检索结果-南通市图书馆

Swift Assembly of Adaptive Thermocell Arrays for Device‑Level Healable and Energy‑Autonomous Motion Sensors

在线全文

学校读者我要写书评

暂无评论

纳微快报:英文版 2023年第11期15卷 104-118页

作者： Xin Lu Daibin Xie kaihua zhu Shouhao Wei Ziwei Mo Chunyu Du Lirong Liang Guangming Chen zhuoxin Liu College of Materials Science and Engineering Shenzhen UniversityShenzhen 518055People’s Republic of China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065People’s Republic of China

The evolution of wearable technology has prompted the need for adaptive,self-healable,and energy-autonomous energy devices.This study innovatively addresses this challenge by introducing an MXene-boosted hydrogel electrolyte,which expedites the assembly process of flexible thermocell(TEC)arrays and thus circumvents the complicated fabrication of typical wearable electronics.Our findings underscore the hydrogel electrolyte’s superior thermoelectrochemical performance under substantial deformations and repeated self-healing cycles.The resulting hydrogel-based TEC yields a maximum power output of 1032.1 nW under theΔT of 20 K when being stretched to 500%for 1000 cycles,corresponding to 80%of its initial state;meanwhile,it sustains 1179.1 nW under theΔT of 20 K even after 60 cuthealing cycles,approximately 92%of its initial state.The as-assembled TEC array exhibits device-level self-healing capability and high adaptability to human body.It is readily applied for touch-based encrypted communication where distinct voltage signals can be converted into alphabet letters;it is also employed as a self-powered sensor to in-situ monitor a variety of body motions for complex human actions.The swift assembly approach,combined with the versatile functionality of the TEC device,paves the way for future advancements in wearable electronics targeting at fitness monitoring and human–machine interfaces.

关键词： Thermocells Flexible devices Wearable applications Low-grade heat harvest MXenes

Spin-orbit torque efficiency enhancement to tungsten-based SOT-MTJs by interface modification with an ultrathin MgO

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第1期67卷 316-317页

作者： Shiyang LU Xiaobai NING Hongchao ZHANG Sixi ZHEN Xiaofei FAN Danrong XIONG Dapeng zhu Gefei WANG Hong-Xi LIU kaihua CAO Weisheng ZHAO Fert Beijing Institute School of Integrated Science and EngineeringBeihang University Truth Memory Corporation

Spin-orbital torque (SOT) based three-terminal magnetic tunnel junctions (MTJs) have attracted much interest as the next generation magnetic random-access memory (MRAM)key device both in the academy and the industry. This is because SOT-MTJs feature high endurance and fast switching speed, benefiting tremendously from the separation of read/write current paths and less incubation time during the write in contrast to the spin-transfer torque (STT) MTJs [1].

关键词：

LaNi_(0.6)Fe_(0.4)O_(3)阴极接触材料导电特性调控及其对SOFC电化学性能的影响

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

无机材料学报 2024年第4期39卷 367-373页

作者：张琨王宇朱腾龙孙凯华韩敏芳钟秦南京理工大学化学与化工学院南京210094 徐州华清京昆能源有限公司徐州221005 清华大学能源与动力工程系北京100084

鉴于平板式固体氧化物燃料电池(SOFC)电堆对低面电阻、高稳定性阴极接触材料的需求,本研究阐明了LaNi_(0.6)Fe_(0.4)O_(3)(LNF)颗粒尺寸调控对导电和SOFC单电池性能演变的影响机制,优化了LNF预处理工艺,降低了接触组件面电阻,提升了SOF... 详细信息

鉴于平板式固体氧化物燃料电池(SOFC)电堆对低面电阻、高稳定性阴极接触材料的需求,本研究阐明了LaNi_(0.6)Fe_(0.4)O_(3)(LNF)颗粒尺寸调控对导电和SOFC单电池性能演变的影响机制,优化了LNF预处理工艺,降低了接触组件面电阻,提升了SOFC单电池性能及热循环稳定性。结果表明:预压造粒的样品(LNF-2)与高温烧结预处理的样品(LNF-3)的面电阻更小,分别为0.074和0.076Ω·cm^(2);在750℃施加1 A/cm^(2)电流负载后,能够更快地进入稳态,并保持颗粒尺寸稳定。其中,LNF-2单电池在750℃下的峰值功率密度0.94 W/cm^(2)较未处理的LNF的0.66 W/cm^(2)高,但在热循环过程中性能衰减较大,下降了20%;而LNF-3单电池在20次热循环后峰值功率密度仅下降了4%。本研究对高可靠SOFC电堆装配及其长寿命稳定运行具有指导及参考价值。

