低温等离子体活化液对血管内皮细胞增殖和血管生成能力的影响

目的探索低温等离子体(low temperature plasma,LTP)产生的活化液(plasma-activated medium,PAM)对人脐静脉血管内皮细胞(human umbilical vein endothelial cells,HUVECs)增殖和血管生成的影响,为未来利用PAM促进创伤愈合和抑制肿瘤血管生成提供理论基础。方法选择HUVECs作为体外研究模型,以LTP处理不同时间(0、15、30、45、60、75 s)后的PAM培养液进行分组干预。采用MTT法和细胞周期法测定PAM对HUVECs活力的影响,通过血管生成实验检测PAM对血管生成的影响,采用荧光探针检测细胞内活性氧(ROS)水平;构建黑色素瘤小鼠模型,免疫组织化学法检测肿瘤组织中CD31的表达以评估血管生成情况。结果LTP处理获得的PAM对HUVECs血管生成具有双向作用,表现为:与对照组(0 s)相比,低剂量(15 s和30 s)处理时,HUVEC细胞活力增加,而高剂量(45 s、60 s和75 s)处理时,细胞活力明显下降(P<0.05);PAM-15 s和PAM-30 s组处于S期的细胞比例明显增高,而PAM-45 s、PAM-60 s、PAM-75 s组处于S期细胞比例显著降低,差异具有统计学意义(P<0.05);PAM-15 s和PAM-30 s组HUVEC血管生成能力增强,而PAM-45 s、PAM-60 s、PAM-75 s组的细胞血管生成能力降低,血管节点、交叉点、网眼数和血管分支数都明显降低(P<0.05)。此外,HUVECs内ROS水平随着LTP处理时间的延长而升高。PAM处理黑色素瘤小鼠后,对照组肿瘤组织中CD31棕黄色阳性信号大面积分布,各PAM处理组肿瘤组织中CD31棕黄色颗粒分布减少。结论短时间LTP处理的PAM促进了HUVEC的增殖和血管生成;而长时间LTP处理的PAM则抑制细胞活力和血管生成。

The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation

The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization.

金宝Prismaflex连续性肾脏替代治疗设备运行原理与故障案例分析

分析金宝Prismaflex连续性肾脏替代治疗(CRRT)机的设计原理和治疗模式,基于设备的基本结构与治疗流程解析CRRT设备出现的压力接头和秤归零测试失败的典型故障案例,提出针对性解决方案及维护保养策略,保障CRRT机稳定高效运行。

基于β-环糊精的高矿化度水中曲拉通X-405的检测新方法

油田压裂用水矿化度高,为了降低压裂用水对紫外光谱法检测聚乙二醇叔辛基苯基醚(曲拉通X-405)产生的影响,采用添加适量β-环糊精(β-CD)作为屏蔽剂来消除压裂用水的干扰作用。研究结果表明,压裂用水能明显降低曲拉通X-405的吸光度和临界胶束浓度(cmc),在压裂用水中,100.0 mg/L曲拉通X-405在最大吸收波长224 nm处的吸光度降幅达6.67%,曲拉通X-405的cmc也由蒸馏水中的103.978 mg/L降低至97.056 mg/L。加入与曲拉通X-405相同物质的量的β-环糊精后,压裂用水对曲拉通X-405吸光度的干扰作用显著降低,100.0 mg/L曲拉通X-405在224 nm处的吸光度降幅仅为1.99%,在20.0~160.0 mg/L范围内,曲拉通X-405在蒸馏水中及在压裂用水中均没有形成胶束,曲拉通X-405的检测回收率也由88.3%~97.4%改善至97.5%~99.6%。等摩尔连续变化法、FT IR及^(1)H NMR结果表明,在水溶液中曲拉通X-405与β-CD按物质的量比1∶1形成包结物,曲拉通X-405分子可以分别从β-CD分子空腔的宽、窄口径两端进入β-CD内腔,包结物的屏蔽作用是降低压裂用水对曲拉通X-405的干扰作用的根本原因。该方法为准确检测高矿化度压裂用水中的曲拉通X-405提供了新参考。

