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Tunnel magnetoresistance with atomically thin two- dimensional hexagonal boron nitride barriers

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Nano Research 2015年第4期8卷 1357-1364页

作者： Andre Dankert M. Venkata Kamalakar Abdul Wajid R. S. Patel Saroj P. Dash Department of Microtechnology and Nanoscience Chalmers University of Technology SE-41296 Goteborg Sweden Department of Physics Birla Institute of Technology and Science Pilani--K K Birla Goa Campus Zuarinagar-403 726 Goa India

The two-dimensional atomically thin insulator hexagonal boron nitride （h-BN） constitutes a new paradigm in tunnel based devices. A large band gap, along with its atomically flat nature without dangling bonds or interface trap states, makes it an ideal candidate for tunnel spin transport in spintronic devices. Here, we demonstrate the tunneling of spin-polarized electrons through large area monolayer h-BN prepared by chemical vapor deposition in magnetic tunnel junctions. In ferromagnet/h-BN/ferromagnet heterostructures fabricated on a chip scale, we show tunnel magnetoresistance at room temperature. Measurements at different bias voltages and on multiple devices with different ferromagnetic electrodes establish the spin polarized tunneling using h-BN barriers. These results open the way for integration of 2D monolayer insulating barriers in active spintronic devices and circuits operating at ambient temperature, and for further exploration of their properties and prospects.

关键词： hexagonal boron nitride 2D layered materials CVD spintronics magnetic tunnel junction tunnel magnetoresistance tunnel barrier

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用蠕墨铸铁生产中速柴油机汽缸盖

铸造 1992年第5期41卷 37-39页

作者：邹仕魁吴文亮宜昌403厂铸造分厂

用蠕墨铸铁生产柴油机汽缸盖可消除其缩松、开裂而产生的渗漏现象,并降低生产成本。生产中搭配使用1~#稀土硅铁合金和6~#稀土镁硅铁合金,适宜的RE_(残)为0．027~0．057%,Mg_残为0.007~0．013%;益于稳定蠕化效果的孕育剂为0.70%75SiFe十0... 详细信息

用蠕墨铸铁生产柴油机汽缸盖可消除其缩松、开裂而产生的渗漏现象,并降低生产成本。生产中搭配使用1~#稀土硅铁合金和6~#稀土镁硅铁合金,适宜的RE_(残)为0．027~0．057%,Mg_残为0.007~0．013%;益于稳定蠕化效果的孕育剂为0.70%75SiFe十0．15%CaSi。

关键词：蠕墨铸铁柴油机汽缸盖稀土

A Multifunctional Hydrogel with Multimodal Self-Powered Sensing Capability and Stable Direct Current Output for Outdoor Plant Monitoring Systems

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Nano-Micro Letters 2025年第4期17卷 1-24页

作者： Xinge Guo Luwei Wang Zhenyang Jin Chengkuo Lee Department of Electrical&Computer Engineering National University of Singapore4 Engineering Drive 3Singapore 117576Singapore Center for Intelligent Sensors and MEMS(CISM) National University of Singapore5 Engineering Drive 1Singapore 117608Singapore NUS Graduate School-Integrative Sciences and Engineering Program(ISEP) National University of SingaporeSingapore 119077Singapore Research Center for Sustainable Urban Farming(SUrF) National University of SingaporeSingapore 117558Singapore

Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability *** systems facilitate informed decisions that enhance efficiency in broader environmental *** outdoor systems equipped with energy harvesters and self-powered sensors often struggle with fluctuating energy sources,low durability under harsh conditions,non-transparent or non-biocompatible materials,and complex ***,a multifunctional hydrogel is developed,which can fulfill all the above requirements and build selfsustainable outdoor monitoring systems solely by *** can serve as a stable energy harvester that continuously generates direct current output with an average power density of 1.9 W m^(-3)for nearly 60 days of operation in normal environments(24℃,60%RH),with an energy density of around 1.36×10^(7)J m^(-3).It also shows good self-recoverability in severe environments(45℃,30%RH)in nearly 40 days of continuous ***,this hydrogel enables noninvasive and self-powered monitoring of leaf relative water content,providing critical data on evaluating plant health,previously obtainable only through invasive or high-power consumption *** potential extends to acting as other self-powered environmental *** multifunctional hydrogel enables self-sustainable outdoor systems with scalable and low-cost production,paving the way for future agriculture.