关键词：固体氧化物燃料电池(SOFC) 阴极接触材料 LaNi_(0.6)Fe_(0.4)O_(3) 热循环

模拟增温对植物叶片δ^(13)C值的影响:全球Meta分析

在线全文

学校读者我要写书评

暂无评论

生态学报 2024年第12期44卷 5412-5421页

作者：张莉莉叶志成廖凯华朱青赖晓明郭长强中国科学院南京地理与湖泊研究所中国科学院流域地理学重点实验室南京210008 中国科学院大学南京学院南京211135 中国科学院南京地理与湖泊研究所鄱阳湖湖泊湿地综合研究站九江332899

温室气体大量排放导致的全球变暖是最为关注的环境问题之一,这会直接影响植物的生长与发育进而影响群落组成乃至生态系统的结构和功能。水分利用效率作为植物叶片通过光合作用调节水分生理过程的指标,是联系生态系统碳循环与水循环关系... 详细信息

温室气体大量排放导致的全球变暖是最为关注的环境问题之一,这会直接影响植物的生长与发育进而影响群落组成乃至生态系统的结构和功能。水分利用效率作为植物叶片通过光合作用调节水分生理过程的指标,是联系生态系统碳循环与水循环关系的关键,反映了植被生态系统对立地环境快速调整和资源变化的适应策略,是当前全球变化研究中的重点。植物叶片碳稳定同位素比值(δ^(13)C)是反映植物长期水分利用效率的关键指标,但全球气候变暖对植物叶片δ^(13)C值的影响仍存在较大争议。该研究利用Meta分析整合全球范围内51份相关研究文献中的371组数据,较为系统地评估模拟增温对植物叶片δ^(13)C及其生理生态指标的影响。结果表明,模拟增温能够使叶片δ^(13)C值显著升高0.6%(P<0.001),同时对叶片呼吸速率R_(d)、气孔导度G_(s)、净光合作用速率P_(n)、碳C的效应值分别为0.237、0.062、-0.140、-0.019 (P<0.05)。模拟增温处理在增强植物光合作用的同时提高了叶片呼吸速率(R_(d)),导致光合产物不断被消耗、叶片碳(C)降低,最终使叶片P_(n)降低并且叶片δ^(13)C产生富集现象。通过进一步对影响因素分析发现,叶片δ^(13)C值对增温的响应主要受增温时间、高程和年均气温等控制(相对重要性指数分别为1.00、0.97和0.92)。另外,模拟增温时选用不同的增温模式对叶片δ^(13)C值也具有显著不同的影响,采用红外线加热、土柱置换和电缆增温等方法对叶片δ^(13)C值具有正向促进作用(效应值分别为0.70、0.44和0.35),而采用遮阳屏与开顶箱增温等方法具有负向作用(效应值分别为-0.17和-0.09)。研究结论对于深入理解全球变化背景下植物水分利用的响应特征具有重要的理论意义,以期为今后该领域的植物生长研究提供理论依据和有效支撑。

关键词：模拟增温叶片δ^(13)C Meta分析气孔导度呼吸速率植物水分利用效率

Response of soil hydrological processes to soil rock fragments:A global Meta-analysis

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2023年第9期66卷 2066-2080页

作者： Yongwu WANG Qing zhu Xiaoming LAI kaihua LIAO Changqiang GUO Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China College of Nanjing University of Chinese Academy of SciencesNanjing 211135China

The rock fragment(RF)has been widely observed in the soil solum or on the soil surface.It regulates soil hydrological processes(SHPs)and thus has great impacts on soil and water conservation.However,responses of SHPs to RF characteristics(position,content,coverage area,mulching thickness,and size)remain unclear.Based on the dataset extracted from 168 published studies,effects of RF characteristics on SHPs(soil loss rate,evaporation rate,surface runoff rate,infiltration rate,soil water content,and soil water storage)and saturated hydraulic conductivity(Ks)were discussed in this study.Results showed that RFs completely inserted into the soil solum(CO_INS)improved the Ks by 6.9%,runoff rate by 12.8%,and soil loss rate by 22.3%,while it reduced the evaporation rate by 30.7%,infiltration rate by 15.4%,and soil water content by 9.9%.With the RF content(kg kg−1)increasing,its effects on these SHPs were strengthened.The RFs resting on the surface and partially covering soil surface(PA_COV)improved the infiltration rate but reduced the evaporation rate by 36.9%,surface runoff rate by 25.4%,and soil loss rate by 59.3%.This in turn enhanced soil water content and storage.However,as the RF coverage(%in area)increasing,the cross-sectional area of water flow decreased,and thus the infiltration rate reduced.The RFs completely mulch on the soil surface(CO_MUL)reduced the evaporation rate by 59.5%and infiltration rate by 76.5%but improved the soil water content and storage.Except the infiltration rate,the effects of CO_MUL on SHPs were strengthened as mulch thickness(cm)increased.The RFs partially embedded into soil surface(PA_EMB)promoted surface runoff rate by 15.3%,soil loss rate by 34.7%,and soil water content by 24.3%,but reduce the infiltration rate.However,the surface runoff rate was reduced at high embedded coverage due to increased tortuosity of water flow.In addition,the RF size exerted weaker effects on SHPs than RF positions,content,coverage,and mulch thickness.Our findings enhanced the understanding of SHP responses

