空调制冷铜管“铜铝渗蚀”开裂失效分析

空调换热器制冷铜管在安装数月后出现开裂泄漏制冷剂现象。对开裂的管材进行化学成分、力学性能、断口及金相检验分析。结果表明,Al-Cu渗蚀导致铜管底壁变薄,装配、运转应力导致开裂。追踪生产过程,发现火焰自动钎焊工艺中存在的Al-Cu渗蚀现象为铜管底壁变薄主要原因,据此提出相应的有效解决方案。     

Factor structure of the CES-D and measurement invariance across gender for low-income Puerto Ricans in a probability sample.

Objective: The authors of this study aimed to evaluate 2-factor structures for the Center for Epidemiologic Studies Depression Scale (CES-D) reported in the literature to determine which one proves to be a better fit with the data on low-income Puerto Ricans living on the island. Method: The sample consisted of 3,504 civilian noninstitutionalized Puerto Ricans, ranging in age from 18 to 64 who were living in low-income areas of Puerto Rico. A confirmatory factor analysis (CFA) was implemented, and model fit was assessed with the Tucker–Lewis Index (TLI), the comparative fit index (CFI), and the root-mean-square error of approximation (RMSEA). Results: The CFA results obtained for the Radloff (1977) and Guarnaccia, Angel, and Worobey (1989) models show that neither model obtained adequate fit indexes. Exploratory factor analysis revealed that the 2-factor structure not only obtained better fit indexes (TLI = .948, CFI = .955, RMSEA = .048) but also reflected a better conceptual organization of the factors (basically divided into 2 components: Negative Affect and Positive Affect). When we assessed the model fit by gender, the model consistently fit the data for the female subsample but not for the male one. Conclusions: Results confirm the need to address the issues related to measurement equivalence for specific cultural and language gaps in assessment of depressive symptoms. Lack of factor invariance across gender also raises the question of the appropriateness of this measure for the male subsample and the need for further research in the manifestation of depression in this group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The ability to regulate emotion is associated with greater well-being, income, and socioeconomic status.

Are people who are best able to implement strategies to regulate their emotional expressive behavior happier and more successful than their counterparts? Although past research has examined individual variation in knowledge of the most effective emotion regulation strategies, little is known about how individual differences in the ability to actually implement these strategies, as assessed objectively in the laboratory, are associated with external criteria. In two studies, we examined how individual variation in the ability to modify emotional expressive behavior in response to evocative stimuli is related to well-being and financial success. Study 1 showed that individuals who can best suppress their emotional reaction to an acoustic startle are happiest with their lives. Study 2 showed that individuals who can best amplify their emotional reaction to a disgust-eliciting movie are happiest with their lives and have the highest disposable income and socioeconomic status. Thus, being able to implement emotion regulation strategies in the laboratory is closely linked to well-being and financial success. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

0-1背包问题的预期效率和线性拟合求解

为了进一步优化0-1背包问题的解,就背包容量、物体个数、物体重量、物体价格和物体性价比之间的关系进行深入的分析研究,构建了一个基于数学理论的线性拟合模型,与预期效率相结合,给出了一个解决0-1背包问题的混合算法。给出了三组实验,测试ρ<0.7时的算例,当背包容量改变时,与萤火虫群算法相比,该算法提高了目标函数值的收敛速度,同时节省了存储空间;与单纯的预期效率算法相比,该算法能够求得最优解,而单纯的预期效率算法则不能。实验结果表明,预期效率和线性拟合混合算法具有合理性及准确性,该算法能够应用于解决实际的0-1背包问题。     

FAHP改进Shapley值法进行工程科技创新收益分配

从合作博弈论视角分析了工程科技合作创新收益合理分配的问题,运用Shapley值法对创新联盟的收益进行初次分配;基于模糊综合评价法（FAHP）从科技创新角色重要性、合作意识、成本投入、企业实力、承担风险等量化评价各创新成员的实际贡献率,据此修正初次分配Shapley值。用工程实际创新案例进行了计算分析,结果表明改进的分配方法合理地提高了核心创新单位和承担风险大的单位的收益,分配结果与成员在联盟中的价值相匹配,有利于创新联盟的稳定,具有可操作性和实用性,可为合作创新收益分配提供理论依据与方法。     

光伏发电项目的国民经济评价

为了促进光伏发电产业的发展,我国颁布了电价补贴等一系列优惠政策,使发电企业实现了盈利,但是这对于国家来说是否是合理的和可持续发展的,需要从国民经济发展的角度进行分析判断。考虑光伏项目的影响因素,针对国民经济成本和收益建立了相应的计算模型,应用国民经济评价方法对光伏发电项目的国民经济性进行了评价,并采用敏感性分析法定量分析了各主要因素对光伏发电项目国民经济性的影响。评价结果表明：目前在我国部分地区光伏发电尚不具备国民经济合理性。最后,对光伏发电的发展时机与发展路线提出了优化建议。     

基于相似度的软件可信性评估方法

为了提高软件可信评估的精确性,提出利用关联可信属性之间相似度的计算结果评估软件的可信性。首先建立可信证据模型、可信属性的数据结构和可信期望模型,便于数据的统一定制和下一步处理。然后对分定性可信属性、定量可信属性进行相似度的计算;根据各自的特点,定性可信属性利用Jaccard系数求解,定量属性则利用了相似度理论进行计算。最后,将该方法应用于实例进行验证,结果验证了它的有效性和稳定性。     

在线报价系统中基于商品销售期有限的定价策略

在线报价销售模式是近年来出现的一种不同于传统定价模式下的销售模式。针对在这一销售模式下当商品的销售期限和库存有限时销售商如何制定最优限制价格的问题,利用优化的方法建立了销售商的最大期望收益模型,并对该模型进行数值分析,得出了销售商的最优限制价格与商品销售期限和初始库存水平之间的关系。结果表明销售商应根据商品的销售期限和初始库存水平制定其限制价格。     

基于自然图像块相似性和稀疏先验性的图像复原

针对物体成像过程受光学系统散焦、运动、大气扰动及光电噪声等因素影响,导致光学系统获取的图像存在噪声、模糊、畸变等降质问题,对基于自然图像块相似性和自然图像稀疏先验信息的图像复原方法进行研究,提出一种泛化的基于图像块相似性和自然图像稀疏先验的图像复原框架。首先,在研究自然图像稀疏先验模型的基础上比较了几种图像块的相似性模型,比较结果表明在图像复原中利用图像块的高相似性先验条件模型能够提升图像复原的性能;接着,构建和优化了基于图像块的期望log相似性模型,减少了运行时间,简化了学习过程;最后,通过构建一种近似的最大后验估计（MAP）算法,最终实现了基于优化的期望块log相似性和混合高斯模型（GMM）的图像复原。仿真实验结果表明,所提方法能够很好地复原包含有各种模糊和加性噪声的退化图像,所得图像的峰值信噪比（PSNR）和结构相似度（SSIM）都优于当前技术条件下的其他稀疏先验复原方法,并具有更好的视觉效果。