成套产品定价方法研究

在给出成套产品定价的概念的基础上,通过一个简单的算例来说明成套产品定价方法的思想,给出了纯成套产品定价方法的总收益大于产品单卖时的总收益的条件,并给出了混合成套产品定价时最优成套出售的套数k^#存在的区间。     

An individual-based model for competingDrosophila populations

An individual-based model forDrosophila is formulated, based on competition amongst larvae consuming the same batch of food. The predictions of the model are supported by data for single speciesDrosophila populations reared in the laboratory. The model is used to build a simple discrete model for the dynamics ofDrosophila populations that are kept over a number of generations. The dynamics of a single species is shown to give either a stable equilibrium or fluctuations which can be periodic or chaotic. When the dynamics of a species in the absence of the other is periodic or chaotic, we found coexistence or two alternative states, on neither of which the species can coexist.     

感官欣赏与理性欣赏的重要环节——音乐欣赏课的教学与实践

本文认为，要提高音乐欣赏能力，使审美意识达到更高的境界，就必须掌握音乐理论基础知识，了解各种不同形式、不同体裁的音乐理作品的风格与特点，从而在理论上为独立分析音乐作品打下一个基础。这是音乐欣赏课的出发点     

Service Utilization Patterns Among Adolescent Mothers Residing in Three-Generational Households

ABSTRACT

This qualitative study used in-depth interviews to better understand the social service experiences and identified needs of 26 demographically diverse adolescent mothers and their mothers, who resided together in three-generational households. Most dyads accessed community services, particularly parenting and emotional supports, financial and material assistance, and medical care, and desired short-term assistance related to their circumstances and newly expanded families, rather than long-term support. The most commonly identified barrier to service utilization involved income eligibility guidelines. In light of welfare reform policies and the current economic climate, this research underscores the need for transitional supports for families, including assistance with basic needs. In terms of implications for social work practice and future research, adolescent mothers may need formal supports as they pursue independence after they leave their mothers’ care. Future research could further explore, within other communities and longitudinally, whether these preliminary trends hold true.     

Parental Identity and Reflected‐Appraisals: Measurement and Gender Dynamics

A new theoretical model for parental identity, reflected‐appraisals, and behavior was proposed. Parental identity and behavior in married parents were then investigated as a function of partner's and perceived reflected‐appraisals, taking into account gender context effects. Sixty‐four married couples completed the Caregiving and Breadwinning Identity and Reflected‐Appraisal Inventory (CBIRAI), developed for this study to assess parental caregiving and breadwinning identity and reflected‐appraisals, as well as caregiving and breadwinning behavior measures. The model was confirmed for fathers and partially confirmed for mothers. Specifically, caregiving identity and behavior in fathers, and breadwinning identity in mothers were functions of perceived reflected‐appraisals. Limitations and implications are discussed.     

Adolescent Mothers and Depression: Predictors of Resilience and Risk Through the Toddler Years

ABSTRACT

This study investigated predictors of depression in 278 African-American, 206 European-American, and 122 Hispanic teen mothers approximately 36 months after the birth while controlling for depression 14 months after the birth. Predictor variables were age, ethnicity, mastery, knowledge of development, and parental distress. Younger teens were not more depressed than older teens. Although there were not significant differences by ethnicity in 14 month depression, significant differences were evident at 36 months. European-American mothers were the most depressed, whereas Hispanic mothers were the least depressed. Parental distress was positively associated with depression at 36 months while controlling for depression at 14 months. This study provides information for targeting teen mothers at the highest risk for depression through the toddler years, as well as spurs ideas for intervention stategies.     

智能型单总线温度控制器设计

介绍了单总线数字式温度传感器（ＤＳ１８２０）的技术特性以及基于ＡＴ８９Ｃ２０５１单片机温度控制应用系统的硬件电路设计和软件程序设计。     

Mother and Grandmother Parenting in Low‐Income Three‐Generation Rural Households

This study draws data from the Family Life Project to examine parenting behaviors observed for 105 mothers and grandmothers raising an infant in rural low‐income multigenerational households. Multilevel models are used to examine the relationships between maternal age and psychological distress and parenting of the infant by both generations. The findings indicate that young maternal age is a risk factor for less sensitive parenting in the presence of other risks, including psychological distress. Further, young maternal age is associated with negative parenting behaviors by grandmothers only. Grandmothers and mothers displayed similar levels of negative intrusive parenting, but different factors were linked to the observed parenting of each generation. These findings contribute to understanding the benefits and risks of three‐generation households.     

单片微机MCS-51实时测量系统中一批数据的一种数字滤波方法

提出了一种在单片微机实时测量系统中对成批数据进行二次算术平均数字滤波的一种方法，具有节省内存、编程简洁、运行较快的特点，滤波系数ｎ，ｍ和采样间隔ＴＳ通过键盘设置，是对在一定范围内波动变化的参量进行预处理的一种较好方法