Liquid injectivity in a SAG foam process:Effect of permeability

Foam is utilized in enhanced oil recovery and CO_(2) sequestration.Surfactant-alternating-gas(SAG)is a preferred approach for placing foam into reservoirs,due to it enhances gas injection and minimizes corrosion in facilities.Our previous studies with similar permeability cores show that during SAG injection,several banks occupy the area near the well where fluid exhibits distinct behaviour.However,underground reservoirs are heterogeneous,often layered.It is crucial to understand the effect of permeability on fluid behaviour and injectivity in a SAG process.In this work,coreflood experiments are conducted in cores with permeabilities ranging from 16 to 2300 mD.We observe the same sequence of banks in cores with different permeabilities.However,the speed at which banks propagate and their overall mobility can vary depending on permeability.At higher permeabilities,the gas-dissolution bank and the forced-imbibition bank progress more rapidly during liquid injection.The total mobilities of both banks decrease with permeability.By utilizing a bank-propagation model,we scale up our experimental findings and compare them to results obtained using the Peaceman equation.Our findings reveal that the liquid injectivity in a SAG foam process is misestimated by conventional simulators based on the Peaceman equation.The lower the formation permeability,the greater the error.

New insights on the high-corrosion resistance of UHP Mg-Ge alloys tested in a simulated physiological environment

UHP Mg-Ge alloys was recently found to provide excellent corrosion resistance.This paper provides new insights on the mechanism of improved corrosion resistance of UHP Mg-Ge alloys in Hanks’solution.The studied UHP Mg-0.5Ge and UHP Mg-1Ge alloys showed superior corrosion resistance compared to UHP Mg and WE43,with the Mg-1Ge exhibiting the best corrosion performance.The exceptional corrosion resistance of the UHP alloy is attributed to(i)Mg_(2)Ge’s ability to suppress cathodic kinetics,(ii)Ge’s capability to accelerate the formation of a highly passive layer,and the(iii)low amounts of corrosion-accelerating impurities.

多波段FMCW雷达低慢小探测数据集(LSS-FMCWR-1.0)及高分辨微动特征提取方法

无人机等低慢小目标探测对雷达目标检测和识别技术提出了很高的挑战,迫切需要构建相关数据集,支撑低慢小探测技术的发展和应用。该文公开了一个多波段调频连续波(FMCW)雷达低慢小目标探测数据集,基于Ku波段和L波段的FMCW雷达采集6种类型的无人机回波数据,通过雷达调制周期和调制带宽,具备不同时域和频域分辨和测量能力,构建了多波段FMCW雷达低慢小探测数据集(LSS-FMCWR-1.0)。为了进一步提升无人机微动特征提取能力,该文提出基于局部极大值同步提取变换的无人机微动提取和参数估计方法,在短时傅里叶变换的基础上提取时频能量最大值,保留有用信号分量,实现精细化时频表示。基于LSS-FMCWR-1.0进行验证分析,结果表明该方法相较于传统时频方法,熵值平均降低了5.3 dB,旋翼叶长估计误差降低了27.7%,所提方法兼顾高时频分辨率和较高的参数估计精度,为后续目标识别奠定了基础。

Tunable spectral continuous shift of high-order harmonic generation in atoms by a plasmon-assisted shaping pulse

We delve into the phenomenon of high-order harmonic generation within a helium atom under the influence of a plasmon-assisted shaping pulse.Our findings reveal an intriguing manipulation of the frequency peak position in the harmonic emission by adjusting the absolute phase parameter within the frequency domain of the shaping pulse.This phenomenon holds potential significance for experimental setups necessitating precisely tuned single harmonics.Notably,we observe a modulated shift in the created harmonic photon energy,spanning an impressive range of 1.2 eV.This frequency peak shift is rooted in the asymmetry exhibited by the rising and falling edges of the laser pulse,directly influencing the position of the peak frequency emission.Our study quantifies the dependence of this tuning range and the asymmetry of the laser pulse,offering valuable insights into the underlying mechanisms driving this phenomenon.Furthermore,our investigation uncovers the emergence of semi-integer order harmonics as the phase parameter is altered.We attribute this discovery to the intricate interference between harmonics generated by the primary and secondary return cores.This observation introduces an innovative approach for generating semi-integer order harmonics,thus expanding our understanding of high-order harmonic generation.Ultimately,our work contributes to the broader comprehension of complex phenomena in laser-matter interactions and provides a foundation for harnessing these effects in various applications,particularly those involving precise spectral control and the generation of unique harmonic patterns.

