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31.
新疆陆梁油田呼图壁河组油藏发育一类特殊的薄层底水型油藏,其特点是油层厚度薄,构造幅度低,底水能量大,利用水平井开采,表现出无水采油期短、含水率上升速度快、产量递减大的特点。针对这些问题,采用水平井数值模拟方法,建立了考虑摩擦压力损失的水平井井筒模型,明确了摩擦压力损失对水平井的压力分布以及水平段产量的影响,在此基础上,分析研究了水平井底水锥进的水脊特征,判断了水平井出水位置,提出了封堵出水井段并结合油藏工程方法确定了水平井合理产液量,从而达到抑制底水快速锥进,减小压力损失,降低含水率上升速度的目的。 相似文献
32.
Prominent authors in the behavioral genetics tradition have long argued that shared environments do not meaningfully shape intelligence and academic achievement. However, we argue that these conclusions are erroneous due to large violations of the additivity assumption underlying behavioral genetics methods – that sources of genetic and shared and nonshared environmental variance are independent and non-interactive. This is compounded in some cases by the theoretical equation of the effective and objective environments, where the former is defined by whether siblings are made more or less similar, and the latter by whether siblings are equally subject to the environmental characteristic in question. Using monozygotic twin fixed effects models, which compare outcomes among genetically identical pairs, we show that many characteristics of objectively shared environments significantly moderate the effects of nonshared environments on adolescent academic achievement and verbal intelligence, violating the additivity assumption of behavioral genetic methods. Importantly, these effects would be categorized as nonshared environmental influences in standard twin models despite their roots in shared environments. These findings should encourage caution among those who claim that the frequently trivial variance attributed to shared environments in behavioral genetic models means that families, schools, and neighborhoods do not meaningfully influence these outcomes. 相似文献
33.
聂清华 《长春工程学院学报(社会科学版)》2015,(2):67-70
鉴于信用证具有比较强的收汇保障的性能和贸易融资功能,因此也一直是我国出口企业贸易结算的首选,使用率高居90%。但是近年来,其结算的“霸主”地位不断弱化,并由此对我国外贸出口产生了较大的不利影响。本文探讨了其中具体的原因及影响,并辅以对策。 相似文献
34.
Gillian Peiser 《Intercultural Education》2015,26(5):361-376
This paper reports on a small-scale project involving an online school exchange between two classes of 12-/13-year olds located in the North of England and the Ruhr area of Germany. The overarching aim of the project was to develop intercultural understanding in foreign language learning through communication in an online environment. Analysing data from website posts, lesson observations, student questionnaires and interviews, the paper investigates the extent to which the project realised this goal, and examines emerging practical and pedagogical issues. Comparing the processes and outcomes of this project in secondary education to similar projects in Higher Education (HE), the research found that the young people learnt more than older students about cultural similarities than differences. They were thus less likely to be party to cultural misunderstandings, developing friendly relationships and openness towards a people of a different culture. However, their failure to notice differences may have been due to a lack of in-depth discussion and absence of more demanding student tasks. The paper concludes that in order to develop more sophisticated intercultural learning, expertise derived from telecollaboration in HE needs to be adapted to the lower secondary school context, drawing particularly on auto-ethnography and ethnographic interviewing. 相似文献
35.
Isabel Baño-Piñero María Emilia Martínez-Roche Manuel Canteras-Jordana César Carrillo-García Esteban Orenes-Piñero 《Women and birth : journal of the Australian College of Midwives》2018,31(4):e239-e244
Background
The rates of breastfeeding worldwide are slowly improving since 1996. Europe is still trailing behind the global breastfeeding incidence and prevalence rates. Thus, breastfeeding promotion, protection, prolongation and support have become an important challenge as breastfeeding sharply decreases in the first six months of life.Objectives
The aim of this project is to determine, assess and identify the real impact of breastfeeding support networks in Murcia (Spain).Methods
After searching unsuccessfully for a validated questionnaire, a specific one was developed and validated for measuring the impact of formal and informal support networks through five dimensions: satisfaction, consultation, experience, problems and support. The questionnaire was provided to 500 mothers with experience in breastfeeding, who brought their children to baby paediatricians between 2 June and 27 November 2014. Upon completion of the survey and fieldwork, a detailed statistical analysis was conducted.Results
The degree of satisfaction perceived by the users of the services of support breastfeeding networks is remarkable. In addition, mothers who clarified their doubts and discussed their problems with health professionals and/or breastfeeding support networks were more likely to breastfeed for a longer duration compared to those who did not (p = 0.005). Furthermore, mothers who sought support in breastfeeding are more likely to breastfeed for more than 6 months (p < 0.0005).Conclusion
Based on this information, we conclude that breastfeeding support networks have a positive influence in the duration of a women’s decision to breastfeed. 相似文献36.
