物性型湿度传感器及其应用

在科学技术日益发达的今天，湿度的监测与控制在国民经济各个部门，在国防，科研及人民生活等许多领域有着非常广泛的应用。众所周知，湿度的测量具有一定的复杂性，而对湿度进行控制则更不易实现。这样，人们熟知的毛发湿度计、千湿球湿度计等已不能满足现代要求的实际需要，为此，人们研制了各种湿度传感器。

传感器的应用与发展

传感器作为信息获取装置(器件)而成为自动检测和监测系统、自动控制系统、智能机器的主要组成部分。社会生产方式的变革,要求各行各业都要高度自动化、信息化、智能化。因此,传感器显得特别重要。本文通俗地阐述了传感器在生产方式变革中的作用,并就物理型传感器的发展概况作了简要论述。

浅谈传感技术在风电机中的应用

当前我国可再生清洁能源——风电在全国沿海地区、高原地区蓬勃发展。由于风机工作地区的环境和气候条件比较恶劣，使得对风机实行远距离监测、监控很是必要。传感器技术应用，使风机自动化控制成为可能。本文就传感技术在风机中的应用，作粗浅的分析。

传感技术的发展趋势

本文阐述了目前国内外传感技术发展的现状及其趋势．

Amino Acid Sensing Using an Ion-Sensitive Field-Effect Transistor

Ion-sensitive field-effect transistor （ISFET）-based biosensor for amino acids was proposed, and the response of the sensor to amino acids was evaluated. As a molecular recognition element, aminoacyl-tRNA synthetase which would be expected to have high selectivity for the corresponding amino acids was used, aminoacyl-tRNA synthetase was coated onto an ISFET electrode, and the response of the biosensor to amino acids was evaluated. The amino acid sensor for tyrosine showed a selective response to tyrosine because of the specific binding ability of aminoacyl-tRNA synthetase for tyrosine and from 300μM to 900 μM of tyrosine could be measured （r2 〉 0.969）.

Viscoelastic Analysis of a Surface Acoustic Wave Gas Sensor Coated by a New Deposition Technique

An analysis of the response of surface acoustic wave sensors coated with polymer film based on new coating deposition （self-assemble and molecularly imprinted technology） is described and the response formulas are hence deduced. Using the real part of shear modulus, the polymer can be classified into three types： glassy film, glassy-rubbery film and rubbery film, Experimental results show that the attenuation response is in better consistence with the simulation than in Martin＇s theory, but the velocity response does not accord with the calculation exactly. Maybe it is influenced by the experimental methods and environment. In addition, simulations of gas sorption for polymer films are performed. As for glassy film, the SAW sensor response increases with increasing fihn thickness, and the relationship between the sensor response and the concentration of gas is pretty linear, while as for glassy-rubbery flint and rubbery film, the relationship between the sensor sensitivity anti concentration of gas is very complicated. The ultimately calculated results indicate that the relationship between the sensor response and frequency is not always linear due to the viscoelastic prooerties of the polymer.

Relationship between coal size reduction and energy input in Hardgrove mill

Hardgrove grindability index （HGI） is an important indicator of coal grindability, and is one of the most important parameters to determine the capacity of coal pulverizer in power station. However, HGI is an empirical grindability index without linkages to any known physical parameters. To investigate the effect of energy input on the grinding in Hardgrove mill. a T20WN torque meter was installed on the shaft of a modified Hardgrove mill to record the torque driving the mill. Samples from four kinds of coals with HGI ranging from 36 to 72 were prepared according to the procedure of standard HGI test and ground in a modified Hardgrove mill at different revolutions. The relation of sample size reduction degree to specific comminution energy （Ecs） was studied with Shi-Kojovic model, The results show that Shi-Kojovic model predicted well the coal size reduction degree with Ecs in Hardgrove mill. The griadability index given by Shi-Kojovic model has a similar trend with HGI. The relation of sample size reduction degree to Ecs reveals that HGI has a non-linear relationship with effective specific energy in Hardgrove mill, which explains the non-linear relation of HG1 to industrial pulverizer capacity.

Perspectives in application of biosensors for the modernization of traditional Chinese medicine

Biosensor is an instrument which is sensitive to biological material and converts its concentration into electrical signals.Organisms such as enzymes, antibodies, tissues, cells and so on can selectively identify specific substances. Thesemolecular recognition functions can be combined with the target, such as the binding of antibodies and antigens, and thebinding of enzymes to the substrate through the recognition process. Biosensor has the advantages of high specificity,high sensitivity, fast reaction speed, low cost and easy operation. It has wide application prospect in food, pharmacy,chemical industry, clinical examination, biomedicine, environmental monitoring and so on, especially as a newtechnology means, in the field of modern herbal medicine research influence. Studies have demonstrated that thebiosensing technology has been applied to, traditional Chinese medicine （TCM） targets, isolation and purification ofTCM, the mechanism of TCM, quality control of TCM, the active ingredients detection of TCM and other basicresearches. Biosensor technology has made an important contribution to the research of modern herbal medicine, and hasbecome a Hot-spot in future research.

