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Linear spectral unmixing algorithm for modelling suspendedsediment concentration of ash oods, upper Tekeze River, Ethiopia 预览
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作者 Hagos GGebreslassie Assefa MMelesse +1 位作者 Kevin Bishop Azage GGebremariam 《国际泥沙研究:英文版》 SCIE 2020年第1期79-90,共12页
Flash floods are the highest sediment transporting agent,but are inaccessible for in-situ sampling and have rarely been analyzed by remote sensing technology.Laboratory and field experiments were done to develop linea... Flash floods are the highest sediment transporting agent,but are inaccessible for in-situ sampling and have rarely been analyzed by remote sensing technology.Laboratory and field experiments were done to develop linear spectral unmixing(LSU)remote sensing model and evaluate its performance in simulating the suspended sediment concentration(SSC)in flash floods.The models were developed from continuous monitoring in the laboratory and the onsite spectral signature of river bed sediment deposits and flash floods in the Tekeze River and in its tributary,the Tsirare River.The Pearson correlation coefficient was used to determine the variability of correlations between reflectance and SSCs.The coefficient of determination(R2)and root mean square of error(RMSE)were used to evaluate the performance of the generated models.The results found that the Pearson correlation coefficient between SSCs and reflectance varied based on the level of the SSCs,geological colors,and grain sizes.The performance of the LSU model and empirical remote sensing approaches were computed to be R2?0.92,and RMSE-±0.76 g/l in the Tsirare River and R2-0.91,and RMSE-±0.73 g/l in the Tekeze River and R2?0.81,RMSE-±2.65 g/l in the Tsirare river and R2?0.76,RMSE-±10.87 g/l in the Tekeze River,respectively.Hence,the LSU approach of remote sensing was found to be relatively accurate in monitoring and modeling the variability of SSCs that could be applied to the upper Tekeze River basin. 展开更多
关键词 Empirical remote sensing Flash floods Linear spectral unmixing Suspended sediment concentration Tekeze River
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Development of Magnetic Compound Fluid Rubber Sensor for Practical Usage on &gamma;-Irradiation and Energy Harvesting for Broad-Band Electromagnetic Waves 预览
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作者 Kunio Shimada Ryo Ikeda +1 位作者 Hiroshige Kikura Hideharu Takahashi 《力学国际期刊(英文)》 2019年第9期205-231,共27页
We have performed sequential studies on new types of soft rubber for their application as artificial skin in robots and haptic sensors. Based on a proposed electrolytic polymerization method and novel adhesion techniq... We have performed sequential studies on new types of soft rubber for their application as artificial skin in robots and haptic sensors. Based on a proposed electrolytic polymerization method and novel adhesion technique for rubber and a metal that utilizes a metal complex hydrate, we have developed an MCF rubber sensor. This sensor uses a magnetic compound fluid (MCF), natural rubber (NR-latex) or chloroprene rubber latex (CR-latex), and requires the application of a magnetic field. The potential application of the developed sensor in various engineering scenarios and our daily lives is significant. In this regard, we investigated the effects of &gamma;-irradiation, infrared radiation, microwaves, and a thermal source on the MCF rubber sensor. We established that the MCF rubber is effective enough to be used for power generation of broadband electro-magnetic waves from &gamma;-rays to microwaves, including the range of the solar spectrum, which is the typical characteristic obtained in the present investigation. The remarkable attribute is that the MCF rubber sensor dose is not degraded by &gamma;-irradiation. We also demonstrated the effectiveness of the MCF rubber sensor in energy harvesting. 展开更多
关键词 Γ-IRRADIATION Photovoltaics Energy Harvesting Mechanical Property Thermal Source Infrared Rays Electromagnetic Waves Induced Voltage Natural RUBBER Chloroprene RUBBER Adhesion Electrolytic Polymerization MAGNETIC Cluster MAGNETIC Field MAGNETIC COMPOUND FLUID (MCF) Sensing Robot