关键词： Self-powered sensor Hydrogel Energy harvester Outdoor farming Self-sustainable IoT

Early Pliocene Paleoceanography of the Vityaz Fracture Zone,Central Indian Ridge

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Acta Geologica Sinica(English Edition) 2007年第4期81卷 614-621页

作者： M.V.S.GUPTHA Ranadip BANERJEE Lina P.MERGULHAO Priyanka BANERJEE G.PARTHIBAN Manish TEWARI National Institute of Oceanography Dona Paula Goa-403 004India Department of Geological Sciences Jadavpur University Kolkata700032India Physical Research Laboratory Navrangpura AhmedabadIndia

Planktic foraminifera from the calcareous substrate of a ferromanganese crust in the Vityaz Fracture Zone （VFZ）, Central Indian Ridge were studied to reconstruct the early Pliocene paleoceanography of this region. Eleven species of planktic foraminifera were encountered, among them Globorotalia menardii, Neogloboquadrina dutertrei, Globigerina bulloides and Globigerinoides tuber are prominent. Predominance of N. dutertrei in the top 3 cm of the carbonate substrate is attributed to an influx of fresh water which eventually triggered their productivity by increasing the nutrient level. The presence of G. bulloides and G. menardii in significant proportions in deeper layers suggests the prevalence of open ocean upwelling. The bulk chemical compositions of the substrate at different depth intervals indicates higher enrichment of trace metals in the upper sections which could have been supplied through oceanic water by the chemical weathering of terrestrial matter during the peak of Pliocene Asian monsoon. Thus, it is concluded that during the early Pliocene the biogenic components of the substrate were distinctly contributed by both upwelling and productivity triggered by an influx of fresh water originating from the intensification of the Asian monsoon during the early Pliocene Period.

关键词： Central Indian Ridge Vityaz Fracture Zone ferromanganese crust biogenic bloom,freshwater influx Neogene climate change spores Asian monsoon

A DECISION-MAKING FRAMEWORK FOR VEGETATED ROOFING SYSTEM SELECTION

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Journal of Green Building 2008年第4期3卷 138-153页

作者： Elizabeth J.Grant James R.Jones School of Architecture+Design Virginia Polytechnic Institute and State University403B Cowgill HallBlacksburgVirginia 24061 USA

Design frequently involves making tradeoffs to obtain the“optimal”solution to a design problem,often using intuition or past experience as a *** vegetated roofing is a relatively complex and comparatively new technology to many practitioners,a rational,explicit method to help organize and rank the tradeoffs made during the design process is *** research comprises the creation of a framework diagramming the decision process involved in the selection of vegetated roofi ng *** literature review,case studies and interviews with experts,the available knowledge is captured and organized to determine the critical parameters affecting design *** important evaluative categories are identifi ed and parameters within these categories are addressed in the context of a decision support system for green roof designers.A summation of the total importance of the advantages represented by each alternative is used to determine the most feasible green roof system for a particular *** framework is demonstrated and compared with green roof designers’decision-making processes and conclusions are drawn regarding its effectiveness.

关键词： vegetated roof green roof decision support system decision-making framework Choosing By Advantages

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两相流环缝塞式喷管设计方法

航空学报 2007年第6期28卷 1339-1344页

作者：谢侃刘宇任军学廖云飞北京航空航天大学403教研室北京100083

在常滞后两相流假设下,提出改进的Angelino理想型面法和改进的"二次曲线+三次曲线"造型法设计两相流环缝塞式喷管;计算了这两种改进方法设计的塞式喷管性能。算例表明:在两相流条件下与未考虑两相流效应的气相理想方法设计的型面相比,... 详细信息

