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1.
热释电探测器及其应用   总被引:6,自引:0,他引:6  
贺凤成  王本 《红外技术》1994,16(3):8-13
详细论述了热释电探测器的工作原理,推导出探测器电流响应率、电压响应率、等效噪声功率和探测率的解析表达式,得出了电压响应率、电流响应率与斩波频率的关系。给出热释电材料的选择原则,介绍了热释电探测器的目前应用领域及未来可能的应用领域。  相似文献   

2.
文章研究了p-GaN/i-GaN/n-A l0.3Ga0.7N异质结背照式p-i-n可见盲紫外探测器的制备与性能。器件的响应区域为310~365nm,最大响应率为0.046A/W,对应的内量子效率为19%,优值因子R0A达到1.77×108Ω.cm2,相应的在363nm处的探测率D*=2.6×1012cmHz1/2W-1。  相似文献   

3.
首先介绍了InGaAs台面探测器的研究进展,然后为了验证利用台面结制作背照射器件的可行性,利用分子束外延(MBE)方法生长的掺杂InGaAs吸收层PIN InP/InGaAs/InP双异质结外延材料,通过台面制作、钝化、电极生长、背面抛光等工艺,制备了8元台面InGaAs探测器,并测试了正照射和背照射时,器件的Ⅰ-Ⅴ、信号和响应光谱。测试结果表明,正照射和背照射情况下,器件的响应信号差别不大,正照射下器件的平均峰值探测率为4.1×10^11cm·Hz^1/2·W^-1,背照射下器件的平均峰值探测率为4.0×10^11cm·Hz^1/2·W^-1,但背照射情况下器件的响应光谱在短波方向有更好的截止。  相似文献   

4.
辛志君 《红外技术》1992,14(4):7-10
从理论上计算了均匀稳定辐射与小光点飞点扫描光照得到的SPRITE探测器探测率间的关系。在低空间频率范围内,后者和前者的探测率比近似等于SPRITE探测器的调制传递函数,接近于1。同时,喇叭形读出区可显著提高SPRITE探测器的探测率。采用典型参数计算,其结果表明,一条SPRITE探测器可相当于55个相同几何形状和工作条件的分离串扫线列光导探测器或17个背景限光导探测器,并具此提出了一种新的光导探测器构思。  相似文献   

5.
顾伯奇  康蓉 《红外技术》1998,20(5):23-26,14
描述了波段探测率的测试方法和实验计算,给出了探测器的测试和计算结果。还描述了红外探测器的波段响应率在遥感技术中的应用,并讨论了用波段探测率(和波段响应率)替代峰值探测率(和峰值响应率)的可能性和优越性。  相似文献   

6.
波段探测率D△λ及其测试方法讨论   总被引:2,自引:0,他引:2  
  相似文献   

7.
8.
介绍了红外焦平面(简称FPA)探测器黑体探测率Dbb^*的定义和测试方法,比较了用点黑体辐射源和平黑体辐射源的对FPA探测器的响应率Rbb测试结果,讨论了FPA探测器的伏安特性对信号输出的影响。  相似文献   

9.
信噪比是评估红外探测器是否能满足探测要求、系统设计是否合理的一个重要参数.描述了一种红外波段光栅衍射效率测量系统的信噪比计算方法,通过引入波段探测率D△λ*,使得计算更为简便,并对新方法与传统方法进行了比较和讨论.  相似文献   

10.
11.
高性能片式多层氧化锌压敏电阻器材料研究   总被引:2,自引:2,他引:0  
对非Bi系氧化锌压敏电阻材料进行了系统研究。研究结果表明:在ZnO基体材料中,添加适量PbO、Co2O3、Cr2O3、MnO2、ZrO2、TiO2、Sb2O3 、B2O3等非Bi系添加剂,采用传统陶瓷制备工艺和合适烧结工艺,可获得a >50、IL<1 mA、烧结温度低于1 100℃的实用非Bi系氧化锌电阻瓷料。采用该瓷料,利用MLC工艺,选用Pd30/Ag70电极浆料,制作出V1mA<30 V、a >30、IL<1 mA的片式多层压敏电阻器。  相似文献   

