supply under Mode 2(fresh air volume:2200m3/h)compared to Mode 1(fresh air volume:1100m3/h).By analysing the spreading process of droplets sprayed at different locations in the passenger car and with different particle sizes,the removal trends for droplets are found to be similar under the two air supply modes.However,when increasing the fresh air flow volume,the droplets in the middle and front areas of the passenger car are removed faster.When the droplets had dispersed for 60s,Mode 2 exhibited a removal rate approximately 1%–3%higher than Mode 1 for small and medium-sized droplets with diameters of 10 and 50μm.While those in the rear area,the situation is reversed,with Mode 1 slightly surpassing Mode 2 by 1%–3%.For large droplets with a diameter of 100μm,both modes achieved a removal rate of over 96%in all three regions at the 60 s.The results can provide guidance for air supply modes of passenger cars of high-speed trains,thus suppressing the spread of virus-carrying droplets and reducing the risk of viral infection among passengers.

Patient-derived induced pluripotent stem cells with a MERTK mutation exhibit cell junction abnormalities and aberrant cellular differentiation potential

BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease mechanisms.However,iPSCs carrying specific mutations may limit their clinical applications due to certain inherent characteristics.AIM To investigate the impact of MERTK mutations on hiPSCs and determine whether hiPSC-derived extracellular vesicles(EVs)influence anomalous cell junction and differentiation potential.METHODS We employed a non-integrating reprogramming technique to generate peripheral blood-derived hiPSCs with and hiPSCs without a MERTK mutation.Chromo-somal karyotype analysis,flow cytometry,and immunofluorescent staining were utilized for hiPSC identification.Transcriptomics and proteomics were employed to elucidate the expression patterns associated with cell junction abnormalities and cellular differentiation potential.Additionally,EVs were isolated from the supernatant,and their RNA and protein cargos were examined to investigate the involvement of hiPSC-derived EVs in stem cell junction and differentiation.RESULTS The generated hiPSCs,both with and without a MERTK mutation,exhibited normal karyotype and expressed pluripotency markers;however,hiPSCs with a MERTK mutation demonstrated anomalous adhesion capability and differentiation potential,as confirmed by transcriptomic and proteomic profiling.Furthermore,hiPSC-derived EVs were involved in various biological processes,including cell junction and differentiation.CONCLUSION HiPSCs with a MERTK mutation displayed altered junction characteristics and aberrant differentiation potential.Furthermore,hiPSC-derived EVs played a regulatory role in various biological processes,including cell junction and differentiation.

Pannexins in the musculoskeletal system:new targets for development and disease progression

During cell differentiation,growth,and development,cells can respond to extracellular stimuli through communication channels.Pannexin(Panx)family and connexin(Cx)family are two important types of channel-forming proteins.Panx family contains three members(Panx1-3)and is expressed widely in bone,cartilage and muscle.Although there is no sequence homology between Panx family and Cx family,they exhibit similar configurations and functions.Similar to Cxs,the key roles of Panxs in the maintenance of physiological functions of the musculoskeletal system and disease progression were gradually revealed later.Here,we seek to elucidate the structure of Panxs and their roles in regulating processes such as osteogenesis,chondrogenesis,and muscle growth.We also focus on the comparison between Cx and Panx.As a new key target,Panxs expression imbalance and dysfunction in muscle and the therapeutic potentials of Panxs in joint diseases are also discussed.