Organic transistor for bioelectronic applications

Organic field-effect transistors(OFETs) are recently considered to be attractive candidate for bioelectronic applications owing to their prominent biocompatibility,intrinsical flexibility,and potentially low cost associated with their solution processibility.Over the last few years,bioelectronic-application-motivated OFETs have attracted increasing attention towards next generation of biosensors,healthcare elements and artificial neural interfaces.This mini review highlights the basic principles and recent progress in OFET based bioelectronics devices.The key strategies and the forecast perspectives of this research field are also briefly summarized.

Multifunctional devices based on planar microsupercapacitors:Progress and challenges

With the boom of portable,wearable,and implantable smart electronics in the last decade,the demand for multifunctional microscale electrochemical energy storage devices has increased.Owing to their excellent rate performance,high power density,long cycling lifetime,easy fabrication,and integration,multifunctional planar microsupercapacitors(PMSCs)are deemed as one of the ideal micropower sources for next-generation flexible on-chip electronics.Therefore,we offer a comprehensive overview of the recent progress regarding multifunctional devices based on PMSCs,including stretchable,self-healing,stimulus-responsive,thermosensitive,biodegradable,and temperaturetolerant microdevices.We also emphasize the unique applications of multifunctionally integrated PMSCs in the construction of self-powered and sensor-integrated systems in terms of multifunctional operation modes.Finally,the key challenges and future prospects related to these multifunctional devices are discussed to stimulate further research in this flourishing field.

Aptamer-based competitive electrochemical assay of small biomolecules

A convenient aptamer-based competitive electrochemical biosensor for a small biomolecule,adenosine,was described. The sensing surface was fabricated by self-assembly of an aptamer/mercaptohexanol monolayer on a gold disk electrode. The principle of this aptasensor is based on the competition between an adenosine target molecule and a ferrocene-conjugated signaling DNA strand for the aptamer binding site on the sensing surface. Due to the competitive nature of this assay,the electrochemical responses of the surface captured ferrocene are inversely proportional to log[adenosine] in the range from 0.05 to 3.2 μM,with a detection limit of 25 nM. Moreover,the aptasensor also shows high selectivity for adenosine. The proposed aptasensor thus holds great potential for the detection of other small biomolecules.

Porous silicon biosensor for detection of variable domain of heavy-chain of HCAb antibody

In this paper, we produce porous silicon （PSi） by electrochemical etching, and it is the first time to evaluate the performance of label-free porous silicon biosensor for detection of variable domain of heavy chain of heavy-chain antibody （VHH）. The binding of hen egg white lysozyme （HEWL） and VHH causes a red shift in the reflection spectrum of the biosensor. The red shift is proportional to the VHH concenlration in the range from 14 gg.ml-I to 30 pg.ml~ with a detection limit of 0.648 ng.ml~. The research is useful for the development of label-free biosensor applied in the rapid and sensitive determination of small molecules.

A nano-functionalized real-time electrochemiluminescent biosensor for alanine transaminase assay

An electrochemiluminescent (ECL) biosensor was constructed for selective assay of alanine aminotransferase (ALT) based on the enzymatically catalyzed oxidation of pyruvate by pyruvate oxidase (PYOD). The composite of potassium ferricyanide and carbon nanotube was adopted to pre-functionalize the basal platinum electrode while the potassium ferricyanide acted as the activator of PYOD. The ALT catalyzed the reaction of L-alanine and-ketoglutarate to produce pyruvate which could be further enzymatically oxidized by PYOD to yield H2O2 to intensify the ECL of luminol. The biosensor showed rapid response for real-time measurement of ALT in the linear concentration range from 0.00475 to 350 U/L (r = 0.993) with a relatively standard deviation of 2.5% (CALT = 47.5 U/L,n = 6). The biosensor was applied to assay the ALT in rat serum with average recovery of 90.5%.

The measurement and model construction of complex permittivity of vegetation

The complex permittivity of targeted objects is an important factor that influences its microwave radiation and scattering characteristics.In the quantitative research of microwave remote sensing,the study of the dielectric properties of the vegetation to establish the relationship between its specific physical parameters and complex permittivity is fundamental.In this study,six categories of vegetation samples were collected at the city of Zhangye,a key research area of the Heihe watershed allied telemetry experimental research.The vector network analyzer E8362B was used to measure the complex permittivity of these samples from 0.2 to 20 GHz by the coaxial probe technique.The research focused mainly on the corn leaves,and an empirical model was established between the gravimetric moisture and the real/imaginary parts of complex permittivity at the main frequency points of microwave sensors.Furthermore,the empirical model and the classical Debye-Cole model were compared and verified by the measured data collected from the Huailai County of Hebei Province.The results show that the newly- established empirical model is more accurate and more practical as compared to the traditional Debye-Cole model.