关键词： Critical zone Meta-analysis Soil hydrology Soil water Watershed

Evaluation of nine major satellite soil moisture products in a typical subtropical monsoon region with complex land surface characteristics

在线全文

学校读者我要写书评

暂无评论

International Soil and Water Conservation Research 2022年第3期10卷 518-529页

作者： Liuyang Li Ya Liu Qing zhu kaihua Liao Xiaoming Lai Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing210008China University of Chinese Academy of Sciences Beijing100049China

Assessing accuracies of satellite soil moisture(SM)products in areas with strong anthropogenic activities,abundant precipitation,and dense vegetation is important but limited.In this study,performances of nine satellite SM products,including the European Space Agency Climate Change Initiative(ESA CCI),and the ascending and descending products of the Advanced Microwave Scanning Radiometer 2(AMSR2),Chinese Fengyun-3B(FY3B),Chinese Fengyun-3C(FY3C),and Soil Moisture Active Passive(SMAP),were evaluated against in-situ SM in the Yangtze River Delta(YRD)from 2015 to 2018.Results showed that the ESA CCI outperformed other products,with averaged correlation coefficient(R)of 0.522,correlation coefficient for SM anomalies(Rano)of 0.419,and unbiased root mean square error(ubRMSE)of 0.040 m^(3)m^(-3),followed by the SMAP_A and SMAP_D.Overestimation was observed in the AMSR2 products(Bias>0.081 m^(3)m^(-3)),while underestimation was found in the FY3B and FY3C products(Bias<-0.104 m^(3)m^(-3)).Moreover,R values decreased with the increase in water area percentage(WAP),land cover heterogeneity(GSI),fractional vegetation cover(FVC),and precipitation(PRE).Threshold values were observed at 3%for the WAP,0.05 for the FVC,and 900 mm yr^(-1)for the PRE,below which sharp declines of accuracy were observed.The WAP,GSI,and FVC were divided into five sub-classes with their values increasing with the sub-class level(I to V).Correlations coefficients between these perturbing factors and R(correlation between satellite and in-situ SM)increased as sub-class levels increased.Under sub-classes I,II,and III,these three factors had limited influences on accuracies of satellite SM products.However,under sub-classes IV and V,significant impacts of these three perturbing factors were observed.Moreover,when sub-classes of the PRE increased from I to V,correlations between Bias and PRE decreased first and then increased.These findings can help to determine suitable satellite SM products in the YRD and similar areas.

关键词： Remote sensing Soil moisture Soil water content The yangtze river delta

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

黄河流域创新发展现状、需求与对策研究

中国科学院院刊 2024年第6期39卷 947-956页

作者：陈凯华蔺洁薛超凯段炜钰朱浪梅路东柱侯保荣中国科学院大学公共政策与管理学院北京100190 中国科学院科技战略咨询研究院北京100190 山东理工大学管理学院淄博255012 中国科学院海洋研究所青岛266000

黄河贯穿我国东中西部9个省级行政区,不仅是我国重要的生态安全屏障,也是我国重要的经济发展带。黄河流域创新发展是落实国家创新驱动发展战略、区域协调发展战略、西部大开发战略及黄河流域生态保护和高质量发展战略的重要路径。但是,... 详细信息