Track-Pattern-Based Characteristics of Extratropical Transitioning Tropical Cyclones in the Western North Pacific

Based on the Regional Specialized Meteorological Center(RSMC)Tokyo-Typhoon Center best-track data and the NCEP-NCAR reanalysis dataset,extratropical transitioning(ET)tropical cyclones(ETCs)over the western North Pacific(WNP)during 1951–2021 are classified into six clusters using the fuzzy c-means clustering method(FCM)according to their track patterns.The characteristics of the six hard-clustered ETCs with the highest membership coefficient are shown.Most tropical cyclones(TCs)that were assigned to clusters C2,C5,and C6 made landfall over eastern Asian countries,which severely threatened these regions.Among landfalling TCs,93.2%completed their ET after landfall,whereas 39.8%of ETCs completed their transition within one day.The frequency of ETCs over the WNP has decreased in the past four decades,wherein cluster C5 demonstrated a significant decrease on both interannual and interdecadal timescales with the expansion and intensification of the western Pacific subtropical high(WPSH).This large-scale circulation pattern is favorable for C2 and causes it to become the dominant track pattern,owning to it containing the largest number of intensifying ETCs among the six clusters,a number that has increased insignificantly over the past four decades.The surface roughness variation and three-dimensional background circulation led to C5 containing the maximum number of landfalling TCs and a minimum number of intensifying ETCs.Our results will facilitate a better understanding of the spatiotemporal distributions of ET events and associated environment background fields,which will benefit the effective monitoring of these events over the WNP.

Comparison study on measurement of rail weld joint between inertial reference method and multi-point chord reference method

Purpose – Straightness measurement of rail weld joint is of essential importance to railway maintenance. Dueto the lack of efficient measurement equipment, there has been limited in-depth research on rail weld joint with a5-m wavelength range, leaving a significant knowledge gap in this field.Design/methodology/approach – In this study, the authors used the well-established inertial referencemethod (IR-method), and the state-of-the-art multi-point chord reference method (MCR-method). Two methodshave been applied in different types of rail straightness measurement trollies, respectively. These instrumentswere tested in a high-speed rail section within a certain region of China. The test results were ultimatelyvalidated through using traditional straightedge and feeler gauge methods as reference data to evaluate the railweld joint straightness within the 5-m wavelength range.Findings – The research reveals that IR-method and MCR-method produce reasonably similar measurementresults for wavelengths below 1 m. However, MCR-method outperforms IR-method in terms of accuracy forwavelengths exceeding 3 m. Furthermore, it was observed that IR-method, while operating at a slower speed,carries the risk of derailing and is incapable of detecting rail weld joints and low joints within the track.Originality/value – The research compare two methods’ measurement effects in a longer wavelength rangeand demonstrate the superiority of MCR-method.

Mechanisms of Sophora flavescens in the treatment of cervical squamous cell carcinoma based on comprehensive biological analysis,network pharmacology,and experimental verification

Objective:This study used comprehensive bioinformatics analysis and network pharmacology analysis to investigate the potentially relevant mechanisms of Sophora flavescens against cervical squamous cell carcinoma.Methods:Consistently altered genes involved in cervical squamous cell cancerization were analyzed in the GEO database.The chemical ingredients and target genes of Sophora flavescens were explored using the TCMSP database.We obtained the potential therapeutic targets of Sophora flavescens by intersecting the above genesets and validated them in the GEPIA database.The interaction between Sophora flavescens and target genes was predicted by molecular docking.RT-qPCR was used to verify the changes of target genes in HeLa cells treated with Sophora flavescens.Single-gene GSEA functional analysis were performed to determine the molecular mechanisms.Results:Fifteen genes related to the transformation of cervical squamous cell carcinoma were identified,among which AR and ESR1 were confirmed as targets for kaempferol,wighteone,formononetin,and phaseolinon.These compounds are the active ingredients in Sophora flavescens.Low expressions of AR and ESR1 correlate with a poor prognosis,while Sophora flavescens treatment increases the expression of AR and ESR1 in HeLa.GSEA analysis showed that AR and ESR1 mainly participate in the epithelial-mesenchymal transition in cervical squamous cell carcinoma.Conclusion:Sophora flavescens exert anti-tumor effects by targeting AR and ESR1,which may regulate cancer metastasis.

