A new approach to study organic solar cell using Lambert W-function

Organic photovoltaic solar cells bear an important potential of development in the search for low-cost modules for the production of domestic electricity. One of the main differences between inorganic and organic solar cells is that photo-excitation in these materials does not automatically lead to the generation of free charge carriers, but to bind electron–hole pairs (exciton) with a binding energy of about 0.4 eV. Till now various numerical methods using approximations have been reported to study different aspects of organic solar cells. For the first time an accurate method using Lambert W-function is presented to study different parameters of organic solar cells.     

Analysis of S-SEED''s characteristics in optical switch

This article introduces the basic structure of a symmetric self-electrooptic effect device （S-SEED）, and applies the Kirchoff＇ s current law and a purely equivalent capacitive model, to analyze S-SEED＇s switch characteristics. Linear approximation and N-segment approximation are utilized to obtain S-SEED＇s voltage-time （V-T） and characteristics. Theoretical analysis is verified by simulations, and the results demonstrate that the precision of S-SEED＇s switch time can satisfy the requirement in applications with linear approximation. Moreover, the simulations compare S-SEED＇s switch characteristics with different input powers and input contrast ratios, which reveal that increasing input contrast ratio is an effective way to improve S-SEED＇s switch characteristics.     

多孔硅发光二极管的载流子传输特性研究

制备AI／多孔硅／c-Si／Al结构的多孔硅发光二极管，利用其I-V特性关系，以及在不同温度下其I-V特性的变化，结合多孔硅的特殊微结构及性质，分析了多孔硅发光二极管中载流子的产生和传输过程；通过比较其发光猝灭前后I-V特性的变化，解释了发光猝灭的原因。提出了如果在低电场下能够实现大量载流子在限制性Si微粒中复合．是提高多孔硅电致发光效率的一个途径。     

Evaluating dynamic performance: The influence of salient Gestalt characteristics on performance ratings.

It is well recognized that performance changes over time. However, the effect of these changes on overall assessments of performance is largely unknown. In a laboratory experiment, we examined the influence of salient Gestalt characteristics of a dynamic performance profile on supervisory ratings. We manipulated performance trend (flat, linear-improving, linear-deteriorating, U-shaped, and ∩-shaped), performance variation (small, large), and performance mean (negative, zero, positive) within subjects and display format (graphic, tabular) between subjects. Participants received and evaluated information about the weekly performance of different employees over a simulated 26-week period. Results showed strong main effects on performance ratings of both performance mean and performance trend, as well as interactions with display format. Theoretical and practical implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is evidence-based practice diverse enough? Philosophy of science considerations.

In its policy rationale for evidence-based practice in psychology (EBPP), the APA Presidential Task Force on Evidence-Based Practice (see record 2006-05893-001) claims to have constituted itself with "scientists and practitioners from a wide range of perspectives and traditions, reflecting the diverse perspectives within the field" (p. 273). We applaud this attention to diversity but contend that an entire perspective of the debate was omitted in the Task Force's newly approved policy and its underlying report. The failure to consider a philosophy of science perspective led the Task Force to make a number of epistemological assumptions that are not based on evidence or rationale and that thus violate the very spirit of evidence-based decision making. In this comment, we reveal a few of these assumptions and discuss their detrimental consequences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

History of depression and smoking cessation outcome: A meta-analysis.

The authors conducted a meta-analysis of published studies to (a) evaluate the premise that a history of major depression is associated with failure to quit smoking and (b) identify factors that moderate the relationship between history of depression and cessation outcome. Fifteen studies met the selection requirements and were coded for various study methodology and treatment characteristics. DSTAT was used to calculate individual study effect sizes, determine the mean effect size across studies. and test for moderator effects. No differences in either short-term (≤ 3 months) or long-term abstinence rates (≥ 6 months) were observed between smokers positive versus negative for history of depression. Lifetime history of major depression does not appear to be an independent risk factor for cessation failure in smoking cessation treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

用单透镜变换由多模光纤出射的大功率Nd：YAG激光束的特性

根据理论假设，通过选取单透镜的参数和位置，计算说明了单透镜使经由多模光纤出射的大功率Ｎｄ：ＹＡＧ激光束的发射角压缩，光束聚焦效率提高，光束截面场为高斯分布；文中的计算结果符合已知规律，从而说明了理论假设的正确性。     

ETR Ⅱ-30调速器液压控制系统

ETRⅠ-30调速器是瑞士爱舍维斯工厂生产的具有PID调节规律的电液调速器。本文对其液压控制系统作了较详细的介绍,供有关人员参考。     

Room temperature characterization of Hg1-xCdxTe P-on-n heterostructure photodiodes

Measurements of 77K R_oA and 300K reverse bias dynamic impedance (R_dA) products at one volt reverse bias has been carried out to assess the degree of correlation of this figure of merit. Planar P-on-n heterostructures were grown on near lattice-matched CdZnTe substrates with Hg_1-xCd_xTe (0.20< x <0.30) by molecular beam epitaxy. These devices were passivated with CdTe and doped with indium and arsenic as n- and p-type dopants, respectively. Current-voltage characteristic of these devices exhibit thermally generated dark currents at small and modest reverse bias. We have observed that R_oA values of these long wavelength infrared P-on-n heterostructure photodiodes at 77K correlate with room temperature R_dA values. Diode arrays with high room temperature R_dA values at one volt reverse bias also have high R_oA values at 77K. Similarly, low R_dA values at room temperature indicate poor performance at 77K where deviation from diffusion current occurs at reverse bias of 0.2 to 1 volt at room temperature. The results presented here, for a small samples of devices, demonstrate that room temperature measurements of current-voltage characteristics to evaluate Hg_1-xCd_xTe (0.22< x <0.28) diode performance and array uniformity at lower temperatures can be used. This provides an acceptable criteria for further study at lower temperatures.     

高分辨率显示屏特性分析用光学透镜设计

描述了高分率显示屏特性分析用的光学透镜的特点和设计要求。分析了调焦镜头和镜头位置调节两种结构的优缺点，推导了屏厚变化（即物距变化）对测量精度影响的表达式。给出了设计实例。实验测量结果与理论分析基本上一致。