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Optimal Energy-Efficient Transmission for Hybrid Spectrum Sharing in Cooperative Cognitive Radio Networks 预览
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作者 Linna Hu Rui Shi +3 位作者 Minghe Mao Zhiyu Chen Hongxi Zhou Weiliang Li 《中国通信:英文版》 SCIE CSCD 2019年第6期150-161,共12页
In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user syste... In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user systems to achieve the maximum energy efficiency in a cognitive network based on hybrid spectrum sharing,meanwhile considering the maximum transmit power,user quality of service(QoS)requirements,interference limitations,and primary user protection.The optimization of energy efficient sensing time and power allocation is formulated as a non-convex optimization problem.The Dinkelbach’s method is adopted to solve this problem and to transform the non-convex optimization problem in fractional form into an equivalent optimization problem in the form of subtraction.Then,an iterative power allocation algorithm is proposed to solve the optimization problem.The simulation results show the effectiveness of the proposed algorithms for energy-efficient resource allocation in the cognitive network. 展开更多
关键词 cognitive radio networks COOPERATIVE SPECTRUM SENSING ENERGY-EFFICIENCY HYBRID SPECTRUM sharing power control SENSING time optimization
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Carbon dots prepared for fluorescence and chemiluminescence sensing
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作者 Meng-Li Liu Bin-Bin Chen +1 位作者 Chun-Mei Li Cheng-Zhi Huang 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第8期968-981,共14页
Carbon dots(CDs) have attracted considerable research interest in recent years due to their unique optical properties, chemical inertness, facile synthesis from a wide range of starting materials, and advantages over ... Carbon dots(CDs) have attracted considerable research interest in recent years due to their unique optical properties, chemical inertness, facile synthesis from a wide range of starting materials, and advantages over classic quantum dots and organic dyes.Various methods have been developed for preparing the CDs, including chemical oxidation, hydro/solvothermal method,electrochemical method, microwave-assisted synthesis, and direct carbonization method. Importantly, the superior electronic properties of CDs including efficient light harvesting and prominent photoinduced electron transfer have aroused considerable attention in fluorescence(FL) and chemiluminescence(CL) sensing field. In this review, we aim to demonstrate the recent progress of CDs in the synthesis, FL and CL sensing applications. This review gives new insights into how to use different synthetic methods to tune the structure of the CDs, with the major focus on FL and CL sensing. 展开更多
关键词 CARBON DOTS synthesis approach FLUORESCENCE SENSING CHEMILUMINESCENCE SENSING detection mechanism
Determining the spatial distribution of soil properties using the environmental covariates and multivariate statistical analysis: a case study in semi-arid regions of Iran 预览
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作者 Mojtaba ZERAATPISHEH Shamsollah AYOUBI +1 位作者 Magboul SULIEMAN JesusRODRIGO-COMINO 《干旱区科学:英文版》 SCIE CSCD 2019年第4期551-566,共16页
Natural soil-forming factors such as landforms, parent materials or biota lead to high variability in soil properties. However, there is not enough research quantifying which environmental factor(s) can be the most re... Natural soil-forming factors such as landforms, parent materials or biota lead to high variability in soil properties. However, there is not enough research quantifying which environmental factor(s) can be the most relevant to predicting soil properties at the catchment scale in semi-arid areas. Thus, this research aims to investigate the ability of multivariate statistical analyses to distinguish which soil properties follow a clear spatial pattern conditioned by specific environmental characteristics in a semi-arid region of Iran. To achieve this goal, we digitized parent materials and landforms by recent