滁菊叶提取物对鲜香菇的涂膜保鲜效果研究

滁菊茎、叶中含有黄酮类和绿原酸等物质,这些天然组分具有抗氧化、清除自由基、抗癌、抑菌、消炎、解毒、利胆、降压和升高白细胞以及显著增加胃肠蠕动和促进胃液分泌等药理作用.利用其抗菌作用,将滁菊叶提取物对新鲜香菇进行涂膜处理,通过对其感官、可溶性固形物、维生素C含量、总酸含量、蛋白质含量等指标的测定,判断其保鲜效果;最终实现滁菊种植业的增值以及延长新鲜香菇货架期的目的.     

Dielectrophoretic manipulation of ribosomal RNA

The manipulation of ribosomal RNA (rRNA) extracted from E. coli cells by dielectrophoresis (DEP) has been demonstrated over the range of 3 kHz-50 MHz using interdigitated microelectrodes. Quantitative measurement using total internal reflection fluorescence microscopy of the time dependent collection indicated a positive DEP response characterized by a plateau between 3 kHz and 1 MHz followed by a decrease in response at higher frequencies. Negative DEP was observed above 9 MHz. The positive DEP response below 1 MHz is described by the Clausius-Mossotti model and corresponds to an induced dipole moment of 3300 D with a polarizability of 7.8×10(-32) F m(2). The negative DEP response above 9 MHz indicates that the rRNA molecules exhibit a net moment of -250 D, to give an effective permittivity value of 78.5 ε(0), close to that of the aqueous suspending medium, and a relatively small surface conductance value of ～0.1 nS. This suggests that our rRNA samples have a fairly open structure accessible to the surrounding water molecules, with counterions strongly bound to the charged phosphate groups in the rRNA backbone. These results are the first demonstration of DEP for fast capture and release of rRNA units, opening new opportunities for rRNA-based biosensing devices.     

如何提高初中物理复习课的课堂效率

在新课程改革的教育大变革时期．在新课程标准的评价方式下,究竟如何上好物理课的单元复习课．激发学生复习课的浓厚兴趣,提高单元复习课的课堂效率．使单元复习课的三维教学目标得到较好的实现呢？我从2008秋季开始进行“单元知识网络建构”的单元复习课教学模式的实践探索,2009年秋季开始进行“单元知识网络建构的评价”实验研究,通过两年的教学尝试,逐渐形成了单元复习课建构单元知识网络的基本教学模式：课堂上通过忆、找、连、说、议五环节,构建单元知识框架：课后将框架中各板块知识点细化,形成单元知识网络;教学中以自评、互评和师评相结合．     

会议缩微平片及其目录的组织管理

会议缩微平片及其目录的组织管理韩艳（大连海事大学图书馆）当前，不少图书馆购进了缩微乎片，而且，从图书馆的发展趋势来看，其数量会与日俱增。本人多年从事特种文献管理工作，试就会议缩微平片及其目录的组织管理工作谈点粗浅看法。一、会议缩微平片的特征及其组织方...     

Modeling emotional,cognitive, and behavioral predictors of peer acceptance

Integrating principles of differential emotions theory and social information-processing theory, this study examined a model of emotional, cognitive, and behavioral predictors of peer acceptance in a sample of 201 early elementary school-age children (mean age = 7 years, 5 months). A path analytic model showed that social skills mediated the effect of emotion knowledge on both same- and opposite-sex social preference, but social skills and verbal ability were more strongly related to opposite-sex peer acceptance. These findings suggest that adaptive social skills constitute a mechanism through which children express their emotion knowledge and achieve peer acceptance. Results also supported findings of previous studies that showed that emotion knowledge mediated the effect of verbal ability on social skills. Findings from the present study have specific implications for emotion-centered prevention programs that aim to improve children's socioemotional competence and enhance the likelihood of peer acceptance.     