12.
Laser action at 1315 nm on the I(/sup 2/P/sub 1/2/)/spl rarr/I(/sup 2/P/sub 3/2/) transition of atomic iodine is conventionally obtained by a near-resonant energy transfer from O/sub 2/(a/sup 1//spl Delta/) which is produced using wet-solution chemistry. The system difficulties of chemically producing O/sub 2/(a/sup 1//spl Delta/) have motivated investigations into gas phase methods to produce O/sub 2/(a/sup 1//spl Delta/) using low-pressure electric discharges. We report on the path that led to the measurement of positive gain on the 1315-nm transition of atomic iodine where the O/sub 2/(a/sup 1//spl Delta/) was produced in a flowing electric discharge. Atomic oxygen was found to play both positive and deleterious roles in this system, and as such the excess atomic oxygen was scavenged by NO/sub 2/ to minimize the deleterious effects. The discharge production of O/sub 2/(a/sup 1//spl Delta/) was enhanced by the addition of a small proportion of NO to lower the ionization threshold of the gas mixture. The electric discharge was upstream of a continuously flowing supersonic cavity, which was employed to lower the temperature of the flow and shift the equilibrium of atomic iodine more in favor of the I(/sup 2/P/sub 1/2/) state. A tunable diode laser system capable of scanning the entire line shape of the (3,4) hyperfine transition of iodine provided the gain measurements.  相似文献   

13.
BACKGROUND: Adenosine A1 receptors (A1ARs) modulate various aspects of renal functions, such as hormone release, hemodynamics and tubular absorption. Here we set up to demonstrate the expression of A1ARs in an immortalized cell line (HK-2) derived from normal adult human proximal tubule. We also examined the mechanism whereby A1ARs signal in HK-2 cells and their potential role in renal physiology such as sodium-dependent phosphate transport. METHODS: Ligand binding assay of A1ARs was performed using plasma membranes of HK-2 cells and a selective high-affinity A1AR radioligand [3H]DPCPX. HK-2 cells in 96-well plates were treated with various agents (forskolin, adenosine receptor agonists, and antagonists) to activate or inhibit adenylate cyclase. Intracellular cyclic AMP accumulation was measured using cAMP flashplates. mRNA levels of adenosine receptors in HK-2 cells was determined by real-time PCR technique. Sodium-dependent phosphate transport across cell membrane was measured after 15-minute incubation of phosphorus-33 in transport buffer with HK-2 cells at room temperature. RESULTS: In HK-2 cells, A1ARs were expressed at a density of 211 +/- 74 fmol/mg membrane proteins. [3H]DPCPX bound to A1ARs on HK-2 cell membranes with Kd of 8.3 +/- 2.2 nM. Activation of A1ARs inhibited isoproterenol-stimulated adenylate cyclase activity through pertussis toxin-sensitive Gi protein in HK-2 cells. Coexpression of adenosine A2a receptors at a seemingly lower level than A1ARs was revealed by synergistically activating adenylate cyclase with forskolin. Real-time RT-PCR further demonstrated the expression of both A1AR and A2aAR in HK-2 cells. Sodium-dependent phosphate transport was augmented by activation of A1ARs in HK-2 cells. CONCLUSION: A1ARs are expressed in human proximal tubule epithelial (HK-2) cells and modulate sodium-dependent phosphate transport.  相似文献   

14.
一阶相关免疫函数的新构造方法与计数   总被引:3,自引:0,他引:3       下载免费PDF全文
本文研究了一阶相关免疫函数构造、计数问题,提出了一种新的一阶相关免疫函数的构造方法,由此得到了大量的一阶相关免疫函数;并通过这种构造方法给出了一个目前最好的一阶相关免疫函数个数下界,此下界比现有的结果至少改进了(22<em>n-1+2n)/(2n+8-210).  相似文献   

15.
The OMDR (optical-microwave double resonance) spectrum of 87 Rb with the aim of using a frequency-stabilized GaAs semiconductor laser instead of an Rb lamp as a pumping source in a gas-cell-type Rb frequency standard. Natural isotope 87Rb was sealed in a glass cell with buffer gases (Ar/N2=1.2, total pressure=39 torr). The double resonance signal in the 5P1/2(F=2)←5S1/2( F=1) transition appearing at the resonance to the F=2←1 hyperfine transition of the 5S1/2 state was detected. The optimum operational cell temperature was 56°C. The peak-to-peak frequency width of the atomic hyperfine resonance discriminator used to stabilize the microwave frequency shifts induced by detuning of the laser frequency, changes in the laser and microwave powers, and temperature drift of the cell were investigated  相似文献   