orthophotography. Also, we extracted ten topographical attributes and five remote sensing variables from a digital elevation model(DEM) and the Landsat Enhanced Thematic Mapper(ETM), respectively. These factors were contrasted for 334 soil samples(depth of 0–30 cm). Cluster analysis and soil maps reveal that Cluster 1 comprises of limestones, massive limestones and mixed deposits of conglomerates with low soil organic carbon(SOC) and clay contents, and Cluster 2 is composed of soils that originated from quaternary and early quaternary parent materials such as terraces, alluvial fans, lake deposits, and marls or conglomerates that register the highest SOC content and the lowest sand and silt contents. Further, it is confirmed that soils with the highest SOC and clay contents are located in wetlands, lagoons, alluvial fans and piedmonts, while soils with the lowest SOC and clay contents are located in dissected alluvial fans, eroded hills, rock outcrops and steep hills. The results of principal component analysis using the remote sensing data and topographical attributes identify five main components, which explain 73.3% of the total variability of soil properties. Environmental factors such as hillslope morphology and all of the remote sensing variables can largely explain SOC variability, but no significant correlation is found for soil texture and calcium carbonate equivalent contents. Therefore, we conclud 展开更多
关键词 soil properties remote sensing data topographical attributes MULTIVARIATE statistical analyses GEOGRAPHIC information systems land management
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智能化无人机植保作业关键技术及研究进展 预览
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作者 徐旻 张瑞瑞 +2 位作者 陈立平 唐青 徐刚 《智慧农业》 2019年第2期20-33,共14页
搭载高性能传感器和施药装备的农业植保无人机系统是精准农业领域具有代表性的智能装备之一。本研究首先从前端田间作业环境动态感知技术出发,阐述了无人机光谱成像遥感、多传感器融合的SLAM实时环境建模等技术在无人机植保作业方面的... 搭载高性能传感器和施药装备的农业植保无人机系统是精准农业领域具有代表性的智能装备之一。本研究首先从前端田间作业环境动态感知技术出发,阐述了无人机光谱成像遥感、多传感器融合的SLAM实时环境建模等技术在无人机植保作业方面的应用情况;然后对精准施药过程建模与优化控制有关的前沿技术进行了分析,包括旋翼下方风场结构演化及雾滴沉积过程仿真建模、多区域全覆盖条件下的智能作业路径规划、精准变量施药控制等;最后论述了作业效果评估与过程监管相关技术的发展现状,包括施药作业质量评价方法、基于云平台数据管理的全过程可视化监管等。在总结现有技术发展现状基础上,对未来智能化无人机植保关键技术发展趋势进行了预测,阐明了光谱图像获取与计算智能的深度学习识别聚类、基于高精度雾滴谱和风场模型预测的精准变量施药作业路径规划、基于传感器实时数据的作业质量评估和作业监管等新技术手段,将在遥感信息反演、药液飘移抑制、作业效率优化、施药过程管控等方面带来革命性的进步,使植保作业数据化、透明化,全过程可观可控,推动农业生产管理从机械化向智能化和智慧化迈进。 展开更多
关键词 无人机 植保 智能 感知 施药
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Deep Learning Based Channel Estimation in Fog Radio Access Networks 预览
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作者 Zhendong Mao Shi Yan 《中国通信:英文版》 SCIE CSCD 2019年第11期16-28,共13页
As a promising paradigm of the fifth generation networks,fog radio access network(F-RAN)has attracted lots of attention nowadays.To fully utilize the promising gain of F-RANs,the acquisition of accurate channel state ... As a promising paradigm of the fifth generation networks,fog radio access network(F-RAN)has attracted lots of attention nowadays.To fully utilize the promising gain of F-RANs,the acquisition of accurate channel state information is significant.However,conventional channel estimation approaches are not suitable in F-RANs due to the large training and feedback overhead.In this paper,we consider the channel estimation in F-RANs with fog access point(F-AP)equipped with massive antennas.Thanks to the computing ability of F-AP and the sparsity of channel matrices in angular domain,Gated Recurrent Unit(GRU),a data-driven based channel estimation is proposed at F-AP to reduce the training and feedback overhead.The GRU-based method can capture the hidden sparsity structure automatically through the network training.Moreover,to further improve the channel estimation,a bidirectional GRU based method is proposed,whose target channel structure is decided by previous and subsequent structures.We compare the performance of our proposed channel estimation with traditional methods(Orthogonal Matching Pursuit(OMP)and Simultaneous OMP(SOMP)).Simulation results show that the proposed approaches have better performance compared with the traditional OMP and SOMP methods. 展开更多
关键词 fog radio access network(F-RAN) massive MIMO compressive sensing deep learning gated recurrent unit(GRU)