糖尿病与非糖尿病患者社区获得性高毒肺炎克雷伯菌肝脓肿临床及病原学特征比较

高毒力肺炎克雷伯菌(hypervirulent Klebsiella pneumoniae,HvKP)造成侵袭性感染已在全球范围内被广泛报道,其感染者主要集中在患有糖尿病(diabetes mellitus,DM)、慢性肝病等基础疾病的社区人群,且容易发生全身迁徙性感染。本研究收集了本院2013年1月~2018年12月社区获得性肺炎克雷伯菌肝脓肿患者377名,男性占65.8%,其中49.6%有DM。DM患者易发生眼部及中枢神经系统(central nervous system,CNS)感染,治疗过程中更需要持续的局部脓肿引流,其中血糖控制差的患者继发血流感染(bloodstream infections,BSI)的比率更高。共获得HvKP菌株219株,K1/K2血清型占总数81.7%,K2型患者发生BSI的比率高于K1型。PCR检测结果表明,毒力基因(rmpA、areo、kfu、allS、iroN、magA、uge、wcaG)在K1/K2型菌株的携带率明显高于non-K1/K2型,ST23和ST65是最常见的多位点序列分型(multilocus sequence typing,MLST),分别属于K1及K2血清型。另外收集35株经典肺炎克雷伯菌(classic Klebsiella pneumoniae,cKP),其血清分型主要以非K1/K2型为主。HvKP的毒力基因携带率及黏性程度明显高于cKP,前者造成的原发性肝脓肿患者易出现多组织器官感染,但对除氨苄西林以外的临床常用抗菌药物表现出更高敏感性,经过有效的治疗,患者的总体预后较好。本研究对社区获得性高毒肺炎克雷伯菌的病原学特征进行分析,并结合患者临床特征进行阐述,可对临床及科研工作起到一定参考价值。

Cdc42EP3对结直肠癌细胞迁移和侵袭的影响

目的:探讨Cdc42EP3在结直肠癌(colorectal cancer,CRC)转移中的作用及相关作用机制。方法:回顾性收集2010年12月至2011年12月于南京医科大学附属淮安第一医院诊治的97例CRC患者的术后病理蜡块,同时收集相关临床病理资料。采用免疫组织化学法检测Cdc42EP3在癌组织与相应正常组织中的表达,随后通过统计学方法分析差异表达,并评估表达水平与临床病理学参数及生存预后之间的相关性。干扰CRC细胞Cdc42EP3的表达后,应用Transwell技术检测Cdc42EP3对CRC细胞的迁移及侵袭能力的影响,并使用Western blot技术检测EMT相关蛋白的表达。通过基因芯片技术及生物信息学分析预测Cdc42EP3的下游靶点STAT1,并通过回复实验验证。结果:Cdc42EP3在癌组织中的表达水平显著高于相应正常组织(P<0.001),并与肿瘤的淋巴结转移(P=0.011)、TNM分期(P=0.008)及患者生存预后(P<0.001)之间呈显著相关性。干扰Cdc42EP3表达后,CRC细胞的迁移及侵袭能力均明显减弱(P<0.01)。预测出Cdc42EP3的下游靶点STAT1。在CRC细胞中,干扰Cdc42EP3表达可提高内源性STAT1蛋白水平,过表达STAT1具有与Cdc42EP3表达下降类似的肿瘤抑制作用,而STAT1表达下降可削弱Cdc42EP3敲低所致的肿瘤抑制作用(P<0.05)。结论:Cdc42EP3在CRC组织中高表达。Cdc42EP3通过调控STAT1的表达促进CRC细胞的迁移及侵袭。

