诱变培育蝴蝶兰

“花中王子”蝴蝶兰又称蝶兰,是国际名贵花卉,属多年生植物。蝴蝶兰分布于热带,主要生长在菲律宾、马来半岛及我国台湾省。其花形如彩蝶飞舞,色彩艳丽,花的雄蕊和雌蕊在一个花柱上,花粉块状,花粉处于柱头前端的药帽下,被药帽保护着。蝴蝶兰在全世界约有50种原生种,经杂交选育的栽培品种有1000多种。     

花粉的妙用

随植物种类不同,花粉大小、形态、颜色各异。最大花粉的直径为150～200微米,如南瓜,最小的只有4～5微米,如勿忘草。别看花粉形体小,用途却不少。植物传种的微尘花粉壁含有蛋白质,这种蛋白质是识別雌蕊柱头的重要物质。当花粉落到雌蕊的柱头上时,花粉壁中的蛋白质与柱头的蛋白薄膜相互识别,如果两者“亲和”,花粉便萌发长出花粉管。花粉管沿花柱进入子房,经过胚珠到达胚囊之中,顶端破裂,两个精子     

月季品种的叶表皮形态多样性研究

利用光学显微镜对15个月季品种的叶表皮微形态结构进行观察和分析.研究表明,月季品种间叶表皮细胞的形态差异较大,从四边形到多边形和无规则形均有发现,垂周壁式样为上表皮平直至深波纹形,下表皮为浅波纹或深波纹;气孔器多分布于月季叶片的下表皮,气孔器的排列形式多为无规则形,少数为辐射形,气孔器形状多为长椭圆形,少数为宽椭圆形,气孔器外围角质层纹饰多呈明显环状外缘,保卫细胞两极呈现角质区不同程度加厚.比较不同类型月季品种的叶表皮形态发现,叶表皮细胞垂周壁式样、气孔器类型和形状、保卫细胞两极特征在不同类型月季园艺组中存在较为明显的差异,可作为不同园艺组月季品种区分和鉴定的依据.     

《自然》中有关植物学的知识及教学建议(下)

四、植物的花:一朵完全的花由花柄、花托、花萼、花冠、雄蕊和雌蕊六部分组成。花萼由萼片组成,花冠由花瓣组成。花萼和花冠合称花被,是花的外层部分,有保护雄蕊和雌蕊的作用,同时虫媒花的花被可招引昆虫,有利花的传粉。雌蕊和雄蕊合称花蕊,是花的主要部分。一个雄蕊由花丝和花药组成。花丝着生在花托上。花丝顶端着生花药。花药中有花粉囊,里面包有花粉。一个雌蕊由子房、花柱和柱头组成。雌蕊顶端部分为柱头,是接受花粉的地方。花柱是柱头和子房之间的部分,是花粉管由柱头进入子房的通道。子房是雌蕊基部膨大的部分。受精后,子房发育成果实,子房内胚珠发育成种子。     

气孔的结构和功能

气孔是指两个特化的保卫细胞合围而成的胞间隙。气孔和保卫细胞总称气孔器。广义的气孔概念是指气孔器。气孔广泛分布在植物的茎、叶、花果的表皮上，以叶片表皮上数量最多。气孔既是植物体与外界进行气体交换的门户，又是水分蒸腾的通道。根外施肥和喷洒农药时，均由气孔进入。对不同植物来说，气孔的构造和生理功能基本一致，但是它在单位面积中的数目多少及叶片不同部位的分布特点却各有不同。有的植物的上、下表皮均有气孔，如小麦、玉米、向日葵等；有些植物的气孔只分布在上表皮，如浮水植物睡莲、浮萍等；有些植物的气孔则仅分布于下表皮，如榕树、百合等；沉水植物如眼子菜、金鱼藻等，叶片上一般不具有气孔。气孔的分布依植物的种类而异，气孔数目较多的植物，气体交换及蒸腾作用均较快。生长于较为干旱地区的植物，如夹竹桃等，气孔分布于下表皮，且深陷于叶肉中，其气体交换及蒸腾作用都比较慢，可适应干旱缺水的环境。     

短梗五加叶形态结构

利用扫描电子显微镜技术研究了短梗五加叶片结构,研究结果是：其叶近轴面表皮细胞排列紧密,有腺毛分布,远轴面表皮具气孔,气孔多分布在叶脉处．中脉维管束排列近环状．叶肉细胞有栅栏组织和海绵组织之分．叶柄近圆形,堆管束为7—8束．     

安徽皇甫山五种黄精属植物叶表皮气孔研究

本文报道了安徽省皇甫山黄精属 (PolugonatuMill)五种植物在LM下表皮气孔的五项指标 :气孔类型、气孔分布特征及气孔指数等。旨在为进一步探讨百合科植物属种间关系提供资料     