《Social Development》2018,27(3):495-509
Parents' reactions to children's emotions shape their psychosocial outcomes. Extant research on emotion socialization primarily uses variable‐centered approaches. This study explores family patterns of maternal and paternal responses to children's sadness in relation to psychosocial outcomes in middle childhood. Fifty‐one families with 8‐ to 12‐year‐old children participated. Mothers and fathers reported their reactions to children's sadness and children's social competence and psychological adjustment. Cluster analyses revealed three family patterns: Supportive (high supportive and low non‐supportive reactions from both parents), Not Supportive (low supportive reactions from both parents), and Father Dominant (high paternal supportive and non‐supportive reactions, low maternal supportive and non‐supportive reactions). Supportive families had children with higher social competence and more internalizing symptoms whereas Father Dominant families had children with lower social competence and fewer internalizing symptoms. Not Supportive families had children with average social competence and fewer internalizing symptoms. Findings are discussed in relation to the “divergence model” which proposes that a diverse range of parental responses to children's sadness, rather than a uniformly supportive approach, may facilitate children's psychosocial adjustment. 相似文献
37.
Karin Jarnkvist 《Marriage & Family Review》2019,55(1):38-58
Previous research reveals that the temporal ordering of childbearing and marriage can have an impact on the meaning of first-time marriage. This article aims to obtain a deeper understanding of meaning-making of first-time marriage in relation to childbearing. Narrative interviews with 16 brides and grooms in 8 couples in Sweden were conducted. The material was analyzed in relation to the temporal ordering of childbearing and marriage. The study reveals that the construction of meaning of marriage does not only relate to the temporal context. Social factors such as social class or family formation might also be relevant for how meaning is constructed. This article contributes to a deeper understanding of meaning-making as a relational process constructed within particular contexts. 相似文献
38.
The study surveyed 506 employees in the United States to test the effect of internal communication (i.e., corporate-level symmetrical and leadership-level responsive communications) on fostering a positive emotional culture characterized by companionate love, joy, pride, and gratitude. In addition, we tested the interplay between corporate internal communication and a positive emotional culture and its influence on supportive employee behaviors, specifically, organizational citizenship behavior (OCB) and employee advocacy. Results indicated that symmetrical communication and responsive leadership communication cultivated a positive emotional culture in organizations. Such culture also fostered employee OCB and advocacy. Moreover, corporate symmetrical communication directly and positively influenced employee OCB. Finally, this study found that employee OCB positively affected employee advocacy. The theoretical and practical implications of the findings for public relations scholars and practitioners were discussed. 相似文献
39.
40.
本文基于期望效用最大化和L1-中位数估计研究了在线投资组合选择问题。与EG(Exponential Gradient)策略仅利用单期价格信息估计价格趋势不同,本文将利用多期价格信息估计价格趋势,以提高在线策略的性能。首先,基于多期价格数据,利用L1-中位数估计得到预期价格趋势。然后,通过期望效用最大化,提出一个新的具有线型时间复杂度的在线策略,EGLM(Exponential Gradient via L1-Median)。并通过相对熵函数定义资产权重向量的距离,进而证明了EGLM策略具有泛证券投资组合性质。最后,利用国内外6个证券市场的历史数据进行实证分析,结果表明相较于UP(Universal Portfolio)策略和EG策略,EGLM策略有更好的竞争性能。 相似文献