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In situ Synthesis of PANI/CuO Nanocomposites for Non-Enzymatic Electrochemical Glucose Sensing 预览
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作者 Gul Rahman Mustifuz Ur Rahman Zainab Najaf 《应用化学杂志》 2019年第2期38-47,共10页
We report the in situ synthesis of polyaniline/copper oxide (PANI/CuO) nanocomposites and their characterization as electrocatalyst for non-enzymatic electrochemical glucose detection. Copper oxide (CuO) nanoparticles... We report the in situ synthesis of polyaniline/copper oxide (PANI/CuO) nanocomposites and their characterization as electrocatalyst for non-enzymatic electrochemical glucose detection. Copper oxide (CuO) nanoparticles were prepared by wet chemical precipitation method followed by thermal treatment while the composites of PANI and CuO were synthesized by in situ chemical polymerization of aniline with definite amount of CuO. X-ray diffraction (XRD) results revealed that the composites are predominantly amorphous. The composite formation was confirmed by fourier transform infrared (FTIR) and UV-Vis spectroscopy analysis. The surface morphology was greatly altered with the amount of CuO in composite structure. PANI/CuO nanocomposites were coated on copper substrate to investigate their electrocatalytic activity for glucose sensing. PANI/CuO with 10 wt.% CuO exhibited good response towards electrochemical glucose oxidation. 展开更多
关键词 POLYANILINE Copper Oxide NANOCOMPOSITES ELECTROCATALYST GLUCOSE Sensing
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Target-activated and ratiometric photochromic probe for “double-check” detection of toxic thiols in live cells
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作者 Youxin Fu Xing Zhang +3 位作者 Feng Cao Wenhui Wang Guangren Qian Junji Zhang 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第9期1204-1212,共9页
Photochromic molecules can achieve reversible isomerization upon alternate light irradiations, which offers a great opportunity to improve the precision of analytes detection and imaging in complicated biological envi... Photochromic molecules can achieve reversible isomerization upon alternate light irradiations, which offers a great opportunity to improve the precision of analytes detection and imaging in complicated biological environments. Previous reported photochromic probe exhibited only mono-color switching and an initially fluorescence-ON state that may cause high background signal and impose an adverse impact on the desired sensing precision. To overcome this set-back, we developed a novel photochromic probe with an analyte-activation mode for ratiometric sensing of toxic thiols in both real water samples and live cells. The dynamic dual-fluorescence signal is released only after the fast and selective cleavage of the 2,4-dinitrophenyl sulfonate by the targeted thiophenol derivatives. Consequently, a "double-check" with synchronized dual-fluorescence blinking for analyte detection is successfully employed upon alternate light triggers with rapid response(k=7.2×10~(-2) s~(-1)), high sensitivity(LOD=6.1 nM) as well as selectivity of thiophenol derivatives over other common thiol species(e.g., GSH, Cys and Hcy). The photochromic probe was successfully introduced to the fast and on-site detection of highly toxic thiophenols in real waste water samples. Moreover, by using confocal laser-scanning microscopy(CLSM) and flow cytometric analysis, the potential applications of this ratiometric photochromic probe for trace toxic thiol sensing in live cells are examined. 展开更多
关键词 PHOTOCHROMISM RATIOMETRIC PROBE live cell imaging target-activation thiol sensing
荧光共轭聚合物的合成策略及其应用研究 预览
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作者 尹伟东 马拉毛草 马恒昌 《功能材料》 EI CAS CSCD 北大核心 2019年第11期11030-11037,11044,共9页
有机共轭聚合物在发光材料中具有良好的应用前景而倍受研究者们的关注。相对于荧光小分子来说,荧光共轭聚合物具有结构多样性、功能化强、可加工性好和合成简单等优势。近年来,荧光共轭聚合物材料在化学传感、生物成像、光电器件和有害... 有机共轭聚合物在发光材料中具有良好的应用前景而倍受研究者们的关注。相对于荧光小分子来说,荧光共轭聚合物具有结构多样性、功能化强、可加工性好和合成简单等优势。近年来,荧光共轭聚合物材料在化学传感、生物成像、光电器件和有害物的吸附与降解等领域显示了重要的应用价值。综述了以suzuki偶联反应聚合、Sonogashira反应聚合、Wittig-Heck-McMurry反应聚合等方法合成共轭聚合物以及在荧光调控、化学传感、刺激响应、生物细胞成像、气体吸附及有机染料降解等方面的应用。设计合成具有特异性识别、更高灵敏度、更容易加工、卓越稳定性和功能化强的荧光共轭聚合物是主要的研究方向。 展开更多