央地间文化纽带与财政转移支付

财政转移支付是实现区域均衡发展和共同富裕的重要政策工具,但央地间的信息不对称降低了资源配置效率。本文认为,转移支付的分配者与地方间的文化纽带会帮助纠正信息不对称问题,提高资源配置效率。本文利用部长更替的准自然实验构造了渐进双重差分模型,实证结果显示,在任部长会给其出生地文化区的人均专项转移支付带来18.41万元的增长,相当于平均水平的10.7%;这一结果是稳健性的,且效应受到部长掌握资源的多寡以及文化纽带的强弱所影响;由文化纽带配置的专项资金能显著提振当地经济,且刺激效应大于其他的专项资金。本文的结果有助于我们理解传统文化如何嵌入国家治理体系并提高治理效率,对中国式现代化的实现提供了理论支撑。

Estimation of speed-related car body acceleration limits with quantile regression

Purpose–This study aimed to facilitate a rapid evaluation of track service status and vehicle ride comfort based on car body acceleration.Consequently,a low-cost,data-driven approach was proposed for analyzing speed-related acceleration limits in metro systems.Design/methodology/approach–A portable sensing terminal was developed to realize easy and efficient detection of car body acceleration.Further,field measurements were performed on a 51.95-km metro line.Data from 272 metro sections were tested as a case study,and a quantile regression method was proposed to fit the control limits of the car body acceleration at different speeds using the measured data.Findings–First,the frequency statistics of the measured data in the speed-acceleration dimension indicated that the car body acceleration was primarily concentrated within the constant speed stage,particularly at speeds of 15.4,18.3,and 20.9 m/s.Second,resampling was performed according to the probability density distribution of car body acceleration for different speed domains to achieve data balance.Finally,combined with the traditional linear relationship between speed and acceleration,the statistical relationships between the speed and car body acceleration under different quantiles were determined.We concluded the lateral/vertical quantiles of 0.8989/0.9895,0.9942/0.997,and 0.9998/0.993 as being excellent,good,and qualified control limits,respectively,for the lateral and vertical acceleration of the car body.In addition,regression lines for the speedrelated acceleration limits at other quantiles(0.5,0.75,2s,and 3s)were obtained.Originality/value–The proposed method is expected to serve as a reference for further studies on speedrelated acceleration limits in rail transit systems.

Intelligent pavement condition survey:Overview of current researches and practices

Automated pavement condition survey is of critical importance to road network management.There are three primary tasks involved in pavement condition surveys,namely data collection,data processing and condition evaluation.Artificial intelligence(AI)has achieved many breakthroughs in almost every aspect of modern technology over the past decade,and undoubtedly offers a more robust approach to automated pavement condition survey.This article aims to provide a comprehensive review on data collection systems,data processing algorithms and condition evaluation methods proposed between 2010 and 2023 for intelligent pavement condition survey.In particular,the data collection system includes AI-driven hardware devices and automated pavement data collection vehicles.The AI-driven hardware devices including right-of-way(ROW)cameras,ground penetrating radar(GPR)devices,light detection and ranging(LiDAR)devices,and advanced laser imaging systems,etc.These different hardware components can be selectively mounted on a vehicle to simultaneously collect multimedia information about the pavement.In addition,this article pays close attention to the application of artificial intelligence methods in detecting pavement distresses,measuring pavement roughness,identifying pavement rutting,analyzing skid resistance and evaluating structural strength of pavements.Based upon the analysis of a variety of the state-of-the-art artificial intelligence methodologies,remaining challenges and future needs with respect to intelligent pavement condition survey are discussed eventually.

