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环球科学 2024年第9期 70-77页

作者：达纳·麦肯齐戚译引(译) 不详

如果没有学生伊丽莎白公主的帮助,勒内·笛卡尔很可能不会发现关于4个圆的笛卡尔定理。这篇来自《科学美国人》法国版的文章生动讲述了这个定理的发现过程,揭开了伊丽莎白公主被历史隐去的光辉。

关键词：《科学美国人》笛卡尔伊丽莎白定理公主

环氧树脂-聚氨酯含砂抗滑封层设计及性能研究

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热固性树脂 2024年第3期39卷 52-56页

作者：达娜·塔布斯叶奋新疆大学建筑工程学院新疆乌鲁木齐830017 同济大学交通运输工程学院上海200092

为提高水泥路面耐久性及抗滑性,设计了多层结构含砂封层,即先喷涂无溶剂环氧树脂胶结料和抗滑颗粒组成的含砂雾封层,待其常温固化后,再用双组分无溶剂聚氨酯进行封层。通过材料性能试验及路用性能试验对封层材料的各组分进行确定及评价... 详细信息

为提高水泥路面耐久性及抗滑性,设计了多层结构含砂封层,即先喷涂无溶剂环氧树脂胶结料和抗滑颗粒组成的含砂雾封层,待其常温固化后,再用双组分无溶剂聚氨酯进行封层。通过材料性能试验及路用性能试验对封层材料的各组分进行确定及评价。结果表明:环氧树脂胶结料的A、B组分质量比为2∶1,聚氨酯胶结料的A、B组分质量比为5∶1时,封层表干时间符合施工和易性,效果最佳。粘结强度试验结果表明,当稀释剂质量分数为3%时,环氧树脂胶结料的粘结强度比未添加稀释剂时仅降低23%,且起到了降粘作用。聚氨酯不含稀释剂时,粘结性能最优。对优选配比后的封层试件进行7200次磨耗试验,结果表明:抗滑颗粒类型对封层试件磨耗前后的BPN变化值及质量损失率影响最大。确定环氧树脂胶结料涂布量为0.6 kg/m^(2),抗滑颗粒为金刚砂,洒布量为0.5~0.7 kg/m^(2),长期磨耗测试表明所设计的雾封层具有更好的耐久性,有利于延长水泥路面的使用寿命。

关键词：环氧树脂聚氨酯含砂雾封层水泥路面防滑磨耗试验耐久性

Internet of Things (IoT) Security Enhancement Using XGboost Machine Learning Techniques

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Computers, Materials & Continua 2023年第10期77卷 717-732页

作者： dana F.Doghramachi Siddeeq Y.Ameen Department of Information Systems Engineering Techniques Erbil Technical Engineering CollegeErbil Polytechnic UniversityErbil44001Iraq Department of Energy Engineering Technical College of EngineeringDuhok Polytechnic UniversityDuhok42001Iraq

The rapid adoption of the Internet of Things(IoT)across industries has revolutionized daily life by providing essential services and leisure ***,the inadequate software protection in IoT devices exposes them to cyberattacks with severe *** Detection Systems(IDS)are vital in mitigating these risks by detecting abnormal network behavior and monitoring safe network *** security research community has shown particular interest in leveraging Machine Learning(ML)approaches to develop practical IDS applications for general cyber networks and IoT ***,most available datasets related to Industrial IoT suffer from imbalanced class *** study proposes a methodology that involves dataset preprocessing,including data cleaning,encoding,and *** class imbalance is addressed by employing the Synthetic Minority Oversampling Technique(SMOTE)and performing feature reduction using correlation *** ML classifiers,including Logistic Regression,multi-layer perceptron,Decision Trees,Random Forest,and XGBoost,are employed to model IoT *** effectiveness and robustness of the proposed method evaluate using the IoTID20 dataset,which represents current imbalanced IoT *** results highlight that the XGBoost model,integrated with SMOTE,achieves outstanding attack detection accuracy of 0.99 in binary classification,0.99 in multi-class classification,and 0.81 in multiple *** findings demonstrate our approach’s significant improvements to attack detection in imbalanced IoT datasets,establishing its superiority over existing IDS frameworks.