关键词 荧光共轭聚合物 生物成像 传感 吸附降解
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Infant Cry Language Analysis and Recognition: An Experimental Approach 预览
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作者 Lichuan Liu Wei Li +1 位作者 Xianwen Wu Benjamin X. Zhou 《自动化学报:英文版》 CSCD 2019年第3期778-788,共11页
Recently, lots of research has been directed towards natural language processing. However, the baby’s cry, which serves as the primary means of communication for infants, has not yet been extensively explored, becaus... Recently, lots of research has been directed towards natural language processing. However, the baby’s cry, which serves as the primary means of communication for infants, has not yet been extensively explored, because it is not a language that can be easily understood. Since cry signals carry information about a babies’ wellbeing and can be understood by experienced parents and experts to an extent, recognition and analysis of an infant’s cry is not only possible, but also has profound medical and societal applications. In this paper, we obtain and analyze audio features of infant cry signals in time and frequency domains. Based on the related features, we can classify given cry signals to specific cry meanings for cry language recognition. Features extracted from audio feature space include linear predictive coding (LPC), linear predictive cepstral coefficients (LPCC), Bark frequency cepstral coefficients (BFCC), and Mel frequency cepstral coefficients (MFCC). Compressed sensing technique was used for classification and practical data were used to design and verify the proposed approaches. Experiments show that the proposed infant cry recognition approaches offer accurate and promising results. 展开更多
关键词 Compressed SENSING FEATURE extraction INFANT CRY signal language RECOGNITION
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Basics on the use of acid-sensing ion channels’ inhibitors as therapeutics 预览
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作者 Jamileh Dibas Houssam Al-Saad Adnan Dibas 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第3期395-398,共4页
Since the discovery of acid-sensing ion channels in 1997,their importance in the health of neurons and other non-neuronal cells has gained significant importance.Acid-sensing ion channels play important roles in media... Since the discovery of acid-sensing ion channels in 1997,their importance in the health of neurons and other non-neuronal cells has gained significant importance.Acid-sensing ion channels play important roles in mediating pain sensation during diseases such as stroke,inflammation,arthritis,cancer,and recently migraine.More interestingly,acid-sensing ion channels may explain the sex differences in pain between males and females.Also,the ability of acid-sensing ion channel blockers to exert neuroprotective effects in a number of neurodegenerative diseases has added a new dimension to their therapeutic value.The current failure rate of -45% of new drugs (dueto toxicity issues)and saving of up to 7 years in the life span of drug approval makes drug repurposing a high priority.If acid-sensing ion channels'blockers undergo what is known as "drug repurposing",there is a great potential to bring them as medications with known safety profiles to new patient populations.However,the route of administration remains a big challenge due to their poor penetration of the blood brain and retinal barriers.In this review,the promise of using acid-sensing ion channel blockers as neuroprotective drugs is discussed. 展开更多
关键词 OPTIC nerve GLAUCOMA NEURODEGENERATION NEUROPROTECTION acid sensing ion channel CALPAIN
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CBSC: A Crowdsensing System for Automatic Calibrating of Barometers
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作者 Hai-Bo Ye Xuan-Song Li +1 位作者 Li Sheng Kai Dong 《计算机科学技术学报:英文版》 SCIE EI CSCD 2019年第5期1007-1019,共13页
