Sexual Frequency and the Stability of Marital and Cohabiting Unions

Prior research found that lower sexual frequency and satisfaction were associated with higher rates of divorce, but little research had examined the role of sexual activity in the dissolution of cohabiting unions. We drew upon social exchange theory to hypothesize why sexual frequency is more important in cohabitation: (a) cohabitors' lower costs of finding sexual alternatives, (b) cohabitors' lower barriers to ending the relationship in the form of union‐specific economic and noneconomic capital, and (c) cohabitors' higher expectations for sexual activity. Using the National Survey of Families and Households (N = 5,902), we examined the relationship between sexual frequency and union dissolution. Results indicated that low sexual frequency was associated with significantly higher rates of union dissolution among cohabitors than married couples.     

基于单片机AT89C51的全自动变频恒压供水系统

介绍了一种新型的变频恒压供水系统.该系统根据供水管网的用水情况,调整水泵投入台数及转速,实行全自动恒压供水,达到高效节能的目的;其水泵用变频器软启动,对电网无冲击,能延长水泵的使用寿命.     

当代大学生社会稳定观教育研究

大学生是维护社会稳定的重要力量,但又处于政治心理不成熟的阶段,其政治热情对社会稳定具有双重影响.应当科学解读社会稳定观,寻求大学生社会稳定观教育的着力点,让社会稳定观念深入人心,人人维护社会稳定.     

分析对流-扩散方程显格式稳定性的一种方法

给出了分析二维对流-扩散方程FTCS显格式（时间向前,空间中心的差分格式）稳定条件的一种方法.这种方法可用于分析一维到高维对流-扩散方程差分格式的稳定性.     

参差重复频率分析和设计

雷达工作于脉冲工作状态时不可避免的会出现盲速现象。可通过参差重频的方法减少盲速带来的影响。在推导频率响应的基础上,该文采用最优化设计的方法进行参差周期的设计,详细考虑并推导得到了最优化搜索中几个重要参数,给出了其解析表达式。仿真结果和频率响应图表明,该方法得到的参差周期能将慢速扩大到原来盲速的数倍以上,有效地减少了盲速的影响。     

低频度事件保险产品选择谈判决策模型

本文考虑在低频度事件中保险产品选择问题,用效用理论及模糊数学知识建立了产品选择模型,并给出了算例,找到了使双方均满意的最优产品。     

Combining Food Frequency and Survey Data to Quantify Long-Term Dietary Exposure: A Methyl Mercury Case Study

Twenty-four-hour recall data from the Continuing Survey of Food Intake by Individuals (CSFII) are frequently used to estimate dietary exposure for risk assessment. Food frequency questionnaires are traditional instruments of epidemiological research; however, their application in dietary exposure and risk assessment has been limited. This article presents a probabilistic method of bridging the National Health and Nutrition Examination Survey (NHANES) food frequency and the CSFII data to estimate longitudinal (usual) intake, using a case study of seafood mercury exposures for two population subgroups (females 16 to 49 years and children 1 to 5 years). Two hundred forty-nine CSFII food codes were mapped into 28 NHANES fish/shellfish categories. FDA and state/local seafood mercury data were used. A uniform distribution with minimum and maximum blood-diet ratios of 0.66 to 1.07 was assumed. A probabilistic assessment was conducted to estimate distributions of individual 30-day average daily fish/shellfish intakes, methyl mercury exposure, and blood levels. The upper percentile estimates of fish and shellfish intakes based on the 30-day daily averages were lower than those based on two- and three-day daily averages. These results support previous findings that distributions of "usual" intakes based on a small number of consumption days provide overestimates in the upper percentiles. About 10% of the females (16 to 49 years) and children (1 to 5 years) may be exposed to mercury levels above the EPA's RfD. The predicted 75th and 90th percentile blood mercury levels for the females in the 16-to-49-year group were similar to those reported by NHANES. The predicted 90th percentile blood mercury levels for children in the 1-to-5-year subgroup was similar to NHANES and the 75th percentile estimates were slightly above the NHANES.     

邓小平的经济发展观与我国宪法中经济制度的完善

我国现行宪法中经济制度的内容,历经四度修改,条款涉及较多,这固然为我国的经济体制改革提供了宪法保障,但另一方面,也使人们深切关注宪法的稳定性和权威性,"良性违宪"引起的修宪终不是正常的宪法现象。本文旨在研读邓小平的经济发展观,并以此作为完善经济制度的指导思想,使宪法中的经济制度既能不断适应生产力的发展需要,又能保持适当的稳定性,提高宪法权威,促进"依宪治国"理念的形成。     

Estimating the fundamental frequency of a periodic function

In this paper we consider the problem of estimation of the fundamental frequency of a periodic function, which has several applications in Speech Signal Processing. The problem was originally proposed by Hannan (1974) and later on Quinn and Thomson (1991) provided an estimation procedure of the unknown parameters. It is observed that the estimation procedure of Quinn and Thomson (1991) is quite involved numerically. In this paper we propose to use two simple estimators and it is observed that their performance are quite satisfactory. Asymptotic properties of the proposed estimators are obtained. The large sample properties of the estimators are compared theoretically. We present some simulation results to compare their small sample performance. One speech data is analyzed using this particular model.     

思想政治教育的经济稳定功能研究

稳定在改革开放和现代化建设中被摆在压倒一切的位置上,经济稳定是整个社会稳定的基础和前提,思想政治教育和经济稳定有着十分密切的关系。文章从保证经济发展的性质和方向,导向思想和行为,凝聚人们的力量,激励群众的积极性、主动性、创造性,调节人们的心理、情绪、关系和利益以及转化人们的认识和行为等方面对思想政治教育的经济稳定功能进行了探讨。