16.
在气体样品池条件下,研究了Rb(5PJ) (Ne、N2)碰撞能量转移过程.对于5PJ与Ne的碰撞,电子态能量仅能转移为Ne原子的平动能.在与N2的碰撞中,向分子振转态的转移是重要的.调频半导体激光器稍微调离共振线,激发Rb原子至Rb(5P3/2)态,在不同的Ne或N2气压下,测量了5P1/2→5S1/2与5P3/2→5S1/2荧光强度比.利用速率方程分析,可以得到碰撞转移速率系数,对于Ne,5P3/2→5P1/2转移速率系数为1.53×10-12cm3s-1.对于N2,由5PJ Ne和5PJ N2二种情况下5P1/2与5P3/2荧光的相对强度比,利用最小二乘法确定5P3/2→5P1/2.转移速率系数为8.83×1011cm3s-1,5PJ态猝灭速率系数为1.25×10-10cm3s-1.对实验结果进行了定性的讨论.  相似文献   

17.
目的:初步分析丝裂原活化蛋白激酶家族成员ERKl/2在BMP9诱导间充质干细胞成骨分化中的作用及可能机制。方法:BMP9重组病毒感染巳H10T1/2细胞,Westemblot检测ERKl/2激酶的磷酸化。ERKl/2的特异性抑制剂PD98059阻断ERKl/2活性,细胞化学染色和活定量检测碱性磷酸酶(AlkalinePhosphatase,ALP)的表达情况;Westernblot检测骨桥蛋白(Osteopontin,OPN)表达,茜素红染色检测钙盐沉积情;荧光素酶报告基因实验检测srn日d经典途径的变化。RNA干扰抑制ERK1/2表达,分析其对-于BMP9诱导的C3H10T1/2细胞ALP活性和钙沉积的影响。结果:BMP9可以促进ERK1/2激酶的磷酸化;ERK1/2抑制剂PD98059可增强由BMP9诱导的c3H10T1/2细胞早期和晚期成骨化,并促进由BMP9诱导的Smad经典途径的活化;RNA干扰导致ERK1/2基因沉默同样也可促进BMP9诱导的QHIOT1/2细胞成骨分化。结:BMP9可以促进ERKI/2蛋白激酶的活化,而阻断ERK1/2蛋白激酶可进一步增强BMP9诱导的GH10T1/2细胞成骨分化。腺性况盐分论  相似文献   

18.
Some properties of rotation symmetric orbits were proposed in n dimensional vector space over finite field of characteristic 2,a matrix on the distributions of number pairs such as 00,01 and 11 was defined,and a new characterization of 2-resilient rotation symmetric functions was introduced.Constructions of rotation symmetric 2-resilient Boolean functions with 4t-1 number of variables were presented by modifying the support of the linear rotation symmetric functions,such as f0(x)=x1+x2+…+xn,where n=4t-1.At last,an example was demonstrated to introduce the spirit of the proposed method to construct 2-resilient rotation symmetric functions with 4t-1 number of variables.  相似文献   

19.
Helix traveling-wave tube equations were formulated under Eulerian-fluid approximations, extending the nonlinearity up to the third-order. Closed-form solutions for the nonlinear equations were obtained by the method of Laplace transforms for the circuit electric field, which was then interpreted, for RF output power. The RF fundamental output power estimated by the present Eulerian theory was validated against that done by the Lagrangian analysis and the regime of agreement of the two theories was ascertained. Then within this range of validity were found the third-order intermodulation products at the frequencies 2f1-f2 and 2f2-f1, for the case of two-balanced signal inputs, one at the frequency f1 and the other at f2. The multisignal output power spectrum predicted by the two theories also showed a fairly close agreement. The role of the two additional second harmonic signals injected at the input, one at the frequency 2f1 and the other at 2f2, in controlling the third-order intermodulation products (distortion) was next studied by the simple Eulerian hydrodynamic analysis. By harmonic injection at the signal frequency 2f1 (2f2) alone, the intermodulation product at 2f1-f2 (2f2-f1) could be reduced but not at 2f2-f1 (2f1-f2). For the reduction of both the intermodulation products, the harmonic inputs at the frequencies 2f1 and 2f2, respectively, need to be simultaneously injected. In particular, the optimum values of the RF input power levels and phases of the second harmonic inputs relative to the corresponding fundamental inputs, which would result in a minimum in the third-order intermodulation distortion in the device, were found  相似文献   

20.
设正整数n、m和r满足n=4m,r=2m-1 -1,基于Niho序列集和d型函数构造了一类4值低相关序列集S(r).该序列集中序列的数目为2n,相关函数的最大边峰值2(n+2)/2+1,序列的周期为2n-1.通过Key的方法,证明了该序列集中序列线性复杂度的F界为n(2n/2-3+2).该序列集与江文峰等人构造的序列集具有相同的相关函数值和序列数目,但拥有更大的线性复杂度.  相似文献   

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