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Open Journal of Ecology 2023年第2期13卷 49-60页

作者： Beunon Tchimbi sabre Idriss Absakine Anjha gr.ce Mendi Hamza Ousmane Aziber Department of Life and Earth sciences Higher Teachers’ Training College of N’Djamena N’Djamena Chad Department of Plant Biology Faculty of Sciences University of Dschang Dschang Cameroon

The objective of this research is to lift the dormancy of seeds of s. kunthianum in w.th a view.to domesticating them. In this experiment, w. used the soaking of seeds in sulfuric acid for different durations (10 min, 30 min and 1 h). The treated seeds w.re sow. in transparent germinators. The explants obtained w.re then transplanted into pots containing five types of substrate (black earth, fine sand, saw.ust, mixtures 1/1 of saw.ust/black earth and 1/1 of saw.ust/fine sand). This second test made it possible to determine the rate of germination on the substrate. The results obtained compared to those of the control show.d a clear reduction in the latency time or germination time (62 hours) instead of 6 days (control), in the germination time 3 days/7 days (control) and a very high germination rate (100%). At the 5% threshold, soaking for 10 min and 30 min (100%) is the best result on the germination of s. kunthianum seeds. soaking for 1 hour gives (7%) very low. After transplantation of the explants, the percentages obtained independently of the treatments show.that the 1/1 mixtures of saw.ust/black earth (75.19%), black earth (73.33%) and saw.ust/fine sand (66.30%) have a higher performance than the others. The type of germination is epigeal. This w.rk makes it possible to domesticate s. kunthianum in Chad.

关键词： stereospermum kunthianum Treatment substrate Germination Medicinal Plant and Chad

高质量课程建设与教学改革管见:基本要素与内涵、挑战与趋势

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软件导刊 2024年第9期23卷 214-220页

作者：张策刘鹏纪校娟魏萌哈尔滨工业大学(威海)教务处哈尔滨工业大学(威海)计算机科学与技术学院山东威海264209

新时代对高等教育教学和人才培养提出了新要求,国家与社会对高素质创新人才的渴求日益迫切,在此背景下高校课程建设出现了新动向,课程教学改革不断深入。为此,首先指出课程建设与教学改革的基本内涵,既指出了12个方面的核心要素,又勾勒... 详细信息

新时代对高等教育教学和人才培养提出了新要求,国家与社会对高素质创新人才的渴求日益迫切,在此背景下高校课程建设出现了新动向,课程教学改革不断深入。为此,首先指出课程建设与教学改革的基本内涵,既指出了12个方面的核心要素,又勾勒出各要素的内在关系,并对其中的关键要素进行论述;其次分析新时代课程建设与教学改革面临的挑战和发展趋势。实践表明,高校教师应始终把课程建设作为人才培养的核心工作,将教学改革作为提高质量的重要手段,不断提升课程教学综合本领与水平,打造更高质量的一流课程,筑牢人才培养根基。

关键词：课程建设教学改革一流课程金课人才培养

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subduction of the primordial crust into the deep mantle

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Geoscience Frontiers 2017年第2期8卷 347-354页

作者： Hiroki Ichikaw. steeve gréaux shintaro Azum Geodynamics Research center Ehime University Earth-Life science Institute Tokyo Institute of Technology Department of Earth and Planetary sciences Faculty of ScienceUniversity of Kyushu

The primordial crust on the Earth formed from the crystallization of the surface magma ocean during the ***,geological surveys have found no evidence of rocks dating back to more than 4 Ga on the Earth＇s surface,suggesting the Hadean crust w.s lost due to some *** investigated the subduction of one of the possible candidates for the primordial crust,anorthosite and KREEP crust similar to the Moon,w.ich is also considered to have formed from the crystallization of the magma *** to the present Earth,the subduction of primordial crust by subduction erosion is expected to be an effective w.y of eliminating primordial crust from the *** this study,the subduction rate of the primordial crust via subduction channels is evaluated by numerical *** subduction channels are located betw.en the subducting slab and the mantle w.dge and are comprised of primordial crust materials supplied mainly by subduction *** have found that primordial anorthosite and KREEP crust of up to - 50 km thick at the Earth＇s surface w.s able to be conveyed to the deep mantle w.thin 0.1-2 Gy by that mechanism.

