基于氧化铝陶瓷的无线无源湿度传感器的制备和测试

通过湿度感应技术与近场电磁耦合原理相结合,构成了基于氧化铝陶瓷的无线无源湿度传感系统。此传感器包含叉指电容与电感线圈构成的LC谐振电路和由聚酰亚胺薄膜构成的湿敏结构。当聚酰亚胺薄膜吸收水分子后,聚酰亚胺和水组成的复合体系的介电常数发生变化,导致LC电路的谐振频率发生改变,通过读取天线将传感器频率信号读取出来。搭建湿度测试平台对传感器进行测试,结果表明传感器的谐振频率随着密闭环境中空气湿度的线性增大而呈线性减小的趋势。当湿度从50%RH变化到88%RH的时候,传感器谐振频率从113.712 1 MHz变化到92.311 5 MHz,灵敏度为0.545MHz/%RH。     

用于高空气象探测的聚酰亚胺薄膜湿敏电容研究

设计制作了一种基于MEMS技术,可应用于高空湿度探测的薄膜湿敏电容.电容采用三明治结构,聚酰亚胺薄膜作为湿度敏感层材料,金作为上、下电极.测试结果表明,在15%RH~95%RH的全量程范围内,湿敏电容的合格率≥80%,灵敏度约为0.29pF/%RH,线性误差<1.5%RH,湿滞较小,响应时间小于4 s,温度系数好,具有良好的长期稳定性.研究表明,制作的湿敏电容综合指标良好,适合批量生产,可以满足高空气象探测要求.     

自动气象站备用相对湿度传感器高湿偏小原因排查

利用2018年4月1—15日的部分小时数据,对比两套自动气象站相对湿度传感器测量值,业务站的相对湿度在85%RH以上,备用站的相对湿度偏小5%～8%RH。采取如下措施:①常规(物理连接、主采集器、温湿分采集器的工作电压等)检查;②等电位接地检查;③备用站相对湿度传感器实验室检定等方法。结果发现,备用站相对湿度传感器98%RH的检定点,误差在最大允许误差的临界点,更换备用站相对湿度传感器后问题解决。建议如下:应定时或不定时,结合每月仪器检查或极端天气过程后,对两套自动气象站相对湿度传感器的测量值进行对比,发现问题及时检查处理或报告上级业务部门。     

一种新颖的光纤环行腔式电流传感器

聚焦光纤电流传感器中电流灵敏度低的问题,提出新的光纤环行腔式电流传感器.该电流传感器将光纤环行腔与电流传感器结合在一起,采用脉冲光作为检测信号.利用脉冲信号在环行腔内多次通过传感头的特点,有效提高系统的电流灵敏度.该结构与传统光纤电流传感器相比,并且具有结构简单、装配容易、成本低等优点.     

PVDF足底力传感器设计

为了检测步行时足底的受力信息,设计了一种新型结构的足底三轴力传感器.传感器为一正三棱锥状结构体,由硬质橡胶材料的正三棱锥状体和与之相配的环氧树脂凹槽叠合而成.锥体的叠合分形面放置了高分子压电敏感材料聚偏二氟乙烯(PVDF),足底受力通过凸凹结合面传递.足底受力时3个分形面上的PVDF输出3路压电信号,通过解耦运算得到足底三轴力.实验表明,该传感器具有良好的灵敏度和测量精度,并且由于结构的独特性,抗过载能力好,适用于足底力测量.     

基于导电膜电阻拉—敏效应的混凝土裂缝分布式监测技术

为了对混凝土结构裂缝进行分布式监测,提出利用高分子导电膜具有的电阻拉—敏效应,将其涂覆在混凝土结构表面作为传感器,实现混凝土裂缝分布式监测的新方法;对其机理进行了研究,提出了导电膜拉—敏效应的模型;分别以塑料板和混凝土预制板作为试验构件,在实验室进行了导电膜作为传感器监测构件变形、开裂和裂缝发展的验证性试验。试验结果表明,采用导电膜作为传感器能及时、准确判断混凝土构件裂缝出现的时机,并能对裂缝的发展状况进行连续监测,最小监测裂缝宽度为0.02mm。     

分子印迹膜的光学检测研究

作为一种新型的精密检测技术和高效的分离技术,分子印迹技术具有空间专一识别特性,是近年来集高分子合成、分子设计、分子识别、仿生工程等众多学科优势发展起来的一支新兴的边缘学科[1].分子印迹聚合物具有天然抗体的识别性能和高分子的抗腐蚀性能双重优点,因而被广泛应用于环境监测、生物工程、临床医学、食品工程等众多领域.而分子印迹技术应用于传感器时,以往传统的方法主要为电化学方法,如电导传感器、压电传感器等[2,3],本文着重探讨了将分子印迹技术应用于光学传感器测定的研究.     

高分子湿度传感器研究进展

湿度是一个重要的物理量，航空航天、计量等许多环境中需要在高温下进行湿度的测量。目前用于低温下测量的湿敏传感器主要有三类：电解质湿度传感器、半导体陶瓷湿度传感器和有机高分子聚合物湿度传感器。高分子湿度传感器现已在气象、纺织、食品加工及蔬菜保鲜等方面广泛应用。本文重点分析了高分子湿度传感器的发展趋势。     

基于碳纳米管的呼吸传感器及便携式系统设计

提出了一种新颖的基于碳纳米管的呼吸传感器.传感器芯片通过微加工工艺制造,采用简单的叉指状金属侧壁电极结构.电极上覆盖了一层碳纳米管薄膜层,极大地增强了传感器对呼吸气体的敏感性.以该传感器作为核心,设计了呼吸监测系统电路,包括信号发生器、I/V转换放大器、A/D转换器、以及基于FPGA的数字解调器、LCD显示模块、SD卡数据存储模块、呼吸异常报警模块7个部分,实现了该呼吸传感器系统的便携化.测试结果表明,呼吸传感器便携式系统具有响应快、回复快、灵敏度高、抗干扰强等优点.     

几种典型湿度传感器的原理和概要分析

湿度是一个重要的物理量,航空航天、计量等许多环境中需要在高温下进行湿度的测量.目前用于低温下测量的湿敏传感器主要有3类:电解质湿度传感器、半导体陶瓷湿度传感器和有机高分子聚合物湿度传感器.对湿度传感器的几种典型原理作了简要介绍,概要分析了湿度传感器用于高温测量的发展趋势.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the