花的构造

一朵花由花萼,花冠（由花瓣组成）、雄蕊、雌蕊四部分组成。雄蕊位于花被内,是花的雄性生殖器官。由花丝和花药组成。花丝着生在花托上,花药着生在花丝顶端。花药中有花粉囊,里面有花粉。雌蕊位于花的中央,是花的雌性生殖器官,由柱头。花柱、子房三部分组成。     

气孔的发育及其类型

气孔是植物体与外界进行气体交换的门户,又是水份蒸腾的通道,还是外界水份和农药、肥料的入口。围绕气孔的是两个保卫细胞,所以,气孔是开口处和两个保卫细胞的统称。气孔周围往往还有一些不同于表皮的细胞叫副卫细胞,两者构成气孔复体。一、气孔的发育气孔分布在植物体地上部分的茎叶器官表皮中,主要在叶的下表皮(少数植物例外)。在幼嫩植物的茎尖叶原基或表皮原处分生组织活动的主要时期完成以     

葱是观察气孔的好材料

做观察叶的结构实验时,对气孔的观察常常以蚕豆叶的下表皮作为实验材料,由于蚕豆的种植受季节限制,很难满足实验教学的需要,改用葱作实验材料,效果很好。葱的分布广泛,不受地区和季节限制,葱的管状叶无上下表皮之分,其表皮易剥离,取材方便,且气孔的分布较多。在...     

Examining Personal,Perceived, Treatment,and Self-Stigma in College Students: The Role of Parent Beliefs and Mental Health Literacy

ABSTRACT

Although college student mental health concerns are on the rise, many struggling students do not seek psychological treatment when needed. Stigma toward psychological treatment has been demonstrated to influence intent to seek treatment in college student populations. This study aimed to identify factors that predict treatment stigma in college students by examining other forms of student-held stigma, parent-held stigma, and mental health literacy. Results indicated that student-held personal, perceived, and self-stigma all predicted student attitudes toward treatment, while parent-held personal stigma was found to predict self-stigma in students. Those individuals who had received previous education about psychological disorders had lower levels of personal stigma, and, surprisingly, higher levels of self-stigma. Implications for campus outreach programming are discussed.     

Mental Health Stigma,Self-Concealment,and Help-Seeking Attitudes among Asian American and European American College Students with No Help-Seeking Experience

The present study examined whether mental health stigma (i.e., negative attitudes toward people with a psychological disorder) and self-concealment are unique predictors of help-seeking attitudes in Asian American and European American college students with no history of seeking professional psychological services. The Asian American group had less favorable help-seeking attitudes overall, lower levels of stigma tolerance and interpersonal openness, greater mental health stigma, and greater self-concealment than the European American group. Mental health stigma and self-concealment were unique predictors of help-seeking attitudes overall in both groups. However, mental health stigma was not a unique predictor of recognition of need for psychotherapeutic help and confidence in mental health practitioners, the components of help-seeking attitudes theorized to be most associated with actual help-seeking behavior. Self-concealment was a unique predictor of confidence in mental health practitioners in the Asian American group, but not in the European American group.     

Ethnic stigma, academic anxiety, and intrinsic motivation in middle childhood

Previous research addressing the dynamics of stigma and academics has focused on African American adolescents and adults. The present study examined stigma awareness, academic anxiety, and intrinsic motivation among 451 young (ages 6-11) and diverse (African American, Chinese, Dominican, Russian, and European American) students. Results indicated that ethnic-minority children reported higher stigma awareness than European American children. For all children, stigma awareness was associated with higher academic anxiety and lower intrinsic motivation. Despite these associations, ethnic-minority children reported higher levels of intrinsic motivation than their European American peers. A significant portion of the higher intrinsic motivation among Dominican students was associated with their higher levels of school belonging, suggesting that supportive school environments may be important sources of intrinsic motivation among some ethnic-minority children.     

Help-Seeking Stigma in Asian American College Women: the Role of Disordered Eating Cognitions and Psychological Inflexibility

Help-seeking stigma is considered a major obstacle to seeking professional psychological services in Asian American college women. Informed in part by objectification theory and the psychological flexibility model of behavior change, the present cross-sectional study examines the role of disordered eating cognition and psychological inflexibility in help-seeking stigma among a sample of Asian American college women (N = 257). More specifically, this study examined whether disordered eating cognitions and psychological inflexibility would mediate the association between psychological distress and stigma tolerance for seeking psychological services in this group. Results revealed that both greater disordered eating cognition and greater psychological inflexibility were associated with lower stigma tolerance, and each of them uniquely mediated the association between greater psychological distress and lower stigma tolerance. These findings suggest that disordered eating cognitions and avoidance-based coping and beliefs may contribute to help-seeking stigma and its association with psychological distress. Limitations of the study and the directions of future research are discussed.     