关键词： IoT detection system machine learning SMOTE XGboost

Forest Disturbance Enhanced the Activity of Epedaphic Collembola in Windthrown Stands of the High Tatra Mountains

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Journal of Mountain Science 2014年第2期11卷 449-463页

作者： Veronika URBANOVIOVá dana MIKLISOVá Lubomír KOVá Institute of Biology and Ecology Faculty of Science P.J. Safárik UniversityMoyzesova 11 Kosice 04001 Slovakia Institute of Parasitology Slovak Academy of SciencesHlinkova 3 Kosice 04001 Slovakia

The study aimed to assess the response of ep- and hemiedaphic Collembola communities(activity, richness, community structure) to a disturbance, the subsequent management regime and to the season(summer, winter) in a High Tatra Mountains spruce forest destroyed by a *** and clear-cut resulted in an initial increase in the activity of Collembola inhabiting open areas,opportunistic or generalist species, while forest specialists diminished in numbers or *** results indicated that treatment with nonextracted fallen trees(NEX) provided a better chance for forest species to survive compared with their survival in open habitats of extracted(EXT) and wildfire(FIR) treatments. Great species' potential of NEX treatment was indicated by Chao2 estimator and activity/species rarefaction curves. Communities of NEX treatment were more similar to the reference(REF) treatment, documented by ordination and cluster analyses. Thus, leaving fallen timber after a windthrow to natural process of succession is suitable for survival of forest species and maintenance of diversity in forests restoration than timber *** structure in wildfire(FIR) stands was the most dissimilar to the other treatments. Most of the species trapped in this treatment belonged to hemiedaphic life forms, while the activity of larger epedaphic species diminished. In contrast, the highest number of trapped Collembola in EXT treatment was connected with the larger-bodied epigeic species with fast dispersal ability. The trapping period affected both the number of individuals and species richness;Collembola activity and species diversity in the individual treatments were lower in winter compared with the summer period. Several species increased activity during the winter period, namely Folsomia penicula, Friesea mirabilis, F. truncata, Hypogastrura socialis and Protaphorura aurantiaca.

关键词： Wildfire Windstorm Clear-cutting Collembola Spruce forest

Response of phenology- and yield-related traits of maize to elevated temperature in a temperate region

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The Crop Journal 2017年第4期5卷 305-316页

作者： dana Shim Kyu-Jong Lee Byun-Woo Lee Department of Plant Science Seoul National University Seoul 151-921 Republic of Korea Research Institute for Agriculture and Life Sciences Seoul National University Seoul 151-921 Republic of Korea

Extreme high temperatures detrimental to maize production are projected to occur more frequently with future climate *** and yield-related traits were investigated under several levels of elevated temperature in two early-maturing hybrid cultivars:Junda 6(grown in northeastern China)and Chalok 1(grown in South Korea).They were cultivated in plastic houses in Suwon,Korea(37.27°N,126.99°E)held at target temperatures of ambient(AT),AT+1.5°C,AT+3°C,and AT+5°C at one sowing date in 2013 and three different sowing dates in *** and reproductive growth durations showed variation depending on sowing date,experimental year,and *** duration tended to decrease,but not necessarily,with temperature elevation,but somewhat increased again above a certain *** temperature-dependent variation was greater during grain filling than in the vegetative period before *** temperature showed no significant effects on duration or peak dates of silking and anthesis,and thus on anthesis–silking *** yield tended to decrease with temperature elevation above ambient,showing a sharper linear decrease with mean growing season temperature increase in Junda 6 than in Chalok *** decrease in kernel number accounted for a much greater contribution to the yield reductions due to temperature elevation than did the decrease in individual kernel weight in both *** harvestable kernel weight was not significantly affected by temperature elevation *** number showed a linear decrease with mean growth temperature from early ear formation to early grain-filling stage,with Junda 6 showing a much severer decrease than Chalok *** number reduction due to temperature elevation was attributable more to the decrease in differentiated ovule number than to the decrease in kernel set in Chalok 1,but largely to the decrease of kernel set in Junda 6.