The mobile crowdsensing software systems can complete large-scale and complex sensing tasks with the help of the collective intelligence from large numbers of ordinary users. In this paper, we build a typical crowdsen... The mobile crowdsensing software systems can complete large-scale and complex sensing tasks with the help of the collective intelligence from large numbers of ordinary users. In this paper, we build a typical crowdsensing system, which can efficiently calibrate large numbers of smartphone barometer sensors. The barometer sensor now becomes a very common sensor on smartphones. It is very useful in many applications, such as positioning, environment sensing and activity detection. Unfortunately, most smartphone barometers today are not accurate enough, and it is rather challenging to efficiently calibrate a large number of smartphone barometers. Here, we try to achieve this goal by designing a crowdsensingbased smartphone calibration system, which is called CBSC. It makes use of low-power barometers on smartphones and needs few reference points and little human assistant. We propose a hidden Markov model for peer-to-peer calibration, and calibrate all the barometers by solving a minimum dominating set problem. The field studies show that CBSC can get an accuracy of within 0.1 hPa in 84% cases. Compared with the traditional solutions, CBSC is more practical and the accuracy is satisfying. The experience gained when building this system can also help the development of other crowdsensing-based systems. 展开更多
关键词 crowdsensing SYSTEM SMARTPHONE SENSING BAROMETER CALIBRATION
MOF晶体薄膜材料的制备及应用
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作者 王丹 王正帮 +2 位作者 王敬锋 鲁雄刚 周忠福 《工程科学学报》 CSCD 北大核心 2019年第3期292-306,共15页
作为纳米技术领域的一种新材料,金属-有机骨架(metal-organic framework,MOF)薄膜材料(也称为SURMOFs)获得了越来越多研究者的关注.多种合成方法的不断提出,为大量合成膜厚度、均匀性、形态、甚至维度均可控的MOF薄膜材料提供了可能性,... 作为纳米技术领域的一种新材料,金属-有机骨架(metal-organic framework,MOF)薄膜材料(也称为SURMOFs)获得了越来越多研究者的关注.多种合成方法的不断提出,为大量合成膜厚度、均匀性、形态、甚至维度均可控的MOF薄膜材料提供了可能性,并为薄膜材料在更多领域中的应用提供了机会.本文首先介绍了MOF薄膜材料基于液相或真空的各种合成方法及其适用范围,其中,获得高质量薄膜的最有效方法之一是在基底材料上沉积自组装单层(SAMs),进而诱导MOF薄膜的成核及生长.其次,总结了近年来MOF薄膜材料在分离、催化、传感等领域的研究进展,以及为满足环境可持续发展和对清洁能源的需求,新发展起来的在光催化、储能、光伏以及制备各种电子器件领域的应用.在此基础上,讨论了限制MOF薄膜实际应用的因素(例如薄膜生长机制需要更深入的研究、薄膜质量及薄膜热电性能等有待进一步提高等),对相关领域未来的研究方向进行了展望,以期为MOF薄膜材料进一步的研究发展提供理论参考. 展开更多
关键词 金属-有机框架薄膜 液相外延法 催化 传感器 储能
华北平原冬小麦种植面积变化及对地下水消耗的影响(英文)
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作者 吴喜芳 齐永青 +3 位作者 沈彦俊 杨伟 张玉翠 近藤昭彦 《地理学报:英文版》 SCIE CSCD 2019年第6期891-908,共18页
The North China Plain is one of the most water-stressed areas in China. Irrigation of winter wheat mainly utilizes groundwater resources, which has resulted in severe environmental problems. Accurate estimation of cro... The North China Plain is one of the most water-stressed areas in China. Irrigation of winter wheat mainly utilizes groundwater resources, which has resulted in severe environmental problems. Accurate estimation of crop water consumption and net irrigation water consumption is crucial to guarantee the management of agricultural water resources. An actual crop evapotranspiration(ET) estimation model was proposed, by combining FAO Penman-Monteith method with remote sensing data. The planting area of winter wheat has a significant impact on water consumption;therefore, the planting area was also retrieved. The estimated ET showed good agreement with field-observed ET at four stations. The average relative bias and root mean square error(RMSE) for ET estimation were –2.2% and 25.5 mm, respectively. The results showed the planting area and water consumption of winter wheat had a decreasing trend in the Northern Hebei Plain(N-HBP) and Southern Hebei Plain(S-HBP). Moreover, in these two regions, there was a significant negative correlation between accumulated net irrigation water consumption and groundwater table. The total net irrigation water consumption in the N-HBP and S-HBP accounted for 12.9×10~9 m~3 and 31.9×10~9 m~3 during 2001–2016, respectively. Before and after 2001, the decline rate of groundwater table had a decreasing trend, as did the planting area of winter wheat in the N-HBP and S-HBP. The decrease of winter wheat planting area alleviated the decline of groundwater table in these two regions while the total net irrigation water consumption was both up to 28.5×10~9 m~3 during 2001–2016 in the Northwestern Shandong Plain(NW-SDP) and Northern Henan Plain(N-HNP). In these two regions, there was no significant correlation between accumulated net irrigation water consumption and groundwater table. The Yellow River was able to supply irrigation and the groundwater table had no significant declining trend. 展开更多