杭州地区2012~2018年耐甲氧西林金黄色葡萄球菌的分子流行病学特征及其变化趋势

耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)是威胁全球的公共卫生问题,给社会和患者造成严重的安全威胁,因此明确MRSA耐药性和时空分布的多态性对于其感染的诊治和防控至关重要。本研究通过收集本院162株MRSA菌株,将所有菌株根据标准区分为社区获得性(community-associated)MRSA(CA-MRSA)和医院获得性(hospital-associated)MRSA(HA-MRSA),利用聚合酶链式反应(polymerase chain reaction,PCR)测定MRSA菌株的多位点序列分型(multilocus sequence typing,MLST),葡萄球菌盒式染色体序列(staphylococcal chromosome cassette mec,SCCmec)、葡萄球菌A蛋白(staphylococcal protein A,spa)基因多态性,以及杀白细胞毒素(Panton-Valentine leucocidin,PVL),分析了杭州地区不同年份(2012~2018年)MRSA菌株的分子特征。结果共发现16种ST型和30种spa型。ST型以ST5型为主(96/162,59.3%),spa分型以t311型为主(83/162,51.2%)。发现5种SCCmec分型,以SCCmec II型最为常见(101/162,61.7%),ST5-II-t311是本地区的第一优势MRSA克隆。2014~2018年,ST5型MRSA的患病率逐渐下降,而ST59型MRSA的患病率上升。同时,本研究检出家畜相关耐甲氧西林金黄色葡萄球菌(livestock-associated methicillin-resistant Staphylococcus aureus,LA-MRSA)ST398和ST9。PVL基因阳性MRSA菌株共28株(28/162,17.3%),最常见的PVL阳性克隆是ST59-IVa-t437。CA-MRSA与HA-MRSA相比,ST型为ST5的比例较低(9.1%vs 67.1%,P=0.000),ST59的比例较高(63.6%vs 11.4%,P=0.000),且CA-MRSA携带PVL阳性基因的可能性更高(36.4%vs 14.3%,P=0.028)。上述结果表明,MRSA的分子类型越来越多样化,ST5-II-t311是本地区MRSA的优势克隆,但在2014~2018年呈下降趋势,而社区相关性克隆菌株ST59型MRSA在2014~2018年呈逐年上升趋势。

紫花苜蓿胚性愈伤组织诱导与增殖的研究

为在不同栽培苜蓿(Medicago sativa)品种上,建立稳定、快速且高效的组织培养体系,本试验以品种‘游客’、‘Paola’和‘Sardi7’为研究材料,探究了苜蓿外植体、激素配比及金属离子(Cu 2+、Ag+),对其胚性愈伤组织的诱导效果。结果表明:下胚轴为诱导愈伤组织的最佳外植体;MS+1 mg·L^(-1)2,4-D+0.2 mg·L^(-1)KT为培养基时‘游客’和‘Paola’胚性愈伤诱导率分别为24.7%,16.7%;MS+2 mg·L^(-1)2,4-D+0.2 mg·L^(-1)KT为培养基时‘Sardi7’胚性愈伤诱导效果最佳为27.3%;1μmol·L^(-1)和5μmol·L^(-1)Cu^(2+)均能显著促进‘Sardi7’‘游客’和‘Paola’愈伤组织的诱导;5μmol·L^(-1)Ag^(+)显著诱导‘游客’和‘Paola’形成胚性愈伤组织,诱导率分别提高25.3%,46.7%(P<0.05)。本研究探索了诱导苜蓿愈伤组织的最佳外植体及其培养条件、金属离子促进不同苜蓿品种再生的作用,为突破同源四倍体栽培苜蓿品种基因型上的限制、提高胚性愈伤组织出愈率提供了思路。

HPLC-ELSD法测定积雪草中积雪草苷及羟基积雪草苷的含量

积雪草提取物通常被用作化妆品原料,有美白、抗氧化等功效,发挥此功效的主要物质有积雪草苷、羟基积雪草苷。采用高效液相色谱-蒸发光散射检测(HPLC-ELSD)技术,建立了测定积雪草中积雪草苷和羟基积雪草苷含量的方法。选用Unitary C18色谱柱(4.6×250 mm,5μm),以乙腈-水为流动相,梯度洗脱,流速1 mL/min,柱温为30℃,采用Agilent 1260 InfinityⅡ蒸发光散射检测器(漂移管温度70℃,载气流速1.6 L/min)。研究表明,积雪草苷和羟基积雪草苷质量浓度分别在100~702 mg/L,105~738 mg/L范围内,峰面积与质量浓度线性关系良好,相关系数分别为0.9996和0.9997。积雪草苷和羟基积雪草苷平均加样回收率分别为101.20%,98.30%。相对标准偏差(RSD)均在3%以内。方法简单,准确度高,分离效果好,干扰少,可用于积雪草中积雪草苷和羟基积雪草苷的含量测定。

On the Key Dynamical Processes Supporting the 21.7 Zhengzhou Record-breaking Hourly Rainfall in China