关键词： Maize Elevated temperature Phenology Yield Yield-related traits

Ultrafast plasmon dynamics in asymmetric gold nanodimers

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Chinese Physics B 2022年第6期31卷 387-395页

作者： Bereket Dalga dana Alemayehu Nana Koya Xiaowei Song Jingquan Lin School of Science Changchun University of Science and TechnologyChangchun 130022China Department of Physics College of Natural and Computational SciencesWolaita Sodo UniversityP.O.Box 138Wlaita SodoEthiopia

We theoretically investigate the effect of symmetry breaking on the ultrafast plasmon responses of Au nanodisk(ND)dimers by varying the diameter of one of the constituent *** the case of a single ultrafast laser pulse,we demonstrate that the ultrafast responses of Au ND homodimer can be significantly modified due to the effect of symmetry *** symmetric dimer shows a single broad spectral peak,whereas the size-asymmetric dimer shows three spectral *** first system displays at most one temporal maximum and no beats in ultrafast temporal,whereas the second system may have three temporal maxima and two beats due to a combination of broken symmetry and the coherent superposition between various plasmon modes induced by the ultra-short laser ***,the shape of temporal dynamics of the size-asymmetric dimer is significantly deformed due to the excitation of local plasmon modes with different wavelength ***,the decay time of the amplitude of the local field is longer and oscillates with a high frequency due to the narrower linewidth and red-shifted spectral *** show that the ultrafast plasmon responses of both dimers can be controlled by varying the relative phase and time delays between a pair of two *** results will open new paths to understanding ultrafast plasmon responses in asymmetric heterodimers with suitable properties for different applications.

关键词： ultrafast plasmon dynamics coherent control spectral intensity temporal maximum

A Jacobian-Free Newton Krylov Implicit-Explicit Time Integration Method for Incompressible Flow Problems

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Communications in Computational Physics 2013年第5期13卷 1408-1431页

作者： Samet Y.Kadioglu dana A.Knoll Department of Mathematical Engineering Yildiz Technical University34210 Davutpasa-EsenlerIstanbulTurkey Fuels Modeling and Simulation Department Idaho National LaboratoryP.O.Box 1625MS 3840Idaho FallsID 83415USA Theoretical Division Los Alamos National LaboratoryP.O.Box 1663MS B-216Los AlamosNM87545USA

We have introduced a fully second order IMplicit/EXplicit(IMEX)time integration technique for solving the compressible Euler equations plus nonlinear heat conduction problems(also known as the radiation hydrodynamics problems)in Kadioglu et al.,***[22,24].In this paper,we study the implications when this method is applied to the incompressible Navier-Stokes(N-S)*** IMEX method is applied to the incompressible flow equations in the following *** hyperbolic terms of the flow equations are solved explicitly exploiting the well understood explicit *** the other hand,an implicit strategy is employed for the non-hyperbolic *** explicit part is embedded in the implicit step in such a way that it is solved as part of the non-linear function evaluation within the framework of the Jacobian-Free Newton Krylov(JFNK)method[8,29,31].This is done to obtain a self-consistent implementation of the IMEX method that eliminates the potential order reduction in time accuracy due to the specific operator *** employ a simple yet quite effective fractional step projection methodology(similar to those in[11,19,21,30])as our preconditioner inside the JFNK *** present results from several test *** each test,we show second order time ***,we present a study for the algorithm performance of the JFNK solver with the new projection method based preconditioner.

关键词： Incompressible flow Navier-Stokes equations IMEX method JFNK method preconditioner

A tunable ferroelectric based unreleased RF resonator

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Microsystems & Nanoengineering 2020年第1期6卷 1334-1340页

作者： Yanbo He Bichoy Bahr Mengwei Si Peide Ye dana Weinstein Purdue University West LafayetteINUSA Kilby Labs Texas InstrumentsDallasTXUSA