第二配位层磺酸根在电催化析氢反应中的作用

析氢反应涉及电子和质子转移过程,即PCET过程,需要较大的过电势才可以驱动析氢反应发生.因此,合成过电势低,活性高的催化剂成为研究热点.自然界中,铁铁氢化酶可以将质子高效地还原成氢气.经研究,铁铁氢化酶的结构中有一个氨基基团位于活性金属中心铁的一侧,因此可以精准、有效地将质子传递给金属铁,从而提高催化效率.受自然界启发,很多分子催化剂模拟了自然界中氢化酶的结构,在分子内引入proton-relay基团,促进了析氢过程中PCET的过程.但目前只有关于这类分子催化剂通过促进质子传输进而提高催化效率的文献报道,尚未发现有关其改变氢氢成键方式的研究.前期工作中,本课题组设计合成了卟啉镓并用于电催化质子还原的研究.利用循环伏安法对其析氢活性进行了测试,发现分别以三氟乙酸(TFA)和醋酸(HOAc)作为质子源时,催化析氢的电化学行为不同.在强酸(TFA)体系中,催化剂在经历了两电子还原后,生成的金属氢化物可以直接和质子发生反应,生成氢气.但是在弱酸(HOAc)体系中,生成的金属氢化物需要再经过一电子的还原才可以驱动整个催化反应的进行.在该工作的基础上,通过调研文献得知,在分子内引入酸基团时,可以极大地增加中心金属周围的质子浓度,并且改善质子传输的速率.基于以上想法,在卟啉镓的分子内引入了磺酸基团作为proton-relay的中心,使催化剂能够在弱酸存在的体系中实现强酸的催化析氢路径.本文合成了第二配位层带磺酸基团的卟啉镓化合物(1).在弱酸(HOAc)作为外加质子源时,利用循环伏安法证明了生成的镓氢化合物是真正的活性物种,可以驱动整个催化析氢反应的发生.循环伏安法实验结果表明,化合物1具有很高的催化活性,其TOF值可以达到1.3×10^(5)s^(-1).为了进一步研究催化机理,通过停留光谱实验对该反应进行了原位监测,将化合物1两电子还原后形成的物种(12-)与HOAc的乙腈溶液混合,混合液的紫外光谱可以迅速变回到化合物1原始的光谱,进一步证明了引入磺酸基团可以使生成的镓氢化合物能够直接与弱酸(HOAc)发生反应生成氢气.理论计算结果表明,引入磺酸基团可以显著地降低氢氢成键的能垒.因此,引入磺酸基团,利用限域效应使催化剂周围的质子浓度和强度增强,从而使催化剂能够在弱酸体系中通过强酸的催化路径生成氢气.综上,本文阐明了第二配位层proton-relay基团具有促进质子转移和调控氢氢成键过程的作用,为设计具有优异电催化析氢性能的分子催化剂提供了新的思路.

Oral pathogen aggravates atherosclerosis by inducing smooth muscle cell apoptosis and repressing macrophage efferocytosis

Periodontitis imparting the increased risk of atherosclerotic cardiovascular diseases is partially due to the immune subversion of the oral pathogen,particularly the Porphyromonas gingivalis(P.gingivalis),by inducing apoptosis.However,it remains obscure whether accumulated apoptotic cells in P.gingivalis-accelerated plaque formation are associated with impaired macrophage clearance.

Effect of radiolysis of TODGA on the extraction of TODGA/n-dodecane toward Eu(Ⅲ):an experimental and DFT study

N,N,N′,N′-Tetraoctyl diglycolamide(TODGA)is one of the most promising extractants tailored for high-level liquid radioactive waste treatment during nuclear fuel reprocessing.Theγ-radiolysis of TODGA(0.2 mol/L)in n-dodecane(n DD)solution with and without pre-equilibrated 3.0 mol/L HNO_(3)was investigated using HPLC and UPLC-QTOF-MS and compared with theγ-radiolysis of neat TODGA in this study.With increased absorbed doses,the concentration of TODGA decreased exponentially for the studied systems.Moreover,pre-equilibration with HNO_(3)(3.0 mol/L)slightly influenced theγ-radiolysis of TODGA in n DD.Seven radiolytic products generated from the rupture of the C–C,C–O,and C–N bonds in TODGA were identified in the studied extraction system.The influence ofγ-radiation on TODGA/n DD for the extraction of Eu(Ⅲ)was evaluated using the first combination of extraction experiments and density functional theory(DFT)calculations,in which the complexations of Eu(Ⅲ)with TODGA and its radiolytic products were systematically compared.Based on the radiolysis kinetic model of TODGA,the slope curve of the distribution ratio of Eu(Ⅲ)(D_(Eu))and the absorbed dose,and fluorescence titration analysis,the empirical equation of the absorbed dose and D_(Eu)was obtained successfully.Below 300 kGy,the experimental D_(Eu)agreed well with the obtained empirical equation for TODGA/n DD.Conversely,at a high absorbed dose,the experimental D_(Eu)was higher than the theoretical D_(Eu)based on the empirical equation because the radiolytic products of TODGA with similar coordination structures still possessed partial complexation toward Eu(Ⅲ),which was confirmed by DFT calculations.This work provides a method to predict the extraction distribution ratio of an irradiated extractant system and to understand the complex extraction process.