关键词 NORTH China Plain PLANTING area WINTER wheat remote sensing net IRRIGATION water consumption
华北平原2002年和2012年农业土地利用变化(英文)
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作者 张玉翠 齐永青 +2 位作者 沈彦俊 王红营 潘学鹏 《地理学报:英文版》 SCIE CSCD 2019年第6期909-921,共13页
Based on the MODIS NDVI data and Landsat TM/ETM data of 2002 and 2012, this paper extracts the planting area of winter wheat–summer maize, single spring maize, cotton and forest/fruit trees, vegetable and paddy, and ... Based on the MODIS NDVI data and Landsat TM/ETM data of 2002 and 2012, this paper extracts the planting area of winter wheat–summer maize, single spring maize, cotton and forest/fruit trees, vegetable and paddy, and made the agricultural land use map of the North China Plain(NCP). Agricultural land use area accounted for 63.32% compared to the total area of the NCP in 2002. And it increased to 65.66% in 2012, which mainly caused by the vegetables and forest/fruit trees increasing. Planting areas of winter wheat–summer maize, cotton, single spring maize, forest/fruit trees, vegetables and paddy were 5031.21×10~3, 865.90×10~3, 1226.10×10~3, 1271.17×10~3, 648.02×10~3, 216.51×10~3 ha in 2012. Rank of changes was: vegetables(+45%) > forest/fruit trees(+27.4%) > paddy(–23.7%) > cotton(–20.4%) > single spring maize(+17.3%) > winter wheat–summer maize(–0.6%). In developed region like Beijing and Tianjin, planting area of crops with high economic benefit(such as fruit trees and vegetables) increased significantly. Government policies for groundwater protection caused obvious decline of winter wheat cultivation in Hebei Province. Cotton planting in Shandong Province decreased more than 200,000 ha during 2002–2012. The data products will be published in the website: http://hydro.sjziam.ac.cn/Default.aspx. To clarify the agricultural land use in the NCP will be very helpful for the regional agricultural water consumption research, which is the serious problem in the NCP. 展开更多
关键词 NORTH China PLAIN REMOTE SENSING agricultural land use change CROPS
Development of a Tactile and Slip Sensor with a Biomimetic Structure-enhanced Sensing Mechanism
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作者 Yonggang Jiang Zhiqiang Ma +3 位作者 Bonan Cao Longlong Gong Lin Feng Deyuan Zhang 《仿生工程学报:英文版》 SCIE EI CSCD 2019年第1期47-55,共9页
Tactile and slip sensors have gained tremendous attention for their promising applications in the fields of smart robotics,implantable medical devices and minimally invasive surgery.Inspired by the structure-enhanced ... Tactile and slip sensors have gained tremendous attention for their promising applications in the fields of smart robotics,implantable medical devices and minimally invasive surgery.Inspired by the structure-enhanced sensing mechanisms of human fingertips and tree frog toes,we developed a tactile and slip sensor by combining biomimetic surface microstructures with highly sensitive P(VDF-TrFE)nanofiber sensors on a flexible polyimide substrate.As the surface microstructures could mediate the micro-vibration induced by slip motion,the frequencies of output signals revealed a strong correlation with the periods of microstructures.In addition,we proposed a method to discriminate touch force from slip motion using the criterion of standard deviation of time delay from the output signals of neighboring sensor elements. 展开更多
关键词 TACTILE SENSOR SLIP detection NANOFIBER microstructure BIOMIMETIC SENSING
Essential oils of Origanum compactum increase membrane permeability, disturb cell membrane integrity, and suppress quorumsensing phenotype in bacteria 预览
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作者 Abdelhakim Bouyahya Jamal Abrini +1 位作者 Nadia Dakka Youssef Bakri 《药物分析学报:英文版》 CAS CSCD 2019年第5期301-311,共11页