An extremely heavy rainfall event occurred in Zhengzhou,China,on 20 July 2021 and produced an hourly rainfall rate of 201.9 mm,which broke the station record for China's Mainland.Based on radar observations and a convection-permitting simulation using the WRF-ARW model,this paper investigates the multiscale processes,especially those at the mesoscale,that support the extreme observed hourly rainfall.Results show that the extreme rainfall occurred in an environment characteristic of warm-sector heavy rainfall,with abundant warm moist air transported from the ocean by an abnormally northward-displaced western Pacific subtropical high and Typhoon In-Fa(2021).However,rather than through back building and echo training of convective cells often found in warm-sector heavy rainfall events,this extreme hourly rainfall event was caused by a single,quasi-stationary storm in Zhengzhou.Scale separation analysis reveals that the extreme-rainproducing storm was supported and maintained by the dynamic lifting of low-level converging flows from the north,south,and east of the storm.The low-level northerly flow originated from a mesoscale barrier jet on the eastern slope of the Taihang Mountain due to terrain blocking of large-scale easterly flows,which reached an overall balance with the southerly winds in association with a low-level meso-β-scale vortex located to the west of Zhengzhou.The large-scale easterly inflows that fed the deep convection via transport of thermodynamically unstable air into the storm prevented the eastward propagation of the weak,shallow cold pool.As a result,the convective storm was nearly stationary over Zhengzhou,resulting in record-breaking hourly precipitation.

Initiating Binary Metal Oxides Microcubes Electromagnetic Wave Absorber Toward Ultrabroad Absorption Bandwidth Through Interfacial and Defects Modulation

Cobalt nickel bimetallic oxides(NiCo_(2)O_(4))have received numerous attentions in terms of their controllable morphology,high temperature,corrosion resistance and strong electromagnetic wave(EMW)absorption capability.However,broadening the absorption bandwidth is still a huge challenge for NiCo_(2)O_(4)-based absorbers.Herein,the unique NiCo_(2)O_(4)@C core-shell microcubes with hollow structures were fabricated via a facile sacrificial template strategy.The concentration of oxygen vacancies and morphologies of the three-dimensional(3D)cubic hollow core-shell NiCo_(2)O_(4)@C framework were effectively optimized by adjusting the calcination temperature.The specially designed 3D framework structure facilitated the multiple reflections of incident electromagnetic waves and provided rich interfaces between multiple components,generating significant interfacial polarization losses.Dipole polarizations induced by oxygen vacancies could further enhance the attenuation ability for the incident EM waves.The optimized NiCo_(2)O_(4)@C hollow microcubes exhibit superior EMW absorption capability with minimum RL(RLmin)of-84.45 dB at 8.4 GHz for the thickness of 3.0 mm.Moreover,ultrabroad effective absorption bandwidth(EAB)as large as 12.48 GHz(5.52-18 GHz)is obtained.This work is believed to illuminate the path to synthesis of high-performance cobalt nickel bimetallic oxides for EMW absorbers with excellent EMW absorption capability,especially in broadening effective absorption bandwidth.

中国情境下产业创新生态系统评述与思考

产业创新生态系统理论的推演是一个理论间更新迭代的过程,从1912年熊彼特提出“创新”的概念,到阿德纳提出创新生态系统理论,再到众多学者对产业创新生态系统理论的论述,理论体系的建构是不断螺旋上升的。本文在前人的研究基础上,运用辩证逻辑进行解读,以揭示其内在的一致性。同时,借助Citespace软件进行关键词共现、聚类及突现并绘制图谱,以期对国内外产业创新生态系统问题的研究有所裨益。具体研究结果如下:首先,产业创新生态系统的研究,沿着产业创新到产业创新系统再到产业创新生态系统的发展脉络。其次,热点研究主题呈现多领域融合、多学科交叉的特点,并聚焦于创新主体、创新能力、价值共创、协同创新等主题。最后,在中国本土情境下,未来研究方向应注重数字技术、中国元素和产业创新生态系统的融合,以期推动中国式现代化进程。

A dynamic large-deformation particle finite element method for geotechnical applications based on Abaqus

In this paper,the application of Abaqus-based particle finite element method(PFEM)is extended from static to dynamic large deformation.The PFEM is based on periodic mesh regeneration with Delaunay triangulation to avoid mesh distortion.Additional mesh smoothing and boundary node smoothing techniques are incorporated to improve the mesh quality and solution accuracy.The field variables are mapped from the old to the new mesh using the closest point projection method to minimize the mapping error.The procedures of the proposed Abaqus-based dynamic PFEM(Abaqus-DPFEM)analysis and its implementation in Abaqus are detailed.The accuracy and robustness of the proposed approach are examined via four illustrative numerical examples.The numerical results show a satisfactory agreement with published results and further confirm the applicability of the Abaqus-DPFEM to solving dynamic large-deformation problems in geotechnical engineering.