Designing interstitial boron-doped tunnel-type vanadium dioxide cathode for enhancing zinc ion storage capability

Chemical doping is a powerful method to intrinsically tailor the electrochemical properties of electrode materials.Here,an interstitial boron-doped tunnel-type VO_(2)(B)is constructed via a facile hydrothermal method.Various analysis techniques demonstrate that boron resides in the interstitial site of VO_(2)(B)and such interstitial doping can boost the zinc storage kinetics and structural stability of VO_(2)(B)cathode during cycling.Interestingly,we found that the boron doping level has a saturation limit peculiarity as proved by the quantitative analysis.Notably,the 2 at.%boron-doped VO_(2)(B)shows enhanced zinc ion storage performance with a high storage capacity of 281.7 mAh g^(-1) at 0.1 A g^(-1),excellent rate performance of 142.2 mAh g^(-1) at 20 A g^(-1),and long cycle stability up to 1000 cycles with the capacity retention of 133.3 mAh g^(-1) at 5 A g^(-1).Additionally,the successful preparation of the boron-doped tunneltype α-MnO_(2) further indicates that the interstitial boron doping approach is a general strategy,which supplies a new chance to design other types of functional electrode materials for multivalence batteries.

新时代甘肃红色文化资源数字化传播机制研究

甘肃红色文化资源在全国红色文化资源中独一无二、影响深远,在革命建设和改革中留下了独一无二的红色资源,可以充分利用信息技术的优势实现甘肃红色文化资源数字化传播。新时代甘肃红色文化资源数字化传播的不仅具有资源本身的优势,还有信息技术与政府的有力支撑,更重要是新时代甘肃红色文化资源数字化传播承载着一定的价值意蕴:一是有利于推动实现红色文化大众化;二是有利于增强四个自信;三是有利于为建设幸福美好新甘肃提供精神动力。因此,新时代甘肃红色文化资源数字化传播要健全政府政策引导机制,建立技术研发保障机制,完善红色文化资源保护研究机制。

Effect of Initial Microstructure Prior to Extrusion on the Microstructure and Mechanical Properties of Extruded AZ80 Alloy with a Low Temperature and a Low Ratio

Magnesium(Mg)alloys are the lightest metal structural material for engineering applications and therefore have a wide market of applications.However,compared to steel and aluminum alloys,Mg alloys have lower mechanical properties,which greatly limits their application.Extrusion is one of the most important processing methods for Mg and its alloys.However,the effect of such a heterogeneous microstructure achieved at low temperatures on the mechanical properties is lacking investigation.In this work,commercial AZ80 alloys with different initial microstructures(as-cast and as-homogenized)were selected and extruded at a low extrusion temperature of 220℃and a low extrusion ratio of 4.The microstructure and mechanical properties of the two extruded AZ80 alloys were investigated.The results show that homogenized-extruded(HE)sample exhibits higher strength than the cast-extruded(CE)sample,which is mainly attributed to the high number density of fine dynamic precipitates and the high fraction of recrystallized ultrafine grains.Compared to the coarse compounds existing in CE sample,the fine dynamical precipitates of Mg17(Al,Zn)12form in the HE sample can effectively promote the dynamical recrystallization during extrusion,while they exhibit a similar effect on the size and orientation of the recrystallized grains.These results can facilitate the designing of high-strength wrought magnesium alloys by rational microstructure construction.