The aim of this study was to investigate antibacterial activity of Origanum compactum essential oils collected at three phenological stages on Escherichia coli and Bacillus subtilis. The antibacterial activity was eva... The aim of this study was to investigate antibacterial activity of Origanum compactum essential oils collected at three phenological stages on Escherichia coli and Bacillus subtilis. The antibacterial activity was evaluated using the agar-well diffusion assay. The MIC and MBC values were determined using the micro-dilution assay. The investigation of the antibacterial action was carried out by the evaluation of the effect of O. compactum essential oils on the antibacterial kinetic growth, the integrity of cell membrane and permeability of the cell membrane. The anti-quorum sensing activity was tested by the inhibition of the biofilm formation. The findings of this study showed that O. compactum essential oil has potent antibacterial activities against E. coli and B. subtilis. The lowest inhibition value against B. subtilis was obtained with O. compactum essential oil at the post-flowering stage (MIC=MBC=0.0312%(v/v)). The antibacterial mechanisms of O. compactum essential oils are related to the disturbing of the cell membrane integrity and the increasing of the membrane permeability, which leads to the leakage of genetic materials (DNA and RNA). Moreover, O. compactum essential oils inhibited the formation of the biofilms, a phenotype that has been known to be quorum sensing regulated. 展开更多
关键词 ORIGANUM COMPACTUM Essential oil Antibacterial action Cell membrane QUORUM sensing inhibition
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Dynamic Matching-Based Spectrum Detection in Cognitive Radio Networks 预览
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作者 Yu Gu Qingqi Pei Hongning Li 《中国通信:英文版》 SCIE CSCD 2019年第4期47-58,共12页
Cognitive Radio Network provides an opportunity to reduce the spectrum resource crisis by allowing secondary users to access the idle spectrum allocated to primary users.The precondition of spectrum sharing is to obta... Cognitive Radio Network provides an opportunity to reduce the spectrum resource crisis by allowing secondary users to access the idle spectrum allocated to primary users.The precondition of spectrum sharing is to obtain the Spectrum Availability Information(SAI).Energy detection is a typical technology to get SAI.With the mobility of primary users,the energy received by secondary users varies greatly with the distance from the target primary users.Most of the existing energy detection algorithms that use fixed thresholds are not suitable.We propose a Dynamic Matching-Based Spectrum Detection(DMBSD)scheme which can detect sensing data,reduce the impact of malicious data and make final sensing results more accurate with dynamic threshold setting and data matching.Simulation results show that the proposed scheme can detect tempered data,and increase detection probability by decreasing false alarm probability and missed detection probability. 展开更多
关键词 COGNITIVE radio SPECTRUM SENSING degradation DOMAIN dynamic MATCHING
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Research and Development of Portable Health Monitor 预览
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作者 Wenzhou Fang Linghong Fan Qingan Niu 《洞察-体育科学》 2019年第1期14-19,共6页
With the improvement of quality of life nowadays, the health requirements is also increased, the traditional health monitor has been unable to meet people's needs, in order to get real-time detection of physiologi... With the improvement of quality of life nowadays, the health requirements is also increased, the traditional health monitor has been unable to meet people's needs, in order to get real-time detection of physiological parameters, realtime understanding of the physical condition, miniature health monitor for strong research and development. This paper briefly introduces the characteristics of the traditional monitor and its research and development, and analyzes the research and development of the multi-parameter health monitor, and emphasizes the research of the body sign signal based on the volume pulse wave, and fi nally puts forward the research on the future portable health monitor, miniature monitor view, draw the portable health monitor will have a good development prospects. 展开更多
关键词 PORTABLE PHYSIOLOGICAL parameters VOLUME PULSE WAVE integrated SENSING
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