出生次序、父母受教育程度与大学生认知方式

独生子女与非独生子女大学生认知方式差异显著,非独生子女大学生不同出生次序认知方式无显著差异;大学生认知方式与父亲受教育程度有关,父亲受教育程度中等的大学生认知方式得分显著高于父亲受教育程度较低的大学生,同时也高于父亲受教育程度较高的大学生,但差异并不显著;母亲受教育程度为高、中、低的大学生认知方式差异不显著。     

Self‐stigma and domains of well‐being in high school youth: Associations with self‐efficacy,self‐esteem,and self‐criticism

Self‐stigma is a phenomenon in which negative public stereotypes about mental illness are internalized and can undermine help‐seeking. Unfortunately, little is known about how self‐stigmatization relates to positive well‐being indicators among youth. A sample of 134 high school students completed established measures of self‐stigma, well‐being, self‐esteem, self‐efficacy, and self‐criticism. Analyses confirmed that self‐stigma was associated with overall well‐being and five well‐being subscales (autonomy, environmental mastery, personal growth, positive relations, and self‐acceptance); the strongest associations were with autonomy and positive relations with others. The majority of these associations still held when simultaneously controlling for self‐esteem, self‐efficacy, and self‐criticism. Taken together, findings point to the need for greater awareness of self‐stigma along with an explicit focus on the promotion of protective well‐being in prevention work and interventions designed to alleviate the tendency for young people to internalize stigma. Additionally, findings have theoretical implications for the “why try” model of self‐stigma.     

Stigma of school counselling among Israeli adolescents as a function of ethnicity,counselling orientation and contact frequency

The stigma of counselling frequently affects those groups who need it most. This has certainly been the case in junior high schools in Israel. The research focused on the attitudes toward counselling of 2296 Israeli adolescents. Data analysis showed that students of Asian-African origin (Oriental) who occupy a lower socio-economic stratum, feel more stigmatized by counselling than their European-American origin (Ashkenasic) counterparts, even though they appreciate it more. Both groups experienced less stigma when the counselling service was hybridized with normative functions. Moreover, expanding the frequency of contact with the counsellor was found to increase rather than eliminate vulnerability to stigma among the Oriental students, thus suggesting that varying the nature, and therefore the perception, of the service is a more productive approach.     

Mode of communication, perceived level of understanding, and perceived quality of life in youth who are deaf or hard of hearing

Given the important role of parent-youth communication in adolescent well-being and quality of life, we sought to examine the relationship between specific communication variables and youth perceived quality of life in general and as a deaf or hard-of-hearing (DHH) individual. A convenience sample of 230 youth (mean age = 14.1, standard deviation = 2.2; 24% used sign only, 40% speech only, and 36% sign + speech) was surveyed on communication-related issues, generic and DHH-specific quality of life, and depression symptoms. Higher youth perception of their ability to understand parents' communication was significantly correlated with perceived quality of life as well as lower reported depressive symptoms and lower perceived stigma. Youth who use speech as their single mode of communication were more likely to report greater stigma associated with being DHH than youth who used both speech and sign. These findings demonstrate the importance of youths' perceptions of communication with their parents on generic and DHH-specific youth quality of life.     

Disordered Eating Cognitions as Predictors of Attitudes toward Seeking Professional Psychological Services

The present study investigated whether young adults’ disordered eating cognitions predicted attitudes toward seeking professional psychological services. Two hundred and eighty three 18- to 24-year-old undergraduate students completed a survey package that included measures of disordered eating cognitions and help-seeking attitudes. Hierarchical regression analyses revealed that greater disordered eating cognitions uniquely predicted lower degrees of favorable help-seeking attitudes overall, lower stigma tolerance with respect to seeking professional psychological services, lower interpersonal openness in the context of help-seeking, and lower confidence in psychological professionals. The findings suggest that outreach interventions should, among other things, focus on stigma associated with help-seeking and disordered eating problems.     

唯美主义与“新流氓主义”的调适:《幻洲》半月刊

1926年由叶灵凤和潘汉年等人成立的幻社以《幻洲》半月刊为主要活动阵地,上部"象牙之塔"由叶灵凤负责编辑,倡导唯美主义思潮;下部"十字街头"由潘汉年负责编辑,发出"新流氓主义"的呼声。《幻洲》半月刊风格的这种调适象征着上海唯美主义都市化的趋势,也显示出与鸳鸯蝴蝶派等旧海派不同的新海派作家风格的渐趋成型。