正面进光InGaAs/InP SAGM APD器件的研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

长波长InGaAs.APD光接收组件

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CsI(T1)晶体探测器APD读出的温度效应

对中国科学院近代物理研究所自行生长的铊激活碘化铯闪烁晶体CsI(T1)光输出及Hamamtsu公司生产的S8664-1010型雪崩光二极管(APD)增益对温度的依赖关系做了系统研究.结果表明,CsI(T1)晶体光产额在室温范围内随着温度的增加而增加,在-2℃—8℃温度范围内的平均温度系数为0.67%/℃,在8℃—25℃温度范围内的平均温度系数为0.33%/℃.而对所使用的APD,其增益在室温范围内的温度系数为-3.68%/℃(工作电压400V).APD结合CsI(T1)晶体在室温下对~(137)Cs的662keYγ射线的能量分辨可达5.1%.

Temperature effects of CsI(Tl) crystal detector with APD readout

The temperature dependences of the light output of CsI(Tl) crystal grown at IMP and of the gain of the Hamamatsu S8664-1010 avalanche photodiode (APD) have been investigated systematically. The light output of the CsI(Tl) crystal increases with temperature by 0.67%/degrees C in the region from -2 degrees C to 8 degrees C, and by 0.33%/degrees C in the region from 8 degrees C to 25 degrees C, while the gain of the tested APD decreases by -3.68%/degrees C (working voltage 400V) on average in the room temperature range. The best energy resolution 5.1% of the CsI(Tl) with APD was obtained for the 662keV gamma ray from Cs-137 radiation source.

Informe de resultados programa mejoramiento de la competitividad del sector artesano de la población victima y vulnerable APD 2013.

253 hojas : ilustraciones, fotografías, mapas, esquemas.

Reliability, validity and acceptability of modified response formats of APD instruments for children using AAC

A pilot study consisting of a parent questionnaire, four APD tests and an acceptability questionnaire were presented to normal hearing and cognitively developing children between the ages of 8-12 years. Responses to a standard and modified response format of the APD tests were obtained over two test sessions. Results indicated that the modified response formats of the four APD tests were acceptable, fairly reliable and three out of the four APD tests were valid.

Evaluation of APD and SiPM Matrices as Sensors for Monolithic PET Detector Block

Gamma detectors based on monolithic scintillator blocks coupled to APDs matrices have proved to be a good alternative to pixelated ones for PET scanners. They provide comparable spatial resolution, improve the sensitivity and make easier the mechanical design of the system. In this study we evaluate by means of Geant4-based simulations the possibility of replacing the APDs by SiPMs. Several commercial matrices of light sensors coupled to LYSO:Ce monolithic blocks have been simulated and compared. Regarding the spatial resolution and linearity of the detector, SiPMs with high photo detection efficiency could become an advantageous replacement for the APDs

Quantitative electroencephalographic comodulation : an investigation of patterns in chronic fatigue syndrome

Introduction. This is a pilot study of quantitative electro-encephalographic (QEEG) comodulation analysis, which is used to assist in identifying regional brain differences in those people suffering from chronic fatigue syndrome (CFS) compared to a normative database. The QEEG comodulation analysis examines spatial-temporal cross-correlation of spectral estimates in the resting dominant frequency band. A pattern shown by Sterman and Kaiser (2001) and referred to as the anterior posterior dissociation (APD) discloses a significant reduction in shared functional modulation between frontal and centro-parietal areas of the cortex. This research attempts to examine whether this pattern is evident in CFS. Method. Eleven adult participants, diagnosed by a physician as having CFS, were involved in QEEG data collection. Nineteen-channel cap recordings were made in five conditions: eyes-closed baseline, eyes-open, reading task one, math computations task two, and a second eyes-closed baseline. Results. Four of the 11 participants showed an anterior posterior dissociation pattern for the eyes-closed resting dominant frequency. However, seven of the 11 participants did not show this pattern. Examination of the mean 8-12 Hz amplitudes across three cortical regions (frontal, central and parietal) indicated a trend of higher overall alpha levels in the parietal region in CFS patients who showed the APD pattern compared to those who did not have this pattern. All patients showing the pattern were free of medication, while 71% of those absent of the pattern were using antidepressant medications. Conclusions. Although the sample is small, it is suggested that this method of evaluating the disorder holds promise. The fact that this pattern was not consistently represented in the CFS sample could be explained by the possibility of subtypes of CFS, or perhaps co-morbid conditions. Further, the use of antidepressant medications may mask the pattern by altering the temporal characteristics of the EEG. The results of this pilot study indicate that further research is warranted to verify that the pattern holds across the wider population of CFS sufferers.