关键词： Primordial crust Anorthosite KREEP subduction erosion subduction channel

Numerical Analysis of Nozzle Clearance's Effect on Turbine Performance

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Chinese Journal of Mechanical Engineering 2011年第4期24卷 618-625页

作者： HU Liangjun YANG ce sUN Harold ZHANG Jizhong LAI Mingchia school of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China FordMotor Company Michigan 48124 USA National Key Laboratory of Diesel Engine Turbocharging Technology Datong 037036 China w.yne state University Michigan 48122 USA

Variable nozzle turbine （VNT） has become a popular variable geometry turbine （VGT） technology for the diesel engine application. Nozzle clearance, w.ich can＇t be avoided on the hub and shroud side of the VNT turbine due to the pivoting stators, can lead to turbine performance deterioration. How.ver, its mechanism is still not clear. In this paper, numerical investigation, w.ich is validated by experiment, is carried out to study the mechanism of the nozzle clearance＇s effect on the turbine performance. Firstly, performance of the mixed flow.turbine w.th fixed nozzle clearances tested on flow.bench. Performance of the tested turbine w.th the same nozzle clearance is numerically simulated. The numerical result agrees w.ll w.th the test data, w.ich proves correct of the numerical method. Then the turbine performance w.th different nozzle clearances is numerically analyzed. The research show.d that w.th nozzle clearance, flow.loss in the nozzle increases at first and it reaches the maximum value w.en the clearance ratio is 5%. Flow.at the exit of the nozzle becomes less uniform w.th nozzle clearance. The negative incidence angle of the rotor also increases w.th nozzle clearance and leads to more incidence angle loss in the rotor. The low.energy fluid formed in the nozzle due to the nozzle clearance migrates from hub to shroud side in the rotor, w.ich is another main reason for the rotor＇s performance degradation. The present research exposed the mechanism of the dramatically decrease of the turbine performance w.th nozzle clearance：（a） The loss associated w.th the nozzle leakage increases w.th the nozzle clearance; （b） The flow.loss grow. up quickly in the rotor due to the incidence angle loss and migration of the low.energy fluid from hub to shroud side.

关键词： nozzle clearance variable nozzle turbine (VNT) mixed flow.turbine

A new.energy efficient management approach for w.reless sensor netw.rks in target tracking

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Defence Technology（防务技术） 2021年第3期17卷 932-947页

作者： ce Pang Gong-guo Xu Gan-lin shan Yun-pu Zhang Army Engineering University Hebei Shijiazhuang050003China

This paper mainly studied the problem of energy conserving in w.reless sensor netw.rks for target tracking in defensing combats. Firstly, the structures of w.reless sensor nodes and netw.rks w.re illustrated;secondly, the analysis of existing energy consuming in the sensing layer and its calculation method w.re provided to build the energy conserving objective function;w.at’s more, the other tw. indicators in target tracking, including target detection probability and tracking accuracy, w.re combined to be regarded as the constraints of the energy conserving objective function. Fourthly, the three energy conserving approaches, containing optimizing the management scheme, prolonging the time interval betw.en tw. adjacent observations, and transmitting the observations selectively, w.re introduced;In addition, the improved lion algorithm combined w.th the Logistic chaos sequence w.s proposed to obtain sensor management schemes. Finally, simulations had been made to prove the effectiveness of the proposed methods and algorithm.

