学术期刊属性研究

在编辑传播学界关于学术期刊属性的研究上,普遍存在着一个突出的问题,这就是论者们几乎不假思索地认为“学术期刊是商品”。我们认为,这是一个很大的误区,这种认识在理论上是错误的,在实践上是有害的。首先,“学术期刊商品论”是自相矛盾的;其次,“学术期刊商品论”与马克思主义经济学是相悖的;再次,“学术期刊商品论”与普遍存在的事实是恰恰相反的。学术期刊和学术事业是一项创新的事业,它关系一个国家的生存安危,对此,江泽民同志曾经反复强调,创新是一个民族进步的灵魂,是国家兴旺发达的不竭动力之源。因此,对待学术和学术期刊事业应当像对待军队、警察机构一样,不能也不可能使其商品化,学术期刊应该走自己的健康发展之路。     

ANOTHER LOOK AT THE STRATIFICATION OF EDUCATIONAL TRANSITIONS: THE LOGISTIC RESPONSE MODEL WITH PARTIAL PROPORTIONALITY CONSTRAINTS

In this paper we reanalyze Robert D. Mare's highly influential work on educational transitions among American men born in the first half of the 20th century. Contrary to previous belief, Mare found that the effects of socioeconomic background variables decline regularly across educational transitions in conditional logistic regression analyses. We have reconfirmed Mare's findings and tested them by introducing a modified logistic response model that constrains selected social background effects to vary proportionally across educational transitions. We refer to our preferred model as the logistic response model with partial proportionality constraints (LRPPC). The model can easily be estimated in Stata or using other standard statistical software. Partial proportionality constraints may also prove useful in interpopulation comparisons based on other linear models.     

中草药添加剂对蛋鸡的效应研究进展(续)

3 .2　滋阴生血、养血调血　中兽医学认为精血是畜禽正常生理功能活动的基本物质 ,由脾胃水谷精微气化而成。精血充盈 ,则体壮神旺 ,肌肉发达 ,四肢强劲有力 ,皮毛光泽滋润 ,母鸡则“日日生蛋不绝”。刘深廷等[17] (1995 )以增蛋灵 (陈皮、黄芪、白芍、川芎、当归、补骨脂、益母草、麦芽、罗勒 )按 1.5 %比例混料饲喂 2 0 0 0只罗曼蛋鸡 90ｄ ,能使产蛋率提高 5 .2 1% ,饲料利用率提高 7.2 7%。血红蛋白增加 2 .8ｇ % (Ｐ <0 .0 1) ;血清总蛋白增加 0 .85ｇ % (Ｐ <0 .0 5 ) ;血清白蛋白增加 0 .73ｇ % (Ｐ <0 .0 5 ) ;血清胆固醇增加 37.0 …     

环上矩阵的加权Moore-Penrose逆

研究相对于M和N的加权Moore-Penrose逆，得到带有对合反自同构的有单位元的结合环R上的一类可分解矩阵的加权Moore-Penrose逆存在的充分必要条件，当M和N为单位矩阵时，相对于M和N的加权Moore-Penrose逆就是大家熟悉的Moore-Penrose逆．从某种意义上说，相对于M和N的加权Moore-Penrose逆也是相对于M和N的广义Moore-Penrose逆的推广．结论一方面可特殊化到Moore-Penrose逆的情形，另一方面可得到有关A相对于M和N的广义Moore-Penrose逆的结论．     

How Welfare Policies Affect Adolescents' School Outcomes: A Synthesis of Evidence From Experimental Studies

Using data from 8 random assignment studies and employing meta‐analytic techniques, this article provides systematic evidence that welfare and work policies targeted at low‐income parents have small adverse effects on some school outcomes among adolescents ages 12 to 18 years at follow‐up. These adverse effects were observed mostly for school performance outcomes and occurred in programs that required mothers to work or participate in employment‐related activities and those that encouraged mothers to work voluntarily. The most pronounced negative effects on school outcomes occurred for the group of adolescents who had a younger sibling, possibly because of the increased home and sibling care responsibilities they assumed as their mothers increased their employment.     

听力教学中背景知识激发浅议

听力水平的提高是英语学习者多种技能的综合反映,也是教师多种教学策略恰当运用的结果。背景知识的激发对学习者听力的理解起着举足轻重的作用。创设“逼真”和“真实”的情境,着重呈现长期记忆与短期记忆材料,丰富“暖身活动”内涵是实现听力教学中背景知识激发的有效途径和方法。     

More than Myth: The Developmental Significance of Romantic Relationships During Adolescence

Adolescents' romantic relationships have attracted popular interest, but, until recently, little scientific curiosity. Research has been impeded by erroneous assumptions that adolescent relationships are trivial and transitory, that they provide little information beyond measures of the influence of parent‐child and peer relationships, and that their impact is primarily associated with problems of behavior and adjustment. This article proposes that distinguishing five features of romantic relationships (involvement, partner selection, relationship content, quality, and cognitive and emotional processes) is essential to describing adolescents' relationships and their developmental significance. These distinctions also help to clarify the role of context, age‐related variations, and individual differences in the impact of romantic experiences. Research is needed to illuminate questions of how and under what conditions romantic relationships affect individual development and how romantic and other close relationships jointly influence developmental trajectories during adolescence.     

Farmers,the Practice of Farming and the Future of Agroforestry: An Application of Bourdieu's Concepts of Field and Habitus

Abstract Agroforestry, the practice of raising crops and trees together in ways that are mutually beneficial, provides farmers with an alternative to more conventional farming practices. In this paper, we apply Bourdieu's concepts of “field” and “habitus” in an attempt to better understand the practice of farming and the role that agroforestry may have in farming systems. Analysis is based on qualitative and quantitative interviews of farmers and other key informants in two regions, Fox‐Wyaconda Watershed in northeast Missouri and Scott County in southeast Missouri. Within the field of farming, farmers emphasized the importance of economic, family and rental relations. Important habitus considerations include different interpretations of what constitutes farming and what constitutes forestry. Based on Bourdieu's theoretical framework, we offer three alternative paths of social change that may lead to more widespread utilization of agroforestry.