Exploring the parameter space of a rabbit ventricular action potential model to investigate the effect of variation on action potential and calcium transients

Computational models for cardiomyocyte action potentials (AP) often make use of a large parameter set. This parameter set can contain some elements that are fitted to experimental data independently of any other element, some elements that are derived concurrently with other elements to match experimental data, and some elements that are derived purely from phenomenological fitting to produce the desired AP output. Furthermore, models can make use of several different data sets, not always derived for the same conditions or even the same species. It is consequently uncertain whether the parameter set for a given model is physiologically accurate. Furthermore, it is only recently that the possibility of degeneracy in parameter values in producing a given simulation output has started to be addressed. In this study, we examine the effects of varying two parameters (the L-type calcium current (I(CaL)) and the delayed rectifier potassium current (I(Ks))) in a computational model of a rabbit ventricular cardiomyocyte AP on both the membrane potential (V(m)) and calcium (Ca(2+)) transient. It will subsequently be determined if there is degeneracy in this model to these parameter values, which will have important implications on the stability of these models to cell-to-cell parameter variation, and also whether the current methodology for generating parameter values is flawed. The accuracy of AP duration (APD) as an indicator of AP shape will also be assessed.

Accelerated professional development and peer consultation : two strategies for continuing professional education for nurses

A comparison was made of accelerated professional development (APD) for nurses (n=64), involving peer consultation and reflective practice, and peer consultation alone (n=30). Although APD participants had a higher completion rate, improvements in caregiver behaviors and work environment were not significantly different.

Who is seeing the dietitian? we are only seeing the tip of the iceberg

Poor dietary choices are associated with overweight and obesity and the development of chronic conditions. Over 12 million (~60%) Australians are currently overweight or obese. Accredited Practicing Dietitians (APDs) are the experts in nutrition and diet therapy, equipped to provide services and counselling to assist individuals in making dietary modifications to prevent or manage diet-related conditions. However, no existing research has investigated the proportion or characteristics of the Australian population that may be accessing APDs. Data from 25,906 participants in the 2004/05 National Health Survey (NHS) were analysed using logistic regression to identify the sociodemographic and health characteristics of individuals accessing an APD or Nutritionist. Only 0.4% (n = 105) of the sample reported accessing a Dietitian or Nutritionist, this was half the amount accessing a Naturopath. Diabetes Mellitus, cardiovascular disease and obesity were all significantly associated with having seen a Dietitian, and over 90% of those accessing services had a long-term condition. Of the total sample only 10% of those with a diet-related condition had seen an APD or Nutritionist. Household income and education were not associated with accessing an APD. Exploration around the barriers to referral and accessing services may be warranted to assist in enhancing the profile of APDs among the population and other healthcare professionals. The current number of approximately 5000 registered APDs is unlikely to be able to service the proportion of the population who require dietary intervention; further avenues for prevention, rather than acute treatment, and novel strategies for service provision also need to be explored.

Implementation study of relay selection schemes for energy harvesting WSNs

We propose energy harvesting technologies and cooperative relaying techniques to power the devices and improve reliability. We propose schemes to (a) maximize the packet reception ratio (PRR) by cooperation and (b) minimize the average packet delay (APD) by cooperation amongst nodes. Our key result and insight from the testbed implementation is about total data transmitted by each relay. A greedy policy that relays more data under a good harvesting condition turns out to be a sub optimal policy. This is because, energy replenishment is a slow process. The optimal scheme offers a low APD and also improves PRR.