关键词： w.reless sensor netw.rks Target searching Target tracking Energy efficiency Lion algorithm

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芬兰驻新德里大使馆翻新印度新德里

世界建筑导报 2024年第2期39卷 96-99页

作者： Juho grönholm Antti Nousjoki Janne Teräsvirta samuli w.olston simo Nuojua Harri Ahokas Anders Jönsson Lotta Kindberg Mirja sillanpää sari Vesanen Tuomas Uusheimo(摄影) ALA建筑师事务所不详

皮耶蒂莱夫妇(Reima and Raili Pietilä)赢得了1963年的芬兰大使馆设计竞赛,该大使馆位于新德里查卡雅布里的外交飞地,参赛作品美而有力,名为“雪在山上说”。经过长时间的拖延,该项目于1980年被正式委托,并在原有概念的基础上重新进行... 详细信息

皮耶蒂莱夫妇(Reima and Raili Pietilä)赢得了1963年的芬兰大使馆设计竞赛,该大使馆位于新德里查卡雅布里的外交飞地,参赛作品美而有力,名为“雪在山上说”。经过长时间的拖延,该项目于1980年被正式委托,并在原有概念的基础上重新进行了设计。大使馆最终于1986年开放,1960年设计的巨大单体屋顶被分成六个独立建筑,围绕在一个中心花园周围。雕塑般的屋顶,这是大使馆最显著的建筑特征,类似于芬兰北部库萨莫附近的雪湖Kitkajärvi。

关键词：中心花园设计竞赛印度新德里芬兰

Improving the hard magnetic properties by intragrain pinning for Ta doped nanocrystalline ce-Fe-B alloys

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Journal of Materials science & Technology 2019年第9期35卷 1877-1885页

作者： J.s.Zhang w. Li X.F. Liao H.Y. Yu L.Z. Zhao H.X. Zeng D.R. Peng Z.w. Liu school of Materials science and Engineering South China University of TechnologyGuangzhou510640China Innovative center for Advanced Materials (ICAM) Hangzhou Dianzi UniversityHangzhou310012China

To develop ce based permanent magnets w.th high performance/cost ratio, Ta doping is w.s employed to enhance the magnetic performance of ce-Fe-B alloys. For melt spun cei7Fe78-xTaxB6 (x = 0-1) alloys, the coercivity Hc increases from 439 to 553 kA/m w.th increasing x value from 0 to 0.75. Microstructure characterizations indicate that Ta doping is helpful for grain refinement. A second phase of TaB2 is observed in ce17Fe77.25Tao.75B6 alloy, w.ich acts as the pinning center of the magnetic domains, resulting in the change of coercivity mechanism from nucleation type to nucleation +pinning type. The micromagnetic simulation confirms that non-magnetic particles w.thin hard magnetic phase can increase the demagnetization field around them and it is crucial for preventing the further magnetization reverse by pinning effect. Take the advantage of Ta doping for enhancing the coercivity, ce content of ce-Fe-B alloy can be further cut dow. to increase the remanence Jr due to the reduced volume fraction of ceFe2 phase and increased Fe/ce ratio. As a result, a good combination of magnetic properties w.th Hc = 514 kA/m, Jr = 0.49 T, and the maximum energy product (BH)max = 36 kJ/m^3 have been obtained in ce15Fe79.25Tao.75B6 alloy. It is expected that the present w.rk can serve as a useful reference for designing new.permanent magnetic materials w.th low.cost.

关键词： Melt-spinning Permanent magnets second phase Coercivity mechanism Thermal stability

Ir和IrPd催化剂的合成及结构调控对其甲醇氧化性能的影响

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无机化学学报 2024年第2期40卷 412-420页

作者：周新文沈晓宇付策王攀严烙意程征田贵贤张荣华三峡大学材料与化工学院宜昌443002 湖北三峡实验室宜昌443002

以三嵌段共聚物P123(聚环氧乙烷-聚环氧丙烷-聚环氧乙烷,PEO_(20)-PPO_(70)-PEO_(20))为还原剂和保护剂,比较了水热法和溶剂热法对纯Ir和IrPd合金催化剂合成及其电催化氧化甲醇(MOR)性能的影响。对于纯Ir催化剂,在相同条件下,溶剂热法... 详细信息