在常滞后两相流假设下,提出改进的Angelino理想型面法和改进的"二次曲线+三次曲线"造型法设计两相流环缝塞式喷管;计算了这两种改进方法设计的塞式喷管性能。算例表明:在两相流条件下与未考虑两相流效应的气相理想方法设计的型面相比,改进的Angelino法设计的型面长度缩短近33%,推力增大约1%;改进的"二次曲线+三次曲线"造型法设计的型面长度减小近6%,性能提高约4%。

关键词：固体火箭发动机两相流理想型面曲线造型数值模拟塞式喷管

毫米波辐照对小鼠腺垂体、睾丸和肾上腺皮质超微结构的影响

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中国病理生理杂志 1993年第2期9卷 255-258页

作者：杜忠民郭鹞第四军医大学403-1研究室西安710033

本实验用频率36.11GHz,功率密度为5mW/cm^2的毫米波,每天30分钟,连续5天照射小鼠背部,于照后1、3、5、7天时处死,观察腺垂体、肾上腺和睾九的超微结构变化。结果发现照射后腺垂体部分促生长激素细胞、促性腺激素细胞出现一定程度的退行... 详细信息

本实验用频率36.11GHz,功率密度为5mW/cm^2的毫米波,每天30分钟,连续5天照射小鼠背部,于照后1、3、5、7天时处死,观察腺垂体、肾上腺和睾九的超微结构变化。结果发现照射后腺垂体部分促生长激素细胞、促性腺激素细胞出现一定程度的退行性变化,后期有分裂刺激现象。睾丸生精上皮细胞有一定程度的损伤性变化,少数细胞还见有凝固性坏死。睾丸支持细胞、间质细胞和肾上腺皮质细胞仅见轻微变化。上述结果证明低功率密度毫米波辐射对小鼠内分泌系统有一定程度的生物学效应。

关键词：辐射效应内分泌腺微波辐射小鼠

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集

好家长 2025年第01期 46-47页

作者：代悦琪南京汉开书院七(1)班

我要走进清透的风里，我要披上阳光的丝绸，在草尖的露珠里沐浴，和云相视一笑，和蝈蝈一起吟唱古老的民谣，再去暴雨中，集一个闪电的签名，这便是我所要集，集几张自然的明信片。集几张自然的明信片，与傍晚的浮云并肩在天空中，一起...

我要走进清透的风里，我要披上阳光的丝绸，在草尖的露珠里沐浴，和云相视一笑，和蝈蝈一起吟唱古老的民谣，再去暴雨中，集一个闪电的签名，这便是我所要集，集几张自然的明信片。集几张自然的明信片，与傍晚的浮云并肩在天空中，一起走进一个蔚蓝的午后。一阵阵清新空旷的气息扑面而来，柔风挑起我的视线，引领我向平静如湖面的蓝天望去。

关键词：

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塞式喷管底部特性研究

航空学报 2005年第1期26卷 18-22页

作者：王长辉刘宇廖云飞北京航空航天大学403教研室北京100083

基于实验数据和数值模拟结果,研究了外界反压和底部二次流对塞式喷管底部的影响。实验表明,底部压强分布相对较均匀,底部在不同外界反压下具有不同的气动状态。如果主流在底部受压缩,底部有气动开放的趋势;如果主流在底部受膨胀,底部有... 详细信息

基于实验数据和数值模拟结果,研究了外界反压和底部二次流对塞式喷管底部的影响。实验表明,底部压强分布相对较均匀,底部在不同外界反压下具有不同的气动状态。如果主流在底部受压缩,底部有气动开放的趋势;如果主流在底部受膨胀,底部有气动闭合的趋势;如果底部同时存在压缩和膨胀,其状态与受到压缩和膨胀的相对强弱有关。二次流的注入使底部开闭过渡点的压比值升高,底部闭合后的压强值增大,有利于防止底部开闭过渡时推力出现较大幅度降低。二次流流量达到主流的2 0%后,加大底部二次流流量不再影响底部压强,过多地注入反而会降低塞式喷管的总体效率,1 5%～2 0%主流流量的二次流注入是比较好的选择。

关键词：火箭发动机推进系统实验塞式喷管底部性能