首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
三甲胺[N(CH3)3]MIS传感器的研制   总被引:1,自引:0,他引:1  
研制探测鱼鲜度的传感元件。用含铟杂质的TiO2材料作溅射靶,采用氩离子束镀膜机在硅片上镀膜。用常规蒸铝技术和光刻技术制成MIS结构2。结果表明:在1MHz的测试频率下,当三甲胺浓度从0变化到0.1%,时电容发生了250%的变化。在3V的偏压下,电流改变了450%,直接用鲜鱼测试时,在25h内该结构的电容和电流的响应很敏感,且接近线性关系。  相似文献   

2.
以TiO2为材料制作的Al/TiO2/Si MIS结构对与鱼鲜度有关的三甲胺气体有良好的响应。实验表明:当三甲胺体积分数从0~103×10-6变化时,在1MH的测试频率下,样品的电容值改变了250%;在3V的偏压下,电流变化了450%。鲜鱼死后在25h内,在较高温度下样品的(C-t)和(I-t)关系响应敏感。并通过分析TiO2膜各组分的介电常数,解释了样品的电容随体积分数变化的机理。提出了吸附模型,鉴于化学吸附产生的正电荷对界面势垒和电场的影响,结合Fowler-Norheim(F-N)隧道穿透机构对电流一体积分数(I—D)关系进行解释。  相似文献   

3.
以TiO为材料制作的Al/TiO2/SiMIS结构对与鱼鲜度有关的三甲胺气体有良好的响应。实验表明:当三甲胺体积分数从0-10^3×10^-6变化时,在1MHZ的测试频率下,样品的电容值改变了250%;在3V的偏上,电流变化了450%。鲜鱼死后在25h内,在较高温度下样吕的(C-t)和(I-t)关系响应敏感,并通过分析了TiO2膜各组分的介电常数,解释了样品的电容随体积分数变化的机理。提出了吸附模  相似文献   

4.
用氩离子束镀膜法制备BaTiO3/Si结构,并在400~900℃的温度下用氮气保护进行退火,用常规蒸铝技术制成Al/BaTiO3/Si湿度传感器。用俄歇电子能谱分析BaTiO3膜的化学组分。采用高频电容—电压测试仪测定BaTiO3/Si结构的固定电荷密度,分析固定电荷密度与退火的关系。结果表明:固定电荷密度达1011cm-2数量级。经900℃、60分钟退火后固定电荷密度下降至19%到20%。随着固定电荷密度的减少,湿度传感器的响应时间延长了60%,而击穿电压提高了7倍。  相似文献   

5.
从甲壳素出发,先制备了3种不同脱乙酰度的壳聚糖,选择过硫酸铵-亚硫酸氢钠为氧化还原体系引发剂,合成了壳聚糖接枝丙烯酰胺聚合物;通过红外光谱,电镜扫描对聚合物进行结构表征,结果表明壳聚糖结构发生了变化,通过在相同条件下比较壳聚糖不同脱乙酰度对接枝率的影响,得出了在脱乙酰度为68.5%时聚合物的接枝率最大为250%,其最佳合成工艺为:m(壳聚糖):m(丙烯酰胺)=1:5,引发剂用量为体系质量分数的0.3%~0.4%,温度55~60℃,反应时间为2.5~3.0h。  相似文献   

6.
基于空间平滑技术和矩阵重构技术,提出了一种相干信源下波达方向估计的新算法。算法在非高斯冲击噪声下,能对波达方向进行有效地估计。与基于分数低阶矩算法以及基于分数低阶矩平滑算法相比较,新算法能在信噪比为-5dB时,提高40%的成功估计概率。信噪比为0dB-10dB时,成功概率大约提高20%,且均方根误差被降低近20%-50%。计算机仿真结果验证了算法的有效性。  相似文献   

7.
为了研究磁刺激对大鼠脑缺血再灌注功能恢复的影响,利用储能电容对线圈放电产生脉冲磁场的原理,设计制作了一套磁刺激电源电路。晶闸管作为开关元件控制电容的充放电,结果在负载回路中得到脉冲大电流,电流流经线圈在其周围空间产生强脉冲磁场。实验有助于进一步探索磁刺激对生物体的保护作用机理。  相似文献   

8.
本文描述了二维模型下电容合的直流放电计算过程。发展了适用于任意结构下非正交坐标系的算法。提出了决定边界条件的相关技术,程序设计中发展了网络生成系统,使程序更适用,并且用图表说明了半导体机械中的一种典型的应用。  相似文献   

9.
本文描述了二维模型下电容耦合的直流放电计算过程.发展了适用于任意结构下非正交坐标系的算法.提出了决定边界条件的相关技术.程序设计中发展了网格生成系统,使程序更适用.并且用图表说明了半导体机械中的一种典型的应用.  相似文献   

10.
在野外施工中,采集链断点的判断是采集链维修尤其突出的问题。电容法测量采集链断点的位置是一种早期测试模拟电缆的常用方法,用它测试数字电缆一样适用有效。虽然测试有较大的误差,但在工地没有大线探伤仪等仪器情况下,用电容法能够及时找出电缆断点,有利于及时维修或更换,保证不影响现场生产进度。  相似文献   

11.
12.
Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.  相似文献   

13.
Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.  相似文献   

14.
正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied  相似文献   

15.
16.
《山地科学学报》2014,(4):I0004-I0009
<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.  相似文献   

17.
<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by  相似文献   

18.
S 《山地科学学报》2008,5(1):63-72
Livestock behaviour in the Pyrenees includes free grazing and a long resting period that provokes the accumulation of dung and urine in some places,so-called camping areas. The aims of this study were (i) to analyze any change in floral composition,and in nutritional and chemical contents of plants in a livestock camping area; and (ii) to relate the floral composition with soil chemical properties. In a linear transect,five sampling zones were established,from the centre of the camping area to the surrounding Nardus stricta-dominant pasture. The above ground plant biomass and the topsoil were sampled in each zone with 6 replicates per zone. Plant species were classified and weighed to calculate above ground biomass,nutritional and chemical contents,and Shannon diversity and evenness indices. Additionally,soils were sampled in two periods,at the beginning and at the end of grazing period. Soil available nutrients (nitrate,ammonium,phosphorus,potassium,calcium and magnesium),total nitrogen,organic carbon and pH were measured.
Plant chemical contents (protein,lignin and others) were significantly related to the proportions of grasses,legumes and other plants; so,the protein content is positively correlated with legumes plant biomass while lignin content is negatively correlated with grasses. Both plant and soil nutrients increased linearly towards the centre of the camping area. However,the relationship among plant species richness,diversity and evenness relative to its position along the studied transect was bell-shaped. From the outskirts to the centre of the camping area,plants with low nutrient demand were progressively replaced by those with medium and high nutrients demand and by pioneers.
Nardus stricta-dominant pasture has low plant diversity and plant nutrient content as well as a poor soil nutrient availability. The presence of the camping area introduced patches with more soil nutrients and new species in the large spatial scale. However at a small spatial scale,the strong soil nutrien  相似文献   

19.
The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.  相似文献   

20.
正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprehensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号