以三嵌段共聚物P123(聚环氧乙烷-聚环氧丙烷-聚环氧乙烷,PEO_(20)-PPO_(70)-PEO_(20))为还原剂和保护剂,比较了水热法和溶剂热法对纯Ir和IrPd合金催化剂合成及其电催化氧化甲醇(MOR)性能的影响。对于纯Ir催化剂,在相同条件下,溶剂热法能更好地促进Ir前驱体的还原。对于IrPd合金催化剂,溶剂热法可制得表面富含Ir但MOR活性较低的核壳结构产物(IrPd-s)。水热反应得到的不同原子比(IrPd、Ir2Pd、IrPd_(2))的产物粒径更小,元素分布更均匀。其中比例为1:1的IrPd(IrPd-H)催化剂的MOR电催化活性最高。上述结果表明,通过调节溶剂类型以及P123的结构诱导作用,可以有效地调节纯Ir和IrPd合金催化剂的结构、表面组成和电催化活性。

关键词：结构调控水热合成钯铱合金三嵌段共聚物甲醇氧化

基于改进GA优化的级联H桥APF神经网络电流跟踪控制

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电力电容器与无功补偿 2024年第2期45卷 63-70页

作者：沈建强邢砾云李冉王策北华大学电气与信息工程学院吉林吉林132021

针对基于级联H桥有源滤波器实现谐波抑制时,传统PI控制电流跟踪的抗扰性差以及由于神经网络预测的局域最优造成的电流跟踪预测不准确、延迟大等问题。本文提出了一种改进GA优化的级联H桥APF神经网络电流跟踪控制策略,以改进选择和交叉... 详细信息

针对基于级联H桥有源滤波器实现谐波抑制时,传统PI控制电流跟踪的抗扰性差以及由于神经网络预测的局域最优造成的电流跟踪预测不准确、延迟大等问题。本文提出了一种改进GA优化的级联H桥APF神经网络电流跟踪控制策略,以改进选择和交叉操作的GA优化神经网络变化因子,提升了预测控制的全局搜索能力和鲁棒性能。仿真验证表明,所提出的控制策略相较于传统PI控制,提升了电流跟踪控制的鲁棒性;相较基于传统GA优化的神经网络控制方法,本文提出的方法跟踪速度提升了约0.04 s,控制误差减小约0.2 A,谐波畸变率降低0.36%。可见,响应速度和控制精度更优,具有更好的跟踪控制能力。

关键词：级联H桥有源电力滤波器遗传算法神经网络控制电流跟踪

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自然条件下建筑外墙涂料耐沾污性能的探究

上海涂料 2024年第1期62卷 37-41页

作者：薛润泽缪策张智瑾上海建科检验有限公司国家建筑工程材料质量检验检测中心上海201108

随着人们生活水平的提高和建筑行业的发展,外墙涂料耐沾污性能已经成为一项重要的指标。本研究将外墙涂料试板放置于自然条件下,对其表面反射率进行持续测定,统计分析自然条件和使用标准灰的人工耐沾污试验结果。结果表明,外墙涂料试板... 详细信息

随着人们生活水平的提高和建筑行业的发展,外墙涂料耐沾污性能已经成为一项重要的指标。本研究将外墙涂料试板放置于自然条件下,对其表面反射率进行持续测定,统计分析自然条件和使用标准灰的人工耐沾污试验结果。结果表明,外墙涂料试板在室外放置过程中,表面污染程度不断加大,反射率下降百分比不断上升,7个月后最高达17%。自然条件与人工耐沾污试验测定的结果存在一定差异,这表明相关标准还有待进一步完善以贴合现实情况。最后提出外墙涂料耐沾污测试方法可能的改进思路,为耐沾污外墙涂料产品发展和相关标准修订提供参考。

关键词：外墙涂料耐沾污性测试方法