A Review of Issues in Deaf Education Under Nigeria's 6-3-3-4 Education System

This article examines issues affecting the education of deaf people under Nigeria's 6-3-3-4 system of education. The system was introduced in 1976 and serves all categories of learners in Nigeria, irrespective of disability. The broad aim of education under the system is to provide all Nigerian learners a wide variety of educational and vocational opportunities to ensure the optimum development of their potential. Evidence indicates that the implementation of the 6-3-3-4 system in Nigerian schools, including schools for the deaf, remains unsatisfactory. A plethora of problems running the gamut from inadequate personnel training programs, lack of facilities, failure of inclusion programs, to limited vocational preparation opportunities, inadequate funding of services, and absence of a legislation supporting the implementation of the 6-3-3-4 system are identified as the major factors militating against the effective implementation of the system in Nigerian schools, including schools for the deaf. The implications for improvements in these areas to achieve a more meaningful implementation of the 6-3-3-4 system are discussed.     

贝贝 汪汪

贝贝和汪汪是邻居。贝贝住在汪汪的东南,地势较高;汪汪住在贝贝的西北,地势较低。     

Neighborhood views on the definition and etiology of child maltreatment

OBJECTIVE: The purpose of this study, as part of a larger study on neighborhoods and child maltreatment, was to determine how parents residing in neighborhoods with differing profiles of risk for child maltreatment reports defined child abuse and neglect and viewed its etiology. METHOD: Parents (n = 400) were systematically selected from neighborhoods (n=20) with different profiles of risk for child maltreatment report rates. As part of a larger interview, parents were asked to generate lists of behaviors that they would define as child abuse and neglect and to rate 13 etiological factors on a 10 point scale as to their contribution to the occurrence of child maltreatment. RESULTS: While there were differences in definitional emphases, with African-American parents including behaviors of neglect and European-American parents including behaviors of physical abuse, there was marked congruence on the catalogue of behaviors that parents would define as child abuse and neglect. Four factors were identified that explained almost two-thirds of the variance in parents' etiological explanations: poverty and family disruption, substance abuse and stress; lack of moral and family values; and individual pathology. These factors were related to neighborhood conditions, individual perceptions of neighborhood and individual characteristics. CONCLUSIONS: Community-based programs aimed at preventing or ameliorating child maltreatment must have at their very core an understanding of how populations being served define child maltreatment and why they believe that it occurs.     

Protection styles of prostitutes' clients: intentions,behavior, and considerations in relation to AIDS

The perceived costs and benefits of condom use within the context of commercial sex were examined in interviews with 87 clients of female Dutch prostitutes. 8 types of condom users were identified: convinced (46% of the study group), guilty conscience (11%), anti-ridden (13%), defaulting (6%), maximum selective (8%), minimum selective (3%), indifferent (8%), and recalcitrant (5%). Clients who consistently used condoms take responsibility for both the pleasure and safety of their sexual encounter; their attitude toward prostitution is positive and straightforward. Guilty conscience users are motivated to use condoms by feelings of guilt toward their wife and are ambivalent about their participation in commercial sex. Angst-ridden users are motivated to seek out prostitutes more by loneliness than the pursuit of sexual pleasure; they view their personal risk of acquired immunodeficiency syndrome (AIDS) as higher than that reported by consistent users and thus are motivated by fear to use condoms. Defaulting users perceive themselves as the victims of temptation and express a lack of control over the sexual encounter that places them at risk of unprotected sex. Maximum selective users are consistent in using condoms in sex with prostitutes, except when it involves a prostitute whom they see regularly and frequently. Minimum selective users seek frequent contact with prostitutes and base condom use on a subjective assessment of whether the woman is healthy or not. Indifferent users, often disabled and lonely men with no other source of sexual contact, base their condom use or nonuse solely on the wishes of the prostitute. Finally, recalcitrant users are characterized by a desire for power and protest condom use. In general, consistent condom use was related to a positive evaluation of prostitutes, positive attitudes toward the advantages of condom use, an internal locus of control with regard to health, and a higher level of education.