This paper introduces the first tunable ferroelectric capacitor(FeCAP)-based unreleased RF MEMS resonator,integrated seamlessly in Texas Instruments’130 nm Ferroelectric RAM(FeRAM)*** designs presented here are monolithically integrated in solid-state CMOS technology,with no post-processing or release step typical of other MEMS *** array of FeCAPs in this complementary metal-oxide-semiconductor(CMOS)technology’s back-end-of-line(BEOL)process were used to define the acoustic resonance cavity as well as the electromechanical *** achieve high quality factor(Q)of the resonator,acoustic waveguiding for vertical confinement within the CMOS stack is studied and *** design considerations are discussed to obtain lateral confinement and suppression of spurious *** FeCAP resonator is demonstrated with fundamental resonance at 703 MHz and Q of *** gives a frequency-quality factor product f·Q=7:11×10^(11) which is 1.6×higher than the most state-of-the-art Pb(Zr,Ti)O_(3)(PZT)*** to the ferroelectric characteristics of the FeCAPs,transduction of the resonator can be switched on and off by adjusting the electric *** this case,the resonance can be turned off completely at±0.3 V corresponding to the coercive voltage of the constituent FeCAP *** novel switchable resonators may have promising applications in on-chip timing,ad-hoc radio front ends,and chip-scale sensors.

关键词： resonator tunable switched

Nanomaterials for treating cardiovascular diseases:A review

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Bioactive Materials 2017年第4期2卷 185-198页

作者： Wensen Jiang dana Rutherford Tiffany Vuong Huinan Liu Materials Science and Engineering University of CaliforniaRiversideRiversideCA92521USA Department of Bioengineering University of CaliforniaRiversideRiversideCA92521USA

Nanomaterials such as nanostructured surfaces,nanoparticles,and nanocomposites represent new viable sources for future therapeutics for cardiovascular *** special properties of nanomaterials such as their intrinsic physiochemical properties,surface energy and surface topographies could actively enhance desirable cellular responses within the cardiovascular system,projecting a growing potential for clinical *** progress on nanomaterials opened up new opportunities for treating cardiovascular *** translation of nanomaterials into cardiovascular applications requires a comprehensive understanding of both nanomaterials and biomedicine,and,thus,it is critical to stress current advancements on both *** this review,the authors introduced crucial fabrication techniques for promising nanomaterials for cardiovascular *** review highlighted the key elements to consider for their fabrication,properties and *** important concerns relevant to cardiovascular nanomaterials,such as cellular responses to nanomaterials and the toxicity of nanomaterials,are also *** review provided an overview of necessary knowledge and key concerns on nanomaterials specific for treating cardiovascular diseases,from the perspectives of both material science and biomedicine.

关键词： Nanomaterials Cardiovascular diseases Fabrication Nanostructured surfaces Nanoparticles and nanocomposites

PPARγ在神经系统发育及相关疾病中的研究进展

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生命科学研究 2024年第2期28卷 128-134页

作者：卢淑娴祝远贺丹党琳陕西中医药大学医学科研实验中心中国陕西咸阳712000 陕西中医药大学基础医学院中国陕西咸阳712000

过氧化物酶体增殖物激活受体γ (peroxisome proliferator-activated receptor gamma, PPARγ)作为配体依赖型核内转录因子,是经典的脂代谢调控因子,参与机体脂肪生成、葡萄糖代谢、血管生成和炎症发生等多种生物过程。除了在脂肪酸代... 详细信息

过氧化物酶体增殖物激活受体γ (peroxisome proliferator-activated receptor gamma, PPARγ)作为配体依赖型核内转录因子,是经典的脂代谢调控因子,参与机体脂肪生成、葡萄糖代谢、血管生成和炎症发生等多种生物过程。除了在脂肪酸代谢活跃部位高水平表达, PPARγ在神经系统也大量存在,近年来越来越多的研究开始关注PPARγ在神经系统中扮演的角色。本文综述了PPARγ在神经系统发育及相关疾病发生发展中的重要作用:PPARγ通过调控机体炎症反应因子参与神经系统炎症过程;在中枢神经系统或周围神经系统发生外因损伤时, PPARγ通过抑炎或促进再生表现出神经保护功能;在帕金森病、阿尔茨海默病等神经退行性疾病中,调控PPARγ的表达可以起到延缓病程或临床治疗的效果;在视网膜病变中, PPARγ可以通过保护视网膜神经节细胞起到缓解作用。这些总结工作可以为PPARγ在神经系统发育和相关疾病进程中的调控机制研究及配体类药物开发提供参考资料。

关键词：过氧化物酶体增殖物激活受体γ(PPARγ) 神经系统炎症配体神经退行性疾病