黄河贯穿我国东中西部9个省级行政区,不仅是我国重要的生态安全屏障,也是我国重要的经济发展带。黄河流域创新发展是落实国家创新驱动发展战略、区域协调发展战略、西部大开发战略及黄河流域生态保护和高质量发展战略的重要路径。但是,黄河流域生态环境承载能力差、产业发展“倚能倚重”特征明显、民生保障能力不足,制约了黄河流域创新驱动发展转型的速度和质量。黄河流域必须加快创新驱动发展转型,强化宏观统筹、协同推进与深化改革,加快部署黄河流域科技创新一体化发展战略,系统谋划建设黄河流域科技创新大走廊,推动形成创新引领生态保护与经济社会协调发展的新格局。基于此,文章从生态保护、产业发展、社会发展3个方面系统分析黄河流域创新发展现状与需求,提出黄河流域实现创新发展的总体思路,并从加强生态领域科技创新合作、推动科技赋能产业体系转型升级、推进科技赋能社会服务提质增效、强化重点区域科技创新能力提升和统筹推进全流域科技体制改革5个方面提出对策建议。

关键词：黄河流域创新发展科技创新生态保护产业发展社会发展

基于Morris和Sobol法的茶园地上部生物量与氮磷流失模拟敏感性分析

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

水土保持研究 2024年第2期31卷 43-51,59页

作者：叶志成张莉莉廖凯华朱青赖晓明郭长强中国科学院南京地理与湖泊研究所流域地理学重点实验室南京210008 中国科学院大学南京学院南京211135

[目的]揭示土壤、地形和作物参数对DNDC模型模拟的茶园地上部生物量与氮磷流失量的影响程度,识别各模型输出的最敏感参数,为模型的率定提供指导方案。[方法]基于天目湖流域茶园径流小区数据和DNDC模型,应用定性的Morris法和定量的Sobol... 详细信息

[目的]揭示土壤、地形和作物参数对DNDC模型模拟的茶园地上部生物量与氮磷流失量的影响程度,识别各模型输出的最敏感参数,为模型的率定提供指导方案。[方法]基于天目湖流域茶园径流小区数据和DNDC模型,应用定性的Morris法和定量的Sobol法对模拟的茶园地上部生物量、氮磷流失量(包括氮磷淋失量和含氮气体排放量)和水分渗漏量进行敏感性分析,评估了各个模型输出结果的敏感参数,并借助蒙特卡洛方法量化模型输出的不确定性。[结果]对地上部生物量产生最主要影响的参数为成熟作物中籽粒占总生物量之比;对氮淋失量产生最主要影响的参数为土壤黏粒含量;对磷淋失量产生最主要影响的参数为土壤容重;对水分渗漏量产生最主要影响的参数为坡度;对N_(2)O排放量产生最主要影响的参数为初始土壤有机碳含量;对NO排放量和对NH3排放量产生最主要影响的参数为土壤pH。各输出结果中,磷淋失量的不确定性最大,变异系数为43.84%;水分渗漏量的不确定性最小,变异系数为2.36%。Morris法和Sobol法相比,Morris法优在方便省时,Sobol法优在准确全面,两种方法得到的参数敏感度排序总相关性为0.86,具有一定可替代性。[结论]在率定模型之前,先应用Morris法确定敏感参数的范围,再应用Sobol法精确量化,从而快速准确地筛选出模型敏感参数。在此基础上,固定非敏感参数,先重点校正敏感作物参数,再校正敏感土壤参数。本研究可为DNDC模型参数的本地化提供科学支撑,提高该模型对天目湖流域茶园生态系统的模拟精度和效率。

关键词：敏感性分析 DNDC模型天目湖流域

Mechanism of field-like torque in spin-orbit torque switching of perpendicular magnetic tunnel junction

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2022年第10期65卷 109-114页

作者： Yudong zhuo Wenlong Cai Daoqian zhu Hongchao Zhang Ao Du kaihua Cao Jialiang Yin Yan Huang Kewen Shi Weisheng Zhao Fert Beijing Institute MIIT Key Laboratory of SpintronicsSchool of Integrated Circuit Science and EngineeringBeihang UniversityBeijing 100191China Beihang-Goertek Joint Microelectronics Institute Qingdao Research InstituteBeihang UniversityQingdao 266000China

The current-induced spin-orbit torque(SOT) is one of the most promising ways for high speed and low power spintronics devices. However, the mechanism of SOT driven magnetization reversal, especially the role of the field-like torque(FLT), is still unclear. Here, we report the observed promotion and suppression of switching by FLT, which depends on the relative direction of FLT and spin polarization. Our results reveal that the FLT could modulate the switching speed and power consumption by affecting the work done by the damping-like torque, and leads two different reversal dynamical paths during the switching.Furthermore, the origin of incubation time in SOT induced switching is clarified simultaneously.

关键词： spin-orbit torque field-like torque magnetization reversal magnetic tunnel junction